TMP

super long message  awdjbhkwbegfkhjewvbfhre vgfhj ejbsfhjkr besfhjkr besjkf breshjk gberj fn

.github/workflows/check-commit-msg.yml

@@ -0,0 +1,24 @@
+name: Check Commit Messages
+
+on:
+  pull_request:
+
+
+jobs:
+  length:
+    name: Check that length of commit messages are <72 characters
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Fetch branch data from origin
+        run: git fetch origin
+      - run: |
+          COMMIT_MESSAGES=$(git log --combined --format=%s origin/$GITHUB_BASE_REF..HEAD)
+          echo $COMMIT_MESSAGES
+          for MESSAGE in $COMMIT_MESSAGES; do
+            LENGTH=$(echo $MESSAGE | wc -c)
+            if [ $LENGTH -gt 72 ]; then
+              echo "Commit message \"$MESSAGE\" is too long ($LENGTH characters). Please keep commit messages under 72 characters."
+              exit 1
+            fi
+          done

.github/workflows/ci.yml

@@ -17,6 +17,24 @@ jobs:
     - name: Check Formatting
       run: cargo fmt -- --check
 
+  typos:
+    name: Check for typos
+    runs-on: ubuntu-latest
+    timeout-minutes: 30
+    steps:
+      - uses: actions/checkout@v4
+      - uses: taiki-e/install-action@v2
+        with:
+          tool: typos-cli
+      - name: run typos
+        run: typos
+      - name: Typos info
+        if: failure()
+        run: |
+          echo 'To fix typos, please run `typos -w`'
+          echo 'To check for a diff, run `typos`'
+          echo 'You can find typos here: https://crates.io/crates/typos'
+
   tests:
     name: Test ${{ matrix.toolchain }} ${{ matrix.platform.name }}
     runs-on: ${{ matrix.platform.os }}
@@ -127,6 +145,13 @@ jobs:
     - name: Build crate
       run: cargo $CMD build $OPTIONS
 
+    # Test only on Linux x86_64, so we avoid spending unnecessary CI hours.
+    - name: Test dpi crate
+      if: >
+        contains(matrix.platform.name, 'Linux 64bit') &&
+        matrix.toolchain != '1.70.0'
+      run: cargo test -p dpi
+
     - name: Build tests
       if: >
         !contains(matrix.platform.target, 'redox') &&

CHANGELOG.md

@@ -11,6 +11,10 @@ Unreleased` header.
 
 # Unreleased
 
+- Deprecate `EventLoop::run` in favor of `EventLoop::run_app`.
+- Deprecate `EventLoopExtRunOnDemand::run_on_demand` in favor of `EventLoop::run_app_on_demand`.
+- Deprecate `EventLoopExtPumpEvents::pump_events` in favor of `EventLoopExtPumpEvents::pump_app_events`.
+- Add `ApplicationHandler<T>` trait which mimics `Event<T>`.
 - Move `dpi` types to its own crate, and re-export it from the root crate.
 - Implement `Sync` for `EventLoopProxy<T: Send>`.
 - **Breaking:** Move `Window::new` to `ActiveEventLoop::create_window` and `EventLoop::create_window` (with the latter being deprecated).
@@ -48,6 +52,20 @@ Unreleased` header.
 - Add `Window::default_attributes` to get default `WindowAttributes`.
 - `log` has been replaced with `tracing`. The old behavior can be emulated by setting the `log` feature on the `tracing` crate.
 
+# 0.29.15
+
+- On X11, fix crash due to xsettings query on systems with incomplete xsettings.
+
+# 0.29.14
+
+- On X11/Wayland, fix `text` and `text_with_all_modifiers` not being `None` during compose.
+- On Wayland, don't reapply cursor grab when unchanged.
+- On X11, fix a bug where some mouse events would be unexpectedly filtered out.
+
+# 0.29.13
+
+- On Web, fix possible crash with `ControlFlow::Wait` and `ControlFlow::WaitUntil`.
+
 # 0.29.12
 
 - On X11, fix use after free during xinput2 handling.

CODE_OF_CONDUCT.md

@@ -0,0 +1,6 @@
+# Code of Conduct
+
+The `rust-windowing` project adheres to the [Rust Code of Conduct]. This
+describes the minimum behavior expected from all contributors.
+
+[Rust Code of Conduct]: https://www.rust-lang.org/policies/code-of-conduct

CONTRIBUTING.md

@@ -1,169 +1,57 @@
-# Contribution Guidelines
+# Winit Contributing Guidelines
 
-This document contains guidelines for contributing code to winit. It has to be
+## Scope
-followed in order for your patch to be approved and applied.
+[See `FEATURES.md`](./FEATURES.md). When requesting or implementing a new Winit feature, you should
+consider whether or not it's directly related to window creation or input handling. If it isn't, it
+may be worth creating a separate crate that extends Winit's API to add that functionality.
 
-## Contributing
 
-Anyone can contribute to winit, however given that it's a cross platform
+## Reporting an issue
-windowing toolkit getting certain changes incorporated upstream could be
-challenging.
 
-To save your time it's wise to check already opened [pull requests][prs] and
+When reporting an issue, in order to help the maintainers understand what the problem is, please make
-[issues][issues]. In general, bug fixes and missing implementations are always
+your description of the issue as detailed as possible:
-accepted, however new API proposals should go into the issue first. When in
-doubt contact us on [matrix][matrix] or via opening an issue.
 
-### Submitting your work and handling review
+- if it is a bug, please provide a clear explanation of what happens, what should happen, and how to
+  reproduce the issue, ideally by providing a minimal program exhibiting the problem
+- if it is a feature request, please provide a clear argumentation about why you believe this feature
+  should be supported by winit
 
-All patches have to be sent on Github as [pull requests][prs]. To simplify your
+## Making a pull request
-life during review it's recommended to check the "give contributors write access
-to the branch" checkbox.
 
-#### Creating commits
+When making a code contribution to winit, before opening your pull request, please make sure that:
 
-When creating a commit, follow these general rules:
+- your patch builds with Winit's minimal supported rust version - Rust 1.70.
-  - Try to limit the first line (title) of the commit message to 50 characters,
+- you tested your modifications on all the platforms impacted, or if not possible, detail which platforms
-    but not more than 60 characters.
+  were not tested, and what should be tested, so that a maintainer or another contributor can test them
-  - The commit starts with an uppercase latter and everything else must be
+- you updated any relevant documentation in winit
-    lowercase, unless you quote a symbol, like `Window`.
+- you left comments in your code explaining any part that is not straightforward, so that the
-  - Use the body of the commit message to actually explain what your patch does
+  maintainers and future contributors don't have to try to guess what your code is supposed to do
-    and why it is useful. Even if your patch is a one line fix, the description
+- your PR adds an entry to the changelog file if the introduced change is relevant to winit users.
-    is not limited in length and may span over multiple paragraphs. Use proper
-    English syntax, grammar and punctuation. The body is generally wrapped
-    at 72 characters.
-  - If you're a downstream user and your fixing your issue, consider to link it
-    like `Links: URL` in the end of the commit message.
-  - Try to address only one issue/topic per commit.
-  - Prefer describing your changes in imperative mood, e.g. *"make xyzzy do
-    frotz"* instead of *"[This patch] makes xyzzy do frotz"* or *"[I] changed
-    xyzzy to do frotz"*, as if you are giving orders to the codebase to change
-    its behaviour.
-  - When fixing an issue from https://github.com/rust-windowing/winit/issues,
-    ensure to have it include in the end of the commit. See other commits
-    on how it's done.
-  - When in doubt, follow the format and layout of the recent existing commits.
 
-The maintainers will fixup your commit message when applying the patch, but it's
+  You needn't worry about the added entry causing conflicts, the maintainer that merges the PR will
-still recommended to follow the rules above to make the life of maintainers
+  handle those for you when merging (see below).
-easier.
+- if your PR affects the platform compatibility of one or more features or adds another feature, the
+  relevant sections in [`FEATURES.md`](https://github.com/rust-windowing/winit/blob/master/FEATURES.md#features)
+  should be updated.
 
-If you want to communicate something to reviewers, but it doesn't belong to
+Once your PR is open, you can ask for a review by a maintainer of your platform. Winit's merging policy
-the commit message, write that under `--` on PR body. Your PR could look like:
+is that a PR must be approved by at least two maintainers of winit before being merged, including
+at least a maintainer of the platform (a maintainer making a PR themselves counts as approving it).
 
-  ```
+Once your PR is deemed ready, the merging maintainer will take care of resolving conflicts in
-  TITLE (matches commit title)
+`CHANGELOG.md` (but you must resolve other conflicts yourself). Doing this requires that you check the
-
+"give contributors write access to the branch" checkbox when creating the PR.
-  Body (matches commit body)
-
-  --
-
-  Your arbitrary message goes here.
-
-  Various checkboxes PR template required you to fill.
-  ```
-
-#### Handling review
-
-During the review process certain events could require an action from your side,
-to communication more efficient the common patterns and reactions are described
-below.
-
-_Event:_ The CI fails to build, but it looks like not your fault. Not
-communicating so, could result into maintainers not looking into your patch,
-unless they CI that CI pass.\
-_Desired behavior:_ Write a message saying roughly the following "The CI failure
-is unrelated", so maintainers will fix it for you.
-
-_Event:_ Collaborator requested review on your PR.\
-_Desired behavior:_ Once you address the request, you _should_ re-request review
-with the github's UI. If you don't agree with what maintainer suggested, you
-should object that and re-request the review. That will indicate that the
-_ball_ is on maintainer's side.
-
-_Event:_ You've opened a PR, but maintainer shortly after commented that they
-want to work on that _themselves_.\
-_Desired behavior:_ Discusses with maintainer their plans if they were not
-outlined in the initial response, because such response means that they
-are not interested in reviewing your code. Such thing could happen when
-underestimating complexity of the task you're solving or when your patch
-mandate certain downstream designs.
-
-[prs]: https://github.com/rust-windowing/winit/pulls
-[issues]: https://github.com/rust-windowing/winit/issues
-[matrix]: https://matrix.to/#/#rust-windowing:matrix.org
 
 ## Maintainers
 
-Winit has plenty of maintainers with different backgrounds, experience level,
+The current maintainers for each platform are listed in the [CODEOWNERS](.github/CODEOWNERS) file.
-and reasons to be winit maintainer in the first place. To ensure that winit's
-code quality is not decreasing over time and to make it easier to teach new
-maintainers the _winit way of doing things_ the common policies and routines
-are defined in this section.
 
-The current maintainers for each platform are listed in [this file][CODEOWNERS].
+## Release process
-
-### Contributions handling
-
-The maintainer must ensure that the external contributions meet the winit's
-quality standards. If it's not, it **is maintainer's responsibility** to bring
-it on par, which includes:
-
-  - Decline the patch if it tries to achieve short term goals instead of solving
-    the problem in general. In such case maintainer must communicate that **as
-    early as possible**, so contributors don't spend their time on something
-    that won't be accepted in the end.
-  - Ensure that formatting is consistent and `CHANGELOG` messages are clear
-    for the end users.
-  - Improve the commit message, so it'll be easier for other maintainers to
-    understand the motivation without going through all the discussions on the
-    particular patch/PR.
-  - Ensure that the proposed patch doesn't break platform parity. If the
-    breakage is desired by contributor, an issue should be opened to discuss
-    with other maintainers before merging.
-  - Always fix CI issues before merging if they don't originate from the
-    submitted work.
-
-However, maintainer must always give a leeway for external contributors, so they
-don't feel discouraged contributing, for example:
-
-  - Suggest a patch to resolve style issues, if it's the only issue with the
-    submitted work. Keep in mind that pushing the resolution yourself is not
-    desired, because contributor might not agree with what you did.
-  - Be more explicit on how things should be done if you doesn't like the
-    approach.
-  - Suggest to finish PR for them if they're absent for a while and you need the
-    proposed changes to move forward with something. In such case maintainer
-    must preserve attribution with `Co-authored-by`, `Suggested-by`, or keep
-    the original commiter.
-  - Rebase their work for them when massive changes to winit codebase were
-    introduced.
-
-When reviewing code of other maintainers all of the above is on the maintainer
-who submitted the patch. Interested maintainers could help push the work over
-the finish line, but teaching other maintainers should be preferred.
-
-When contributor is _regular_ in winit, the maintainer should slowly start
-requiring contributor to match *maintainer* quality standards when writing
-patches and commit messages.
-
-### Contributing
-
-When submitting a patch maintainer should follow the general contributing
-guidelines, however all soft rules (e.g `Try to`), become strict.
-
-To make life simpler for other maintainers it's suggested to create your branch
-under the project repository instead of your own fork. The naming scheme is
-`github_user_name/branch_name`. Doing so will make your work easier to rebase
-for other maintainers when you're absent.
-
-### Release process
 
 Given that winit is a widely used library, we should be able to make a patch
 releases at any time we want without blocking the development of new features.
 
-To achieve these goals, a new branch is created for every new release. Releases
+To achieve these goals, a new branch is created for every new release. Releases and later patch releases are committed and tagged in this branch.
-and later patch releases are committed and tagged in this branch.
 
