Changeset 154535 in webkit

Timestamp:

Aug 23, 2013, 5:30:00 PM (12 years ago)

Author:

Simon Fraser

Message:

Improve scrolling behavior in iTunes
​https://bugs.webkit.org/show_bug.cgi?id=120241
<rdar://problem/14825344>

Reviewed by Sam Weinig.

When vertically scrolling a page with horizontally scrollable overflow areas,
vertical scroll gestures would be interrupted when wheel events with non-zero
X deltas were intercepted by the overflow areas.

Fix by storing a small history of wheel events deltas and using
it to determine of the scroll gesture is primarily vertical or horizontal.
When this is detected, avoid dispatching scroll events on the on the
non-dominant axis.

Currently this behavior is conditionalized to only apply in iTunes.

• page/EventHandler.cpp:

(WebCore::EventHandler::EventHandler):
(WebCore::EventHandler::recordWheelEventDelta):
(WebCore::deltaIsPredominantlyVertical):
(WebCore::EventHandler::dominantScrollGestureDirection):
(WebCore::EventHandler::handleWheelEvent):
(WebCore::EventHandler::defaultWheelEventHandler):

• page/EventHandler.h:
• platform/RuntimeApplicationChecks.cpp:

(WebCore::applicationIsITunes):

• platform/RuntimeApplicationChecks.h:

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• page/EventHandler.cpp (modified) (5 diffs)
• page/EventHandler.h (modified) (3 diffs)
• platform/RuntimeApplicationChecks.cpp (modified) (1 diff)
• platform/RuntimeApplicationChecks.h (modified) (1 diff)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2013-08-23  Simon Fraser  <simon.fraser@apple.com>
+
+        Improve scrolling behavior in iTunes
+        https://bugs.webkit.org/show_bug.cgi?id=120241
+        <rdar://problem/14825344>
+
+        Reviewed by Sam Weinig.
+
+        When vertically scrolling a page with horizontally scrollable overflow areas,
+        vertical scroll gestures would be interrupted when wheel events with non-zero
+        X deltas were intercepted by the overflow areas.
+        
+        Fix by storing a small history of wheel events deltas and using
+        it to determine of the scroll gesture is primarily vertical or horizontal.
+        When this is detected, avoid dispatching scroll events on the on the
+        non-dominant axis.
+        
+        Currently this behavior is conditionalized to only apply in iTunes.
+
+        * page/EventHandler.cpp:
+        (WebCore::EventHandler::EventHandler):
+        (WebCore::EventHandler::recordWheelEventDelta):
+        (WebCore::deltaIsPredominantlyVertical):
+        (WebCore::EventHandler::dominantScrollGestureDirection):
+        (WebCore::EventHandler::handleWheelEvent):
+        (WebCore::EventHandler::defaultWheelEventHandler):
+        * page/EventHandler.h:
+        * platform/RuntimeApplicationChecks.cpp:
+        (WebCore::applicationIsITunes):
+        * platform/RuntimeApplicationChecks.h:
+
 2013-08-23  Pratik Solanki  <psolanki@apple.com>
 

trunk/Source/WebCore/page/EventHandler.cpp

@@ -76 +76 @@
 #include "RenderView.h"
 #include "RenderWidget.h"
+#include "RuntimeApplicationChecks.h"
 #include "ScrollAnimator.h"
 #include "Scrollbar.h"
@@ -333 +334 @@
     , m_mousePositionIsUnknown(true)
     , m_mouseDownTimestamp(0)
+    , m_inTrackingScrollGesturePhase(false)
     , m_widgetIsLatched(false)
 #if PLATFORM(MAC)
@@ -2436 +2438 @@
 #endif
 
