Bump version to 0.22.0 (#1500)

There are two PRs I'm aware of that should be relatively trivial to get
merged, which would fix some issues. Other than those, I don't think it
makes sense to wait on anything.

 - Fix Windows crash: https://github.com/rust-windowing/winit/pull/1459
 - Fix macOS mouse reports: https://github.com/rust-windowing/winit/pull/1490

While #1459 seems pretty essential to actually make winit run, #1490 is
much less important and can probably be ignored if there aren't any
resources to merge it.

.github/workflows/ci.yml

@@ -17,7 +17,7 @@ jobs:
   Check_Formatting:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
     - uses: hecrj/setup-rust-action@v1
       with:
         rust-version: stable
@@ -54,7 +54,7 @@ jobs:
 
     runs-on: ${{ matrix.platform.os }}
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
     # Used to cache cargo-web
     - name: Cache cargo folder
       uses: actions/cache@v1

.github/workflows/publish.yml

@@ -9,7 +9,7 @@ jobs:
   Publish:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
     - uses: hecrj/setup-rust-action@v1
       with:
         rust-version: stable

CHANGELOG.md

@@ -1,4 +1,23 @@
-# Unreleased
+# 0.22.0 (2020-03-07)
+
+- On Windows, fix minor timing issue in wait_until_time_or_msg
+- On Windows, rework handling of request_redraw() to address panics.
+- On macOS, fix `set_simple_screen` to remember frame excluding title bar.
+- On Wayland, fix coordinates in touch events when scale factor isn't 1.
+- On Wayland, fix color from `close_button_icon_color` not applying.
+- Ignore locale if unsupported by X11 backend
+- On Wayland, Add HiDPI cursor support
+- On Web, add the ability to query "Light" or "Dark" system theme send `ThemeChanged` on change.
+- Fix `Event::to_static` returning `None` for user events.
+- On Wayland, Hide CSD for fullscreen windows.
+- On Windows, ignore spurious mouse move messages.
+- **Breaking:** Move `ModifiersChanged` variant from `DeviceEvent` to `WindowEvent`.
+- On Windows, add `IconExtWindows` trait which exposes creating an `Icon` from an external file or embedded resource
+- Add `BadIcon::OsError` variant for when OS icon functionality fails
+- On Windows, fix crash at startup on systems that do not properly support Windows' Dark Mode
+- Revert On macOS, fix not sending ReceivedCharacter event for specific keys combinations.
+- on macOS, fix incorrect ReceivedCharacter events for some key combinations.
+- **Breaking:** Use `i32` instead of `u32` for position type in `WindowEvent::Moved`.
 
 # 0.21.0 (2020-02-04)
 
@@ -20,7 +39,6 @@
 # 0.20.0 (2020-01-05)
 
 - On X11, fix `ModifiersChanged` emitting incorrect modifier change events
-
 - **Breaking**: Overhaul how Winit handles DPI:
   + Window functions and events now return `PhysicalSize` instead of `LogicalSize`.
   + Functions that take `Size` or `Position` types can now take either `Logical` or `Physical` types.

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "winit"
-version = "0.21.0"
+version = "0.22.0"
 authors = ["The winit contributors", "Pierre Krieger <pierre.krieger1708@gmail.com>"]
 description = "Cross-platform window creation library."
 edition = "2018"
@@ -28,7 +28,7 @@ raw-window-handle = "0.3"
 bitflags = "1"
 
 [dev-dependencies]
-image = "0.21"
+image = "0.23"
 simple_logger = "1"
 
 [target.'cfg(target_os = "android")'.dependencies.android_glue]
@@ -77,7 +77,7 @@ features = [
 wayland-client = { version = "0.23.0", features = [ "dlopen", "egl", "cursor", "eventloop"] }
 mio = "0.6"
 mio-extras = "2.0"
-smithay-client-toolkit = "0.6"
+smithay-client-toolkit = "^0.6.6"
 x11-dl = "2.18.3"
 percent-encoding = "2.0"
 
@@ -101,6 +101,8 @@ features = [
     'HtmlCanvasElement',
     'HtmlElement',
     'KeyboardEvent',
+    'MediaQueryList',
+    'MediaQueryListEvent',
     'MouseEvent',
     'Node',
     'PointerEvent',

FEATURES.md

@@ -149,6 +149,9 @@ If your PR makes notable changes to Winit's features, please update this section
 * Getting the device idiom
 * Getting the preferred video mode
 
+### Web
+* Get if systems preferred color scheme is "dark"
+
 ## Usability
 * `serde`: Enables serialization/deserialization of certain types with Serde. (Maintainer: @Osspial)
 

README.md

@@ -7,7 +7,7 @@
 
 ```toml
 [dependencies]
-winit = "0.21.0"
+winit = "0.22.0"
 ```
 
 ## [Documentation](https://docs.rs/winit)

examples/control_flow.rs

@@ -0,0 +1,119 @@
+use std::{thread, time};
+
+use winit::{
+    event::{Event, KeyboardInput, WindowEvent},
+    event_loop::{ControlFlow, EventLoop},
+    window::WindowBuilder,
+};
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+enum Mode {
+    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() {
+    simple_logger::init().unwrap();
+
+    println!("Press '1' to switch to Wait mode.");
+    println!("Press '2' to switch to WaitUntil mode.");
+    println!("Press '3' to switch to Poll mode.");
+    println!("Press 'R' to toggle request_redraw() calls.");
+    println!("Press 'Esc' to close the window.");
+
+    let event_loop = EventLoop::new();
+    let window = WindowBuilder::new()
+        .with_title("Press 1, 2, 3 to change control flow mode. Press R to toggle redraw requests.")
+        .build(&event_loop)
+        .unwrap();
+
+    let mut mode = Mode::Wait;
+    let mut request_redraw = false;
+    let mut wait_cancelled = false;
+    let mut close_requested = false;
+
+    event_loop.run(move |event, _, control_flow| {
+        use winit::event::{ElementState, StartCause, VirtualKeyCode};
+        println!("{:?}", event);
+        match event {
+            Event::NewEvents(start_cause) => {
+                wait_cancelled = mode == Mode::WaitUntil;
+                match start_cause {
+                    StartCause::ResumeTimeReached {
+                        start: _,
+                        requested_resume: _,
+                    } => {
+                        wait_cancelled = false;
+                    }
+                    _ => (),
+                }
+            }
+            Event::WindowEvent { event, .. } => match event {
+                WindowEvent::CloseRequested => {
+                    close_requested = true;
+                }
+                WindowEvent::KeyboardInput {
+                    input:
+                        KeyboardInput {
+                            virtual_keycode: Some(virtual_code),
+                            state: ElementState::Pressed,
+                            ..
+                        },
+                    ..
+                } => match virtual_code {
+                    VirtualKeyCode::Key1 => {
+                        mode = Mode::Wait;
+                        println!("\nmode: {:?}\n", mode);
+                    }
+                    VirtualKeyCode::Key2 => {
+                        mode = Mode::WaitUntil;
+                        println!("\nmode: {:?}\n", mode);
+                    }
+                    VirtualKeyCode::Key3 => {
+                        mode = Mode::Poll;
+                        println!("\nmode: {:?}\n", mode);
+                    }
+                    VirtualKeyCode::R => {
+                        request_redraw = !request_redraw;
+                        println!("\nrequest_redraw: {}\n", request_redraw);
+                    }
+                    VirtualKeyCode::Escape => {
+                        close_requested = true;
+                    }
+                    _ => (),
+                },
+                _ => (),
+            },
+            Event::MainEventsCleared => {
+                if request_redraw && !wait_cancelled && !close_requested {
+                    window.request_redraw();
+                }
+                if close_requested {
+                    *control_flow = ControlFlow::Exit;
+                }
+            }
+            Event::RedrawRequested(_window_id) => {}
+            Event::RedrawEventsCleared => {
+                *control_flow = match mode {
+                    Mode::Wait => ControlFlow::Wait,
+                    Mode::WaitUntil => {
+                        if wait_cancelled {
+                            *control_flow
+                        } else {
+                            ControlFlow::WaitUntil(time::Instant::now() + WAIT_TIME)
+                        }
+                    }
+                    Mode::Poll => {
+                        thread::sleep(POLL_SLEEP_TIME);
+                        ControlFlow::Poll
+                    }
+                };
+            }
+            _ => (),
+        }
+    });
+}

examples/cursor_grab.rs

@@ -38,6 +38,7 @@ fn main() {
                         _ => (),
                     }
                 }
+                WindowEvent::ModifiersChanged(m) => modifiers = m,
                 _ => (),
             },
             Event::DeviceEvent { event, .. } => match event {
@@ -46,7 +47,6 @@ fn main() {
                     ElementState::Pressed => println!("mouse button {} pressed", button),
                     ElementState::Released => println!("mouse button {} released", button),
                 },
-                DeviceEvent::ModifiersChanged(m) => modifiers = m,
                 _ => (),
             },
             _ => (),

examples/request_redraw_threaded.rs

@@ -0,0 +1,39 @@
+use std::{thread, time};
+
+use winit::{
+    event::{Event, WindowEvent},
+    event_loop::{ControlFlow, EventLoop},
+    window::WindowBuilder,
+};
+
+fn main() {
+    simple_logger::init().unwrap();
+    let event_loop = EventLoop::new();
+
+    let window = WindowBuilder::new()
+        .with_title("A fantastic window!")
+        .build(&event_loop)
+        .unwrap();
+
+    thread::spawn(move || loop {
+        thread::sleep(time::Duration::from_secs(1));
+        window.request_redraw();
+    });
+
+    event_loop.run(move |event, _, control_flow| {
+        println!("{:?}", event);
+
+        *control_flow = ControlFlow::Wait;
+
+        match event {
+            Event::WindowEvent { event, .. } => match event {
+                WindowEvent::CloseRequested => *control_flow = ControlFlow::Exit,
+                _ => (),
+            },
+            Event::RedrawRequested(_) => {
+                println!("\nredrawing!\n");
+            }
+            _ => (),
+        }
+    });
+}

examples/window_icon.rs

@@ -45,13 +45,11 @@ fn main() {
 
 fn load_icon(path: &Path) -> Icon {
     let (icon_rgba, icon_width, icon_height) = {
-        let image = image::open(path).expect("Failed to open icon path");
-        use image::{GenericImageView, Pixel};
+        let image = image::open(path)
+            .expect("Failed to open icon path")
+            .into_rgba();
         let (width, height) = image.dimensions();
-        let mut rgba = Vec::with_capacity((width * height) as usize * 4);
-        for (_, _, pixel) in image.pixels() {
-            rgba.extend_from_slice(&pixel.to_rgba().data);
-        }
+        let rgba = image.into_raw();
         (rgba, width, height)
     };
     Icon::from_rgba(icon_rgba, icon_width, icon_height).expect("Failed to open icon")

src/dpi.rs

@@ -151,8 +151,8 @@ impl Pixel for f64 {
 /// anywhere other than winit, it's recommended to validate them using this function before passing them to winit;
 /// otherwise, you risk panics.
 #[inline]
-pub fn validate_scale_factor(dpi_factor: f64) -> bool {
-    dpi_factor.is_sign_positive() && dpi_factor.is_normal()
+pub fn validate_scale_factor(scale_factor: f64) -> bool {
+    scale_factor.is_sign_positive() && scale_factor.is_normal()
 }
 
 /// A position represented in logical pixels.
@@ -178,16 +178,16 @@ impl<P: Pixel> LogicalPosition<P> {
     #[inline]
     pub fn from_physical<T: Into<PhysicalPosition<X>>, X: Pixel>(
         physical: T,
-        dpi_factor: f64,
+        scale_factor: f64,
     ) -> Self {
-        physical.into().to_logical(dpi_factor)
+        physical.into().to_logical(scale_factor)
     }
 
     #[inline]
-    pub fn to_physical<X: Pixel>(&self, dpi_factor: f64) -> PhysicalPosition<X> {
-        assert!(validate_scale_factor(dpi_factor));
-        let x = self.x.into() * dpi_factor;
-        let y = self.y.into() * dpi_factor;
+    pub fn to_physical<X: Pixel>(&self, scale_factor: f64) -> PhysicalPosition<X> {
+        assert!(validate_scale_factor(scale_factor));
+        let x = self.x.into() * scale_factor;
+        let y = self.y.into() * scale_factor;
         PhysicalPosition::new(x, y).cast()
     }
 
@@ -243,16 +243,16 @@ impl<P: Pixel> PhysicalPosition<P> {
     #[inline]
     pub fn from_logical<T: Into<LogicalPosition<X>>, X: Pixel>(
         logical: T,
-        dpi_factor: f64,
+        scale_factor: f64,
     ) -> Self {
-        logical.into().to_physical(dpi_factor)
+        logical.into().to_physical(scale_factor)
     }
 
     #[inline]
-    pub fn to_logical<X: Pixel>(&self, dpi_factor: f64) -> LogicalPosition<X> {
-        assert!(validate_scale_factor(dpi_factor));
-        let x = self.x.into() / dpi_factor;
-        let y = self.y.into() / dpi_factor;
+    pub fn to_logical<X: Pixel>(&self, scale_factor: f64) -> LogicalPosition<X> {
+        assert!(validate_scale_factor(scale_factor));
+        let x = self.x.into() / scale_factor;
+        let y = self.y.into() / scale_factor;
         LogicalPosition::new(x, y).cast()
     }
 
@@ -306,15 +306,18 @@ impl<P> LogicalSize<P> {
 
 impl<P: Pixel> LogicalSize<P> {
     #[inline]
-    pub fn from_physical<T: Into<PhysicalSize<X>>, X: Pixel>(physical: T, dpi_factor: f64) -> Self {
-        physical.into().to_logical(dpi_factor)
+    pub fn from_physical<T: Into<PhysicalSize<X>>, X: Pixel>(
+        physical: T,
+        scale_factor: f64,
+    ) -> Self {
+        physical.into().to_logical(scale_factor)
     }
 
     #[inline]
-    pub fn to_physical<X: Pixel>(&self, dpi_factor: f64) -> PhysicalSize<X> {
-        assert!(validate_scale_factor(dpi_factor));
-        let width = self.width.into() * dpi_factor;
-        let height = self.height.into() * dpi_factor;
+    pub fn to_physical<X: Pixel>(&self, scale_factor: f64) -> PhysicalSize<X> {
+        assert!(validate_scale_factor(scale_factor));
+        let width = self.width.into() * scale_factor;
+        let height = self.height.into() * scale_factor;
         PhysicalSize::new(width, height).cast()
     }
 
@@ -368,15 +371,15 @@ impl<P> PhysicalSize<P> {
 
 impl<P: Pixel> PhysicalSize<P> {
     #[inline]
-    pub fn from_logical<T: Into<LogicalSize<X>>, X: Pixel>(logical: T, dpi_factor: f64) -> Self {
-        logical.into().to_physical(dpi_factor)
+    pub fn from_logical<T: Into<LogicalSize<X>>, X: Pixel>(logical: T, scale_factor: f64) -> Self {
+        logical.into().to_physical(scale_factor)
     }
 
     #[inline]
-    pub fn to_logical<X: Pixel>(&self, dpi_factor: f64) -> LogicalSize<X> {
-        assert!(validate_scale_factor(dpi_factor));
-        let width = self.width.into() / dpi_factor;
-        let height = self.height.into() / dpi_factor;
+    pub fn to_logical<X: Pixel>(&self, scale_factor: f64) -> LogicalSize<X> {
+        assert!(validate_scale_factor(scale_factor));
+        let width = self.width.into() / scale_factor;
+        let height = self.height.into() / scale_factor;
         LogicalSize::new(width, height).cast()
     }
 
@@ -426,17 +429,17 @@ impl Size {
         size.into()
     }
 
-    pub fn to_logical<P: Pixel>(&self, dpi_factor: f64) -> LogicalSize<P> {
+    pub fn to_logical<P: Pixel>(&self, scale_factor: f64) -> LogicalSize<P> {
         match *self {
-            Size::Physical(size) => size.to_logical(dpi_factor),
+            Size::Physical(size) => size.to_logical(scale_factor),
             Size::Logical(size) => size.cast(),
         }
     }
 
-    pub fn to_physical<P: Pixel>(&self, dpi_factor: f64) -> PhysicalSize<P> {
+    pub fn to_physical<P: Pixel>(&self, scale_factor: f64) -> PhysicalSize<P> {
         match *self {
             Size::Physical(size) => size.cast(),
-            Size::Logical(size) => size.to_physical(dpi_factor),
+            Size::Logical(size) => size.to_physical(scale_factor),
         }
     }
 }
@@ -468,17 +471,17 @@ impl Position {
         position.into()
     }
 
-    pub fn to_logical<P: Pixel>(&self, dpi_factor: f64) -> LogicalPosition<P> {
+    pub fn to_logical<P: Pixel>(&self, scale_factor: f64) -> LogicalPosition<P> {
         match *self {
-            Position::Physical(position) => position.to_logical(dpi_factor),
+            Position::Physical(position) => position.to_logical(scale_factor),
             Position::Logical(position) => position.cast(),
         }
     }
 
-    pub fn to_physical<P: Pixel>(&self, dpi_factor: f64) -> PhysicalPosition<P> {
+    pub fn to_physical<P: Pixel>(&self, scale_factor: f64) -> PhysicalPosition<P> {
         match *self {
             Position::Physical(position) => position.cast(),
-            Position::Logical(position) => position.to_physical(dpi_factor),
+            Position::Logical(position) => position.to_physical(scale_factor),
         }
     }
 }

src/event.rs

@@ -139,7 +139,7 @@ impl<'a, T> Event<'a, T> {
             WindowEvent { window_id, event } => event
                 .to_static()
                 .map(|event| WindowEvent { window_id, event }),
-            UserEvent(_) => None,
+            UserEvent(event) => Some(UserEvent(event)),
             DeviceEvent { device_id, event } => Some(DeviceEvent { device_id, event }),
             NewEvents(cause) => Some(NewEvents(cause)),
             MainEventsCleared => Some(MainEventsCleared),
@@ -185,7 +185,7 @@ pub enum WindowEvent<'a> {
     Resized(PhysicalSize<u32>),
 
     /// The position of the window has changed. Contains the window's new position.
-    Moved(PhysicalPosition<u32>),
+    Moved(PhysicalPosition<i32>),
 
     /// The window has been requested to close.
     CloseRequested,
@@ -235,6 +235,13 @@ pub enum WindowEvent<'a> {
         is_synthetic: bool,
     },
 
+    /// The keyboard modifiers have changed.
+    ///
+    /// Platform-specific behavior:
+    /// - **Web**: This API is currently unimplemented on the web. This isn't by design - it's an
+    ///   issue, and it should get fixed - but it's the current state of the API.
+    ModifiersChanged(ModifiersState),
+
     /// The cursor has moved on the window.
     CursorMoved {
         device_id: DeviceId,
@@ -243,7 +250,7 @@ pub enum WindowEvent<'a> {
         /// limited by the display area and it may have been transformed by the OS to implement effects such as cursor
         /// acceleration, it should not be used to implement non-cursor-like interactions such as 3D camera control.
         position: PhysicalPosition<f64>,
-        #[deprecated = "Deprecated in favor of DeviceEvent::ModifiersChanged"]
+        #[deprecated = "Deprecated in favor of WindowEvent::ModifiersChanged"]
         modifiers: ModifiersState,
     },
 
@@ -258,7 +265,7 @@ pub enum WindowEvent<'a> {
         device_id: DeviceId,
         delta: MouseScrollDelta,
         phase: TouchPhase,
-        #[deprecated = "Deprecated in favor of DeviceEvent::ModifiersChanged"]
+        #[deprecated = "Deprecated in favor of WindowEvent::ModifiersChanged"]
         modifiers: ModifiersState,
     },
 