 The exact steps for an exemplary `0.2.0` release might look like this:
   1. Initially, the version on the latest master is `0.1.0`
@@ -179,5 +67,3 @@ When doing a patch release, the process is similar:
   2. Checkout the `v0.2.x` branch
   3. Cherry-pick the required non-breaking changes into the `v0.2.x`
   4. Follow steps 3-7 of the regular release example
-
-[CODEOWNERS]: .github/CODEOWNERS

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "winit"
-version = "0.29.12"
+version = "0.29.15"
 authors = ["The winit contributors", "Pierre Krieger <pierre.krieger1708@gmail.com>"]
 description = "Cross-platform window creation library."
 keywords = ["windowing"]
@@ -188,7 +188,7 @@ wayland-backend = { version = "0.3.0", default_features = false, features = ["cl
 wayland-client = { version = "0.31.1", optional = true }
 wayland-protocols = { version = "0.31.0", features = [ "staging"], optional = true }
 wayland-protocols-plasma = { version = "0.2.0", features = [ "client" ], optional = true }
-x11-dl = { version = "2.18.5", optional = true }
+x11-dl = { version = "2.19.1", optional = true }
 x11rb = { version = "0.13.0", default-features = false, features = ["allow-unsafe-code", "dl-libxcb", "randr", "resource_manager", "xinput", "xkb"], optional = true }
 xkbcommon-dl = "0.4.2"
 

README.md

@@ -8,7 +8,7 @@
 
 ```toml
 [dependencies]
-winit = "0.29.12"
+winit = "0.29.15"
 ```
 
 ## [Documentation](https://docs.rs/winit)

dpi/CHANGELOG.md

@@ -0,0 +1,16 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+Please keep one empty line before and after all headers. (This is required for
+`git` to produce a conflict when a release is made while a PR is open and the
+PR's changelog entry would go into the wrong section).
+
+And please only add new entries to the top of this list, right below the `#
+Unreleased` header.
+
+# Unreleased
+
+# 0.1.0
+
+- Add `LogicalUnit`, `PhysicalUnit` and `PixelUnit` types and related functions.

dpi/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "dpi"
-version = "0.0.0"
+version = "0.1.0"
 description = "Types for handling UI scaling"
 keywords = ["DPI", "HiDPI", "scale-factor"]
 categories = ["gui"]

dpi/src/lib.rs

@@ -35,8 +35,8 @@
 //!
 //! ### Position and Size types
 //!
-//! The [`PhysicalPosition`] / [`PhysicalSize`] types correspond with the actual pixels on the
+//! The [`PhysicalPosition`] / [`PhysicalSize`] / [`PhysicalUnit`] types correspond with the actual pixels on the
-//! device, and the [`LogicalPosition`] / [`LogicalSize`] types correspond to the physical pixels
+//! device, and the [`LogicalPosition`] / [`LogicalSize`] / [`LogicalUnit`] types correspond to the physical pixels
 //! divided by the scale factor.
 //!
 //! The position and size types are generic over their exact pixel type, `P`, to allow the
@@ -128,6 +128,238 @@ pub fn validate_scale_factor(scale_factor: f64) -> bool {
     scale_factor.is_sign_positive() && scale_factor.is_normal()
 }
 
+/// A logical pixel unit.
+#[derive(Debug, Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Default, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+pub struct LogicalUnit<P>(pub P);
+
+impl<P> LogicalUnit<P> {
+    /// Represents a minimum logical unit of [`f64::MAX`].
+    pub const MIN: LogicalUnit<f64> = LogicalUnit::new(f64::MIN);
+    /// Represents a logical unit of `0_f64`.
+    pub const ZERO: LogicalUnit<f64> = LogicalUnit::new(0.0);
+    /// Represents a maximum logical unit that is equal to [`f64::MAX`].
+    pub const MAX: LogicalUnit<f64> = LogicalUnit::new(f64::MAX);
+
+    #[inline]
+    pub const fn new(v: P) -> Self {
+        LogicalUnit(v)
+    }
+}
+
+impl<P: Pixel> LogicalUnit<P> {
+    #[inline]
+    pub fn from_physical<T: Into<PhysicalUnit<X>>, X: Pixel>(
+        physical: T,
+        scale_factor: f64,
+    ) -> Self {
+        physical.into().to_logical(scale_factor)
+    }
+
+    #[inline]
+    pub fn to_physical<X: Pixel>(&self, scale_factor: f64) -> PhysicalUnit<X> {
+        assert!(validate_scale_factor(scale_factor));
+        PhysicalUnit::new(self.0.into() * scale_factor).cast()
+    }
+
+    #[inline]
+    pub fn cast<X: Pixel>(&self) -> LogicalUnit<X> {
+        LogicalUnit(self.0.cast())
+    }
+}
+
+impl<P: Pixel, X: Pixel> From<X> for LogicalUnit<P> {
+    fn from(v: X) -> LogicalUnit<P> {
+        LogicalUnit::new(v.cast())
+    }
+}
+
+impl<P: Pixel> From<LogicalUnit<P>> for u8 {
+    fn from(v: LogicalUnit<P>) -> u8 {
+        v.0.cast()
+    }
+}
+
+impl<P: Pixel> From<LogicalUnit<P>> for u16 {
+    fn from(v: LogicalUnit<P>) -> u16 {
+        v.0.cast()
+    }
+}
+
+impl<P: Pixel> From<LogicalUnit<P>> for u32 {
+    fn from(v: LogicalUnit<P>) -> u32 {
+        v.0.cast()
+    }
+}
+
+impl<P: Pixel> From<LogicalUnit<P>> for i8 {
+    fn from(v: LogicalUnit<P>) -> i8 {
+        v.0.cast()
+    }
+}
+
+impl<P: Pixel> From<LogicalUnit<P>> for i16 {
+    fn from(v: LogicalUnit<P>) -> i16 {
+        v.0.cast()
+    }
+}
+
+impl<P: Pixel> From<LogicalUnit<P>> for i32 {
+    fn from(v: LogicalUnit<P>) -> i32 {
+        v.0.cast()
+    }
+}
+
+impl<P: Pixel> From<LogicalUnit<P>> for f32 {
+    fn from(v: LogicalUnit<P>) -> f32 {
+        v.0.cast()
+    }
+}
+
+impl<P: Pixel> From<LogicalUnit<P>> for f64 {
+    fn from(v: LogicalUnit<P>) -> f64 {
+        v.0.cast()
+    }
+}
+
+/// A physical pixel unit.
+#[derive(Debug, Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Default, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+pub struct PhysicalUnit<P>(pub P);
+
+impl<P> PhysicalUnit<P> {
+    /// Represents a minimum physical unit of [`f64::MAX`].
+    pub const MIN: LogicalUnit<f64> = LogicalUnit::new(f64::MIN);
+    /// Represents a physical unit of `0_f64`.
+    pub const ZERO: LogicalUnit<f64> = LogicalUnit::new(0.0);
+    /// Represents a maximum physical unit that is equal to [`f64::MAX`].
+    pub const MAX: LogicalUnit<f64> = LogicalUnit::new(f64::MAX);
+
+    #[inline]
+    pub const fn new(v: P) -> Self {
+        PhysicalUnit(v)
+    }
+}
+
+impl<P: Pixel> PhysicalUnit<P> {
+    #[inline]
+    pub fn from_logical<T: Into<LogicalUnit<X>>, X: Pixel>(logical: T, scale_factor: f64) -> Self {
+        logical.into().to_physical(scale_factor)
+    }
+
+    #[inline]
+    pub fn to_logical<X: Pixel>(&self, scale_factor: f64) -> LogicalUnit<X> {
+        assert!(validate_scale_factor(scale_factor));
+        LogicalUnit::new(self.0.into() / scale_factor).cast()
+    }
+
+    #[inline]
+    pub fn cast<X: Pixel>(&self) -> PhysicalUnit<X> {
+        PhysicalUnit(self.0.cast())
+    }
+}
+
+impl<P: Pixel, X: Pixel> From<X> for PhysicalUnit<P> {
+    fn from(v: X) -> PhysicalUnit<P> {
+        PhysicalUnit::new(v.cast())
+    }
+}
+
+impl<P: Pixel> From<PhysicalUnit<P>> for u8 {
+    fn from(v: PhysicalUnit<P>) -> u8 {
+        v.0.cast()
+    }
+}
+
+impl<P: Pixel> From<PhysicalUnit<P>> for u16 {
+    fn from(v: PhysicalUnit<P>) -> u16 {
+        v.0.cast()
+    }
+}
+
+impl<P: Pixel> From<PhysicalUnit<P>> for u32 {
+    fn from(v: PhysicalUnit<P>) -> u32 {
+        v.0.cast()
+    }
+}
+
+impl<P: Pixel> From<PhysicalUnit<P>> for i8 {
+    fn from(v: PhysicalUnit<P>) -> i8 {
+        v.0.cast()
+    }
+}
+
+impl<P: Pixel> From<PhysicalUnit<P>> for i16 {
+    fn from(v: PhysicalUnit<P>) -> i16 {
+        v.0.cast()
+    }
+}
+
+impl<P: Pixel> From<PhysicalUnit<P>> for i32 {
+    fn from(v: PhysicalUnit<P>) -> i32 {
+        v.0.cast()
+    }
+}
+
+impl<P: Pixel> From<PhysicalUnit<P>> for f32 {
+    fn from(v: PhysicalUnit<P>) -> f32 {
+        v.0.cast()
+    }
+}
+
+impl<P: Pixel> From<PhysicalUnit<P>> for f64 {
+    fn from(v: PhysicalUnit<P>) -> f64 {
+        v.0.cast()
+    }
+}
+
+/// A pixel unit that's either physical or logical.
+pub enum PixelUnit {
+    Physical(PhysicalUnit<i32>),
+    Logical(LogicalUnit<f64>),
+}
+
+impl PixelUnit {
+    /// Represents a minimum logical unit of [`f64::MAX`].
+    pub const MIN: PixelUnit = PixelUnit::Logical(LogicalUnit::new(f64::MIN));
+    /// Represents a logical unit of `0_f64`.
+    pub const ZERO: PixelUnit = PixelUnit::Logical(LogicalUnit::new(0.0));
+    /// Represents a maximum logical unit that is equal to [`f64::MAX`].
+    pub const MAX: PixelUnit = PixelUnit::Logical(LogicalUnit::new(f64::MAX));
+
+    pub fn new<S: Into<PixelUnit>>(unit: S) -> PixelUnit {
+        unit.into()
+    }
+
+    pub fn to_logical<P: Pixel>(&self, scale_factor: f64) -> LogicalUnit<P> {
+        match *self {
+            PixelUnit::Physical(unit) => unit.to_logical(scale_factor),
+            PixelUnit::Logical(unit) => unit.cast(),
+        }
+    }
+
+    pub fn to_physical<P: Pixel>(&self, scale_factor: f64) -> PhysicalUnit<P> {
+        match *self {
+            PixelUnit::Physical(unit) => unit.cast(),
+            PixelUnit::Logical(unit) => unit.to_physical(scale_factor),
+        }
+    }
+}
+
+impl<P: Pixel> From<PhysicalUnit<P>> for PixelUnit {
+    #[inline]
+    fn from(unit: PhysicalUnit<P>) -> PixelUnit {
+        PixelUnit::Physical(unit.cast())
+    }
+}
+
+impl<P: Pixel> From<LogicalUnit<P>> for PixelUnit {
+    #[inline]
+    fn from(unit: LogicalUnit<P>) -> PixelUnit {
+        PixelUnit::Logical(unit.cast())
+    }
+}
+
 /// A position represented in logical pixels.
 ///
 /// The position is stored as floats, so please be careful. Casting floats to integers truncates the
@@ -730,6 +962,43 @@ mod tests {
         assert!(!validate_scale_factor(f64::NEG_INFINITY));
     }
 
+    #[test]
+    fn test_logical_unity() {
+        let log_unit = LogicalUnit::new(1.0);
+        assert_eq!(log_unit.to_physical::<u32>(1.0), PhysicalUnit::new(1));
+        assert_eq!(log_unit.to_physical::<u32>(2.0), PhysicalUnit::new(2));
+        assert_eq!(log_unit.cast::<u32>(), LogicalUnit::new(1));
+        assert_eq!(
+            log_unit,
+            LogicalUnit::from_physical(PhysicalUnit::new(1.0), 1.0)
+        );
+        assert_eq!(
+            log_unit,
+            LogicalUnit::from_physical(PhysicalUnit::new(2.0), 2.0)
+        );
+        assert_eq!(LogicalUnit::from(2.0), LogicalUnit::new(2.0));
+
+        let x: f64 = log_unit.into();
+        assert_eq!(x, 1.0);
+    }
+
+    #[test]
+    fn test_physical_unit() {
+        assert_eq!(
+            PhysicalUnit::from_logical(LogicalUnit::new(1.0), 1.0),
+            PhysicalUnit::new(1)
+        );
+        assert_eq!(
+            PhysicalUnit::from_logical(LogicalUnit::new(2.0), 0.5),
+            PhysicalUnit::new(1)
+        );
+        assert_eq!(PhysicalUnit::from(2.0), PhysicalUnit::new(2.0,));
+        assert_eq!(PhysicalUnit::from(2.0), PhysicalUnit::new(2.0));
+
+        let x: f64 = PhysicalUnit::new(1).into();
+        assert_eq!(x, 1.0);
+    }
+
     #[test]
     fn test_logical_position() {
         let log_pos = LogicalPosition::new(1.0, 2.0);

examples/control_flow.rs

@@ -3,29 +3,30 @@
 use std::thread;
 #[cfg(not(web_platform))]
 use std::time;
+
 #[cfg(web_platform)]
 use web_time as time;
 
-use winit::{
+use winit::application::ApplicationHandler;
-    event::{ElementState, Event, KeyEvent, WindowEvent},
+use winit::event::{ElementState, KeyEvent, StartCause, WindowEvent};
-    event_loop::{ControlFlow, EventLoop},
+use winit::event_loop::{ActiveEventLoop, ControlFlow, EventLoop};
-    keyboard::{Key, NamedKey},
+use winit::keyboard::{Key, NamedKey};
-    window::Window,
+use winit::window::{Window, WindowId};
-};
 
 #[path = "util/fill.rs"]
 mod fill;
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+const WAIT_TIME: time::Duration = time::Duration::from_millis(100);
+const POLL_SLEEP_TIME: time::Duration = time::Duration::from_millis(100);
+
+#[derive(Default, Debug, Clone, Copy, PartialEq, Eq)]
 enum Mode {
+    #[default]
     Wait,
     WaitUntil,
     Poll,
 }
 
-const WAIT_TIME: time::Duration = time::Duration::from_millis(100);
-const POLL_SLEEP_TIME: time::Duration = time::Duration::from_millis(100);
-
 fn main() -> Result<(), impl std::error::Error> {
     tracing_subscriber::fmt::init();
 
@@ -37,96 +38,110 @@ fn main() -> Result<(), impl std::error::Error> {
 
     let event_loop = EventLoop::new().unwrap();
 
-    let mut mode = Mode::Wait;
+    let mut app = ControlFlowDemo::default();
-    let mut request_redraw = false;
+    event_loop.run_app(&mut app)
-    let mut wait_cancelled = false;
+}
-    let mut close_requested = false;
 
