DPI version 0.1.2

This commit does not represent a release and only synchronizes CHANGELOG
from the latest release.

.github/PULL_REQUEST_TEMPLATE.md

@@ -2,4 +2,3 @@
 - [ ] Added an entry to the `changelog` module if knowledge of this change could be valuable to users
 - [ ] Updated documentation to reflect any user-facing changes, including notes of platform-specific behavior
 - [ ] Created or updated an example program if it would help users understand this functionality
-- [ ] Updated [feature matrix](https://github.com/rust-windowing/winit/blob/master/FEATURES.md), if new features were added or implemented

.github/workflows/ci.yml

@@ -74,15 +74,19 @@ jobs:
           - { name: 'iOS Aarch64',        target: aarch64-apple-ios,        os: macos-latest,    }
           - { name: 'Web',                target: wasm32-unknown-unknown,   os: ubuntu-latest,   }
         exclude:
-          # Web on nightly needs extra arguments
+              # Web on nightly needs extra arguments
+
           - toolchain: nightly
-            platform: { name: 'Web', target: wasm32-unknown-unknown, os: ubuntu-latest }
+            platform: { name: 'Web' }
+            # Rustup is broken.
+          - toolchain: nightly
+            platform: { name: 'Windows 32bit GNU' }
           # Android is tested on stable-3
           - toolchain: '1.73'
-            platform: { name: 'Android', target: aarch64-linux-android, os: ubuntu-latest, options: '--package=winit --features=android-native-activity', cmd: 'apk --' }
+            platform: { name: 'Android' }
           # Redox OS doesn't follow MSRV
           - toolchain: '1.73'
-            platform: { name: 'Redox OS', target: x86_64-unknown-redox, os: ubuntu-latest }
+            platform: { name: 'Redox OS' }
         include:
           - toolchain: '1.73'
             platform: { name: 'Android', target: aarch64-linux-android, os: ubuntu-latest, options: '--package=winit --features=android-native-activity', cmd: 'apk --' }
@@ -181,6 +185,12 @@ jobs:
         contains(matrix.platform.name, 'Linux 64bit') &&
         matrix.toolchain != '1.73'
       run: cargo test -p dpi
+      
+    - name: Check dpi crate (no_std)
+      if: >
+        contains(matrix.platform.name, 'Linux 64bit') &&
+        matrix.toolchain != '1.73'
+      run: cargo check -p dpi --no-default-features
 
     - name: Build tests
       if: >

CONTRIBUTING.md

@@ -19,6 +19,16 @@ All patches have to be sent on Github as [pull requests][prs]. To simplify your
 life during review it's recommended to check the "give contributors write access
 to the branch" checkbox.
 
+We use unstable Rustfmt options across the project, so please run
+`cargo +nightly fmt` before submitting your work. If you are unable to do so,
+the maintainers can do it for you before merging, just state so in your pull
+request description. For details on how to use nightly, consult [the
+documentation][toolchains].
+
+When editing markdown files (`.md`) they must be wrapped at 80 characters.
+
+[toolchains]: https://rust-lang.github.io/rustup/concepts/toolchains.html
+
 #### Handling review
 
 During the review process certain events could require an action from your side,

Cargo.toml

@@ -21,7 +21,7 @@ name = "winit"
 readme = "README.md"
 repository.workspace = true
 rust-version.workspace = true
-version = "0.30.5"
+version = "0.30.10"
 
 [package.metadata.docs.rs]
 features = [
@@ -78,10 +78,10 @@ cfg_aliases = "0.2.1"
 [dependencies]
 bitflags = "2"
 cursor-icon = "1.1.0"
-dpi = { version = "0.1.1", path = "dpi" }
+dpi = { version = "0.1.2", path = "dpi" }
 rwh_06 = { package = "raw-window-handle", version = "0.6", features = ["std"] }
 serde = { workspace = true, optional = true }
-smol_str = "0.2.0"
+smol_str = "0.3"
 tracing = { version = "0.1.40", default-features = false }
 
 [dev-dependencies]
@@ -104,14 +104,15 @@ ndk = { version = "0.9.0", features = ["rwh_06"], default-features = false }
 
 # AppKit or UIKit
 [target.'cfg(target_vendor = "apple")'.dependencies]
-block2 = "0.5.1"
-core-foundation = "0.9.3"
-objc2 = "0.5.2"
+block2 = "0.6.1"
+dispatch2 = { version = "0.3.0", default-features = false, features = ["std", "objc2"] }
+objc2 = "0.6.1"
 
 # AppKit
 [target.'cfg(target_os = "macos")'.dependencies]
-core-graphics = "0.23.1"
-objc2-app-kit = { version = "0.2.2", features = [
+objc2-app-kit = { version = "0.3.1", default-features = false, features = [
+    "std",
+    "objc2-core-foundation",
     "NSAppearance",
     "NSApplication",
     "NSBitmapImageRep",
@@ -128,6 +129,7 @@ objc2-app-kit = { version = "0.2.2", features = [
     "NSMenu",
     "NSMenuItem",
     "NSOpenGLView",
+    "NSPanel",
     "NSPasteboard",
     "NSResponder",
     "NSRunningApplication",
@@ -140,9 +142,37 @@ objc2-app-kit = { version = "0.2.2", features = [
     "NSWindowScripting",
     "NSWindowTabGroup",
 ] }
-objc2-foundation = { version = "0.2.2", features = [
+objc2-core-foundation = { version = "0.3.1", default-features = false, features = [
+    "std",
     "block2",
-    "dispatch",
+    "CFBase",
+    "CFCGTypes",
+    "CFData",
+    "CFRunLoop",
+    "CFString",
+    "CFUUID",
+] }
+objc2-core-graphics = { version = "0.3.1", default-features = false, features = [
+    "std",
+    "libc",
+    "CGDirectDisplay",
+    "CGDisplayConfiguration",
+    "CGDisplayFade",
+    "CGError",
+    "CGRemoteOperation",
+    "CGWindowLevel",
+] }
+objc2-core-video = { version = "0.3.1", default-features = false, features = [
+    "std",
+    "objc2-core-graphics",
+    "CVBase",
+    "CVReturn",
+    "CVDisplayLink",
+] }
+objc2-foundation = { version = "0.3.1", default-features = false, features = [
+    "std",
+    "block2",
+    "objc2-core-foundation",
     "NSArray",
     "NSAttributedString",
     "NSData",
@@ -164,20 +194,29 @@ objc2-foundation = { version = "0.2.2", features = [
 
 # UIKit
 [target.'cfg(all(target_vendor = "apple", not(target_os = "macos")))'.dependencies]
-objc2-foundation = { version = "0.2.2", features = [
+objc2-core-foundation = { version = "0.3.1", default-features = false, features = [
+    "std",
+    "CFCGTypes",
+    "CFBase",
+    "CFRunLoop",
+    "CFString",
+] }
+objc2-foundation = { version = "0.3.1", default-features = false, features = [
+    "std",
     "block2",
-    "dispatch",
+    "objc2-core-foundation",
     "NSArray",
     "NSEnumerator",
     "NSGeometry",
     "NSObjCRuntime",
     "NSOperation",
     "NSString",
-    "NSProcessInfo",
     "NSThread",
     "NSSet",
 ] }
-objc2-ui-kit = { version = "0.2.2", features = [
+objc2-ui-kit = { version = "0.3.1", default-features = false, features = [
+    "std",
+    "objc2-core-foundation",
     "UIApplication",
     "UIDevice",
     "UIEvent",
@@ -203,7 +242,7 @@ objc2-ui-kit = { version = "0.2.2", features = [
 # Windows
 [target.'cfg(target_os = "windows")'.dependencies]
 unicode-segmentation = "1.7.1"
-windows-sys = { version = "0.52.0", features = [
+windows-sys = { version = "0.59.0", features = [
     "Win32_Devices_HumanInterfaceDevice",
     "Win32_Foundation",
     "Win32_Globalization",
@@ -249,12 +288,12 @@ sctk = { package = "smithay-client-toolkit", version = "0.19.2", default-feature
     "calloop",
 ], optional = true }
 sctk-adwaita = { version = "0.10.1", default-features = false, optional = true }
-wayland-backend = { version = "0.3.5", default-features = false, features = [
+wayland-backend = { version = "0.3.10", default-features = false, features = [
     "client_system",
 ], optional = true }
-wayland-client = { version = "0.31.4", optional = true }
-wayland-protocols = { version = "0.32.2", features = ["staging"], optional = true }
-wayland-protocols-plasma = { version = "0.3.2", features = ["client"], optional = true }
+wayland-client = { version = "0.31.10", optional = true }
+wayland-protocols = { version = "0.32.8", features = ["staging"], optional = true }
+wayland-protocols-plasma = { version = "0.3.8", features = ["client"], optional = true }
 x11-dl = { version = "2.19.1", optional = true }
 x11rb = { version = "0.13.0", default-features = false, features = [
     "allow-unsafe-code",

FEATURES.md

@@ -47,201 +47,3 @@ through the implementation work necessary to function on all platforms. When one
 gets implemented across all platforms, a PR can be opened to upgrade the feature to a core feature.
 If that gets accepted, the platform-specific functions get deprecated and become permanently
 exposed through the core, cross-platform API.
-
-# Features
-
-## Extending this section
-
-If your PR makes notable changes to Winit's features, please update this section as follows:
-
-- If your PR adds a new feature, add a brief description to the relevant section. If the feature is a core
-  feature, add a row to the feature matrix and describe what platforms the feature has been implemented on.
-
-- If your PR begins a new API rework, add a row to the `Pending API Reworks` table. If the PR implements the
-  API rework on all relevant platforms, please move it to the `Completed API Reworks` table.
-
-- If your PR implements an already-existing feature on a new platform, either mark the feature as *completed*,
-  or mark it as *mostly completed* and link to an issue describing the problems with the implementation.
-
-## Core
-
-### Windowing
-- **Window initialization**: Winit allows the creation of a window
-- **Providing pointer to init OpenGL**: Winit provides the necessary pointers to initialize a working opengl context
-- **Providing pointer to init Vulkan**: Same as OpenGL but for Vulkan
-- **Window decorations**: The windows created by winit are properly decorated, and the decorations can
-  be deactivated
-- **Window decorations toggle**: Decorations can be turned on or off after window creation
-- **Window resizing**: The windows created by winit can be resized and generate the appropriate events
-  when they are. The application can precisely control its window size if desired.
-- **Window resize increments**: When the window gets resized, the application can choose to snap the window's
-  size to specific values.
-- **Window transparency**: Winit allows the creation of windows with a transparent background.
-- **Window maximization**: The windows created by winit can be maximized upon creation.
-- **Window maximization toggle**: The windows created by winit can be maximized and unmaximized after
-  creation.
-- **Window minimization**: The windows created by winit can be minimized after creation.
-- **Fullscreen**: The windows created by winit can be put into fullscreen mode.
-- **Fullscreen toggle**: The windows created by winit can be switched to and from fullscreen after
-  creation.
-- **Exclusive fullscreen**: Winit allows changing the video mode of the monitor
-  for fullscreen windows and, if applicable, captures the monitor for exclusive
-  use by this application.
-- **HiDPI support**: Winit assists developers in appropriately scaling HiDPI content.
-- **Popup / modal windows**: Windows can be created relative to the client area of other windows, and parent
-  windows can be disabled in favor of popup windows. This feature also guarantees that popup windows
-  get drawn above their owner.
-
-
-### System Information
-- **Monitor list**: Retrieve the list of monitors and their metadata, including which one is primary.
-- **Video mode query**: Monitors can be queried for their supported fullscreen video modes (consisting of resolution, refresh rate, and bit depth).
-
-### Input Handling
-- **Mouse events**: Generating mouse events associated with pointer motion, click, and scrolling events.
-- **Mouse set location**: Forcibly changing the location of the pointer.
-- **Cursor locking**: Locking the cursor inside the window so it cannot move.
-- **Cursor confining**: Confining the cursor to the window bounds so it cannot leave them.
-- **Cursor icon**: Changing the cursor icon or hiding the cursor.
-- **Cursor image**: Changing the cursor to your own image.
-- **Cursor hittest**: Handle or ignore mouse events for a window.
-- **Touch events**: Single-touch events.
-- **Touch pressure**: Touch events contain information about the amount of force being applied.
-- **Multitouch**: Multi-touch events, including cancellation of a gesture.
-- **Keyboard events**: Properly processing keyboard events using the user-specified keymap and
-  translating keypresses into UTF-8 characters, handling dead keys and IMEs.
-- **Drag & Drop**: Dragging content into winit, detecting when content enters, drops, or if the drop is cancelled.
-- **Raw Device Events**: Capturing input from input devices without any OS filtering.
-- **Gamepad/Joystick events**: Capturing input from gamepads and joysticks.
-- **Device movement events**: Capturing input from the device gyroscope and accelerometer.
-
-## Platform
-### Windows
-* Setting the name of the internal window class
-* Setting the taskbar icon
-* Setting the parent window
-* Setting a menu bar
-* `WS_EX_NOREDIRECTIONBITMAP` support
-* Theme the title bar according to Windows 10 Dark Mode setting or set a preferred theme
-* Changing a system-drawn backdrop
-* Setting the window border color
-* Setting the title bar background color
-* Setting the title color
-* Setting the corner rounding preference
-
-### macOS
-* Window activation policy
-* Window movable by background
-* Transparent titlebar
-* Hidden titlebar
-* Hidden titlebar buttons
-* Full-size content view
-* Accepts first mouse
-* Set a preferred theme and get current theme.
-
-### Unix
-* Window urgency
-* X11 Window Class
-* X11 Override Redirect Flag
-* GTK Theme Variant
-* Base window size
-* Setting the X11 parent window
-
-### iOS
-* Get the `UIScreen` object pointer
-* Setting the `UIView` hidpi factor
-* Valid orientations
-* Home indicator visibility
-* Status bar visibility and style
-* Deferring system gestures
-* Getting the preferred video mode
-
-### Web
-* Get if the systems preferred color scheme is "dark"
-
-## Compatibility Matrix
-
-Legend:
-
-- ✔️: Works as intended
-- ▢: Mostly works, but some bugs are known
-- ❌: Missing feature or large bugs making it unusable
-- **N/A**: Not applicable for this platform
-- ❓: Unknown status
-
-### Windowing
-|Feature                          |Windows|MacOS   |Linux x11   |Linux Wayland  |Android|iOS    |Web      |Redox OS|
-|-------------------------------- | ----- | ----   | -------    | -----------   | ----- | ----- | -------- | ------ |
-|Window initialization            |✔️     |✔️     |▢[#5]      |✔️             |▢[#33]|▢[#33] |✔️        |✔️      |
-|Providing pointer to init OpenGL |✔️     |✔️     |✔️         |✔️             |✔️     |✔️    |**N/A**|✔️      |
-|Providing pointer to init Vulkan |✔️     |✔️     |✔️         |✔️             |✔️     |❓     |**N/A**|**N/A** |
-|Window decorations               |✔️     |✔️     |✔️         |✔️             |**N/A**|**N/A**|**N/A**|✔️      |
-|Window decorations toggle        |✔️     |✔️     |✔️         |✔️             |**N/A**|**N/A**|**N/A**|**N/A** |
-|Window resizing                  |✔️     |✔️     |✔️         |✔️        |**N/A**|**N/A**|✔️        |✔️      |
-|Window resize increments         |✔️     |✔️     |✔️         |❌             |**N/A**|**N/A**|**N/A**|**N/A** |
-|Window transparency              |✔️     |✔️     |✔️         |✔️             |**N/A**|**N/A**|N/A        |✔️      |
-|Window blur                      |❌    |❌    |❌        |✔️             |**N/A**|**N/A**|N/A        |❌     |
-|Window maximization              |✔️     |✔️     |✔️         |✔️             |**N/A**|**N/A**|**N/A**|**N/A** |
-|Window maximization toggle       |✔️     |✔️     |✔️         |✔️             |**N/A**|**N/A**|**N/A**|**N/A** |
-|Window minimization              |✔️     |✔️     |✔️         |✔️             |**N/A**|**N/A**|**N/A**|**N/A** |
-|Fullscreen                       |✔️     |✔️     |✔️         |✔️             |**N/A**|✔️     |✔️        |**N/A** |
-|Fullscreen toggle                |✔️     |✔️     |✔️         |✔️             |**N/A**|✔️     |✔️        |**N/A** |
-|Exclusive fullscreen             |✔️     |✔️     |✔️         |**N/A**         |❌    |✔️     |**N/A**|**N/A** |
-|HiDPI support                    |✔️     |✔️     |✔️         |✔️             |✔️     |✔️    |✔️    |❌      |
-|Popup windows                    |❌     |❌     |❌         |❌             |❌    |❌     |**N/A**|**N/A** |
-
-### System information
-|Feature          |Windows|MacOS |Linux x11|Linux Wayland|Android|iOS      |Web      |Redox OS|
-|---------------- | ----- | ---- | ------- | ----------- | ----- | ------- | -------- | ------ |
-|Monitor list     |✔️    |✔️    |✔️       |✔️          |✔️     |✔️      |**N/A**|❌      |
-|Video mode query |✔️    |✔️    |✔️       |✔️          |✔️     |✔️      |**N/A**|❌      |
-
-### Input handling
-|Feature                 |Windows   |MacOS   |Linux x11|Linux Wayland|Android|iOS    |Web      |Redox OS|
-|----------------------- | -----    | ----   | ------- | ----------- | ----- | ----- | -------- | ------ |
-|Mouse events            |✔️       |▢[#63]  |✔️       |✔️          |**N/A**|**N/A**|✔️        |✔️      |
-|Mouse set location      |✔️       |✔️      |✔️       |✔️(when locked)  |**N/A**|**N/A**|**N/A**|**N/A** |
-|Cursor locking          |❌       |✔️      |❌       |✔️          |**N/A**|**N/A**|✔️        |❌      |
-|Cursor confining        |✔️       |❌      |✔️       |✔️          |**N/A**|**N/A**|❌       |❌      |
-|Cursor icon             |✔️       |✔️      |✔️       |✔️          |**N/A**|**N/A**|✔️        |**N/A** |
-|Cursor image            |✔️       |✔️      |✔️       |✔️          |**N/A**|**N/A**|✔️        |**N/A** |
-|Cursor hittest          |✔️       |✔️      |✔️       |✔️          |**N/A**|**N/A**|❌        |❌      |
-|Touch events            |✔️       |❌      |✔️       |✔️          |✔️    |✔️     |✔️        |**N/A** |
-|Touch pressure          |✔️       |❌      |❌       |❌          |❌    |✔️     |✔️        |**N/A** |
-|Multitouch              |✔️       |❌      |✔️       |✔️          |✔️    |✔️     |❌        |**N/A** |
-|Keyboard events         |✔️       |✔️      |✔️       |✔️          |✔️    |❌     |✔️        |✔️      |
-|Drag & Drop             |▢[#720]  |▢[#720] |▢[#720]  |▢[#720]   |**N/A**|**N/A**|❓        |**N/A** |
-|Raw Device Events       |▢[#750]  |▢[#750] |▢[#750]  |❌          |❌    |❌     |❓        |**N/A** |
-|Gamepad/Joystick events |❌[#804] |❌      |❌       |❌          |❌    |❌     |❓        |**N/A** |
-|Device movement events  |❓        |❓       |❓       |❓           |❌    |❌     |❓        |**N/A** |
-|Drag window with cursor |✔️       |✔️      |✔️       |✔️          |**N/A**|**N/A**|**N/A**   |**N/A** |
-|Resize with cursor      |✔️       |❌       |✔️       |✔️       |**N/A**|**N/A**|**N/A**   |**N/A** |
-
-### Pending API Reworks
-Changes in the API that have been agreed upon but aren't implemented across all platforms.
-
-|Feature                             |Windows|MacOS |Linux x11|Linux Wayland|Android|iOS    |Web      |Redox OS|
-|------------------------------      | ----- | ---- | ------- | ----------- | ----- | ----- | -------- | ------ |
-|New API for HiDPI ([#315] [#319])   |✔️      |✔️     |✔️        |✔️            |✔️      |✔️      |❓        |❓      |
-|Event Loop 2.0 ([#459])             |✔️      |✔️     |✔️        |✔️            |✔️      |✔️      |❓        |✔️       |
-|Keyboard Input 2.0 ([#753])         |✔️      |✔️     |✔️        |✔️            |✔️      |❌     |✔️         |✔️       |
-
-### Completed API Reworks
-|Feature                             |Windows|MacOS |Linux x11|Linux Wayland|Android|iOS    |Web      |Redox OS|
-|------------------------------      | ----- | ---- | ------- | ----------- | ----- | ----- | -------- | ------ |
-
-[#165]: https://github.com/rust-windowing/winit/issues/165
-[#219]: https://github.com/rust-windowing/winit/issues/219
-[#242]: https://github.com/rust-windowing/winit/issues/242
-[#306]: https://github.com/rust-windowing/winit/issues/306
-[#315]: https://github.com/rust-windowing/winit/issues/315
-[#319]: https://github.com/rust-windowing/winit/issues/319
-[#33]: https://github.com/rust-windowing/winit/issues/33
-[#459]: https://github.com/rust-windowing/winit/issues/459
-[#5]: https://github.com/rust-windowing/winit/issues/5
-[#63]: https://github.com/rust-windowing/winit/issues/63
-[#720]: https://github.com/rust-windowing/winit/issues/720
-[#721]: https://github.com/rust-windowing/winit/issues/721
-[#750]: https://github.com/rust-windowing/winit/issues/750
-[#753]: https://github.com/rust-windowing/winit/issues/753
-[#804]: https://github.com/rust-windowing/winit/issues/804

README.md

@@ -2,13 +2,13 @@
 
 [![Crates.io](https://img.shields.io/crates/v/winit.svg)](https://crates.io/crates/winit)
 [![Docs.rs](https://docs.rs/winit/badge.svg)](https://docs.rs/winit)
-[![Master Docs](https://img.shields.io/github/actions/workflow/status/rust-windowing/winit/docs.yml?branch=master&label=master%20docs
+[![UNSTABLE docs](https://img.shields.io/github/actions/workflow/status/rust-windowing/winit/docs.yml?branch=master&label=UNSTABLE%20docs
 )](https://rust-windowing.github.io/winit/winit/index.html)
 [![CI Status](https://github.com/rust-windowing/winit/workflows/CI/badge.svg)](https://github.com/rust-windowing/winit/actions)
 
 ```toml
 [dependencies]
-winit = "0.30.5"
+winit = "0.30.10"
 ```
 
 ## [Documentation](https://docs.rs/winit)
@@ -33,6 +33,10 @@ Winit is designed to be a low-level brick in a hierarchy of libraries. Consequen
 show something on the window you need to use the platform-specific getters provided by winit, or
 another library.
 
+## CONTRIBUING
+
+For contributing guidelines see [CONTRIBUTING.md](./CONTRIBUTING.md).
+
 ## MSRV Policy
 
 This crate's Minimum Supported Rust Version (MSRV) is **1.73**. Changes to
@@ -66,4 +70,10 @@ same MSRV policy.
 
 ### Platform-specific usage
 
-Check out the [`winit::platform`](https://rust-windowing.github.io/winit/winit/platform/index.html) module for platform-specific usage.
+Check out the [`winit::platform`](https://docs.rs/winit/latest/winit/platform/index.html) module for platform-specific usage.
+
+### Repository License
+
+Note that the license in `LICENSE` doesn't apply in full to the DPI package [./dpi](./dpi).
+Full details can be found in that folder's README.
+<!-- This doesn't apply to users of the Winit crate, but this is also the repository level README -->

dpi/CHANGELOG.md

@@ -11,7 +11,10 @@ Unreleased` header.
 
 ## Unreleased
 
+## 0.1.2
+
 - Added `Insets`, `LogicalInsets` and `PhysicalInsets` types.
+- Make `no_std` compatible. If you use this functionality, DPI's license has changed.
 
 ## 0.1.1
 

dpi/Cargo.toml

@@ -3,16 +3,22 @@ categories = ["gui"]
 description = "Types for handling UI scaling"
 edition.workspace = true
 keywords = ["DPI", "HiDPI", "scale-factor"]
-license.workspace = true
+# N.B. This is "AND", because of the imported libm code.
+license = "Apache-2.0 AND MIT"
 name = "dpi"
 repository.workspace = true
 rust-version.workspace = true
-version = "0.1.1"
+version = "0.1.2"
 
 [features]
+default = ["std"]
+
 mint = ["dep:mint"]
 serde = ["dep:serde"]
 
+# Access mathematical functions using the standard library implementations
+std = []
+
 [dependencies]
 mint = { workspace = true, optional = true }
 serde = { workspace = true, optional = true }

dpi/LICENSE-LIBM-MIT

@@ -0,0 +1,51 @@
+rust-lang/libm as a whole is available for use under the MIT license:
+
+------------------------------------------------------------------------------
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+------------------------------------------------------------------------------
+
+This Rust library contains the following copyrights:
+
+    Copyright (c) 2018 Jorge Aparicio
+
+Portions of this software are derived from third-party works licensed under
+terms compatible with the above MIT license:
+
+* musl libc https://www.musl-libc.org/. This library contains the following
+  copyright:
+
+      Copyright © 2005-2020 Rich Felker, et al.
+
+* The CORE-MATH project https://core-math.gitlabpages.inria.fr/. CORE-MATH
+  routines are available under the MIT license on a per-file basis.
+
+The musl libc COPYRIGHT file also includes the following notice relevant to
+math portions of the library:
+
+------------------------------------------------------------------------------
+Much of the math library code (src/math/* and src/complex/*) is
+Copyright © 1993,2004 Sun Microsystems or
+Copyright © 2003-2011 David Schultz or
+Copyright © 2003-2009 Steven G. Kargl or
+Copyright © 2003-2009 Bruce D. Evans or
+Copyright © 2008 Stephen L. Moshier or
+Copyright © 2017-2018 Arm Limited
+and labelled as such in comments in the individual source files. All
+have been licensed under extremely permissive terms.
+------------------------------------------------------------------------------

dpi/README.md

@@ -0,0 +1,18 @@
+# DPI
+
+Full docs can be found on docs.rs.
+
+## License
+
+Most of DPI is licensed under the Apache License, Version 2.0 ([LICENSE](LICENSE)).
+All files except for `src/libm.rs` (and `LICENSE-LIBM-MIT`) are available solely under that license.
+
+For its `no_std` support, DPI uses code from the [libm](https://crates.io/crates/libm) crate.
+This is in the `libm.rs` file, and is licensed solely under the MIT Licence ([LICENSE-LIBM-MIT](LICENSE-LIBM-MIT)).
+That file contains details of all potentially applicable copyright notices.
+This is feature gated to only be included if you disable the `std` feature, otherwise it will not be compiled into your final binary
+(and so these license terms will not apply).
+
+Overall, this means that the license for this crate depends on what features you have enabled.
+If you enable the `std` feature, then DPI uses only code available under the Apache-2.0 license, and so can be used under the terms of that license.
+However, if you disable the `std` feature, then both these licenses must be followed to use the crate as a whole.

dpi/src/lib.rs

@@ -54,13 +54,25 @@
 //!
 //! * `serde`: Enables serialization/deserialization of certain types with [Serde](https://crates.io/crates/serde).
 //! * `mint`: Enables mint (math interoperability standard types) conversions.
+//! * `std` (enabled by default): Uses the standard library mathematical functions (normally through
+//!   your target platform's libm). This feature also changes the library's license from `Apache-2.0
+//!   AND MIT` to `APACHE-2.0` (only). For full details, see the package README.
 //!
+//! To use this library on a target without the standard library available, you should disable
+//! default features (thus disabling the `std` feature, with the license consequences thereof).
 //!
 //! [points]: https://en.wikipedia.org/wiki/Point_(typography)
 //! [picas]: https://en.wikipedia.org/wiki/Pica_(typography)
 
 #![cfg_attr(docsrs, feature(doc_auto_cfg, doc_cfg_hide), doc(cfg_hide(doc, docsrs)))]
-#![forbid(unsafe_code)]
+#![cfg_attr(feature = "std", forbid(unsafe_code))]
+#![no_std]
+
+#[cfg(not(feature = "std"))]
+mod libm;
+
+#[cfg(any(feature = "std", test))]
+extern crate std;
 
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
@@ -74,32 +86,32 @@ pub trait Pixel: Copy + Into<f64> {
 
 impl Pixel for u8 {
     fn from_f64(f: f64) -> Self {
-        f.round() as u8
+        round(f) as u8
     }
 }
 impl Pixel for u16 {
     fn from_f64(f: f64) -> Self {
-        f.round() as u16
+        round(f) as u16
     }
 }
 impl Pixel for u32 {
     fn from_f64(f: f64) -> Self {
-        f.round() as u32
+        round(f) as u32
     }
 }
 impl Pixel for i8 {
     fn from_f64(f: f64) -> Self {
-        f.round() as i8
+        round(f) as i8
     }
 }
 impl Pixel for i16 {
     fn from_f64(f: f64) -> Self {
-        f.round() as i16
+        round(f) as i16
     }
 }
 impl Pixel for i32 {
     fn from_f64(f: f64) -> Self {
-        f.round() as i32
+        round(f) as i32
     }
 }
 impl Pixel for f32 {
@@ -113,6 +125,15 @@ impl Pixel for f64 {
     }
 }
 
+/// Round f to the closest integer, rounding away from `0.0`
+#[inline]
+fn round(f: f64) -> f64 {
+    #[cfg(feature = "std")]
+    return f.round();
+    #[cfg(not(feature = "std"))]
+    return libm::round(f);
+}
+
 /// Checks that the scale factor is a normal positive `f64`.
 ///
 /// All functions that take a scale factor assert that this will return `true`. If you're sourcing
@@ -1270,20 +1291,20 @@ mod tests {
     // Eat coverage for the Debug impls et al
     #[test]
     fn ensure_attrs_do_not_panic() {
-        let _ = format!("{:?}", LogicalPosition::<u32>::default().clone());
+        let _ = std::format!("{:?}", LogicalPosition::<u32>::default().clone());
         HashSet::new().insert(LogicalPosition::<u32>::default());
 
-        let _ = format!("{:?}", PhysicalPosition::<u32>::default().clone());
+        let _ = std::format!("{:?}", PhysicalPosition::<u32>::default().clone());
         HashSet::new().insert(PhysicalPosition::<u32>::default());
 
-        let _ = format!("{:?}", LogicalSize::<u32>::default().clone());
+        let _ = std::format!("{:?}", LogicalSize::<u32>::default().clone());
         HashSet::new().insert(LogicalSize::<u32>::default());
 
-        let _ = format!("{:?}", PhysicalSize::<u32>::default().clone());
+        let _ = std::format!("{:?}", PhysicalSize::<u32>::default().clone());
         HashSet::new().insert(PhysicalSize::<u32>::default());
 
-        let _ = format!("{:?}", Size::Physical((1, 2).into()).clone());
-        let _ = format!("{:?}", Position::Physical((1, 2).into()).clone());
+        let _ = std::format!("{:?}", Size::Physical((1, 2).into()).clone());
+        let _ = std::format!("{:?}", Position::Physical((1, 2).into()).clone());
     }
 
     #[test]

dpi/src/libm.rs

@@ -0,0 +1,56 @@
+// Copyright (c) 2018 Jorge Aparicio
+// Copyright © 2005-2020 Rich Felker, et al.
+// Copyright © 1993,2004 Sun Microsystems or
+// Copyright © 2003-2011 David Schultz or
+// Copyright © 2003-2009 Steven G. Kargl or
+// Copyright © 2003-2009 Bruce D. Evans or
+// Copyright © 2008 Stephen L. Moshier or
+// Copyright © 2017-2018 Arm Limited
+// SPDX-License-Identifier: MIT
+// This file is licensed solely under the terms discussed in LICENSE-LIBM-MIT at the crate root.
+// See the package-level README for full details.
+
+// Taken from https://github.com/rust-lang/libm/blob/master/src/math/mod.rs#L1
+macro_rules! force_eval {
+    ($e:expr) => {
+        unsafe { ::core::ptr::read_volatile(&$e) }
+    };
+}
+
+// Taken from https://github.com/rust-lang/libm/blob/libm-v0.2.11/src/math/round.rs
+pub(crate) fn round(x: f64) -> f64 {
+    trunc(x + copysign(0.5 - 0.25 * f64::EPSILON, x))
+}
+
+// Adapted from: https://github.com/rust-lang/libm/blob/libm-v0.2.11/src/math/trunc.rs#L8-L12
+#[allow(clippy::needless_late_init /*, reason = "The original libm code uses this style" */)]
+fn trunc(x: f64) -> f64 {
+    let x1p120 = f64::from_bits(0x4770000000000000); // 0x1p120f === 2 ^ 120
+
+    let mut i: u64 = x.to_bits();
+    let mut e: i64 = ((i >> 52) & 0x7ff) as i64 - 0x3ff + 12;
+    let m: u64;
+
+    if e >= 52 + 12 {
+        return x;
+    }
+    if e < 12 {
+        e = 1;
+    }
+    m = -1i64 as u64 >> e;
+    if (i & m) == 0 {
+        return x;
+    }
+    force_eval!(x + x1p120);
+    i &= !m;
+    f64::from_bits(i)
+}
+
+// Taken from https://github.com/rust-lang/libm/blob/libm-v0.2.11/src/math/copysign.rs
+fn copysign(x: f64, y: f64) -> f64 {
+    let mut ux = x.to_bits();
+    let uy = y.to_bits();
+    ux &= (!0) >> 1;
+    ux |= uy & (1 << 63);
+    f64::from_bits(ux)
+}

examples/child_window.rs

@@ -13,12 +13,37 @@ fn main() -> Result<(), impl std::error::Error> {
     #[path = "util/fill.rs"]
     mod fill;
 
+    #[derive(Debug)]
+    struct WindowData {
+        window: Box<dyn Window>,
+        color: u32,
+    }
+
+    impl WindowData {
+        fn new(window: Box<dyn Window>, color: u32) -> Self {
+            Self { window, color }
+        }
+    }
+
+    #[derive(Default, Debug)]
     struct Application {
-        parent_window_id: WindowId,
-        windows: HashMap<WindowId, Box<dyn Window>>,
+        parent_window_id: Option<WindowId>,
+        windows: HashMap<WindowId, WindowData>,
     }
 
     impl ApplicationHandler for Application {
+        fn can_create_surfaces(&mut self, event_loop: &dyn ActiveEventLoop) {
+            let attributes = WindowAttributes::default()
+                .with_title("parent window")
+                .with_position(Position::Logical(LogicalPosition::new(0.0, 0.0)))
+                .with_surface_size(LogicalSize::new(640.0f32, 480.0f32));
+            let window = event_loop.create_window(attributes).unwrap();
+            println!("Parent window id: {:?})", window.id());
+            self.parent_window_id = Some(window.id());
+
+            self.windows.insert(window.id(), WindowData::new(window, 0xffbbbbbb));
+        }
+
         fn window_event(
             &mut self,
             event_loop: &dyn ActiveEventLoop,
@@ -42,15 +67,24 @@ fn main() -> Result<(), impl std::error::Error> {
                     event: KeyEvent { state: ElementState::Pressed, .. },
                     ..
                 } => {
-                    let parent_window = self.windows.get(&self.parent_window_id).unwrap();
-                    let child_window = spawn_child_window(parent_window.as_ref(), event_loop);
+                    let child_index = self.windows.len() - 1;
+                    let child_color =
+                        0xff000000 + 3_u32.pow((child_index + 2).rem_euclid(16) as u32);
+
+                    let parent_window = self.windows.get(&self.parent_window_id.unwrap()).unwrap();
+                    let child_window =
+                        spawn_child_window(parent_window.window.as_ref(), event_loop, child_index);
                     let child_id = child_window.id();
                     println!("Child window created with id: {child_id:?}");
-                    self.windows.insert(child_id, child_window);
+                    self.windows.insert(child_id, WindowData::new(child_window, child_color));
                 },
                 WindowEvent::RedrawRequested => {
                     if let Some(window) = self.windows.get(&window_id) {
-                        fill::fill_window(window.as_ref());
+                        if window_id == self.parent_window_id.unwrap() {
+                            fill::fill_window(window.window.as_ref());
+                        } else {
+                            fill::fill_window_with_color(window.window.as_ref(), window.color);
+                        }
                     }
                 },
                 _ => (),
@@ -58,29 +92,23 @@ fn main() -> Result<(), impl std::error::Error> {
         }
     }
 
-    fn init(event_loop: &dyn ActiveEventLoop) -> Application {
-        let attributes = WindowAttributes::default()
-            .with_title("parent window")
-            .with_position(Position::Logical(LogicalPosition::new(0.0, 0.0)))
-            .with_surface_size(LogicalSize::new(640.0f32, 480.0f32));
-        let window = event_loop.create_window(attributes).unwrap();
-
-        println!("Parent window id: {:?})", window.id());
-
-        let parent_window_id = window.id();
-        let windows = HashMap::from([(window.id(), window)]);
-        Application { parent_window_id, windows }
-    }
-
     fn spawn_child_window(
         parent: &dyn Window,
         event_loop: &dyn ActiveEventLoop,
+        child_count: usize,
     ) -> Box<dyn Window> {
         let parent = parent.raw_window_handle().unwrap();
+
+        // As child count increases, x goes from 0*128 to 5*128 and then repeats
+        let x: f64 = child_count.rem_euclid(5) as f64 * 128.0;
+
+        // After 5 windows have been put side by side horizontally, a new row starts
+        let y: f64 = (child_count / 5) as f64 * 96.0;
+
         let mut window_attributes = WindowAttributes::default()
             .with_title("child window")
-            .with_surface_size(LogicalSize::new(200.0f32, 200.0f32))
-            .with_position(Position::Logical(LogicalPosition::new(0.0, 0.0)))
+            .with_surface_size(LogicalSize::new(128.0f32, 96.0))
+            .with_position(Position::Logical(LogicalPosition::new(x, y)))
             .with_visible(true);
         // `with_parent_window` is unsafe. Parent window must be a valid window.
         window_attributes = unsafe { window_attributes.with_parent_window(Some(parent)) };
@@ -89,7 +117,7 @@ fn main() -> Result<(), impl std::error::Error> {
     }
 
     let event_loop = EventLoop::new().unwrap();
-    event_loop.run(init)
+    event_loop.run_app(Application::default())
 }
 
 #[cfg(not(any(x11_platform, macos_platform, windows_platform)))]

examples/control_flow.rs

@@ -43,31 +43,16 @@ fn main() -> Result<(), impl std::error::Error> {
 
     let event_loop = EventLoop::new().unwrap();
 
-    event_loop.run(ControlFlowDemo::new)
+    event_loop.run_app(ControlFlowDemo::default())
 }
 
+#[derive(Default, Debug)]
 struct ControlFlowDemo {
     mode: Mode,
     request_redraw: bool,
     wait_cancelled: bool,
     close_requested: bool,
-    window: Box<dyn Window>,
-}
-
-impl ControlFlowDemo {
-    fn new(event_loop: &dyn ActiveEventLoop) -> Self {
-        let window_attributes = WindowAttributes::default().with_title(
-            "Press 1, 2, 3 to change control flow mode. Press R to toggle redraw requests.",
-        );
-        let window = event_loop.create_window(window_attributes).unwrap();
-        Self {
-            mode: Mode::default(),
-            request_redraw: false,
-            wait_cancelled: false,
-            close_requested: false,
-            window,
-        }
-    }
+    window: Option<Box<dyn Window>>,
 }
 
 impl ApplicationHandler for ControlFlowDemo {
@@ -80,6 +65,13 @@ impl ApplicationHandler for ControlFlowDemo {
         }
     }
 
+    fn can_create_surfaces(&mut self, event_loop: &dyn ActiveEventLoop) {
+        let window_attributes = WindowAttributes::default().with_title(
+            "Press 1, 2, 3 to change control flow mode. Press R to toggle redraw requests.",
+        );
+        self.window = Some(event_loop.create_window(window_attributes).unwrap());
+    }
+
     fn window_event(
         &mut self,
         _event_loop: &dyn ActiveEventLoop,
@@ -120,8 +112,9 @@ impl ApplicationHandler for ControlFlowDemo {
                 _ => (),
             },
             WindowEvent::RedrawRequested => {
-                self.window.pre_present_notify();
-                fill::fill_window(&*self.window);
+                let window = self.window.as_ref().unwrap();
+                window.pre_present_notify();
+                fill::fill_window(window.as_ref());
             },
             _ => (),
         }
@@ -129,7 +122,7 @@ impl ApplicationHandler for ControlFlowDemo {
 
     fn about_to_wait(&mut self, event_loop: &dyn ActiveEventLoop) {
         if self.request_redraw && !self.wait_cancelled && !self.close_requested {
-            self.window.request_redraw();
+            self.window.as_ref().unwrap().request_redraw();
         }
 
         match self.mode {

examples/dnd.rs

@@ -0,0 +1,65 @@
+use std::error::Error;
+
+use winit::application::ApplicationHandler;
+use winit::event::WindowEvent;
+use winit::event_loop::{ActiveEventLoop, EventLoop};
+use winit::window::{Window, WindowAttributes, WindowId};
+
+#[path = "util/fill.rs"]
+mod fill;
+#[path = "util/tracing.rs"]
+mod tracing;
+
+fn main() -> Result<(), Box<dyn Error>> {
+    tracing::init();
+
+    let event_loop = EventLoop::new()?;
+
+    let app = Application::new();
+    Ok(event_loop.run_app(app)?)
+}
+
+/// Application state and event handling.
+#[derive(Debug)]
+struct Application {
+    window: Option<Box<dyn Window>>,
+}
+
+impl Application {
+    fn new() -> Self {
+        Self { window: None }
+    }
+}
+
+impl ApplicationHandler for Application {
+    fn can_create_surfaces(&mut self, event_loop: &dyn ActiveEventLoop) {
+        let window_attributes =
+            WindowAttributes::default().with_title("Drag and drop files on me!");
+        self.window = Some(event_loop.create_window(window_attributes).unwrap());
+    }
+
+    fn window_event(
+        &mut self,
+        event_loop: &dyn ActiveEventLoop,
+        _window_id: WindowId,
+        event: WindowEvent,
+    ) {
+        match event {
+            WindowEvent::DragLeft { .. }
+            | WindowEvent::DragEntered { .. }
+            | WindowEvent::DragMoved { .. }
+            | WindowEvent::DragDropped { .. } => {
+                println!("{:?}", event);
+            },
+            WindowEvent::RedrawRequested => {
+                let window = self.window.as_ref().unwrap();
+                window.pre_present_notify();
+                fill::fill_window(window.as_ref());
+            },
+            WindowEvent::CloseRequested => {
+                event_loop.exit();
+            },
+            _ => {},
+        }
+    }
+}

examples/pump_events.rs

@@ -8,7 +8,7 @@ fn main() -> std::process::ExitCode {
     use std::time::Duration;
 
     use winit::application::ApplicationHandler;
-    use winit::event::{StartCause, WindowEvent};
+    use winit::event::WindowEvent;
     use winit::event_loop::{ActiveEventLoop, EventLoop};
     use winit::platform::pump_events::{EventLoopExtPumpEvents, PumpStatus};
     use winit::window::{Window, WindowAttributes, WindowId};
@@ -16,18 +16,15 @@ fn main() -> std::process::ExitCode {
     #[path = "util/fill.rs"]
     mod fill;
 
-    #[derive(Default)]
+    #[derive(Default, Debug)]
     struct PumpDemo {
         window: Option<Box<dyn Window>>,
     }
 
     impl ApplicationHandler for PumpDemo {
-        fn new_events(&mut self, event_loop: &dyn ActiveEventLoop, cause: StartCause) {
-            if matches!(cause, StartCause::Init) && self.window.is_none() {
-                let window_attributes =
-                    WindowAttributes::default().with_title("A fantastic window!");
-                self.window = Some(event_loop.create_window(window_attributes).unwrap());
-            }
+        fn can_create_surfaces(&mut self, event_loop: &dyn ActiveEventLoop) {
+            let window_attributes = WindowAttributes::default().with_title("A fantastic window!");
+            self.window = Some(event_loop.create_window(window_attributes).unwrap());
         }
 
         fn window_event(

examples/run_on_demand.rs

@@ -14,24 +14,13 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     #[path = "util/fill.rs"]
     mod fill;
 
-    #[derive(Default)]
+    #[derive(Default, Debug)]
     struct App {
         idx: usize,
         window_id: Option<WindowId>,
         window: Option<Box<dyn Window>>,
     }
 
-    impl App {
-        fn init_window(&mut self, event_loop: &dyn ActiveEventLoop) {
-            let window_attributes = WindowAttributes::default()
-                .with_title("Fantastic window number one!")
-                .with_surface_size(winit::dpi::LogicalSize::new(128.0, 128.0));
-            let window = event_loop.create_window(window_attributes).unwrap();
-            self.window_id = Some(window.id());
-            self.window = Some(window);
-        }
-    }
-
     impl ApplicationHandler for App {
         fn about_to_wait(&mut self, _event_loop: &dyn ActiveEventLoop) {
             if let Some(window) = self.window.as_ref() {
@@ -39,6 +28,15 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
             }
         }
 
+        fn can_create_surfaces(&mut self, event_loop: &dyn ActiveEventLoop) {
+            let window_attributes = WindowAttributes::default()
+                .with_title("Fantastic window number one!")
+                .with_surface_size(winit::dpi::LogicalSize::new(128.0, 128.0));
+            let window = event_loop.create_window(window_attributes).unwrap();
+            self.window_id = Some(window.id());
+            self.window = Some(window);
+        }
+
         fn window_event(
             &mut self,
             event_loop: &dyn ActiveEventLoop,
@@ -83,20 +81,14 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     let mut event_loop = EventLoop::new().unwrap();
 
     let mut app = App { idx: 1, ..Default::default() };
-    event_loop.run_on_demand(|event_loop| {
-        app.init_window(event_loop);
-        &mut app
-    })?;
+    event_loop.run_app_on_demand(&mut app)?;
 
     println!("--------------------------------------------------------- Finished first loop");
     println!("--------------------------------------------------------- Waiting 5 seconds");
     std::thread::sleep(Duration::from_secs(5));
 
     app.idx += 1;
-    event_loop.run_on_demand(|event_loop| {
-        app.init_window(event_loop);
-        &mut app
-    })?;
+    event_loop.run_app_on_demand(&mut app)?;
     println!("--------------------------------------------------------- Finished second loop");
     Ok(())
 }

examples/util/fill.rs

@@ -9,7 +9,12 @@
 
 #[allow(unused_imports)]
 pub use platform::cleanup_window;
+#[allow(unused_imports)]
 pub use platform::fill_window;
+#[allow(unused_imports)]
+pub use platform::fill_window_with_animated_color;
+#[allow(unused_imports)]
+pub use platform::fill_window_with_color;
 
 #[cfg(not(any(target_os = "android", target_os = "ios")))]
 mod platform {
@@ -70,7 +75,7 @@ mod platform {
         }
     }
 
-    pub fn fill_window(window: &dyn Window) {
+    pub fn fill_window_with_color(window: &dyn Window, color: u32) {
         GC.with(|gc| {
             let size = window.surface_size();
             let (Some(width), Some(height)) =
@@ -84,17 +89,31 @@ mod platform {
             let surface =
                 gc.get_or_insert_with(|| GraphicsContext::new(window)).create_surface(window);
 
-            // Fill a buffer with a solid color.
-            const DARK_GRAY: u32 = 0xff181818;
+            // Fill a buffer with a solid color
 
             surface.resize(width, height).expect("Failed to resize the softbuffer surface");
 
             let mut buffer = surface.buffer_mut().expect("Failed to get the softbuffer buffer");
-            buffer.fill(DARK_GRAY);
+            buffer.fill(color);
             buffer.present().expect("Failed to present the softbuffer buffer");
         })
     }
 
+    #[allow(dead_code)]
+    pub fn fill_window(window: &dyn Window) {
+        fill_window_with_color(window, 0xff181818);
+    }
+
+    #[allow(dead_code)]
+    pub fn fill_window_with_animated_color(window: &dyn Window, start: std::time::Instant) {
+        let time = start.elapsed().as_secs_f32() * 1.5;
+        let blue = (time.sin() * 255.0) as u32;
+        let green = ((time.cos() * 255.0) as u32) << 8;
+        let red = ((1.0 - time.sin() * 255.0) as u32) << 16;
+        let color = red | green | blue;
+        fill_window_with_color(window, color);
+    }
+
     #[allow(dead_code)]
     pub fn cleanup_window(window: &dyn Window) {
         GC.with(|gc| {
@@ -108,10 +127,24 @@ mod platform {
 
 #[cfg(any(target_os = "android", target_os = "ios"))]
 mod platform {
+    #[allow(dead_code)]
     pub fn fill_window(_window: &dyn winit::window::Window) {
         // No-op on mobile platforms.
     }
 
+    #[allow(dead_code)]
+    pub fn fill_window_with_color(_window: &dyn winit::window::Window, _color: u32) {
+        // No-op on mobile platforms.
+    }
+
+    #[allow(dead_code)]
+    pub fn fill_window_with_animated_color(
+        _window: &dyn winit::window::Window,
+        _start: std::time::Instant,
+    ) {
+        // No-op on mobile platforms.
+    }
+
     #[allow(dead_code)]
     pub fn cleanup_window(_window: &dyn winit::window::Window) {
         // No-op on mobile platforms.

examples/x11_embed.rs

@@ -12,29 +12,41 @@ fn main() -> Result<(), Box<dyn Error>> {
     #[path = "util/fill.rs"]
     mod fill;
 
+    #[derive(Debug)]
     pub struct XEmbedDemo {
-        window: Box<dyn Window>,
+        parent_window_id: u32,
+        window: Option<Box<dyn Window>>,
     }
 
     impl ApplicationHandler for XEmbedDemo {
+        fn can_create_surfaces(&mut self, event_loop: &dyn ActiveEventLoop) {
+            let window_attributes = WindowAttributes::default()
+                .with_title("An embedded window!")
+                .with_surface_size(winit::dpi::LogicalSize::new(128.0, 128.0))
+                .with_embed_parent_window(self.parent_window_id);
+
+            self.window = Some(event_loop.create_window(window_attributes).unwrap());
+        }
+
         fn window_event(
             &mut self,
             event_loop: &dyn ActiveEventLoop,
             _window_id: WindowId,
             event: WindowEvent,
         ) {
+            let window = self.window.as_ref().unwrap();
             match event {
                 WindowEvent::CloseRequested => event_loop.exit(),
                 WindowEvent::RedrawRequested => {
-                    self.window.pre_present_notify();
-                    fill::fill_window(&*self.window);
+                    window.pre_present_notify();
+                    fill::fill_window(window.as_ref());
                 },
                 _ => (),
             }
         }
 
         fn about_to_wait(&mut self, _event_loop: &dyn ActiveEventLoop) {
-            self.window.request_redraw();
+            self.window.as_ref().unwrap().request_redraw();
         }
     }
 
@@ -47,15 +59,7 @@ fn main() -> Result<(), Box<dyn Error>> {
     tracing_subscriber::fmt::init();
     let event_loop = EventLoop::new()?;
 
-    Ok(event_loop.run(|event_loop| {
-        let window_attributes = WindowAttributes::default()
-            .with_title("An embedded window!")
-            .with_surface_size(winit::dpi::LogicalSize::new(128.0, 128.0))
-            .with_embed_parent_window(parent_window_id);
-
-        let window = event_loop.create_window(window_attributes).unwrap();
-        XEmbedDemo { window }
-    })?)
+    Ok(event_loop.run_app(XEmbedDemo { parent_window_id, window: None })?)
 }
 
 #[cfg(not(x11_platform))]

src/application.rs

@@ -2,13 +2,21 @@
 
 use crate::event::{DeviceEvent, DeviceId, StartCause, WindowEvent};
 use crate::event_loop::ActiveEventLoop;
-#[cfg(any(docsrs, macos_platform))]
+#[cfg(macos_platform)]
 use crate::platform::macos::ApplicationHandlerExtMacOS;
 use crate::window::WindowId;
 
-/// The handler of the application events.
+/// The handler of application-level events.
 ///
-/// This is [dropped][std::ops::Drop] when the event loop is being shut down.
+/// See [the top-level docs] for example usage, and [`EventLoop::run_app`] for an overview of when
+/// events are delivered.
+///
+/// This is [dropped] when the event loop is shut down. Note that this only works if you're passing
+/// the entire state to [`EventLoop::run_app`] (passing `&mut app` won't work).
+///
+/// [the top-level docs]: crate
+/// [`EventLoop::run_app`]: crate::event_loop::EventLoop::run_app
+/// [dropped]: std::ops::Drop
 pub trait ApplicationHandler {
     /// Emitted when new events arrive from the OS to be processed.
     ///
@@ -59,7 +67,6 @@ pub trait ApplicationHandler {
     ///
     /// [`resumed()`]: Self::resumed()
     /// [`suspended()`]: Self::suspended()
-    /// [`exiting()`]: Self::exiting()
     fn resumed(&mut self, event_loop: &dyn ActiveEventLoop) {
         let _ = event_loop;
     }
@@ -103,9 +110,7 @@ pub trait ApplicationHandler {
     ///
     /// [`can_create_surfaces()`]: Self::can_create_surfaces()
     /// [`destroy_surfaces()`]: Self::destroy_surfaces()
-    fn can_create_surfaces(&mut self, event_loop: &dyn ActiveEventLoop) {
-        let _ = event_loop;
-    }
+    fn can_create_surfaces(&mut self, event_loop: &dyn ActiveEventLoop);
 
     /// Called after a wake up is requested using [`EventLoopProxy::wake_up()`].
     ///
@@ -146,6 +151,8 @@ pub trait ApplicationHandler {
     ///     # ) {
     ///     # }
     ///     #
+    ///     # fn can_create_surfaces(&mut self, _event_loop: &dyn ActiveEventLoop) {}
+    ///     #
     ///     fn proxy_wake_up(&mut self, _event_loop: &dyn ActiveEventLoop) {
     ///         // Iterate current events, since wake-ups may have been merged.
     ///         //
@@ -171,7 +178,7 @@ pub trait ApplicationHandler {
     ///         loop {
     ///             println!("sending: {i}");
     ///             if sender.send(i).is_err() {
-    ///                 // Stop sending once `MyApp` is dropped
+    ///                 // Stop sending once the receiver is dropped
     ///                 break;
     ///             }
     ///             // Trigger the wake-up _after_ we placed the event in the channel.
@@ -182,7 +189,7 @@ pub trait ApplicationHandler {
     ///         }
     ///     });
     ///
-    ///     event_loop.run(|_event_loop| MyApp { receiver })?;
+    ///     event_loop.run_app(MyApp { receiver })?;
     ///
     ///     background_thread.join().unwrap();
     ///
@@ -202,6 +209,10 @@ pub trait ApplicationHandler {
     );
 
     /// Emitted when the OS sends an event to a device.
+    ///
+    /// For this to be called, it must be enabled with [`EventLoop::listen_device_events`].
+    ///
+    /// [`EventLoop::listen_device_events`]: crate::event_loop::EventLoop::listen_device_events
     fn device_event(
         &mut self,
         event_loop: &dyn ActiveEventLoop,
@@ -257,7 +268,7 @@ pub trait ApplicationHandler {
     /// to the user. This is a good place to stop refreshing UI, running animations and other visual
     /// things. It is driven by Android's [`onStop()`] method.
     ///
-    /// After this event the application either receives [`resumed()`] again, or [`exiting()`].
+    /// After this event the application either receives [`resumed()`] again, or will exit.
     ///
     /// [`onStop()`]: https://developer.android.com/reference/android/app/Activity#onStop()
     ///
@@ -267,7 +278,6 @@ pub trait ApplicationHandler {
     ///
     /// [`resumed()`]: Self::resumed()
     /// [`suspended()`]: Self::suspended()
-    /// [`exiting()`]: Self::exiting()
     fn suspended(&mut self, event_loop: &dyn ActiveEventLoop) {
         let _ = event_loop;
     }
@@ -285,13 +295,13 @@ pub trait ApplicationHandler {
     /// with the [`onStop`] lifecycle event which typically results in the surface to be destroyed
     /// after the app becomes invisible.
     ///
-    /// Applications that need to run on Android must be able to handle their underlying
-    /// [`SurfaceView`] being destroyed, which in turn indirectly invalidates any existing
-    /// render surfaces that may have been created outside of Winit (such as an `EGLSurface`,
-    /// [`VkSurfaceKHR`] or [`wgpu::Surface`]).
+    /// Applications that need to run on Android should assume their [`NativeWindow`] has been
+    /// destroyed, which indirectly invalidates any existing render surfaces that may have been
+    /// created outside of Winit (such as an `EGLSurface`, [`VkSurfaceKHR`] or [`wgpu::Surface`]).
     ///
-    /// This means that in this method, you must drop all render surfaces before the event callback
-    /// completes, and only re-create them in or after [`can_create_surfaces()`] is next recieved.
+    /// When receiving [`destroy_surfaces()`] Android applications should drop all render surfaces
+    /// before the event callback completes, which may be re-created when the application next
+    /// receives [`can_create_surfaces()`].
     ///
     /// [`NativeWindow`]: https://developer.android.com/ndk/reference/group/a-native-window
     /// [`Surface`]: https://developer.android.com/reference/android/view/Surface
@@ -340,7 +350,7 @@ pub trait ApplicationHandler {
     /// The macOS-specific handler.
     ///
     /// The return value from this should not change at runtime.
-    #[cfg(any(docsrs, macos_platform))]
+    #[cfg(macos_platform)]
     #[inline(always)]
     fn macos_handler(&mut self) -> Option<&mut dyn ApplicationHandlerExtMacOS> {
         None
@@ -409,7 +419,7 @@ impl<A: ?Sized + ApplicationHandler> ApplicationHandler for &mut A {
         (**self).memory_warning(event_loop);
     }
 
-    #[cfg(any(docsrs, macos_platform))]
+    #[cfg(macos_platform)]
     #[inline]
     fn macos_handler(&mut self) -> Option<&mut dyn ApplicationHandlerExtMacOS> {
         (**self).macos_handler()
@@ -478,7 +488,7 @@ impl<A: ?Sized + ApplicationHandler> ApplicationHandler for Box<A> {
         (**self).memory_warning(event_loop);
     }
 
-    #[cfg(any(docsrs, macos_platform))]
+    #[cfg(macos_platform)]
     #[inline]
     fn macos_handler(&mut self) -> Option<&mut dyn ApplicationHandlerExtMacOS> {
         (**self).macos_handler()

src/changelog/unreleased.md

@@ -59,29 +59,29 @@ changelog entry.
 - Implement `Clone`, `Copy`, `Debug`, `Deserialize`, `Eq`, `Hash`, `Ord`, `PartialEq`, `PartialOrd`
   and `Serialize` on many types.
 - Add `MonitorHandle::current_video_mode()`.
-- On Android, the soft keyboard can now be shown using `Window::set_ime_allowed`.
-- Add basic iOS IME support. The soft keyboard can now be shown using `Window::set_ime_allowed`.
 - Add `ApplicationHandlerExtMacOS` trait, and a `macos_handler` method to `ApplicationHandler` which returns a `dyn ApplicationHandlerExtMacOS` which allows for macOS specific extensions to winit.
 - Add a `standard_key_binding` method to the `ApplicationHandlerExtMacOS` trait. This allows handling of standard keybindings such as "go to end of line" on macOS.
-- On macOS, add `WindowExtMacOS::set_borderless_game` and `WindowAttributesExtMacOS::with_borderless_game`
-  to fully disable the menu bar and dock in Borderless Fullscreen as commonly done in games.
 - On macOS, add `WindowExtMacOS::set_unified_titlebar` and `WindowAttributesExtMacOS::with_unified_titlebar`
   to use a larger style of titlebar.
 - Add `WindowId::into_raw()` and `from_raw()`.
 - Add `PointerKind`, `PointerSource`, `ButtonSource`, `FingerId`, `primary` and `position` to all
   pointer events as part of the pointer event overhaul.
 - Add `DeviceId::into_raw()` and `from_raw()`.
-- On X11, the `window` example now understands the `X11_VISUAL_ID` and `X11_SCREEN_ID` env
-  variables to test the respective modifiers of window creation.
 - Added `Window::surface_position`, which is the position of the surface inside the window.
 - Added `Window::safe_area`, which describes the area of the surface that is unobstructed.
-- On X11 and Wayland, improved scancode conversions for more obscure key codes.
-- On Windows, improved scancode conversions for more obscure key codes.
+- On X11, Wayland, Windows and macOS, improved scancode conversions for more obscure key codes.
+- Add ability to make non-activating window on macOS using `NSPanel` with `NSWindowStyleMask::NonactivatingPanel`.
+- Implement `MonitorHandleProvider` for `MonitorHandle` to access common monitor API.
+- On X11, set an "area" attribute on XIM input connection to convey the cursor area.
+- Implement `CustomCursorProvider` for `CustomCursor` to access cursor API.
+- Add `CustomCursorSource::Url`, `CustomCursorSource::from_animation`.
+- Implement `CustomIconProvider` for `RgbaIcon`.
+- Add `icon` module that exposes winit's icon API.
 
 ### Changed
 
-- Change `ActiveEventLoop` to be a trait.
-- Change `Window` to be a trait.
+- Change `ActiveEventLoop` and `Window` to be traits, and added `cast_ref`/`cast_mut`/`cast`
+  methods to extract the backend type from those.
 - `ActiveEventLoop::create_window` now returns `Box<dyn Window>`.
 - `ApplicationHandler` now uses `dyn ActiveEventLoop`.
 - On Web, let events wake up event loop immediately when using `ControlFlow::Poll`.
@@ -114,10 +114,8 @@ changelog entry.
 - Changed how `ModifiersState` is serialized by Serde.
 - `VideoModeHandle::refresh_rate_millihertz()` and `bit_depth()` now return a `Option<NonZero*>`.
 - `MonitorHandle::position()` now returns an `Option`.
-- On iOS and macOS, remove custom application delegates. You are now allowed to override the
+- On macOS, remove custom application delegates. You are now allowed to override the
   application delegate yourself.
-- On iOS, no longer act as-if the application successfully open all URLs. Override
-  `application:didFinishLaunchingWithOptions:` and provide the desired behaviour yourself.
 - On X11, remove our dependency on libXcursor. (#3749)
 - Renamed the following APIs to make it clearer that the sizes apply to the underlying surface:
   - `WindowEvent::Resized` to `SurfaceResized`.
@@ -164,6 +162,39 @@ changelog entry.
 - On X11, use bottom-right corner for IME hotspot in `Window::set_ime_cursor_area`.
 - On macOS and iOS, no longer emit `ScaleFactorChanged` upon window creation.
 - On macOS, no longer emit `Focused` upon window creation.
+- On iOS, emit more events immediately, instead of queuing them.
+- Update `smol_str` to version `0.3`
+- Rename `VideoModeHandle` to `VideoMode`, now it only stores plain data.
+- Make `Fullscreen::Exclusive` contain `(MonitorHandle, VideoMode)`.
+- Reworked the file drag-and-drop API.
+
+  The `WindowEvent::DroppedFile`, `WindowEvent::HoveredFile` and `WindowEvent::HoveredFileCancelled`
+  events have been removed, and replaced with `WindowEvent::DragEntered`, `WindowEvent::DragMoved`,
+  `WindowEvent::DragDropped` and `WindowEvent::DragLeft`.
+
+  The old drag-and-drop events were emitted once per file. This occurred when files were *first*
+  hovered over the window, dropped, or left the window. The new drag-and-drop events are emitted
+  once per set of files dragged, and include a list of all dragged files. They also include the
+  pointer position.
+
+  The rough correspondence is:
+  - `WindowEvent::HoveredFile` -> `WindowEvent::DragEntered`
+  - `WindowEvent::DroppedFile` -> `WindowEvent::DragDropped`
+  - `WindowEvent::HoveredFileCancelled` -> `WindowEvent::DragLeft`
+
+  The `WindowEvent::DragMoved` event is entirely new, and is emitted whenever the pointer moves
+  whilst files are being dragged over the window. It doesn't contain any file paths, just the
+  pointer position.
+- Updated `objc2` to `v0.6`.
+- Updated `windows-sys` to `v0.59`.
+  - To match the corresponding changes in `windows-sys`, the `HWND`, `HMONITOR`, and `HMENU` types
+    now alias to `*mut c_void` instead of `isize`.
+- Removed `KeyEventExtModifierSupplement`, and made the fields `text_with_all_modifiers` and
+  `key_without_modifiers` public on `KeyEvent` instead.
+- Move `window::Fullscreen` to `monitor::Fullscreen`.
+- Renamed "super" key to "meta", to match the naming in the W3C specification.
+  `NamedKey::Super` still exists, but it's non-functional and deprecated, `NamedKey::Meta` should be used instead.
+- Move `IconExtWindows` into `WinIcon`.
 
 ### Removed
 
@@ -195,18 +226,18 @@ changelog entry.
 - Remove `WindowEvent::Touch` and `Touch` in favor of the new `PointerKind`, `PointerSource` and
  `ButtonSource` as part of the new pointer event overhaul.
 - Remove `Force::altitude_angle`.
-- Removed `Window::inner_position`, use the new `Window::surface_position` instead.
+- Remove `Window::inner_position`, use the new `Window::surface_position` instead.
+- Remove `CustomCursorExtWeb`, use the `CustomCursorSource`.
+- Remove `CustomCursor::from_rgba`, use `CustomCursorSource` instead.
+- Remove `ApplicationHandler::exited`, the event loop being shut down can now be listened to in
+  the `Drop` impl on the application handler.
+- Remove `NamedKey::Space`, match on `Key::Character(" ")` instead.
+- Remove `PartialEq` impl for `WindowAttributes`.
 
