DPI version 0.1.0

The conversion of PhysicalUnit was wrongly computed and the tests were
not running on the CI for the dpi crate, thus it was missed, even though
the test was correctly failing.

Signed-off-by: John Nunley <dev@notgull.net>
Signed-off-by: Kirill Chibisov <contact@kchibisov.com>

.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).
@@ -46,6 +50,23 @@ Unreleased` header.
 - **Breaking:** Changed the signature of `EventLoop::with_user_event` to return a builder.
 - **Breaking:** Removed `EventLoopBuilder::with_user_event`, the functionality is now available in `EventLoop::with_user_event`.
 - 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.
+- 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.
+- On X11, filter close to zero values in mouse device events
 
 # 0.29.11
 

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

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "winit"
-version = "0.29.11"
+version = "0.29.14"
 authors = ["The winit contributors", "Pierre Krieger <pierre.krieger1708@gmail.com>"]
 description = "Cross-platform window creation library."
 keywords = ["windowing"]
@@ -64,17 +64,18 @@ cfg_aliases = "0.2.0"
 [dependencies]
 bitflags = "2"
 cursor-icon = "1.1.0"
-log = "0.4"
 rwh_04 = { package = "raw-window-handle", version = "0.4", optional = true }
 rwh_05 = { package = "raw-window-handle", version = "0.5.2", features = ["std"], optional = true }
 rwh_06 = { package = "raw-window-handle", version = "0.6", features = ["std"], optional = true }
 serde = { workspace = true, optional = true }
 smol_str = "0.2.0"
 dpi = { path = "dpi" }
+tracing = { version = "0.1.40", default_features = false }
 
 [dev-dependencies]
 image = { version = "0.24.0", default-features = false, features = ["png"] }
-simple_logger = { version = "4.2.0", default_features = false }
+tracing = { version = "0.1.40", default_features = false, features = ["log"] }
+tracing-subscriber = { version = "0.3.18", features = ["env-filter"] }
 winit = { path = ".", features = ["rwh_05"] }
 
 [target.'cfg(not(any(target_os = "android", target_os = "ios")))'.dev-dependencies]
@@ -187,7 +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 = "0.29.11"
+winit = "0.29.14"
 ```
 
 ## [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
-//! device, and the [`LogicalPosition`] / [`LogicalSize`] types correspond to the physical pixels
+//! The [`PhysicalPosition`] / [`PhysicalSize`] / [`PhysicalUnit`] types correspond with the actual pixels on the
+//! 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

@@ -3,32 +3,32 @@
 use std::thread;
 #[cfg(not(web_platform))]
 use std::time;
+
 #[cfg(web_platform)]
 use web_time as time;
 
-use simple_logger::SimpleLogger;
-use winit::{
-    event::{ElementState, Event, KeyEvent, WindowEvent},
-    event_loop::{ControlFlow, EventLoop},
-    keyboard::{Key, NamedKey},
-    window::Window,
-};
+use winit::application::ApplicationHandler;
+use winit::event::{ElementState, KeyEvent, StartCause, WindowEvent};
+use winit::event_loop::{ActiveEventLoop, ControlFlow, EventLoop};
+use winit::keyboard::{Key, NamedKey};
+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> {
-    SimpleLogger::new().init().unwrap();
+    tracing_subscriber::fmt::init();
 
     println!("Press '1' to switch to Wait mode.");
     println!("Press '2' to switch to WaitUntil mode.");
@@ -38,96 +38,110 @@ fn main() -> Result<(), impl std::error::Error> {
 
     let event_loop = EventLoop::new().unwrap();
 
-    let mut mode = Mode::Wait;
-    let mut request_redraw = false;
-    let mut wait_cancelled = false;
-    let mut close_requested = false;
+    let mut app = ControlFlowDemo::default();
+    event_loop.run_app(&mut app)
+}
 
-    let mut window = None;
-    event_loop.run(move |event, event_loop| {
-        use winit::event::StartCause;
+#[derive(Default)]
+struct ControlFlowDemo {
+    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) => {
-                wait_cancelled = match start_cause {
-                    StartCause::WaitCancelled { .. } => mode == Mode::WaitUntil,
-                    _ => false,
-                }
+            WindowEvent::CloseRequested => {
+                self.close_requested = true;
             }
-            Event::Resumed => {
-                let window_attributes = Window::default_attributes().with_title(
-                    "Press 1, 2, 3 to change control flow mode. Press R to toggle redraw requests.",
-                );
-                window = Some(event_loop.create_window(window_attributes).unwrap());
-            }
-            Event::WindowEvent { event, .. } => match event {
-                WindowEvent::CloseRequested => {
-                    close_requested = true;
+            WindowEvent::KeyboardInput {
+                event:
+                    KeyEvent {
+                        logical_key: key,
+                        state: ElementState::Pressed,
+                        ..
+                    },
+                ..
+            } => 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 {
-                    event:
-                        KeyEvent {
-                            logical_key: key,
-                            state: ElementState::Pressed,
-                            ..
-                        },
-                    ..
-                } => match key.as_ref() {
-                    // WARNING: Consider using `key_without_modifiers()` if available on your platform.
-                    // See the `key_binding` example
-                    Key::Character("1") => {
-                        mode = Mode::Wait;
-                        println!("\nmode: {mode:?}\n");
-                    }
-                    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);
+                Key::Character("2") => {
+                    self.mode = Mode::WaitUntil;
+                    println!("\nmode: {:?}\n", self.mode);
+                }
+                Key::Character("3") => {
+                    self.mode = Mode::Poll;
+                    println!("\nmode: {:?}\n", self.mode);
+                }
+                Key::Character("r") => {
+                    self.request_redraw = !self.request_redraw;
+                    println!("\nrequest_redraw: {}\n", self.request_redraw);
+                }
+                Key::Named(NamedKey::Escape) => {
+                    self.close_requested = true;
                 }
                 _ => (),
             },
-            Event::AboutToWait => {
-                if request_redraw && !wait_cancelled && !close_requested {
-                    window.as_ref().unwrap().request_redraw();
-                }
-
-                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();
-                }
+            WindowEvent::RedrawRequested => {
+                let window = self.window.as_ref().unwrap();
+                window.pre_present_notify();
+                fill::fill_window(window);
             }
             _ => (),
         }
-    })
+    }
+
+    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

@@ -11,51 +11,59 @@
 fn main() -> std::process::ExitCode {
     use std::{process::ExitCode, thread::sleep, time::Duration};
 
-    use simple_logger::SimpleLogger;
-    use winit::{
-        event::{Event, WindowEvent},
-        event_loop::EventLoop,
-        platform::pump_events::{EventLoopExtPumpEvents, PumpStatus},
-        window::Window,
-    };
+    use winit::application::ApplicationHandler;
+    use winit::event::WindowEvent;
+    use winit::event_loop::{ActiveEventLoop, EventLoop};
+    use winit::platform::pump_events::{EventLoopExtPumpEvents, PumpStatus};
+    use winit::window::{Window, WindowId};
 
     #[path = "util/fill.rs"]
     mod fill;
 
-    let mut event_loop = EventLoop::new().unwrap();
+    #[derive(Default)]
+    struct PumpDemo {
+        window: Option<Window>,
+    }
 
-    SimpleLogger::new().init().unwrap();
+    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());
+        }
 
-    let mut window = None;
+        fn window_event(
+            &mut self,
+            event_loop: &ActiveEventLoop,
+            _window_id: WindowId,
+            event: WindowEvent,
+        ) {
+            println!("{event:?}");
 
-    loop {
-        let timeout = Some(Duration::ZERO);
-        let status = event_loop.pump_events(timeout, |event, event_loop| {
-            if let Event::WindowEvent { event, .. } = &event {
-                // Print only Window events to reduce noise
-                println!("{event:?}");
-            }
+            let window = match self.window.as_ref() {
+                Some(window) => window,
+                None => return,
+            };
 
             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();
+                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 app = PumpDemo::default();
+
+    loop {
+        let timeout = Some(Duration::ZERO);
+        let status = event_loop.pump_app_events(timeout, &mut app);
 
         if let PumpStatus::Exit(exit_code) = status {
             break ExitCode::from(exit_code as u8);

examples/run_on_demand.rs

@@ -2,88 +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 simple_logger::SimpleLogger;
-
-    use winit::{
-        error::EventLoopError,
-        event::{Event, WindowEvent},
-        event_loop::EventLoop,
-        platform::run_on_demand::EventLoopExtRunOnDemand,
-        window::{Window, WindowId},
-    };
+    use winit::application::ApplicationHandler;
+    use winit::event::WindowEvent;
+    use winit::event_loop::{ActiveEventLoop, EventLoop};
+    use winit::platform::run_on_demand::EventLoopExtRunOnDemand;
+    use winit::window::{Window, WindowId};
 
     #[path = "util/fill.rs"]
     mod fill;
 
     #[derive(Default)]
     struct App {
+        idx: usize,
         window_id: Option<WindowId>,
         window: Option<Window>,
     }
 
-    SimpleLogger::new().init().unwrap();
-    let mut event_loop = EventLoop::new().unwrap();
-
-    fn run_app(event_loop: &mut EventLoop<()>, idx: usize) -> Result<(), EventLoopError> {
-        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);
+    impl ApplicationHandler for App {
+        fn about_to_wait(&mut self, _event_loop: &ActiveEventLoop) {
+            if let Some(window) = self.window.as_ref() {
+                window.request_redraw();
             }
-        })
+        }
+
+        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::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(())
+    event_loop.run_app(&mut state).map_err(Into::into)
 }
 
 #[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
-        // is moved inside the closure.
+        // SAFETY: we drop the context right before the event loop is stopped, thus making it safe.
         #[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) {
-        println!("Device event: {event:?}");
+    fn device_event(
+        &mut self,
+        _event_loop: &ActiveEventLoop,
+        device_id: DeviceId,
+        event: DeviceEvent,
+    ) {
+        println!("Device {device_id:?} event: {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"
-            };
+    fn resumed(&mut self, event_loop: &ActiveEventLoop) {
+        println!("Resumed the event loop");
+        self.dump_monitors(event_loop);
 
-            if let Some(name) = monitor.name() {
-                println!("{intro}: {name}");
-            } else {
-                println!("{intro}: [no name]");
-            }
+        // Create initial window.
+        self.create_window(event_loop, None)
+            .expect("failed to create initial window");
 
-            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!();
-            }
+        self.print_help();
+    }
 
-            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
-                );
-            }
+    fn about_to_wait(&mut self, event_loop: &ActiveEventLoop) {
+        if self.windows.is_empty() {
+            println!("No windows left, exiting...");
+            event_loop.exit();
         }
     }
 
-    /// 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(),
-            );
-        }
+    #[cfg(not(any(android_platform, ios_platform)))]
+    fn exiting(&mut self, _event_loop: &ActiveEventLoop) {
+        // We must drop the context here.
