Add timestamps to events

Cargo.toml

@@ -60,6 +60,7 @@ objc2-core-foundation = { version = "0.3.2", default-features = false }
 objc2-core-graphics = { version = "0.3.2", default-features = false }
 objc2-core-video = { version = "0.3.2", default-features = false }
 objc2-foundation = { version = "0.3.2", default-features = false }
+objc2-quartz-core = { version = "0.3.2", default-features = false }
 objc2-ui-kit = { version = "0.3.2", default-features = false }
 
 # Windows dependencies.

clippy.toml

@@ -1,11 +1,4 @@
 # Using allow-invalid because this is platform-specific code
-disallowed-macros = [
-    { path = "std::print", reason = "works badly on web", replacement = "tracing::info" },
-    { path = "std::println", reason = "works badly on web", replacement = "tracing::info" },
-    { path = "std::eprint", reason = "works badly on web", replacement = "tracing::error" },
-    { path = "std::eprintln", reason = "works badly on web", replacement = "tracing::error" },
-    { path = "std::dbg", reason = "leftover debugging aid, remove it or use tracing" },
-]
 disallowed-methods = [
     { allow-invalid = true, path = "objc2_app_kit::NSView::visibleRect", reason = "We expose a render target to the user, and visibility is not really relevant to that (and can break if you don't use the rectangle position as well). Use `frame` instead." },
     { allow-invalid = true, path = "objc2_app_kit::NSWindow::setFrameTopLeftPoint", reason = "Not sufficient when working with Winit's coordinate system, use `flip_window_screen_coordinates` instead" },

winit-appkit/Cargo.toml

@@ -107,6 +107,7 @@ objc2-foundation = { workspace = true, features = [
     "NSThread",
     "NSValue",
 ] }
+objc2-quartz-core = { workspace = true, features = ["std", "CABase"] }
 winit-common = { workspace = true, features = ["core-foundation", "event-handler"] }
 
 [dev-dependencies]

winit-appkit/src/app.rs

@@ -9,7 +9,6 @@ use objc2::runtime::{Imp, Sel};
 use objc2::sel;
 use objc2_app_kit::{NSApplication, NSEvent, NSEventModifierFlags, NSEventType};
 use objc2_foundation::MainThreadMarker;
-use tracing::trace_span;
 use winit_core::event::{DeviceEvent, ElementState};
 
 use super::app_state::AppState;
@@ -22,10 +21,6 @@ static ORIGINAL: MainThreadBound<Cell<Option<SendEvent>>> = {
 };
 
 extern "C-unwind" fn send_event(app: &NSApplication, sel: Sel, event: &NSEvent) {
-    // This can be a bit noisy, since `event` is fairly large. Note that you can use
-    // `RUST_LOG='trace,winit_appkit::app=warn'` if you're debugging and want TRACE-level logs but
-    // not this.
-    let _entered = trace_span!("sendEvent:", ?event).entered();
     let mtm = MainThreadMarker::from(app);
 
     // Normally, holding Cmd + any key never sends us a `keyUp` event for that key.
@@ -103,6 +98,7 @@ pub(crate) fn override_send_event(global_app: &NSApplication) {
 }
 
 fn maybe_dispatch_device_event(app_state: &Rc<AppState>, event: &NSEvent) {
+    let time = app_state.event_time(event);
     let event_type = event.r#type();
     #[allow(non_upper_case_globals)]
     match event_type {
@@ -115,7 +111,7 @@ fn maybe_dispatch_device_event(app_state: &Rc<AppState>, event: &NSEvent) {
 
             if delta_x != 0.0 || delta_y != 0.0 {
                 app_state.maybe_queue_with_handler(move |app, event_loop| {
-                    app.device_event(event_loop, None, DeviceEvent::PointerMotion {
+                    app.device_event(event_loop, None, time, DeviceEvent::PointerMotion {
                         delta: (delta_x, delta_y),
                     });
                 });
@@ -124,7 +120,7 @@ fn maybe_dispatch_device_event(app_state: &Rc<AppState>, event: &NSEvent) {
         NSEventType::LeftMouseDown | NSEventType::RightMouseDown | NSEventType::OtherMouseDown => {
             let button = event.buttonNumber() as u32;
             app_state.maybe_queue_with_handler(move |app, event_loop| {
-                app.device_event(event_loop, None, DeviceEvent::Button {
+                app.device_event(event_loop, None, time, DeviceEvent::Button {
                     button,
                     state: ElementState::Pressed,
                 });
@@ -133,7 +129,7 @@ fn maybe_dispatch_device_event(app_state: &Rc<AppState>, event: &NSEvent) {
         NSEventType::LeftMouseUp | NSEventType::RightMouseUp | NSEventType::OtherMouseUp => {
             let button = event.buttonNumber() as u32;
             app_state.maybe_queue_with_handler(move |app, event_loop| {
-                app.device_event(event_loop, None, DeviceEvent::Button {
+                app.device_event(event_loop, None, time, DeviceEvent::Button {
                     button,
                     state: ElementState::Released,
                 });

winit-appkit/src/app_state.rs

@@ -2,11 +2,14 @@ use std::cell::{Cell, OnceCell, RefCell};
 use std::mem;
 use std::rc::Rc;
 use std::sync::Arc;
-use std::time::Instant;
+use std::time::{Duration, Instant};
 
 use dispatch2::MainThreadBound;
 use objc2::MainThreadMarker;
-use objc2_app_kit::NSApplication;
+use objc2_app_kit::{NSApplication, NSApplicationActivationPolicy, NSEvent, NSRunningApplication};
+use objc2_foundation::{NSNotification, NSTimeInterval};
+use objc2_quartz_core::CACurrentMediaTime;
+use tracing::warn;
 use winit_common::core_foundation::{EventLoopProxy, MainRunLoop};
 use winit_common::event_handler::EventHandler;
 use winit_core::application::ApplicationHandler;
@@ -15,17 +18,24 @@ use winit_core::event_loop::ControlFlow;
 use winit_core::window::WindowId;
 
 use super::event_loop::{ActiveEventLoop, notify_windows_of_exit, stop_app_immediately};
+use super::menu;
 use super::observer::EventLoopWaker;
 
 #[derive(Debug)]
 pub(super) struct AppState {
     mtm: MainThreadMarker,
+    activation_policy: Option<NSApplicationActivationPolicy>,
+    default_menu: bool,
+    activate_ignoring_other_apps: bool,
     run_loop: MainRunLoop,
     event_loop_proxy: Arc<EventLoopProxy>,
     event_handler: EventHandler,
+    stop_on_launch: Cell<bool>,
     stop_before_wait: Cell<bool>,
     stop_after_wait: Cell<bool>,
     stop_on_redraw: Cell<bool>,
+    /// Whether `applicationDidFinishLaunching:` has been run or not.
+    is_launched: Cell<bool>,
     /// Whether an `EventLoop` is currently running.
     is_running: Cell<bool>,
     /// Whether the user has requested the event loop to exit.
@@ -35,6 +45,8 @@ pub(super) struct AppState {
     start_time: Cell<Option<Instant>>,
     wait_timeout: Cell<Option<Instant>>,
     pending_redraw: RefCell<Vec<WindowId>>,
+    startup_instant: Instant,
+    startup_timestamp: NSTimeInterval,
     // NOTE: This is strongly referenced by our `NSWindowDelegate` and our `NSView` subclass, and
     // as such should be careful to not add fields that, in turn, strongly reference those.
 }
@@ -45,19 +57,40 @@ static GLOBAL: MainThreadBound<OnceCell<Rc<AppState>>> =
     MainThreadBound::new(OnceCell::new(), unsafe { MainThreadMarker::new_unchecked() });
 
 impl AppState {
-    pub(super) fn setup_global(mtm: MainThreadMarker) -> Option<Rc<Self>> {
+    pub(super) fn setup_global(
+        mtm: MainThreadMarker,
+        activation_policy: Option<NSApplicationActivationPolicy>,
+        default_menu: bool,
+        activate_ignoring_other_apps: bool,
+    ) -> Option<Rc<Self>> {
         let event_loop_proxy = Arc::new(EventLoopProxy::new(mtm, move || {
             Self::get(mtm).with_handler(|app, event_loop| app.proxy_wake_up(event_loop));
         }));
 
+        // Prime dylib caches etc.
+        let _ = CACurrentMediaTime();
+
+        // Find the current Rust timestamp.
+        let startup_instant = Instant::now();
+        // Find the timestamp
+        //
+        // `NSProcessInfo::processInfo().systemUptime()` needs the required reason manifest,
+        // `CACurrentMediaTime` (currently) doesn't, so we use that instead.
+        let startup_timestamp = CACurrentMediaTime();
+
         let this = Rc::new(Self {
             mtm,
+            activation_policy,
+            default_menu,
+            activate_ignoring_other_apps,
             run_loop: MainRunLoop::get(mtm),
             event_loop_proxy,
             event_handler: EventHandler::new(),
+            stop_on_launch: Cell::new(false),
             stop_before_wait: Cell::new(false),
             stop_after_wait: Cell::new(false),
             stop_on_redraw: Cell::new(false),
+            is_launched: Cell::new(false),
             is_running: Cell::new(false),
             exit: Cell::new(false),
             control_flow: Cell::new(ControlFlow::default()),
@@ -65,6 +98,8 @@ impl AppState {
             start_time: Cell::new(None),
             wait_timeout: Cell::new(None),
             pending_redraw: RefCell::new(vec![]),
+            startup_instant,
+            startup_timestamp,
         });
 
         GLOBAL.get(mtm).set(this.clone()).ok().and(Some(this))
@@ -78,6 +113,81 @@ impl AppState {
             .clone()
     }
 
+    pub(crate) fn event_time(&self, event: &NSEvent) -> Instant {
+        if event.timestamp() == 0.0 {
+            warn!(?event, "got zero timestamp");
+            return Instant::now();
+        }
+        let duration_since_startup = event.timestamp() - self.startup_timestamp;
+        let duration_since_startup = Duration::from_secs_f64(duration_since_startup as f64);
+        self.startup_instant + duration_since_startup
+    }
+
+    // NOTE: This notification will, globally, only be emitted once,
+    // no matter how many `EventLoop`s the user creates.
+    pub fn did_finish_launching(self: &Rc<Self>, _notification: &NSNotification) {
+        trace_scope!("NSApplicationDidFinishLaunchingNotification");
+        self.is_launched.set(true);
+
+        let app = NSApplication::sharedApplication(self.mtm);
+        // We need to delay setting the activation policy and activating the app
+        // until `applicationDidFinishLaunching` has been called. Otherwise the
+        // menu bar is initially unresponsive on macOS 10.15.
+        if let Some(activation_policy) = self.activation_policy {
+            app.setActivationPolicy(activation_policy);
+        } else {
+            // If no activation policy is explicitly provided, and the application
+            // is bundled, do not set the activation policy at all, to allow the
+            // package manifest to define the behavior via LSUIElement.
+            //
+            // See:
+            // - https://github.com/rust-windowing/winit/issues/261
+            // - https://github.com/rust-windowing/winit/issues/3958
+            let is_bundled =
+                NSRunningApplication::currentApplication().bundleIdentifier().is_some();
+            if !is_bundled {
+                app.setActivationPolicy(NSApplicationActivationPolicy::Regular);
+            }
+        }
+
+        #[allow(deprecated)]
+        app.activateIgnoringOtherApps(self.activate_ignoring_other_apps);
+
+        if self.default_menu {
+            // The menubar initialization should be before the `NewEvents` event, to allow
+            // overriding of the default menu even if it's created
+            menu::initialize(&app);
+        }
+
+        self.waker.borrow_mut().start();
+
+        self.set_is_running(true);
+        self.dispatch_init_events();
+
+        // If the application is being launched via `EventLoop::pump_app_events()` then we'll
+        // want to stop the app once it is launched (and return to the external loop)
+        //
+        // In this case we still want to consider Winit's `EventLoop` to be "running",
+        // so we call `start_running()` above.
+        if self.stop_on_launch.get() {
+            // NOTE: the original idea had been to only stop the underlying `RunLoop`
+            // for the app but that didn't work as expected (`-[NSApplication run]`
+            // effectively ignored the attempt to stop the RunLoop and re-started it).
+            //
+            // So we return from `pump_events` by stopping the application.
+            let app = NSApplication::sharedApplication(self.mtm);
+            stop_app_immediately(&app);
+        }
+    }
+
+    pub fn will_terminate(self: &Rc<Self>, _notification: &NSNotification) {
+        trace_scope!("NSApplicationWillTerminateNotification");
+        let app = NSApplication::sharedApplication(self.mtm);
+        notify_windows_of_exit(&app);
+        self.event_handler.terminate();
+        self.internal_exit();
+    }
+
     /// Place the event handler in the application state for the duration
     /// of the given closure.
     pub fn set_event_handler<R>(
@@ -88,14 +198,17 @@ impl AppState {
         self.event_handler.set(Box::new(handler), closure)
     }
 
-    pub fn terminate_event_handler(&self) {
-        self.event_handler.terminate();
-    }
-
     pub fn event_loop_proxy(&self) -> &Arc<EventLoopProxy> {
         &self.event_loop_proxy
     }
 
+    /// If `pump_events` is called to progress the event loop then we
+    /// bootstrap the event loop via `-[NSApplication run]` but will use
+    /// `CFRunLoopRunInMode` for subsequent calls to `pump_events`.
+    pub fn set_stop_on_launch(&self) {
+        self.stop_on_launch.set(true);
+    }
+
     pub fn set_stop_before_wait(&self, value: bool) {
         self.stop_before_wait.set(value)
     }
@@ -124,6 +237,10 @@ impl AppState {
         self.set_wait_timeout(None);
     }
 
+    pub fn is_launched(&self) -> bool {
+        self.is_launched.get()
+    }
+
     pub fn set_is_running(&self, value: bool) {
         self.is_running.set(value)
     }
@@ -157,7 +274,12 @@ impl AppState {
         // -> Don't go back into the event handler when our callstack originates from there
         if !self.event_handler.in_use() {
             self.with_handler(|app, event_loop| {
-                app.window_event(event_loop, window_id, WindowEvent::RedrawRequested);
+                app.window_event(
+                    event_loop,
+                    window_id,
+                    Instant::now(),
+                    WindowEvent::RedrawRequested,
+                );
             });
 
