api: make EventLoopProxy wrap an opaque type

The proxy is intended to be Clone, thus use `Arc` for it internally and don't require backends for it to be `Clone`. Use `EventLoopProxyProvider` to hide the backend's proxy implementation details. Co-authored-by: daxpedda <[email protected]>
rust-windowing · Nov 12, 2024 · 3a60cba · 3a60cba
1 parent ae4c449
commit 3a60cba
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Showing 24 changed files with 256 additions and 307 deletions.
diff --git a/src/event_loop.rs b/src/event_loop.rs
@@ -13,6 +13,7 @@ use std::marker::PhantomData;
 #[cfg(any(x11_platform, wayland_platform))]
 use std::os::unix::io::{AsFd, AsRawFd, BorrowedFd, RawFd};
 use std::sync::atomic::{AtomicBool, AtomicUsize, Ordering};
+use std::sync::Arc;
 #[cfg(not(web_platform))]
 use std::time::{Duration, Instant};
 
@@ -452,10 +453,21 @@ impl rwh_06::HasDisplayHandle for OwnedDisplayHandle {
     }
 }
 
+pub(crate) trait EventLoopProxyProvider: Send + Sync {
+    /// See [`EventLoopProxy::wake_up`] for details.
+    fn wake_up(&self);
+}
+
 /// Control the [`EventLoop`], possibly from a different thread, without referencing it directly.
 #[derive(Clone)]
 pub struct EventLoopProxy {
-    pub(crate) event_loop_proxy: platform_impl::EventLoopProxy,
+    pub(crate) proxy: Arc<dyn EventLoopProxyProvider>,
+}
+
+impl fmt::Debug for EventLoopProxy {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("EventLoopProxy").finish_non_exhaustive()
+    }
 }
 
 impl EventLoopProxy {
@@ -475,13 +487,11 @@ impl EventLoopProxy {
     ///
     /// [#3687]: https://github.com/rust-windowing/winit/pull/3687
     pub fn wake_up(&self) {
-        self.event_loop_proxy.wake_up();
+        self.proxy.wake_up();
     }
-}
 
-impl fmt::Debug for EventLoopProxy {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_struct("ActiveEventLoop").finish_non_exhaustive()
+    pub(crate) fn new(proxy: Arc<dyn EventLoopProxyProvider>) -> Self {
+        Self { proxy }
     }
 }
 

diff --git a/src/platform_impl/android/mod.rs b/src/platform_impl/android/mod.rs
@@ -18,7 +18,8 @@ use crate::error::{EventLoopError, NotSupportedError, RequestError};
 use crate::event::{self, DeviceId, FingerId, Force, StartCause, SurfaceSizeWriter};
 use crate::event_loop::{
     ActiveEventLoop as RootActiveEventLoop, ControlFlow, DeviceEvents,
-    EventLoopProxy as RootEventLoopProxy, OwnedDisplayHandle as RootOwnedDisplayHandle,
+    EventLoopProxy as CoreEventLoopProxy, EventLoopProxyProvider,
+    OwnedDisplayHandle as RootOwnedDisplayHandle,
 };
 use crate::monitor::MonitorHandle as RootMonitorHandle;
 use crate::platform::pump_events::PumpStatus;
@@ -131,12 +132,13 @@ impl EventLoop {
     pub(crate) fn new(
         attributes: &PlatformSpecificEventLoopAttributes,
     ) -> Result<Self, EventLoopError> {
-        let proxy_wake_up = Arc::new(AtomicBool::new(false));
-
         let android_app = attributes.android_app.as_ref().expect(
             "An `AndroidApp` as passed to android_main() is required to create an `EventLoop` on \
              Android",
         );
+
+        let event_loop_proxy = Arc::new(EventLoopProxy::new(android_app.create_waker()));
+
         let redraw_flag = SharedFlag::new();
 
         Ok(Self {
@@ -147,7 +149,7 @@ impl EventLoop {
                 control_flow: Cell::new(ControlFlow::default()),
                 exit: Cell::new(false),
                 redraw_requester: RedrawRequester::new(&redraw_flag, android_app.create_waker()),
-                proxy_wake_up,
+                event_loop_proxy,
             },
             redraw_flag,
             loop_running: false,
@@ -276,7 +278,7 @@ impl EventLoop {
             },
         }
 