 ### Fixed
 
 - On Orbital, `MonitorHandle::name()` now returns `None` instead of a dummy name.
-- On macOS, fix `WindowEvent::Moved` sometimes being triggered unnecessarily on resize.
-- On macOS, package manifest definitions of `LSUIElement` will no longer be overridden with the
-  default activation policy, unless explicitly provided during initialization.
-- On macOS, fix crash when calling `drag_window()` without a left click present.
-- On X11, key events forward to IME anyway, even when it's disabled.
-- On Windows, make `ControlFlow::WaitUntil` work more precisely using `CREATE_WAITABLE_TIMER_HIGH_RESOLUTION`.
-- On X11, creating windows on screen that is not the first one (e.g. `DISPLAY=:0.1`) works again.
-- On X11, creating windows while passing `with_x11_screen(non_default_screen)` works again.
-- On X11, fix XInput handling that prevented a new window from getting the focus in some cases.
 - On iOS, fixed `SurfaceResized` and `Window::surface_size` not reporting the size of the actual surface.
+- On macOS, fixed the scancode conversion for audio volume keys.
+- On macOS, fixed the scancode conversion for `IntlBackslash`.
+- On macOS, fixed redundant `SurfaceResized` event at window creation.

src/changelog/v0.30.md

@@ -1,3 +1,89 @@
+## 0.30.10
+
+### Added
+
+- On Windows, add `IconExtWindows::from_resource_name`.
+- On Windows, add `CursorGrabMode::Locked`.
+- On Wayland, add `WindowExtWayland::xdg_toplevel`.
+
+### Changed
+
+- On macOS, no longer need control of the main `NSApplication` class (which means you can now override it yourself).
+- On iOS, remove custom application delegates. You are now allowed to override the
+  application delegate yourself.
+- On iOS, no longer act as-if the application successfully open all URLs. Override
+  `application:didFinishLaunchingWithOptions:` and provide the desired behaviour yourself.
+
+### Fixed
+
+- On Windows, fixed ~500 ms pause when clicking the title bar during continuous redraw.
+- On macOS, `WindowExtMacOS::set_simple_fullscreen` now honors `WindowExtMacOS::set_borderless_game`
+- On X11 and Wayland, fixed pump_events with `Some(Duration::Zero)` blocking with `Wait` polling mode
+- On Wayland, fixed a crash when consequently calling `set_cursor_grab` without pointer focus.
+- On Wayland, ensure that external event loop is woken-up when using pump_events and integrating via `FD`.
+- On Wayland, apply fractional scaling to custom cursors.
+- On macOS, fixed `run_app_on_demand` returning without closing open windows.
+- On macOS, fixed `VideoMode::refresh_rate_millihertz` for fractional refresh rates.
+- On macOS, store monitor handle to avoid panics after going in/out of sleep.
+- On macOS, allow certain invalid monitor handles and return `None` instead of panicking.
+- On Windows, fixed `Ime::Preedit` cursor offset calculation.
+
+## 0.30.9
+
+### Changed
+
+- On Wayland, no longer send an explicit clearing `Ime::Preedit` just prior to a new `Ime::Preedit`.
+
+### Fixed
+
+- On X11, fix crash with uim.
+- On X11, fix modifiers for keys that were sent by the same X11 request.
+- On iOS, fix high CPU usage even when using `ControlFlow::Wait`.
+
+## 0.30.8
+
+### Added
+
+- `ActivationToken::from_raw` and `ActivationToken::into_raw`.
+- On X11, add a workaround for disabling IME on GNOME.
+
+### Fixed
+
+- On Windows, fixed the event loop not waking on accessibility requests.
+- On X11, fixed cursor grab mode state tracking on error.
+
+## 0.30.7
+
+### Fixed
+
+- On X11, fixed KeyboardInput delivered twice when IME enabled.
+
+## 0.30.6
+
+### Added
+
+- On macOS, add `WindowExtMacOS::set_borderless_game` and `WindowAttributesExtMacOS::with_borderless_game`
+  to fully disable the menu bar and dock in Borderless Fullscreen as commonly done in games.
+- On X11, the `window` example now understands the `X11_VISUAL_ID` and `X11_SCREEN_ID` env
+  variables to test the respective modifiers of window creation.
+- On Android, the soft keyboard can now be shown using `Window::set_ime_allowed`.
+- Add basic iOS IME support. The soft keyboard can now be shown using `Window::set_ime_allowed`.
+
+### Fixed
+
+- On macOS, fix `WindowEvent::Moved` sometimes being triggered unnecessarily on resize.
+- On macOS, package manifest definitions of `LSUIElement` will no longer be overridden with the
+  default activation policy, unless explicitly provided during initialization.
+- On macOS, fix crash when calling `drag_window()` without a left click present.
+- On X11, key events forward to IME anyway, even when it's disabled.
+- On Windows, make `ControlFlow::WaitUntil` work more precisely using `CREATE_WAITABLE_TIMER_HIGH_RESOLUTION`.
+- On X11, creating windows on screen that is not the first one (e.g. `DISPLAY=:0.1`) works again.
+- On X11, creating windows while passing `with_x11_screen(non_default_screen)` works again.
+- On X11, fix XInput handling that prevented a new window from getting the focus in some cases.
+- On macOS, fix crash when pressing Caps Lock in certain configurations.
+- On iOS, fixed `MonitorHandle`'s `PartialEq` and `Hash` implementations.
+- On macOS, fixed undocumented cursors (e.g. zoom, resize, help) always appearing to be invalid and falling back to the default cursor.
+
 ## 0.30.5
 
 ### Added

src/cursor.rs

@@ -1,13 +1,15 @@
 use core::fmt;
 use std::error::Error;
-use std::hash::{Hash, Hasher};
+use std::hash::Hash;
+use std::ops::Deref;
 use std::sync::Arc;
+use std::time::Duration;
 
 use cursor_icon::CursorIcon;
 
-use crate::platform_impl::{PlatformCustomCursor, PlatformCustomCursorSource};
+use crate::utils::{impl_dyn_casting, AsAny};
 
-/// The maximum width and height for a cursor when using [`CustomCursor::from_rgba`].
+/// The maximum width and height for a cursor when using [`CustomCursorSource::from_rgba`].
 pub const MAX_CURSOR_SIZE: u16 = 2048;
 
 const PIXEL_SIZE: usize = 4;
@@ -51,19 +53,20 @@ impl From<CustomCursor> for Cursor {
 /// # use winit::event_loop::ActiveEventLoop;
 /// # use winit::window::Window;
 /// # fn scope(event_loop: &dyn ActiveEventLoop, window: &dyn Window) {
-/// use winit::window::CustomCursor;
+/// use winit::window::CustomCursorSource;
 ///
 /// let w = 10;
 /// let h = 10;
 /// let rgba = vec![255; (w * h * 4) as usize];
 ///
 /// #[cfg(not(target_family = "wasm"))]
-/// let source = CustomCursor::from_rgba(rgba, w, h, w / 2, h / 2).unwrap();
+/// let source = CustomCursorSource::from_rgba(rgba, w, h, w / 2, h / 2).unwrap();
 ///
 /// #[cfg(target_family = "wasm")]
-/// let source = {
-///     use winit::platform::web::CustomCursorExtWeb;
-///     CustomCursor::from_url(String::from("http://localhost:3000/cursor.png"), 0, 0)
+/// let source = CustomCursorSource::Url {
+///     url: String::from("http://localhost:3000/cursor.png"),
+///     hotspot_x: 0,
+///     hotspot_y: 0,
 /// };
 ///
 /// if let Ok(custom_cursor) = event_loop.create_custom_cursor(source) {
@@ -71,50 +74,96 @@ impl From<CustomCursor> for Cursor {
 /// }
 /// # }
 /// ```
-#[derive(Clone, Debug, Eq, Hash, PartialEq)]
-pub struct CustomCursor {
-    /// Platforms should make sure this is cheap to clone.
-    pub(crate) inner: PlatformCustomCursor,
+#[derive(Clone, Debug)]
+pub struct CustomCursor(pub(crate) Arc<dyn CustomCursorProvider>);
+
+pub trait CustomCursorProvider: AsAny + fmt::Debug + Send + Sync {
+    /// Whether a cursor was backed by animation.
+    fn is_animated(&self) -> bool;
 }
 
-impl CustomCursor {
-    /// Creates a new cursor from an rgba buffer.
-    ///
-    /// The alpha channel is assumed to be **not** premultiplied.
-    pub fn from_rgba(
-        rgba: impl Into<Vec<u8>>,
-        width: u16,
-        height: u16,
-        hotspot_x: u16,
-        hotspot_y: u16,
-    ) -> Result<CustomCursorSource, BadImage> {
-        let _span =
-            tracing::debug_span!("winit::Cursor::from_rgba", width, height, hotspot_x, hotspot_y)
-                .entered();
-
-        Ok(CustomCursorSource {
-            inner: PlatformCustomCursorSource::from_rgba(
-                rgba.into(),
-                width,
-                height,
-                hotspot_x,
-                hotspot_y,
-            )?,
-        })
+impl PartialEq for CustomCursor {
+    fn eq(&self, other: &Self) -> bool {
+        Arc::ptr_eq(&self.0, &other.0)
     }
 }
 
+impl Eq for CustomCursor {}
+
+impl Hash for CustomCursor {
+    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
+        Arc::as_ptr(&self.0).hash(state);
+    }
+}
+
+impl Deref for CustomCursor {
+    type Target = dyn CustomCursorProvider;
+
+    fn deref(&self) -> &Self::Target {
+        self.0.deref()
+    }
+}
+
+impl_dyn_casting!(CustomCursorProvider);
+
 /// Source for [`CustomCursor`].
 ///
 /// See [`CustomCursor`] for more details.
 #[derive(Debug, Clone, Eq, Hash, PartialEq)]
-pub struct CustomCursorSource {
-    // Some platforms don't support custom cursors.
-    #[allow(dead_code)]
-    pub(crate) inner: PlatformCustomCursorSource,
+pub enum CustomCursorSource {
+    /// Cursor that is backed by RGBA image.
+    ///
+    /// See [CustomCursorSource::from_rgba] for more.
+    ///
+    /// ## Platform-specific
+    ///
+    /// - **iOS / Android / Orbital:** Unsupported
+    Image(CursorImage),
+    /// Animated cursor.
+    ///
+    /// See [CustomCursorSource::from_animation] for more.
+    ///
+    /// ## Platform-specific
+    ///
+    /// - **iOS / Android / Wayland / Windows / X11 / macOS / Orbital:** Unsupported
+    Animation(CursorAnimation),
+    /// Creates a new cursor from a URL pointing to an image.
+    /// It uses the [url css function](https://developer.mozilla.org/en-US/docs/Web/CSS/url),
+    /// but browser support for image formats is inconsistent. Using [PNG] is recommended.
+    ///
+    /// [PNG]: https://en.wikipedia.org/wiki/PNG
+    ///
+    /// ## Platform-specific
+    ///
+    /// - **iOS / Android / Wayland / Windows / X11 / macOS / Orbital:** Unsupported
+    Url { hotspot_x: u16, hotspot_y: u16, url: String },
 }
 
-/// An error produced when using [`CustomCursor::from_rgba`] with invalid arguments.
+impl CustomCursorSource {
+    /// Creates a new cursor from an rgba buffer.
+    ///
+    /// The alpha channel is assumed to be **not** premultiplied.
+    pub fn from_rgba(
+        rgba: Vec<u8>,
+        width: u16,
+        height: u16,
+        hotspot_x: u16,
+        hotspot_y: u16,
+    ) -> Result<Self, BadImage> {
+        CursorImage::from_rgba(rgba, width, height, hotspot_x, hotspot_y).map(Self::Image)
+    }
+
+    /// Crates a new animated cursor from multiple [`CustomCursor`]s
+    /// Supplied `cursors` can't be empty or other animations.
+    pub fn from_animation(
+        duration: Duration,
+        cursors: Vec<CustomCursor>,
+    ) -> Result<Self, BadAnimation> {
+        CursorAnimation::new(duration, cursors).map(Self::Animation)
+    }
+}
+
+/// An error produced when using [`CustomCursorSource::from_rgba`] with invalid arguments.
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 #[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 pub enum BadImage {
@@ -164,47 +213,30 @@ impl fmt::Display for BadImage {
 
 impl Error for BadImage {}
 
-/// Platforms export this directly as `PlatformCustomCursorSource` if they need to only work with
-/// images.
-#[allow(dead_code)]
-#[derive(Debug, Clone, Eq, Hash, PartialEq)]
-pub(crate) struct OnlyCursorImageSource(pub(crate) CursorImage);
+/// An error produced when using [`CustomCursorSource::from_animation`] with invalid arguments.
+#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub enum BadAnimation {
+    /// Produced when no cursors were supplied.
+    Empty,
+    /// Produced when a supplied cursor is an animation.
+    Animation,
+}
 
-#[allow(dead_code)]
-impl OnlyCursorImageSource {
-    pub(crate) fn from_rgba(
-        rgba: Vec<u8>,
-        width: u16,
-        height: u16,
-        hotspot_x: u16,
-        hotspot_y: u16,
-    ) -> Result<Self, BadImage> {
-        CursorImage::from_rgba(rgba, width, height, hotspot_x, hotspot_y).map(Self)
+impl fmt::Display for BadAnimation {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::Empty => write!(f, "No cursors supplied"),
+            Self::Animation => write!(f, "A supplied cursor is an animation"),
+        }
     }
 }
 
-/// Platforms export this directly as `PlatformCustomCursor` if they don't implement caching.
-#[allow(dead_code)]
-#[derive(Debug, Clone)]
-pub(crate) struct OnlyCursorImage(pub(crate) Arc<CursorImage>);
-
-impl Hash for OnlyCursorImage {
-    fn hash<H: Hasher>(&self, state: &mut H) {
-        Arc::as_ptr(&self.0).hash(state);
-    }
-}
-
-impl PartialEq for OnlyCursorImage {
-    fn eq(&self, other: &Self) -> bool {
-        Arc::ptr_eq(&self.0, &other.0)
-    }
-}
-
-impl Eq for OnlyCursorImage {}
+impl Error for BadAnimation {}
 
 #[derive(Debug, Clone, Eq, Hash, PartialEq)]
 #[allow(dead_code)]
-pub(crate) struct CursorImage {
+pub struct CursorImage {
     pub(crate) rgba: Vec<u8>,
     pub(crate) width: u16,
     pub(crate) height: u16,
@@ -247,20 +279,22 @@ impl CursorImage {
     }
 }
 
-// Platforms that don't support cursors will export this as `PlatformCustomCursor`.
-#[derive(Debug, Clone, Hash, PartialEq, Eq)]
-pub(crate) struct NoCustomCursor;
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct CursorAnimation {
+    pub(crate) duration: Duration,
+    pub(crate) cursors: Vec<CustomCursor>,
+}
 
-#[allow(dead_code)]
-impl NoCustomCursor {
-    pub(crate) fn from_rgba(
-        rgba: Vec<u8>,
-        width: u16,
-        height: u16,
-        hotspot_x: u16,
-        hotspot_y: u16,
-    ) -> Result<Self, BadImage> {
-        CursorImage::from_rgba(rgba, width, height, hotspot_x, hotspot_y)?;
-        Ok(Self)
+impl CursorAnimation {
+    pub fn new(duration: Duration, cursors: Vec<CustomCursor>) -> Result<Self, BadAnimation> {
+        if cursors.is_empty() {
+            return Err(BadAnimation::Empty);
+        }
+
+        if cursors.iter().any(|cursor| cursor.is_animated()) {
+            return Err(BadAnimation::Animation);
+        }
+
+        Ok(Self { duration, cursors })
     }
 }

src/event.rs

@@ -14,60 +14,9 @@ use crate::dpi::{PhysicalPosition, PhysicalSize};
 use crate::error::RequestError;
 use crate::event_loop::AsyncRequestSerial;
 use crate::keyboard::{self, ModifiersKeyState, ModifiersKeys, ModifiersState};
-use crate::platform_impl;
 #[cfg(doc)]
 use crate::window::Window;
-use crate::window::{ActivationToken, Theme, WindowId};
-
-// TODO: Remove once the backends can call `ApplicationHandler` methods directly. For now backends
-// like Windows and Web require `Event` to wire user events, otherwise each backend will have to
-// wrap `Event` in some other structure.
-/// Describes a generic event.
-///
-/// See the module-level docs for more information on the event loop manages each event.
-#[allow(dead_code)]
-#[derive(Debug, Clone, PartialEq)]
-pub(crate) enum Event {
-    /// See [`ApplicationHandler::new_events()`] for details.
-    ///
-    /// [`ApplicationHandler::new_events()`]: crate::application::ApplicationHandler::new_events()
-    NewEvents(StartCause),
-
-    /// See [`ApplicationHandler::window_event()`] for details.
-    ///
-    /// [`ApplicationHandler::window_event()`]: crate::application::ApplicationHandler::window_event()
-    #[allow(clippy::enum_variant_names)]
-    WindowEvent { window_id: WindowId, event: WindowEvent },
-
-    /// See [`ApplicationHandler::device_event()`] for details.
-    ///
-    /// [`ApplicationHandler::device_event()`]: crate::application::ApplicationHandler::device_event()
-    #[allow(clippy::enum_variant_names)]
-    DeviceEvent { device_id: Option<DeviceId>, event: DeviceEvent },
-
-    /// See [`ApplicationHandler::suspended()`] for details.
-    ///
-    /// [`ApplicationHandler::suspended()`]: crate::application::ApplicationHandler::suspended()
-    Suspended,
-
-    /// See [`ApplicationHandler::resumed()`] for details.
-    ///
-    /// [`ApplicationHandler::resumed()`]: crate::application::ApplicationHandler::resumed()
-    Resumed,
-
-    /// See [`ApplicationHandler::about_to_wait()`] for details.
-    ///
-    /// [`ApplicationHandler::about_to_wait()`]: crate::application::ApplicationHandler::about_to_wait()
-    AboutToWait,
-
-    /// See [`ApplicationHandler::memory_warning()`] for details.
-    ///
-    /// [`ApplicationHandler::memory_warning()`]: crate::application::ApplicationHandler::memory_warning()
-    MemoryWarning,
-
-    /// User requested a wake up.
-    UserWakeUp,
-}
+use crate::window::{ActivationToken, Theme};
 
 /// Describes the reason the event loop is resuming.
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
@@ -130,23 +79,42 @@ pub enum WindowEvent {
     /// The window has been destroyed.
     Destroyed,
 
-    /// A file has been dropped into the window.
-    ///
-    /// When the user drops multiple files at once, this event will be emitted for each file
-    /// separately.
-    DroppedFile(PathBuf),
-
-    /// A file is being hovered over the window.
-    ///
-    /// When the user hovers multiple files at once, this event will be emitted for each file
-    /// separately.
-    HoveredFile(PathBuf),
-
-    /// A file was hovered, but has exited the window.
-    ///
-    /// There will be a single `HoveredFileCancelled` event triggered even if multiple files were
-    /// hovered.
-    HoveredFileCancelled,
+    /// A file drag operation has entered the window.
+    DragEntered {
+        /// List of paths that are being dragged onto the window.
+        paths: Vec<PathBuf>,
+        /// (x,y) coordinates in pixels relative to the top-left corner of the window. May be
+        /// negative on some platforms if something is dragged over a window's decorations (title
+        /// bar, frame, etc).
+        position: PhysicalPosition<f64>,
+    },
+    /// A file drag operation has moved over the window.
+    DragMoved {
+        /// (x,y) coordinates in pixels relative to the top-left corner of the window. May be
+        /// negative on some platforms if something is dragged over a window's decorations (title
+        /// bar, frame, etc).
+        position: PhysicalPosition<f64>,
+    },
+    /// The file drag operation has dropped file(s) on the window.
+    DragDropped {
+        /// List of paths that are being dragged onto the window.
+        paths: Vec<PathBuf>,
+        /// (x,y) coordinates in pixels relative to the top-left corner of the window. May be
+        /// negative on some platforms if something is dragged over a window's decorations (title
+        /// bar, frame, etc).
+        position: PhysicalPosition<f64>,
+    },
+    /// The file drag operation has been cancelled or left the window.
+    DragLeft {
+        /// (x,y) coordinates in pixels relative to the top-left corner of the window. May be
+        /// negative on some platforms if something is dragged over a window's decorations (title
+        /// bar, frame, etc).
+        ///
+        /// ## Platform-specific
+        ///
+        /// - **Windows:** Always emits [`None`].
+        position: Option<PhysicalPosition<f64>>,
+    },
 
     /// The window gained or lost focus.
     ///
@@ -162,6 +130,7 @@ pub enum WindowEvent {
     /// - **Windows:** The shift key overrides NumLock. In other words, while shift is held down,
     ///   numpad keys act as if NumLock wasn't active. When this is used, the OS sends fake key
     ///   events which are not marked as `is_synthetic`.
+    /// - **iOS:** Unsupported.
     KeyboardInput {
         device_id: Option<DeviceId>,
         event: KeyEvent,
@@ -365,10 +334,18 @@ pub enum WindowEvent {
 
     /// Touchpad pressure event.
     ///
-    /// At the moment, only supported on Apple forcetouch-capable macbooks.
-    /// The parameters are: pressure level (value between 0 and 1 representing how hard the
-    /// touchpad is being pressed) and stage (integer representing the click level).
-    TouchpadPressure { device_id: Option<DeviceId>, pressure: f32, stage: i64 },
+    /// ## Platform-specific
+    ///
+    /// - **macOS**: Only supported on Apple forcetouch-capable macbooks.
+    /// - **Android / iOS / Wayland / X11 / Windows / Orbital / Web:** Unsupported.
+    TouchpadPressure {
+        device_id: Option<DeviceId>,
+        /// Value between 0 and 1 representing how hard the touchpad is being
+        /// pressed.
+        pressure: f32,
+        /// Represents the click level.
+        stage: i64,
+    },
 
     /// The window's scale factor has changed.
     ///
@@ -510,7 +487,7 @@ pub enum PointerSource {
         /// - **MacOS / Orbital / Wayland / X11:** Always emits [`None`].
         /// - **Android:** Will never be [`None`]. If the device doesn't support pressure
         ///   sensitivity, force will either be 0.0 or 1.0. Also see the
-        ///   [android documentation](https://developer.android.com/reference/android/view/MotionEvent#AXIS_PRESSURE).#[derive(Debug, Clone, Copy, PartialEq)]
+        ///   [android documentation](https://developer.android.com/reference/android/view/MotionEvent#AXIS_PRESSURE).
         /// - **Web:** Will never be [`None`]. If the device doesn't support pressure sensitivity,
         ///   force will be 0.5 when a button is pressed or 0.0 otherwise.
         force: Option<Force>,
@@ -629,10 +606,12 @@ impl FingerId {
 ///
 /// Useful for interactions that diverge significantly from a conventional 2D GUI, such as 3D camera
 /// or first-person game controls. Many physical actions, such as mouse movement, can produce both
-/// device and window events. Because window events typically arise from virtual devices
+/// device and [window events]. Because window events typically arise from virtual devices
 /// (corresponding to GUI pointers and keyboard focus) the device IDs may not match.
 ///
 /// Note that these events are delivered regardless of input focus.
+///
+/// [window events]: WindowEvent
 #[derive(Clone, Copy, Debug, PartialEq)]
 pub enum DeviceEvent {
     /// Change in physical position of a pointing device.
@@ -645,11 +624,11 @@ pub enum DeviceEvent {
     /// **Web:** Only returns raw data, not OS accelerated, if [`CursorGrabMode::Locked`] is used
     /// and browser support is available, see
     #[cfg_attr(
-        any(web_platform, docsrs),
+        web_platform,
         doc = "[`ActiveEventLoopExtWeb::is_cursor_lock_raw()`][crate::platform::web::ActiveEventLoopExtWeb::is_cursor_lock_raw()]."
     )]
     #[cfg_attr(
-        not(any(web_platform, docsrs)),
+        not(web_platform),
         doc = "`ActiveEventLoopExtWeb::is_cursor_lock_raw()`."
     )]
     ///
@@ -719,12 +698,6 @@ pub struct KeyEvent {
     /// you somehow see this in the wild, we'd like to know :)
     pub physical_key: keyboard::PhysicalKey,
 
-    // Allowing `broken_intra_doc_links` for `logical_key`, because
-    // `key_without_modifiers` is not available on all platforms
-    #[cfg_attr(
-        not(any(windows_platform, macos_platform, x11_platform, wayland_platform)),
-        allow(rustdoc::broken_intra_doc_links)
-    )]
     /// This value is affected by all modifiers except <kbd>Ctrl</kbd>.
     ///
     /// This has two use cases:
@@ -740,7 +713,7 @@ pub struct KeyEvent {
     /// - **Web:** Dead keys might be reported as the real key instead of `Dead` depending on the
     ///   browser/OS.
     ///
-    /// [`key_without_modifiers`]: crate::platform::modifier_supplement::KeyEventExtModifierSupplement::key_without_modifiers
+    /// [`key_without_modifiers`]: Self::key_without_modifiers
     pub logical_key: keyboard::Key,
 
     /// Contains the text produced by this keypress.
@@ -761,7 +734,7 @@ pub struct KeyEvent {
     /// This is `None` if the current keypress cannot
     /// be interpreted as text.
     ///
-    /// See also: `text_with_all_modifiers()`
+    /// See also [`text_with_all_modifiers`][Self::text_with_all_modifiers].
     pub text: Option<SmolStr>,
 
     /// Contains the location of this key on the keyboard.
@@ -817,13 +790,33 @@ pub struct KeyEvent {
     /// ```
     pub repeat: bool,
 
-    /// Platform-specific key event information.
+    /// Similar to [`text`][Self::text], except that this is affected by <kbd>Ctrl</kbd>.
     ///
-    /// On Windows, Linux and macOS, this type contains the key without modifiers and the text with
-    /// all modifiers applied.
+    /// For example, pressing <kbd>Ctrl</kbd>+<kbd>a</kbd> produces `Some("\x01")`.
     ///
-    /// On Android, iOS, Redox and Web, this type is a no-op.
-    pub(crate) platform_specific: platform_impl::KeyEventExtra,
+    /// ## Platform-specific
+    ///
+    /// - **Android:** Unimplemented, this field is always the same value as `text`.
+    /// - **iOS:** Unimplemented, this field is always the same value as `text`.
+    /// - **Web:** Unsupported, this field is always the same value as `text`.
+    pub text_with_all_modifiers: Option<SmolStr>,
+
+    /// This value ignores all modifiers including, but not limited to <kbd>Shift</kbd>,
+    /// <kbd>Caps Lock</kbd>, and <kbd>Ctrl</kbd>. In most cases this means that the
+    /// unicode character in the resulting string is lowercase.
+    ///
+    /// This is useful for key-bindings / shortcut key combinations.
+    ///
+    /// In case [`logical_key`][Self::logical_key] reports [`Dead`][keyboard::Key::Dead],
+    /// this will still report the key as `Character` according to the current keyboard
+    /// layout. This value cannot be `Dead`.
+    ///
+    /// ## Platform-specific
+    ///
+    /// - **Android:** Unimplemented, this field is always the same value as `logical_key`.
+    /// - **iOS:** Unimplemented, this field is always the same value as `logical_key`.
+    /// - **Web:** Unsupported, this field is always the same value as `logical_key`.
+    pub key_without_modifiers: keyboard::Key,
 }
 
 /// Describes keyboard modifiers event.
@@ -876,12 +869,12 @@ impl Modifiers {
 
     /// The state of the left super key.
     pub fn lsuper_state(&self) -> ModifiersKeyState {
-        self.mod_state(ModifiersKeys::LSUPER)
+        self.mod_state(ModifiersKeys::LMETA)
     }
 
     /// The state of the right super key.
     pub fn rsuper_state(&self) -> ModifiersKeyState {
-        self.mod_state(ModifiersKeys::RSUPER)
+        self.mod_state(ModifiersKeys::RMETA)
     }
 
     fn mod_state(&self, modifier: ModifiersKeys) -> ModifiersKeyState {
@@ -1134,122 +1127,108 @@ mod tests {
 
     macro_rules! foreach_event {
         ($closure:expr) => {{
+            foreach_event!(window: $closure);
+            foreach_event!(device: $closure);
+        }};
+        (window: $closure:expr) => {{
             #[allow(unused_mut)]
-            let mut x = $closure;
+            let mut with_window_event: &mut dyn FnMut(event::WindowEvent) = &mut $closure;
             let fid = event::FingerId::from_raw(0);
 
-            #[allow(deprecated)]
-            {
-                use crate::event::Event::*;
-                use crate::event::Ime::Enabled;
-                use crate::event::WindowEvent::*;
-                use crate::event::{PointerKind, PointerSource};
-                use crate::window::WindowId;
+            use crate::event::Ime::Enabled;
+            use crate::event::WindowEvent::*;
+            use crate::event::{PointerKind, PointerSource};
 
-                // Mainline events.
-                let wid = WindowId::from_raw(0);
-                x(NewEvents(event::StartCause::Init));
-                x(AboutToWait);
-                x(Suspended);
-                x(Resumed);
+            with_window_event(CloseRequested);
+            with_window_event(Destroyed);
+            with_window_event(Focused(true));
+            with_window_event(Moved((0, 0).into()));
+            with_window_event(SurfaceResized((0, 0).into()));
+            with_window_event(DragEntered { paths: vec!["x.txt".into()], position: (0, 0).into() });
+            with_window_event(DragMoved { position: (0, 0).into() });
+            with_window_event(DragDropped { paths: vec!["x.txt".into()], position: (0, 0).into() });
+            with_window_event(DragLeft { position: Some((0, 0).into()) });
+            with_window_event(Ime(Enabled));
+            with_window_event(PointerMoved {
+                device_id: None,
+                primary: true,
+                position: (0, 0).into(),
+                source: PointerSource::Mouse,
+            });
+            with_window_event(ModifiersChanged(event::Modifiers::default()));
+            with_window_event(PointerEntered {
+                device_id: None,
+                primary: true,
+                position: (0, 0).into(),
+                kind: PointerKind::Mouse,
+            });
+            with_window_event(PointerLeft {
+                primary: true,
+                device_id: None,
+                position: Some((0, 0).into()),
+                kind: PointerKind::Mouse,
+            });
+            with_window_event(MouseWheel {
+                device_id: None,
+                delta: event::MouseScrollDelta::LineDelta(0.0, 0.0),
+                phase: event::TouchPhase::Started,
+            });
+            with_window_event(PointerButton {
+                device_id: None,
+                primary: true,
+                state: event::ElementState::Pressed,
+                position: (0, 0).into(),
+                button: event::MouseButton::Other(0).into(),
+            });
+            with_window_event(PointerButton {
+                device_id: None,
+                primary: true,
+                state: event::ElementState::Released,
+                position: (0, 0).into(),
+                button: event::ButtonSource::Touch {
+                    finger_id: fid,
+                    force: Some(event::Force::Normalized(0.0)),
+                },
+            });
+            with_window_event(PinchGesture {
+                device_id: None,
+                delta: 0.0,
+                phase: event::TouchPhase::Started,
+            });
+            with_window_event(DoubleTapGesture { device_id: None });
+            with_window_event(RotationGesture {
+                device_id: None,
+                delta: 0.0,
+                phase: event::TouchPhase::Started,
+            });
+            with_window_event(PanGesture {
+                device_id: None,
+                delta: PhysicalPosition::<f32>::new(0.0, 0.0),
+                phase: event::TouchPhase::Started,
+            });
+            with_window_event(TouchpadPressure { device_id: None, pressure: 0.0, stage: 0 });
+            with_window_event(ThemeChanged(crate::window::Theme::Light));
+            with_window_event(Occluded(true));
+        }};
+        (device: $closure:expr) => {{
+            use event::DeviceEvent::*;
 
-                // Window events.
-                let with_window_event = |wev| x(WindowEvent { window_id: wid, event: wev });
+            #[allow(unused_mut)]
+            let mut with_device_event: &mut dyn FnMut(event::DeviceEvent) = &mut $closure;
 
-                with_window_event(CloseRequested);
-                with_window_event(Destroyed);
-                with_window_event(Focused(true));
-                with_window_event(Moved((0, 0).into()));
-                with_window_event(SurfaceResized((0, 0).into()));
-                with_window_event(DroppedFile("x.txt".into()));
-                with_window_event(HoveredFile("x.txt".into()));
-                with_window_event(HoveredFileCancelled);
-                with_window_event(Ime(Enabled));
-                with_window_event(PointerMoved {
-                    device_id: None,
-                    primary: true,
-                    position: (0, 0).into(),
-                    source: PointerSource::Mouse,
-                });
-                with_window_event(ModifiersChanged(event::Modifiers::default()));
-                with_window_event(PointerEntered {
-                    device_id: None,
-                    primary: true,
-                    position: (0, 0).into(),
-                    kind: PointerKind::Mouse,
-                });
-                with_window_event(PointerLeft {
-                    primary: true,
-                    device_id: None,
-                    position: Some((0, 0).into()),
-                    kind: PointerKind::Mouse,
-                });
-                with_window_event(MouseWheel {
-                    device_id: None,
-                    delta: event::MouseScrollDelta::LineDelta(0.0, 0.0),
-                    phase: event::TouchPhase::Started,
-                });
-                with_window_event(PointerButton {
-                    device_id: None,
-                    primary: true,
-                    state: event::ElementState::Pressed,
-                    position: (0, 0).into(),
-                    button: event::MouseButton::Other(0).into(),
-                });
-                with_window_event(PointerButton {
-                    device_id: None,
-                    primary: true,
-                    state: event::ElementState::Released,
-                    position: (0, 0).into(),
-                    button: event::ButtonSource::Touch {
-                        finger_id: fid,
-                        force: Some(event::Force::Normalized(0.0)),
-                    },
-                });
-                with_window_event(PinchGesture {
-                    device_id: None,
-                    delta: 0.0,
-                    phase: event::TouchPhase::Started,
-                });
-                with_window_event(DoubleTapGesture { device_id: None });
-                with_window_event(RotationGesture {
-                    device_id: None,
-                    delta: 0.0,
-                    phase: event::TouchPhase::Started,
-                });
-                with_window_event(PanGesture {
-                    device_id: None,
-                    delta: PhysicalPosition::<f32>::new(0.0, 0.0),
-                    phase: event::TouchPhase::Started,
-                });
-                with_window_event(TouchpadPressure { device_id: None, pressure: 0.0, stage: 0 });
-                with_window_event(ThemeChanged(crate::window::Theme::Light));
-                with_window_event(Occluded(true));
-            }
-
-            #[allow(deprecated)]
-            {
-                use event::DeviceEvent::*;
-
-                let with_device_event =
-                    |dev_ev| x(event::Event::DeviceEvent { device_id: None, event: dev_ev });
-
-                with_device_event(PointerMotion { delta: (0.0, 0.0).into() });
-                with_device_event(MouseWheel {
-                    delta: event::MouseScrollDelta::LineDelta(0.0, 0.0),
-                });
-                with_device_event(Button { button: 0, state: event::ElementState::Pressed });
-            }
+            with_device_event(PointerMotion { delta: (0.0, 0.0).into() });
+            with_device_event(MouseWheel { delta: event::MouseScrollDelta::LineDelta(0.0, 0.0) });
+            with_device_event(Button { button: 0, state: event::ElementState::Pressed });
         }};
     }
 
-    #[allow(clippy::redundant_clone)]
+    #[allow(clippy::clone_on_copy)]
     #[test]
     fn test_event_clone() {
-        foreach_event!(|event: event::Event| {
+        foreach_event!(|event| {
             let event2 = event.clone();
             assert_eq!(event, event2);
-        })
+        });
     }
 
     #[test]
@@ -1267,7 +1246,7 @@ mod tests {
     #[allow(clippy::clone_on_copy)]
     #[test]
     fn ensure_attrs_do_not_panic() {
-        foreach_event!(|event: event::Event| {
+        foreach_event!(|event| {
             let _ = format!("{event:?}");
         });
         let _ = event::StartCause::Init.clone();

src/event_loop.rs

@@ -25,7 +25,7 @@ use crate::application::ApplicationHandler;
 use crate::error::{EventLoopError, RequestError};
 use crate::monitor::MonitorHandle;
 use crate::platform_impl;
-use crate::utils::AsAny;
+use crate::utils::{impl_dyn_casting, AsAny};
 use crate::window::{CustomCursor, CustomCursorSource, Theme, Window, WindowAttributes};
 
 /// Provides a way to retrieve events from the system and from the windows that were registered to
@@ -43,6 +43,7 @@ use crate::window::{CustomCursor, CustomCursorSource, Theme, Window, WindowAttri
 /// [`EventLoopProxy`] allows you to wake up an `EventLoop` from another thread.
 ///
 /// [`Window`]: crate::window::Window
+#[derive(Debug)]
 pub struct EventLoop {
     pub(crate) event_loop: platform_impl::EventLoop,
     pub(crate) _marker: PhantomData<*mut ()>, // Not Send nor Sync
@@ -54,7 +55,7 @@ pub struct EventLoop {
 /// easier. But note that constructing multiple event loops is not supported.
 ///
 /// This can be created using [`EventLoop::builder`].
-#[derive(Default, PartialEq, Eq, Hash)]
+#[derive(Default, Debug, PartialEq, Eq, Hash)]
 pub struct EventLoopBuilder {
     pub(crate) platform_specific: platform_impl::PlatformSpecificEventLoopAttributes,
 }
@@ -117,18 +118,6 @@ impl EventLoopBuilder {
     }
 }
 
-impl fmt::Debug for EventLoopBuilder {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_struct("EventLoopBuilder").finish_non_exhaustive()
-    }
-}
-
-impl fmt::Debug for EventLoop {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_struct("EventLoop").finish_non_exhaustive()
-    }
-}
-
 /// Set through [`ActiveEventLoop::set_control_flow()`].
 ///
 /// Indicates the desired behavior of the event loop after [`about_to_wait`] is called.
@@ -195,39 +184,49 @@ impl EventLoop {
 }
 
 impl EventLoop {
-    /// Run the event loop on the current thread.
-    ///
-    /// You pass in a closure that returns your application state. This closure has access to the
-    /// currently running event loop, allowing you to initialize your windows and surfaces in here.
-    ///
-    /// See the [`set_control_flow()`] docs on how to change the event loop's behavior.
+    /// Run the application with the event loop on the calling thread.
     ///
     /// ## Event loop flow
     ///
     /// This function internally handles the different parts of a traditional event-handling loop.
-    /// You could imagine this method being implemented like this:
+    /// You can imagine this method as being implemented like this:
     ///
     /// ```rust,ignore
-    /// // Initialize.
-    /// let mut app = init_closure(event_loop);
     /// let mut start_cause = StartCause::Init;
     ///
-    /// // Run loop.
-    /// while !elwt.exiting() {
+    /// // Run the event loop.
+    /// while !event_loop.exiting() {
     ///     // Wake up.
     ///     app.new_events(event_loop, start_cause);
     ///
-    ///     // Handle events by the user.
-    ///     for (device_id, event) in incoming_device_events {
-    ///         app.device_event(event_loop, device_id, event);
+    ///     // Indicate that surfaces can now safely be created.
+    ///     if start_cause == StartCause::Init {
+    ///         app.can_create_surfaces(event_loop);
     ///     }
-    ///     for (window_id, event) in incoming_window_events {
-    ///         app.window_event(event_loop, window_id, event);
+    ///
+    ///     // Handle proxy wake-up event.
+    ///     if event_loop.proxy_wake_up_set() {
+    ///         event_loop.proxy_wake_up_clear();
+    ///         app.proxy_wake_up(event_loop);
+    ///     }
+    ///
+    ///     // Handle actions done by the user / system such as moving the cursor, resizing the
+    ///     // window, changing the window theme, etc.
+    ///     for event in event_loop.events() {
+    ///         match event {
+    ///             window event => app.window_event(event_loop, window_id, event),
+    ///             device event => app.device_event(event_loop, device_id, event),
+    ///         }
+    ///     }
+    ///
+    ///     // Handle redraws.
+    ///     for window_id in event_loop.pending_redraws() {
+    ///         app.window_event(event_loop, window_id, WindowEvent::RedrawRequested);
     ///     }
     ///
     ///     // Done handling events, wait until we're woken up again.
     ///     app.about_to_wait(event_loop);
-    ///     start_cause = wait_if_necessary();
+    ///     start_cause = event_loop.wait_if_necessary();
     /// }
     ///
     /// // Finished running, drop application state.
@@ -235,7 +234,8 @@ impl EventLoop {
     /// ```
     ///
     /// This is of course a very coarse-grained overview, and leaves out timing details like
-    /// [`ControlFlow::WaitUntil`] and life-cycle methods like [`ApplicationHandler::resumed`].
+    /// [`ControlFlow::WaitUntil`] and life-cycle methods like [`ApplicationHandler::resumed`], but
+    /// it should give you an idea of how things fit together.
     ///
     /// ## Platform-specific
     ///
@@ -247,11 +247,11 @@ impl EventLoop {
     ///
     ///   Web applications are recommended to use
     #[cfg_attr(
-        any(web_platform, docsrs),
+        web_platform,
         doc = "  [`EventLoopExtWeb::spawn_app()`][crate::platform::web::EventLoopExtWeb::spawn_app()]"
     )]
-    #[cfg_attr(not(any(web_platform, docsrs)), doc = "  `EventLoopExtWeb::spawn_app()`")]
-    ///   [^1] instead of [`run()`] to avoid the need for the Javascript exception trick, and to
+    #[cfg_attr(not(web_platform), doc = "  `EventLoopExtWeb::spawn_app()`")]
+    ///   [^1] instead of [`run_app()`] to avoid the need for the Javascript exception trick, and to
     ///   make   it clearer that the event loop runs asynchronously (via the browser's own,
     ///   internal, event   loop) and doesn't block the current thread of execution like it does
     ///   on other platforms.
@@ -261,20 +261,11 @@ impl EventLoop {
     /// [^1]: `spawn_app()` is only available on the Web platform.
     ///
     /// [`set_control_flow()`]: ActiveEventLoop::set_control_flow()
-    /// [`run()`]: Self::run()
+    /// [`run_app()`]: Self::run_app()
     #[inline]
     #[cfg(not(all(web_platform, target_feature = "exception-handling")))]
-    pub fn run<A: ApplicationHandler>(
-        self,
-        init_closure: impl FnOnce(&dyn ActiveEventLoop) -> A,
-    ) -> Result<(), EventLoopError> {
-        self.event_loop.run(init_closure)
-    }
-
-    /// Run the event loop with the given application state.
-    #[deprecated = "less flexible version of `run`"]
     pub fn run_app<A: ApplicationHandler>(self, app: A) -> Result<(), EventLoopError> {
-        self.run(|_event_loop| app)
+        self.event_loop.run_app(app)
     }
 
     /// Creates an [`EventLoopProxy`] that can be used to dispatch user events
@@ -356,7 +347,7 @@ impl AsRawFd for EventLoop {
     }
 }
 
-pub trait ActiveEventLoop: AsAny {
+pub trait ActiveEventLoop: AsAny + fmt::Debug {
     /// Creates an [`EventLoopProxy`] that can be used to dispatch user events
     /// to the main event loop, possibly from another thread.
     fn create_proxy(&self) -> EventLoopProxy;
@@ -390,10 +381,10 @@ pub trait ActiveEventLoop: AsAny {
     ///
     /// **Web:** Only returns the current monitor without
     #[cfg_attr(
-        any(web_platform, docsrs),
+        web_platform,
         doc = "[detailed monitor permissions][crate::platform::web::ActiveEventLoopExtWeb::request_detailed_monitor_permission]."
     )]
-    #[cfg_attr(not(any(web_platform, docsrs)), doc = "detailed monitor permissions.")]
+    #[cfg_attr(not(web_platform), doc = "detailed monitor permissions.")]
     fn available_monitors(&self) -> Box<dyn Iterator<Item = MonitorHandle>>;
 
     /// Returns the primary monitor of the system.
@@ -405,10 +396,10 @@ pub trait ActiveEventLoop: AsAny {
     /// - **Wayland:** Always returns `None`.
     /// - **Web:** Always returns `None` without
     #[cfg_attr(
-        any(web_platform, docsrs),
+        web_platform,
         doc = "  [detailed monitor permissions][crate::platform::web::ActiveEventLoopExtWeb::request_detailed_monitor_permission]."
     )]
-    #[cfg_attr(not(any(web_platform, docsrs)), doc = "  detailed monitor permissions.")]
+    #[cfg_attr(not(web_platform), doc = "  detailed monitor permissions.")]
     fn primary_monitor(&self) -> Option<MonitorHandle>;
 
     /// Change if or when [`DeviceEvent`]s are captured.
@@ -439,12 +430,21 @@ pub trait ActiveEventLoop: AsAny {
     /// Gets the current [`ControlFlow`].
     fn control_flow(&self) -> ControlFlow;
 
-    /// This stops the event loop.
+    /// Stop the event loop.
+    ///
+    /// ## Platform-specific
+    ///
+    /// ### iOS
+    ///
+    /// It is not possible to programmatically exit/quit an application on iOS, so this function is
+    /// a no-op there. See also [this technical Q&A][qa1561].
+    ///
+    /// [qa1561]: https://developer.apple.com/library/archive/qa/qa1561/_index.html
     fn exit(&self);
 
-    /// Returns if the [`EventLoop`] is about to stop.
+    /// Returns whether the [`EventLoop`] is about to stop.
     ///
-    /// See [`exit()`][Self::exit].
+    /// Set by [`exit()`][Self::exit].
     fn exiting(&self) -> bool;
 
     /// Gets a persistent reference to the underlying platform display.
@@ -462,6 +462,8 @@ impl HasDisplayHandle for dyn ActiveEventLoop + '_ {
     }
 }
 
+impl_dyn_casting!(ActiveEventLoop);
+
 /// A proxy for the underlying display handle.
 ///
 /// The purpose of this type is to provide a cheaply cloneable handle to the underlying
@@ -508,23 +510,17 @@ impl PartialEq for OwnedDisplayHandle {
 
 impl Eq for OwnedDisplayHandle {}
 
-pub(crate) trait EventLoopProxyProvider: Send + Sync {
+pub(crate) trait EventLoopProxyProvider: Send + Sync + fmt::Debug {
     /// See [`EventLoopProxy::wake_up`] for details.
     fn wake_up(&self);
 }
 
 /// Control the [`EventLoop`], possibly from a different thread, without referencing it directly.
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct EventLoopProxy {
     pub(crate) proxy: Arc<dyn EventLoopProxyProvider>,
 }
 
-impl fmt::Debug for EventLoopProxy {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_struct("EventLoopProxy").finish_non_exhaustive()
-    }
-}
-
 impl EventLoopProxy {
     /// Wake up the [`EventLoop`], resulting in [`ApplicationHandler::proxy_wake_up()`] being
     /// called.

src/icon.rs

@@ -1,7 +1,20 @@
 use std::error::Error;
+use std::sync::Arc;
 use std::{fmt, io, mem};
 
-use crate::platform_impl::PlatformIcon;
+use crate::utils::{impl_dyn_casting, AsAny};
+
+pub(crate) const PIXEL_SIZE: usize = mem::size_of::<Pixel>();
+
+/// An icon used for the window titlebar, taskbar, etc.
+#[allow(dead_code)]
+#[derive(Debug, Clone)]
+pub struct Icon(pub(crate) Arc<dyn IconProvider>);
+
+// TODO remove that once split.
+pub trait IconProvider: AsAny + fmt::Debug + Send + Sync {}
+
+impl_dyn_casting!(IconProvider);
 
 #[repr(C)]
 #[derive(Debug)]
@@ -12,10 +25,8 @@ pub(crate) struct Pixel {
     pub(crate) a: u8,
 }
 
-pub(crate) const PIXEL_SIZE: usize = mem::size_of::<Pixel>();
-
 #[derive(Debug)]
-/// An error produced when using [`Icon::from_rgba`] with invalid arguments.
+/// An error produced when using [`RgbaIcon::new`] with invalid arguments.
 pub enum BadIcon {
     /// Produced when the length of the `rgba` argument isn't divisible by 4, thus `rgba` can't be
     /// safely interpreted as 32bpp RGBA pixels.
@@ -50,69 +61,48 @@ impl fmt::Display for BadIcon {
 
 impl Error for BadIcon {}
 
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub(crate) struct RgbaIcon {
-    pub(crate) rgba: Vec<u8>,
+#[derive(Debug, Clone)]
+pub struct RgbaIcon {
     pub(crate) width: u32,
     pub(crate) height: u32,
+    pub(crate) rgba: Vec<u8>,
 }
 
-/// For platforms which don't have window icons (e.g. Web)
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub(crate) struct NoIcon;
-
-#[allow(dead_code)] // These are not used on every platform
-mod constructors {
-    use super::*;
-
-    impl RgbaIcon {
-        pub fn from_rgba(rgba: Vec<u8>, width: u32, height: u32) -> Result<Self, BadIcon> {
-            if rgba.len() % PIXEL_SIZE != 0 {
-                return Err(BadIcon::ByteCountNotDivisibleBy4 { byte_count: rgba.len() });
-            }
-            let pixel_count = rgba.len() / PIXEL_SIZE;
-            if pixel_count != (width * height) as usize {
-                Err(BadIcon::DimensionsVsPixelCount {
-                    width,
-                    height,
-                    width_x_height: (width * height) as usize,
-                    pixel_count,
-                })
-            } else {
-                Ok(RgbaIcon { rgba, width, height })
-            }
+impl RgbaIcon {
+    pub fn new(rgba: Vec<u8>, width: u32, height: u32) -> Result<Self, BadIcon> {
+        if rgba.len() % PIXEL_SIZE != 0 {
+            return Err(BadIcon::ByteCountNotDivisibleBy4 { byte_count: rgba.len() });
+        }
+        let pixel_count = rgba.len() / PIXEL_SIZE;
+        if pixel_count != (width * height) as usize {
+            Err(BadIcon::DimensionsVsPixelCount {
+                width,
+                height,
+                width_x_height: (width * height) as usize,
+                pixel_count,
+            })
+        } else {
+            Ok(RgbaIcon { rgba, width, height })
         }
     }
 
-    impl NoIcon {
-        pub fn from_rgba(rgba: Vec<u8>, width: u32, height: u32) -> Result<Self, BadIcon> {
-            // Create the rgba icon anyway to validate the input
-            let _ = RgbaIcon::from_rgba(rgba, width, height)?;
-            Ok(NoIcon)
-        }
+    pub fn width(&self) -> u32 {
+        self.width
+    }
+
+    pub fn height(&self) -> u32 {
+        self.height
+    }
+
+    pub fn buffer(&self) -> &[u8] {
+        self.rgba.as_slice()
     }
 }
 
-/// An icon used for the window titlebar, taskbar, etc.
-#[derive(Clone, Eq, Hash, PartialEq)]
-pub struct Icon {
-    pub(crate) inner: PlatformIcon,
-}
+impl IconProvider for RgbaIcon {}
 
-impl fmt::Debug for Icon {
-    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
-        fmt::Debug::fmt(&self.inner, formatter)
-    }
-}
-
-impl Icon {
-    /// Creates an icon from 32bpp RGBA data.
-    ///
-    /// The length of `rgba` must be divisible by 4, and `width * height` must equal
-    /// `rgba.len() / 4`. Otherwise, this will return a `BadIcon` error.
-    pub fn from_rgba(rgba: Vec<u8>, width: u32, height: u32) -> Result<Self, BadIcon> {
-        let _span = tracing::debug_span!("winit::Icon::from_rgba", width, height).entered();
-
-        Ok(Icon { inner: PlatformIcon::from_rgba(rgba, width, height)? })
+impl From<RgbaIcon> for Icon {
+    fn from(value: RgbaIcon) -> Self {
+        Self(Arc::new(value))
     }
 }

src/keyboard.rs

@@ -1,4 +1,5 @@
 //! Types related to the keyboard.
+#![cfg_attr(feature = "serde", allow(deprecated))] // https://github.com/serde-rs/serde/issues/2195
 
 // This file contains a substantial portion of the UI Events Specification by the W3C. In
 // particular, the variant names within `Key` and `KeyCode` and their documentation are modified
@@ -283,11 +284,7 @@ impl PartialEq<PhysicalKey> for NativeKeyCode {
 
 /// Code representing the location of a physical key
 ///
-/// This mostly conforms to the UI Events Specification's [`KeyboardEvent.code`] with a few
-/// exceptions:
-/// - The keys that the specification calls "MetaLeft" and "MetaRight" are named "SuperLeft" and
-///   "SuperRight" here.
-/// - The key that the specification calls "Super" is reported as `Unidentified` here.
+/// This conforms to the UI Events Specification's [`KeyboardEvent.code`].
 ///
 /// [`KeyboardEvent.code`]: https://w3c.github.io/uievents-code/#code-value-tables
 #[non_exhaustive]
@@ -420,7 +417,7 @@ pub enum KeyCode {
     /// <kbd>CapsLock</kbd> or <kbd>⇪</kbd>
     CapsLock,
     /// The application context menu key, which is typically found between the right
-    /// <kbd>Super</kbd> key and the right <kbd>Control</kbd> key.
+    /// <kbd>Meta</kbd> key and the right <kbd>Control</kbd> key.
     ContextMenu,
     /// <kbd>Control</kbd> or <kbd>⌃</kbd>
     ControlLeft,
@@ -429,9 +426,9 @@ pub enum KeyCode {
     /// <kbd>Enter</kbd> or <kbd>↵</kbd>. Labeled <kbd>Return</kbd> on Apple keyboards.
     Enter,
     /// The Windows, <kbd>⌘</kbd>, <kbd>Command</kbd>, or other OS symbol key.
-    SuperLeft,
+    MetaLeft,
     /// The Windows, <kbd>⌘</kbd>, <kbd>Command</kbd>, or other OS symbol key.
-    SuperRight,
+    MetaRight,
     /// <kbd>Shift</kbd> or <kbd>⇧</kbd>
     ShiftLeft,
     /// <kbd>Shift</kbd> or <kbd>⇧</kbd>
@@ -613,9 +610,11 @@ pub enum KeyCode {
     AudioVolumeMute,
     AudioVolumeUp,
     WakeUp,
-    // Legacy modifier key. Also called "Super" in certain places.
-    Meta,
     // Legacy modifier key.
+    #[deprecated = "marked as legacy in the spec, use Meta instead"]
+    Super,
+    // Legacy modifier key.
+    #[deprecated = "marked as legacy in the spec, use Meta instead"]
     Hyper,
     Turbo,
     Abort,
@@ -741,12 +740,7 @@ pub enum KeyCode {
 
 /// A [`Key::Named`] value
 ///
-/// This mostly conforms to the UI Events Specification's [`KeyboardEvent.key`] with a few
-/// exceptions:
-/// - The `Super` variant here, is named `Meta` in the aforementioned specification. (There's
-///   another key which the specification calls `Super`. That does not exist here.)
-/// - The `Space` variant here, can be identified by the character it generates in the
-///   specification.
+/// This conforms to the UI Events Specification's [`KeyboardEvent.key`].
 ///
 /// [`KeyboardEvent.key`]: https://w3c.github.io/uievents-key/
 #[non_exhaustive]
@@ -791,24 +785,22 @@ pub enum NamedKey {
     /// The Symbol modifier key (used on some virtual keyboards).
     Symbol,
     SymbolLock,
-    // Legacy modifier key. Also called "Super" in certain places.
-    Meta,
     // Legacy modifier key.
+    #[deprecated = "marked as legacy in the spec, use Meta instead"]
+    Super,
+    // Legacy modifier key.
+    #[deprecated = "marked as legacy in the spec, use Meta instead"]
     Hyper,
-    /// Used to enable "super" modifier function for interpreting concurrent or subsequent keyboard
+    /// Used to enable "meta" modifier function for interpreting concurrent or subsequent keyboard
     /// input. This key value is used for the "Windows Logo" key and the Apple `Command` or `⌘`
     /// key.
-    ///
-    /// Note: In some contexts (e.g. the Web) this is referred to as the "Meta" key.
-    Super,
+    Meta,
     /// The `Enter` or `↵` key. Used to activate current selection or accept current input. This
     /// key value is also used for the `Return` (Macintosh numpad) key. This key value is also
     /// used for the Android `KEYCODE_DPAD_CENTER`.
     Enter,
     /// The Horizontal Tabulation `Tab` key.
     Tab,
-    /// Used in text to insert a space between words. Usually located below the character keys.
-    Space,
     /// Navigate or traverse downward. (`KEYCODE_DPAD_DOWN`)
     ArrowDown,
     /// Navigate or traverse leftward. (`KEYCODE_DPAD_LEFT`)
@@ -864,7 +856,7 @@ pub enum NamedKey {
     Attn,
     Cancel,
     /// Show the application’s context menu.
-    /// This key is commonly found between the right `Super` key and the right `Control` key.
+    /// This key is commonly found between the right `Meta` key and the right `Control` key.
     ContextMenu,
     /// The `Esc` key. This key was originally used to initiate an escape sequence, but is
     /// now more generally used to exit or "escape" the current context, such as closing a dialog
@@ -1583,7 +1575,6 @@ impl NamedKey {
             NamedKey::Enter => Some("\r"),
             NamedKey::Backspace => Some("\x08"),
             NamedKey::Tab => Some("\t"),
-            NamedKey::Space => Some(" "),
             NamedKey::Escape => Some("\x1b"),
             _ => None,
         }
@@ -1709,7 +1700,9 @@ bitflags! {
         /// The "alt" key.
         const ALT = 0b100 << 6;
         /// This is the "windows" key on PC and "command" key on Mac.
-        const SUPER = 0b100 << 9;
+        const META = 0b100 << 9;
+        #[deprecated = "use META instead"]
+        const SUPER = Self::META.bits();
     }
 }
 
@@ -1729,9 +1722,9 @@ impl ModifiersState {
         self.intersects(Self::ALT)
     }
 
-    /// Returns `true` if the super key is pressed.
-    pub fn super_key(&self) -> bool {
-        self.intersects(Self::SUPER)
+    /// Returns `true` if the meta key is pressed.
+    pub fn meta_key(&self) -> bool {
+        self.intersects(Self::META)
     }
 }
 
@@ -1764,7 +1757,11 @@ bitflags! {
         const RCONTROL = 0b0000_1000;
         const LALT     = 0b0001_0000;
         const RALT     = 0b0010_0000;
-        const LSUPER   = 0b0100_0000;
-        const RSUPER   = 0b1000_0000;
+        const LMETA    = 0b0100_0000;
+        const RMETA    = 0b1000_0000;
+        #[deprecated = "use LMETA instead"]
+        const LSUPER   = Self::LMETA.bits();
+        #[deprecated = "use RMETA instead"]
+        const RSUPER   = Self::RMETA.bits();
     }
 }

src/lib.rs

@@ -1,14 +1,24 @@
 //! Winit is a cross-platform window creation and event loop management library.
 //!
+//! # Building windows
+//!
+//! Before you can create a [`Window`], you first need to build an [`EventLoop`]. This is done with
+//! the [`EventLoop::new()`] function.
+//!
+//! ```no_run
+//! use winit::event_loop::EventLoop;
+//!
+//! # // Intentionally use `fn main` for clarity
+//! fn main() {
+//!     let event_loop = EventLoop::new().unwrap();
+//!     // ...
+//! }
+//! ```
+//!
+//! Then you create a [`Window`] with [`create_window`].
+//!
 //! # Event handling
 //!
-//! Basically all of the functionality that Winit exposes requires an [`ActiveEventLoop`], which you
-//! can get access to by running an [`EventLoop`] using [`EventLoop::new()`] and
-//! [`EventLoop::run()`].
-//!
-//! Once it's running, you can create your [`Window`]s with [`ActiveEventLoop::create_window()`] by
-//! passing in the desired [`WindowAttributes`].
-//!
 //! Once a [`Window`] has been created, it will generate different *events*. A [`Window`] object can
 //! generate [`WindowEvent`]s when certain input events occur, such as a cursor moving over the
 //! window or a key getting pressed while the window is focused. Devices can generate
@@ -16,10 +26,8 @@
 //! Some user activity, like mouse movement, can generate both a [`WindowEvent`] *and* a
 //! [`DeviceEvent`].
 //!
-//! You retrieve by implementing [`ApplicationHandler`] for a new type, which will be the state of
-//! your application. The methods in this trait will continuously receive events until
-//! [`ActiveEventLoop::exit()`] is used, at which point your application state will be dropped, and
-//! the application shuts down.
+//! You can retrieve events by calling [`EventLoop::run_app()`]. This function will dispatch events
+//! for every [`Window`] that was created with that particular [`EventLoop`].
 //!
 //! Winit no longer uses a `EventLoop::poll_events() -> impl Iterator<Event>`-based event loop
 //! model, since that can't be implemented properly on some platforms (e.g Web, iOS) and works
@@ -40,20 +48,28 @@
 //! use winit::application::ApplicationHandler;
 //! use winit::event::WindowEvent;
 //! use winit::event_loop::{ActiveEventLoop, ControlFlow, EventLoop};
-//! use winit::window::{Window, WindowId};
+//! use winit::window::{Window, WindowId, WindowAttributes};
 //!
+//! #[derive(Default)]
 //! struct App {
-//!     window: Box<dyn Window>,
+//!     window: Option<Box<dyn Window>>,
 //! }
 //!
 //! impl ApplicationHandler for App {
+//!     fn can_create_surfaces(&mut self, event_loop: &dyn ActiveEventLoop) {
+//!         // The event loop has launched, and we can initialize our UI state.
+//!
+//!         // Create a simple window with default attributes.
+//!         self.window = Some(event_loop.create_window(WindowAttributes::default()).unwrap());
+//!     }
+//!
 //!     fn window_event(
 //!         &mut self,
 //!         event_loop: &dyn ActiveEventLoop,
 //!         id: WindowId,
 //!         event: WindowEvent,
 //!     ) {
-//!         // Called by `EventLoop::run` when a new event happens on the window.
+//!         // Called by `EventLoop::run_app` when a new event happens on the window.
 //!         match event {
 //!             WindowEvent::CloseRequested => {
 //!                 println!("The close button was pressed; stopping");
@@ -73,7 +89,7 @@
 //!                 // You only need to call this if you've determined that you need to redraw in
 //!                 // applications which do not always need to. Applications that redraw continuously
 //!                 // can render here instead.
-//!                 self.window.request_redraw();
+//!                 self.window.as_ref().unwrap().request_redraw();
 //!             },
 //!             _ => (),
 //!         }
@@ -96,19 +112,8 @@
 //!     // input, and uses significantly less power/CPU time than ControlFlow::Poll.
 //!     event_loop.set_control_flow(ControlFlow::Wait);
 //!
-//!     // Launch and begin running our event loop.
-//!     event_loop.run(|event_loop| {
-//!         // The event loop has launched, and we can initialize our UI state in this closure.
-//!
-//!         // Create a simple window with default attributes.
-//!         let window = event_loop
-//!             .create_window(Window::default_attributes())
-//!             .expect("failed creating window");
-//!
-//!         // Give our newly created application state to Winit, which will, when necessary, call
-//!         // the `ApplicationHandler` methods configured above.
-//!         App { window }
-//!     })?;
+//!     // Launch and begin running the event loop.
+//!     event_loop.run_app(App::default())?;
 //!
 //!     Ok(())
 //! }
@@ -258,21 +263,17 @@
 //! |32-bit ARM Android                  |`arm-linux-androideabi`             |Android        |
 //! |64-bit SPARC Linux with glibc       |`sparc64-unknown-linux-gnu`         |X11, Wayland   |
 //!
-//! [`ActiveEventLoop`]: event_loop::ActiveEventLoop
 //! [`EventLoop`]: event_loop::EventLoop
 //! [`EventLoop::new()`]: event_loop::EventLoop::new
-//! [`EventLoop::run()`]: event_loop::EventLoop::run
-//! [`ActiveEventLoop::exit()`]: event_loop::ActiveEventLoop::exit
+//! [`EventLoop::run_app()`]: event_loop::EventLoop::run_app
+//! [`exit()`]: event_loop::ActiveEventLoop::exit
 //! [`Window`]: window::Window
 //! [`WindowId`]: window::WindowId
 //! [`WindowAttributes`]: window::WindowAttributes
-//! [window_new]: window::Window::new
-//! [`ActiveEventLoop::create_window()`]: event_loop::ActiveEventLoop::create_window
+//! [`create_window`]: event_loop::ActiveEventLoop::create_window
 //! [`Window::id()`]: window::Window::id
 //! [`WindowEvent`]: event::WindowEvent
 //! [`DeviceEvent`]: event::DeviceEvent
-//! [`ApplicationHandler`]: application::ApplicationHandler
-//! [`Event::UserEvent`]: event::Event::UserEvent
 //! [`raw_window_handle`]: ./window/struct.Window.html#method.raw_window_handle
 //! [`raw_display_handle`]: ./window/struct.Window.html#method.raw_display_handle
 //! [^1]: `EventLoopExtPumpEvents::pump_app_events()` is only available on Windows, macOS, Android, X11 and Wayland.
@@ -287,6 +288,8 @@
 #![cfg_attr(docsrs, feature(doc_auto_cfg, doc_cfg_hide), doc(cfg_hide(doc, docsrs)))]
 #![allow(clippy::missing_safety_doc)]
 #![warn(clippy::uninlined_format_args)]
+// TODO: wasm-binding needs to be updated for that to be resolved, for now just silence it.
+#![cfg_attr(web_platform, allow(unknown_lints, wasm_c_abi))]
 
 // Re-export DPI types so that users don't have to put it in Cargo.toml.
 #[doc(inline)]
@@ -301,7 +304,7 @@ pub mod error;
 mod cursor;
 pub mod event;
 pub mod event_loop;
-mod icon;
+pub mod icon;
 pub mod keyboard;
 pub mod monitor;
 mod platform_impl;

src/monitor.rs

@@ -5,141 +5,97 @@
 //! methods, which return an iterator of [`MonitorHandle`]:
 //! - [`ActiveEventLoop::available_monitors`][crate::event_loop::ActiveEventLoop::available_monitors].
 //! - [`Window::available_monitors`][crate::window::Window::available_monitors].
+use std::borrow::Cow;
+use std::fmt;
 use std::num::{NonZeroU16, NonZeroU32};
+use std::ops::Deref;
+use std::sync::Arc;
 
 use crate::dpi::{PhysicalPosition, PhysicalSize};
-use crate::platform_impl;
-
-/// Describes a fullscreen video mode of a monitor.
-///
-/// Can be acquired with [`MonitorHandle::video_modes`].
-#[derive(Clone, PartialEq, Eq, Hash)]
-pub struct VideoModeHandle {
-    pub(crate) video_mode: platform_impl::VideoModeHandle,
-}
-
-impl std::fmt::Debug for VideoModeHandle {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        self.video_mode.fmt(f)
-    }
-}
-
-impl PartialOrd for VideoModeHandle {
-    fn partial_cmp(&self, other: &VideoModeHandle) -> Option<std::cmp::Ordering> {
-        Some(self.cmp(other))
-    }
-}
-
-impl Ord for VideoModeHandle {
-    fn cmp(&self, other: &VideoModeHandle) -> std::cmp::Ordering {
-        self.monitor().cmp(&other.monitor()).then(
-            self.size()
-                .cmp(&other.size())
-                .then(
-                    self.refresh_rate_millihertz()
-                        .cmp(&other.refresh_rate_millihertz())
-                        .then(self.bit_depth().cmp(&other.bit_depth())),
-                )
-                .reverse(),
-        )
-    }
-}
-
-impl VideoModeHandle {
-    /// Returns the resolution of this video mode. This **must not** be used to create your
-    /// rendering surface. Use [`Window::surface_size()`] instead.
-    ///
-    /// [`Window::surface_size()`]: crate::window::Window::surface_size
-    #[inline]
-    pub fn size(&self) -> PhysicalSize<u32> {
-        self.video_mode.size()
-    }
-
-    /// Returns the bit depth of this video mode, as in how many bits you have
-    /// available per color. This is generally 24 bits or 32 bits on modern
-    /// systems, depending on whether the alpha channel is counted or not.
-    #[inline]
-    pub fn bit_depth(&self) -> Option<NonZeroU16> {
-        self.video_mode.bit_depth()
-    }
-
-    /// Returns the refresh rate of this video mode in mHz.
-    #[inline]
-    pub fn refresh_rate_millihertz(&self) -> Option<NonZeroU32> {
-        self.video_mode.refresh_rate_millihertz()
-    }
-
-    /// Returns the monitor that this video mode is valid for. Each monitor has
-    /// a separate set of valid video modes.
-    #[inline]
-    pub fn monitor(&self) -> MonitorHandle {
-        MonitorHandle { inner: self.video_mode.monitor() }
-    }
-}
-
-impl std::fmt::Display for VideoModeHandle {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        write!(
-            f,
-            "{}x{} {}{}",
-            self.size().width,
-            self.size().height,
-            self.refresh_rate_millihertz().map(|rate| format!("@ {rate} mHz ")).unwrap_or_default(),
-            self.bit_depth().map(|bit_depth| format!("({bit_depth} bpp)")).unwrap_or_default(),
-        )
-    }
-}
+use crate::utils::{impl_dyn_casting, AsAny};
 
 /// Handle to a monitor.
 ///
-/// Allows you to retrieve information about a given monitor and can be used in [`Window`] creation.
+/// Allows you to retrieve basic information and metadata about a monitor.
+///
+/// Can be used in [`Window`] creation to place the window on a specific
+/// monitor.
+///
+/// This can be retrieved from one of the following methods, which return an
+/// iterator of [`MonitorHandle`]s:
+/// - [`ActiveEventLoop::available_monitors`](crate::event_loop::ActiveEventLoop::available_monitors).
+/// - [`Window::available_monitors`](crate::window::Window::available_monitors).
 ///
 /// ## Platform-specific
 ///
 /// **Web:** A [`MonitorHandle`] created without
 #[cfg_attr(
-    any(web_platform, docsrs),
+    web_platform,
     doc = "[detailed monitor permissions][crate::platform::web::ActiveEventLoopExtWeb::request_detailed_monitor_permission]."
 )]
-#[cfg_attr(not(any(web_platform, docsrs)), doc = "detailed monitor permissions.")]
+#[cfg_attr(not(web_platform), doc = "detailed monitor permissions.")]
 /// will always represent the current monitor the browser window is in instead of a specific
 /// monitor. See
 #[cfg_attr(
-    any(web_platform, docsrs),
+    web_platform,
     doc = "[`MonitorHandleExtWeb::is_detailed()`][crate::platform::web::MonitorHandleExtWeb::is_detailed]"
 )]
-#[cfg_attr(not(any(web_platform, docsrs)), doc = "`MonitorHandleExtWeb::is_detailed()`")]
+#[cfg_attr(not(web_platform), doc = "`MonitorHandleExtWeb::is_detailed()`")]
 /// to check.
 ///
 /// [`Window`]: crate::window::Window
-#[derive(Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
-pub struct MonitorHandle {
-    pub(crate) inner: platform_impl::MonitorHandle,
-}
+#[derive(Debug, Clone)]
+pub struct MonitorHandle(pub(crate) Arc<dyn MonitorHandleProvider>);
 
-impl std::fmt::Debug for MonitorHandle {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        self.inner.fmt(f)
+impl Deref for MonitorHandle {
+    type Target = dyn MonitorHandleProvider;
+
+    fn deref(&self) -> &Self::Target {
+        self.0.as_ref()
     }
 }
 
-impl MonitorHandle {
+impl PartialEq for MonitorHandle {
+    fn eq(&self, other: &Self) -> bool {
+        self.0.as_ref().eq(other.0.as_ref())
+    }
+}
+
+impl Eq for MonitorHandle {}
+
+/// Provider of the [`MonitorHandle`].
+pub trait MonitorHandleProvider: AsAny + fmt::Debug + Send + Sync {
+    /// Identifier for this monitor.
+    ///
+    /// The representation of this modifier is not guaranteed and should be used only to compare
+    /// monitors.
+    fn id(&self) -> u128;
+
+    /// Native platform identifier of this monitor.
+    ///
+    /// # Platform-specific
+    ///
+    /// - **Windows**: This is `HMONITOR`.
+    /// - **macOS**: This is `CGDirectDisplayID`.
+    /// - **iOS**: This is `UIScreen*`.
+    /// - **Wayland**: This is the ID of the `wl_output` device.
+    /// - **X11**: This is the ID of the CRTC.
+    /// - **Web**: This is an internal ID not meant for consumption.
+    fn native_id(&self) -> u64;
+
     /// Returns a human-readable name of the monitor.
     ///
-    /// Returns `None` if the monitor doesn't exist anymore.
+    /// Returns `None` if the monitor doesn't exist anymore or the name couldn't be obtained.
     ///
     /// ## Platform-specific
     ///
     /// **Web:** Always returns [`None`] without
     #[cfg_attr(
-        any(web_platform, docsrs),
+        web_platform,
         doc = "[detailed monitor permissions][crate::platform::web::ActiveEventLoopExtWeb::request_detailed_monitor_permission]."
     )]
-    #[cfg_attr(not(any(web_platform, docsrs)), doc = "detailed monitor permissions.")]
-    #[inline]
-    pub fn name(&self) -> Option<String> {
-        self.inner.name()
-    }
+    #[cfg_attr(not(web_platform), doc = "detailed monitor permissions.")]
+    fn name(&self) -> Option<Cow<'_, str>>;
 
     /// Returns the top-left corner position of the monitor in desktop coordinates.
     ///
@@ -151,14 +107,11 @@ impl MonitorHandle {
     ///
     /// **Web:** Always returns [`None`] without
     #[cfg_attr(
-        any(web_platform, docsrs),
+        web_platform,
         doc = "[detailed monitor permissions][crate::platform::web::ActiveEventLoopExtWeb::request_detailed_monitor_permission]."
     )]
-    #[cfg_attr(not(any(web_platform, docsrs)), doc = "detailed monitor permissions.")]
-    #[inline]
-    pub fn position(&self) -> Option<PhysicalPosition<i32>> {
-        self.inner.position()
-    }
+    #[cfg_attr(not(web_platform), doc = "detailed monitor permissions.")]
+    fn position(&self) -> Option<PhysicalPosition<i32>>;
 
     /// Returns the scale factor of the underlying monitor. To map logical pixels to physical
     /// pixels and vice versa, use [`Window::scale_factor`].
@@ -172,27 +125,81 @@ impl MonitorHandle {
     /// - **Android:** Always returns 1.0.
     /// - **Web:** Always returns `0.0` without
     #[cfg_attr(
-        any(web_platform, docsrs),
+        web_platform,
         doc = "  [detailed monitor permissions][crate::platform::web::ActiveEventLoopExtWeb::request_detailed_monitor_permission]."
     )]
-    #[cfg_attr(not(any(web_platform, docsrs)), doc = "  detailed monitor permissions.")]
+    #[cfg_attr(not(web_platform), doc = "  detailed monitor permissions.")]
     ///
     #[rustfmt::skip]
     /// [`Window::scale_factor`]: crate::window::Window::scale_factor
-    #[inline]
-    pub fn scale_factor(&self) -> f64 {
-        self.inner.scale_factor()
-    }
+    fn scale_factor(&self) -> f64;
 
-    /// Returns the currently active video mode of this monitor.
-    #[inline]
-    pub fn current_video_mode(&self) -> Option<VideoModeHandle> {
-        self.inner.current_video_mode().map(|video_mode| VideoModeHandle { video_mode })
-    }
+    fn current_video_mode(&self) -> Option<VideoMode>;
 
     /// Returns all fullscreen video modes supported by this monitor.
-    #[inline]
-    pub fn video_modes(&self) -> impl Iterator<Item = VideoModeHandle> {
-        self.inner.video_modes().map(|video_mode| VideoModeHandle { video_mode })
+    fn video_modes(&self) -> Box<dyn Iterator<Item = VideoMode>>;
+}
+
+impl PartialEq for dyn MonitorHandleProvider + '_ {
+    fn eq(&self, other: &Self) -> bool {
+        self.id() == other.id()
     }
 }
+
+impl Eq for dyn MonitorHandleProvider + '_ {}
+
+impl_dyn_casting!(MonitorHandleProvider);
+
+/// Describes a fullscreen video mode of a monitor.
+///
+/// Can be acquired with [`MonitorHandleProvider::video_modes`].
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct VideoMode {
+    pub(crate) size: PhysicalSize<u32>,
+    pub(crate) bit_depth: Option<NonZeroU16>,
+    pub(crate) refresh_rate_millihertz: Option<NonZeroU32>,
+}
+
+impl VideoMode {
+    /// Returns the resolution of this video mode. This **must not** be used to create your
+    /// rendering surface. Use [`Window::surface_size()`] instead.
+    ///
+    /// [`Window::surface_size()`]: crate::window::Window::surface_size
+    pub fn size(&self) -> PhysicalSize<u32> {
+        self.size
+    }
+
+    /// Returns the bit depth of this video mode, as in how many bits you have
+    /// available per color. This is generally 24 bits or 32 bits on modern
+    /// systems, depending on whether the alpha channel is counted or not.
+    pub fn bit_depth(&self) -> Option<NonZeroU16> {
+        self.bit_depth
+    }
+
+    /// Returns the refresh rate of this video mode in mHz.
+    pub fn refresh_rate_millihertz(&self) -> Option<NonZeroU32> {
+        self.refresh_rate_millihertz
+    }
+}
+
+impl fmt::Display for VideoMode {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(
+            f,
+            "{}x{} {}{}",
+            self.size.width,
+            self.size.height,
+            self.refresh_rate_millihertz.map(|rate| format!("@ {rate} mHz ")).unwrap_or_default(),
+            self.bit_depth.map(|bit_depth| format!("({bit_depth} bpp)")).unwrap_or_default(),
+        )
+    }
+}
+
+/// Fullscreen modes.
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub enum Fullscreen {
+    Exclusive(MonitorHandle, VideoMode),
+
+    /// Providing `None` to `Borderless` will fullscreen on the current monitor.
+    Borderless(Option<MonitorHandle>),
+}

src/platform/android.rs

@@ -62,7 +62,7 @@
 //! If your application is currently based on `NativeActivity` via the `ndk-glue` crate and building
 //! with `cargo apk`, then the minimal changes would be:
 //! 1. Remove `ndk-glue` from your `Cargo.toml`
-//! 2. Enable the `"android-native-activity"` feature for Winit: `winit = { version = "0.30.5",
+//! 2. Enable the `"android-native-activity"` feature for Winit: `winit = { version = "0.30.10",
 //!    features = [ "android-native-activity" ] }`
 //! 3. Add an `android_main` entrypoint (as above), instead of using the '`[ndk_glue::main]` proc
 //!    macro from `ndk-macros` (optionally add a dependency on `android_logger` and initialize
@@ -101,20 +101,19 @@ pub trait WindowExtAndroid {
 
 impl WindowExtAndroid for dyn Window + '_ {
     fn content_rect(&self) -> Rect {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.content_rect()
     }
 
     fn config(&self) -> ConfigurationRef {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.config()
     }
 }
 
 impl ActiveEventLoopExtAndroid for dyn ActiveEventLoop + '_ {
     fn android_app(&self) -> &AndroidApp {
-        let event_loop =
-            self.as_any().downcast_ref::<crate::platform_impl::ActiveEventLoop>().unwrap();
+        let event_loop = self.cast_ref::<crate::platform_impl::ActiveEventLoop>().unwrap();
         &event_loop.app
     }
 }

src/platform/ios.rs

@@ -85,12 +85,9 @@
 //!
 //!  - applicationDidBecomeActive is Resumed
 //!  - applicationWillResignActive is Suspended
-//!  - applicationWillTerminate is LoopExiting
+//!  - applicationWillTerminate corresponds to `Drop`ping the application handler.
 //!
-//! Keep in mind that after LoopExiting event is received every attempt to draw with
-//! opengl will result in segfault.
-//!
-//! Also note that app may not receive the LoopExiting event if suspended; it might be SIGKILL'ed.
+//! Note that an app may not receive the `Drop` event if suspended; it might be SIGKILL'ed.
 //!
 //! ## Custom `UIApplicationDelegate`
 //!
@@ -107,7 +104,8 @@ use std::os::raw::c_void;
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
 