             // `pump_events` will request to stop immediately _after_ dispatching RedrawRequested
@@ -257,7 +379,12 @@ impl AppState {
         let redraw = mem::take(&mut *self.pending_redraw.borrow_mut());
         for window_id in redraw {
             self.with_handler(|app, event_loop| {
-                app.window_event(event_loop, window_id, WindowEvent::RedrawRequested);
+                app.window_event(
+                    event_loop,
+                    window_id,
+                    Instant::now(),
+                    WindowEvent::RedrawRequested,
+                );
             });
         }
         self.with_handler(|app, event_loop| {

winit-appkit/src/cursor.rs

@@ -5,10 +5,7 @@ use std::sync::OnceLock;
 use objc2::rc::Retained;
 use objc2::runtime::Sel;
 use objc2::{AllocAnyThread, ClassType, available, msg_send, sel};
-use objc2_app_kit::{
-    NSBitmapImageRep, NSCursor, NSCursorFrameResizeDirections, NSCursorFrameResizePosition,
-    NSDeviceRGBColorSpace, NSImage,
-};
+use objc2_app_kit::{NSBitmapImageRep, NSCursor, NSDeviceRGBColorSpace, NSImage};
 use objc2_foundation::{
     NSData, NSDictionary, NSNumber, NSObject, NSPoint, NSSize, NSString, ns_string,
 };
@@ -207,155 +204,23 @@ pub(crate) fn cursor_from_icon(icon: CursorIcon) -> Retained<NSCursor> {
         CursorIcon::NotAllowed | CursorIcon::NoDrop => NSCursor::operationNotAllowedCursor(),
         CursorIcon::ContextMenu => NSCursor::contextualMenuCursor(),
         CursorIcon::Crosshair => NSCursor::crosshairCursor(),
-        CursorIcon::EResize => {
-            if available!(macos = 15.0) {
-                NSCursor::frameResizeCursorFromPosition_inDirections(
-                    NSCursorFrameResizePosition::Right,
-                    NSCursorFrameResizeDirections::Outward,
-                )
-            } else {
-                NSCursor::resizeRightCursor()
-            }
-        },
-        CursorIcon::NResize => {
-            if available!(macos = 15.0) {
-                NSCursor::frameResizeCursorFromPosition_inDirections(
-                    NSCursorFrameResizePosition::Top,
-                    NSCursorFrameResizeDirections::Outward,
-                )
-            } else {
-                NSCursor::resizeUpCursor()
-            }
-        },
-        CursorIcon::WResize => {
-            if available!(macos = 15.0) {
-                NSCursor::frameResizeCursorFromPosition_inDirections(
-                    NSCursorFrameResizePosition::Left,
-                    NSCursorFrameResizeDirections::Outward,
-                )
-            } else {
-                NSCursor::resizeLeftCursor()
-            }
-        },
-        CursorIcon::SResize => {
-            if available!(macos = 15.0) {
-                NSCursor::frameResizeCursorFromPosition_inDirections(
-                    NSCursorFrameResizePosition::Bottom,
-                    NSCursorFrameResizeDirections::Outward,
-                )
-            } else {
-                NSCursor::resizeDownCursor()
-            }
-        },
-        CursorIcon::EwResize => {
-            if available!(macos = 15.0) {
-                NSCursor::frameResizeCursorFromPosition_inDirections(
-                    NSCursorFrameResizePosition::Right,
-                    NSCursorFrameResizeDirections::All,
-                )
-            } else {
-                NSCursor::resizeLeftRightCursor()
-            }
-        },
-        CursorIcon::NsResize => {
-            if available!(macos = 15.0) {
-                NSCursor::frameResizeCursorFromPosition_inDirections(
-                    NSCursorFrameResizePosition::Top,
-                    NSCursorFrameResizeDirections::All,
-                )
-            } else {
-                NSCursor::resizeUpDownCursor()
-            }
-        },
-        CursorIcon::NeResize => {
-            if available!(macos = 15.0) {
-                NSCursor::frameResizeCursorFromPosition_inDirections(
-                    NSCursorFrameResizePosition::TopRight,
-                    NSCursorFrameResizeDirections::Outward,
-                )
-            } else {
-                _windowResizeNorthEastCursor()
-            }
-        },
-        CursorIcon::NwResize => {
-            if available!(macos = 15.0) {
-                NSCursor::frameResizeCursorFromPosition_inDirections(
-                    NSCursorFrameResizePosition::TopLeft,
-                    NSCursorFrameResizeDirections::Outward,
-                )
-            } else {
-                _windowResizeNorthWestCursor()
-            }
-        },
-        CursorIcon::SeResize => {
-            if available!(macos = 15.0) {
-                NSCursor::frameResizeCursorFromPosition_inDirections(
-                    NSCursorFrameResizePosition::BottomRight,
-                    NSCursorFrameResizeDirections::Outward,
-                )
-            } else {
-                _windowResizeSouthEastCursor()
-            }
-        },
-        CursorIcon::SwResize => {
-            if available!(macos = 15.0) {
-                NSCursor::frameResizeCursorFromPosition_inDirections(
-                    NSCursorFrameResizePosition::BottomLeft,
-                    NSCursorFrameResizeDirections::Outward,
-                )
-            } else {
-                _windowResizeSouthWestCursor()
-            }
-        },
-        CursorIcon::NeswResize => {
-            if available!(macos = 15.0) {
-                NSCursor::frameResizeCursorFromPosition_inDirections(
-                    NSCursorFrameResizePosition::TopRight,
-                    NSCursorFrameResizeDirections::All,
-                )
-            } else {
-                _windowResizeNorthEastSouthWestCursor()
-            }
-        },
-        CursorIcon::NwseResize => {
-            if available!(macos = 15.0) {
-                NSCursor::frameResizeCursorFromPosition_inDirections(
-                    NSCursorFrameResizePosition::TopLeft,
-                    NSCursorFrameResizeDirections::All,
-                )
-            } else {
-                _windowResizeNorthWestSouthEastCursor()
-            }
-        },
-        CursorIcon::ColResize => {
-            if available!(macos = 15.0) {
-                NSCursor::columnResizeCursor()
-            } else {
-                NSCursor::resizeLeftRightCursor()
-            }
-        },
-        CursorIcon::RowResize => {
-            if available!(macos = 15.0) {
-                NSCursor::rowResizeCursor()
-            } else {
-                NSCursor::resizeUpDownCursor()
-            }
-        },
-        CursorIcon::ZoomIn => {
-            if available!(macos = 15.0) {
-                NSCursor::zoomInCursor()
-            } else {
-                _zoomInCursor()
-            }
-        },
-        CursorIcon::ZoomOut => {
-            if available!(macos = 15.0) {
-                NSCursor::zoomOutCursor()
-            } else {
-                _zoomOutCursor()
-            }
-        },
+        CursorIcon::EResize => NSCursor::resizeRightCursor(),
+        CursorIcon::NResize => NSCursor::resizeUpCursor(),
+        CursorIcon::WResize => NSCursor::resizeLeftCursor(),
+        CursorIcon::SResize => NSCursor::resizeDownCursor(),
+        CursorIcon::EwResize | CursorIcon::ColResize => NSCursor::resizeLeftRightCursor(),
+        CursorIcon::NsResize | CursorIcon::RowResize => NSCursor::resizeUpDownCursor(),
         CursorIcon::Help => _helpCursor(),
+        CursorIcon::ZoomIn if available!(macos = 15.0) => NSCursor::zoomInCursor(),
+        CursorIcon::ZoomIn => _zoomInCursor(),
+        CursorIcon::ZoomOut if available!(macos = 15.0) => NSCursor::zoomOutCursor(),
+        CursorIcon::ZoomOut => _zoomOutCursor(),
+        CursorIcon::NeResize => _windowResizeNorthEastCursor(),
+        CursorIcon::NwResize => _windowResizeNorthWestCursor(),
+        CursorIcon::SeResize => _windowResizeSouthEastCursor(),
+        CursorIcon::SwResize => _windowResizeSouthWestCursor(),
+        CursorIcon::NeswResize => _windowResizeNorthEastSouthWestCursor(),
+        CursorIcon::NwseResize => _windowResizeNorthWestSouthEastCursor(),
         // This is the wrong semantics for `Wait`, but it's the same as
         // what's used in Safari and Chrome.
         CursorIcon::Wait | CursorIcon::Progress => busyButClickableCursor(),

winit-appkit/src/event_loop.rs

@@ -7,13 +7,12 @@ use objc2::runtime::ProtocolObject;
 use objc2::{MainThreadMarker, available};
 use objc2_app_kit::{
     NSApplication, NSApplicationActivationPolicy, NSApplicationDidFinishLaunchingNotification,
-    NSApplicationWillTerminateNotification, NSRunningApplication, NSWindow,
+    NSApplicationWillTerminateNotification, NSWindow,
 };
 use objc2_core_foundation::{CFIndex, CFRunLoopActivity, kCFRunLoopCommonModes};
 use objc2_foundation::{NSNotificationCenter, NSObjectProtocol};
 use rwh_06::HasDisplayHandle;
-use tracing::debug_span;
-use winit_common::core_foundation::{MainRunLoop, MainRunLoopObserver, tracing_observers};
+use winit_common::core_foundation::{MainRunLoop, MainRunLoopObserver};
 use winit_core::application::ApplicationHandler;
 use winit_core::cursor::{CustomCursor as CoreCustomCursor, CustomCursorSource};
 use winit_core::error::{EventLoopError, RequestError};
@@ -31,8 +30,8 @@ use super::cursor::CustomCursor;
 use super::event::dummy_event;
 use super::monitor;
 use super::notification_center::create_observer;
+use crate::ActivationPolicy;
 use crate::window::Window;
-use crate::{ActivationPolicy, menu};
 
 #[derive(Debug)]
 pub struct ActiveEventLoop {
@@ -150,9 +149,9 @@ pub struct EventLoop {
     // the system instead cleans it up next time it would have posted a notification to it.
     //
     // Though we do still need to keep the observers around to prevent them from being deallocated.
+    _did_finish_launching_observer: Retained<ProtocolObject<dyn NSObjectProtocol>>,
     _will_terminate_observer: Retained<ProtocolObject<dyn NSObjectProtocol>>,
 
-    _tracing_observers: Option<(MainRunLoopObserver, MainRunLoopObserver)>,
     _before_waiting_observer: MainRunLoopObserver,
     _after_waiting_observer: MainRunLoopObserver,
 }
@@ -175,8 +174,20 @@ impl EventLoop {
         let mtm = MainThreadMarker::new()
             .expect("on macOS, `EventLoop` must be created on the main thread!");
 
-        let app_state =
-            AppState::setup_global(mtm).ok_or_else(|| EventLoopError::RecreationAttempt)?;
+        let activation_policy = match attributes.activation_policy {
+            None => None,
+            Some(ActivationPolicy::Regular) => Some(NSApplicationActivationPolicy::Regular),
+            Some(ActivationPolicy::Accessory) => Some(NSApplicationActivationPolicy::Accessory),
+            Some(ActivationPolicy::Prohibited) => Some(NSApplicationActivationPolicy::Prohibited),
+        };
+
+        let app_state = AppState::setup_global(
+            mtm,
+            activation_policy,
+            attributes.default_menu,
+            attributes.activate_ignoring_other_apps,
+        )
+        .ok_or_else(|| EventLoopError::RecreationAttempt)?;
 
         // Initialize the application (if it has not already been).
         let app = NSApplication::sharedApplication(mtm);
@@ -186,50 +197,41 @@ impl EventLoop {
 
         let center = NSNotificationCenter::defaultCenter();
 
-        // Handle `terminate:`. This may happen if:
-        // - The user uses the context menu in the Dock icon.
-        // - Or the `Quit` menu item we install with the default menu (including via. the keyboard
-        //   shortcut).
-        // - Maybe other cases?
-        //
-        // In these cases, AppKit is going to call `std::process::exit`, so we won't get the chance
-        // to return to the user from `EventLoop::run_app`. So we have to clean up and drop their
-        // windows and application here too.
         let weak_app_state = Rc::downgrade(&app_state);
-        let _will_terminate_observer = create_observer(
+        let _did_finish_launching_observer = create_observer(
             &center,
-            unsafe { NSApplicationWillTerminateNotification },
+            // `applicationDidFinishLaunching:`
+            unsafe { NSApplicationDidFinishLaunchingNotification },
             move |notification| {
-                let _entered = debug_span!("applicationWillTerminate").entered();
-
-                let app = notification.object().unwrap().downcast::<NSApplication>().unwrap();
-                notify_windows_of_exit(&app);
-
                 if let Some(app_state) = weak_app_state.upgrade() {
-                    app_state.terminate_event_handler();
-                    app_state.internal_exit();
+                    app_state.did_finish_launching(notification);
+                }
+            },
+        );
+
+        let weak_app_state = Rc::downgrade(&app_state);
+        let _will_terminate_observer = create_observer(
+            &center,
+            // `applicationWillTerminate:`
+            unsafe { NSApplicationWillTerminateNotification },
+            move |notification| {
+                if let Some(app_state) = weak_app_state.upgrade() {
+                    app_state.will_terminate(notification);
                 }
             },
         );
 
-        // Set up run loop observers for calling `new_events` and `about_to_wait`.
         let main_loop = MainRunLoop::get(mtm);
         let mode = unsafe { kCFRunLoopCommonModes }.unwrap();
 
