winit-wayland: add pointer gesture hold

winit-core/src/event.rs

@@ -269,6 +269,20 @@ pub enum WindowEvent {
         button: ButtonSource,
     },
 
+    /// Multi-finger hold gesture on the touchpad or touchscreen without movement.
+    ///
+    /// The `phase` field indicates the lifecycle of the hold gesture:
+    /// - `Started`: One or more fingers are in contact with the touchpad/touchscreen.
+    /// - `Ended`: All fingers have been lifted from the touchpad/touchscreen.
+    /// - `Cancelled`: The hold gesture was interrupted, for example when another finger touches the
+    ///   touchpad (causing a new `Started` event with more fingers), or when movement begins and
+    ///   transitions to other gestures like pinch, pan, or rotation.
+    ///
+    /// ## Platform-specific
+    ///
+    /// - Only available on **Wayland**.
+    HoldGesture { device_id: Option<DeviceId>, phase: TouchPhase },
+
     /// Two-finger pinch gesture, often used for magnification.
     ///
     /// ## Platform-specific
@@ -1006,9 +1020,17 @@ pub enum Ime {
 #[derive(Debug, Hash, PartialEq, Eq, Clone, Copy)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub enum TouchPhase {
+    /// Initial touch contact or gesture start, for example when one or more fingers touch the
+    /// screen or touchpad.
     Started,
+    /// The touch contact point changed, for example without lifting the finger.
     Moved,
+    /// All touch contact points have been lifted from the touchscreen or touchpad.
+    ///
+    /// This event is important as it should clear any state or event in flight that was
+    /// generated by the preceding `Started` and `Moved` events.
     Ended,
+    /// The event was cancelled and should cancel any event in flight and clear state.
     Cancelled,
 }