 cfcb56f5b9
			
		
	
	
		cfcb56f5b9
		
			
		
	
	
	
	
		
			
			# Objective
- Continue to pare down the uses on NonSend resources in the engine. In
this case, EventLoopProxy used to be `!Sync`, but is now `Sync` in the
latest version of winit.
## Solution
- New type `EventLoopProxy` as `EventLoopProxyWrapper` to make it into a
normal resource.
- Update the `custom_user_event` example as it no longer needs to
indirectly access the `EventLoopProxy` through a static variable
anymore.
## Testing
- Ran the example. The resource exists just for users to use, so there
aren't any in engine uses for it currently.
---
## Changelog
- make EventLoopProxy into a regular resource. 
## Migration Guide
`EventLoopProxy` has been renamed to `EventLoopProxyWrapper` and is now
`Send`, making it an ordinary resource.
Before:
```rust
event_loop_system(event_loop: NonSend<EventLoopProxy<MyEvent>>) {
    event_loop.send_event(MyEvent);
}
```
After:
```rust
event_loop_system(event_loop: Res<EventLoopProxy<MyEvent>>) {
    event_loop.send_event(MyEvent);
}
```
		
	
			
		
			
				
	
	
		
			113 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			Rust
		
	
	
	
	
	
			
		
		
	
	
			113 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			Rust
		
	
	
	
	
	
| //! Shows how to create a custom event that can be handled by `winit`'s event loop.
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| 
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| use bevy::prelude::*;
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| use bevy::winit::{EventLoopProxyWrapper, WakeUp, WinitPlugin};
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| use std::fmt::Formatter;
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| 
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| #[derive(Default, Debug, Event)]
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| enum CustomEvent {
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|     #[default]
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|     WakeUp,
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|     Key(char),
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| }
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| 
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| impl std::fmt::Display for CustomEvent {
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|     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
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|         match self {
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|             Self::WakeUp => write!(f, "Wake up"),
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|             Self::Key(ch) => write!(f, "Key: {ch}"),
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|         }
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|     }
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| }
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| 
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| fn main() {
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|     let winit_plugin = WinitPlugin::<CustomEvent>::default();
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| 
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|     App::new()
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|         .add_plugins(
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|             DefaultPlugins
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|                 .build()
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|                 // Only one event type can be handled at once
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|                 // so we must disable the default event type
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|                 .disable::<WinitPlugin<WakeUp>>()
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|                 .add(winit_plugin),
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|         )
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|         .add_systems(
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|             Startup,
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|             (
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|                 setup,
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|                 #[cfg(target_arch = "wasm32")]
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|                 wasm::setup_js_closure,
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|             ),
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|         )
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|         .add_systems(Update, (send_event, handle_event))
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|         .run();
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| }
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| 
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| fn setup(mut commands: Commands) {
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|     commands.spawn(Camera2dBundle::default());
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| }
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| 
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| fn send_event(
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|     input: Res<ButtonInput<KeyCode>>,
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|     event_loop_proxy: Res<EventLoopProxyWrapper<CustomEvent>>,
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| ) {
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|     if input.just_pressed(KeyCode::Space) {
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|         let _ = event_loop_proxy.send_event(CustomEvent::WakeUp);
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|     }
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| 
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|     // This simulates sending a custom event through an external thread.
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|     #[cfg(not(target_arch = "wasm32"))]
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|     if input.just_pressed(KeyCode::KeyE) {
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|         let event_loop_proxy = event_loop_proxy.clone();
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|         let handler = std::thread::spawn(move || {
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|             let _ = event_loop_proxy.clone().send_event(CustomEvent::Key('e'));
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|         });
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| 
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|         handler.join().unwrap();
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|     }
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| }
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| 
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| fn handle_event(mut events: EventReader<CustomEvent>) {
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|     for evt in events.read() {
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|         info!("Received event: {evt:?}");
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|     }
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| }
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| 
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| /// Since the [`EventLoopProxy`] can be exposed to the javascript environment, it can
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| /// be used to send events inside the loop, to be handled by a system or simply to wake up
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| /// the loop if that's currently waiting for a timeout or a user event.
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| #[cfg(target_arch = "wasm32")]
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| pub(crate) mod wasm {
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|     use super::*;
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|     use bevy::winit::EventLoopProxy;
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|     use wasm_bindgen::prelude::*;
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|     use wasm_bindgen::JsCast;
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|     use web_sys::KeyboardEvent;
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| 
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|     pub(crate) fn setup_js_closure(event_loop: Res<EventLoopProxyWrapper<CustomEvent>>) {
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|         let window = web_sys::window().unwrap();
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|         let document = window.document().unwrap();
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| 
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|         let event_loop = event_loop.clone();
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|         let closure = Closure::wrap(Box::new(move |event: KeyboardEvent| {
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|             let key = event.key();
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|             if key == "e" {
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|                 send_custom_event('e', &event_loop).unwrap();
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|             }
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|         }) as Box<dyn FnMut(KeyboardEvent)>);
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| 
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|         document
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|             .add_event_listener_with_callback("keydown", closure.as_ref().unchecked_ref())
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|             .unwrap();
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| 
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|         closure.forget();
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|     }
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| 
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|     fn send_custom_event(ch: char, proxy: &EventLoopProxy<CustomEvent>) -> Result<(), String> {
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|         proxy
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|             .send_event(CustomEvent::Key(ch))
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|             .map_err(|_| "Failed to send event".to_string())
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|     }
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| }
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