-        // Tracing observers have the lowest and highest orderings.
-        let _tracing_observers = tracing_observers(mtm).inspect(|(start, end)| {
-            main_loop.add_observer(start, mode);
-            main_loop.add_observer(end, mode);
-        });
-
         let app_state_clone = Rc::clone(&app_state);
         let _before_waiting_observer = MainRunLoopObserver::new(
             mtm,
             CFRunLoopActivity::BeforeWaiting,
             true,
-            // Queued with the second-lowest priority (tracing observers use the lowest) to ensure
-            // it is processed after other observers.
-            CFIndex::MAX - 1,
+            // Queued with the lowest priority to ensure it is processed after other observers.
+            // Without that, we'd get a `LoopExiting` after `AboutToWait`.
+            CFIndex::MAX,
             move |_| app_state_clone.cleared(),
         );
         main_loop.add_observer(&_before_waiting_observer, mode);
@@ -239,109 +241,18 @@ impl EventLoop {
             mtm,
             CFRunLoopActivity::AfterWaiting,
             true,
-            // Queued with the second-highest priority (tracing observers use the highest) to
-            // ensure it is processed before other observers.
-            CFIndex::MIN + 1,
+            // Queued with the highest priority to ensure it is processed before other observers.
+            CFIndex::MIN,
             move |_| app_state_clone.wakeup(),
         );
         main_loop.add_observer(&_after_waiting_observer, mode);
 
-        // Run `finishLaunching` just in case it works.
-        app.finishLaunching();
-        // Now _ideally_, calling `finishLaunching` should be enough for the application to, you
-        // know, launch (create the a dock icon etc.), but unfortunately, this doesn't happen for
-        // various godforsaken reasons... The only way to make the application properly launch is by
-        // calling `NSApplication::run`.
-        //
-        // So we check if the application hasn't finished launching, and if it hasn't, we run it
-        // once to finish it.
-        //
-        // This is _very_ important, there's a _lot_ of weird and subtle state that requires that
-        // the application is launched properly, including window creation, the menu bar,
-        // activation, see:
-        // - https://github.com/rust-windowing/winit/pull/1903
-        // - https://github.com/rust-windowing/winit/pull/1922
-        // - https://github.com/rust-windowing/winit/issues/2238
-        // - https://github.com/rust-windowing/winit/issues/2051
-        // - https://github.com/rust-windowing/winit/issues/2087
-        // - https://developer.apple.com/forums/thread/772169
-        //
-        // This approach is similar to what other cross-platform windowing libraries do (except that
-        // we do it without a delegate to allow users to override that):
-        // - GLFW delegate: https://github.com/glfw/glfw/blob/3.4/src/cocoa_init.m#L439-L443
-        // - GLFW launch: https://github.com/glfw/glfw/blob/3.4/src/cocoa_init.m#L634-L635
-        // - FLTK delegate: https://github.com/fltk/fltk/blob/release-1.4.4/src/Fl_cocoa.mm#L1604-L1607
-        // - FLTK launch: https://github.com/fltk/fltk/blob/release-1.4.4/src/Fl_cocoa.mm#L1903-L1919
-        // - Stackoverflow issue: https://stackoverflow.com/questions/48020222/how-to-make-nsapp-run-not-block/67626393#67626393
-        if !NSRunningApplication::currentApplication().isFinishedLaunching() {
-            // Register an observer to stop the application immediately after launching.
-            //
-            // NOTE: This notification will, globally, only be emitted once, no matter how many
-            // `EventLoop`s the user creates. We detect it with `isFinishedLaunching` above.
-            let did_finish_launching_observer = create_observer(
-                &center,
-                unsafe { NSApplicationDidFinishLaunchingNotification },
-                move |notification| {
-                    let _entered = debug_span!("applicationDidFinishLaunching").entered();
-
-                    let app = notification.object().unwrap().downcast::<NSApplication>().unwrap();
-
-                    // Stop the application, to make the `app.run()` call below return.
-                    stop_app_immediately(&app);
-                },
-            );
-
-            // We call `stop_app_immediately` above, so this should return after launching.
-            app.run();
-
-            // The observer should've been called at this point.
-            drop(did_finish_launching_observer);
-
-            // We _could_ keep trying if we failed to initialize, but that would potentially lead
-            // to an infinite loop, it's probably better to just continue.
-            debug_assert!(NSRunningApplication::currentApplication().isFinishedLaunching());
-        }
-
-        // We need to delay setting the activation policy and activating the app until
-        // `applicationDidFinishLaunching:` has been called, otherwise the menu bar is initially
-        // unresponsive on macOS 10.15.
-        if let Some(activation_policy) = attributes.activation_policy {
-            app.setActivationPolicy(match activation_policy {
-                ActivationPolicy::Regular => NSApplicationActivationPolicy::Regular,
-                ActivationPolicy::Accessory => NSApplicationActivationPolicy::Accessory,
-                ActivationPolicy::Prohibited => NSApplicationActivationPolicy::Prohibited,
-            });
-        } else {
-            // If no activation policy is explicitly provided, and the application
-            // is bundled, do not set the activation policy at all, to allow the
-            // package manifest to define the behavior via LSUIElement.
-            //
-            // See:
-            // - https://github.com/rust-windowing/winit/issues/261
-            // - https://github.com/rust-windowing/winit/issues/3958
-            let is_bundled =
-                NSRunningApplication::currentApplication().bundleIdentifier().is_some();
-            if !is_bundled {
-                app.setActivationPolicy(NSApplicationActivationPolicy::Regular);
-            }
-        }
-
-        // TODO: Use `app.activate()` instead on newer OS versions?
-        #[expect(deprecated)]
-        app.activateIgnoringOtherApps(attributes.activate_ignoring_other_apps);
-
-        if attributes.default_menu {
-            // The default menubar initialization should be before everything else, to allow
-            // overriding it even if it's created.
-            menu::initialize(&app);
-        }
-
         Ok(EventLoop {
             app,
             app_state: app_state.clone(),
             window_target: ActiveEventLoop { app_state, mtm },
+            _did_finish_launching_observer,
             _will_terminate_observer,
-            _tracing_observers,
             _before_waiting_observer,
             _after_waiting_observer,
         })
@@ -359,7 +270,6 @@ impl EventLoop {
         &mut self,
         app: A,
     ) -> Result<(), EventLoopError> {
-        let _entered = debug_span!("run_app_on_demand").entered();
         self.app_state.clear_exit();
         self.app_state.set_event_handler(app, || {
             autoreleasepool(|_| {
@@ -369,9 +279,11 @@ impl EventLoop {
                 self.app_state.set_stop_after_wait(false);
                 self.app_state.set_stop_on_redraw(false);
 
-                debug_assert!(!self.app_state.is_running());
-                self.app_state.set_is_running(true);
-                self.app_state.dispatch_init_events();
+                if self.app_state.is_launched() {
+                    debug_assert!(!self.app_state.is_running());
+                    self.app_state.set_is_running(true);
+                    self.app_state.dispatch_init_events();
+                }
 
                 // NOTE: Make sure to not run the application re-entrantly, as that'd be confusing.
                 self.app.run();
@@ -388,10 +300,19 @@ impl EventLoop {
         timeout: Option<Duration>,
         app: A,
     ) -> PumpStatus {
-        let _entered = debug_span!("pump_app_events").entered();
         self.app_state.set_event_handler(app, || {
             autoreleasepool(|_| {
-                if !self.app_state.is_running() {
+                // As a special case, if the application hasn't been launched yet then we at least
+                // run the loop until it has fully launched.
+                if !self.app_state.is_launched() {
+                    debug_assert!(!self.app_state.is_running());
+
+                    self.app_state.set_stop_on_launch();
+                    self.app.run();
+
+                    // Note: we dispatch `NewEvents(Init)` + `Resumed` events after the application
+                    // has launched
+                } else if !self.app_state.is_running() {
                     // Even though the application may have been launched, it's possible we aren't
                     // running if the `EventLoop` was run before and has since
                     // exited. This indicates that we just starting to re-run

winit-appkit/src/lib.rs

@@ -50,13 +50,15 @@
 //! }
 //!
 //! fn main() -> Result<(), Box<dyn std::error::Error>> {
-//!     // Register the delegate before Winit gets a chance to touch things.
+//!     let event_loop = EventLoop::new()?;
+//!
 //!     let mtm = MainThreadMarker::new().unwrap();
 //!     let delegate = AppDelegate::new(mtm);
+//!     // Important: Call `sharedApplication` after `EventLoop::new`,
+//!     // doing it before is not yet supported.
 //!     let app = NSApplication::sharedApplication(mtm);
 //!     app.setDelegate(Some(ProtocolObject::from_ref(&*delegate)));
 //!
-//!     let event_loop = EventLoop::new()?;
 //!     // event_loop.run_app(&mut my_app);
 //!     Ok(())
 //! }

winit-appkit/src/util.rs

@@ -1,10 +1,37 @@
 use objc2_core_graphics::CGError;
+use tracing::trace;
 use winit_core::error::OsError;
 
 macro_rules! os_error {
     ($error:expr) => {{ winit_core::error::OsError::new(line!(), file!(), $error) }};
 }
 
+macro_rules! trace_scope {
+    ($s:literal) => {
+        let _crate = $crate::util::TraceGuard::new(module_path!(), $s);
+    };
+}
+
+pub(crate) struct TraceGuard {
+    module_path: &'static str,
+    called_from_fn: &'static str,
+}
+
+impl TraceGuard {
+    #[inline]
+    pub(crate) fn new(module_path: &'static str, called_from_fn: &'static str) -> Self {
+        trace!(target = module_path, "Triggered `{}`", called_from_fn);
+        Self { module_path, called_from_fn }
+    }
+}
+
+impl Drop for TraceGuard {
+    #[inline]
+    fn drop(&mut self) {
+        trace!(target = self.module_path, "Completed `{}`", self.called_from_fn);
+    }
+}
+
 #[track_caller]
 pub(crate) fn cgerr(err: CGError) -> Result<(), OsError> {
     if err == CGError::Success { Ok(()) } else { Err(os_error!(format!("CGError {err:?}"))) }

winit-appkit/src/view.rs

@@ -2,11 +2,12 @@
 use std::cell::{Cell, RefCell};
 use std::collections::{HashMap, VecDeque};
 use std::rc::Rc;
+use std::time::Instant;
 
 use dpi::{LogicalPosition, LogicalSize};
 use objc2::rc::Retained;
 use objc2::runtime::{AnyObject, Sel};
-use objc2::{AnyThread, DefinedClass, MainThreadMarker, define_class, msg_send};
+use objc2::{AnyThread, DefinedClass, MainThreadMarker, MainThreadOnly, define_class, msg_send};
 use objc2_app_kit::{
     NSApplication, NSCursor, NSEvent, NSEventPhase, NSResponder, NSTextInputClient, NSTrackingArea,
     NSTrackingAreaOptions, NSView, NSWindow,
@@ -16,7 +17,7 @@ use objc2_foundation::{
     NSArray, NSAttributedString, NSAttributedStringKey, NSCopying, NSMutableAttributedString,
     NSNotFound, NSObject, NSPoint, NSRange, NSRect, NSSize, NSString, NSUInteger,
 };
-use tracing::{debug_span, trace_span};
+use tracing::warn;
 use winit_core::event::{
     DeviceEvent, ElementState, Ime, KeyEvent, Modifiers, MouseButton, MouseScrollDelta,
     PointerKind, PointerSource, TouchPhase, WindowEvent,
@@ -154,7 +155,7 @@ define_class!(
         // Not a normal method on `NSView`, it's triggered by `NSViewFrameDidChangeNotification`.
         #[unsafe(method(viewFrameDidChangeNotification:))]
         fn frame_did_change(&self, _notification: Option<&AnyObject>) {
-            let _entered = debug_span!("NSViewFrameDidChangeNotification").entered();
+            trace_scope!("NSViewFrameDidChangeNotification");
 
             // Emit resize event here rather than from windowDidResize because:
             // 1. When a new window is created as a tab, the frame size may change without a window
@@ -169,7 +170,7 @@ define_class!(
 
         #[unsafe(method(drawRect:))]
         fn draw_rect(&self, _rect: NSRect) {
-            let _entered = debug_span!("drawRect:").entered();
+            trace_scope!("drawRect:");
 
             self.ivars().app_state.handle_redraw(window_id(&self.window()));
 
@@ -178,7 +179,7 @@ define_class!(
 
         #[unsafe(method(acceptsFirstResponder))]
         fn accepts_first_responder(&self) -> bool {
-            let _entered = trace_span!("acceptsFirstResponder").entered();
+            trace_scope!("acceptsFirstResponder");
             true
         }
 
@@ -192,13 +193,13 @@ define_class!(
         // extension for using `NSTouchBar`
         #[unsafe(method_id(touchBar))]
         fn touch_bar(&self) -> Option<Retained<NSObject>> {
-            let _entered = debug_span!("touchBar").entered();
+            trace_scope!("touchBar");
             None
         }
 
         #[unsafe(method(resetCursorRects))]
         fn reset_cursor_rects(&self) {
-            let _entered = debug_span!("resetCursorRects").entered();
+            trace_scope!("resetCursorRects");
             let bounds = self.bounds();
             let cursor_state = self.ivars().cursor_state.borrow();
             // We correctly invoke `addCursorRect` only from inside `resetCursorRects`
@@ -213,13 +214,13 @@ define_class!(
     unsafe impl NSTextInputClient for WinitView {
         #[unsafe(method(hasMarkedText))]
         fn has_marked_text(&self) -> bool {
-            let _entered = debug_span!("hasMarkedText").entered();
+            trace_scope!("hasMarkedText");
             self.ivars().marked_text.borrow().length() > 0
         }
 
         #[unsafe(method(markedRange))]
         fn marked_range(&self) -> NSRange {
-            let _entered = debug_span!("markedRange").entered();
+            trace_scope!("markedRange");
             let length = self.ivars().marked_text.borrow().length();
             if length > 0 {
                 NSRange::new(0, length)
@@ -231,7 +232,7 @@ define_class!(
 
         #[unsafe(method(selectedRange))]
         fn selected_range(&self) -> NSRange {
-            let _entered = debug_span!("selectedRange").entered();
+            trace_scope!("selectedRange");
             // Documented to return `{NSNotFound, 0}` if there is no selection.
             NSRange::new(NSNotFound as NSUInteger, 0)
         }
@@ -244,7 +245,7 @@ define_class!(
             _replacement_range: NSRange,
         ) {
             // TODO: Use _replacement_range, requires changing the event to report surrounding text.
-            let _entered = debug_span!("setMarkedText:selectedRange:replacementRange:").entered();
+            trace_scope!("setMarkedText:selectedRange:replacementRange:");
 
             let (marked_text, string) = if let Some(string) =
                 string.downcast_ref::<NSAttributedString>()
@@ -298,7 +299,7 @@ define_class!(
 
