Use removal of window component to signal closing window, some clean …

…up/renaming

crates/bevy_render/src/view/window.rs

@@ -115,7 +115,7 @@ fn extract_windows(
     }
 
     for closed_window in closed.iter() {
-        extracted_windows.remove(&closed_window.entity);
+        extracted_windows.remove(&closed_window.window);
     }
 }
 

crates/bevy_window/src/event.rs

@@ -46,12 +46,14 @@ pub struct WindowCloseRequested {
     pub window: Entity,
 }
 
-/// An event that is sent whenever a window is closed. This will be sent by the
-/// handler for [`WindowCloseRequested`] or similar.
+/// An event that is sent whenever a window is closed. This will be sent by the window
+/// backend
 #[derive(Debug, Clone)]
 pub struct WindowClosed {
     /// Window that has been closed.
-    /// TODO: Does this entity actually exist anymore?
+    ///
+    /// Note that this entity probably no longer exists
+    /// by the time this event is received.
     pub window: Entity,
 }
 /// An event reporting that the mouse cursor has moved inside a window.
@@ -124,7 +126,7 @@ pub struct WindowBackendScaleFactorChanged {
 /// Events related to files being dragged and dropped on a window.
 #[derive(Debug, Clone)]
 pub enum FileDragAndDrop {
-    /// File is being dropped into a window. 
+    /// File is being dropped into a window.
     DroppedFile {
         /// Window the file was dropped into.
         window: Entity,

crates/bevy_window/src/system.rs

@@ -22,7 +22,7 @@ pub fn exit_on_all_closed(mut app_exit_events: EventWriter<AppExit>, windows: Qu
 /// Exit the application when the primary window has been closed
 ///
 /// This system is added by the [`WindowPlugin`]
-/// 
+///
 /// [`WindowPlugin`]: crate::WindowPlugin
 pub fn exit_on_primary_closed(
     mut app_exit_events: EventWriter<AppExit>,
@@ -55,32 +55,27 @@ pub fn exit_on_primary_closed(
 /// Ensure that you read the caveats documented on that field if doing so.
 ///
 /// [`WindowPlugin`]: crate::WindowPlugin
-pub fn close_when_requested(
-    mut closed: EventReader<WindowCloseRequested>,
-    mut window_closed: EventWriter<WindowClosed>,
-) {
+pub fn close_when_requested(mut commands: Commands, mut closed: EventReader<WindowCloseRequested>) {
     for event in closed.iter() {
-        window_closed.send(WindowClosed {
-            window: event.window,
-        });
+        commands.entity(event.window).remove::<Window>();
     }
 }
 
 /// Close the focused window whenever the escape key (<kbd>Esc</kbd>) is pressed
 ///
 /// This is useful for examples or prototyping.
 pub fn close_on_esc(
+    mut commands: Commands,
     focused_windows: Query<(Entity, &WindowFocus)>,
-    mut window_closed: EventWriter<WindowClosed>,
     input: Res<Input<KeyCode>>,
 ) {
-    for (entity, focus) in focused_windows.iter() {
+    for (window, focus) in focused_windows.iter() {
         if !focus.focused() {
             continue;
         }
 
         if input.just_pressed(KeyCode::Escape) {
-            window_closed.send(WindowClosed { window: entity });
+            commands.entity(window).remove::<Window>();
         }
     }
 }

crates/bevy_winit/src/lib.rs

@@ -9,9 +9,9 @@ use core::panic;
 
 use bevy_ecs::system::{SystemParam, SystemState};
 use system::{
-    create_window_system, update_cursor, update_cursor_position, update_resize_constraints,
-    update_resolution, update_title, update_window_mode, update_window_position,
-    update_window_state, window_destroyed,
+    create_window, despawn_window, update_cursor, update_cursor_position,
+    update_resize_constraints, update_resolution, update_title, update_window_mode,
+    update_window_position, update_window_state,
 };
 
 pub use winit_config::*;
@@ -67,7 +67,7 @@ impl Plugin for WinitPlugin {
                     .with_system(update_cursor_position)
                     .with_system(update_resize_constraints),
             )
-            .add_system_to_stage(CoreStage::Last, window_destroyed);
+            .add_system_to_stage(CoreStage::PostUpdate, despawn_window.after(ModifiesWindows));
 
         #[cfg(target_arch = "wasm32")]
         app.add_plugin(web_resize::CanvasParentResizePlugin);
@@ -86,7 +86,7 @@ impl Plugin for WinitPlugin {
             // Here we need to create a winit-window and give it a WindowHandle which the renderer can use.
             // It needs to be spawned before the start of the startup-stage, so we cannot use a regular system.
             // Instead we need to create the window and spawn it using direct world access
-            create_window_system(commands, &**event_loop, new_windows, winit_windows);
+            create_window(commands, &**event_loop, new_windows, winit_windows);
         }
 
         system_state.apply(&mut app.world);
@@ -199,18 +199,13 @@ impl Default for WinitPersistentState {
     }
 }
 
