On macOS, resize simple fullscreen on window move

Fixes #1118.

CHANGELOG.md

@@ -15,6 +15,7 @@ And please only add new entries to the top of this list, right below the `# Unre
 - On Wayland, fix rounding issues when doing resize.
 - On macOS, fix wrong focused state on startup.
 - On Windows, fix crash on setting taskbar when using Visual Studio debugger.
+- On macOS, resize simple fullscreen windows on windowDidChangeScreen events.
 
 # 0.28.1
 

examples/fullscreen.rs

@@ -5,6 +5,9 @@ use winit::event::{ElementState, Event, KeyboardInput, VirtualKeyCode, WindowEve
 use winit::event_loop::EventLoop;
 use winit::window::{Fullscreen, WindowBuilder};
 
+#[cfg(target_os = "macos")]
+use winit::platform::macos::WindowExtMacOS;
+
 fn main() {
     SimpleLogger::new().init().unwrap();
     let event_loop = EventLoop::new();
@@ -32,6 +35,8 @@ fn main() {
     println!("- Esc\tExit");
     println!("- F\tToggle exclusive fullscreen mode");
     println!("- B\tToggle borderless mode");
+    #[cfg(target_os = "macos")]
+    println!("- C\tToggle simple fullscreen mode");
     println!("- S\tNext screen");
     println!("- M\tNext mode for this screen");
     println!("- D\tToggle window decorations");
@@ -67,6 +72,10 @@ fn main() {
                         println!("Setting mode: {fullscreen:?}");
                         window.set_fullscreen(fullscreen);
                     }
+                    #[cfg(target_os = "macos")]
+                    VirtualKeyCode::C => {
+                        window.set_simple_fullscreen(!window.simple_fullscreen());
+                    }
                     VirtualKeyCode::S => {
                         monitor_index += 1;
                         if let Some(mon) = elwt.available_monitors().nth(monitor_index) {

src/platform_impl/macos/window.rs

@@ -150,7 +150,7 @@ pub struct SharedState {
     pub(crate) target_fullscreen: Option<Option<Fullscreen>>,
     pub maximized: bool,
     pub standard_frame: Option<NSRect>,
-    is_simple_fullscreen: bool,
+    pub(crate) is_simple_fullscreen: bool,
     pub saved_style: Option<NSWindowStyleMask>,
     /// Presentation options saved before entering `set_simple_fullscreen`, and
     /// restored upon exiting it. Also used when transitioning from Borderless to
@@ -1317,6 +1317,10 @@ impl WindowExtMacOS for WinitWindow {
             // Tell our window's state that we're in fullscreen
             shared_state_lock.is_simple_fullscreen = true;
 
+            // Drop shared state lock before calling app.setPresentationOptions, because
+            // it will call our windowDidChangeScreen listener which reacquires the lock
+            drop(shared_state_lock);
+
             // Simulate pre-Lion fullscreen by hiding the dock and menu bar
             let presentation_options =
                 NSApplicationPresentationOptions::NSApplicationPresentationAutoHideDock
@@ -1341,11 +1345,17 @@ impl WindowExtMacOS for WinitWindow {
             self.set_style_mask_sync(new_mask);
             shared_state_lock.is_simple_fullscreen = false;
 
-            if let Some(presentation_opts) = shared_state_lock.save_presentation_opts {
+            let save_presentation_opts = shared_state_lock.save_presentation_opts;
+            let frame = shared_state_lock.saved_standard_frame();
+
+            // Drop shared state lock before calling app.setPresentationOptions, because
+            // it will call our windowDidChangeScreen listener which reacquires the lock
+            drop(shared_state_lock);
+
+            if let Some(presentation_opts) = save_presentation_opts {
                 app.setPresentationOptions(presentation_opts);
             }
 
-            let frame = shared_state_lock.saved_standard_frame();
             self.setFrame_display(frame, true);
             self.setMovable(true);
 

src/platform_impl/macos/window_delegate.rs

@@ -409,6 +409,20 @@ declare_class!(
                 self.queue_event(WindowEvent::ThemeChanged(theme));
             }
         }
+
+        #[sel(windowDidChangeScreen:)]
+        fn window_did_change_screen(&self, _: Option<&Object>) {
+            trace_scope!("windowDidChangeScreen:");
+            let is_simple_fullscreen = self
+                .window
+                .lock_shared_state("window_did_change_screen")
+                .is_simple_fullscreen;
+            if is_simple_fullscreen {
+                if let Some(screen) = self.window.screen() {
+                    self.window.setFrame_display(screen.frame(), true);
+                }
+            }
+        }
     }
 );