[webdriver] Add synchronization for wheel action (#37260)

Implement action synchronization for wheel event. Previously only done
for pointer here https://github.com/servo/servo/pull/36932.

Testing:
`tests/wpt/meta/webdriver/tests/classic/perform_actions/wheel.py`

---------

Signed-off-by: PotatoCP <kenzieradityatirtarahardja18@gmail.com>

components/compositing/compositor.rs

@@ -673,7 +673,7 @@ impl IOCompositor {
                 let point = dppx.transform_point(Point2D::new(x, y));
                 webview_renderer.dispatch_point_input_event(
                     InputEvent::MouseButton(MouseButtonEvent::new(action, button, point))
-                        .with_webdriver_message_id(Some(message_id)),
+                        .with_webdriver_message_id(message_id),
                 );
             },
 
@@ -686,11 +686,18 @@ impl IOCompositor {
                 let point = dppx.transform_point(Point2D::new(x, y));
                 webview_renderer.dispatch_point_input_event(
                     InputEvent::MouseMove(MouseMoveEvent::new(point))
-                        .with_webdriver_message_id(Some(message_id)),
+                        .with_webdriver_message_id(message_id),
                 );
             },
 
-            CompositorMsg::WebDriverWheelScrollEvent(webview_id, x, y, delta_x, delta_y) => {
+            CompositorMsg::WebDriverWheelScrollEvent(
+                webview_id,
+                x,
+                y,
+                delta_x,
+                delta_y,
+                message_id,
+            ) => {
                 let Some(webview_renderer) = self.webview_renderers.get_mut(webview_id) else {
                     warn!("Handling input event for unknown webview: {webview_id}");
                     return;
@@ -705,8 +712,10 @@ impl IOCompositor {
                 let point = dppx.transform_point(Point2D::new(x, y));
                 let scroll_delta =
                     dppx.transform_vector(Vector2D::new(delta_x as f32, delta_y as f32));
-                webview_renderer
-                    .dispatch_point_input_event(InputEvent::Wheel(WheelEvent { delta, point }));
+                webview_renderer.dispatch_point_input_event(
+                    InputEvent::Wheel(WheelEvent::new(delta, point))
+                        .with_webdriver_message_id(message_id),
+                );
                 webview_renderer.on_webdriver_wheel_action(scroll_delta, point);
             },
 

components/constellation/constellation.rs

@@ -4899,10 +4899,20 @@ where
                         webview_id, x, y, msg_id,
                     ));
             },
-            WebDriverCommandMsg::WheelScrollAction(webview, x, y, delta_x, delta_y) => {
+            WebDriverCommandMsg::WheelScrollAction(
+                webview_id,
+                x,
+                y,
+                delta_x,
+                delta_y,
+                msg_id,
+                response_sender,
+            ) => {
+                self.webdriver.input_command_response_sender = Some(response_sender);
+
                 self.compositor_proxy
                     .send(CompositorMsg::WebDriverWheelScrollEvent(
-                        webview, x, y, delta_x, delta_y,
+                        webview_id, x, y, delta_x, delta_y, msg_id,
                     ));
             },
             WebDriverCommandMsg::TakeScreenshot(webview_id, rect, response_sender) => {

components/shared/compositing/lib.rs

@@ -111,12 +111,12 @@ pub enum CompositorMsg {
         MouseButton,
         f32,
         f32,
-        WebDriverMessageId,
+        Option<WebDriverMessageId>,
     ),
     /// WebDriver mouse move event
-    WebDriverMouseMoveEvent(WebViewId, f32, f32, WebDriverMessageId),
+    WebDriverMouseMoveEvent(WebViewId, f32, f32, Option<WebDriverMessageId>),
     // Webdriver wheel scroll event
-    WebDriverWheelScrollEvent(WebViewId, f32, f32, f64, f64),
+    WebDriverWheelScrollEvent(WebViewId, f32, f32, f64, f64, Option<WebDriverMessageId>),
 
     /// Inform WebRender of the existence of this pipeline.
     SendInitialTransaction(WebRenderPipelineId),

components/shared/embedder/input_events.rs

@@ -54,7 +54,7 @@ impl InputEvent {
             InputEvent::MouseButton(event) => event.webdriver_id,
             InputEvent::MouseMove(event) => event.webdriver_id,
             InputEvent::Touch(..) => None,
-            InputEvent::Wheel(..) => None,
+            InputEvent::Wheel(event) => event.webdriver_id,
         }
     }
 
@@ -71,7 +71,9 @@ impl InputEvent {
                 event.webdriver_id = webdriver_id;
             },
             InputEvent::Touch(..) => {},
-            InputEvent::Wheel(..) => {},
+            InputEvent::Wheel(ref mut event) => {
+                event.webdriver_id = webdriver_id;
+            },
         };
 
         self
@@ -275,6 +277,17 @@ pub struct WheelDelta {
 pub struct WheelEvent {
     pub delta: WheelDelta,
     pub point: DevicePoint,
+    webdriver_id: Option<WebDriverMessageId>,
+}
+
+impl WheelEvent {
+    pub fn new(delta: WheelDelta, point: DevicePoint) -> Self {
+        WheelEvent {
+            delta,
+            point,
+            webdriver_id: None,
+        }
+    }
 }
 