@@ -267,7 +274,7 @@ pub enum WindowEvent<'a> {
         device_id: DeviceId,
         state: ElementState,
         button: MouseButton,
-        #[deprecated = "Deprecated in favor of DeviceEvent::ModifiersChanged"]
+        #[deprecated = "Deprecated in favor of WindowEvent::ModifiersChanged"]
         modifiers: ModifiersState,
     },
 
@@ -341,6 +348,7 @@ impl<'a> WindowEvent<'a> {
                 input,
                 is_synthetic,
             }),
+            ModifiersChanged(modifiers) => Some(ModifiersChanged(modifiers)),
             #[allow(deprecated)]
             CursorMoved {
                 device_id,
@@ -464,16 +472,6 @@ pub enum DeviceEvent {
 
     Key(KeyboardInput),
 
-    /// The keyboard modifiers have changed.
-    ///
-    /// This is tracked internally to avoid tracking errors arising from modifier key state changes when events from
-    /// this device are not being delivered to the application, e.g. due to keyboard focus being elsewhere.
-    ///
-    /// Platform-specific behavior:
-    /// - **Web**: This API is currently unimplemented on the web. This isn't by design - it's an
-    ///   issue, and it should get fixed - but it's the current state of the API.
-    ModifiersChanged(ModifiersState),
-
     Text {
         codepoint: char,
     },
@@ -502,7 +500,7 @@ pub struct KeyboardInput {
     ///
     /// This is tracked internally to avoid tracking errors arising from modifier key state changes when events from
     /// this device are not being delivered to the application, e.g. due to keyboard focus being elsewhere.
-    #[deprecated = "Deprecated in favor of DeviceEvent::ModifiersChanged"]
+    #[deprecated = "Deprecated in favor of WindowEvent::ModifiersChanged"]
     pub modifiers: ModifiersState,
 }
 

src/icon.rs

@@ -1,4 +1,5 @@
-use std::{error::Error, fmt, mem};
+use crate::platform_impl::PlatformIcon;
+use std::{error::Error, fmt, io, mem};
 
 #[repr(C)]
 #[derive(Debug)]
@@ -11,7 +12,7 @@ pub(crate) struct Pixel {
 
 pub(crate) const PIXEL_SIZE: usize = mem::size_of::<Pixel>();
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[derive(Debug)]
 /// An error produced when using `Icon::from_rgba` with invalid arguments.
 pub enum BadIcon {
     /// Produced when the length of the `rgba` argument isn't divisible by 4, thus `rgba` can't be
@@ -25,6 +26,8 @@ pub enum BadIcon {
         width_x_height: usize,
         pixel_count: usize,
     },
+    /// Produced when underlying OS functionality failed to create the icon
+    OsError(io::Error),
 }
 
 impl fmt::Display for BadIcon {
@@ -43,6 +46,7 @@ impl fmt::Display for BadIcon {
                 "The specified dimensions ({:?}x{:?}) don't match the number of pixels supplied by the `rgba` argument ({:?}). For those dimensions, the expected pixel count is {:?}.",
                 width, height, pixel_count, width_x_height,
             ),
+            BadIcon::OsError(e) => write!(f, "OS error when instantiating the icon: {:?}", e),
         }
     }
 }
@@ -54,38 +58,78 @@ impl Error for BadIcon {
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
-/// An icon used for the window titlebar, taskbar, etc.
-pub struct Icon {
+pub(crate) struct RgbaIcon {
     pub(crate) rgba: Vec<u8>,
     pub(crate) width: u32,
     pub(crate) height: u32,
 }
 
+/// For platforms which don't have window icons (e.g. web)
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub(crate) struct NoIcon;
+
+#[allow(dead_code)] // These are not used on every platform
+mod constructors {
+    use super::*;
+
+    impl RgbaIcon {
+        /// Creates an `Icon` from 32bpp RGBA data.
+        ///
+        /// The length of `rgba` must be divisible by 4, and `width * height` must equal
+        /// `rgba.len() / 4`. Otherwise, this will return a `BadIcon` error.
+        pub fn from_rgba(rgba: Vec<u8>, width: u32, height: u32) -> Result<Self, BadIcon> {
+            if rgba.len() % PIXEL_SIZE != 0 {
+                return Err(BadIcon::ByteCountNotDivisibleBy4 {
+                    byte_count: rgba.len(),
+                });
+            }
+            let pixel_count = rgba.len() / PIXEL_SIZE;
+            if pixel_count != (width * height) as usize {
+                Err(BadIcon::DimensionsVsPixelCount {
+                    width,
+                    height,
+                    width_x_height: (width * height) as usize,
+                    pixel_count,
+                })
+            } else {
+                Ok(RgbaIcon {
+                    rgba,
+                    width,
+                    height,
+                })
+            }
+        }
+    }
+
+    impl NoIcon {
+        pub fn from_rgba(rgba: Vec<u8>, width: u32, height: u32) -> Result<Self, BadIcon> {
+            // Create the rgba icon anyway to validate the input
+            let _ = RgbaIcon::from_rgba(rgba, width, height)?;
+            Ok(NoIcon)
+        }
+    }
+}
+
+/// An icon used for the window titlebar, taskbar, etc.
+#[derive(Clone)]
+pub struct Icon {
+    pub(crate) inner: PlatformIcon,
+}
+
+impl fmt::Debug for Icon {
+    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
+        fmt::Debug::fmt(&self.inner, formatter)
+    }
+}
+
 impl Icon {
     /// Creates an `Icon` from 32bpp RGBA data.
     ///
     /// The length of `rgba` must be divisible by 4, and `width * height` must equal
     /// `rgba.len() / 4`. Otherwise, this will return a `BadIcon` error.
     pub fn from_rgba(rgba: Vec<u8>, width: u32, height: u32) -> Result<Self, BadIcon> {
-        if rgba.len() % PIXEL_SIZE != 0 {
-            return Err(BadIcon::ByteCountNotDivisibleBy4 {
-                byte_count: rgba.len(),
-            });
-        }
-        let pixel_count = rgba.len() / PIXEL_SIZE;
-        if pixel_count != (width * height) as usize {
-            Err(BadIcon::DimensionsVsPixelCount {
-                width,
-                height,
-                width_x_height: (width * height) as usize,
-                pixel_count,
-            })
-        } else {
-            Ok(Icon {
-                rgba,
-                width,
-                height,
-            })
-        }
+        Ok(Icon {
+            inner: PlatformIcon::from_rgba(rgba, width, height)?,
+        })
     }
 }

src/platform/unix.rs

@@ -446,7 +446,8 @@ impl<T: Theme> SCTKTheme for WaylandTheme<T> {
     }
 
     fn get_close_button_icon_color(&self, status: SCTKButtonState) -> [u8; 4] {
-        self.0.close_button_color(ButtonState::from_sctk(status))
+        self.0
+            .close_button_icon_color(ButtonState::from_sctk(status))
     }
 
     fn get_maximize_button_color(&self, status: SCTKButtonState) -> [u8; 4] {

src/platform/web.rs

@@ -14,6 +14,9 @@ use stdweb::web::html_element::CanvasElement;
 #[cfg(feature = "stdweb")]
 pub trait WindowExtStdweb {
     fn canvas(&self) -> CanvasElement;
+
+    /// Whether the browser reports the preferred color scheme to be "dark".
+    fn is_dark_mode(&self) -> bool;
 }
 
 #[cfg(feature = "web-sys")]
@@ -22,6 +25,9 @@ use web_sys::HtmlCanvasElement;
 #[cfg(feature = "web-sys")]
 pub trait WindowExtWebSys {
     fn canvas(&self) -> HtmlCanvasElement;
+
+    /// Whether the browser reports the preferred color scheme to be "dark".
+    fn is_dark_mode(&self) -> bool;
 }
 
 #[cfg(feature = "stdweb")]

src/platform/windows.rs

@@ -1,16 +1,19 @@
 #![cfg(target_os = "windows")]
 
 use std::os::raw::c_void;
+use std::path::Path;
 
 use libc;
+use winapi::shared::minwindef::WORD;
 use winapi::shared::windef::HWND;
 
 use crate::{
+    dpi::PhysicalSize,
     event::DeviceId,
     event_loop::EventLoop,
     monitor::MonitorHandle,
-    platform_impl::EventLoop as WindowsEventLoop,
-    window::{Icon, Window, WindowBuilder},
+    platform_impl::{EventLoop as WindowsEventLoop, WinIcon},
+    window::{BadIcon, Icon, Window, WindowBuilder},
 };
 
 /// Additional methods on `EventLoop` that are specific to Windows.
@@ -171,3 +174,40 @@ impl DeviceIdExtWindows for DeviceId {
         self.0.persistent_identifier()
     }
 }
+
+/// Additional methods on `Icon` that are specific to Windows.
+pub trait IconExtWindows: Sized {
+    /// Create an icon from a file path.
+    ///
+    /// Specify `size` to load a specific icon size from the file, or `None` to load the default
+    /// icon size from the file.
+    ///
+    /// In cases where the specified size does not exist in the file, Windows may perform scaling
+    /// to get an icon of the desired size.
+    fn from_path<P: AsRef<Path>>(path: P, size: Option<PhysicalSize<u32>>)
+        -> Result<Self, BadIcon>;
+
+    /// Create an icon from a resource embedded in this executable or library.
+    ///
+    /// Specify `size` to load a specific icon size from the file, or `None` to load the default
+    /// icon size from the file.
+    ///
+    /// In cases where the specified size does not exist in the file, Windows may perform scaling
+    /// to get an icon of the desired size.
+    fn from_resource(ordinal: WORD, size: Option<PhysicalSize<u32>>) -> Result<Self, BadIcon>;
+}
+
+impl IconExtWindows for Icon {
+    fn from_path<P: AsRef<Path>>(
+        path: P,
+        size: Option<PhysicalSize<u32>>,
+    ) -> Result<Self, BadIcon> {
+        let win_icon = WinIcon::from_path(path, size)?;
+        Ok(Icon { inner: win_icon })
+    }
+
+    fn from_resource(ordinal: WORD, size: Option<PhysicalSize<u32>>) -> Result<Self, BadIcon> {
+        let win_icon = WinIcon::from_resource(ordinal, size)?;
+        Ok(Icon { inner: win_icon })
+    }
+}

src/platform_impl/android/mod.rs

@@ -22,6 +22,8 @@ use crate::{
 use raw_window_handle::{android::AndroidHandle, RawWindowHandle};
 use CreationError::OsError;
 
+pub(crate) use crate::icon::NoIcon as PlatformIcon;
+
 pub type OsError = std::io::Error;
 
 pub struct EventLoop {
@@ -61,10 +63,10 @@ impl EventLoop {
         while let Ok(event) = self.event_rx.try_recv() {
             let e = match event {
                 android_glue::Event::EventMotion(motion) => {
-                    let dpi_factor = MonitorHandle.scale_factor();
+                    let scale_factor = MonitorHandle.scale_factor();
                     let location = LogicalPosition::from_physical(
                         (motion.x as f64, motion.y as f64),
-                        dpi_factor,
+                        scale_factor,
                     );
                     Some(Event::WindowEvent {
                         window_id: RootWindowId(WindowId),
@@ -102,9 +104,9 @@ impl EventLoop {
                     if native_window.is_null() {
                         None
                     } else {
-                        let dpi_factor = MonitorHandle.scale_factor();
+                        let scale_factor = MonitorHandle.scale_factor();
                         let physical_size = MonitorHandle.size();
-                        let size = LogicalSize::from_physical(physical_size, dpi_factor);
+                        let size = LogicalSize::from_physical(physical_size, scale_factor);
                         Some(Event::WindowEvent {
                             window_id: RootWindowId(WindowId),
                             event: WindowEvent::Resized(size),
@@ -319,9 +321,9 @@ impl Window {
         if self.native_window.is_null() {
             None
         } else {
-            let dpi_factor = self.scale_factor();
+            let scale_factor = self.scale_factor();
             let physical_size = self.current_monitor().size();
-            Some(LogicalSize::from_physical(physical_size, dpi_factor))
+            Some(LogicalSize::from_physical(physical_size, scale_factor))
         }
     }
 

src/platform_impl/ios/mod.rs

@@ -83,6 +83,8 @@ pub use self::{
     window::{PlatformSpecificWindowBuilderAttributes, Window, WindowId},
 };
 
+pub(crate) use crate::icon::NoIcon as PlatformIcon;
+
 #[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub struct DeviceId {
     uiscreen: ffi::id,

src/platform_impl/ios/view.rs

@@ -127,12 +127,12 @@ unsafe fn get_view_class(root_view_class: &'static Class) -> &'static Class {
                 let screen_space: id = msg_send![screen, coordinateSpace];
                 let screen_frame: CGRect =
                     msg_send![object, convertRect:bounds toCoordinateSpace:screen_space];
-                let dpi_factor: CGFloat = msg_send![screen, scale];
+                let scale_factor: CGFloat = msg_send![screen, scale];
                 let size = crate::dpi::LogicalSize {
                     width: screen_frame.size.width as f64,
                     height: screen_frame.size.height as f64,
                 }
-                .to_physical(dpi_factor.into());
+                .to_physical(scale_factor.into());
                 app_state::handle_nonuser_event(EventWrapper::StaticEvent(Event::WindowEvent {
                     window_id: RootWindowId(window.into()),
                     event: WindowEvent::Resized(size),
@@ -162,15 +162,15 @@ unsafe fn get_view_class(root_view_class: &'static Class) -> &'static Class {
                 // `setContentScaleFactor` may be called with a value of 0, which means "reset the
                 // content scale factor to a device-specific default value", so we can't use the
                 // parameter here. We can query the actual factor using the getter
-                let dpi_factor: CGFloat = msg_send![object, contentScaleFactor];
+                let scale_factor: CGFloat = msg_send![object, contentScaleFactor];
                 assert!(
-                    !dpi_factor.is_nan()
-                        && dpi_factor.is_finite()
-                        && dpi_factor.is_sign_positive()
-                        && dpi_factor > 0.0,
+                    !scale_factor.is_nan()
+                        && scale_factor.is_finite()
+                        && scale_factor.is_sign_positive()
+                        && scale_factor > 0.0,
                     "invalid scale_factor set on UIView",
                 );
-                let scale_factor: f64 = dpi_factor.into();
+                let scale_factor: f64 = scale_factor.into();
                 let bounds: CGRect = msg_send![object, bounds];
                 let screen: id = msg_send![window, screen];
                 let screen_space: id = msg_send![screen, coordinateSpace];

src/platform_impl/ios/window.rs

@@ -83,8 +83,8 @@ impl Inner {
                 x: safe_area.origin.x as f64,
                 y: safe_area.origin.y as f64,
             };
-            let dpi_factor = self.scale_factor();
-            Ok(position.to_physical(dpi_factor))
+            let scale_factor = self.scale_factor();
+            Ok(position.to_physical(scale_factor))
         }
     }
 
@@ -95,15 +95,15 @@ impl Inner {
                 x: screen_frame.origin.x as f64,
                 y: screen_frame.origin.y as f64,
             };
-            let dpi_factor = self.scale_factor();
-            Ok(position.to_physical(dpi_factor))
+            let scale_factor = self.scale_factor();
+            Ok(position.to_physical(scale_factor))
         }
     }
 
     pub fn set_outer_position(&self, physical_position: Position) {
         unsafe {
-            let dpi_factor = self.scale_factor();
-            let position = physical_position.to_logical::<f64>(dpi_factor);
+            let scale_factor = self.scale_factor();
+            let position = physical_position.to_logical::<f64>(scale_factor);
             let screen_frame = self.screen_frame();
             let new_screen_frame = CGRect {
                 origin: CGPoint {
@@ -119,25 +119,25 @@ impl Inner {
 
     pub fn inner_size(&self) -> PhysicalSize<u32> {
         unsafe {
-            let dpi_factor = self.scale_factor();
+            let scale_factor = self.scale_factor();
             let safe_area = self.safe_area_screen_space();
             let size = LogicalSize {
                 width: safe_area.size.width as f64,
                 height: safe_area.size.height as f64,
             };
-            size.to_physical(dpi_factor)
+            size.to_physical(scale_factor)
         }
     }
 
     pub fn outer_size(&self) -> PhysicalSize<u32> {
         unsafe {
-            let dpi_factor = self.scale_factor();
+            let scale_factor = self.scale_factor();
             let screen_frame = self.screen_frame();
             let size = LogicalSize {
                 width: screen_frame.size.width as f64,
                 height: screen_frame.size.height as f64,
             };
-            size.to_physical(dpi_factor)
+            size.to_physical(scale_factor)
         }
     }
 
@@ -355,8 +355,8 @@ impl Window {
 
             let frame = match window_attributes.inner_size {
                 Some(dim) => {
-                    let dpi_factor = msg_send![screen, scale];
-                    let size = dim.to_logical::<f64>(dpi_factor);
+                    let scale_factor = msg_send![screen, scale];
+                    let size = dim.to_logical::<f64>(scale_factor);
                     CGRect {
                         origin: screen_bounds.origin,
                         size: CGSize {
@@ -400,8 +400,8 @@ impl Window {
 
             // Like the Windows and macOS backends, we send a `ScaleFactorChanged` and `Resized`
             // event on window creation if the DPI factor != 1.0
-            let dpi_factor: CGFloat = msg_send![view, contentScaleFactor];
-            let scale_factor: f64 = dpi_factor.into();
+            let scale_factor: CGFloat = msg_send![view, contentScaleFactor];
+            let scale_factor: f64 = scale_factor.into();
             if scale_factor != 1.0 {
                 let bounds: CGRect = msg_send![view, bounds];
                 let screen: id = msg_send![window, screen];

src/platform_impl/linux/mod.rs

@@ -18,6 +18,8 @@ use crate::{
     window::{CursorIcon, Fullscreen, WindowAttributes},
 };
 
+pub(crate) use crate::icon::RgbaIcon as PlatformIcon;
+
 pub mod wayland;
 pub mod x11;
 
@@ -584,13 +586,12 @@ impl<T: 'static> EventLoop<T> {
     }
 
     pub fn new_x11_any_thread() -> Result<EventLoop<T>, XNotSupported> {
-        X11_BACKEND
-            .lock()
-            .as_ref()
-            .map(Arc::clone)
-            .map(x11::EventLoop::new)
-            .map(EventLoop::X)
-            .map_err(|err| err.clone())
+        let xconn = match X11_BACKEND.lock().as_ref() {
+            Ok(xconn) => xconn.clone(),
+            Err(err) => return Err(err.clone()),
+        };
+
+        Ok(EventLoop::X(x11::EventLoop::new(xconn)))
     }
 
     #[inline]

src/platform_impl/linux/wayland/event_loop.rs

@@ -39,7 +39,10 @@ use crate::{
     window::{CursorIcon, WindowId as RootWindowId},
 };
 
-use super::{window::WindowStore, DeviceId, WindowId};
+use super::{
+    window::{DecorationsAction, WindowStore},
+    DeviceId, WindowId,
+};
 
 use smithay_client_toolkit::{
     output::OutputMgr,
@@ -90,6 +93,7 @@ pub struct CursorManager {
     locked_pointers: Vec<ZwpLockedPointerV1>,
     cursor_visible: bool,
     current_cursor: CursorIcon,
+    scale_factor: u32,
 }
 
 impl CursorManager {
@@ -101,6 +105,7 @@ impl CursorManager {
             locked_pointers: Vec::new(),
             cursor_visible: true,
             current_cursor: CursorIcon::default(),
+            scale_factor: 1,
         }
     }
 
