Create custom cursor with directly with event loop

Replace the `CustomCursorBuilder` with the `CustomCursorSource` and
perform the loading of the cursor via the
`EventLoop::create_custom_cursor` instead of passing it to the builder
itself.

This follows the `EventLoop::create_window` API.

CHANGELOG.md

@@ -25,10 +25,10 @@ Unreleased` header.
 - On Windows, macOS, X11, Wayland and Web, implement setting images as cursors. See the `custom_cursors.rs` example.
   - **Breaking:** Remove `Window::set_cursor_icon`
   - Add `WindowBuilder::with_cursor` and `Window::set_cursor` which takes a `CursorIcon` or `CustomCursor`
-  - Add `CustomCursor`
   - Add `CustomCursor::from_rgba` to allow creating cursor images from RGBA data.
   - Add `CustomCursorExtWebSys::from_url` to allow loading cursor images from URLs.
   - Add `CustomCursorExtWebSys::from_animation` to allow creating animated cursors from other `CustomCursor`s.
+  - Add `{Active,}EventLoop::create_custom_cursor` to load custom cursor image sources.
 - On macOS, add services menu.
 - **Breaking:** On Web, remove queuing fullscreen request in absence of transient activation.
 - On Web, fix setting cursor icon overriding cursor visibility.

examples/window.rs

@@ -20,7 +20,8 @@ use winit::event::{MouseButton, MouseScrollDelta};
 use winit::event_loop::{ActiveEventLoop, EventLoop};
 use winit::keyboard::{Key, ModifiersState};
 use winit::window::{
-    Cursor, CursorGrabMode, CustomCursor, Fullscreen, Icon, ResizeDirection, Theme,
+    Cursor, CursorGrabMode, CustomCursor, CustomCursorSource, Fullscreen, Icon, ResizeDirection,
+    Theme,
 };
 use winit::window::{Window, WindowId};
 
@@ -57,7 +58,6 @@ fn main() -> Result<(), Box<dyn Error>> {
         Event::Resumed => {
             println!("Resumed the event loop");
             state.dump_monitors(event_loop);
-            state.load_custom_cursors(event_loop);
 
             // Create initial window.
             state
@@ -108,11 +108,11 @@ struct Application {
 }
 
 impl Application {
-    fn new<T>(_event_loop: &EventLoop<T>) -> Self {
+    fn new<T>(event_loop: &EventLoop<T>) -> Self {
         // SAFETY: the context is dropped inside the loop, since the state we're using
         // is moved inside the closure.
         #[cfg(not(any(android_platform, ios_platform)))]
-        let context = unsafe { Context::from_raw(_event_loop.raw_display_handle()).unwrap() };
+        let context = unsafe { Context::from_raw(event_loop.raw_display_handle()).unwrap() };
 
         // You'll have to choose an icon size at your own discretion. On X11, the desired size varies
         // by WM, and on Windows, you still have to account for screen scaling. Here we use 32px,
@@ -122,12 +122,19 @@ impl Application {
 
         let icon = load_icon(Path::new(path));
 
+        println!("Loading cursor assets");
+        let custom_cursors = vec![
+            event_loop.create_custom_cursor(decode_cursor(include_bytes!("data/cross.png"))),
+            event_loop.create_custom_cursor(decode_cursor(include_bytes!("data/cross2.png"))),
+            event_loop.create_custom_cursor(decode_cursor(include_bytes!("data/gradient.png"))),
+        ];
+
         Self {
             #[cfg(not(any(android_platform, ios_platform)))]
             context,
+            custom_cursors,
             icon,
             windows: Default::default(),
-            custom_cursors: Vec::new(),
         }
     }
 
@@ -411,15 +418,6 @@ impl Application {
         }
     }
 
-    fn load_custom_cursors(&mut self, event_loop: &ActiveEventLoop) {
-        println!("Loading cursor assets");
-        self.custom_cursors = vec![
-            decode_cursor(include_bytes!("data/cross.png"), event_loop),
-            decode_cursor(include_bytes!("data/cross2.png"), event_loop),
-            decode_cursor(include_bytes!("data/gradient.png"), event_loop),
-        ];
-    }
-
     /// Process the key binding.
     fn process_key_binding(key: &str, mods: &ModifiersState) -> Option<Action> {
         KEY_BINDINGS.iter().find_map(|binding| {
@@ -852,14 +850,12 @@ impl fmt::Display for Action {
     }
 }
 