-        if self.window_target.proxy_wake_up.swap(false, Ordering::Relaxed) {
+        if self.window_target.event_loop_proxy.wake_up.swap(false, Ordering::Relaxed) {
             app.proxy_wake_up(&self.window_target);
         }
 
@@ -562,7 +564,8 @@ impl EventLoop {
         self.pending_redraw |= self.redraw_flag.get_and_reset();
 
         timeout = if self.running
-            && (self.pending_redraw || self.window_target.proxy_wake_up.load(Ordering::Relaxed))
+            && (self.pending_redraw
+                || self.window_target.event_loop_proxy.wake_up.load(Ordering::Relaxed))
         {
             // If we already have work to do then we don't want to block on the next poll
             Some(Duration::ZERO)
@@ -595,7 +598,7 @@ impl EventLoop {
                     self.pending_redraw |= self.redraw_flag.get_and_reset();
                     if !self.running
                         || (!self.pending_redraw
-                            && !self.window_target.proxy_wake_up.load(Ordering::Relaxed))
+                            && !self.window_target.event_loop_proxy.wake_up.load(Ordering::Relaxed))
                     {
                         return;
                     }
@@ -634,15 +637,20 @@ impl EventLoop {
     }
 }
 
-#[derive(Clone)]
 pub struct EventLoopProxy {
-    proxy_wake_up: Arc<AtomicBool>,
+    wake_up: AtomicBool,
     waker: AndroidAppWaker,
 }
 
 impl EventLoopProxy {
-    pub fn wake_up(&self) {
-        self.proxy_wake_up.store(true, Ordering::Relaxed);
+    fn new(waker: AndroidAppWaker) -> Self {
+        Self { wake_up: AtomicBool::new(false), waker }
+    }
+}
+
+impl EventLoopProxyProvider for EventLoopProxy {
+    fn wake_up(&self) {
+        self.wake_up.store(true, Ordering::Relaxed);
         self.waker.wake();
     }
 }
@@ -652,7 +660,7 @@ pub struct ActiveEventLoop {
     control_flow: Cell<ControlFlow>,
     exit: Cell<bool>,
     redraw_requester: RedrawRequester,
-    proxy_wake_up: Arc<AtomicBool>,
+    event_loop_proxy: Arc<EventLoopProxy>,
 }
 
 impl ActiveEventLoop {
@@ -662,12 +670,8 @@ impl ActiveEventLoop {
 }
 
 impl RootActiveEventLoop for ActiveEventLoop {
-    fn create_proxy(&self) -> RootEventLoopProxy {
-        let event_loop_proxy = EventLoopProxy {
-            proxy_wake_up: self.proxy_wake_up.clone(),
-            waker: self.app.create_waker(),
-        };
-        RootEventLoopProxy { event_loop_proxy }
+    fn create_proxy(&self) -> CoreEventLoopProxy {
+        CoreEventLoopProxy::new(self.event_loop_proxy.clone())
     }
 
     fn create_window(

diff --git a/src/platform_impl/apple/appkit/app_state.rs b/src/platform_impl/apple/appkit/app_state.rs
@@ -1,15 +1,15 @@
 use std::cell::{Cell, OnceCell, RefCell};
 use std::mem;
 use std::rc::{Rc, Weak};
-use std::sync::atomic::{AtomicBool, Ordering as AtomicOrdering};
+use std::sync::atomic::Ordering as AtomicOrdering;
 use std::sync::Arc;
 use std::time::Instant;
 
 use objc2_app_kit::{NSApplication, NSApplicationActivationPolicy};
 use objc2_foundation::{MainThreadMarker, NSNotification};
 
 use super::super::event_handler::EventHandler;
-use super::event_loop::{stop_app_immediately, ActiveEventLoop, PanicInfo};
+use super::event_loop::{stop_app_immediately, ActiveEventLoop, EventLoopProxy, PanicInfo};
 use super::menu;
 use super::observer::{EventLoopWaker, RunLoop};
 use crate::application::ApplicationHandler;
@@ -24,7 +24,7 @@ pub(super) struct AppState {
     default_menu: bool,
     activate_ignoring_other_apps: bool,
     run_loop: RunLoop,
-    proxy_wake_up: Arc<AtomicBool>,
+    event_loop_proxy: Arc<EventLoopProxy>,
     event_handler: EventHandler,
     stop_on_launch: Cell<bool>,
     stop_before_wait: Cell<bool>,
@@ -72,7 +72,7 @@ impl AppState {
         let this = Rc::new(AppState {
             mtm,
             activation_policy,
-            proxy_wake_up: Arc::new(AtomicBool::new(false)),
+            event_loop_proxy: Arc::new(EventLoopProxy::new()),
             default_menu,
             activate_ignoring_other_apps,
             run_loop: RunLoop::main(mtm),
@@ -165,8 +165,8 @@ impl AppState {
         self.event_handler.set(handler, closure)
     }
 