-    let mut window = None;
+#[derive(Default)]
-    event_loop.run(move |event, event_loop| {
+struct ControlFlowDemo {
-        use winit::event::StartCause;
+    mode: Mode,
+    request_redraw: bool,
+    wait_cancelled: bool,
+    close_requested: bool,
+    window: Option<Window>,
+}
+
+impl ApplicationHandler for ControlFlowDemo {
+    fn new_events(&mut self, _event_loop: &ActiveEventLoop, cause: StartCause) {
+        println!("new_events: {cause:?}");
+
+        self.wait_cancelled = match cause {
+            StartCause::WaitCancelled { .. } => self.mode == Mode::WaitUntil,
+            _ => false,
+        }
+    }
+
+    fn resumed(&mut self, event_loop: &ActiveEventLoop) {
+        let window_attributes = Window::default_attributes().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: &ActiveEventLoop,
+        _window_id: WindowId,
+        event: WindowEvent,
+    ) {
         println!("{event:?}");
+
         match event {
-            Event::NewEvents(start_cause) => {
+            WindowEvent::CloseRequested => {
-                wait_cancelled = match start_cause {
+                self.close_requested = true;
-                    StartCause::WaitCancelled { .. } => mode == Mode::WaitUntil,
-                    _ => false,
-                }
             }
-            Event::Resumed => {
+            WindowEvent::KeyboardInput {
-                let window_attributes = Window::default_attributes().with_title(
+                event:
-                    "Press 1, 2, 3 to change control flow mode. Press R to toggle redraw requests.",
+                    KeyEvent {
-                );
+                        logical_key: key,
-                window = Some(event_loop.create_window(window_attributes).unwrap());
+                        state: ElementState::Pressed,
-            }
+                        ..
-            Event::WindowEvent { event, .. } => match event {
+                    },
-                WindowEvent::CloseRequested => {
+                ..
-                    close_requested = true;
+            } => match key.as_ref() {
+                // WARNING: Consider using `key_without_modifiers()` if available on your platform.
+                // See the `key_binding` example
+                Key::Character("1") => {
+                    self.mode = Mode::Wait;
+                    println!("\nmode: {:?}\n", self.mode);
                 }
-                WindowEvent::KeyboardInput {
+                Key::Character("2") => {
-                    event:
+                    self.mode = Mode::WaitUntil;
-                        KeyEvent {
+                    println!("\nmode: {:?}\n", self.mode);
-                            logical_key: key,
+                }
-                            state: ElementState::Pressed,
+                Key::Character("3") => {
-                            ..
+                    self.mode = Mode::Poll;
-                        },
+                    println!("\nmode: {:?}\n", self.mode);
-                    ..
+                }
-                } => match key.as_ref() {
+                Key::Character("r") => {
-                    // WARNING: Consider using `key_without_modifiers()` if available on your platform.
+                    self.request_redraw = !self.request_redraw;
-                    // See the `key_binding` example
+                    println!("\nrequest_redraw: {}\n", self.request_redraw);
-                    Key::Character("1") => {
+                }
-                        mode = Mode::Wait;
+                Key::Named(NamedKey::Escape) => {
-                        println!("\nmode: {mode:?}\n");
+                    self.close_requested = true;
-                    }
-                    Key::Character("2") => {
-                        mode = Mode::WaitUntil;
-                        println!("\nmode: {mode:?}\n");
-                    }
-                    Key::Character("3") => {
-                        mode = Mode::Poll;
-                        println!("\nmode: {mode:?}\n");
-                    }
-                    Key::Character("r") => {
-                        request_redraw = !request_redraw;
-                        println!("\nrequest_redraw: {request_redraw}\n");
-                    }
-                    Key::Named(NamedKey::Escape) => {
-                        close_requested = true;
-                    }
-                    _ => (),
-                },
-                WindowEvent::RedrawRequested => {
-                    let window = window.as_ref().unwrap();
-                    window.pre_present_notify();
-                    fill::fill_window(window);
                 }
                 _ => (),
             },
-            Event::AboutToWait => {
+            WindowEvent::RedrawRequested => {
-                if request_redraw && !wait_cancelled && !close_requested {
+                let window = self.window.as_ref().unwrap();
-                    window.as_ref().unwrap().request_redraw();
+                window.pre_present_notify();
-                }
+                fill::fill_window(window);
-
-                match mode {
-                    Mode::Wait => event_loop.set_control_flow(ControlFlow::Wait),
-                    Mode::WaitUntil => {
-                        if !wait_cancelled {
-                            event_loop.set_control_flow(ControlFlow::WaitUntil(
-                                time::Instant::now() + WAIT_TIME,
-                            ));
-                        }
-                    }
-                    Mode::Poll => {
-                        thread::sleep(POLL_SLEEP_TIME);
-                        event_loop.set_control_flow(ControlFlow::Poll);
-                    }
-                };
-
-                if close_requested {
-                    event_loop.exit();
-                }
             }
             _ => (),
         }
-    })
+    }
+
+    fn about_to_wait(&mut self, event_loop: &ActiveEventLoop) {
+        if self.request_redraw && !self.wait_cancelled && !self.close_requested {
+            self.window.as_ref().unwrap().request_redraw();
+        }
+
+        match self.mode {
+            Mode::Wait => event_loop.set_control_flow(ControlFlow::Wait),
+            Mode::WaitUntil => {
+                if !self.wait_cancelled {
+                    event_loop
+                        .set_control_flow(ControlFlow::WaitUntil(time::Instant::now() + WAIT_TIME));
+                }
+            }
+            Mode::Poll => {
+                thread::sleep(POLL_SLEEP_TIME);
+                event_loop.set_control_flow(ControlFlow::Poll);
+            }
+        };
+
+        if self.close_requested {
+            event_loop.exit();
+        }
+    }
 }

examples/pump_events.rs

@@ -11,50 +11,59 @@
 fn main() -> std::process::ExitCode {
     use std::{process::ExitCode, thread::sleep, time::Duration};
 
-    use winit::{
+    use winit::application::ApplicationHandler;
-        event::{Event, WindowEvent},
+    use winit::event::WindowEvent;
-        event_loop::EventLoop,
+    use winit::event_loop::{ActiveEventLoop, EventLoop};
-        platform::pump_events::{EventLoopExtPumpEvents, PumpStatus},
+    use winit::platform::pump_events::{EventLoopExtPumpEvents, PumpStatus};
-        window::Window,
+    use winit::window::{Window, WindowId};
-    };
 
     #[path = "util/fill.rs"]
     mod fill;
 
+    #[derive(Default)]
+    struct PumpDemo {
+        window: Option<Window>,
+    }
+
+    impl ApplicationHandler for PumpDemo {
+        fn resumed(&mut self, event_loop: &ActiveEventLoop) {
+            let window_attributes = Window::default_attributes().with_title("A fantastic window!");
+            self.window = Some(event_loop.create_window(window_attributes).unwrap());
+        }
+
+        fn window_event(
+            &mut self,
+            event_loop: &ActiveEventLoop,
+            _window_id: WindowId,
+            event: WindowEvent,
+        ) {
+            println!("{event:?}");
+
+            let window = match self.window.as_ref() {
+                Some(window) => window,
+                None => return,
+            };
+
+            match event {
+                WindowEvent::CloseRequested => event_loop.exit(),
+                WindowEvent::RedrawRequested => {
+                    fill::fill_window(window);
+                    window.request_redraw();
+                }
+                _ => (),
+            }
+        }
+    }
+
     let mut event_loop = EventLoop::new().unwrap();
 
     tracing_subscriber::fmt::init();
 
-    let mut window = None;
+    let mut app = PumpDemo::default();
 
     loop {
         let timeout = Some(Duration::ZERO);
-        let status = event_loop.pump_events(timeout, |event, event_loop| {
+        let status = event_loop.pump_app_events(timeout, &mut app);
-            if let Event::WindowEvent { event, .. } = &event {
-                // Print only Window events to reduce noise
-                println!("{event:?}");
-            }
-
-            match event {
-                Event::Resumed => {
-                    let window_attributes =
-                        Window::default_attributes().with_title("A fantastic window!");
-                    window = Some(event_loop.create_window(window_attributes).unwrap());
-                }
-                Event::WindowEvent { event, .. } => {
-                    let window = window.as_ref().unwrap();
-                    match event {
-                        WindowEvent::CloseRequested => event_loop.exit(),
-                        WindowEvent::RedrawRequested => fill::fill_window(window),
-                        _ => (),
-                    }
-                }
-                Event::AboutToWait => {
-                    window.as_ref().unwrap().request_redraw();
-                }
-                _ => (),
-            }
-        });
 
         if let PumpStatus::Exit(exit_code) = status {
             break ExitCode::from(exit_code as u8);

examples/run_on_demand.rs

@@ -2,86 +2,94 @@
 
 // Limit this example to only compatible platforms.
 #[cfg(any(windows_platform, macos_platform, x11_platform, wayland_platform,))]
-fn main() -> Result<(), impl std::error::Error> {
+fn main() -> Result<(), Box<dyn std::error::Error>> {
     use std::time::Duration;
 
-    use winit::{
+    use winit::application::ApplicationHandler;
-        error::EventLoopError,
+    use winit::event::WindowEvent;
-        event::{Event, WindowEvent},
+    use winit::event_loop::{ActiveEventLoop, EventLoop};
-        event_loop::EventLoop,
+    use winit::platform::run_on_demand::EventLoopExtRunOnDemand;
-        platform::run_on_demand::EventLoopExtRunOnDemand,
+    use winit::window::{Window, WindowId};
-        window::{Window, WindowId},
-    };
 
     #[path = "util/fill.rs"]
     mod fill;
 
     #[derive(Default)]
     struct App {
+        idx: usize,
         window_id: Option<WindowId>,
         window: Option<Window>,
     }
 
-    tracing_subscriber::fmt::init();
+    impl ApplicationHandler for App {
-    let mut event_loop = EventLoop::new().unwrap();
+        fn about_to_wait(&mut self, _event_loop: &ActiveEventLoop) {
-
+            if let Some(window) = self.window.as_ref() {
-    fn run_app(event_loop: &mut EventLoop<()>, idx: usize) -> Result<(), EventLoopError> {
+                window.request_redraw();
-        let mut app = App::default();
-
-        event_loop.run_on_demand(move |event, event_loop| {
-            println!("Run {idx}: {:?}", event);
-
-            if let Some(window) = &app.window {
-                match event {
-                    Event::WindowEvent {
-                        event: WindowEvent::CloseRequested,
-                        window_id,
-                    } if window.id() == window_id => {
-                        println!("--------------------------------------------------------- Window {idx} CloseRequested");
-                        fill::cleanup_window(window);
-                        app.window = None;
-                    }
-                    Event::AboutToWait => window.request_redraw(),
-                    Event::WindowEvent {
-                        event: WindowEvent::RedrawRequested,
-                        ..
-                    }  => {
-                        fill::fill_window(window);
-                    }
-                    _ => (),
-                }
-            } else if let Some(id) = app.window_id {
-                match event {
-                    Event::WindowEvent {
-                        event: WindowEvent::Destroyed,
-                        window_id,
-                    } if id == window_id => {
-                        println!("--------------------------------------------------------- Window {idx} Destroyed");
-                        app.window_id = None;
-                        event_loop.exit();
-                    }
-                    _ => (),
-                }
-            } else if let Event::Resumed = event {
-                let window_attributes = Window::default_attributes()
-                        .with_title("Fantastic window number one!")
-                        .with_inner_size(winit::dpi::LogicalSize::new(128.0, 128.0));
-                let window = event_loop.create_window(window_attributes).unwrap();
-                app.window_id = Some(window.id());
-                app.window = Some(window);
             }
-        })
+        }
+
+        fn resumed(&mut self, event_loop: &ActiveEventLoop) {
+            let window_attributes = Window::default_attributes()
+                .with_title("Fantastic window number one!")
+                .with_inner_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: &ActiveEventLoop,
+            window_id: WindowId,
+            event: WindowEvent,
+        ) {
+            if event == WindowEvent::Destroyed && self.window_id == Some(window_id) {
+                println!(
+                    "--------------------------------------------------------- Window {} Destroyed",
+                    self.idx
+                );
+                self.window_id = None;
+                event_loop.exit();
+                return;
+            }
+
+            let window = match self.window.as_mut() {
+                Some(window) => window,
+                None => return,
+            };
+
+            match event {
+                WindowEvent::CloseRequested => {
+                    println!("--------------------------------------------------------- Window {} CloseRequested", self.idx);
+                    fill::cleanup_window(window);
+                    self.window = None;
+                }
+                WindowEvent::RedrawRequested => {
+                    fill::fill_window(window);
+                }
+                _ => (),
+            }
+        }
     }
 
-    run_app(&mut event_loop, 1)?;
+    tracing_subscriber::fmt::init();
+
+    let mut event_loop = EventLoop::new().unwrap();
+
+    let mut app = App {
+        idx: 1,
+        ..Default::default()
+    };
+    event_loop.run_app_on_demand(&mut app)?;
 
     println!("--------------------------------------------------------- Finished first loop");
     println!("--------------------------------------------------------- Waiting 5 seconds");
     std::thread::sleep(Duration::from_secs(5));
 
-    let ret = run_app(&mut event_loop, 2);
+    app.idx += 1;
+    event_loop.run_app_on_demand(&mut app)?;
     println!("--------------------------------------------------------- Finished second loop");
-    ret
+    Ok(())
 }
 
 #[cfg(not(any(windows_platform, macos_platform, x11_platform, wayland_platform,)))]

examples/window.rs

@@ -14,8 +14,9 @@ use rwh_05::HasRawDisplayHandle;
 #[cfg(not(any(android_platform, ios_platform)))]
 use softbuffer::{Context, Surface};
 
+use winit::application::ApplicationHandler;
 use winit::dpi::{LogicalSize, PhysicalPosition, PhysicalSize};
-use winit::event::{DeviceEvent, DeviceId, Event, Ime, WindowEvent};
+use winit::event::{DeviceEvent, DeviceId, Ime, WindowEvent};
 use winit::event::{MouseButton, MouseScrollDelta};
 use winit::event_loop::{ActiveEventLoop, EventLoop};
 use winit::keyboard::{Key, ModifiersState};
@@ -53,38 +54,7 @@ fn main() -> Result<(), Box<dyn Error>> {
 
     let mut state = Application::new(&event_loop);
 
-    event_loop.run(move |event, event_loop| match event {
+    event_loop.run_app(&mut state).map_err(Into::into)
-        Event::NewEvents(_) => (),
-        Event::Resumed => {
-            println!("Resumed the event loop");
-            state.dump_monitors(event_loop);
-
-            // Create initial window.
-            state
-                .create_window(event_loop, None)
-                .expect("failed to create initial window");
-
-            state.print_help();
-        }
-        Event::AboutToWait => {
-            if state.windows.is_empty() {
-                println!("No windows left, exiting...");
-                event_loop.exit();
-            }
-        }
-        Event::WindowEvent { window_id, event } => {
-            state.handle_window_event(event_loop, window_id, event)
-        }
-        Event::DeviceEvent { device_id, event } => {
-            state.handle_device_event(event_loop, device_id, event)
-        }
-        Event::UserEvent(event) => {
-            println!("User event: {event:?}");
-        }
-        Event::Suspended | Event::LoopExiting | Event::MemoryWarning => (),
-    })?;
-
-    Ok(())
 }
 
