On macOS, fix WindowEvent::Destroyed isn't emitted

CHANGELOG.md

@@ -8,6 +8,7 @@ And please only add new entries to the top of this list, right below the `# Unre
 
 # Unreleased
 
+- On macOS, fix `WindowEvent::Destroyed` isn't emitted when the window is dropped.
 - On Windows and macOS, add `Window::title` to query the current window title.
 - On Windows, fix focusing menubar when pressing `Alt`.
 - On MacOS, made `accepts_first_mouse` configurable.

src/event.rs

@@ -331,6 +331,9 @@ pub enum WindowEvent<'a> {
     CloseRequested,
 
     /// The window has been destroyed.
+    ///
+    /// However, it won't get emitted if the window is closed by the event loop set to exit.
+    /// Use [`Event::LoopDestroyed`] to check such behaviour instead.
     Destroyed,
 
     /// A file has been dropped into the window.

src/platform_impl/macos/mod.rs

@@ -51,13 +51,13 @@ pub(crate) const DEVICE_ID: RootDeviceId = RootDeviceId(DeviceId);
 pub(crate) struct Window {
     pub(crate) window: Id<WinitWindow, Shared>,
     // We keep this around so that it doesn't get dropped until the window does.
-    _delegate: Id<WinitWindowDelegate, Shared>,
+    pub(crate) delegate: Id<WinitWindowDelegate, Shared>,
 }
 
 impl Drop for Window {
     fn drop(&mut self) {
         // Ensure the window is closed
-        util::close_async(Id::into_super(self.window.clone()));
+        util::close_async(self.delegate.clone());
     }
 }
 
@@ -84,8 +84,8 @@ impl Window {
         attributes: WindowAttributes,
         pl_attribs: PlatformSpecificWindowBuilderAttributes,
     ) -> Result<Self, RootOsError> {
-        let (window, _delegate) = autoreleasepool(|_| WinitWindow::new(attributes, pl_attribs))?;
-        Ok(Window { window, _delegate })
+        let (window, delegate) = autoreleasepool(|_| WinitWindow::new(attributes, pl_attribs))?;
+        Ok(Window { window, delegate })
     }
 }
 

src/platform_impl/macos/util/async.rs

@@ -6,6 +6,7 @@ use dispatch::Queue;
 use objc2::foundation::{is_main_thread, CGFloat, NSPoint, NSSize, NSString};
 use objc2::rc::{autoreleasepool, Id, Shared};
 
+use crate::platform_impl::platform::window_delegate::WinitWindowDelegate;
 use crate::{
     dpi::LogicalSize,
     platform_impl::platform::{
@@ -218,11 +219,11 @@ pub(crate) fn set_title_async(window: &NSWindow, title: String) {
 //
 // ArturKovacs: It's important that this operation keeps the underlying window alive
 // through the `Id` because otherwise it would dereference free'd memory
-pub(crate) fn close_async(window: Id<NSWindow, Shared>) {
-    let window = MainThreadSafe(window);
+pub(crate) fn close_async(delegate: Id<WinitWindowDelegate, Shared>) {
+    let delegate = MainThreadSafe(delegate);
     Queue::main().exec_async(move || {
         autoreleasepool(move |_| {
-            window.close();
+            delegate.window.close();
         });
     });
 }

src/platform_impl/macos/window_delegate.rs

@@ -25,7 +25,7 @@ use crate::{
 declare_class!(
     #[derive(Debug)]
     pub(crate) struct WinitWindowDelegate {
-        window: IvarDrop<Id<WinitWindow, Shared>>,
+        pub(crate) window: IvarDrop<Id<WinitWindow, Shared>>,
 
         // TODO: It's possible for delegate methods to be called asynchronously,
         // causing data races / `RefCell` panics.