Fix missed RedrawRequested and WindowCloseRequested events with UpdateMode::Reactive (part 2)

Cargo.toml

@@ -3635,6 +3635,15 @@ doc-scrape-examples = true
 [package.metadata.example.minimizing]
 hidden = true
 
+[[example]]
+name = "desktop_request_redraw"
+path = "tests/window/desktop_request_redraw.rs"
+doc-scrape-examples = true
+required-features = ["bevy_dev_tools"]
+
+[package.metadata.example.desktop_request_redraw]
+hidden = true
+
 [[example]]
 name = "window_resizing"
 path = "examples/window/window_resizing.rs"

crates/bevy_winit/src/state.rs

@@ -537,16 +537,11 @@ impl<T: Event> ApplicationHandler<T> for WinitAppRunnerState<T> {
 impl<T: Event> WinitAppRunnerState<T> {
     fn redraw_requested(&mut self, event_loop: &ActiveEventLoop) {
         let mut redraw_event_reader = EventCursor::<RequestRedraw>::default();
+        let mut close_event_reader = EventCursor::<WindowCloseRequested>::default();
 
         let mut focused_windows_state: SystemState<(Res<WinitSettings>, Query<(Entity, &Window)>)> =
             SystemState::new(self.world_mut());
 
-        if let Some(app_redraw_events) = self.world().get_resource::<Events<RequestRedraw>>() {
-            if redraw_event_reader.read(app_redraw_events).last().is_some() {
-                self.redraw_requested = true;
-            }
-        }
-
         let (config, windows) = focused_windows_state.get(self.world());
         let focused = windows.iter().any(|(_, window)| window.focused);
 
@@ -655,6 +650,26 @@ impl<T: Event> WinitAppRunnerState<T> {
                 self.redraw_requested = true;
             }
 
+            // Read RequestRedraw events that may have been sent during the update
+            if let Some(app_redraw_events) = self.world().get_resource::<Events<RequestRedraw>>() {
+                if redraw_event_reader.read(app_redraw_events).last().is_some() {
+                    self.redraw_requested = true;
+                }
+            }
+
+            // Running the app may have produced WindowCloseRequested events that should be processed
+            if let Some(close_request_events) =
+                self.world().get_resource::<Events<WindowCloseRequested>>()
+            {
+                if close_event_reader
+                    .read(close_request_events)
+                    .last()
+                    .is_some()
+                {
+                    self.redraw_requested = true;
+                }
+            }
+
             // Running the app may have changed the WinitSettings resource, so we have to re-extract it.
             let (config, windows) = focused_windows_state.get(self.world());
             let focused = windows.iter().any(|(_, window)| window.focused);

tests/window/desktop_request_redraw.rs

@@ -0,0 +1,109 @@
+//! Desktop request redraw
+use bevy::{
+    dev_tools::fps_overlay::{FpsOverlayConfig, FpsOverlayPlugin},
+    prelude::*,
+    window::RequestRedraw,
+    winit::WinitSettings,
+};
+
+fn main() {
+    App::new()
+        .add_plugins(DefaultPlugins)
+        .add_plugins(MeshPickingPlugin)
+        // Enable the FPS overlay with a high resolution refresh interval. This makes it
+        // easier to validate that UpdateMode is behaving correctly when desktop_app is used.
+        // The FPS counter should essentially pause when the cube is not rotating and should
+        // update rapidly when the cube is rotating or there is input (e.g. moving the mouse).
+        //
+        // Left and Right clicking the cube should roggle rotation on/off.
+        .add_plugins(FpsOverlayPlugin {
+            config: FpsOverlayConfig {
+                text_config: TextFont {
+                    font_size: 12.0,
+                    ..default()
+                },
+                text_color: Color::srgb(0.0, 1.0, 0.0),
+                refresh_interval: core::time::Duration::from_millis(16),
+                ..default()
+            },
+        })
+        .insert_resource(WinitSettings::desktop_app())
+        .add_systems(Startup, setup)
+        .add_systems(Update, (update, redraw.after(update)))
+        .run();
+}
+
+#[derive(Component)]
+struct AnimationActive;
+
+fn setup(
+    mut commands: Commands,
+    mut meshes: ResMut<Assets<Mesh>>,
+    mut materials: ResMut<Assets<StandardMaterial>>,
+) {
+    commands.spawn((
+        Camera3d::default(),
+        Transform::from_xyz(0.0, 5.0, 0.0).looking_at(Vec3::ZERO, Vec3::Y),
+    ));
+
+    commands.spawn((
+        PointLight {
+            intensity: 1e6,
+            ..Default::default()
+        },
+        Transform::from_xyz(-1.0, 5.0, 1.0),
+    ));
+
+    let node = Node {
+        display: Display::Block,
+        padding: UiRect::all(Val::Px(10.0)),
+        row_gap: Val::Px(10.0),
+        ..Default::default()
+    };
+
+    commands.spawn((
+        node.clone(),
+        children![
+            (
+                node.clone(),
+                children![Text::new("Right click cube to pause animation")]
+            ),
+            (
+                node.clone(),
+                children![Text::new("Left click cube to start animation")]
+            )
+        ],
+    ));
+
+    commands
+        .spawn((
+            Mesh3d(meshes.add(Cuboid::from_length(1.0))),
+            MeshMaterial3d(materials.add(Color::WHITE)),
+            AnimationActive,
+        ))
+        .observe(
+            |trigger: Trigger<Pointer<Click>>, mut commands: Commands| match trigger.button {
+                PointerButton::Primary => {
+                    commands.entity(trigger.target()).insert(AnimationActive);
+                }
+                PointerButton::Secondary => {
+                    commands
+                        .entity(trigger.target())
+                        .remove::<AnimationActive>();
+                }
+                _ => {}
+            },
+        );
+}
+
+fn update(time: Res<Time>, mut query: Query<&mut Transform, With<AnimationActive>>) {
+    if let Ok(mut transform) = query.single_mut() {
+        transform.rotate_x(time.delta_secs().min(1.0 / 60.0));
+    }
+}
+
+fn redraw(mut commands: Commands, query: Query<Entity, With<AnimationActive>>) {
+    if query.iter().next().is_some() {
+        commands.send_event(RequestRedraw);
+    }
+}