+        self.context = None;
     }
 }
 
@@ -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

@@ -3,40 +3,37 @@ use std::error::Error;
 
 #[cfg(x11_platform)]
 fn main() -> Result<(), Box<dyn Error>> {
-    use simple_logger::SimpleLogger;
-
-    use winit::{
-        event::{Event, WindowEvent},
-        event_loop::EventLoop,
-        platform::x11::WindowAttributesExtX11,
-        window::Window,
-    };
+    use winit::application::ApplicationHandler;
+    use winit::event::WindowEvent;
+    use winit::event_loop::{ActiveEventLoop, EventLoop};
+    use winit::platform::x11::WindowAttributesExtX11;
+    use winit::window::{Window, WindowId};
 
     #[path = "util/fill.rs"]
     mod fill;
 
-    // First argument should be a 32-bit X11 window ID.
-    let parent_window_id = std::env::args()
-        .nth(1)
-        .ok_or("Expected a 32-bit X11 window ID as the first argument.")?
-        .parse::<u32>()?;
+    pub struct XEmbedDemo {
+        parent_window_id: u32,
+        window: Option<Window>,
+    }
 
-    SimpleLogger::new().init().unwrap();
-    let event_loop = EventLoop::new()?;
-
-    let mut window = None;
-    event_loop.run(move |event, event_loop| match event {
-        Event::Resumed => {
+    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(parent_window_id);
+                .with_embed_parent_window(self.parent_window_id);
 
-            window = Some(event_loop.create_window(window_attributes).unwrap());
+            self.window = Some(event_loop.create_window(window_attributes).unwrap());
         }
-        Event::WindowEvent { event, .. } => {
-            let window = window.as_ref().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 => {
@@ -46,13 +43,26 @@ fn main() -> Result<(), Box<dyn Error>> {
                 _ => (),
             }
         }
-        Event::AboutToWait => {
-            window.as_ref().unwrap().request_redraw();
-        }
-        _ => (),
-    })?;
 
-    Ok(())
+        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)
+        .ok_or("Expected a 32-bit X11 window ID as the first argument.")?
+        .parse::<u32>()?;
+
+    tracing_subscriber::fmt::init();
+    let event_loop = EventLoop::new()?;
+
+    let mut app = XEmbedDemo {
+        parent_window_id,
+        window: None,
+    };
+    event_loop.run_app(&mut app).map_err(Into::into)
 }
 
 #[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

@@ -88,6 +88,15 @@ impl CustomCursor {
         hotspot_x: u16,
         hotspot_y: u16,
     ) -> Result<CustomCursorSource, BadImage> {
+        let _span = tracing::debug_span!(
+            "winit::Cursor::from_rgba",
+            width,
+            height,
+            hotspot_x,
+            hotspot_y
+        )
+        .entered();
+
         Ok(CustomCursorSource {
             inner: PlatformCustomCursorSource::from_rgba(
                 rgba.into(),
@@ -186,6 +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) {
-//!         event_handler(e, elwt);
+//!     for event in (window events, user events, device events) {
+//!         // This will pick the right method on the application based on the event.
+//!         app.handle_event(event_loop, event);
 //!     }
 //!
-//!     for w in (redraw windows) {
-//!         event_handler(RedrawRequested(w), elwt);
+//!     for window_id in (redraw windows) {
+//!         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
-    /// 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.
+    /// [`ApplicationHandler::new_events`]: crate::application::ApplicationHandler::new_events
     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
-    ///
-    /// 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
+    /// [`ApplicationHandler::suspended`]: crate::application::ApplicationHandler::suspended
     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
-    /// 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
+    /// [`ApplicationHandler::resumed`]: crate::application::ApplicationHandler::resumed
     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
-    /// 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.
+    /// [`ApplicationHandler::about_to_wait`]: crate::application::ApplicationHandler::about_to_wait
     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
-    /// gets emitted. You generally want to treat this as a "do on quit" event.
+    /// [`ApplicationHandler::exiting`]: crate::application::ApplicationHandler::exiting
     LoopExiting,
 
-    /// Emitted when the application has received a memory warning.
+    /// See [`ApplicationHandler::memory_warning`] for details.
     ///
-    /// ## 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 / Wayland / Windows / Orbital:** Unsupported.
+    /// [`ApplicationHandler::memory_warning`]: crate::application::ApplicationHandler::memory_warning
     MemoryWarning,
 }
 
@@ -781,6 +638,31 @@ pub struct KeyEvent {
     /// On some systems, holding down a key for some period of time causes that key to be repeated
     /// as though it were being pressed and released repeatedly. This field is `true` if and only if
     /// this event is the result of one of those repeats.
+    ///
+    /// # Example
+    ///
+    /// In games, you often want to ignore repated key events - this can be
+    /// done by ignoring events where this property is set.
+    ///
+    /// ```
+    /// use winit::event::{WindowEvent, KeyEvent, ElementState};
+    /// use winit::keyboard::{KeyCode, PhysicalKey};
+    /// # let window_event = WindowEvent::RedrawRequested; // To make the example compile
+    /// match window_event {
+    ///     WindowEvent::KeyboardInput {
+    ///         event: KeyEvent {
+    ///             physical_key: PhysicalKey::Code(KeyCode::KeyW),
+    ///             state: ElementState::Pressed,
+    ///             repeat: false,
+    ///             ..
+    ///         },
+    ///         ..
+    ///     } => {
+    ///          // The physical key `W` was pressed, and it was not a repeat
+    ///     }
+    ///     _ => {} // Handle other events
+    /// }
+    /// ```
     pub repeat: bool,
 
     /// Platform-specific key event information.

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};
@@ -109,6 +110,8 @@ impl<T> EventLoopBuilder<T> {
     )]
     #[inline]
     pub fn build(&mut self) -> Result<EventLoop<T>, EventLoopError> {
+        let _span = tracing::debug_span!("winit::EventLoopBuilder::build").entered();
+
         if EVENT_LOOP_CREATED.swap(true, Ordering::Relaxed) {
             return Err(EventLoopError::RecreationAttempt);
         }
@@ -213,8 +216,22 @@ impl<T> EventLoop<T> {
         }
     }
 
-    /// Runs the event loop in the calling thread and calls the given `event_handler` closure
-    /// to dispatch any pending events.
+    /// See [`run_app`].
+    ///
+    /// [`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.
     ///
@@ -229,10 +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.
@@ -240,15 +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()
-    /// [^1]: `EventLoopExtWebSys::spawn()` is only available on Web.
+    /// [`run_app()`]: Self::run_app()
+    /// [^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>
-    where
-        F: FnMut(Event<T>, &ActiveEventLoop),
-    {
-        self.event_loop.run(event_handler)
+    pub fn run_app<A: ApplicationHandler<T>>(self, app: &mut A) -> Result<(), EventLoopError> {
+        self.event_loop
+            .run(|event, event_loop| dispatch_event_for_app(app, event_loop, event))
     }
 
     /// Creates an [`EventLoopProxy`] that can be used to dispatch user events
@@ -274,6 +289,12 @@ impl<T> EventLoop<T> {
     ///
     /// [`DeviceEvent`]: crate::event::DeviceEvent
     pub fn listen_device_events(&self, allowed: DeviceEvents) {
+        let _span = tracing::debug_span!(
+            "winit::EventLoop::listen_device_events",
+            allowed = ?allowed
+        )
+        .entered();
+
         self.event_loop
             .window_target()
             .p
@@ -295,6 +316,12 @@ impl<T> EventLoop<T> {
     #[deprecated = "use `ActiveEventLoop::create_window` instead"]
     #[inline]
     pub fn create_window(&self, window_attributes: WindowAttributes) -> Result<Window, OsError> {
+        let _span = tracing::debug_span!(
+            "winit::EventLoop::create_window",
+            window_attributes = ?window_attributes
+        )
+        .entered();
+
         let window =
             platform_impl::Window::new(&self.event_loop.window_target().p, window_attributes)?;
         Ok(Window { window })
@@ -328,11 +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()
     }
@@ -342,11 +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()
     }
@@ -363,18 +390,28 @@ impl ActiveEventLoop {
     ///   see the web platform module for more information.
     #[inline]
     pub fn create_window(&self, window_attributes: WindowAttributes) -> Result<Window, OsError> {
+        let _span = tracing::debug_span!(
+            "winit::ActiveEventLoop::create_window",
+            window_attributes = ?window_attributes
+        )
+        .entered();
+
         let window = platform_impl::Window::new(&self.p, window_attributes)?;
         Ok(Window { window })
     }
 
     /// Create custom cursor.
     pub fn create_custom_cursor(&self, custom_cursor: CustomCursorSource) -> CustomCursor {
+        let _span = tracing::debug_span!("winit::ActiveEventLoop::create_custom_cursor",).entered();
+
         self.p.create_custom_cursor(custom_cursor)
     }
 
     /// Returns the list of all the monitors available on the system.
     #[inline]
     pub fn available_monitors(&self) -> impl Iterator<Item = MonitorHandle> {
+        let _span = tracing::debug_span!("winit::ActiveEventLoop::available_monitors",).entered();
+
         #[allow(clippy::useless_conversion)] // false positive on some platforms
         self.p
             .available_monitors()
@@ -391,6 +428,8 @@ impl ActiveEventLoop {
     /// **Wayland / Web:** Always returns `None`.