@@ -145,6 +150,11 @@ impl CursorManager {
         }
     }
 
+    pub fn update_scale_factor(&mut self, scale: u32) {
+        self.scale_factor = scale;
+        self.reload_cursor_style();
+    }
+
     fn set_cursor_icon_impl(&mut self, cursor: CursorIcon) {
         let cursor = match cursor {
             CursorIcon::Alias => "link",
@@ -193,7 +203,7 @@ impl CursorManager {
         for pointer in self.pointers.iter() {
             // Ignore erros, since we don't want to fail hard in case we can't find a proper cursor
             // in a given theme.
-            let _ = pointer.set_cursor(cursor, None);
+            let _ = pointer.set_cursor_with_scale(cursor, self.scale_factor, None);
         }
     }
 
@@ -706,6 +716,13 @@ impl<T> EventLoop<T> {
                 crate::window::WindowId(crate::platform_impl::WindowId::Wayland(window.wid));
             if let Some(frame) = window.frame {
                 if let Some((w, h)) = window.newsize {
+                    // Update decorations state
+                    match window.decorations_action {
+                        Some(DecorationsAction::Hide) => frame.set_decorate(false),
+                        Some(DecorationsAction::Show) => frame.set_decorate(true),
+                        None => (),
+                    }
+
                     // mutter (GNOME Wayland) relies on `set_geometry` to reposition window in case
                     // it overlaps mutter's `bounding box`, so we can't avoid this resize call,
                     // which calls `set_geometry` under the hood, for now.
@@ -728,6 +745,13 @@ impl<T> EventLoop<T> {
                 }
 
                 if let Some(dpi) = window.new_dpi {
+                    // Update cursor scale factor
+                    {
+                        self.cursor_manager
+                            .lock()
+                            .unwrap()
+                            .update_scale_factor(dpi as u32);
+                    };
                     let dpi = dpi as f64;
                     let logical_size = LogicalSize::<f64>::from(*window.size);
                     let mut new_inner_size = logical_size.to_physical(dpi);
@@ -742,6 +766,8 @@ impl<T> EventLoop<T> {
 
                     let (w, h) = new_inner_size.to_logical::<u32>(dpi).into();
                     frame.resize(w, h);
+                    // Refresh frame to rescale decorations
+                    frame.refresh();
                     *window.size = (w, h);
                 }
             }

src/platform_impl/linux/wayland/keyboard.rs

@@ -8,9 +8,7 @@ use smithay_client_toolkit::{
     reexports::client::protocol::{wl_keyboard, wl_seat},
 };
 
-use crate::event::{
-    DeviceEvent, ElementState, KeyboardInput, ModifiersState, VirtualKeyCode, WindowEvent,
-};
+use crate::event::{ElementState, KeyboardInput, ModifiersState, VirtualKeyCode, WindowEvent};
 
 pub fn init_keyboard(
     seat: &wl_seat::WlSeat,
@@ -33,9 +31,24 @@ pub fn init_keyboard(
                     let wid = make_wid(&surface);
                     my_sink.send_window_event(WindowEvent::Focused(true), wid);
                     *target.lock().unwrap() = Some(wid);
+
+                    let modifiers = *modifiers_tracker.lock().unwrap();
+
+                    if !modifiers.is_empty() {
+                        my_sink.send_window_event(WindowEvent::ModifiersChanged(modifiers), wid);
+                    }
                 }
                 KbEvent::Leave { surface, .. } => {
                     let wid = make_wid(&surface);
+                    let modifiers = *modifiers_tracker.lock().unwrap();
+
+                    if !modifiers.is_empty() {
+                        my_sink.send_window_event(
+                            WindowEvent::ModifiersChanged(ModifiersState::empty()),
+                            wid,
+                        );
+                    }
+
                     my_sink.send_window_event(WindowEvent::Focused(false), wid);
                     *target.lock().unwrap() = None;
                 }
@@ -88,7 +101,9 @@ pub fn init_keyboard(
 
                     *modifiers_tracker.lock().unwrap() = modifiers;
 
-                    my_sink.send_device_event(DeviceEvent::ModifiersChanged(modifiers), DeviceId);
+                    if let Some(wid) = *target.lock().unwrap() {
+                        my_sink.send_window_event(WindowEvent::ModifiersChanged(modifiers), wid);
+                    }
                 }
             }
         },

src/platform_impl/linux/wayland/pointer.rs

@@ -1,5 +1,6 @@
 use std::sync::{Arc, Mutex};
 
+use crate::dpi::LogicalPosition;
 use crate::event::{
     DeviceEvent, ElementState, ModifiersState, MouseButton, MouseScrollDelta, TouchPhase,
     WindowEvent,
@@ -76,13 +77,16 @@ pub fn implement_pointer(
                                 },
                                 wid,
                             );
+
+                            let position = LogicalPosition::new(surface_x, surface_y)
+                                .to_physical(scale_factor);
+
                             sink.send_window_event(
                                 WindowEvent::CursorMoved {
                                     device_id: crate::event::DeviceId(
                                         crate::platform_impl::DeviceId::Wayland(DeviceId),
                                     ),
-                                    position: (surface_x * scale_factor, surface_y * scale_factor)
-                                        .into(),
+                                    position,
                                     modifiers: modifiers_tracker.lock().unwrap().clone(),
                                 },
                                 wid,
@@ -109,15 +113,18 @@ pub fn implement_pointer(
                         ..
                     } => {
                         if let Some(surface) = mouse_focus.as_ref() {
-                            let scale_factor = surface::get_dpi_factor(&surface) as f64;
                             let wid = make_wid(surface);
+
+                            let scale_factor = surface::get_dpi_factor(&surface) as f64;
+                            let position = LogicalPosition::new(surface_x, surface_y)
+                                .to_physical(scale_factor);
+
                             sink.send_window_event(
                                 WindowEvent::CursorMoved {
                                     device_id: crate::event::DeviceId(
                                         crate::platform_impl::DeviceId::Wayland(DeviceId),
                                     ),
-                                    position: (surface_x * scale_factor, surface_y * scale_factor)
-                                        .into(),
+                                    position,
                                     modifiers: modifiers_tracker.lock().unwrap().clone(),
                                 },
                                 wid,

src/platform_impl/linux/wayland/touch.rs

@@ -1,17 +1,22 @@
 use std::sync::{Arc, Mutex};
 
+use crate::dpi::LogicalPosition;
 use crate::event::{TouchPhase, WindowEvent};
 
-use super::{event_loop::EventsSink, window::WindowStore, DeviceId, WindowId};
+use super::{event_loop::EventsSink, make_wid, window::WindowStore, DeviceId};
+
+use smithay_client_toolkit::surface;
 
 use smithay_client_toolkit::reexports::client::protocol::{
     wl_seat,
+    wl_surface::WlSurface,
     wl_touch::{Event as TouchEvent, WlTouch},
 };
 
+// location is in logical coordinates.
 struct TouchPoint {
-    wid: WindowId,
-    location: (f64, f64),
+    surface: WlSurface,
+    position: LogicalPosition<f64>,
     id: i32,
 }
 
@@ -31,21 +36,24 @@ pub(crate) fn implement_touch(
                     } => {
                         let wid = store.find_wid(&surface);
                         if let Some(wid) = wid {
+                            let scale_factor = surface::get_dpi_factor(&surface) as f64;
+                            let position = LogicalPosition::new(x, y);
+
                             sink.send_window_event(
                                 WindowEvent::Touch(crate::event::Touch {
                                     device_id: crate::event::DeviceId(
                                         crate::platform_impl::DeviceId::Wayland(DeviceId),
                                     ),
                                     phase: TouchPhase::Started,
-                                    location: (x, y).into(),
+                                    location: position.to_physical(scale_factor),
                                     force: None, // TODO
                                     id: id as u64,
                                 }),
                                 wid,
                             );
                             pending_ids.push(TouchPoint {
-                                wid,
-                                location: (x, y),
+                                surface,
+                                position,
                                 id,
                             });
                         }
@@ -54,52 +62,63 @@ pub(crate) fn implement_touch(
                         let idx = pending_ids.iter().position(|p| p.id == id);
                         if let Some(idx) = idx {
                             let pt = pending_ids.remove(idx);
+
+                            let scale_factor = surface::get_dpi_factor(&pt.surface) as f64;
+                            let location = pt.position.to_physical(scale_factor);
+
                             sink.send_window_event(
                                 WindowEvent::Touch(crate::event::Touch {
                                     device_id: crate::event::DeviceId(
                                         crate::platform_impl::DeviceId::Wayland(DeviceId),
                                     ),
                                     phase: TouchPhase::Ended,
-                                    location: pt.location.into(),
+                                    location,
                                     force: None, // TODO
                                     id: id as u64,
                                 }),
-                                pt.wid,
+                                make_wid(&pt.surface),
                             );
                         }
                     }
                     TouchEvent::Motion { id, x, y, .. } => {
                         let pt = pending_ids.iter_mut().find(|p| p.id == id);
                         if let Some(pt) = pt {
-                            pt.location = (x, y);
+                            pt.position = LogicalPosition::new(x, y);
+
+                            let scale_factor = surface::get_dpi_factor(&pt.surface) as f64;
+                            let location = pt.position.to_physical(scale_factor);
+
                             sink.send_window_event(
                                 WindowEvent::Touch(crate::event::Touch {
                                     device_id: crate::event::DeviceId(
                                         crate::platform_impl::DeviceId::Wayland(DeviceId),
                                     ),
                                     phase: TouchPhase::Moved,
-                                    location: (x, y).into(),
+                                    location,
                                     force: None, // TODO
                                     id: id as u64,
                                 }),
-                                pt.wid,
+                                make_wid(&pt.surface),
                             );
                         }
                     }
                     TouchEvent::Frame => (),
                     TouchEvent::Cancel => {
                         for pt in pending_ids.drain(..) {
+                            let scale_factor = surface::get_dpi_factor(&pt.surface) as f64;
+                            let location = pt.position.to_physical(scale_factor);
+
                             sink.send_window_event(
                                 WindowEvent::Touch(crate::event::Touch {
                                     device_id: crate::event::DeviceId(
                                         crate::platform_impl::DeviceId::Wayland(DeviceId),
                                     ),
                                     phase: TouchPhase::Cancelled,
-                                    location: pt.location.into(),
+                                    location,
                                     force: None, // TODO
                                     id: pt.id as u64,
                                 }),
-                                pt.wid,
+                                make_wid(&pt.surface),
                             );
                         }
                     }

src/platform_impl/linux/wayland/window.rs

@@ -41,6 +41,13 @@ pub struct Window {
     need_refresh: Arc<Mutex<bool>>,
     fullscreen: Arc<Mutex<bool>>,
     cursor_grab_changed: Arc<Mutex<Option<bool>>>, // Update grab state
+    decorated: Arc<Mutex<bool>>,
+}
+
+#[derive(Clone, Copy, Debug)]
+pub enum DecorationsAction {
+    Hide,
+    Show,
 }
 
 impl Window {
@@ -69,6 +76,9 @@ impl Window {
 
         let window_store = evlp.store.clone();
 
+        let decorated = Arc::new(Mutex::new(attributes.decorations));
+        let pending_decorations_action = Arc::new(Mutex::new(None));
+
         let my_surface = surface.clone();
         let mut frame = SWindow::<ConceptFrame>::init_from_env(
             &evlp.env,
@@ -83,7 +93,23 @@ impl Window {
                         if window.surface.as_ref().equals(&my_surface.as_ref()) {
                             window.newsize = new_size;
                             *(window.need_refresh.lock().unwrap()) = true;
-                            *(window.fullscreen.lock().unwrap()) = is_fullscreen;
+                            {
+                                // Get whether we're in fullscreen
+                                let mut fullscreen = window.fullscreen.lock().unwrap();
+                                // Fullscreen state was changed, so update decorations
+                                if *fullscreen != is_fullscreen {
+                                    let decorated = { *window.decorated.lock().unwrap() };
+                                    if decorated {
+                                        *window.pending_decorations_action.lock().unwrap() =
+                                            if is_fullscreen {
+                                                Some(DecorationsAction::Hide)
+                                            } else {
+                                                Some(DecorationsAction::Show)
+                                            };
+                                    }
+                                }
+                                *fullscreen = is_fullscreen;
+                            }
                             *(window.need_frame_refresh.lock().unwrap()) = true;
                             return;
                         }
@@ -174,6 +200,8 @@ impl Window {
             frame: Arc::downgrade(&frame),
             current_dpi: 1,
             new_dpi: None,
+            decorated: decorated.clone(),
+            pending_decorations_action: pending_decorations_action.clone(),
         });
         evlp.evq.borrow_mut().sync_roundtrip().unwrap();
 
@@ -189,6 +217,7 @@ impl Window {
             cursor_manager,
             fullscreen,
             cursor_grab_changed,
+            decorated,
         })
     }
 
@@ -277,6 +306,7 @@ impl Window {
     }
 
     pub fn set_decorations(&self, decorate: bool) {
+        *(self.decorated.lock().unwrap()) = decorate;
         self.frame.lock().unwrap().set_decorate(decorate);
         *(self.need_frame_refresh.lock().unwrap()) = true;
     }
@@ -409,6 +439,8 @@ struct InternalWindow {
     frame: Weak<Mutex<SWindow<ConceptFrame>>>,
     current_dpi: i32,
     new_dpi: Option<i32>,
+    decorated: Arc<Mutex<bool>>,
+    pending_decorations_action: Arc<Mutex<Option<DecorationsAction>>>,
 }
 
 pub struct WindowStore {
@@ -425,6 +457,7 @@ pub struct WindowStoreForEach<'a> {
     pub surface: &'a wl_surface::WlSurface,
     pub wid: WindowId,
     pub frame: Option<&'a mut SWindow<ConceptFrame>>,
+    pub decorations_action: Option<DecorationsAction>,
 }
 
 impl WindowStore {
@@ -482,6 +515,7 @@ impl WindowStore {
             let opt_arc = window.frame.upgrade();
             let mut opt_mutex_lock = opt_arc.as_ref().map(|m| m.lock().unwrap());
             let mut size = { *window.size.lock().unwrap() };
+            let decorations_action = { window.pending_decorations_action.lock().unwrap().take() };
             f(WindowStoreForEach {
                 newsize: window.newsize.take(),
                 size: &mut size,
@@ -492,6 +526,7 @@ impl WindowStore {
                 surface: &window.surface,
                 wid: make_wid(&window.surface),
                 frame: opt_mutex_lock.as_mut().map(|m| &mut **m),
+                decorations_action,
             });
             *window.size.lock().unwrap() = size;
             if let Some(dpi) = window.new_dpi.take() {

src/platform_impl/linux/x11/event_processor.rs

@@ -32,6 +32,8 @@ pub(super) struct EventProcessor<T: 'static> {
     // Number of touch events currently in progress
     pub(super) num_touch: u32,
     pub(super) first_touch: Option<u64>,
+    // Currently focused window belonging to this process
+    pub(super) active_window: Option<ffi::Window>,
 }
 
 impl<T: 'static> EventProcessor<T> {
@@ -136,11 +138,12 @@ impl<T: 'static> EventProcessor<T> {
                         if let Some(modifiers) =
                             self.device_mod_state.update_state(&state, modifier)
                         {
-                            let device_id = mkdid(util::VIRTUAL_CORE_KEYBOARD);
-                            callback(Event::DeviceEvent {
-                                device_id,
-                                event: DeviceEvent::ModifiersChanged(modifiers),
-                            });
+                            if let Some(window_id) = self.active_window {
+                                callback(Event::WindowEvent {
+                                    window_id: mkwid(window_id),
+                                    event: WindowEvent::ModifiersChanged(modifiers),
+                                });
+                            }
                         }
                     }
                 }
@@ -872,44 +875,58 @@ impl<T: 'static> EventProcessor<T> {
                     ffi::XI_FocusIn => {
                         let xev: &ffi::XIFocusInEvent = unsafe { &*(xev.data as *const _) };
 
-                        let window_id = mkwid(xev.event);
-
                         wt.ime
                             .borrow_mut()
                             .focus(xev.event)
                             .expect("Failed to focus input context");
 
-                        callback(Event::WindowEvent {
-                            window_id,
-                            event: Focused(true),
-                        });
-
                         let modifiers = ModifiersState::from_x11(&xev.mods);
 
-                        update_modifiers!(modifiers, None);
+                        self.device_mod_state.update_state(&modifiers, None);
 
-                        // The deviceid for this event is for a keyboard instead of a pointer,
-                        // so we have to do a little extra work.
-                        let pointer_id = self
-                            .devices
-                            .borrow()
-                            .get(&DeviceId(xev.deviceid))
-                            .map(|device| device.attachment)
-                            .unwrap_or(2);
+                        if self.active_window != Some(xev.event) {
+                            self.active_window = Some(xev.event);
 
-                        let position = PhysicalPosition::new(xev.event_x, xev.event_y);
+                            let window_id = mkwid(xev.event);
+                            let position = PhysicalPosition::new(xev.event_x, xev.event_y);
 
-                        callback(Event::WindowEvent {
-                            window_id,
-                            event: CursorMoved {
-                                device_id: mkdid(pointer_id),
-                                position,
-                                modifiers,
-                            },
-                        });
+                            callback(Event::WindowEvent {
+                                window_id,
+                                event: Focused(true),
+                            });
 
-                        // Issue key press events for all pressed keys
-                        self.handle_pressed_keys(window_id, ElementState::Pressed, &mut callback);
+                            if !modifiers.is_empty() {
+                                callback(Event::WindowEvent {
+                                    window_id,
+                                    event: WindowEvent::ModifiersChanged(modifiers),
+                                });
+                            }
+
+                            // The deviceid for this event is for a keyboard instead of a pointer,
+                            // so we have to do a little extra work.
+                            let pointer_id = self
+                                .devices
+                                .borrow()
+                                .get(&DeviceId(xev.deviceid))
+                                .map(|device| device.attachment)
+                                .unwrap_or(2);
+
+                            callback(Event::WindowEvent {
+                                window_id,
+                                event: CursorMoved {
+                                    device_id: mkdid(pointer_id),
+                                    position,
+                                    modifiers,
+                                },
+                            });
+
+                            // Issue key press events for all pressed keys
+                            self.handle_pressed_keys(
+                                window_id,
+                                ElementState::Pressed,
+                                &mut callback,
+                            );
+                        }
                     }
                     ffi::XI_FocusOut => {
                         let xev: &ffi::XIFocusOutEvent = unsafe { &*(xev.data as *const _) };
@@ -921,15 +938,26 @@ impl<T: 'static> EventProcessor<T> {
                             .unfocus(xev.event)
                             .expect("Failed to unfocus input context");
 
-                        let window_id = mkwid(xev.event);
+                        if self.active_window.take() == Some(xev.event) {
+                            let window_id = mkwid(xev.event);
 
-                        // Issue key release events for all pressed keys
-                        self.handle_pressed_keys(window_id, ElementState::Released, &mut callback);
+                            // Issue key release events for all pressed keys
+                            self.handle_pressed_keys(
+                                window_id,
+                                ElementState::Released,
+                                &mut callback,
+                            );
 
-                        callback(Event::WindowEvent {
-                            window_id,
-                            event: Focused(false),
-                        })
+                            callback(Event::WindowEvent {
+                                window_id,
+                                event: WindowEvent::ModifiersChanged(ModifiersState::empty()),
+                            });
+
+                            callback(Event::WindowEvent {
+                                window_id,
+                                event: Focused(false),
+                            })
+                        }
                     }
 
                     ffi::XI_TouchBegin | ffi::XI_TouchUpdate | ffi::XI_TouchEnd => {
@@ -1084,10 +1112,12 @@ impl<T: 'static> EventProcessor<T> {
                             let new_modifiers = self.device_mod_state.modifiers();
 