-use crate::monitor::{MonitorHandle, VideoModeHandle};
+use crate::monitor::{MonitorHandle, VideoMode};
+use crate::platform_impl::MonitorHandle as IosMonitorHandle;
 use crate::window::{Window, WindowAttributes};
 
 /// Additional methods on [`Window`] that are specific to iOS.
@@ -115,10 +113,11 @@ pub trait WindowExtIOS {
     /// Sets the [`contentScaleFactor`] of the underlying [`UIWindow`] to `scale_factor`.
     ///
     /// The default value is device dependent, and it's recommended GLES or Metal applications set
-    /// this to [`MonitorHandle::scale_factor()`].
+    /// this to [`MonitorHandleProvider::scale_factor()`].
     ///
     /// [`UIWindow`]: https://developer.apple.com/documentation/uikit/uiwindow?language=objc
     /// [`contentScaleFactor`]: https://developer.apple.com/documentation/uikit/uiview/1622657-contentscalefactor?language=objc
+    /// [`MonitorHandleProvider::scale_factor()`]: crate::monitor::MonitorHandleProvider::scale_factor()
     fn set_scale_factor(&self, scale_factor: f64);
 
     /// Sets the valid orientations for the [`Window`].
@@ -212,25 +211,25 @@ pub trait WindowExtIOS {
 impl WindowExtIOS for dyn Window + '_ {
     #[inline]
     fn set_scale_factor(&self, scale_factor: f64) {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.maybe_wait_on_main(move |w| w.set_scale_factor(scale_factor));
     }
 
     #[inline]
     fn set_valid_orientations(&self, valid_orientations: ValidOrientations) {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.maybe_wait_on_main(move |w| w.set_valid_orientations(valid_orientations));
     }
 
     #[inline]
     fn set_prefers_home_indicator_hidden(&self, hidden: bool) {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.maybe_wait_on_main(move |w| w.set_prefers_home_indicator_hidden(hidden));
     }
 
     #[inline]
     fn set_preferred_screen_edges_deferring_system_gestures(&self, edges: ScreenEdge) {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.maybe_wait_on_main(move |w| {
             w.set_preferred_screen_edges_deferring_system_gestures(edges)
         });
@@ -238,19 +237,19 @@ impl WindowExtIOS for dyn Window + '_ {
 
     #[inline]
     fn set_prefers_status_bar_hidden(&self, hidden: bool) {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.maybe_wait_on_main(move |w| w.set_prefers_status_bar_hidden(hidden));
     }
 
     #[inline]
     fn set_preferred_status_bar_style(&self, status_bar_style: StatusBarStyle) {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.maybe_wait_on_main(move |w| w.set_preferred_status_bar_style(status_bar_style))
     }
 
     #[inline]
     fn recognize_pinch_gesture(&self, should_recognize: bool) {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.maybe_wait_on_main(move |w| w.recognize_pinch_gesture(should_recognize));
     }
 
@@ -261,7 +260,7 @@ impl WindowExtIOS for dyn Window + '_ {
         minimum_number_of_touches: u8,
         maximum_number_of_touches: u8,
     ) {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.maybe_wait_on_main(move |w| {
             w.recognize_pan_gesture(
                 should_recognize,
@@ -273,13 +272,13 @@ impl WindowExtIOS for dyn Window + '_ {
 
     #[inline]
     fn recognize_doubletap_gesture(&self, should_recognize: bool) {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.maybe_wait_on_main(move |w| w.recognize_doubletap_gesture(should_recognize));
     }
 
     #[inline]
     fn recognize_rotation_gesture(&self, should_recognize: bool) {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.maybe_wait_on_main(move |w| w.recognize_rotation_gesture(should_recognize));
     }
 }
@@ -289,10 +288,11 @@ pub trait WindowAttributesExtIOS {
     /// Sets the [`contentScaleFactor`] of the underlying [`UIWindow`] to `scale_factor`.
     ///
     /// The default value is device dependent, and it's recommended GLES or Metal applications set
-    /// this to [`MonitorHandle::scale_factor()`].
+    /// this to [`MonitorHandleProvider::scale_factor()`].
     ///
     /// [`UIWindow`]: https://developer.apple.com/documentation/uikit/uiwindow?language=objc
     /// [`contentScaleFactor`]: https://developer.apple.com/documentation/uikit/uiview/1622657-contentscalefactor?language=objc
+    /// [`MonitorHandleProvider::scale_factor()`]: crate::monitor::MonitorHandleProvider::scale_factor()
     fn with_scale_factor(self, scale_factor: f64) -> Self;
 
     /// Sets the valid orientations for the [`Window`].
@@ -384,23 +384,25 @@ pub trait MonitorHandleExtIOS {
     /// [`UIScreen`]: https://developer.apple.com/documentation/uikit/uiscreen?language=objc
     fn ui_screen(&self) -> *mut c_void;
 
-    /// Returns the preferred [`VideoModeHandle`] for this monitor.
+    /// Returns the preferred [`VideoMode`] for this monitor.
     ///
     /// This translates to a call to [`-[UIScreen preferredMode]`](https://developer.apple.com/documentation/uikit/uiscreen/1617823-preferredmode?language=objc).
-    fn preferred_video_mode(&self) -> VideoModeHandle;
+    fn preferred_video_mode(&self) -> VideoMode;
 }
 
 impl MonitorHandleExtIOS for MonitorHandle {
     #[inline]
     fn ui_screen(&self) -> *mut c_void {
         // SAFETY: The marker is only used to get the pointer of the screen
-        let mtm = unsafe { objc2_foundation::MainThreadMarker::new_unchecked() };
-        objc2::rc::Retained::as_ptr(self.inner.ui_screen(mtm)) as *mut c_void
+        let mtm = unsafe { objc2::MainThreadMarker::new_unchecked() };
+        let monitor = self.cast_ref::<IosMonitorHandle>().unwrap();
+        objc2::rc::Retained::as_ptr(monitor.ui_screen(mtm)) as *mut c_void
     }
 
     #[inline]
-    fn preferred_video_mode(&self) -> VideoModeHandle {
-        VideoModeHandle { video_mode: self.inner.preferred_video_mode() }
+    fn preferred_video_mode(&self) -> VideoMode {
+        let monitor = self.cast_ref::<IosMonitorHandle>().unwrap();
+        monitor.preferred_video_mode()
     }
 }
 

src/platform/macos.rs

@@ -21,26 +21,21 @@
 #![cfg_attr(not(target_os = "macos"), doc = "```ignore")]
 //! use objc2::rc::Retained;
 //! use objc2::runtime::ProtocolObject;
-//! use objc2::{declare_class, msg_send_id, mutability, ClassType, DeclaredClass};
+//! use objc2::{define_class, msg_send, DefinedClass, MainThreadMarker, MainThreadOnly};
 //! use objc2_app_kit::{NSApplication, NSApplicationDelegate};
-//! use objc2_foundation::{NSArray, NSURL, MainThreadMarker, NSObject, NSObjectProtocol};
+//! use objc2_foundation::{NSArray, NSURL, NSObject, NSObjectProtocol};
 //! use winit::event_loop::EventLoop;
 //!
-//! declare_class!(
+//! define_class!(
+//!     #[unsafe(super(NSObject))]
+//!     #[thread_kind = MainThreadOnly]
+//!     #[name = "AppDelegate"]
 //!     struct AppDelegate;
 //!
-//!     unsafe impl ClassType for AppDelegate {
-//!         type Super = NSObject;
-//!         type Mutability = mutability::MainThreadOnly;
-//!         const NAME: &'static str = "MyAppDelegate";
-//!     }
-//!
-//!     impl DeclaredClass for AppDelegate {}
-//!
 //!     unsafe impl NSObjectProtocol for AppDelegate {}
 //!
 //!     unsafe impl NSApplicationDelegate for AppDelegate {
-//!         #[method(application:openURLs:)]
+//!         #[unsafe(method(application:openURLs:))]
 //!         fn application_openURLs(&self, application: &NSApplication, urls: &NSArray<NSURL>) {
 //!             // Note: To specifically get `application:openURLs:` to work, you _might_
 //!             // have to bundle your application. This is not done in this example.
@@ -51,7 +46,7 @@
 //!
 //! impl AppDelegate {
 //!     fn new(mtm: MainThreadMarker) -> Retained<Self> {
-//!         unsafe { msg_send_id![super(mtm.alloc().set_ivars(())), init] }
+//!         unsafe { msg_send![super(Self::alloc(mtm).set_ivars(())), init] }
 //!     }
 //! }
 //!
@@ -65,7 +60,7 @@
 //!     let app = NSApplication::sharedApplication(mtm);
 //!     app.setDelegate(Some(ProtocolObject::from_ref(&*delegate)));
 //!
-//!     // event_loop.run(|event_loop| { ... })?;
+//!     // event_loop.run_app(&mut my_app);
 //!     Ok(())
 //! }
 //! ```
@@ -78,6 +73,7 @@ use serde::{Deserialize, Serialize};
 use crate::application::ApplicationHandler;
 use crate::event_loop::{ActiveEventLoop, EventLoopBuilder};
 use crate::monitor::MonitorHandle;
+use crate::platform_impl::MonitorHandle as MacOsMonitorHandle;
 use crate::window::{Window, WindowAttributes, WindowId};
 
 /// Additional methods on [`Window`] that are specific to MacOS.
@@ -155,7 +151,9 @@ pub trait WindowExtMacOS {
     /// Getter for the [`WindowExtMacOS::set_option_as_alt`].
     fn option_as_alt(&self) -> OptionAsAlt;
 
-    /// Disable the Menu Bar and Dock in Borderless Fullscreen mode. Useful for games.
+    /// Disable the Menu Bar and Dock in Simple or Borderless Fullscreen mode. Useful for games.
+    /// The effect is applied when [`WindowExtMacOS::set_simple_fullscreen`] or
+    /// [`Window::set_fullscreen`] is called.
     fn set_borderless_game(&self, borderless_game: bool);
 
     /// Getter for the [`WindowExtMacOS::set_borderless_game`].
@@ -172,109 +170,109 @@ pub trait WindowExtMacOS {
 impl WindowExtMacOS for dyn Window + '_ {
     #[inline]
     fn simple_fullscreen(&self) -> bool {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.maybe_wait_on_main(|w| w.simple_fullscreen())
     }
 
     #[inline]
     fn set_simple_fullscreen(&self, fullscreen: bool) -> bool {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.maybe_wait_on_main(move |w| w.set_simple_fullscreen(fullscreen))
     }
 
     #[inline]
     fn has_shadow(&self) -> bool {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.maybe_wait_on_main(|w| w.has_shadow())
     }
 
     #[inline]
     fn set_has_shadow(&self, has_shadow: bool) {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.maybe_wait_on_main(move |w| w.set_has_shadow(has_shadow));
     }
 
     #[inline]
     fn set_tabbing_identifier(&self, identifier: &str) {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.maybe_wait_on_main(|w| w.set_tabbing_identifier(identifier))
     }
 
     #[inline]
     fn tabbing_identifier(&self) -> String {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.maybe_wait_on_main(|w| w.tabbing_identifier())
     }
 
     #[inline]
     fn select_next_tab(&self) {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.maybe_wait_on_main(|w| w.select_next_tab());
     }
 
     #[inline]
     fn select_previous_tab(&self) {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.maybe_wait_on_main(|w| w.select_previous_tab());
     }
 
     #[inline]
     fn select_tab_at_index(&self, index: usize) {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.maybe_wait_on_main(move |w| w.select_tab_at_index(index));
     }
 
     #[inline]
     fn num_tabs(&self) -> usize {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.maybe_wait_on_main(|w| w.num_tabs())
     }
 
     #[inline]
     fn is_document_edited(&self) -> bool {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.maybe_wait_on_main(|w| w.is_document_edited())
     }
 
     #[inline]
     fn set_document_edited(&self, edited: bool) {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.maybe_wait_on_main(move |w| w.set_document_edited(edited));
     }
 
     #[inline]
     fn set_option_as_alt(&self, option_as_alt: OptionAsAlt) {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.maybe_wait_on_main(move |w| w.set_option_as_alt(option_as_alt));
     }
 
     #[inline]
     fn option_as_alt(&self) -> OptionAsAlt {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.maybe_wait_on_main(|w| w.option_as_alt())
     }
 
     #[inline]
     fn set_borderless_game(&self, borderless_game: bool) {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.maybe_wait_on_main(|w| w.set_borderless_game(borderless_game))
     }
 
     #[inline]
     fn is_borderless_game(&self) -> bool {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.maybe_wait_on_main(|w| w.is_borderless_game())
     }
 
     #[inline]
     fn set_unified_titlebar(&self, unified_titlebar: bool) {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.maybe_wait_on_main(|w| w.set_unified_titlebar(unified_titlebar))
     }
 
     #[inline]
     fn unified_titlebar(&self) -> bool {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.maybe_wait_on_main(|w| w.unified_titlebar())
     }
 }
@@ -332,6 +330,13 @@ pub trait WindowAttributesExtMacOS {
     fn with_borderless_game(self, borderless_game: bool) -> Self;
     /// See [`WindowExtMacOS::set_unified_titlebar`] for details on what this means if set.
     fn with_unified_titlebar(self, unified_titlebar: bool) -> Self;
+    /// Use [`NSPanel`] window with [`NonactivatingPanel`] window style mask instead of
+    /// [`NSWindow`].
+    ///
+    /// [`NSWindow`]: https://developer.apple.com/documentation/appkit/NSWindow?language=objc
+    /// [`NSPanel`]: https://developer.apple.com/documentation/appkit/NSPanel?language=objc
+    /// [`NonactivatingPanel`]: https://developer.apple.com/documentation/appkit/nswindow/stylemask-swift.struct/nonactivatingpanel?language=objc
+    fn with_panel(self, panel: bool) -> Self;
 }
 
 impl WindowAttributesExtMacOS for WindowAttributes {
@@ -412,6 +417,12 @@ impl WindowAttributesExtMacOS for WindowAttributes {
         self.platform_specific.unified_titlebar = unified_titlebar;
         self
     }
+
+    #[inline]
+    fn with_panel(mut self, panel: bool) -> Self {
+        self.platform_specific.panel = panel;
+        self
+    }
 }
 
 pub trait EventLoopBuilderExtMacOS {
@@ -491,22 +502,16 @@ impl EventLoopBuilderExtMacOS for EventLoopBuilder {
 
 /// Additional methods on [`MonitorHandle`] that are specific to MacOS.
 pub trait MonitorHandleExtMacOS {
-    /// Returns the identifier of the monitor for Cocoa.
-    fn native_id(&self) -> u32;
     /// Returns a pointer to the NSScreen representing this monitor.
     fn ns_screen(&self) -> Option<*mut c_void>;
 }
 
 impl MonitorHandleExtMacOS for MonitorHandle {
-    #[inline]
-    fn native_id(&self) -> u32 {
-        self.inner.native_identifier()
-    }
-
     fn ns_screen(&self) -> Option<*mut c_void> {
+        let monitor = self.cast_ref::<MacOsMonitorHandle>().unwrap();
         // SAFETY: We only use the marker to get a pointer
-        let mtm = unsafe { objc2_foundation::MainThreadMarker::new_unchecked() };
-        self.inner.ns_screen(mtm).map(|s| objc2::rc::Retained::as_ptr(&s) as _)
+        let mtm = unsafe { objc2::MainThreadMarker::new_unchecked() };
+        monitor.ns_screen(mtm).map(|s| objc2::rc::Retained::as_ptr(&s) as _)
     }
 }
 
@@ -529,32 +534,28 @@ pub trait ActiveEventLoopExtMacOS {
 impl ActiveEventLoopExtMacOS for dyn ActiveEventLoop + '_ {
     fn hide_application(&self) {
         let event_loop = self
-            .as_any()
-            .downcast_ref::<crate::platform_impl::ActiveEventLoop>()
+            .cast_ref::<crate::platform_impl::ActiveEventLoop>()
             .expect("non macOS event loop on macOS");
         event_loop.hide_application()
     }
 
     fn hide_other_applications(&self) {
         let event_loop = self
-            .as_any()
-            .downcast_ref::<crate::platform_impl::ActiveEventLoop>()
+            .cast_ref::<crate::platform_impl::ActiveEventLoop>()
             .expect("non macOS event loop on macOS");
         event_loop.hide_other_applications()
     }
 
     fn set_allows_automatic_window_tabbing(&self, enabled: bool) {
         let event_loop = self
-            .as_any()
-            .downcast_ref::<crate::platform_impl::ActiveEventLoop>()
+            .cast_ref::<crate::platform_impl::ActiveEventLoop>()
             .expect("non macOS event loop on macOS");
         event_loop.set_allows_automatic_window_tabbing(enabled);
     }
 
     fn allows_automatic_window_tabbing(&self) -> bool {
         let event_loop = self
-            .as_any()
-            .downcast_ref::<crate::platform_impl::ActiveEventLoop>()
+            .cast_ref::<crate::platform_impl::ActiveEventLoop>()
             .expect("non macOS event loop on macOS");
         event_loop.allows_automatic_window_tabbing()
     }

src/platform/mod.rs

@@ -2,23 +2,23 @@
 //!
 //! Only the modules corresponding to the platform you're compiling to will be available.
 
-#[cfg(any(android_platform, docsrs))]
+#[cfg(android_platform)]
 pub mod android;
-#[cfg(any(ios_platform, docsrs))]
+#[cfg(ios_platform)]
 pub mod ios;
-#[cfg(any(macos_platform, docsrs))]
+#[cfg(macos_platform)]
 pub mod macos;
-#[cfg(any(orbital_platform, docsrs))]
+#[cfg(orbital_platform)]
 pub mod orbital;
-#[cfg(any(x11_platform, wayland_platform, docsrs))]
+#[cfg(any(x11_platform, wayland_platform))]
 pub mod startup_notify;
-#[cfg(any(wayland_platform, docsrs))]
+#[cfg(wayland_platform)]
 pub mod wayland;
-#[cfg(any(web_platform, docsrs))]
+#[cfg(web_platform)]
 pub mod web;
-#[cfg(any(windows_platform, docsrs))]
+#[cfg(windows_platform)]
 pub mod windows;
-#[cfg(any(x11_platform, docsrs))]
+#[cfg(x11_platform)]
 pub mod x11;
 
 #[allow(unused_imports)]
@@ -42,15 +42,5 @@ pub mod run_on_demand;
 ))]
 pub mod pump_events;
 
-#[cfg(any(
-    windows_platform,
-    macos_platform,
-    x11_platform,
-    wayland_platform,
-    orbital_platform,
-    docsrs
-))]
-pub mod modifier_supplement;
-
 #[cfg(any(windows_platform, macos_platform, x11_platform, wayland_platform, docsrs))]
 pub mod scancode;

src/platform/modifier_supplement.rs

@@ -1,35 +0,0 @@
-use crate::event::KeyEvent;
-use crate::keyboard::Key;
-
-/// Additional methods for the `KeyEvent` which cannot be implemented on all
-/// platforms.
-pub trait KeyEventExtModifierSupplement {
-    /// Identical to `KeyEvent::text` but this is affected by <kbd>Ctrl</kbd>.
-    ///
-    /// For example, pressing <kbd>Ctrl</kbd>+<kbd>a</kbd> produces `Some("\x01")`.
-    fn text_with_all_modifiers(&self) -> Option<&str>;
-
-    /// This value ignores all modifiers including,
-    /// but not limited to <kbd>Shift</kbd>, <kbd>Caps Lock</kbd>,
-    /// and <kbd>Ctrl</kbd>. In most cases this means that the
-    /// unicode character in the resulting string is lowercase.
-    ///
-    /// This is useful for key-bindings / shortcut key combinations.
-    ///
-    /// In case `logical_key` reports `Dead`, this will still report the
-    /// key as `Character` according to the current keyboard layout. This value
-    /// cannot be `Dead`.
-    fn key_without_modifiers(&self) -> Key;
-}
-
-impl KeyEventExtModifierSupplement for KeyEvent {
-    #[inline]
-    fn text_with_all_modifiers(&self) -> Option<&str> {
-        self.platform_specific.text_with_all_modifiers.as_ref().map(|s| s.as_str())
-    }
-
-    #[inline]
-    fn key_without_modifiers(&self) -> Key {
-        self.platform_specific.key_without_modifiers.clone()
-    }
-}

src/platform/pump_events.rs

@@ -47,19 +47,19 @@ pub trait EventLoopExtPumpEvents {
     /// buffered and handled outside of Winit include:
     /// - `RedrawRequested` events, used to schedule rendering.
     ///
-    ///     macOS for example uses a `drawRect` callback to drive rendering
-    ///     within applications and expects rendering to be finished before
-    ///     the `drawRect` callback returns.
+    ///   macOS for example uses a `drawRect` callback to drive rendering
+    ///   within applications and expects rendering to be finished before
+    ///   the `drawRect` callback returns.
     ///
-    ///     For portability it's strongly recommended that applications should
-    ///     keep their rendering inside the closure provided to Winit.
+    ///   For portability it's strongly recommended that applications should
+    ///   keep their rendering inside the closure provided to Winit.
     /// - Any lifecycle events, such as `Suspended` / `Resumed`.
     ///
-    ///     The handling of these events needs to be synchronized with the
-    ///     operating system and it would never be appropriate to buffer a
-    ///     notification that your application has been suspended or resumed and
-    ///     then handled that later since there would always be a chance that
-    ///     other lifecycle events occur while the event is buffered.
+    ///   The handling of these events needs to be synchronized with the
+    ///   operating system and it would never be appropriate to buffer a
+    ///   notification that your application has been suspended or resumed and
+    ///   then handled that later since there would always be a chance that
+    ///   other lifecycle events occur while the event is buffered.
     ///
     /// ## Supported Platforms
     ///

src/platform/run_on_demand.rs

@@ -1,14 +1,16 @@
 use crate::application::ApplicationHandler;
 use crate::error::EventLoopError;
-use crate::event_loop::{ActiveEventLoop, EventLoop};
+use crate::event_loop::EventLoop;
 #[cfg(doc)]
-use crate::{platform::pump_events::EventLoopExtPumpEvents, window::Window};
+use crate::{
+    event_loop::ActiveEventLoop, platform::pump_events::EventLoopExtPumpEvents, window::Window,
+};
 
 /// Additional methods on [`EventLoop`] to return control flow to the caller.
 pub trait EventLoopExtRunOnDemand {
     /// Run the application with the event loop on the calling thread.
     ///
-    /// Unlike [`EventLoop::run`], this function accepts non-`'static` (i.e. non-`move`)
+    /// Unlike [`EventLoop::run_app`], this function accepts non-`'static` (i.e. non-`move`)
     /// closures and it is possible to return control back to the caller without
     /// consuming the `EventLoop` (by using [`exit()`]) and
     /// so the event loop can be re-run after it has exit.
@@ -21,7 +23,7 @@ pub trait EventLoopExtRunOnDemand {
     /// to while maintaining the full state of your application. (If you need something like this
     /// you can look at the [`EventLoopExtPumpEvents::pump_app_events()`] API)
     ///
-    /// Each time `run_on_demand` is called the startup sequence of `init`, followed by
+    /// Each time `run_app_on_demand` is called the startup sequence of `init`, followed by
     /// `resume` is being preserved.
     ///
     /// See the [`set_control_flow()`] docs on how to change the event loop's behavior.
@@ -31,14 +33,14 @@ pub trait EventLoopExtRunOnDemand {
     ///   to the caller (specifically this is impossible on iOS and Web - though with the Web
     ///   backend it is possible to use
     #[cfg_attr(
-        any(web_platform, docsrs),
+        web_platform,
         doc = "  [`EventLoopExtWeb::spawn_app()`][crate::platform::web::EventLoopExtWeb::spawn_app()]"
     )]
-    #[cfg_attr(not(any(web_platform, docsrs)), doc = "  `EventLoopExtWeb::spawn_app()`")]
+    #[cfg_attr(not(web_platform), doc = "  `EventLoopExtWeb::spawn_app()`")]
     ///   [^1] more than once instead).
     /// - No [`Window`] state can be carried between separate runs of the event loop.
     ///
-    /// You are strongly encouraged to use [`EventLoop::run()`] for portability, unless you
+    /// You are strongly encouraged to use [`EventLoop::run_app()`] for portability, unless you
     /// specifically need the ability to re-run a single event loop more than once
     ///
     /// # Supported Platforms
@@ -58,18 +60,12 @@ pub trait EventLoopExtRunOnDemand {
     ///
     /// [`exit()`]: ActiveEventLoop::exit()
     /// [`set_control_flow()`]: ActiveEventLoop::set_control_flow()
-    fn run_on_demand<A: ApplicationHandler>(
-        &mut self,
-        init_closure: impl FnOnce(&dyn ActiveEventLoop) -> A,
-    ) -> Result<(), EventLoopError>;
+    fn run_app_on_demand<A: ApplicationHandler>(&mut self, app: A) -> Result<(), EventLoopError>;
 }
 
 impl EventLoopExtRunOnDemand for EventLoop {
-    fn run_on_demand<A: ApplicationHandler>(
-        &mut self,
-        init_closure: impl FnOnce(&dyn ActiveEventLoop) -> A,
-    ) -> Result<(), EventLoopError> {
-        self.event_loop.run_on_demand(init_closure)
+    fn run_app_on_demand<A: ApplicationHandler>(&mut self, app: A) -> Result<(), EventLoopError> {
+        self.event_loop.run_app_on_demand(app)
     }
 }
 

src/platform/startup_notify.rs

@@ -65,9 +65,9 @@ impl EventLoopExtStartupNotify for dyn ActiveEventLoop + '_ {
         let _is_wayland = self.is_wayland();
 
         if _is_wayland {
-            env::var(WAYLAND_VAR).ok().map(ActivationToken::_new)
+            env::var(WAYLAND_VAR).ok().map(ActivationToken::from_raw)
         } else {
-            env::var(X11_VAR).ok().map(ActivationToken::_new)
+            env::var(X11_VAR).ok().map(ActivationToken::from_raw)
         }
     }
 }
@@ -75,15 +75,12 @@ impl EventLoopExtStartupNotify for dyn ActiveEventLoop + '_ {
 impl WindowExtStartupNotify for dyn Window + '_ {
     fn request_activation_token(&self) -> Result<AsyncRequestSerial, RequestError> {
         #[cfg(wayland_platform)]
-        if let Some(window) = self.as_any().downcast_ref::<crate::platform_impl::wayland::Window>()
-        {
+        if let Some(window) = self.cast_ref::<crate::platform_impl::wayland::Window>() {
             return window.request_activation_token();
         }
 
         #[cfg(x11_platform)]
-        if let Some(window) =
-            self.as_any().downcast_ref::<crate::platform_impl::x11::window::Window>()
-        {
+        if let Some(window) = self.cast_ref::<crate::platform_impl::x11::window::Window>() {
             return window.request_activation_token();
         }
 
@@ -111,6 +108,6 @@ pub fn reset_activation_token_env() {
 ///
 /// This could be used before running daemon processes.
 pub fn set_activation_token_env(token: ActivationToken) {
-    env::set_var(X11_VAR, &token._token);
-    env::set_var(WAYLAND_VAR, token._token);
+    env::set_var(X11_VAR, &token.token);
+    env::set_var(WAYLAND_VAR, token.token);
 }

src/platform/wayland.rs

@@ -13,8 +13,12 @@
 //! * `wayland-csd-adwaita` (default).
 //! * `wayland-csd-adwaita-crossfont`.
 //! * `wayland-csd-adwaita-notitle`.
+
+use std::ffi::c_void;
+use std::ptr::NonNull;
+
 use crate::event_loop::{ActiveEventLoop, EventLoop, EventLoopBuilder};
-use crate::monitor::MonitorHandle;
+use crate::platform_impl::wayland::Window;
 pub use crate::window::Theme;
 use crate::window::{Window as CoreWindow, WindowAttributes};
 
@@ -27,7 +31,7 @@ pub trait ActiveEventLoopExtWayland {
 impl ActiveEventLoopExtWayland for dyn ActiveEventLoop + '_ {
     #[inline]
     fn is_wayland(&self) -> bool {
-        self.as_any().downcast_ref::<crate::platform_impl::wayland::ActiveEventLoop>().is_some()
+        self.cast_ref::<crate::platform_impl::wayland::ActiveEventLoop>().is_some()
     }
 }
 
@@ -73,9 +77,17 @@ impl EventLoopBuilderExtWayland for EventLoopBuilder {
 /// Additional methods on [`Window`] that are specific to Wayland.
 ///
 /// [`Window`]: crate::window::Window
-pub trait WindowExtWayland {}
+pub trait WindowExtWayland {
+    /// Returns `xdg_toplevel` of the window or [`None`] if the window is X11 window.
+    fn xdg_toplevel(&self) -> Option<NonNull<c_void>>;
+}
 
-impl WindowExtWayland for dyn CoreWindow + '_ {}
+impl WindowExtWayland for dyn CoreWindow + '_ {
+    #[inline]
+    fn xdg_toplevel(&self) -> Option<NonNull<c_void>> {
+        self.cast_ref::<Window>()?.xdg_toplevel()
+    }
+}
 
 /// Additional methods on [`WindowAttributes`] that are specific to Wayland.
 pub trait WindowAttributesExtWayland {
@@ -97,16 +109,3 @@ impl WindowAttributesExtWayland for WindowAttributes {
         self
     }
 }
-
-/// Additional methods on `MonitorHandle` that are specific to Wayland.
-pub trait MonitorHandleExtWayland {
-    /// Returns the inner identifier of the monitor.
-    fn native_id(&self) -> u32;
-}
-
-impl MonitorHandleExtWayland for MonitorHandle {
-    #[inline]
-    fn native_id(&self) -> u32 {
-        self.inner.native_identifier()
-    }
-}

src/platform/web.rs

@@ -46,8 +46,8 @@ use std::error::Error;
 use std::fmt::{self, Display, Formatter};
 use std::future::Future;
 use std::pin::Pin;
+use std::sync::Arc;
 use std::task::{Context, Poll};
-use std::time::Duration;
 
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
@@ -58,8 +58,8 @@ use crate::application::ApplicationHandler;
 use crate::cursor::CustomCursorSource;
 use crate::error::NotSupportedError;
 use crate::event_loop::{ActiveEventLoop, EventLoop};
-use crate::monitor::MonitorHandle;
-use crate::platform_impl::PlatformCustomCursorSource;
+use crate::monitor::MonitorHandleProvider;
+use crate::platform_impl::MonitorHandle as WebMonitorHandle;
 #[cfg(web_platform)]
 use crate::platform_impl::{
     CustomCursorFuture as PlatformCustomCursorFuture,
@@ -105,29 +105,23 @@ pub trait WindowExtWeb {
 impl WindowExtWeb for dyn Window + '_ {
     #[inline]
     fn canvas(&self) -> Option<Ref<'_, HtmlCanvasElement>> {
-        self.as_any()
-            .downcast_ref::<crate::platform_impl::Window>()
-            .expect("non Web window on Web")
-            .canvas()
+        self.cast_ref::<crate::platform_impl::Window>().expect("non Web window on Web").canvas()
     }
 
     fn prevent_default(&self) -> bool {
-        self.as_any()
-            .downcast_ref::<crate::platform_impl::Window>()
+        self.cast_ref::<crate::platform_impl::Window>()
             .expect("non Web window on Web")
             .prevent_default()
     }
 
     fn set_prevent_default(&self, prevent_default: bool) {
-        self.as_any()
-            .downcast_ref::<crate::platform_impl::Window>()
+        self.cast_ref::<crate::platform_impl::Window>()
             .expect("non Web window on Web")
             .set_prevent_default(prevent_default)
     }
 
     fn is_cursor_lock_raw(&self) -> bool {
-        self.as_any()
-            .downcast_ref::<crate::platform_impl::Window>()
+        self.cast_ref::<crate::platform_impl::Window>()
             .expect("non Web window on Web")
             .is_cursor_lock_raw()
     }
@@ -190,10 +184,10 @@ pub trait EventLoopExtWeb {
     /// Initializes the winit event loop.
     ///
     /// Unlike
-    #[cfg_attr(all(web_platform, target_feature = "exception-handling"), doc = "`run()`")]
+    #[cfg_attr(all(web_platform, target_feature = "exception-handling"), doc = "`run_app()`")]
     #[cfg_attr(
         not(all(web_platform, target_feature = "exception-handling")),
-        doc = "[`run()`]"
+        doc = "[`run_app()`]"
     )]
     /// [^1], this returns immediately, and doesn't throw an exception in order to
     /// satisfy its [`!`] return type.
@@ -206,9 +200,9 @@ pub trait EventLoopExtWeb {
     ///
     #[cfg_attr(
         not(all(web_platform, target_feature = "exception-handling")),
-        doc = "[`run()`]: EventLoop::run()"
+        doc = "[`run_app()`]: EventLoop::run_app()"
     )]
-    /// [^1]: `run()` is _not_ available on Wasm when the target supports `exception-handling`.
+    /// [^1]: `run_app()` is _not_ available on Wasm when the target supports `exception-handling`.
     fn spawn_app<A: ApplicationHandler + 'static>(self, app: A);
 
     /// Sets the strategy for [`ControlFlow::Poll`].
@@ -253,12 +247,18 @@ pub trait EventLoopExtWeb {
     ///
     /// [`MonitorHandle`]s don't automatically make use of this after permission is granted. New
     /// [`MonitorHandle`]s have to be created instead.
+    ///
+    /// [`MonitorHandle`]: crate::monitor::MonitorHandle
     fn request_detailed_monitor_permission(&self) -> MonitorPermissionFuture;
 
     /// Returns whether the user has given permission to access detailed monitor information.
     ///
     /// [`MonitorHandle`]s don't automatically make use of detailed monitor information after
     /// permission is granted. New [`MonitorHandle`]s have to be created instead.
+    ///
+    /// [`MonitorHandle`]: crate::monitor::MonitorHandle
+    ///
+    /// [`MonitorHandle`]: crate::monitor::MonitorHandle
     fn has_detailed_monitor_permission(&self) -> HasMonitorPermissionFuture;
 }
 
@@ -348,12 +348,16 @@ pub trait ActiveEventLoopExtWeb {
     ///
     /// [`MonitorHandle`]s don't automatically make use of this after permission is granted. New
     /// [`MonitorHandle`]s have to be created instead.
+    ///
+    /// [`MonitorHandle`]: crate::monitor::MonitorHandle
     fn request_detailed_monitor_permission(&self) -> MonitorPermissionFuture;
 
     /// Returns whether the user has given permission to access detailed monitor information.
     ///
     /// [`MonitorHandle`]s don't automatically make use of detailed monitor information after
     /// permission is granted. New [`MonitorHandle`]s have to be created instead.
+    ///
+    /// [`MonitorHandle`]: crate::monitor::MonitorHandle
     fn has_detailed_monitor_permission(&self) -> bool;
 }
 
@@ -361,8 +365,7 @@ impl ActiveEventLoopExtWeb for dyn ActiveEventLoop + '_ {
     #[inline]
     fn create_custom_cursor_async(&self, source: CustomCursorSource) -> CustomCursorFuture {
         let event_loop = self
-            .as_any()
-            .downcast_ref::<crate::platform_impl::ActiveEventLoop>()
+            .cast_ref::<crate::platform_impl::ActiveEventLoop>()
             .expect("non Web event loop on Web");
         event_loop.create_custom_cursor_async(source)
     }
@@ -370,8 +373,7 @@ impl ActiveEventLoopExtWeb for dyn ActiveEventLoop + '_ {
     #[inline]
     fn set_poll_strategy(&self, strategy: PollStrategy) {
         let event_loop = self
-            .as_any()
-            .downcast_ref::<crate::platform_impl::ActiveEventLoop>()
+            .cast_ref::<crate::platform_impl::ActiveEventLoop>()
             .expect("non Web event loop on Web");
         event_loop.set_poll_strategy(strategy);
     }
@@ -379,8 +381,7 @@ impl ActiveEventLoopExtWeb for dyn ActiveEventLoop + '_ {
     #[inline]
     fn poll_strategy(&self) -> PollStrategy {
         let event_loop = self
-            .as_any()
-            .downcast_ref::<crate::platform_impl::ActiveEventLoop>()
+            .cast_ref::<crate::platform_impl::ActiveEventLoop>()
             .expect("non Web event loop on Web");
         event_loop.poll_strategy()
     }
@@ -388,8 +389,7 @@ impl ActiveEventLoopExtWeb for dyn ActiveEventLoop + '_ {
     #[inline]
     fn set_wait_until_strategy(&self, strategy: WaitUntilStrategy) {
         let event_loop = self
-            .as_any()
-            .downcast_ref::<crate::platform_impl::ActiveEventLoop>()
+            .cast_ref::<crate::platform_impl::ActiveEventLoop>()
             .expect("non Web event loop on Web");
         event_loop.set_wait_until_strategy(strategy);
     }
@@ -397,8 +397,7 @@ impl ActiveEventLoopExtWeb for dyn ActiveEventLoop + '_ {
     #[inline]
     fn wait_until_strategy(&self) -> WaitUntilStrategy {
         let event_loop = self
-            .as_any()
-            .downcast_ref::<crate::platform_impl::ActiveEventLoop>()
+            .cast_ref::<crate::platform_impl::ActiveEventLoop>()
             .expect("non Web event loop on Web");
         event_loop.wait_until_strategy()
     }
@@ -406,8 +405,7 @@ impl ActiveEventLoopExtWeb for dyn ActiveEventLoop + '_ {
     #[inline]
     fn is_cursor_lock_raw(&self) -> bool {
         let event_loop = self
-            .as_any()
-            .downcast_ref::<crate::platform_impl::ActiveEventLoop>()
+            .cast_ref::<crate::platform_impl::ActiveEventLoop>()
             .expect("non Web event loop on Web");
         event_loop.is_cursor_lock_raw()
     }
@@ -415,8 +413,7 @@ impl ActiveEventLoopExtWeb for dyn ActiveEventLoop + '_ {
     #[inline]
     fn has_multiple_screens(&self) -> Result<bool, NotSupportedError> {
         let event_loop = self
-            .as_any()
-            .downcast_ref::<crate::platform_impl::ActiveEventLoop>()
+            .cast_ref::<crate::platform_impl::ActiveEventLoop>()
             .expect("non Web event loop on Web");
         event_loop.has_multiple_screens()
     }
@@ -424,8 +421,7 @@ impl ActiveEventLoopExtWeb for dyn ActiveEventLoop + '_ {
     #[inline]
     fn request_detailed_monitor_permission(&self) -> MonitorPermissionFuture {
         let event_loop = self
-            .as_any()
-            .downcast_ref::<crate::platform_impl::ActiveEventLoop>()
+            .cast_ref::<crate::platform_impl::ActiveEventLoop>()
             .expect("non Web event loop on Web");
         MonitorPermissionFuture(event_loop.request_detailed_monitor_permission())
     }
@@ -433,8 +429,7 @@ impl ActiveEventLoopExtWeb for dyn ActiveEventLoop + '_ {
     #[inline]
     fn has_detailed_monitor_permission(&self) -> bool {
         let event_loop = self
-            .as_any()
-            .downcast_ref::<crate::platform_impl::ActiveEventLoop>()
+            .cast_ref::<crate::platform_impl::ActiveEventLoop>()
             .expect("non Web event loop on Web");
         event_loop.has_detailed_monitor_permission()
     }
@@ -491,73 +486,6 @@ pub enum WaitUntilStrategy {
     Worker,
 }
 
-pub trait CustomCursorExtWeb {
-    /// Returns if this cursor is an animation.
-    fn is_animation(&self) -> bool;
-
-    /// Creates a new cursor from a URL pointing to an image.
-    /// It uses the [url css function](https://developer.mozilla.org/en-US/docs/Web/CSS/url),
-    /// but browser support for image formats is inconsistent. Using [PNG] is recommended.
-    ///
-    /// [PNG]: https://en.wikipedia.org/wiki/PNG
-    fn from_url(url: String, hotspot_x: u16, hotspot_y: u16) -> CustomCursorSource;
-
-    /// Crates a new animated cursor from multiple [`CustomCursor`]s.
-    /// Supplied `cursors` can't be empty or other animations.
-    fn from_animation(
-        duration: Duration,
-        cursors: Vec<CustomCursor>,
-    ) -> Result<CustomCursorSource, BadAnimation>;
-}
-
-impl CustomCursorExtWeb for CustomCursor {
-    fn is_animation(&self) -> bool {
-        self.inner.animation
-    }
-
-    fn from_url(url: String, hotspot_x: u16, hotspot_y: u16) -> CustomCursorSource {
-        CustomCursorSource { inner: PlatformCustomCursorSource::Url { url, hotspot_x, hotspot_y } }
-    }
-
-    fn from_animation(
-        duration: Duration,
-        cursors: Vec<CustomCursor>,
-    ) -> Result<CustomCursorSource, BadAnimation> {
-        if cursors.is_empty() {
-            return Err(BadAnimation::Empty);
-        }
-
-        if cursors.iter().any(CustomCursor::is_animation) {
-            return Err(BadAnimation::Animation);
-        }
-
-        Ok(CustomCursorSource {
-            inner: PlatformCustomCursorSource::Animation { duration, cursors },
-        })
-    }
-}
-
-/// An error produced when using [`CustomCursor::from_animation`] with invalid arguments.
-#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
-#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-pub enum BadAnimation {
-    /// Produced when no cursors were supplied.
-    Empty,
-    /// Produced when a supplied cursor is an animation.
-    Animation,
-}
-
-impl fmt::Display for BadAnimation {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            Self::Empty => write!(f, "No cursors supplied"),
-            Self::Animation => write!(f, "A supplied cursor is an animation"),
-        }
-    }
-}
-
-impl Error for BadAnimation {}
-
 #[cfg(not(web_platform))]
 struct PlatformCustomCursorFuture;
 
@@ -568,7 +496,7 @@ impl Future for CustomCursorFuture {
     type Output = Result<CustomCursor, CustomCursorError>;
 
     fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-        Pin::new(&mut self.0).poll(cx).map_ok(|cursor| CustomCursor { inner: cursor })
+        Pin::new(&mut self.0).poll(cx).map_ok(|cursor| CustomCursor(Arc::new(cursor)))
     }
 }
 
@@ -650,6 +578,8 @@ impl Future for HasMonitorPermissionFuture {
 }
 
 /// Additional methods on [`MonitorHandle`] that are specific to the Web.
+///
+/// [`MonitorHandle`]: crate::monitor::MonitorHandle
 pub trait MonitorHandleExtWeb {
     /// Returns whether the screen is internal to the device or external.
     ///
@@ -677,28 +607,31 @@ pub trait MonitorHandleExtWeb {
     /// specific monitor.
     ///
     /// See [`ActiveEventLoopExtWeb::request_detailed_monitor_permission()`].
+    ///
+    /// [`MonitorHandle`]: crate::monitor::MonitorHandle
     fn is_detailed(&self) -> bool;
 }
 
-impl MonitorHandleExtWeb for MonitorHandle {
+impl MonitorHandleExtWeb for dyn MonitorHandleProvider + '_ {
     fn is_internal(&self) -> Option<bool> {
-        self.inner.is_internal()
+        self.cast_ref::<WebMonitorHandle>().unwrap().is_internal()
     }
 
     fn orientation(&self) -> OrientationData {
-        self.inner.orientation()
+        self.cast_ref::<WebMonitorHandle>().unwrap().orientation()
     }
 
     fn request_lock(&self, orientation_lock: OrientationLock) -> OrientationLockFuture {
-        OrientationLockFuture(self.inner.request_lock(orientation_lock))
+        let future = self.cast_ref::<WebMonitorHandle>().unwrap().request_lock(orientation_lock);
+        OrientationLockFuture(future)
     }
 
     fn unlock(&self) -> Result<(), OrientationLockError> {
-        self.inner.unlock()
+        self.cast_ref::<WebMonitorHandle>().unwrap().unlock()
     }
 
     fn is_detailed(&self) -> bool {
-        self.inner.is_detailed()
+        self.cast_ref::<WebMonitorHandle>().unwrap().is_detailed()
     }
 }
 

src/platform/windows.rs

@@ -6,6 +6,7 @@ use std::borrow::Borrow;
 use std::ffi::c_void;
 use std::ops::Deref;
 use std::path::Path;
+use std::sync::Arc;
 
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
@@ -15,15 +16,16 @@ use windows_sys::Win32::Foundation::HANDLE;
 use crate::dpi::PhysicalSize;
 use crate::event::DeviceId;
 use crate::event_loop::EventLoopBuilder;
-use crate::monitor::MonitorHandle;
-use crate::window::{BadIcon, Icon, Window, WindowAttributes};
+use crate::icon::BadIcon;
+use crate::platform_impl::RaiiIcon;
+use crate::window::{Icon, Window, WindowAttributes};
 
 /// Window Handle type used by Win32 API
-pub type HWND = isize;
+pub type HWND = *mut c_void;
 /// Menu Handle type used by Win32 API
-pub type HMENU = isize;
+pub type HMENU = *mut c_void;
 /// Monitor Handle type used by Win32 API
-pub type HMONITOR = isize;
+pub type HMONITOR = *mut c_void;
 
 /// Describes a system-drawn backdrop material of a window.
 ///
@@ -344,37 +346,37 @@ pub trait WindowExtWindows {
 impl WindowExtWindows for dyn Window + '_ {
     #[inline]
     fn set_enable(&self, enabled: bool) {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.set_enable(enabled)
     }
 
     #[inline]
     fn set_taskbar_icon(&self, taskbar_icon: Option<Icon>) {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.set_taskbar_icon(taskbar_icon)
     }
 
     #[inline]
     fn set_skip_taskbar(&self, skip: bool) {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.set_skip_taskbar(skip)
     }
 
     #[inline]
     fn set_undecorated_shadow(&self, shadow: bool) {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.set_undecorated_shadow(shadow)
     }
 
     #[inline]
     fn set_system_backdrop(&self, backdrop_type: BackdropType) {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.set_system_backdrop(backdrop_type)
     }
 
     #[inline]
     fn set_border_color(&self, color: Option<Color>) {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.set_border_color(color.unwrap_or(Color::NONE))
     }
 
@@ -383,26 +385,26 @@ impl WindowExtWindows for dyn Window + '_ {
         // The windows docs don't mention NONE as a valid options but it works in practice and is
         // useful to circumvent the Windows option "Show accent color on title bars and
         // window borders"
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.set_title_background_color(color.unwrap_or(Color::NONE))
     }
 
     #[inline]
     fn set_title_text_color(&self, color: Color) {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.set_title_text_color(color)
     }
 
     #[inline]
     fn set_corner_preference(&self, preference: CornerPreference) {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         window.set_corner_preference(preference)
     }
 
     unsafe fn window_handle_any_thread(
         &self,
     ) -> Result<rwh_06::WindowHandle<'_>, rwh_06::HandleError> {
-        let window = self.as_any().downcast_ref::<crate::platform_impl::Window>().unwrap();
+        let window = self.cast_ref::<crate::platform_impl::Window>().unwrap();
         unsafe {
             let handle = window.rwh_06_no_thread_check()?;
 
@@ -618,27 +620,6 @@ impl WindowAttributesExtWindows for WindowAttributes {
     }
 }
 
-/// Additional methods on `MonitorHandle` that are specific to Windows.
-pub trait MonitorHandleExtWindows {
-    /// Returns the name of the monitor adapter specific to the Win32 API.
-    fn native_id(&self) -> String;
-
-    /// Returns the handle of the monitor - `HMONITOR`.
-    fn hmonitor(&self) -> HMONITOR;
-}
-
-impl MonitorHandleExtWindows for MonitorHandle {
-    #[inline]
-    fn native_id(&self) -> String {
-        self.inner.native_identifier()
-    }
-
-    #[inline]
-    fn hmonitor(&self) -> HMONITOR {
-        self.inner.hmonitor()
-    }
-}
-
 /// Additional methods on `DeviceId` that are specific to Windows.
 pub trait DeviceIdExtWindows {
     /// Returns an identifier that persistently refers to this specific device.
@@ -659,8 +640,24 @@ impl DeviceIdExtWindows for DeviceId {
     }
 }
 
-/// Additional methods on `Icon` that are specific to Windows.
-pub trait IconExtWindows: Sized {
+/// Windows specific `Icon`.
+///
+/// Windows icons can be created from files, or from the [`embedded resources`](https://learn.microsoft.com/en-us/windows/win32/menurc/about-resource-files).
+///
+/// The `ICON` resource definition statement use the following syntax:
+/// ```rc
+/// nameID ICON filename
+/// ```
+/// `nameID` is a unique name or a 16-bit unsigned integer value identifying the resource,
+/// `filename` is the name of the file that contains the resource.
+///
+/// More information about the `ICON` resource can be found at [`Microsoft Learn`](https://learn.microsoft.com/en-us/windows/win32/menurc/icon-resource) portal.
+#[derive(Clone, PartialEq, Eq, Hash)]
+pub struct WinIcon {
+    pub(crate) inner: Arc<RaiiIcon>,
+}
+
+impl WinIcon {
     /// Create an icon from a file path.
     ///
     /// Specify `size` to load a specific icon size from the file, or `None` to load the default
@@ -668,30 +665,88 @@ pub trait IconExtWindows: Sized {
     ///
     /// In cases where the specified size does not exist in the file, Windows may perform scaling
     /// to get an icon of the desired size.
-    fn from_path<P: AsRef<Path>>(path: P, size: Option<PhysicalSize<u32>>)
-        -> Result<Self, BadIcon>;
+    pub fn from_path<P: AsRef<Path>>(
+        path: P,
+        size: Option<PhysicalSize<u32>>,
+    ) -> Result<Self, BadIcon> {
+        Self::from_path_impl(path, size)
+    }
 
-    /// Create an icon from a resource embedded in this executable or library.
+    /// Create an icon from a resource embedded in this executable or library by its ordinal id.
+    ///
+    /// The valid `ordinal` values range from 1 to [`u16::MAX`] (inclusive). The value `0` is an
+    /// invalid ordinal id, but it can be used with [`from_resource_name`] as `"0"`.
+    ///
+    /// [`from_resource_name`]: Self::from_resource_name
     ///
     /// Specify `size` to load a specific icon size from the file, or `None` to load the default
     /// icon size from the file.
     ///
     /// In cases where the specified size does not exist in the file, Windows may perform scaling
     /// to get an icon of the desired size.
-    fn from_resource(ordinal: u16, size: Option<PhysicalSize<u32>>) -> Result<Self, BadIcon>;
-}
-
-impl IconExtWindows for Icon {
-    fn from_path<P: AsRef<Path>>(
-        path: P,
+    pub fn from_resource(
+        resource_id: u16,
         size: Option<PhysicalSize<u32>>,
     ) -> Result<Self, BadIcon> {
-        let win_icon = crate::platform_impl::WinIcon::from_path(path, size)?;
-        Ok(Icon { inner: win_icon })
+        Self::from_resource_impl(resource_id, size)
     }
 
-    fn from_resource(ordinal: u16, size: Option<PhysicalSize<u32>>) -> Result<Self, BadIcon> {
-        let win_icon = crate::platform_impl::WinIcon::from_resource(ordinal, size)?;
-        Ok(Icon { inner: win_icon })
+    /// Create an icon from a resource embedded in this executable or library by its name.
+    ///
+    /// Specify `size` to load a specific icon size from the file, or `None` to load the default
+    /// icon size from the file.
+    ///
+    /// In cases where the specified size does not exist in the file, Windows may perform scaling
+    /// to get an icon of the desired size.
+    ///
+    /// # Notes
+    ///
+    /// Consider the following resource definition statements:
+    /// ```rc
+    /// app     ICON "app.ico"
+    /// 1       ICON "a.ico"
+    /// 0027    ICON "custom.ico"
+    /// 0       ICON "alt.ico"
+    /// ```
+    ///
+    /// Due to some internal implementation details of the resource embedding/loading process on
+    /// Windows platform, strings that can be interpreted as 16-bit unsigned integers (`"1"`,
+    /// `"002"`, etc.) cannot be used as valid resource names, and instead should be passed into
+    /// [`from_resource`]:
+    ///
+    /// [`from_resource`]: Self::from_resource
+    ///
+    /// ```rust,no_run
+    /// use winit::platform::windows::WinIcon;
+    ///
+    /// assert!(WinIcon::from_resource_name("app", None).is_ok());
+    /// assert!(WinIcon::from_resource(1, None).is_ok());
+    /// assert!(WinIcon::from_resource(27, None).is_ok());
+    /// assert!(WinIcon::from_resource_name("27", None).is_err());
+    /// assert!(WinIcon::from_resource_name("0027", None).is_err());
+    /// ```
+    ///
+    /// While `0` cannot be used as an ordinal id (see [`from_resource`]), it can be used as a
+    /// name:
+    ///
+    /// [`from_resource`]: IconExtWindows::from_resource
+    ///
+    /// ```rust,no_run
+    /// # use winit::platform::windows::WinIcon;
+    /// # use winit::window::Icon;
+    /// assert!(WinIcon::from_resource_name("0", None).is_ok());
+    /// assert!(WinIcon::from_resource(0, None).is_err());
+    /// ```
+    pub fn from_resource_name(
+        resource_name: &str,
+        size: Option<PhysicalSize<u32>>,
+    ) -> Result<Self, BadIcon> {
+        Self::from_resource_name_impl(resource_name, size)
+    }
+}
+
+impl From<WinIcon> for Icon {
+    fn from(value: WinIcon) -> Self {
+        Self(Arc::new(value))
     }
 }

src/platform/x11.rs

@@ -4,7 +4,6 @@ use serde::{Deserialize, Serialize};
 
 use crate::dpi::Size;
 use crate::event_loop::{ActiveEventLoop, EventLoop, EventLoopBuilder};
-use crate::monitor::MonitorHandle;
 use crate::window::{Window as CoreWindow, WindowAttributes};
 
 /// X window type. Maps directly to
@@ -80,7 +79,7 @@ pub type XWindow = u32;
 #[inline]
 pub fn register_xlib_error_hook(hook: XlibErrorHook) {
     // Append new hook.
-    crate::platform_impl::XLIB_ERROR_HOOKS.lock().unwrap().push(hook);
+    crate::platform_impl::x11::XLIB_ERROR_HOOKS.lock().unwrap().push(hook);
 }
 
 /// Additional methods on [`ActiveEventLoop`] that are specific to X11.
@@ -92,7 +91,7 @@ pub trait ActiveEventLoopExtX11 {
 impl ActiveEventLoopExtX11 for dyn ActiveEventLoop + '_ {
     #[inline]
     fn is_x11(&self) -> bool {
-        self.as_any().downcast_ref::<crate::platform_impl::x11::ActiveEventLoop>().is_some()
+        self.cast_ref::<crate::platform_impl::x11::ActiveEventLoop>().is_some()
     }
 }
 
@@ -240,16 +239,3 @@ impl WindowAttributesExtX11 for WindowAttributes {
         self
     }
 }
-
-/// Additional methods on `MonitorHandle` that are specific to X11.
-pub trait MonitorHandleExtX11 {
-    /// Returns the inner identifier of the monitor.
-    fn native_id(&self) -> u32;
-}
-
-impl MonitorHandleExtX11 for MonitorHandle {
-    #[inline]
-    fn native_id(&self) -> u32 {
-        self.inner.native_identifier()
-    }
-}

src/platform_impl/android/keycodes.rs

@@ -143,8 +143,8 @@ pub fn to_physical_key(keycode: Keycode) -> PhysicalKey {
         Keycode::AltLeft => KeyCode::AltLeft,
         Keycode::AltRight => KeyCode::AltRight,
 
-        Keycode::MetaLeft => KeyCode::SuperLeft,
-        Keycode::MetaRight => KeyCode::SuperRight,
+        Keycode::MetaLeft => KeyCode::MetaLeft,
+        Keycode::MetaRight => KeyCode::MetaRight,
 
         Keycode::LeftBracket => KeyCode::BracketLeft,
         Keycode::RightBracket => KeyCode::BracketRight,
@@ -309,7 +309,7 @@ pub fn to_logical(key_char: Option<KeyMapChar>, keycode: Keycode) -> Key {
             ShiftLeft => Key::Named(NamedKey::Shift),
             ShiftRight => Key::Named(NamedKey::Shift),
             Tab => Key::Named(NamedKey::Tab),
-            Space => Key::Named(NamedKey::Space),
+            Space => Key::Character(" ".into()),
             Sym => Key::Named(NamedKey::Symbol),
             Explorer => Key::Named(NamedKey::LaunchWebBrowser),
             Envelope => Key::Named(NamedKey::LaunchMail),
@@ -340,8 +340,8 @@ pub fn to_logical(key_char: Option<KeyMapChar>, keycode: Keycode) -> Key {
             CtrlRight => Key::Named(NamedKey::Control),
             CapsLock => Key::Named(NamedKey::CapsLock),
             ScrollLock => Key::Named(NamedKey::ScrollLock),
-            MetaLeft => Key::Named(NamedKey::Super),
-            MetaRight => Key::Named(NamedKey::Super),
+            MetaLeft => Key::Named(NamedKey::Meta),
+            MetaRight => Key::Named(NamedKey::Meta),
             Function => Key::Named(NamedKey::Fn),
             Sysrq => Key::Named(NamedKey::PrintScreen),
             Break => Key::Named(NamedKey::Pause),

src/platform_impl/android/mod.rs

@@ -1,6 +1,5 @@
 use std::cell::Cell;
 use std::hash::Hash;
-use std::num::{NonZeroU16, NonZeroU32};
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::{Arc, Mutex};
 use std::time::{Duration, Instant};
@@ -21,21 +20,15 @@ use crate::event_loop::{
     EventLoopProxy as CoreEventLoopProxy, EventLoopProxyProvider,
     OwnedDisplayHandle as CoreOwnedDisplayHandle,
 };
-use crate::monitor::MonitorHandle as RootMonitorHandle;
+use crate::monitor::{Fullscreen, MonitorHandle as CoreMonitorHandle};
 use crate::platform::pump_events::PumpStatus;
 use crate::window::{
-    self, CursorGrabMode, CustomCursor, CustomCursorSource, Fullscreen, ImePurpose,
-    ResizeDirection, Theme, Window as CoreWindow, WindowAttributes, WindowButtons, WindowId,
-    WindowLevel,
+    self, CursorGrabMode, CustomCursor, CustomCursorSource, ImePurpose, ResizeDirection, Theme,
+    Window as CoreWindow, WindowAttributes, WindowButtons, WindowId, WindowLevel,
 };
 
 mod keycodes;
 
-pub(crate) use crate::cursor::{
-    NoCustomCursor as PlatformCustomCursor, NoCustomCursor as PlatformCustomCursorSource,
-};
-pub(crate) use crate::icon::NoIcon as PlatformIcon;
-
 static HAS_FOCUS: AtomicBool = AtomicBool::new(true);
 
 /// Returns the minimum `Option<Duration>`, taking into account that `None`
@@ -45,7 +38,7 @@ fn min_timeout(a: Option<Duration>, b: Option<Duration>) -> Option<Duration> {
     a.map_or(b, |a_timeout| b.map_or(Some(a_timeout), |b_timeout| Some(a_timeout.min(b_timeout))))
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 struct SharedFlagSetter {
     flag: Arc<AtomicBool>,
 }
@@ -55,6 +48,7 @@ impl SharedFlagSetter {
     }
 }
 
+#[derive(Debug)]
 struct SharedFlag {
     flag: Arc<AtomicBool>,
 }
@@ -83,6 +77,12 @@ pub struct RedrawRequester {
     waker: AndroidAppWaker,
 }
 
+impl fmt::Debug for RedrawRequester {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("RedrawRequester").field("flag", &self.flag).finish_non_exhaustive()
+    }
+}
+
 impl RedrawRequester {
     fn new(flag: &SharedFlag, waker: AndroidAppWaker) -> Self {
         RedrawRequester { flag: flag.setter(), waker }
@@ -97,9 +97,7 @@ impl RedrawRequester {
     }
 }
 
-#[derive(Debug, Clone, Eq, PartialEq, Hash)]
-pub struct KeyEventExtra {}
-
+#[derive(Debug)]
 pub struct EventLoop {
     pub(crate) android_app: AndroidApp,
     window_target: ActiveEventLoop,
@@ -479,7 +477,8 @@ impl EventLoop {
                                 location: keycodes::to_location(keycode),
                                 repeat: key.repeat_count() > 0,
                                 text: None,
-                                platform_specific: KeyEventExtra {},
+                                text_with_all_modifiers: None,
+                                key_without_modifiers: keycodes::to_logical(key_char, keycode),
                             },
                             is_synthetic: false,
                         };
@@ -496,21 +495,15 @@ impl EventLoop {
         input_status
     }
 
-    pub fn run<A: ApplicationHandler>(
-        mut self,
-        init_closure: impl FnOnce(&dyn RootActiveEventLoop) -> A,
-    ) -> Result<(), EventLoopError> {
-        self.run_on_demand(init_closure)
+    pub fn run_app<A: ApplicationHandler>(mut self, app: A) -> Result<(), EventLoopError> {
+        self.run_app_on_demand(app)
     }
 
-    pub fn run_on_demand<A: ApplicationHandler>(
+    pub fn run_app_on_demand<A: ApplicationHandler>(
         &mut self,
-        init_closure: impl FnOnce(&dyn RootActiveEventLoop) -> A,
+        mut app: A,
     ) -> Result<(), EventLoopError> {
         self.window_target.clear_exit();
-
-        let mut app = init_closure(&self.window_target);
-
         loop {
             match self.pump_app_events(None, &mut app) {
                 PumpStatus::Exit(0) => {
@@ -646,6 +639,12 @@ pub struct EventLoopProxy {
     waker: AndroidAppWaker,
 }
 
+impl fmt::Debug for EventLoopProxy {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("EventLoopProxy").field("wake_up", &self.wake_up).finish_non_exhaustive()
+    }
+}
+
 impl EventLoopProxy {
     fn new(waker: AndroidAppWaker) -> Self {
         Self { wake_up: AtomicBool::new(false), waker }
@@ -659,6 +658,7 @@ impl EventLoopProxyProvider for EventLoopProxy {
     }
 }
 
+#[derive(Debug)]
 pub struct ActiveEventLoop {
     pub(crate) app: AndroidApp,
     control_flow: Cell<ControlFlow>,
@@ -692,11 +692,11 @@ impl RootActiveEventLoop for ActiveEventLoop {
         Err(NotSupportedError::new("create_custom_cursor is not supported").into())
     }
 
-    fn available_monitors(&self) -> Box<dyn Iterator<Item = RootMonitorHandle>> {
+    fn available_monitors(&self) -> Box<dyn Iterator<Item = CoreMonitorHandle>> {
         Box::new(std::iter::empty())
     }
 
-    fn primary_monitor(&self) -> Option<RootMonitorHandle> {
+    fn primary_monitor(&self) -> Option<CoreMonitorHandle> {
         None
     }
 
@@ -751,6 +751,7 @@ impl rwh_06::HasDisplayHandle for OwnedDisplayHandle {
 #[derive(Clone, Copy, Debug, Default, Eq, PartialEq)]
 pub struct PlatformSpecificWindowAttributes;
 
+#[derive(Debug)]
 pub(crate) struct Window {
     app: AndroidApp,
     redraw_requester: RedrawRequester,
@@ -815,15 +816,15 @@ impl CoreWindow for Window {
         GLOBAL_WINDOW
     }
 
-    fn primary_monitor(&self) -> Option<RootMonitorHandle> {
+    fn primary_monitor(&self) -> Option<CoreMonitorHandle> {
         None
     }
 
-    fn available_monitors(&self) -> Box<dyn Iterator<Item = RootMonitorHandle>> {
+    fn available_monitors(&self) -> Box<dyn Iterator<Item = CoreMonitorHandle>> {
         Box::new(std::iter::empty())
     }
 
-    fn current_monitor(&self) -> Option<RootMonitorHandle> {
+    fn current_monitor(&self) -> Option<CoreMonitorHandle> {
         None
     }
 
@@ -1009,52 +1010,6 @@ impl Display for OsError {
     }
 }
 
-#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub struct MonitorHandle;
-
-impl MonitorHandle {
-    pub fn name(&self) -> Option<String> {
-        unreachable!()
-    }
-
-    pub fn position(&self) -> Option<PhysicalPosition<i32>> {
-        unreachable!()
-    }
-
-    pub fn scale_factor(&self) -> f64 {
-        unreachable!()
-    }
-
-    pub fn current_video_mode(&self) -> Option<VideoModeHandle> {
-        unreachable!()
-    }
-
-    pub fn video_modes(&self) -> std::iter::Empty<VideoModeHandle> {
-        unreachable!()
-    }
-}
-
-#[derive(Clone, Debug, Eq, Hash, PartialEq)]
-pub struct VideoModeHandle;
-
-impl VideoModeHandle {
-    pub fn size(&self) -> PhysicalSize<u32> {
-        unreachable!()
-    }
-
-    pub fn bit_depth(&self) -> Option<NonZeroU16> {
-        unreachable!()
-    }
-
-    pub fn refresh_rate_millihertz(&self) -> Option<NonZeroU32> {
-        unreachable!()
-    }
-
-    pub fn monitor(&self) -> MonitorHandle {
-        unreachable!()
-    }
-}
-
 fn screen_size(app: &AndroidApp) -> PhysicalSize<u32> {
     if let Some(native_window) = app.native_window() {
         PhysicalSize::new(native_window.width() as _, native_window.height() as _)

src/platform_impl/apple/appkit/app.rs

@@ -1,51 +1,101 @@
 #![allow(clippy::unnecessary_cast)]
 
+use std::cell::Cell;
+use std::mem;
 use std::rc::Rc;
 
-use objc2::{declare_class, msg_send, mutability, ClassType, DeclaredClass};
-use objc2_app_kit::{NSApplication, NSEvent, NSEventModifierFlags, NSEventType, NSResponder};
-use objc2_foundation::{MainThreadMarker, NSObject};
+use dispatch2::MainThreadBound;
+use objc2::runtime::{Imp, Sel};
+use objc2::sel;
+use objc2_app_kit::{NSApplication, NSEvent, NSEventModifierFlags, NSEventType};
+use objc2_foundation::MainThreadMarker;
 
 use super::app_state::AppState;
 use crate::event::{DeviceEvent, ElementState};
 
-declare_class!(
-    pub(super) struct WinitApplication;
+type SendEvent = extern "C-unwind" fn(&NSApplication, Sel, &NSEvent);
 
-    unsafe impl ClassType for WinitApplication {
-        #[inherits(NSResponder, NSObject)]
-        type Super = NSApplication;
-        type Mutability = mutability::MainThreadOnly;
-        const NAME: &'static str = "WinitApplication";
-    }
+static ORIGINAL: MainThreadBound<Cell<Option<SendEvent>>> = {
+    // SAFETY: Creating in a `const` context, where there is no concept of the main thread.
+    MainThreadBound::new(Cell::new(None), unsafe { MainThreadMarker::new_unchecked() })
+};
 
-    impl DeclaredClass for WinitApplication {}
+extern "C-unwind" fn send_event(app: &NSApplication, sel: Sel, event: &NSEvent) {
+    let mtm = MainThreadMarker::from(app);
 
-    unsafe impl WinitApplication {
-        // Normally, holding Cmd + any key never sends us a `keyUp` event for that key.
-        // Overriding `sendEvent:` like this fixes that. (https://stackoverflow.com/a/15294196)
-        // Fun fact: Firefox still has this bug! (https://bugzilla.mozilla.org/show_bug.cgi?id=1299553)
-        #[method(sendEvent:)]
-        fn send_event(&self, event: &NSEvent) {
-            // For posterity, there are some undocumented event types
-            // (https://github.com/servo/cocoa-rs/issues/155)
-            // but that doesn't really matter here.
-            let event_type = unsafe { event.r#type() };
-            let modifier_flags = unsafe { event.modifierFlags() };
-            if event_type == NSEventType::KeyUp
-                && modifier_flags.contains(NSEventModifierFlags::NSEventModifierFlagCommand)
-            {
-                if let Some(key_window) = self.keyWindow() {
-                    key_window.sendEvent(event);
-                }
-            } else {
-                let app_state = AppState::get(MainThreadMarker::from(self));
-                maybe_dispatch_device_event(&app_state, event);
-                unsafe { msg_send![super(self), sendEvent: event] }
-            }
+    // Normally, holding Cmd + any key never sends us a `keyUp` event for that key.
+    // Overriding `sendEvent:` fixes that. (https://stackoverflow.com/a/15294196)
+    // Fun fact: Firefox still has this bug! (https://bugzilla.mozilla.org/show_bug.cgi?id=1299553)
+    //
+    // For posterity, there are some undocumented event types
+    // (https://github.com/servo/cocoa-rs/issues/155)
+    // but that doesn't really matter here.
+    let event_type = unsafe { event.r#type() };
+    let modifier_flags = unsafe { event.modifierFlags() };
+    if event_type == NSEventType::KeyUp && modifier_flags.contains(NSEventModifierFlags::Command) {
+        if let Some(key_window) = app.keyWindow() {
+            key_window.sendEvent(event);
         }
+        return;
     }
-);
+
+    // Events are generally scoped to the window level, so the best way
+    // to get device events is to listen for them on NSApplication.
+    let app_state = AppState::get(mtm);
+    maybe_dispatch_device_event(&app_state, event);
+
+    let original = ORIGINAL.get(mtm).get().expect("no existing sendEvent: handler set");
+    original(app, sel, event)
+}
+
+/// Override the [`sendEvent:`][NSApplication::sendEvent] method on the given application class.
+///
+/// The previous implementation created a subclass of [`NSApplication`], however we would like to
+/// give the user full control over their `NSApplication`, so we override the method here using
+/// method swizzling instead.
+///
+/// This _should_ also allow two versions of Winit to exist in the same application.
+///
+/// See the following links for more info on method swizzling:
+/// - <https://nshipster.com/method-swizzling/>
+/// - <https://spin.atomicobject.com/method-swizzling-objective-c/>
+/// - <https://web.archive.org/web/20130308110627/http://cocoadev.com/wiki/MethodSwizzling>
+///
+/// NOTE: This function assumes that the passed in application object is the one returned from
+/// [`NSApplication::sharedApplication`], i.e. the one and only global shared application object.
+/// For testing though, we allow it to be a different object.
+pub(crate) fn override_send_event(global_app: &NSApplication) {
+    let mtm = MainThreadMarker::from(global_app);
+    let class = global_app.class();
+
+    let method =
+        class.instance_method(sel!(sendEvent:)).expect("NSApplication must have sendEvent: method");
+
+    // SAFETY: Converting our `sendEvent:` implementation to an IMP.
+    let overridden = unsafe { mem::transmute::<SendEvent, Imp>(send_event) };
+
+    // If we've already overridden the method, don't do anything.
+    // FIXME(madsmtm): Use `std::ptr::fn_addr_eq` (Rust 1.85) once available in MSRV.
+    #[allow(unknown_lints, unpredictable_function_pointer_comparisons)]
+    if overridden == method.implementation() {
+        return;
+    }
+
+    // SAFETY: Our implementation has:
+    // 1. The same signature as `sendEvent:`.
+    // 2. Does not impose extra safety requirements on callers.
+    let original = unsafe { method.set_implementation(overridden) };
+
+    // SAFETY: This is the actual signature of `sendEvent:`.
+    let original = unsafe { mem::transmute::<Imp, SendEvent>(original) };
+
+    // NOTE: If NSApplication was safe to use from multiple threads, then this would potentially be
+    // a (checked) race-condition, since one could call `sendEvent:` before the original had been
+    // stored here.
+    //
+    // It is only usable from the main thread, however, so we're good!
+    ORIGINAL.get(mtm).set(Some(original));
+}
 
 fn maybe_dispatch_device_event(app_state: &Rc<AppState>, event: &NSEvent) {
     let event_type = unsafe { event.r#type() };
@@ -87,3 +137,52 @@ fn maybe_dispatch_device_event(app_state: &Rc<AppState>, event: &NSEvent) {
         _ => (),
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use objc2::rc::Retained;
+    use objc2::{define_class, msg_send, ClassType};
+    use objc2_app_kit::NSResponder;
+    use objc2_foundation::NSObject;
+
+    use super::*;
+
+    #[test]
+    fn test_override() {
+        // FIXME(madsmtm): Ensure this always runs (maybe use cargo-nextest or `--test-threads=1`?)
+        let Some(mtm) = MainThreadMarker::new() else { return };
+
+        // Create a new application, without making it the shared application.
+        let app = unsafe { NSApplication::new(mtm) };
+        override_send_event(&app);
+        // Test calling twice works.
+        override_send_event(&app);
+
+        // FIXME(madsmtm): Can't test this yet, need some way to mock AppState.
+        // unsafe {
+        //     let event = super::super::event::dummy_event().unwrap();
+        //     app.sendEvent(&event)
+        // }
+    }
+
+    #[test]
+    fn test_custom_class() {
+        let Some(_mtm) = MainThreadMarker::new() else { return };
+
+        define_class!(
+            #[unsafe(super(NSApplication, NSResponder, NSObject))]
+            #[name = "TestApplication"]
+            pub(super) struct TestApplication;
+
+            impl TestApplication {
+                #[unsafe(method(sendEvent:))]
+                fn send_event(&self, _event: &NSEvent) {
+                    todo!()
+                }
+            }
+        );
+
+        let app: Retained<TestApplication> = unsafe { msg_send![TestApplication::class(), new] };
+        override_send_event(&app);
+    }
+}

src/platform_impl/apple/appkit/app_state.rs

@@ -1,20 +1,22 @@
 use std::cell::{Cell, OnceCell, RefCell};
 use std::mem;
 use std::rc::{Rc, Weak};
-use std::sync::atomic::Ordering as AtomicOrdering;
 use std::sync::Arc;
 use std::time::Instant;
 