     #[inline]
     pub fn primary_monitor(&self) -> Option<MonitorHandle> {
+        let _span = tracing::debug_span!("winit::ActiveEventLoop::primary_monitor",).entered();
+
         self.p
             .primary_monitor()
             .map(|inner| MonitorHandle { inner })
@@ -408,6 +447,12 @@ impl ActiveEventLoop {
     ///
     /// [`DeviceEvent`]: crate::event::DeviceEvent
     pub fn listen_device_events(&self, allowed: DeviceEvents) {
+        let _span = tracing::debug_span!(
+            "winit::ActiveEventLoop::listen_device_events",
+            allowed = ?allowed
+        )
+        .entered();
+
         self.p.listen_device_events(allowed);
     }
 
@@ -425,6 +470,8 @@ impl ActiveEventLoop {
     ///
     /// See [`LoopExiting`](Event::LoopExiting).
     pub fn exit(&self) {
+        let _span = tracing::debug_span!("winit::ActiveEventLoop::exit",).entered();
+
         self.p.exit()
     }
 
@@ -530,6 +577,8 @@ impl<T: 'static> EventLoopProxy<T> {
     ///
     /// [`UserEvent(event)`]: Event::UserEvent
     pub fn send_event(&self, event: T) -> Result<(), EventLoopClosed<T>> {
+        let _span = tracing::debug_span!("winit::EventLoopProxy::send_event",).entered();
+
         self.event_loop_proxy.send_event(event)
     }
 }
@@ -592,3 +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/icon.rs

@@ -118,6 +118,8 @@ impl Icon {
     /// The length of `rgba` must be divisible by 4, and `width * height` must equal
     /// `rgba.len() / 4`. Otherwise, this will return a `BadIcon` error.
     pub fn from_rgba(rgba: Vec<u8>, width: u32, height: u32) -> Result<Self, BadIcon> {
+        let _span = tracing::debug_span!("winit::Icon::from_rgba", width, height).entered();
+
         Ok(Icon {
             inner: PlatformIcon::from_rgba(rgba, width, height)?,
         })

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::{
-//!     event::{Event, WindowEvent},
-//!     event_loop::{ControlFlow, EventLoop},
-//!     window::Window,
-//! };
+//! use winit::application::ApplicationHandler;
+//! use winit::event::WindowEvent;
+//! use winit::event_loop::{ActiveEventLoop, ControlFlow, EventLoop};
+//! 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;
-//!
-//! 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.
-//!         },
-//!         _ => ()
-//!     }
-//! });
+//! let mut app = App::default();
+//! event_loop.run_app(&mut app);
 //! ```
 //!
 //! [`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 = "0.29.11", features = [ "android-native-activity" ] }`
+//! 2. Enable the `"android-native-activity"` feature for Winit: `winit = { version = "0.29.14", 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::{
-    event::Event,
-    event_loop::{ActiveEventLoop, EventLoop},
-};
-
-/// The return status for `pump_events`
-pub enum PumpStatus {
-    /// Continue running external loop.
-    Continue,
-    /// Exit external loop.
-    Exit(i32),
-}
+use crate::application::ApplicationHandler;
+use crate::event::Event;
+use crate::event_loop::{self, ActiveEventLoop, EventLoop};
 
 /// 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::{
-    error::EventLoopError,
-    event::Event,
-    event_loop::{ActiveEventLoop, EventLoop},
-};
+use crate::application::ApplicationHandler;
+use crate::error::EventLoopError;
+use crate::event::Event;
+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
-    /// to dispatch any window system events.
+    /// See [`run_app_on_demand`].
     ///
-    /// 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
-    /// `NewEvents(Init)` and `Resumed` event (even on platforms that have no suspend/resume
-    /// lifecycle) - which can be used to consistently initialize application state.
+    /// Each time `run_app_on_demand` is called the startup sequence of `init`, followed by
+    /// `resume` is being preserved.
     ///
     /// See the [`set_control_flow()`] docs on how to change the event loop's behavior.
     ///
@@ -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
-    /// the ability to re-run a single event loop more than once
+    /// You are strongly encouraged to use [`EventLoop::run_app()`] for portability, unless you
+    /// specifically need the ability to re-run a single event loop more than once
     ///
     /// # Supported Platforms
     /// - 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>
-    where
-        F: FnMut(Event<Self::UserEvent>, &ActiveEventLoop);
+    fn run_app_on_demand<A: ApplicationHandler<Self::UserEvent>>(
+        &mut self,
+        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/android/keycodes.rs

@@ -174,7 +174,7 @@ pub fn character_map_and_combine_key(
     let key_map = match app.device_key_character_map(device_id) {
         Ok(key_map) => key_map,
         Err(err) => {
-            log::warn!("Failed to look up `KeyCharacterMap` for device {device_id}: {err:?}");
+            tracing::warn!("Failed to look up `KeyCharacterMap` for device {device_id}: {err:?}");
             return None;
         }
     };
@@ -188,7 +188,7 @@ pub fn character_map_and_combine_key(
                         Ok(Some(key)) => Some(key),
                         Ok(None) => None,
                         Err(err) => {
-                            log::warn!("KeyEvent: Failed to combine 'dead key' accent '{accent}' with '{unicode}': {err:?}");
+                            tracing::warn!("KeyEvent: Failed to combine 'dead key' accent '{accent}' with '{unicode}': {err:?}");
                             None
                         }
                     }
@@ -213,7 +213,7 @@ pub fn character_map_and_combine_key(
             None
         }
         Err(err) => {
-            log::warn!("KeyEvent: Failed to get key map character: {err:?}");
+            tracing::warn!("KeyEvent: Failed to get key map character: {err:?}");
             *combining_accent = None;
             None
         }

src/platform_impl/android/mod.rs

@@ -16,7 +16,7 @@ use android_activity::input::{InputEvent, KeyAction, Keycode, MotionAction};
 use android_activity::{
     AndroidApp, AndroidAppWaker, ConfigurationRef, InputStatus, MainEvent, Rect,
 };
-use log::{debug, trace, warn};
+use tracing::{debug, trace, warn};
 
 use crate::{
     cursor::Cursor,
@@ -330,7 +330,7 @@ impl<T: 'static> EventLoop<T> {
                 }
             },
             Err(err) => {
-                log::warn!("Failed to get input events iterator: {err:?}");
+                tracing::warn!("Failed to get input events iterator: {err:?}");
             }
         }
 
@@ -1014,7 +1014,7 @@ impl Window {
         if let Some(native_window) = self.app.native_window().as_ref() {
             native_window.raw_window_handle()
         } else {
-            log::error!("Cannot get the native window, it's null and will always be null before Event::Resumed and after Event::Suspended. Make sure you only call this function between those events.");
+            tracing::error!("Cannot get the native window, it's null and will always be null before Event::Resumed and after Event::Suspended. Make sure you only call this function between those events.");
             Err(rwh_06::HandleError::Unavailable)
         }
     }

src/platform_impl/ios/app_state.rs

@@ -622,9 +622,9 @@ pub(crate) fn handle_nonuser_events<I: IntoIterator<Item = EventWrapper>>(
         match wrapper {
             EventWrapper::StaticEvent(event) => {
                 if !processing_redraws && event.is_redraw() {
-                    log::info!("processing `RedrawRequested` during the main event loop");
+                    tracing::info!("processing `RedrawRequested` during the main event loop");
                 } else if processing_redraws && !event.is_redraw() {
-                    log::warn!(
+                    tracing::warn!(
                         "processing non `RedrawRequested` event after the main event loop: {:#?}",
                         event
                     );
@@ -676,9 +676,9 @@ pub(crate) fn handle_nonuser_events<I: IntoIterator<Item = EventWrapper>>(
             match wrapper {
                 EventWrapper::StaticEvent(event) => {
                     if !processing_redraws && event.is_redraw() {
-                        log::info!("processing `RedrawRequested` during the main event loop");
+                        tracing::info!("processing `RedrawRequested` during the main event loop");
                     } else if processing_redraws && !event.is_redraw() {
-                        log::warn!(
+                        tracing::warn!(
                             "processing non-`RedrawRequested` event after the main event loop: {:#?}",
                             event
                         );
@@ -911,7 +911,7 @@ macro_rules! os_capabilities {
         impl OSCapabilities {$(
             $(#[$attr])*
             pub fn $error_name(&self, extra_msg: &str) {
-                log::warn!(
+                tracing::warn!(
                     concat!("`", $objc_call, "` requires iOS {}.{}+. This device is running iOS {}.{}.{}. {}"),
                     $major, $minor, self.os_version.majorVersion, self.os_version.minorVersion, self.os_version.patchVersion,
                     extra_msg

src/platform_impl/ios/event_loop.rs

@@ -85,7 +85,7 @@ impl ActiveEventLoop {
     pub(crate) fn exit(&self) {
         // https://developer.apple.com/library/archive/qa/qa1561/_index.html
         // it is not possible to quit an iOS app gracefully and programmatically
-        log::warn!("`ControlFlow::Exit` ignored on iOS");
+        tracing::warn!("`ControlFlow::Exit` ignored on iOS");
     }
 
     pub(crate) fn exiting(&self) -> bool {
@@ -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

@@ -3,10 +3,10 @@
 use std::collections::VecDeque;
 
 use icrate::Foundation::{CGFloat, CGPoint, CGRect, CGSize, MainThreadBound, MainThreadMarker};
-use log::{debug, warn};
 use objc2::rc::Id;
 use objc2::runtime::{AnyObject, NSObject};
 use objc2::{class, declare_class, msg_send, msg_send_id, mutability, ClassType, DeclaredClass};
+use tracing::{debug, warn};
 
 use super::app_state::EventWrapper;
 use super::uikit::{
@@ -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

@@ -4,10 +4,10 @@ use std::ptr::{self, NonNull};
 use std::sync::atomic::{AtomicBool, Ordering};
 
 use crate::utils::Lazy;
-use log::warn;
 use smol_str::SmolStr;
 #[cfg(wayland_platform)]
 use std::os::unix::io::OwnedFd;
+use tracing::warn;
 use xkbcommon_dl::{
     self as xkb, xkb_compose_status, xkb_context, xkb_context_flags, xkbcommon_compose_handle,
     xkbcommon_handle, XkbCommon, XkbCommonCompose,
@@ -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) => {
-                let state = self.context.compose_state1.as_mut().unwrap();
-                Ok(state.get_string(self.context.scratch_buffer))
-            }
+            ComposeStatus::Accepted(status) => match status {
+                xkb_compose_status::XKB_COMPOSE_COMPOSED => {
+                    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(()),
         }
     }
@@ -451,7 +456,7 @@ fn byte_slice_to_smol_str(bytes: &[u8]) -> Option<SmolStr> {
     std::str::from_utf8(bytes)
         .map(SmolStr::new)
         .map_err(|e| {
-            log::warn!(
+            tracing::warn!(
                 "UTF-8 received from libxkbcommon ({:?}) was invalid: {e}",
                 bytes
             )

src/platform_impl/linux/mod.rs

@@ -687,7 +687,7 @@ unsafe extern "C" fn x_error_callback(
 
         // Don't log error.
         if !error_handled {
-            log::error!("X11 error: {:#?}", error);
+            tracing::error!("X11 error: {:#?}", error);
             // XXX only update the error, if it wasn't handled by any of the hooks.