                             if modifiers != new_modifiers {
-                                callback(Event::DeviceEvent {
-                                    device_id,
-                                    event: DeviceEvent::ModifiersChanged(new_modifiers),
-                                });
+                                if let Some(window_id) = self.active_window {
+                                    callback(Event::WindowEvent {
+                                        window_id: mkwid(window_id),
+                                        event: WindowEvent::ModifiersChanged(new_modifiers),
+                                    });
+                                }
                             }
                         }
                     }

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

@@ -21,7 +21,8 @@ unsafe fn open_im(xconn: &Arc<XConnection>, locale_modifiers: &CStr) -> Option<f
     // XSetLocaleModifiers returns...
     // * The current locale modifiers if it's given a NULL pointer.
     // * The new locale modifiers if we succeeded in setting them.
-    // * NULL if the locale modifiers string is malformed.
+    // * NULL if the locale modifiers string is malformed or if the
+    //   current locale is not supported by Xlib.
     (xconn.xlib.XSetLocaleModifiers)(locale_modifiers.as_ptr());
 
     let im = (xconn.xlib.XOpenIM)(

src/platform_impl/linux/x11/mod.rs

@@ -29,6 +29,7 @@ use std::{
     mem::{self, MaybeUninit},
     ops::Deref,
     os::raw::*,
+    ptr,
     rc::Rc,
     slice,
     sync::{mpsc, Arc, Mutex, Weak},
@@ -105,7 +106,25 @@ impl<T: 'static> EventLoop<T> {
         // Input methods will open successfully without setting the locale, but it won't be
         // possible to actually commit pre-edit sequences.
         unsafe {
+            // Remember default locale to restore it if target locale is unsupported
+            // by Xlib
+            let default_locale = setlocale(LC_CTYPE, ptr::null());
             setlocale(LC_CTYPE, b"\0".as_ptr() as *const _);
+
+            // Check if set locale is supported by Xlib.
+            // If not, calls to some Xlib functions like `XSetLocaleModifiers`
+            // will fail.
+            let locale_supported = (xconn.xlib.XSupportsLocale)() == 1;
+            if !locale_supported {
+                let unsupported_locale = setlocale(LC_CTYPE, ptr::null());
+                warn!(
+                    "Unsupported locale \"{}\". Restoring default locale \"{}\".",
+                    CStr::from_ptr(unsupported_locale).to_string_lossy(),
+                    CStr::from_ptr(default_locale).to_string_lossy()
+                );
+                // Restore default locale
+                setlocale(LC_CTYPE, default_locale);
+            }
         }
         let ime = RefCell::new({
             let result = Ime::new(Arc::clone(&xconn));
@@ -206,6 +225,7 @@ impl<T: 'static> EventLoop<T> {
             device_mod_state: Default::default(),
             num_touch: 0,
             first_touch: None,
+            active_window: None,
         };
 
         // Register for device hotplug events

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

@@ -1,5 +1,5 @@
 use super::*;
-use crate::window::{Icon, Pixel, PIXEL_SIZE};
+use crate::icon::{Icon, Pixel, PIXEL_SIZE};
 
 impl Pixel {
     pub fn to_packed_argb(&self) -> Cardinal {
@@ -18,13 +18,14 @@ impl Pixel {
 
 impl Icon {
     pub(crate) fn to_cardinals(&self) -> Vec<Cardinal> {
-        assert_eq!(self.rgba.len() % PIXEL_SIZE, 0);
-        let pixel_count = self.rgba.len() / PIXEL_SIZE;
-        assert_eq!(pixel_count, (self.width * self.height) as usize);
+        let rgba_icon = &self.inner;
+        assert_eq!(rgba_icon.rgba.len() % PIXEL_SIZE, 0);
+        let pixel_count = rgba_icon.rgba.len() / PIXEL_SIZE;
+        assert_eq!(pixel_count, (rgba_icon.width * rgba_icon.height) as usize);
         let mut data = Vec::with_capacity(pixel_count);
-        data.push(self.width as Cardinal);
-        data.push(self.height as Cardinal);
-        let pixels = self.rgba.as_ptr() as *const Pixel;
+        data.push(rgba_icon.width as Cardinal);
+        data.push(rgba_icon.height as Cardinal);
+        let pixels = rgba_icon.rgba.as_ptr() as *const Pixel;
         for pixel_index in 0..pixel_count {
             let pixel = unsafe { &*pixels.offset(pixel_index as isize) };
             data.push(pixel.to_packed_argb());

src/platform_impl/linux/x11/window.rs

@@ -136,23 +136,23 @@ impl UnownedWindow {
                 })
                 .unwrap_or_else(|| monitors.swap_remove(0))
         };
-        let dpi_factor = guessed_monitor.scale_factor();
+        let scale_factor = guessed_monitor.scale_factor();
 
-        info!("Guessed window scale factor: {}", dpi_factor);
+        info!("Guessed window scale factor: {}", scale_factor);
 
         let max_inner_size: Option<(u32, u32)> = window_attrs
             .max_inner_size
-            .map(|size| size.to_physical::<u32>(dpi_factor).into());
+            .map(|size| size.to_physical::<u32>(scale_factor).into());
         let min_inner_size: Option<(u32, u32)> = window_attrs
             .min_inner_size
-            .map(|size| size.to_physical::<u32>(dpi_factor).into());
+            .map(|size| size.to_physical::<u32>(scale_factor).into());
 
         let dimensions = {
             // x11 only applies constraints when the window is actively resized
             // by the user, so we have to manually apply the initial constraints
             let mut dimensions: (u32, u32) = window_attrs
                 .inner_size
-                .map(|size| size.to_physical::<u32>(dpi_factor))
+                .map(|size| size.to_physical::<u32>(scale_factor))
                 .or_else(|| Some((800, 600).into()))
                 .map(Into::into)
                 .unwrap();
@@ -324,10 +324,10 @@ impl UnownedWindow {
             {
                 let mut min_inner_size = window_attrs
                     .min_inner_size
-                    .map(|size| size.to_physical::<u32>(dpi_factor));
+                    .map(|size| size.to_physical::<u32>(scale_factor));
                 let mut max_inner_size = window_attrs
                     .max_inner_size
-                    .map(|size| size.to_physical::<u32>(dpi_factor));
+                    .map(|size| size.to_physical::<u32>(scale_factor));
 
                 if !window_attrs.resizable {
                     if util::wm_name_is_one_of(&["Xfwm4"]) {
@@ -351,12 +351,12 @@ impl UnownedWindow {
                 normal_hints.set_resize_increments(
                     pl_attribs
                         .resize_increments
-                        .map(|size| size.to_physical::<u32>(dpi_factor).into()),
+                        .map(|size| size.to_physical::<u32>(scale_factor).into()),
                 );
                 normal_hints.set_base_size(
                     pl_attribs
                         .base_size
-                        .map(|size| size.to_physical::<u32>(dpi_factor).into()),
+                        .map(|size| size.to_physical::<u32>(scale_factor).into()),
                 );
                 xconn.set_normal_hints(window.xwindow, normal_hints).queue();
             }
@@ -1053,8 +1053,8 @@ impl UnownedWindow {
 
     #[inline]
     pub fn set_inner_size(&self, size: Size) {
-        let dpi_factor = self.scale_factor();
-        let (width, height) = size.to_physical::<u32>(dpi_factor).into();
+        let scale_factor = self.scale_factor();
+        let (width, height) = size.to_physical::<u32>(scale_factor).into();
         self.set_inner_size_physical(width, height);
     }
 
@@ -1097,16 +1097,16 @@ impl UnownedWindow {
 
     pub(crate) fn adjust_for_dpi(
         &self,
-        old_dpi_factor: f64,
-        new_dpi_factor: f64,
+        old_scale_factor: f64,
+        new_scale_factor: f64,
         width: u32,
         height: u32,
         shared_state: &SharedState,
     ) -> (u32, u32) {
-        let scale_factor = new_dpi_factor / old_dpi_factor;
+        let scale_factor = new_scale_factor / old_scale_factor;
         self.update_normal_hints(|normal_hints| {
             let dpi_adjuster =
-                |size: Size| -> (u32, u32) { size.to_physical::<u32>(new_dpi_factor).into() };
+                |size: Size| -> (u32, u32) { size.to_physical::<u32>(new_scale_factor).into() };
             let max_size = shared_state.max_inner_size.map(&dpi_adjuster);
             let min_size = shared_state.min_inner_size.map(&dpi_adjuster);
             let resize_increments = shared_state.resize_increments.map(&dpi_adjuster);
@@ -1146,12 +1146,12 @@ impl UnownedWindow {
 
         self.set_maximizable_inner(resizable).queue();
 
-        let dpi_factor = self.scale_factor();
+        let scale_factor = self.scale_factor();
         let min_inner_size = min_size
-            .map(|size| size.to_physical::<u32>(dpi_factor))
+            .map(|size| size.to_physical::<u32>(scale_factor))
             .map(Into::into);
         let max_inner_size = max_size
-            .map(|size| size.to_physical::<u32>(dpi_factor))
+            .map(|size| size.to_physical::<u32>(scale_factor))
             .map(Into::into);
         self.update_normal_hints(|normal_hints| {
             normal_hints.set_min_size(min_inner_size);

src/platform_impl/macos/mod.rs

@@ -25,6 +25,8 @@ use crate::{
     error::OsError as RootOsError, event::DeviceId as RootDeviceId, window::WindowAttributes,
 };
 
+pub(crate) use crate::icon::NoIcon as PlatformIcon;
+
 #[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub struct DeviceId;
 

src/platform_impl/macos/view.rs

@@ -50,13 +50,13 @@ impl Default for CursorState {
     }
 }
 
-struct ViewState {
+pub(super) struct ViewState {
     ns_window: id,
     pub cursor_state: Arc<Mutex<CursorState>>,
     ime_spot: Option<(f64, f64)>,
     raw_characters: Option<String>,
     is_key_down: bool,
-    modifiers: ModifiersState,
+    pub(super) modifiers: ModifiersState,
     tracking_rect: Option<NSInteger>,
 }
 
@@ -383,8 +383,13 @@ extern "C" fn reset_cursor_rects(this: &Object, _sel: Sel) {
     }
 }
 
-extern "C" fn has_marked_text(_this: &Object, _sel: Sel) -> BOOL {
-    YES
+extern "C" fn has_marked_text(this: &Object, _sel: Sel) -> BOOL {
+    unsafe {
+        trace!("Triggered `hasMarkedText`");
+        let marked_text: id = *this.get_ivar("markedText");
+        trace!("Completed `hasMarkedText`");
+        (marked_text.length() > 0) as i8
+    }
 }
 
 extern "C" fn marked_range(this: &Object, _sel: Sel) -> NSRange {
@@ -618,6 +623,19 @@ fn retrieve_keycode(event: id) -> Option<VirtualKeyCode> {
     })
 }
 
+// Update `state.modifiers` if `event` has something different
+fn update_potentially_stale_modifiers(state: &mut ViewState, event: id) {
+    let event_modifiers = event_mods(event);
+    if state.modifiers != event_modifiers {
+        state.modifiers = event_modifiers;
+
+        AppState::queue_event(EventWrapper::StaticEvent(Event::WindowEvent {
+            window_id: WindowId(get_window_id(state.ns_window)),
+            event: WindowEvent::ModifiersChanged(state.modifiers),
+        }));
+    }
+}
+
 extern "C" fn key_down(this: &Object, _sel: Sel, event: id) {
     trace!("Triggered `keyDown`");
     unsafe {
@@ -633,6 +651,8 @@ extern "C" fn key_down(this: &Object, _sel: Sel, event: id) {
 
         let is_repeat = msg_send![event, isARepeat];
 
+        update_potentially_stale_modifiers(state, event);
+
         #[allow(deprecated)]
         let window_event = Event::WindowEvent {
             window_id,
@@ -686,6 +706,8 @@ extern "C" fn key_up(this: &Object, _sel: Sel, event: id) {
         let scancode = get_scancode(event) as u32;
         let virtual_keycode = retrieve_keycode(event);
 
+        update_potentially_stale_modifiers(state, event);
+
         #[allow(deprecated)]
         let window_event = Event::WindowEvent {
             window_id: WindowId(get_window_id(state.ns_window)),
@@ -750,16 +772,18 @@ extern "C" fn flags_changed(this: &Object, _sel: Sel, event: id) {
             events.push_back(window_event);
         }
 
+        let window_id = WindowId(get_window_id(state.ns_window));
+
         for event in events {
             AppState::queue_event(EventWrapper::StaticEvent(Event::WindowEvent {
-                window_id: WindowId(get_window_id(state.ns_window)),
+                window_id,
                 event,
             }));
         }
 
-        AppState::queue_event(EventWrapper::StaticEvent(Event::DeviceEvent {
-            device_id: DEVICE_ID,
-            event: DeviceEvent::ModifiersChanged(state.modifiers),
+        AppState::queue_event(EventWrapper::StaticEvent(Event::WindowEvent {
+            window_id,
+            event: WindowEvent::ModifiersChanged(state.modifiers),
         }));
     }
     trace!("Completed `flagsChanged`");
@@ -801,6 +825,8 @@ extern "C" fn cancel_operation(this: &Object, _sel: Sel, _sender: id) {
 
         let event: id = msg_send![NSApp(), currentEvent];
 
+        update_potentially_stale_modifiers(state, event);
+
         #[allow(deprecated)]
         let window_event = Event::WindowEvent {
             window_id: WindowId(get_window_id(state.ns_window)),
@@ -826,6 +852,8 @@ fn mouse_click(this: &Object, event: id, button: MouseButton, button_state: Elem
         let state_ptr: *mut c_void = *this.get_ivar("winitState");
         let state = &mut *(state_ptr as *mut ViewState);
 
+        update_potentially_stale_modifiers(state, event);
+
         let window_event = Event::WindowEvent {
             window_id: WindowId(get_window_id(state.ns_window)),
             event: WindowEvent::MouseInput {
@@ -889,6 +917,8 @@ fn mouse_motion(this: &Object, event: id) {
         let y = view_rect.size.height as f64 - view_point.y as f64;
         let logical_position = LogicalPosition::new(x, y);
 
+        update_potentially_stale_modifiers(state, event);
+
         let window_event = Event::WindowEvent {
             window_id: WindowId(get_window_id(state.ns_window)),
             event: WindowEvent::CursorMoved {
@@ -918,7 +948,7 @@ extern "C" fn other_mouse_dragged(this: &Object, _sel: Sel, event: id) {
     mouse_motion(this, event);
 }
 
-extern "C" fn mouse_entered(this: &Object, _sel: Sel, event: id) {
+extern "C" fn mouse_entered(this: &Object, _sel: Sel, _event: id) {
     trace!("Triggered `mouseEntered`");
     unsafe {
         let state_ptr: *mut c_void = *this.get_ivar("winitState");
@@ -932,7 +962,6 @@ extern "C" fn mouse_entered(this: &Object, _sel: Sel, event: id) {
         };
 
         AppState::queue_event(EventWrapper::StaticEvent(enter_event));
-        mouse_motion(this, event);
     }
     trace!("Completed `mouseEntered`");
 }
@@ -982,6 +1011,8 @@ extern "C" fn scroll_wheel(this: &Object, _sel: Sel, event: id) {
         let state_ptr: *mut c_void = *this.get_ivar("winitState");
         let state = &mut *(state_ptr as *mut ViewState);
 
+        update_potentially_stale_modifiers(state, event);
+
         let window_event = Event::WindowEvent {
             window_id: WindowId(get_window_id(state.ns_window)),
             event: WindowEvent::MouseWheel {

src/platform_impl/macos/window.rs

@@ -340,7 +340,7 @@ impl UnownedWindow {
 
         let input_context = unsafe { util::create_input_context(*ns_view) };
 
-        let dpi_factor = unsafe { NSWindow::backingScaleFactor(*ns_window) as f64 };
+        let scale_factor = unsafe { NSWindow::backingScaleFactor(*ns_window) as f64 };
 
         unsafe {
             if win_attribs.transparent {
@@ -350,11 +350,11 @@ impl UnownedWindow {
 
             ns_app.activateIgnoringOtherApps_(YES);
             win_attribs.min_inner_size.map(|dim| {
-                let logical_dim = dim.to_logical(dpi_factor);
+                let logical_dim = dim.to_logical(scale_factor);
                 set_min_inner_size(*ns_window, logical_dim)
             });
             win_attribs.max_inner_size.map(|dim| {
-                let logical_dim = dim.to_logical(dpi_factor);
+                let logical_dim = dim.to_logical(scale_factor);
                 set_max_inner_size(*ns_window, logical_dim)
             });
 
@@ -378,7 +378,7 @@ impl UnownedWindow {
         let decorations = win_attribs.decorations;
         let inner_rect = win_attribs
             .inner_size
-            .map(|size| size.to_physical(dpi_factor));
+            .map(|size| size.to_physical(scale_factor));
 
         let window = Arc::new(UnownedWindow {
             ns_view,
@@ -450,8 +450,8 @@ impl UnownedWindow {
             frame_rect.origin.x as f64,
             util::bottom_left_to_top_left(frame_rect),
         );
-        let dpi_factor = self.scale_factor();
-        Ok(position.to_physical(dpi_factor))
+        let scale_factor = self.scale_factor();
+        Ok(position.to_physical(scale_factor))
     }
 
     pub fn inner_position(&self) -> Result<PhysicalPosition<i32>, NotSupportedError> {
@@ -462,13 +462,13 @@ impl UnownedWindow {
             content_rect.origin.x as f64,
             util::bottom_left_to_top_left(content_rect),
         );
-        let dpi_factor = self.scale_factor();
-        Ok(position.to_physical(dpi_factor))
+        let scale_factor = self.scale_factor();
+        Ok(position.to_physical(scale_factor))
     }
 
     pub fn set_outer_position(&self, position: Position) {
-        let dpi_factor = self.scale_factor();
-        let position = position.to_logical(dpi_factor);
+        let scale_factor = self.scale_factor();
+        let position = position.to_logical(scale_factor);
         let dummy = NSRect::new(
             NSPoint::new(
                 position.x,
@@ -488,8 +488,8 @@ impl UnownedWindow {
         let view_frame = unsafe { NSView::frame(*self.ns_view) };
         let logical: LogicalSize<f64> =
             (view_frame.size.width as f64, view_frame.size.height as f64).into();
-        let dpi_factor = self.scale_factor();
-        logical.to_physical(dpi_factor)
+        let scale_factor = self.scale_factor();
+        logical.to_physical(scale_factor)
     }
 
     #[inline]
@@ -497,15 +497,15 @@ impl UnownedWindow {
         let view_frame = unsafe { NSWindow::frame(*self.ns_window) };
         let logical: LogicalSize<f64> =
             (view_frame.size.width as f64, view_frame.size.height as f64).into();
-        let dpi_factor = self.scale_factor();
-        logical.to_physical(dpi_factor)
+        let scale_factor = self.scale_factor();
+        logical.to_physical(scale_factor)
     }
 
     #[inline]
     pub fn set_inner_size(&self, size: Size) {
         unsafe {
-            let dpi_factor = self.scale_factor();
-            util::set_content_size_async(*self.ns_window, size.to_logical(dpi_factor));
+            let scale_factor = self.scale_factor();
+            util::set_content_size_async(*self.ns_window, size.to_logical(scale_factor));
         }
     }
 
@@ -515,8 +515,8 @@ impl UnownedWindow {
                 width: 0.0,
                 height: 0.0,
             }));
-            let dpi_factor = self.scale_factor();
-            set_min_inner_size(*self.ns_window, dimensions.to_logical(dpi_factor));
+            let scale_factor = self.scale_factor();
+            set_min_inner_size(*self.ns_window, dimensions.to_logical(scale_factor));
         }
     }
 
