Add smart magnification gesture

examples/touchpad_gestures.rs

@@ -29,6 +29,9 @@ fn main() {
                         println!("Zoomed out {}", delta);
                     }
                 }
+                WindowEvent::TouchpadSmartMagnify { .. } => {
+                    println!("Smart zoom");
+                }
                 WindowEvent::TouchpadRotate { delta, .. } => {
                     if delta > 0.0 {
                         println!("Rotated counterclockwise {}", delta);

src/event.rs

@@ -444,6 +444,13 @@ pub enum WindowEvent<'a> {
         phase: TouchPhase,
     },
 
+    /// Touchpad smart magnification event.
+    ///
+    /// ## Platform-specific
+    ///
+    /// - Only available on **macOS**.
+    TouchpadSmartMagnify { device_id: DeviceId },
+
     /// Touchpad rotation event with two-finger rotation gesture.
     ///
     /// Positive delta values indicate rotation counterclockwise and
@@ -590,6 +597,9 @@ impl Clone for WindowEvent<'static> {
                 delta: *delta,
                 phase: *phase,
             },
+            TouchpadSmartMagnify { device_id } => TouchpadSmartMagnify {
+                device_id: *device_id,
+            },
             TouchpadRotate {
                 device_id,
                 delta,
@@ -696,6 +706,7 @@ impl<'a> WindowEvent<'a> {
                 delta,
                 phase,
             }),
+            TouchpadSmartMagnify { device_id } => Some(TouchpadSmartMagnify { device_id }),
             TouchpadRotate {
                 device_id,
                 delta,

src/platform_impl/macos/view.rs

@@ -859,6 +859,20 @@ declare_class!(
             AppState::queue_event(EventWrapper::StaticEvent(window_event));
         }
 
+        #[sel(smartMagnifyWithEvent:)]
+        fn smart_magnify_with_event(&self, _event: &NSEvent) {
+            trace_scope!("smartMagnifyWithEvent:");
+
+            let window_event = Event::WindowEvent {
+                window_id: self.window_id(),
+                event: WindowEvent::TouchpadSmartMagnify {
+                    device_id: DEVICE_ID,
+                },
+            };
+
+            AppState::queue_event(EventWrapper::StaticEvent(window_event));
+        }
+
         #[sel(rotateWithEvent:)]
         fn rotate_with_event(&self, event: &NSEvent) {
             trace_scope!("rotateWithEvent:");