             *xconn.latest_error.lock().unwrap() = Some(error);
         }

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

@@ -584,7 +584,7 @@ impl<T: 'static> EventLoop<T> {
         };
 
         self.event_loop.dispatch(timeout, state).map_err(|error| {
-            log::error!("Error dispatching event loop: {}", error);
+            tracing::error!("Error dispatching event loop: {}", error);
             error.into()
         })
     }

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

@@ -5,7 +5,7 @@ use std::time::Duration;
 
 use calloop::timer::{TimeoutAction, Timer};
 use calloop::{LoopHandle, RegistrationToken};
-use log::warn;
+use tracing::warn;
 
 use sctk::reexports::client::protocol::wl_keyboard::WlKeyboard;
 use sctk::reexports::client::protocol::wl_keyboard::{

src/platform_impl/linux/wayland/state.rs

@@ -133,7 +133,7 @@ impl WinitState {
         ) {
             Ok(c) => Some(c),
             Err(e) => {
-                log::warn!("Subcompositor protocol not available, ignoring CSD: {e:?}");
+                tracing::warn!("Subcompositor protocol not available, ignoring CSD: {e:?}");
                 None
             }
         };

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

@@ -14,7 +14,7 @@ use sctk::shell::xdg::window::Window as SctkWindow;
 use sctk::shell::xdg::window::WindowDecorations;
 use sctk::shell::WaylandSurface;
 
-use log::warn;
+use tracing::warn;
 
 use crate::dpi::{LogicalSize, PhysicalPosition, PhysicalSize, Position, Size};
 use crate::error::{ExternalError, NotSupportedError, OsError as RootOsError};

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

@@ -5,7 +5,7 @@ use std::sync::{Arc, Mutex, Weak};
 use std::time::Duration;
 
 use ahash::HashSet;
-use log::{info, warn};
+use tracing::{info, warn};
 
 use sctk::reexports::client::backend::ObjectId;
 use sctk::reexports::client::protocol::wl_seat::WlSeat;
@@ -727,7 +727,7 @@ impl WindowState {
             RootCustomCursor {
                 inner: PlatformCustomCursor::X(_),
             } => {
-                log::error!("passed a X11 cursor to Wayland backend");
+                tracing::error!("passed a X11 cursor to Wayland backend");
                 return;
             }
         };
@@ -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

@@ -33,9 +33,10 @@ use crate::platform_impl::platform::common::xkb::Context;
 use crate::platform_impl::platform::x11::ime::{ImeEvent, ImeEventReceiver, ImeRequest};
 use crate::platform_impl::platform::x11::ActiveEventLoop;
 use crate::platform_impl::platform::ActiveEventLoop as PlatformActiveEventLoop;
+use crate::platform_impl::x11::util::cookie::GenericEventCookie;
 use crate::platform_impl::x11::{
     atoms::*, mkdid, mkwid, util, CookieResultExt, Device, DeviceId, DeviceInfo, Dnd, DndState,
-    GenericEventCookie, ImeReceiver, ScrollOrientation, UnownedWindow, WindowId,
+    ImeReceiver, ScrollOrientation, UnownedWindow, WindowId,
 };
 
 /// The maximum amount of X modifiers to replay.
@@ -184,14 +185,15 @@ impl EventProcessor {
             }
             xlib::GenericEvent => {
                 let wt = Self::window_target(&self.target);
-                let xev = match GenericEventCookie::from_event(&wt.xconn, *xev) {
-                    Some(xev) if xev.cookie.extension as u8 == self.xi2ext.major_opcode => {
-                        xev.cookie
-                    }
-                    _ => return,
-                };
+                let xev: GenericEventCookie =
+                    match GenericEventCookie::from_event(wt.xconn.clone(), *xev) {
+                        Some(xev) if xev.extension() == self.xi2ext.major_opcode => xev,
+                        _ => return,
+                    };
 
-                match xev.evtype {
+                let evtype = xev.evtype();
+
+                match evtype {
                     ty @ xinput2::XI_ButtonPress | ty @ xinput2::XI_ButtonRelease => {
                         let state = if ty == xinput2::XI_ButtonPress {
                             ElementState::Pressed
@@ -199,7 +201,7 @@ impl EventProcessor {
                             ElementState::Released
                         };
 
-                        let xev: &XIDeviceEvent = unsafe { &*(xev.data as *const _) };
+                        let xev: &XIDeviceEvent = unsafe { xev.as_event() };
                         self.update_mods_from_xinput2_event(
                             &xev.mods,
                             &xev.group,
@@ -209,7 +211,7 @@ impl EventProcessor {
                         self.xinput2_button_input(xev, state, &mut callback);
                     }
                     xinput2::XI_Motion => {
-                        let xev: &XIDeviceEvent = unsafe { &*(xev.data as *const _) };
+                        let xev: &XIDeviceEvent = unsafe { xev.as_event() };
                         self.update_mods_from_xinput2_event(
                             &xev.mods,
                             &xev.group,
@@ -219,11 +221,11 @@ impl EventProcessor {
                         self.xinput2_mouse_motion(xev, &mut callback);
                     }
                     xinput2::XI_Enter => {
-                        let xev: &XIEnterEvent = unsafe { &*(xev.data as *const _) };
+                        let xev: &XIEnterEvent = unsafe { xev.as_event() };
                         self.xinput2_mouse_enter(xev, &mut callback);
                     }
                     xinput2::XI_Leave => {
-                        let xev: &XILeaveEvent = unsafe { &*(xev.data as *const _) };
+                        let xev: &XILeaveEvent = unsafe { xev.as_event() };
                         self.update_mods_from_xinput2_event(
                             &xev.mods,
                             &xev.group,
@@ -233,51 +235,51 @@ impl EventProcessor {
                         self.xinput2_mouse_left(xev, &mut callback);
                     }
                     xinput2::XI_FocusIn => {
-                        let xev: &XIFocusInEvent = unsafe { &*(xev.data as *const _) };
+                        let xev: &XIFocusInEvent = unsafe { xev.as_event() };
                         self.xinput2_focused(xev, &mut callback);
                     }
                     xinput2::XI_FocusOut => {
-                        let xev: &XIFocusOutEvent = unsafe { &*(xev.data as *const _) };
+                        let xev: &XIFocusOutEvent = unsafe { xev.as_event() };
                         self.xinput2_unfocused(xev, &mut callback);
                     }
                     xinput2::XI_TouchBegin | xinput2::XI_TouchUpdate | xinput2::XI_TouchEnd => {
-                        let phase = match xev.evtype {
+                        let phase = match evtype {
                             xinput2::XI_TouchBegin => TouchPhase::Started,
                             xinput2::XI_TouchUpdate => TouchPhase::Moved,
                             xinput2::XI_TouchEnd => TouchPhase::Ended,
                             _ => unreachable!(),
                         };
 
-                        let xev: &XIDeviceEvent = unsafe { &*(xev.data as *const _) };
+                        let xev: &XIDeviceEvent = unsafe { xev.as_event() };
                         self.xinput2_touch(xev, phase, &mut callback);
                     }
                     xinput2::XI_RawButtonPress | xinput2::XI_RawButtonRelease => {
-                        let state = match xev.evtype {
+                        let state = match evtype {
                             xinput2::XI_RawButtonPress => ElementState::Pressed,
                             xinput2::XI_RawButtonRelease => ElementState::Released,
                             _ => unreachable!(),
                         };
 
-                        let xev: &XIRawEvent = unsafe { &*(xev.data as *const _) };
+                        let xev: &XIRawEvent = unsafe { xev.as_event() };
                         self.xinput2_raw_button_input(xev, state, &mut callback);
                     }
                     xinput2::XI_RawMotion => {
-                        let xev: &XIRawEvent = unsafe { &*(xev.data as *const _) };
+                        let xev: &XIRawEvent = unsafe { xev.as_event() };
                         self.xinput2_raw_mouse_motion(xev, &mut callback);
                     }
                     xinput2::XI_RawKeyPress | xinput2::XI_RawKeyRelease => {
-                        let state = match xev.evtype {
+                        let state = match evtype {
                             xinput2::XI_RawKeyPress => ElementState::Pressed,
                             xinput2::XI_RawKeyRelease => ElementState::Released,
                             _ => unreachable!(),
                         };
 
-                        let xev: &xinput2::XIRawEvent = unsafe { &*(xev.data as *const _) };
+                        let xev: &xinput2::XIRawEvent = unsafe { xev.as_event() };
                         self.xinput2_raw_key_input(xev, state, &mut callback);
                     }
 
                     xinput2::XI_HierarchyChanged => {
-                        let xev: &XIHierarchyEvent = unsafe { &*(xev.data as *const _) };
+                        let xev: &XIHierarchyEvent = unsafe { xev.as_event() };
                         self.xinput2_hierarchy_changed(xev, &mut callback);
                     }
                     _ => {}
@@ -979,7 +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 {
@@ -1518,8 +1520,8 @@ impl EventProcessor {
         let mask =
             unsafe { slice::from_raw_parts(xev.valuators.mask, xev.valuators.mask_len as usize) };
         let mut value = xev.raw_values;
-        let mut mouse_delta = (0.0, 0.0);
-        let mut scroll_delta = (0.0, 0.0);
+        let mut mouse_delta = util::Delta::default();
+        let mut scroll_delta = util::Delta::default();
         for i in 0..xev.valuators.mask_len * 8 {
             if !xinput2::XIMaskIsSet(mask, i) {
                 continue;
@@ -1529,10 +1531,10 @@ impl EventProcessor {
             // We assume that every XInput2 device with analog axes is a pointing device emitting
             // relative coordinates.
             match i {
-                0 => mouse_delta.0 = x,
-                1 => mouse_delta.1 = x,
-                2 => scroll_delta.0 = x as f32,
-                3 => scroll_delta.1 = x as f32,
+                0 => mouse_delta.set_x(x),
+                1 => mouse_delta.set_y(x),
+                2 => scroll_delta.set_x(x as f32),
+                3 => scroll_delta.set_y(x as f32),
                 _ => {}
             }
 
@@ -1548,7 +1550,7 @@ impl EventProcessor {
             value = unsafe { value.offset(1) };
         }
 
-        if mouse_delta != (0.0, 0.0) {
+        if let Some(mouse_delta) = mouse_delta.consume() {
             let event = Event::DeviceEvent {
                 device_id: did,
                 event: DeviceEvent::MouseMotion { delta: mouse_delta },
@@ -1556,7 +1558,7 @@ impl EventProcessor {
             callback(&self.target, event);
         }
 
-        if scroll_delta != (0.0, 0.0) {
+        if let Some(scroll_delta) = scroll_delta.consume() {
             let event = Event::DeviceEvent {
                 device_id: did,
                 event: DeviceEvent::MouseWheel {
@@ -1776,7 +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/ime/context.rs

@@ -86,7 +86,7 @@ extern "C" fn preedit_draw_callback(
     let chg_range =
         call_data.chg_first as usize..(call_data.chg_first + call_data.chg_length) as usize;
     if chg_range.start > client_data.text.len() || chg_range.end > client_data.text.len() {
-        log::warn!(
+        tracing::warn!(
             "invalid chg range: buffer length={}, but chg_first={} chg_lengthg={}",
             client_data.text.len(),
             call_data.chg_first,

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

@@ -10,9 +10,9 @@ use std::sync::{
     Arc,
 };
 
-use log::debug;
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
+use tracing::debug;
 
 use super::{ffi, util, XConnection, XError};
 

src/platform_impl/linux/x11/mod.rs

@@ -18,7 +18,7 @@ use calloop::generic::Generic;
 use calloop::EventLoop as Loop;
 use calloop::{ping::Ping, Readiness};
 use libc::{setlocale, LC_CTYPE};
-use log::warn;
+use tracing::warn;
 
 use x11rb::connection::RequestConnection;
 use x11rb::errors::{ConnectError, ConnectionError, IdsExhausted, ReplyError};
@@ -66,6 +66,9 @@ const ALL_DEVICES: u16 = 0;
 const ALL_MASTER_DEVICES: u16 = 1;
 const ICONIC_STATE: u32 = 3;
 
+/// The underlying x11rb connection that we are using.