@@ -526,8 +526,8 @@ impl UnownedWindow {
                 width: std::f32::MAX as f64,
                 height: std::f32::MAX as f64,
             }));
-            let dpi_factor = self.scale_factor();
-            set_max_inner_size(*self.ns_window, dimensions.to_logical(dpi_factor));
+            let scale_factor = self.scale_factor();
+            set_max_inner_size(*self.ns_window, dimensions.to_logical(scale_factor));
         }
     }
 
@@ -594,9 +594,9 @@ impl UnownedWindow {
     #[inline]
     pub fn set_cursor_position(&self, cursor_position: Position) -> Result<(), ExternalError> {
         let physical_window_position = self.inner_position().unwrap();
-        let dpi_factor = self.scale_factor();
-        let window_position = physical_window_position.to_logical::<CGFloat>(dpi_factor);
-        let logical_cursor_position = cursor_position.to_logical::<CGFloat>(dpi_factor);
+        let scale_factor = self.scale_factor();
+        let window_position = physical_window_position.to_logical::<CGFloat>(scale_factor);
+        let logical_cursor_position = cursor_position.to_logical::<CGFloat>(scale_factor);
         let point = appkit::CGPoint {
             x: logical_cursor_position.x + window_position.x,
             y: logical_cursor_position.y + window_position.y,
@@ -933,8 +933,8 @@ impl UnownedWindow {
 
     #[inline]
     pub fn set_ime_position(&self, spot: Position) {
-        let dpi_factor = self.scale_factor();
-        let logical_spot = spot.to_logical(dpi_factor);
+        let scale_factor = self.scale_factor();
+        let logical_spot = spot.to_logical(scale_factor);
         unsafe {
             view::set_ime_position(
                 *self.ns_view,
@@ -1028,7 +1028,11 @@ impl WindowExtMacOS for UnownedWindow {
 
             if fullscreen {
                 // Remember the original window's settings
-                shared_state_lock.standard_frame = Some(NSWindow::frame(*self.ns_window));
+                // Exclude title bar
+                shared_state_lock.standard_frame = Some(NSWindow::contentRectForFrameRect_(
+                    *self.ns_window,
+                    NSWindow::frame(*self.ns_window),
+                ));
                 shared_state_lock.saved_style = Some(self.ns_window.styleMask());
                 shared_state_lock.save_presentation_opts = Some(app.presentationOptions_());
 

src/platform_impl/macos/window_delegate.rs

@@ -16,11 +16,12 @@ use objc::{
 
 use crate::{
     dpi::LogicalSize,
-    event::{Event, WindowEvent},
+    event::{Event, ModifiersState, WindowEvent},
     platform_impl::platform::{
         app_state::AppState,
         event::{EventProxy, EventWrapper},
         util::{self, IdRef},
+        view::ViewState,
         window::{get_window_id, UnownedWindow},
     },
     window::{Fullscreen, WindowId},
@@ -43,7 +44,7 @@ pub struct WindowDelegateState {
     previous_position: Option<(f64, f64)>,
 
     // Used to prevent redundant events.
-    previous_dpi_factor: f64,
+    previous_scale_factor: f64,
 }
 
 impl WindowDelegateState {
@@ -55,7 +56,7 @@ impl WindowDelegateState {
             window: Arc::downgrade(&window),
             initial_fullscreen,
             previous_position: None,
-            previous_dpi_factor: scale_factor,
+            previous_scale_factor: scale_factor,
         };
 
         if scale_factor != 1.0 {
@@ -82,11 +83,11 @@ impl WindowDelegateState {
 
     pub fn emit_static_scale_factor_changed_event(&mut self) {
         let scale_factor = self.get_scale_factor();
-        if scale_factor == self.previous_dpi_factor {
+        if scale_factor == self.previous_scale_factor {
             return ();
         };
 
-        self.previous_dpi_factor = scale_factor;
+        self.previous_scale_factor = scale_factor;
         let wrapper = EventWrapper::EventProxy(EventProxy::DpiChangedProxy {
             ns_window: IdRef::retain(*self.ns_window),
             suggested_size: self.view_size(),
@@ -319,6 +320,29 @@ extern "C" fn window_did_become_key(this: &Object, _: Sel, _: id) {
 extern "C" fn window_did_resign_key(this: &Object, _: Sel, _: id) {
     trace!("Triggered `windowDidResignKey:`");
     with_state(this, |state| {
+        // It happens rather often, e.g. when the user is Cmd+Tabbing, that the
+        // NSWindowDelegate will receive a didResignKey event despite no event
+        // being received when the modifiers are released.  This is because
+        // flagsChanged events are received by the NSView instead of the
+        // NSWindowDelegate, and as a result a tracked modifiers state can quite
+        // easily fall out of synchrony with reality.  This requires us to emit
+        // a synthetic ModifiersChanged event when we lose focus.
+        //
+        // Here we (very unsafely) acquire the winitState (a ViewState) from the
+        // Object referenced by state.ns_view (an IdRef, which is dereferenced
+        // to an id)
+        let view_state: &mut ViewState = unsafe {
+            let ns_view: &Object = (*state.ns_view).as_ref().expect("failed to deref");
+            let state_ptr: *mut c_void = *ns_view.get_ivar("winitState");
+            &mut *(state_ptr as *mut ViewState)
+        };
+
+        // Both update the state and emit a ModifiersChanged event.
+        if !view_state.modifiers.is_empty() {
+            view_state.modifiers = ModifiersState::empty();
+            state.emit_event(WindowEvent::ModifiersChanged(view_state.modifiers));
+        }
+
         state.emit_event(WindowEvent::Focused(false));
     });
     trace!("Completed `windowDidResignKey:`");

src/platform_impl/web/event_loop/window_target.rs

@@ -2,7 +2,7 @@ use super::{backend, device, proxy::Proxy, runner, window};
 use crate::dpi::{PhysicalSize, Size};
 use crate::event::{DeviceId, ElementState, Event, KeyboardInput, TouchPhase, WindowEvent};
 use crate::event_loop::ControlFlow;
-use crate::window::WindowId;
+use crate::window::{Theme, WindowId};
 use std::clone::Clone;
 
 pub struct WindowTarget<T: 'static> {
@@ -199,5 +199,18 @@ impl<T> WindowTarget<T> {
             });
             runner.request_redraw(WindowId(id));
         });
+
+        let runner = self.runner.clone();
+        canvas.on_dark_mode(move |is_dark_mode| {
+            let theme = if is_dark_mode {
+                Theme::Dark
+            } else {
+                Theme::Light
+            };
+            runner.send_event(Event::WindowEvent {
+                window_id: WindowId(id),
+                event: WindowEvent::ThemeChanged(theme),
+            });
+        });
     }
 }

src/platform_impl/web/mod.rs

@@ -44,3 +44,5 @@ pub use self::window::{
     Id as WindowId, PlatformSpecificBuilderAttributes as PlatformSpecificWindowBuilderAttributes,
     Window,
 };
+
+pub(crate) use crate::icon::NoIcon as PlatformIcon;

src/platform_impl/web/stdweb/canvas.rs

@@ -6,6 +6,7 @@ use crate::platform_impl::{OsError, PlatformSpecificWindowBuilderAttributes};
 
 use std::cell::RefCell;
 use std::rc::Rc;
+use stdweb::js;
 use stdweb::traits::IPointerEvent;
 use stdweb::unstable::TryInto;
 use stdweb::web::event::{
@@ -240,6 +241,22 @@ impl Canvas {
         self.on_fullscreen_change = Some(self.add_event(move |_: FullscreenChangeEvent| handler()));
     }
 
+    pub fn on_dark_mode<F>(&mut self, handler: F)
+    where
+        F: 'static + FnMut(bool),
+    {
+        // TODO: upstream to stdweb
+        js! {
+            var handler = @{handler};
+
+            if (window.matchMedia) {
+                window.matchMedia("(prefers-color-scheme: dark)").addListener(function(e) {
+                    handler(event.matches)
+                });
+            }
+        }
+    }
+
     fn add_event<E, F>(&self, mut handler: F) -> EventListenerHandle
     where
         E: ConcreteEvent,

src/platform_impl/web/stdweb/mod.rs

@@ -10,6 +10,7 @@ use crate::platform::web::WindowExtStdweb;
 use crate::window::Window;
 
 use stdweb::js;
+use stdweb::unstable::TryInto;
 use stdweb::web::event::BeforeUnloadEvent;
 use stdweb::web::window;
 use stdweb::web::IEventTarget;
@@ -31,6 +32,15 @@ impl WindowExtStdweb for Window {
     fn canvas(&self) -> CanvasElement {
         self.window.canvas().raw().clone()
     }
+
+    fn is_dark_mode(&self) -> bool {
+        // TODO: upstream to stdweb
+        let is_dark_mode = js! {
+            return (window.matchMedia && window.matchMedia("(prefers-color-scheme: dark)").matches)
+        };
+
+        is_dark_mode.try_into().expect("should return a bool")
+    }
 }
 
 pub fn window_size() -> LogicalSize<f64> {

src/platform_impl/web/web_sys/canvas.rs

@@ -8,7 +8,10 @@ use std::cell::RefCell;
 use std::rc::Rc;
 
 use wasm_bindgen::{closure::Closure, JsCast};
-use web_sys::{Event, FocusEvent, HtmlCanvasElement, KeyboardEvent, PointerEvent, WheelEvent};
+use web_sys::{
+    Event, FocusEvent, HtmlCanvasElement, KeyboardEvent, MediaQueryListEvent, PointerEvent,
+    WheelEvent,
+};
 
 pub struct Canvas {
     /// Note: resizing the HTMLCanvasElement should go through `backend::set_canvas_size` to ensure the DPI factor is maintained.
@@ -26,6 +29,7 @@ pub struct Canvas {
     on_mouse_wheel: Option<Closure<dyn FnMut(WheelEvent)>>,
     on_fullscreen_change: Option<Closure<dyn FnMut(Event)>>,
     wants_fullscreen: Rc<RefCell<bool>>,
+    on_dark_mode: Option<Closure<dyn FnMut(MediaQueryListEvent)>>,
 }
 
 impl Drop for Canvas {
@@ -77,6 +81,7 @@ impl Canvas {
             on_mouse_wheel: None,
             on_fullscreen_change: None,
             wants_fullscreen: Rc::new(RefCell::new(false)),
+            on_dark_mode: None,
         })
     }
 
@@ -251,6 +256,28 @@ impl Canvas {
             Some(self.add_event("fullscreenchange", move |_: Event| handler()));
     }
 
+    pub fn on_dark_mode<F>(&mut self, mut handler: F)
+    where
+        F: 'static + FnMut(bool),
+    {
+        let window = web_sys::window().expect("Failed to obtain window");
+
+        self.on_dark_mode = window
+            .match_media("(prefers-color-scheme: dark)")
+            .ok()
+            .flatten()
+            .and_then(|media| {
+                let closure = Closure::wrap(Box::new(move |event: MediaQueryListEvent| {
+                    handler(event.matches())
+                }) as Box<dyn FnMut(_)>);
+
+                media
+                    .add_listener_with_opt_callback(Some(&closure.as_ref().unchecked_ref()))
+                    .map(|_| closure)
+                    .ok()
+            });
+    }
+
     fn add_event<E, F>(&self, event_name: &str, mut handler: F) -> Closure<dyn FnMut(E)>
     where
         E: 'static + AsRef<web_sys::Event> + wasm_bindgen::convert::FromWasmAbi,

src/platform_impl/web/web_sys/mod.rs

@@ -38,6 +38,17 @@ impl WindowExtWebSys for Window {
     fn canvas(&self) -> HtmlCanvasElement {
         self.window.canvas().raw().clone()
     }
+
+    fn is_dark_mode(&self) -> bool {
+        let window = web_sys::window().expect("Failed to obtain window");
+
+        window
+            .match_media("(prefers-color-scheme: dark)")
+            .ok()
+            .flatten()
+            .map(|media| media.matches())
+            .unwrap_or(false)
+    }
 }
 
 pub fn window_size() -> LogicalSize<f64> {

src/platform_impl/windows/dark_mode.rs

@@ -6,9 +6,10 @@ use std::os::windows::ffi::OsStrExt;
 use winapi::{
     shared::{
         basetsd::SIZE_T,
-        minwindef::{BOOL, DWORD, UINT, ULONG, WORD},
+        minwindef::{BOOL, DWORD, FALSE, UINT, ULONG, WORD},
         ntdef::{LPSTR, NTSTATUS, NT_SUCCESS, PVOID, WCHAR},
         windef::HWND,
+        winerror::S_OK,
     },
     um::{libloaderapi, uxtheme, winuser},
 };
@@ -44,9 +45,8 @@ lazy_static! {
                 };
 
                 let status = (rtl_get_version)(&mut vi as _);
-                assert!(NT_SUCCESS(status));
 
-                if vi.dwMajorVersion == 10 && vi.dwMinorVersion == 0 {
+                if NT_SUCCESS(status) && vi.dwMajorVersion == 10 && vi.dwMinorVersion == 0 {
                     Some(vi.dwBuildNumber)
                 } else {
                     None
@@ -82,22 +82,15 @@ pub fn try_dark_mode(hwnd: HWND) -> bool {
             LIGHT_THEME_NAME.as_ptr()
         };
 
-        unsafe {
-            assert_eq!(
-                0,
-                uxtheme::SetWindowTheme(hwnd, theme_name as _, std::ptr::null())
-            );
+        let status = unsafe { uxtheme::SetWindowTheme(hwnd, theme_name as _, std::ptr::null()) };
 
-            set_dark_mode_for_window(hwnd, is_dark_mode)
-        }
-
-        is_dark_mode
+        status == S_OK && set_dark_mode_for_window(hwnd, is_dark_mode)
     } else {
         false
     }
 }
 
-fn set_dark_mode_for_window(hwnd: HWND, is_dark_mode: bool) {
+fn set_dark_mode_for_window(hwnd: HWND, is_dark_mode: bool) -> bool {
     // Uses Windows undocumented API SetWindowCompositionAttribute,
     // as seen in win32-darkmode example linked at top of file.
 
@@ -132,11 +125,12 @@ fn set_dark_mode_for_window(hwnd: HWND, is_dark_mode: bool) {
                 cbData: std::mem::size_of_val(&is_dark_mode_bigbool) as _,
             };
 
-            assert_eq!(
-                1,
-                set_window_composition_attribute(hwnd, &mut data as *mut _)
-            );
+            let status = set_window_composition_attribute(hwnd, &mut data as *mut _);
+
+            status != FALSE
         }
+    } else {
+        false
     }
 }
 
@@ -205,7 +199,7 @@ fn is_high_contrast() -> bool {
         )
     };
 
-    (ok > 0) && ((HCF_HIGHCONTRASTON & hc.dwFlags) == 1)
+    ok != FALSE && (HCF_HIGHCONTRASTON & hc.dwFlags) == 1
 }
 
 fn widestring(src: &'static str) -> Vec<u16> {

src/platform_impl/windows/event_loop.rs

@@ -50,9 +50,7 @@ use crate::{
         dark_mode::try_dark_mode,
         dpi::{become_dpi_aware, dpi_to_scale_factor, enable_non_client_dpi_scaling},
         drop_handler::FileDropHandler,
-        event::{
-            self, handle_extended_keys, process_key_params, vkey_to_winit_vkey, ModifiersStateSide,
-        },
+        event::{self, handle_extended_keys, process_key_params, vkey_to_winit_vkey},
         monitor, raw_input, util,
         window_state::{CursorFlags, WindowFlags, WindowState},
         wrap_device_id, WindowId, DEVICE_ID,
@@ -108,7 +106,6 @@ impl<T> SubclassInput<T> {
 struct ThreadMsgTargetSubclassInput<T: 'static> {
     event_loop_runner: EventLoopRunnerShared<T>,
     user_event_receiver: Receiver<T>,
-    modifiers_state: ModifiersStateSide,
 }
 
 impl<T> ThreadMsgTargetSubclassInput<T> {
@@ -221,69 +218,68 @@ impl<T: 'static> EventLoop<T> {
                 }
 
                 runner.new_events();
-                loop {
-                    if !unread_message_exists {
-                        if 0 == winuser::PeekMessageW(&mut msg, ptr::null_mut(), 0, 0, 1) {
-                            break;
-                        }
-                    }
-                    if msg.message == winuser::WM_PAINT {
-                        unread_message_exists = true;
-                        break;
-                    }
-                    winuser::TranslateMessage(&mut msg);
-                    winuser::DispatchMessageW(&mut msg);
-
-                    unread_message_exists = false;
-                }
-                runner.main_events_cleared();
                 loop {
                     if !unread_message_exists {
                         if 0 == winuser::PeekMessageW(
                             &mut msg,
                             ptr::null_mut(),
-                            winuser::WM_PAINT,
-                            winuser::WM_PAINT,
-                            1,
+                            0,
+                            0,
+                            winuser::PM_REMOVE,
                         ) {
                             break;
                         }
                     }
-
                     winuser::TranslateMessage(&mut msg);
                     winuser::DispatchMessageW(&mut msg);
 
                     unread_message_exists = false;
-                }
-                if runner.redraw_events_cleared().events_buffered() {
-                    if runner.control_flow() == ControlFlow::Exit {
-                        break 'main;
-                    }
-                    continue;
-                }
 
-                if !unread_message_exists {
-                    let control_flow = runner.control_flow();
-                    match control_flow {
-                        ControlFlow::Exit => break 'main,
-                        ControlFlow::Wait => {
-                            if 0 == winuser::GetMessageW(&mut msg, ptr::null_mut(), 0, 0) {
-                                break 'main;
-                            }
-                            unread_message_exists = true;
-                        }
-                        ControlFlow::WaitUntil(resume_time) => {
-                            wait_until_time_or_msg(resume_time);
-                        }
-                        ControlFlow::Poll => (),
+                    if msg.message == winuser::WM_PAINT {
+                        // An "external" redraw was requested.
+                        // Note that the WM_PAINT has been dispatched and
+                        // has caused the event loop to emit the MainEventsCleared event.
+                        // See EventLoopRunner::process_event().
+                        // The call to main_events_cleared() below will do nothing.
+                        break;
                     }
                 }
+                // Make sure we emit the MainEventsCleared event if no WM_PAINT message was received.
+                runner.main_events_cleared();
+                // Drain eventual WM_PAINT messages sent if user called request_redraw()
+                // during handling of MainEventsCleared.
+                loop {
+                    if 0 == winuser::PeekMessageW(
+                        &mut msg,
+                        ptr::null_mut(),
+                        winuser::WM_PAINT,
+                        winuser::WM_PAINT,
+                        winuser::PM_QS_PAINT | winuser::PM_REMOVE,
+                    ) {
+                        break;
+                    }
+
+                    winuser::TranslateMessage(&mut msg);
+                    winuser::DispatchMessageW(&mut msg);
+                }
+                runner.redraw_events_cleared();
+                match runner.control_flow() {
+                    ControlFlow::Exit => break 'main,
+                    ControlFlow::Wait => {
+                        if 0 == winuser::GetMessageW(&mut msg, ptr::null_mut(), 0, 0) {
+                            break 'main;
+                        }
+                        unread_message_exists = true;
+                    }
+                    ControlFlow::WaitUntil(resume_time) => {
+                        wait_until_time_or_msg(resume_time);
+                    }
+                    ControlFlow::Poll => (),
+                }
             }
         }
 
-        unsafe {
-            runner.call_event_handler(Event::LoopDestroyed);
-        }
+        runner.destroy_loop();
         runner.destroy_runner();
     }
 
@@ -320,11 +316,9 @@ fn main_thread_id() -> DWORD {
     unsafe { MAIN_THREAD_ID }
 }
 