-fn decode_cursor(bytes: &[u8], window_target: &ActiveEventLoop) -> CustomCursor {
+fn decode_cursor(bytes: &[u8]) -> CustomCursorSource {
     let img = image::load_from_memory(bytes).unwrap().to_rgba8();
     let samples = img.into_flat_samples();
     let (_, w, h) = samples.extents();
     let (w, h) = (w as u16, h as u16);
-    let builder = CustomCursor::from_rgba(samples.samples, w, h, w / 2, h / 2).unwrap();
-
-    builder.build(window_target)
+    CustomCursor::from_rgba(samples.samples, w, h, w / 2, h / 2).unwrap()
 }
 
 fn load_icon(path: &Path) -> Icon {

src/cursor.rs

@@ -5,8 +5,7 @@ use std::{error::Error, hash::Hash};
 
 use cursor_icon::CursorIcon;
 
-use crate::event_loop::ActiveEventLoop;
-use crate::platform_impl::{self, PlatformCustomCursor, PlatformCustomCursorBuilder};
+use crate::platform_impl::{PlatformCustomCursor, PlatformCustomCursorSource};
 
 /// The maximum width and height for a cursor when using [`CustomCursor::from_rgba`].
 pub const MAX_CURSOR_SIZE: u16 = 2048;
@@ -59,15 +58,15 @@ impl From<CustomCursor> for Cursor {
 /// let rgba = vec![255; (w * h * 4) as usize];
 ///
 /// #[cfg(not(target_family = "wasm"))]
-/// let builder = CustomCursor::from_rgba(rgba, w, h, w / 2, h / 2).unwrap();
+/// let source = CustomCursor::from_rgba(rgba, w, h, w / 2, h / 2).unwrap();
 ///
 /// #[cfg(target_family = "wasm")]
-/// let builder = {
+/// let source = {
 ///     use winit::platform::web::CustomCursorExtWebSys;
 ///     CustomCursor::from_url(String::from("http://localhost:3000/cursor.png"), 0, 0)
 /// };
 ///
-/// let custom_cursor = builder.build(&event_loop);
+/// let custom_cursor = event_loop.create_custom_cursor(source);
 ///
 /// window.set_cursor(custom_cursor.clone());
 /// # }
@@ -88,9 +87,9 @@ impl CustomCursor {
         height: u16,
         hotspot_x: u16,
         hotspot_y: u16,
-    ) -> Result<CustomCursorBuilder, BadImage> {
-        Ok(CustomCursorBuilder {
-            inner: PlatformCustomCursorBuilder::from_rgba(
+    ) -> Result<CustomCursorSource, BadImage> {
+        Ok(CustomCursorSource {
+            inner: PlatformCustomCursorSource::from_rgba(
                 rgba.into(),
                 width,
                 height,
@@ -101,20 +100,12 @@ impl CustomCursor {
     }
 }
 
-/// Builds a [`CustomCursor`].
+/// Source for [`CustomCursor`].
 ///
 /// See [`CustomCursor`] for more details.
 #[derive(Debug)]
-pub struct CustomCursorBuilder {
-    pub(crate) inner: PlatformCustomCursorBuilder,
-}
-
-impl CustomCursorBuilder {
-    pub fn build(self, window_target: &ActiveEventLoop) -> CustomCursor {
-        CustomCursor {
-            inner: PlatformCustomCursor::build(self.inner, &window_target.p),
-        }
-    }
+pub struct CustomCursorSource {
+    pub(crate) inner: PlatformCustomCursorSource,
 }
 