         #[unsafe(method(unmarkText))]
         fn unmark_text(&self) {
-            let _entered = debug_span!("unmarkText").entered();
+            trace_scope!("unmarkText");
             *self.ivars().marked_text.borrow_mut() = NSMutableAttributedString::new();
 
             let input_context = self.inputContext().expect("input context");
@@ -315,7 +316,7 @@ define_class!(
 
         #[unsafe(method_id(validAttributesForMarkedText))]
         fn valid_attributes_for_marked_text(&self) -> Retained<NSArray<NSAttributedStringKey>> {
-            let _entered = trace_span!("validAttributesForMarkedText").entered();
+            trace_scope!("validAttributesForMarkedText");
             NSArray::new()
         }
 
@@ -325,14 +326,13 @@ define_class!(
             _range: NSRange,
             _actual_range: *mut NSRange,
         ) -> Option<Retained<NSAttributedString>> {
-            let _entered =
-                trace_span!("attributedSubstringForProposedRange:actualRange:").entered();
+            trace_scope!("attributedSubstringForProposedRange:actualRange:");
             None
         }
 
         #[unsafe(method(characterIndexForPoint:))]
         fn character_index_for_point(&self, _point: NSPoint) -> NSUInteger {
-            let _entered = debug_span!("characterIndexForPoint:").entered();
+            trace_scope!("characterIndexForPoint:");
             0
         }
 
@@ -342,7 +342,7 @@ define_class!(
             _range: NSRange,
             _actual_range: *mut NSRange,
         ) -> NSRect {
-            let _entered = debug_span!("firstRectForCharacterRange:actualRange:").entered();
+            trace_scope!("firstRectForCharacterRange:actualRange:");
 
             // Guard when the view is no longer in a window during teardown.
             let Some(window) = (**self).window() else {
@@ -358,7 +358,7 @@ define_class!(
         #[unsafe(method(insertText:replacementRange:))]
         fn insert_text(&self, string: &NSObject, _replacement_range: NSRange) {
             // TODO: Use _replacement_range, requires changing the event to report surrounding text.
-            let _entered = debug_span!("insertText:replacementRange:").entered();
+            trace_scope!("insertText:replacementRange:");
 
             let string = if let Some(string) = string.downcast_ref::<NSAttributedString>() {
                 string.string().to_string()
@@ -383,7 +383,7 @@ define_class!(
         // "human readable" character happens, i.e. newlines, tabs, and Ctrl+C.
         #[unsafe(method(doCommandBySelector:))]
         fn do_command_by_selector(&self, command: Sel) {
-            let _entered = debug_span!("doCommandBySelector:").entered();
+            trace_scope!("doCommandBySelector:");
 
             // We shouldn't forward any character from just committed text, since we'll end up
             // sending it twice with some IMEs like Korean one. We'll also always send
@@ -422,7 +422,7 @@ define_class!(
     impl WinitView {
         #[unsafe(method(keyDown:))]
         fn key_down(&self, event: &NSEvent) {
-            let _entered = debug_span!("keyDown:").entered();
+            trace_scope!("keyDown:");
             {
                 let mut prev_input_source = self.ivars().input_source.borrow_mut();
                 let current_input_source = self.current_input_source();
@@ -481,7 +481,7 @@ define_class!(
 
         #[unsafe(method(keyUp:))]
         fn key_up(&self, event: &NSEvent) {
-            let _entered = debug_span!("keyUp:").entered();
+            trace_scope!("keyUp:");
 
             let event = replace_event(event, self.option_as_alt());
             self.update_modifiers(&event, false);
@@ -498,14 +498,14 @@ define_class!(
 
         #[unsafe(method(flagsChanged:))]
         fn flags_changed(&self, event: &NSEvent) {
-            let _entered = debug_span!("flagsChanged:").entered();
+            trace_scope!("flagsChanged:");
 
             self.update_modifiers(event, true);
         }
 
         #[unsafe(method(insertTab:))]
         fn insert_tab(&self, _sender: Option<&AnyObject>) {
-            let _entered = debug_span!("insertTab:").entered();
+            trace_scope!("insertTab:");
             let window = self.window();
             if let Some(first_responder) = window.firstResponder() {
                 if *first_responder == ***self {
@@ -516,7 +516,7 @@ define_class!(
 
         #[unsafe(method(insertBackTab:))]
         fn insert_back_tab(&self, _sender: Option<&AnyObject>) {
-            let _entered = debug_span!("insertBackTab:").entered();
+            trace_scope!("insertBackTab:");
             let window = self.window();
             if let Some(first_responder) = window.firstResponder() {
                 if *first_responder == ***self {
@@ -530,7 +530,7 @@ define_class!(
         #[unsafe(method(cancelOperation:))]
         fn cancel_operation(&self, _sender: Option<&AnyObject>) {
             let mtm = MainThreadMarker::from(self);
-            let _entered = debug_span!("cancelOperation:").entered();
+            trace_scope!("cancelOperation:");
 
             let event = NSApplication::sharedApplication(mtm)
                 .currentEvent()
@@ -559,73 +559,71 @@ define_class!(
 
         #[unsafe(method(mouseDown:))]
         fn mouse_down(&self, event: &NSEvent) {
-            let _entered = debug_span!("mouseDown:").entered();
+            trace_scope!("mouseDown:");
             self.mouse_motion(event);
             self.mouse_click(event, ElementState::Pressed);
         }
 
         #[unsafe(method(mouseUp:))]
         fn mouse_up(&self, event: &NSEvent) {
-            let _entered = debug_span!("mouseUp:").entered();
+            trace_scope!("mouseUp:");
             self.mouse_motion(event);
             self.mouse_click(event, ElementState::Released);
         }
 
         #[unsafe(method(rightMouseDown:))]
         fn right_mouse_down(&self, event: &NSEvent) {
-            let _entered = debug_span!("rightMouseDown:").entered();
+            trace_scope!("rightMouseDown:");
             self.mouse_motion(event);
             self.mouse_click(event, ElementState::Pressed);
         }
 
         #[unsafe(method(rightMouseUp:))]
         fn right_mouse_up(&self, event: &NSEvent) {
-            let _entered = debug_span!("rightMouseUp:").entered();
+            trace_scope!("rightMouseUp:");
             self.mouse_motion(event);
             self.mouse_click(event, ElementState::Released);
         }
 
         #[unsafe(method(otherMouseDown:))]
         fn other_mouse_down(&self, event: &NSEvent) {
-            let _entered = debug_span!("otherMouseDown:").entered();
+            trace_scope!("otherMouseDown:");
             self.mouse_motion(event);
             self.mouse_click(event, ElementState::Pressed);
         }
 
         #[unsafe(method(otherMouseUp:))]
         fn other_mouse_up(&self, event: &NSEvent) {
-            let _entered = debug_span!("otherMouseUp:").entered();
+            trace_scope!("otherMouseUp:");
             self.mouse_motion(event);
             self.mouse_click(event, ElementState::Released);
         }
 
+        // No tracing on these because that would be overly verbose
+
         #[unsafe(method(mouseMoved:))]
         fn mouse_moved(&self, event: &NSEvent) {
-            let _entered = debug_span!("mouseMoved:").entered();
             self.mouse_motion(event);
         }
 
         #[unsafe(method(mouseDragged:))]
         fn mouse_dragged(&self, event: &NSEvent) {
-            let _entered = debug_span!("mouseDragged:").entered();
             self.mouse_motion(event);
         }
 
         #[unsafe(method(rightMouseDragged:))]
         fn right_mouse_dragged(&self, event: &NSEvent) {
-            let _entered = debug_span!("rightMouseDragged:").entered();
             self.mouse_motion(event);
         }
 
         #[unsafe(method(otherMouseDragged:))]
         fn other_mouse_dragged(&self, event: &NSEvent) {
-            let _entered = debug_span!("otherMouseDragged:").entered();
             self.mouse_motion(event);
         }
 
         #[unsafe(method(mouseEntered:))]
         fn mouse_entered(&self, event: &NSEvent) {
-            let _entered = debug_span!("mouseEntered:").entered();
+            trace_scope!("mouseEntered:");
 
             let position = self.mouse_view_point(event).to_physical(self.scale_factor());
 
@@ -639,7 +637,7 @@ define_class!(
 
         #[unsafe(method(mouseExited:))]
         fn mouse_exited(&self, event: &NSEvent) {
-            let _entered = debug_span!("mouseExited:").entered();
+            trace_scope!("mouseExited:");
 
             let position = self.mouse_view_point(event).to_physical(self.scale_factor());
 
@@ -653,7 +651,7 @@ define_class!(
 
         #[unsafe(method(scrollWheel:))]
         fn scroll_wheel(&self, event: &NSEvent) {
-            let _entered = debug_span!("scrollWheel:").entered();
+            trace_scope!("scrollWheel:");
 
             self.mouse_motion(event);
 
@@ -684,15 +682,16 @@ define_class!(
 
             self.update_modifiers(event, false);
 
+            let time = self.ivars().app_state.event_time(event);
             self.ivars().app_state.maybe_queue_with_handler(move |app, event_loop| {
-                app.device_event(event_loop, None, DeviceEvent::MouseWheel { delta })
+                app.device_event(event_loop, None, time, DeviceEvent::MouseWheel { delta })
             });
             self.queue_event(WindowEvent::MouseWheel { device_id: None, delta, phase });
         }
 
         #[unsafe(method(magnifyWithEvent:))]
         fn magnify_with_event(&self, event: &NSEvent) {
-            let _entered = debug_span!("magnifyWithEvent:").entered();
+            trace_scope!("magnifyWithEvent:");
 
             self.mouse_motion(event);
 
@@ -714,7 +713,7 @@ define_class!(
 
         #[unsafe(method(smartMagnifyWithEvent:))]
         fn smart_magnify_with_event(&self, event: &NSEvent) {
-            let _entered = debug_span!("smartMagnifyWithEvent:").entered();
+            trace_scope!("smartMagnifyWithEvent:");
 
             self.mouse_motion(event);
 
@@ -723,7 +722,7 @@ define_class!(
 
         #[unsafe(method(rotateWithEvent:))]
         fn rotate_with_event(&self, event: &NSEvent) {
-            let _entered = debug_span!("rotateWithEvent:").entered();
+            trace_scope!("rotateWithEvent:");
 
             self.mouse_motion(event);
 
@@ -745,7 +744,7 @@ define_class!(
 
         #[unsafe(method(pressureChangeWithEvent:))]
         fn pressure_change_with_event(&self, event: &NSEvent) {
-            let _entered = debug_span!("pressureChangeWithEvent:").entered();
+            trace_scope!("pressureChangeWithEvent:");
 
             self.queue_event(WindowEvent::TouchpadPressure {
                 device_id: None,
@@ -759,13 +758,13 @@ define_class!(
         // https://github.com/chromium/chromium/blob/a86a8a6bcfa438fa3ac2eba6f02b3ad1f8e0756f/ui/views/cocoa/bridged_content_view.mm#L816
         #[unsafe(method(_wantsKeyDownForEvent:))]
         fn wants_key_down_for_event(&self, _event: &NSEvent) -> bool {
-            let _entered = debug_span!("_wantsKeyDownForEvent:").entered();
+            trace_scope!("_wantsKeyDownForEvent:");
             true
         }
 
         #[unsafe(method(acceptsFirstMouse:))]
         fn accepts_first_mouse(&self, _event: &NSEvent) -> bool {
-            let _entered = debug_span!("acceptsFirstMouse:").entered();
+            trace_scope!("acceptsFirstMouse:");
             self.ivars().accepts_first_mouse
         }
     }
@@ -848,9 +847,16 @@ impl WinitView {
     }
 
     fn queue_event(&self, event: WindowEvent) {
+        let app = NSApplication::sharedApplication(self.mtm());
         let window_id = window_id(&self.window());
+        let time = if let Some(nsevent) = app.currentEvent() {
+            self.ivars().app_state.event_time(&nsevent)
+        } else {
+            warn!("queued event with wrong timestamp, no active NSEvent found");
+            Instant::now()
+        };
         self.ivars().app_state.maybe_queue_with_handler(move |app, event_loop| {
-            app.window_event(event_loop, window_id, event);
+            app.window_event(event_loop, window_id, time, event);
         });
     }
 

winit-appkit/src/window.rs

@@ -8,7 +8,6 @@ use objc2::rc::{Retained, autoreleasepool};
 use objc2::{MainThreadMarker, Message, define_class};
 use objc2_app_kit::{NSPanel, NSResponder, NSWindow};
 use objc2_foundation::NSObject;
-use tracing::trace_span;
 use winit_core::cursor::Cursor;
 use winit_core::error::RequestError;
 use winit_core::icon::Icon;
@@ -351,13 +350,13 @@ define_class!(
     impl WinitWindow {
         #[unsafe(method(canBecomeMainWindow))]
         fn can_become_main_window(&self) -> bool {
-            let _entered = trace_span!("canBecomeMainWindow").entered();
+            trace_scope!("canBecomeMainWindow");
             true
         }
 
