[macOS] If you scroll the page without moving the mouse, we fail to u…

…pdate the cursor as things scroll underneath it https://bugs.webkit.org/show_bug.cgi?id=273335 rdar://122347347 Reviewed by Tim Horton. If you don't move the mouse after loading a page, we'll never update the cursor after scrolling via the trackpad. This is because the web process never gets an updated mouse position if the only events we handle are wheel events, which are handled entirely in the UI process (in the absence of JS wheel event handlers). Fix by explicitly sending `setLastKnownMousePosition()` to EventHandler when we know that we're not going to send the wheel events to the web process. Only do this on the `began` event, since we don't want to flood the web process with new IPC when the position doesn't change (wheel gestures usually keep the same position throughout). Even when we did send wheel events to the web process, they would fail to update the last known mouse position, so fix that in `EventHandler::handleWheelEventInternal()`. I tried to write a test, but it was impossible to make it not flakey (it's attached to the radar). However, the test revealed a race condition; the reload raced with the WebPage::m_pageScrolledHysteresis timer, and sometimes this would cause `WebPage::pageDidScroll()` to get called right after we've constructed the new ScrollView with a zero scroll position, which would get saved to the history item, and clobber the previously saved scroll offset; this caused the scroll offset to get reset on reload. Fix by having `WebPage::didCommitLoad()` call `cancel()` `m_pageScrolledHysteresis`, which needs to implemented in HysteresisActivity, with a test. * Source/WebCore/PAL/pal/HysteresisActivity.h: (PAL::HysteresisActivity::cancel): * Source/WebCore/page/EventHandler.cpp: (WebCore::EventHandler::handleMousePressEvent): (WebCore::EventHandler::handleMouseDoubleClickEvent): (WebCore::EventHandler::handleMouseMoveEvent): (WebCore::EventHandler::handleMouseReleaseEvent): (WebCore::EventHandler::handleMouseForceEvent): (WebCore::EventHandler::handleWheelEventInternal): (WebCore::EventHandler::setLastKnownMousePosition): * Source/WebCore/page/EventHandler.h: * Source/WebKit/UIProcess/WebPageProxy.cpp: (WebKit::WebPageProxy::continueWheelEventHandling): * Source/WebKit/WebProcess/WebPage/WebPage.cpp: (WebKit::WebPage::setLastKnownMousePosition): (WebKit::WebPage::didCommitLoad): * Source/WebKit/WebProcess/WebPage/WebPage.h: * Source/WebKit/WebProcess/WebPage/WebPage.messages.in: * Tools/TestWebKitAPI/Tests/WebCore/HysteresisActivityTests.cpp: (TestWebKitAPI::TEST(HysteresisActivity, Cancelation)): Canonical link: https://commits.webkit.org/278297@main
WebKit · May 3, 2024 · e7ab50a · e7ab50a
1 parent f2a9b39
commit e7ab50a
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Showing 8 changed files with 78 additions and 10 deletions.
diff --git a/Source/WebCore/PAL/pal/HysteresisActivity.h b/Source/WebCore/PAL/pal/HysteresisActivity.h
@@ -66,6 +66,13 @@ class HysteresisActivity {
         m_timer.startOneShot(m_hysteresisSeconds);
     }
 
+    void cancel()
+    {
+        m_active = false;
+        if (m_timer.isActive())
+            m_timer.stop();
+    }
+
     void impulse()
     {
         if (m_active)

diff --git a/Source/WebCore/page/EventHandler.cpp b/Source/WebCore/page/EventHandler.cpp
@@ -1822,7 +1822,7 @@ HandleUserInputEventResult EventHandler::handleMousePressEvent(const PlatformMou
 
     m_mousePressed = true;
     m_capturesDragging = true;
-    setLastKnownMousePosition(platformMouseEvent);
+    setLastKnownMousePosition(platformMouseEvent.position(), platformMouseEvent.globalPosition());
     m_mouseDownTimestamp = platformMouseEvent.timestamp();
 #if ENABLE(DRAG_SUPPORT)
     m_mouseDownMayStartDrag = false;
@@ -1964,7 +1964,7 @@ bool EventHandler::handleMouseDoubleClickEvent(const PlatformMouseEvent& platfor
 
     // We get this instead of a second mouse-up 
     m_mousePressed = false;
-    setLastKnownMousePosition(platformMouseEvent);
+    setLastKnownMousePosition(platformMouseEvent.position(), platformMouseEvent.globalPosition());
 
     constexpr OptionSet<HitTestRequest::Type> hitType { HitTestRequest::Type::Release, HitTestRequest::Type::DisallowUserAgentShadowContent };
     MouseEventWithHitTestResults mouseEvent = prepareMouseEvent(hitType, platformMouseEvent);
@@ -2114,7 +2114,7 @@ HandleUserInputEventResult EventHandler::handleMouseMoveEvent(const PlatformMous
     }
 #endif
 