 /// An error produced when using [`CustomCursor::from_rgba`] with invalid arguments.
@@ -175,12 +166,14 @@ impl fmt::Display for BadImage {
 
 impl Error for BadImage {}
 
-/// Platforms export this directly as `PlatformCustomCursorBuilder` if they need to only work with images.
+/// Platforms export this directly as `PlatformCustomCursorSource` if they need to only work with
+/// images.
+#[allow(dead_code)]
 #[derive(Debug)]
-pub(crate) struct OnlyCursorImageBuilder(pub(crate) CursorImage);
+pub(crate) struct OnlyCursorImageSource(pub(crate) CursorImage);
 
 #[allow(dead_code)]
-impl OnlyCursorImageBuilder {
+impl OnlyCursorImageSource {
     pub(crate) fn from_rgba(
         rgba: Vec<u8>,
         width: u16,
@@ -210,16 +203,6 @@ impl PartialEq for OnlyCursorImage {
 
 impl Eq for OnlyCursorImage {}
 
-#[allow(dead_code)]
-impl OnlyCursorImage {
-    pub(crate) fn build(
-        builder: OnlyCursorImageBuilder,
-        _: &platform_impl::ActiveEventLoop,
-    ) -> Self {
-        Self(Arc::new(builder.0))
-    }
-}
-
 #[derive(Debug)]
 #[allow(dead_code)]
 pub(crate) struct CursorImage {
@@ -294,8 +277,4 @@ impl NoCustomCursor {
         CursorImage::from_rgba(rgba, width, height, hotspot_x, hotspot_y)?;
         Ok(Self)
     }
-
-    fn build(self, _: &platform_impl::ActiveEventLoop) -> NoCustomCursor {
-        self
-    }
 }

src/event_loop.rs

@@ -19,7 +19,7 @@ use std::time::{Duration, Instant};
 use web_time::{Duration, Instant};
 
 use crate::error::{EventLoopError, OsError};
-use crate::window::{Window, WindowAttributes};
+use crate::window::{CustomCursor, CustomCursorSource, Window, WindowAttributes};
 use crate::{event::Event, monitor::MonitorHandle, platform_impl};
 
 /// Provides a way to retrieve events from the system and from the windows that were registered to
@@ -299,6 +299,14 @@ impl<T> EventLoop<T> {
             platform_impl::Window::new(&self.event_loop.window_target().p, window_attributes)?;
         Ok(Window { window })
     }
+
+    /// Create custom cursor.
+    pub fn create_custom_cursor(&self, custom_cursor: CustomCursorSource) -> CustomCursor {
+        self.event_loop
+            .window_target()
+            .p
+            .create_custom_cursor(custom_cursor)
+    }
 }
 
 #[cfg(feature = "rwh_06")]
@@ -360,6 +368,11 @@ impl ActiveEventLoop {
         Ok(Window { window })
     }
 
+    /// Create custom cursor.
+    pub fn create_custom_cursor(&self, custom_cursor: CustomCursorSource) -> CustomCursor {
+        self.p.create_custom_cursor(custom_cursor)
+    }
+
     #[inline]
     pub fn available_monitors(&self) -> impl Iterator<Item = MonitorHandle> {
         #[allow(clippy::useless_conversion)] // false positive on some platforms

src/platform/web.rs

@@ -37,12 +37,12 @@ use std::time::Duration;
 #[cfg(web_platform)]
 use web_sys::HtmlCanvasElement;
 
-use crate::cursor::CustomCursorBuilder;
+use crate::cursor::CustomCursorSource;
 use crate::event::Event;
 use crate::event_loop::{ActiveEventLoop, EventLoop};
 #[cfg(web_platform)]
 use crate::platform_impl::CustomCursorFuture as PlatformCustomCursorFuture;
-use crate::platform_impl::{PlatformCustomCursor, PlatformCustomCursorBuilder};
+use crate::platform_impl::PlatformCustomCursorSource;
 use crate::window::{CustomCursor, Window, WindowAttributes};
 