         #[unsafe(method(canBecomeKeyWindow))]
         fn can_become_key_window(&self) -> bool {
-            let _entered = trace_span!("canBecomeKeyWindow").entered();
+            trace_scope!("canBecomeKeyWindow");
             true
         }
     }
@@ -375,7 +374,7 @@ define_class!(
         // it doesn't if window doesn't have NSWindowStyleMask::Titled
         #[unsafe(method(canBecomeKeyWindow))]
         fn can_become_key_window(&self) -> bool {
-            let _entered = trace_span!("canBecomeKeyWindow").entered();
+            trace_scope!("canBecomeKeyWindow");
             true
         }
     }

winit-appkit/src/window_delegate.rs

@@ -5,6 +5,7 @@ use std::ffi::c_void;
 use std::ptr;
 use std::rc::Rc;
 use std::sync::{Arc, Mutex};
+use std::time::Instant;
 
 use dpi::{
     LogicalInsets, LogicalPosition, LogicalSize, PhysicalInsets, PhysicalPosition, PhysicalSize,
@@ -41,7 +42,7 @@ use objc2_foundation::{
     NSObjectNSDelayedPerforming, NSObjectNSKeyValueObserverRegistration, NSObjectProtocol, NSPoint,
     NSRect, NSSize, NSString, ns_string,
 };
-use tracing::{debug_span, trace, warn};
+use tracing::{trace, warn};
 use winit_common::core_foundation::MainRunLoop;
 use winit_core::cursor::Cursor;
 use winit_core::error::{NotSupportedError, RequestError};
@@ -121,14 +122,14 @@ define_class!(
     unsafe impl NSWindowDelegate for WindowDelegate {
         #[unsafe(method(windowShouldClose:))]
         fn window_should_close(&self, _: Option<&AnyObject>) -> bool {
-            let _entered = debug_span!("windowShouldClose:").entered();
+            trace_scope!("windowShouldClose:");
             self.queue_event(WindowEvent::CloseRequested);
             false
         }
 
         #[unsafe(method(windowWillClose:))]
         fn window_will_close(&self, _: Option<&AnyObject>) {
-            let _entered = debug_span!("windowWillClose:").entered();
+            trace_scope!("windowWillClose:");
             // `setDelegate:` retains the previous value and then autoreleases it
             autoreleasepool(|_| {
                 // Since El Capitan, we need to be careful that delegate methods can't
@@ -140,14 +141,14 @@ define_class!(
 
         #[unsafe(method(windowDidResize:))]
         fn window_did_resize(&self, _: Option<&AnyObject>) {
-            let _entered = debug_span!("windowDidResize:").entered();
+            trace_scope!("windowDidResize:");
             // NOTE: WindowEvent::SurfaceResized is reported using NSViewFrameDidChangeNotification.
             self.emit_move_event();
         }
 
         #[unsafe(method(windowWillStartLiveResize:))]
         fn window_will_start_live_resize(&self, _: Option<&AnyObject>) {
-            let _entered = debug_span!("windowWillStartLiveResize:").entered();
+            trace_scope!("windowWillStartLiveResize:");
 
             let increments = self.ivars().surface_resize_increments.get();
             self.set_resize_increments_inner(increments);
@@ -155,20 +156,20 @@ define_class!(
 
         #[unsafe(method(windowDidEndLiveResize:))]
         fn window_did_end_live_resize(&self, _: Option<&AnyObject>) {
-            let _entered = debug_span!("windowDidEndLiveResize:").entered();
+            trace_scope!("windowDidEndLiveResize:");
             self.set_resize_increments_inner(NSSize::new(1., 1.));
         }
 
         // This won't be triggered if the move was part of a resize.
         #[unsafe(method(windowDidMove:))]
         fn window_did_move(&self, _: Option<&AnyObject>) {
-            let _entered = debug_span!("windowDidMove:").entered();
+            trace_scope!("windowDidMove:");
             self.emit_move_event();
         }
 
         #[unsafe(method(windowDidChangeBackingProperties:))]
         fn window_did_change_backing_properties(&self, _: Option<&AnyObject>) {
-            let _entered = debug_span!("windowDidChangeBackingProperties:").entered();
+            trace_scope!("windowDidChangeBackingProperties:");
             let scale_factor = self.scale_factor();
             if scale_factor == self.ivars().previous_scale_factor.get() {
                 return;
@@ -184,7 +185,7 @@ define_class!(
 
         #[unsafe(method(windowDidBecomeKey:))]
         fn window_did_become_key(&self, _: Option<&AnyObject>) {
-            let _entered = debug_span!("windowDidBecomeKey:").entered();
+            trace_scope!("windowDidBecomeKey:");
             // TODO: center the cursor if the window had mouse grab when it
             // lost focus
             self.queue_event(WindowEvent::Focused(true));
@@ -192,7 +193,7 @@ define_class!(
 
         #[unsafe(method(windowDidResignKey:))]
         fn window_did_resign_key(&self, _: Option<&AnyObject>) {
-            let _entered = debug_span!("windowDidResignKey:").entered();
+            trace_scope!("windowDidResignKey:");
             // It happens rather often, e.g. when the user is Cmd+Tabbing, that the
             // NSWindowDelegate will receive a didResignKey event despite no event
             // being received when the modifiers are released. This is because
@@ -208,7 +209,7 @@ define_class!(
         /// Invoked when before enter fullscreen
         #[unsafe(method(windowWillEnterFullScreen:))]
         fn window_will_enter_fullscreen(&self, _: Option<&AnyObject>) {
-            let _entered = debug_span!("windowWillEnterFullScreen:").entered();
+            trace_scope!("windowWillEnterFullScreen:");
 
             self.ivars().maximized.set(self.is_zoomed());
             let mut fullscreen = self.ivars().fullscreen.borrow_mut();
@@ -236,7 +237,7 @@ define_class!(
         /// Invoked when before exit fullscreen
         #[unsafe(method(windowWillExitFullScreen:))]
         fn window_will_exit_fullscreen(&self, _: Option<&AnyObject>) {
-            let _entered = debug_span!("windowWillExitFullScreen:").entered();
+            trace_scope!("windowWillExitFullScreen:");
 
             self.ivars().in_fullscreen_transition.set(true);
         }
@@ -247,7 +248,7 @@ define_class!(
             _: Option<&AnyObject>,
             proposed_options: NSApplicationPresentationOptions,
         ) -> NSApplicationPresentationOptions {
-            let _entered = debug_span!("window:willUseFullScreenPresentationOptions:").entered();
+            trace_scope!("window:willUseFullScreenPresentationOptions:");
             // Generally, games will want to disable the menu bar and the dock. Ideally,
             // this would be configurable by the user. Unfortunately because of our
             // `CGShieldingWindowLevel() + 1` hack (see `set_fullscreen`), our window is
@@ -270,7 +271,7 @@ define_class!(
         /// Invoked when entered fullscreen
         #[unsafe(method(windowDidEnterFullScreen:))]
         fn window_did_enter_fullscreen(&self, _: Option<&AnyObject>) {
-            let _entered = debug_span!("windowDidEnterFullScreen:").entered();
+            trace_scope!("windowDidEnterFullScreen:");
             self.ivars().initial_fullscreen.set(false);
             self.ivars().in_fullscreen_transition.set(false);
             if let Some(target_fullscreen) = self.ivars().target_fullscreen.take() {
@@ -281,7 +282,7 @@ define_class!(
         /// Invoked when exited fullscreen
         #[unsafe(method(windowDidExitFullScreen:))]
         fn window_did_exit_fullscreen(&self, _: Option<&AnyObject>) {
-            let _entered = debug_span!("windowDidExitFullScreen:").entered();
+            trace_scope!("windowDidExitFullScreen:");
 
             self.restore_state_from_fullscreen();
             self.ivars().in_fullscreen_transition.set(false);
@@ -308,7 +309,7 @@ define_class!(
         /// work you may have done to prepare to enter full-screen mode.
         #[unsafe(method(windowDidFailToEnterFullScreen:))]
         fn window_did_fail_to_enter_fullscreen(&self, _: Option<&AnyObject>) {
-            let _entered = debug_span!("windowDidFailToEnterFullScreen:").entered();
+            trace_scope!("windowDidFailToEnterFullScreen:");
             self.ivars().in_fullscreen_transition.set(false);
             self.ivars().target_fullscreen.replace(None);
             if self.ivars().initial_fullscreen.get() {
@@ -327,7 +328,7 @@ define_class!(
         // Invoked when the occlusion state of the window changes
         #[unsafe(method(windowDidChangeOcclusionState:))]
         fn window_did_change_occlusion_state(&self, _: Option<&AnyObject>) {
-            let _entered = debug_span!("windowDidChangeOcclusionState:").entered();
+            trace_scope!("windowDidChangeOcclusionState:");
             let visible = self.window().occlusionState().contains(NSWindowOcclusionState::Visible);
             self.queue_event(WindowEvent::Occluded(!visible));
 
@@ -348,7 +349,7 @@ define_class!(
 
         #[unsafe(method(windowDidChangeScreen:))]
         fn window_did_change_screen(&self, _: Option<&AnyObject>) {
-            let _entered = debug_span!("windowDidChangeScreen:").entered();
+            trace_scope!("windowDidChangeScreen:");
             let is_simple_fullscreen = self.ivars().is_simple_fullscreen.get();
             if is_simple_fullscreen {
                 if let Some(screen) = self.window().screen() {
@@ -362,7 +363,7 @@ define_class!(
         /// Invoked when the dragged image enters destination bounds or frame
         #[unsafe(method(draggingEntered:))]
         fn dragging_entered(&self, sender: &ProtocolObject<dyn NSDraggingInfo>) -> bool {
-            let _entered = debug_span!("draggingEntered:").entered();
+            trace_scope!("draggingEntered:");
 
             use std::path::PathBuf;
 
@@ -393,7 +394,7 @@ define_class!(
 
         #[unsafe(method(wantsPeriodicDraggingUpdates))]
         fn wants_periodic_dragging_updates(&self) -> bool {
-            let _entered = debug_span!("wantsPeriodicDraggingUpdates:").entered();
+            trace_scope!("wantsPeriodicDraggingUpdates:");
             true
         }
 
@@ -401,7 +402,7 @@ define_class!(
         /// modification of the dragging operation or mouse-pointer position.
         #[unsafe(method(draggingUpdated:))]
         fn dragging_updated(&self, sender: &ProtocolObject<dyn NSDraggingInfo>) -> bool {
-            let _entered = debug_span!("draggingUpdated:").entered();
+            trace_scope!("draggingUpdated:");
 
             let dl = sender.draggingLocation();
             let dl = self.view().convertPoint_fromView(dl, None);
@@ -416,14 +417,14 @@ define_class!(
         /// Invoked when the image is released
         #[unsafe(method(prepareForDragOperation:))]
         fn prepare_for_drag_operation(&self, _sender: &NSObject) -> bool {
-            let _entered = debug_span!("prepareForDragOperation:").entered();
+            trace_scope!("prepareForDragOperation:");
             true
         }
 
         /// Invoked after the released image has been removed from the screen
         #[unsafe(method(performDragOperation:))]
         fn perform_drag_operation(&self, sender: &ProtocolObject<dyn NSDraggingInfo>) -> bool {
-            let _entered = debug_span!("performDragOperation:").entered();
+            trace_scope!("performDragOperation:");
 
             use std::path::PathBuf;
 
@@ -455,13 +456,13 @@ define_class!(
         /// Invoked when the dragging operation is complete
         #[unsafe(method(concludeDragOperation:))]
         fn conclude_drag_operation(&self, _sender: Option<&NSObject>) {
-            let _entered = debug_span!("concludeDragOperation:").entered();
+            trace_scope!("concludeDragOperation:");
         }
 
         /// Invoked when the dragging operation is cancelled
         #[unsafe(method(draggingExited:))]
         fn dragging_exited(&self, sender: Option<&ProtocolObject<dyn NSDraggingInfo>>) {
-            let _entered = debug_span!("draggingExited:").entered();
+            trace_scope!("draggingExited:");
 
             let position = sender.map(|sender| {
                 let dl = sender.draggingLocation();
@@ -483,7 +484,7 @@ define_class!(
             change: Option<&NSDictionary<NSKeyValueChangeKey, AnyObject>>,
             _context: *mut c_void,
         ) {
-            let _entered = debug_span!("observeValueForKeyPath:ofObject:change:context:").entered();
+            trace_scope!("observeValueForKeyPath:ofObject:change:context:");
             // NOTE: We don't _really_ need to check the key path, as there should only be one, but
             // in the future we might want to observe other key paths.
             if key_path == Some(ns_string!("effectiveAppearance")) {
@@ -903,9 +904,16 @@ impl WindowDelegate {
     }
 
     pub(crate) fn queue_event(&self, event: WindowEvent) {
+        let app = NSApplication::sharedApplication(self.mtm());
         let window_id = window_id(self.window());
+        let time = if let Some(nsevent) = app.currentEvent() {
+            self.ivars().app_state.event_time(&nsevent)
+        } else {
+            warn!("queued event with wrong timestamp, no active NSEvent found");
+            Instant::now()
+        };
         self.ivars().app_state.maybe_queue_with_handler(move |app, event_loop| {
-            app.window_event(event_loop, window_id, event);
+            app.window_event(event_loop, window_id, time, event);
         });
     }
 

winit-common/src/core_foundation/main_run_loop.rs

@@ -9,7 +9,7 @@ use std::cell::Cell;
 
 use objc2::MainThreadMarker;
 use objc2_core_foundation::{CFRetained, CFRunLoop, CFRunLoopMode, kCFRunLoopDefaultMode};
-use tracing::{Span, error};
+use tracing::error;
 
 use super::MainRunLoopObserver;
 