-    pub fn proxy_wake_up(&self) -> Arc<AtomicBool> {
-        self.proxy_wake_up.clone()
+    pub fn event_loop_proxy(&self) -> &Arc<EventLoopProxy> {
+        &self.event_loop_proxy
     }
 
     /// If `pump_events` is called to progress the event loop then we
@@ -350,7 +350,7 @@ impl AppState {
             return;
         }
 
-        if self.proxy_wake_up.swap(false, AtomicOrdering::Relaxed) {
+        if self.event_loop_proxy.wake_up.swap(false, AtomicOrdering::Relaxed) {
             self.with_handler(|app, event_loop| app.proxy_wake_up(event_loop));
         }
 

diff --git a/src/platform_impl/apple/appkit/event_loop.rs b/src/platform_impl/apple/appkit/event_loop.rs
@@ -5,7 +5,6 @@ use std::panic::{catch_unwind, resume_unwind, RefUnwindSafe, UnwindSafe};
 use std::ptr;
 use std::rc::{Rc, Weak};
 use std::sync::atomic::{AtomicBool, Ordering as AtomicOrdering};
-use std::sync::Arc;
 use std::time::{Duration, Instant};
 
 use core_foundation::base::{CFIndex, CFRelease};
@@ -32,7 +31,8 @@ use crate::application::ApplicationHandler;
 use crate::error::{EventLoopError, RequestError};
 use crate::event_loop::{
     ActiveEventLoop as RootActiveEventLoop, ControlFlow, DeviceEvents,
-    EventLoopProxy as RootEventLoopProxy, OwnedDisplayHandle as RootOwnedDisplayHandle,
+    EventLoopProxy as CoreEventLoopProxy, EventLoopProxyProvider,
+    OwnedDisplayHandle as RootOwnedDisplayHandle,
 };
 use crate::monitor::MonitorHandle as RootMonitorHandle;
 use crate::platform::macos::ActivationPolicy;
@@ -95,9 +95,8 @@ impl ActiveEventLoop {
 }
 
 impl RootActiveEventLoop for ActiveEventLoop {
-    fn create_proxy(&self) -> RootEventLoopProxy {
-        let event_loop_proxy = EventLoopProxy::new(self.app_state.proxy_wake_up());
-        RootEventLoopProxy { event_loop_proxy }
+    fn create_proxy(&self) -> CoreEventLoopProxy {
+        CoreEventLoopProxy::new(self.app_state.event_loop_proxy().clone())
     }
 
     fn create_window(
@@ -436,8 +435,9 @@ pub fn stop_app_on_panic<F: FnOnce() -> R + UnwindSafe, R>(
     }
 }
 
+#[derive(Debug)]
 pub struct EventLoopProxy {
-    proxy_wake_up: Arc<AtomicBool>,
+    pub(crate) wake_up: AtomicBool,
     source: CFRunLoopSourceRef,
 }
 
@@ -452,14 +452,8 @@ impl Drop for EventLoopProxy {
     }
 }
 
-impl Clone for EventLoopProxy {
-    fn clone(&self) -> Self {
-        EventLoopProxy::new(self.proxy_wake_up.clone())
-    }
-}
-
 impl EventLoopProxy {
-    fn new(proxy_wake_up: Arc<AtomicBool>) -> Self {
+    pub(crate) fn new() -> Self {
         unsafe {
             // just wake up the eventloop
             extern "C" fn event_loop_proxy_handler(_: *const c_void) {}
@@ -483,14 +477,16 @@ impl EventLoopProxy {
             CFRunLoopAddSource(rl, source, kCFRunLoopCommonModes);
             CFRunLoopWakeUp(rl);
 
-            EventLoopProxy { proxy_wake_up, source }
+            EventLoopProxy { wake_up: AtomicBool::new(false), source }
         }
     }
+}
 