+type X11rbConnection = x11rb::xcb_ffi::XCBConnection;
+
 type X11Source = Generic<BorrowedFd<'static>>;
 
 struct WakeSender<T> {
@@ -480,7 +483,7 @@ impl<T: 'static> EventLoop<T> {
             .dispatch(timeout, &mut self.state)
             .map_err(std::io::Error::from)
         {
-            log::error!("Failed to poll for events: {error:?}");
+            tracing::error!("Failed to poll for events: {error:?}");
             let exit_code = error.raw_os_error().unwrap_or(1);
             self.set_exit_code(exit_code);
             return;
@@ -564,7 +567,7 @@ impl<T: 'static> EventLoop<T> {
                     callback(event, &self.event_processor.target)
                 }
                 Some(Err(e)) => {
-                    log::error!("Failed to get activation token: {}", e);
+                    tracing::error!("Failed to get activation token: {}", e);
                 }
                 None => {}
             }
@@ -884,6 +887,9 @@ pub enum X11Error {
 
     /// Unable to parse xsettings.
     XsettingsParse(xsettings::ParserError),
+
+    /// Failed to get property.
+    GetProperty(util::GetPropertyError),
 }
 
 impl fmt::Display for X11Error {
@@ -893,6 +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!(
@@ -985,8 +992,11 @@ impl From<xsettings::ParserError> for X11Error {
     }
 }
 
-/// The underlying x11rb connection that we are using.
-type X11rbConnection = x11rb::xcb_ffi::XCBConnection;
+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>;
@@ -1003,34 +1013,6 @@ impl<'a, E: fmt::Debug> CookieResultExt for Result<VoidCookie<'a>, E> {
     }
 }
 
-/// XEvents of type GenericEvent store their actual data in an XGenericEventCookie data structure. This is a wrapper to
-/// extract the cookie from a GenericEvent XEvent and release the cookie data once it has been processed
-struct GenericEventCookie<'a> {
-    xconn: &'a XConnection,
-    cookie: ffi::XGenericEventCookie,
-}
-
-impl<'a> GenericEventCookie<'a> {
-    fn from_event(xconn: &XConnection, event: ffi::XEvent) -> Option<GenericEventCookie<'_>> {
-        unsafe {
-            let mut cookie: ffi::XGenericEventCookie = From::from(event);
-            if (xconn.xlib.XGetEventData)(xconn.display, &mut cookie) == ffi::True {
-                Some(GenericEventCookie { xconn, cookie })
-            } else {
-                None
-            }
-        }
-    }
-}
-
-impl<'a> Drop for GenericEventCookie<'a> {
-    fn drop(&mut self) {
-        unsafe {
-            (self.xconn.xlib.XFreeEventData)(self.xconn.display, &mut self.cookie);
-        }
-    }
-}
-
 fn mkwid(w: xproto::Window) -> crate::window::WindowId {
     crate::window::WindowId(crate::platform_impl::platform::WindowId(w as _))
 }

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

@@ -0,0 +1,55 @@
+use std::ffi::c_int;
+use std::sync::Arc;
+
+use x11_dl::xlib::{self, XEvent, XGenericEventCookie};
+
+use crate::platform_impl::x11::XConnection;
+
+/// XEvents of type GenericEvent store their actual data in an XGenericEventCookie data structure.
+/// This is a wrapper to extract the cookie from a GenericEvent XEvent and release the cookie data
+/// once it has been processed
+pub struct GenericEventCookie {
+    cookie: XGenericEventCookie,
+    xconn: Arc<XConnection>,
+}
+
+impl GenericEventCookie {
+    pub fn from_event(xconn: Arc<XConnection>, event: XEvent) -> Option<GenericEventCookie> {
+        unsafe {
+            let mut cookie: XGenericEventCookie = From::from(event);
+            if (xconn.xlib.XGetEventData)(xconn.display, &mut cookie) == xlib::True {
+                Some(GenericEventCookie { cookie, xconn })
+            } else {
+                None
+            }
+        }
+    }
+
+    #[inline]
+    pub fn extension(&self) -> u8 {
+        self.cookie.extension as u8
+    }
+
+    #[inline]
+    pub fn evtype(&self) -> c_int {
+        self.cookie.evtype
+    }
+
+    /// Borrow inner event data as `&T`.
+    ///
+    /// ## SAFETY
+    ///
+    /// The caller must ensure that the event has the `T` inside of it.
+    #[inline]
+    pub unsafe fn as_event<T>(&self) -> &T {
+        unsafe { &*(self.cookie.data as *const _) }
+    }
+}
+
+impl Drop for GenericEventCookie {
+    fn drop(&mut self) {
+        unsafe {
+            (self.xconn.xlib.XFreeEventData)(self.xconn.display, &mut self.cookie);
+        }
+    }
+}

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

@@ -45,7 +45,7 @@ impl XConnection {
             self.flush_requests()?;
             Ok(true)
         } else {
-            log::error!("Could not select XKB events: The XKB extension is not initialized!");
+            tracing::error!("Could not select XKB events: The XKB extension is not initialized!");
             Ok(false)
         }
     }

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

@@ -8,6 +8,7 @@ use std::{
 };
 
 mod client_msg;
+pub mod cookie;
 mod cursor;
 mod geometry;
 mod hint;
@@ -15,13 +16,15 @@ mod icon;
 mod input;
 pub mod keys;
 pub(crate) mod memory;
+mod mouse;
 mod randr;
 mod window_property;
 mod wm;
 mod xmodmap;
 
 pub use self::{
-    cursor::*, geometry::*, hint::*, input::*, window_property::*, wm::*, xmodmap::ModifierKeymap,
+    cursor::*, geometry::*, hint::*, input::*, mouse::*, window_property::*, wm::*,
+    xmodmap::ModifierKeymap,
 };
 
 use super::{atoms::*, ffi, VoidCookie, X11Error, XConnection, XError};

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

@@ -0,0 +1,52 @@
+//! Utilities for handling mouse events.
+
+/// Recorded mouse delta designed to filter out noise.
+pub struct Delta<T> {
+    x: T,
+    y: T,
+}
+
+impl<T: Default> Default for Delta<T> {
+    fn default() -> Self {
+        Self {
+            x: Default::default(),
+            y: Default::default(),
+        }
+    }
+}
+
+impl<T: Default> Delta<T> {
+    pub(crate) fn set_x(&mut self, x: T) {
+        self.x = x;
+    }
+
+    pub(crate) fn set_y(&mut self, y: T) {
+        self.y = y;
+    }
+}
+
+macro_rules! consume {
+    ($this:expr, $ty:ty) => {{
+        let this = $this;
+        let (x, y) = match (this.x.abs() < <$ty>::EPSILON, this.y.abs() < <$ty>::EPSILON) {
+            (true, true) => return None,
+            (false, true) => (this.x, 0.0),
+            (true, false) => (0.0, this.y),
+            (false, false) => (this.x, this.y),
+        };
+
+        Some((x, y))
+    }};
+}
+
+impl Delta<f32> {
+    pub(crate) fn consume(self) -> Option<(f32, f32)> {
+        consume!(self, f32)
+    }
+}
+
+impl Delta<f64> {
+    pub(crate) fn consume(self) -> Option<(f64, f64)> {
+        consume!(self, f64)
+    }
+}

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

@@ -4,7 +4,7 @@ use super::*;
 use crate::platform_impl::platform::x11::monitor;
 use crate::{dpi::validate_scale_factor, platform_impl::platform::x11::VideoModeHandle};
 
-use log::warn;
+use tracing::warn;
 use x11rb::protocol::randr::{self, ConnectionExt as _};
 
 /// Represents values of `WINIT_HIDPI_FACTOR`.
@@ -44,7 +44,7 @@ impl XConnection {
                 Ok(Some(dpi)) => return Some(dpi),
                 Ok(None) => {}
                 Err(err) => {
-                    log::warn!("failed to fetch XSettings: {err}");
+                    tracing::warn!("failed to fetch XSettings: {err}");
                 }
             }
         }
@@ -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 bytemuck::{NoUninit, Pod};
+use std::error::Error;
+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/window.rs

@@ -7,7 +7,7 @@ use std::{
     sync::{Arc, Mutex, MutexGuard},
 };
 
-use log::{debug, info, warn};
+use tracing::{debug, info, warn};
 use x11rb::{
     connection::Connection,
     properties::{WmHints, WmSizeHints, WmSizeHintsSpecification},
@@ -1573,7 +1573,7 @@ impl UnownedWindow {
             #[cfg(wayland_platform)]
             Cursor::Custom(RootCustomCursor {
                 inner: PlatformCustomCursor::Wayland(_),
-            }) => log::error!("passed a Wayland cursor to X11 backend"),
+            }) => tracing::error!("passed a Wayland cursor to X11 backend"),
         }
     }
 
@@ -1857,7 +1857,7 @@ impl UnownedWindow {
                 )
                 .expect_then_ignore_error("Failed to send client message");
             if let Err(e) = self.xconn.flush_requests() {
-                log::error!(
+                tracing::error!(
                     "`flush` returned an error when focusing the window. Error was: {}",
                     e
                 );

src/platform_impl/linux/x11/xdisplay.rs

@@ -121,7 +121,7 @@ impl XConnection {
 
         let xsettings_screen = Self::new_xsettings_screen(&xcb, default_screen);
         if xsettings_screen.is_none() {
-            log::warn!("error setting XSETTINGS; Xft options won't reload automatically")
+            tracing::warn!("error setting XSETTINGS; Xft options won't reload automatically")
         }
 
         // Fetch atoms.