@@ -49,8 +49,7 @@ impl MainRunLoop {
     /// This queuing could be implemented in the following several ways with subtle differences in
     /// timing. This list is sorted in rough order in which they are run:
     ///
-    /// 1. Using `CFRunLoopPerformBlock` or `-[NSRunLoop performBlock:]` to queue a closure to run
-    ///    the next time runloop sources are processed.
+    /// 1. Using `CFRunLoopPerformBlock` or `-[NSRunLoop performBlock:]`.
     ///
     /// 2. Using `-[NSObject performSelectorOnMainThread:withObject:waitUntilDone:]` or wrapping the
     ///    event in `NSEvent` and posting that to `-[NSApplication postEvent:atStart:]` (both
@@ -74,17 +73,9 @@ impl MainRunLoop {
     /// put the event at the very front of the queue, to be handled as soon as possible after
     /// handling whatever event it's currently handling.
     pub fn queue_closure(&self, closure: impl FnOnce() + 'static) {
-        // We use this to run a closure asynchronously at a later point, so it also makes sense to
-        // re-enter the current span when running the queued closure.
-        let span = Span::current();
-
         // Convert `FnOnce()` to `Block<dyn Fn()>`.
         let closure = Cell::new(Some(closure));
         let block = block2::RcBlock::new(move || {
-            // Running this block happens inside a `CFRunLoopSource`, but the spans that we emit for
-            // that are (intentionally) overwritten by entering the span from before.
-            let _enter = span.enter();
-
             debug_assert!(MainThreadMarker::new().is_some());
             if let Some(closure) = closure.take() {
                 closure()

winit-common/src/core_foundation/mod.rs

@@ -6,9 +6,7 @@
 mod event_loop_proxy;
 mod main_run_loop;
 mod main_run_loop_observer;
-mod tracing_observers;
 
 pub use self::event_loop_proxy::*;
 pub use self::main_run_loop::*;
 pub use self::main_run_loop_observer::*;
-pub use self::tracing_observers::*;

winit-common/src/core_foundation/tracing_observers.rs

@@ -1,146 +0,0 @@
-use std::cell::RefCell;
-use std::rc::Rc;
-
-use objc2::MainThreadMarker;
-use objc2_core_foundation::{CFIndex, CFRunLoop, CFRunLoopActivity, kCFRunLoopDefaultMode};
-use tracing::span::EnteredSpan;
-use tracing::{Level, error, field, span_enabled, trace_span};
-
-use crate::core_foundation::MainRunLoopObserver;
-
-/// Create two run loop observers that add TRACE-level [spans][tracing::span].
-///
-/// This is useful when debugging run loops, it makes it easier to see in which run loop activity an
-/// event is triggered inside (if any).
-///
-/// When debugging these interactions, it can also be useful to configure your tracing subscriber
-/// with `.with_span_events(tracing_subscriber::fmt::format::FmtSpan::ACTIVE)` to emit events upon
-/// entering and exiting these stages.
-pub fn tracing_observers(
-    mtm: MainThreadMarker,
-) -> Option<(MainRunLoopObserver, MainRunLoopObserver)> {
-    // Observers are a bit costly, so don't create them if the tracing-level for this module is
-    // configured to disable them.
-    if !span_enabled!(Level::TRACE) {
-        return None;
-    }
-
-    /// The state that we think the runloop is currently in.
-    ///
-    /// The order of activities we observe if waiting twice looks something like:
-    /// - CFRunLoopActivity::Entry
-    /// - CFRunLoopActivity::BeforeTimers
-    /// - CFRunLoopActivity::BeforeSources
-    /// - CFRunLoopActivity::BeforeWaiting
-    /// - CFRunLoopActivity::AfterWaiting
-    /// - CFRunLoopActivity::BeforeTimers
-    /// - CFRunLoopActivity::BeforeSources
-    /// - CFRunLoopActivity::BeforeWaiting
-    /// - CFRunLoopActivity::AfterWaiting
-    /// - CFRunLoopActivity::Exit
-    ///
-    /// And if not waiting, it looks something like:
-    /// - CFRunLoopActivity::Entry
-    /// - CFRunLoopActivity::BeforeTimers
-    /// - CFRunLoopActivity::BeforeSources
-    /// - CFRunLoopActivity::Exit
-    #[derive(Default)]
-    #[allow(unused)] // EnteredSpans are kept around
-    enum RunLoopState {
-        /// Currently processing `Entry`/`Exit` observers.
-        #[default]
-        Entered,
-        /// Currently processing timers or `BeforeTimers` observers.
-        Timers(EnteredSpan),
-        /// Currently processing sources or `BeforeSources` observers.
-        Sources(EnteredSpan),
-        /// Currently waiting or processing `BeforeWaiting`/`AfterWaiting` observers.
-        Waiting(EnteredSpan),
-    }
-
-    // A list of currently entered (outer) spans and their state.
-    //
-    // This is a list because runloops can be run recursively.
-    let spans: Rc<RefCell<Vec<(EnteredSpan, RunLoopState)>>> = Rc::new(RefCell::new(Vec::new()));
-    let spans_clone = Rc::clone(&spans);
-
-    // An observer at the start of run loop activities.
-    let activities = CFRunLoopActivity::Entry
-        | CFRunLoopActivity::BeforeTimers
-        | CFRunLoopActivity::BeforeSources
-        | CFRunLoopActivity::BeforeWaiting;
-    let start = MainRunLoopObserver::new(mtm, activities, true, CFIndex::MIN, move |activity| {
-        match activity {
-            // Add an outer span for each runloop iteration.
-            CFRunLoopActivity::Entry => {
-                let span = trace_span!("inside runloop", mode = field::Empty);
-
-                // Get the mode dynamically, the observer may added to multiple different modes.
-                let mode = CFRunLoop::current().unwrap().current_mode().unwrap();
-                // Mode isn't interesting if it's the default mode.
-                if &*mode != unsafe { kCFRunLoopDefaultMode }.unwrap() {
-                    span.record("mode", field::display(mode));
-                }
-
-                let entered = span.entered();
-                spans.borrow_mut().push((entered, RunLoopState::Entered));
-            },
-
-            // Add inner spans that help inspecting the state the runloop is in.
-            CFRunLoopActivity::BeforeTimers => {
-                if let Some((_, state)) = spans.borrow_mut().last_mut() {
-                    *state = RunLoopState::Entered; // Drop any previous spans.
-                    *state = RunLoopState::Timers(trace_span!("processing timers").entered());
-                } else {
-                    error!("unbalanced observer invocations");
-                }
-            },
-            CFRunLoopActivity::BeforeSources => {
-                if let Some((_, state)) = spans.borrow_mut().last_mut() {
-                    *state = RunLoopState::Entered; // Drop any previous spans.
-                    *state = RunLoopState::Sources(trace_span!("processing sources").entered());
-                } else {
-                    error!("unbalanced observer invocations");
-                }
-            },
-            CFRunLoopActivity::BeforeWaiting => {
-                if let Some((_, state)) = spans.borrow_mut().last_mut() {
-                    *state = RunLoopState::Entered; // Drop any previous spans.
-                    *state = RunLoopState::Waiting(trace_span!("waiting").entered());
-                } else {
-                    error!("unbalanced observer invocations");
-                }
-            },
-
-            activity => unreachable!("unexpected activity: {activity:?}"),
-        }
-    });
-
-    // An observer at the end of run loop activities.
-    let activities = CFRunLoopActivity::AfterWaiting | CFRunLoopActivity::Exit;
-    let end = MainRunLoopObserver::new(mtm, activities, true, CFIndex::MAX, move |activity| {
-        match activity {
-            CFRunLoopActivity::AfterWaiting => {
-                if let Some((_, state)) = spans_clone.borrow_mut().last_mut() {
-                    // Transition from the waiting state to the initial state.
-                    *state = RunLoopState::Entered;
-                } else {
-                    error!("unbalanced observer invocations");
-                }
-            },
-
-            CFRunLoopActivity::Exit => {
-                if let Some((span, state)) = spans_clone.borrow_mut().pop() {
-                    drop(state); // Explicitly exit and drop inner span.
-                    drop(span); // Explicitly exit and drop outer span.
-                } else {
-                    error!("unbalanced observer invocations");
-                }
-            },
-
-            activity => unreachable!("unexpected activity: {activity:?}"),
-        }
-    });
-
-    Some((start, end))
-}

winit-common/src/event_handler.rs

@@ -79,10 +79,6 @@ impl EventHandler {
                         // Allowed, happens if the handler was cleared manually
                         // elsewhere (such as in `applicationWillTerminate:`).
                     },
-                    // We use `eprintln!` here over `tracing::error!`, since we're going to abort
-                    // immediately after this, and it'd be annoying for the user if they didn't get
-                    // any feedback on that if they don't have a tracing subscriber.
-                    #[allow(clippy::disallowed_macros)]
                     Err(_) => {
                         // Note: This is not expected to ever happen, this
                         // module generally controls the `RefCell`, and

winit-core/src/application/mod.rs

@@ -1,4 +1,9 @@
 //! End user application handling.
+#[cfg(not(target_family = "wasm"))]
+use std::time::Instant;
+
+#[cfg(target_family = "wasm")]
+use web_time::Instant;
 
 use crate::event::{DeviceEvent, DeviceId, StartCause, WindowEvent};
 use crate::event_loop::ActiveEventLoop;
@@ -192,10 +197,14 @@ pub trait ApplicationHandler {
     }
 
     /// Emitted when the OS sends an event to a winit window.
+    ///
+    /// Contains the ID of the window, the event, and the time the event was received. Note that
+    /// since events are queued, the time will differ from [`Instant::now()`].
     fn window_event(
         &mut self,
         event_loop: &dyn ActiveEventLoop,
         window_id: WindowId,
+        timestamp: Instant,
         event: WindowEvent,
     );
 
@@ -206,9 +215,10 @@ pub trait ApplicationHandler {
         &mut self,
         event_loop: &dyn ActiveEventLoop,
         device_id: Option<DeviceId>,
+        timestamp: Instant,
         event: DeviceEvent,
     ) {
-        let _ = (event_loop, device_id, event);
+        let _ = (event_loop, device_id, timestamp, event);
     }
 
     /// Emitted when the event loop is about to block and wait for new events.
@@ -372,9 +382,10 @@ impl<A: ?Sized + ApplicationHandler> ApplicationHandler for &mut A {
         &mut self,
         event_loop: &dyn ActiveEventLoop,
         window_id: WindowId,
+        timestamp: Instant,
         event: WindowEvent,
     ) {
-        (**self).window_event(event_loop, window_id, event);
+        (**self).window_event(event_loop, window_id, timestamp, event);
     }
 
     #[inline]
@@ -382,9 +393,10 @@ impl<A: ?Sized + ApplicationHandler> ApplicationHandler for &mut A {
         &mut self,
         event_loop: &dyn ActiveEventLoop,
         device_id: Option<DeviceId>,
+        timestamp: Instant,
         event: DeviceEvent,
     ) {
-        (**self).device_event(event_loop, device_id, event);
+        (**self).device_event(event_loop, device_id, timestamp, event);
     }
 
     #[inline]
@@ -440,9 +452,10 @@ impl<A: ?Sized + ApplicationHandler> ApplicationHandler for Box<A> {
         &mut self,
         event_loop: &dyn ActiveEventLoop,
         window_id: WindowId,
+        timestamp: Instant,
         event: WindowEvent,
     ) {
-        (**self).window_event(event_loop, window_id, event);
+        (**self).window_event(event_loop, window_id, timestamp, event);
     }
 
     #[inline]
@@ -450,9 +463,10 @@ impl<A: ?Sized + ApplicationHandler> ApplicationHandler for Box<A> {
         &mut self,
         event_loop: &dyn ActiveEventLoop,
         device_id: Option<DeviceId>,
+        timestamp: Instant,
         event: DeviceEvent,
     ) {
-        (**self).device_event(event_loop, device_id, event);
+        (**self).device_event(event_loop, device_id, timestamp, event);
     }
 
     #[inline]

winit-uikit/src/event_loop.rs

@@ -12,8 +12,7 @@ use objc2_ui_kit::{
     UIApplicationWillResignActiveNotification, UIApplicationWillTerminateNotification, UIScreen,
 };
 use rwh_06::HasDisplayHandle;
-use tracing::debug_span;
-use winit_common::core_foundation::{MainRunLoop, MainRunLoopObserver, tracing_observers};
+use winit_common::core_foundation::{MainRunLoop, MainRunLoopObserver};
 use winit_core::application::ApplicationHandler;
 use winit_core::cursor::{CustomCursor, CustomCursorSource};
 use winit_core::error::{EventLoopError, NotSupportedError, RequestError};
@@ -135,7 +134,6 @@ pub struct EventLoop {
     _will_terminate_observer: Retained<ProtocolObject<dyn NSObjectProtocol>>,
     _did_receive_memory_warning_observer: Retained<ProtocolObject<dyn NSObjectProtocol>>,
 
-    _tracing_observers: Option<(MainRunLoopObserver, MainRunLoopObserver)>,
     _wakeup_observer: MainRunLoopObserver,
     _main_events_cleared_observer: MainRunLoopObserver,
     _events_cleared_observer: MainRunLoopObserver,
@@ -161,7 +159,6 @@ impl EventLoop {
             // `application:didFinishLaunchingWithOptions:`
             unsafe { UIApplicationDidFinishLaunchingNotification },
             move |_| {
-                let _entered = debug_span!("UIApplicationDidFinishLaunchingNotification").entered();
                 app_state::did_finish_launching(mtm);
             },
         );
@@ -169,27 +166,19 @@ impl EventLoop {
             &center,
             // `applicationDidBecomeActive:`
             unsafe { UIApplicationDidBecomeActiveNotification },
-            move |_| {
-                let _entered = debug_span!("UIApplicationDidBecomeActiveNotification").entered();
-                app_state::handle_resumed(mtm)
-            },
+            move |_| app_state::handle_resumed(mtm),
         );
         let _will_resign_active_observer = create_observer(
             &center,
             // `applicationWillResignActive:`
             unsafe { UIApplicationWillResignActiveNotification },
-            move |_| {
-                let _entered = debug_span!("UIApplicationWillResignActiveNotification").entered();
-                app_state::handle_suspended(mtm)
-            },
+            move |_| app_state::handle_suspended(mtm),
         );
         let _will_enter_foreground_observer = create_observer(
             &center,
             // `applicationWillEnterForeground:`
             unsafe { UIApplicationWillEnterForegroundNotification },
             move |notification| {
-                let _entered =
-                    debug_span!("UIApplicationWillEnterForegroundNotification").entered();
                 let app = notification.object().expect(
                     "UIApplicationWillEnterForegroundNotification to have application object",
                 );
@@ -204,7 +193,6 @@ impl EventLoop {
             // `applicationDidEnterBackground:`
             unsafe { UIApplicationDidEnterBackgroundNotification },
             move |notification| {
-                let _entered = debug_span!("UIApplicationDidEnterBackgroundNotification").entered();
                 let app = notification.object().expect(
                     "UIApplicationDidEnterBackgroundNotification to have application object",
                 );
@@ -219,7 +207,6 @@ impl EventLoop {
             // `applicationWillTerminate:`
             unsafe { UIApplicationWillTerminateNotification },
             move |notification| {
-                let _entered = debug_span!("UIApplicationWillTerminateNotification").entered();
                 let app = notification
                     .object()
                     .expect("UIApplicationWillTerminateNotification to have application object");
@@ -233,29 +220,18 @@ impl EventLoop {
             &center,
             // `applicationDidReceiveMemoryWarning:`
             unsafe { UIApplicationDidReceiveMemoryWarningNotification },
-            move |_| {
-                let _entered =
-                    debug_span!("UIApplicationDidReceiveMemoryWarningNotification").entered();
-                app_state::handle_memory_warning(mtm)
-            },
+            move |_| app_state::handle_memory_warning(mtm),
         );
 
         let main_loop = MainRunLoop::get(mtm);
         let mode = unsafe { kCFRunLoopDefaultMode }.unwrap();
 