 #[allow(dead_code)]
@@ -104,15 +74,14 @@ struct Application {
     ///
     /// With OpenGL it could be EGLDisplay.
     #[cfg(not(any(android_platform, ios_platform)))]
-    context: Context,
+    context: Option<Context>,
 }
 
 impl Application {
     fn new<T>(event_loop: &EventLoop<T>) -> Self {
-        // SAFETY: the context is dropped inside the loop, since the state we're using
+        // SAFETY: we drop the context right before the event loop is stopped, thus making it safe.
-        // is moved inside the closure.
         #[cfg(not(any(android_platform, ios_platform)))]
-        let context = unsafe { Context::from_raw(event_loop.raw_display_handle()).unwrap() };
+        let context = Some(unsafe { Context::from_raw(event_loop.raw_display_handle()).unwrap() });
 
         // You'll have to choose an icon size at your own discretion. On X11, the desired size varies
         // by WM, and on Windows, you still have to account for screen scaling. Here we use 32px,
@@ -227,7 +196,97 @@ impl Application {
         }
     }
 
-    fn handle_window_event(
+    fn dump_monitors(&self, event_loop: &ActiveEventLoop) {
+        println!("Monitors information");
+        let primary_monitor = event_loop.primary_monitor();
+        for monitor in event_loop.available_monitors() {
+            let intro = if primary_monitor.as_ref() == Some(&monitor) {
+                "Primary monitor"
+            } else {
+                "Monitor"
+            };
+
+            if let Some(name) = monitor.name() {
+                println!("{intro}: {name}");
+            } else {
+                println!("{intro}: [no name]");
+            }
+
+            let PhysicalSize { width, height } = monitor.size();
+            print!("  Current mode: {width}x{height}");
+            if let Some(m_hz) = monitor.refresh_rate_millihertz() {
+                println!(" @ {}.{} Hz", m_hz / 1000, m_hz % 1000);
+            } else {
+                println!();
+            }
+
+            let PhysicalPosition { x, y } = monitor.position();
+            println!("  Position: {x},{y}");
+
+            println!("  Scale factor: {}", monitor.scale_factor());
+
+            println!("  Available modes (width x height x bit-depth):");
+            for mode in monitor.video_modes() {
+                let PhysicalSize { width, height } = mode.size();
+                let bits = mode.bit_depth();
+                let m_hz = mode.refresh_rate_millihertz();
+                println!(
+                    "    {width}x{height}x{bits} @ {}.{} Hz",
+                    m_hz / 1000,
+                    m_hz % 1000
+                );
+            }
+        }
+    }
+
+    /// Process the key binding.
+    fn process_key_binding(key: &str, mods: &ModifiersState) -> Option<Action> {
+        KEY_BINDINGS.iter().find_map(|binding| {
+            binding
+                .is_triggered_by(&key, mods)
+                .then_some(binding.action)
+        })
+    }
+
+    /// Process mouse binding.
+    fn process_mouse_binding(button: MouseButton, mods: &ModifiersState) -> Option<Action> {
+        MOUSE_BINDINGS.iter().find_map(|binding| {
+            binding
+                .is_triggered_by(&button, mods)
+                .then_some(binding.action)
+        })
+    }
+
+    fn print_help(&self) {
+        println!("Keyboard bindings:");
+        for binding in KEY_BINDINGS {
+            println!(
+                "{}{:<10} - {} ({})",
+                modifiers_to_string(binding.mods),
+                binding.trigger,
+                binding.action,
+                binding.action.help(),
+            );
+        }
+        println!("Mouse bindings:");
+        for binding in MOUSE_BINDINGS {
+            println!(
+                "{}{:<10} - {} ({})",
+                modifiers_to_string(binding.mods),
+                mouse_button_to_string(binding.trigger),
+                binding.action,
+                binding.action.help(),
+            );
+        }
+    }
+}
+
+impl ApplicationHandler<UserEvent> for Application {
+    fn user_event(&mut self, _event_loop: &ActiveEventLoop, event: UserEvent) {
+        println!("User event: {event:?}");
+    }
+
+    fn window_event(
         &mut self,
         event_loop: &ActiveEventLoop,
         window_id: WindowId,
@@ -333,7 +392,7 @@ impl Application {
                     println!("Preedit: {}, with caret at {:?}", text, caret_pos);
                 }
                 Ime::Commit(text) => {
-                    println!("Commited: {}", text);
+                    println!("Committed: {}", text);
                 }
                 Ime::Disabled => println!("IME disabled for Window={window_id:?}"),
             },
@@ -371,92 +430,37 @@ impl Application {
         }
     }
 
-    fn handle_device_event(&mut self, _: &ActiveEventLoop, _: DeviceId, event: DeviceEvent) {
+    fn device_event(
-        println!("Device event: {event:?}");
+        &mut self,
+        _event_loop: &ActiveEventLoop,
+        device_id: DeviceId,
+        event: DeviceEvent,
+    ) {
+        println!("Device {device_id:?} event: {event:?}");
     }
 
-    fn dump_monitors(&self, event_loop: &ActiveEventLoop) {
+    fn resumed(&mut self, event_loop: &ActiveEventLoop) {
-        println!("Monitors information");
+        println!("Resumed the event loop");
-        let primary_monitor = event_loop.primary_monitor();
+        self.dump_monitors(event_loop);
-        for monitor in event_loop.available_monitors() {
-            let intro = if primary_monitor.as_ref() == Some(&monitor) {
-                "Primary monitor"
-            } else {
-                "Monitor"
-            };
 
-            if let Some(name) = monitor.name() {
+        // Create initial window.
-                println!("{intro}: {name}");
+        self.create_window(event_loop, None)
-            } else {
+            .expect("failed to create initial window");
-                println!("{intro}: [no name]");
-            }
 
-            let PhysicalSize { width, height } = monitor.size();
+        self.print_help();
-            print!("  Current mode: {width}x{height}");
+    }
-            if let Some(m_hz) = monitor.refresh_rate_millihertz() {
-                println!(" @ {}.{} Hz", m_hz / 1000, m_hz % 1000);
-            } else {
-                println!();
-            }
 
-            let PhysicalPosition { x, y } = monitor.position();
+    fn about_to_wait(&mut self, event_loop: &ActiveEventLoop) {
-            println!("  Position: {x},{y}");
+        if self.windows.is_empty() {
-
+            println!("No windows left, exiting...");
-            println!("  Scale factor: {}", monitor.scale_factor());
+            event_loop.exit();
-
-            println!("  Available modes (width x height x bit-depth):");
-            for mode in monitor.video_modes() {
-                let PhysicalSize { width, height } = mode.size();
-                let bits = mode.bit_depth();
-                let m_hz = mode.refresh_rate_millihertz();
-                println!(
-                    "    {width}x{height}x{bits} @ {}.{} Hz",
-                    m_hz / 1000,
-                    m_hz % 1000
-                );
-            }
         }
     }
 
-    /// Process the key binding.
+    #[cfg(not(any(android_platform, ios_platform)))]
-    fn process_key_binding(key: &str, mods: &ModifiersState) -> Option<Action> {
+    fn exiting(&mut self, _event_loop: &ActiveEventLoop) {
-        KEY_BINDINGS.iter().find_map(|binding| {
+        // We must drop the context here.
-            binding
+        self.context = None;
-                .is_triggered_by(&key, mods)
-                .then_some(binding.action)
-        })
-    }
-
-    /// Process mouse binding.
-    fn process_mouse_binding(button: MouseButton, mods: &ModifiersState) -> Option<Action> {
-        MOUSE_BINDINGS.iter().find_map(|binding| {
-            binding
-                .is_triggered_by(&button, mods)
-                .then_some(binding.action)
-        })
-    }
-
-    fn print_help(&self) {
-        println!("Keyboard bindings:");
-        for binding in KEY_BINDINGS {
-            println!(
-                "{}{:<10} - {} ({})",
-                modifiers_to_string(binding.mods),
-                binding.trigger,
-                binding.action,
-                binding.action.help(),
-            );
-        }
-        println!("Mouse bindings:");
-        for binding in MOUSE_BINDINGS {
-            println!(
-                "{}{:<10} - {} ({})",
-                modifiers_to_string(binding.mods),
-                mouse_button_to_string(binding.trigger),
-                binding.action,
-                binding.action.help(),
-            );
-        }
     }
 }
 
@@ -496,11 +500,11 @@ struct WindowState {
 }
 
 impl WindowState {
-    fn new(application: &Application, window: Window) -> Result<Self, Box<dyn Error>> {
+    fn new(app: &Application, window: Window) -> Result<Self, Box<dyn Error>> {
         // SAFETY: the surface is dropped before the `window` which provided it with handle, thus
         // it doesn't outlive it.
         #[cfg(not(any(android_platform, ios_platform)))]
-        let surface = unsafe { Surface::new(&application.context, &window)? };
+        let surface = unsafe { Surface::new(app.context.as_ref().unwrap(), &window)? };
 
         let theme = window.theme().unwrap_or(Theme::Dark);
         println!("Theme: {theme:?}");
@@ -515,7 +519,7 @@ impl WindowState {
         let mut state = Self {
             #[cfg(macos_platform)]
             option_as_alt: window.option_as_alt(),
-            custom_idx: application.custom_cursors.len() - 1,
+            custom_idx: app.custom_cursors.len() - 1,
             cursor_grab: CursorGrabMode::None,
             named_idx,
             #[cfg(not(any(android_platform, ios_platform)))]

examples/x11_embed.rs

@@ -3,16 +3,52 @@ use std::error::Error;
 
 #[cfg(x11_platform)]
 fn main() -> Result<(), Box<dyn Error>> {
-    use winit::{
+    use winit::application::ApplicationHandler;
-        event::{Event, WindowEvent},
+    use winit::event::WindowEvent;
-        event_loop::EventLoop,
+    use winit::event_loop::{ActiveEventLoop, EventLoop};
-        platform::x11::WindowAttributesExtX11,
+    use winit::platform::x11::WindowAttributesExtX11;
-        window::Window,
+    use winit::window::{Window, WindowId};
-    };
 
     #[path = "util/fill.rs"]
     mod fill;
 
+    pub struct XEmbedDemo {
+        parent_window_id: u32,
+        window: Option<Window>,
+    }
+
+    impl ApplicationHandler for XEmbedDemo {
+        fn resumed(&mut self, event_loop: &ActiveEventLoop) {
+            let window_attributes = Window::default_attributes()
+                .with_title("An embedded window!")
+                .with_inner_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: &ActiveEventLoop,
+            _window_id: WindowId,
+            event: WindowEvent,
+        ) {
+            let window = self.window.as_ref().unwrap();
+            match event {
+                WindowEvent::CloseRequested => event_loop.exit(),
+                WindowEvent::RedrawRequested => {
+                    window.pre_present_notify();
+                    fill::fill_window(window);
+                }
+                _ => (),
+            }
+        }
+
+        fn about_to_wait(&mut self, _event_loop: &ActiveEventLoop) {
+            self.window.as_ref().unwrap().request_redraw();
+        }
+    }
+
     // First argument should be a 32-bit X11 window ID.
     let parent_window_id = std::env::args()
         .nth(1)
@@ -22,35 +58,11 @@ fn main() -> Result<(), Box<dyn Error>> {
     tracing_subscriber::fmt::init();
     let event_loop = EventLoop::new()?;
 
-    let mut window = None;
+    let mut app = XEmbedDemo {
-    event_loop.run(move |event, event_loop| match event {
+        parent_window_id,
-        Event::Resumed => {
+        window: None,
-            let window_attributes = Window::default_attributes()
+    };
-                .with_title("An embedded window!")
+    event_loop.run_app(&mut app).map_err(Into::into)
-                .with_inner_size(winit::dpi::LogicalSize::new(128.0, 128.0))
-                .with_embed_parent_window(parent_window_id);
-
-            window = Some(event_loop.create_window(window_attributes).unwrap());
-        }
-        Event::WindowEvent { event, .. } => {
-            let window = window.as_ref().unwrap();
-
-            match event {
-                WindowEvent::CloseRequested => event_loop.exit(),
-                WindowEvent::RedrawRequested => {
-                    window.pre_present_notify();
-                    fill::fill_window(window);
-                }
-                _ => (),
-            }
-        }
-        Event::AboutToWait => {
-            window.as_ref().unwrap().request_redraw();
-        }
-        _ => (),
-    })?;
-
-    Ok(())
 }
 