-// Returns true if the wait time was reached, and false if a message must be processed.
-unsafe fn wait_until_time_or_msg(wait_until: Instant) -> bool {
-    let mut msg = mem::zeroed();
+unsafe fn wait_until_time_or_msg(wait_until: Instant) {
     let now = Instant::now();
-    if now <= wait_until {
+    if now < wait_until {
         // MsgWaitForMultipleObjects tends to overshoot just a little bit. We subtract 1 millisecond
         // from the requested time and spinlock for the remainder to compensate for that.
         let resume_reason = winuser::MsgWaitForMultipleObjectsEx(
@@ -336,16 +330,16 @@ unsafe fn wait_until_time_or_msg(wait_until: Instant) -> bool {
         );
 
         if resume_reason == winerror::WAIT_TIMEOUT {
+            let mut msg = mem::zeroed();
             while Instant::now() < wait_until {
                 if 0 != winuser::PeekMessageW(&mut msg, ptr::null_mut(), 0, 0, 0) {
-                    return false;
+                    break;
                 }
             }
         }
     }
-
-    return true;
 }
+
 // Implementation taken from https://github.com/rust-lang/rust/blob/db5476571d9b27c862b95c1e64764b0ac8980e23/src/libstd/sys/windows/mod.rs
 fn dur2timeout(dur: Duration) -> DWORD {
     // Note that a duration is a (u64, u32) (seconds, nanoseconds) pair, and the
@@ -555,7 +549,6 @@ fn thread_event_target_window<T>(event_loop_runner: EventLoopRunnerShared<T>) ->
         let subclass_input = ThreadMsgTargetSubclassInput {
             event_loop_runner,
             user_event_receiver: rx,
-            modifiers_state: ModifiersStateSide::default(),
         };
         let input_ptr = Box::into_raw(Box::new(subclass_input));
         let subclass_result = commctrl::SetWindowSubclass(
@@ -608,6 +601,27 @@ fn normalize_pointer_pressure(pressure: u32) -> Option<Force> {
     }
 }
 
+/// Emit a `ModifiersChanged` event whenever modifiers have changed.
+fn update_modifiers<T>(window: HWND, subclass_input: &SubclassInput<T>) {
+    use crate::event::WindowEvent::ModifiersChanged;
+
+    let modifiers = event::get_key_mods();
+    let mut window_state = subclass_input.window_state.lock();
+    if window_state.modifiers_state != modifiers {
+        window_state.modifiers_state = modifiers;
+
+        // Drop lock
+        drop(window_state);
+
+        unsafe {
+            subclass_input.send_event(Event::WindowEvent {
+                window_id: RootWindowId(WindowId(window)),
+                event: ModifiersChanged(modifiers),
+            });
+        }
+    }
+}
+
 /// Any window whose callback is configured to this function will have its events propagated
 /// through the events loop of the thread the window was created in.
 //
@@ -640,13 +654,6 @@ unsafe extern "system" fn public_window_callback<T: 'static>(
         }
 
         winuser::WM_NCLBUTTONDOWN => {
-            // jumpstart the modal loop
-            winuser::RedrawWindow(
-                window,
-                ptr::null(),
-                ptr::null_mut(),
-                winuser::RDW_INTERNALPAINT,
-            );
             if wparam == winuser::HTCAPTION as _ {
                 winuser::PostMessageW(window, winuser::WM_MOUSEMOVE, 0, 0);
             }
@@ -676,7 +683,6 @@ unsafe extern "system" fn public_window_callback<T: 'static>(
         }
 
         winuser::WM_PAINT => {
-            subclass_input.event_loop_runner.main_events_cleared();
             subclass_input.send_event(Event::RedrawRequested(RootWindowId(WindowId(window))));
             commctrl::DefSubclassProc(window, msg, wparam, lparam)
         }
@@ -733,7 +739,7 @@ unsafe extern "system" fn public_window_callback<T: 'static>(
             let windowpos = lparam as *const winuser::WINDOWPOS;
             if (*windowpos).flags & winuser::SWP_NOMOVE != winuser::SWP_NOMOVE {
                 let physical_position =
-                    PhysicalPosition::new((*windowpos).x as u32, (*windowpos).y as u32);
+                    PhysicalPosition::new((*windowpos).x as i32, (*windowpos).y as i32);
                 subclass_input.send_event(Event::WindowEvent {
                     window_id: RootWindowId(WindowId(window)),
                     event: Moved(physical_position),
@@ -858,15 +864,27 @@ unsafe extern "system" fn public_window_callback<T: 'static>(
             let x = windowsx::GET_X_LPARAM(lparam) as f64;
             let y = windowsx::GET_Y_LPARAM(lparam) as f64;
             let position = PhysicalPosition::new(x, y);
+            let cursor_moved;
+            {
+                // handle spurious WM_MOUSEMOVE messages
+                // see https://devblogs.microsoft.com/oldnewthing/20031001-00/?p=42343
+                // and http://debugandconquer.blogspot.com/2015/08/the-cause-of-spurious-mouse-move.html
+                let mut w = subclass_input.window_state.lock();
+                cursor_moved = w.mouse.last_position != Some(position);
+                w.mouse.last_position = Some(position);
+            }
+            if cursor_moved {
+                update_modifiers(window, subclass_input);
 
-            subclass_input.send_event(Event::WindowEvent {
-                window_id: RootWindowId(WindowId(window)),
-                event: CursorMoved {
-                    device_id: DEVICE_ID,
-                    position,
-                    modifiers: event::get_key_mods(),
-                },
-            });
+                subclass_input.send_event(Event::WindowEvent {
+                    window_id: RootWindowId(WindowId(window)),
+                    event: CursorMoved {
+                        device_id: DEVICE_ID,
+                        position,
+                        modifiers: event::get_key_mods(),
+                    },
+                });
+            }
 
             0
         }
@@ -897,6 +915,8 @@ unsafe extern "system" fn public_window_callback<T: 'static>(
             let value = value as i32;
             let value = value as f32 / winuser::WHEEL_DELTA as f32;
 
+            update_modifiers(window, subclass_input);
+
             subclass_input.send_event(Event::WindowEvent {
                 window_id: RootWindowId(WindowId(window)),
                 event: WindowEvent::MouseWheel {
@@ -917,6 +937,8 @@ unsafe extern "system" fn public_window_callback<T: 'static>(
             let value = value as i32;
             let value = value as f32 / winuser::WHEEL_DELTA as f32;
 
+            update_modifiers(window, subclass_input);
+
             subclass_input.send_event(Event::WindowEvent {
                 window_id: RootWindowId(WindowId(window)),
                 event: WindowEvent::MouseWheel {
@@ -936,6 +958,8 @@ unsafe extern "system" fn public_window_callback<T: 'static>(
                 commctrl::DefSubclassProc(window, msg, wparam, lparam)
             } else {
                 if let Some((scancode, vkey)) = process_key_params(wparam, lparam) {
+                    update_modifiers(window, subclass_input);
+
                     #[allow(deprecated)]
                     subclass_input.send_event(Event::WindowEvent {
                         window_id: RootWindowId(WindowId(window)),
@@ -966,6 +990,8 @@ unsafe extern "system" fn public_window_callback<T: 'static>(
         winuser::WM_KEYUP | winuser::WM_SYSKEYUP => {
             use crate::event::ElementState::Released;
             if let Some((scancode, vkey)) = process_key_params(wparam, lparam) {
+                update_modifiers(window, subclass_input);
+
                 #[allow(deprecated)]
                 subclass_input.send_event(Event::WindowEvent {
                     window_id: RootWindowId(WindowId(window)),
@@ -989,6 +1015,8 @@ unsafe extern "system" fn public_window_callback<T: 'static>(
 
             capture_mouse(window, &mut *subclass_input.window_state.lock());
 
+            update_modifiers(window, subclass_input);
+
             subclass_input.send_event(Event::WindowEvent {
                 window_id: RootWindowId(WindowId(window)),
                 event: MouseInput {
@@ -1008,6 +1036,8 @@ unsafe extern "system" fn public_window_callback<T: 'static>(
 
             release_mouse(&mut *subclass_input.window_state.lock());
 
+            update_modifiers(window, subclass_input);
+
             subclass_input.send_event(Event::WindowEvent {
                 window_id: RootWindowId(WindowId(window)),
                 event: MouseInput {
@@ -1027,6 +1057,8 @@ unsafe extern "system" fn public_window_callback<T: 'static>(
 
             capture_mouse(window, &mut *subclass_input.window_state.lock());
 
+            update_modifiers(window, subclass_input);
+
             subclass_input.send_event(Event::WindowEvent {
                 window_id: RootWindowId(WindowId(window)),
                 event: MouseInput {
@@ -1046,6 +1078,8 @@ unsafe extern "system" fn public_window_callback<T: 'static>(
 
             release_mouse(&mut *subclass_input.window_state.lock());
 
+            update_modifiers(window, subclass_input);
+
             subclass_input.send_event(Event::WindowEvent {
                 window_id: RootWindowId(WindowId(window)),
                 event: MouseInput {
@@ -1065,6 +1099,8 @@ unsafe extern "system" fn public_window_callback<T: 'static>(
 
             capture_mouse(window, &mut *subclass_input.window_state.lock());
 
+            update_modifiers(window, subclass_input);
+
             subclass_input.send_event(Event::WindowEvent {
                 window_id: RootWindowId(WindowId(window)),
                 event: MouseInput {
@@ -1084,6 +1120,8 @@ unsafe extern "system" fn public_window_callback<T: 'static>(
 
             release_mouse(&mut *subclass_input.window_state.lock());
 
+            update_modifiers(window, subclass_input);
+
             subclass_input.send_event(Event::WindowEvent {
                 window_id: RootWindowId(WindowId(window)),
                 event: MouseInput {
@@ -1104,6 +1142,8 @@ unsafe extern "system" fn public_window_callback<T: 'static>(
 
             capture_mouse(window, &mut *subclass_input.window_state.lock());
 
+            update_modifiers(window, subclass_input);
+
             subclass_input.send_event(Event::WindowEvent {
                 window_id: RootWindowId(WindowId(window)),
                 event: MouseInput {
@@ -1124,6 +1164,8 @@ unsafe extern "system" fn public_window_callback<T: 'static>(
 
             release_mouse(&mut *subclass_input.window_state.lock());
 
+            update_modifiers(window, subclass_input);
+
             subclass_input.send_event(Event::WindowEvent {
                 window_id: RootWindowId(WindowId(window)),
                 event: MouseInput {
@@ -1332,6 +1374,8 @@ unsafe extern "system" fn public_window_callback<T: 'static>(
                     winuser::MapVirtualKeyA(windows_keycode as _, winuser::MAPVK_VK_TO_VSC);
                 let virtual_keycode = event::vkey_to_winit_vkey(windows_keycode);
 
+                update_modifiers(window, subclass_input);
+
                 #[allow(deprecated)]
                 subclass_input.send_event(Event::WindowEvent {
                     window_id: RootWindowId(WindowId(window)),
@@ -1357,7 +1401,11 @@ unsafe extern "system" fn public_window_callback<T: 'static>(
         }
 
         winuser::WM_KILLFOCUS => {
-            use crate::event::{ElementState::Released, WindowEvent::Focused};
+            use crate::event::{
+                ElementState::Released,
+                ModifiersState,
+                WindowEvent::{Focused, ModifiersChanged},
+            };
             for windows_keycode in event::get_pressed_keys() {
                 let scancode =
                     winuser::MapVirtualKeyA(windows_keycode as _, winuser::MAPVK_VK_TO_VSC);
@@ -1379,6 +1427,12 @@ unsafe extern "system" fn public_window_callback<T: 'static>(
                 })
             }
 
+            subclass_input.window_state.lock().modifiers_state = ModifiersState::empty();
+            subclass_input.send_event(Event::WindowEvent {
+                window_id: RootWindowId(WindowId(window)),
+                event: ModifiersChanged(ModifiersState::empty()),
+            });
+
             subclass_input.send_event(Event::WindowEvent {
                 window_id: RootWindowId(WindowId(window)),
                 event: Focused(false),
@@ -1422,7 +1476,7 @@ unsafe extern "system" fn public_window_callback<T: 'static>(
 
             if window_state.min_size.is_some() || window_state.max_size.is_some() {
                 if let Some(min_size) = window_state.min_size {
-                    let min_size = min_size.to_physical(window_state.dpi_factor);
+                    let min_size = min_size.to_physical(window_state.scale_factor);
                     let (width, height): (u32, u32) = util::adjust_size(window, min_size).into();
                     (*mmi).ptMinTrackSize = POINT {
                         x: width as i32,
@@ -1430,7 +1484,7 @@ unsafe extern "system" fn public_window_callback<T: 'static>(
                     };
                 }
                 if let Some(max_size) = window_state.max_size {
-                    let max_size = max_size.to_physical(window_state.dpi_factor);
+                    let max_size = max_size.to_physical(window_state.scale_factor);
                     let (width, height): (u32, u32) = util::adjust_size(window, max_size).into();
                     (*mmi).ptMaxTrackSize = POINT {
                         x: width as i32,
@@ -1452,15 +1506,15 @@ unsafe extern "system" fn public_window_callback<T: 'static>(
             // application since they are the same".
             // https://msdn.microsoft.com/en-us/library/windows/desktop/dn312083(v=vs.85).aspx
             let new_dpi_x = u32::from(LOWORD(wparam as DWORD));
-            let new_dpi_factor = dpi_to_scale_factor(new_dpi_x);
-            let old_dpi_factor: f64;
+            let new_scale_factor = dpi_to_scale_factor(new_dpi_x);
+            let old_scale_factor: f64;
 
             let allow_resize = {
                 let mut window_state = subclass_input.window_state.lock();
-                old_dpi_factor = window_state.dpi_factor;
-                window_state.dpi_factor = new_dpi_factor;
+                old_scale_factor = window_state.scale_factor;
+                window_state.scale_factor = new_scale_factor;
 
-                if new_dpi_factor == old_dpi_factor {
+                if new_scale_factor == old_scale_factor {
                     return 0;
                 }
 
@@ -1516,15 +1570,15 @@ unsafe extern "system" fn public_window_callback<T: 'static>(
                 // We calculate our own size because the default suggested rect doesn't do a great job
                 // of preserving the window's logical size.
                 true => old_physical_inner_size
-                    .to_logical::<f64>(old_dpi_factor)
-                    .to_physical::<u32>(new_dpi_factor),
+                    .to_logical::<f64>(old_scale_factor)
+                    .to_physical::<u32>(new_scale_factor),
                 false => old_physical_inner_size,
             };
 
             let _ = subclass_input.send_event(Event::WindowEvent {
                 window_id: RootWindowId(WindowId(window)),
                 event: ScaleFactorChanged {
-                    scale_factor: new_dpi_factor,
+                    scale_factor: new_scale_factor,
                     new_inner_size: &mut new_physical_inner_size,
                 },
             });
@@ -1720,50 +1774,39 @@ unsafe extern "system" fn thread_event_target_callback<T: 'static>(
             };
             let in_modal_loop = subclass_input.event_loop_runner.in_modal_loop();
             if in_modal_loop {
+                let runner = &subclass_input.event_loop_runner;
+                runner.main_events_cleared();
+                // Drain eventual WM_PAINT messages sent if user called request_redraw()
+                // during handling of MainEventsCleared.
                 let mut msg = mem::zeroed();
-                if 0 == winuser::PeekMessageW(&mut msg, ptr::null_mut(), 0, 0, 0) {
-                    if msg.message != 0 && msg.message != winuser::WM_PAINT {
-                        queue_call_again();
-                        return 0;
+                loop {
+                    if 0 == winuser::PeekMessageW(
+                        &mut msg,
+                        ptr::null_mut(),
+                        winuser::WM_PAINT,
+                        winuser::WM_PAINT,
+                        winuser::PM_QS_PAINT | winuser::PM_REMOVE,
+                    ) {
+                        break;
                     }
 
-                    subclass_input.event_loop_runner.main_events_cleared();
-                    loop {
-                        if 0 == winuser::PeekMessageW(
-                            &mut msg,
-                            ptr::null_mut(),
-                            winuser::WM_PAINT,
-                            winuser::WM_PAINT,
-                            1,
-                        ) {
-                            break;
-                        }
-
-                        if msg.hwnd != window {
-                            winuser::TranslateMessage(&mut msg);
-                            winuser::DispatchMessageW(&mut msg);
-                        }
+                    if msg.hwnd != window {
+                        winuser::TranslateMessage(&mut msg);
+                        winuser::DispatchMessageW(&mut msg);
                     }
                 }
-
-                // we don't borrow until here because TODO SAFETY
-                let runner = &subclass_input.event_loop_runner;
-                if runner.redraw_events_cleared().events_buffered() {
-                    queue_call_again();
-                    runner.new_events();
-                } else {
-                    match runner.control_flow() {
-                        // Waiting is handled by the modal loop.
-                        ControlFlow::Exit | ControlFlow::Wait => runner.new_events(),
-                        ControlFlow::WaitUntil(resume_time) => {
-                            wait_until_time_or_msg(resume_time);
-                            runner.new_events();
-                            queue_call_again();
-                        }
-                        ControlFlow::Poll => {
-                            runner.new_events();
-                            queue_call_again();
-                        }
+                runner.redraw_events_cleared();
+                match runner.control_flow() {
+                    // Waiting is handled by the modal loop.
+                    ControlFlow::Exit | ControlFlow::Wait => runner.new_events(),
+                    ControlFlow::WaitUntil(resume_time) => {
+                        wait_until_time_or_msg(resume_time);
+                        runner.new_events();
+                        queue_call_again();
+                    }
+                    ControlFlow::Poll => {
+                        runner.new_events();
+                        queue_call_again();
                     }
                 }
             }
@@ -1787,10 +1830,9 @@ unsafe extern "system" fn thread_event_target_callback<T: 'static>(
 
         winuser::WM_INPUT => {
             use crate::event::{
-                DeviceEvent::{Button, Key, ModifiersChanged, Motion, MouseMotion, MouseWheel},
+                DeviceEvent::{Button, Key, Motion, MouseMotion, MouseWheel},
                 ElementState::{Pressed, Released},
                 MouseScrollDelta::LineDelta,
-                VirtualKeyCode,
             };
 
             if let Some(data) = raw_input::get_raw_input_data(lparam as _) {
@@ -1869,48 +1911,6 @@ unsafe extern "system" fn thread_event_target_callback<T: 'static>(
                         {
                             let virtual_keycode = vkey_to_winit_vkey(vkey);
 
