Remove generic parameter T from EventLoopWindowTarget

CHANGELOG.md

@@ -11,6 +11,7 @@ Unreleased` header.
 
 # Unreleased
 
+- **Breaking:** Removed unnecessary generic parameter `T` from `EventLoopWindowTarget`.
 - On Windows, macOS, X11, Wayland and Web, implement setting images as cursors. See the `custom_cursors.rs` example.
   - **Breaking:** Remove `Window::set_cursor_icon`
   - Add `WindowBuilder::with_cursor` and `Window::set_cursor` which takes a `CursorIcon` or `CustomCursor`

examples/child_window.rs

@@ -23,7 +23,7 @@ fn main() -> Result<(), impl std::error::Error> {
 
     fn spawn_child_window(
         parent: &Window,
-        event_loop: &EventLoopWindowTarget<()>,
+        event_loop: &EventLoopWindowTarget,
         windows: &mut HashMap<WindowId, Window>,
     ) {
         let parent = parent.raw_window_handle().unwrap();

examples/custom_cursors.rs

@@ -18,7 +18,7 @@ use {
 #[cfg(wasm_platform)]
 static COUNTER: AtomicU64 = AtomicU64::new(0);
 
-fn decode_cursor<T>(bytes: &[u8], window_target: &EventLoopWindowTarget<T>) -> CustomCursor {
+fn decode_cursor(bytes: &[u8], window_target: &EventLoopWindowTarget) -> CustomCursor {
     let img = image::load_from_memory(bytes).unwrap().to_rgba8();
     let samples = img.into_flat_samples();
     let (_, w, h) = samples.extents();

src/cursor.rs

@@ -111,7 +111,7 @@ pub struct CustomCursorBuilder {
 }
 
 impl CustomCursorBuilder {
-    pub fn build<T>(self, window_target: &EventLoopWindowTarget<T>) -> CustomCursor {
+    pub fn build(self, window_target: &EventLoopWindowTarget) -> CustomCursor {
         CustomCursor {
             inner: PlatformCustomCursor::build(self.inner, &window_target.p),
         }
@@ -213,10 +213,7 @@ impl Eq for OnlyCursorImage {}
 
 #[allow(dead_code)]
 impl OnlyCursorImage {
-    fn build<T>(
-        builder: OnlyCursorImageBuilder,
-        _: &platform_impl::EventLoopWindowTarget<T>,
-    ) -> Self {
+    fn build(builder: OnlyCursorImageBuilder, _: &platform_impl::EventLoopWindowTarget) -> Self {
         Self(Arc::new(builder.0))
     }
 }
@@ -296,7 +293,7 @@ impl NoCustomCursor {
         Ok(Self)
     }
 
-    fn build<T>(self, _: &platform_impl::EventLoopWindowTarget<T>) -> NoCustomCursor {
+    fn build(self, _: &platform_impl::EventLoopWindowTarget) -> NoCustomCursor {
         self
     }
 }

src/event_loop.rs

@@ -48,9 +48,9 @@ pub struct EventLoop<T: 'static> {
 /// your callback. [`EventLoop`] will coerce into this type (`impl<T> Deref for
 /// EventLoop<T>`), so functions that take this as a parameter can also take
 /// `&EventLoop`.
-pub struct EventLoopWindowTarget<T: 'static> {
-    pub(crate) p: platform_impl::EventLoopWindowTarget<T>,
-    pub(crate) _marker: PhantomData<*mut T>, // Not Send nor Sync + invariant over T
+pub struct EventLoopWindowTarget {
+    pub(crate) p: platform_impl::EventLoopWindowTarget,
+    pub(crate) _marker: PhantomData<*mut ()>, // Not Send nor Sync
 }
 
 /// Object that allows building the event loop.
@@ -142,7 +142,7 @@ impl<T> fmt::Debug for EventLoop<T> {
     }
 }
 
-impl<T> fmt::Debug for EventLoopWindowTarget<T> {
+impl fmt::Debug for EventLoopWindowTarget {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.pad("EventLoopWindowTarget { .. }")
     }
@@ -241,7 +241,7 @@ impl<T> EventLoop<T> {
     #[cfg(not(all(wasm_platform, target_feature = "exception-handling")))]
     pub fn run<F>(self, event_handler: F) -> Result<(), EventLoopError>
     where
-        F: FnMut(Event<T>, &EventLoopWindowTarget<T>),
+        F: FnMut(Event<T>, &EventLoopWindowTarget),
     {
         self.event_loop.run(event_handler)
     }
@@ -298,13 +298,13 @@ impl<T> AsRawFd for EventLoop<T> {
 }
 
 impl<T> Deref for EventLoop<T> {
-    type Target = EventLoopWindowTarget<T>;
-    fn deref(&self) -> &EventLoopWindowTarget<T> {
+    type Target = EventLoopWindowTarget;
+    fn deref(&self) -> &EventLoopWindowTarget {
         self.event_loop.window_target()
     }
 }
 