+use dispatch2::MainThreadBound;
+use objc2::MainThreadMarker;
 use objc2_app_kit::{NSApplication, NSApplicationActivationPolicy, NSRunningApplication};
-use objc2_foundation::{MainThreadMarker, NSNotification};
+use objc2_foundation::NSNotification;
 
 use super::super::event_handler::EventHandler;
-use super::event_loop::{stop_app_immediately, EventLoopProxy, PanicInfo};
+use super::super::event_loop_proxy::EventLoopProxy;
+use super::event_loop::{notify_windows_of_exit, stop_app_immediately, ActiveEventLoop, PanicInfo};
 use super::menu;
 use super::observer::{EventLoopWaker, RunLoop};
 use crate::application::ApplicationHandler;
 use crate::event::{StartCause, WindowEvent};
-use crate::event_loop::{ActiveEventLoop, ControlFlow};
+use crate::event_loop::ControlFlow;
 use crate::window::WindowId;
 
 #[derive(Debug)]
@@ -45,22 +47,10 @@ pub(super) struct AppState {
     // as such should be careful to not add fields that, in turn, strongly reference those.
 }
 
-// TODO(madsmtm): Use `MainThreadBound` once that is possible in `static`s.
-struct StaticMainThreadBound<T>(T);
-
-impl<T> StaticMainThreadBound<T> {
-    const fn get(&self, _mtm: MainThreadMarker) -> &T {
-        &self.0
-    }
-}
-
-unsafe impl<T> Send for StaticMainThreadBound<T> {}
-unsafe impl<T> Sync for StaticMainThreadBound<T> {}
-
-// SAFETY: Creating `StaticMainThreadBound` in a `const` context, where there is no concept of the
+// SAFETY: Creating `MainThreadBound` in a `const` context, where there is no concept of the
 // main thread.
-static GLOBAL: StaticMainThreadBound<OnceCell<Rc<AppState>>> =
-    StaticMainThreadBound(OnceCell::new());
+static GLOBAL: MainThreadBound<OnceCell<Rc<AppState>>> =
+    MainThreadBound::new(OnceCell::new(), unsafe { MainThreadMarker::new_unchecked() });
 
 impl AppState {
     pub(super) fn setup_global(
@@ -69,13 +59,17 @@ impl AppState {
         default_menu: bool,
         activate_ignoring_other_apps: bool,
     ) -> Rc<Self> {
-        let this = Rc::new(AppState {
+        let event_loop_proxy = Arc::new(EventLoopProxy::new(mtm, move || {
+            Self::get(mtm).with_handler(|app, event_loop| app.proxy_wake_up(event_loop));
+        }));
+
+        let this = Rc::new(Self {
             mtm,
             activation_policy,
-            event_loop_proxy: Arc::new(EventLoopProxy::new()),
             default_menu,
             activate_ignoring_other_apps,
             run_loop: RunLoop::main(mtm),
+            event_loop_proxy,
             event_handler: EventHandler::new(),
             stop_on_launch: Cell::new(false),
             stop_before_wait: Cell::new(false),
@@ -162,26 +156,20 @@ impl AppState {
 
     pub fn will_terminate(self: &Rc<Self>, _notification: &NSNotification) {
         trace_scope!("NSApplicationWillTerminateNotification");
-        // TODO: Notify every window that it will be destroyed, like done in iOS?
-        self.with_handler(|app, event_loop| {
-            app.exiting(event_loop);
-        });
+        let app = NSApplication::sharedApplication(self.mtm);
+        notify_windows_of_exit(&app);
+        self.event_handler.terminate();
         self.internal_exit();
     }
 
     /// Place the event handler in the application state for the duration
     /// of the given closure.
-    pub fn set_init_closure<A: ApplicationHandler, R>(
+    pub fn set_event_handler<R>(
         &self,
-        init_closure: impl FnOnce(&dyn ActiveEventLoop) -> A,
+        handler: impl ApplicationHandler,
         closure: impl FnOnce() -> R,
     ) -> R {
-        let init_closure = Box::new(
-            |active_event_loop: &'_ dyn ActiveEventLoop| -> Box<dyn ApplicationHandler + '_> {
-                Box::new(init_closure(active_event_loop))
-            },
-        );
-        self.event_handler.set(init_closure, closure)
+        self.event_handler.set(Box::new(handler), closure)
     }
 
     pub fn event_loop_proxy(&self) -> &Arc<EventLoopProxy> {
@@ -365,10 +353,6 @@ impl AppState {
             return;
         }
 
-        if self.event_loop_proxy.wake_up.swap(false, AtomicOrdering::Relaxed) {
-            self.with_handler(|app, event_loop| app.proxy_wake_up(event_loop));
-        }
-
         let redraw = mem::take(&mut *self.pending_redraw.borrow_mut());
         for window_id in redraw {
             self.with_handler(|app, event_loop| {
@@ -382,6 +366,7 @@ impl AppState {
         if self.exiting() {
             let app = NSApplication::sharedApplication(self.mtm);
             stop_app_immediately(&app);
+            notify_windows_of_exit(&app);
         }
 
         if self.stop_before_wait.get() {

src/platform_impl/apple/appkit/cursor.rs

@@ -4,28 +4,40 @@ use std::sync::OnceLock;
 
 use objc2::rc::Retained;
 use objc2::runtime::Sel;
-use objc2::{msg_send_id, sel, ClassType};
+use objc2::{available, msg_send, sel, AllocAnyThread, ClassType};
 use objc2_app_kit::{NSBitmapImageRep, NSCursor, NSDeviceRGBColorSpace, NSImage};
 use objc2_foundation::{
-    ns_string, NSData, NSDictionary, NSNumber, NSObject, NSObjectProtocol, NSPoint, NSSize,
-    NSString,
+    ns_string, NSData, NSDictionary, NSNumber, NSObject, NSPoint, NSSize, NSString,
 };
 
-use crate::cursor::{CursorImage, OnlyCursorImageSource};
-use crate::error::RequestError;
+use crate::cursor::{CursorImage, CustomCursorProvider, CustomCursorSource};
+use crate::error::{NotSupportedError, RequestError};
 use crate::window::CursorIcon;
 
 #[derive(Clone, Debug, PartialEq, Eq, Hash)]
 pub struct CustomCursor(pub(crate) Retained<NSCursor>);
 
+impl CustomCursorProvider for CustomCursor {
+    fn is_animated(&self) -> bool {
+        false
+    }
+}
+
 // SAFETY: NSCursor is immutable and thread-safe
 // TODO(madsmtm): Put this logic in objc2-app-kit itself
 unsafe impl Send for CustomCursor {}
 unsafe impl Sync for CustomCursor {}
 
 impl CustomCursor {
-    pub(crate) fn new(cursor: OnlyCursorImageSource) -> Result<CustomCursor, RequestError> {
-        cursor_from_image(&cursor.0).map(Self)
+    pub(crate) fn new(cursor: CustomCursorSource) -> Result<CustomCursor, RequestError> {
+        let cursor = match cursor {
+            CustomCursorSource::Image(cursor_image) => cursor_image,
+            CustomCursorSource::Animation { .. } | CustomCursorSource::Url { .. } => {
+                return Err(NotSupportedError::new("unsupported cursor kind").into())
+            },
+        };
+
+        cursor_from_image(&cursor).map(Self)
     }
 }
 
@@ -67,8 +79,8 @@ pub(crate) fn default_cursor() -> Retained<NSCursor> {
 
 unsafe fn try_cursor_from_selector(sel: Sel) -> Option<Retained<NSCursor>> {
     let cls = NSCursor::class();
-    if cls.responds_to(sel) {
-        let cursor: Retained<NSCursor> = unsafe { msg_send_id![cls, performSelector: sel] };
+    if unsafe { msg_send![cls, respondsToSelector: sel] } {
+        let cursor: Retained<NSCursor> = unsafe { msg_send![cls, performSelector: sel] };
         Some(cursor)
     } else {
         tracing::warn!("cursor `{sel}` appears to be invalid");
@@ -130,25 +142,21 @@ unsafe fn load_webkit_cursor(name: &NSString) -> Retained<NSCursor> {
     // TODO: Handle PLists better
     let info_path = cursor_path.stringByAppendingPathComponent(ns_string!("info.plist"));
     let info: Retained<NSDictionary<NSObject, NSObject>> = unsafe {
-        msg_send_id![
+        msg_send![
             <NSDictionary<NSObject, NSObject>>::class(),
             dictionaryWithContentsOfFile: &*info_path,
         ]
     };
     let mut x = 0.0;
-    if let Some(n) = info.get(&*ns_string!("hotx")) {
-        if n.is_kind_of::<NSNumber>() {
-            let ptr: *const NSObject = n;
-            let ptr: *const NSNumber = ptr.cast();
-            x = unsafe { &*ptr }.as_cgfloat()
+    if let Some(n) = info.objectForKey(ns_string!("hotx")) {
+        if let Ok(n) = n.downcast::<NSNumber>() {
+            x = n.as_cgfloat();
         }
     }
     let mut y = 0.0;
-    if let Some(n) = info.get(&*ns_string!("hotx")) {
-        if n.is_kind_of::<NSNumber>() {
-            let ptr: *const NSObject = n;
-            let ptr: *const NSNumber = ptr.cast();
-            y = unsafe { &*ptr }.as_cgfloat()
+    if let Some(n) = info.objectForKey(ns_string!("hoty")) {
+        if let Ok(n) = n.downcast::<NSNumber>() {
+            y = n.as_cgfloat();
         }
     }
 
@@ -188,6 +196,7 @@ pub(crate) fn invisible_cursor() -> Retained<NSCursor> {
     CURSOR.get_or_init(|| CustomCursor(new_invisible())).0.clone()
 }
 
+#[allow(deprecated)]
 pub(crate) fn cursor_from_icon(icon: CursorIcon) -> Retained<NSCursor> {
     match icon {
         CursorIcon::Default => default_cursor(),
@@ -208,7 +217,9 @@ pub(crate) fn cursor_from_icon(icon: CursorIcon) -> Retained<NSCursor> {
         CursorIcon::EwResize | CursorIcon::ColResize => NSCursor::resizeLeftRightCursor(),
         CursorIcon::NsResize | CursorIcon::RowResize => NSCursor::resizeUpDownCursor(),
         CursorIcon::Help => _helpCursor(),
+        CursorIcon::ZoomIn if available!(macos = 15.0) => unsafe { NSCursor::zoomInCursor() },
         CursorIcon::ZoomIn => _zoomInCursor(),
+        CursorIcon::ZoomOut if available!(macos = 15.0) => unsafe { NSCursor::zoomOutCursor() },
         CursorIcon::ZoomOut => _zoomOutCursor(),
         CursorIcon::NeResize => _windowResizeNorthEastCursor(),
         CursorIcon::NwResize => _windowResizeNorthWestCursor(),

src/platform_impl/apple/appkit/event.rs

@@ -1,10 +1,10 @@
-use std::ffi::c_void;
+use std::ptr::NonNull;
 
-use core_foundation::base::CFRelease;
-use core_foundation::data::{CFDataGetBytePtr, CFDataRef};
+use dispatch2::run_on_main;
 use objc2::rc::Retained;
 use objc2_app_kit::{NSEvent, NSEventModifierFlags, NSEventSubtype, NSEventType};
-use objc2_foundation::{run_on_main, NSPoint};
+use objc2_core_foundation::{CFData, CFRetained};
+use objc2_foundation::NSPoint;
 use smol_str::SmolStr;
 
 use super::ffi;
@@ -14,37 +14,29 @@ use crate::keyboard::{
     PhysicalKey,
 };
 
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub struct KeyEventExtra {
-    pub text_with_all_modifiers: Option<SmolStr>,
-    pub key_without_modifiers: Key,
-}
-
 /// Ignores ALL modifiers.
 pub fn get_modifierless_char(scancode: u16) -> Key {
-    let mut string = [0; 16];
-    let input_source;
-    let layout;
-    unsafe {
-        input_source = ffi::TISCopyCurrentKeyboardLayoutInputSource();
-        if input_source.is_null() {
-            tracing::error!("`TISCopyCurrentKeyboardLayoutInputSource` returned null ptr");
-            return Key::Unidentified(NativeKey::MacOS(scancode));
-        }
-        let layout_data =
-            ffi::TISGetInputSourceProperty(input_source, ffi::kTISPropertyUnicodeKeyLayoutData);
-        if layout_data.is_null() {
-            CFRelease(input_source as *mut c_void);
-            tracing::error!("`TISGetInputSourceProperty` returned null ptr");
-            return Key::Unidentified(NativeKey::MacOS(scancode));
-        }
-        layout = CFDataGetBytePtr(layout_data as CFDataRef) as *const ffi::UCKeyboardLayout;
-    }
+    let Some(ptr) = NonNull::new(unsafe { ffi::TISCopyCurrentKeyboardLayoutInputSource() }) else {
+        tracing::error!("`TISCopyCurrentKeyboardLayoutInputSource` returned null ptr");
+        return Key::Unidentified(NativeKey::MacOS(scancode));
+    };
+    let input_source = unsafe { CFRetained::from_raw(ptr) };
+
+    let layout_data = unsafe {
+        ffi::TISGetInputSourceProperty(&input_source, ffi::kTISPropertyUnicodeKeyLayoutData)
+    };
+    let Some(layout_data) = (unsafe { layout_data.cast::<CFData>().as_ref() }) else {
+        tracing::error!("`TISGetInputSourceProperty` returned null ptr");
+        return Key::Unidentified(NativeKey::MacOS(scancode));
+    };
+
+    let layout = layout_data.byte_ptr().cast();
     let keyboard_type = run_on_main(|_mtm| unsafe { ffi::LMGetKbdType() });
 
     let mut result_len = 0;
     let mut dead_keys = 0;
     let modifiers = 0;
+    let mut string = [0; 16];
     let translate_result = unsafe {
         ffi::UCKeyTranslate(
             layout,
@@ -59,9 +51,6 @@ pub fn get_modifierless_char(scancode: u16) -> Key {
             string.as_mut_ptr(),
         )
     };
-    unsafe {
-        CFRelease(input_source as *mut c_void);
-    }
     if translate_result != 0 {
         tracing::error!("`UCKeyTranslate` returned with the non-zero value: {}", translate_result);
         return Key::Unidentified(NativeKey::MacOS(scancode));
@@ -92,17 +81,12 @@ fn get_logical_key_char(ns_event: &NSEvent, modifierless_chars: &str) -> Key {
 /// Create `KeyEvent` for the given `NSEvent`.
 ///
 /// This function shouldn't be called when the IME input is in process.
-pub(crate) fn create_key_event(
-    ns_event: &NSEvent,
-    is_press: bool,
-    is_repeat: bool,
-    key_override: Option<PhysicalKey>,
-) -> KeyEvent {
+pub(crate) fn create_key_event(ns_event: &NSEvent, is_press: bool, is_repeat: bool) -> KeyEvent {
     use ElementState::{Pressed, Released};
     let state = if is_press { Pressed } else { Released };
 
     let scancode = unsafe { ns_event.keyCode() };
-    let mut physical_key = key_override.unwrap_or_else(|| scancode_to_physicalkey(scancode as u32));
+    let mut physical_key = scancode_to_physicalkey(scancode as u32);
 
     // NOTE: The logical key should heed both SHIFT and ALT if possible.
     // For instance:
@@ -111,20 +95,15 @@ pub(crate) fn create_key_event(
     // * Pressing CTRL SHIFT A: logical key should also be "A"
     // This is not easy to tease out of `NSEvent`, but we do our best.
 
-    let text_with_all_modifiers: Option<SmolStr> = if key_override.is_some() {
+    let characters = unsafe { ns_event.characters() }.map(|s| s.to_string()).unwrap_or_default();
+    let text_with_all_modifiers = if characters.is_empty() {
         None
     } else {
-        let characters =
-            unsafe { ns_event.characters() }.map(|s| s.to_string()).unwrap_or_default();
-        if characters.is_empty() {
-            None
-        } else {
-            if matches!(physical_key, PhysicalKey::Unidentified(_)) {
-                // The key may be one of the funky function keys
-                physical_key = extra_function_key_to_code(scancode, &characters);
-            }
-            Some(SmolStr::new(characters))
+        if matches!(physical_key, PhysicalKey::Unidentified(_)) {
+            // The key may be one of the funky function keys
+            physical_key = extra_function_key_to_code(scancode, &characters);
         }
+        Some(SmolStr::new(characters))
     };
 
     let key_from_code = code_to_key(physical_key, scancode);
@@ -133,8 +112,8 @@ pub(crate) fn create_key_event(
         let key_without_modifiers = get_modifierless_char(scancode);
 
         let modifiers = unsafe { ns_event.modifierFlags() };
-        let has_ctrl = modifiers.contains(NSEventModifierFlags::NSEventModifierFlagControl);
-        let has_cmd = modifiers.contains(NSEventModifierFlags::NSEventModifierFlagCommand);
+        let has_ctrl = modifiers.contains(NSEventModifierFlags::Control);
+        let has_cmd = modifiers.contains(NSEventModifierFlags::Command);
 
         let logical_key = match text_with_all_modifiers.as_ref() {
             // Only checking for ctrl and cmd here, not checking for alt because we DO want to
@@ -172,7 +151,8 @@ pub(crate) fn create_key_event(
         repeat: is_repeat,
         state,
         text,
-        platform_specific: KeyEventExtra { text_with_all_modifiers, key_without_modifiers },
+        text_with_all_modifiers,
+        key_without_modifiers,
     }
 }
 
@@ -182,28 +162,34 @@ pub fn code_to_key(key: PhysicalKey, scancode: u16) -> Key {
         PhysicalKey::Unidentified(code) => return Key::Unidentified(code.into()),
     };
 
+    // Roughly same handling as Firefox and Chromium:
+    // https://searchfox.org/mozilla-central/rev/c597e9c789ad36af84a0370d395be066b7dc94f4/widget/NativeKeyToDOMKeyName.h
+    // https://chromium.googlesource.com/chromium/src.git/+/010a75a426c4a2292955a52f480e9251cacf750e/ui/events/keycodes/keyboard_code_conversion_mac.mm#100
     Key::Named(match code {
         KeyCode::Enter => NamedKey::Enter,
         KeyCode::Tab => NamedKey::Tab,
-        KeyCode::Space => NamedKey::Space,
+        KeyCode::Space => return Key::Character(" ".into()),
         KeyCode::Backspace => NamedKey::Backspace,
         KeyCode::Escape => NamedKey::Escape,
-        KeyCode::SuperRight => NamedKey::Super,
-        KeyCode::SuperLeft => NamedKey::Super,
+        KeyCode::MetaRight => NamedKey::Meta,
+        KeyCode::MetaLeft => NamedKey::Meta,
         KeyCode::ShiftLeft => NamedKey::Shift,
         KeyCode::AltLeft => NamedKey::Alt,
         KeyCode::ControlLeft => NamedKey::Control,
         KeyCode::ShiftRight => NamedKey::Shift,
         KeyCode::AltRight => NamedKey::Alt,
         KeyCode::ControlRight => NamedKey::Control,
+        KeyCode::CapsLock => NamedKey::CapsLock,
 
         KeyCode::NumLock => NamedKey::NumLock,
         KeyCode::AudioVolumeUp => NamedKey::AudioVolumeUp,
         KeyCode::AudioVolumeDown => NamedKey::AudioVolumeDown,
+        KeyCode::AudioVolumeMute => NamedKey::AudioVolumeMute,
 
         // Other numpad keys all generate text on macOS (if I understand correctly)
         KeyCode::NumpadEnter => NamedKey::Enter,
 
+        KeyCode::Fn => NamedKey::Fn,
         KeyCode::F1 => NamedKey::F1,
         KeyCode::F2 => NamedKey::F2,
         KeyCode::F3 => NamedKey::F3,
@@ -224,17 +210,27 @@ pub fn code_to_key(key: PhysicalKey, scancode: u16) -> Key {
         KeyCode::F18 => NamedKey::F18,
         KeyCode::F19 => NamedKey::F19,
         KeyCode::F20 => NamedKey::F20,
+        KeyCode::F21 => NamedKey::F21,
+        KeyCode::F22 => NamedKey::F22,
+        KeyCode::F23 => NamedKey::F23,
+        KeyCode::F24 => NamedKey::F24,
 
         KeyCode::Insert => NamedKey::Insert,
         KeyCode::Home => NamedKey::Home,
         KeyCode::PageUp => NamedKey::PageUp,
         KeyCode::Delete => NamedKey::Delete,
         KeyCode::End => NamedKey::End,
+        KeyCode::Help => NamedKey::Help,
         KeyCode::PageDown => NamedKey::PageDown,
         KeyCode::ArrowLeft => NamedKey::ArrowLeft,
         KeyCode::ArrowRight => NamedKey::ArrowRight,
         KeyCode::ArrowDown => NamedKey::ArrowDown,
         KeyCode::ArrowUp => NamedKey::ArrowUp,
+        KeyCode::ContextMenu => NamedKey::ContextMenu,
+
+        KeyCode::Lang2 => NamedKey::Eisu,
+        KeyCode::Lang1 => NamedKey::KanjiMode,
+
         _ => return Key::Unidentified(NativeKey::MacOS(scancode)),
     })
 }
@@ -246,8 +242,8 @@ pub fn code_to_location(key: PhysicalKey) -> KeyLocation {
     };
 
     match code {
-        KeyCode::SuperRight => KeyLocation::Right,
-        KeyCode::SuperLeft => KeyLocation::Left,
+        KeyCode::MetaRight => KeyLocation::Right,
+        KeyCode::MetaLeft => KeyLocation::Left,
         KeyCode::ShiftLeft => KeyLocation::Left,
         KeyCode::AltLeft => KeyLocation::Left,
         KeyCode::ControlLeft => KeyLocation::Left,
@@ -318,28 +314,21 @@ pub(super) fn event_mods(event: &NSEvent) -> Modifiers {
     let mut state = ModifiersState::empty();
     let mut pressed_mods = ModifiersKeys::empty();
 
-    state
-        .set(ModifiersState::SHIFT, flags.contains(NSEventModifierFlags::NSEventModifierFlagShift));
+    state.set(ModifiersState::SHIFT, flags.contains(NSEventModifierFlags::Shift));
     pressed_mods.set(ModifiersKeys::LSHIFT, flags.contains(NX_DEVICELSHIFTKEYMASK));
     pressed_mods.set(ModifiersKeys::RSHIFT, flags.contains(NX_DEVICERSHIFTKEYMASK));
 
-    state.set(
-        ModifiersState::CONTROL,
-        flags.contains(NSEventModifierFlags::NSEventModifierFlagControl),
-    );
+    state.set(ModifiersState::CONTROL, flags.contains(NSEventModifierFlags::Control));
     pressed_mods.set(ModifiersKeys::LCONTROL, flags.contains(NX_DEVICELCTLKEYMASK));
     pressed_mods.set(ModifiersKeys::RCONTROL, flags.contains(NX_DEVICERCTLKEYMASK));
 
-    state.set(ModifiersState::ALT, flags.contains(NSEventModifierFlags::NSEventModifierFlagOption));
+    state.set(ModifiersState::ALT, flags.contains(NSEventModifierFlags::Option));
     pressed_mods.set(ModifiersKeys::LALT, flags.contains(NX_DEVICELALTKEYMASK));
     pressed_mods.set(ModifiersKeys::RALT, flags.contains(NX_DEVICERALTKEYMASK));
 
-    state.set(
-        ModifiersState::SUPER,
-        flags.contains(NSEventModifierFlags::NSEventModifierFlagCommand),
-    );
-    pressed_mods.set(ModifiersKeys::LSUPER, flags.contains(NX_DEVICELCMDKEYMASK));
-    pressed_mods.set(ModifiersKeys::RSUPER, flags.contains(NX_DEVICERCMDKEYMASK));
+    state.set(ModifiersState::META, flags.contains(NSEventModifierFlags::Command));
+    pressed_mods.set(ModifiersKeys::LMETA, flags.contains(NX_DEVICELCMDKEYMASK));
+    pressed_mods.set(ModifiersKeys::RMETA, flags.contains(NX_DEVICERCMDKEYMASK));
 
     Modifiers { state, pressed_mods }
 }
@@ -377,6 +366,7 @@ pub(crate) fn physicalkey_to_scancode(physical_key: PhysicalKey) -> Option<u32>
         KeyCode::KeyX => Some(0x07),
         KeyCode::KeyC => Some(0x08),
         KeyCode::KeyV => Some(0x09),
+        KeyCode::IntlBackslash => Some(0x0a),
         KeyCode::KeyB => Some(0x0b),
         KeyCode::KeyQ => Some(0x0c),
         KeyCode::KeyW => Some(0x0d),
@@ -419,21 +409,24 @@ pub(crate) fn physicalkey_to_scancode(physical_key: PhysicalKey) -> Option<u32>
         KeyCode::Backquote => Some(0x32),
         KeyCode::Backspace => Some(0x33),
         KeyCode::Escape => Some(0x35),
-        KeyCode::SuperRight => Some(0x36),
-        KeyCode::SuperLeft => Some(0x37),
+        KeyCode::MetaRight => Some(0x36),
+        KeyCode::MetaLeft => Some(0x37),
         KeyCode::ShiftLeft => Some(0x38),
+        KeyCode::CapsLock => Some(0x39),
         KeyCode::AltLeft => Some(0x3a),
         KeyCode::ControlLeft => Some(0x3b),
         KeyCode::ShiftRight => Some(0x3c),
         KeyCode::AltRight => Some(0x3d),
         KeyCode::ControlRight => Some(0x3e),
+        KeyCode::Fn => Some(0x3f),
         KeyCode::F17 => Some(0x40),
         KeyCode::NumpadDecimal => Some(0x41),
         KeyCode::NumpadMultiply => Some(0x43),
         KeyCode::NumpadAdd => Some(0x45),
         KeyCode::NumLock => Some(0x47),
-        KeyCode::AudioVolumeUp => Some(0x49),
-        KeyCode::AudioVolumeDown => Some(0x4a),
+        KeyCode::AudioVolumeUp => Some(0x48),
+        KeyCode::AudioVolumeDown => Some(0x49),
+        KeyCode::AudioVolumeMute => Some(0x4a),
         KeyCode::NumpadDivide => Some(0x4b),
         KeyCode::NumpadEnter => Some(0x4c),
         KeyCode::NumpadSubtract => Some(0x4e),
@@ -452,17 +445,22 @@ pub(crate) fn physicalkey_to_scancode(physical_key: PhysicalKey) -> Option<u32>
         KeyCode::Numpad8 => Some(0x5b),
         KeyCode::Numpad9 => Some(0x5c),
         KeyCode::IntlYen => Some(0x5d),
+        KeyCode::IntlRo => Some(0x5e),
+        KeyCode::NumpadComma => Some(0x5f),
         KeyCode::F5 => Some(0x60),
         KeyCode::F6 => Some(0x61),
         KeyCode::F7 => Some(0x62),
         KeyCode::F3 => Some(0x63),
         KeyCode::F8 => Some(0x64),
         KeyCode::F9 => Some(0x65),
+        KeyCode::Lang2 => Some(0x66),
         KeyCode::F11 => Some(0x67),
+        KeyCode::Lang1 => Some(0x68),
         KeyCode::F13 => Some(0x69),
         KeyCode::F16 => Some(0x6a),
         KeyCode::F14 => Some(0x6b),
         KeyCode::F10 => Some(0x6d),
+        KeyCode::ContextMenu => Some(0x6e),
         KeyCode::F12 => Some(0x6f),
         KeyCode::F15 => Some(0x71),
         KeyCode::Insert => Some(0x72),
@@ -478,11 +476,26 @@ pub(crate) fn physicalkey_to_scancode(physical_key: PhysicalKey) -> Option<u32>
         KeyCode::ArrowRight => Some(0x7c),
         KeyCode::ArrowDown => Some(0x7d),
         KeyCode::ArrowUp => Some(0x7e),
+        KeyCode::Power => Some(0x7f),
         _ => None,
     }
 }
 
 pub(crate) fn scancode_to_physicalkey(scancode: u32) -> PhysicalKey {
+    // Follows what Chromium and Firefox do:
+    // https://chromium.googlesource.com/chromium/src.git/+/3e1a26c44c024d97dc9a4c09bbc6a2365398ca2c/ui/events/keycodes/dom/dom_code_data.inc
+    // https://searchfox.org/mozilla-central/rev/c597e9c789ad36af84a0370d395be066b7dc94f4/widget/NativeKeyToDOMCodeName.h
+    //
+    // See also:
+    // Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/Headers/Events.h
+    //
+    // Also see https://developer.apple.com/documentation/appkit/function-key-unicode-values:
+    //
+    // > the system handles some function keys at a lower level and your app never sees them.
+    // > Examples include the Volume Up key, Volume Down key, Volume Mute key, Eject key, and
+    // > Function key found on many Macs.
+    //
+    // So the handling of some of these is mostly for show.
     PhysicalKey::Code(match scancode {
         0x00 => KeyCode::KeyA,
         0x01 => KeyCode::KeyS,
@@ -494,7 +507,11 @@ pub(crate) fn scancode_to_physicalkey(scancode: u32) -> PhysicalKey {
         0x07 => KeyCode::KeyX,
         0x08 => KeyCode::KeyC,
         0x09 => KeyCode::KeyV,
-        // 0x0a => World 1,
+        // This key is typically located near LeftShift key, roughly the same location as backquote
+        // (`) on Windows' US layout.
+        //
+        // The keycap varies on international keyboards.
+        0x0a => KeyCode::IntlBackslash,
         0x0b => KeyCode::KeyB,
         0x0c => KeyCode::KeyQ,
         0x0d => KeyCode::KeyW,
@@ -536,10 +553,10 @@ pub(crate) fn scancode_to_physicalkey(scancode: u32) -> PhysicalKey {
         0x31 => KeyCode::Space,
         0x32 => KeyCode::Backquote,
         0x33 => KeyCode::Backspace,
-        // 0x34 => unknown,
+        // 0x34 => unknown, // kVK_Powerbook_KeypadEnter
         0x35 => KeyCode::Escape,
-        0x36 => KeyCode::SuperRight,
-        0x37 => KeyCode::SuperLeft,
+        0x36 => KeyCode::MetaRight,
+        0x37 => KeyCode::MetaLeft,
         0x38 => KeyCode::ShiftLeft,
         0x39 => KeyCode::CapsLock,
         0x3a => KeyCode::AltLeft,
@@ -555,15 +572,10 @@ pub(crate) fn scancode_to_physicalkey(scancode: u32) -> PhysicalKey {
         // 0x44 => unknown,
         0x45 => KeyCode::NumpadAdd,
         // 0x46 => unknown,
-        0x47 => KeyCode::NumLock,
-        // 0x48 => KeyCode::NumpadClear,
-
-        // TODO: (Artur) for me, kVK_VolumeUp is 0x48
-        // macOS 10.11
-        // /System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/
-        // Versions/A/Headers/Events.h
-        0x49 => KeyCode::AudioVolumeUp,
-        0x4a => KeyCode::AudioVolumeDown,
+        0x47 => KeyCode::NumLock, // kVK_ANSI_KeypadClear
+        0x48 => KeyCode::AudioVolumeUp,
+        0x49 => KeyCode::AudioVolumeDown,
+        0x4a => KeyCode::AudioVolumeMute,
         0x4b => KeyCode::NumpadDivide,
         0x4c => KeyCode::NumpadEnter,
         // 0x4d => unknown,
@@ -583,23 +595,23 @@ pub(crate) fn scancode_to_physicalkey(scancode: u32) -> PhysicalKey {
         0x5b => KeyCode::Numpad8,
         0x5c => KeyCode::Numpad9,
         0x5d => KeyCode::IntlYen,
-        // 0x5e => JIS Ro,
-        // 0x5f => unknown,
+        0x5e => KeyCode::IntlRo,
+        0x5f => KeyCode::NumpadComma,
         0x60 => KeyCode::F5,
         0x61 => KeyCode::F6,
         0x62 => KeyCode::F7,
         0x63 => KeyCode::F3,
         0x64 => KeyCode::F8,
         0x65 => KeyCode::F9,
-        // 0x66 => JIS Eisuu (macOS),
+        0x66 => KeyCode::Lang2,
         0x67 => KeyCode::F11,
-        // 0x68 => JIS Kanna (macOS),
+        0x68 => KeyCode::Lang1,
         0x69 => KeyCode::F13,
         0x6a => KeyCode::F16,
         0x6b => KeyCode::F14,
         // 0x6c => unknown,
         0x6d => KeyCode::F10,
-        // 0x6e => unknown,
+        0x6e => KeyCode::ContextMenu,
         0x6f => KeyCode::F12,
         // 0x70 => unknown,
         0x71 => KeyCode::F15,
@@ -616,11 +628,7 @@ pub(crate) fn scancode_to_physicalkey(scancode: u32) -> PhysicalKey {
         0x7c => KeyCode::ArrowRight,
         0x7d => KeyCode::ArrowDown,
         0x7e => KeyCode::ArrowUp,
-        // 0x7f =>  unknown,
-
-        // 0xA is the caret (^) an macOS's German QERTZ layout. This key is at the same location as
-        // backquote (`) on Windows' US layout.
-        0xa => KeyCode::Backquote,
+        0x7f => KeyCode::Power, // On 10.7 and 10.8 only
         _ => return PhysicalKey::Unidentified(NativeKeyCode::MacOS(scancode as u16)),
     })
 }

src/platform_impl/apple/appkit/event_loop.rs

@@ -1,29 +1,23 @@
 use std::any::Any;
 use std::cell::Cell;
-use std::os::raw::c_void;
+use std::fmt;
 use std::panic::{catch_unwind, resume_unwind, RefUnwindSafe, UnwindSafe};
-use std::ptr;
 use std::rc::{Rc, Weak};
-use std::sync::atomic::{AtomicBool, Ordering as AtomicOrdering};
 use std::sync::Arc;
 use std::time::{Duration, Instant};
 
-use core_foundation::base::{CFIndex, CFRelease};
-use core_foundation::runloop::{
-    kCFRunLoopCommonModes, CFRunLoopAddSource, CFRunLoopGetMain, CFRunLoopSourceContext,
-    CFRunLoopSourceCreate, CFRunLoopSourceRef, CFRunLoopSourceSignal, CFRunLoopWakeUp,
-};
 use objc2::rc::{autoreleasepool, Retained};
-use objc2::{msg_send_id, sel, ClassType};
+use objc2::runtime::ProtocolObject;
+use objc2::{available, MainThreadMarker};
 use objc2_app_kit::{
     NSApplication, NSApplicationActivationPolicy, NSApplicationDidFinishLaunchingNotification,
     NSApplicationWillTerminateNotification, NSWindow,
 };
-use objc2_foundation::{MainThreadMarker, NSNotificationCenter, NSObject, NSObjectProtocol};
+use objc2_foundation::{NSNotificationCenter, NSObjectProtocol};
 use rwh_06::HasDisplayHandle;
 
 use super::super::notification_center::create_observer;
-use super::app::WinitApplication;
+use super::app::override_send_event;
 use super::app_state::AppState;
 use super::cursor::CustomCursor;
 use super::event::dummy_event;
@@ -33,20 +27,25 @@ use crate::application::ApplicationHandler;
 use crate::error::{EventLoopError, RequestError};
 use crate::event_loop::{
     ActiveEventLoop as RootActiveEventLoop, ControlFlow, DeviceEvents,
-    EventLoopProxy as CoreEventLoopProxy, EventLoopProxyProvider,
-    OwnedDisplayHandle as CoreOwnedDisplayHandle,
+    EventLoopProxy as CoreEventLoopProxy, OwnedDisplayHandle as CoreOwnedDisplayHandle,
 };
-use crate::monitor::MonitorHandle as RootMonitorHandle;
+use crate::monitor::MonitorHandle as CoreMonitorHandle;
 use crate::platform::macos::ActivationPolicy;
 use crate::platform::pump_events::PumpStatus;
 use crate::platform_impl::Window;
-use crate::window::{CustomCursor as RootCustomCursor, CustomCursorSource, Theme};
+use crate::window::{CustomCursor as CoreCustomCursor, CustomCursorSource, Theme};
 
 #[derive(Default)]
 pub struct PanicInfo {
     inner: Cell<Option<Box<dyn Any + Send + 'static>>>,
 }
 
+impl fmt::Debug for PanicInfo {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("PanicInfo").finish_non_exhaustive()
+    }
+}
+
 // WARNING:
 // As long as this struct is used through its `impl`, it is UnwindSafe.
 // (If `get_mut` is called on `inner`, unwind safety may get broken.)
@@ -111,17 +110,21 @@ impl RootActiveEventLoop for ActiveEventLoop {
     fn create_custom_cursor(
         &self,
         source: CustomCursorSource,
-    ) -> Result<RootCustomCursor, RequestError> {
-        Ok(RootCustomCursor { inner: CustomCursor::new(source.inner)? })
+    ) -> Result<CoreCustomCursor, RequestError> {
+        Ok(CoreCustomCursor(Arc::new(CustomCursor::new(source)?)))
     }
 
-    fn available_monitors(&self) -> Box<dyn Iterator<Item = RootMonitorHandle>> {
-        Box::new(monitor::available_monitors().into_iter().map(|inner| RootMonitorHandle { inner }))
+    fn available_monitors(&self) -> Box<dyn Iterator<Item = CoreMonitorHandle>> {
+        Box::new(
+            monitor::available_monitors()
+                .into_iter()
+                .map(|monitor| CoreMonitorHandle(Arc::new(monitor))),
+        )
     }
 
     fn primary_monitor(&self) -> Option<crate::monitor::MonitorHandle> {
         let monitor = monitor::primary_monitor();
-        Some(RootMonitorHandle { inner: monitor })
+        Some(CoreMonitorHandle(Arc::new(monitor)))
     }
 
     fn listen_device_events(&self, _allowed: DeviceEvents) {}
@@ -129,7 +132,8 @@ impl RootActiveEventLoop for ActiveEventLoop {
     fn system_theme(&self) -> Option<Theme> {
         let app = NSApplication::sharedApplication(self.mtm);
 
-        if app.respondsToSelector(sel!(effectiveAppearance)) {
+        // Dark appearance was introduced in macOS 10.14
+        if available!(macos = 10.14) {
             Some(super::window_delegate::appearance_to_theme(&app.effectiveAppearance()))
         } else {
             Some(Theme::Light)
@@ -168,6 +172,7 @@ impl rwh_06::HasDisplayHandle for ActiveEventLoop {
     }
 }
 
+#[derive(Debug)]
 pub struct EventLoop {
     /// Store a reference to the application for convenience.
     ///
@@ -183,8 +188,8 @@ pub struct EventLoop {
     // the system instead cleans it up next time it would have posted a notification to it.
     //
     // Though we do still need to keep the observers around to prevent them from being deallocated.
-    _did_finish_launching_observer: Retained<NSObject>,
-    _will_terminate_observer: Retained<NSObject>,
+    _did_finish_launching_observer: Retained<ProtocolObject<dyn NSObjectProtocol>>,
+    _will_terminate_observer: Retained<ProtocolObject<dyn NSObjectProtocol>>,
 }
 
 #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
@@ -207,16 +212,6 @@ impl EventLoop {
         let mtm = MainThreadMarker::new()
             .expect("on macOS, `EventLoop` must be created on the main thread!");
 
-        let app: Retained<NSApplication> =
-            unsafe { msg_send_id![WinitApplication::class(), sharedApplication] };
-
-        if !app.is_kind_of::<WinitApplication>() {
-            panic!(
-                "`winit` requires control over the principal class. You must create the event \
-                 loop before other parts of your application initialize NSApplication"
-            );
-        }
-
         let activation_policy = match attributes.activation_policy {
             None => None,
             Some(ActivationPolicy::Regular) => Some(NSApplicationActivationPolicy::Regular),
@@ -231,6 +226,12 @@ impl EventLoop {
             attributes.activate_ignoring_other_apps,
         );
 
+        // Initialize the application (if it has not already been).
+        let app = NSApplication::sharedApplication(mtm);
+
+        // Override `sendEvent:` on the application to forward to our application state.
+        override_send_event(&app);
+
         let center = unsafe { NSNotificationCenter::defaultCenter() };
 
         let weak_app_state = Rc::downgrade(&app_state);
@@ -274,23 +275,20 @@ impl EventLoop {
         &self.window_target
     }
 
-    pub fn run<A: ApplicationHandler>(
-        mut self,
-        init_closure: impl FnOnce(&dyn RootActiveEventLoop) -> A,
-    ) -> Result<(), EventLoopError> {
-        self.run_on_demand(init_closure)
+    pub fn run_app<A: ApplicationHandler>(mut self, app: A) -> Result<(), EventLoopError> {
+        self.run_app_on_demand(app)
     }
 
     // NB: we don't base this on `pump_events` because for `MacOs` we can't support
     // `pump_events` elegantly (we just ask to run the loop for a "short" amount of
     // time and so a layered implementation would end up using a lot of CPU due to
     // redundant wake ups.
-    pub fn run_on_demand<A: ApplicationHandler>(
+    pub fn run_app_on_demand<A: ApplicationHandler>(
         &mut self,
-        init_closure: impl FnOnce(&dyn RootActiveEventLoop) -> A,
+        app: A,
     ) -> Result<(), EventLoopError> {
         self.app_state.clear_exit();
-        self.app_state.set_init_closure(init_closure, || {
+        self.app_state.set_event_handler(app, || {
             autoreleasepool(|_| {
                 // clear / normalize pump_events state
                 self.app_state.set_wait_timeout(None);
@@ -304,8 +302,8 @@ impl EventLoop {
                     self.app_state.dispatch_init_events();
                 }
 
-                // SAFETY: We do not run the application re-entrantly
-                unsafe { self.app.run() };
+                // NOTE: Make sure to not run the application re-entrantly, as that'd be confusing.
+                self.app.run();
 
                 // While the app is running it's possible that we catch a panic
                 // to avoid unwinding across an objective-c ffi boundary, which
@@ -326,9 +324,9 @@ impl EventLoop {
     pub fn pump_app_events<A: ApplicationHandler>(
         &mut self,
         timeout: Option<Duration>,
-        mut app: A,
+        app: A,
     ) -> PumpStatus {
-        self.app_state.set_event_handler(&mut app, || {
+        self.app_state.set_event_handler(app, || {
             autoreleasepool(|_| {
                 // As a special case, if the application hasn't been launched yet then we at least
                 // run the loop until it has fully launched.
@@ -336,8 +334,7 @@ impl EventLoop {
                     debug_assert!(!self.app_state.is_running());
 
                     self.app_state.set_stop_on_launch();
-                    // SAFETY: We do not run the application re-entrantly
-                    unsafe { self.app.run() };
+                    self.app.run();
 
                     // Note: we dispatch `NewEvents(Init)` + `Resumed` events after the application
                     // has launched
@@ -369,8 +366,7 @@ impl EventLoop {
                         },
                     }
                     self.app_state.set_stop_on_redraw(true);
-                    // SAFETY: We do not run the application re-entrantly
-                    unsafe { self.app.run() };
+                    self.app.run();
                 }
 
                 // While the app is running it's possible that we catch a panic
@@ -411,6 +407,22 @@ pub(super) fn stop_app_immediately(app: &NSApplication) {
     });
 }
 
+/// Tell all windows to close.
+///
+/// This will synchronously trigger `WindowEvent::Destroyed` within
+/// `windowWillClose:`, giving the application one last chance to handle
+/// those events. It doesn't matter if the user also ends up closing the
+/// windows in `Window`'s `Drop` impl, once a window has been closed once, it
+/// stays closed.
+///
+/// This ensures that no windows linger on after the event loop has exited,
+/// see <https://github.com/rust-windowing/winit/issues/4135>.
+pub(super) fn notify_windows_of_exit(app: &NSApplication) {
+    for window in app.windows() {
+        window.close();
+    }
+}
+
 /// Catches panics that happen inside `f` and when a panic
 /// happens, stops the `sharedApplication`
 #[inline]
@@ -436,62 +448,3 @@ pub fn stop_app_on_panic<F: FnOnce() -> R + UnwindSafe, R>(
         },
     }
 }
-
-#[derive(Debug)]
-pub struct EventLoopProxy {
-    pub(crate) wake_up: AtomicBool,
-    source: CFRunLoopSourceRef,
-}
-
-unsafe impl Send for EventLoopProxy {}
-unsafe impl Sync for EventLoopProxy {}
-
-impl Drop for EventLoopProxy {
-    fn drop(&mut self) {
-        unsafe {
-            CFRelease(self.source as _);
-        }
-    }
-}
-
-impl EventLoopProxy {
-    pub(crate) fn new() -> Self {
-        unsafe {
-            // just wake up the eventloop
-            extern "C" fn event_loop_proxy_handler(_: *const c_void) {}
-
-            // adding a Source to the main CFRunLoop lets us wake it up and
-            // process user events through the normal OS EventLoop mechanisms.
-            let rl = CFRunLoopGetMain();
-            let mut context = CFRunLoopSourceContext {
-                version: 0,
-                info: ptr::null_mut(),
-                retain: None,
-                release: None,
-                copyDescription: None,
-                equal: None,
-                hash: None,
-                schedule: None,
-                cancel: None,
-                perform: event_loop_proxy_handler,
-            };
-            let source = CFRunLoopSourceCreate(ptr::null_mut(), CFIndex::MAX - 1, &mut context);
-            CFRunLoopAddSource(rl, source, kCFRunLoopCommonModes);
-            CFRunLoopWakeUp(rl);
-
-            EventLoopProxy { wake_up: AtomicBool::new(false), source }
-        }
-    }
-}
-
-impl EventLoopProxyProvider for EventLoopProxy {
-    fn wake_up(&self) {
-        self.wake_up.store(true, AtomicOrdering::Relaxed);
-        unsafe {
-            // Let the main thread know there's a new event.
-            CFRunLoopSourceSignal(self.source);
-            let rl = CFRunLoopGetMain();
-            CFRunLoopWakeUp(rl);
-        }
-    }
-}

src/platform_impl/apple/appkit/ffi.rs

@@ -1,62 +1,18 @@
 // TODO: Upstream these
 
-#![allow(dead_code, non_snake_case, non_upper_case_globals)]
+#![allow(non_upper_case_globals)]
 
 use std::ffi::c_void;
 
-use core_foundation::array::CFArrayRef;
-use core_foundation::dictionary::CFDictionaryRef;
-use core_foundation::string::CFStringRef;
-use core_foundation::uuid::CFUUIDRef;
-use core_graphics::base::CGError;
-use core_graphics::display::{CGDirectDisplayID, CGDisplayConfigRef};
 use objc2::ffi::NSInteger;
 use objc2::runtime::AnyObject;
+use objc2_core_foundation::{cf_type, CFString, CFUUID};
+use objc2_core_graphics::CGDirectDisplayID;
 
-pub type CGDisplayFadeInterval = f32;
-pub type CGDisplayReservationInterval = f32;
-pub type CGDisplayBlendFraction = f32;
-
-pub const kCGDisplayBlendNormal: f32 = 0.0;
-pub const kCGDisplayBlendSolidColor: f32 = 1.0;
-
-pub type CGDisplayFadeReservationToken = u32;
-pub const kCGDisplayFadeReservationInvalidToken: CGDisplayFadeReservationToken = 0;
-
-pub type Boolean = u8;
-pub const FALSE: Boolean = 0;
-pub const TRUE: Boolean = 1;
-
-pub const kCGErrorSuccess: i32 = 0;
-pub const kCGErrorFailure: i32 = 1000;
-pub const kCGErrorIllegalArgument: i32 = 1001;
-pub const kCGErrorInvalidConnection: i32 = 1002;
-pub const kCGErrorInvalidContext: i32 = 1003;
-pub const kCGErrorCannotComplete: i32 = 1004;
-pub const kCGErrorNotImplemented: i32 = 1006;
-pub const kCGErrorRangeCheck: i32 = 1007;
-pub const kCGErrorTypeCheck: i32 = 1008;
-pub const kCGErrorInvalidOperation: i32 = 1010;
-pub const kCGErrorNoneAvailable: i32 = 1011;
-
-pub const IO1BitIndexedPixels: &str = "P";
-pub const IO2BitIndexedPixels: &str = "PP";
-pub const IO4BitIndexedPixels: &str = "PPPP";
-pub const IO8BitIndexedPixels: &str = "PPPPPPPP";
 pub const IO16BitDirectPixels: &str = "-RRRRRGGGGGBBBBB";
 pub const IO32BitDirectPixels: &str = "--------RRRRRRRRGGGGGGGGBBBBBBBB";
 
 pub const kIO30BitDirectPixels: &str = "--RRRRRRRRRRGGGGGGGGGGBBBBBBBBBB";
-pub const kIO64BitDirectPixels: &str = "-16R16G16B16";
-
-pub const kIO16BitFloatPixels: &str = "-16FR16FG16FB16";
-pub const kIO32BitFloatPixels: &str = "-32FR32FG32FB32";
-
-pub const IOYUV422Pixels: &str = "Y4U2V2";
-pub const IO8BitOverlayPixels: &str = "O8";
-
-pub type CGWindowLevel = i32;
-pub type CGDisplayModeRef = *mut c_void;
 
 // `CGDisplayCreateUUIDFromDisplayID` comes from the `ColorSync` framework.
 // However, that framework was only introduced "publicly" in macOS 10.13.
@@ -67,54 +23,13 @@ pub type CGDisplayModeRef = *mut c_void;
 // https://developer.apple.com/library/archive/documentation/MacOSX/Conceptual/OSX_Technology_Overview/SystemFrameworks/SystemFrameworks.html#//apple_ref/doc/uid/TP40001067-CH210-BBCFFIEG
 #[link(name = "ApplicationServices", kind = "framework")]
 extern "C" {
-    pub fn CGDisplayCreateUUIDFromDisplayID(display: CGDirectDisplayID) -> CFUUIDRef;
+    pub fn CGDisplayCreateUUIDFromDisplayID(display: CGDirectDisplayID) -> *mut CFUUID;
+
+    pub fn CGDisplayGetDisplayIDFromUUID(uuid: &CFUUID) -> CGDirectDisplayID;
 }
 
 #[link(name = "CoreGraphics", kind = "framework")]
 extern "C" {
-    pub fn CGRestorePermanentDisplayConfiguration();
-    pub fn CGDisplayCapture(display: CGDirectDisplayID) -> CGError;
-    pub fn CGDisplayRelease(display: CGDirectDisplayID) -> CGError;
-    pub fn CGConfigureDisplayFadeEffect(
-        config: CGDisplayConfigRef,
-        fadeOutSeconds: CGDisplayFadeInterval,
-        fadeInSeconds: CGDisplayFadeInterval,
-        fadeRed: f32,
-        fadeGreen: f32,
-        fadeBlue: f32,
-    ) -> CGError;
-    pub fn CGAcquireDisplayFadeReservation(
-        seconds: CGDisplayReservationInterval,
-        token: *mut CGDisplayFadeReservationToken,
-    ) -> CGError;
-    pub fn CGDisplayFade(
-        token: CGDisplayFadeReservationToken,
-        duration: CGDisplayFadeInterval,
-        startBlend: CGDisplayBlendFraction,
-        endBlend: CGDisplayBlendFraction,
-        redBlend: f32,
-        greenBlend: f32,
-        blueBlend: f32,
-        synchronous: Boolean,
-    ) -> CGError;
-    pub fn CGReleaseDisplayFadeReservation(token: CGDisplayFadeReservationToken) -> CGError;
-    pub fn CGShieldingWindowLevel() -> CGWindowLevel;
-    pub fn CGDisplaySetDisplayMode(
-        display: CGDirectDisplayID,
-        mode: CGDisplayModeRef,
-        options: CFDictionaryRef,
-    ) -> CGError;
-    pub fn CGDisplayCopyAllDisplayModes(
-        display: CGDirectDisplayID,
-        options: CFDictionaryRef,
-    ) -> CFArrayRef;
-    pub fn CGDisplayModeGetPixelWidth(mode: CGDisplayModeRef) -> usize;
-    pub fn CGDisplayModeGetPixelHeight(mode: CGDisplayModeRef) -> usize;
-    pub fn CGDisplayModeGetRefreshRate(mode: CGDisplayModeRef) -> f64;
-    pub fn CGDisplayModeCopyPixelEncoding(mode: CGDisplayModeRef) -> CFStringRef;
-    pub fn CGDisplayModeRetain(mode: CGDisplayModeRef);
-    pub fn CGDisplayModeRelease(mode: CGDisplayModeRef);
-
     // Wildly used private APIs; Apple uses them for their Terminal.app.
     pub fn CGSMainConnectionID() -> *mut AnyObject;
     pub fn CGSSetWindowBackgroundBlurRadius(
@@ -124,50 +39,12 @@ extern "C" {
     ) -> i32;
 }
 
-mod core_video {
-    use super::*;
-
-    #[link(name = "CoreVideo", kind = "framework")]
-    extern "C" {}
-
-    // CVBase.h
-
-    pub type CVTimeFlags = i32; // int32_t
-    pub const kCVTimeIsIndefinite: CVTimeFlags = 1 << 0;
-
-    #[repr(C)]
-    #[derive(Debug, Clone)]
-    pub struct CVTime {
-        pub time_value: i64, // int64_t
-        pub time_scale: i32, // int32_t
-        pub flags: i32,      // int32_t
-    }
-
-    // CVReturn.h
-
-    pub type CVReturn = i32; // int32_t
-    pub const kCVReturnSuccess: CVReturn = 0;
-
-    // CVDisplayLink.h
-
-    pub type CVDisplayLinkRef = *mut c_void;
-
-    extern "C" {
-        pub fn CVDisplayLinkCreateWithCGDisplay(
-            displayID: CGDirectDisplayID,
-            displayLinkOut: *mut CVDisplayLinkRef,
-        ) -> CVReturn;
-        pub fn CVDisplayLinkGetNominalOutputVideoRefreshPeriod(
-            displayLink: CVDisplayLinkRef,
-        ) -> CVTime;
-        pub fn CVDisplayLinkRelease(displayLink: CVDisplayLinkRef);
-    }
-}
-
-pub use core_video::*;
 #[repr(transparent)]
 pub struct TISInputSource(std::ffi::c_void);
-pub type TISInputSourceRef = *mut TISInputSource;
+
+cf_type!(
+    unsafe impl TISInputSource {}
+);
 
 #[repr(transparent)]
 pub struct UCKeyboardLayout(std::ffi::c_void);
@@ -184,15 +61,15 @@ pub const kUCKeyTranslateNoDeadKeysMask: OptionBits = 1;
 
 #[link(name = "Carbon", kind = "framework")]
 extern "C" {
-    pub static kTISPropertyUnicodeKeyLayoutData: CFStringRef;
+    pub static kTISPropertyUnicodeKeyLayoutData: &'static CFString;
 
     #[allow(non_snake_case)]
     pub fn TISGetInputSourceProperty(
-        inputSource: TISInputSourceRef,
-        propertyKey: CFStringRef,
+        inputSource: &TISInputSource,
+        propertyKey: &CFString,
     ) -> *mut c_void;
 
-    pub fn TISCopyCurrentKeyboardLayoutInputSource() -> TISInputSourceRef;
+    pub fn TISCopyCurrentKeyboardLayoutInputSource() -> *mut TISInputSource;
 
     pub fn LMGetKbdType() -> u8;
 
@@ -210,45 +87,3 @@ extern "C" {
         unicodeString: *mut UniChar,
     ) -> OSStatus;
 }
-
-// CGWindowLevel.h
-//
-// Note: There are two different things at play in this header:
-// `CGWindowLevel` and `CGWindowLevelKey`.
-//
-// It seems like there was a push towards using "key" values instead of the
-// raw window level values, and then you were supposed to use
-// `CGWindowLevelForKey` to get the actual level.
-//
-// But the values that `NSWindowLevel` has are compiled in, and as such has
-// to remain ABI compatible, so they're safe for us to hardcode as well.
-#[allow(dead_code, non_upper_case_globals)]
-mod window_level {
-    const kCGNumReservedWindowLevels: i32 = 16;
-    const kCGNumReservedBaseWindowLevels: i32 = 5;
-
-    pub const kCGBaseWindowLevel: i32 = i32::MIN;
-    pub const kCGMinimumWindowLevel: i32 = kCGBaseWindowLevel + kCGNumReservedBaseWindowLevels;
-    pub const kCGMaximumWindowLevel: i32 = i32::MAX - kCGNumReservedWindowLevels;
-
-    pub const kCGDesktopWindowLevel: i32 = kCGMinimumWindowLevel + 20;
-    pub const kCGDesktopIconWindowLevel: i32 = kCGDesktopWindowLevel + 20;
-    pub const kCGBackstopMenuLevel: i32 = -20;
-    pub const kCGNormalWindowLevel: i32 = 0;
-    pub const kCGFloatingWindowLevel: i32 = 3;
-    pub const kCGTornOffMenuWindowLevel: i32 = 3;
-    pub const kCGModalPanelWindowLevel: i32 = 8;
-    pub const kCGUtilityWindowLevel: i32 = 19;
-    pub const kCGDockWindowLevel: i32 = 20;
-    pub const kCGMainMenuWindowLevel: i32 = 24;
-    pub const kCGStatusWindowLevel: i32 = 25;
-    pub const kCGPopUpMenuWindowLevel: i32 = 101;
-    pub const kCGOverlayWindowLevel: i32 = 102;
-    pub const kCGHelpWindowLevel: i32 = 200;
-    pub const kCGDraggingWindowLevel: i32 = 500;
-    pub const kCGScreenSaverWindowLevel: i32 = 1000;
-    pub const kCGAssistiveTechHighWindowLevel: i32 = 1500;
-    pub const kCGCursorWindowLevel: i32 = kCGMaximumWindowLevel - 1;
-}
-
-pub use window_level::*;

src/platform_impl/apple/appkit/menu.rs

@@ -1,8 +1,8 @@
 use objc2::rc::Retained;
 use objc2::runtime::Sel;
-use objc2::sel;
+use objc2::{sel, MainThreadMarker};
 use objc2_app_kit::{NSApplication, NSEventModifierFlags, NSMenu, NSMenuItem};
-use objc2_foundation::{ns_string, MainThreadMarker, NSProcessInfo, NSString};
+use objc2_foundation::{ns_string, NSProcessInfo, NSString};
 
 struct KeyEquivalent<'a> {
     key: &'a NSString,
@@ -48,10 +48,7 @@ pub fn initialize(app: &NSApplication) {
         Some(sel!(hideOtherApplications:)),
         Some(KeyEquivalent {
             key: ns_string!("h"),
-            masks: Some(
-                NSEventModifierFlags::NSEventModifierFlagOption
-                    | NSEventModifierFlags::NSEventModifierFlagCommand,
-            ),
+            masks: Some(NSEventModifierFlags::Option | NSEventModifierFlags::Command),
         }),
     );
 

src/platform_impl/apple/appkit/mod.rs

@@ -14,14 +14,10 @@ mod view;
 mod window;
 mod window_delegate;
 
-pub(crate) use self::cursor::CustomCursor as PlatformCustomCursor;
-pub(crate) use self::event::{physicalkey_to_scancode, scancode_to_physicalkey, KeyEventExtra};
+pub(crate) use self::event::{physicalkey_to_scancode, scancode_to_physicalkey};
 pub(crate) use self::event_loop::{
     ActiveEventLoop, EventLoop, PlatformSpecificEventLoopAttributes,
 };
-pub(crate) use self::monitor::{MonitorHandle, VideoModeHandle};
+pub(crate) use self::monitor::MonitorHandle;
 pub(crate) use self::window::Window;
 pub(crate) use self::window_delegate::PlatformSpecificWindowAttributes;
-pub(crate) use crate::cursor::OnlyCursorImageSource as PlatformCustomCursorSource;
-pub(crate) use crate::icon::NoIcon as PlatformIcon;
-pub(crate) use crate::platform_impl::Fullscreen;

src/platform_impl/apple/appkit/monitor.rs

@@ -1,38 +1,38 @@
 #![allow(clippy::unnecessary_cast)]
 
 use std::collections::VecDeque;
-use std::fmt;
 use std::num::{NonZeroU16, NonZeroU32};
+use std::ptr::NonNull;
+use std::{fmt, ptr};
 
-use core_foundation::array::{CFArrayGetCount, CFArrayGetValueAtIndex};
-use core_foundation::base::{CFRelease, TCFType};
-use core_foundation::string::CFString;
-use core_graphics::display::{
-    CGDirectDisplayID, CGDisplay, CGDisplayBounds, CGDisplayCopyDisplayMode,
-};
+use dispatch2::run_on_main;
 use objc2::rc::Retained;
-use objc2::runtime::AnyObject;
+use objc2::MainThreadMarker;
 use objc2_app_kit::NSScreen;
-use objc2_foundation::{ns_string, run_on_main, MainThreadMarker, NSNumber, NSPoint, NSRect};
+use objc2_core_foundation::{CFArray, CFRetained, CFUUID};
+use objc2_core_graphics::{
+    CGDirectDisplayID, CGDisplayBounds, CGDisplayCopyAllDisplayModes, CGDisplayCopyDisplayMode,
+    CGDisplayMode, CGDisplayModelNumber, CGGetActiveDisplayList, CGMainDisplayID,
+};
+use objc2_core_video::{kCVReturnSuccess, CVDisplayLink, CVTimeFlags};
+use objc2_foundation::{ns_string, NSNumber, NSPoint, NSRect};
+use tracing::warn;
 
 use super::ffi;
+use super::util::cgerr;
 use crate::dpi::{LogicalPosition, PhysicalPosition, PhysicalSize};
+use crate::monitor::{MonitorHandleProvider, VideoMode};
 
 #[derive(Clone)]
 pub struct VideoModeHandle {
-    size: PhysicalSize<u32>,
-    bit_depth: Option<NonZeroU16>,
-    refresh_rate_millihertz: Option<NonZeroU32>,
+    pub(crate) mode: VideoMode,
     pub(crate) monitor: MonitorHandle,
     pub(crate) native_mode: NativeDisplayMode,
 }
 
 impl PartialEq for VideoModeHandle {
     fn eq(&self, other: &Self) -> bool {
-        self.size == other.size
-            && self.bit_depth == other.bit_depth
-            && self.refresh_rate_millihertz == other.refresh_rate_millihertz
-            && self.monitor == other.monitor
+        self.monitor == other.monitor && self.mode == other.mode
     }
 }
 
@@ -40,9 +40,6 @@ impl Eq for VideoModeHandle {}
 
 impl std::hash::Hash for VideoModeHandle {
     fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
-        self.size.hash(state);
-        self.bit_depth.hash(state);
-        self.refresh_rate_millihertz.hash(state);
         self.monitor.hash(state);
     }
 }
@@ -50,46 +47,28 @@ impl std::hash::Hash for VideoModeHandle {
 impl std::fmt::Debug for VideoModeHandle {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         f.debug_struct("VideoModeHandle")
-            .field("size", &self.size)
-            .field("bit_depth", &self.bit_depth)
-            .field("refresh_rate_millihertz", &self.refresh_rate_millihertz)
+            .field("mode", &self.mode)
             .field("monitor", &self.monitor)
             .finish()
     }
 }
 
-pub struct NativeDisplayMode(pub ffi::CGDisplayModeRef);
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct NativeDisplayMode(pub CFRetained<CGDisplayMode>);
 
 unsafe impl Send for NativeDisplayMode {}
 unsafe impl Sync for NativeDisplayMode {}
 
-impl Drop for NativeDisplayMode {
-    fn drop(&mut self) {
-        unsafe {
-            ffi::CGDisplayModeRelease(self.0);
-        }
-    }
-}
-
-impl Clone for NativeDisplayMode {
-    fn clone(&self) -> Self {
-        unsafe {
-            ffi::CGDisplayModeRetain(self.0);
-        }
-        NativeDisplayMode(self.0)
-    }
-}
-
 impl VideoModeHandle {
     fn new(
         monitor: MonitorHandle,
-        mode: NativeDisplayMode,
+        native_mode: NativeDisplayMode,
         refresh_rate_millihertz: Option<NonZeroU32>,
     ) -> Self {
         unsafe {
+            #[allow(deprecated)]
             let pixel_encoding =
-                CFString::wrap_under_create_rule(ffi::CGDisplayModeCopyPixelEncoding(mode.0))
-                    .to_string();
+                CGDisplayMode::pixel_encoding(Some(&native_mode.0)).unwrap().to_string();
             let bit_depth = if pixel_encoding.eq_ignore_ascii_case(ffi::IO32BitDirectPixels) {
                 32
             } else if pixel_encoding.eq_ignore_ascii_case(ffi::IO16BitDirectPixels) {
@@ -100,132 +79,139 @@ impl VideoModeHandle {
                 unimplemented!()
             };
 
-            VideoModeHandle {
+            let mode = VideoMode {
                 size: PhysicalSize::new(
-                    ffi::CGDisplayModeGetPixelWidth(mode.0) as u32,
-                    ffi::CGDisplayModeGetPixelHeight(mode.0) as u32,
+                    CGDisplayMode::pixel_width(Some(&native_mode.0)) as u32,
+                    CGDisplayMode::pixel_height(Some(&native_mode.0)) as u32,
                 ),
                 refresh_rate_millihertz,
                 bit_depth: NonZeroU16::new(bit_depth),
-                monitor: monitor.clone(),
-                native_mode: mode,
-            }
-        }
-    }
+            };
 
-    pub fn size(&self) -> PhysicalSize<u32> {
-        self.size
-    }
-
-    pub fn bit_depth(&self) -> Option<NonZeroU16> {
-        self.bit_depth
-    }
-
-    pub fn refresh_rate_millihertz(&self) -> Option<NonZeroU32> {
-        self.refresh_rate_millihertz
-    }
-
-    pub fn monitor(&self) -> MonitorHandle {
-        self.monitor.clone()
-    }
-}
-
-#[derive(Clone)]
-pub struct MonitorHandle(CGDirectDisplayID);
-
-// `CGDirectDisplayID` changes on video mode change, so we cannot rely on that
-// for comparisons, but we can use `CGDisplayCreateUUIDFromDisplayID` to get an
-// unique identifier that persists even across system reboots
-impl PartialEq for MonitorHandle {
-    fn eq(&self, other: &Self) -> bool {
-        unsafe {
-            ffi::CGDisplayCreateUUIDFromDisplayID(self.0)
-                == ffi::CGDisplayCreateUUIDFromDisplayID(other.0)
+            VideoModeHandle { mode, monitor: monitor.clone(), native_mode }
         }
     }
 }
 
-impl Eq for MonitorHandle {}
-
-impl PartialOrd for MonitorHandle {
-    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
-        Some(self.cmp(other))
-    }
-}
-
-impl Ord for MonitorHandle {
-    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
-        unsafe {
-            ffi::CGDisplayCreateUUIDFromDisplayID(self.0)
-                .cmp(&ffi::CGDisplayCreateUUIDFromDisplayID(other.0))
-        }
-    }
-}
-
-impl std::hash::Hash for MonitorHandle {
-    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
-        unsafe {
-            ffi::CGDisplayCreateUUIDFromDisplayID(self.0).hash(state);
-        }
-    }
-}
-
-pub fn available_monitors() -> VecDeque<MonitorHandle> {
-    if let Ok(displays) = CGDisplay::active_displays() {
-        let mut monitors = VecDeque::with_capacity(displays.len());
-        for display in displays {
-            monitors.push_back(MonitorHandle(display));
-        }
-        monitors
-    } else {
-        VecDeque::with_capacity(0)
-    }
-}
-
-pub fn primary_monitor() -> MonitorHandle {
-    MonitorHandle(CGDisplay::main().id)
-}
-
-impl fmt::Debug for MonitorHandle {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_struct("MonitorHandle")
-            .field("name", &self.name())
-            .field("native_identifier", &self.native_identifier())
-            .field("position", &self.position())
-            .field("scale_factor", &self.scale_factor())
-            .finish_non_exhaustive()
-    }
-}
+/// `CGDirectDisplayID` is documented as:
+/// > a framebuffer, a color correction (gamma) table, and possibly an attached monitor.
+///
+/// That is, it doesn't actually represent the monitor itself. Instead, we use the UUID of the
+/// monitor, as retrieved from `CGDisplayCreateUUIDFromDisplayID` (this makes the monitor ID stable,
+/// even across reboots and video mode changes).
+///
+/// NOTE: I'd be perfectly valid to store `[u8; 16]` in here instead, we only store `CFUUID` to
+/// avoid having to re-create it when we want to fetch the display ID.
+#[derive(Clone, PartialEq, Eq, Hash)]
+pub struct MonitorHandle(CFRetained<CFUUID>);
 
 impl MonitorHandle {
-    pub fn new(id: CGDirectDisplayID) -> Self {
-        MonitorHandle(id)
+    /// Internal comparisons of [`MonitorHandle`]s are done first requesting a UUID for the handle.
+    fn uuid(&self) -> u128 {
+        u128::from_ne_bytes(self.0.uuid_bytes().into())
+    }
+
+    fn display_id(&self) -> CGDirectDisplayID {
+        unsafe { ffi::CGDisplayGetDisplayIDFromUUID(&self.0) }
+    }
+
+    #[track_caller]
+    pub(crate) fn new(display_id: CGDirectDisplayID) -> Option<Self> {
+        // kCGNullDirectDisplay
+        if display_id == 0 {
+            // `CGDisplayCreateUUIDFromDisplayID` checks kCGNullDirectDisplay internally.
+            warn!("constructing monitor from invalid display ID 0; falling back to main monitor");
+        }
+        // SAFETY: Valid to call.
+        let ptr = unsafe { ffi::CGDisplayCreateUUIDFromDisplayID(display_id) };
+        let ptr = NonNull::new(ptr)?;
+        // SAFETY: `CGDisplayCreateUUIDFromDisplayID` is a "create" function, so the pointer has
+        // +1 retain count.
+        let uuid = unsafe { CFRetained::from_raw(ptr) };
+        Some(Self(uuid))
+    }
+
+    fn refresh_rate_millihertz(&self) -> Option<NonZeroU32> {
+        let current_display_mode =
+            NativeDisplayMode(unsafe { CGDisplayCopyDisplayMode(self.display_id()) }.unwrap());
+        refresh_rate_millihertz(self.display_id(), &current_display_mode)
+    }
+
+    pub fn video_mode_handles(&self) -> impl Iterator<Item = VideoModeHandle> {
+        let refresh_rate_millihertz = self.refresh_rate_millihertz();
+        let monitor = self.clone();
+
+        let array = unsafe { CGDisplayCopyAllDisplayModes(self.display_id(), None) };
+        let modes = if let Some(array) = array {
+            // SAFETY: `CGDisplayCopyAllDisplayModes` is documented to return an array of
+            // display modes.
+            unsafe { CFRetained::cast_unchecked::<CFArray<CGDisplayMode>>(array) }
+        } else {
+            // Occasionally, certain CalDigit Thunderbolt Hubs report a spurious monitor during
+            // sleep/wake/cycling monitors. It tends to have null or 1 video mode only.
+            // See <https://github.com/bevyengine/bevy/issues/17827>.
+            warn!(monitor = ?self, "failed to get a list of display modes");
+            CFArray::empty()
+        };
+
+        modes.into_iter().map(move |mode| {
+            let cg_refresh_rate_hertz = unsafe { CGDisplayMode::refresh_rate(Some(&mode)) };
+
+            // CGDisplayModeGetRefreshRate returns 0.0 for any display that
+            // isn't a CRT
+            let refresh_rate_millihertz = if cg_refresh_rate_hertz > 0.0 {
+                NonZeroU32::new((cg_refresh_rate_hertz * 1000.0).round() as u32)
+            } else {
+                refresh_rate_millihertz
+            };
+
+            VideoModeHandle::new(monitor.clone(), NativeDisplayMode(mode), refresh_rate_millihertz)
+        })
+    }
+
+    pub(crate) fn ns_screen(&self, mtm: MainThreadMarker) -> Option<Retained<NSScreen>> {
+        let uuid = self.uuid();
+        NSScreen::screens(mtm).into_iter().find(|screen| {
+            let other_native_id = get_display_id(screen);
+            if let Some(other) = MonitorHandle::new(other_native_id) {
+                uuid == other.uuid()
+            } else {
+                // Display ID was just fetched from live NSScreen, but can still result in `None`
+                // with certain Thunderbolt docked monitors.
+                warn!(other_native_id, "comparing against screen with invalid display ID");
+                false
+            }
+        })
+    }
+}
+
+impl MonitorHandleProvider for MonitorHandle {
+    fn id(&self) -> u128 {
+        self.uuid()
+    }
+
+    fn native_id(&self) -> u64 {
+        self.display_id() as _
     }
 
