Web: Window::canvas() now returns a reference

src/changelog/unreleased.md

@@ -76,6 +76,7 @@ changelog entry.
 - Change signature of `EventLoop::run_app`, `EventLoopExtPumpEvents::pump_app_events` and
   `EventLoopExtRunOnDemand::run_app_on_demand` to accept a `impl ApplicationHandler` directly,
   instead of requiring a `&mut` reference to it.
+- On Web, `Window::canvas()` now returns a reference.
 
 ### Removed
 

src/platform/web.rs

@@ -42,6 +42,7 @@
 //! [`WindowEvent::Touch`]: crate::event::WindowEvent::Touch
 //! [`Window::set_outer_position()`]: crate::window::Window::set_outer_position
 
+use std::cell::Ref;
 use std::error::Error;
 use std::fmt::{self, Display, Formatter};
 use std::future::Future;
@@ -74,7 +75,7 @@ pub struct HtmlCanvasElement;
 pub trait WindowExtWeb {
     /// Only returns the canvas if called from inside the window context (the
     /// main thread).
-    fn canvas(&self) -> Option<HtmlCanvasElement>;
+    fn canvas(&self) -> Option<Ref<'_, HtmlCanvasElement>>;
 
     /// Returns [`true`] if calling `event.preventDefault()` is enabled.
     ///
@@ -94,7 +95,7 @@ pub trait WindowExtWeb {
 
 impl WindowExtWeb for Window {
     #[inline]
-    fn canvas(&self) -> Option<HtmlCanvasElement> {
+    fn canvas(&self) -> Option<Ref<'_, HtmlCanvasElement>> {
         self.window.canvas()
     }
 

src/platform_impl/web/event_loop/runner.rs

@@ -55,7 +55,7 @@ struct Execution {
     navigator: Navigator,
     document: Document,
     #[allow(clippy::type_complexity)]
-    all_canvases: RefCell<Vec<(WindowId, Weak<RefCell<backend::Canvas>>, DispatchRunner<Inner>)>>,
+    all_canvases: RefCell<Vec<(WindowId, Weak<backend::Canvas>, DispatchRunner<Inner>)>>,
     redraw_pending: RefCell<HashSet<WindowId>>,
     destroy_pending: RefCell<VecDeque<WindowId>>,
     pub(crate) monitor: Rc<MonitorHandler>,
@@ -121,7 +121,7 @@ impl Runner {
             EventWrapper::Event(event) => (self.event_handler)(event),
             EventWrapper::ScaleChange { canvas, size, scale } => {
                 if let Some(canvas) = canvas.upgrade() {
-                    canvas.borrow().handle_scale_change(
+                    canvas.handle_scale_change(
                         runner,
                         |event| (self.event_handler)(event),
                         size,
@@ -209,7 +209,7 @@ impl Shared {
     pub fn add_canvas(
         &self,
         id: WindowId,
-        canvas: Weak<RefCell<backend::Canvas>>,
+        canvas: Weak<backend::Canvas>,
         runner: DispatchRunner<Inner>,
     ) {
         self.0.all_canvases.borrow_mut().push((id, canvas, runner));
@@ -456,7 +456,7 @@ impl Shared {
                             // - not visible and we don't know if it intersects yet
                             // - visible and intersects
                             if let (false, Some(true) | None) | (true, Some(true)) =
-                                (is_visible, canvas.borrow().is_intersecting)
+                                (is_visible, canvas.is_intersecting.get())
                             {
                                 runner.send_event(Event::WindowEvent {
                                     window_id: *id,
@@ -772,7 +772,6 @@ impl Shared {
             // In case any remaining `Window`s are still not dropped, we will need
             // to explicitly remove the event handlers associated with their canvases.
             if let Some(canvas) = canvas.upgrade() {
-                let mut canvas = canvas.borrow_mut();
                 canvas.remove_listeners();
             }
         }
@@ -816,7 +815,7 @@ impl Shared {
             DeviceEvents::WhenFocused => {
                 self.0.all_canvases.borrow().iter().any(|(_, canvas, _)| {
                     if let Some(canvas) = canvas.upgrade() {
-                        canvas.borrow().has_focus.get()
+                        canvas.has_focus.get()
                     } else {
                         false
                     }
@@ -886,7 +885,7 @@ impl WeakShared {
 
 pub(crate) enum EventWrapper {
     Event(Event),
-    ScaleChange { canvas: Weak<RefCell<backend::Canvas>>, size: PhysicalSize<u32>, scale: f64 },
+    ScaleChange { canvas: Weak<backend::Canvas>, size: PhysicalSize<u32>, scale: f64 },
 }
 
 impl From<Event> for EventWrapper {

src/platform_impl/web/event_loop/window_target.rs

@@ -1,4 +1,4 @@
-use std::cell::{Cell, RefCell};
+use std::cell::Cell;
 use std::clone::Clone;
 use std::iter;
 use std::rc::Rc;
@@ -79,9 +79,8 @@ impl ActiveEventLoop {
         CustomCursorFuture(CustomCursor::new_async(self, source.inner))
     }
 
-    pub fn register(&self, canvas: &Rc<RefCell<backend::Canvas>>, id: WindowId) {
+    pub fn register(&self, canvas: &Rc<backend::Canvas>, id: WindowId) {
         let canvas_clone = canvas.clone();
-        let mut canvas = canvas.borrow_mut();
         #[cfg(any(feature = "rwh_04", feature = "rwh_05"))]
         canvas.set_attribute("data-raw-handle", &id.0.to_string());
 
@@ -604,7 +603,6 @@ impl ActiveEventLoop {
                 let canvas = canvas_clone.clone();
 
                 move |new_size| {
-                    let canvas = canvas.borrow();
                     canvas.set_current_size(new_size);
                     if canvas.old_size() != new_size {
                         canvas.set_old_size(new_size);
@@ -622,15 +620,15 @@ impl ActiveEventLoop {
         canvas.on_intersection(move |is_intersecting| {
             // only fire if visible while skipping the first event if it's intersecting
             if backend::is_visible(runner.document())
-                && !(is_intersecting && canvas_clone.borrow().is_intersecting.is_none())
+                && !(is_intersecting && canvas_clone.is_intersecting.get().is_none())
             {
                 runner.send_event(Event::WindowEvent {
                     window_id: RootWindowId(id),
                     event: WindowEvent::Occluded(!is_intersecting),
                 });
             }
 
-            canvas_clone.borrow_mut().is_intersecting = Some(is_intersecting);
+            canvas_clone.is_intersecting.set(Some(is_intersecting));
         });
 
         let runner = self.runner.clone();