-impl<T> EventLoopWindowTarget<T> {
+impl EventLoopWindowTarget {
     /// Returns the list of all the monitors available on the system.
     #[inline]
     pub fn available_monitors(&self) -> impl Iterator<Item = MonitorHandle> {
@@ -370,7 +370,7 @@ impl<T> EventLoopWindowTarget<T> {
 }
 
 #[cfg(feature = "rwh_06")]
-impl<T> rwh_06::HasDisplayHandle for EventLoopWindowTarget<T> {
+impl rwh_06::HasDisplayHandle for EventLoopWindowTarget {
     fn display_handle(&self) -> Result<rwh_06::DisplayHandle<'_>, rwh_06::HandleError> {
         let raw = self.p.raw_display_handle_rwh_06()?;
         // SAFETY: The display will never be deallocated while the event loop is alive.
@@ -379,7 +379,7 @@ impl<T> rwh_06::HasDisplayHandle for EventLoopWindowTarget<T> {
 }
 
 #[cfg(feature = "rwh_05")]
-unsafe impl<T> rwh_05::HasRawDisplayHandle for EventLoopWindowTarget<T> {
+unsafe impl rwh_05::HasRawDisplayHandle for EventLoopWindowTarget {
     /// Returns a [`rwh_05::RawDisplayHandle`] for the event loop.
     fn raw_display_handle(&self) -> rwh_05::RawDisplayHandle {
         self.p.raw_display_handle_rwh_05()

src/platform/android.rs

@@ -30,7 +30,7 @@ impl WindowExtAndroid for Window {
     }
 }
 
-impl<T> EventLoopWindowTargetExtAndroid for EventLoopWindowTarget<T> {}
+impl EventLoopWindowTargetExtAndroid for EventLoopWindowTarget {}
 
 /// Additional methods on [`WindowBuilder`] that are specific to Android.
 pub trait WindowBuilderExtAndroid {}

src/platform/macos.rs

@@ -388,7 +388,7 @@ pub trait EventLoopWindowTargetExtMacOS {
     fn allows_automatic_window_tabbing(&self) -> bool;
 }
 
-impl<T> EventLoopWindowTargetExtMacOS for EventLoopWindowTarget<T> {
+impl EventLoopWindowTargetExtMacOS for EventLoopWindowTarget {
     fn hide_application(&self) {
         self.p.hide_application()
     }

src/platform/pump_events.rs

@@ -174,15 +174,15 @@ pub trait EventLoopExtPumpEvents {
     ///   callback.
     fn pump_events<F>(&mut self, timeout: Option<Duration>, event_handler: F) -> PumpStatus
     where
-        F: FnMut(Event<Self::UserEvent>, &EventLoopWindowTarget<Self::UserEvent>);
+        F: FnMut(Event<Self::UserEvent>, &EventLoopWindowTarget);
 }
 
 impl<T> EventLoopExtPumpEvents for EventLoop<T> {
     type UserEvent = T;
 
     fn pump_events<F>(&mut self, timeout: Option<Duration>, event_handler: F) -> PumpStatus
     where
-        F: FnMut(Event<Self::UserEvent>, &EventLoopWindowTarget<Self::UserEvent>),
+        F: FnMut(Event<Self::UserEvent>, &EventLoopWindowTarget),
     {
         self.event_loop.pump_events(timeout, event_handler)
     }

src/platform/run_on_demand.rs

@@ -66,22 +66,22 @@ pub trait EventLoopExtRunOnDemand {
     /// [`set_control_flow()`]: EventLoopWindowTarget::set_control_flow()
     fn run_on_demand<F>(&mut self, event_handler: F) -> Result<(), EventLoopError>
     where
-        F: FnMut(Event<Self::UserEvent>, &EventLoopWindowTarget<Self::UserEvent>);
+        F: FnMut(Event<Self::UserEvent>, &EventLoopWindowTarget);
 }
 
 impl<T> EventLoopExtRunOnDemand for EventLoop<T> {
     type UserEvent = T;
 
     fn run_on_demand<F>(&mut self, event_handler: F) -> Result<(), EventLoopError>
     where
-        F: FnMut(Event<Self::UserEvent>, &EventLoopWindowTarget<Self::UserEvent>),
+        F: FnMut(Event<Self::UserEvent>, &EventLoopWindowTarget),
     {
         self.event_loop.window_target().clear_exit();
         self.event_loop.run_on_demand(event_handler)
     }
 }
 