     // TODO: Be smarter about this:
+    //
     // <https://github.com/glfw/glfw/blob/57cbded0760a50b9039ee0cb3f3c14f60145567c/src/cocoa_monitor.m#L44-L126>
-    pub fn name(&self) -> Option<String> {
-        let MonitorHandle(display_id) = *self;
-        let screen_num = CGDisplay::new(display_id).model_number();
-        Some(format!("Monitor #{screen_num}"))
+    fn name(&self) -> Option<std::borrow::Cow<'_, str>> {
+        let screen_num = unsafe { CGDisplayModelNumber(self.display_id()) };
+        Some(format!("Monitor #{screen_num}").into())
     }
 
-    #[inline]
-    pub fn native_identifier(&self) -> u32 {
-        self.0
-    }
-
-    #[inline]
-    pub fn position(&self) -> Option<PhysicalPosition<i32>> {
+    fn position(&self) -> Option<PhysicalPosition<i32>> {
         // This is already in screen coordinates. If we were using `NSScreen`,
         // then a conversion would've been needed:
         // flip_window_screen_coordinates(self.ns_screen(mtm)?.frame())
-        let bounds = unsafe { CGDisplayBounds(self.native_identifier()) };
+        let bounds = unsafe { CGDisplayBounds(self.display_id()) };
         let position = LogicalPosition::new(bounds.origin.x, bounds.origin.y);
         Some(position.to_physical(self.scale_factor()))
     }
 
-    pub fn scale_factor(&self) -> f64 {
+    fn scale_factor(&self) -> f64 {
         run_on_main(|mtm| {
             match self.ns_screen(mtm) {
                 Some(screen) => screen.backingScaleFactor() as f64,
@@ -234,67 +220,58 @@ impl MonitorHandle {
         })
     }
 
-    fn refresh_rate_millihertz(&self) -> Option<NonZeroU32> {
-        let current_display_mode =
-            NativeDisplayMode(unsafe { CGDisplayCopyDisplayMode(self.0) } as _);
-        refresh_rate_millihertz(self.0, &current_display_mode)
+    fn current_video_mode(&self) -> Option<VideoMode> {
+        let mode =
+            NativeDisplayMode(unsafe { CGDisplayCopyDisplayMode(self.display_id()) }.unwrap());
+        let refresh_rate_millihertz = refresh_rate_millihertz(self.display_id(), &mode);
+        Some(VideoModeHandle::new(self.clone(), mode, refresh_rate_millihertz).mode)
     }
 
-    pub fn current_video_mode(&self) -> Option<VideoModeHandle> {
-        let mode = NativeDisplayMode(unsafe { CGDisplayCopyDisplayMode(self.0) } as _);
-        let refresh_rate_millihertz = refresh_rate_millihertz(self.0, &mode);
-        Some(VideoModeHandle::new(self.clone(), mode, refresh_rate_millihertz))
+    fn video_modes(&self) -> Box<dyn Iterator<Item = VideoMode>> {
+        Box::new(self.video_mode_handles().map(|mode| mode.mode))
+    }
+}
+
+pub fn available_monitors() -> VecDeque<MonitorHandle> {
+    let mut expected_count = 0;
+    let res = cgerr(unsafe { CGGetActiveDisplayList(0, ptr::null_mut(), &mut expected_count) });
+    if res.is_err() {
+        return VecDeque::with_capacity(0);
     }
 
-    pub fn video_modes(&self) -> impl Iterator<Item = VideoModeHandle> {
-        let refresh_rate_millihertz = self.refresh_rate_millihertz();
-        let monitor = self.clone();
+    let mut displays: Vec<CGDirectDisplayID> = vec![0; expected_count as usize];
+    let mut actual_count = 0;
+    let res = cgerr(unsafe {
+        CGGetActiveDisplayList(expected_count, displays.as_mut_ptr(), &mut actual_count)
+    });
+    displays.truncate(actual_count as usize);
 
-        unsafe {
-            let modes = {
-                let array = ffi::CGDisplayCopyAllDisplayModes(self.0, std::ptr::null());
-                assert!(!array.is_null(), "failed to get list of display modes");
-                let array_count = CFArrayGetCount(array);
-                let modes: Vec<_> = (0..array_count)
-                    .map(move |i| {
-                        let mode = CFArrayGetValueAtIndex(array, i) as *mut _;
-                        ffi::CGDisplayModeRetain(mode);
-                        mode
-                    })
-                    .collect();
-                CFRelease(array as *const _);
-                modes
-            };
-
-            modes.into_iter().map(move |mode| {
-                let cg_refresh_rate_hertz = ffi::CGDisplayModeGetRefreshRate(mode).round() as i64;
-
-                // CGDisplayModeGetRefreshRate returns 0.0 for any display that
-                // isn't a CRT
-                let refresh_rate_millihertz = if cg_refresh_rate_hertz > 0 {
-                    NonZeroU32::new((cg_refresh_rate_hertz * 1000) as u32)
-                } else {
-                    refresh_rate_millihertz
-                };
-
-                VideoModeHandle::new(
-                    monitor.clone(),
-                    NativeDisplayMode(mode),
-                    refresh_rate_millihertz,
-                )
-            })
-        }
+    if res.is_err() {
+        return VecDeque::with_capacity(0);
     }
 
-    pub(crate) fn ns_screen(&self, mtm: MainThreadMarker) -> Option<Retained<NSScreen>> {
-        let uuid = unsafe { ffi::CGDisplayCreateUUIDFromDisplayID(self.0) };
-        NSScreen::screens(mtm).into_iter().find(|screen| {
-            let other_native_id = get_display_id(screen);
-            let other_uuid = unsafe {
-                ffi::CGDisplayCreateUUIDFromDisplayID(other_native_id as CGDirectDisplayID)
-            };
-            uuid == other_uuid
-        })
+    let mut monitors = VecDeque::with_capacity(displays.len());
+    for display in displays {
+        // Display ID just fetched from `CGGetActiveDisplayList`, should be fine to unwrap.
+        monitors.push_back(MonitorHandle::new(display).expect("invalid display ID"));
+    }
+    monitors
+}
+
+pub fn primary_monitor() -> MonitorHandle {
+    // Display ID just fetched from `CGMainDisplayID`, should be fine to unwrap.
+    MonitorHandle::new(unsafe { CGMainDisplayID() }).expect("invalid display ID")
+}
+
+impl fmt::Debug for MonitorHandle {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("MonitorHandle")
+            .field("name", &self.name())
+            .field("uuid", &self.uuid())
+            .field("display_id", &self.display_id())
+            .field("position", &self.position())
+            .field("scale_factor", &self.scale_factor())
+            .finish_non_exhaustive()
     }
 }
 
@@ -306,15 +283,14 @@ pub(crate) fn get_display_id(screen: &NSScreen) -> u32 {
 
         // Retrieve the CGDirectDisplayID associated with this screen
         //
-        // SAFETY: The value from @"NSScreenNumber" in deviceDescription is guaranteed
-        // to be an NSNumber. See documentation for `deviceDescription` for details:
+        // The value from @"NSScreenNumber" in deviceDescription is guaranteed
+        // to be an NSNumber. See documentation for details:
         // <https://developer.apple.com/documentation/appkit/nsscreen/1388360-devicedescription?language=objc>
         let obj = device_description
-            .get(key)
-            .expect("failed getting screen display id from device description");
-        let obj: *const AnyObject = obj;
-        let obj: *const NSNumber = obj.cast();
-        let obj: &NSNumber = unsafe { &*obj };
+            .objectForKey(key)
+            .expect("failed getting screen display id from device description")
+            .downcast::<NSNumber>()
+            .expect("NSScreenNumber must be NSNumber");
 
         obj.as_u32()
     })
@@ -335,7 +311,7 @@ pub(crate) fn flip_window_screen_coordinates(frame: NSRect) -> NSPoint {
     // It is intentional that we use `CGMainDisplayID` (as opposed to
     // `NSScreen::mainScreen`), because that's what the screen coordinates
     // are relative to, no matter which display the window is currently on.
-    let main_screen_height = CGDisplay::main().bounds().size.height;
+    let main_screen_height = unsafe { CGDisplayBounds(CGMainDisplayID()) }.size.height;
 
     let y = main_screen_height - frame.size.height - frame.origin.y;
     NSPoint::new(frame.origin.x, y)
@@ -343,26 +319,81 @@ pub(crate) fn flip_window_screen_coordinates(frame: NSRect) -> NSPoint {
 
 fn refresh_rate_millihertz(id: CGDirectDisplayID, mode: &NativeDisplayMode) -> Option<NonZeroU32> {
     unsafe {
-        let refresh_rate = ffi::CGDisplayModeGetRefreshRate(mode.0);
+        let refresh_rate = CGDisplayMode::refresh_rate(Some(&mode.0));
         if refresh_rate > 0.0 {
             return NonZeroU32::new((refresh_rate * 1000.0).round() as u32);
         }
 
         let mut display_link = std::ptr::null_mut();
-        if ffi::CVDisplayLinkCreateWithCGDisplay(id, &mut display_link) != ffi::kCVReturnSuccess {
+        #[allow(deprecated)]
+        if CVDisplayLink::create_with_cg_display(id, NonNull::from(&mut display_link))
+            != kCVReturnSuccess
+        {
             return None;
         }
-        let time = ffi::CVDisplayLinkGetNominalOutputVideoRefreshPeriod(display_link);
-        ffi::CVDisplayLinkRelease(display_link);
+        let display_link = CFRetained::from_raw(NonNull::new(display_link).unwrap());
+        #[allow(deprecated)]
+        let time = display_link.nominal_output_video_refresh_period();
 
         // This value is indefinite if an invalid display link was specified
-        if time.flags & ffi::kCVTimeIsIndefinite != 0 {
+        if time.flags & CVTimeFlags::IsIndefinite.0 != 0 {
             return None;
         }
 
-        (time.time_scale as i64)
-            .checked_div(time.time_value)
+        (time.timeScale as i64)
+            .checked_div(time.timeValue)
             .map(|v| (v * 1000) as u32)
             .and_then(NonZeroU32::new)
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn uuid_stable() {
+        let handle_a = MonitorHandle::new(1).unwrap();
+        let handle_b = MonitorHandle::new(1).unwrap();
+        assert_eq!(handle_a, handle_b);
+        assert_eq!(handle_a.display_id(), handle_b.display_id());
+        assert_eq!(handle_a.uuid(), handle_b.uuid());
+
+        let handle_a = primary_monitor();
+        let handle_b = primary_monitor();
+        assert_eq!(handle_a, handle_b);
+        assert_eq!(handle_a.display_id(), handle_b.display_id());
+        assert_eq!(handle_a.uuid(), handle_b.uuid());
+    }
+
+    /// Test the MonitorHandle::new fallback.
+    #[test]
+    fn monitorhandle_from_zero() {
+        let handle0 = MonitorHandle::new(0).unwrap();
+        let handle1 = MonitorHandle::new(1).unwrap();
+        assert_eq!(handle0, handle1);
+        assert_eq!(handle0.display_id(), handle1.display_id());
+        assert_eq!(handle0.uuid(), handle1.uuid());
+    }
+
+    #[test]
+    fn from_invalid_id() {
+        // Assume there are never this many monitors connected.
+        assert!(MonitorHandle::new(10000).is_none());
+    }
+
+    /// Test that calling `CGDisplayGetDisplayIDFromUUID` on an invalid UUID returns an invalid
+    /// display ID.
+    #[test]
+    fn invalid_monitor_handle() {
+        // `CGMainDisplayID` must be called to avoid:
+        // ```
+        // Assertion failed: (did_initialize), function CGS_REQUIRE_INIT, file CGInitialization.c, line 44.
+        // ```
+        // See https://github.com/JXA-Cookbook/JXA-Cookbook/issues/27#issuecomment-277517668
+        let _ = unsafe { CGMainDisplayID() };
+
+        let handle = MonitorHandle(CFUUID::new(None).unwrap());
+        assert_eq!(handle.display_id(), 0);
+    }
+}

src/platform_impl/apple/appkit/observer.rs

@@ -9,22 +9,16 @@ use std::ptr;
 use std::rc::Weak;
 use std::time::Instant;
 
-use block2::Block;
-use core_foundation::base::{CFIndex, CFOptionFlags, CFRelease, CFTypeRef};
-use core_foundation::date::CFAbsoluteTimeGetCurrent;
-use core_foundation::runloop::{
-    kCFRunLoopAfterWaiting, kCFRunLoopBeforeWaiting, kCFRunLoopCommonModes, kCFRunLoopDefaultMode,
-    kCFRunLoopExit, CFRunLoopActivity, CFRunLoopAddObserver, CFRunLoopAddTimer, CFRunLoopGetMain,
-    CFRunLoopObserverCallBack, CFRunLoopObserverContext, CFRunLoopObserverCreate,
-    CFRunLoopObserverRef, CFRunLoopRef, CFRunLoopTimerCreate, CFRunLoopTimerInvalidate,
-    CFRunLoopTimerRef, CFRunLoopTimerSetNextFireDate, CFRunLoopWakeUp,
+use objc2::MainThreadMarker;
+use objc2_core_foundation::{
+    kCFRunLoopCommonModes, kCFRunLoopDefaultMode, CFAbsoluteTimeGetCurrent, CFIndex, CFRetained,
+    CFRunLoop, CFRunLoopActivity, CFRunLoopObserver, CFRunLoopObserverCallBack,
+    CFRunLoopObserverContext, CFRunLoopTimer,
 };
-use objc2_foundation::MainThreadMarker;
 use tracing::error;
 
 use super::app_state::AppState;
 use super::event_loop::{stop_app_on_panic, PanicInfo};
-use super::ffi;
 
 unsafe fn control_flow_handler<F>(panic_info: *mut c_void, f: F)
 where
@@ -48,8 +42,8 @@ where
 }
 
 // begin is queued with the highest priority to ensure it is processed before other observers
-extern "C" fn control_flow_begin_handler(
-    _: CFRunLoopObserverRef,
+extern "C-unwind" fn control_flow_begin_handler(
+    _: *mut CFRunLoopObserver,
     activity: CFRunLoopActivity,
     panic_info: *mut c_void,
 ) {
@@ -57,7 +51,7 @@ extern "C" fn control_flow_begin_handler(
         control_flow_handler(panic_info, |panic_info| {
             #[allow(non_upper_case_globals)]
             match activity {
-                kCFRunLoopAfterWaiting => {
+                CFRunLoopActivity::AfterWaiting => {
                     // trace!("Triggered `CFRunLoopAfterWaiting`");
                     AppState::get(MainThreadMarker::new().unwrap()).wakeup(panic_info);
                     // trace!("Completed `CFRunLoopAfterWaiting`");
@@ -70,8 +64,8 @@ extern "C" fn control_flow_begin_handler(
 
 // end is queued with the lowest priority to ensure it is processed after other observers
 // without that, LoopExiting would  get sent after AboutToWait
-extern "C" fn control_flow_end_handler(
-    _: CFRunLoopObserverRef,
+extern "C-unwind" fn control_flow_end_handler(
+    _: *mut CFRunLoopObserver,
     activity: CFRunLoopActivity,
     panic_info: *mut c_void,
 ) {
@@ -79,12 +73,12 @@ extern "C" fn control_flow_end_handler(
         control_flow_handler(panic_info, |panic_info| {
             #[allow(non_upper_case_globals)]
             match activity {
-                kCFRunLoopBeforeWaiting => {
+                CFRunLoopActivity::BeforeWaiting => {
                     // trace!("Triggered `CFRunLoopBeforeWaiting`");
                     AppState::get(MainThreadMarker::new().unwrap()).cleared(panic_info);
                     // trace!("Completed `CFRunLoopBeforeWaiting`");
                 },
-                kCFRunLoopExit => (), // unimplemented!(), // not expected to ever happen
+                CFRunLoopActivity::Exit => (), /* unimplemented!(), // not expected to ever happen */
                 _ => unreachable!(),
             }
         });
@@ -92,44 +86,32 @@ extern "C" fn control_flow_end_handler(
 }
 
 #[derive(Debug)]
-pub struct RunLoop(CFRunLoopRef);
-
-impl Default for RunLoop {
-    fn default() -> Self {
-        Self(ptr::null_mut())
-    }
-}
+pub struct RunLoop(CFRetained<CFRunLoop>);
 
 impl RunLoop {
     pub fn main(mtm: MainThreadMarker) -> Self {
         // SAFETY: We have a MainThreadMarker here, which means we know we're on the main thread, so
         // scheduling (and scheduling a non-`Send` block) to that thread is allowed.
         let _ = mtm;
-        RunLoop(unsafe { CFRunLoopGetMain() })
+        RunLoop(CFRunLoop::main().unwrap())
     }
 
     pub fn wakeup(&self) {
-        unsafe { CFRunLoopWakeUp(self.0) }
+        self.0.wake_up();
     }
 
     unsafe fn add_observer(
         &self,
-        flags: CFOptionFlags,
+        flags: CFRunLoopActivity,
+        // The lower the value, the sooner this will run
         priority: CFIndex,
         handler: CFRunLoopObserverCallBack,
         context: *mut CFRunLoopObserverContext,
     ) {
-        let observer = unsafe {
-            CFRunLoopObserverCreate(
-                ptr::null_mut(),
-                flags,
-                ffi::TRUE, // Indicates we want this to run repeatedly
-                priority,  // The lower the value, the sooner this will run
-                handler,
-                context,
-            )
-        };
-        unsafe { CFRunLoopAddObserver(self.0, observer, kCFRunLoopCommonModes) };
+        let observer =
+            unsafe { CFRunLoopObserver::new(None, flags.0, true, priority, handler, context) }
+                .unwrap();
+        self.0.add_observer(Some(&observer), unsafe { kCFRunLoopCommonModes });
     }
 
     /// Submit a closure to run on the main thread as the next step in the run loop, before other
@@ -166,10 +148,6 @@ impl RunLoop {
     /// put the event at the very front of the queue, to be handled as soon as possible after
     /// handling whatever event it's currently handling.
     pub fn queue_closure(&self, closure: impl FnOnce() + 'static) {
-        extern "C" {
-            fn CFRunLoopPerformBlock(rl: CFRunLoopRef, mode: CFTypeRef, block: &Block<dyn Fn()>);
-        }
-
         // Convert `FnOnce()` to `Block<dyn Fn()>`.
         let closure = Cell::new(Some(closure));
         let block = block2::RcBlock::new(move || {
@@ -195,10 +173,10 @@ impl RunLoop {
         // and be delivered to the application afterwards.
         //
         // [#1779]: https://github.com/rust-windowing/winit/issues/1779
-        let mode = unsafe { kCFRunLoopDefaultMode as CFTypeRef };
+        let mode = unsafe { kCFRunLoopDefaultMode.unwrap() };
 
         // SAFETY: The runloop is valid, the mode is a `CFStringRef`, and the block is `'static`.
-        unsafe { CFRunLoopPerformBlock(self.0, mode, &block) }
+        unsafe { self.0.perform_block(Some(mode), Some(&block)) }
     }
 }
 
@@ -213,15 +191,15 @@ pub fn setup_control_flow_observers(mtm: MainThreadMarker, panic_info: Weak<Pani
             copyDescription: None,
         };
         run_loop.add_observer(
-            kCFRunLoopAfterWaiting,
+            CFRunLoopActivity::AfterWaiting,
             CFIndex::MIN,
-            control_flow_begin_handler,
+            Some(control_flow_begin_handler),
             &mut context as *mut _,
         );
         run_loop.add_observer(
-            kCFRunLoopExit | kCFRunLoopBeforeWaiting,
+            CFRunLoopActivity::Exit | CFRunLoopActivity::BeforeWaiting,
             CFIndex::MAX,
-            control_flow_end_handler,
+            Some(control_flow_end_handler),
             &mut context as *mut _,
         );
     }
@@ -229,7 +207,7 @@ pub fn setup_control_flow_observers(mtm: MainThreadMarker, panic_info: Weak<Pani
 
 #[derive(Debug)]
 pub struct EventLoopWaker {
-    timer: CFRunLoopTimerRef,
+    timer: CFRetained<CFRunLoopTimer>,
 
     /// An arbitrary instant in the past, that will trigger an immediate wake
     /// We save this as the `next_fire_date` for consistency so we can
@@ -244,30 +222,28 @@ pub struct EventLoopWaker {
 
 impl Drop for EventLoopWaker {
     fn drop(&mut self) {
-        unsafe {
-            CFRunLoopTimerInvalidate(self.timer);
-            CFRelease(self.timer as _);
-        }
+        self.timer.invalidate();
     }
 }
 
 impl EventLoopWaker {
     pub(crate) fn new() -> Self {
-        extern "C" fn wakeup_main_loop(_timer: CFRunLoopTimerRef, _info: *mut c_void) {}
+        extern "C-unwind" fn wakeup_main_loop(_timer: *mut CFRunLoopTimer, _info: *mut c_void) {}
         unsafe {
             // Create a timer with a 0.1µs interval (1ns does not work) to mimic polling.
             // It is initially setup with a first fire time really far into the
             // future, but that gets changed to fire immediately in did_finish_launching
-            let timer = CFRunLoopTimerCreate(
-                ptr::null_mut(),
+            let timer = CFRunLoopTimer::new(
+                None,
                 f64::MAX,
                 0.000_000_1,
                 0,
                 0,
-                wakeup_main_loop,
+                Some(wakeup_main_loop),
                 ptr::null_mut(),
-            );
-            CFRunLoopAddTimer(CFRunLoopGetMain(), timer, kCFRunLoopCommonModes);
+            )
+            .unwrap();
+            CFRunLoop::main().unwrap().add_timer(Some(&timer), kCFRunLoopCommonModes);
             Self { timer, start_instant: Instant::now(), next_fire_date: None }
         }
     }
@@ -275,14 +251,14 @@ impl EventLoopWaker {
     pub fn stop(&mut self) {
         if self.next_fire_date.is_some() {
             self.next_fire_date = None;
-            unsafe { CFRunLoopTimerSetNextFireDate(self.timer, f64::MAX) }
+            self.timer.set_next_fire_date(f64::MAX);
         }
     }
 
     pub fn start(&mut self) {
         if self.next_fire_date != Some(self.start_instant) {
             self.next_fire_date = Some(self.start_instant);
-            unsafe { CFRunLoopTimerSetNextFireDate(self.timer, f64::MIN) }
+            self.timer.set_next_fire_date(f64::MIN);
         }
     }
 
@@ -295,13 +271,11 @@ impl EventLoopWaker {
             Some(instant) => {
                 if self.next_fire_date != Some(instant) {
                     self.next_fire_date = Some(instant);
-                    unsafe {
-                        let current = CFAbsoluteTimeGetCurrent();
-                        let duration = instant - now;
-                        let fsecs = duration.subsec_nanos() as f64 / 1_000_000_000.0
-                            + duration.as_secs() as f64;
-                        CFRunLoopTimerSetNextFireDate(self.timer, current + fsecs)
-                    }
+                    let current = CFAbsoluteTimeGetCurrent();
+                    let duration = instant - now;
+                    let fsecs = duration.subsec_nanos() as f64 / 1_000_000_000.0
+                        + duration.as_secs() as f64;
+                    self.timer.set_next_fire_date(current + fsecs);
                 }
             },
             None => {

src/platform_impl/apple/appkit/util.rs

@@ -1,5 +1,8 @@
+use objc2_core_graphics::CGError;
 use tracing::trace;
 
+use crate::error::OsError;
+
 macro_rules! trace_scope {
     ($s:literal) => {
         let _crate =
@@ -26,3 +29,12 @@ impl Drop for TraceGuard {
         trace!(target = self.module_path, "Completed `{}`", self.called_from_fn);
     }
 }
+
+#[track_caller]
+pub(crate) fn cgerr(err: CGError) -> Result<(), OsError> {
+    if err == CGError::Success {
+        Ok(())
+    } else {
+        Err(os_error!(format!("CGError {err:?}")))
+    }
+}

src/platform_impl/apple/appkit/view.rs

@@ -4,17 +4,16 @@ use std::collections::{HashMap, VecDeque};
 use std::ptr;
 use std::rc::Rc;
 
-use objc2::rc::{Retained, WeakId};
+use objc2::rc::Retained;
 use objc2::runtime::{AnyObject, Sel};
-use objc2::{declare_class, msg_send_id, mutability, sel, ClassType, DeclaredClass};
+use objc2::{define_class, msg_send, DefinedClass, MainThreadMarker};
 use objc2_app_kit::{
     NSApplication, NSCursor, NSEvent, NSEventPhase, NSResponder, NSTextInputClient,
-    NSTrackingRectTag, NSView, NSViewFrameDidChangeNotification,
+    NSTrackingRectTag, NSView, NSWindow,
 };
 use objc2_foundation::{
-    MainThreadMarker, NSArray, NSAttributedString, NSAttributedStringKey, NSCopying,
-    NSMutableAttributedString, NSNotFound, NSNotificationCenter, NSObject, NSObjectProtocol,
-    NSPoint, NSRange, NSRect, NSSize, NSString, NSUInteger,
+    NSArray, NSAttributedString, NSAttributedStringKey, NSCopying, NSMutableAttributedString,
+    NSNotFound, NSObject, NSPoint, NSRange, NSRect, NSSize, NSString, NSUInteger,
 };
 
 use super::app_state::AppState;
@@ -23,11 +22,11 @@ use super::event::{
     code_to_key, code_to_location, create_key_event, event_mods, lalt_pressed, ralt_pressed,
     scancode_to_physicalkey,
 };
-use super::window::WinitWindow;
+use super::window::window_id;
 use crate::dpi::{LogicalPosition, LogicalSize};
 use crate::event::{
-    DeviceEvent, ElementState, Ime, Modifiers, MouseButton, MouseScrollDelta, PointerKind,
-    PointerSource, TouchPhase, WindowEvent,
+    DeviceEvent, ElementState, Ime, KeyEvent, Modifiers, MouseButton, MouseScrollDelta,
+    PointerKind, PointerSource, TouchPhase, WindowEvent,
 };
 use crate::keyboard::{Key, KeyCode, KeyLocation, ModifiersState, NamedKey};
 use crate::platform::macos::OptionAsAlt;
@@ -82,7 +81,7 @@ fn key_to_modifier(key: &Key) -> Option<ModifiersState> {
     match key {
         Key::Named(NamedKey::Alt) => Some(ModifiersState::ALT),
         Key::Named(NamedKey::Control) => Some(ModifiersState::CONTROL),
-        Key::Named(NamedKey::Super) => Some(ModifiersState::SUPER),
+        Key::Named(NamedKey::Meta) => Some(ModifiersState::META),
         Key::Named(NamedKey::Shift) => Some(ModifiersState::SHIFT),
         _ => None,
     }
@@ -93,7 +92,7 @@ fn get_right_modifier_code(key: &Key) -> KeyCode {
         Key::Named(NamedKey::Alt) => KeyCode::AltRight,
         Key::Named(NamedKey::Control) => KeyCode::ControlRight,
         Key::Named(NamedKey::Shift) => KeyCode::ShiftRight,
-        Key::Named(NamedKey::Super) => KeyCode::SuperRight,
+        Key::Named(NamedKey::Meta) => KeyCode::MetaRight,
         _ => unreachable!(),
     }
 }
@@ -103,7 +102,7 @@ fn get_left_modifier_code(key: &Key) -> KeyCode {
         Key::Named(NamedKey::Alt) => KeyCode::AltLeft,
         Key::Named(NamedKey::Control) => KeyCode::ControlLeft,
         Key::Named(NamedKey::Shift) => KeyCode::ShiftLeft,
-        Key::Named(NamedKey::Super) => KeyCode::SuperLeft,
+        Key::Named(NamedKey::Meta) => KeyCode::MetaLeft,
         _ => unreachable!(),
     }
 }
@@ -134,35 +133,25 @@ pub struct ViewState {
     marked_text: RefCell<Retained<NSMutableAttributedString>>,
     accepts_first_mouse: bool,
 
-    // Weak reference because the window keeps a strong reference to the view
-    _ns_window: WeakId<WinitWindow>,
-
     /// The state of the `Option` as `Alt`.
     option_as_alt: Cell<OptionAsAlt>,
 }
 
-declare_class!(
+define_class!(
+    #[unsafe(super(NSView, NSResponder, NSObject))]
+    #[ivars = ViewState]
+    #[name = "WinitView"]
     pub(super) struct WinitView;
 
-    unsafe impl ClassType for WinitView {
-        #[inherits(NSResponder, NSObject)]
-        type Super = NSView;
-        type Mutability = mutability::MainThreadOnly;
-        const NAME: &'static str = "WinitView";
-    }
-
-    impl DeclaredClass for WinitView {
-        type Ivars = ViewState;
-    }
-
-    unsafe impl WinitView {
-        #[method(isFlipped)]
+    /// This documentation attribute makes rustfmt work for some reason?
+    impl WinitView {
+        #[unsafe(method(isFlipped))]
         fn is_flipped(&self) -> bool {
             // `winit` uses the upper-left corner as the origin.
             true
         }
 
-        #[method(viewDidMoveToWindow)]
+        #[unsafe(method(viewDidMoveToWindow))]
         fn view_did_move_to_window(&self) {
             trace_scope!("viewDidMoveToWindow");
             if let Some(tracking_rect) = self.ivars().tracking_rect.take() {
@@ -177,9 +166,10 @@ declare_class!(
             self.ivars().tracking_rect.set(Some(tracking_rect));
         }
 
-        #[method(frameDidChange:)]
-        fn frame_did_change(&self, _event: &NSEvent) {
-            trace_scope!("frameDidChange:");
+        // Not a normal method on `NSView`, it's triggered by `NSViewFrameDidChangeNotification`.
+        #[unsafe(method(viewFrameDidChangeNotification:))]
+        fn frame_did_change(&self, _notification: Option<&AnyObject>) {
+            trace_scope!("NSViewFrameDidChangeNotification");
             if let Some(tracking_rect) = self.ivars().tracking_rect.take() {
                 self.removeTrackingRect(tracking_rect);
             }
@@ -192,41 +182,45 @@ declare_class!(
             self.ivars().tracking_rect.set(Some(tracking_rect));
 
             // Emit resize event here rather than from windowDidResize because:
-            // 1. When a new window is created as a tab, the frame size may change without a window resize occurring.
-            // 2. Even when a window resize does occur on a new tabbed window, it contains the wrong size (includes tab height).
+            // 1. When a new window is created as a tab, the frame size may change without a window
+            //    resize occurring.
+            // 2. Even when a window resize does occur on a new tabbed window, it contains the wrong
+            //    size (includes tab height).
             let logical_size = LogicalSize::new(rect.size.width as f64, rect.size.height as f64);
             let size = logical_size.to_physical::<u32>(self.scale_factor());
             self.queue_event(WindowEvent::SurfaceResized(size));
         }
 
-        #[method(drawRect:)]
+        #[unsafe(method(drawRect:))]
         fn draw_rect(&self, _rect: NSRect) {
             trace_scope!("drawRect:");
 
-            // It's a workaround for https://github.com/rust-windowing/winit/issues/2640, don't replace with `self.window_id()`.
-            if let Some(window) = self.ivars()._ns_window.load() {
-                self.ivars().app_state.handle_redraw(window.id());
-            }
+            self.ivars().app_state.handle_redraw(window_id(&self.window()));
 
             // This is a direct subclass of NSView, no need to call superclass' drawRect:
         }
 
-        #[method(acceptsFirstResponder)]
+        #[unsafe(method(acceptsFirstResponder))]
         fn accepts_first_responder(&self) -> bool {
             trace_scope!("acceptsFirstResponder");
             true
         }
 
         // This is necessary to prevent a beefy terminal error on MacBook Pros:
-        // IMKInputSession [0x7fc573576ff0 presentFunctionRowItemTextInputViewWithEndpoint:completionHandler:] : [self textInputContext]=0x7fc573558e10 *NO* NSRemoteViewController to client, NSError=Error Domain=NSCocoaErrorDomain Code=4099 "The connection from pid 0 was invalidated from this process." UserInfo={NSDebugDescription=The connection from pid 0 was invalidated from this process.}, com.apple.inputmethod.EmojiFunctionRowItem
-        // TODO: Add an API extension for using `NSTouchBar`
-        #[method_id(touchBar)]
+        // IMKInputSession [0x7fc573576ff0
+        // presentFunctionRowItemTextInputViewWithEndpoint:completionHandler:] : [self
+        // textInputContext]=0x7fc573558e10 *NO* NSRemoteViewController to client, NSError=Error
+        // Domain=NSCocoaErrorDomain Code=4099 "The connection from pid 0 was invalidated from this
+        // process." UserInfo={NSDebugDescription=The connection from pid 0 was invalidated from
+        // this process.}, com.apple.inputmethod.EmojiFunctionRowItem TODO: Add an API
+        // extension for using `NSTouchBar`
+        #[unsafe(method_id(touchBar))]
         fn touch_bar(&self) -> Option<Retained<NSObject>> {
             trace_scope!("touchBar");
             None
         }
 
-        #[method(resetCursorRects)]
+        #[unsafe(method(resetCursorRects))]
         fn reset_cursor_rects(&self) {
             trace_scope!("resetCursorRects");
             let bounds = self.bounds();
@@ -241,13 +235,13 @@ declare_class!(
     }
 
     unsafe impl NSTextInputClient for WinitView {
-        #[method(hasMarkedText)]
+        #[unsafe(method(hasMarkedText))]
         fn has_marked_text(&self) -> bool {
             trace_scope!("hasMarkedText");
             self.ivars().marked_text.borrow().length() > 0
         }
 
-        #[method(markedRange)]
+        #[unsafe(method(markedRange))]
         fn marked_range(&self) -> NSRange {
             trace_scope!("markedRange");
             let length = self.ivars().marked_text.borrow().length();
@@ -259,14 +253,14 @@ declare_class!(
             }
         }
 
-        #[method(selectedRange)]
+        #[unsafe(method(selectedRange))]
         fn selected_range(&self) -> NSRange {
             trace_scope!("selectedRange");
             // Documented to return `{NSNotFound, 0}` if there is no selection.
             NSRange::new(NSNotFound as NSUInteger, 0)
         }
 
-        #[method(setMarkedText:selectedRange:replacementRange:)]
+        #[unsafe(method(setMarkedText:selectedRange:replacementRange:))]
         fn set_marked_text(
             &self,
             string: &NSObject,
@@ -276,23 +270,15 @@ declare_class!(
             // TODO: Use _replacement_range, requires changing the event to report surrounding text.
             trace_scope!("setMarkedText:selectedRange:replacementRange:");
 
-            // SAFETY: This method is guaranteed to get either a `NSString` or a `NSAttributedString`.
-            let (marked_text, string) = if string.is_kind_of::<NSAttributedString>() {
-                let string: *const NSObject = string;
-                let string: *const NSAttributedString = string.cast();
-                let string = unsafe { &*string };
-                (
-                    NSMutableAttributedString::from_attributed_nsstring(string),
-                    string.string(),
-                )
+            let (marked_text, string) = if let Some(string) =
+                string.downcast_ref::<NSAttributedString>()
+            {
+                (NSMutableAttributedString::from_attributed_nsstring(string), string.string())
+            } else if let Some(string) = string.downcast_ref::<NSString>() {
+                (NSMutableAttributedString::from_nsstring(string), string.copy())
             } else {
-                let string: *const NSObject = string;
-                let string: *const NSString = string.cast();
-                let string = unsafe { &*string };
-                (
-                    NSMutableAttributedString::from_nsstring(string),
-                    string.copy(),
-                )
+                // This method is guaranteed to get either a `NSString` or a `NSAttributedString`.
+                panic!("unexpected text {string:?}")
             };
 
             // Update marked text.
@@ -328,7 +314,7 @@ declare_class!(
             self.queue_event(WindowEvent::Ime(Ime::Preedit(string.to_string(), cursor_range)));
         }
 
-        #[method(unmarkText)]
+        #[unsafe(method(unmarkText))]
         fn unmark_text(&self) {
             trace_scope!("unmarkText");
             *self.ivars().marked_text.borrow_mut() = NSMutableAttributedString::new();
@@ -345,13 +331,13 @@ declare_class!(
             }
         }
 
-        #[method_id(validAttributesForMarkedText)]
+        #[unsafe(method_id(validAttributesForMarkedText))]
         fn valid_attributes_for_marked_text(&self) -> Retained<NSArray<NSAttributedStringKey>> {
             trace_scope!("validAttributesForMarkedText");
             NSArray::new()
         }
 
-        #[method_id(attributedSubstringForProposedRange:actualRange:)]
+        #[unsafe(method_id(attributedSubstringForProposedRange:actualRange:))]
         fn attributed_substring_for_proposed_range(
             &self,
             _range: NSRange,
@@ -361,42 +347,36 @@ declare_class!(
             None
         }
 
-        #[method(characterIndexForPoint:)]
+        #[unsafe(method(characterIndexForPoint:))]
         fn character_index_for_point(&self, _point: NSPoint) -> NSUInteger {
             trace_scope!("characterIndexForPoint:");
             0
         }
 
-        #[method(firstRectForCharacterRange:actualRange:)]
+        #[unsafe(method(firstRectForCharacterRange:actualRange:))]
         fn first_rect_for_character_range(
             &self,
             _range: NSRange,
             _actual_range: *mut NSRange,
         ) -> NSRect {
             trace_scope!("firstRectForCharacterRange:actualRange:");
-            let rect = NSRect::new(
-                self.ivars().ime_position.get(),
-                self.ivars().ime_size.get()
-            );
+            let rect = NSRect::new(self.ivars().ime_position.get(), self.ivars().ime_size.get());
             // Return value is expected to be in screen coordinates, so we need a conversion here
-            self.window()
-                .convertRectToScreen(self.convertRect_toView(rect, None))
+            self.window().convertRectToScreen(self.convertRect_toView(rect, None))
         }
 
-        #[method(insertText:replacementRange:)]
+        #[unsafe(method(insertText:replacementRange:))]
         fn insert_text(&self, string: &NSObject, _replacement_range: NSRange) {
             // TODO: Use _replacement_range, requires changing the event to report surrounding text.
             trace_scope!("insertText:replacementRange:");
 
-            // SAFETY: This method is guaranteed to get either a `NSString` or a `NSAttributedString`.
-            let string = if string.is_kind_of::<NSAttributedString>() {
-                let string: *const NSObject = string;
-                let string: *const NSAttributedString = string.cast();
-                unsafe { &*string }.string().to_string()
+            let string = if let Some(string) = string.downcast_ref::<NSAttributedString>() {
+                string.string().to_string()
+            } else if let Some(string) = string.downcast_ref::<NSString>() {
+                string.to_string()
             } else {
-                let string: *const NSObject = string;
-                let string: *const NSString = string.cast();
-                unsafe { &*string }.to_string()
+                // This method is guaranteed to get either a `NSString` or a `NSAttributedString`.
+                panic!("unexpected text {string:?}")
             };
 
             let is_control = string.chars().next().is_some_and(|c| c.is_control());
@@ -409,15 +389,16 @@ declare_class!(
             }
         }
 
-        // Basically, we're sent this message whenever a keyboard event that doesn't generate a "human
-        // readable" character happens, i.e. newlines, tabs, and Ctrl+C.
-        #[method(doCommandBySelector:)]
+        // Basically, we're sent this message whenever a keyboard event that doesn't generate a
+        // "human readable" character happens, i.e. newlines, tabs, and Ctrl+C.
+        #[unsafe(method(doCommandBySelector:))]
         fn do_command_by_selector(&self, command: Sel) {
             trace_scope!("doCommandBySelector:");
 
-            // We shouldn't forward any character from just committed text, since we'll end up sending
-            // it twice with some IMEs like Korean one. We'll also always send `Enter` in that case,
-            // which is not desired given it was used to confirm IME input.
+            // We shouldn't forward any character from just committed text, since we'll end up
+            // sending it twice with some IMEs like Korean one. We'll also always send
+            // `Enter` in that case, which is not desired given it was used to confirm
+            // IME input.
             if self.ivars().ime_state.get() == ImeState::Committed {
                 return;
             }
@@ -431,10 +412,14 @@ declare_class!(
             }
 
             // Send command action to user if they requested it.
-            let window_id = self.window().id();
+            let window_id = window_id(&self.window());
             self.ivars().app_state.maybe_queue_with_handler(move |app, event_loop| {
                 if let Some(handler) = app.macos_handler() {
-                    handler.standard_key_binding(event_loop, window_id, command.name());
+                    handler.standard_key_binding(
+                        event_loop,
+                        window_id,
+                        command.name().to_str().unwrap(),
+                    );
                 }
             });
 
@@ -444,8 +429,9 @@ declare_class!(
         }
     }
 
-    unsafe impl WinitView {
-        #[method(keyDown:)]
+    /// This documentation attribute makes rustfmt work for some reason?
+    impl WinitView {
+        #[unsafe(method(keyDown:))]
         fn key_down(&self, event: &NSEvent) {
             trace_scope!("keyDown:");
             {
@@ -488,14 +474,14 @@ declare_class!(
                     // Allow normal input after the commit.
                     self.ivars().ime_state.set(ImeState::Ground);
                     true
-                }
+                },
                 ImeState::Preedit => true,
                 // `key_down` could result in preedit clear, so compare old and current state.
                 _ => old_ime_state != self.ivars().ime_state.get(),
             };
 
             if !had_ime_input || self.ivars().forward_key_to_app.get() {
-                let key_event = create_key_event(&event, true, unsafe { event.isARepeat() }, None);
+                let key_event = create_key_event(&event, true, unsafe { event.isARepeat() });
                 self.queue_event(WindowEvent::KeyboardInput {
                     device_id: None,
                     event: key_event,
@@ -504,7 +490,7 @@ declare_class!(
             }
         }
 
-        #[method(keyUp:)]
+        #[unsafe(method(keyUp:))]
         fn key_up(&self, event: &NSEvent) {
             trace_scope!("keyUp:");
 
@@ -512,26 +498,23 @@ declare_class!(
             self.update_modifiers(&event, false);
 
             // We want to send keyboard input when we are currently in the ground state.
-            if matches!(
-                self.ivars().ime_state.get(),
-                ImeState::Ground | ImeState::Disabled
-            ) {
+            if matches!(self.ivars().ime_state.get(), ImeState::Ground | ImeState::Disabled) {
                 self.queue_event(WindowEvent::KeyboardInput {
                     device_id: None,
-                    event: create_key_event(&event, false, false, None),
+                    event: create_key_event(&event, false, false),
                     is_synthetic: false,
                 });
             }
         }
 
-        #[method(flagsChanged:)]
+        #[unsafe(method(flagsChanged:))]
         fn flags_changed(&self, event: &NSEvent) {
             trace_scope!("flagsChanged:");
 
             self.update_modifiers(event, true);
         }
 
-        #[method(insertTab:)]
+        #[unsafe(method(insertTab:))]
         fn insert_tab(&self, _sender: Option<&AnyObject>) {
             trace_scope!("insertTab:");
             let window = self.window();
@@ -542,7 +525,7 @@ declare_class!(
             }
         }
 
-        #[method(insertBackTab:)]
+        #[unsafe(method(insertBackTab:))]
         fn insert_back_tab(&self, _sender: Option<&AnyObject>) {
             trace_scope!("insertBackTab:");
             let window = self.window();
@@ -555,7 +538,7 @@ declare_class!(
 
         // Allows us to receive Cmd-. (the shortcut for closing a dialog)
         // https://bugs.eclipse.org/bugs/show_bug.cgi?id=300620#c6
-        #[method(cancelOperation:)]
+        #[unsafe(method(cancelOperation:))]
         fn cancel_operation(&self, _sender: Option<&AnyObject>) {
             let mtm = MainThreadMarker::from(self);
             trace_scope!("cancelOperation:");
@@ -565,7 +548,7 @@ declare_class!(
                 .expect("could not find current event");
 
             self.update_modifiers(&event, false);
-            let event = create_key_event(&event, true, unsafe { event.isARepeat() }, None);
+            let event = create_key_event(&event, true, unsafe { event.isARepeat() });
 
             self.queue_event(WindowEvent::KeyboardInput {
                 device_id: None,
@@ -585,42 +568,42 @@ declare_class!(
         //
         // See https://github.com/rust-windowing/winit/pull/1490 for history.
 
-        #[method(mouseDown:)]
+        #[unsafe(method(mouseDown:))]
         fn mouse_down(&self, event: &NSEvent) {
             trace_scope!("mouseDown:");
             self.mouse_motion(event);
             self.mouse_click(event, ElementState::Pressed);
         }
 
-        #[method(mouseUp:)]
+        #[unsafe(method(mouseUp:))]
         fn mouse_up(&self, event: &NSEvent) {
             trace_scope!("mouseUp:");
             self.mouse_motion(event);
             self.mouse_click(event, ElementState::Released);
         }
 
-        #[method(rightMouseDown:)]
+        #[unsafe(method(rightMouseDown:))]
         fn right_mouse_down(&self, event: &NSEvent) {
             trace_scope!("rightMouseDown:");
             self.mouse_motion(event);
             self.mouse_click(event, ElementState::Pressed);
         }
 
-        #[method(rightMouseUp:)]
+        #[unsafe(method(rightMouseUp:))]
         fn right_mouse_up(&self, event: &NSEvent) {
             trace_scope!("rightMouseUp:");
             self.mouse_motion(event);
             self.mouse_click(event, ElementState::Released);
         }
 
-        #[method(otherMouseDown:)]
+        #[unsafe(method(otherMouseDown:))]
         fn other_mouse_down(&self, event: &NSEvent) {
             trace_scope!("otherMouseDown:");
             self.mouse_motion(event);
             self.mouse_click(event, ElementState::Pressed);
         }
 
-        #[method(otherMouseUp:)]
+        #[unsafe(method(otherMouseUp:))]
         fn other_mouse_up(&self, event: &NSEvent) {
             trace_scope!("otherMouseUp:");
             self.mouse_motion(event);
@@ -629,27 +612,27 @@ declare_class!(
 
         // No tracing on these because that would be overly verbose
 
-        #[method(mouseMoved:)]
+        #[unsafe(method(mouseMoved:))]
         fn mouse_moved(&self, event: &NSEvent) {
             self.mouse_motion(event);
         }
 
-        #[method(mouseDragged:)]
+        #[unsafe(method(mouseDragged:))]
         fn mouse_dragged(&self, event: &NSEvent) {
             self.mouse_motion(event);
         }
 
-        #[method(rightMouseDragged:)]
+        #[unsafe(method(rightMouseDragged:))]
         fn right_mouse_dragged(&self, event: &NSEvent) {
             self.mouse_motion(event);
         }
 
-        #[method(otherMouseDragged:)]
+        #[unsafe(method(otherMouseDragged:))]
         fn other_mouse_dragged(&self, event: &NSEvent) {
             self.mouse_motion(event);
         }
 
-        #[method(mouseEntered:)]
+        #[unsafe(method(mouseEntered:))]
         fn mouse_entered(&self, event: &NSEvent) {
             trace_scope!("mouseEntered:");
 
@@ -663,7 +646,7 @@ declare_class!(
             });
         }
 
-        #[method(mouseExited:)]
+        #[unsafe(method(mouseExited:))]
         fn mouse_exited(&self, event: &NSEvent) {
             trace_scope!("mouseExited:");
 
@@ -677,7 +660,7 @@ declare_class!(
             });
         }
 
-        #[method(scrollWheel:)]
+        #[unsafe(method(scrollWheel:))]
         fn scroll_wheel(&self, event: &NSEvent) {
             trace_scope!("scrollWheel:");
 
@@ -694,9 +677,9 @@ declare_class!(
             };
 
             // The "momentum phase," if any, has higher priority than touch phase (the two should
-            // be mutually exclusive anyhow, which is why the API is rather incoherent). If no momentum
-            // phase is recorded (or rather, the started/ended cases of the momentum phase) then we
-            // report the touch phase.
+            // be mutually exclusive anyhow, which is why the API is rather incoherent). If no
+            // momentum phase is recorded (or rather, the started/ended cases of the
+            // momentum phase) then we report the touch phase.
             #[allow(non_upper_case_globals)]
             let phase = match unsafe { event.momentumPhase() } {
                 NSEventPhase::MayBegin | NSEventPhase::Began => TouchPhase::Started,
@@ -710,17 +693,13 @@ declare_class!(
 
             self.update_modifiers(event, false);
 
-            self.ivars().app_state.maybe_queue_with_handler(move |app, event_loop|
+            self.ivars().app_state.maybe_queue_with_handler(move |app, event_loop| {
                 app.device_event(event_loop, None, DeviceEvent::MouseWheel { delta })
-            );
-            self.queue_event(WindowEvent::MouseWheel {
-                device_id: None,
-                delta,
-                phase,
             });
+            self.queue_event(WindowEvent::MouseWheel { device_id: None, delta, phase });
         }
 
-        #[method(magnifyWithEvent:)]
+        #[unsafe(method(magnifyWithEvent:))]
         fn magnify_with_event(&self, event: &NSEvent) {
             trace_scope!("magnifyWithEvent:");
 
@@ -742,18 +721,16 @@ declare_class!(
             });
         }
 
-        #[method(smartMagnifyWithEvent:)]
+        #[unsafe(method(smartMagnifyWithEvent:))]
         fn smart_magnify_with_event(&self, event: &NSEvent) {
             trace_scope!("smartMagnifyWithEvent:");
 
             self.mouse_motion(event);
 
-            self.queue_event(WindowEvent::DoubleTapGesture {
-                device_id: None,
-            });
+            self.queue_event(WindowEvent::DoubleTapGesture { device_id: None });
         }
 
-        #[method(rotateWithEvent:)]
+        #[unsafe(method(rotateWithEvent:))]
         fn rotate_with_event(&self, event: &NSEvent) {
             trace_scope!("rotateWithEvent:");
 
@@ -775,7 +752,7 @@ declare_class!(
             });
         }
 
-        #[method(pressureChangeWithEvent:)]
+        #[unsafe(method(pressureChangeWithEvent:))]
         fn pressure_change_with_event(&self, event: &NSEvent) {
             trace_scope!("pressureChangeWithEvent:");
 
@@ -789,13 +766,13 @@ declare_class!(
         // Allows us to receive Ctrl-Tab and Ctrl-Esc.
         // Note that this *doesn't* help with any missing Cmd inputs.
         // https://github.com/chromium/chromium/blob/a86a8a6bcfa438fa3ac2eba6f02b3ad1f8e0756f/ui/views/cocoa/bridged_content_view.mm#L816
-        #[method(_wantsKeyDownForEvent:)]
+        #[unsafe(method(_wantsKeyDownForEvent:))]
         fn wants_key_down_for_event(&self, _event: &NSEvent) -> bool {
             trace_scope!("_wantsKeyDownForEvent:");
             true
         }
 
-        #[method(acceptsFirstMouse:)]
+        #[unsafe(method(acceptsFirstMouse:))]
         fn accepts_first_mouse(&self, _event: &NSEvent) -> bool {
             trace_scope!("acceptsFirstMouse:");
             self.ivars().accepts_first_mouse
@@ -806,11 +783,10 @@ declare_class!(
 impl WinitView {
     pub(super) fn new(
         app_state: &Rc<AppState>,
-        window: &WinitWindow,
         accepts_first_mouse: bool,
         option_as_alt: OptionAsAlt,
+        mtm: MainThreadMarker,
     ) -> Retained<Self> {
-        let mtm = MainThreadMarker::from(window);
         let this = mtm.alloc().set_ivars(ViewState {
             app_state: Rc::clone(app_state),
             cursor_state: Default::default(),
@@ -825,38 +801,21 @@ impl WinitView {
             forward_key_to_app: Default::default(),
             marked_text: Default::default(),
             accepts_first_mouse,
-            _ns_window: WeakId::new(&window.retain()),
             option_as_alt: Cell::new(option_as_alt),
         });
-        let this: Retained<Self> = unsafe { msg_send_id![super(this), init] };
-
-        this.setPostsFrameChangedNotifications(true);
-        let notification_center = unsafe { NSNotificationCenter::defaultCenter() };
-        unsafe {
-            notification_center.addObserver_selector_name_object(
-                &this,
-                sel!(frameDidChange:),
-                Some(NSViewFrameDidChangeNotification),
-                Some(&this),
-            )
-        }
+        let this: Retained<Self> = unsafe { msg_send![super(this), init] };
 
         *this.ivars().input_source.borrow_mut() = this.current_input_source();
 
         this
     }
 
-    fn window(&self) -> Retained<WinitWindow> {
-        // TODO: Simply use `window` property on `NSView`.
-        // That only returns a window _after_ the view has been attached though!
-        // (which is incompatible with `frameDidChange:`)
-        //
-        // unsafe { msg_send_id![self, window] }
-        self.ivars()._ns_window.load().expect("view to have a window")
+    fn window(&self) -> Retained<NSWindow> {
+        (**self).window().expect("view must be installed in a window")
     }
 
     fn queue_event(&self, event: WindowEvent) {
-        let window_id = self.window().id();
+        let window_id = window_id(&self.window());
         self.ivars().app_state.maybe_queue_with_handler(move |app, event_loop| {
             app.window_event(event_loop, window_id, event);
         });
@@ -962,22 +921,34 @@ impl WinitView {
                 let scancode = unsafe { ns_event.keyCode() };
                 let physical_key = scancode_to_physicalkey(scancode as u32);
 
-                // We'll correct the `is_press` later.
-                let mut event = create_key_event(ns_event, false, false, Some(physical_key));
-
-                let key = code_to_key(physical_key, scancode);
+                let logical_key = code_to_key(physical_key, scancode);
                 // Ignore processing of unknown modifiers because we can't determine whether
                 // it was pressed or release reliably.
-                let Some(event_modifier) = key_to_modifier(&key) else {
+                //
+                // Furthermore, sometimes normal keys are reported inside flagsChanged:, such as
+                // when holding Caps Lock while pressing another key, see:
+                // https://github.com/alacritty/alacritty/issues/8268
+                let Some(event_modifier) = key_to_modifier(&logical_key) else {
                     break 'send_event;
                 };
-                event.physical_key = physical_key;
-                event.logical_key = key.clone();
-                event.location = code_to_location(physical_key);
+
+                let mut event = KeyEvent {
+                    location: code_to_location(physical_key),
+                    logical_key: logical_key.clone(),
+                    physical_key,
+                    repeat: false,
+                    // We'll correct this later.
+                    state: Pressed,
+                    text: None,
+                    text_with_all_modifiers: None,
+                    key_without_modifiers: logical_key.clone(),
+                };
+
                 let location_mask = ModLocationMask::from_location(event.location);
 
                 let mut phys_mod_state = self.ivars().phys_modifiers.borrow_mut();
-                let phys_mod = phys_mod_state.entry(key).or_insert(ModLocationMask::empty());
+                let phys_mod =
+                    phys_mod_state.entry(logical_key).or_insert(ModLocationMask::empty());
 
                 let is_active = current_modifiers.state().contains(event_modifier);
                 let mut events = VecDeque::with_capacity(2);
@@ -1132,7 +1103,7 @@ fn replace_event(event: &NSEvent, option_as_alt: OptionAsAlt) -> Retained<NSEven
         OptionAsAlt::Both if ev_mods.alt_key() => true,
         _ => false,
     } && !ev_mods.control_key()
-        && !ev_mods.super_key();
+        && !ev_mods.meta_key();
 
     if ignore_alt_characters {
         let ns_chars = unsafe {

src/platform_impl/apple/appkit/window.rs

@@ -1,22 +1,26 @@
 #![allow(clippy::unnecessary_cast)]
 
+use std::sync::Arc;
+
+use dispatch2::MainThreadBound;
 use dpi::{Position, Size};
 use objc2::rc::{autoreleasepool, Retained};
-use objc2::{declare_class, mutability, ClassType, DeclaredClass};
-use objc2_app_kit::{NSResponder, NSWindow};
-use objc2_foundation::{MainThreadBound, MainThreadMarker, NSObject};
+use objc2::{define_class, MainThreadMarker, Message};
+use objc2_app_kit::{NSPanel, NSResponder, NSWindow};
+use objc2_foundation::NSObject;
 
 use super::event_loop::ActiveEventLoop;
 use super::window_delegate::WindowDelegate;
 use crate::error::RequestError;
-use crate::monitor::MonitorHandle as CoreMonitorHandle;
+use crate::monitor::{Fullscreen, MonitorHandle as CoreMonitorHandle};
 use crate::window::{
-    Cursor, Fullscreen, Icon, ImePurpose, Theme, UserAttentionType, Window as CoreWindow,
-    WindowAttributes, WindowButtons, WindowId, WindowLevel,
+    Cursor, Icon, ImePurpose, Theme, UserAttentionType, Window as CoreWindow, WindowAttributes,
+    WindowButtons, WindowId, WindowLevel,
 };
 
+#[derive(Debug)]
 pub(crate) struct Window {
-    window: MainThreadBound<Retained<WinitWindow>>,
+    window: MainThreadBound<Retained<NSWindow>>,
     /// The window only keeps a weak reference to this, so we must keep it around here.
     delegate: MainThreadBound<Retained<WindowDelegate>>,
 }
@@ -64,7 +68,7 @@ impl Window {
 impl Drop for Window {
     fn drop(&mut self) {
         // Restore the video mode.
-        if matches!(self.fullscreen(), Some(Fullscreen::Exclusive(_))) {
+        if matches!(self.fullscreen(), Some(Fullscreen::Exclusive(_, _))) {
             self.set_fullscreen(None);
         }
 
@@ -204,11 +208,11 @@ impl CoreWindow for Window {
     }
 
     fn set_fullscreen(&self, fullscreen: Option<Fullscreen>) {
-        self.maybe_wait_on_main(|delegate| delegate.set_fullscreen(fullscreen.map(Into::into)))
+        self.maybe_wait_on_main(|delegate| delegate.set_fullscreen(fullscreen))
     }
 
     fn fullscreen(&self) -> Option<Fullscreen> {
-        self.maybe_wait_on_main(|delegate| delegate.fullscreen().map(Into::into))
+        self.maybe_wait_on_main(|delegate| delegate.fullscreen())
     }
 
     fn set_decorations(&self, decorations: bool) {
@@ -305,21 +309,24 @@ impl CoreWindow for Window {
 
     fn current_monitor(&self) -> Option<CoreMonitorHandle> {
         self.maybe_wait_on_main(|delegate| {
-            delegate.current_monitor().map(|inner| CoreMonitorHandle { inner })
+            delegate.current_monitor().map(|monitor| CoreMonitorHandle(Arc::new(monitor)))
         })
     }
 
     fn available_monitors(&self) -> Box<dyn Iterator<Item = CoreMonitorHandle>> {
         self.maybe_wait_on_main(|delegate| {
             Box::new(
-                delegate.available_monitors().into_iter().map(|inner| CoreMonitorHandle { inner }),
+                delegate
+                    .available_monitors()
+                    .into_iter()
+                    .map(|monitor| CoreMonitorHandle(Arc::new(monitor))),
             )
         })
     }
 
     fn primary_monitor(&self) -> Option<CoreMonitorHandle> {
         self.maybe_wait_on_main(|delegate| {
-            delegate.primary_monitor().map(|inner| CoreMonitorHandle { inner })
+            delegate.primary_monitor().map(|monitor| CoreMonitorHandle(Arc::new(monitor)))
         })
     }
 
@@ -332,27 +339,21 @@ impl CoreWindow for Window {
     }
 }
 
-declare_class!(
+define_class!(
+    #[unsafe(super(NSWindow, NSResponder, NSObject))]
+    #[name = "WinitWindow"]
     #[derive(Debug)]
     pub struct WinitWindow;
 
-    unsafe impl ClassType for WinitWindow {
-        #[inherits(NSResponder, NSObject)]
-        type Super = NSWindow;
-        type Mutability = mutability::MainThreadOnly;
-        const NAME: &'static str = "WinitWindow";
-    }
-
-    impl DeclaredClass for WinitWindow {}
-
-    unsafe impl WinitWindow {
-        #[method(canBecomeMainWindow)]
+    /// This documentation attribute makes rustfmt work for some reason?
+    impl WinitWindow {
+        #[unsafe(method(canBecomeMainWindow))]
         fn can_become_main_window(&self) -> bool {
             trace_scope!("canBecomeMainWindow");
             true
         }
 
-        #[method(canBecomeKeyWindow)]
+        #[unsafe(method(canBecomeKeyWindow))]
         fn can_become_key_window(&self) -> bool {
             trace_scope!("canBecomeKeyWindow");
             true
@@ -360,8 +361,24 @@ declare_class!(
     }
 );
 
-impl WinitWindow {
-    pub(super) fn id(&self) -> WindowId {
-        WindowId::from_raw(self as *const Self as usize)
+define_class!(
+    #[unsafe(super(NSPanel, NSWindow, NSResponder, NSObject))]
+    #[name = "WinitPanel"]
+    #[derive(Debug)]
+    pub struct WinitPanel;
+
+    /// This documentation attribute makes rustfmt work for some reason?
+    impl WinitPanel {
+        // although NSPanel can become key window
+        // it doesn't if window doesn't have NSWindowStyleMask::Titled
+        #[unsafe(method(canBecomeKeyWindow))]
+        fn can_become_key_window(&self) -> bool {
+            trace_scope!("canBecomeKeyWindow");
+            true
+        }
     }
+);
+
+pub(super) fn window_id(window: &NSWindow) -> WindowId {
+    WindowId::from_raw(window as *const _ as usize)
 }

src/platform_impl/apple/event_handler.rs

@@ -1,55 +1,33 @@
-use std::cell::Cell;
+use std::cell::RefCell;
 use std::{fmt, mem};
 
 use crate::application::ApplicationHandler;
-use crate::event_loop::ActiveEventLoop;
 
 /// A helper type for storing a reference to `ApplicationHandler`, allowing interior mutable access
 /// to it within the execution of a closure.
 #[derive(Default)]
 pub(crate) struct EventHandler {
-    state: Cell<State>,
-}
-
-type InitClosure<'handler> =
-    Box<dyn FnOnce(&dyn ActiveEventLoop) -> Box<dyn ApplicationHandler + 'handler> + 'handler>;
-
-#[derive(Default)]
-enum State {
-    /// Not registered by the event loop.
-    #[default]
-    NotRegistered,
-    /// The event is registered by the event loop.
-    Registered(InitClosure<'static>),
-    /// The application has been initialized, and we're ready to handle events.
-    Ready(Box<dyn ApplicationHandler + 'static>),
-    /// Currently executing the handler.
-    CurrentlyExecuting,
-    /// The application has been terminated.
-    Terminated,
-    // TODO: Invalid state?
+    /// This can be in the following states:
+    /// - Not registered by the event loop, or terminated (None).
+    /// - Present (Some(handler)).
+    /// - Currently executing the handler / in use (RefCell borrowed).
+    inner: RefCell<Option<Box<dyn ApplicationHandler + 'static>>>,
 }
 
 impl fmt::Debug for EventHandler {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        let state = self.state.replace(State::CurrentlyExecuting);
-        // NOTE: We're very careful not to panic inside the "critial" section here.
-        let string = match &state {
-            State::NotRegistered => "<not registered>",
-            State::Registered(_) => "<registered>",
-            State::Ready(_) => "<ready>",
-            State::CurrentlyExecuting => "<currently executing>",
-            State::Terminated => "<terminated>",
+        let state = match self.inner.try_borrow().as_deref() {
+            Ok(Some(_)) => "<available>",
+            Ok(None) => "<not set>",
+            Err(_) => "<in use>",
         };
-        self.state.set(state);
-
-        f.debug_struct("EventHandler").field("state", &string).finish_non_exhaustive()
+        f.debug_struct("EventHandler").field("state", &state).finish_non_exhaustive()
     }
 }
 
 impl EventHandler {
-    pub(crate) const fn new() -> Self {
-        Self { state: Cell::new(State::NotRegistered) }
+    pub(crate) fn new() -> Self {
+        Self { inner: RefCell::new(None) }
     }
 
     /// Set the event loop handler for the duration of the given closure.
@@ -59,7 +37,7 @@ impl EventHandler {
     /// from within the closure.
     pub(crate) fn set<'handler, R>(
         &self,
-        init_closure: InitClosure<'handler>,
+        app: Box<dyn ApplicationHandler + 'handler>,
         closure: impl FnOnce() -> R,
     ) -> R {
         // SAFETY: We extend the lifetime of the handler here so that we can
@@ -68,9 +46,14 @@ impl EventHandler {
         // This is sound, since we make sure to unset the handler again at the
         // end of this function, and as such the lifetime isn't actually
         // extended beyond `'handler`.
-        let handler = unsafe { mem::transmute::<InitClosure<'handler>, InitClosure<'static>>(app) };
+        let handler = unsafe {
+            mem::transmute::<
+                Box<dyn ApplicationHandler + 'handler>,
+                Box<dyn ApplicationHandler + 'static>,
+            >(app)
+        };
 
-        match self.state.try_borrow_mut().as_deref_mut() {
+        match self.inner.try_borrow_mut().as_deref_mut() {
             Ok(Some(_)) => {
                 unreachable!("tried to set handler while another was already set");
             },
@@ -86,12 +69,15 @@ impl EventHandler {
 
         impl Drop for ClearOnDrop<'_> {
             fn drop(&mut self) {
-                match self.0.state.try_borrow_mut().as_deref_mut() {
+                match self.0.inner.try_borrow_mut().as_deref_mut() {
                     Ok(data @ Some(_)) => {
-                        *data = None;
+                        let handler = data.take();
+                        // Explicitly `Drop` the application handler.
+                        drop(handler);
                     },
                     Ok(None) => {
-                        tracing::error!("tried to clear handler, but no handler was set");
+                        // Allowed, happens if the handler was cleared manually
+                        // elsewhere (such as in `applicationWillTerminate:`).
                     },
                     Err(_) => {
                         // Note: This is not expected to ever happen, this
@@ -118,30 +104,25 @@ impl EventHandler {
         // soundness.
     }
 
-    fn init(&self) {}
-
-    fn terminate(&self) {}
-
     #[cfg(target_os = "macos")]
     pub(crate) fn in_use(&self) -> bool {
         self.inner.try_borrow().is_err()
     }
 
-    #[cfg(target_os = "macos")]
     pub(crate) fn ready(&self) -> bool {
         matches!(self.inner.try_borrow().as_deref(), Ok(Some(_)))
     }
 
-    pub(crate) fn handle(&self, callback: impl FnOnce(&mut dyn ApplicationHandler)) {
+    pub(crate) fn handle(&self, callback: impl FnOnce(&mut (dyn ApplicationHandler + '_))) {
         match self.inner.try_borrow_mut().as_deref_mut() {
-            Ok(Some(user_app)) => {
+            Ok(Some(ref mut user_app)) => {
                 // It is important that we keep the reference borrowed here,
                 // so that `in_use` can properly detect that the handler is
                 // still in use.
                 //
                 // If the handler unwinds, the `RefMut` will ensure that the
                 // handler is no longer borrowed.
-                callback(user_app);
+                callback(&mut **user_app);
             },
             Ok(None) => {
                 // `NSApplication`, our app state and this handler are all
@@ -155,4 +136,21 @@ impl EventHandler {
             },
         }
     }
+
+    pub(crate) fn terminate(&self) {
+        match self.inner.try_borrow_mut().as_deref_mut() {
+            Ok(data @ Some(_)) => {
+                let handler = data.take();
+                // Explicitly `Drop` the application handler.
+                drop(handler);
+            },
+            Ok(None) => {
+                // When terminating, we expect the application handler to still be registered.
+                tracing::error!("tried to clear handler, but no handler was set");
+            },
+            Err(_) => {
+                panic!("tried to clear handler while an event is currently being handled");
+            },
+        }
+    }
 }

src/platform_impl/apple/event_loop_proxy.rs

@@ -0,0 +1,124 @@
+use std::os::raw::c_void;
+use std::sync::Arc;
+
+use objc2::MainThreadMarker;
+use objc2_core_foundation::{
+    kCFRunLoopCommonModes, CFIndex, CFRetained, CFRunLoop, CFRunLoopSource, CFRunLoopSourceContext,
+};
+
+use crate::event_loop::EventLoopProxyProvider;
+
+/// A waker that signals a `CFRunLoopSource` on the main thread.
+///
+/// We use this to integrate with the system as cleanly as possible (instead of e.g. keeping an
+/// atomic around that we check on each iteration of the event loop).
+///
+/// See <https://developer.apple.com/documentation/corefoundation/cfrunloopsource?language=objc>.
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub(crate) struct EventLoopProxy {
+    source: CFRetained<CFRunLoopSource>,
+    /// Cached value of `CFRunLoopGetMain`.
+    main_loop: CFRetained<CFRunLoop>,
+}
+
+// FIXME(madsmtm): Mark `CFRunLoopSource` + `CFRunLoop` as `Send` + `Sync`.
+unsafe impl Send for EventLoopProxy {}
+unsafe impl Sync for EventLoopProxy {}
+
+impl EventLoopProxy {
+    /// Create a new proxy, registering it to be performed on the main thread.
+    ///
+    /// The provided closure should call `proxy_wake_up` on the application.
+    pub(crate) fn new<F: Fn() + 'static>(mtm: MainThreadMarker, signaller: F) -> Self {
+        // We use an `Arc` here to make sure that the reference-counting of the signal container is
+        // atomic (`Retained`/`CFRetained` would be valid alternatives too).
+        let signaller = Arc::new(signaller);
+
+        unsafe extern "C-unwind" fn retain<F>(info: *const c_void) -> *const c_void {
+            // SAFETY: The pointer was passed to `CFRunLoopSourceContext.info` below.
+            unsafe { Arc::increment_strong_count(info.cast::<F>()) };
+            info
+        }
+        unsafe extern "C-unwind" fn release<F>(info: *const c_void) {
+            // SAFETY: The pointer was passed to `CFRunLoopSourceContext.info` below.
+            unsafe { Arc::decrement_strong_count(info.cast::<F>()) };
+        }
+
+        // Pointer equality / hashing.
+        extern "C-unwind" fn equal(info1: *const c_void, info2: *const c_void) -> u8 {
+            (info1 == info2) as u8
+        }
+        extern "C-unwind" fn hash(info: *const c_void) -> usize {
+            info as usize
+        }
+
+        // Call the provided closure.
+        unsafe extern "C-unwind" fn perform<F: Fn()>(info: *mut c_void) {
+            // SAFETY: The pointer was passed to `CFRunLoopSourceContext.info` below.
+            let signaller = unsafe { &*info.cast::<F>() };
+            (signaller)();
+        }
+
+        // Fire last.
+        let order = CFIndex::MAX - 1;
+
+        // This is marked `mut` to match the signature of `CFRunLoopSourceCreate`, but the
+        // information is copied, and not actually mutated.
+        let mut context = CFRunLoopSourceContext {
+            version: 0,
+            // This is retained on creation.
+            info: Arc::as_ptr(&signaller) as *mut c_void,
+            retain: Some(retain::<F>),
+            release: Some(release::<F>),
+            copyDescription: None,
+            equal: Some(equal),
+            hash: Some(hash),
+            schedule: None,
+            cancel: None,
+            perform: Some(perform::<F>),
+        };
+
+        // SAFETY: The normal callbacks are thread-safe (`retain`/`release` use atomics, and
+        // `equal`/`hash` only access a pointer).
+        //
+        // Note that the `perform` callback isn't thread-safe (we don't have `F: Send + Sync`), but
+        // that's okay, since we are on the main thread, and the source is only added to the main
+        // run loop (below), and hence only performed there.
+        //
+        // Keeping the closure alive beyond this scope is fine, because `F: 'static`.
+        let source = unsafe {
+            let _ = mtm;
+            CFRunLoopSource::new(None, order, &mut context).unwrap()
+        };
+
+        // Register the source to be performed on the main thread.
+        let main_loop = CFRunLoop::main().unwrap();
+        unsafe { main_loop.add_source(Some(&source), kCFRunLoopCommonModes) };
+
+        Self { source, main_loop }
+    }
+
+    // FIXME(madsmtm): Use this on macOS too.
+    // More difficult there, since the user can re-start the event loop.
+    #[cfg_attr(target_os = "macos", allow(dead_code))]
+    pub(crate) fn invalidate(&self) {
+        // NOTE: We do NOT fire this on `Drop`, since we want the proxy to be cloneable, such that
+        // we only need to register a single source even if there's multiple proxies in use.
+        self.source.invalidate();
+    }
+}
+
+impl EventLoopProxyProvider for EventLoopProxy {
+    fn wake_up(&self) {
+        // Signal the source, which ends up later invoking `perform` on the main thread.
+        //
+        // Multiple signals in quick succession are automatically coalesced into a single signal.
+        self.source.signal();
+
+        // Let the main thread know there's a new event.
+        //
+        // This is required since we may be (probably are) running on a different thread, and the
+        // main loop may be sleeping (and `CFRunLoopSourceSignal` won't wake it).
+        self.main_loop.wake_up();
+    }
+}

src/platform_impl/apple/mod.rs

@@ -3,6 +3,7 @@
 #[cfg(target_os = "macos")]
 mod appkit;
 mod event_handler;
+mod event_loop_proxy;
 mod notification_center;
 #[cfg(not(target_os = "macos"))]
 mod uikit;

src/platform_impl/apple/notification_center.rs

@@ -2,7 +2,10 @@ use std::ptr::NonNull;
 
 use block2::RcBlock;
 use objc2::rc::Retained;
-use objc2_foundation::{NSNotification, NSNotificationCenter, NSNotificationName, NSObject};
+use objc2::runtime::ProtocolObject;
+use objc2_foundation::{
+    NSNotification, NSNotificationCenter, NSNotificationName, NSObjectProtocol,
+};
 