@@ -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
-            .get_property(
-                owner.owner,
-                atoms[_XSETTINGS_SETTINGS],
-                atoms[_XSETTINGS_SETTINGS],
-            )
-            .unwrap();
+        let data: Vec<u8> = self.get_property(
+            owner.owner,
+            atoms[_XSETTINGS_SETTINGS],
+            atoms[_XSETTINGS_SETTINGS],
+        )?;
 
         // 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",
@@ -471,10 +471,10 @@ fn window_activation_hack(app: &NSApplication) {
         // This way we preserve the user's desired initial visibility status
         // TODO: Also filter on the type/"level" of the window, and maybe other things?
         if window.isVisible() {
-            log::trace!("Activating visible window");
+            tracing::trace!("Activating visible window");
             window.makeKeyAndOrderFront(None);
         } else {
-            log::trace!("Skipping activating invisible window");
+            tracing::trace!("Skipping activating invisible window");
         }
     })
 }

src/platform_impl/macos/cursor.rs

@@ -71,7 +71,7 @@ unsafe fn try_cursor_from_selector(sel: Sel) -> Option<Id<NSCursor>> {
         let cursor: Id<NSCursor> = unsafe { msg_send_id![cls, performSelector: sel] };
         Some(cursor)
     } else {
-        log::warn!("cursor `{sel}` appears to be invalid");
+        tracing::warn!("cursor `{sel}` appears to be invalid");
         None
     }
 }

src/platform_impl/macos/event.rs

@@ -36,14 +36,14 @@ pub fn get_modifierless_char(scancode: u16) -> Key {
     unsafe {
         input_source = ffi::TISCopyCurrentKeyboardLayoutInputSource();
         if input_source.is_null() {
-            log::error!("`TISCopyCurrentKeyboardLayoutInputSource` returned null ptr");
+            tracing::error!("`TISCopyCurrentKeyboardLayoutInputSource` returned null ptr");
             return Key::Unidentified(NativeKey::MacOS(scancode));
         }
         let layout_data =
             ffi::TISGetInputSourceProperty(input_source, ffi::kTISPropertyUnicodeKeyLayoutData);
         if layout_data.is_null() {
             CFRelease(input_source as *mut c_void);
-            log::error!("`TISGetInputSourceProperty` returned null ptr");
+            tracing::error!("`TISGetInputSourceProperty` returned null ptr");
             return Key::Unidentified(NativeKey::MacOS(scancode));
         }
         layout = CFDataGetBytePtr(layout_data as CFDataRef) as *const ffi::UCKeyboardLayout;
@@ -71,7 +71,7 @@ pub fn get_modifierless_char(scancode: u16) -> Key {
         CFRelease(input_source as *mut c_void);
     }
     if translate_result != 0 {
-        log::error!(
+        tracing::error!(
             "`UCKeyTranslate` returned with the non-zero value: {}",
             translate_result
         );

src/platform_impl/macos/event_handler.rs

@@ -71,7 +71,7 @@ impl EventHandler {
                         *data = None;
                     }
                     Ok(None) => {
-                        log::error!("tried to clear handler, but no handler was set");
+                        tracing::error!("tried to clear handler, but no handler was set");
                     }
                     Err(_) => {
                         // Note: This is not expected to ever happen, this
@@ -125,7 +125,7 @@ impl EventHandler {
                 // `NSApplication`, our app delegate and this handler are all
                 // global state and so it's not impossible that we could get
                 // an event after the application has exited the `EventLoop`.
-                log::error!("tried to run event handler, but no handler was set");
+                tracing::error!("tried to run event handler, but no handler was set");
             }
             Err(_) => {
                 // Prevent re-entrancy.

src/platform_impl/macos/util.rs

@@ -1,5 +1,5 @@
 use icrate::Foundation::{NSNotFound, NSRange, NSUInteger};
-use log::trace;
+use tracing::trace;
 
 pub const EMPTY_RANGE: NSRange = NSRange {
     location: NSNotFound as NSUInteger,
@@ -20,7 +20,7 @@ pub(crate) struct TraceGuard {
 impl TraceGuard {
     #[inline]
     pub(crate) fn new(module_path: &'static str, called_from_fn: &'static str) -> Self {
-        trace!(target: module_path, "Triggered `{}`", called_from_fn);
+        trace!(target = module_path, "Triggered `{}`", called_from_fn);
         Self {
             module_path,
             called_from_fn,
@@ -31,6 +31,10 @@ impl TraceGuard {
 impl Drop for TraceGuard {
     #[inline]
     fn drop(&mut self) {
-        trace!(target: self.module_path, "Completed `{}`", self.called_from_fn);
+        trace!(
+            target = self.module_path,
+            "Completed `{}`",
+            self.called_from_fn
+        );
     }
 }

src/platform_impl/macos/view.rs

@@ -338,7 +338,7 @@ declare_class!(
                 // Leave the Preedit self.ivars()
                 self.ivars().ime_state.set(ImeState::Ground);
             } else {
-                log::warn!("Expected to have IME enabled when receiving unmarkText");
+                tracing::warn!("Expected to have IME enabled when receiving unmarkText");
             }
         }
 

src/platform_impl/orbital/event_loop.rs

@@ -537,7 +537,7 @@ impl<T: 'static> EventLoop<T> {
                 }
             }
             other => {
-                log::warn!("unhandled event: {:?}", other);
+                tracing::warn!("unhandled event: {:?}", other);
             }
         }
     }

src/platform_impl/web/cursor.rs

@@ -301,7 +301,9 @@ impl CursorHandler {
                         };
                     }
                     ImageState::Failed(error) => {
-                        log::error!("trying to load custom cursor that has failed to load: {error}")
+                        tracing::error!(
+                            "trying to load custom cursor that has failed to load: {error}"
+                        )
                     }
                     ImageState::Image(_) => {
                         drop(state);
@@ -413,7 +415,7 @@ impl Inner {
                 self.set_style();
             }
             ImageState::Failed(error) => {
-                log::error!("custom cursor failed to load: {error}");
+                tracing::error!("custom cursor failed to load: {error}");
                 self.cursor = previous.into()
             }
             ImageState::Loading { .. } => unreachable!("notified without being ready"),

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
-    /// `EventLoop::run` takes ownership of the `EventLoop`, we can be certain
+    /// The `EventLoop` is exited after being started with `EventLoop::run_app`. Since
+    /// `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/event.rs

@@ -190,7 +190,7 @@ pub fn key_location(event: &KeyboardEvent) -> KeyLocation {
         KeyboardEvent::DOM_KEY_LOCATION_NUMPAD => KeyLocation::Numpad,
         KeyboardEvent::DOM_KEY_LOCATION_STANDARD => KeyLocation::Standard,
         location => {
-            log::warn!("Unexpected key location: {location}");
+            tracing::warn!("Unexpected key location: {location}");
             KeyLocation::Standard
         }
     }

src/platform_impl/web/web_sys/resize_scaling.rs

@@ -1,5 +1,5 @@
 use js_sys::{Array, Object};
-use log::warn;
+use tracing::warn;
 use wasm_bindgen::prelude::{wasm_bindgen, Closure};
 use wasm_bindgen::{JsCast, JsValue};
 use web_sys::{

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
-            .add_event_listener_with_callback("message", closure.as_ref().unchecked_ref())
-            .expect("Failed to set message handler");
+        port_1.set_onmessage(Some(closure.as_ref().unchecked_ref()));
         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/drop_handler.rs

@@ -18,7 +18,7 @@ use windows_sys::{
     },
 };
 
-use log::debug;
+use tracing::debug;
 
 use crate::platform_impl::platform::{
     definitions::{IDataObjectVtbl, IDropTarget, IDropTargetVtbl, IUnknownVtbl},

src/platform_impl/windows/event_loop.rs

@@ -536,7 +536,7 @@ impl ActiveEventLoop {
         let inner = match WinCursor::new(&source.inner.0) {
             Ok(cursor) => cursor,
             Err(err) => {
-                log::warn!("Failed to create custom cursor: {err}");
+                tracing::warn!("Failed to create custom cursor: {err}");
                 WinCursor::Failed
             }
         };

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/platform_impl/windows/keyboard.rs

@@ -32,8 +32,8 @@ use windows_sys::Win32::{
     },
 };
 
-use log::{trace, warn};
 use smol_str::SmolStr;
+use tracing::{trace, warn};
 use unicode_segmentation::UnicodeSegmentation;
 
 use crate::{

src/platform_impl/windows/monitor.rs

@@ -236,7 +236,7 @@ impl MonitorHandle {
         let monitor_info = match get_monitor_info(self.0) {
             Ok(monitor_info) => monitor_info,
             Err(error) => {
-                log::warn!("Error from get_monitor_info: {error}");
+                tracing::warn!("Error from get_monitor_info: {error}");
                 return modes.into_iter().map(mod_map);
             }
         };

src/platform_impl/windows/window.rs

@@ -59,7 +59,7 @@ use windows_sys::Win32::{
     },
 };
 
-use log::warn;
+use tracing::warn;
 
 use crate::{
     cursor::Cursor,

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
@@ -528,6 +497,8 @@ impl Window {
     /// Returns an identifier unique to the window.
     #[inline]
     pub fn id(&self) -> WindowId {
+        let _span = tracing::debug_span!("winit::Window::id",).entered();
+
         self.window.maybe_wait_on_main(|w| WindowId(w.id()))
     }
 
@@ -591,6 +562,8 @@ impl Window {
     /// [`contentScaleFactor`]: https://developer.apple.com/documentation/uikit/uiview/1622657-contentscalefactor?language=objc
     #[inline]
     pub fn scale_factor(&self) -> f64 {
+        let _span = tracing::debug_span!("winit::Window::scale_factor",).entered();
+
         self.window.maybe_wait_on_main(|w| w.scale_factor())
     }
 
@@ -622,6 +595,8 @@ impl Window {
     /// [`WindowEvent::RedrawRequested`]: crate::event::WindowEvent::RedrawRequested
     #[inline]
     pub fn request_redraw(&self) {
+        let _span = tracing::debug_span!("winit::Window::request_redraw",).entered();
+
         self.window.maybe_queue_on_main(|w| w.request_redraw())
     }
 
@@ -658,6 +633,8 @@ impl Window {
     /// [`WindowEvent::RedrawRequested`]: crate::event::WindowEvent::RedrawRequested
     #[inline]
     pub fn pre_present_notify(&self) {
+        let _span = tracing::debug_span!("winit::Window::pre_present_notify",).entered();
+
         self.window.maybe_queue_on_main(|w| w.pre_present_notify());
     }
 
@@ -674,6 +651,8 @@ impl Window {
     // at least, then this function should be provided through a platform specific
     // extension trait
     pub fn reset_dead_keys(&self) {
+        let _span = tracing::debug_span!("winit::Window::reset_dead_keys",).entered();
+
         self.window.maybe_queue_on_main(|w| w.reset_dead_keys())
     }
 }
@@ -696,6 +675,8 @@ impl Window {
     /// [safe area]: https://developer.apple.com/documentation/uikit/uiview/2891103-safeareainsets?language=objc
     #[inline]
     pub fn inner_position(&self) -> Result<PhysicalPosition<i32>, NotSupportedError> {
+        let _span = tracing::debug_span!("winit::Window::inner_position",).entered();
+
         self.window.maybe_wait_on_main(|w| w.inner_position())
     }
 
@@ -717,6 +698,8 @@ impl Window {
     /// - **Android / Wayland:** Always returns [`NotSupportedError`].