 #[cfg(not(web_platform))]
@@ -200,9 +200,18 @@ pub trait ActiveEventLoopExtWebSys {
     ///
     /// [`ControlFlow::Poll`]: crate::event_loop::ControlFlow::Poll
     fn poll_strategy(&self) -> PollStrategy;
+
+    /// Async version of [`ActiveEventLoop::create_custom_cursor()`] which waits until the
+    /// cursor has completely finished loading.
+    fn create_custom_cursor_async(&self, source: CustomCursorSource) -> CustomCursorFuture;
 }
 
 impl ActiveEventLoopExtWebSys for ActiveEventLoop {
+    #[inline]
+    fn create_custom_cursor_async(&self, source: CustomCursorSource) -> CustomCursorFuture {
+        self.p.create_custom_cursor_async(source)
+    }
+
     #[inline]
     fn set_poll_strategy(&self, strategy: PollStrategy) {
         self.p.set_poll_strategy(strategy);
@@ -249,24 +258,24 @@ pub trait CustomCursorExtWebSys {
     /// but browser support for image formats is inconsistent. Using [PNG] is recommended.
     ///
     /// [PNG]: https://en.wikipedia.org/wiki/PNG
-    fn from_url(url: String, hotspot_x: u16, hotspot_y: u16) -> CustomCursorBuilder;
+    fn from_url(url: String, hotspot_x: u16, hotspot_y: u16) -> CustomCursorSource;
 
     /// Crates a new animated cursor from multiple [`CustomCursor`]s.
     /// Supplied `cursors` can't be empty or other animations.
     fn from_animation(
         duration: Duration,
         cursors: Vec<CustomCursor>,
-    ) -> Result<CustomCursorBuilder, BadAnimation>;
+    ) -> Result<CustomCursorSource, BadAnimation>;
 }
 
 impl CustomCursorExtWebSys for CustomCursor {
     fn is_animation(&self) -> bool {
         self.inner.animation
     }
 
-    fn from_url(url: String, hotspot_x: u16, hotspot_y: u16) -> CustomCursorBuilder {
-        CustomCursorBuilder {
-            inner: PlatformCustomCursorBuilder::Url {
+    fn from_url(url: String, hotspot_x: u16, hotspot_y: u16) -> CustomCursorSource {
+        CustomCursorSource {
+            inner: PlatformCustomCursorSource::Url {
                 url,
                 hotspot_x,
                 hotspot_y,
@@ -277,7 +286,7 @@ impl CustomCursorExtWebSys for CustomCursor {
     fn from_animation(
         duration: Duration,
         cursors: Vec<CustomCursor>,
-    ) -> Result<CustomCursorBuilder, BadAnimation> {
+    ) -> Result<CustomCursorSource, BadAnimation> {
         if cursors.is_empty() {
             return Err(BadAnimation::Empty);
         }
@@ -286,8 +295,8 @@ impl CustomCursorExtWebSys for CustomCursor {
             return Err(BadAnimation::Animation);
         }
 
-        Ok(CustomCursorBuilder {
-            inner: PlatformCustomCursorBuilder::Animation { duration, cursors },
+        Ok(CustomCursorSource {
+            inner: PlatformCustomCursorSource::Animation { duration, cursors },
         })
     }
 }
@@ -312,26 +321,11 @@ impl fmt::Display for BadAnimation {
 
 impl Error for BadAnimation {}
 
-pub trait CustomCursorBuilderExtWebSys {
-    /// Async version of [`CustomCursorBuilder::build()`] which waits until the
-    /// cursor has completely finished loading.
-    fn build_async(self, window_target: &ActiveEventLoop) -> CustomCursorFuture;
-}
-
-impl CustomCursorBuilderExtWebSys for CustomCursorBuilder {
-    fn build_async(self, window_target: &ActiveEventLoop) -> CustomCursorFuture {
-        CustomCursorFuture(PlatformCustomCursor::build_async(
-            self.inner,
-            &window_target.p,
-        ))
-    }
-}
-
 #[cfg(not(web_platform))]
 struct PlatformCustomCursorFuture;
 
 #[derive(Debug)]
-pub struct CustomCursorFuture(PlatformCustomCursorFuture);
+pub struct CustomCursorFuture(pub(crate) PlatformCustomCursorFuture);
 
 impl Future for CustomCursorFuture {
     type Output = Result<CustomCursor, CustomCursorError>;