 /// Observe the given notification.
 ///
@@ -12,7 +15,7 @@ pub fn create_observer(
     center: &NSNotificationCenter,
     name: &NSNotificationName,
     handler: impl Fn(&NSNotification) + 'static,
-) -> Retained<NSObject> {
+) -> Retained<ProtocolObject<dyn NSObjectProtocol>> {
     let block = RcBlock::new(move |notification: NonNull<NSNotification>| {
         handler(unsafe { notification.as_ref() });
     });

src/platform_impl/apple/uikit/app_state.rs

@@ -3,32 +3,28 @@
 use std::cell::{OnceCell, RefCell, RefMut};
 use std::collections::HashSet;
 use std::os::raw::c_void;
-use std::sync::atomic::Ordering;
-use std::sync::{Arc, Mutex, OnceLock};
+use std::sync::{Arc, Mutex};
 use std::time::Instant;
 use std::{mem, ptr};
 
-use core_foundation::base::CFRelease;
-use core_foundation::date::CFAbsoluteTimeGetCurrent;
-use core_foundation::runloop::{
-    kCFRunLoopCommonModes, CFRunLoopAddTimer, CFRunLoopGetMain, CFRunLoopRef, CFRunLoopTimerCreate,
-    CFRunLoopTimerInvalidate, CFRunLoopTimerRef, CFRunLoopTimerSetNextFireDate,
-};
+use dispatch2::MainThreadBound;
 use objc2::rc::Retained;
-use objc2::sel;
-use objc2_foundation::{
-    CGRect, CGSize, MainThreadMarker, NSInteger, NSObjectProtocol, NSOperatingSystemVersion,
-    NSProcessInfo,
+use objc2::MainThreadMarker;
+use objc2_core_foundation::{
+    kCFRunLoopCommonModes, CFAbsoluteTimeGetCurrent, CFRetained, CFRunLoop, CFRunLoopTimer, CGRect,
+    CGSize,
 };
-use objc2_ui_kit::{UIApplication, UICoordinateSpace, UIView, UIWindow};
+use objc2_ui_kit::{UIApplication, UICoordinateSpace, UIView};
 
 use super::super::event_handler::EventHandler;
+use super::super::event_loop_proxy::EventLoopProxy;
 use super::window::WinitUIWindow;
-use super::{ActiveEventLoop, EventLoopProxy};
+use super::ActiveEventLoop;
 use crate::application::ApplicationHandler;
 use crate::dpi::PhysicalSize;
-use crate::event::{Event, StartCause, SurfaceSizeWriter, WindowEvent};
+use crate::event::{StartCause, SurfaceSizeWriter, WindowEvent};
 use crate::event_loop::ControlFlow;
+use crate::window::WindowId;
 
 macro_rules! bug {
     ($($msg:tt)*) => {
@@ -47,45 +43,17 @@ macro_rules! bug_assert {
 /// This is stored separately from AppState, since AppState needs to be accessible while the handler
 /// is executing.
 fn get_handler(mtm: MainThreadMarker) -> &'static EventHandler {
-    // TODO(madsmtm): Use `MainThreadBound` once that is possible in `static`s.
-    struct StaticMainThreadBound<T>(T);
-
-    impl<T> StaticMainThreadBound<T> {
-        const fn get(&self, _mtm: MainThreadMarker) -> &T {
-            &self.0
-        }
-    }
-
-    unsafe impl<T> Send for StaticMainThreadBound<T> {}
-    unsafe impl<T> Sync for StaticMainThreadBound<T> {}
-
     // SAFETY: Creating `StaticMainThreadBound` in a `const` context, where there is no concept
     // of the main thread.
-    static GLOBAL: StaticMainThreadBound<OnceCell<EventHandler>> =
-        StaticMainThreadBound(OnceCell::new());
+    static GLOBAL: MainThreadBound<OnceCell<EventHandler>> =
+        MainThreadBound::new(OnceCell::new(), unsafe { MainThreadMarker::new_unchecked() });
 
     GLOBAL.get(mtm).get_or_init(EventHandler::new)
 }
 
-fn handle_event(mtm: MainThreadMarker, event: Event) {
-    let event_loop = &ActiveEventLoop { mtm };
-    get_handler(mtm).handle(|app| match event {
-        Event::NewEvents(cause) => app.new_events(event_loop, cause),
-        Event::WindowEvent { window_id, event } => app.window_event(event_loop, window_id, event),
-        Event::DeviceEvent { device_id, event } => app.device_event(event_loop, device_id, event),
-        Event::UserWakeUp => app.proxy_wake_up(event_loop),
-        Event::Suspended => app.suspended(event_loop),
-        Event::Resumed => app.resumed(event_loop),
-        Event::CreateSurfaces => app.can_create_surfaces(event_loop),
-        Event::AboutToWait => app.about_to_wait(event_loop),
-        Event::LoopExiting => app.exiting(event_loop),
-        Event::MemoryWarning => app.memory_warning(event_loop),
-    })
-}
-
 #[derive(Debug)]
 pub(crate) enum EventWrapper {
-    StaticEvent(Event),
+    Window { window_id: WindowId, event: WindowEvent },
     ScaleFactorChanged(ScaleFactorChanged),
 }
 
@@ -96,14 +64,9 @@ pub struct ScaleFactorChanged {
     pub(super) scale_factor: f64,
 }
 
-enum UserCallbackTransitionResult<'a> {
-    Success { active_control_flow: ControlFlow, processing_redraws: bool },
-    ReentrancyPrevented { queued_events: &'a mut Vec<EventWrapper> },
-}
-
-impl Event {
+impl EventWrapper {
     fn is_redraw(&self) -> bool {
-        matches!(self, Event::WindowEvent { event: WindowEvent::RedrawRequested, .. })
+        matches!(self, Self::Window { event: WindowEvent::RedrawRequested, .. })
     }
 }
 
@@ -112,18 +75,12 @@ impl Event {
 #[must_use = "dropping `AppStateImpl` without inspecting it is probably a bug"]
 enum AppStateImpl {
     Initial {
-        queued_events: Vec<EventWrapper>,
         queued_gpu_redraws: HashSet<Retained<WinitUIWindow>>,
     },
     ProcessingEvents {
         queued_gpu_redraws: HashSet<Retained<WinitUIWindow>>,
         active_control_flow: ControlFlow,
     },
-    // special state to deal with reentrancy and prevent mutable aliasing.
-    InUserCallback {
-        queued_events: Vec<EventWrapper>,
-        queued_gpu_redraws: HashSet<Retained<WinitUIWindow>>,
-    },
     ProcessingRedraws {
         active_control_flow: ControlFlow,
     },
@@ -140,10 +97,11 @@ pub(crate) struct AppState {
     control_flow: ControlFlow,
     waker: EventLoopWaker,
     event_loop_proxy: Arc<EventLoopProxy>,
+    queued_events: Vec<EventWrapper>,
 }
 
 impl AppState {
-    pub(crate) fn get_mut(_mtm: MainThreadMarker) -> RefMut<'static, AppState> {
+    pub(crate) fn get_mut(mtm: MainThreadMarker) -> RefMut<'static, AppState> {
         // basically everything in UIKit requires the main thread, so it's pointless to use the
         // std::sync APIs.
         // must be mut because plain `static` requires `Sync`
@@ -155,19 +113,21 @@ impl AppState {
         if guard.is_none() {
             #[inline(never)]
             #[cold]
-            fn init_guard(guard: &mut RefMut<'static, Option<AppState>>) {
-                let waker = EventLoopWaker::new(unsafe { CFRunLoopGetMain() });
+            fn init_guard(guard: &mut RefMut<'static, Option<AppState>>, mtm: MainThreadMarker) {
+                let waker = EventLoopWaker::new(CFRunLoop::main().unwrap());
+                let event_loop_proxy = Arc::new(EventLoopProxy::new(mtm, move || {
+                    get_handler(mtm).handle(|app| app.proxy_wake_up(&ActiveEventLoop { mtm }));
+                }));
+
                 **guard = Some(AppState {
-                    app_state: Some(AppStateImpl::Initial {
-                        queued_events: Vec::new(),
-                        queued_gpu_redraws: HashSet::new(),
-                    }),
+                    app_state: Some(AppStateImpl::Initial { queued_gpu_redraws: HashSet::new() }),
                     control_flow: ControlFlow::default(),
                     waker,
-                    event_loop_proxy: Arc::new(EventLoopProxy::new()),
+                    event_loop_proxy,
+                    queued_events: Vec::new(),
                 });
             }
-            init_guard(&mut guard);
+            init_guard(&mut guard, mtm);
         }
         RefMut::map(guard, |state| state.as_mut().unwrap())
     }
@@ -217,48 +177,34 @@ impl AppState {
         matches!(self.state(), AppStateImpl::Terminated)
     }
 
-    fn did_finish_launching_transition(&mut self) -> Vec<EventWrapper> {
-        let (events, queued_gpu_redraws) = match self.take_state() {
-            AppStateImpl::Initial { queued_events, queued_gpu_redraws } => {
-                (queued_events, queued_gpu_redraws)
-            },
+    fn did_finish_launching_transition(&mut self) {
+        let queued_gpu_redraws = match self.take_state() {
+            AppStateImpl::Initial { queued_gpu_redraws } => queued_gpu_redraws,
             s => bug!("unexpected state {:?}", s),
         };
         self.set_state(AppStateImpl::ProcessingEvents {
             active_control_flow: self.control_flow,
             queued_gpu_redraws,
         });
-        events
     }
 
-    fn wakeup_transition(&mut self) -> Option<EventWrapper> {
+    fn wakeup_transition(&mut self) -> Option<StartCause> {
         // before `AppState::did_finish_launching` is called, pretend there is no running
         // event loop.
         if !self.has_launched() || self.has_terminated() {
             return None;
         }
 
-        let event = match (self.control_flow, self.take_state()) {
-            (ControlFlow::Poll, AppStateImpl::PollFinished) => {
-                EventWrapper::StaticEvent(Event::NewEvents(StartCause::Poll))
-            },
+        let start_cause = match (self.control_flow, self.take_state()) {
+            (ControlFlow::Poll, AppStateImpl::PollFinished) => StartCause::Poll,
             (ControlFlow::Wait, AppStateImpl::Waiting { start }) => {
-                EventWrapper::StaticEvent(Event::NewEvents(StartCause::WaitCancelled {
-                    start,
-                    requested_resume: None,
-                }))
+                StartCause::WaitCancelled { start, requested_resume: None }
             },
             (ControlFlow::WaitUntil(requested_resume), AppStateImpl::Waiting { start }) => {
                 if Instant::now() >= requested_resume {
-                    EventWrapper::StaticEvent(Event::NewEvents(StartCause::ResumeTimeReached {
-                        start,
-                        requested_resume,
-                    }))
+                    StartCause::ResumeTimeReached { start, requested_resume }
                 } else {
-                    EventWrapper::StaticEvent(Event::NewEvents(StartCause::WaitCancelled {
-                        start,
-                        requested_resume: Some(requested_resume),
-                    }))
+                    StartCause::WaitCancelled { start, requested_resume: Some(requested_resume) }
                 }
             },
             s => bug!("`EventHandler` unexpectedly woke up {:?}", s),
@@ -268,55 +214,7 @@ impl AppState {
             queued_gpu_redraws: Default::default(),
             active_control_flow: self.control_flow,
         });
-        Some(event)
-    }
-
-    fn try_user_callback_transition(&mut self) -> UserCallbackTransitionResult<'_> {
-        // If we're not able to process an event due to recursion or `Init` not having been sent out
-        // yet, then queue the events up.
-        match self.state_mut() {
-            &mut AppStateImpl::Initial { ref mut queued_events, .. }
-            | &mut AppStateImpl::InUserCallback { ref mut queued_events, .. } => {
-                // A lifetime cast: early returns are not currently handled well with NLL, but
-                // polonius handles them well. This transmute is a safe workaround.
-                return unsafe {
-                    mem::transmute::<
-                        UserCallbackTransitionResult<'_>,
-                        UserCallbackTransitionResult<'_>,
-                    >(UserCallbackTransitionResult::ReentrancyPrevented {
-                        queued_events,
-                    })
-                };
-            },
-
-            &mut AppStateImpl::ProcessingEvents { .. }
-            | &mut AppStateImpl::ProcessingRedraws { .. } => {},
-
-            s @ &mut AppStateImpl::PollFinished { .. }
-            | s @ &mut AppStateImpl::Waiting { .. }
-            | s @ &mut AppStateImpl::Terminated => {
-                bug!("unexpected attempted to process an event {:?}", s)
-            },
-        }
-
-        let (queued_gpu_redraws, active_control_flow, processing_redraws) = match self.take_state()
-        {
-            AppStateImpl::Initial { .. } | AppStateImpl::InUserCallback { .. } => unreachable!(),
-            AppStateImpl::ProcessingEvents { queued_gpu_redraws, active_control_flow } => {
-                (queued_gpu_redraws, active_control_flow, false)
-            },
-            AppStateImpl::ProcessingRedraws { active_control_flow } => {
-                (Default::default(), active_control_flow, true)
-            },
-            AppStateImpl::PollFinished { .. }
-            | AppStateImpl::Waiting { .. }
-            | AppStateImpl::Terminated => unreachable!(),
-        };
-        self.set_state(AppStateImpl::InUserCallback {
-            queued_events: Vec::new(),
-            queued_gpu_redraws,
-        });
-        UserCallbackTransitionResult::Success { active_control_flow, processing_redraws }
+        Some(start_cause)
     }
 
     fn main_events_cleared_transition(&mut self) -> HashSet<Retained<WinitUIWindow>> {
@@ -344,6 +242,7 @@ impl AppState {
             (ControlFlow::Wait, ControlFlow::Wait) => {
                 let start = Instant::now();
                 self.set_state(AppStateImpl::Waiting { start });
+                self.waker.stop()
             },
             (ControlFlow::WaitUntil(old_instant), ControlFlow::WaitUntil(new_instant))
                 if old_instant == new_instant =>
@@ -372,7 +271,7 @@ impl AppState {
     fn terminated_transition(&mut self) {
         match self.replace_state(AppStateImpl::Terminated) {
             AppStateImpl::ProcessingEvents { .. } => {},
-            s => bug!("`LoopExiting` happened while not processing events {:?}", s),
+            s => bug!("terminated while not processing events {:?}", s),
         }
     }
 
@@ -393,21 +292,24 @@ pub(crate) fn queue_gl_or_metal_redraw(mtm: MainThreadMarker, window: Retained<W
     let mut this = AppState::get_mut(mtm);
     match this.state_mut() {
         &mut AppStateImpl::Initial { ref mut queued_gpu_redraws, .. }
-        | &mut AppStateImpl::ProcessingEvents { ref mut queued_gpu_redraws, .. }
-        | &mut AppStateImpl::InUserCallback { ref mut queued_gpu_redraws, .. } => {
+        | &mut AppStateImpl::ProcessingEvents { ref mut queued_gpu_redraws, .. } => {
             let _ = queued_gpu_redraws.insert(window);
         },
         s @ &mut AppStateImpl::ProcessingRedraws { .. }
         | s @ &mut AppStateImpl::Waiting { .. }
-        | s @ &mut AppStateImpl::PollFinished { .. } => bug!("unexpected state {:?}", s),
+        | s @ &mut AppStateImpl::PollFinished => bug!("unexpected state {:?}", s),
         &mut AppStateImpl::Terminated => {
             panic!("Attempt to create a `Window` after the app has terminated")
         },
     }
 }
 
-pub(crate) fn launch(mtm: MainThreadMarker, app: &mut dyn ApplicationHandler, run: impl FnOnce()) {
-    get_handler(mtm).set(app, run)
+pub(crate) fn launch<R>(
+    mtm: MainThreadMarker,
+    app: impl ApplicationHandler,
+    run: impl FnOnce() -> R,
+) -> R {
+    get_handler(mtm).set(Box::new(app), run)
 }
 
 pub fn did_finish_launching(mtm: MainThreadMarker) {
@@ -418,27 +320,24 @@ pub fn did_finish_launching(mtm: MainThreadMarker) {
     // have to drop RefMut because the window setup code below can trigger new events
     drop(this);
 
-    let events = AppState::get_mut(mtm).did_finish_launching_transition();
+    AppState::get_mut(mtm).did_finish_launching_transition();
 
-    let events = [
-        EventWrapper::StaticEvent(Event::NewEvents(StartCause::Init)),
-        EventWrapper::StaticEvent(Event::CreateSurfaces),
-    ]
-    .into_iter()
-    .chain(events);
-    handle_nonuser_events(mtm, events);
+    get_handler(mtm).handle(|app| app.new_events(&ActiveEventLoop { mtm }, StartCause::Init));
+    get_handler(mtm).handle(|app| app.can_create_surfaces(&ActiveEventLoop { mtm }));
+    handle_nonuser_events(mtm, []);
 }
 
 // AppState::did_finish_launching handles the special transition `Init`
 pub fn handle_wakeup_transition(mtm: MainThreadMarker) {
     let mut this = AppState::get_mut(mtm);
-    let wakeup_event = match this.wakeup_transition() {
+    let cause = match this.wakeup_transition() {
         None => return,
-        Some(wakeup_event) => wakeup_event,
+        Some(cause) => cause,
     };
     drop(this);
 
-    handle_nonuser_event(mtm, wakeup_event)
+    get_handler(mtm).handle(|app| app.new_events(&ActiveEventLoop { mtm }, cause));
+    handle_nonuser_events(mtm, []);
 }
 
 pub(crate) fn handle_nonuser_event(mtm: MainThreadMarker, event: EventWrapper) {
@@ -454,132 +353,66 @@ pub(crate) fn handle_nonuser_events<I: IntoIterator<Item = EventWrapper>>(
         return;
     }
 
-    let (active_control_flow, processing_redraws) = match this.try_user_callback_transition() {
-        UserCallbackTransitionResult::ReentrancyPrevented { queued_events } => {
-            queued_events.extend(events);
-            return;
-        },
-        UserCallbackTransitionResult::Success { active_control_flow, processing_redraws } => {
-            (active_control_flow, processing_redraws)
-        },
-    };
+    if !get_handler(mtm).ready() {
+        // Prevent re-entrancy; queue the events up for once we're done handling the event instead.
+        this.queued_events.extend(events);
+        return;
+    }
+
+    let processing_redraws = matches!(this.state(), AppStateImpl::ProcessingRedraws { .. });
     drop(this);
 
-    for wrapper in events {
-        match wrapper {
-            EventWrapper::StaticEvent(event) => {
-                if !processing_redraws && event.is_redraw() {
-                    tracing::info!("processing `RedrawRequested` during the main event loop");
-                } else if processing_redraws && !event.is_redraw() {
-                    tracing::warn!(
-                        "processing non `RedrawRequested` event after the main event loop: {:#?}",
-                        event
-                    );
-                }
-                handle_event(mtm, event)
-            },
-            EventWrapper::ScaleFactorChanged(event) => handle_hidpi_proxy(mtm, event),
+    for event in events {
+        if !processing_redraws && event.is_redraw() {
+            tracing::info!("processing `RedrawRequested` during the main event loop");
+        } else if processing_redraws && !event.is_redraw() {
+            tracing::warn!(
+                "processing non `RedrawRequested` event after the main event loop: {:#?}",
+                event
+            );
         }
+        handle_wrapped_event(mtm, event)
     }
 
     loop {
         let mut this = AppState::get_mut(mtm);
-        let queued_events = match this.state_mut() {
-            &mut AppStateImpl::InUserCallback { ref mut queued_events, queued_gpu_redraws: _ } => {
-                mem::take(queued_events)
-            },
-            s => bug!("unexpected state {:?}", s),
-        };
+        let queued_events = mem::take(&mut this.queued_events);
         if queued_events.is_empty() {
-            let queued_gpu_redraws = match this.take_state() {
-                AppStateImpl::InUserCallback { queued_events: _, queued_gpu_redraws } => {
-                    queued_gpu_redraws
-                },
-                _ => unreachable!(),
-            };
-            this.app_state = Some(if processing_redraws {
-                bug_assert!(
-                    queued_gpu_redraws.is_empty(),
-                    "redraw queued while processing redraws"
-                );
-                AppStateImpl::ProcessingRedraws { active_control_flow }
-            } else {
-                AppStateImpl::ProcessingEvents { queued_gpu_redraws, active_control_flow }
-            });
             break;
         }
         drop(this);
 
-        for wrapper in queued_events {
-            match wrapper {
-                EventWrapper::StaticEvent(event) => {
-                    if !processing_redraws && event.is_redraw() {
-                        tracing::info!("processing `RedrawRequested` during the main event loop");
-                    } else if processing_redraws && !event.is_redraw() {
-                        tracing::warn!(
-                            "processing non-`RedrawRequested` event after the main event loop: \
-                             {:#?}",
-                            event
-                        );
-                    }
-                    handle_event(mtm, event)
-                },
-                EventWrapper::ScaleFactorChanged(event) => handle_hidpi_proxy(mtm, event),
+        for event in queued_events {
+            if !processing_redraws && event.is_redraw() {
+                tracing::info!("processing `RedrawRequested` during the main event loop");
+            } else if processing_redraws && !event.is_redraw() {
+                tracing::warn!(
+                    "processing non-`RedrawRequested` event after the main event loop: {:#?}",
+                    event
+                );
             }
+            handle_wrapped_event(mtm, event);
         }
     }
 }
 
 fn handle_user_events(mtm: MainThreadMarker) {
-    let mut this = AppState::get_mut(mtm);
-    let (active_control_flow, processing_redraws) = match this.try_user_callback_transition() {
-        UserCallbackTransitionResult::ReentrancyPrevented { .. } => {
-            bug!("unexpected attempted to process an event")
-        },
-        UserCallbackTransitionResult::Success { active_control_flow, processing_redraws } => {
-            (active_control_flow, processing_redraws)
-        },
-    };
-    if processing_redraws {
+    let this = AppState::get_mut(mtm);
+    if matches!(this.state(), AppStateImpl::ProcessingRedraws { .. }) {
         bug!("user events attempted to be sent out while `ProcessingRedraws`");
     }
-    let event_loop_proxy = this.event_loop_proxy().clone();
     drop(this);
 
-    if event_loop_proxy.wake_up.swap(false, Ordering::Relaxed) {
-        handle_event(mtm, Event::UserWakeUp);
-    }
-
     loop {
         let mut this = AppState::get_mut(mtm);
-        let queued_events = match this.state_mut() {
-            &mut AppStateImpl::InUserCallback { ref mut queued_events, queued_gpu_redraws: _ } => {
-                mem::take(queued_events)
-            },
-            s => bug!("unexpected state {:?}", s),
-        };
+        let queued_events = mem::take(&mut this.queued_events);
         if queued_events.is_empty() {
-            let queued_gpu_redraws = match this.take_state() {
-                AppStateImpl::InUserCallback { queued_events: _, queued_gpu_redraws } => {
-                    queued_gpu_redraws
-                },
-                _ => unreachable!(),
-            };
-            this.app_state =
-                Some(AppStateImpl::ProcessingEvents { queued_gpu_redraws, active_control_flow });
             break;
         }
         drop(this);
 
-        for wrapper in queued_events {
-            match wrapper {
-                EventWrapper::StaticEvent(event) => handle_event(mtm, event),
-                EventWrapper::ScaleFactorChanged(event) => handle_hidpi_proxy(mtm, event),
-            }
-        }
-
-        if event_loop_proxy.wake_up.swap(false, Ordering::Relaxed) {
-            handle_event(mtm, Event::UserWakeUp);
+        for event in queued_events {
+            handle_wrapped_event(mtm, event);
         }
     }
 }
@@ -590,17 +423,11 @@ pub(crate) fn send_occluded_event_for_all_windows(application: &UIApplication, o
     let mut events = Vec::new();
     #[allow(deprecated)]
     for window in application.windows().iter() {
-        if window.is_kind_of::<WinitUIWindow>() {
-            // SAFETY: We just checked that the window is a `winit` window
-            let window = unsafe {
-                let ptr: *const UIWindow = window;
-                let ptr: *const WinitUIWindow = ptr.cast();
-                &*ptr
-            };
-            events.push(EventWrapper::StaticEvent(Event::WindowEvent {
+        if let Ok(window) = window.downcast::<WinitUIWindow>() {
+            events.push(EventWrapper::Window {
                 window_id: window.id(),
                 event: WindowEvent::Occluded(occluded),
-            }));
+            });
         }
     }
     handle_nonuser_events(mtm, events);
@@ -623,62 +450,78 @@ pub fn handle_main_events_cleared(mtm: MainThreadMarker) {
     let redraw_events: Vec<EventWrapper> = this
         .main_events_cleared_transition()
         .into_iter()
-        .map(|window| {
-            EventWrapper::StaticEvent(Event::WindowEvent {
-                window_id: window.id(),
-                event: WindowEvent::RedrawRequested,
-            })
+        .map(|window| EventWrapper::Window {
+            window_id: window.id(),
+            event: WindowEvent::RedrawRequested,
         })
         .collect();
     drop(this);
 
     handle_nonuser_events(mtm, redraw_events);
-    handle_nonuser_event(mtm, EventWrapper::StaticEvent(Event::AboutToWait));
+    get_handler(mtm).handle(|app| app.about_to_wait(&ActiveEventLoop { mtm }));
+    handle_nonuser_events(mtm, []);
 }
 
 pub fn handle_events_cleared(mtm: MainThreadMarker) {
     AppState::get_mut(mtm).events_cleared_transition();
 }
 
+pub(crate) fn handle_resumed(mtm: MainThreadMarker) {
+    get_handler(mtm).handle(|app| app.resumed(&ActiveEventLoop { mtm }));
+    handle_nonuser_events(mtm, []);
+}
+
+pub(crate) fn handle_suspended(mtm: MainThreadMarker) {
+    get_handler(mtm).handle(|app| app.suspended(&ActiveEventLoop { mtm }));
+    handle_nonuser_events(mtm, []);
+}
+
+pub(crate) fn handle_memory_warning(mtm: MainThreadMarker) {
+    get_handler(mtm).handle(|app| app.memory_warning(&ActiveEventLoop { mtm }));
+    handle_nonuser_events(mtm, []);
+}
+
 pub(crate) fn terminated(application: &UIApplication) {
     let mtm = MainThreadMarker::from(application);
 
     let mut events = Vec::new();
     #[allow(deprecated)]
     for window in application.windows().iter() {
-        if window.is_kind_of::<WinitUIWindow>() {
-            // SAFETY: We just checked that the window is a `winit` window
-            let window = unsafe {
-                let ptr: *const UIWindow = window;
-                let ptr: *const WinitUIWindow = ptr.cast();
-                &*ptr
-            };
-            events.push(EventWrapper::StaticEvent(Event::WindowEvent {
+        if let Ok(window) = window.downcast::<WinitUIWindow>() {
+            events.push(EventWrapper::Window {
                 window_id: window.id(),
                 event: WindowEvent::Destroyed,
-            }));
+            });
         }
     }
     handle_nonuser_events(mtm, events);
 
     let mut this = AppState::get_mut(mtm);
     this.terminated_transition();
+    // Prevent EventLoopProxy from firing again.
+    this.event_loop_proxy.invalidate();
     drop(this);
 
-    handle_event(mtm, Event::LoopExiting)
+    get_handler(mtm).terminate();
+}
+
+fn handle_wrapped_event(mtm: MainThreadMarker, event: EventWrapper) {
+    match event {
+        EventWrapper::Window { window_id, event } => get_handler(mtm)
+            .handle(|app| app.window_event(&ActiveEventLoop { mtm }, window_id, event)),
+        EventWrapper::ScaleFactorChanged(event) => handle_hidpi_proxy(mtm, event),
+    }
 }
 
 fn handle_hidpi_proxy(mtm: MainThreadMarker, event: ScaleFactorChanged) {
     let ScaleFactorChanged { suggested_size, scale_factor, window } = event;
     let new_surface_size = Arc::new(Mutex::new(suggested_size));
-    let event = Event::WindowEvent {
-        window_id: window.id(),
-        event: WindowEvent::ScaleFactorChanged {
+    get_handler(mtm).handle(|app| {
+        app.window_event(&ActiveEventLoop { mtm }, window.id(), WindowEvent::ScaleFactorChanged {
             scale_factor,
             surface_size_writer: SurfaceSizeWriter::new(Arc::downgrade(&new_surface_size)),
-        },
-    };
-    handle_event(mtm, event);
+        });
+    });
     let (view, screen_frame) = get_view_and_screen_frame(&window);
     let physical_size = *new_surface_size.lock().unwrap();
     drop(new_surface_size);
@@ -699,46 +542,44 @@ fn get_view_and_screen_frame(window: &WinitUIWindow) -> (Retained<UIView>, CGRec
 }
 
 struct EventLoopWaker {
-    timer: CFRunLoopTimerRef,
+    timer: CFRetained<CFRunLoopTimer>,
 }
 
 impl Drop for EventLoopWaker {
     fn drop(&mut self) {
-        unsafe {
-            CFRunLoopTimerInvalidate(self.timer);
-            CFRelease(self.timer as _);
-        }
+        self.timer.invalidate();
     }
 }
 
 impl EventLoopWaker {
-    fn new(rl: CFRunLoopRef) -> EventLoopWaker {
-        extern "C" fn wakeup_main_loop(_timer: CFRunLoopTimerRef, _info: *mut c_void) {}
+    fn new(rl: CFRetained<CFRunLoop>) -> EventLoopWaker {
+        extern "C-unwind" fn wakeup_main_loop(_timer: *mut CFRunLoopTimer, _info: *mut c_void) {}
         unsafe {
             // Create a timer with a 0.1µs interval (1ns does not work) to mimic polling.
             // It is initially setup with a first fire time really far into the
             // future, but that gets changed to fire immediately in did_finish_launching
-            let timer = CFRunLoopTimerCreate(
-                ptr::null_mut(),
+            let timer = CFRunLoopTimer::new(
+                None,
                 f64::MAX,
                 0.000_000_1,
                 0,
                 0,
-                wakeup_main_loop,
+                Some(wakeup_main_loop),
                 ptr::null_mut(),
-            );
-            CFRunLoopAddTimer(rl, timer, kCFRunLoopCommonModes);
+            )
+            .unwrap();
+            rl.add_timer(Some(&timer), kCFRunLoopCommonModes);
 
             EventLoopWaker { timer }
         }
     }
 
     fn stop(&mut self) {
-        unsafe { CFRunLoopTimerSetNextFireDate(self.timer, f64::MAX) }
+        self.timer.set_next_fire_date(f64::MAX);
     }
 
     fn start(&mut self) {
-        unsafe { CFRunLoopTimerSetNextFireDate(self.timer, f64::MIN) }
+        self.timer.set_next_fire_date(f64::MIN);
     }
 
     fn start_at(&mut self, instant: Instant) {
@@ -746,99 +587,11 @@ impl EventLoopWaker {
         if now >= instant {
             self.start();
         } else {
-            unsafe {
-                let current = CFAbsoluteTimeGetCurrent();
-                let duration = instant - now;
-                let fsecs =
-                    duration.subsec_nanos() as f64 / 1_000_000_000.0 + duration.as_secs() as f64;
-                CFRunLoopTimerSetNextFireDate(self.timer, current + fsecs)
-            }
+            let current = CFAbsoluteTimeGetCurrent();
+            let duration = instant - now;
+            let fsecs =
+                duration.subsec_nanos() as f64 / 1_000_000_000.0 + duration.as_secs() as f64;
+            self.timer.set_next_fire_date(current + fsecs);
         }
     }
 }
-
-macro_rules! os_capabilities {
-    (
-        $(
-            $(#[$attr:meta])*
-            $error_name:ident: $objc_call:literal,
-            $name:ident: $major:literal-$minor:literal
-        ),*
-        $(,)*
-    ) => {
-        #[derive(Clone, Debug)]
-        pub struct OSCapabilities {
-            $(
-                pub $name: bool,
-            )*
-
-            os_version: NSOperatingSystemVersion,
-        }
-
-        impl OSCapabilities {
-            fn from_os_version(os_version: NSOperatingSystemVersion) -> Self {
-                $(let $name = meets_requirements(os_version, $major, $minor);)*
-                Self { $($name,)* os_version, }
-            }
-        }
-
-        impl OSCapabilities {$(
-            $(#[$attr])*
-            pub fn $error_name(&self, extra_msg: &str) {
-                tracing::warn!(
-                    concat!("`", $objc_call, "` requires iOS {}.{}+. This device is running iOS {}.{}.{}. {}"),
-                    $major, $minor, self.os_version.majorVersion, self.os_version.minorVersion, self.os_version.patchVersion,
-                    extra_msg
-                )
-            }
-        )*}
-    };
-}
-
-os_capabilities! {
-    /// <https://developer.apple.com/documentation/uikit/uiview/2891103-safeareainsets?language=objc>
-    #[allow(unused)] // error message unused
-    safe_area_err_msg: "-[UIView safeAreaInsets]",
-    safe_area: 11-0,
-    /// <https://developer.apple.com/documentation/uikit/uiviewcontroller/2887509-setneedsupdateofhomeindicatoraut?language=objc>
-    home_indicator_hidden_err_msg: "-[UIViewController setNeedsUpdateOfHomeIndicatorAutoHidden]",
-    home_indicator_hidden: 11-0,
-    /// <https://developer.apple.com/documentation/uikit/uiviewcontroller/2887507-setneedsupdateofscreenedgesdefer?language=objc>
-    defer_system_gestures_err_msg: "-[UIViewController setNeedsUpdateOfScreenEdgesDeferringSystem]",
-    defer_system_gestures: 11-0,
-    /// <https://developer.apple.com/documentation/uikit/uiscreen/2806814-maximumframespersecond?language=objc>
-    maximum_frames_per_second_err_msg: "-[UIScreen maximumFramesPerSecond]",
-    maximum_frames_per_second: 10-3,
-    /// <https://developer.apple.com/documentation/uikit/uitouch/1618110-force?language=objc>
-    #[allow(unused)] // error message unused
-    force_touch_err_msg: "-[UITouch force]",
-    force_touch: 9-0,
-}
-
-fn meets_requirements(
-    version: NSOperatingSystemVersion,
-    required_major: NSInteger,
-    required_minor: NSInteger,
-) -> bool {
-    (version.majorVersion, version.minorVersion) >= (required_major, required_minor)
-}
-
-fn get_version() -> NSOperatingSystemVersion {
-    let process_info = NSProcessInfo::processInfo();
-    let atleast_ios_8 = process_info.respondsToSelector(sel!(operatingSystemVersion));
-    // Winit requires atleast iOS 8 because no one has put the time into supporting earlier os
-    // versions. Older iOS versions are increasingly difficult to test. For example, Xcode 11 does
-    // not support debugging on devices with an iOS version of less than 8. Another example, in
-    // order to use an iOS simulator older than iOS 8, you must download an older version of Xcode
-    // (<9), and at least Xcode 7 has been tested to not even run on macOS 10.15 - Xcode 8 might?
-    //
-    // The minimum required iOS version is likely to grow in the future.
-    assert!(atleast_ios_8, "`winit` requires iOS version 8 or greater");
-    process_info.operatingSystemVersion()
-}
-
-pub fn os_capabilities() -> OSCapabilities {
-    // Cache the version lookup for efficiency
-    static OS_CAPABILITIES: OnceLock<OSCapabilities> = OnceLock::new();
-    OS_CAPABILITIES.get_or_init(|| OSCapabilities::from_os_version(get_version())).clone()
-}

src/platform_impl/apple/uikit/event_loop.rs

@@ -1,39 +1,32 @@
-use std::ffi::{c_char, c_int, c_void};
-use std::ptr::{self, NonNull};
-use std::sync::atomic::{AtomicBool, Ordering as AtomicOrdering};
+use std::ffi::c_void;
+use std::ptr;
 use std::sync::Arc;
 
-use core_foundation::base::{CFIndex, CFRelease};
-use core_foundation::runloop::{
-    kCFRunLoopAfterWaiting, kCFRunLoopBeforeWaiting, kCFRunLoopCommonModes, kCFRunLoopDefaultMode,
-    kCFRunLoopExit, CFRunLoopActivity, CFRunLoopAddObserver, CFRunLoopAddSource, CFRunLoopGetMain,
-    CFRunLoopObserverCreate, CFRunLoopObserverRef, CFRunLoopSourceContext, CFRunLoopSourceCreate,
-    CFRunLoopSourceInvalidate, CFRunLoopSourceRef, CFRunLoopSourceSignal, CFRunLoopWakeUp,
-};
 use objc2::rc::Retained;
-use objc2::{msg_send_id, ClassType};
-use objc2_foundation::{MainThreadMarker, NSNotificationCenter, NSObject};
+use objc2::runtime::ProtocolObject;
+use objc2::{msg_send, ClassType, MainThreadMarker};
+use objc2_core_foundation::{
+    kCFRunLoopDefaultMode, CFIndex, CFRunLoop, CFRunLoopActivity, CFRunLoopObserver,
+};
+use objc2_foundation::{NSNotificationCenter, NSObjectProtocol};
 use objc2_ui_kit::{
     UIApplication, UIApplicationDidBecomeActiveNotification,
     UIApplicationDidEnterBackgroundNotification, UIApplicationDidFinishLaunchingNotification,
-    UIApplicationDidReceiveMemoryWarningNotification, UIApplicationMain,
-    UIApplicationWillEnterForegroundNotification, UIApplicationWillResignActiveNotification,
-    UIApplicationWillTerminateNotification, UIScreen,
+    UIApplicationDidReceiveMemoryWarningNotification, UIApplicationWillEnterForegroundNotification,
+    UIApplicationWillResignActiveNotification, UIApplicationWillTerminateNotification, UIScreen,
 };
 use rwh_06::HasDisplayHandle;
 
 use super::super::notification_center::create_observer;
-use super::app_state::{send_occluded_event_for_all_windows, AppState, EventWrapper};
+use super::app_state::{send_occluded_event_for_all_windows, AppState};
 use super::{app_state, monitor, MonitorHandle};
 use crate::application::ApplicationHandler;
 use crate::error::{EventLoopError, NotSupportedError, RequestError};
-use crate::event::Event;
 use crate::event_loop::{
     ActiveEventLoop as RootActiveEventLoop, ControlFlow, DeviceEvents,
-    EventLoopProxy as CoreEventLoopProxy, EventLoopProxyProvider,
-    OwnedDisplayHandle as CoreOwnedDisplayHandle,
+    EventLoopProxy as CoreEventLoopProxy, OwnedDisplayHandle as CoreOwnedDisplayHandle,
 };
-use crate::monitor::MonitorHandle as RootMonitorHandle;
+use crate::monitor::MonitorHandle as CoreMonitorHandle;
 use crate::platform_impl::Window;
 use crate::window::{CustomCursor, CustomCursorSource, Theme, Window as CoreWindow};
 
@@ -61,14 +54,18 @@ impl RootActiveEventLoop for ActiveEventLoop {
         Err(NotSupportedError::new("create_custom_cursor is not supported").into())
     }
 
-    fn available_monitors(&self) -> Box<dyn Iterator<Item = RootMonitorHandle>> {
-        Box::new(monitor::uiscreens(self.mtm).into_iter().map(|inner| RootMonitorHandle { inner }))
+    fn available_monitors(&self) -> Box<dyn Iterator<Item = CoreMonitorHandle>> {
+        Box::new(
+            monitor::uiscreens(self.mtm)
+                .into_iter()
+                .map(|monitor| CoreMonitorHandle(Arc::new(monitor))),
+        )
     }
 
     fn primary_monitor(&self) -> Option<crate::monitor::MonitorHandle> {
         #[allow(deprecated)]
         let monitor = MonitorHandle::new(UIScreen::mainScreen(self.mtm));
-        Some(RootMonitorHandle { inner: monitor })
+        Some(CoreMonitorHandle(Arc::new(monitor)))
     }
 
     fn listen_device_events(&self, _allowed: DeviceEvents) {}
@@ -121,6 +118,7 @@ impl HasDisplayHandle for OwnedDisplayHandle {
     }
 }
 
+#[derive(Debug)]
 pub struct EventLoop {
     mtm: MainThreadMarker,
     window_target: ActiveEventLoop,
@@ -129,13 +127,13 @@ pub struct EventLoop {
     // system instead cleans it up next time it would have posted a notification to it.
     //
     // Though we do still need to keep the observers around to prevent them from being deallocated.
-    _did_finish_launching_observer: Retained<NSObject>,
-    _did_become_active_observer: Retained<NSObject>,
-    _will_resign_active_observer: Retained<NSObject>,
-    _will_enter_foreground_observer: Retained<NSObject>,
-    _did_enter_background_observer: Retained<NSObject>,
-    _will_terminate_observer: Retained<NSObject>,
-    _did_receive_memory_warning_observer: Retained<NSObject>,
+    _did_finish_launching_observer: Retained<ProtocolObject<dyn NSObjectProtocol>>,
+    _did_become_active_observer: Retained<ProtocolObject<dyn NSObjectProtocol>>,
+    _will_resign_active_observer: Retained<ProtocolObject<dyn NSObjectProtocol>>,
+    _will_enter_foreground_observer: Retained<ProtocolObject<dyn NSObjectProtocol>>,
+    _did_enter_background_observer: Retained<ProtocolObject<dyn NSObjectProtocol>>,
+    _will_terminate_observer: Retained<ProtocolObject<dyn NSObjectProtocol>>,
+    _did_receive_memory_warning_observer: Retained<ProtocolObject<dyn NSObjectProtocol>>,
 }
 
 #[derive(Default, Debug, Copy, Clone, PartialEq, Eq, Hash)]
@@ -174,17 +172,13 @@ impl EventLoop {
             &center,
             // `applicationDidBecomeActive:`
             unsafe { UIApplicationDidBecomeActiveNotification },
-            move |_| {
-                app_state::handle_nonuser_event(mtm, EventWrapper::StaticEvent(Event::Resumed));
-            },
+            move |_| app_state::handle_resumed(mtm),
         );
         let _will_resign_active_observer = create_observer(
             &center,
             // `applicationWillResignActive:`
             unsafe { UIApplicationWillResignActiveNotification },
-            move |_| {
-                app_state::handle_nonuser_event(mtm, EventWrapper::StaticEvent(Event::Suspended));
-            },
+            move |_| app_state::handle_suspended(mtm),
         );
         let _will_enter_foreground_observer = create_observer(
             &center,
@@ -194,9 +188,9 @@ impl EventLoop {
                 let app = unsafe { notification.object() }.expect(
                     "UIApplicationWillEnterForegroundNotification to have application object",
                 );
-                // SAFETY: The `object` in `UIApplicationWillEnterForegroundNotification` is
-                // documented to be `UIApplication`.
-                let app: Retained<UIApplication> = unsafe { Retained::cast(app) };
+                // The `object` in `UIApplicationWillEnterForegroundNotification` is documented to
+                // be `UIApplication`.
+                let app = app.downcast::<UIApplication>().unwrap();
                 send_occluded_event_for_all_windows(&app, false);
             },
         );
@@ -208,9 +202,9 @@ impl EventLoop {
                 let app = unsafe { notification.object() }.expect(
                     "UIApplicationDidEnterBackgroundNotification to have application object",
                 );
-                // SAFETY: The `object` in `UIApplicationDidEnterBackgroundNotification` is
-                // documented to be `UIApplication`.
-                let app: Retained<UIApplication> = unsafe { Retained::cast(app) };
+                // The `object` in `UIApplicationDidEnterBackgroundNotification` is documented to be
+                // `UIApplication`.
+                let app = app.downcast::<UIApplication>().unwrap();
                 send_occluded_event_for_all_windows(&app, true);
             },
         );
@@ -221,9 +215,9 @@ impl EventLoop {
             move |notification| {
                 let app = unsafe { notification.object() }
                     .expect("UIApplicationWillTerminateNotification to have application object");
-                // SAFETY: The `object` in `UIApplicationWillTerminateNotification` is
-                // (somewhat) documented to be `UIApplication`.
-                let app: Retained<UIApplication> = unsafe { Retained::cast(app) };
+                // The `object` in `UIApplicationWillTerminateNotification` is (somewhat) documented
+                // to be `UIApplication`.
+                let app = app.downcast::<UIApplication>().unwrap();
                 app_state::terminated(&app);
             },
         );
@@ -231,12 +225,7 @@ impl EventLoop {
             &center,
             // `applicationDidReceiveMemoryWarning:`
             unsafe { UIApplicationDidReceiveMemoryWarningNotification },
-            move |_| {
-                app_state::handle_nonuser_event(
-                    mtm,
-                    EventWrapper::StaticEvent(Event::MemoryWarning),
-                );
-            },
+            move |_| app_state::handle_memory_warning(mtm),
         );
 
         Ok(EventLoop {
@@ -252,9 +241,9 @@ impl EventLoop {
         })
     }
 
-    pub fn run_app<A: ApplicationHandler>(self, mut app: A) -> ! {
+    pub fn run_app<A: ApplicationHandler>(self, app: A) -> ! {
         let application: Option<Retained<UIApplication>> =
-            unsafe { msg_send_id![UIApplication::class(), sharedApplication] };
+            unsafe { msg_send![UIApplication::class(), sharedApplication] };
         assert!(
             application.is_none(),
             "\
@@ -262,24 +251,9 @@ impl EventLoop {
              `EventLoop::run_app` calls `UIApplicationMain` on iOS",
         );
 
-        extern "C" {
-            // These functions are in crt_externs.h.
-            fn _NSGetArgc() -> *mut c_int;
-            fn _NSGetArgv() -> *mut *mut *mut c_char;
-        }
-
-        app_state::launch(self.mtm, &mut app, || unsafe {
-            UIApplicationMain(
-                *_NSGetArgc(),
-                NonNull::new(*_NSGetArgv()).unwrap(),
-                // We intentionally override neither the application nor the delegate, to allow
-                // the user to do so themselves!
-                None,
-                None,
-            );
-        });
-
-        unreachable!()
+        // We intentionally override neither the application nor the delegate,
+        // to allow the user to do so themselves!
+        app_state::launch(self.mtm, app, || UIApplication::main(None, None, self.mtm))
     }
 
     pub fn window_target(&self) -> &dyn RootActiveEventLoop {
@@ -287,78 +261,19 @@ impl EventLoop {
     }
 }
 
-pub struct EventLoopProxy {
-    pub(crate) wake_up: AtomicBool,
-    source: CFRunLoopSourceRef,
-}
-
-unsafe impl Send for EventLoopProxy {}
-unsafe impl Sync for EventLoopProxy {}
-
-impl Drop for EventLoopProxy {
-    fn drop(&mut self) {
-        unsafe {
-            CFRunLoopSourceInvalidate(self.source);
-            CFRelease(self.source as _);
-        }
-    }
-}
-
-impl EventLoopProxy {
-    pub(crate) fn new() -> EventLoopProxy {
-        unsafe {
-            // just wake up the eventloop
-            extern "C" fn event_loop_proxy_handler(_: *const c_void) {}
-
-            // adding a Source to the main CFRunLoop lets us wake it up and
-            // process user events through the normal OS EventLoop mechanisms.
-            let rl = CFRunLoopGetMain();
-            let mut context = CFRunLoopSourceContext {
-                version: 0,
-                info: ptr::null_mut(),
-                retain: None,
-                release: None,
-                copyDescription: None,
-                equal: None,
-                hash: None,
-                schedule: None,
-                cancel: None,
-                perform: event_loop_proxy_handler,
-            };
-            let source = CFRunLoopSourceCreate(ptr::null_mut(), CFIndex::MAX - 1, &mut context);
-            CFRunLoopAddSource(rl, source, kCFRunLoopCommonModes);
-            CFRunLoopWakeUp(rl);
-
-            EventLoopProxy { wake_up: AtomicBool::new(false), source }
-        }
-    }
-}
-
-impl EventLoopProxyProvider for EventLoopProxy {
-    fn wake_up(&self) {
-        self.wake_up.store(true, AtomicOrdering::Relaxed);
-        unsafe {
-            // let the main thread know there's a new event
-            CFRunLoopSourceSignal(self.source);
-            let rl = CFRunLoopGetMain();
-            CFRunLoopWakeUp(rl);
-        }
-    }
-}
-
 fn setup_control_flow_observers() {
     unsafe {
         // begin is queued with the highest priority to ensure it is processed before other
         // observers
-        extern "C" fn control_flow_begin_handler(
-            _: CFRunLoopObserverRef,
+        extern "C-unwind" fn control_flow_begin_handler(
+            _: *mut CFRunLoopObserver,
             activity: CFRunLoopActivity,
             _: *mut c_void,
         ) {
             let mtm = MainThreadMarker::new().unwrap();
             #[allow(non_upper_case_globals)]
             match activity {
-                kCFRunLoopAfterWaiting => app_state::handle_wakeup_transition(mtm),
+                CFRunLoopActivity::AfterWaiting => app_state::handle_wakeup_transition(mtm),
                 _ => unreachable!(),
             }
         }
@@ -374,65 +289,68 @@ fn setup_control_flow_observers() {
         // registers for every `CFRunLoopAddObserver` call on an iPad Air 2 running iOS 11.4.
         //
         // Also tested to be `0x1e8480` on iPhone 8, iOS 13 beta 4.
-        extern "C" fn control_flow_main_end_handler(
-            _: CFRunLoopObserverRef,
+        extern "C-unwind" fn control_flow_main_end_handler(
+            _: *mut CFRunLoopObserver,
             activity: CFRunLoopActivity,
             _: *mut c_void,
         ) {
             let mtm = MainThreadMarker::new().unwrap();
             #[allow(non_upper_case_globals)]
             match activity {
-                kCFRunLoopBeforeWaiting => app_state::handle_main_events_cleared(mtm),
-                kCFRunLoopExit => {}, // may happen when running on macOS
+                CFRunLoopActivity::BeforeWaiting => app_state::handle_main_events_cleared(mtm),
+                CFRunLoopActivity::Exit => {}, // may happen when running on macOS
                 _ => unreachable!(),
             }
         }
 
         // end is queued with the lowest priority to ensure it is processed after other observers
-        extern "C" fn control_flow_end_handler(
-            _: CFRunLoopObserverRef,
+        extern "C-unwind" fn control_flow_end_handler(
+            _: *mut CFRunLoopObserver,
             activity: CFRunLoopActivity,
             _: *mut c_void,
         ) {
             let mtm = MainThreadMarker::new().unwrap();
             #[allow(non_upper_case_globals)]
             match activity {
-                kCFRunLoopBeforeWaiting => app_state::handle_events_cleared(mtm),
-                kCFRunLoopExit => {}, // may happen when running on macOS
+                CFRunLoopActivity::BeforeWaiting => app_state::handle_events_cleared(mtm),
+                CFRunLoopActivity::Exit => {}, // may happen when running on macOS
                 _ => unreachable!(),
             }
         }
 
-        let main_loop = CFRunLoopGetMain();
+        let main_loop = CFRunLoop::main().unwrap();
 
-        let begin_observer = CFRunLoopObserverCreate(
-            ptr::null_mut(),
-            kCFRunLoopAfterWaiting,
-            1, // repeat = true
+        let begin_observer = CFRunLoopObserver::new(
+            None,
+            CFRunLoopActivity::AfterWaiting.0,
+            true,
             CFIndex::MIN,
-            control_flow_begin_handler,
+            Some(control_flow_begin_handler),
             ptr::null_mut(),
-        );
-        CFRunLoopAddObserver(main_loop, begin_observer, kCFRunLoopDefaultMode);
+        )
+        .unwrap();
+        main_loop.add_observer(Some(&begin_observer), kCFRunLoopDefaultMode);
 
-        let main_end_observer = CFRunLoopObserverCreate(
-            ptr::null_mut(),
-            kCFRunLoopExit | kCFRunLoopBeforeWaiting,
-            1, // repeat = true
+        let main_end_observer = CFRunLoopObserver::new(
+            None,
+            (CFRunLoopActivity::Exit | CFRunLoopActivity::BeforeWaiting).0,
+            true,
             0, // see comment on `control_flow_main_end_handler`
-            control_flow_main_end_handler,
+            Some(control_flow_main_end_handler),
             ptr::null_mut(),
-        );
-        CFRunLoopAddObserver(main_loop, main_end_observer, kCFRunLoopDefaultMode);
+        )
+        .unwrap();
+        main_loop.add_observer(Some(&main_end_observer), kCFRunLoopDefaultMode);
 
-        let end_observer = CFRunLoopObserverCreate(
-            ptr::null_mut(),
-            kCFRunLoopExit | kCFRunLoopBeforeWaiting,
-            1, // repeat = true
+        let end_observer = CFRunLoopObserver::new(
+            None,
+            (CFRunLoopActivity::Exit | CFRunLoopActivity::BeforeWaiting).0,
+            true,
             CFIndex::MAX,
-            control_flow_end_handler,
+            Some(control_flow_end_handler),
             ptr::null_mut(),
-        );
-        CFRunLoopAddObserver(main_loop, end_observer, kCFRunLoopDefaultMode);
+        )
+        .unwrap();
+        main_loop.add_observer(Some(&end_observer), kCFRunLoopDefaultMode);
     }
 }

src/platform_impl/apple/uikit/mod.rs

@@ -10,18 +10,10 @@ mod window;
 use std::fmt;
 
 pub(crate) use self::event_loop::{
-    ActiveEventLoop, EventLoop, EventLoopProxy, PlatformSpecificEventLoopAttributes,
+    ActiveEventLoop, EventLoop, PlatformSpecificEventLoopAttributes,
 };
-pub(crate) use self::monitor::{MonitorHandle, VideoModeHandle};
+pub(crate) use self::monitor::MonitorHandle;
 pub(crate) use self::window::{PlatformSpecificWindowAttributes, Window};
-pub(crate) use crate::cursor::{
-    NoCustomCursor as PlatformCustomCursor, NoCustomCursor as PlatformCustomCursorSource,
-};
-pub(crate) use crate::icon::NoIcon as PlatformIcon;
-pub(crate) use crate::platform_impl::Fullscreen;
-
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub struct KeyEventExtra {}
 
 #[derive(Debug)]
 pub enum OsError {}

src/platform_impl/apple/uikit/monitor.rs

@@ -1,30 +1,29 @@
 #![allow(clippy::unnecessary_cast)]
 
-use std::collections::{BTreeSet, VecDeque};
-use std::num::{NonZeroU16, NonZeroU32};
+use std::collections::VecDeque;
+use std::num::NonZeroU32;
 use std::{fmt, hash, ptr};
 
-use objc2::mutability::IsRetainable;
+use dispatch2::{run_on_main, MainThreadBound};
 use objc2::rc::Retained;
-use objc2::Message;
-use objc2_foundation::{run_on_main, MainThreadBound, MainThreadMarker, NSInteger};
+use objc2::{available, MainThreadMarker, Message};
+use objc2_foundation::NSInteger;
 use objc2_ui_kit::{UIScreen, UIScreenMode};
 
-use super::app_state;
-use crate::dpi::{PhysicalPosition, PhysicalSize};
-use crate::monitor::VideoModeHandle as RootVideoModeHandle;
+use crate::dpi::PhysicalPosition;
+use crate::monitor::{MonitorHandleProvider, VideoMode};
 
 // Workaround for `MainThreadBound` implementing almost no traits
 #[derive(Debug)]
 struct MainThreadBoundDelegateImpls<T>(MainThreadBound<Retained<T>>);
 
-impl<T: IsRetainable + Message> Clone for MainThreadBoundDelegateImpls<T> {
+impl<T: Message> Clone for MainThreadBoundDelegateImpls<T> {
     fn clone(&self) -> Self {
         Self(run_on_main(|mtm| MainThreadBound::new(Retained::clone(self.0.get(mtm)), mtm)))
     }
 }
 
-impl<T: IsRetainable + Message> hash::Hash for MainThreadBoundDelegateImpls<T> {
+impl<T: Message> hash::Hash for MainThreadBoundDelegateImpls<T> {
     fn hash<H: hash::Hasher>(&self, state: &mut H) {
         // SAFETY: Marker only used to get the pointer
         let mtm = unsafe { MainThreadMarker::new_unchecked() };
@@ -32,7 +31,7 @@ impl<T: IsRetainable + Message> hash::Hash for MainThreadBoundDelegateImpls<T> {
     }
 }
 
-impl<T: IsRetainable + Message> PartialEq for MainThreadBoundDelegateImpls<T> {
+impl<T: Message> PartialEq for MainThreadBoundDelegateImpls<T> {
     fn eq(&self, other: &Self) -> bool {
         // SAFETY: Marker only used to get the pointer
         let mtm = unsafe { MainThreadMarker::new_unchecked() };
@@ -40,14 +39,12 @@ impl<T: IsRetainable + Message> PartialEq for MainThreadBoundDelegateImpls<T> {
     }
 }
 
-impl<T: IsRetainable + Message> Eq for MainThreadBoundDelegateImpls<T> {}
+impl<T: Message> Eq for MainThreadBoundDelegateImpls<T> {}
 
 #[derive(Debug, PartialEq, Eq, Hash, Clone)]
 pub struct VideoModeHandle {
-    pub(crate) size: (u32, u32),
-    pub(crate) refresh_rate_millihertz: Option<NonZeroU32>,
+    pub(crate) mode: VideoMode,
     screen_mode: MainThreadBoundDelegateImpls<UIScreenMode>,
-    pub(crate) monitor: MonitorHandle,
 }
 
 impl VideoModeHandle {
@@ -58,30 +55,18 @@ impl VideoModeHandle {
     ) -> VideoModeHandle {
         let refresh_rate_millihertz = refresh_rate_millihertz(&uiscreen);
         let size = screen_mode.size();
-        VideoModeHandle {
-            size: (size.width as u32, size.height as u32),
+        let mode = VideoMode {
+            size: (size.width as u32, size.height as u32).into(),
+            bit_depth: None,
             refresh_rate_millihertz,
+        };
+
+        VideoModeHandle {
+            mode,
             screen_mode: MainThreadBoundDelegateImpls(MainThreadBound::new(screen_mode, mtm)),
-            monitor: MonitorHandle::new(uiscreen),
         }
     }
 
-    pub fn size(&self) -> PhysicalSize<u32> {
-        self.size.into()
-    }
-
-    pub fn bit_depth(&self) -> Option<NonZeroU16> {
-        None
-    }
-
-    pub fn refresh_rate_millihertz(&self) -> Option<NonZeroU32> {
-        self.refresh_rate_millihertz
-    }
-
-    pub fn monitor(&self) -> MonitorHandle {
-        self.monitor.clone()
-    }
-
     pub(super) fn screen_mode(&self, mtm: MainThreadMarker) -> &Retained<UIScreenMode> {
         self.screen_mode.0.get(mtm)
     }
@@ -91,6 +76,60 @@ pub struct MonitorHandle {
     ui_screen: MainThreadBound<Retained<UIScreen>>,
 }
 
+impl MonitorHandleProvider for MonitorHandle {
+    fn id(&self) -> u128 {
+        self.native_id() as _
+    }
+
+    fn native_id(&self) -> u64 {
+        // SAFETY: Only getting the pointer.
+        let mtm = unsafe { MainThreadMarker::new_unchecked() };
+        Retained::as_ptr(self.ui_screen.get(mtm)) as u64
+    }
+
+    fn name(&self) -> Option<std::borrow::Cow<'_, str>> {
+        run_on_main(|mtm| {
+            #[allow(deprecated)]
+            let main = UIScreen::mainScreen(mtm);
+            if *self.ui_screen(mtm) == main {
+                Some("Primary".into())
+            } else if Some(self.ui_screen(mtm)) == main.mirroredScreen().as_ref() {
+                Some("Mirrored".into())
+            } else {
+                #[allow(deprecated)]
+                UIScreen::screens(mtm)
+                    .iter()
+                    .position(|rhs| rhs == *self.ui_screen(mtm))
+                    .map(|idx| idx.to_string().into())
+            }
+        })
+    }
+
+    fn position(&self) -> Option<PhysicalPosition<i32>> {
+        let bounds = self.ui_screen.get_on_main(|ui_screen| ui_screen.nativeBounds());
+        Some((bounds.origin.x as f64, bounds.origin.y as f64).into())
+    }
+
+    fn scale_factor(&self) -> f64 {
+        self.ui_screen.get_on_main(|ui_screen| ui_screen.nativeScale()) as f64
+    }
+
+    fn current_video_mode(&self) -> Option<VideoMode> {
+        Some(run_on_main(|mtm| {
+            VideoModeHandle::new(
+                self.ui_screen(mtm).clone(),
+                self.ui_screen(mtm).currentMode().unwrap(),
+                mtm,
+            )
+            .mode
+        }))
+    }
+
+    fn video_modes(&self) -> Box<dyn Iterator<Item = VideoMode>> {
+        Box::new(self.video_modes())
+    }
+}
+
 impl Clone for MonitorHandle {
     fn clone(&self) -> Self {
         run_on_main(|mtm| Self {
@@ -101,13 +140,20 @@ impl Clone for MonitorHandle {
 
 impl hash::Hash for MonitorHandle {
     fn hash<H: hash::Hasher>(&self, state: &mut H) {
-        (self as *const Self).hash(state);
+        // SAFETY: Only getting the pointer.
+        let mtm = unsafe { MainThreadMarker::new_unchecked() };
+        Retained::as_ptr(self.ui_screen.get(mtm)).hash(state);
     }
 }
 
 impl PartialEq for MonitorHandle {
     fn eq(&self, other: &Self) -> bool {
-        ptr::eq(self, other)
+        // SAFETY: Only getting the pointer.
+        let mtm = unsafe { MainThreadMarker::new_unchecked() };
+        ptr::eq(
+            Retained::as_ptr(self.ui_screen.get(mtm)),
+            Retained::as_ptr(other.ui_screen.get(mtm)),
+        )
     }
 }
 
@@ -121,8 +167,10 @@ impl PartialOrd for MonitorHandle {
 
 impl Ord for MonitorHandle {
     fn cmp(&self, other: &Self) -> std::cmp::Ordering {
+        // SAFETY: Only getting the pointer.
         // TODO: Make a better ordering
-        (self as *const Self).cmp(&(other as *const Self))
+        let mtm = unsafe { MainThreadMarker::new_unchecked() };
+        Retained::as_ptr(self.ui_screen.get(mtm)).cmp(&Retained::as_ptr(other.ui_screen.get(mtm)))
     }
 }
 
@@ -143,79 +191,42 @@ impl MonitorHandle {
         Self { ui_screen: MainThreadBound::new(ui_screen, mtm) }
     }
 
-    pub fn name(&self) -> Option<String> {
-        run_on_main(|mtm| {
-            #[allow(deprecated)]
-            let main = UIScreen::mainScreen(mtm);
-            if *self.ui_screen(mtm) == main {
-                Some("Primary".to_string())
-            } else if Some(self.ui_screen(mtm)) == main.mirroredScreen().as_ref() {
-                Some("Mirrored".to_string())
-            } else {
-                #[allow(deprecated)]
-                UIScreen::screens(mtm)
-                    .iter()
-                    .position(|rhs| rhs == &**self.ui_screen(mtm))
-                    .map(|idx| idx.to_string())
-            }
-        })
-    }
-
-    pub fn position(&self) -> Option<PhysicalPosition<i32>> {
-        let bounds = self.ui_screen.get_on_main(|ui_screen| ui_screen.nativeBounds());
-        Some((bounds.origin.x as f64, bounds.origin.y as f64).into())
-    }
-
-    pub fn scale_factor(&self) -> f64 {
-        self.ui_screen.get_on_main(|ui_screen| ui_screen.nativeScale()) as f64
-    }
-
-    pub fn current_video_mode(&self) -> Option<VideoModeHandle> {
-        Some(run_on_main(|mtm| {
-            VideoModeHandle::new(
-                self.ui_screen(mtm).clone(),
-                self.ui_screen(mtm).currentMode().unwrap(),
-                mtm,
-            )
-        }))
-    }
-
-    pub fn video_modes(&self) -> impl Iterator<Item = VideoModeHandle> {
+    pub fn video_modes_handles(&self) -> impl Iterator<Item = VideoModeHandle> {
         run_on_main(|mtm| {
             let ui_screen = self.ui_screen(mtm);
-            // Use Ord impl of RootVideoModeHandle
 
-            let modes: BTreeSet<_> = ui_screen
+            ui_screen
                 .availableModes()
                 .into_iter()
-                .map(|mode| RootVideoModeHandle {
-                    video_mode: VideoModeHandle::new(ui_screen.clone(), mode, mtm),
-                })
-                .collect();
-
-            modes.into_iter().map(|mode| mode.video_mode)
+                .map(|mode| VideoModeHandle::new(ui_screen.clone(), mode, mtm))
+                .collect::<Vec<_>>()
+                .into_iter()
         })
     }
 
+    pub fn video_modes(&self) -> impl Iterator<Item = VideoMode> {
+        self.video_modes_handles().map(|handle| handle.mode)
+    }
+
     pub(crate) fn ui_screen(&self, mtm: MainThreadMarker) -> &Retained<UIScreen> {
         self.ui_screen.get(mtm)
     }
 
-    pub fn preferred_video_mode(&self) -> VideoModeHandle {
+    pub fn preferred_video_mode(&self) -> VideoMode {
         run_on_main(|mtm| {
             VideoModeHandle::new(
                 self.ui_screen(mtm).clone(),
                 self.ui_screen(mtm).preferredMode().unwrap(),
                 mtm,
             )
+            .mode
         })
     }
 }
 
 fn refresh_rate_millihertz(uiscreen: &UIScreen) -> Option<NonZeroU32> {
     let refresh_rate_millihertz: NSInteger = {
-        let os_capabilities = app_state::os_capabilities();
-        if os_capabilities.maximum_frames_per_second {
+        if available!(ios = 10.3, tvos = 10.2) {
             uiscreen.maximumFramesPerSecond()
         } else {
             // https://developer.apple.com/library/archive/technotes/tn2460/_index.html
@@ -228,7 +239,9 @@ fn refresh_rate_millihertz(uiscreen: &UIScreen) -> Option<NonZeroU32> {
             //
             // FIXME: earlier OSs could calculate the refresh rate using
             // `-[CADisplayLink duration]`.
-            os_capabilities.maximum_frames_per_second_err_msg("defaulting to 60 fps");
+            tracing::warn!(
+                "`maximumFramesPerSecond` requires iOS 10.3+ or tvOS 10.2+. Defaulting to 60 fps"
+            );
             60
         }
     };
@@ -240,3 +253,27 @@ pub fn uiscreens(mtm: MainThreadMarker) -> VecDeque<MonitorHandle> {
     #[allow(deprecated)]
     UIScreen::screens(mtm).into_iter().map(MonitorHandle::new).collect()
 }
+
+#[cfg(test)]
+mod tests {
+    use objc2_foundation::NSSet;
+
+    use super::*;
+
+    // Test that UIScreen pointer comparisons are correct.
+    #[test]
+    #[allow(deprecated)]
+    fn screen_comparisons() {
+        // Test code, doesn't matter that it's not thread safe
+        let mtm = unsafe { MainThreadMarker::new_unchecked() };
+
+        assert!(ptr::eq(&*UIScreen::mainScreen(mtm), &*UIScreen::mainScreen(mtm)));
+
+        let main = UIScreen::mainScreen(mtm);
+        assert!(UIScreen::screens(mtm).iter().any(|screen| ptr::eq(&*screen, &*main)));
+
+        assert!(unsafe {
+            NSSet::setWithArray(&UIScreen::screens(mtm)).containsObject(&UIScreen::mainScreen(mtm))
+        });
+    }
+}

src/platform_impl/apple/uikit/view.rs

@@ -3,8 +3,9 @@ use std::cell::{Cell, RefCell};
 
 use objc2::rc::Retained;
 use objc2::runtime::{NSObjectProtocol, ProtocolObject};
-use objc2::{declare_class, msg_send, msg_send_id, mutability, sel, ClassType, DeclaredClass};
-use objc2_foundation::{CGFloat, CGPoint, CGRect, MainThreadMarker, NSObject, NSSet, NSString};
+use objc2::{available, define_class, msg_send, sel, DefinedClass, MainThreadMarker};
+use objc2_core_foundation::{CGFloat, CGPoint, CGRect};
+use objc2_foundation::{NSObject, NSSet, NSString};
 use objc2_ui_kit::{
     UIEvent, UIForceTouchCapability, UIGestureRecognizer, UIGestureRecognizerDelegate,
     UIGestureRecognizerState, UIKeyInput, UIPanGestureRecognizer, UIPinchGestureRecognizer,
@@ -17,11 +18,10 @@ use super::app_state::{self, EventWrapper};
 use super::window::WinitUIWindow;
 use crate::dpi::PhysicalPosition;
 use crate::event::{
-    ButtonSource, ElementState, Event, FingerId, Force, KeyEvent, PointerKind, PointerSource,
-    TouchPhase, WindowEvent,
+    ButtonSource, ElementState, FingerId, Force, KeyEvent, PointerKind, PointerSource, TouchPhase,
+    WindowEvent,
 };
 use crate::keyboard::{Key, KeyCode, KeyLocation, NamedKey, NativeKeyCode, PhysicalKey};
-use crate::platform_impl::KeyEventExtra;
 use crate::window::WindowAttributes;
 
 pub struct WinitViewState {
@@ -39,36 +39,26 @@ pub struct WinitViewState {
     fingers: Cell<u8>,
 }
 
-declare_class!(
+define_class!(
+    #[unsafe(super(UIView, UIResponder, NSObject))]
+    #[name = "WinitUIView"]
+    #[ivars = WinitViewState]
     pub(crate) struct WinitView;
 
-    unsafe impl ClassType for WinitView {
-        #[inherits(UIResponder, NSObject)]
-        type Super = UIView;
-        type Mutability = mutability::MainThreadOnly;
-        const NAME: &'static str = "WinitUIView";
-    }
-
-    impl DeclaredClass for WinitView {
-        type Ivars = WinitViewState;
-    }
-
-    unsafe impl WinitView {
-        #[method(drawRect:)]
+    /// This documentation attribute makes rustfmt work for some reason?
+    impl WinitView {
+        #[unsafe(method(drawRect:))]
         fn draw_rect(&self, rect: CGRect) {
             let mtm = MainThreadMarker::new().unwrap();
             let window = self.window().unwrap();
-            app_state::handle_nonuser_event(
-                mtm,
-                EventWrapper::StaticEvent(Event::WindowEvent {
-                    window_id: window.id(),
-                    event: WindowEvent::RedrawRequested,
-                }),
-            );
+            app_state::handle_nonuser_event(mtm, EventWrapper::Window {
+                window_id: window.id(),
+                event: WindowEvent::RedrawRequested,
+            });
             let _: () = unsafe { msg_send![super(self), drawRect: rect] };
         }
 