     #[inline]
     pub fn outer_position(&self) -> Result<PhysicalPosition<i32>, NotSupportedError> {
+        let _span = tracing::debug_span!("winit::Window::outer_position",).entered();
+
         self.window.maybe_wait_on_main(|w| w.outer_position())
     }
 
@@ -749,6 +732,12 @@ impl Window {
     #[inline]
     pub fn set_outer_position<P: Into<Position>>(&self, position: P) {
         let position = position.into();
+        let _span = tracing::debug_span!(
+            "winit::Window::set_outer_position",
+            position = ?position
+        )
+        .entered();
+
         self.window
             .maybe_queue_on_main(move |w| w.set_outer_position(position))
     }
@@ -767,6 +756,8 @@ impl Window {
     /// [`transform`]: https://developer.mozilla.org/en-US/docs/Web/CSS/transform
     #[inline]
     pub fn inner_size(&self) -> PhysicalSize<u32> {
+        let _span = tracing::debug_span!("winit::Window::inner_size",).entered();
+
         self.window.maybe_wait_on_main(|w| w.inner_size())
     }
 
@@ -808,6 +799,11 @@ impl Window {
     #[must_use]
     pub fn request_inner_size<S: Into<Size>>(&self, size: S) -> Option<PhysicalSize<u32>> {
         let size = size.into();
+        let _span = tracing::debug_span!(
+            "winit::Window::request_inner_size",
+            size = ?size
+        )
+        .entered();
         self.window
             .maybe_wait_on_main(|w| w.request_inner_size(size))
     }
@@ -825,6 +821,7 @@ impl Window {
     ///   [`Window::inner_size`]._
     #[inline]
     pub fn outer_size(&self) -> PhysicalSize<u32> {
+        let _span = tracing::debug_span!("winit::Window::outer_size",).entered();
         self.window.maybe_wait_on_main(|w| w.outer_size())
     }
 
@@ -848,6 +845,11 @@ impl Window {
     #[inline]
     pub fn set_min_inner_size<S: Into<Size>>(&self, min_size: Option<S>) {
         let min_size = min_size.map(|s| s.into());
+        let _span = tracing::debug_span!(
+            "winit::Window::set_min_inner_size",
+            min_size = ?min_size
+        )
+        .entered();
         self.window
             .maybe_queue_on_main(move |w| w.set_min_inner_size(min_size))
     }
@@ -872,6 +874,11 @@ impl Window {
     #[inline]
     pub fn set_max_inner_size<S: Into<Size>>(&self, max_size: Option<S>) {
         let max_size = max_size.map(|s| s.into());
+        let _span = tracing::debug_span!(
+            "winit::Window::max_size",
+            max_size = ?max_size
+        )
+        .entered();
         self.window
             .maybe_queue_on_main(move |w| w.set_max_inner_size(max_size))
     }
@@ -883,6 +890,7 @@ impl Window {
     /// - **iOS / Android / Web / Wayland / Windows / Orbital:** Always returns [`None`].
     #[inline]
     pub fn resize_increments(&self) -> Option<PhysicalSize<u32>> {
+        let _span = tracing::debug_span!("winit::Window::resize_increments",).entered();
         self.window.maybe_wait_on_main(|w| w.resize_increments())
     }
 
@@ -899,6 +907,11 @@ impl Window {
     #[inline]
     pub fn set_resize_increments<S: Into<Size>>(&self, increments: Option<S>) {
         let increments = increments.map(Into::into);
+        let _span = tracing::debug_span!(
+            "winit::Window::set_resize_increments",
+            increments = ?increments
+        )
+        .entered();
         self.window
             .maybe_queue_on_main(move |w| w.set_resize_increments(increments))
     }
@@ -913,6 +926,7 @@ impl Window {
     /// - **iOS / Android:** Unsupported.
     #[inline]
     pub fn set_title(&self, title: &str) {
+        let _span = tracing::debug_span!("winit::Window::set_title", title).entered();
         self.window.maybe_wait_on_main(|w| w.set_title(title))
     }
 
@@ -931,6 +945,7 @@ impl Window {
     /// - **X11:** Can only be set while building the window, with [`WindowAttributes::with_transparent`].
     #[inline]
     pub fn set_transparent(&self, transparent: bool) {
+        let _span = tracing::debug_span!("winit::Window::set_transparent", transparent).entered();
         self.window
             .maybe_queue_on_main(move |w| w.set_transparent(transparent))
     }
@@ -945,6 +960,7 @@ impl Window {
     /// - **Wayland:** Only works with org_kde_kwin_blur_manager protocol.
     #[inline]
     pub fn set_blur(&self, blur: bool) {
+        let _span = tracing::debug_span!("winit::Window::set_blur", blur).entered();
         self.window.maybe_queue_on_main(move |w| w.set_blur(blur))
     }
 
@@ -958,6 +974,7 @@ impl Window {
     /// - **iOS:** Can only be called on the main thread.
     #[inline]
     pub fn set_visible(&self, visible: bool) {
+        let _span = tracing::debug_span!("winit::Window::set_visible", visible).entered();
         self.window
             .maybe_queue_on_main(move |w| w.set_visible(visible))
     }
@@ -972,6 +989,7 @@ impl Window {
     /// - **Wayland / iOS / Android / Web:** Unsupported.
     #[inline]
     pub fn is_visible(&self) -> Option<bool> {
+        let _span = tracing::debug_span!("winit::Window::is_visible",).entered();
         self.window.maybe_wait_on_main(|w| w.is_visible())
     }
 
@@ -991,6 +1009,7 @@ impl Window {
     /// [`WindowEvent::Resized`]: crate::event::WindowEvent::Resized
     #[inline]
     pub fn set_resizable(&self, resizable: bool) {
+        let _span = tracing::debug_span!("winit::Window::set_resizable", resizable).entered();
         self.window
             .maybe_queue_on_main(move |w| w.set_resizable(resizable))
     }
@@ -1003,6 +1022,7 @@ impl Window {
     /// - **iOS / Android / Web:** Unsupported.
     #[inline]
     pub fn is_resizable(&self) -> bool {
+        let _span = tracing::debug_span!("winit::Window::is_resizable",).entered();
         self.window.maybe_wait_on_main(|w| w.is_resizable())
     }
 
@@ -1013,6 +1033,11 @@ impl Window {
     /// - **Wayland / X11 / Orbital:** Not implemented.
     /// - **Web / iOS / Android:** Unsupported.
     pub fn set_enabled_buttons(&self, buttons: WindowButtons) {
+        let _span = tracing::debug_span!(
+            "winit::Window::set_enabled_buttons",
+            buttons = ?buttons
+        )
+        .entered();
         self.window
             .maybe_queue_on_main(move |w| w.set_enabled_buttons(buttons))
     }
@@ -1024,6 +1049,7 @@ impl Window {
     /// - **Wayland / X11 / Orbital:** Not implemented. Always returns [`WindowButtons::all`].
     /// - **Web / iOS / Android:** Unsupported. Always returns [`WindowButtons::all`].
     pub fn enabled_buttons(&self) -> WindowButtons {
+        let _span = tracing::debug_span!("winit::Window::enabled_buttons",).entered();
         self.window.maybe_wait_on_main(|w| w.enabled_buttons())
     }
 
@@ -1035,6 +1061,7 @@ impl Window {
     /// - **Wayland:** Un-minimize is unsupported.
     #[inline]
     pub fn set_minimized(&self, minimized: bool) {
+        let _span = tracing::debug_span!("winit::Window::set_minimized", minimized).entered();
         self.window
             .maybe_queue_on_main(move |w| w.set_minimized(minimized))
     }
@@ -1053,6 +1080,7 @@ impl Window {
     /// - **iOS / Android / Web / Orbital:** Unsupported.
     #[inline]
     pub fn is_minimized(&self) -> Option<bool> {
+        let _span = tracing::debug_span!("winit::Window::is_minimized",).entered();
         self.window.maybe_wait_on_main(|w| w.is_minimized())
     }
 
@@ -1063,6 +1091,7 @@ impl Window {
     /// - **iOS / Android / Web:** Unsupported.
     #[inline]
     pub fn set_maximized(&self, maximized: bool) {
+        let _span = tracing::debug_span!("winit::Window::set_maximized", maximized).entered();
         self.window
             .maybe_queue_on_main(move |w| w.set_maximized(maximized))
     }
@@ -1074,6 +1103,7 @@ impl Window {
     /// - **iOS / Android / Web:** Unsupported.
     #[inline]
     pub fn is_maximized(&self) -> bool {
+        let _span = tracing::debug_span!("winit::Window::is_maximized",).entered();
         self.window.maybe_wait_on_main(|w| w.is_maximized())
     }
 
@@ -1102,6 +1132,11 @@ impl Window {
     /// [transient activation]: https://developer.mozilla.org/en-US/docs/Glossary/Transient_activation
     #[inline]
     pub fn set_fullscreen(&self, fullscreen: Option<Fullscreen>) {
+        let _span = tracing::debug_span!(
+            "winit::Window::set_fullscreen",
+            fullscreen = ?fullscreen
+        )
+        .entered();
         self.window
             .maybe_queue_on_main(move |w| w.set_fullscreen(fullscreen.map(|f| f.into())))
     }
@@ -1116,6 +1151,7 @@ impl Window {
     /// - **Web:** Can only return `None` or `Borderless(None)`.
     #[inline]
     pub fn fullscreen(&self) -> Option<Fullscreen> {
+        let _span = tracing::debug_span!("winit::Window::fullscreen",).entered();
         self.window
             .maybe_wait_on_main(|w| w.fullscreen().map(|f| f.into()))
     }
@@ -1131,6 +1167,7 @@ impl Window {
     /// - **iOS / Android / Web:** No effect.
