Wheel event does not stop macOS smooth keyboard scroll

https://bugs.webkit.org/show_bug.cgi?id=244303 rdar://99101109 Reviewed by Tim Horton. Currently, if you enable EventHandlerDrivenSmoothKeyboardScrolling, scroll using the keyboard, then immediately after use the trackpad to scroll, the webpage will scroll back to the position where the keyboard scroll left off. This patch improves the smooth scroll setting so that a wheel event tells the KeyboardScrollingAnimator to stop scrolling. This adds a method to KeyboardScrollingAnimator, stopScrollingImmediately that can be called to stop the animation without taking the time To decelerate, which is what should happen when a wheel event Interrupts the keyboard scroll. * LayoutTests/fast/scrolling/mac/keyboard-scrolling-with-mouse-scroll.html: * Source/WebCore/platform/KeyboardScrollingAnimator.cpp (WebCore::KeyboardScrollingAnimator::stopScrollingImmediately): * Source/WebCore/platform/KeyboardScrollingAnimator.h * Source/WebKit/WebProcess/WebPage/EventDispatcher.cpp Canonical link: https://commits.webkit.org/254561@main
WebKit · Sep 16, 2022 · 8c822fa15adbdecd22d0c3ece07c9e9aa2260af1 · 8c822fa
1 parent 1cbf001
commit 8c822fa15adbdecd22d0c3ece07c9e9aa2260af1
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Showing 5 changed files with 66 additions and 3 deletions.
diff --git a/LayoutTests/fast/scrolling/mac/keyboard-scrolling-with-mouse-scroll-expected.txt b/LayoutTests/fast/scrolling/mac/keyboard-scrolling-with-mouse-scroll-expected.txt
@@ -0,0 +1,5 @@
+PASS successfullyParsed is true
+
+TEST COMPLETE
+Successful.
+
diff --git a/LayoutTests/fast/scrolling/mac/keyboard-scrolling-with-mouse-scroll.html b/LayoutTests/fast/scrolling/mac/keyboard-scrolling-with-mouse-scroll.html
@@ -0,0 +1,43 @@
+<!DOCTYPE html> <!-- webkit-test-runner [ useFlexibleViewport=true EventHandlerDrivenSmoothKeyboardScrollingEnabled=true ] -->
+
+<html>
+
+<head>
+    <script src="../../../resources/ui-helper.js"></script>
+    <script src="../../../resources/js-test.js"></script>
+    <meta name="viewport" content="initial-scale=1.5, user-scalable=no">
+    <script>
+        if (window.testRunner) {
+            testRunner.dumpAsText();
+            testRunner.waitUntilDone();
+        }
+
+        async function runTest()
+        {
+            if (!window.testRunner || !testRunner.runUIScript)
+                return;
+
+            await UIHelper.rawKeyDown("downArrow");
+
+            setTimeout(async () => {
+                await UIHelper.rawKeyUp("downArrow");
+                await UIHelper.mouseWheelScrollAt(10, 10, 0, 1, 0, 10);
+
+                const position = window.scrollY;
+                if (position <= 1) 
+                    debug("Successful.");
+                else
+                    debug("Unsuccessful. window.scrollY == " + position);
+
+                testRunner.notifyDone();
+            }, 100);
+        }
+    </script>
+</head>
+
+<body onload="runTest()">
+    <div style="height: 5000px;">
+    </div>
+</body>
+
+</html>
diff --git a/Source/WebCore/platform/KeyboardScrollingAnimator.cpp b/Source/WebCore/platform/KeyboardScrollingAnimator.cpp
@@ -270,9 +270,7 @@ bool KeyboardScrollingAnimator::beginKeyboardScrollGesture(ScrollDirection direc
 
     auto scrollableDirections = scrollableDirectionsFromPosition(m_scrollAnimator.currentPosition());
     if (!scrollableDirections.at(boxSideForDirection(direction))) {
-        m_scrollTriggeringKeyIsPressed = false;
-        m_scrollController.didStopKeyboardScrolling();
-        m_velocity = { };
+        stopScrollingImmediately();
         return false;
     }
 
@@ -345,7 +343,13 @@ void KeyboardScrollingAnimator::handleKeyUpEvent()
         return;
 
     stopKeyboardScrollAnimation();
+}
+
+void KeyboardScrollingAnimator::stopScrollingImmediately()
+{
     m_scrollTriggeringKeyIsPressed = false;
+    m_scrollController.didStopKeyboardScrolling();
+    m_velocity = { };
 }
 
 } // namespace WebCore
diff --git a/Source/WebCore/platform/KeyboardScrollingAnimator.h b/Source/WebCore/platform/KeyboardScrollingAnimator.h
@@ -57,6 +57,7 @@ class KeyboardScrollingAnimator : public CanMakeWeakPtr<KeyboardScrollingAnimato
     bool beginKeyboardScrollGesture(ScrollDirection, ScrollGranularity);
     void handleKeyUpEvent();
     void updateKeyboardScrollPosition(MonotonicTime);
+    WEBCORE_EXPORT void stopScrollingImmediately();
 
 private:
     void stopKeyboardScrollAnimation();

diff --git a/Source/WebKit/WebProcess/WebPage/EventDispatcher.cpp b/Source/WebKit/WebProcess/WebPage/EventDispatcher.cpp
@@ -104,6 +104,16 @@ void EventDispatcher::initializeConnection(IPC::Connection* connection)
 void EventDispatcher::internalWheelEvent(PageIdentifier pageID, const WebWheelEvent& wheelEvent, RectEdges<bool> rubberBandableEdges, WheelEventOrigin wheelEventOrigin)
 {
     auto processingSteps = OptionSet<WebCore::WheelEventProcessingSteps> { WheelEventProcessingSteps::MainThreadForScrolling, WheelEventProcessingSteps::MainThreadForBlockingDOMEventDispatch };
+
+    ensureOnMainRunLoop([pageID] {
+        if (auto* webPage = WebProcess::singleton().webPage(pageID)) {
+            if (auto* corePage = webPage->corePage()) {
+                if (auto* keyboardScrollingAnimator = corePage->currentKeyboardScrollingAnimator())
+                    keyboardScrollingAnimator->stopScrollingImmediately();
+            }
+        }
+    });
+
 #if ENABLE(ASYNC_SCROLLING) && ENABLE(SCROLLING_THREAD)
     do {
         auto platformWheelEvent = platform(wheelEvent);