-    setLastKnownMousePosition(platformMouseEvent);
+    setLastKnownMousePosition(platformMouseEvent.position(), platformMouseEvent.globalPosition());
 
     if (m_hoverTimer.isActive())
         m_hoverTimer.stop();
@@ -2280,7 +2280,7 @@ HandleUserInputEventResult EventHandler::handleMouseReleaseEvent(const PlatformM
 #endif
 
     m_mousePressed = false;
-    setLastKnownMousePosition(platformMouseEvent);
+    setLastKnownMousePosition(platformMouseEvent.position(), platformMouseEvent.globalPosition());
 
     if (m_svgPan) {
         m_svgPan = false;
@@ -2354,7 +2354,7 @@ bool EventHandler::handleMouseForceEvent(const PlatformMouseEvent& event)
     }
 #endif
 
-    setLastKnownMousePosition(event);
+    setLastKnownMousePosition(event.position(), event.globalPosition());
 
     OptionSet<HitTestRequest::Type> hitType { HitTestRequest::Type::DisallowUserAgentShadowContent };
 
@@ -3138,6 +3138,7 @@ HandleUserInputEventResult EventHandler::handleWheelEventInternal(const Platform
     auto allowsScrollingState = SetForScope(m_currentWheelEventAllowsScrolling, processingSteps.contains(WheelEventProcessingSteps::SynchronousScrolling));
 
     setFrameWasScrolledByUser();
+    setLastKnownMousePosition(event.position(), event.globalPosition());
 
     if (m_frame->isMainFrame()) {
         RefPtr page = m_frame->page();
@@ -5142,10 +5143,10 @@ HandleUserInputEventResult EventHandler::dispatchSyntheticTouchEventIfEnabled(co
 }
 #endif // ENABLE(TOUCH_EVENTS)
 
-void EventHandler::setLastKnownMousePosition(const PlatformMouseEvent& event)
+void EventHandler::setLastKnownMousePosition(IntPoint position, IntPoint globalPosition)
 {
-    m_lastKnownMousePosition = event.position();
-    m_lastKnownMouseGlobalPosition = event.globalPosition();
+    m_lastKnownMousePosition = position;
+    m_lastKnownMouseGlobalPosition = globalPosition;
 }
 
 void EventHandler::setImmediateActionStage(ImmediateActionStage stage)

diff --git a/Source/WebCore/page/EventHandler.h b/Source/WebCore/page/EventHandler.h
@@ -227,6 +227,8 @@ class EventHandler final : public CanMakeCheckedPtr<EventHandler> {
     void defaultWheelEventHandler(Node*, WheelEvent&);
     void wheelEventWasProcessedByMainThread(const PlatformWheelEvent&, OptionSet<EventHandling>);
 
+    WEBCORE_EXPORT void setLastKnownMousePosition(IntPoint position, IntPoint globalPosition);
+
     bool handlePasteGlobalSelection(const PlatformMouseEvent&);
 
 #if ENABLE(IOS_TOUCH_EVENTS) || ENABLE(IOS_GESTURE_EVENTS)
@@ -588,8 +590,6 @@ class EventHandler final : public CanMakeCheckedPtr<EventHandler> {
     bool isKeyEventAllowedInFullScreen(const PlatformKeyboardEvent&) const;
 #endif
 
-    void setLastKnownMousePosition(const PlatformMouseEvent&);
-
 #if ENABLE(CURSOR_VISIBILITY)
     void startAutoHideCursorTimer();
     void cancelAutoHideCursorTimer();

diff --git a/Source/WebKit/UIProcess/WebPageProxy.cpp b/Source/WebKit/UIProcess/WebPageProxy.cpp
@@ -3627,6 +3627,11 @@ void WebPageProxy::continueWheelEventHandling(const WebWheelEvent& wheelEvent, c
     LOG_WITH_STREAM(WheelEvents, stream << "WebPageProxy::continueWheelEventHandling - " << result);
 
     if (!result.needsMainThreadProcessing()) {
+        if (wheelEvent.phase() == WebWheelEvent::Phase::PhaseBegan) {
+            // When wheel events are handled entirely in the UI process, we still need to tell the web process where the mouse is for cursor updates.
+            sendToProcessContainingFrame(m_mainFrame->frameID(), Messages::WebPage::SetLastKnownMousePosition(m_mainFrame->frameID(), wheelEvent.position(), wheelEvent.globalPosition()));
+        }
+
         wheelEventHandlingCompleted(result.wasHandled);
         return;
     }

diff --git a/Source/WebKit/WebProcess/WebPage/WebPage.cpp b/Source/WebKit/WebProcess/WebPage/WebPage.cpp
@@ -3555,6 +3555,15 @@ void WebPage::mouseEvent(FrameIdentifier frameID, const WebMouseEvent& mouseEven
     completionHandler(mouseEvent.type(), handled, std::nullopt);
 }
 
