feat(macos): add ExitRequested event

.changes/macos_exit_requested_event.md

@@ -0,0 +1,5 @@
+---
+"tao": minor
+---
+
+Added `event::ExitRequested` handle for dock icon exit on macOS.

examples/README.md

@@ -17,6 +17,7 @@ Run the `cargo run --example <file_name>` to see how each example works.
 - `cursor_grab`: prevent the cursor from going outside the window.
 - `cursor`: set different cursor icons.
 - `drag_window`: allow dragging window when hold left mouse and move.
+- `exit_requested_event`: handle for dock icon exit on macOS.
 - `min_max_size`: set smallest/largest window size you can zoom.
 - `minimize`: minimize window.
 - `monitor_list`: list all available monitors.
@@ -30,4 +31,4 @@ Run the `cargo run --example <file_name>` to see how each example works.
 - `transparent`: make a transparent window.
 - `video_modes`: example that lists all video modes of primary monitor
 - `window_icon`: add window icon.
-- `window`: example that makes a window.
+- `window`: example that makes a window.

examples/exit_requested_event.rs

@@ -0,0 +1,42 @@
+// Copyright 2014-2021 The winit contributors
+// Copyright 2021-2023 Tauri Programme within The Commons Conservancy
+// SPDX-License-Identifier: Apache-2.0
+
+use tao::{
+    event::{Event, WindowEvent},
+    event_loop::{ControlFlow, EventLoop},
+    window::Window,
+};
+
+#[allow(clippy::single_match)]
+fn main() {
+    let event_loop = EventLoop::new();
+
+    let mut window = Some(Window::new(&event_loop).unwrap());
+
+    event_loop.run(move |event, event_loop, control_flow| {
+        *control_flow = ControlFlow::Wait;
+
+        match event {
+            Event::WindowEvent {
+                event: WindowEvent::CloseRequested,
+                ..
+            } => {
+                // drop the window
+                window = None;
+            }
+            Event::MainEventsCleared => {
+                if let Some(w) = &window {
+                    w.request_redraw();
+                }
+            }
+            Event::ExitRequested => {
+                println!("Exit requested");
+
+                // drop the window
+                window = None;
+            }
+            _ => (),
+        }
+    });
+}

src/event.rs

@@ -143,6 +143,13 @@ pub enum Event<'a, T: 'static> {
   /// - **Other**: Unsupported.
   #[non_exhaustive]
   Reopen { has_visible_windows: bool },
+
+  /// The MacOS dock has requested to quit the application.
+  ///
+  /// ## Platform-specific
+  /// - **macOS**: https://developer.apple.com/documentation/appkit/nsapplicationdelegate/1428642-applicationshouldterminate
+  /// - **Other**: Unsupported.
+  ExitRequested,
 }
 
 impl<T: Clone> Clone for Event<'static, T> {
@@ -171,6 +178,7 @@ impl<T: Clone> Clone for Event<'static, T> {
       } => Reopen {
         has_visible_windows: *has_visible_windows,
       },
+      ExitRequested => ExitRequested,
     }
   }
 }
@@ -195,6 +203,7 @@ impl<'a, T> Event<'a, T> {
       } => Ok(Reopen {
         has_visible_windows,
       }),
+      ExitRequested => Ok(ExitRequested),
     }
   }
 
@@ -221,6 +230,7 @@ impl<'a, T> Event<'a, T> {
       } => Some(Reopen {
         has_visible_windows,
       }),
+      ExitRequested => Some(ExitRequested),
     }
   }
 }

src/platform_impl/macos/app_delegate.rs

@@ -19,9 +19,12 @@ use std::{
 
 use cocoa::foundation::{NSArray, NSURL};
 use std::ffi::CStr;
+use std::os::raw::c_int;
 
 static AUX_DELEGATE_STATE_NAME: &str = "auxState";
 
+const NS_TERMINATE_LATER: c_int = 2;
+
 pub struct AuxDelegateState {
   /// We store this value in order to be able to defer setting the activation policy until
   /// after the app has finished launching. If the activation policy is set earlier, the
@@ -47,6 +50,10 @@ lazy_static! {
       sel!(applicationDidFinishLaunching:),
       did_finish_launching as extern "C" fn(&Object, Sel, id),
     );
+    decl.add_method(
+      sel!(applicationShouldTerminate:),
+      application_should_terminate as extern "C" fn(&Object, Sel, id) -> c_int,
+    );
     decl.add_method(
       sel!(applicationWillTerminate:),
       application_will_terminate as extern "C" fn(&Object, Sel, id),
@@ -106,6 +113,13 @@ extern "C" fn did_finish_launching(this: &Object, _: Sel, _: id) {
   trace!("Completed `applicationDidFinishLaunching`");
 }
 
+extern "C" fn application_should_terminate(_: &Object, _: Sel, _: id) -> c_int {
+  trace!("Triggered `applicationShouldTerminate`");
+  AppState::should_exit();
+  trace!("Completed `applicationShouldTerminate`");
+  NS_TERMINATE_LATER
+}
+
 extern "C" fn application_will_terminate(_: &Object, _: Sel, _: id) {
   trace!("Triggered `applicationWillTerminate`");
   AppState::exit();

src/platform_impl/macos/app_state.rs

@@ -270,6 +270,10 @@ impl AppState {
     }));
   }
 
+  pub fn should_exit() {
+    HANDLER.handle_nonuser_event(EventWrapper::StaticEvent(Event::ExitRequested));
+  }
+
   pub fn exit() -> i32 {
     HANDLER.set_in_callback(true);
     HANDLER.handle_nonuser_event(EventWrapper::StaticEvent(Event::LoopDestroyed));