-        // Tracing observers have the lowest and highest orderings.
-        let _tracing_observers = tracing_observers(mtm).inspect(|(start, end)| {
-            main_loop.add_observer(start, mode);
-            main_loop.add_observer(end, mode);
-        });
-
         let _wakeup_observer = MainRunLoopObserver::new(
             mtm,
             CFRunLoopActivity::AfterWaiting,
             true,
-            // Queued with the second-highest priority (tracing observers use the highest) to
-            // ensure it is processed before other observers.
-            CFIndex::MIN + 1,
+            // Queued with the highest priority to ensure it is processed before other observers.
+            CFIndex::MIN,
             move |_| app_state::handle_wakeup_transition(mtm),
         );
         main_loop.add_observer(&_wakeup_observer, mode);
@@ -265,17 +241,17 @@ impl EventLoop {
             CFRunLoopActivity::BeforeWaiting,
             true,
             // Core Animation registers its `CFRunLoopObserver` that performs drawing operations in
-            // `CA::Transaction::ensure_implicit` with a priority of `2000000`. We set the
+            // `CA::Transaction::ensure_implicit` with a priority of `0x1e8480`. We set the
             // main_end priority to be 0, in order to send `AboutToWait` before `RedrawRequested`.
             // This value was chosen conservatively to guard against apple using different
             // priorities for their redraw observers in different OS's or on different devices. If
             // it so happens that it's too conservative, the main symptom would be non-redraw
             // events coming in after `AboutToWait`.
             //
-            // The value of `2000000` was determined by inspecting stack traces and the associated
+            // The value of `0x1e8480` was determined by inspecting stack traces and the associated
             // registers for every `CFRunLoopAddObserver` call on an iPad Air 2 running iOS 11.4.
             //
-            // Also tested to be `2000000` on iPhone 8, iOS 13 beta 4.
+            // Also tested to be `0x1e8480` on iPhone 8, iOS 13 beta 4.
             0,
             move |_| app_state::handle_main_events_cleared(mtm),
         );
@@ -285,9 +261,8 @@ impl EventLoop {
             mtm,
             CFRunLoopActivity::BeforeWaiting,
             true,
-            // Queued with the second-lowest priority (tracing observers use the lowest) to ensure
-            // it is processed after other observers.
-            CFIndex::MAX - 1,
+            // Queued with the lowest priority to ensure it is processed after other observers.
+            CFIndex::MAX,
             move |_| app_state::handle_events_cleared(mtm),
         );
         main_loop.add_observer(&_events_cleared_observer, mode);
@@ -302,7 +277,6 @@ impl EventLoop {
             _did_enter_background_observer,
             _will_terminate_observer,
             _did_receive_memory_warning_observer,
-            _tracing_observers,
             _wakeup_observer,
             _main_events_cleared_observer,
             _events_cleared_observer,

winit-uikit/src/view.rs

@@ -13,7 +13,7 @@ use objc2_ui_kit::{
     UIResponder, UIRotationGestureRecognizer, UITapGestureRecognizer, UITextInputTraits, UITouch,
     UITouchPhase, UITouchType, UITraitEnvironment, UIView,
 };
-use tracing::{debug, debug_span, trace_span};
+use tracing::debug;
 use winit_core::event::{
     ButtonSource, ElementState, FingerId, Force, KeyEvent, PointerKind, PointerSource,
     TabletToolAngle, TabletToolButton, TabletToolData, TabletToolKind, TouchPhase, WindowEvent,
@@ -48,7 +48,6 @@ define_class!(
     impl WinitView {
         #[unsafe(method(drawRect:))]
         fn draw_rect(&self, rect: CGRect) {
-            let _entered = debug_span!("drawRect:").entered();
             let mtm = MainThreadMarker::new().unwrap();
             let window = self.window().unwrap();
             app_state::handle_nonuser_event(mtm, EventWrapper::Window {
@@ -60,7 +59,6 @@ define_class!(
 
         #[unsafe(method(layoutSubviews))]
         fn layout_subviews(&self) {
-            let _entered = debug_span!("layoutSubviews").entered();
             let mtm = MainThreadMarker::new().unwrap();
             let _: () = unsafe { msg_send![super(self), layoutSubviews] };
 
@@ -81,7 +79,6 @@ define_class!(
 
         #[unsafe(method(setContentScaleFactor:))]
         fn set_content_scale_factor(&self, untrusted_scale_factor: CGFloat) {
-            let _entered = debug_span!("setContentScaleFactor:").entered();
             let mtm = MainThreadMarker::new().unwrap();
             let _: () =
                 unsafe { msg_send![super(self), setContentScaleFactor: untrusted_scale_factor] };
@@ -127,7 +124,6 @@ define_class!(
 
         #[unsafe(method(safeAreaInsetsDidChange))]
         fn safe_area_changed(&self) {
-            let _entered = debug_span!("safeAreaInsetsDidChange").entered();
             debug!("safeAreaInsetsDidChange was called, requesting redraw");
             // When the safe area changes we want to make sure to emit a redraw event
             self.setNeedsDisplay();
@@ -135,31 +131,26 @@ define_class!(
 
         #[unsafe(method(touchesBegan:withEvent:))]
         fn touches_began(&self, touches: &NSSet<UITouch>, _event: Option<&UIEvent>) {
-            let _entered = debug_span!("touchesBegan:withEvent:").entered();
             self.handle_touches(touches)
         }
 
         #[unsafe(method(touchesMoved:withEvent:))]
         fn touches_moved(&self, touches: &NSSet<UITouch>, _event: Option<&UIEvent>) {
-            let _entered = debug_span!("touchesMoved:withEvent:").entered();
             self.handle_touches(touches)
         }
 
         #[unsafe(method(touchesEnded:withEvent:))]
         fn touches_ended(&self, touches: &NSSet<UITouch>, _event: Option<&UIEvent>) {
-            let _entered = debug_span!("touchesEnded:withEvent:").entered();
             self.handle_touches(touches)
         }
 
         #[unsafe(method(touchesCancelled:withEvent:))]
         fn touches_cancelled(&self, touches: &NSSet<UITouch>, _event: Option<&UIEvent>) {
-            let _entered = debug_span!("touchesCancelled:withEvent:").entered();
             self.handle_touches(touches)
         }
 
         #[unsafe(method(pinchGesture:))]
         fn pinch_gesture(&self, recognizer: &UIPinchGestureRecognizer) {
-            let _entered = debug_span!("pinchGesture:").entered();
             let window = self.window().unwrap();
 
             let (phase, delta) = match recognizer.state() {
@@ -194,7 +185,6 @@ define_class!(
 
         #[unsafe(method(doubleTapGesture:))]
         fn double_tap_gesture(&self, recognizer: &UITapGestureRecognizer) {
-            let _entered = debug_span!("doubleTapGesture:").entered();
             let window = self.window().unwrap();
 
             if recognizer.state() == UIGestureRecognizerState::Ended {
@@ -210,7 +200,6 @@ define_class!(
 
         #[unsafe(method(rotationGesture:))]
         fn rotation_gesture(&self, recognizer: &UIRotationGestureRecognizer) {
-            let _entered = debug_span!("rotationGesture:").entered();
             let window = self.window().unwrap();
 
             let (phase, delta) = match recognizer.state() {
@@ -255,7 +244,6 @@ define_class!(
 
         #[unsafe(method(panGesture:))]
         fn pan_gesture(&self, recognizer: &UIPanGestureRecognizer) {
-            let _entered = debug_span!("panGesture:").entered();
             let window = self.window().unwrap();
 
             let translation = recognizer.translationInView(Some(self));
@@ -308,7 +296,6 @@ define_class!(
 
         #[unsafe(method(canBecomeFirstResponder))]
         fn can_become_first_responder(&self) -> bool {
-            let _entered = trace_span!("canBecomeFirstResponder").entered();
             true
         }
     }
@@ -322,10 +309,6 @@ define_class!(
             _gesture_recognizer: &UIGestureRecognizer,
             _other_gesture_recognizer: &UIGestureRecognizer,
         ) -> bool {
-            let _entered = trace_span!(
-                "gestureRecognizer:shouldRecognizeSimultaneouslyWithGestureRecognizer:"
-            )
-            .entered();
             true
         }
     }
@@ -335,19 +318,16 @@ define_class!(
     unsafe impl UIKeyInput for WinitView {
         #[unsafe(method(hasText))]
         fn has_text(&self) -> bool {
-            let _entered = debug_span!("hasText").entered();
             true
         }
 
         #[unsafe(method(insertText:))]
         fn insert_text(&self, text: &NSString) {
-            let _entered = debug_span!("insertText:").entered();
             self.handle_insert_text(text)
         }
 
         #[unsafe(method(deleteBackward))]
         fn delete_backward(&self) {
-            let _entered = debug_span!("deleteBackward").entered();
             self.handle_delete_backward()
         }
     }

winit-uikit/src/view_controller.rs

@@ -7,7 +7,6 @@ use objc2_ui_kit::{
     UIDevice, UIInterfaceOrientationMask, UIRectEdge, UIResponder, UIStatusBarStyle,
     UIUserInterfaceIdiom, UIView, UIViewController,
 };
-use tracing::trace_span;
 
 use crate::{ScreenEdge, StatusBarStyle, ValidOrientations, WindowAttributesIos};
 
@@ -29,37 +28,31 @@ define_class!(
     impl WinitViewController {
         #[unsafe(method(shouldAutorotate))]
         fn should_autorotate(&self) -> bool {
-            let _entered = trace_span!("shouldAutorotate").entered();
             true
         }
 
         #[unsafe(method(prefersStatusBarHidden))]
         fn prefers_status_bar_hidden(&self) -> bool {
-            let _entered = trace_span!("prefersStatusBarHidden").entered();
             self.ivars().prefers_status_bar_hidden.get()
         }
 
         #[unsafe(method(preferredStatusBarStyle))]
         fn preferred_status_bar_style(&self) -> UIStatusBarStyle {
-            let _entered = trace_span!("preferredStatusBarStyle").entered();
             self.ivars().preferred_status_bar_style.get()
         }
 
         #[unsafe(method(prefersHomeIndicatorAutoHidden))]
         fn prefers_home_indicator_auto_hidden(&self) -> bool {
-            let _entered = trace_span!("prefersHomeIndicatorAutoHidden").entered();
             self.ivars().prefers_home_indicator_auto_hidden.get()
         }
 
         #[unsafe(method(supportedInterfaceOrientations))]
         fn supported_orientations(&self) -> UIInterfaceOrientationMask {
-            let _entered = trace_span!("supportedInterfaceOrientations").entered();
             self.ivars().supported_orientations.get()
         }
 
         #[unsafe(method(preferredScreenEdgesDeferringSystemGestures))]
         fn preferred_screen_edges_deferring_system_gestures(&self) -> UIRectEdge {
-            let _entered = trace_span!("preferredScreenEdgesDeferringSystemGestures").entered();
             self.ivars().preferred_screen_edges_deferring_system_gestures.get()
         }
     }

winit-uikit/src/window.rs

@@ -16,7 +16,7 @@ use objc2_ui_kit::{
     UIApplication, UICoordinateSpace, UIEdgeInsets, UIResponder, UIScreen,
     UIScreenOverscanCompensation, UIViewController, UIWindow,
 };
-use tracing::{debug, debug_span, warn};
+use tracing::{debug, warn};
 use winit_core::cursor::Cursor;
 use winit_core::error::{NotSupportedError, RequestError};
 use winit_core::event::WindowEvent;
@@ -46,7 +46,6 @@ define_class!(
     impl WinitUIWindow {
         #[unsafe(method(becomeKeyWindow))]
         fn become_key_window(&self) {
-            let _entered = debug_span!("becomeKeyWindow").entered();
             let mtm = MainThreadMarker::new().unwrap();
             app_state::handle_nonuser_event(mtm, EventWrapper::Window {
                 window_id: self.id(),
@@ -57,7 +56,6 @@ define_class!(
 
         #[unsafe(method(resignKeyWindow))]
         fn resign_key_window(&self) {
-            let _entered = debug_span!("resignKeyWindow").entered();
             let mtm = MainThreadMarker::new().unwrap();
             app_state::handle_nonuser_event(mtm, EventWrapper::Window {
                 window_id: self.id(),

winit-win32/src/keyboard_layout.rs

@@ -387,7 +387,11 @@ impl LayoutCache {
                 let unicode = Self::to_unicode_string(&key_state, vk, scancode, locale_id);
                 let key = match unicode {
                     ToUnicodeResult::Str(str) => Key::Character(SmolStr::new(str)),
-                    ToUnicodeResult::Dead(dead_char) => Key::Dead(dead_char),
+                    ToUnicodeResult::Dead(dead_char) => {
+                        // println!("{:?} - {:?} produced dead {:?}", key_code, mod_state,
+                        // dead_char);
+                        Key::Dead(dead_char)
+                    },
                     ToUnicodeResult::None => {
                         let has_alt = mod_state.contains(WindowsModifiers::ALT);
                         let has_ctrl = mod_state.contains(WindowsModifiers::CONTROL);

winit-x11/src/util/mod.rs

@@ -66,6 +66,7 @@ impl XConnection {
     // All util functions that abstract an async function will return a `Flusher`.
     pub fn flush_requests(&self) -> Result<(), XError> {
         unsafe { (self.xlib.XFlush)(self.display) };
+        // println!("XFlush");
         // This isn't necessarily a useful time to check for errors (since our request hasn't
         // necessarily been processed yet)
         self.check_errors()
@@ -73,6 +74,7 @@ impl XConnection {
 
     pub fn sync_with_server(&self) -> Result<(), XError> {
         unsafe { (self.xlib.XSync)(self.display, ffi::False) };
+        // println!("XSync");
         self.check_errors()
     }
 }

winit/build.rs

@@ -1,9 +1,7 @@
 use cfg_aliases::cfg_aliases;
 
