Modify gesture event types for WebView-tag scroll bubbling.

Source/web/WebViewImpl.cpp

 /*
  * Copyright (C) 2011, 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 669 matching lines @@
             return handleGestureEvent(syntheticGestureEvent);
     }
     return false;
 }
 
 bool WebViewImpl::handleGestureEvent(const WebGestureEvent& event)
 {
     if (!m_client)
         return false;
 
+

[tdresser, 2015/09/15 13:13:08]

Remove space.

[wjmaclean, 2015/09/15 15:02:48]

Done.

     bool eventSwallowed = false;
     bool eventCancelled = false; // for disambiguation
 
     // Special handling for slow-path fling gestures.
     switch (event.type) {
     case WebInputEvent::GestureFlingStart: {
         if (mainFrameImpl()->frame()->eventHandler().isScrollbarHandlingGestures())
             break;
         endActiveFlingAnimation();
         m_client->cancelScheduledContentIntents();
         m_positionOnFlingStart = WebPoint(event.x, event.y);
         m_globalPositionOnFlingStart = WebPoint(event.globalX, event.globalY);
         m_flingModifier = event.modifiers;
         m_flingSourceDevice = event.sourceDevice;
         OwnPtr<WebGestureCurve> flingCurve = adoptPtr(Platform::current()->createFlingAnimationCurve(event.sourceDevice, WebFloatPoint(event.data.flingStart.velocityX, event.data.flingStart.velocityY), WebSize()));
         ASSERT(flingCurve);
         m_gestureAnimation = WebActiveGestureAnimation::createAtAnimationStart(flingCurve.release(), this);
         scheduleAnimation();
         eventSwallowed = true;
 
+        // Plugins may need to see GestureFlingStart to balance
+        // GestureScrollBegin (since the former replaces GestureScrollEnd when
+        // transitioning to a fling).
+        PlatformGestureEventBuilder platformEvent(mainFrameImpl()->frameView(), event);
+        mainFrameImpl()->frame()->eventHandler().handleGestureScrollEvent(platformEvent);

[tdresser, 2015/09/15 13:13:08]

Why do we need to explicitly repost the fling? Can it take the same path that
other gestures are taking?

[wjmaclean, 2015/09/15 15:02:48]

No, the GestureFlingStart gets dropped on the floor in EventHandler. Even in
this pathway, doesn't the eventSwallowed = true mean it never propagates past
this point?

[tdresser, 2015/09/15 15:28:29]

I wonder if by not swallowing the event we could avoid having to explicitly
repost. I'm not certain either way, but it might be worth trying.

+
         m_client->didHandleGestureEvent(event, eventCancelled);
         return eventSwallowed;
     }
     case WebInputEvent::GestureFlingCancel:
         if (endActiveFlingAnimation())
             eventSwallowed = true;
 
         m_client->didHandleGestureEvent(event, eventCancelled);
         return eventSwallowed;
     default:
@@ skipping 1137 matching lines @@
     // Create synthetic wheel events as necessary for fling.
     if (m_gestureAnimation) {
         if (m_gestureAnimation->animate(validFrameTime.lastFrameTimeMonotonic))
             scheduleAnimation();
         else {
             endActiveFlingAnimation();
 
             PlatformGestureEvent endScrollEvent(PlatformEvent::GestureScrollEnd,
                 m_positionOnFlingStart, m_globalPositionOnFlingStart,
                 IntSize(), 0, false, false, false, false);
-            endScrollEvent.setScrollGestureData(0, 0, 0, 0, true, false);
+            endScrollEvent.setScrollGestureData(0, 0, 0, 0, true, false, 0);

[tdresser, 2015/09/15 13:13:08]

-1

We might want to define a constant for this, indicating that this means that the
event is not reposted.

[wjmaclean, 2015/09/15 15:02:48]

Done.

 
             mainFrameImpl()->frame()->eventHandler().handleGestureScrollEnd(endScrollEvent);
         }
     }
 
     if (!m_page)
         return;
 
     // FIXME: This should probably be using the local root?
     if (m_page->mainFrame()->isLocalFrame())
@@ skipping 2533 matching lines @@
     if (m_pageColorOverlay)
         m_pageColorOverlay->update();
     if (InspectorOverlayImpl* overlay = inspectorOverlay()) {
         PageOverlay* inspectorPageOverlay = overlay->pageOverlay();
         if (inspectorPageOverlay)
             inspectorPageOverlay->update();
     }
 }
 
 } // namespace blink