-        #[method(layoutSubviews)]
+        #[unsafe(method(layoutSubviews))]
         fn layout_subviews(&self) {
             let mtm = MainThreadMarker::new().unwrap();
             let _: () = unsafe { msg_send![super(self), layoutSubviews] };
@@ -82,16 +72,13 @@ declare_class!(
             .to_physical(scale_factor);
 
             let window = self.window().unwrap();
-            app_state::handle_nonuser_event(
-                mtm,
-                EventWrapper::StaticEvent(Event::WindowEvent {
-                    window_id: window.id(),
-                    event: WindowEvent::SurfaceResized(size),
-                }),
-            );
+            app_state::handle_nonuser_event(mtm, EventWrapper::Window {
+                window_id: window.id(),
+                event: WindowEvent::SurfaceResized(size),
+            });
         }
 
-        #[method(setContentScaleFactor:)]
+        #[unsafe(method(setContentScaleFactor:))]
         fn set_content_scale_factor(&self, untrusted_scale_factor: CGFloat) {
             let mtm = MainThreadMarker::new().unwrap();
             let _: () =
@@ -124,50 +111,46 @@ declare_class!(
             let window_id = window.id();
             app_state::handle_nonuser_events(
                 mtm,
-                std::iter::once(EventWrapper::ScaleFactorChanged(
-                    app_state::ScaleFactorChanged {
-                        window,
-                        scale_factor,
-                        suggested_size: size.to_physical(scale_factor),
-                    },
-                ))
-                .chain(std::iter::once(EventWrapper::StaticEvent(
-                    Event::WindowEvent {
-                        window_id,
-                        event: WindowEvent::SurfaceResized(size.to_physical(scale_factor)),
-                    },
-                ))),
+                std::iter::once(EventWrapper::ScaleFactorChanged(app_state::ScaleFactorChanged {
+                    window,
+                    scale_factor,
+                    suggested_size: size.to_physical(scale_factor),
+                }))
+                .chain(std::iter::once(EventWrapper::Window {
+                    window_id,
+                    event: WindowEvent::SurfaceResized(size.to_physical(scale_factor)),
+                })),
             );
         }
 
-        #[method(safeAreaInsetsDidChange)]
+        #[unsafe(method(safeAreaInsetsDidChange))]
         fn safe_area_changed(&self) {
             debug!("safeAreaInsetsDidChange was called, requesting redraw");
             // When the safe area changes we want to make sure to emit a redraw event
             self.setNeedsDisplay();
         }
 
-        #[method(touchesBegan:withEvent:)]
+        #[unsafe(method(touchesBegan:withEvent:))]
         fn touches_began(&self, touches: &NSSet<UITouch>, _event: Option<&UIEvent>) {
             self.handle_touches(touches)
         }
 
-        #[method(touchesMoved:withEvent:)]
+        #[unsafe(method(touchesMoved:withEvent:))]
         fn touches_moved(&self, touches: &NSSet<UITouch>, _event: Option<&UIEvent>) {
             self.handle_touches(touches)
         }
 
-        #[method(touchesEnded:withEvent:)]
+        #[unsafe(method(touchesEnded:withEvent:))]
         fn touches_ended(&self, touches: &NSSet<UITouch>, _event: Option<&UIEvent>) {
             self.handle_touches(touches)
         }
 
-        #[method(touchesCancelled:withEvent:)]
+        #[unsafe(method(touchesCancelled:withEvent:))]
         fn touches_cancelled(&self, touches: &NSSet<UITouch>, _event: Option<&UIEvent>) {
             self.handle_touches(touches)
         }
 
-        #[method(pinchGesture:)]
+        #[unsafe(method(pinchGesture:))]
         fn pinch_gesture(&self, recognizer: &UIPinchGestureRecognizer) {
             let window = self.window().unwrap();
 
@@ -175,54 +158,48 @@ declare_class!(
                 UIGestureRecognizerState::Began => {
                     self.ivars().pinch_last_delta.set(recognizer.scale());
                     (TouchPhase::Started, 0.0)
-                }
+                },
                 UIGestureRecognizerState::Changed => {
                     let last_scale: f64 = self.ivars().pinch_last_delta.replace(recognizer.scale());
                     (TouchPhase::Moved, recognizer.scale() - last_scale)
-                }
+                },
                 UIGestureRecognizerState::Ended => {
                     let last_scale: f64 = self.ivars().pinch_last_delta.replace(0.0);
                     (TouchPhase::Moved, recognizer.scale() - last_scale)
-                }
+                },
                 UIGestureRecognizerState::Cancelled | UIGestureRecognizerState::Failed => {
                     self.ivars().rotation_last_delta.set(0.0);
                     // Pass -delta so that action is reversed
                     (TouchPhase::Cancelled, -recognizer.scale())
-                }
+                },
                 state => panic!("unexpected recognizer state: {state:?}"),
             };
 
-            let gesture_event = EventWrapper::StaticEvent(Event::WindowEvent {
+            let gesture_event = EventWrapper::Window {
                 window_id: window.id(),
-                event: WindowEvent::PinchGesture {
-                    device_id: None,
-                    delta: delta as f64,
-                    phase,
-                },
-            });
+                event: WindowEvent::PinchGesture { device_id: None, delta: delta as f64, phase },
+            };
 
             let mtm = MainThreadMarker::new().unwrap();
             app_state::handle_nonuser_event(mtm, gesture_event);
         }
 
-        #[method(doubleTapGesture:)]
+        #[unsafe(method(doubleTapGesture:))]
         fn double_tap_gesture(&self, recognizer: &UITapGestureRecognizer) {
             let window = self.window().unwrap();
 
             if recognizer.state() == UIGestureRecognizerState::Ended {
-                let gesture_event = EventWrapper::StaticEvent(Event::WindowEvent {
+                let gesture_event = EventWrapper::Window {
                     window_id: window.id(),
-                    event: WindowEvent::DoubleTapGesture {
-                        device_id: None,
-                    },
-                });
+                    event: WindowEvent::DoubleTapGesture { device_id: None },
+                };
 
                 let mtm = MainThreadMarker::new().unwrap();
                 app_state::handle_nonuser_event(mtm, gesture_event);
             }
         }
 
-        #[method(rotationGesture:)]
+        #[unsafe(method(rotationGesture:))]
         fn rotation_gesture(&self, recognizer: &UIRotationGestureRecognizer) {
             let window = self.window().unwrap();
 
@@ -231,41 +208,42 @@ declare_class!(
                     self.ivars().rotation_last_delta.set(0.0);
 
                     (TouchPhase::Started, 0.0)
-                }
+                },
                 UIGestureRecognizerState::Changed => {
-                    let last_rotation = self.ivars().rotation_last_delta.replace(recognizer.rotation());
+                    let last_rotation =
+                        self.ivars().rotation_last_delta.replace(recognizer.rotation());
 
                     (TouchPhase::Moved, recognizer.rotation() - last_rotation)
-                }
+                },
                 UIGestureRecognizerState::Ended => {
                     let last_rotation = self.ivars().rotation_last_delta.replace(0.0);
 
                     (TouchPhase::Ended, recognizer.rotation() - last_rotation)
-                }
+                },
                 UIGestureRecognizerState::Cancelled | UIGestureRecognizerState::Failed => {
                     self.ivars().rotation_last_delta.set(0.0);
 
                     // Pass -delta so that action is reversed
                     (TouchPhase::Cancelled, -recognizer.rotation())
-                }
+                },
                 state => panic!("unexpected recognizer state: {state:?}"),
             };
 
             // Make delta negative to match macos, convert to degrees
-            let gesture_event = EventWrapper::StaticEvent(Event::WindowEvent {
+            let gesture_event = EventWrapper::Window {
                 window_id: window.id(),
                 event: WindowEvent::RotationGesture {
                     device_id: None,
                     delta: -delta.to_degrees() as _,
                     phase,
                 },
-            });
+            };
 
             let mtm = MainThreadMarker::new().unwrap();
             app_state::handle_nonuser_event(mtm, gesture_event);
         }
 
-        #[method(panGesture:)]
+        #[unsafe(method(panGesture:))]
         fn pan_gesture(&self, recognizer: &UIPanGestureRecognizer) {
             let window = self.window().unwrap();
 
@@ -276,7 +254,7 @@ declare_class!(
                     self.ivars().pan_last_delta.set(translation);
 
                     (TouchPhase::Started, 0.0, 0.0)
-                }
+                },
                 UIGestureRecognizerState::Changed => {
                     let last_pan: CGPoint = self.ivars().pan_last_delta.replace(translation);
 
@@ -284,39 +262,40 @@ declare_class!(
                     let dy = translation.y - last_pan.y;
 
                     (TouchPhase::Moved, dx, dy)
-                }
+                },
                 UIGestureRecognizerState::Ended => {
-                    let last_pan: CGPoint = self.ivars().pan_last_delta.replace(CGPoint{x:0.0, y:0.0});
+                    let last_pan: CGPoint =
+                        self.ivars().pan_last_delta.replace(CGPoint { x: 0.0, y: 0.0 });
 
                     let dx = translation.x - last_pan.x;
                     let dy = translation.y - last_pan.y;
 
                     (TouchPhase::Ended, dx, dy)
-                }
+                },
                 UIGestureRecognizerState::Cancelled | UIGestureRecognizerState::Failed => {
-                    let last_pan: CGPoint = self.ivars().pan_last_delta.replace(CGPoint{x:0.0, y:0.0});
+                    let last_pan: CGPoint =
+                        self.ivars().pan_last_delta.replace(CGPoint { x: 0.0, y: 0.0 });
 
                     // Pass -delta so that action is reversed
                     (TouchPhase::Cancelled, -last_pan.x, -last_pan.y)
-                }
+                },
                 state => panic!("unexpected recognizer state: {state:?}"),
             };
 
-
-            let gesture_event = EventWrapper::StaticEvent(Event::WindowEvent {
+            let gesture_event = EventWrapper::Window {
                 window_id: window.id(),
                 event: WindowEvent::PanGesture {
                     device_id: None,
                     delta: PhysicalPosition::new(dx as _, dy as _),
                     phase,
                 },
-            });
+            };
 
             let mtm = MainThreadMarker::new().unwrap();
             app_state::handle_nonuser_event(mtm, gesture_event);
         }
 
-        #[method(canBecomeFirstResponder)]
+        #[unsafe(method(canBecomeFirstResponder))]
         fn can_become_first_responder(&self) -> bool {
             true
         }
@@ -325,27 +304,30 @@ declare_class!(
     unsafe impl NSObjectProtocol for WinitView {}
 
     unsafe impl UIGestureRecognizerDelegate for WinitView {
-        #[method(gestureRecognizer:shouldRecognizeSimultaneouslyWithGestureRecognizer:)]
-        fn should_recognize_simultaneously(&self, _gesture_recognizer: &UIGestureRecognizer, _other_gesture_recognizer: &UIGestureRecognizer) -> bool {
+        #[unsafe(method(gestureRecognizer:shouldRecognizeSimultaneouslyWithGestureRecognizer:))]
+        fn should_recognize_simultaneously(
+            &self,
+            _gesture_recognizer: &UIGestureRecognizer,
+            _other_gesture_recognizer: &UIGestureRecognizer,
+        ) -> bool {
             true
         }
     }
 
-    unsafe impl UITextInputTraits for WinitView {
-    }
+    unsafe impl UITextInputTraits for WinitView {}
 
     unsafe impl UIKeyInput for WinitView {
-        #[method(hasText)]
+        #[unsafe(method(hasText))]
         fn has_text(&self) -> bool {
             true
         }
 
-        #[method(insertText:)]
+        #[unsafe(method(insertText:))]
         fn insert_text(&self, text: &NSString) {
             self.handle_insert_text(text)
         }
 
-        #[method(deleteBackward)]
+        #[unsafe(method(deleteBackward))]
         fn delete_backward(&self) {
             self.handle_delete_backward()
         }
@@ -371,7 +353,7 @@ impl WinitView {
             primary_finger: Cell::new(None),
             fingers: Cell::new(0),
         });
-        let this: Retained<Self> = unsafe { msg_send_id![super(this), initWithFrame: frame] };
+        let this: Retained<Self> = unsafe { msg_send![super(this), initWithFrame: frame] };
 
         this.setMultipleTouchEnabled(true);
 
@@ -383,8 +365,8 @@ impl WinitView {
     }
 
     fn window(&self) -> Option<Retained<WinitUIWindow>> {
-        // SAFETY: `WinitView`s are always installed in a `WinitUIWindow`
-        (**self).window().map(|window| unsafe { Retained::cast(window) })
+        // `WinitView`s should always be installed in a `WinitUIWindow`
+        (**self).window().map(|window| window.downcast().unwrap())
     }
 
     pub(crate) fn recognize_pinch_gesture(&self, should_recognize: bool) {
@@ -479,13 +461,12 @@ impl WinitView {
     fn handle_touches(&self, touches: &NSSet<UITouch>) {
         let window = self.window().unwrap();
         let mut touch_events = Vec::new();
-        let os_supports_force = app_state::os_capabilities().force_touch;
         for touch in touches {
             let logical_location = touch.locationInView(None);
             let touch_type = touch.r#type();
             let force = if let UITouchType::Pencil = touch_type {
                 None
-            } else if os_supports_force {
+            } else if available!(ios = 9.0, tvos = 9.0, visionos = 1.0) {
                 let trait_collection = self.traitCollection();
                 let touch_capability = trait_collection.forceTouchCapability();
                 // Both the OS _and_ the device need to be checked for force touch support.
@@ -502,7 +483,7 @@ impl WinitView {
             } else {
                 None
             };
-            let touch_id = touch as *const UITouch as usize;
+            let touch_id = Retained::as_ptr(&touch) as usize;
             let phase = touch.phase();
             let position = {
                 let scale_factor = self.contentScaleFactor();
@@ -538,7 +519,7 @@ impl WinitView {
                         }
                     };
 
-                    touch_events.push(EventWrapper::StaticEvent(Event::WindowEvent {
+                    touch_events.push(EventWrapper::Window {
                         window_id,
                         event: WindowEvent::PointerEntered {
                             device_id: None,
@@ -550,8 +531,8 @@ impl WinitView {
                                 PointerKind::Touch(finger_id)
                             },
                         },
-                    }));
-                    touch_events.push(EventWrapper::StaticEvent(Event::WindowEvent {
+                    });
+                    touch_events.push(EventWrapper::Window {
                         window_id,
                         event: WindowEvent::PointerButton {
                             device_id: None,
@@ -564,7 +545,7 @@ impl WinitView {
                                 ButtonSource::Touch { finger_id, force }
                             },
                         },
-                    }));
+                    });
                 },
                 UITouchPhase::Moved => {
                     let (primary, source) = if let UITouchType::Pencil = touch_type {
@@ -576,7 +557,7 @@ impl WinitView {
                         })
                     };
 
-                    touch_events.push(EventWrapper::StaticEvent(Event::WindowEvent {
+                    touch_events.push(EventWrapper::Window {
                         window_id,
                         event: WindowEvent::PointerMoved {
                             device_id: None,
@@ -584,7 +565,7 @@ impl WinitView {
                             position,
                             source,
                         },
-                    }));
+                    });
                 },
                 // 2 is UITouchPhase::Stationary and is not expected here
                 UITouchPhase::Ended | UITouchPhase::Cancelled => {
@@ -600,7 +581,7 @@ impl WinitView {
                     };
 
                     if let UITouchPhase::Ended = phase {
-                        touch_events.push(EventWrapper::StaticEvent(Event::WindowEvent {
+                        touch_events.push(EventWrapper::Window {
                             window_id,
                             event: WindowEvent::PointerButton {
                                 device_id: None,
@@ -613,10 +594,10 @@ impl WinitView {
                                     ButtonSource::Touch { finger_id, force }
                                 },
                             },
-                        }));
+                        });
                     }
 
-                    touch_events.push(EventWrapper::StaticEvent(Event::WindowEvent {
+                    touch_events.push(EventWrapper::Window {
                         window_id,
                         event: WindowEvent::PointerLeft {
                             device_id: None,
@@ -628,7 +609,7 @@ impl WinitView {
                                 PointerKind::Touch(finger_id)
                             },
                         },
-                    }));
+                    });
                 },
                 _ => panic!("unexpected touch phase: {phase:?}"),
             }
@@ -647,29 +628,30 @@ impl WinitView {
             text.to_string().chars().flat_map(|c| {
                 let text = smol_str::SmolStr::from_iter([c]);
                 // Emit both press and release events
-                [ElementState::Pressed, ElementState::Released].map(|state| {
-                    EventWrapper::StaticEvent(Event::WindowEvent {
-                        window_id,
-                        event: WindowEvent::KeyboardInput {
-                            event: KeyEvent {
-                                text: if state == ElementState::Pressed {
-                                    Some(text.clone())
-                                } else {
-                                    None
-                                },
-                                state,
-                                location: KeyLocation::Standard,
-                                repeat: false,
-                                logical_key: Key::Character(text.clone()),
-                                physical_key: PhysicalKey::Unidentified(
-                                    NativeKeyCode::Unidentified,
-                                ),
-                                platform_specific: KeyEventExtra {},
+                [ElementState::Pressed, ElementState::Released].map(|state| EventWrapper::Window {
+                    window_id,
+                    event: WindowEvent::KeyboardInput {
+                        device_id: None,
+                        event: KeyEvent {
+                            text: if state == ElementState::Pressed {
+                                Some(text.clone())
+                            } else {
+                                None
                             },
-                            is_synthetic: false,
-                            device_id: None,
+                            state,
+                            location: KeyLocation::Standard,
+                            repeat: false,
+                            logical_key: Key::Character(text.clone()),
+                            physical_key: PhysicalKey::Unidentified(NativeKeyCode::Unidentified),
+                            text_with_all_modifiers: if state == ElementState::Pressed {
+                                Some(text.clone())
+                            } else {
+                                None
+                            },
+                            key_without_modifiers: Key::Character(text.clone()),
                         },
-                    })
+                        is_synthetic: false,
+                    },
                 })
             }),
         );
@@ -681,23 +663,22 @@ impl WinitView {
         let mtm = MainThreadMarker::new().unwrap();
         app_state::handle_nonuser_events(
             mtm,
-            [ElementState::Pressed, ElementState::Released].map(|state| {
-                EventWrapper::StaticEvent(Event::WindowEvent {
-                    window_id,
-                    event: WindowEvent::KeyboardInput {
-                        device_id: None,
-                        event: KeyEvent {
-                            state,
-                            logical_key: Key::Named(NamedKey::Backspace),
-                            physical_key: PhysicalKey::Code(KeyCode::Backspace),
-                            platform_specific: KeyEventExtra {},
-                            repeat: false,
-                            location: KeyLocation::Standard,
-                            text: None,
-                        },
-                        is_synthetic: false,
+            [ElementState::Pressed, ElementState::Released].map(|state| EventWrapper::Window {
+                window_id,
+                event: WindowEvent::KeyboardInput {
+                    device_id: None,
+                    event: KeyEvent {
+                        state,
+                        logical_key: Key::Named(NamedKey::Backspace),
+                        physical_key: PhysicalKey::Code(KeyCode::Backspace),
+                        repeat: false,
+                        location: KeyLocation::Standard,
+                        text: None,
+                        text_with_all_modifiers: None,
+                        key_without_modifiers: Key::Named(NamedKey::Backspace),
                     },
-                })
+                    is_synthetic: false,
+                },
             }),
         );
     }

src/platform_impl/apple/uikit/view_controller.rs

@@ -1,14 +1,13 @@
 use std::cell::Cell;
 
 use objc2::rc::Retained;
-use objc2::{declare_class, msg_send_id, mutability, ClassType, DeclaredClass};
-use objc2_foundation::{MainThreadMarker, NSObject};
+use objc2::{available, define_class, msg_send, DefinedClass, MainThreadMarker};
+use objc2_foundation::NSObject;
 use objc2_ui_kit::{
     UIDevice, UIInterfaceOrientationMask, UIRectEdge, UIResponder, UIStatusBarStyle,
     UIUserInterfaceIdiom, UIView, UIViewController,
 };
 
-use super::app_state::{self};
 use crate::platform::ios::{ScreenEdge, StatusBarStyle, ValidOrientations};
 use crate::window::WindowAttributes;
 
@@ -20,51 +19,42 @@ pub struct ViewControllerState {
     preferred_screen_edges_deferring_system_gestures: Cell<UIRectEdge>,
 }
 
-declare_class!(
+define_class!(
+    #[unsafe(super(UIViewController, UIResponder, NSObject))]
+    #[name = "WinitUIViewController"]
+    #[ivars = ViewControllerState]
     pub(crate) struct WinitViewController;
 
-    unsafe impl ClassType for WinitViewController {
-        #[inherits(UIResponder, NSObject)]
-        type Super = UIViewController;
-        type Mutability = mutability::MainThreadOnly;
-        const NAME: &'static str = "WinitUIViewController";
-    }
-
-    impl DeclaredClass for WinitViewController {
-        type Ivars = ViewControllerState;
-    }
-
-    unsafe impl WinitViewController {
-        #[method(shouldAutorotate)]
+    /// This documentation attribute makes rustfmt work for some reason?
+    impl WinitViewController {
+        #[unsafe(method(shouldAutorotate))]
         fn should_autorotate(&self) -> bool {
             true
         }
 
-        #[method(prefersStatusBarHidden)]
+        #[unsafe(method(prefersStatusBarHidden))]
         fn prefers_status_bar_hidden(&self) -> bool {
             self.ivars().prefers_status_bar_hidden.get()
         }
 
-        #[method(preferredStatusBarStyle)]
+        #[unsafe(method(preferredStatusBarStyle))]
         fn preferred_status_bar_style(&self) -> UIStatusBarStyle {
             self.ivars().preferred_status_bar_style.get()
         }
 
-        #[method(prefersHomeIndicatorAutoHidden)]
+        #[unsafe(method(prefersHomeIndicatorAutoHidden))]
         fn prefers_home_indicator_auto_hidden(&self) -> bool {
             self.ivars().prefers_home_indicator_auto_hidden.get()
         }
 
-        #[method(supportedInterfaceOrientations)]
+        #[unsafe(method(supportedInterfaceOrientations))]
         fn supported_orientations(&self) -> UIInterfaceOrientationMask {
             self.ivars().supported_orientations.get()
         }
 
-        #[method(preferredScreenEdgesDeferringSystemGestures)]
+        #[unsafe(method(preferredScreenEdgesDeferringSystemGestures))]
         fn preferred_screen_edges_deferring_system_gestures(&self) -> UIRectEdge {
-            self.ivars()
-                .preferred_screen_edges_deferring_system_gestures
-                .get()
+            self.ivars().preferred_screen_edges_deferring_system_gestures.get()
         }
     }
 );
@@ -87,11 +77,13 @@ impl WinitViewController {
 
     pub(crate) fn set_prefers_home_indicator_auto_hidden(&self, val: bool) {
         self.ivars().prefers_home_indicator_auto_hidden.set(val);
-        let os_capabilities = app_state::os_capabilities();
-        if os_capabilities.home_indicator_hidden {
+        if available!(ios = 11.0, visionos = 1.0) {
             self.setNeedsUpdateOfHomeIndicatorAutoHidden();
         } else {
-            os_capabilities.home_indicator_hidden_err_msg("ignoring")
+            tracing::warn!(
+                "`setNeedsUpdateOfHomeIndicatorAutoHidden` requires iOS 11.0+ or visionOS. \
+                 Ignoring"
+            );
         }
     }
 
@@ -101,11 +93,13 @@ impl WinitViewController {
             UIRectEdge(val.bits().into())
         };
         self.ivars().preferred_screen_edges_deferring_system_gestures.set(val);
-        let os_capabilities = app_state::os_capabilities();
-        if os_capabilities.defer_system_gestures {
+        if available!(ios = 11.0, visionos = 1.0) {
             self.setNeedsUpdateOfScreenEdgesDeferringSystemGestures();
         } else {
-            os_capabilities.defer_system_gestures_err_msg("ignoring")
+            tracing::warn!(
+                "`setNeedsUpdateOfScreenEdgesDeferringSystemGestures` requires iOS 11.0+ or \
+                 visionOS. Ignoring"
+            );
         }
     }
 
@@ -146,7 +140,7 @@ impl WinitViewController {
             supported_orientations: Cell::new(UIInterfaceOrientationMask::All),
             preferred_screen_edges_deferring_system_gestures: Cell::new(UIRectEdge::empty()),
         });
-        let this: Retained<Self> = unsafe { msg_send_id![super(this), init] };
+        let this: Retained<Self> = unsafe { msg_send![super(this), init] };
 
         this.set_prefers_status_bar_hidden(
             window_attributes.platform_specific.prefers_status_bar_hidden,

src/platform_impl/apple/uikit/window.rs

@@ -1,12 +1,13 @@
 #![allow(clippy::unnecessary_cast)]
 
 use std::collections::VecDeque;
+use std::sync::Arc;
 
+use dispatch2::MainThreadBound;
 use objc2::rc::Retained;
-use objc2::{class, declare_class, msg_send, msg_send_id, mutability, ClassType, DeclaredClass};
-use objc2_foundation::{
-    CGFloat, CGPoint, CGRect, CGSize, MainThreadBound, MainThreadMarker, NSObject, NSObjectProtocol,
-};
+use objc2::{available, class, define_class, msg_send, MainThreadMarker};
+use objc2_core_foundation::{CGFloat, CGPoint, CGRect, CGSize};
+use objc2_foundation::{NSObject, NSObjectProtocol};
 use objc2_ui_kit::{
     UIApplication, UICoordinateSpace, UIEdgeInsets, UIResponder, UIScreen,
     UIScreenOverscanCompensation, UIViewController, UIWindow,
@@ -16,59 +17,47 @@ use tracing::{debug, warn};
 use super::app_state::EventWrapper;
 use super::view::WinitView;
 use super::view_controller::WinitViewController;
-use super::{app_state, monitor, ActiveEventLoop, Fullscreen, MonitorHandle};
+use super::{app_state, monitor, ActiveEventLoop, MonitorHandle};
 use crate::cursor::Cursor;
 use crate::dpi::{
     LogicalInsets, LogicalPosition, LogicalSize, PhysicalInsets, PhysicalPosition, PhysicalSize,
     Position, Size,
 };
 use crate::error::{NotSupportedError, RequestError};
-use crate::event::{Event, WindowEvent};
+use crate::event::WindowEvent;
 use crate::icon::Icon;
-use crate::monitor::MonitorHandle as CoreMonitorHandle;
+use crate::monitor::{Fullscreen, MonitorHandle as CoreMonitorHandle};
 use crate::platform::ios::{ScreenEdge, StatusBarStyle, ValidOrientations};
 use crate::window::{
     CursorGrabMode, ImePurpose, ResizeDirection, Theme, UserAttentionType, Window as CoreWindow,
     WindowAttributes, WindowButtons, WindowId, WindowLevel,
 };
 
-declare_class!(
+define_class!(
+    #[unsafe(super(UIWindow, UIResponder, NSObject))]
+    #[name = "WinitUIWindow"]
     #[derive(Debug, PartialEq, Eq, Hash)]
     pub(crate) struct WinitUIWindow;
 
-    unsafe impl ClassType for WinitUIWindow {
-        #[inherits(UIResponder, NSObject)]
-        type Super = UIWindow;
-        type Mutability = mutability::MainThreadOnly;
-        const NAME: &'static str = "WinitUIWindow";
-    }
-
-    impl DeclaredClass for WinitUIWindow {}
-
-    unsafe impl WinitUIWindow {
-        #[method(becomeKeyWindow)]
+    /// This documentation attribute makes rustfmt work for some reason?
+    impl WinitUIWindow {
+        #[unsafe(method(becomeKeyWindow))]
         fn become_key_window(&self) {
             let mtm = MainThreadMarker::new().unwrap();
-            app_state::handle_nonuser_event(
-                mtm,
-                EventWrapper::StaticEvent(Event::WindowEvent {
-                    window_id: self.id(),
-                    event: WindowEvent::Focused(true),
-                }),
-            );
+            app_state::handle_nonuser_event(mtm, EventWrapper::Window {
+                window_id: self.id(),
+                event: WindowEvent::Focused(true),
+            });
             let _: () = unsafe { msg_send![super(self), becomeKeyWindow] };
         }
 
-        #[method(resignKeyWindow)]
+        #[unsafe(method(resignKeyWindow))]
         fn resign_key_window(&self) {
             let mtm = MainThreadMarker::new().unwrap();
-            app_state::handle_nonuser_event(
-                mtm,
-                EventWrapper::StaticEvent(Event::WindowEvent {
-                    window_id: self.id(),
-                    event: WindowEvent::Focused(false),
-                }),
-            );
+            app_state::handle_nonuser_event(mtm, EventWrapper::Window {
+                window_id: self.id(),
+                event: WindowEvent::Focused(false),
+            });
             let _: () = unsafe { msg_send![super(self), resignKeyWindow] };
         }
     }
@@ -86,18 +75,23 @@ impl WinitUIWindow {
         // into very confusing issues with the window not being properly activated.
         //
         // Winit ensures this by not allowing access to `ActiveEventLoop` before handling events.
-        let this: Retained<Self> = unsafe { msg_send_id![mtm.alloc(), initWithFrame: frame] };
+        let this: Retained<Self> = unsafe { msg_send![mtm.alloc(), initWithFrame: frame] };
 
         this.setRootViewController(Some(view_controller));
 
-        match window_attributes.fullscreen.clone().map(Into::into) {
-            Some(Fullscreen::Exclusive(ref video_mode)) => {
-                let monitor = video_mode.monitor();
+        match window_attributes.fullscreen.clone() {
+            Some(Fullscreen::Exclusive(monitor, ref video_mode)) => {
+                let monitor = monitor.cast_ref::<MonitorHandle>().unwrap();
                 let screen = monitor.ui_screen(mtm);
-                screen.setCurrentMode(Some(video_mode.screen_mode(mtm)));
+                if let Some(video_mode) =
+                    monitor.video_modes_handles().find(|mode| &mode.mode == video_mode)
+                {
+                    screen.setCurrentMode(Some(video_mode.screen_mode(mtm)));
+                }
                 this.setScreen(screen);
             },
             Some(Fullscreen::Borderless(Some(ref monitor))) => {
+                let monitor = monitor.cast_ref::<MonitorHandle>().unwrap();
                 let screen = monitor.ui_screen(mtm);
                 this.setScreen(screen);
             },
@@ -205,8 +199,7 @@ impl Inner {
     }
 
     pub fn safe_area(&self) -> PhysicalInsets<u32> {
-        // Only available on iOS 11.0
-        let insets = if app_state::os_capabilities().safe_area {
+        let insets = if available!(ios = 11.0, tvos = 11.0, visionos = 1.0) {
             self.view.safeAreaInsets()
         } else {
             // Assume the status bar frame is the only thing that obscures the view
@@ -312,12 +305,19 @@ impl Inner {
     pub(crate) fn set_fullscreen(&self, monitor: Option<Fullscreen>) {
         let mtm = MainThreadMarker::new().unwrap();
         let uiscreen = match &monitor {
-            Some(Fullscreen::Exclusive(video_mode)) => {
-                let uiscreen = video_mode.monitor.ui_screen(mtm);
-                uiscreen.setCurrentMode(Some(video_mode.screen_mode(mtm)));
+            Some(Fullscreen::Exclusive(monitor, video_mode)) => {
+                let monitor = monitor.cast_ref::<MonitorHandle>().unwrap();
+                let uiscreen = monitor.ui_screen(mtm);
+                if let Some(video_mode) =
+                    monitor.video_modes_handles().find(|mode| &mode.mode == video_mode)
+                {
+                    uiscreen.setCurrentMode(Some(video_mode.screen_mode(mtm)));
+                }
                 uiscreen.clone()
             },
-            Some(Fullscreen::Borderless(Some(monitor))) => monitor.ui_screen(mtm).clone(),
+            Some(Fullscreen::Borderless(Some(monitor))) => {
+                monitor.cast_ref::<MonitorHandle>().unwrap().ui_screen(mtm).clone()
+            },
             Some(Fullscreen::Borderless(None)) => {
                 self.current_monitor_inner().ui_screen(mtm).clone()
             },
@@ -355,7 +355,7 @@ impl Inner {
             && screen_space_bounds.size.width == screen_bounds.size.width
             && screen_space_bounds.size.height == screen_bounds.size.height
         {
-            Some(Fullscreen::Borderless(Some(monitor)))
+            Some(Fullscreen::Borderless(Some(CoreMonitorHandle(Arc::new(monitor)))))
         } else {
             None
         }
@@ -465,6 +465,7 @@ impl Inner {
     }
 }
 
+#[derive(Debug)]
 pub struct Window {
     inner: MainThreadBound<Inner>,
 }
@@ -487,10 +488,13 @@ impl Window {
 
         #[allow(deprecated)]
         let main_screen = UIScreen::mainScreen(mtm);
-        let fullscreen = window_attributes.fullscreen.clone().map(Into::into);
+        let fullscreen = window_attributes.fullscreen.clone();
         let screen = match fullscreen {
-            Some(Fullscreen::Exclusive(ref video_mode)) => video_mode.monitor.ui_screen(mtm),
-            Some(Fullscreen::Borderless(Some(ref monitor))) => monitor.ui_screen(mtm),
+            Some(Fullscreen::Exclusive(ref monitor, _))
+            | Some(Fullscreen::Borderless(Some(ref monitor))) => {
+                let monitor = monitor.cast_ref::<MonitorHandle>().unwrap();
+                monitor.ui_screen(mtm)
+            },
             Some(Fullscreen::Borderless(None)) | None => &main_screen,
         };
 
@@ -675,12 +679,12 @@ impl CoreWindow for Window {
         self.maybe_wait_on_main(|delegate| delegate.is_maximized())
     }
 
-    fn set_fullscreen(&self, fullscreen: Option<crate::window::Fullscreen>) {
-        self.maybe_wait_on_main(|delegate| delegate.set_fullscreen(fullscreen.map(Into::into)))
+    fn set_fullscreen(&self, fullscreen: Option<Fullscreen>) {
+        self.maybe_wait_on_main(|delegate| delegate.set_fullscreen(fullscreen))
     }
 
-    fn fullscreen(&self) -> Option<crate::window::Fullscreen> {
-        self.maybe_wait_on_main(|delegate| delegate.fullscreen().map(Into::into))
+    fn fullscreen(&self) -> Option<Fullscreen> {
+        self.maybe_wait_on_main(|delegate| delegate.fullscreen())
     }
 
     fn set_decorations(&self, decorations: bool) {
@@ -776,21 +780,24 @@ impl CoreWindow for Window {
 
     fn current_monitor(&self) -> Option<CoreMonitorHandle> {
         self.maybe_wait_on_main(|delegate| {
-            delegate.current_monitor().map(|inner| CoreMonitorHandle { inner })
+            delegate.current_monitor().map(|monitor| CoreMonitorHandle(Arc::new(monitor)))
         })
     }
 
     fn available_monitors(&self) -> Box<dyn Iterator<Item = CoreMonitorHandle>> {
         self.maybe_wait_on_main(|delegate| {
             Box::new(
-                delegate.available_monitors().into_iter().map(|inner| CoreMonitorHandle { inner }),
+                delegate
+                    .available_monitors()
+                    .into_iter()
+                    .map(|monitor| CoreMonitorHandle(Arc::new(monitor))),
             )
         })
     }
 
     fn primary_monitor(&self) -> Option<CoreMonitorHandle> {
         self.maybe_wait_on_main(|delegate| {
-            delegate.primary_monitor().map(|inner| CoreMonitorHandle { inner })
+            delegate.primary_monitor().map(|monitor| CoreMonitorHandle(Arc::new(monitor)))
         })
     }
 

src/platform_impl/linux/common/xkb/keymap.rs

@@ -166,8 +166,8 @@ pub fn scancode_to_physicalkey(scancode: u32) -> PhysicalKey {
         122 => KeyCode::Lang1,
         123 => KeyCode::Lang2,
         124 => KeyCode::IntlYen,
-        125 => KeyCode::SuperLeft,
-        126 => KeyCode::SuperRight,
+        125 => KeyCode::MetaLeft,
+        126 => KeyCode::MetaRight,
         127 => KeyCode::ContextMenu,
         128 => KeyCode::BrowserStop,
         129 => KeyCode::Again,
@@ -419,8 +419,8 @@ pub fn physicalkey_to_scancode(key: PhysicalKey) -> Option<u32> {
         KeyCode::Lang1 => Some(122),
         KeyCode::Lang2 => Some(123),
         KeyCode::IntlYen => Some(124),
-        KeyCode::SuperLeft => Some(125),
-        KeyCode::SuperRight => Some(126),
+        KeyCode::MetaLeft => Some(125),
+        KeyCode::MetaRight => Some(126),
         KeyCode::ContextMenu => Some(127),
         KeyCode::BrowserStop => Some(128),
         KeyCode::Again => Some(129),
@@ -622,16 +622,20 @@ pub fn keysym_to_key(keysym: u32) -> Key {
         keysyms::Control_R => NamedKey::Control,
         keysyms::Caps_Lock => NamedKey::CapsLock,
         // keysyms::Shift_Lock => NamedKey::ShiftLock,
-
-        // keysyms::Meta_L => NamedKey::Meta,
-        // keysyms::Meta_R => NamedKey::Meta,
         keysyms::Alt_L => NamedKey::Alt,
         keysyms::Alt_R => NamedKey::Alt,
-        keysyms::Super_L => NamedKey::Super,
-        keysyms::Super_R => NamedKey::Super,
+        #[allow(deprecated)]
         keysyms::Hyper_L => NamedKey::Hyper,
+        #[allow(deprecated)]
         keysyms::Hyper_R => NamedKey::Hyper,
 
+        // Browsers map X11's Super keys to Meta, so we do that as well.
+        keysyms::Super_L => NamedKey::Meta,
+        keysyms::Super_R => NamedKey::Meta,
+        // The actual Meta keys do not seem to be used by browsers, so we don't do that either.
+        // keysyms::Meta_L => NamedKey::Super,
+        // keysyms::Meta_R => NamedKey::Super,
+
         // XKB function and modifier keys
         // keysyms::ISO_Lock => NamedKey::IsoLock,
         // keysyms::ISO_Level2_Latch => NamedKey::IsoLevel2Latch,
@@ -724,7 +728,7 @@ pub fn keysym_to_key(keysym: u32) -> Key {
         keysyms::_3270_PrintScreen => NamedKey::PrintScreen,
         keysyms::_3270_Enter => NamedKey::Enter,
 
-        keysyms::space => NamedKey::Space,
+        keysyms::space => return Key::Character(" ".into()),
         // exclam..Sinh_kunddaliya
 
         // XFree86

src/platform_impl/linux/common/xkb/mod.rs

@@ -16,7 +16,6 @@ use {x11_dl::xlib_xcb::xcb_connection_t, xkbcommon_dl::x11::xkbcommon_x11_handle
 
 use crate::event::{ElementState, KeyEvent};
 use crate::keyboard::{Key, KeyLocation};
-use crate::platform_impl::KeyEventExtra;
 use crate::utils::Lazy;
 
 mod compose;
@@ -198,9 +197,16 @@ impl KeyContext<'_> {
         let (key_without_modifiers, _) = event.key_without_modifiers();
         let text_with_all_modifiers = event.text_with_all_modifiers();
 
-        let platform_specific = KeyEventExtra { text_with_all_modifiers, key_without_modifiers };
-
-        KeyEvent { physical_key, logical_key, text, location, state, repeat, platform_specific }
+        KeyEvent {
+            physical_key,
+            logical_key,
+            text,
+            location,
+            state,
+            repeat,
+            text_with_all_modifiers,
+            key_without_modifiers,
+        }
     }
 
     fn keysym_to_utf8_raw(&mut self, keysym: u32) -> Option<SmolStr> {

src/platform_impl/linux/common/xkb/state.rs

@@ -183,7 +183,7 @@ impl From<ModifiersState> for crate::keyboard::ModifiersState {
         to_mods.set(crate::keyboard::ModifiersState::SHIFT, mods.shift);
         to_mods.set(crate::keyboard::ModifiersState::CONTROL, mods.ctrl);
         to_mods.set(crate::keyboard::ModifiersState::ALT, mods.alt);
-        to_mods.set(crate::keyboard::ModifiersState::SUPER, mods.logo);
+        to_mods.set(crate::keyboard::ModifiersState::META, mods.logo);
         to_mods
     }
 }

src/platform_impl/linux/mod.rs

@@ -4,31 +4,18 @@
 compile_error!("Please select a feature to build for unix: `x11`, `wayland`");
 
 use std::env;
-use std::num::{NonZeroU16, NonZeroU32};
 use std::os::unix::io::{AsFd, AsRawFd, BorrowedFd, RawFd};
 use std::time::Duration;
-#[cfg(x11_platform)]
-use std::{ffi::CStr, mem::MaybeUninit, os::raw::*, sync::Arc, sync::Mutex};
-
-use smol_str::SmolStr;
 
 pub(crate) use self::common::xkb::{physicalkey_to_scancode, scancode_to_physicalkey};
-#[cfg(x11_platform)]
-use self::x11::{XConnection, XError, XNotSupported};
 use crate::application::ApplicationHandler;
-pub(crate) use crate::cursor::OnlyCursorImageSource as PlatformCustomCursorSource;
 #[cfg(x11_platform)]
 use crate::dpi::Size;
-use crate::dpi::{PhysicalPosition, PhysicalSize};
 use crate::error::{EventLoopError, NotSupportedError};
 use crate::event_loop::ActiveEventLoop;
-pub(crate) use crate::icon::RgbaIcon as PlatformIcon;
-use crate::keyboard::Key;
 use crate::platform::pump_events::PumpStatus;
 #[cfg(x11_platform)]
-use crate::platform::x11::{WindowType as XWindowType, XlibErrorHook};
-#[cfg(x11_platform)]
-use crate::utils::Lazy;
+use crate::platform::x11::WindowType as XWindowType;
 use crate::window::ActivationToken;
 
 pub(crate) mod common;
@@ -103,18 +90,6 @@ impl Default for PlatformSpecificWindowAttributes {
     }
 }
 
-#[cfg(x11_platform)]
-pub(crate) static X11_BACKEND: Lazy<Mutex<Result<Arc<XConnection>, XNotSupported>>> =
-    Lazy::new(|| Mutex::new(XConnection::new(Some(x_error_callback)).map(Arc::new)));
-
-#[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
-pub enum MonitorHandle {
-    #[cfg(x11_platform)]
-    X(x11::MonitorHandle),
-    #[cfg(wayland_platform)]
-    Wayland(wayland::MonitorHandle),
-}
-
 /// `x11_or_wayland!(match expr; Enum(foo) => foo.something())`
 /// expands to the equivalent of
 /// ```ignore
@@ -143,133 +118,7 @@ macro_rules! x11_or_wayland {
     };
 }
 
-impl MonitorHandle {
-    #[inline]
-    pub fn name(&self) -> Option<String> {
-        x11_or_wayland!(match self; MonitorHandle(m) => m.name())
-    }
-
-    #[inline]
-    pub fn native_identifier(&self) -> u32 {
-        x11_or_wayland!(match self; MonitorHandle(m) => m.native_identifier())
-    }
-
-    #[inline]
-    pub fn position(&self) -> Option<PhysicalPosition<i32>> {
-        x11_or_wayland!(match self; MonitorHandle(m) => m.position())
-    }
-
-    #[inline]
-    pub fn scale_factor(&self) -> f64 {
-        x11_or_wayland!(match self; MonitorHandle(m) => m.scale_factor() as _)
-    }
-
-    #[inline]
-    pub fn current_video_mode(&self) -> Option<VideoModeHandle> {
-        x11_or_wayland!(match self; MonitorHandle(m) => m.current_video_mode())
-    }
-
-    #[inline]
-    pub fn video_modes(&self) -> Box<dyn Iterator<Item = VideoModeHandle>> {
-        x11_or_wayland!(match self; MonitorHandle(m) => Box::new(m.video_modes()))
-    }
-}
-
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub enum VideoModeHandle {
-    #[cfg(x11_platform)]
-    X(x11::VideoModeHandle),
-    #[cfg(wayland_platform)]
-    Wayland(wayland::VideoModeHandle),
-}
-
-impl VideoModeHandle {
-    #[inline]
-    pub fn size(&self) -> PhysicalSize<u32> {
-        x11_or_wayland!(match self; VideoModeHandle(m) => m.size())
-    }
-
-    #[inline]
-    pub fn bit_depth(&self) -> Option<NonZeroU16> {
-        x11_or_wayland!(match self; VideoModeHandle(m) => m.bit_depth())
-    }
-
-    #[inline]
-    pub fn refresh_rate_millihertz(&self) -> Option<NonZeroU32> {
-        x11_or_wayland!(match self; VideoModeHandle(m) => m.refresh_rate_millihertz())
-    }
-
-    #[inline]
-    pub fn monitor(&self) -> MonitorHandle {
-        x11_or_wayland!(match self; VideoModeHandle(m) => m.monitor(); as MonitorHandle)
-    }
-}
-
-#[derive(Debug, Clone, Eq, PartialEq, Hash)]
-pub struct KeyEventExtra {
-    pub text_with_all_modifiers: Option<SmolStr>,
-    pub key_without_modifiers: Key,
-}
-
-#[derive(Clone, Debug, Eq, Hash, PartialEq)]
-pub(crate) enum PlatformCustomCursor {
-    #[cfg(wayland_platform)]
-    Wayland(wayland::CustomCursor),
-    #[cfg(x11_platform)]
-    X(x11::CustomCursor),
-}
-
-/// Hooks for X11 errors.
-#[cfg(x11_platform)]
-pub(crate) static XLIB_ERROR_HOOKS: Mutex<Vec<XlibErrorHook>> = Mutex::new(Vec::new());
-
-#[cfg(x11_platform)]
-unsafe extern "C" fn x_error_callback(
-    display: *mut x11::ffi::Display,
-    event: *mut x11::ffi::XErrorEvent,
-) -> c_int {
-    let xconn_lock = X11_BACKEND.lock().unwrap_or_else(|e| e.into_inner());
-    if let Ok(ref xconn) = *xconn_lock {
-        // Call all the hooks.
-        let mut error_handled = false;
-        for hook in XLIB_ERROR_HOOKS.lock().unwrap().iter() {
-            error_handled |= hook(display as *mut _, event as *mut _);
-        }
-
-        // `assume_init` is safe here because the array consists of `MaybeUninit` values,
-        // which do not require initialization.
-        let mut buf: [MaybeUninit<c_char>; 1024] = unsafe { MaybeUninit::uninit().assume_init() };
-        unsafe {
-            (xconn.xlib.XGetErrorText)(
-                display,
-                (*event).error_code as c_int,
-                buf.as_mut_ptr() as *mut c_char,
-                buf.len() as c_int,
-            )
-        };
-        let description =
-            unsafe { CStr::from_ptr(buf.as_ptr() as *const c_char) }.to_string_lossy();
-
-        let error = unsafe {
-            XError {
-                description: description.into_owned(),
-                error_code: (*event).error_code,
-                request_code: (*event).request_code,
-                minor_code: (*event).minor_code,
-            }
-        };
-
-        // Don't log error.
-        if !error_handled {
-            tracing::error!("X11 error: {:#?}", error);
-            // XXX only update the error, if it wasn't handled by any of the hooks.
-            *xconn.latest_error.lock().unwrap() = Some(error);
-        }
-    }
-    // Fun fact: this return value is completely ignored.
-    0
-}
-
+#[derive(Debug)]
 pub enum EventLoop {
     #[cfg(wayland_platform)]
     Wayland(Box<wayland::EventLoop>),
@@ -329,9 +178,9 @@ impl EventLoop {
         // Create the display based on the backend.
         match backend {
             #[cfg(wayland_platform)]
-            Backend::Wayland => EventLoop::new_wayland_any_thread().map_err(Into::into),
+            Backend::Wayland => EventLoop::new_wayland_any_thread(),
             #[cfg(x11_platform)]
-            Backend::X => EventLoop::new_x11_any_thread().map_err(Into::into),
+            Backend::X => EventLoop::new_x11_any_thread(),
         }
     }
 
@@ -342,12 +191,7 @@ impl EventLoop {
 
     #[cfg(x11_platform)]
     fn new_x11_any_thread() -> Result<EventLoop, EventLoopError> {
-        let xconn = match X11_BACKEND.lock().unwrap_or_else(|e| e.into_inner()).as_ref() {
-            Ok(xconn) => xconn.clone(),
-            Err(err) => return Err(os_error!(err.clone()).into()),
-        };
-
-        Ok(EventLoop::X(x11::EventLoop::new(xconn)))
+        x11::EventLoop::new().map(EventLoop::X)
     }
 
     #[inline]
@@ -360,18 +204,15 @@ impl EventLoop {
         }
     }
 
-    pub fn run<A: ApplicationHandler>(
-        self,
-        init_closure: impl FnOnce(&dyn ActiveEventLoop) -> A,
-    ) -> Result<(), EventLoopError> {
-        x11_or_wayland!(match self; EventLoop(evlp) => evlp.run(init_closure))
+    pub fn run_app<A: ApplicationHandler>(self, app: A) -> Result<(), EventLoopError> {
+        x11_or_wayland!(match self; EventLoop(evlp) => evlp.run_app(app))
     }
 
-    pub fn run_on_demand<A: ApplicationHandler>(
+    pub fn run_app_on_demand<A: ApplicationHandler>(
         &mut self,
-        init_closure: impl FnOnce(&dyn ActiveEventLoop) -> A,
+        app: A,
     ) -> Result<(), EventLoopError> {
-        x11_or_wayland!(match self; EventLoop(evlp) => evlp.run_on_demand(init_closure))
+        x11_or_wayland!(match self; EventLoop(evlp) => evlp.run_app_on_demand(app))
     }
 
     pub fn pump_app_events<A: ApplicationHandler>(

src/platform_impl/linux/wayland/event_loop/mod.rs

@@ -3,27 +3,33 @@
 use std::cell::{Cell, RefCell};
 use std::io::Result as IOResult;
 use std::mem;
+use std::os::fd::OwnedFd;
 use std::os::unix::io::{AsFd, AsRawFd, BorrowedFd, RawFd};
 use std::sync::atomic::Ordering;
-use std::sync::{Arc, Mutex};
+use std::sync::{Arc, Condvar, Mutex};
+use std::thread::JoinHandle;
 use std::time::{Duration, Instant};
 
+use calloop::ping::Ping;
+use rustix::event::{PollFd, PollFlags};
+use rustix::pipe::{self, PipeFlags};
 use sctk::reexports::calloop_wayland_source::WaylandSource;
 use sctk::reexports::client::{globals, Connection, QueueHandle};
+use tracing::warn;
 
 use crate::application::ApplicationHandler;
-use crate::cursor::OnlyCursorImage;
 use crate::dpi::LogicalSize;
-use crate::error::{EventLoopError, OsError, RequestError};
-use crate::event::{Event, StartCause, SurfaceSizeWriter, WindowEvent};
+use crate::error::{EventLoopError, NotSupportedError, OsError, RequestError};
+use crate::event::{DeviceEvent, StartCause, SurfaceSizeWriter, WindowEvent};
 use crate::event_loop::{
     ActiveEventLoop as RootActiveEventLoop, ControlFlow, DeviceEvents,
     OwnedDisplayHandle as CoreOwnedDisplayHandle,
 };
+use crate::monitor::MonitorHandle as CoreMonitorHandle;
 use crate::platform::pump_events::PumpStatus;
 use crate::platform_impl::platform::min_timeout;
-use crate::platform_impl::PlatformCustomCursor;
-use crate::window::{CustomCursor as RootCustomCursor, CustomCursorSource, Theme};
+use crate::platform_impl::wayland::types::cursor::WaylandCustomCursor;
+use crate::window::{CustomCursor as CoreCustomCursor, CustomCursorSource, Theme};
 
 mod proxy;
 pub mod sink;
@@ -31,6 +37,7 @@ pub mod sink;
 use proxy::EventLoopProxy;
 use sink::EventSink;
 
+use super::output::MonitorHandle;
 use super::state::{WindowCompositorUpdate, WinitState};
 use super::window::state::FrameCallbackState;
 use super::{logical_to_physical_rounded, WindowId};
@@ -38,7 +45,14 @@ pub use crate::event_loop::EventLoopProxy as CoreEventLoopProxy;
 
 type WaylandDispatcher = calloop::Dispatcher<'static, WaylandSource<WinitState>, WinitState>;
 
+#[derive(Debug)]
+pub(crate) enum Event {
+    WindowEvent { window_id: WindowId, event: WindowEvent },
+    DeviceEvent { event: DeviceEvent },
+}
+
 /// The Wayland event loop.
+#[derive(Debug)]
 pub struct EventLoop {
     /// Has `run` or `run_on_demand` been called or a call to `pump_events` that starts the loop
     loop_running: bool,
@@ -60,6 +74,8 @@ pub struct EventLoop {
     // XXX drop after everything else, just to be safe.
     /// Calloop's event loop.
     event_loop: calloop::EventLoop<'static, WinitState>,
+
+    pump_event_notifier: Option<PumpEventNotifier>,
 }
 
 impl EventLoop {
@@ -141,26 +157,21 @@ impl EventLoop {
             wayland_dispatcher,
             event_loop,
             active_event_loop,
+            pump_event_notifier: None,
         };
 
         Ok(event_loop)
     }
 
-    pub fn run<A: ApplicationHandler>(
-        mut self,
-        init_closure: impl FnOnce(&dyn RootActiveEventLoop) -> A,
-    ) -> Result<(), EventLoopError> {
-        self.run_on_demand(init_closure)
+    pub fn run_app<A: ApplicationHandler>(mut self, app: A) -> Result<(), EventLoopError> {
+        self.run_app_on_demand(app)
     }
 
-    pub fn run_on_demand<A: ApplicationHandler>(
+    pub fn run_app_on_demand<A: ApplicationHandler>(
         &mut self,
-        init_closure: impl FnOnce(&dyn RootActiveEventLoop) -> A,
+        mut app: A,
     ) -> Result<(), EventLoopError> {
         self.active_event_loop.clear_exit();
-
-        let mut app = init_closure(&self.active_event_loop);
-
         let exit = loop {
             match self.pump_app_events(None, &mut app) {
                 PumpStatus::Exit(0) => {
@@ -201,11 +212,27 @@ impl EventLoop {
         if !self.exiting() {
             self.poll_events_with_timeout(timeout, &mut app);
         }
+
         if let Some(code) = self.exit_code() {
             self.loop_running = false;
 
             PumpStatus::Exit(code)
         } else {
+            // NOTE: spawn a wake-up thread, thus if we have code reading the wayland connection
+            // in parallel to winit, we ensure that the loop itself is marked as having events.
+            if timeout.is_some() && self.pump_event_notifier.is_none() {
+                self.pump_event_notifier = Some(PumpEventNotifier::spawn(
+                    self.active_event_loop.handle.connection.clone(),
+                    self.active_event_loop.event_loop_awakener.clone(),
+                ));
+            }
+
+            if let Some(pump_event_notifier) = self.pump_event_notifier.as_ref() {
+                // Notify that we don't have to wait, since we're out of winit.
+                *pump_event_notifier.control.0.lock().unwrap() = PumpEventNotifierAction::Monitor;
+                pump_event_notifier.control.1.notify_one();
+            }
+
             PumpStatus::Continue
         }
     }
@@ -269,7 +296,10 @@ impl EventLoop {
 
             // Reduce spurious wake-ups.
             let dispatched_events = self.with_state(|state| state.dispatched_events);
-            if matches!(cause, StartCause::WaitCancelled { .. }) && !dispatched_events {
+            if matches!(cause, StartCause::WaitCancelled { .. })
+                && !dispatched_events
+                && timeout.is_none()
+            {
                 continue;
             }
 
@@ -387,10 +417,9 @@ impl EventLoop {
                 Event::WindowEvent { window_id, event } => {
                     app.window_event(&self.active_event_loop, window_id, event)
                 },
-                Event::DeviceEvent { device_id, event } => {
-                    app.device_event(&self.active_event_loop, device_id, event)
+                Event::DeviceEvent { event } => {
+                    app.device_event(&self.active_event_loop, None, event)
                 },
-                _ => unreachable!("event which is neither device nor window event."),
             }
         }
 
@@ -403,10 +432,9 @@ impl EventLoop {
                 Event::WindowEvent { window_id, event } => {
                     app.window_event(&self.active_event_loop, window_id, event)
                 },
-                Event::DeviceEvent { device_id, event } => {
-                    app.device_event(&self.active_event_loop, device_id, event)
+                Event::DeviceEvent { event } => {
+                    app.device_event(&self.active_event_loop, None, event)
                 },
-                _ => unreachable!("event which is neither device nor window event."),
             }
         }
 
@@ -546,12 +574,13 @@ impl AsRawFd for EventLoop {
     }
 }
 
+#[derive(Debug)]
 pub struct ActiveEventLoop {
     /// Event loop proxy
     event_loop_proxy: CoreEventLoopProxy,
 
     /// The event loop wakeup source.
-    pub event_loop_awakener: calloop::ping::Ping,
+    pub event_loop_awakener: Ping,
 
     /// The main queue used by the event loop.
     pub queue_handle: QueueHandle<WinitState>,
@@ -600,10 +629,15 @@ impl RootActiveEventLoop for ActiveEventLoop {
     fn create_custom_cursor(
         &self,
         cursor: CustomCursorSource,
-    ) -> Result<RootCustomCursor, RequestError> {
-        Ok(RootCustomCursor {
-            inner: PlatformCustomCursor::Wayland(OnlyCursorImage(Arc::from(cursor.inner.0))),
-        })
+    ) -> Result<CoreCustomCursor, RequestError> {
+        let cursor_image = match cursor {
+            CustomCursorSource::Image(cursor_image) => cursor_image,
+            CustomCursorSource::Animation { .. } | CustomCursorSource::Url { .. } => {
+                return Err(NotSupportedError::new("unsupported cursor kind").into())
+            },
+        };
+
+        Ok(CoreCustomCursor(Arc::new(WaylandCustomCursor(cursor_image))))
     }
 
     #[inline]
@@ -619,19 +653,18 @@ impl RootActiveEventLoop for ActiveEventLoop {
         Ok(Box::new(window))
     }
 
-    fn available_monitors(&self) -> Box<dyn Iterator<Item = crate::monitor::MonitorHandle>> {
+    fn available_monitors(&self) -> Box<dyn Iterator<Item = CoreMonitorHandle>> {
         Box::new(
             self.state
                 .borrow()
                 .output_state
                 .outputs()
-                .map(crate::platform_impl::wayland::output::MonitorHandle::new)
-                .map(crate::platform_impl::MonitorHandle::Wayland)
-                .map(|inner| crate::monitor::MonitorHandle { inner }),
+                .map(MonitorHandle::new)
+                .map(|inner| CoreMonitorHandle(Arc::new(inner))),
         )
     }
 
-    fn primary_monitor(&self) -> Option<crate::monitor::MonitorHandle> {
+    fn primary_monitor(&self) -> Option<CoreMonitorHandle> {
         // There's no primary monitor on Wayland.
         None
     }
@@ -665,6 +698,7 @@ impl rwh_06::HasDisplayHandle for ActiveEventLoop {
     }
 }
 
+#[derive(Debug)]
 pub struct OwnedDisplayHandle {
     pub(crate) connection: Connection,
 }
@@ -687,3 +721,84 @@ impl rwh_06::HasDisplayHandle for OwnedDisplayHandle {
         Ok(unsafe { rwh_06::DisplayHandle::borrow_raw(raw.into()) })
     }
 }
+
+#[derive(Debug)]
+struct PumpEventNotifier {
+    /// Whether we're in winit or not.
+    control: Arc<(Mutex<PumpEventNotifierAction>, Condvar)>,
+    /// Waker handle for the working thread.
+    worker_waker: Option<OwnedFd>,
+    /// Thread handle.
+    handle: Option<JoinHandle<()>>,
+}
+
+impl Drop for PumpEventNotifier {
+    fn drop(&mut self) {
+        // Wake-up the thread.
+        if let Some(worker_waker) = self.worker_waker.as_ref() {
+            let _ = rustix::io::write(worker_waker.as_fd(), &[0u8]);
+        }
+        *self.control.0.lock().unwrap() = PumpEventNotifierAction::Monitor;
+        self.control.1.notify_one();
+
+        if let Some(handle) = self.handle.take() {
+            let _ = handle.join();
+        }
+    }
+}
+
+impl PumpEventNotifier {
+    fn spawn(connection: Connection, awakener: Ping) -> Self {
+        // Start from the waiting state.
+        let control = Arc::new((Mutex::new(PumpEventNotifierAction::Pause), Condvar::new()));
+        let control_thread = Arc::clone(&control);
+
+        let (read, write) = match pipe::pipe_with(PipeFlags::CLOEXEC | PipeFlags::NONBLOCK) {
+            Ok((read, write)) => (read, write),
+            Err(_) => return Self { control, handle: None, worker_waker: None },
+        };
+
+        let handle =
+            std::thread::Builder::new().name(String::from("pump_events mon")).spawn(move || {
+                let (lock, cvar) = &*control_thread;
+                'outer: loop {
+                    let mut wait = lock.lock().unwrap();
+                    while *wait == PumpEventNotifierAction::Pause {
+                        wait = cvar.wait(wait).unwrap();
+                    }
+                    // Wake-up the main loop and put this one back to sleep.
+                    *wait = PumpEventNotifierAction::Pause;
+                    drop(wait);
+
+                    while let Some(read_guard) = connection.prepare_read() {
+                        let _ = connection.flush();
+                        let poll_fd = PollFd::from_borrowed_fd(connection.as_fd(), PollFlags::IN);
+                        let pipe_poll_fd = PollFd::from_borrowed_fd(read.as_fd(), PollFlags::IN);
+                        // Read from the `fd` before going back to poll.
+                        if Ok(1) == rustix::io::read(read.as_fd(), &mut [0u8; 1]) {
+                            break 'outer;
+                        }
+                        let _ = rustix::event::poll(&mut [poll_fd, pipe_poll_fd], -1);
+                        // Non-blocking read the connection.
+                        let _ = read_guard.read_without_dispatch();
+                    }
+
+                    awakener.ping();
+                }
+            });
+
+        if let Some(err) = handle.as_ref().err() {
+            warn!("failed to spawn pump_events wake-up thread: {err}");
+        }
+
+        PumpEventNotifier { control, handle: handle.ok(), worker_waker: Some(write) }
+    }
+}
+
+#[derive(Debug, PartialEq, Eq)]
+enum PumpEventNotifierAction {
+    /// Monitor the wayland queue.
+    Monitor,
+    /// Pause monitoring.
+    Pause,
+}

src/platform_impl/linux/wayland/event_loop/proxy.rs

@@ -7,6 +7,7 @@ use sctk::reexports::calloop::ping::Ping;
 use crate::event_loop::{EventLoopProxy as CoreEventLoopProxy, EventLoopProxyProvider};
 
 /// A handle that can be sent across the threads and used to wake up the `EventLoop`.
+#[derive(Debug)]
 pub struct EventLoopProxy {
     ping: Ping,
 }

src/platform_impl/linux/wayland/event_loop/sink.rs

@@ -2,12 +2,13 @@
 
 use std::vec::Drain;
 
-use crate::event::{DeviceEvent, Event, WindowEvent};
+use super::Event;
+use crate::event::{DeviceEvent, WindowEvent};
 use crate::window::WindowId;
 
 /// An event loop's sink to deliver events from the Wayland event callbacks
 /// to the winit's user.
-#[derive(Default)]
+#[derive(Default, Debug)]
 pub struct EventSink {
     pub(crate) window_events: Vec<Event>,
 }
@@ -26,7 +27,7 @@ impl EventSink {
     /// Add new device event to a queue.
     #[inline]
     pub fn push_device_event(&mut self, event: DeviceEvent) {
-        self.window_events.push(Event::DeviceEvent { event, device_id: None });
+        self.window_events.push(Event::DeviceEvent { event });
     }
 
     /// Add new window event to a queue.

src/platform_impl/linux/wayland/mod.rs

@@ -1,12 +1,8 @@
 //! Winit's Wayland backend.
 
-pub use event_loop::{ActiveEventLoop, EventLoop};
-pub use output::{MonitorHandle, VideoModeHandle};
 use sctk::reexports::client::protocol::wl_surface::WlSurface;
 use sctk::reexports::client::Proxy;
-pub use window::Window;
 
-pub(super) use crate::cursor::OnlyCursorImage as CustomCursor;
 use crate::dpi::{LogicalSize, PhysicalSize};
 use crate::window::WindowId;
 
@@ -17,6 +13,9 @@ mod state;
 mod types;
 mod window;
 
+pub use event_loop::{ActiveEventLoop, EventLoop};
+pub use window::Window;
+
 /// Get the WindowId out of the surface.
 #[inline]
 fn make_wid(surface: &WlSurface) -> WindowId {

src/platform_impl/linux/wayland/output.rs

@@ -1,11 +1,12 @@
-use std::num::{NonZeroU16, NonZeroU32};
+use std::borrow::Cow;
+use std::num::NonZeroU32;
 
 use sctk::output::{Mode, OutputData};
 use sctk::reexports::client::protocol::wl_output::WlOutput;
 use sctk::reexports::client::Proxy;
 
-use crate::dpi::{LogicalPosition, PhysicalPosition, PhysicalSize};
-use crate::platform_impl::platform::VideoModeHandle as PlatformVideoModeHandle;
+use crate::dpi::{LogicalPosition, PhysicalPosition};
+use crate::monitor::{MonitorHandleProvider as CoreMonitorHandle, VideoMode};
 
 #[derive(Clone, Debug)]
 pub struct MonitorHandle {
@@ -17,21 +18,24 @@ impl MonitorHandle {
     pub(crate) fn new(proxy: WlOutput) -> Self {
         Self { proxy }
     }
+}
 
-    #[inline]
-    pub fn name(&self) -> Option<String> {
-        let output_data = self.proxy.data::<OutputData>().unwrap();
-        output_data.with_output_info(|info| info.name.clone())
+impl CoreMonitorHandle for MonitorHandle {
+    fn id(&self) -> u128 {
+        self.native_id() as _
     }
 
-    #[inline]
-    pub fn native_identifier(&self) -> u32 {
+    fn native_id(&self) -> u64 {
         let output_data = self.proxy.data::<OutputData>().unwrap();
-        output_data.with_output_info(|info| info.id)
+        output_data.with_output_info(|info| info.id as u64)
     }
 
-    #[inline]
-    pub fn position(&self) -> Option<PhysicalPosition<i32>> {
+    fn name(&self) -> Option<Cow<'_, str>> {
+        let output_data = self.proxy.data::<OutputData>().unwrap();
+        output_data.with_output_info(|info| info.name.clone().map(Cow::Owned))
+    }
+
+    fn position(&self) -> Option<PhysicalPosition<i32>> {
         let output_data = self.proxy.data::<OutputData>().unwrap();
         Some(output_data.with_output_info(|info| {
             info.logical_position.map_or_else(
@@ -47,95 +51,41 @@ impl MonitorHandle {
         }))
     }
 
-    #[inline]
-    pub fn scale_factor(&self) -> i32 {
+    fn scale_factor(&self) -> f64 {
         let output_data = self.proxy.data::<OutputData>().unwrap();
-        output_data.scale_factor()
+        output_data.scale_factor() as f64
     }
 
-    #[inline]
-    pub fn current_video_mode(&self) -> Option<PlatformVideoModeHandle> {
+    fn current_video_mode(&self) -> Option<crate::monitor::VideoMode> {
         let output_data = self.proxy.data::<OutputData>().unwrap();
         output_data.with_output_info(|info| {
             let mode = info.modes.iter().find(|mode| mode.current).cloned();
 
-            mode.map(|mode| {
-                PlatformVideoModeHandle::Wayland(VideoModeHandle::new(self.clone(), mode))
-            })
+            mode.map(wayland_mode_to_core_mode)
         })
     }
 
-    #[inline]
-    pub fn video_modes(&self) -> impl Iterator<Item = PlatformVideoModeHandle> {
+    fn video_modes(&self) -> Box<dyn Iterator<Item = VideoMode>> {
         let output_data = self.proxy.data::<OutputData>().unwrap();
         let modes = output_data.with_output_info(|info| info.modes.clone());
 
-        let monitor = self.clone();
-
-        modes.into_iter().map(move |mode| {
-            PlatformVideoModeHandle::Wayland(VideoModeHandle::new(monitor.clone(), mode))
-        })
+        Box::new(modes.into_iter().map(wayland_mode_to_core_mode))
     }
 }
 
 impl PartialEq for MonitorHandle {
     fn eq(&self, other: &Self) -> bool {
-        self.native_identifier() == other.native_identifier()
+        self.native_id() == other.native_id()
     }
 }
 
 impl Eq for MonitorHandle {}
 
-impl PartialOrd for MonitorHandle {
-    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
-        Some(self.cmp(other))
-    }
-}
-
-impl Ord for MonitorHandle {
-    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
-        self.native_identifier().cmp(&other.native_identifier())
-    }
-}
-
-impl std::hash::Hash for MonitorHandle {
-    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
-        self.native_identifier().hash(state);
-    }
-}
-
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub struct VideoModeHandle {
-    pub(crate) size: PhysicalSize<u32>,
-    pub(crate) refresh_rate_millihertz: Option<NonZeroU32>,
-    pub(crate) monitor: MonitorHandle,
-}
-
-impl VideoModeHandle {
-    fn new(monitor: MonitorHandle, mode: Mode) -> Self {
-        VideoModeHandle {
-            size: (mode.dimensions.0 as u32, mode.dimensions.1 as u32).into(),
-            refresh_rate_millihertz: NonZeroU32::new(mode.refresh_rate as u32),
-            monitor: monitor.clone(),
-        }
-    }
-
-    #[inline]
-    pub fn size(&self) -> PhysicalSize<u32> {
-        self.size
-    }
-
-    #[inline]
-    pub fn bit_depth(&self) -> Option<NonZeroU16> {
-        None
-    }
-
-    #[inline]
-    pub fn refresh_rate_millihertz(&self) -> Option<NonZeroU32> {
-        self.refresh_rate_millihertz
-    }
-
-    pub fn monitor(&self) -> MonitorHandle {
-        self.monitor.clone()
+/// Convert the wayland's [`Mode`] to winit's [`VideoMode`].
+fn wayland_mode_to_core_mode(mode: Mode) -> VideoMode {
+    VideoMode {
+        size: (mode.dimensions.0, mode.dimensions.1).into(),
+        bit_depth: None,
+        refresh_rate_millihertz: NonZeroU32::new(mode.refresh_rate as u32),
     }
 }

src/platform_impl/linux/wayland/seat/mod.rs

@@ -96,8 +96,12 @@ impl SeatHandler for WinitState {
             },
             SeatCapability::Pointer if seat_state.pointer.is_none() => {
                 let surface = self.compositor_state.create_surface(queue_handle);
+                let viewport = self
+                    .viewporter_state
+                    .as_ref()
+                    .map(|state| state.get_viewport(&surface, queue_handle));
                 let surface_id = surface.id();
-                let pointer_data = WinitPointerData::new(seat.clone());
+                let pointer_data = WinitPointerData::new(seat.clone(), viewport);
                 let themed_pointer = self
                     .seat_state
                     .get_pointer_with_theme_and_data(

src/platform_impl/linux/wayland/seat/pointer/mod.rs

@@ -18,6 +18,7 @@ use sctk::reexports::protocols::wp::cursor_shape::v1::client::wp_cursor_shape_ma
 use sctk::reexports::protocols::wp::pointer_constraints::zv1::client::zwp_pointer_constraints_v1::{Lifetime, ZwpPointerConstraintsV1};
 use sctk::reexports::client::globals::{BindError, GlobalList};
 use sctk::reexports::csd_frame::FrameClick;
+use sctk::reexports::protocols::wp::viewporter::client::wp_viewport::WpViewport;
 
 use sctk::compositor::SurfaceData;
 use sctk::globals::GlobalData;
@@ -27,7 +28,10 @@ use sctk::seat::pointer::{
 use sctk::seat::SeatState;
 
 use crate::dpi::{LogicalPosition, PhysicalPosition};
-use crate::event::{ElementState, MouseButton, MouseScrollDelta, PointerSource, PointerKind, TouchPhase, WindowEvent};
+use crate::event::{
+    ElementState, MouseButton, MouseScrollDelta, PointerKind, PointerSource, TouchPhase,
+    WindowEvent,
+};
 
 use crate::platform_impl::wayland::state::WinitState;
 use crate::platform_impl::wayland::{self, WindowId};
@@ -243,13 +247,17 @@ pub struct WinitPointerData {
 
     /// The data required by the sctk.
     sctk_data: PointerData,
+
+    /// Viewport for fractional cursor.
+    viewport: Option<WpViewport>,
 }
 
 impl WinitPointerData {
-    pub fn new(seat: WlSeat) -> Self {
+    pub fn new(seat: WlSeat, viewport: Option<WpViewport>) -> Self {
         Self {
             inner: Mutex::new(WinitPointerDataInner::default()),
             sctk_data: PointerData::new(seat),
+            viewport,
         }
     }
 
@@ -330,6 +338,18 @@ impl WinitPointerData {
             locked_pointer.set_cursor_position_hint(surface_x, surface_y);
         }
     }
+
+    pub fn viewport(&self) -> Option<&WpViewport> {
+        self.viewport.as_ref()
+    }
+}
+
+impl Drop for WinitPointerData {
+    fn drop(&mut self) {
+        if let Some(viewport) = self.viewport.take() {
+            viewport.destroy();
+        }
+    }
 }
 
 impl PointerDataExt for WinitPointerData {
@@ -411,6 +431,7 @@ impl WinitPointerDataExt for WlPointer {
     }
 }
 
+#[derive(Debug)]
 pub struct PointerConstraintsState {
     pointer_constraints: ZwpPointerConstraintsV1,
 }

src/platform_impl/linux/wayland/seat/pointer/relative_pointer.rs

@@ -16,6 +16,7 @@ use crate::event::DeviceEvent;
 use crate::platform_impl::wayland::state::WinitState;
 
 /// Wrapper around the relative pointer.
+#[derive(Debug)]
 pub struct RelativePointerState {
     manager: ZwpRelativePointerManagerV1,
 }

src/platform_impl/linux/wayland/seat/text_input/mod.rs

@@ -14,6 +14,7 @@ use crate::platform_impl::wayland;
 use crate::platform_impl::wayland::state::WinitState;
 use crate::window::ImePurpose;
 
+#[derive(Debug)]
 pub struct TextInputState {
     text_input_manager: ZwpTextInputManagerV3,
 }
@@ -119,11 +120,15 @@ impl Dispatch<ZwpTextInputV3, TextInputData, WinitState> for TextInputState {
                     None => return,
                 };
 
-                // Clear preedit at the start of `Done`.
-                state.events_sink.push_window_event(
-                    WindowEvent::Ime(Ime::Preedit(String::new(), None)),
-                    window_id,
-                );
+                // Clear preedit, unless all we'll be doing next is sending a new preedit.
+                if text_input_data.pending_commit.is_some()
+                    || text_input_data.pending_preedit.is_none()
+                {
+                    state.events_sink.push_window_event(
+                        WindowEvent::Ime(Ime::Preedit(String::new(), None)),
+                        window_id,
+                    );
+                }
 
                 // Send `Commit`.
                 if let Some(text) = text_input_data.pending_commit.take() {

src/platform_impl/linux/wayland/state.rs

@@ -36,6 +36,7 @@ use crate::platform_impl::wayland::window::{WindowRequests, WindowState};
 use crate::platform_impl::wayland::WindowId;
 
 /// Winit's Wayland state.
+#[derive(Debug)]
 pub struct WinitState {
     /// The WlRegistry.
     pub registry_state: RegistryState,

src/platform_impl/linux/wayland/types/cursor.rs

@@ -2,7 +2,16 @@ use cursor_icon::CursorIcon;
 use sctk::reexports::client::protocol::wl_shm::Format;
 use sctk::shm::slot::{Buffer, SlotPool};
 
-use crate::cursor::CursorImage;
+use crate::cursor::{CursorImage, CustomCursorProvider};
+
+// Wrap in our own type to not impl trait on global type.
+#[derive(Debug)]
+pub struct WaylandCustomCursor(pub(crate) CursorImage);
+impl CustomCursorProvider for WaylandCustomCursor {
+    fn is_animated(&self) -> bool {
+        false
+    }
+}
 
 #[derive(Debug)]
 pub enum SelectedCursor {
@@ -26,7 +35,8 @@ pub struct CustomCursor {
 }
 
 impl CustomCursor {
-    pub(crate) fn new(pool: &mut SlotPool, image: &CursorImage) -> Self {
+    pub(crate) fn new(pool: &mut SlotPool, image: &WaylandCustomCursor) -> Self {
+        let image = &image.0;
         let (buffer, canvas) = pool
             .create_buffer(
                 image.width as i32,

src/platform_impl/linux/wayland/types/xdg_activation.rs

@@ -16,6 +16,7 @@ use crate::event_loop::AsyncRequestSerial;
 use crate::platform_impl::wayland::state::WinitState;
 use crate::window::{ActivationToken, WindowId};
 
+#[derive(Debug)]
 pub struct XdgActivationState {
     xdg_activation: XdgActivationV1,
 }
@@ -78,7 +79,7 @@ impl Dispatch<XdgActivationTokenV1, XdgActivationTokenData, WinitState> for XdgA
                 state.events_sink.push_window_event(
                     crate::event::WindowEvent::ActivationTokenDone {
                         serial: *serial,
-                        token: ActivationToken::_new(token),
+                        token: ActivationToken::from_raw(token),
                     },
                     *window_id,
                 );

src/platform_impl/linux/wayland/window/mod.rs

@@ -1,5 +1,7 @@
 //! The Wayland window.
 