-                            // If we ever change the DeviceEvent API to only emit events when a
-                            // window is focused, we'll need to emit synthetic `ModifiersChanged`
-                            // events when Winit windows lose focus so that these don't drift out
-                            // of sync with the actual modifier state.
-                            let old_modifiers_state =
-                                subclass_input.modifiers_state.filter_out_altgr().into();
-                            match virtual_keycode {
-                                Some(VirtualKeyCode::LShift) => subclass_input
-                                    .modifiers_state
-                                    .set(ModifiersStateSide::LSHIFT, pressed),
-                                Some(VirtualKeyCode::RShift) => subclass_input
-                                    .modifiers_state
-                                    .set(ModifiersStateSide::RSHIFT, pressed),
-                                Some(VirtualKeyCode::LControl) => subclass_input
-                                    .modifiers_state
-                                    .set(ModifiersStateSide::LCTRL, pressed),
-                                Some(VirtualKeyCode::RControl) => subclass_input
-                                    .modifiers_state
-                                    .set(ModifiersStateSide::RCTRL, pressed),
-                                Some(VirtualKeyCode::LAlt) => subclass_input
-                                    .modifiers_state
-                                    .set(ModifiersStateSide::LALT, pressed),
-                                Some(VirtualKeyCode::RAlt) => subclass_input
-                                    .modifiers_state
-                                    .set(ModifiersStateSide::RALT, pressed),
-                                Some(VirtualKeyCode::LWin) => subclass_input
-                                    .modifiers_state
-                                    .set(ModifiersStateSide::LLOGO, pressed),
-                                Some(VirtualKeyCode::RWin) => subclass_input
-                                    .modifiers_state
-                                    .set(ModifiersStateSide::RLOGO, pressed),
-                                _ => (),
-                            }
-                            let new_modifiers_state =
-                                subclass_input.modifiers_state.filter_out_altgr().into();
-                            if new_modifiers_state != old_modifiers_state {
-                                subclass_input.send_event(Event::DeviceEvent {
-                                    device_id,
-                                    event: ModifiersChanged(new_modifiers_state),
-                                });
-                            }
-
                             #[allow(deprecated)]
                             subclass_input.send_event(Event::DeviceEvent {
                                 device_id,
@@ -1918,7 +1918,7 @@ unsafe extern "system" fn thread_event_target_callback<T: 'static>(
                                     scancode,
                                     state,
                                     virtual_keycode,
-                                    modifiers: new_modifiers_state,
+                                    modifiers: event::get_key_mods(),
                                 }),
                             });
                         }

src/platform_impl/windows/event_loop/runner.rs

@@ -6,7 +6,7 @@ use crate::{
     dpi::PhysicalSize,
     event::{Event, StartCause, WindowEvent},
     event_loop::ControlFlow,
-    platform_impl::platform::{event_loop::EventLoop, util},
+    platform_impl::platform::event_loop::{util, EventLoop},
     window::WindowId,
 };
 
@@ -14,8 +14,8 @@ pub(crate) type EventLoopRunnerShared<T> = Rc<ELRShared<T>>;
 pub(crate) struct ELRShared<T: 'static> {
     runner: RefCell<Option<EventLoopRunner<T>>>,
     buffer: RefCell<VecDeque<BufferedEvent<T>>>,
-    redraw_buffer: Rc<RefCell<VecDeque<WindowId>>>,
 }
+
 struct EventLoopRunner<T: 'static> {
     control_flow: ControlFlow,
     runner_state: RunnerState,
@@ -23,8 +23,8 @@ struct EventLoopRunner<T: 'static> {
     in_modal_loop: bool,
     event_handler: Box<dyn FnMut(Event<'_, T>, &mut ControlFlow)>,
     panic_error: Option<PanicError>,
-    redraw_buffer: Rc<RefCell<VecDeque<WindowId>>>,
 }
+
 pub type PanicError = Box<dyn Any + Send + 'static>;
 
 pub enum BufferedEvent<T: 'static> {
@@ -32,22 +32,6 @@ pub enum BufferedEvent<T: 'static> {
     ScaleFactorChanged(WindowId, f64, PhysicalSize<u32>),
 }
 
-#[must_use]
-#[derive(Debug, Clone, Copy)]
-pub enum AreEventsBuffered {
-    EventsBuffered,
-    ReadyToSleep,
-}
-
-impl AreEventsBuffered {
-    pub fn events_buffered(&self) -> bool {
-        match self {
-            Self::EventsBuffered => true,
-            Self::ReadyToSleep => false,
-        }
-    }
-}
-
 impl<T> BufferedEvent<T> {
     pub fn from_event(event: Event<'_, T>) -> BufferedEvent<T> {
         match event {
@@ -89,7 +73,6 @@ impl<T> ELRShared<T> {
         ELRShared {
             runner: RefCell::new(None),
             buffer: RefCell::new(VecDeque::new()),
-            redraw_buffer: Default::default(),
         }
     }
 
@@ -97,16 +80,11 @@ impl<T> ELRShared<T> {
     where
         F: FnMut(Event<'_, T>, &mut ControlFlow),
     {
-        let mut runner = EventLoopRunner::new(event_loop, self.redraw_buffer.clone(), f);
+        let mut runner = EventLoopRunner::new(event_loop, f);
         {
             let mut runner_ref = self.runner.borrow_mut();
-            loop {
-                let event = self.buffer.borrow_mut().pop_front();
-                match event {
-                    Some(e) => e.dispatch_event(|e| runner.process_event(e)),
-                    None => break,
-                }
-            }
+            // Dispatch any events that were buffered during the creation of the window
+            self.dispatch_buffered_events(&mut runner);
             *runner_ref = Some(runner);
         }
     }
@@ -119,80 +97,46 @@ impl<T> ELRShared<T> {
         let mut runner_ref = self.runner.borrow_mut();
         if let Some(ref mut runner) = *runner_ref {
             runner.new_events();
-            loop {
-                let buffered_event_opt = self.buffer.borrow_mut().pop_front();
-                match buffered_event_opt {
-                    Some(e) => e.dispatch_event(|e| runner.process_event(e)),
-                    None => break,
-                }
-            }
+            // Dispatch any events that were buffered during the call `new_events`
+            self.dispatch_buffered_events(runner);
         }
     }
 
-    pub(crate) unsafe fn send_event(&self, event: Event<'_, T>) {
-        let handling_redraw = self
-            .runner
-            .borrow()
-            .as_ref()
-            .map(|r| RunnerState::HandlingRedraw == r.runner_state)
-            .unwrap_or(false);
-        let mut send = None;
-        if handling_redraw {
+    pub(crate) fn send_event(&self, event: Event<'_, T>) {
+        if let Err(event) = self.send_event_unbuffered(event) {
+            // If the runner is already borrowed, we're in the middle of an event loop invocation.
+            // Add the event to a buffer to be processed later.
             if let Event::RedrawRequested(_) = event {
-                send = Some(event);
-            } else {
-                self.buffer_event(event);
-            }
-        } else {
-            send = Some(event);
-        }
-        if let Some(event) = send {
-            if let Err(event) = self.send_event_unbuffered(event) {
-                // If the runner is already borrowed, we're in the middle of an event loop invocation. Add
-                // the event to a buffer to be processed later.
-                self.buffer_event(event);
+                panic!("buffering RedrawRequested event");
             }
+            self.buffer
+                .borrow_mut()
+                .push_back(BufferedEvent::from_event(event));
         }
     }
 
-    unsafe fn send_event_unbuffered<'e>(&self, event: Event<'e, T>) -> Result<(), Event<'e, T>> {
+    fn send_event_unbuffered<'e>(&self, event: Event<'e, T>) -> Result<(), Event<'e, T>> {
         if let Ok(mut runner_ref) = self.runner.try_borrow_mut() {
             if let Some(ref mut runner) = *runner_ref {
                 runner.process_event(event);
-
-                let handling_redraw = if let RunnerState::HandlingRedraw = runner.runner_state {
-                    true
-                } else {
-                    false
-                };
-
-                if !handling_redraw {
-                    // Dispatch any events that were buffered during the call to `process_event`.
-                    loop {
-                        // We do this instead of using a `while let` loop because if we use a `while let`
-                        // loop the reference returned `borrow_mut()` doesn't get dropped until the end
-                        // of the loop's body and attempts to add events to the event buffer while in
-                        // `process_event` will fail.
-                        let buffered_event_opt = self.buffer.borrow_mut().pop_front();
-                        match buffered_event_opt {
-                            Some(e) => e.dispatch_event(|e| runner.process_event(e)),
-                            None => break,
-                        }
-                    }
-                }
-
+                // Dispatch any events that were buffered during the call to `process_event`.
+                self.dispatch_buffered_events(runner);
                 return Ok(());
             }
         }
-
         Err(event)
     }
 
-    pub(crate) unsafe fn call_event_handler(&self, event: Event<'static, T>) {
-        if let Ok(mut runner_ref) = self.runner.try_borrow_mut() {
-            if let Some(ref mut runner) = *runner_ref {
-                runner.call_event_handler(event);
-                return;
+    fn dispatch_buffered_events(&self, runner: &mut EventLoopRunner<T>) {
+        // We do this instead of using a `while let` loop because if we use a `while let`
+        // loop the reference returned `borrow_mut()` doesn't get dropped until the end
+        // of the loop's body and attempts to add events to the event buffer while in
+        // `process_event` will fail.
+        loop {
+            let buffered_event_opt = self.buffer.borrow_mut().pop_front();
+            match buffered_event_opt {
+                Some(e) => e.dispatch_event(|e| runner.process_event(e)),
+                None => break,
             }
         }
     }
@@ -201,17 +145,27 @@ impl<T> ELRShared<T> {
         let mut runner_ref = self.runner.borrow_mut();
         if let Some(ref mut runner) = *runner_ref {
             runner.main_events_cleared();
+            if !self.buffer.borrow().is_empty() {
+                warn!("Buffered events while dispatching MainEventsCleared");
+            }
         }
     }
 
-    pub(crate) fn redraw_events_cleared(&self) -> AreEventsBuffered {
+    pub(crate) fn redraw_events_cleared(&self) {
         let mut runner_ref = self.runner.borrow_mut();
         if let Some(ref mut runner) = *runner_ref {
             runner.redraw_events_cleared();
+            if !self.buffer.borrow().is_empty() {
+                warn!("Buffered events while dispatching RedrawEventsCleared");
+            }
         }
-        match self.buffer.borrow().len() {
-            0 => AreEventsBuffered::ReadyToSleep,
-            _ => AreEventsBuffered::EventsBuffered,
+    }
+
+    pub(crate) fn destroy_loop(&self) {
+        if let Ok(mut runner_ref) = self.runner.try_borrow_mut() {
+            if let Some(ref mut runner) = *runner_ref {
+                runner.call_event_handler(Event::LoopDestroyed);
+            }
         }
     }
 
@@ -228,6 +182,17 @@ impl<T> ELRShared<T> {
         let mut runner_ref = self.runner.borrow_mut();
         if let Some(ref mut runner) = *runner_ref {
             runner.in_modal_loop = in_modal_loop;
+            if in_modal_loop {
+                // jumpstart the modal loop
+                unsafe {
+                    winuser::RedrawWindow(
+                        runner.modal_redraw_window,
+                        ptr::null(),
+                        ptr::null_mut(),
+                        winuser::RDW_INTERNALPAINT,
+                    );
+                }
+            }
         }
     }
 
@@ -248,18 +213,6 @@ impl<T> ELRShared<T> {
             ControlFlow::Exit
         }
     }
-
-    fn buffer_event(&self, event: Event<'_, T>) {
-        match event {
-            Event::RedrawRequested(window_id) => {
-                self.redraw_buffer.borrow_mut().push_back(window_id)
-            }
-            _ => self
-                .buffer
-                .borrow_mut()
-                .push_back(BufferedEvent::from_event(event)),
-        }
-    }
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
@@ -275,15 +228,13 @@ enum RunnerState {
     /// The event loop is handling the OS's events and sending them to the user's callback.
     /// `NewEvents` has been sent, and `MainEventsCleared` hasn't.
     HandlingEvents,
+    /// The event loop is handling the redraw events and sending them to the user's callback.
+    /// `MainEventsCleared` has been sent, and `RedrawEventsCleared` hasn't.
     HandlingRedraw,
 }
 
 impl<T> EventLoopRunner<T> {
-    unsafe fn new<F>(
-        event_loop: &EventLoop<T>,
-        redraw_buffer: Rc<RefCell<VecDeque<WindowId>>>,
-        f: F,
-    ) -> EventLoopRunner<T>
+    unsafe fn new<F>(event_loop: &EventLoop<T>, f: F) -> EventLoopRunner<T>
     where
         F: FnMut(Event<'_, T>, &mut ControlFlow),
     {
@@ -297,7 +248,6 @@ impl<T> EventLoopRunner<T> {
                 Box<dyn FnMut(Event<'_, T>, &mut ControlFlow)>,
             >(Box::new(f)),
             panic_error: None,
-            redraw_buffer,
         }
     }
 
@@ -323,6 +273,8 @@ impl<T> EventLoopRunner<T> {
             }
 
             // When `NewEvents` gets sent after an idle depends on the control flow...
+            // Some `NewEvents` are deferred because not all Windows messages trigger an event_loop event.
+            // So we defer the `NewEvents` to when we actually process an event.
             RunnerState::Idle(wait_start) => {
                 match self.control_flow {
                     // If we're polling, send `NewEvents` and immediately move into event processing.
@@ -411,24 +363,21 @@ impl<T> EventLoopRunner<T> {
                 // that was sent after `MainEventsCleared`.
                 ControlFlow::Poll => self.call_event_handler(Event::NewEvents(StartCause::Poll)),
             }
+            self.runner_state = RunnerState::HandlingEvents;
         }
 
         match (self.runner_state, &event) {
-            (RunnerState::HandlingRedraw, Event::RedrawRequested(_)) => {
-                self.call_event_handler(event)
+            (RunnerState::HandlingEvents, Event::RedrawRequested(window_id)) => {
+                self.call_event_handler(Event::MainEventsCleared);
+                self.runner_state = RunnerState::HandlingRedraw;
+                self.call_event_handler(Event::RedrawRequested(*window_id));
             }
-            (RunnerState::New, Event::RedrawRequested(_))
-            | (RunnerState::Idle(..), Event::RedrawRequested(_)) => {
-                self.new_events();
-                self.main_events_cleared();
-                self.call_event_handler(event);
-            }
-            (_, Event::RedrawRequested(_)) => {
-                panic!("redraw event in non-redraw phase");
+            (RunnerState::HandlingRedraw, Event::RedrawRequested(window_id)) => {
+                self.call_event_handler(Event::RedrawRequested(*window_id));
             }
             (RunnerState::HandlingRedraw, _) => {
-                panic!(
-                    "Non-redraw event dispatched durning redraw phase: {:?}",
+                warn!(
+                    "non-redraw event in redraw phase: {:?}",
                     event.map_nonuser_event::<()>().ok()
                 );
             }
@@ -439,16 +388,6 @@ impl<T> EventLoopRunner<T> {
         }
     }
 
-    fn flush_redraws(&mut self) {
-        loop {
-            let redraw_window_opt = self.redraw_buffer.borrow_mut().pop_front();
-            match redraw_window_opt {
-                Some(window_id) => self.process_event(Event::RedrawRequested(window_id)),
-                None => break,
-            }
-        }
-    }
-
     fn main_events_cleared(&mut self) {
         match self.runner_state {
             // If we were handling events, send the MainEventsCleared message.
@@ -457,7 +396,9 @@ impl<T> EventLoopRunner<T> {
                 self.runner_state = RunnerState::HandlingRedraw;
             }
 
-            RunnerState::HandlingRedraw => (),
+            // We already cleared the main events, we don't have to do anything.
+            // This happens when process_events() processed a RedrawRequested event.
+            RunnerState::HandlingRedraw => {}
 
             // If we *weren't* handling events, we don't have to do anything.
             RunnerState::New | RunnerState::Idle(..) => (),
@@ -469,6 +410,7 @@ impl<T> EventLoopRunner<T> {
                     // If we had deferred a Poll, send the Poll NewEvents and MainEventsCleared.
                     ControlFlow::Poll => {
                         self.call_event_handler(Event::NewEvents(StartCause::Poll));
+                        self.runner_state = RunnerState::HandlingEvents;
                         self.call_event_handler(Event::MainEventsCleared);
                         self.runner_state = RunnerState::HandlingRedraw;
                     }
@@ -482,6 +424,7 @@ impl<T> EventLoopRunner<T> {
                                     requested_resume: resume_time,
                                 },
                             ));
+                            self.runner_state = RunnerState::HandlingEvents;
                             self.call_event_handler(Event::MainEventsCleared);
                             self.runner_state = RunnerState::HandlingRedraw;
                         }
@@ -496,57 +439,18 @@ impl<T> EventLoopRunner<T> {
 
     fn redraw_events_cleared(&mut self) {
         match self.runner_state {
-            // If we were handling events, send the MainEventsCleared message.
-            RunnerState::HandlingEvents => {
-                self.call_event_handler(Event::MainEventsCleared);
-                self.runner_state = RunnerState::HandlingRedraw;
-                self.flush_redraws();
-                self.call_event_handler(Event::RedrawEventsCleared);
-                self.runner_state = RunnerState::Idle(Instant::now());
-            }
-
+            // If we were handling redraws, send the RedrawEventsCleared message.
             RunnerState::HandlingRedraw => {
-                self.flush_redraws();
                 self.call_event_handler(Event::RedrawEventsCleared);
                 self.runner_state = RunnerState::Idle(Instant::now());
             }
-
-            // If we *weren't* handling events, we don't have to do anything.
-            RunnerState::New | RunnerState::Idle(..) => (),
-
-            // Some control flows require a NewEvents call even if no events were received. This
-            // branch handles those.
-            RunnerState::DeferredNewEvents(wait_start) => {
-                match self.control_flow {
-                    // If we had deferred a Poll, send the Poll NewEvents and MainEventsCleared.
-                    ControlFlow::Poll => {
-                        self.call_event_handler(Event::NewEvents(StartCause::Poll));
-                        self.call_event_handler(Event::MainEventsCleared);
-                        self.flush_redraws();
-                        self.call_event_handler(Event::RedrawEventsCleared);
-                    }
-                    // If we had deferred a WaitUntil and the resume time has since been reached,
-                    // send the resume notification and MainEventsCleared event.
-                    ControlFlow::WaitUntil(resume_time) => {
-                        if Instant::now() >= resume_time {
-                            self.call_event_handler(Event::NewEvents(
-                                StartCause::ResumeTimeReached {
-                                    start: wait_start,
-                                    requested_resume: resume_time,
-                                },
-                            ));
-                            self.call_event_handler(Event::MainEventsCleared);
-                            self.flush_redraws();
-                            self.call_event_handler(Event::RedrawEventsCleared);
-                        }
-                    }
-                    // If we deferred a wait and no events were received, the user doesn't have to
-                    // get an event.
-                    ControlFlow::Wait | ControlFlow::Exit => (),
-                }
-                // Mark that we've entered an idle state.
-                self.runner_state = RunnerState::Idle(wait_start)
-            }
+            // No event was processed, we don't have to do anything.
+            RunnerState::DeferredNewEvents(_) => (),
+            // Should not happen.
+            _ => warn!(
+                "unexpected state in redraw_events_cleared: {:?}",
+                self.runner_state
+            ),
         }
     }
 

src/platform_impl/windows/icon.rs

@@ -1,15 +1,17 @@
-use std::{io, mem, os::windows::ffi::OsStrExt, path::Path, ptr};
+use std::{fmt, io, iter::once, mem, os::windows::ffi::OsStrExt, path::Path, ptr, sync::Arc};
 
 use winapi::{
     ctypes::{c_int, wchar_t},
     shared::{
-        minwindef::{BYTE, LPARAM, WPARAM},
+        minwindef::{BYTE, LPARAM, WORD, WPARAM},
         windef::{HICON, HWND},
     },
+    um::libloaderapi,
     um::winuser,
 };
 
-use crate::icon::{Icon, Pixel, PIXEL_SIZE};
+use crate::dpi::PhysicalSize;
+use crate::icon::*;
 
 impl Pixel {
     fn to_bgra(&mut self) {
@@ -17,92 +19,149 @@ impl Pixel {
     }
 }
 