-impl<T> EventLoopWindowTarget<T> {
+impl EventLoopWindowTarget {
     /// Clear exit status.
     pub(crate) fn clear_exit(&self) {
         self.p.clear_exit()

src/platform/startup_notify.rs

@@ -55,7 +55,7 @@ pub trait WindowBuilderExtStartupNotify {
     fn with_activation_token(self, token: ActivationToken) -> Self;
 }
 
-impl<T> EventLoopExtStartupNotify for EventLoopWindowTarget<T> {
+impl EventLoopExtStartupNotify for EventLoopWindowTarget {
     fn read_token_from_env(&self) -> Option<ActivationToken> {
         match self.p {
             #[cfg(wayland_platform)]

src/platform/wayland.rs

@@ -12,7 +12,7 @@ pub trait EventLoopWindowTargetExtWayland {
     fn is_wayland(&self) -> bool;
 }
 
-impl<T> EventLoopWindowTargetExtWayland for EventLoopWindowTarget<T> {
+impl EventLoopWindowTargetExtWayland for EventLoopWindowTarget {
     #[inline]
     fn is_wayland(&self) -> bool {
         self.p.is_wayland()

src/platform/web.rs

@@ -172,15 +172,15 @@ pub trait EventLoopExtWebSys {
     /// [^1]: `run()` is _not_ available on WASM when the target supports `exception-handling`.
     fn spawn<F>(self, event_handler: F)
     where
-        F: 'static + FnMut(Event<Self::UserEvent>, &EventLoopWindowTarget<Self::UserEvent>);
+        F: 'static + FnMut(Event<Self::UserEvent>, &EventLoopWindowTarget);
 }
 
 impl<T> EventLoopExtWebSys for EventLoop<T> {
     type UserEvent = T;
 
     fn spawn<F>(self, event_handler: F)
     where
-        F: 'static + FnMut(Event<Self::UserEvent>, &EventLoopWindowTarget<Self::UserEvent>),
+        F: 'static + FnMut(Event<Self::UserEvent>, &EventLoopWindowTarget),
     {
         self.event_loop.spawn(event_handler)
     }
@@ -202,7 +202,7 @@ pub trait EventLoopWindowTargetExtWebSys {
     fn poll_strategy(&self) -> PollStrategy;
 }
 
-impl<T> EventLoopWindowTargetExtWebSys for EventLoopWindowTarget<T> {
+impl EventLoopWindowTargetExtWebSys for EventLoopWindowTarget {
     #[inline]
     fn set_poll_strategy(&self, strategy: PollStrategy) {
         self.p.set_poll_strategy(strategy);
@@ -315,11 +315,11 @@ impl Error for BadAnimation {}
 pub trait CustomCursorBuilderExtWebSys {
     /// Async version of [`CustomCursorBuilder::build()`] which waits until the
     /// cursor has completely finished loading.
-    fn build_async<T>(self, window_target: &EventLoopWindowTarget<T>) -> CustomCursorFuture;
+    fn build_async(self, window_target: &EventLoopWindowTarget) -> CustomCursorFuture;
 }
 
 impl CustomCursorBuilderExtWebSys for CustomCursorBuilder {
-    fn build_async<T>(self, window_target: &EventLoopWindowTarget<T>) -> CustomCursorFuture {
+    fn build_async(self, window_target: &EventLoopWindowTarget) -> CustomCursorFuture {
         CustomCursorFuture(PlatformCustomCursor::build_async(
             self.inner,
             &window_target.p,

src/platform/x11.rs

@@ -95,7 +95,7 @@ pub trait EventLoopWindowTargetExtX11 {
     fn is_x11(&self) -> bool;
 }
 