-// Only relevant for examples and Winit, our usage of println! is fine here.
-#[allow(clippy::disallowed_macros)]
 fn main() {
-    // Dummy invocation to enable change-tracking in build scripts.
+    // The script doesn't depend on our code.
     println!("cargo:rerun-if-changed=build.rs");
 
     // Setup cfg aliases.

winit/examples/child_window.rs

@@ -3,7 +3,6 @@
 fn main() -> Result<(), impl std::error::Error> {
     use std::collections::HashMap;
 
-    use tracing::info;
     use winit::application::ApplicationHandler;
     use winit::dpi::{LogicalPosition, LogicalSize, Position};
     use winit::event::{ElementState, KeyEvent, WindowEvent};
@@ -39,7 +38,7 @@ fn main() -> Result<(), impl std::error::Error> {
                 .with_position(Position::Logical(LogicalPosition::new(0.0, 0.0)))
                 .with_surface_size(LogicalSize::new(640.0f32, 480.0f32));
             let window = event_loop.create_window(attributes).unwrap();
-            info!("Parent window id: {:?})", window.id());
+            println!("Parent window id: {:?})", window.id());
             self.parent_window_id = Some(window.id());
 
             self.windows.insert(window.id(), WindowData::new(window, 0xffbbbbbb));
@@ -57,12 +56,12 @@ fn main() -> Result<(), impl std::error::Error> {
                     event_loop.exit();
                 },
                 WindowEvent::PointerEntered { device_id: _, .. } => {
-                    // On x11, log when the cursor entered in a window even if the child window
+                    // On x11, println when the cursor entered in a window even if the child window
                     // is created by some key inputs.
                     // the child windows are always placed at (0, 0) with size (200, 200) in the
                     // parent window, so we also can see this log when we move
                     // the cursor around (200, 200) in parent window.
-                    info!("cursor entered in the window {window_id:?}");
+                    println!("cursor entered in the window {window_id:?}");
                 },
                 WindowEvent::KeyboardInput {
                     event: KeyEvent { state: ElementState::Pressed, .. },
@@ -76,7 +75,7 @@ fn main() -> Result<(), impl std::error::Error> {
                     let child_window =
                         spawn_child_window(parent_window.window.as_ref(), event_loop, child_index);
                     let child_id = child_window.id();
-                    info!("Child window created with id: {child_id:?}");
+                    println!("Child window created with id: {child_id:?}");
                     self.windows.insert(child_id, WindowData::new(child_window, child_color));
                 },
                 WindowEvent::RedrawRequested => {

winit/examples/control_flow.rs

@@ -4,7 +4,7 @@ use std::thread;
 #[cfg(not(web_platform))]
 use std::time;
 
-use tracing::{info, warn};
+use ::tracing::{info, warn};
 #[cfg(web_platform)]
 use web_time as time;
 use winit::application::ApplicationHandler;

winit/examples/dnd.rs

@@ -1,6 +1,5 @@
 use std::error::Error;
 
-use tracing::info;
 use winit::application::ApplicationHandler;
 use winit::event::WindowEvent;
 use winit::event_loop::{ActiveEventLoop, EventLoop};
@@ -50,7 +49,7 @@ impl ApplicationHandler for Application {
             | WindowEvent::DragEntered { .. }
             | WindowEvent::DragMoved { .. }
             | WindowEvent::DragDropped { .. } => {
-                info!("{event:?}");
+                println!("{event:?}");
             },
             WindowEvent::RedrawRequested => {
                 let window = self.window.as_ref().unwrap();

winit/examples/ime.rs

@@ -76,7 +76,7 @@ impl ApplicationHandler for App {
         self.window = match event_loop.create_window(window_attributes) {
             Ok(window) => Some(window),
             Err(err) => {
-                error!("error creating window: {err}");
+                eprintln!("error creating window: {err}");
                 event_loop.exit();
                 return;
             },
@@ -346,7 +346,7 @@ fn main() -> Result<(), Box<dyn Error>> {
 
     let event_loop = EventLoop::new()?;
 
-    info!(
+    println!(
         r#"This showcases the use of an input method engine (IME) by emulating a text edit field.
 Use CTRL+i to toggle IME support.
 Use CTRL+p to cycle content purpose values.

winit/examples/pump_events.rs

@@ -7,7 +7,6 @@ fn main() -> std::process::ExitCode {
     use std::thread::sleep;
     use std::time::Duration;
 
-    use tracing::info;
     use winit::application::ApplicationHandler;
     use winit::event::WindowEvent;
     use winit::event_loop::pump_events::{EventLoopExtPumpEvents, PumpStatus};
@@ -16,8 +15,6 @@ fn main() -> std::process::ExitCode {
 
     #[path = "util/fill.rs"]
     mod fill;
-    #[path = "util/tracing.rs"]
-    mod tracing;
 
     #[derive(Default, Debug)]
     struct PumpDemo {
@@ -36,7 +33,7 @@ fn main() -> std::process::ExitCode {
             _window_id: WindowId,
             event: WindowEvent,
         ) {
-            info!("{event:?}");
+            println!("{event:?}");
 
             let window = match self.window.as_ref() {
                 Some(window) => window,
@@ -54,10 +51,10 @@ fn main() -> std::process::ExitCode {
         }
     }
 
-    tracing::init();
-
     let mut event_loop = EventLoop::new().unwrap();
 
+    tracing_subscriber::fmt::init();
+
     let mut app = PumpDemo::default();
 
     loop {
@@ -72,12 +69,12 @@ fn main() -> std::process::ExitCode {
         //
         // Since `pump_events` doesn't block it will be important to
         // throttle the loop in the app somehow.
-        info!("Update()");
+        println!("Update()");
         sleep(Duration::from_millis(16));
     }
 }
 
 #[cfg(any(ios_platform, web_platform, orbital_platform))]
 fn main() {
-    panic!("This platform doesn't support pump_events.")
+    println!("This platform doesn't support pump_events.");
 }

winit/examples/run_on_demand.rs

@@ -5,7 +5,6 @@
 fn main() -> Result<(), Box<dyn std::error::Error>> {
     use std::time::Duration;
 
-    use tracing::info;
     use winit::application::ApplicationHandler;
     use winit::event::WindowEvent;
     use winit::event_loop::run_on_demand::EventLoopExtRunOnDemand;
@@ -14,8 +13,6 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
 
     #[path = "util/fill.rs"]
     mod fill;
-    #[path = "util/tracing.rs"]
-    mod tracing;
 
     #[derive(Default, Debug)]
     struct App {
@@ -47,7 +44,10 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
             event: WindowEvent,
         ) {
             if event == WindowEvent::Destroyed && self.window_id == Some(window_id) {
-                info!("Window {} Destroyed", self.idx);
+                println!(
+                    "--------------------------------------------------------- Window {} Destroyed",
+                    self.idx
+                );
                 self.window_id = None;
                 event_loop.exit();
                 return;
@@ -60,7 +60,11 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
 
             match event {
                 WindowEvent::CloseRequested => {
-                    info!("Window {} CloseRequested", self.idx);
+                    println!(
+                        "--------------------------------------------------------- Window {} \
+                         CloseRequested",
+                        self.idx
+                    );
                     fill::cleanup_window(window.as_ref());
                     self.window = None;
                 },
@@ -72,20 +76,20 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
         }
     }
 
-    tracing::init();
+    tracing_subscriber::fmt::init();
 
     let mut event_loop = EventLoop::new().unwrap();
 
     let mut app = App { idx: 1, ..Default::default() };
     event_loop.run_app_on_demand(&mut app)?;
 
-    info!("Finished first loop");
-    info!("Waiting 5 seconds");
+    println!("--------------------------------------------------------- Finished first loop");
+    println!("--------------------------------------------------------- Waiting 5 seconds");
     std::thread::sleep(Duration::from_secs(5));
 
     app.idx += 1;
     event_loop.run_app_on_demand(&mut app)?;
-    info!("Finished second loop");
+    println!("--------------------------------------------------------- Finished second loop");
     Ok(())
 }
 
@@ -97,5 +101,5 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     orbital_platform
 )))]
 fn main() {
-    panic!("This example is not supported on this platform")
+    println!("This example is not supported on this platform");
 }

winit/examples/util/tracing.rs

@@ -23,6 +23,3 @@ pub fn init() {
         )
         .init();
 }
-
-#[allow(unused_imports)]
-pub use ::tracing::*;

winit/examples/window.rs

@@ -1,8 +1,8 @@
 //! Simple winit window example.
 
 use std::error::Error;
+use std::time::Instant;
 
-use tracing::{error, info};
 use winit::application::ApplicationHandler;
 use winit::event::WindowEvent;
 use winit::event_loop::{ActiveEventLoop, EventLoop};
@@ -30,18 +30,24 @@ impl ApplicationHandler for App {
         self.window = match event_loop.create_window(window_attributes) {
             Ok(window) => Some(window),
             Err(err) => {
-                error!("error creating window: {err}");
+                eprintln!("error creating window: {err}");
                 event_loop.exit();
                 return;
             },
         }
     }
 
-    fn window_event(&mut self, event_loop: &dyn ActiveEventLoop, _: WindowId, event: WindowEvent) {
-        info!("{event:?}");
+    fn window_event(
+        &mut self,
+        event_loop: &dyn ActiveEventLoop,
+        _: WindowId,
+        timestamp: Instant,
+        event: WindowEvent,
+    ) {
+        ::tracing::info!("{:?}: {event:?}", timestamp.elapsed());
         match event {
             WindowEvent::CloseRequested => {
-                info!("Close was requested; stopping");
+                println!("Close was requested; stopping");
                 event_loop.exit();
             },
             WindowEvent::SurfaceResized(_) => {
@@ -63,11 +69,21 @@ impl ApplicationHandler for App {
                 fill::fill_window(window.as_ref());
 
                 // For contiguous redraw loop you can request a redraw from here.
-                // window.request_redraw();
+                window.request_redraw();
             },
             _ => (),
         }
     }
+
+    fn device_event(
+        &mut self,
+        _event_loop: &dyn ActiveEventLoop,
+        _device_id: Option<winit::event::DeviceId>,
+        timestamp: Instant,
+        event: winit::event::DeviceEvent,
+    ) {
+        ::tracing::info!("{:?}: {event:?}", timestamp.elapsed());
+    }
 }
 
 fn main() -> Result<(), Box<dyn Error>> {

winit/examples/x11_embed.rs

@@ -11,8 +11,6 @@ fn main() -> Result<(), Box<dyn Error>> {
 
     #[path = "util/fill.rs"]
     mod fill;
-    #[path = "util/tracing.rs"]
-    mod tracing;
 
     #[derive(Debug)]
     pub struct XEmbedDemo {
@@ -60,7 +58,7 @@ fn main() -> Result<(), Box<dyn Error>> {
         .ok_or("Expected a 32-bit X11 window ID as the first argument.")?
         .parse::<u32>()?;
 
-    tracing::init();
+    tracing_subscriber::fmt::init();
     let event_loop = EventLoop::new()?;
 
     Ok(event_loop.run_app(XEmbedDemo { parent_window_id, window: None })?)
@@ -68,5 +66,6 @@ fn main() -> Result<(), Box<dyn Error>> {
 
 #[cfg(not(x11_platform))]
 fn main() -> Result<(), Box<dyn Error>> {
-    panic!("This example is only supported on X11 platforms.")
+    println!("This example is only supported on X11 platforms.");
+    Ok(())
 }

winit/src/changelog/unreleased.md

@@ -46,13 +46,11 @@ changelog entry.
 - On iOS, add Apple Pencil support with force, altitude, and azimuth data.
 - On Redox, add support for missing keyboard scancodes.
 - Implement `Send` and `Sync` for `OwnedDisplayHandle`.
-- Use new macOS 15 cursors for resize icons.
 
 ### Changed
 
 - Updated `windows-sys` to `v0.61`.
 - On older macOS versions (tested up to 12.7.6), applications now receive mouse movement events for unfocused windows, matching the behavior on other platforms.
-- On macOS, the application is now launched in `EventLoop::new` instead of `EventLoop::run_app`. If you're registering a custom delegate, you should now register it before `EventLoop::new`.
 
 ### Fixed
 

winit/src/event_loop.rs

@@ -75,9 +75,6 @@ impl EventLoopBuilder {
     ///   `DISPLAY` respectively when building the event loop.
     /// - **Android:** must be configured with an `AndroidApp` from `android_main()` by calling
     ///   [`.with_android_app(app)`] before calling `.build()`, otherwise it'll panic.
-    /// - **macOS:** this will launch the application, so if you want to register a custom delegate,
-    ///   or otherwise do stuff before `applicationDidFinishLaunching:`, you should do it before
-    ///   this function is called.
     ///
     /// [`platform`]: crate::platform
     #[cfg_attr(
@@ -91,7 +88,7 @@ impl EventLoopBuilder {
     )]
     #[inline]
     pub fn build(&mut self) -> Result<EventLoop, EventLoopError> {
-        let _entered = tracing::debug_span!("winit::EventLoopBuilder::build").entered();
+        let _span = tracing::debug_span!("winit::EventLoopBuilder::build").entered();
 
         // Certain platforms accept a mutable reference in their API.
         #[allow(clippy::unnecessary_mut_passed)]
@@ -265,7 +262,7 @@ impl EventLoop {
     ///
     /// [`DeviceEvent`]: crate::event::DeviceEvent
     pub fn listen_device_events(&self, allowed: DeviceEvents) {
-        let _entered = tracing::debug_span!(
+        let _span = tracing::debug_span!(
             "winit::EventLoop::listen_device_events",
             allowed = ?allowed
         )