 #[cfg(not(x11_platform))]

src/application.rs

@@ -0,0 +1,221 @@
+//! End user application handling.
+
+use crate::event::{DeviceEvent, DeviceId, StartCause, WindowEvent};
+use crate::event_loop::ActiveEventLoop;
+use crate::window::WindowId;
+
+/// The handler of the application events.
+pub trait ApplicationHandler<T: 'static = ()> {
+    /// Emitted when new events arrive from the OS to be processed.
+    ///
+    /// This is a useful place to put code that should be done before you start processing
+    /// events, such as updating frame timing information for benchmarking or checking the
+    /// [`StartCause`] to see if a timer set by
+    /// [`ControlFlow::WaitUntil`](crate::event_loop::ControlFlow::WaitUntil) has elapsed.
+    fn new_events(&mut self, event_loop: &ActiveEventLoop, cause: StartCause) {
+        let _ = (event_loop, cause);
+    }
+
+    /// Emitted when the application has been resumed.
+    ///
+    /// For consistency, all platforms emit a `Resumed` event even if they don't themselves have a
+    /// formal suspend/resume lifecycle. For systems without a formal suspend/resume lifecycle
+    /// the `Resumed` event is always emitted after the [`NewEvents(StartCause::Init)`][StartCause::Init]
+    /// event.
+    ///
+    /// # Portability
+    ///
+    /// It's recommended that applications should only initialize their graphics context and create
+    /// a window after they have received their first `Resumed` event. Some systems
+    /// (specifically Android) won't allow applications to create a render surface until they are
+    /// resumed.
+    ///
+    /// Considering that the implementation of [`Suspended`] and `Resumed` events may be internally
+    /// driven by multiple platform-specific events, and that there may be subtle differences across
+    /// platforms with how these internal events are delivered, it's recommended that applications
+    /// be able to gracefully handle redundant (i.e. back-to-back) [`Suspended`] or `Resumed` events.
+    ///
+    /// Also see [`Suspended`] notes.
+    ///
+    /// ## Android
+    ///
+    /// On Android, the `Resumed` event is sent when a new [`SurfaceView`] has been created. This is
+    /// expected to closely correlate with the [`onResume`] lifecycle event but there may technically
+    /// be a discrepancy.
+    ///
+    /// [`onResume`]: https://developer.android.com/reference/android/app/Activity#onResume()
+    ///
+    /// Applications that need to run on Android must wait until they have been `Resumed`
+    /// before they will be able to create a render surface (such as an `EGLSurface`,
+    /// [`VkSurfaceKHR`] or [`wgpu::Surface`]) which depend on having a
+    /// [`SurfaceView`]. Applications must also assume that if they are [`Suspended`], then their
+    /// render surfaces are invalid and should be dropped.
+    ///
+    /// Also see [`Suspended`] notes.
+    ///
+    /// [`SurfaceView`]: https://developer.android.com/reference/android/view/SurfaceView
+    /// [Activity lifecycle]: https://developer.android.com/guide/components/activities/activity-lifecycle
+    /// [`VkSurfaceKHR`]: https://www.khronos.org/registry/vulkan/specs/1.3-extensions/man/html/VkSurfaceKHR.html
+    /// [`wgpu::Surface`]: https://docs.rs/wgpu/latest/wgpu/struct.Surface.html
+    ///
+    /// ## iOS
+    ///
+    /// On iOS, the `Resumed` event is emitted in response to an [`applicationDidBecomeActive`]
+    /// callback which means the application is "active" (according to the
+    /// [iOS application lifecycle]).
+    ///
+    /// [`applicationDidBecomeActive`]: https://developer.apple.com/documentation/uikit/uiapplicationdelegate/1622956-applicationdidbecomeactive
+    /// [iOS application lifecycle]: https://developer.apple.com/documentation/uikit/app_and_environment/managing_your_app_s_life_cycle
+    ///
+    /// ## Web
+    ///
+    /// On Web, the `Resumed` event is emitted in response to a [`pageshow`] event
+    /// with the property [`persisted`] being true, which means that the page is being
+    /// restored from the [`bfcache`] (back/forward cache) - an in-memory cache that
+    /// stores a complete snapshot of a page (including the JavaScript heap) as the
+    /// user is navigating away.
+    ///
+    /// [`pageshow`]: https://developer.mozilla.org/en-US/docs/Web/API/Window/pageshow_event
+    /// [`persisted`]: https://developer.mozilla.org/en-US/docs/Web/API/PageTransitionEvent/persisted
+    /// [`bfcache`]: https://web.dev/bfcache/
+    /// [`Suspended`]: Self::suspended
+    fn resumed(&mut self, event_loop: &ActiveEventLoop);
+
+    /// Emitted when an event is sent from [`EventLoopProxy::send_event`].
+    ///
+    /// [`EventLoopProxy::send_event`]: crate::event_loop::EventLoopProxy::send_event
+    fn user_event(&mut self, event_loop: &ActiveEventLoop, event: T) {
+        let _ = (event_loop, event);
+    }
+
+    /// Emitted when the OS sends an event to a winit window.
+    fn window_event(
+        &mut self,
+        event_loop: &ActiveEventLoop,
+        window_id: WindowId,
+        event: WindowEvent,
+    );
+
+    /// Emitted when the OS sends an event to a device.
+    fn device_event(
+        &mut self,
+        event_loop: &ActiveEventLoop,
+        device_id: DeviceId,
+        event: DeviceEvent,
+    ) {
+        let _ = (event_loop, device_id, event);
+    }
+
+    /// Emitted when the event loop is about to block and wait for new events.
+    ///
+    /// Most applications shouldn't need to hook into this event since there is no real relationship
+    /// between how often the event loop needs to wake up and the dispatching of any specific events.
+    ///
+    /// High frequency event sources, such as input devices could potentially lead to lots of wake
+    /// ups and also lots of corresponding `AboutToWait` events.
+    ///
+    /// This is not an ideal event to drive application rendering from and instead applications
+    /// should render in response to [`WindowEvent::RedrawRequested`] events.
+    fn about_to_wait(&mut self, event_loop: &ActiveEventLoop) {
+        let _ = event_loop;
+    }
+
+    /// Emitted when the application has been suspended.
+    ///
+    /// # Portability
+    ///
+    /// Not all platforms support the notion of suspending applications, and there may be no
+    /// technical way to guarantee being able to emit a `Suspended` event if the OS has
+    /// no formal application lifecycle (currently only Android, iOS, and Web do). For this reason,
+    /// Winit does not currently try to emit pseudo `Suspended` events before the application
+    /// quits on platforms without an application lifecycle.
+    ///
+    /// Considering that the implementation of `Suspended` and [`Resumed`] events may be internally
+    /// driven by multiple platform-specific events, and that there may be subtle differences across
+    /// platforms with how these internal events are delivered, it's recommended that applications
+    /// be able to gracefully handle redundant (i.e. back-to-back) `Suspended` or [`Resumed`] events.
+    ///
+    /// Also see [`Resumed`] notes.
+    ///
+    /// ## Android
+    ///
+    /// On Android, the `Suspended` event is only sent when the application's associated
+    /// [`SurfaceView`] is destroyed. This is expected to closely correlate with the [`onPause`]
+    /// lifecycle event but there may technically be a discrepancy.
+    ///
+    /// [`onPause`]: https://developer.android.com/reference/android/app/Activity#onPause()
+    ///
+    /// Applications that need to run on Android should assume their [`SurfaceView`] 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`]).
+    ///
+    /// After being `Suspended` on Android applications must drop all render surfaces before
+    /// the event callback completes, which may be re-created when the application is next [`Resumed`].
+    ///
+    /// [`SurfaceView`]: https://developer.android.com/reference/android/view/SurfaceView
+    /// [Activity lifecycle]: https://developer.android.com/guide/components/activities/activity-lifecycle
+    /// [`VkSurfaceKHR`]: https://www.khronos.org/registry/vulkan/specs/1.3-extensions/man/html/VkSurfaceKHR.html
+    /// [`wgpu::Surface`]: https://docs.rs/wgpu/latest/wgpu/struct.Surface.html
+    ///
+    /// ## iOS
+    ///
+    /// On iOS, the `Suspended` event is currently emitted in response to an
+    /// [`applicationWillResignActive`] callback which means that the application is
+    /// about to transition from the active to inactive state (according to the
+    /// [iOS application lifecycle]).
+    ///
+    /// [`applicationWillResignActive`]: https://developer.apple.com/documentation/uikit/uiapplicationdelegate/1622950-applicationwillresignactive
+    /// [iOS application lifecycle]: https://developer.apple.com/documentation/uikit/app_and_environment/managing_your_app_s_life_cycle
+    ///
+    /// ## Web
+    ///
+    /// On Web, the `Suspended` event is emitted in response to a [`pagehide`] event
+    /// with the property [`persisted`] being true, which means that the page is being
+    /// put in the [`bfcache`] (back/forward cache) - an in-memory cache that stores a
+    /// complete snapshot of a page (including the JavaScript heap) as the user is
+    /// navigating away.
+    ///
+    /// [`pagehide`]: https://developer.mozilla.org/en-US/docs/Web/API/Window/pagehide_event
+    /// [`persisted`]: https://developer.mozilla.org/en-US/docs/Web/API/PageTransitionEvent/persisted
+    /// [`bfcache`]: https://web.dev/bfcache/
+    /// [`Resumed`]: Self::resumed
+    fn suspended(&mut self, event_loop: &ActiveEventLoop) {
+        let _ = event_loop;
+    }
+
+    /// Emitted when the event loop is being shut down.
+    ///
+    /// This is irreversible - if this method is called, it is guaranteed that the event loop
+    /// will exist right after.
+    fn exiting(&mut self, event_loop: &ActiveEventLoop) {
+        let _ = event_loop;
+    }
+
+    /// Emitted when the application has received a memory warning.
+    ///
+    /// ## Platform-specific
+    ///
+    /// ### Android
+    ///
+    /// On Android, the `MemoryWarning` event is sent when [`onLowMemory`] was called. The application
+    /// must [release memory] or risk being killed.
+    ///
+    /// [`onLowMemory`]: https://developer.android.com/reference/android/app/Application.html#onLowMemory()
+    /// [release memory]: https://developer.android.com/topic/performance/memory#release
+    ///
+    /// ### iOS
+    ///
+    /// On iOS, the `MemoryWarning` event is emitted in response to an [`applicationDidReceiveMemoryWarning`]
+    /// callback. The application must free as much memory as possible or risk being terminated, see
+    /// [how to respond to memory warnings].
+    ///
+    /// [`applicationDidReceiveMemoryWarning`]: https://developer.apple.com/documentation/uikit/uiapplicationdelegate/1623063-applicationdidreceivememorywarni
+    /// [how to respond to memory warnings]: https://developer.apple.com/documentation/uikit/app_and_environment/managing_your_app_s_life_cycle/responding_to_memory_warnings
+    ///
+    /// ### Others
+    ///
+    /// - **macOS / Orbital / Wayland / Web / Windows:** Unsupported.
+    fn memory_warning(&mut self, event_loop: &ActiveEventLoop) {
+        let _ = event_loop;
+    }
+}

src/cursor.rs

@@ -195,6 +195,7 @@ impl OnlyCursorImageSource {
 }
 
 /// 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>);
 

src/event.rs

@@ -1,36 +1,37 @@
 //! The [`Event`] enum and assorted supporting types.
 //!
-//! These are sent to the closure given to [`EventLoop::run(...)`], where they get
+//! These are sent to the closure given to [`EventLoop::run_app(...)`], where they get
 //! processed and used to modify the program state. For more details, see the root-level documentation.
 //!
 //! Some of these events represent different "parts" of a traditional event-handling loop. You could
-//! approximate the basic ordering loop of [`EventLoop::run(...)`] like this:
+//! approximate the basic ordering loop of [`EventLoop::run_app(...)`] like this:
 //!
 //! ```rust,ignore
 //! let mut start_cause = StartCause::Init;
 //!
 //! while !elwt.exiting() {
-//!     event_handler(NewEvents(start_cause), elwt);
+//!     app.new_events(event_loop, start_cause);
 //!
-//!     for e in (window events, user events, device events) {
+//!     for event in (window events, user events, device events) {
-//!         event_handler(e, elwt);
+//!         // This will pick the right method on the application based on the event.
+//!         app.handle_event(event_loop, event);
 //!     }
 //!
-//!     for w in (redraw windows) {
+//!     for window_id in (redraw windows) {
-//!         event_handler(RedrawRequested(w), elwt);
+//!         app.window_event(event_loop, window_id, RedrawRequested);
 //!     }
 //!
-//!     event_handler(AboutToWait, elwt);
+//!     app.about_to_wait(event_loop);
 //!     start_cause = wait_if_necessary();
 //! }
 //!
-//! event_handler(LoopExiting, elwt);
+//! app.exiting(event_loop);
 //! ```
 //!
 //! This leaves out timing details like [`ControlFlow::WaitUntil`] but hopefully
 //! describes what happens in what order.
 //!
-//! [`EventLoop::run(...)`]: crate::event_loop::EventLoop::run
+//! [`EventLoop::run_app(...)`]: crate::event_loop::EventLoop::run_app
 //! [`ControlFlow::WaitUntil`]: crate::event_loop::ControlFlow::WaitUntil
 use std::path::PathBuf;
 use std::sync::{Mutex, Weak};
@@ -59,199 +60,55 @@ use crate::{
 /// See the module-level docs for more information on the event loop manages each event.
 #[derive(Debug, Clone, PartialEq)]
 pub enum Event<T: 'static> {
-    /// Emitted when new events arrive from the OS to be processed.
+    /// See [`ApplicationHandler::new_events`] for details.
     ///
-    /// This event type is useful as a place to put code that should be done before you start
+    /// [`ApplicationHandler::new_events`]: crate::application::ApplicationHandler::new_events
-    /// processing events, such as updating frame timing information for benchmarking or checking
-    /// the [`StartCause`] to see if a timer set by
-    /// [`ControlFlow::WaitUntil`](crate::event_loop::ControlFlow::WaitUntil) has elapsed.
     NewEvents(StartCause),
 
-    /// Emitted when the OS sends an event to a winit window.
+    /// See [`ApplicationHandler::window_event`] for details.
+    ///
+    /// [`ApplicationHandler::window_event`]: crate::application::ApplicationHandler::window_event
     WindowEvent {
         window_id: WindowId,
         event: WindowEvent,
     },
 
-    /// Emitted when the OS sends an event to a device.
+    /// See [`ApplicationHandler::device_event`] for details.
+    ///
+    /// [`ApplicationHandler::device_event`]: crate::application::ApplicationHandler::device_event
     DeviceEvent {
         device_id: DeviceId,
         event: DeviceEvent,
     },
 
-    /// Emitted when an event is sent from [`EventLoopProxy::send_event`](crate::event_loop::EventLoopProxy::send_event)
+    /// See [`ApplicationHandler::user_event`] for details.
+    ///
+    /// [`ApplicationHandler::user_event`]: crate::application::ApplicationHandler::user_event
     UserEvent(T),
 