     #[inline]
     pub fn set_decorations(&self, decorations: bool) {
+        let _span = tracing::debug_span!("winit::Window::set_decorations", decorations).entered();
         self.window
             .maybe_queue_on_main(move |w| w.set_decorations(decorations))
     }
@@ -1145,6 +1182,7 @@ impl Window {
     /// - **iOS / Android / Web:** Always returns `true`.
     #[inline]
     pub fn is_decorated(&self) -> bool {
+        let _span = tracing::debug_span!("winit::Window::is_decorated",).entered();
         self.window.maybe_wait_on_main(|w| w.is_decorated())
     }
 
@@ -1154,6 +1192,11 @@ impl Window {
     ///
     /// See [`WindowLevel`] for details.
     pub fn set_window_level(&self, level: WindowLevel) {
+        let _span = tracing::debug_span!(
+            "winit::Window::set_window_level",
+            level = ?level
+        )
+        .entered();
         self.window
             .maybe_queue_on_main(move |w| w.set_window_level(level))
     }
@@ -1174,6 +1217,7 @@ impl Window {
     ///   said, it's usually in the same ballpark as on Windows.
     #[inline]
     pub fn set_window_icon(&self, window_icon: Option<Icon>) {
+        let _span = tracing::debug_span!("winit::Window::set_window_icon",).entered();
         self.window
             .maybe_queue_on_main(move |w| w.set_window_icon(window_icon))
     }
@@ -1216,6 +1260,12 @@ impl Window {
     pub fn set_ime_cursor_area<P: Into<Position>, S: Into<Size>>(&self, position: P, size: S) {
         let position = position.into();
         let size = size.into();
+        let _span = tracing::debug_span!(
+            "winit::Window::set_ime_cursor_area",
+            position = ?position,
+            size = ?size,
+        )
+        .entered();
         self.window
             .maybe_queue_on_main(move |w| w.set_ime_cursor_area(position, size))
     }
@@ -1242,6 +1292,7 @@ impl Window {
     /// [`KeyboardInput`]: crate::event::WindowEvent::KeyboardInput
     #[inline]
     pub fn set_ime_allowed(&self, allowed: bool) {
+        let _span = tracing::debug_span!("winit::Window::set_ime_allowed", allowed).entered();
         self.window
             .maybe_queue_on_main(move |w| w.set_ime_allowed(allowed))
     }
@@ -1253,6 +1304,11 @@ impl Window {
     /// - **iOS / Android / Web / Windows / X11 / macOS / Orbital:** Unsupported.
     #[inline]
     pub fn set_ime_purpose(&self, purpose: ImePurpose) {
+        let _span = tracing::debug_span!(
+            "winit::Window::set_ime_purpose",
+            purpose = ?purpose
+        )
+        .entered();
         self.window
             .maybe_queue_on_main(move |w| w.set_ime_purpose(purpose))
     }
@@ -1269,6 +1325,7 @@ impl Window {
     /// - **iOS / Android / Wayland / Orbital:** Unsupported.
     #[inline]
     pub fn focus_window(&self) {
+        let _span = tracing::debug_span!("winit::Window::focus_window",).entered();
         self.window.maybe_queue_on_main(|w| w.focus_window())
     }
 
@@ -1279,6 +1336,7 @@ impl Window {
     /// [`WindowEvent::Focused`]: crate::event::WindowEvent::Focused
     #[inline]
     pub fn has_focus(&self) -> bool {
+        let _span = tracing::debug_span!("winit::Window::has_focus",).entered();
         self.window.maybe_wait_on_main(|w| w.has_focus())
     }
 
@@ -1297,6 +1355,11 @@ impl Window {
     /// - **Wayland:** Requires `xdg_activation_v1` protocol, `None` has no effect.
     #[inline]
     pub fn request_user_attention(&self, request_type: Option<UserAttentionType>) {
+        let _span = tracing::debug_span!(
+            "winit::Window::request_user_attention",
+            request_type = ?request_type
+        )
+        .entered();
         self.window
             .maybe_queue_on_main(move |w| w.request_user_attention(request_type))
     }
@@ -1312,6 +1375,11 @@ impl Window {
     /// - **iOS / Android / Web / Orbital:** Unsupported.
     #[inline]
     pub fn set_theme(&self, theme: Option<Theme>) {
+        let _span = tracing::debug_span!(
+            "winit::Window::set_theme",
+            theme = ?theme
+        )
+        .entered();
         self.window.maybe_queue_on_main(move |w| w.set_theme(theme))
     }
 
@@ -1323,6 +1391,7 @@ impl Window {
     /// - **iOS / Android / Wayland / x11 / Orbital:** Unsupported.
     #[inline]
     pub fn theme(&self) -> Option<Theme> {
+        let _span = tracing::debug_span!("winit::Window::theme",).entered();
         self.window.maybe_wait_on_main(|w| w.theme())
     }
 
@@ -1336,6 +1405,8 @@ impl Window {
     ///
     /// [`NSWindowSharingNone`]: https://developer.apple.com/documentation/appkit/nswindowsharingtype/nswindowsharingnone
     pub fn set_content_protected(&self, protected: bool) {
+        let _span =
+            tracing::debug_span!("winit::Window::set_content_protected", protected).entered();
         self.window
             .maybe_queue_on_main(move |w| w.set_content_protected(protected))
     }
@@ -1347,6 +1418,7 @@ impl Window {
     /// - **iOS / Android / x11 / Wayland / Web:** Unsupported. Always returns an empty string.
     #[inline]
     pub fn title(&self) -> String {
+        let _span = tracing::debug_span!("winit::Window::title",).entered();
         self.window.maybe_wait_on_main(|w| w.title())
     }
 }
@@ -1363,6 +1435,7 @@ impl Window {
     #[inline]
     pub fn set_cursor(&self, cursor: impl Into<Cursor>) {
         let cursor = cursor.into();
+        let _span = tracing::debug_span!("winit::Window::set_cursor",).entered();
         self.window
             .maybe_queue_on_main(move |w| w.set_cursor(cursor))
     }
@@ -1395,6 +1468,11 @@ impl Window {
     #[inline]
     pub fn set_cursor_position<P: Into<Position>>(&self, position: P) -> Result<(), ExternalError> {
         let position = position.into();
+        let _span = tracing::debug_span!(
+            "winit::Window::set_cursor_position",
+            position = ?position
+        )
+        .entered();
         self.window
             .maybe_wait_on_main(|w| w.set_cursor_position(position))
     }
@@ -1415,6 +1493,11 @@ impl Window {
     /// ```
     #[inline]
     pub fn set_cursor_grab(&self, mode: CursorGrabMode) -> Result<(), ExternalError> {
+        let _span = tracing::debug_span!(
+            "winit::Window::set_cursor_grab",
+            mode = ?mode
+        )
+        .entered();
         self.window.maybe_wait_on_main(|w| w.set_cursor_grab(mode))
     }
 
@@ -1432,6 +1515,7 @@ impl Window {
     /// - **iOS / Android:** Unsupported.
     #[inline]
     pub fn set_cursor_visible(&self, visible: bool) {
+        let _span = tracing::debug_span!("winit::Window::set_cursor_visible", visible).entered();
         self.window
             .maybe_queue_on_main(move |w| w.set_cursor_visible(visible))
     }
@@ -1449,6 +1533,7 @@ impl Window {
     /// - **iOS / Android / Web:** Always returns an [`ExternalError::NotSupported`].
     #[inline]
     pub fn drag_window(&self) -> Result<(), ExternalError> {
+        let _span = tracing::debug_span!("winit::Window::drag_window",).entered();
         self.window.maybe_wait_on_main(|w| w.drag_window())
     }
 
@@ -1463,6 +1548,11 @@ impl Window {
     /// - **iOS / Android / Web:** Always returns an [`ExternalError::NotSupported`].
     #[inline]
     pub fn drag_resize_window(&self, direction: ResizeDirection) -> Result<(), ExternalError> {
+        let _span = tracing::debug_span!(
+            "winit::Window::drag_resize_window",
+            direction = ?direction
+        )
+        .entered();
         self.window
             .maybe_wait_on_main(|w| w.drag_resize_window(direction))
     }
@@ -1478,6 +1568,11 @@ impl Window {
     /// [window menu]: https://en.wikipedia.org/wiki/Common_menus_in_Microsoft_Windows#System_menu
     pub fn show_window_menu(&self, position: impl Into<Position>) {
         let position = position.into();
+        let _span = tracing::debug_span!(
+            "winit::Window::show_window_menu",
+            position = ?position
+        )
+        .entered();
         self.window
             .maybe_queue_on_main(move |w| w.show_window_menu(position))
     }
@@ -1492,6 +1587,7 @@ impl Window {
     /// - **iOS / Android / Web / Orbital:** Always returns an [`ExternalError::NotSupported`].
     #[inline]
     pub fn set_cursor_hittest(&self, hittest: bool) -> Result<(), ExternalError> {
+        let _span = tracing::debug_span!("winit::Window::set_cursor_hittest", hittest).entered();
         self.window
             .maybe_wait_on_main(|w| w.set_cursor_hittest(hittest))
     }
@@ -1504,6 +1600,7 @@ impl Window {
     /// Returns `None` if current monitor can't be detected.
     #[inline]
     pub fn current_monitor(&self) -> Option<MonitorHandle> {
+        let _span = tracing::debug_span!("winit::Window::current_monitor",).entered();
         self.window
             .maybe_wait_on_main(|w| w.current_monitor().map(|inner| MonitorHandle { inner }))
     }
@@ -1515,6 +1612,7 @@ impl Window {
     /// [`ActiveEventLoop::available_monitors`]: crate::event_loop::ActiveEventLoop::available_monitors
     #[inline]
     pub fn available_monitors(&self) -> impl Iterator<Item = MonitorHandle> {
+        let _span = tracing::debug_span!("winit::Window::available_monitors",).entered();
         self.window.maybe_wait_on_main(|w| {
             w.available_monitors()
                 .into_iter()
@@ -1535,6 +1633,7 @@ impl Window {
     /// [`ActiveEventLoop::primary_monitor`]: crate::event_loop::ActiveEventLoop::primary_monitor
     #[inline]
     pub fn primary_monitor(&self) -> Option<MonitorHandle> {
+        let _span = tracing::debug_span!("winit::Window::primary_monitor",).entered();
         self.window
             .maybe_wait_on_main(|w| w.primary_monitor().map(|inner| MonitorHandle { inner }))
     }

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