-    pub fn wake_up(&self) {
-        self.proxy_wake_up.store(true, AtomicOrdering::Relaxed);
+impl EventLoopProxyProvider for EventLoopProxy {
+    fn wake_up(&self) {
+        self.wake_up.store(true, AtomicOrdering::Relaxed);
         unsafe {
-            // let the main thread know there's a new event
+            // Let the main thread know there's a new event.
             CFRunLoopSourceSignal(self.source);
             let rl = CFRunLoopGetMain();
             CFRunLoopWakeUp(rl);

diff --git a/src/platform_impl/apple/appkit/mod.rs b/src/platform_impl/apple/appkit/mod.rs
@@ -17,8 +17,7 @@ mod window_delegate;
 pub(crate) use self::cursor::CustomCursor as PlatformCustomCursor;
 pub(crate) use self::event::{physicalkey_to_scancode, scancode_to_physicalkey, KeyEventExtra};
 pub(crate) use self::event_loop::{
-    ActiveEventLoop, EventLoop, EventLoopProxy, OwnedDisplayHandle,
-    PlatformSpecificEventLoopAttributes,
+    ActiveEventLoop, EventLoop, OwnedDisplayHandle, PlatformSpecificEventLoopAttributes,
 };
 pub(crate) use self::monitor::{MonitorHandle, VideoModeHandle};
 pub(crate) use self::window::Window;

diff --git a/src/platform_impl/apple/uikit/app_state.rs b/src/platform_impl/apple/uikit/app_state.rs
@@ -3,7 +3,7 @@
 use std::cell::{OnceCell, RefCell, RefMut};
 use std::collections::HashSet;
 use std::os::raw::c_void;
-use std::sync::atomic::{AtomicBool, Ordering};
+use std::sync::atomic::Ordering;
 use std::sync::{Arc, Mutex, OnceLock};
 use std::time::Instant;
 use std::{mem, ptr};
@@ -24,7 +24,7 @@ use objc2_ui_kit::{UIApplication, UICoordinateSpace, UIView, UIWindow};
 
 use super::super::event_handler::EventHandler;
 use super::window::WinitUIWindow;
-use super::ActiveEventLoop;
+use super::{ActiveEventLoop, EventLoopProxy};
 use crate::application::ApplicationHandler;
 use crate::dpi::PhysicalSize;
 use crate::event::{Event, StartCause, SurfaceSizeWriter, WindowEvent};
@@ -139,7 +139,7 @@ pub(crate) struct AppState {
     app_state: Option<AppStateImpl>,
     control_flow: ControlFlow,
     waker: EventLoopWaker,
-    proxy_wake_up: Arc<AtomicBool>,
+    event_loop_proxy: Arc<EventLoopProxy>,
 }
 
 impl AppState {
@@ -164,7 +164,7 @@ impl AppState {
                     }),
                     control_flow: ControlFlow::default(),
                     waker,
-                    proxy_wake_up: Arc::new(AtomicBool::new(false)),
+                    event_loop_proxy: Arc::new(EventLoopProxy::new()),
                 });
             }
             init_guard(&mut guard);
@@ -376,8 +376,8 @@ impl AppState {
         }
     }
 
-    pub(crate) fn proxy_wake_up(&self) -> Arc<AtomicBool> {
-        self.proxy_wake_up.clone()
+    pub fn event_loop_proxy(&self) -> &Arc<EventLoopProxy> {
+        &self.event_loop_proxy
     }
 
     pub(crate) fn set_control_flow(&mut self, control_flow: ControlFlow) {
@@ -543,10 +543,10 @@ fn handle_user_events(mtm: MainThreadMarker) {
     if processing_redraws {
         bug!("user events attempted to be sent out while `ProcessingRedraws`");
     }
-    let proxy_wake_up = this.proxy_wake_up.clone();
+    let event_loop_proxy = this.event_loop_proxy().clone();
     drop(this);
 
-    if proxy_wake_up.swap(false, Ordering::Relaxed) {
+    if event_loop_proxy.wake_up.swap(false, Ordering::Relaxed) {
         handle_event(mtm, Event::UserWakeUp);
     }
 
@@ -578,7 +578,7 @@ fn handle_user_events(mtm: MainThreadMarker) {
             }
         }
 
-        if proxy_wake_up.swap(false, Ordering::Relaxed) {
+        if event_loop_proxy.wake_up.swap(false, Ordering::Relaxed) {
             handle_event(mtm, Event::UserWakeUp);
         }
     }