+use std::ffi::c_void;
+use std::ptr::NonNull;
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::{Arc, Mutex};
 
@@ -21,12 +23,11 @@ use crate::dpi::{LogicalSize, PhysicalInsets, PhysicalPosition, PhysicalSize, Po
 use crate::error::{NotSupportedError, RequestError};
 use crate::event::{Ime, WindowEvent};
 use crate::event_loop::AsyncRequestSerial;
-use crate::monitor::MonitorHandle as CoreMonitorHandle;
-use crate::platform_impl::{Fullscreen, MonitorHandle as PlatformMonitorHandle};
+use crate::monitor::{Fullscreen, MonitorHandle as CoreMonitorHandle};
+use crate::platform_impl::wayland::output;
 use crate::window::{
-    Cursor, CursorGrabMode, Fullscreen as CoreFullscreen, ImePurpose, ResizeDirection, Theme,
-    UserAttentionType, Window as CoreWindow, WindowAttributes, WindowButtons, WindowId,
-    WindowLevel,
+    Cursor, CursorGrabMode, ImePurpose, ResizeDirection, Theme, UserAttentionType,
+    Window as CoreWindow, WindowAttributes, WindowButtons, WindowId, WindowLevel,
 };
 
 pub(crate) mod state;
@@ -34,6 +35,7 @@ pub(crate) mod state;
 pub use state::WindowState;
 
 /// The Wayland window.
+#[derive(Debug)]
 pub struct Window {
     /// Reference to the underlying SCTK window.
     window: SctkWindow,
@@ -138,19 +140,17 @@ impl Window {
         window_state.set_resizable(attributes.resizable);
 
         // Set startup mode.
-        match attributes.fullscreen.map(Into::into) {
-            Some(Fullscreen::Exclusive(_)) => {
+        match attributes.fullscreen {
+            Some(Fullscreen::Exclusive(..)) => {
                 warn!("`Fullscreen::Exclusive` is ignored on Wayland");
             },
             #[cfg_attr(not(x11_platform), allow(clippy::bind_instead_of_map))]
             Some(Fullscreen::Borderless(monitor)) => {
-                let output = monitor.and_then(|monitor| match monitor {
-                    PlatformMonitorHandle::Wayland(monitor) => Some(monitor.proxy),
-                    #[cfg(x11_platform)]
-                    PlatformMonitorHandle::X(_) => None,
+                let output = monitor.as_ref().and_then(|monitor| {
+                    monitor.cast_ref::<output::MonitorHandle>().map(|handle| &handle.proxy)
                 });
 
-                window.set_fullscreen(output.as_ref())
+                window.set_fullscreen(output)
             },
             _ if attributes.maximized => window.set_maximized(),
             _ => (),
@@ -165,7 +165,7 @@ impl Window {
         if let (Some(xdg_activation), Some(token)) =
             (xdg_activation.as_ref(), attributes.platform_specific.activation_token)
         {
-            xdg_activation.activate(token._token, &surface);
+            xdg_activation.activate(token.token, &surface);
         }
 
         // XXX Do initial commit.
@@ -216,6 +216,10 @@ impl Window {
             window_events_sink,
         })
     }
+
+    pub(crate) fn xdg_toplevel(&self) -> Option<NonNull<c_void>> {
+        NonNull::new(self.window.xdg_toplevel().id().as_ptr().cast())
+    }
 }
 
 impl Window {
@@ -436,26 +440,24 @@ impl CoreWindow for Window {
             .unwrap_or_default()
     }
 
-    fn set_fullscreen(&self, fullscreen: Option<CoreFullscreen>) {
+    fn set_fullscreen(&self, fullscreen: Option<Fullscreen>) {
         match fullscreen {
-            Some(CoreFullscreen::Exclusive(_)) => {
+            Some(Fullscreen::Exclusive(..)) => {
                 warn!("`Fullscreen::Exclusive` is ignored on Wayland");
             },
             #[cfg_attr(not(x11_platform), allow(clippy::bind_instead_of_map))]
-            Some(CoreFullscreen::Borderless(monitor)) => {
-                let output = monitor.and_then(|monitor| match monitor.inner {
-                    PlatformMonitorHandle::Wayland(monitor) => Some(monitor.proxy),
-                    #[cfg(x11_platform)]
-                    PlatformMonitorHandle::X(_) => None,
+            Some(Fullscreen::Borderless(monitor)) => {
+                let output = monitor.as_ref().and_then(|monitor| {
+                    monitor.cast_ref::<output::MonitorHandle>().map(|handle| &handle.proxy)
                 });
 
-                self.window.set_fullscreen(output.as_ref())
+                self.window.set_fullscreen(output)
             },
             None => self.window.unset_fullscreen(),
         }
     }
 
-    fn fullscreen(&self) -> Option<CoreFullscreen> {
+    fn fullscreen(&self) -> Option<Fullscreen> {
         let is_fullscreen = self
             .window_state
             .lock()
@@ -467,7 +469,7 @@ impl CoreWindow for Window {
 
         if is_fullscreen {
             let current_monitor = self.current_monitor();
-            Some(CoreFullscreen::Borderless(current_monitor))
+            Some(Fullscreen::Borderless(current_monitor))
         } else {
             None
         }
@@ -627,8 +629,7 @@ impl CoreWindow for Window {
         data.outputs()
             .next()
             .map(MonitorHandle::new)
-            .map(crate::platform_impl::MonitorHandle::Wayland)
-            .map(|inner| CoreMonitorHandle { inner })
+            .map(|monitor| CoreMonitorHandle(Arc::new(monitor)))
     }
 
     fn available_monitors(&self) -> Box<dyn Iterator<Item = CoreMonitorHandle>> {
@@ -638,8 +639,7 @@ impl CoreWindow for Window {
                 .unwrap()
                 .clone()
                 .into_iter()
-                .map(crate::platform_impl::MonitorHandle::Wayland)
-                .map(|inner| CoreMonitorHandle { inner }),
+                .map(|inner| CoreMonitorHandle(Arc::new(inner))),
         )
     }
 

src/platform_impl/linux/wayland/window/state.rs

@@ -28,8 +28,8 @@ use sctk::subcompositor::SubcompositorState;
 use tracing::{info, warn};
 use wayland_protocols_plasma::blur::client::org_kde_kwin_blur::OrgKdeKwinBlur;
 
-use crate::cursor::CustomCursor as RootCustomCursor;
-use crate::dpi::{LogicalPosition, LogicalSize, PhysicalSize, Size};
+use crate::cursor::CustomCursor as CoreCustomCursor;
+use crate::dpi::{LogicalPosition, LogicalSize, PhysicalPosition, PhysicalSize, Size};
 use crate::error::{NotSupportedError, RequestError};
 use crate::platform_impl::wayland::event_loop::OwnedDisplayHandle;
 use crate::platform_impl::wayland::logical_to_physical_rounded;
@@ -37,9 +37,10 @@ use crate::platform_impl::wayland::seat::{
     PointerConstraintsState, WinitPointerData, WinitPointerDataExt, ZwpTextInputV3Ext,
 };
 use crate::platform_impl::wayland::state::{WindowCompositorUpdate, WinitState};
-use crate::platform_impl::wayland::types::cursor::{CustomCursor, SelectedCursor};
+use crate::platform_impl::wayland::types::cursor::{
+    CustomCursor, SelectedCursor, WaylandCustomCursor,
+};
 use crate::platform_impl::wayland::types::kwin_blur::KWinBlurManager;
-use crate::platform_impl::PlatformCustomCursor;
 use crate::window::{CursorGrabMode, CursorIcon, ImePurpose, ResizeDirection, Theme, WindowId};
 
 #[cfg(feature = "sctk-adwaita")]
@@ -51,6 +52,7 @@ pub type WinitFrame = sctk::shell::xdg::fallback_frame::FallbackFrame<WinitState
 const MIN_WINDOW_SIZE: LogicalSize<u32> = LogicalSize::new(2, 1);
 
 /// The state of the window which is being updated from the [`WinitState`].
+#[derive(Debug)]
 pub struct WindowState {
     /// The connection to Wayland server.
     pub handle: Arc<OwnedDisplayHandle>,
@@ -220,9 +222,9 @@ impl WindowState {
     }
 
     /// Apply closure on the given pointer.
-    fn apply_on_pointer<F: Fn(&ThemedPointer<WinitPointerData>, &WinitPointerData)>(
+    fn apply_on_pointer<F: FnMut(&ThemedPointer<WinitPointerData>, &WinitPointerData)>(
         &self,
-        callback: F,
+        mut callback: F,
     ) {
         self.pointers.iter().filter_map(Weak::upgrade).for_each(|pointer| {
             let data = pointer.pointer().winit_data();
@@ -701,19 +703,18 @@ impl WindowState {
     }
 
     /// Set the custom cursor icon.
-    pub(crate) fn set_custom_cursor(&mut self, cursor: RootCustomCursor) {
-        let cursor = match cursor {
-            RootCustomCursor { inner: PlatformCustomCursor::Wayland(cursor) } => cursor.0,
-            #[cfg(x11_platform)]
-            RootCustomCursor { inner: PlatformCustomCursor::X(_) } => {
-                tracing::error!("passed a X11 cursor to Wayland backend");
+    pub(crate) fn set_custom_cursor(&mut self, cursor: CoreCustomCursor) {
+        let cursor = match cursor.cast_ref::<WaylandCustomCursor>() {
+            Some(cursor) => cursor,
+            None => {
+                tracing::error!("unrecognized cursor passed to Wayland backend");
                 return;
             },
         };
 
         let cursor = {
             let mut pool = self.custom_cursor_pool.lock().unwrap();
-            CustomCursor::new(&mut pool, &cursor)
+            CustomCursor::new(&mut pool, cursor)
         };
 
         if self.cursor_visible {
@@ -724,17 +725,26 @@ impl WindowState {
     }
 
     fn apply_custom_cursor(&self, cursor: &CustomCursor) {
-        self.apply_on_pointer(|pointer, _| {
+        self.apply_on_pointer(|pointer, data| {
             let surface = pointer.surface();
 
-            let scale = surface.data::<SurfaceData>().unwrap().surface_data().scale_factor();
+            let scale = if let Some(viewport) = data.viewport() {
+                let scale = self.scale_factor();
+                let size = PhysicalSize::new(cursor.w, cursor.h).to_logical(scale);
+                viewport.set_destination(size.width, size.height);
+                scale
+            } else {
+                let scale = surface.data::<SurfaceData>().unwrap().surface_data().scale_factor();
+                surface.set_buffer_scale(scale);
+                scale as f64
+            };
 
-            surface.set_buffer_scale(scale);
             surface.attach(Some(cursor.buffer.wl_buffer()), 0, 0);
             if surface.version() >= 4 {
                 surface.damage_buffer(0, 0, cursor.w, cursor.h);
             } else {
-                surface.damage(0, 0, cursor.w / scale, cursor.h / scale);
+                let size = PhysicalSize::new(cursor.w, cursor.h).to_logical(scale);
+                surface.damage(0, 0, size.width, size.height);
             }
             surface.commit();
 
@@ -744,12 +754,9 @@ impl WindowState {
                 .and_then(|data| data.pointer_data().latest_enter_serial())
                 .unwrap();
 
-            pointer.pointer().set_cursor(
-                serial,
-                Some(surface),
-                cursor.hotspot_x / scale,
-                cursor.hotspot_y / scale,
-            );
+            let hotspot =
+                PhysicalPosition::new(cursor.hotspot_x, cursor.hotspot_y).to_logical(scale);
+            pointer.pointer().set_cursor(serial, Some(surface), hotspot.x, hotspot.y);
         });
     }
 
@@ -829,34 +836,51 @@ impl WindowState {
             },
         };
 
-        // Replace the current mode.
-        let old_mode = std::mem::replace(&mut self.cursor_grab_mode.current_grab_mode, mode);
-
-        match old_mode {
-            CursorGrabMode::None => (),
+        let mut unset_old = false;
+        match self.cursor_grab_mode.current_grab_mode {
+            CursorGrabMode::None => unset_old = true,
             CursorGrabMode::Confined => self.apply_on_pointer(|_, data| {
                 data.unconfine_pointer();
+                unset_old = true;
             }),
             CursorGrabMode::Locked => {
-                self.apply_on_pointer(|_, data| data.unlock_pointer());
+                self.apply_on_pointer(|_, data| {
+                    data.unlock_pointer();
+                    unset_old = true;
+                });
             },
         }
 
+        // In case we haven't unset the old mode, it means that we don't have a cursor above
+        // the window, thus just wait for it to re-appear.
+        if !unset_old {
+            return Ok(());
+        }
+
+        let mut set_mode = false;
         let surface = self.window.wl_surface();
         match mode {
             CursorGrabMode::Locked => self.apply_on_pointer(|pointer, data| {
                 let pointer = pointer.pointer();
-                data.lock_pointer(pointer_constraints, surface, pointer, &self.queue_handle)
+                data.lock_pointer(pointer_constraints, surface, pointer, &self.queue_handle);
+                set_mode = true;
             }),
             CursorGrabMode::Confined => self.apply_on_pointer(|pointer, data| {
                 let pointer = pointer.pointer();
-                data.confine_pointer(pointer_constraints, surface, pointer, &self.queue_handle)
+                data.confine_pointer(pointer_constraints, surface, pointer, &self.queue_handle);
+                set_mode = true;
             }),
             CursorGrabMode::None => {
                 // Current lock/confine was already removed.
+                set_mode = true;
             },
         }
 
+        // Replace the current grab mode after we've ensure that it got updated.
+        if set_mode {
+            self.cursor_grab_mode.current_grab_mode = mode;
+        }
+
         Ok(())
     }
 
@@ -1097,7 +1121,7 @@ impl Drop for WindowState {
 }
 
 /// The state of the cursor grabs.
-#[derive(Clone, Copy)]
+#[derive(Clone, Copy, Debug)]
 struct GrabState {
     /// The grab mode requested by the user.
     user_grab_mode: CursorGrabMode,

src/platform_impl/linux/x11/dnd.rs

@@ -4,6 +4,7 @@ use std::path::{Path, PathBuf};
 use std::str::Utf8Error;
 use std::sync::Arc;
 
+use dpi::PhysicalPosition;
 use percent_encoding::percent_decode;
 use x11rb::protocol::xproto::{self, ConnectionExt};
 
@@ -38,6 +39,7 @@ impl From<io::Error> for DndDataParseError {
     }
 }
 
+#[derive(Debug)]
 pub struct Dnd {
     xconn: Arc<XConnection>,
     // Populated by XdndEnter event handler
@@ -45,13 +47,25 @@ pub struct Dnd {
     pub type_list: Option<Vec<xproto::Atom>>,
     // Populated by XdndPosition event handler
     pub source_window: Option<xproto::Window>,
+    // Populated by XdndPosition event handler
+    pub position: PhysicalPosition<f64>,
     // Populated by SelectionNotify event handler (triggered by XdndPosition event handler)
     pub result: Option<Result<Vec<PathBuf>, DndDataParseError>>,
+    // Populated by SelectionNotify event handler (triggered by XdndPosition event handler)
+    pub dragging: bool,
 }
 
 impl Dnd {
     pub fn new(xconn: Arc<XConnection>) -> Result<Self, X11Error> {
-        Ok(Dnd { xconn, version: None, type_list: None, source_window: None, result: None })
+        Ok(Dnd {
+            xconn,
+            version: None,
+            type_list: None,
+            source_window: None,
+            position: PhysicalPosition::default(),
+            result: None,
+            dragging: false,
+        })
     }
 
     pub fn reset(&mut self) {
@@ -59,6 +73,7 @@ impl Dnd {
         self.type_list = None;
         self.source_window = None;
         self.result = None;
+        self.dragging = false;
     }
 
     pub unsafe fn send_status(

src/platform_impl/linux/x11/ime/callbacks.rs

@@ -116,25 +116,21 @@ unsafe fn replace_im(inner: *mut ImeInner) -> Result<(), ReplaceImError> {
 
     let mut new_contexts = HashMap::new();
     for (window, old_context) in unsafe { (*inner).contexts.iter() } {
-        let spot = old_context.as_ref().map(|old_context| old_context.ic_spot);
+        let area = old_context.as_ref().map(|old_context| old_context.ic_area);
 
         // Check if the IME was allowed on that context.
         let is_allowed =
             old_context.as_ref().map(|old_context| old_context.is_allowed()).unwrap_or_default();
 
-        // We can't use the style from the old context here, since it may change on reload, so
-        // pick style from the new XIM based on the old state.
-        let style = if is_allowed { new_im.preedit_style } else { new_im.none_style };
-
         let new_context = {
             let result = unsafe {
                 ImeContext::new(
                     xconn,
-                    new_im.im,
-                    style,
+                    &new_im,
                     *window,
-                    spot,
+                    area,
                     (*inner).event_sender.clone(),
+                    is_allowed,
                 )
             };
             if result.is_err() {

src/platform_impl/linux/x11/ime/context.rs

@@ -1,13 +1,12 @@
 use std::error::Error;
 use std::ffi::CStr;
-use std::os::raw::c_short;
 use std::sync::Arc;
 use std::{fmt, mem, ptr};
 
 use x11_dl::xlib::{XIMCallback, XIMPreeditCaretCallbackStruct, XIMPreeditDrawCallbackStruct};
 
 use super::{ffi, util, XConnection, XError};
-use crate::platform_impl::platform::x11::ime::input_method::{Style, XIMStyle};
+use crate::platform_impl::platform::x11::ime::input_method::{InputMethod, Style, XIMStyle};
 use crate::platform_impl::platform::x11::ime::{ImeEvent, ImeEventSender};
 
 /// IME creation error.
@@ -196,8 +195,8 @@ struct ImeContextClientData {
 // through `ImeInner`.
 pub struct ImeContext {
     pub(crate) ic: ffi::XIC,
-    pub(crate) ic_spot: ffi::XPoint,
-    pub(crate) style: Style,
+    pub(crate) ic_area: ffi::XRectangle,
+    pub(crate) allowed: bool,
     // Since the data is passed shared between X11 XIM callbacks, but couldn't be directly free
     // from there we keep the pointer to automatically deallocate it.
     _client_data: Box<ImeContextClientData>,
@@ -206,11 +205,11 @@ pub struct ImeContext {
 impl ImeContext {
     pub(crate) unsafe fn new(
         xconn: &Arc<XConnection>,
-        im: ffi::XIM,
-        style: Style,
+        im: &InputMethod,
         window: ffi::Window,
-        ic_spot: Option<ffi::XPoint>,
+        ic_area: Option<ffi::XRectangle>,
         event_sender: ImeEventSender,
+        allowed: bool,
     ) -> Result<Self, ImeContextCreationError> {
         let client_data = Box::into_raw(Box::new(ImeContextClientData {
             window,
@@ -219,20 +218,24 @@ impl ImeContext {
             cursor_pos: 0,
         }));
 
+        let style = if allowed { im.preedit_style } else { im.none_style };
+
         let ic = match style as _ {
             Style::Preedit(style) => unsafe {
                 ImeContext::create_preedit_ic(
                     xconn,
-                    im,
+                    im.im,
                     style,
                     window,
                     client_data as ffi::XPointer,
                 )
             },
             Style::Nothing(style) => unsafe {
-                ImeContext::create_nothing_ic(xconn, im, style, window)
+                ImeContext::create_nothing_ic(xconn, im.im, style, window)
+            },
+            Style::None(style) => unsafe {
+                ImeContext::create_none_ic(xconn, im.im, style, window)
             },
-            Style::None(style) => unsafe { ImeContext::create_none_ic(xconn, im, style, window) },
         }
         .ok_or(ImeContextCreationError::Null)?;
 
@@ -240,14 +243,14 @@ impl ImeContext {
 
         let mut context = ImeContext {
             ic,
-            ic_spot: ffi::XPoint { x: 0, y: 0 },
-            style,
+            ic_area: ffi::XRectangle { x: 0, y: 0, width: 0, height: 0 },
+            allowed,
             _client_data: unsafe { Box::from_raw(client_data) },
         };
 
-        // Set the spot location, if it's present.
-        if let Some(ic_spot) = ic_spot {
-            context.set_spot(xconn, ic_spot.x, ic_spot.y)
+        // Set the preedit cursor area, if it's present.
+        if let Some(ic_area) = ic_area {
+            context.set_area(xconn, ic_area.x, ic_area.y, ic_area.width, ic_area.height);
         }
 
         Ok(context)
@@ -348,20 +351,34 @@ impl ImeContext {
     }
 
     pub fn is_allowed(&self) -> bool {
-        !matches!(self.style, Style::None(_))
+        self.allowed
     }
 
-    // Set the spot for preedit text. Setting spot isn't working with libX11 when preedit callbacks
-    // are being used. Certain IMEs do show selection window, but it's placed in bottom left of the
-    // window and couldn't be changed.
-    //
-    // For me see: https://bugs.freedesktop.org/show_bug.cgi?id=1580.
-    pub(crate) fn set_spot(&mut self, xconn: &Arc<XConnection>, x: c_short, y: c_short) {
-        if !self.is_allowed() || self.ic_spot.x == x && self.ic_spot.y == y {
+    /// Set the spot and area for preedit text.
+    ///
+    /// This functionality depends on the libx11 version.
+    ///  - Until libx11 1.8.2, XNSpotLocation was blocked by libx11 in On-The-Spot mode.
+    ///  - Until libx11 1.8.11, XNArea was blocked by libx11 in On-The-Spot mode.
+    ///
+    /// Use of this information is discretionary by input method servers,
+    /// and some may not use it by default, even if they have support.
+    pub(crate) fn set_area(
+        &mut self,
+        xconn: &Arc<XConnection>,
+        x: i16,
+        y: i16,
+        width: u16,
+        height: u16,
+    ) {
+        let ic_area = ffi::XRectangle { x, y, width, height };
+
+        if !self.is_allowed() || self.ic_area == ic_area {
             return;
         }
 
-        self.ic_spot = ffi::XPoint { x, y };
+        self.ic_area = ic_area;
+        let ic_spot =
+            ffi::XPoint { x: x.saturating_add(width as i16), y: y.saturating_add(height as i16) };
 
         unsafe {
             let preedit_attr = util::memory::XSmartPointer::new(
@@ -369,7 +386,9 @@ impl ImeContext {
                 (xconn.xlib.XVaCreateNestedList)(
                     0,
                     ffi::XNSpotLocation_0.as_ptr(),
-                    &self.ic_spot,
+                    &ic_spot,
+                    ffi::XNArea_0.as_ptr(),
+                    &self.ic_area,
                     ptr::null_mut::<()>(),
                 ),
             )

src/platform_impl/linux/x11/ime/input_method.rs

@@ -177,7 +177,7 @@ unsafe fn get_xim_servers(xconn: &Arc<XConnection>) -> Result<Vec<String>, GetXi
         )
         .map_err(GetXimServersError::GetPropertyError)?
         .into_iter()
-        .map(ffi::Atom::from)
+        .map(|atom| atom as _)
         .collect::<Vec<_>>();
 
     let mut names: Vec<*const c_char> = Vec::with_capacity(atoms.len());

src/platform_impl/linux/x11/ime/mod.rs

@@ -5,18 +5,18 @@ mod context;
 mod inner;
 mod input_method;
 
+use std::fmt;
 use std::sync::mpsc::{Receiver, Sender};
 use std::sync::Arc;
 
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
-use tracing::debug;
 
 use self::callbacks::*;
 use self::context::ImeContext;
 pub use self::context::ImeContextCreationError;
 use self::inner::{close_im, ImeInner};
-use self::input_method::{PotentialInputMethods, Style};
+use self::input_method::PotentialInputMethods;
 use super::{ffi, util, XConnection, XError};
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
@@ -36,8 +36,8 @@ pub type ImeEventSender = Sender<(ffi::Window, ImeEvent)>;
 
 /// Request to control XIM handler from the window.
 pub enum ImeRequest {
-    /// Set IME spot position for given `window_id`.
-    Position(ffi::Window, i16, i16),
+    /// Set IME preedit area for given `window_id`.
+    Area(ffi::Window, i16, i16, u16, u16),
 
     /// Allow IME input for the given `window_id`.
     Allow(ffi::Window, bool),
@@ -57,6 +57,12 @@ pub(crate) struct Ime {
     inner: Box<ImeInner>,
 }
 
+impl fmt::Debug for Ime {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("Ime").finish_non_exhaustive()
+    }
+}
+
 impl Ime {
     pub fn new(
         xconn: Arc<XConnection>,
@@ -113,39 +119,26 @@ impl Ime {
     pub fn create_context(
         &mut self,
         window: ffi::Window,
-        with_preedit: bool,
+        with_ime: bool,
     ) -> Result<bool, ImeContextCreationError> {
         let context = if self.is_destroyed() {
             // Create empty entry in map, so that when IME is rebuilt, this window has a context.
             None
         } else {
             let im = self.inner.im.as_ref().unwrap();
-            let style = if with_preedit { im.preedit_style } else { im.none_style };
 
             let context = unsafe {
                 ImeContext::new(
                     &self.inner.xconn,
-                    im.im,
-                    style,
+                    im,
                     window,
                     None,
                     self.inner.event_sender.clone(),
+                    with_ime,
                 )?
             };
 
-            // Check the state on the context, since it could fail to enable or disable preedit.
-            let event = if matches!(style, Style::None(_)) {
-                if with_preedit {
-                    debug!("failed to create IME context with preedit support.")
-                }
-                ImeEvent::Disabled
-            } else {
-                if !with_preedit {
-                    debug!("failed to create IME context without preedit support.")
-                }
-                ImeEvent::Enabled
-            };
-
+            let event = if context.is_allowed() { ImeEvent::Enabled } else { ImeEvent::Disabled };
             self.inner.event_sender.send((window, event)).expect("Failed to send enabled event");
 
             Some(context)
@@ -199,12 +192,12 @@ impl Ime {
         }
     }
 
-    pub fn send_xim_spot(&mut self, window: ffi::Window, x: i16, y: i16) {
+    pub fn send_xim_area(&mut self, window: ffi::Window, x: i16, y: i16, w: u16, h: u16) {
         if self.is_destroyed() {
             return;
         }
         if let Some(&mut Some(ref mut context)) = self.inner.contexts.get_mut(&window) {
-            context.set_spot(&self.xconn, x as _, y as _);
+            context.set_area(&self.xconn, x as _, y as _, w as _, h as _);
         }
     }
 

src/platform_impl/linux/x11/mod.rs

@@ -6,7 +6,7 @@ use std::ops::Deref;
 use std::os::raw::*;
 use std::os::unix::io::{AsFd, AsRawFd, BorrowedFd, RawFd};
 use std::sync::mpsc::{self, Receiver, Sender, TryRecvError};
-use std::sync::{Arc, Weak};
+use std::sync::{Arc, Mutex, Weak};
 use std::time::{Duration, Instant};
 use std::{fmt, mem, ptr, slice, str};
 
@@ -24,19 +24,21 @@ use x11rb::xcb_ffi::ReplyOrIdError;
 
 use crate::application::ApplicationHandler;
 use crate::error::{EventLoopError, RequestError};
-use crate::event::{DeviceId, Event, StartCause, WindowEvent};
+use crate::event::{DeviceId, StartCause, WindowEvent};
 use crate::event_loop::{
     ActiveEventLoop as RootActiveEventLoop, ControlFlow, DeviceEvents,
     EventLoopProxy as CoreEventLoopProxy, EventLoopProxyProvider,
     OwnedDisplayHandle as CoreOwnedDisplayHandle,
 };
+use crate::monitor::MonitorHandle as CoreMonitorHandle;
 use crate::platform::pump_events::PumpStatus;
+use crate::platform::x11::XlibErrorHook;
 use crate::platform_impl::common::xkb::Context;
 use crate::platform_impl::platform::min_timeout;
 use crate::platform_impl::x11::window::Window;
-use crate::platform_impl::PlatformCustomCursor;
+use crate::utils::Lazy;
 use crate::window::{
-    CustomCursor as RootCustomCursor, CustomCursorSource, Theme, Window as CoreWindow,
+    CustomCursor as CoreCustomCursor, CustomCursorSource, Theme, Window as CoreWindow,
     WindowAttributes, WindowId,
 };
 
@@ -71,6 +73,62 @@ type X11rbConnection = x11rb::xcb_ffi::XCBConnection;
 
 type X11Source = Generic<BorrowedFd<'static>>;
 
+#[cfg(x11_platform)]
+pub(crate) static X11_BACKEND: Lazy<Mutex<Result<Arc<XConnection>, XNotSupported>>> =
+    Lazy::new(|| Mutex::new(XConnection::new(Some(x_error_callback)).map(Arc::new)));
+
+/// Hooks for X11 errors.
+#[cfg(x11_platform)]
+pub(crate) static XLIB_ERROR_HOOKS: Mutex<Vec<XlibErrorHook>> = Mutex::new(Vec::new());
+
+#[cfg(x11_platform)]
+unsafe extern "C" fn x_error_callback(
+    display: *mut ffi::Display,
+    event: *mut ffi::XErrorEvent,
+) -> c_int {
+    let xconn_lock = X11_BACKEND.lock().unwrap_or_else(|e| e.into_inner());
+    if let Ok(ref xconn) = *xconn_lock {
+        // Call all the hooks.
+        let mut error_handled = false;
+        for hook in XLIB_ERROR_HOOKS.lock().unwrap().iter() {
+            error_handled |= hook(display as *mut _, event as *mut _);
+        }
+
+        // `assume_init` is safe here because the array consists of `MaybeUninit` values,
+        // which do not require initialization.
+        let mut buf: [MaybeUninit<c_char>; 1024] = unsafe { MaybeUninit::uninit().assume_init() };
+        unsafe {
+            (xconn.xlib.XGetErrorText)(
+                display,
+                (*event).error_code as c_int,
+                buf.as_mut_ptr() as *mut c_char,
+                buf.len() as c_int,
+            )
+        };
+        let description =
+            unsafe { CStr::from_ptr(buf.as_ptr() as *const c_char) }.to_string_lossy();
+
+        let error = unsafe {
+            XError {
+                description: description.into_owned(),
+                error_code: (*event).error_code,
+                request_code: (*event).request_code,
+                minor_code: (*event).minor_code,
+            }
+        };
+
+        // Don't log error.
+        if !error_handled {
+            tracing::error!("X11 error: {:#?}", error);
+            // XXX only update the error, if it wasn't handled by any of the hooks.
+            *xconn.latest_error.lock().unwrap() = Some(error);
+        }
+    }
+    // Fun fact: this return value is completely ignored.
+    0
+}
+
+#[derive(Debug)]
 struct WakeSender<T> {
     sender: Sender<T>,
     waker: Ping,
@@ -91,6 +149,7 @@ impl<T> WakeSender<T> {
     }
 }
 
+#[derive(Debug)]
 struct PeekableReceiver<T> {
     recv: Receiver<T>,
     first: Option<T>,
@@ -127,6 +186,7 @@ impl<T> PeekableReceiver<T> {
     }
 }
 
+#[derive(Debug)]
 pub struct ActiveEventLoop {
     xconn: Arc<XConnection>,
     wm_delete_window: xproto::Atom,
@@ -144,6 +204,7 @@ pub struct ActiveEventLoop {
     device_events: Cell<DeviceEvents>,
 }
 
+#[derive(Debug)]
 pub struct EventLoop {
     loop_running: bool,
     event_loop: Loop<'static, EventLoopState>,
@@ -157,6 +218,7 @@ pub struct EventLoop {
 
 type ActivationToken = (WindowId, crate::event_loop::AsyncRequestSerial);
 
+#[derive(Debug)]
 struct EventLoopState {
     /// The latest readiness state for the x11 file descriptor
     x11_readiness: Readiness,
@@ -166,7 +228,12 @@ struct EventLoopState {
 }
 
 impl EventLoop {
-    pub(crate) fn new(xconn: Arc<XConnection>) -> EventLoop {
+    pub(crate) fn new() -> Result<EventLoop, EventLoopError> {
+        let xconn = match X11_BACKEND.lock().unwrap_or_else(|e| e.into_inner()).as_ref() {
+            Ok(xconn) => xconn.clone(),
+            Err(err) => return Err(os_error!(err.clone()).into()),
+        };
+
         let root = xconn.default_root().root;
         let atoms = xconn.atoms();
 
@@ -359,35 +426,31 @@ impl EventLoop {
 
         event_processor.init_device(ALL_DEVICES);
 
-        EventLoop {
+        let event_loop = EventLoop {
             loop_running: false,
             event_loop,
             event_processor,
             redraw_receiver: PeekableReceiver::from_recv(redraw_channel),
             activation_receiver: PeekableReceiver::from_recv(activation_token_channel),
             state: EventLoopState { x11_readiness: Readiness::EMPTY, proxy_wake_up: false },
-        }
+        };
+
+        Ok(event_loop)
     }
 
     pub(crate) fn window_target(&self) -> &dyn RootActiveEventLoop {
         &self.event_processor.target
     }
 
-    pub fn run<A: ApplicationHandler>(
-        mut self,
-        init_closure: impl FnOnce(&dyn RootActiveEventLoop) -> A,
-    ) -> Result<(), EventLoopError> {
-        self.run_on_demand(init_closure)
+    pub fn run_app<A: ApplicationHandler>(mut self, app: A) -> Result<(), EventLoopError> {
+        self.run_app_on_demand(app)
     }
 
-    pub fn run_on_demand<A: ApplicationHandler>(
+    pub fn run_app_on_demand<A: ApplicationHandler>(
         &mut self,
-        init_closure: impl FnOnce(&dyn RootActiveEventLoop) -> A,
+        mut app: A,
     ) -> Result<(), EventLoopError> {
         self.event_processor.target.clear_exit();
-
-        let mut app = init_closure(&self.event_processor.target);
-
         let exit = loop {
             match self.pump_app_events(None, &mut app) {
                 PumpStatus::Exit(0) => {
@@ -505,6 +568,7 @@ impl EventLoop {
         // If we don't have any pending `_receiver`
         if !self.has_pending()
             && !matches!(&cause, StartCause::ResumeTimeReached { .. } | StartCause::Poll)
+            && timeout.is_none()
         {
             return;
         }
@@ -536,7 +600,7 @@ impl EventLoop {
                 Some(Ok(token)) => {
                     let event = WindowEvent::ActivationTokenDone {
                         serial,
-                        token: crate::window::ActivationToken::_new(token),
+                        token: crate::window::ActivationToken::from_raw(token),
                     };
                     app.window_event(&self.event_processor.target, window_id, event);
                 },
@@ -578,22 +642,7 @@ impl EventLoop {
 
         while unsafe { self.event_processor.poll_one_event(xev.as_mut_ptr()) } {
             let mut xev = unsafe { xev.assume_init() };
-            self.event_processor.process_event(&mut xev, |window_target, event: Event| {
-                if let Event::WindowEvent { window_id, event: WindowEvent::RedrawRequested } = event
-                {
-                    window_target.redraw_sender.send(window_id);
-                } else {
-                    match event {
-                        Event::WindowEvent { window_id, event } => {
-                            app.window_event(window_target, window_id, event)
-                        },
-                        Event::DeviceEvent { device_id, event } => {
-                            app.device_event(window_target, device_id, event)
-                        },
-                        _ => unreachable!("event which is neither device nor window event."),
-                    }
-                }
-            });
+            self.event_processor.process_event(&mut xev, app);
         }
     }
 
@@ -680,29 +729,22 @@ impl RootActiveEventLoop for ActiveEventLoop {
     fn create_custom_cursor(
         &self,
         custom_cursor: CustomCursorSource,
-    ) -> Result<RootCustomCursor, RequestError> {
-        Ok(RootCustomCursor {
-            inner: PlatformCustomCursor::X(CustomCursor::new(self, custom_cursor.inner)?),
-        })
+    ) -> Result<CoreCustomCursor, RequestError> {
+        Ok(CoreCustomCursor(Arc::new(CustomCursor::new(self, custom_cursor)?)))
     }
 
-    fn available_monitors(&self) -> Box<dyn Iterator<Item = crate::monitor::MonitorHandle>> {
+    fn available_monitors(&self) -> Box<dyn Iterator<Item = CoreMonitorHandle>> {
         Box::new(
             self.xconn
                 .available_monitors()
                 .into_iter()
                 .flatten()
-                .map(crate::platform_impl::MonitorHandle::X)
-                .map(|inner| crate::monitor::MonitorHandle { inner }),
+                .map(|monitor| CoreMonitorHandle(Arc::new(monitor))),
         )
     }
 
-    fn primary_monitor(&self) -> Option<crate::monitor::MonitorHandle> {
-        self.xconn
-            .primary_monitor()
-            .ok()
-            .map(crate::platform_impl::MonitorHandle::X)
-            .map(|inner| crate::monitor::MonitorHandle { inner })
+    fn primary_monitor(&self) -> Option<CoreMonitorHandle> {
+        self.xconn.primary_monitor().ok().map(|monitor| CoreMonitorHandle(Arc::new(monitor)))
     }
 
     fn system_theme(&self) -> Option<Theme> {
@@ -781,7 +823,7 @@ impl Deref for DeviceInfo<'_> {
     }
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct EventLoopProxy {
     ping: Ping,
 }

src/platform_impl/linux/x11/monitor.rs

@@ -1,12 +1,12 @@
-use std::num::{NonZeroU16, NonZeroU32};
+use std::num::NonZeroU32;
 
 use x11rb::connection::RequestConnection;
 use x11rb::protocol::randr::{self, ConnectionExt as _};
 use x11rb::protocol::xproto;
 
 use super::{util, X11Error, XConnection};
-use crate::dpi::{PhysicalPosition, PhysicalSize};
-use crate::platform_impl::VideoModeHandle as PlatformVideoModeHandle;
+use crate::dpi::PhysicalPosition;
+use crate::monitor::{MonitorHandleProvider, VideoMode};
 
 // Used for testing. This should always be committed as false.
 const DISABLE_MONITOR_LIST_CACHING: bool = false;
@@ -21,32 +21,13 @@ impl XConnection {
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct VideoModeHandle {
     pub(crate) current: bool,
-    pub(crate) size: (u32, u32),
-    pub(crate) bit_depth: Option<NonZeroU16>,
-    pub(crate) refresh_rate_millihertz: Option<NonZeroU32>,
+    pub(crate) mode: VideoMode,
     pub(crate) native_mode: randr::Mode,
-    pub(crate) monitor: Option<MonitorHandle>,
 }
 
-impl VideoModeHandle {
-    #[inline]
-    pub fn size(&self) -> PhysicalSize<u32> {
-        self.size.into()
-    }
-
-    #[inline]
-    pub fn bit_depth(&self) -> Option<NonZeroU16> {
-        self.bit_depth
-    }
-
-    #[inline]
-    pub fn refresh_rate_millihertz(&self) -> Option<NonZeroU32> {
-        self.refresh_rate_millihertz
-    }
-
-    #[inline]
-    pub fn monitor(&self) -> MonitorHandle {
-        self.monitor.clone().unwrap()
+impl From<VideoModeHandle> for VideoMode {
+    fn from(handle: VideoModeHandle) -> Self {
+        handle.mode
     }
 }
 
@@ -65,7 +46,37 @@ pub struct MonitorHandle {
     /// Used to determine which windows are on this monitor
     pub(crate) rect: util::AaRect,
     /// Supported video modes on this monitor
-    video_modes: Vec<VideoModeHandle>,
+    pub(crate) video_modes: Vec<VideoModeHandle>,
+}
+
+impl MonitorHandleProvider for MonitorHandle {
+    fn id(&self) -> u128 {
+        self.native_id() as _
+    }
+
+    fn native_id(&self) -> u64 {
+        self.id as _
+    }
+
+    fn name(&self) -> Option<std::borrow::Cow<'_, str>> {
+        Some(self.name.as_str().into())
+    }
+
+    fn position(&self) -> Option<PhysicalPosition<i32>> {
+        Some(self.position.into())
+    }
+
+    fn scale_factor(&self) -> f64 {
+        self.scale_factor
+    }
+
+    fn current_video_mode(&self) -> Option<VideoMode> {
+        self.video_modes.iter().find_map(|mode| mode.current.then(|| mode.clone().into()))
+    }
+
+    fn video_modes(&self) -> Box<dyn Iterator<Item = VideoMode>> {
+        Box::new(self.video_modes.clone().into_iter().map(|mode| mode.into()))
+    }
 }
 
 impl PartialEq for MonitorHandle {
@@ -139,38 +150,6 @@ impl MonitorHandle {
         // Zero is an invalid XID value; no real monitor will have it
         self.id == 0
     }
-
-    pub fn name(&self) -> Option<String> {
-        Some(self.name.clone())
-    }
-
-    #[inline]
-    pub fn native_identifier(&self) -> u32 {
-        self.id as _
-    }
-
-    pub fn position(&self) -> Option<PhysicalPosition<i32>> {
-        Some(self.position.into())
-    }
-
-    #[inline]
-    pub fn scale_factor(&self) -> f64 {
-        self.scale_factor
-    }
-
-    #[inline]
-    pub fn current_video_mode(&self) -> Option<PlatformVideoModeHandle> {
-        self.video_modes.iter().find(|mode| mode.current).cloned().map(PlatformVideoModeHandle::X)
-    }
-
-    #[inline]
-    pub fn video_modes(&self) -> impl Iterator<Item = PlatformVideoModeHandle> {
-        let monitor = self.clone();
-        self.video_modes.clone().into_iter().map(move |mut x| {
-            x.monitor = Some(monitor.clone());
-            PlatformVideoModeHandle::X(x)
-        })
-    }
 }
 
 impl XConnection {

src/platform_impl/linux/x11/util/cursor.rs

@@ -9,8 +9,8 @@ use x11rb::protocol::xproto;
 
 use super::super::ActiveEventLoop;
 use super::*;
-use crate::error::RequestError;
-use crate::platform_impl::PlatformCustomCursorSource;
+use crate::cursor::{CustomCursorProvider, CustomCursorSource};
+use crate::error::{NotSupportedError, RequestError};
 use crate::window::CursorIcon;
 
 impl XConnection {
@@ -36,7 +36,7 @@ impl XConnection {
         window: xproto::Window,
         cursor: &CustomCursor,
     ) -> Result<(), X11Error> {
-        self.update_cursor(window, cursor.inner.cursor)
+        self.update_cursor(window, cursor.cursor)
     }
 
     /// Create a cursor from an image.
@@ -170,32 +170,45 @@ pub enum SelectedCursor {
     Named(CursorIcon),
 }
 
+impl Default for SelectedCursor {
+    fn default() -> Self {
+        SelectedCursor::Named(Default::default())
+    }
+}
+
 #[derive(Debug, Clone)]
 pub struct CustomCursor {
-    inner: Arc<CustomCursorInner>,
+    xconn: Arc<XConnection>,
+    cursor: xproto::Cursor,
 }
 
 impl Hash for CustomCursor {
     fn hash<H: Hasher>(&self, state: &mut H) {
-        Arc::as_ptr(&self.inner).hash(state);
+        self.cursor.hash(state);
     }
 }
 
 impl PartialEq for CustomCursor {
     fn eq(&self, other: &Self) -> bool {
-        Arc::ptr_eq(&self.inner, &other.inner)
+        self.cursor == other.cursor
     }
 }
-
 impl Eq for CustomCursor {}
 
 impl CustomCursor {
     pub(crate) fn new(
         event_loop: &ActiveEventLoop,
-        mut cursor: PlatformCustomCursorSource,
+        cursor: CustomCursorSource,
     ) -> Result<CustomCursor, RequestError> {
+        let mut cursor = match cursor {
+            CustomCursorSource::Image(cursor_image) => cursor_image,
+            CustomCursorSource::Animation { .. } | CustomCursorSource::Url { .. } => {
+                return Err(NotSupportedError::new("unsupported cursor kind").into())
+            },
+        };
+
         // Reverse RGBA order to BGRA.
-        cursor.0.rgba.chunks_mut(4).for_each(|chunk| {
+        cursor.rgba.chunks_mut(4).for_each(|chunk| {
             let chunk: &mut [u8; 4] = chunk.try_into().unwrap();
             chunk[0..3].reverse();
 
@@ -209,32 +222,26 @@ impl CustomCursor {
         let cursor = event_loop
             .xconn
             .create_cursor_from_image(
-                cursor.0.width,
-                cursor.0.height,
-                cursor.0.hotspot_x,
-                cursor.0.hotspot_y,
-                &cursor.0.rgba,
+                cursor.width,
+                cursor.height,
+                cursor.hotspot_x,
+                cursor.hotspot_y,
+                &cursor.rgba,
             )
             .map_err(|err| os_error!(err))?;
 
-        Ok(Self { inner: Arc::new(CustomCursorInner { xconn: event_loop.xconn.clone(), cursor }) })
+        Ok(Self { xconn: event_loop.xconn.clone(), cursor })
     }
 }
 
-#[derive(Debug)]
-struct CustomCursorInner {
-    xconn: Arc<XConnection>,
-    cursor: xproto::Cursor,
-}
-
-impl Drop for CustomCursorInner {
+impl Drop for CustomCursor {
     fn drop(&mut self) {
         self.xconn.xcb_connection().free_cursor(self.cursor).map(|r| r.ignore_error()).ok();
     }
 }
 
-impl Default for SelectedCursor {
-    fn default() -> Self {
-        SelectedCursor::Named(Default::default())
+impl CustomCursorProvider for CustomCursor {
+    fn is_animated(&self) -> bool {
+        false
     }
 }

src/platform_impl/linux/x11/util/geometry.rs

@@ -95,7 +95,7 @@ impl FrameExtentsHeuristic {
 
 impl XConnection {
     // This is adequate for inner_position
-    pub fn translate_coords(
+    pub fn translate_coords_root(
         &self,
         window: xproto::Window,
         root: xproto::Window,
@@ -103,6 +103,19 @@ impl XConnection {
         self.xcb_connection().translate_coordinates(window, root, 0, 0)?.reply().map_err(Into::into)
     }
 
+    pub fn translate_coords(
+        &self,
+        src_w: xproto::Window,
+        dst_w: xproto::Window,
+        src_x: i16,
+        src_y: i16,
+    ) -> Result<xproto::TranslateCoordinatesReply, X11Error> {
+        self.xcb_connection()
+            .translate_coordinates(src_w, dst_w, src_x, src_y)?
+            .reply()
+            .map_err(Into::into)
+    }
+
     // This is adequate for surface_size
     pub fn get_geometry(
         &self,
@@ -189,7 +202,7 @@ impl XConnection {
         // that, fullscreen windows often aren't nested.
         let (inner_y_rel_root, child) = {
             let coords = self
-                .translate_coords(window, root)
+                .translate_coords_root(window, root)
                 .expect("Failed to translate window coordinates");
             (coords.dst_y, coords.child)
         };

src/platform_impl/linux/x11/util/randr.rs

@@ -7,6 +7,7 @@ use x11rb::protocol::randr::{self, ConnectionExt as _};
 
 use super::*;
 use crate::dpi::validate_scale_factor;
+use crate::monitor::VideoMode;
 use crate::platform_impl::platform::x11::{monitor, VideoModeHandle};
 
 /// Represents values of `WINIT_HIDPI_FACTOR`.
@@ -82,17 +83,14 @@ impl XConnection {
             // XRROutputInfo contains an array of mode ids that correspond to
             // modes in the array in XRRScreenResources
             .filter(|x| output_modes.iter().any(|id| x.id == *id))
-            .map(|mode| {
-                VideoModeHandle {
-                    current: mode.id == current_mode,
-                    size: (mode.width.into(), mode.height.into()),
+            .map(|mode| VideoModeHandle {
+                current: mode.id == current_mode,
+                mode: VideoMode {
+                    size: (mode.width as u32, mode.height as u32).into(),
                     refresh_rate_millihertz: monitor::mode_refresh_rate_millihertz(mode),
                     bit_depth: NonZeroU16::new(bit_depth as u16),
-                    native_mode: mode.id,
-                    // This is populated in `MonitorHandle::video_modes` as the
-                    // video mode is returned to the user
-                    monitor: None,
-                }
+                },
+                native_mode: mode.id,
             })
             .collect();
 

src/platform_impl/linux/x11/window.rs

@@ -1,3 +1,4 @@
+use std::borrow::Cow;
 use std::ffi::CString;
 use std::mem::replace;
 use std::num::NonZeroU32;
@@ -18,27 +19,31 @@ use x11rb::protocol::{randr, xinput};
 
 use super::util::{self, SelectedCursor};
 use super::{
-    ffi, ActiveEventLoop, CookieResultExt, ImeRequest, ImeSender, VoidCookie, XConnection,
+    ffi, ActiveEventLoop, CookieResultExt, CustomCursor, ImeRequest, ImeSender, VoidCookie,
+    XConnection,
 };
-use crate::cursor::{Cursor, CustomCursor as RootCustomCursor};
+use crate::application::ApplicationHandler;
+use crate::cursor::Cursor;
 use crate::dpi::{PhysicalInsets, PhysicalPosition, PhysicalSize, Position, Size};
 use crate::error::{NotSupportedError, RequestError};
-use crate::event::{Event, SurfaceSizeWriter, WindowEvent};
+use crate::event::{SurfaceSizeWriter, WindowEvent};
 use crate::event_loop::AsyncRequestSerial;
+use crate::icon::RgbaIcon;
+use crate::monitor::{
+    Fullscreen, MonitorHandle as CoreMonitorHandle, MonitorHandleProvider, VideoMode,
+};
 use crate::platform::x11::WindowType;
+use crate::platform_impl::common;
 use crate::platform_impl::x11::atoms::*;
 use crate::platform_impl::x11::{
     xinput_fp1616_to_float, MonitorHandle as X11MonitorHandle, WakeSender, X11Error,
 };
-use crate::platform_impl::{
-    common, Fullscreen, MonitorHandle as PlatformMonitorHandle, PlatformCustomCursor, PlatformIcon,
-    VideoModeHandle as PlatformVideoModeHandle,
-};
 use crate::window::{
     CursorGrabMode, ImePurpose, ResizeDirection, Theme, UserAttentionType, Window as CoreWindow,
     WindowAttributes, WindowButtons, WindowId, WindowLevel,
 };
 
+#[derive(Debug)]
 pub(crate) struct Window(Arc<UnownedWindow>);
 
 impl Deref for Window {
@@ -178,12 +183,12 @@ impl CoreWindow for Window {
         self.0.is_maximized()
     }
 
-    fn set_fullscreen(&self, fullscreen: Option<crate::window::Fullscreen>) {
-        self.0.set_fullscreen(fullscreen.map(Into::into))
+    fn set_fullscreen(&self, fullscreen: Option<Fullscreen>) {
+        self.0.set_fullscreen(fullscreen)
     }
 
-    fn fullscreen(&self) -> Option<crate::window::Fullscreen> {
-        self.0.fullscreen().map(Into::into)
+    fn fullscreen(&self) -> Option<Fullscreen> {
+        self.0.fullscreen()
     }
 
     fn set_decorations(&self, decorations: bool) {
@@ -199,7 +204,11 @@ impl CoreWindow for Window {
     }
 
     fn set_window_icon(&self, window_icon: Option<crate::window::Icon>) {
-        self.0.set_window_icon(window_icon.map(|inner| inner.inner))
+        let icon = match window_icon.as_ref() {
+            Some(icon) => icon.0.cast_ref::<RgbaIcon>(),
+            None => None,
+        };
+        self.0.set_window_icon(icon)
     }
 
     fn set_ime_cursor_area(&self, position: Position, size: Size) {
@@ -274,28 +283,21 @@ impl CoreWindow for Window {
         self.0.set_cursor_hittest(hittest)
     }
 
-    fn current_monitor(&self) -> Option<crate::monitor::MonitorHandle> {
-        self.0
-            .current_monitor()
-            .map(crate::platform_impl::MonitorHandle::X)
-            .map(|inner| crate::monitor::MonitorHandle { inner })
+    fn current_monitor(&self) -> Option<CoreMonitorHandle> {
+        self.0.current_monitor().map(|monitor| CoreMonitorHandle(Arc::new(monitor)))
     }
 
-    fn available_monitors(&self) -> Box<dyn Iterator<Item = crate::monitor::MonitorHandle>> {
+    fn available_monitors(&self) -> Box<dyn Iterator<Item = CoreMonitorHandle>> {
         Box::new(
             self.0
                 .available_monitors()
                 .into_iter()
-                .map(crate::platform_impl::MonitorHandle::X)
-                .map(|inner| crate::monitor::MonitorHandle { inner }),
+                .map(|monitor| CoreMonitorHandle(Arc::new(monitor))),
         )
     }
 
-    fn primary_monitor(&self) -> Option<crate::monitor::MonitorHandle> {
-        self.0
-            .primary_monitor()
-            .map(crate::platform_impl::MonitorHandle::X)
-            .map(|inner| crate::monitor::MonitorHandle { inner })
+    fn primary_monitor(&self) -> Option<CoreMonitorHandle> {
+        self.0.primary_monitor().map(|monitor| CoreMonitorHandle(Arc::new(monitor)))
     }
 
     fn rwh_06_display_handle(&self) -> &dyn rwh_06::HasDisplayHandle {
@@ -327,7 +329,7 @@ impl Drop for Window {
         let xconn = &window.xconn;
 
         // Restore the video mode on drop.
-        if let Some(Fullscreen::Exclusive(_)) = window.fullscreen() {
+        if let Some(Fullscreen::Exclusive(..)) = window.fullscreen() {
             window.set_fullscreen(None);
         }
 
@@ -411,6 +413,7 @@ impl SharedState {
 unsafe impl Send for UnownedWindow {}
 unsafe impl Sync for UnownedWindow {}
 
+#[derive(Debug)]
 pub struct UnownedWindow {
     pub(crate) xconn: Arc<XConnection>, // never changes
     xwindow: xproto::Window,            // never changes
@@ -767,8 +770,10 @@ impl UnownedWindow {
             .check());
 
             // Set window icons
-            if let Some(icon) = window_attrs.window_icon {
-                leap!(window.set_icon_inner(icon.inner)).ignore_error();
+            if let Some(icon) =
+                window_attrs.window_icon.as_ref().and_then(|icon| icon.0.cast_ref::<RgbaIcon>())
+            {
+                leap!(window.set_icon_inner(icon)).ignore_error();
             }
 
             // Opt into handling window close and resize synchronization
@@ -860,8 +865,7 @@ impl UnownedWindow {
 
             if window_attrs.fullscreen.is_some() {
                 if let Some(flusher) =
-                    leap!(window
-                        .set_fullscreen_inner(window_attrs.fullscreen.clone().map(Into::into)))
+                    leap!(window.set_fullscreen_inner(window_attrs.fullscreen.clone()))
                 {
                     flusher.ignore_error()
                 }
@@ -880,7 +884,7 @@ impl UnownedWindow {
 
         // Remove the startup notification if we have one.
         if let Some(startup) = window_attrs.platform_specific.activation_token.as_ref() {
-            leap!(xconn.remove_activation_token(xwindow, &startup._token));
+            leap!(xconn.remove_activation_token(xwindow, &startup.token));
         }
 
         // We never want to give the user a broken window, since by then, it's too late to handle.
@@ -1035,20 +1039,17 @@ impl UnownedWindow {
             // fullscreen, so we can restore it upon exit, as XRandR does not
             // provide a mechanism to set this per app-session or restore this
             // to the desktop video mode as macOS and Windows do
-            (&None, &Some(Fullscreen::Exclusive(PlatformVideoModeHandle::X(ref video_mode))))
-            | (
-                &Some(Fullscreen::Borderless(_)),
-                &Some(Fullscreen::Exclusive(PlatformVideoModeHandle::X(ref video_mode))),
-            ) => {
-                let monitor = video_mode.monitor.as_ref().unwrap();
+            (&None, &Some(Fullscreen::Exclusive(ref monitor, _)))
+            | (&Some(Fullscreen::Borderless(_)), &Some(Fullscreen::Exclusive(ref monitor, _))) => {
+                let id = monitor.native_id() as _;
                 shared_state_lock.desktop_video_mode = Some((
-                    monitor.id,
-                    self.xconn.get_crtc_mode(monitor.id).expect("Failed to get desktop video mode"),
+                    id,
+                    self.xconn.get_crtc_mode(id).expect("Failed to get desktop video mode"),
                 ));
             },
             // Restore desktop video mode upon exiting exclusive fullscreen
-            (&Some(Fullscreen::Exclusive(_)), &None)
-            | (&Some(Fullscreen::Exclusive(_)), &Some(Fullscreen::Borderless(_))) => {
+            (&Some(Fullscreen::Exclusive(..)), &None)
+            | (&Some(Fullscreen::Exclusive(..)), &Some(Fullscreen::Borderless(_))) => {
                 let (monitor_id, mode_id) = shared_state_lock.desktop_video_mode.take().unwrap();
                 self.xconn
                     .set_crtc_config(monitor_id, mode_id)
@@ -1071,26 +1072,35 @@ impl UnownedWindow {
                 flusher.map(Some)
             },
             Some(fullscreen) => {
-                let (video_mode, monitor) = match fullscreen {
-                    Fullscreen::Exclusive(PlatformVideoModeHandle::X(ref video_mode)) => {
-                        (Some(video_mode), video_mode.monitor.clone().unwrap())
-                    },
-                    Fullscreen::Borderless(Some(PlatformMonitorHandle::X(monitor))) => {
-                        (None, monitor)
-                    },
-                    Fullscreen::Borderless(None) => {
-                        (None, self.shared_state_lock().last_monitor.clone())
-                    },
-                    #[cfg(wayland_platform)]
-                    _ => unreachable!(),
-                };
+                let (monitor, video_mode): (Cow<'_, X11MonitorHandle>, Option<&VideoMode>) =
+                    match &fullscreen {
+                        Fullscreen::Exclusive(monitor, video_mode) => {
+                            let monitor = monitor.cast_ref::<X11MonitorHandle>().unwrap();
+                            (Cow::Borrowed(monitor), Some(video_mode))
+                        },
+                        Fullscreen::Borderless(Some(monitor)) => {
+                            let monitor = monitor.cast_ref::<X11MonitorHandle>().unwrap();
+                            (Cow::Borrowed(monitor), None)
+                        },
+                        Fullscreen::Borderless(None) => {
+                            (Cow::Owned(self.shared_state_lock().last_monitor.clone()), None)
+                        },
+                    };
 
                 // Don't set fullscreen on an invalid dummy monitor handle
                 if monitor.is_dummy() {
                     return Ok(None);
                 }
 
-                if let Some(video_mode) = video_mode {
+                if let Some(native_mode) = video_mode.and_then(|requested| {
+                    monitor.video_modes.iter().find_map(|mode| {
+                        if &mode.mode == requested {
+                            Some(mode.native_mode)
+                        } else {
+                            None
+                        }
+                    })
+                }) {
                     // FIXME: this is actually not correct if we're setting the
                     // video mode to a resolution higher than the current
                     // desktop resolution, because XRandR does not automatically
@@ -1117,7 +1127,7 @@ impl UnownedWindow {
                     // this will make someone unhappy, but it's very unusual for
                     // games to want to do this anyway).
                     self.xconn
-                        .set_crtc_config(monitor.id, video_mode.native_mode)
+                        .set_crtc_config(monitor.native_id() as _, native_mode)
                         .expect("failed to set video mode");
                 }
 
@@ -1207,7 +1217,8 @@ impl UnownedWindow {
         &self,
         new_monitor: &X11MonitorHandle,
         maybe_prev_scale_factor: Option<f64>,
-        mut callback: impl FnMut(Event),
+        app: &mut dyn ApplicationHandler,
+        event_loop: &ActiveEventLoop,
     ) {
         // Check if the self is on this monitor
         let monitor = self.shared_state_lock().last_monitor.clone();
@@ -1227,12 +1238,9 @@ impl UnownedWindow {
 
             let old_surface_size = PhysicalSize::new(width, height);
             let surface_size = Arc::new(Mutex::new(PhysicalSize::new(new_width, new_height)));
-            callback(Event::WindowEvent {
-                window_id: self.id(),
-                event: WindowEvent::ScaleFactorChanged {
-                    scale_factor: new_monitor.scale_factor,
-                    surface_size_writer: SurfaceSizeWriter::new(Arc::downgrade(&surface_size)),
-                },
+            app.window_event(event_loop, self.id(), WindowEvent::ScaleFactorChanged {
+                scale_factor: new_monitor.scale_factor,
+                surface_size_writer: SurfaceSizeWriter::new(Arc::downgrade(&surface_size)),
             });
 
             let new_surface_size = *surface_size.lock().unwrap();
@@ -1403,7 +1411,7 @@ impl UnownedWindow {
         self.xconn.flush_requests().expect("Failed to set window-level state");
     }
 
-    fn set_icon_inner(&self, icon: PlatformIcon) -> Result<VoidCookie<'_>, X11Error> {
+    fn set_icon_inner(&self, icon: &RgbaIcon) -> Result<VoidCookie<'_>, X11Error> {
         let atoms = self.xconn.atoms();
         let icon_atom = atoms[_NET_WM_ICON];
         let data = icon.to_cardinals();
@@ -1430,7 +1438,7 @@ impl UnownedWindow {
     }
 
     #[inline]
-    pub(crate) fn set_window_icon(&self, icon: Option<PlatformIcon>) {
+    pub(crate) fn set_window_icon(&self, icon: Option<&RgbaIcon>) {
         match icon {
             Some(icon) => self.set_icon_inner(icon),
             None => self.unset_icon_inner(),
@@ -1516,7 +1524,7 @@ impl UnownedWindow {
         // This should be okay to unwrap since the only error XTranslateCoordinates can return
         // is BadWindow, and if the window handle is bad we have bigger problems.
         self.xconn
-            .translate_coords(self.xwindow, self.root)
+            .translate_coords_root(self.xwindow, self.root)
             .map(|coords| (coords.dst_x.into(), coords.dst_y.into()))
             .unwrap()
     }
@@ -1808,25 +1816,34 @@ impl UnownedWindow {
                     }
                 }
             },
-            Cursor::Custom(RootCustomCursor { inner: PlatformCustomCursor::X(cursor) }) => {
+            Cursor::Custom(cursor) => {
+                let cursor = match cursor.cast_ref::<CustomCursor>() {
+                    Some(cursor) => cursor,
+                    None => {
+                        tracing::error!("unrecognized cursor passed to X11 backend");
+                        return;
+                    },
+                };
+
                 #[allow(clippy::mutex_atomic)]
                 if *self.cursor_visible.lock().unwrap() {
-                    if let Err(err) = self.xconn.set_custom_cursor(self.xwindow, &cursor) {
+                    if let Err(err) = self.xconn.set_custom_cursor(self.xwindow, cursor) {
                         tracing::error!("failed to set window icon: {err}");
                     }
                 }
 
-                *self.selected_cursor.lock().unwrap() = SelectedCursor::Custom(cursor);
-            },
-            #[cfg(wayland_platform)]
-            Cursor::Custom(RootCustomCursor { inner: PlatformCustomCursor::Wayland(_) }) => {
-                tracing::error!("passed a Wayland cursor to X11 backend")
+                *self.selected_cursor.lock().unwrap() = SelectedCursor::Custom(cursor.clone());
             },
         }
     }
 
     #[inline]
     pub fn set_cursor_grab(&self, mode: CursorGrabMode) -> Result<(), RequestError> {
+        // We don't support the locked cursor yet, so ignore it early on.
+        if mode == CursorGrabMode::Locked {
+            return Err(NotSupportedError::new("locked cursor is not implemented on X11").into());
+        }
+
         let mut grabbed_lock = self.cursor_grabbed_mode.lock().unwrap();
         if mode == *grabbed_lock {
             return Ok(());
@@ -1838,6 +1855,7 @@ impl UnownedWindow {
             .xcb_connection()
             .ungrab_pointer(x11rb::CURRENT_TIME)
             .expect_then_ignore_error("Failed to call `xcb_ungrab_pointer`");
+        *grabbed_lock = CursorGrabMode::None;
 
         let result = match mode {
             CursorGrabMode::None => self
@@ -1845,34 +1863,33 @@ impl UnownedWindow {
                 .flush_requests()
                 .map_err(|err| RequestError::Os(os_error!(X11Error::Xlib(err)))),
             CursorGrabMode::Confined => {
-                let result = {
-                    self.xconn
-                        .xcb_connection()
-                        .grab_pointer(
-                            true as _,
-                            self.xwindow,
-                            xproto::EventMask::BUTTON_PRESS
-                                | xproto::EventMask::BUTTON_RELEASE
-                                | xproto::EventMask::ENTER_WINDOW
-                                | xproto::EventMask::LEAVE_WINDOW
-                                | xproto::EventMask::POINTER_MOTION
-                                | xproto::EventMask::POINTER_MOTION_HINT
-                                | xproto::EventMask::BUTTON1_MOTION
-                                | xproto::EventMask::BUTTON2_MOTION
-                                | xproto::EventMask::BUTTON3_MOTION
-                                | xproto::EventMask::BUTTON4_MOTION
-                                | xproto::EventMask::BUTTON5_MOTION
-                                | xproto::EventMask::KEYMAP_STATE,
-                            xproto::GrabMode::ASYNC,
-                            xproto::GrabMode::ASYNC,
-                            self.xwindow,
-                            0u32,
-                            x11rb::CURRENT_TIME,
-                        )
-                        .expect("Failed to call `grab_pointer`")
-                        .reply()
-                        .expect("Failed to receive reply from `grab_pointer`")
-                };
+                let result = self
+                    .xconn
+                    .xcb_connection()
+                    .grab_pointer(
+                        true as _,
+                        self.xwindow,
+                        xproto::EventMask::BUTTON_PRESS
+                            | xproto::EventMask::BUTTON_RELEASE
+                            | xproto::EventMask::ENTER_WINDOW
+                            | xproto::EventMask::LEAVE_WINDOW
+                            | xproto::EventMask::POINTER_MOTION
+                            | xproto::EventMask::POINTER_MOTION_HINT
+                            | xproto::EventMask::BUTTON1_MOTION
+                            | xproto::EventMask::BUTTON2_MOTION
+                            | xproto::EventMask::BUTTON3_MOTION
+                            | xproto::EventMask::BUTTON4_MOTION
+                            | xproto::EventMask::BUTTON5_MOTION
+                            | xproto::EventMask::KEYMAP_STATE,
+                        xproto::GrabMode::ASYNC,
+                        xproto::GrabMode::ASYNC,
+                        self.xwindow,
+                        0u32,
+                        x11rb::CURRENT_TIME,
+                    )
+                    .expect("Failed to call `grab_pointer`")
+                    .reply()
+                    .expect("Failed to receive reply from `grab_pointer`");
 
                 match result.status {
                     xproto::GrabStatus::SUCCESS => Ok(()),
@@ -1892,11 +1909,7 @@ impl UnownedWindow {
                 }
                 .map_err(|err| RequestError::Os(os_error!(err)))
             },
-            CursorGrabMode::Locked => {
-                return Err(
-                    NotSupportedError::new("locked cursor is not implemented on X11").into()
-                );
-            },
+            CursorGrabMode::Locked => return Ok(()),
         };
 
         if result.is_ok() {
@@ -2047,17 +2060,13 @@ impl UnownedWindow {
     #[inline]
     pub fn set_ime_cursor_area(&self, spot: Position, size: Size) {
         let PhysicalPosition { x, y } = spot.to_physical::<i16>(self.scale_factor());
-        let PhysicalSize { width, height } = size.to_physical::<i16>(self.scale_factor());
-        // We only currently support reporting a caret position via XIM.
-        // No IM servers currently process preedit area information from XIM clients
-        // and it is unclear this is even part of the standard protocol.
-        // Fcitx and iBus both assume that the position reported is at the insertion
-        // caret, and by default will place the candidate window under and to the
-        // right of the reported point.
-        let _ = self.ime_sender.lock().unwrap().send(ImeRequest::Position(
+        let PhysicalSize { width, height } = size.to_physical::<u16>(self.scale_factor());
+        let _ = self.ime_sender.lock().unwrap().send(ImeRequest::Area(
             self.xwindow as ffi::Window,
-            x.saturating_add(width),
-            y.saturating_add(height),
+            x,
+            y,
+            width,
+            height,
         ));
     }