-impl<T> EventLoopWindowTargetExtX11 for EventLoopWindowTarget<T> {
+impl EventLoopWindowTargetExtX11 for EventLoopWindowTarget {
     #[inline]
     fn is_x11(&self) -> bool {
         !self.p.is_wayland()

src/platform_impl/android/mod.rs

@@ -4,6 +4,7 @@ use std::{
     cell::Cell,
     collections::VecDeque,
     hash::Hash,
+    marker::PhantomData,
     sync::{
         atomic::{AtomicBool, Ordering},
         mpsc, Arc, Mutex, RwLock,
@@ -140,7 +141,7 @@ pub struct KeyEventExtra {}
 
 pub struct EventLoop<T: 'static> {
     android_app: AndroidApp,
-    window_target: event_loop::EventLoopWindowTarget<T>,
+    window_target: event_loop::EventLoopWindowTarget,
     redraw_flag: SharedFlag,
     user_events_sender: mpsc::Sender<T>,
     user_events_receiver: PeekableReceiver<T>, //must wake looper whenever something gets sent
@@ -187,9 +188,8 @@ impl<T: 'static> EventLoop<T> {
                         &redraw_flag,
                         android_app.create_waker(),
                     ),
-                    _marker: std::marker::PhantomData,
                 },
-                _marker: std::marker::PhantomData,
+                _marker: PhantomData,
             },
             redraw_flag,
             user_events_sender,
@@ -205,7 +205,7 @@ impl<T: 'static> EventLoop<T> {
 
     fn single_iteration<F>(&mut self, main_event: Option<MainEvent<'_>>, callback: &mut F)
     where
-        F: FnMut(event::Event<T>, &RootELW<T>),
+        F: FnMut(event::Event<T>, &RootELW),
     {
         trace!("Mainloop iteration");
 
@@ -377,7 +377,7 @@ impl<T: 'static> EventLoop<T> {
         callback: &mut F,
     ) -> InputStatus
     where
-        F: FnMut(event::Event<T>, &RootELW<T>),
+        F: FnMut(event::Event<T>, &RootELW),
     {
         let mut input_status = InputStatus::Handled;
         match event {
@@ -482,14 +482,14 @@ impl<T: 'static> EventLoop<T> {
 
     pub fn run<F>(mut self, event_handler: F) -> Result<(), EventLoopError>
     where
-        F: FnMut(event::Event<T>, &event_loop::EventLoopWindowTarget<T>),
+        F: FnMut(event::Event<T>, &event_loop::EventLoopWindowTarget),
     {
         self.run_on_demand(event_handler)
     }
 
     pub fn run_on_demand<F>(&mut self, mut event_handler: F) -> Result<(), EventLoopError>
     where
-        F: FnMut(event::Event<T>, &event_loop::EventLoopWindowTarget<T>),
+        F: FnMut(event::Event<T>, &event_loop::EventLoopWindowTarget),
     {
         if self.loop_running {
             return Err(EventLoopError::AlreadyRunning);
@@ -512,7 +512,7 @@ impl<T: 'static> EventLoop<T> {
 
     pub fn pump_events<F>(&mut self, timeout: Option<Duration>, mut callback: F) -> PumpStatus
     where
-        F: FnMut(event::Event<T>, &RootELW<T>),
+        F: FnMut(event::Event<T>, &RootELW),
     {
         if !self.loop_running {
             self.loop_running = true;
@@ -545,7 +545,7 @@ impl<T: 'static> EventLoop<T> {
 
     fn poll_events_with_timeout<F>(&mut self, mut timeout: Option<Duration>, mut callback: F)
     where
-        F: FnMut(event::Event<T>, &RootELW<T>),
+        F: FnMut(event::Event<T>, &RootELW),
     {
         let start = Instant::now();
 
@@ -621,7 +621,7 @@ impl<T: 'static> EventLoop<T> {
         });
     }
 
-    pub fn window_target(&self) -> &event_loop::EventLoopWindowTarget<T> {
+    pub fn window_target(&self) -> &event_loop::EventLoopWindowTarget {
         &self.window_target
     }
 
@@ -665,15 +665,14 @@ impl<T> EventLoopProxy<T> {
     }
 }
 
-pub struct EventLoopWindowTarget<T: 'static> {
+pub struct EventLoopWindowTarget {
     app: AndroidApp,
     control_flow: Cell<ControlFlow>,
     exit: Cell<bool>,
     redraw_requester: RedrawRequester,
-    _marker: std::marker::PhantomData<T>,
 }
 
-impl<T: 'static> EventLoopWindowTarget<T> {
+impl EventLoopWindowTarget {
     pub fn primary_monitor(&self) -> Option<MonitorHandle> {
         Some(MonitorHandle::new(self.app.clone()))
     }
@@ -763,8 +762,8 @@ pub(crate) struct Window {
 }
 
 impl Window {
-    pub(crate) fn new<T: 'static>(
-        el: &EventLoopWindowTarget<T>,
+    pub(crate) fn new(
+        el: &EventLoopWindowTarget,
         _window_attrs: window::WindowAttributes,
         _: PlatformSpecificWindowBuilderAttributes,
     ) -> Result<Self, error::OsError> {