+void WebPage::setLastKnownMousePosition(WebCore::FrameIdentifier frameID, IntPoint eventPoint, IntPoint globalPoint)
+{
+    auto* frame = WebProcess::singleton().webFrame(frameID);
+    if (!frame || !frame->coreLocalFrame() || !frame->coreLocalFrame()->view())
+        return;
+
+    frame->coreLocalFrame()->eventHandler().setLastKnownMousePosition(eventPoint, globalPoint);
+}
+
 void WebPage::flushDeferredDidReceiveMouseEvent()
 {
     if (auto info = std::exchange(m_deferredMouseEventCompletionHandler, std::nullopt))
@@ -7524,6 +7533,9 @@ void WebPage::didCommitLoad(WebFrame* frame)
             scalePage(1, IntPoint());
     }
 
+    // This timer can race with loading and clobber the scroll position saved on the current history item.
+    m_pageScrolledHysteresis.cancel();
+
     m_didUpdateRenderingAfterCommittingLoad = false;
 
 #if PLATFORM(IOS_FAMILY)

diff --git a/Source/WebKit/WebProcess/WebPage/WebPage.h b/Source/WebKit/WebProcess/WebPage/WebPage.h
@@ -1896,6 +1896,8 @@ class WebPage : public API::ObjectImpl<API::Object::Type::BundlePage>, public IP
     void mouseEvent(WebCore::FrameIdentifier, const WebMouseEvent&, std::optional<Vector<SandboxExtension::Handle>>&& sandboxExtensions, CompletionHandler<void(std::optional<WebEventType>, bool, std::optional<WebCore::RemoteUserInputEventData>)>&&);
     void keyEvent(WebCore::FrameIdentifier, const WebKeyboardEvent&, CompletionHandler<void(std::optional<WebEventType>, bool)>&&);
 
+    void setLastKnownMousePosition(WebCore::FrameIdentifier, WebCore::IntPoint eventPoint, WebCore::IntPoint globalPoint);
+
 #if ENABLE(IOS_TOUCH_EVENTS)
     void touchEventSync(const WebTouchEvent&, CompletionHandler<void(bool)>&&);
     void resetPotentialTapSecurityOrigin();

diff --git a/Source/WebKit/WebProcess/WebPage/WebPage.messages.in b/Source/WebKit/WebProcess/WebPage/WebPage.messages.in
@@ -49,6 +49,7 @@ messages -> WebPage LegacyReceiver {
     ExecuteEditCommandWithCallback(String name, String argument) -> ()
     KeyEvent(WebCore::FrameIdentifier frameID, WebKit::WebKeyboardEvent event) -> (std::optional<WebKit::WebEventType> eventType, bool handled)
     MouseEvent(WebCore::FrameIdentifier frameID, WebKit::WebMouseEvent event, std::optional<Vector<WebKit::SandboxExtensionHandle>> sandboxExtensions) -> (std::optional<WebKit::WebEventType> eventType, bool handled, struct std::optional<WebCore::RemoteUserInputEventData> remoteUserInputEventData)
+    SetLastKnownMousePosition(WebCore::FrameIdentifier frameID, WebCore::IntPoint eventPoint, WebCore::IntPoint globalPoint);
 
 #if ENABLE(NOTIFICATIONS)
     ClearNotificationPermissionState()

diff --git a/Tools/TestWebKitAPI/Tests/WebCore/HysteresisActivityTests.cpp b/Tools/TestWebKitAPI/Tests/WebCore/HysteresisActivityTests.cpp
@@ -174,4 +174,44 @@ TEST(HysteresisActivity, ActiveInCallback)
     EXPECT_EQ(*callbackData.state, PAL::HysteresisState::Stopped);
 }
 
+TEST(HysteresisActivity, Cancelation)
+{
+    struct CallbackData {
+        std::optional<PAL::HysteresisState> state;
+        PAL::HysteresisActivity* activity;
+    } callbackData;
+
+    PAL::HysteresisActivity activity([&callbackData](PAL::HysteresisState) {
+        callbackData.state = callbackData.activity->state();
+        if (endTestInCallback)
+            hysteresisTestDone = true;
+    }, hysteresisDuration);
+
+    callbackData.activity = &activity;
+
+    hysteresisTestDone = false;
+    endTestInCallback = false;
+
+    activity.start();
+    EXPECT_TRUE(callbackData.state);
+    EXPECT_EQ(*callbackData.state, PAL::HysteresisState::Started);
+
+    activity.cancel();
+    EXPECT_TRUE(callbackData.state);
+    // The callback does not get called.
+    EXPECT_EQ(*callbackData.state, PAL::HysteresisState::Started);
+
+    activity.impulse();
+    EXPECT_TRUE(callbackData.state);
+    EXPECT_EQ(*callbackData.state, PAL::HysteresisState::Started);
+
+    activity.cancel();
+    EXPECT_TRUE(callbackData.state);
+    // The callback does not get called.
+    EXPECT_EQ(*callbackData.state, PAL::HysteresisState::Started);
+
+    TestWebKitAPI::Util::runFor(2 * hysteresisDuration);
+    EXPECT_FALSE(hysteresisTestDone);
+}
+
 } // namespace TestWebKitAPI