-    /// Emitted when the application has been suspended.
+    /// See [`ApplicationHandler::suspended`] for details.
     ///
-    /// # Portability
+    /// [`ApplicationHandler::suspended`]: crate::application::ApplicationHandler::suspended
-    ///
-    /// Not all platforms support the notion of suspending applications, and there may be no
-    /// technical way to guarantee being able to emit a `Suspended` event if the OS has
-    /// no formal application lifecycle (currently only Android, iOS, and Web do). For this reason,
-    /// Winit does not currently try to emit pseudo `Suspended` events before the application
-    /// quits on platforms without an application lifecycle.
-    ///
-    /// Considering that the implementation of `Suspended` and [`Resumed`] events may be internally
-    /// driven by multiple platform-specific events, and that there may be subtle differences across
-    /// platforms with how these internal events are delivered, it's recommended that applications
-    /// be able to gracefully handle redundant (i.e. back-to-back) `Suspended` or [`Resumed`] events.
-    ///
-    /// Also see [`Resumed`] notes.
-    ///
-    /// ## Android
-    ///
-    /// On Android, the `Suspended` event is only sent when the application's associated
-    /// [`SurfaceView`] is destroyed. This is expected to closely correlate with the [`onPause`]
-    /// lifecycle event but there may technically be a discrepancy.
-    ///
-    /// [`onPause`]: https://developer.android.com/reference/android/app/Activity#onPause()
-    ///
-    /// Applications that need to run on Android should assume their [`SurfaceView`] 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`]).
-    ///
-    /// After being `Suspended` on Android applications must drop all render surfaces before
-    /// the event callback completes, which may be re-created when the application is next [`Resumed`].
-    ///
-    /// [`SurfaceView`]: https://developer.android.com/reference/android/view/SurfaceView
-    /// [Activity lifecycle]: https://developer.android.com/guide/components/activities/activity-lifecycle
-    /// [`VkSurfaceKHR`]: https://www.khronos.org/registry/vulkan/specs/1.3-extensions/man/html/VkSurfaceKHR.html
-    /// [`wgpu::Surface`]: https://docs.rs/wgpu/latest/wgpu/struct.Surface.html
-    ///
-    /// ## iOS
-    ///
-    /// On iOS, the `Suspended` event is currently emitted in response to an
-    /// [`applicationWillResignActive`] callback which means that the application is
-    /// about to transition from the active to inactive state (according to the
-    /// [iOS application lifecycle]).
-    ///
-    /// [`applicationWillResignActive`]: https://developer.apple.com/documentation/uikit/uiapplicationdelegate/1622950-applicationwillresignactive
-    /// [iOS application lifecycle]: https://developer.apple.com/documentation/uikit/app_and_environment/managing_your_app_s_life_cycle
-    ///
-    /// ## Web
-    ///
-    /// On Web, the `Suspended` event is emitted in response to a [`pagehide`] event
-    /// with the property [`persisted`] being true, which means that the page is being
-    /// put in the [`bfcache`] (back/forward cache) - an in-memory cache that stores a
-    /// complete snapshot of a page (including the JavaScript heap) as the user is
-    /// navigating away.
-    ///
-    /// [`pagehide`]: https://developer.mozilla.org/en-US/docs/Web/API/Window/pagehide_event
-    /// [`persisted`]: https://developer.mozilla.org/en-US/docs/Web/API/PageTransitionEvent/persisted
-    /// [`bfcache`]: https://web.dev/bfcache/
-    ///
-    /// [`Resumed`]: Self::Resumed
     Suspended,
 
-    /// Emitted when the application has been resumed.
+    /// See [`ApplicationHandler::resumed`] for details.
     ///
-    /// For consistency, all platforms emit a `Resumed` event even if they don't themselves have a
+    /// [`ApplicationHandler::resumed`]: crate::application::ApplicationHandler::resumed
-    /// formal suspend/resume lifecycle. For systems without a standard suspend/resume lifecycle
-    /// the `Resumed` event is always emitted after the [`NewEvents(StartCause::Init)`][StartCause::Init]
-    /// event.
-    ///
-    /// # Portability
-    ///
-    /// It's recommended that applications should only initialize their graphics context and create
-    /// a window after they have received their first `Resumed` event. Some systems
-    /// (specifically Android) won't allow applications to create a render surface until they are
-    /// resumed.
-    ///
-    /// Considering that the implementation of [`Suspended`] and `Resumed` events may be internally
-    /// driven by multiple platform-specific events, and that there may be subtle differences across
-    /// platforms with how these internal events are delivered, it's recommended that applications
-    /// be able to gracefully handle redundant (i.e. back-to-back) [`Suspended`] or `Resumed` events.
-    ///
-    /// Also see [`Suspended`] notes.
-    ///
-    /// ## Android
-    ///
-    /// On Android, the `Resumed` event is sent when a new [`SurfaceView`] has been created. This is
-    /// expected to closely correlate with the [`onResume`] lifecycle event but there may technically
-    /// be a discrepancy.
-    ///
-    /// [`onResume`]: https://developer.android.com/reference/android/app/Activity#onResume()
-    ///
-    /// Applications that need to run on Android must wait until they have been `Resumed`
-    /// before they will be able to create a render surface (such as an `EGLSurface`,
-    /// [`VkSurfaceKHR`] or [`wgpu::Surface`]) which depend on having a
-    /// [`SurfaceView`]. Applications must also assume that if they are [`Suspended`], then their
-    /// render surfaces are invalid and should be dropped.
-    ///
-    /// Also see [`Suspended`] notes.
-    ///
-    /// [`SurfaceView`]: https://developer.android.com/reference/android/view/SurfaceView
-    /// [Activity lifecycle]: https://developer.android.com/guide/components/activities/activity-lifecycle
-    /// [`VkSurfaceKHR`]: https://www.khronos.org/registry/vulkan/specs/1.3-extensions/man/html/VkSurfaceKHR.html
-    /// [`wgpu::Surface`]: https://docs.rs/wgpu/latest/wgpu/struct.Surface.html
-    ///
-    /// ## iOS
-    ///
-    /// On iOS, the `Resumed` event is emitted in response to an [`applicationDidBecomeActive`]
-    /// callback which means the application is "active" (according to the
-    /// [iOS application lifecycle]).
-    ///
-    /// [`applicationDidBecomeActive`]: https://developer.apple.com/documentation/uikit/uiapplicationdelegate/1622956-applicationdidbecomeactive
-    /// [iOS application lifecycle]: https://developer.apple.com/documentation/uikit/app_and_environment/managing_your_app_s_life_cycle
-    ///
-    /// ## Web
-    ///
-    /// On Web, the `Resumed` event is emitted in response to a [`pageshow`] event
-    /// with the property [`persisted`] being true, which means that the page is being
-    /// restored from the [`bfcache`] (back/forward cache) - an in-memory cache that
-    /// stores a complete snapshot of a page (including the JavaScript heap) as the
-    /// user is navigating away.
-    ///
-    /// [`pageshow`]: https://developer.mozilla.org/en-US/docs/Web/API/Window/pageshow_event
-    /// [`persisted`]: https://developer.mozilla.org/en-US/docs/Web/API/PageTransitionEvent/persisted
-    /// [`bfcache`]: https://web.dev/bfcache/
-    ///
-    /// [`Suspended`]: Self::Suspended
     Resumed,
 
-    /// Emitted when the event loop is about to block and wait for new events.
+    /// See [`ApplicationHandler::about_to_wait`] for details.
     ///
-    /// Most applications shouldn't need to hook into this event since there is no real relationship
+    /// [`ApplicationHandler::about_to_wait`]: crate::application::ApplicationHandler::about_to_wait
-    /// between how often the event loop needs to wake up and the dispatching of any specific events.
-    ///
-    /// High frequency event sources, such as input devices could potentially lead to lots of wake
-    /// ups and also lots of corresponding `AboutToWait` events.
-    ///
-    /// This is not an ideal event to drive application rendering from and instead applications
-    /// should render in response to [`WindowEvent::RedrawRequested`] events.
     AboutToWait,
 
-    /// Emitted when the event loop is being shut down.
+    /// See [`ApplicationHandler::exiting`] for details.
     ///
-    /// This is irreversible - if this event is emitted, it is guaranteed to be the last event that
+    /// [`ApplicationHandler::exiting`]: crate::application::ApplicationHandler::exiting
-    /// gets emitted. You generally want to treat this as a "do on quit" event.
     LoopExiting,
 
-    /// Emitted when the application has received a memory warning.
+    /// See [`ApplicationHandler::memory_warning`] for details.
     ///
-    /// ## Platform-specific
+    /// [`ApplicationHandler::memory_warning`]: crate::application::ApplicationHandler::memory_warning
-    ///
-    /// ### Android
-    ///
-    /// On Android, the `MemoryWarning` event is sent when [`onLowMemory`] was called. The application
-    /// must [release memory] or risk being killed.
-    ///
-    /// [`onLowMemory`]: https://developer.android.com/reference/android/app/Application.html#onLowMemory()
-    /// [release memory]: https://developer.android.com/topic/performance/memory#release
-    ///
-    /// ### iOS
-    ///
-    /// On iOS, the `MemoryWarning` event is emitted in response to an [`applicationDidReceiveMemoryWarning`]
-    /// callback. The application must free as much memory as possible or risk being terminated, see
-    /// [how to respond to memory warnings].
-    ///
-    /// [`applicationDidReceiveMemoryWarning`]: https://developer.apple.com/documentation/uikit/uiapplicationdelegate/1623063-applicationdidreceivememorywarni
-    /// [how to respond to memory warnings]: https://developer.apple.com/documentation/uikit/app_and_environment/managing_your_app_s_life_cycle/responding_to_memory_warnings
-    ///
-    /// ### Others
-    ///
-    /// - **macOS / Wayland / Windows / Orbital:** Unsupported.
     MemoryWarning,
 }
 

src/event_loop.rs

@@ -18,6 +18,7 @@ use std::time::{Duration, Instant};
 #[cfg(web_platform)]
 use web_time::{Duration, Instant};
 
+use crate::application::ApplicationHandler;
 use crate::error::{EventLoopError, OsError};
 use crate::window::{CustomCursor, CustomCursorSource, Window, WindowAttributes};
 use crate::{event::Event, monitor::MonitorHandle, platform_impl};
@@ -215,8 +216,22 @@ impl<T> EventLoop<T> {
         }
     }
 
-    /// Runs the event loop in the calling thread and calls the given `event_handler` closure
+    /// See [`run_app`].
-    /// to dispatch any pending events.
+    ///
+    /// [`run_app`]: Self::run_app
+    #[inline]
+    #[deprecated = "use `EventLoop::run_app` instead"]
+    #[cfg(not(all(web_platform, target_feature = "exception-handling")))]
+    pub fn run<F>(self, event_handler: F) -> Result<(), EventLoopError>
+    where
+        F: FnMut(Event<T>, &ActiveEventLoop),
+    {
+        let _span = tracing::debug_span!("winit::EventLoop::run").entered();
+
+        self.event_loop.run(event_handler)
+    }
+
+    /// Run the application with the event loop on the calling thread.
     ///
     /// See the [`set_control_flow()`] docs on how to change the event loop's behavior.
     ///
@@ -231,10 +246,10 @@ impl<T> EventLoop<T> {
     ///   Web applications are recommended to use
     #[cfg_attr(
         web_platform,
-        doc = "[`EventLoopExtWebSys::spawn()`][crate::platform::web::EventLoopExtWebSys::spawn()]"
+        doc = "[`EventLoopExtWebSys::spawn_app()`][crate::platform::web::EventLoopExtWebSys::spawn_app()]"
     )]
     #[cfg_attr(not(web_platform), doc = "`EventLoopExtWebSys::spawn()`")]
-    ///   [^1] instead of [`run()`] to avoid the need
+    ///   [^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.
@@ -242,17 +257,13 @@ impl<T> EventLoop<T> {
     ///   This function won't be available with `target_feature = "exception-handling"`.
     ///
     /// [`set_control_flow()`]: ActiveEventLoop::set_control_flow()
-    /// [`run()`]: Self::run()
+    /// [`run_app()`]: Self::run_app()
-    /// [^1]: `EventLoopExtWebSys::spawn()` is only available on Web.
+    /// [^1]: `EventLoopExtWebSys::spawn_app()` is only available on Web.
     #[inline]
     #[cfg(not(all(web_platform, target_feature = "exception-handling")))]
-    pub fn run<F>(self, event_handler: F) -> Result<(), EventLoopError>
+    pub fn run_app<A: ApplicationHandler<T>>(self, app: &mut A) -> Result<(), EventLoopError> {
-    where
+        self.event_loop
-        F: FnMut(Event<T>, &ActiveEventLoop),
+            .run(|event, event_loop| dispatch_event_for_app(app, event_loop, event))
-    {
-        let _span = tracing::debug_span!("winit::EventLoop::run").entered();
-
-        self.event_loop.run(event_handler)
     }
 
     /// Creates an [`EventLoopProxy`] that can be used to dispatch user events
@@ -344,11 +355,11 @@ unsafe impl<T> rwh_05::HasRawDisplayHandle for EventLoop<T> {
 impl<T> AsFd for EventLoop<T> {
     /// Get the underlying [EventLoop]'s `fd` which you can register
     /// into other event loop, like [`calloop`] or [`mio`]. When doing so, the
-    /// loop must be polled with the [`pump_events`] API.
+    /// loop must be polled with the [`pump_app_events`] API.
     ///
     /// [`calloop`]: https://crates.io/crates/calloop
     /// [`mio`]: https://crates.io/crates/mio
-    /// [`pump_events`]: crate::platform::pump_events::EventLoopExtPumpEvents::pump_events
+    /// [`pump_app_events`]: crate::platform::pump_events::EventLoopExtPumpEvents::pump_app_events
     fn as_fd(&self) -> BorrowedFd<'_> {
         self.event_loop.as_fd()
     }
@@ -358,11 +369,11 @@ impl<T> AsFd for EventLoop<T> {
 impl<T> AsRawFd for EventLoop<T> {
     /// Get the underlying [EventLoop]'s raw `fd` which you can register
     /// into other event loop, like [`calloop`] or [`mio`]. When doing so, the
-    /// loop must be polled with the [`pump_events`] API.
+    /// loop must be polled with the [`pump_app_events`] API.
     ///
     /// [`calloop`]: https://crates.io/crates/calloop
     /// [`mio`]: https://crates.io/crates/mio
-    /// [`pump_events`]: crate::platform::pump_events::EventLoopExtPumpEvents::pump_events
+    /// [`pump_app_events`]: crate::platform::pump_events::EventLoopExtPumpEvents::pump_app_events
     fn as_raw_fd(&self) -> RawFd {
         self.event_loop.as_raw_fd()
     }
@@ -630,3 +641,23 @@ impl AsyncRequestSerial {
         Self { serial }
     }
 }
+
+/// Shim for various run APIs.
+#[inline(always)]
+pub(crate) fn dispatch_event_for_app<T: 'static, A: ApplicationHandler<T>>(
+    app: &mut A,
+    event_loop: &ActiveEventLoop,
+    event: Event<T>,
+) {
+    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::UserEvent(event) => app.user_event(event_loop, event),
+        Event::Suspended => app.suspended(event_loop),
+        Event::Resumed => app.resumed(event_loop),
+        Event::AboutToWait => app.about_to_wait(event_loop),
+        Event::LoopExiting => app.exiting(event_loop),
+        Event::MemoryWarning => app.memory_warning(event_loop),
+    }
+}