-// TODO: Refactor this to work with new pattern
 pub fn winit_runner(mut app: App) {
-    // TODO: Understand what removing and adding this does
+    // We remove this so that we have ownership over it.
     let mut event_loop = app
         .world
         .remove_non_send_resource::<EventLoop<()>>()
         .unwrap();
-    // let mut create_window_event_reader = app
-    //     .world
-    //     .remove_resource::<WinitCreateWindowReader>()
-    //     .unwrap()
-    //     .0;
+
     let mut app_exit_event_reader = ManualEventReader::<AppExit>::default();
     let mut redraw_event_reader = ManualEventReader::<RequestRedraw>::default();
     let mut winit_state = WinitPersistentState::default();
@@ -600,7 +595,7 @@ pub fn winit_runner(mut app: App) {
                     create_window_system_state.get_mut(&mut app.world);
 
                 // Responsible for creating new windows
-                create_window_system(commands, event_loop, new_windows, winit_windows);
+                create_window(commands, event_loop, new_windows, winit_windows);
 
                 let update = if winit_state.active {
                     // True if _any_ windows are currently being focused

crates/bevy_winit/src/system.rs

@@ -1,8 +1,8 @@
 use bevy_ecs::{
-    entity::Entity,
-    event::EventReader,
+    entity::{Entities, Entity},
+    event::EventWriter,
     prelude::{Added, Changed, With},
-    system::{Commands, NonSendMut, Query, Res},
+    system::{Commands, NonSendMut, Query, RemovedComponents, Res},
 };
 use bevy_utils::tracing::{error, info};
 use bevy_window::{
@@ -22,7 +22,7 @@ use crate::{converters, get_best_videomode, get_fitting_videomode, WinitWindows}
 /// to an entity.
 ///
 /// This will default any necessary components if they are not already added.
-pub fn create_window_system(
+pub fn create_window(
     mut commands: Commands,
     event_loop: &EventLoopWindowTarget<()>,
     created_windows: Query<(Entity, WindowComponents), Added<Window>>,
@@ -58,21 +58,28 @@ pub fn create_window_system(
     }
 }
 
-pub fn window_destroyed(
+pub fn despawn_window(
     mut commands: Commands,
+    entities: &Entities,
     primary: Option<Res<PrimaryWindow>>,
-    mut closed: EventReader<WindowClosed>,
+    closed: RemovedComponents<Window>,
+    mut close_events: EventWriter<WindowClosed>,
     mut winit_windows: NonSendMut<WinitWindows>,
 ) {
-    for event in closed.iter() {
-        winit_windows.remove_window(event.window);
+    for window in closed.iter() {
+        winit_windows.remove_window(window);
+
+        if entities.contains(window) {
+            commands.entity(window).despawn();
+        }
 
-        commands.entity(event.window).despawn();
         if let Some(ref primary) = primary {
-            if primary.window == event.window {
+            if primary.window == window {
                 commands.remove_resource::<PrimaryWindow>();
             }
         }
+
+        close_events.send(WindowClosed { window });
     }
 }
 

crates/bevy_winit/src/winit_windows.rs

@@ -119,8 +119,9 @@ impl WinitWindows {
 
         winit_window.set_cursor_visible(components.cursor.visible());
 
+        // I don't think we can do this immediately with some platforms.
         if components.state.minimized() {
-            winit_window.set_minimized(true);
+            //winit_window.set_minimized(true);
         }
 
         self.window_id_to_winit.insert(entity, winit_window.id());

examples/window/multiple_windows.rs

@@ -8,7 +8,7 @@ use bevy::{
 
 fn main() {
     App::new()
-        // Primary window gets spawned as a result of `DefaultPlugins`
+        // Primary window gets spawned by `DefaultPlugins`
         .add_plugins(DefaultPlugins)
         // A window bundle inserted as a resource acts as the descriptor
         // for a primary window.
@@ -50,6 +50,7 @@ fn setup_extra_windows(mut commands: Commands) {
     let second_window_id = commands
         .spawn_bundle(WindowBundle {
             title: WindowTitle::new("Second window"),
+            // A window can start minimized.
             state: WindowState::Minimized,
             ..Default::default()
         })
@@ -68,6 +69,7 @@ fn setup_extra_windows(mut commands: Commands) {
     let third_window_id = commands
         .spawn_bundle(WindowBundle {
             title: WindowTitle::new("Third window"),
+            // ... or start maximized.
             state: WindowState::Maximized,
             ..Default::default()
         })

examples/window/transparent_window.rs

@@ -15,7 +15,7 @@ fn main() {
         .insert_resource(ClearColor(Color::NONE))
         .insert_resource(WindowBundle {
             // Setting `transparent` allows the `ClearColor`'s alpha value to take effect
-            transparency: WindowTransaprency::Transparent,
+            transparency: WindowTransparency::Transparent,
             // Disabling window decorations to make it feel more like a widget than a window
             decorations: WindowDecorations::Undecorated,
             ..default()