 #[derive(Clone, Debug, Deserialize, Serialize)]

components/shared/embedder/webdriver.rs

@@ -50,7 +50,8 @@ pub enum WebDriverCommandMsg {
         MouseButton,
         f32,
         f32,
-        WebDriverMessageId,
+        // Should never be None.
+        Option<WebDriverMessageId>,
         IpcSender<WebDriverCommandResponse>,
     ),
     /// Act as if the mouse was moved in the browsing context with the given ID.
@@ -58,11 +59,23 @@ pub enum WebDriverCommandMsg {
         WebViewId,
         f32,
         f32,
-        WebDriverMessageId,
+        // None if it's not the last `perform_pointer_move` since we only
+        // expect one response from constellation for each tick actions.
+        Option<WebDriverMessageId>,
         IpcSender<WebDriverCommandResponse>,
     ),
     /// Act as if the mouse wheel is scrolled in the browsing context given the given ID.
-    WheelScrollAction(WebViewId, f32, f32, f64, f64),
+    WheelScrollAction(
+        WebViewId,
+        f32,
+        f32,
+        f64,
+        f64,
+        // None if it's not the last `perform_wheel_scroll` since we only
+        // expect one response from constellation for each tick actions.
+        Option<WebDriverMessageId>,
+        IpcSender<WebDriverCommandResponse>,
+    ),
     /// Set the window size.
     SetWindowSize(WebViewId, DeviceIntSize, IpcSender<Size2D<f32, CSSPixel>>),
     /// Take a screenshot of the window.

components/webdriver_server/actions.rs

@@ -156,12 +156,16 @@ impl Handler {
         &self,
         tick_actions: &TickActions,
     ) -> Result<(), ErrorStatus> {
-        // TODO: Add matches! for wheel and key actions
-        // after implmenting webdriver id for wheel and key events.
+        // TODO: Add matches! for key actions
+        // after implmenting webdriver id for key events.
         let count_non_null_actions_in_tick = tick_actions
             .iter()
             .filter(|(_, action)| {
-                matches!(action, ActionItem::Pointer(PointerActionItem::Pointer(_)))
+                matches!(
+                    action,
+                    ActionItem::Pointer(PointerActionItem::Pointer(_)) |
+                        ActionItem::Wheel(WheelActionItem::Wheel(_))
+                )
             })
             .count();
 
@@ -176,7 +180,7 @@ impl Handler {
                     let current_waiting_id = self
                         .current_action_id
                         .get()
-                        .expect("Current id should be set before dispat_actions_inner is called");
+                        .expect("Current id should be set before dispatch_actions_inner is called");
 
                     if current_waiting_id != response.id {
                         dbg!("Dispatch actions completed with wrong id in response");
@@ -345,7 +349,7 @@ impl Handler {
         }
         pointer_input_state.pressed.insert(action.button);
 
-        let msg_id = self.current_action_id.get().unwrap();
+        let msg_id = self.current_action_id.get();
         let cmd_msg = WebDriverCommandMsg::MouseButtonAction(
             session.webview_id,
             MouseButtonAction::Down,
@@ -375,7 +379,7 @@ impl Handler {
         }
         pointer_input_state.pressed.remove(&action.button);
 
-        let msg_id = self.current_action_id.get().unwrap();
+        let msg_id = self.current_action_id.get();
         let cmd_msg = WebDriverCommandMsg::MouseButtonAction(
             session.webview_id,
             MouseButtonAction::Up,
@@ -496,9 +500,15 @@ impl Handler {
             let current_y = pointer_input_state.y;
 
             // Step 7
-            if x != current_x || y != current_y {
+            // Actually "last" should not be checked here based on spec.
+            // However, we need to send the webdriver id at the final perform.
+            if x != current_x || y != current_y || last {
                 // Step 7.2
-                let msg_id = self.current_action_id.get().unwrap();
+                let msg_id = if last {
+                    self.current_action_id.get()
+                } else {
+                    None
+                };
                 let cmd_msg = WebDriverCommandMsg::MouseMoveAction(
                     session.webview_id,
                     x as f32,
@@ -627,14 +637,23 @@ impl Handler {
         };
 
         // Step 5
-        if delta_x != 0 || delta_y != 0 {
+        // Actually "last" should not be checked here based on spec.
+        // However, we need to send the webdriver id at the final perform.
+        if delta_x != 0 || delta_y != 0 || last {
             // Perform implementation-specific action dispatch steps
+            let msg_id = if last {
+                self.current_action_id.get()
+            } else {
+                None
+            };
             let cmd_msg = WebDriverCommandMsg::WheelScrollAction(
                 session.webview_id,
                 x as f32,
                 y as f32,
                 delta_x as f64,
                 delta_y as f64,
+                msg_id,
+                self.constellation_sender.clone(),
             );
             self.constellation_chan
                 .send(EmbedderToConstellationMessage::WebDriverCommand(cmd_msg))

ports/servoshell/desktop/headed_window.rs

@@ -603,7 +603,7 @@ impl WindowPortsMethods for Window {
                 let phase = winit_phase_to_touch_event_type(phase);
 
                 // Send events
-                webview.notify_input_event(InputEvent::Wheel(WheelEvent { delta, point }));
+                webview.notify_input_event(InputEvent::Wheel(WheelEvent::new(delta, point)));
                 webview.notify_scroll_event(
                     scroll_location,
                     self.webview_relative_mouse_point.get().to_i32(),

tests/wpt/meta/webdriver/tests/classic/perform_actions/wheel.py.ini

@@ -1,13 +1,4 @@
 [wheel.py]
-  [test_scroll_not_scrollable]
-    expected: FAIL
-
-  [test_scroll_scrollable_overflow]
-    expected: FAIL
-
-  [test_scroll_iframe]
-    expected: FAIL
-
   [test_scroll_shadow_tree[outer-open\]]
     expected: FAIL