src/lib.rs

@@ -21,7 +21,7 @@
 //! Some user activity, like mouse movement, can generate both a [`WindowEvent`] *and* a
 //! [`DeviceEvent`]. You can also create and handle your own custom [`Event::UserEvent`]s, if desired.
 //!
-//! You can retrieve events by calling [`EventLoop::run()`]. This function will
+//! You can retrieve events by calling [`EventLoop::run_app()`]. This function will
 //! dispatch events for every [`Window`] that was created with that particular [`EventLoop`], and
 //! will run until [`exit()`] is used, at which point [`Event::LoopExiting`].
 //!
@@ -36,7 +36,7 @@
         x11_platform,
         wayland_platform
     ),
-    doc = "[`EventLoopExtPumpEvents::pump_events()`][platform::pump_events::EventLoopExtPumpEvents::pump_events()]"
+    doc = "[`EventLoopExtPumpEvents::pump_app_events()`][platform::pump_events::EventLoopExtPumpEvents::pump_app_events()]"
 )]
 #![cfg_attr(
     not(any(
@@ -46,18 +46,54 @@
         x11_platform,
         wayland_platform
     )),
-    doc = "`EventLoopExtPumpEvents::pump_events()`"
+    doc = "`EventLoopExtPumpEvents::pump_app_events()`"
 )]
 //! [^1]. See that method's documentation for more reasons about why
 //! it's discouraged beyond compatibility reasons.
 //!
 //!
 //! ```no_run
-//! use winit::{
+//! use winit::application::ApplicationHandler;
-//!     event::{Event, WindowEvent},
+//! use winit::event::WindowEvent;
-//!     event_loop::{ControlFlow, EventLoop},
+//! use winit::event_loop::{ActiveEventLoop, ControlFlow, EventLoop};
-//!     window::Window,
+//! use winit::window::{Window, WindowId};
-//! };
+//!
+//! #[derive(Default)]
+//! struct App {
+//!     window: Option<Window>,
+//! }
+//!
+//! impl ApplicationHandler for App {
+//!     fn resumed(&mut self, event_loop: &ActiveEventLoop) {
+//!         self.window = Some(event_loop.create_window(Window::default_attributes()).unwrap());
+//!     }
+//!
+//!     fn window_event(&mut self, event_loop: &ActiveEventLoop, id: WindowId, event: WindowEvent) {
+//!         match event {
+//!             WindowEvent::CloseRequested => {
+//!                 println!("The close button was pressed; stopping");
+//!                 event_loop.exit();
+//!             },
+//!             WindowEvent::RedrawRequested => {
+//!                 // Redraw the application.
+//!                 //
+//!                 // It's preferable for applications that do not render continuously to render in
+//!                 // this event rather than in AboutToWait, since rendering in here allows
+//!                 // the program to gracefully handle redraws requested by the OS.
+//!
+//!                 // Draw.
+//!
+//!                 // Queue a RedrawRequested event.
+//!                 //
+//!                 // 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.as_ref().unwrap().request_redraw();
+//!             }
+//!             _ => (),
+//!         }
+//!     }
+//! }
 //!
 //! let event_loop = EventLoop::new().unwrap();
 //!
@@ -70,43 +106,8 @@
 //! // input, and uses significantly less power/CPU time than ControlFlow::Poll.
 //! event_loop.set_control_flow(ControlFlow::Wait);
 //!
-//! let mut window = None;
+//! let mut app = App::default();
-//!
+//! event_loop.run_app(&mut app);
-//! event_loop.run(move |event, event_loop| {
-//!     match event {
-//!         Event::Resumed => {
-//!             window = Some(event_loop.create_window(Window::default_attributes()).unwrap());
-//!         }
-//!         Event::WindowEvent {
-//!             event: WindowEvent::CloseRequested,
-//!             ..
-//!         } => {
-//!             println!("The close button was pressed; stopping");
-//!             event_loop.exit();
-//!         },
-//!         Event::AboutToWait => {
-//!             // Application update code.
-//!
-//!             // Queue a RedrawRequested event.
-//!             //
-//!             // 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.
-//!             window.as_ref().unwrap().request_redraw();
-//!         },
-//!         Event::WindowEvent {
-//!             event: WindowEvent::RedrawRequested,
-//!             ..
-//!         } => {
-//!             // Redraw the application.
-//!             //
-//!             // It's preferable for applications that do not render continuously to render in
-//!             // this event rather than in AboutToWait, since rendering in here allows
-//!             // the program to gracefully handle redraws requested by the OS.
-//!         },
-//!         _ => ()
-//!     }
-//! });
 //! ```
 //!
 //! [`WindowEvent`] has a [`WindowId`] member. In multi-window environments, it should be
@@ -164,7 +165,7 @@
 //!
 //! [`EventLoop`]: event_loop::EventLoop
 //! [`EventLoop::new()`]: event_loop::EventLoop::new
-//! [`EventLoop::run()`]: event_loop::EventLoop::run
+//! [`EventLoop::run_app()`]: event_loop::EventLoop::run_app
 //! [`exit()`]: event_loop::ActiveEventLoop::exit
 //! [`Window`]: window::Window
 //! [`WindowId`]: window::WindowId
@@ -178,7 +179,7 @@
 //! [`Event::LoopExiting`]: event::Event::LoopExiting
 //! [`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_events()` is only available on Windows, macOS, Android, X11 and Wayland.
+//! [^1]: `EventLoopExtPumpEvents::pump_app_events()` is only available on Windows, macOS, Android, X11 and Wayland.
 
 #![deny(rust_2018_idioms)]
 #![deny(rustdoc::broken_intra_doc_links)]
@@ -200,6 +201,7 @@ pub use rwh_06 as raw_window_handle;
 #[doc(inline)]
 pub use dpi;
 
+pub mod application;
 #[macro_use]
 pub mod error;
 mod cursor;

src/platform/android.rs

@@ -60,7 +60,7 @@
 //!
 //! 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 = "0.29.12", features = [ "android-native-activity" ] }`
+//! 2. Enable the `"android-native-activity"` feature for Winit: `winit = { version = "0.29.15", 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 logging as above).
 //! 4. Pass a clone of the `AndroidApp` that your application receives to Winit when building your event loop (as shown above).
 

src/platform/pump_events.rs

@@ -1,22 +1,13 @@
 use std::time::Duration;
 
-use crate::{
+use crate::application::ApplicationHandler;
-    event::Event,
+use crate::event::Event;
-    event_loop::{ActiveEventLoop, EventLoop},
+use crate::event_loop::{self, ActiveEventLoop, EventLoop};
-};
-
-/// The return status for `pump_events`
-pub enum PumpStatus {
-    /// Continue running external loop.
-    Continue,
-    /// Exit external loop.
-    Exit(i32),
-}
 
 /// Additional methods on [`EventLoop`] for pumping events within an external event loop
 pub trait EventLoopExtPumpEvents {
     /// A type provided by the user that can be passed through [`Event::UserEvent`].
-    type UserEvent;
+    type UserEvent: 'static;
 
     /// Pump the `EventLoop` to check for and dispatch pending events.
     ///
@@ -113,6 +104,21 @@ pub trait EventLoopExtPumpEvents {
     ///   If you render outside of Winit you are likely to see window resizing artifacts
     ///   since MacOS expects applications to render synchronously during any `drawRect`
     ///   callback.
+    fn pump_app_events<A: ApplicationHandler<Self::UserEvent>>(
+        &mut self,
+        timeout: Option<Duration>,
+        app: &mut A,
+    ) -> PumpStatus {
+        #[allow(deprecated)]
+        self.pump_events(timeout, |event, event_loop| {
+            event_loop::dispatch_event_for_app(app, event_loop, event)
+        })
+    }
+
+    /// See [`pump_app_events`].
+    ///
+    /// [`pump_app_events`]: Self::pump_app_events
+    #[deprecated = "use EventLoopExtPumpEvents::pump_app_events"]
     fn pump_events<F>(&mut self, timeout: Option<Duration>, event_handler: F) -> PumpStatus
     where
         F: FnMut(Event<Self::UserEvent>, &ActiveEventLoop);
@@ -128,3 +134,11 @@ impl<T> EventLoopExtPumpEvents for EventLoop<T> {
         self.event_loop.pump_events(timeout, event_handler)
     }
 }
+
+/// The return status for `pump_events`
+pub enum PumpStatus {
+    /// Continue running external loop.
+    Continue,
+    /// Exit external loop.
+    Exit(i32),
+}

src/platform/run_on_demand.rs

@@ -1,8 +1,7 @@
-use crate::{
+use crate::application::ApplicationHandler;
-    error::EventLoopError,
+use crate::error::EventLoopError;
-    event::Event,
+use crate::event::Event;
-    event_loop::{ActiveEventLoop, EventLoop},
+use crate::event_loop::{self, ActiveEventLoop, EventLoop};
-};
 
 #[cfg(doc)]
 use crate::{platform::pump_events::EventLoopExtPumpEvents, window::Window};
@@ -10,12 +9,19 @@ use crate::{platform::pump_events::EventLoopExtPumpEvents, window::Window};
 /// Additional methods on [`EventLoop`] to return control flow to the caller.
 pub trait EventLoopExtRunOnDemand {
     /// A type provided by the user that can be passed through [`Event::UserEvent`].
-    type UserEvent;
+    type UserEvent: 'static;
 
-    /// Runs the event loop in the calling thread and calls the given `event_handler` closure
+    /// See [`run_app_on_demand`].
-    /// to dispatch any window system events.
     ///
-    /// Unlike [`EventLoop::run`], this function accepts non-`'static` (i.e. non-`move`) closures
+    /// [`run_app_on_demand`]: Self::run_app_on_demand
+    #[deprecated = "use EventLoopExtRunOnDemand::run_app_on_demand"]
+    fn run_on_demand<F>(&mut self, event_handler: F) -> Result<(), EventLoopError>
+    where
+        F: FnMut(Event<Self::UserEvent>, &ActiveEventLoop);
+
+    /// Run the application with the event loop on the calling thread.
+    ///
+    /// 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.
@@ -26,11 +32,10 @@ pub trait EventLoopExtRunOnDemand {
     ///
     /// This API is not designed to run an event loop in bursts that you can exit from and return
     /// to while maintaining the full state of your application. (If you need something like this
-    /// you can look at the [`EventLoopExtPumpEvents::pump_events()`] API)
+    /// you can look at the [`EventLoopExtPumpEvents::pump_app_events()`] API)
     ///
-    /// Each time `run_on_demand` is called the `event_handler` can expect to receive a
+    /// Each time `run_app_on_demand` is called the startup sequence of `init`, followed by
-    /// `NewEvents(Init)` and `Resumed` event (even on platforms that have no suspend/resume
+    /// `resume` is being preserved.
-    /// lifecycle) - which can be used to consistently initialize application state.
     ///
     /// See the [`set_control_flow()`] docs on how to change the event loop's behavior.
     ///
@@ -40,8 +45,8 @@ pub trait EventLoopExtRunOnDemand {
     ///   backend it is possible to use `EventLoopExtWebSys::spawn()`[^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 specifically need
+    /// You are strongly encouraged to use [`EventLoop::run_app()`] for portability, unless you
-    /// the ability to re-run a single event loop more than once
+    /// specifically need the ability to re-run a single event loop more than once
     ///
     /// # Supported Platforms
     /// - Windows
@@ -64,9 +69,15 @@ pub trait EventLoopExtRunOnDemand {
     ///
     /// [`exit()`]: ActiveEventLoop::exit()
     /// [`set_control_flow()`]: ActiveEventLoop::set_control_flow()
-    fn run_on_demand<F>(&mut self, event_handler: F) -> Result<(), EventLoopError>
+    fn run_app_on_demand<A: ApplicationHandler<Self::UserEvent>>(
-    where
+        &mut self,
-        F: FnMut(Event<Self::UserEvent>, &ActiveEventLoop);
+        app: &mut A,
+    ) -> Result<(), EventLoopError> {
+        #[allow(deprecated)]
+        self.run_on_demand(|event, event_loop| {
+            event_loop::dispatch_event_for_app(app, event_loop, event)
+        })
+    }
 }
 
 impl<T> EventLoopExtRunOnDemand for EventLoop<T> {

src/platform/web.rs

@@ -53,9 +53,10 @@ use std::time::Duration;
 #[cfg(web_platform)]
 use web_sys::HtmlCanvasElement;
 
+use crate::application::ApplicationHandler;
 use crate::cursor::CustomCursorSource;
 use crate::event::Event;
-use crate::event_loop::{ActiveEventLoop, EventLoop};
+use crate::event_loop::{self, ActiveEventLoop, EventLoop};
 #[cfg(web_platform)]
 use crate::platform_impl::CustomCursorFuture as PlatformCustomCursorFuture;
 use crate::platform_impl::PlatformCustomCursorSource;
@@ -160,18 +161,18 @@ impl WindowAttributesExtWebSys for WindowAttributes {
 /// Additional methods on `EventLoop` that are specific to the web.
 pub trait EventLoopExtWebSys {
     /// A type provided by the user that can be passed through `Event::UserEvent`.
-    type UserEvent;
+    type UserEvent: 'static;
 
     /// Initializes the winit event loop.
     ///
     /// Unlike
     #[cfg_attr(
         all(web_platform, target_feature = "exception-handling"),
-        doc = "`run()`"
+        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.
@@ -183,9 +184,15 @@ pub trait EventLoopExtWebSys {
     ///
     #[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<Self::UserEvent> + 'static>(self, app: A);
+
+    /// See [`spawn_app`].
+    ///
+    /// [`spawn_app`]: Self::spawn_app
+    #[deprecated = "use EventLoopExtWebSys::spawn_app"]
     fn spawn<F>(self, event_handler: F)
     where
         F: 'static + FnMut(Event<Self::UserEvent>, &ActiveEventLoop);
@@ -194,6 +201,12 @@ pub trait EventLoopExtWebSys {
 impl<T> EventLoopExtWebSys for EventLoop<T> {
     type UserEvent = T;
 
+    fn spawn_app<A: ApplicationHandler<Self::UserEvent> + 'static>(self, mut app: A) {
+        self.event_loop.spawn(move |event, event_loop| {
+            event_loop::dispatch_event_for_app(&mut app, event_loop, event)
+        });
+    }
+
     fn spawn<F>(self, event_handler: F)
     where
         F: 'static + FnMut(Event<Self::UserEvent>, &ActiveEventLoop),

src/platform_impl/ios/event_loop.rs

@@ -182,7 +182,7 @@ impl<T: 'static> EventLoop<T> {
             application.is_none(),
             "\
                 `EventLoop` cannot be `run` after a call to `UIApplicationMain` on iOS\n\
-                 Note: `EventLoop::run` calls `UIApplicationMain` on iOS",
+                 Note: `EventLoop::run_app` calls `UIApplicationMain` on iOS",
         );
 
         let handler = map_user_event(handler, self.receiver);

src/platform_impl/ios/window.rs

@@ -689,7 +689,7 @@ impl Inner {
             let screen_frame = self.rect_to_screen_space(bounds);
             let status_bar_frame = {
                 let app = UIApplication::shared(MainThreadMarker::new().unwrap()).expect(
-                    "`Window::get_inner_position` cannot be called before `EventLoop::run` on iOS",
+                    "`Window::get_inner_position` cannot be called before `EventLoop::run_app` on iOS",
                 );
                 app.statusBarFrame()
             };

