wayland: Also synthesize PanGesture from a pinch

This new event is exactly what was missing for the previous commit.
rust-windowing · Apr 27, 2024 · 8815ac8 · 8815ac8
1 parent 4e04741
commit 8815ac8
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Showing 3 changed files with 19 additions and 7 deletions.
diff --git a/src/changelog/unreleased.md b/src/changelog/unreleased.md
@@ -42,4 +42,4 @@ changelog entry.
 
 ### Added
 
-- On Wayland, add `PinchGesture` and `RotationGesture`
+- On Wayland, add `PinchGesture`, `PanGesture` and `RotationGesture`.
diff --git a/src/event.rs b/src/event.rs
@@ -297,7 +297,7 @@ pub enum WindowEvent {
     ///
     /// ## Platform-specific
     ///
-    /// - Only available on **iOS**.
+    /// - Only available on **iOS** and **Wayland**.
     /// - On iOS, not recognized by default. It must be enabled when needed.
     PanGesture {
         device_id: DeviceId,

diff --git a/src/platform_impl/linux/wayland/seat/pointer/mod.rs b/src/platform_impl/linux/wayland/seat/pointer/mod.rs
@@ -514,7 +514,7 @@ impl Dispatch<ZwpPointerGesturePinchV1, GlobalData, WinitState> for PointerGestu
         _qhandle: &QueueHandle<WinitState>,
     ) {
         let device_id = crate::event::DeviceId(crate::platform_impl::DeviceId::Wayland(DeviceId));
-        let (phase, scale_delta, rotation_delta) = match event {
+        let (phase, pan_delta, scale_delta, rotation_delta) = match event {
             Event::Begin { time: _, serial: _, surface, fingers } => {
                 if fingers != 2 {
                     // We only support two fingers for now.
@@ -526,22 +526,34 @@ impl Dispatch<ZwpPointerGesturePinchV1, GlobalData, WinitState> for PointerGestu
                     None => return,
                 };
 
+                let pan_delta = PhysicalPosition::new(0., 0.);
                 state.window_id = wayland::make_wid(parent_surface);
                 state.previous_scale = 1.;
 
-                (TouchPhase::Started, 0., 0.)
+                (TouchPhase::Started, pan_delta, 0., 0.)
             },
-            Event::Update { time: _, dx: _, dy: _, scale, rotation } => {
+            Event::Update { time: _, dx, dy, scale, rotation } => {
+                let pan_delta = PhysicalPosition::new(dx as f32, dy as f32);
                 let scale_delta = scale - state.previous_scale;
                 state.previous_scale = scale;
-                (TouchPhase::Moved, scale_delta, -rotation as f32)
+                (TouchPhase::Moved, pan_delta, scale_delta, -rotation as f32)
             },
             Event::End { time: _, serial: _, cancelled } => {
+                let pan_delta = PhysicalPosition::new(0., 0.);
                 state.previous_scale = 1.;
-                (if cancelled == 0 { TouchPhase::Ended } else { TouchPhase::Cancelled }, 0., 0.)
+                (
+                    if cancelled == 0 { TouchPhase::Ended } else { TouchPhase::Cancelled },
+                    pan_delta,
+                    0.,
+                    0.,
+                )
             },
             _ => unreachable!("Unknown event {event:?}"),
         };
+        state.events_sink.push_window_event(
+            WindowEvent::PanGesture { device_id, delta: pan_delta, phase },
+            state.window_id,
+        );
         state.events_sink.push_window_event(
             WindowEvent::PinchGesture { device_id, delta: scale_delta, phase },
             state.window_id,