+void EventHandler::recordWheelEventDelta(const PlatformWheelEvent& event)
+{
+    const size_t recentEventCount = 3;
+    
+    m_recentWheelEventDeltas.append(FloatSize(event.deltaX(), event.deltaY()));
+    if (m_recentWheelEventDeltas.size() > recentEventCount)
+        m_recentWheelEventDeltas.removeFirst();
+}
+
+static bool deltaIsPredominantlyVertical(const FloatSize& delta)
+{
+    return fabs(delta.height()) > fabs(delta.width());
+}
+
+EventHandler::DominantScrollGestureDirection EventHandler::dominantScrollGestureDirection() const
+{
+    bool allVertical = m_recentWheelEventDeltas.size();
+    bool allHorizontal = m_recentWheelEventDeltas.size();
+
+    Deque<FloatSize>::const_iterator end = m_recentWheelEventDeltas.end();
+    for (Deque<FloatSize>::const_iterator it = m_recentWheelEventDeltas.begin(); it != end; ++it) {
+        bool isVertical = deltaIsPredominantlyVertical(*it);
+        allVertical &= isVertical;
+        allHorizontal &= !isVertical;
+    }
+    
+    if (allVertical)
+        return DominantScrollDirectionVertical;
+
+    if (allHorizontal)
+        return DominantScrollDirectionHorizontal;
+    
+    return DominantScrollDirectionNone;
+}
+
 bool EventHandler::handleWheelEvent(const PlatformWheelEvent& e)
 {
@@ -2490 +2527 @@
     if (m_baseEventType == PlatformEvent::NoType && shouldTurnVerticalTicksIntoHorizontal(result, e))
         event = event.copyTurningVerticalTicksIntoHorizontalTicks();
+
+#if PLATFORM(MAC)
+    switch (event.phase()) {
+    case PlatformWheelEventPhaseBegan:
+        m_recentWheelEventDeltas.clear();
+        m_inTrackingScrollGesturePhase = true;
+        break;
+    case PlatformWheelEventPhaseEnded:
+        m_inTrackingScrollGesturePhase = false;
+        break;
+    default:
+        break;
+    }
+#endif
+
+    recordWheelEventDelta(event);
 
     if (node) {
@@ -2525 +2578 @@
     ScrollGranularity granularity = wheelGranularityToScrollGranularity(wheelEvent->deltaMode());
     
+    DominantScrollGestureDirection dominantDirection = DominantScrollDirectionNone;
+    // Workaround for scrolling issues in iTunes (<rdar://problem/14758615>).
+    if (m_inTrackingScrollGesturePhase && applicationIsITunes())
+        dominantDirection = dominantScrollGestureDirection();
+    
     // Break up into two scrolls if we need to.  Diagonal movement on 
     // a MacBook pro is an example of a 2-dimensional mouse wheel event (where both deltaX and deltaY can be set).
-    if (scrollNode(wheelEvent->rawDeltaX(), granularity, ScrollLeft, ScrollRight, startNode, &stopNode))
+    if (dominantDirection != DominantScrollDirectionVertical && scrollNode(wheelEvent->rawDeltaX(), granularity, ScrollLeft, ScrollRight, startNode, &stopNode))
         wheelEvent->setDefaultHandled();
     
-    if (scrollNode(wheelEvent->rawDeltaY(), granularity, ScrollUp, ScrollDown, startNode, &stopNode))
+    if (dominantDirection != DominantScrollDirectionHorizontal && scrollNode(wheelEvent->rawDeltaY(), granularity, ScrollUp, ScrollDown, startNode, &stopNode))
         wheelEvent->setDefaultHandled();
     

trunk/Source/WebCore/page/EventHandler.h

@@ -38 +38 @@
 #include "TextGranularity.h"
 #include "Timer.h"
+#include <wtf/Deque.h>
 #include <wtf/Forward.h>
 #include <wtf/OwnPtr.h>
@@ -293 +294 @@
     
     bool shouldTurnVerticalTicksIntoHorizontal(const HitTestResult&, const PlatformWheelEvent&) const;
+    void recordWheelEventDelta(const PlatformWheelEvent&);
+    enum DominantScrollGestureDirection {
+        DominantScrollDirectionNone,
+        DominantScrollDirectionVertical,
+        DominantScrollDirectionHorizontal
+    };
+    DominantScrollGestureDirection dominantScrollGestureDirection() const;
+    
     bool mouseDownMayStartSelect() const { return m_mouseDownMayStartSelect; }
 
@@ -467 +476 @@
     PlatformMouseEvent m_mouseDown;
 
+    Deque<FloatSize> m_recentWheelEventDeltas;
     RefPtr<Node> m_latchedWheelEventNode;
+    bool m_inTrackingScrollGesturePhase;
     bool m_widgetIsLatched;
 

trunk/Source/WebCore/platform/RuntimeApplicationChecks.cpp

@@ -67 +67 @@
 }
 
+bool applicationIsITunes()
+{
+    static bool isITunes = mainBundleIsEqualTo("com.apple.iTunes");
+    return isITunes;
+}
+
 bool applicationIsMicrosoftMessenger()
 {

trunk/Source/WebCore/platform/RuntimeApplicationChecks.h

@@ -33 +33 @@
 bool applicationIsAperture();
 bool applicationIsAppleMail();
+bool applicationIsITunes();
 bool applicationIsMicrosoftMessenger();
 bool applicationIsMicrosoftMyDay();