Fire pointerup/down events for corresponding mouse events.

third_party/WebKit/Source/core/input/EventHandler.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2012 Digia Plc. and/or its subsidiary(-ies)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 297 matching lines @@
     m_capturingMouseEventsNode = nullptr;
     m_previousWheelScrolledNode = nullptr;
     m_targetForTouchID.clear();
     m_touchSequenceDocument.clear();
     m_touchSequenceUserGestureToken.clear();
     clearGestureScrollState();
     m_lastGestureScrollOverWidget = false;
     m_scrollbarHandlingScrollGesture = nullptr;
     m_touchPressed = false;
     m_pointerIdManager.clear();
+    m_preventMouseEventForPointerTypeMouse = false;
     m_inPointerCanceledState = false;
     m_mouseDownMayStartDrag = false;
     m_lastShowPressTimestamp = 0;
     m_lastDeferredTapElement = nullptr;
     m_eventHandlerWillResetCapturingMouseEventsNode = false;
     m_mouseDownMayStartAutoscroll = false;
     m_svgPan = false;
     m_mouseDownPos = IntPoint();
     m_mouseDownTimestamp = 0;
     m_longTapShouldInvokeContextMenu = false;
@@ skipping 634 matching lines @@
             m_resizeScrollableArea = layer->scrollableArea();
             m_resizeScrollableArea->setInResizeMode(true);
             m_offsetFromResizeCorner = LayoutSize(m_resizeScrollableArea->offsetFromResizeCorner(p));
             invalidateClick();
             return true;
         }
     }
 
     m_frame->selection().setCaretBlinkingSuspended(true);
 
-    bool swallowEvent = !dispatchMouseEvent(EventTypeNames::mousedown, mev.innerNode(), m_clickCount, mouseEvent);
+    bool swallowEvent = dispatchPointerEventForMouseEvent(mev.innerNode(), EventTypeNames::pointerdown, mouseEvent);
+    if (swallowEvent) {
+        m_preventMouseEventForPointerTypeMouse = true;
+    }
+    if (!m_preventMouseEventForPointerTypeMouse)
+        swallowEvent = swallowEvent || !dispatchMouseEvent(EventTypeNames::mousedown, mev.innerNode(), m_clickCount, mouseEvent);
+
     // m_selectionInitiationState is initialized after dispatching mousedown
     // event in order not to keep the selection by DOM APIs Because we can't
     // give the user the chance to handle the selection by user action like
     // dragging if we keep the selection in case of mousedown. FireFox also has
     // the same behavior and it's more compatible with other browsers.
     selectionController().initializeSelectionState();
     HitTestResult hitTestResult = hitTestResultInFrame(m_frame, documentPoint, HitTestRequest::ReadOnly);
     InputDeviceCapabilities* sourceCapabilities = mouseEvent.syntheticEventType() == PlatformMouseEvent::FromTouch ? InputDeviceCapabilities::firesTouchEventsSourceCapabilities() :
         InputDeviceCapabilities::doesntFireTouchEventsSourceCapabilities();
     swallowEvent = swallowEvent || handleMouseFocus(MouseEventWithHitTestResults(mouseEvent, hitTestResult), sourceCapabilities);
@@ skipping 263 matching lines @@
 
     HitTestRequest::HitTestRequestType hitType = HitTestRequest::Release;
     HitTestRequest request(hitType);
     MouseEventWithHitTestResults mev = prepareMouseEvent(request, mouseEvent);
     LocalFrame* subframe = m_capturingMouseEventsNode.get() ? subframeForTargetNode(m_capturingMouseEventsNode.get()) : subframeForHitTestResult(mev);
     if (m_eventHandlerWillResetCapturingMouseEventsNode)
         m_capturingMouseEventsNode = nullptr;
     if (subframe && passMouseReleaseEventToSubframe(mev, subframe))
         return true;
 
-    bool swallowMouseUpEvent = !dispatchMouseEvent(EventTypeNames::mouseup, mev.innerNode(), m_clickCount, mouseEvent);
+    bool swallowPointerUpEvent = dispatchPointerEventForMouseEvent(mev.innerNode(), EventTypeNames::pointerup, mouseEvent);
+    bool swallowMouseUpEvent = false;

[Rick Byers, 2015/10/20 19:09:50]

I think there can be cases where blink doesn't directly see this mouseup (which
you probably need tests for).  Eg:
1. mousedown inside one frame, drag out to parent frame and mouseup there (your
state is per-frame, right?)
2. mousedown inside the window, drag out of the window and mouseup there.  This
will be a little trickier - we don't reliably get MouseLeave notifications from
chromium ATM (Lan is working on this).  Perhaps you just want to reset when you
see any mouse event that has no buttons down?