+impl RgbaIcon {
+    fn into_windows_icon(self) -> Result<WinIcon, BadIcon> {
+        let mut rgba = self.rgba;
+        let pixel_count = rgba.len() / PIXEL_SIZE;
+        let mut and_mask = Vec::with_capacity(pixel_count);
+        let pixels =
+            unsafe { std::slice::from_raw_parts_mut(rgba.as_mut_ptr() as *mut Pixel, pixel_count) };
+        for pixel in pixels {
+            and_mask.push(pixel.a.wrapping_sub(std::u8::MAX)); // invert alpha channel
+            pixel.to_bgra();
+        }
+        assert_eq!(and_mask.len(), pixel_count);
+        let handle = unsafe {
+            winuser::CreateIcon(
+                ptr::null_mut(),
+                self.width as c_int,
+                self.height as c_int,
+                1,
+                (PIXEL_SIZE * 8) as BYTE,
+                and_mask.as_ptr() as *const BYTE,
+                rgba.as_ptr() as *const BYTE,
+            ) as HICON
+        };
+        if !handle.is_null() {
+            Ok(WinIcon::from_handle(handle))
+        } else {
+            Err(BadIcon::OsError(io::Error::last_os_error()))
+        }
+    }
+}
+
 #[derive(Debug)]
 pub enum IconType {
     Small = winuser::ICON_SMALL as isize,
     Big = winuser::ICON_BIG as isize,
 }
 
-#[derive(Clone, Debug)]
+#[derive(Debug)]
+struct RaiiIcon {
+    handle: HICON,
+}
+
+#[derive(Clone)]
 pub struct WinIcon {
-    pub handle: HICON,
+    inner: Arc<RaiiIcon>,
 }
 
 unsafe impl Send for WinIcon {}
 
 impl WinIcon {
-    #[allow(dead_code)]
-    pub fn from_path<P: AsRef<Path>>(path: P) -> Result<Self, io::Error> {
-        let wide_path: Vec<u16> = path.as_ref().as_os_str().encode_wide().collect();
+    pub fn as_raw_handle(&self) -> HICON {
+        self.inner.handle
+    }
+
+    pub fn from_path<P: AsRef<Path>>(
+        path: P,
+        size: Option<PhysicalSize<u32>>,
+    ) -> Result<Self, BadIcon> {
+        let wide_path: Vec<u16> = path
+            .as_ref()
+            .as_os_str()
+            .encode_wide()
+            .chain(once(0))
+            .collect();
+
+        // width / height of 0 along with LR_DEFAULTSIZE tells windows to load the default icon size
+        let (width, height) = size.map(Into::into).unwrap_or((0, 0));
+
         let handle = unsafe {
             winuser::LoadImageW(
                 ptr::null_mut(),
                 wide_path.as_ptr() as *const wchar_t,
                 winuser::IMAGE_ICON,
-                0, // 0 indicates that we want to use the actual width
-                0, // and height
-                winuser::LR_LOADFROMFILE,
-            ) as HICON
-        };
-        if !handle.is_null() {
-            Ok(WinIcon { handle })
-        } else {
-            Err(io::Error::last_os_error())
-        }
-    }
-
-    pub fn from_icon(icon: Icon) -> Result<Self, io::Error> {
-        Self::from_rgba(icon.rgba, icon.width, icon.height)
-    }
-
-    pub fn from_rgba(mut rgba: Vec<u8>, width: u32, height: u32) -> Result<Self, io::Error> {
-        assert_eq!(rgba.len() % PIXEL_SIZE, 0);
-        let pixel_count = rgba.len() / PIXEL_SIZE;
-        assert_eq!(pixel_count, (width * height) as usize);
-        let mut and_mask = Vec::with_capacity(pixel_count);
-        let pixels = rgba.as_mut_ptr() as *mut Pixel; // how not to write idiomatic Rust
-        for pixel_index in 0..pixel_count {
-            let pixel = unsafe { &mut *pixels.offset(pixel_index as isize) };
-            and_mask.push(pixel.a.wrapping_sub(std::u8::MAX)); // invert alpha channel
-            pixel.to_bgra();
-        }
-        assert_eq!(and_mask.len(), pixel_count);
-        let handle = unsafe {
-            winuser::CreateIcon(
-                ptr::null_mut(),
                 width as c_int,
                 height as c_int,
-                1,
-                (PIXEL_SIZE * 8) as BYTE,
-                and_mask.as_ptr() as *const BYTE,
-                rgba.as_ptr() as *const BYTE,
+                winuser::LR_DEFAULTSIZE | winuser::LR_LOADFROMFILE,
             ) as HICON
         };
         if !handle.is_null() {
-            Ok(WinIcon { handle })
+            Ok(WinIcon::from_handle(handle))
         } else {
-            Err(io::Error::last_os_error())
+            Err(BadIcon::OsError(io::Error::last_os_error()))
         }
     }
 
+    pub fn from_resource(
+        resource_id: WORD,
+        size: Option<PhysicalSize<u32>>,
+    ) -> Result<Self, BadIcon> {
+        // width / height of 0 along with LR_DEFAULTSIZE tells windows to load the default icon size
+        let (width, height) = size.map(Into::into).unwrap_or((0, 0));
+        let handle = unsafe {
+            winuser::LoadImageW(
+                libloaderapi::GetModuleHandleW(ptr::null_mut()),
+                winuser::MAKEINTRESOURCEW(resource_id),
+                winuser::IMAGE_ICON,
+                width as c_int,
+                height as c_int,
+                winuser::LR_DEFAULTSIZE,
+            ) as HICON
+        };
+        if !handle.is_null() {
+            Ok(WinIcon::from_handle(handle))
+        } else {
+            Err(BadIcon::OsError(io::Error::last_os_error()))
+        }
+    }
+
+    pub fn from_rgba(rgba: Vec<u8>, width: u32, height: u32) -> Result<Self, BadIcon> {
+        let rgba_icon = RgbaIcon::from_rgba(rgba, width, height)?;
+        rgba_icon.into_windows_icon()
+    }
+
     pub fn set_for_window(&self, hwnd: HWND, icon_type: IconType) {
         unsafe {
             winuser::SendMessageW(
                 hwnd,
                 winuser::WM_SETICON,
                 icon_type as WPARAM,
-                self.handle as LPARAM,
+                self.as_raw_handle() as LPARAM,
             );
         }
     }
+
+    fn from_handle(handle: HICON) -> Self {
+        Self {
+            inner: Arc::new(RaiiIcon { handle }),
+        }
+    }
 }
 
-impl Drop for WinIcon {
+impl Drop for RaiiIcon {
     fn drop(&mut self) {
         unsafe { winuser::DestroyIcon(self.handle) };
     }
 }
 
+impl fmt::Debug for WinIcon {
+    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
+        (*self.inner).fmt(formatter)
+    }
+}
+
 pub fn unset_for_window(hwnd: HWND, icon_type: IconType) {
     unsafe {
         winuser::SendMessageW(hwnd, winuser::WM_SETICON, icon_type as WPARAM, 0 as LPARAM);

src/platform_impl/windows/mod.rs

@@ -4,11 +4,15 @@ use winapi::{self, shared::windef::HWND};
 
 pub use self::{
     event_loop::{EventLoop, EventLoopProxy, EventLoopWindowTarget},
+    icon::WinIcon,
     monitor::{MonitorHandle, VideoMode},
     window::Window,
 };
 
-use crate::{event::DeviceId as RootDeviceId, window::Icon};
+pub use self::icon::WinIcon as PlatformIcon;
+
+use crate::event::DeviceId as RootDeviceId;
+use crate::icon::Icon;
 
 #[derive(Clone, Default)]
 pub struct PlatformSpecificWindowBuilderAttributes {

src/platform_impl/windows/util.rs

@@ -116,7 +116,7 @@ pub(crate) fn set_inner_size_physical(window: HWND, x: u32, y: u32) {
                 | winuser::SWP_NOMOVE
                 | winuser::SWP_NOACTIVATE,
         );
-        winuser::UpdateWindow(window);
+        winuser::InvalidateRgn(window, ptr::null_mut(), 0);
     }
 }
 

src/platform_impl/windows/window.rs

@@ -32,18 +32,19 @@ use winapi::{
 use crate::{
     dpi::{PhysicalPosition, PhysicalSize, Position, Size},
     error::{ExternalError, NotSupportedError, OsError as RootOsError},
+    icon::Icon,
     monitor::MonitorHandle as RootMonitorHandle,
     platform_impl::platform::{
         dark_mode::try_dark_mode,
         dpi::{dpi_to_scale_factor, hwnd_dpi},
         drop_handler::FileDropHandler,
         event_loop::{self, EventLoopWindowTarget, DESTROY_MSG_ID},
-        icon::{self, IconType, WinIcon},
+        icon::{self, IconType},
         monitor, util,
         window_state::{CursorFlags, SavedWindow, WindowFlags, WindowState},
         PlatformSpecificWindowBuilderAttributes, WindowId,
     },
-    window::{CursorIcon, Fullscreen, Icon, WindowAttributes},
+    window::{CursorIcon, Fullscreen, WindowAttributes},
 };
 
 /// The Win32 implementation of the main `Window` object.
@@ -187,7 +188,7 @@ impl Window {
                     | winuser::SWP_NOSIZE
                     | winuser::SWP_NOACTIVATE,
             );
-            winuser::UpdateWindow(self.window.0);
+            winuser::InvalidateRgn(self.window.0, ptr::null_mut(), 0);
         }
     }
 
@@ -217,8 +218,8 @@ impl Window {
 
     #[inline]
     pub fn set_inner_size(&self, size: Size) {
-        let dpi_factor = self.scale_factor();
-        let (width, height) = size.to_physical::<u32>(dpi_factor).into();
+        let scale_factor = self.scale_factor();
+        let (width, height) = size.to_physical::<u32>(scale_factor).into();
 
         let window_state = Arc::clone(&self.window_state);
         let window = self.window.clone();
@@ -325,13 +326,13 @@ impl Window {
 
     #[inline]
     pub fn scale_factor(&self) -> f64 {
-        self.window_state.lock().dpi_factor
+        self.window_state.lock().scale_factor
     }
 
     #[inline]
     pub fn set_cursor_position(&self, position: Position) -> Result<(), ExternalError> {
-        let dpi_factor = self.scale_factor();
-        let (x, y) = position.to_physical::<i32>(dpi_factor).into();
+        let scale_factor = self.scale_factor();
+        let (x, y) = position.to_physical::<i32>(scale_factor).into();
 
         let mut point = POINT { x, y };
         unsafe {
@@ -402,7 +403,7 @@ impl Window {
                     let client_rect = util::get_client_rect(window.0).unwrap();
                     window_state_lock.saved_window = Some(SavedWindow {
                         client_rect,
-                        dpi_factor: window_state_lock.dpi_factor,
+                        scale_factor: window_state_lock.scale_factor,
                     });
                 }
                 _ => (),
@@ -506,17 +507,17 @@ impl Window {
                             size.1 as i32,
                             winuser::SWP_ASYNCWINDOWPOS | winuser::SWP_NOZORDER,
                         );
-                        winuser::UpdateWindow(window.0);
+                        winuser::InvalidateRgn(window.0, ptr::null_mut(), 0);
                     }
                 }
                 None => {
                     let mut window_state_lock = window_state.lock();
                     if let Some(SavedWindow {
                         client_rect,
-                        dpi_factor,
+                        scale_factor,
                     }) = window_state_lock.saved_window.take()
                     {
-                        window_state_lock.dpi_factor = dpi_factor;
+                        window_state_lock.scale_factor = scale_factor;
                         drop(window_state_lock);
                         let client_rect = util::adjust_window_rect(window.0, client_rect).unwrap();
 
@@ -532,7 +533,7 @@ impl Window {
                                     | winuser::SWP_NOZORDER
                                     | winuser::SWP_NOACTIVATE,
                             );
-                            winuser::UpdateWindow(window.0);
+                            winuser::InvalidateRgn(window.0, ptr::null_mut(), 0);
                         }
                     }
                 }
@@ -576,12 +577,11 @@ impl Window {
     }
 
     #[inline]
-    pub fn set_window_icon(&self, mut window_icon: Option<Icon>) {
-        let window_icon = window_icon
-            .take()
-            .map(|icon| WinIcon::from_icon(icon).expect("Failed to create `ICON_SMALL`"));
+    pub fn set_window_icon(&self, window_icon: Option<Icon>) {
         if let Some(ref window_icon) = window_icon {
-            window_icon.set_for_window(self.window.0, IconType::Small);
+            window_icon
+                .inner
+                .set_for_window(self.window.0, IconType::Small);
         } else {
             icon::unset_for_window(self.window.0, IconType::Small);
         }
@@ -589,12 +589,11 @@ impl Window {
     }
 
     #[inline]
-    pub fn set_taskbar_icon(&self, mut taskbar_icon: Option<Icon>) {
-        let taskbar_icon = taskbar_icon
-            .take()
-            .map(|icon| WinIcon::from_icon(icon).expect("Failed to create `ICON_BIG`"));
+    pub fn set_taskbar_icon(&self, taskbar_icon: Option<Icon>) {
         if let Some(ref taskbar_icon) = taskbar_icon {
-            taskbar_icon.set_for_window(self.window.0, IconType::Big);
+            taskbar_icon
+                .inner
+                .set_for_window(self.window.0, IconType::Big);
         } else {
             icon::unset_for_window(self.window.0, IconType::Big);
         }
@@ -636,7 +635,7 @@ unsafe impl Sync for WindowWrapper {}
 unsafe impl Send for WindowWrapper {}
 
 unsafe fn init<T: 'static>(
-    mut attributes: WindowAttributes,
+    attributes: WindowAttributes,
     pl_attribs: PlatformSpecificWindowBuilderAttributes,
     event_loop: &EventLoopWindowTarget<T>,
 ) -> Result<Window, RootOsError> {
@@ -645,25 +644,8 @@ unsafe fn init<T: 'static>(
         .chain(Some(0).into_iter())
         .collect::<Vec<_>>();
 
-    let window_icon = {
-        let icon = attributes.window_icon.take().map(WinIcon::from_icon);
-        if let Some(icon) = icon {
-            Some(icon.map_err(|e| os_error!(e))?)
-        } else {
-            None
-        }
-    };
-    let taskbar_icon = {
-        let icon = attributes.window_icon.take().map(WinIcon::from_icon);
-        if let Some(icon) = icon {
-            Some(icon.map_err(|e| os_error!(e))?)
-        } else {
-            None
-        }
-    };
-
     // registering the window class
-    let class_name = register_window_class(&window_icon, &taskbar_icon);
+    let class_name = register_window_class(&attributes.window_icon, &pl_attribs.taskbar_icon);
 
     let mut window_flags = WindowFlags::empty();
     window_flags.set(WindowFlags::DECORATIONS, attributes.decorations);
@@ -712,7 +694,7 @@ unsafe fn init<T: 'static>(
     }
 
     let dpi = hwnd_dpi(real_window.0);
-    let dpi_factor = dpi_to_scale_factor(dpi);
+    let scale_factor = dpi_to_scale_factor(dpi);
 
     // making the window transparent
     if attributes.transparent && !pl_attribs.no_redirection_bitmap {
@@ -756,9 +738,8 @@ unsafe fn init<T: 'static>(
     let window_state = {
         let window_state = WindowState::new(
             &attributes,
-            window_icon,
-            taskbar_icon,
-            dpi_factor,
+            pl_attribs.taskbar_icon,
+            scale_factor,
             dark_mode,
         );
         let window_state = Arc::new(Mutex::new(window_state));
@@ -787,8 +768,8 @@ unsafe fn init<T: 'static>(
 }
 
 unsafe fn register_window_class(
-    window_icon: &Option<WinIcon>,
-    taskbar_icon: &Option<WinIcon>,
+    window_icon: &Option<Icon>,
+    taskbar_icon: &Option<Icon>,
 ) -> Vec<u16> {
     let class_name: Vec<_> = OsStr::new("Window Class")
         .encode_wide()
@@ -797,11 +778,11 @@ unsafe fn register_window_class(
 
     let h_icon = taskbar_icon
         .as_ref()
-        .map(|icon| icon.handle)
+        .map(|icon| icon.inner.as_raw_handle())
         .unwrap_or(ptr::null_mut());
     let h_icon_small = window_icon
         .as_ref()
-        .map(|icon| icon.handle)
+        .map(|icon| icon.inner.as_raw_handle())
         .unwrap_or(ptr::null_mut());
 
     let class = winuser::WNDCLASSEXW {

src/platform_impl/windows/window_state.rs

@@ -1,6 +1,8 @@
 use crate::{
-    dpi::Size,
-    platform_impl::platform::{event_loop, icon::WinIcon, util},
+    dpi::{PhysicalPosition, Size},
+    event::ModifiersState,
+    icon::Icon,
+    platform_impl::platform::{event_loop, util},
     window::{CursorIcon, Fullscreen, WindowAttributes},
 };
 use parking_lot::MutexGuard;
@@ -14,7 +16,6 @@ use winapi::{
 };
 
 /// Contains information about states and the window that the callback is going to use.
-#[derive(Clone)]
 pub struct WindowState {
     pub mouse: MouseProperties,
 
@@ -22,16 +23,14 @@ pub struct WindowState {
     pub min_size: Option<Size>,
     pub max_size: Option<Size>,
 
-    pub window_icon: Option<WinIcon>,
-    pub taskbar_icon: Option<WinIcon>,
+    pub window_icon: Option<Icon>,
+    pub taskbar_icon: Option<Icon>,
 
     pub saved_window: Option<SavedWindow>,
-    pub dpi_factor: f64,
+    pub scale_factor: f64,
 
+    pub modifiers_state: ModifiersState,
     pub fullscreen: Option<Fullscreen>,
-    /// Used to supress duplicate redraw attempts when calling `request_redraw` multiple
-    /// times in `MainEventsCleared`.
-    pub queued_out_of_band_redraw: bool,
     pub is_dark_mode: bool,
     pub high_surrogate: Option<u16>,
     window_flags: WindowFlags,
@@ -40,7 +39,7 @@ pub struct WindowState {
 #[derive(Clone)]
 pub struct SavedWindow {
     pub client_rect: RECT,
-    pub dpi_factor: f64,
+    pub scale_factor: f64,
 }
 
 #[derive(Clone)]
@@ -48,6 +47,7 @@ pub struct MouseProperties {
     pub cursor: CursorIcon,
     pub buttons_down: u32,
     cursor_flags: CursorFlags,
+    pub last_position: Option<PhysicalPosition<f64>>,
 }
 
 bitflags! {
@@ -96,9 +96,8 @@ bitflags! {
 impl WindowState {
     pub fn new(
         attributes: &WindowAttributes,
-        window_icon: Option<WinIcon>,
-        taskbar_icon: Option<WinIcon>,
-        dpi_factor: f64,
+        taskbar_icon: Option<Icon>,
+        scale_factor: f64,
         is_dark_mode: bool,
     ) -> WindowState {
         WindowState {
@@ -106,19 +105,20 @@ impl WindowState {
                 cursor: CursorIcon::default(),
                 buttons_down: 0,
                 cursor_flags: CursorFlags::empty(),
+                last_position: None,
             },
 
             min_size: attributes.min_inner_size,
             max_size: attributes.max_inner_size,
 
-            window_icon,
+            window_icon: attributes.window_icon.clone(),
             taskbar_icon,
 
             saved_window: None,
-            dpi_factor,
+            scale_factor,
 
+            modifiers_state: ModifiersState::default(),
             fullscreen: None,
-            queued_out_of_band_redraw: false,
             is_dark_mode,
             high_surrogate: None,
             window_flags: WindowFlags::empty(),
@@ -268,7 +268,7 @@ impl WindowFlags {
                         | winuser::SWP_NOSIZE
                         | winuser::SWP_NOACTIVATE,
                 );
-                winuser::UpdateWindow(window);
+                winuser::InvalidateRgn(window, ptr::null_mut(), 0);
             }
         }
 

src/window.rs

@@ -9,7 +9,7 @@ use crate::{
     platform_impl,
 };
 
-pub use crate::icon::*;
+pub use crate::icon::{BadIcon, Icon};
 
 /// Represents a window.
 ///