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

@@ -373,10 +373,15 @@ impl<'a, 'b> KeyEventResults<'a, 'b> {
 
     fn composed_text(&mut self) -> Result<Option<SmolStr>, ()> {
         match self.compose {
-            ComposeStatus::Accepted(xkb_compose_status::XKB_COMPOSE_COMPOSED) => {
+            ComposeStatus::Accepted(status) => match status {
-                let state = self.context.compose_state1.as_mut().unwrap();
+                xkb_compose_status::XKB_COMPOSE_COMPOSED => {
-                Ok(state.get_string(self.context.scratch_buffer))
+                    let state = self.context.compose_state1.as_mut().unwrap();
-            }
+                    Ok(state.get_string(self.context.scratch_buffer))
+                }
+                xkb_compose_status::XKB_COMPOSE_COMPOSING
+                | xkb_compose_status::XKB_COMPOSE_CANCELLED => Ok(None),
+                xkb_compose_status::XKB_COMPOSE_NOTHING => Err(()),
+            },
             _ => Err(()),
         }
     }

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

@@ -826,9 +826,14 @@ impl WindowState {
 
     /// Set the cursor grabbing state on the top-level.
     pub fn set_cursor_grab(&mut self, mode: CursorGrabMode) -> Result<(), ExternalError> {
-        // Replace the user grabbing mode.
+        if self.cursor_grab_mode.user_grab_mode == mode {
+            return Ok(());
+        }
+
+        self.set_cursor_grab_inner(mode)?;
+        // Update user grab on success.
         self.cursor_grab_mode.user_grab_mode = mode;
-        self.set_cursor_grab_inner(mode)
+        Ok(())
     }
 
     /// Reload the hints for minimum and maximum sizes.

src/platform_impl/linux/x11/event_processor.rs

@@ -981,7 +981,7 @@ impl EventProcessor {
 
         // Always update the modifiers when we're not replaying.
         if !replay {
-            self.udpate_mods_from_core_event(window_id, xev.state as u16, &mut callback);
+            self.update_mods_from_core_event(window_id, xev.state as u16, &mut callback);
         }
 
         if keycode != 0 && !self.is_composing {
@@ -1778,7 +1778,7 @@ impl EventProcessor {
         self.send_modifiers(window_id, mods.into(), true, &mut callback)
     }
 
-    pub fn udpate_mods_from_core_event<T: 'static, F>(
+    pub fn update_mods_from_core_event<T: 'static, F>(
         &mut self,
         window_id: crate::window::WindowId,
         state: u16,

src/platform_impl/linux/x11/mod.rs

@@ -887,6 +887,9 @@ pub enum X11Error {
 
     /// Unable to parse xsettings.
     XsettingsParse(xsettings::ParserError),
+
+    /// Failed to get property.
+    GetProperty(util::GetPropertyError),
 }
 
 impl fmt::Display for X11Error {
@@ -896,6 +899,7 @@ impl fmt::Display for X11Error {
             X11Error::Connect(e) => write!(f, "X11 connection error: {}", e),
             X11Error::Connection(e) => write!(f, "X11 connection error: {}", e),
             X11Error::XidsExhausted(e) => write!(f, "XID range exhausted: {}", e),
+            X11Error::GetProperty(e) => write!(f, "Failed to get X property {}", e),
             X11Error::X11(e) => write!(f, "X11 error: {:?}", e),
             X11Error::UnexpectedNull(s) => write!(f, "Xlib function returned null: {}", s),
             X11Error::InvalidActivationToken(s) => write!(
@@ -988,6 +992,12 @@ impl From<xsettings::ParserError> for X11Error {
     }
 }
 
+impl From<util::GetPropertyError> for X11Error {
+    fn from(value: util::GetPropertyError) -> Self {
+        Self::GetProperty(value)
+    }
+}
+
 /// Type alias for a void cookie.
 type VoidCookie<'a> = x11rb::cookie::VoidCookie<'a, X11rbConnection>;
 

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

@@ -30,8 +30,8 @@ macro_rules! consume {
         let this = $this;
         let (x, y) = match (this.x.abs() < <$ty>::EPSILON, this.y.abs() < <$ty>::EPSILON) {
             (true, true) => return None,
-            (true, false) => (this.x, 0.0),
+            (false, true) => (this.x, 0.0),
-            (false, true) => (0.0, this.y),
+            (true, false) => (0.0, this.y),
             (false, false) => (this.x, this.y),
         };
 

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

@@ -53,6 +53,7 @@ impl XConnection {
             .get_string("Xft.dpi", "")
             .and_then(|s| f64::from_str(s).ok())
     }
+
     pub fn get_output_info(
         &self,
         resources: &monitor::ScreenResources,

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

@@ -1,13 +1,18 @@
-use super::*;
+use std::error::Error;
-use bytemuck::{NoUninit, Pod};
+use std::fmt;
 use std::sync::Arc;
 
+use bytemuck::{NoUninit, Pod};
+
 use x11rb::connection::Connection;
 use x11rb::errors::ReplyError;
 
-pub type Cardinal = u32;
+use super::*;
+
 pub const CARDINAL_SIZE: usize = mem::size_of::<u32>();
 
+pub type Cardinal = u32;
+
 #[derive(Debug, Clone)]
 pub enum GetPropertyError {
     X11rbError(Arc<ReplyError>),
@@ -15,12 +20,6 @@ pub enum GetPropertyError {
     FormatMismatch(c_int),
 }
 
-impl<T: Into<ReplyError>> From<T> for GetPropertyError {
-    fn from(e: T) -> Self {
-        Self::X11rbError(Arc::new(e.into()))
-    }
-}
-
 impl GetPropertyError {
     pub fn is_actual_property_type(&self, t: xproto::Atom) -> bool {
         if let GetPropertyError::TypeMismatch(actual_type) = *self {
@@ -31,6 +30,24 @@ impl GetPropertyError {
     }
 }
 
+impl<T: Into<ReplyError>> From<T> for GetPropertyError {
+    fn from(e: T) -> Self {
+        Self::X11rbError(Arc::new(e.into()))
+    }
+}
+
+impl fmt::Display for GetPropertyError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            GetPropertyError::X11rbError(err) => err.fmt(f),
+            GetPropertyError::TypeMismatch(err) => write!(f, "type mismatch: {err}"),
+            GetPropertyError::FormatMismatch(err) => write!(f, "format mismatch: {err}"),
+        }
+    }
+}
+
+impl Error for GetPropertyError {}
+
 // Number of 32-bit chunks to retrieve per iteration of get_property's inner loop.
 // To test if `get_property` works correctly, set this to 1.
 const PROPERTY_BUFFER_SIZE: u32 = 1024; // 4k of RAM ought to be enough for anyone!

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

@@ -16,7 +16,7 @@ const NUM_MODS: usize = 8;
 #[derive(Debug, Default)]
 pub struct ModifierKeymap {
     // Maps keycodes to modifiers
-    modifers: HashSet<XKeyCode>,
+    modifiers: HashSet<XKeyCode>,
 }
 
 impl ModifierKeymap {
@@ -25,7 +25,7 @@ impl ModifierKeymap {
     }
 
     pub fn is_modifier(&self, keycode: XKeyCode) -> bool {
-        self.modifers.contains(&keycode)
+        self.modifiers.contains(&keycode)
     }
 
     pub fn reload_from_x_connection(&mut self, xconn: &super::XConnection) {
@@ -48,9 +48,9 @@ impl ModifierKeymap {
         let keys = unsafe {
             slice::from_raw_parts(keymap.modifiermap as *const _, keys_per_mod * NUM_MODS)
         };
-        self.modifers.clear();
+        self.modifiers.clear();
         for key in keys {
-            self.modifers.insert(*key);
+            self.modifiers.insert(*key);
         }
     }
 }

src/platform_impl/linux/x11/xdisplay.rs

@@ -159,7 +159,7 @@ impl XConnection {
 
         // Get PropertyNotify events from the XSETTINGS window.
         // TODO: The XSETTINGS window here can change. In the future, listen for DestroyNotify on this window
-        // in order to accomodate for a changed window here.
+        // in order to accommodate for a changed window here.
         let selector_window = xcb
             .get_selection_owner(xsettings_screen)
             .ok()?

src/platform_impl/linux/x11/xsettings.rs

@@ -33,13 +33,11 @@ impl XConnection {
             .reply()?;
 
         // Read the _XSETTINGS_SETTINGS property.
-        let data: Vec<u8> = self
+        let data: Vec<u8> = self.get_property(
-            .get_property(
+            owner.owner,
-                owner.owner,
+            atoms[_XSETTINGS_SETTINGS],
-                atoms[_XSETTINGS_SETTINGS],
+            atoms[_XSETTINGS_SETTINGS],
-                atoms[_XSETTINGS_SETTINGS],
+        )?;
-            )
-            .unwrap();
 
         // Parse the property.
         let dpi_setting = read_settings(&data)?

src/platform_impl/macos/app_delegate.rs

@@ -91,7 +91,7 @@ declare_class!(
             self.set_is_running(true);
             self.dispatch_init_events();
 
-            // If the application is being launched via `EventLoop::pump_events()` then we'll
+            // If the application is being launched via `EventLoop::pump_app_events()` then we'll
             // want to stop the app once it is launched (and return to the external loop)
             //
             // In this case we still want to consider Winit's `EventLoop` to be "running",

src/platform_impl/web/event_loop/runner.rs

@@ -75,8 +75,8 @@ enum RunnerEnum {
     Pending,
     /// The `EventLoop` is being run.
     Running(Runner),
-    /// The `EventLoop` is exited after being started with `EventLoop::run`. Since
+    /// The `EventLoop` is exited after being started with `EventLoop::run_app`. Since
-    /// `EventLoop::run` takes ownership of the `EventLoop`, we can be certain
+    /// `EventLoop::run_app` takes ownership of the `EventLoop`, we can be certain
     /// that this event loop will never be run again.
     Destroyed,
 }
@@ -735,7 +735,7 @@ impl Shared {
         // * `self`, i.e. the item which triggered this event loop wakeup, which
         //   is usually a `wasm-bindgen` `Closure`, which will be dropped after
         //   returning to the JS glue code.
-        // * The `ActiveEventLoop` leaked inside `EventLoop::run` due to the
+        // * The `ActiveEventLoop` leaked inside `EventLoop::run_app` due to the
         //   JS exception thrown at the end.
         // * For each undropped `Window`:
         //     * The `register_redraw_request` closure.

src/platform_impl/web/web_sys/schedule.rs

@@ -117,9 +117,7 @@ impl Schedule {
         let channel = MessageChannel::new().unwrap();
         let closure = Closure::new(f);
         let port_1 = channel.port1();
-        port_1
+        port_1.set_onmessage(Some(closure.as_ref().unchecked_ref()));
-            .add_event_listener_with_callback("message", closure.as_ref().unchecked_ref())
-            .expect("Failed to set message handler");
         port_1.start();
 
         let port_2 = channel.port2();
@@ -178,6 +176,7 @@ impl Drop for Schedule {
             } => {
                 window.clear_timeout_with_handle(*handle);
                 port.close();
+                port.set_onmessage(None);
             }
         }
     }

src/platform_impl/windows/ime.rs

@@ -45,12 +45,12 @@ impl ImeContext {
         let mut boundary_before_char = 0;
 
         for (attr, chr) in attrs.into_iter().zip(text.chars()) {
-            let char_is_targetted =
+            let char_is_targeted =
                 attr as u32 == ATTR_TARGET_CONVERTED || attr as u32 == ATTR_TARGET_NOTCONVERTED;
 
-            if first.is_none() && char_is_targetted {
+            if first.is_none() && char_is_targeted {
                 first = Some(boundary_before_char);
-            } else if first.is_some() && last.is_none() && !char_is_targetted {
+            } else if first.is_some() && last.is_none() && !char_is_targeted {
                 last = Some(boundary_before_char);
             }
 

src/window.rs

@@ -20,7 +20,7 @@ use serde::{Deserialize, Serialize};
 ///
 /// The window is closed when dropped.
 ///
-/// # Threading
+/// ## Threading
 ///
 /// This is `Send + Sync`, meaning that it can be freely used from other
 /// threads.
@@ -30,37 +30,6 @@ use serde::{Deserialize, Serialize};
 /// window from a thread other than the main, the code is scheduled to run on
 /// the main thread, and your thread may be blocked until that completes.
 ///
-/// # Example
-///
-/// ```no_run
-/// use winit::{
-///     event::{Event, WindowEvent},
-///     event_loop::{ControlFlow, EventLoop},
-///     window::Window,
-/// };
-///
-/// let mut event_loop = EventLoop::new().unwrap();
-/// event_loop.set_control_flow(ControlFlow::Wait);
-/// let mut windows = Vec::new();
-///
-/// event_loop.run(move |event, event_loop| {
-///     match event {
-///         Event::Resumed => {
-///             let window = event_loop.create_window(Window::default_attributes()).unwrap();
-///             windows.push(window);
-///         }
-///         Event::WindowEvent {
-///             event: WindowEvent::CloseRequested,
-///             ..
-///         } => {
-///             windows.clear();
-///             event_loop.exit();
-///         }
-///         _ => (),
-///     }
-/// });
-/// ```
-///
 /// ## Platform-specific
 ///
 /// **Web:** The [`Window`], which is represented by a `HTMLElementCanvas`, can

typos.toml

@@ -0,0 +1,6 @@
+# documentation: https://github.com/crate-ci/typos/blob/master/docs/reference.md
+
+[default.extend-identifiers]
+ptd = "ptd"                         # From winwows_sys::Win32::System::Com::FORMATETC { ptd, ..}
+requestor = "requestor"             # From x11_dl::xlib::XSelectionEvent { requestor ..}
+XF86_Calculater = "XF86_Calculater" # From xkbcommon_dl::keysyms::XF86_Calculater