[mustaq, 2015/10/21 15:17:21]

Yes, this is dependent on Lan's work. Filed crbug/545647 to track this, added a
TODO for now.

I think a reasonable fix would need some mousemove cleanup. Firing pointercancel
on mouse exit could be an intermediate fix but that would still need some
mousemove fix.

Relying on no-button mouseevents sounds scary to me, like our redundant
mousemove bugs.

[mustaq, 2015/10/22 16:42:52]

Here is a patch that resets the "prevent-ME" state upon seeing a no-button
native event as you suggested above.

[Rick Byers, 2015/10/22 21:31:51]

I played with edge a bit here.  To match their behavior I think something like
this is necessary (even if we were getting reliable MouseLeave notifications). 
Note the difference between dragging (with the mouse down) out of a window and
back in, and dragging out, then lifting and moving back in.  The later
definitely cleared the "PREVENT MOUSE EVENT flag" even though no pointerup or
pointercancel was dispatched.  This is perhaps a bug in the spec, do you want to
file one and see what the Edge folks say?  I suspect they'll suggest adding
specific wording around clearing the flag on any event with button=0.

+    if (!m_preventMouseEventForPointerTypeMouse)
+        swallowMouseUpEvent = !dispatchMouseEvent(EventTypeNames::mouseup, mev.innerNode(), m_clickCount, mouseEvent);
 
     bool contextMenuEvent = mouseEvent.button() == RightButton;
 #if OS(MACOSX)
     // FIXME: The Mac port achieves the same behavior by checking whether the context menu is currently open in WebPage::mouseEvent(). Consider merging the implementations.
     if (mouseEvent.button() == LeftButton && mouseEvent.modifiers() & PlatformEvent::CtrlKey)
         contextMenuEvent = true;
 #endif
 
     bool swallowClickEvent = false;
     if (m_clickCount > 0 && !contextMenuEvent && mev.innerNode() && m_clickNode && mev.innerNode()->canParticipateInComposedTree() && m_clickNode->canParticipateInComposedTree()) {
         // Updates distribution because a 'mouseup' event listener can make the
         // tree dirty at dispatchMouseEvent() invocation above.
         // Unless distribution is updated, commonAncestor would hit ASSERT.
         // Both m_clickNode and mev.innerNode() don't need to be updated
         // because commonAncestor() will exit early if their documents are different.
         m_clickNode->updateDistribution();
         if (Node* clickTargetNode = mev.innerNode()->commonAncestor(*m_clickNode, parentForClickEvent))
             swallowClickEvent = !dispatchMouseEvent(EventTypeNames::click, clickTargetNode, m_clickCount, mouseEvent);
     }
 
     if (m_resizeScrollableArea) {
         m_resizeScrollableArea->setInResizeMode(false);
         m_resizeScrollableArea = nullptr;
     }
 
     bool swallowMouseReleaseEvent = false;
-    if (!swallowMouseUpEvent)
+    if (!swallowPointerUpEvent && !swallowMouseUpEvent)
         swallowMouseReleaseEvent = handleMouseReleaseEvent(mev);
 
     invalidateClick();
 
-    return swallowMouseUpEvent || swallowClickEvent || swallowMouseReleaseEvent;
+    m_preventMouseEventForPointerTypeMouse = false;
+    return swallowPointerUpEvent || swallowMouseUpEvent || swallowClickEvent || swallowMouseReleaseEvent;
 }
 
 bool EventHandler::dispatchDragEvent(const AtomicString& eventType, Node* dragTarget, const PlatformMouseEvent& event, DataTransfer* dataTransfer)
 {
     FrameView* view = m_frame->view();
 
     // FIXME: We might want to dispatch a dragleave even if the view is gone.
     if (!view)
         return false;
 
@@ skipping 2701 matching lines @@
 PlatformEvent::Modifiers EventHandler::accessKeyModifiers()
 {
 #if OS(MACOSX)
     return static_cast<PlatformEvent::Modifiers>(PlatformEvent::CtrlKey | PlatformEvent::AltKey);
 #else
     return PlatformEvent::AltKey;
 #endif
 }
 
 } // namespace blink