Suppressed MEs for gestures from cancelled PEs

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

Index: third_party/WebKit/Source/core/input/EventHandler.cpp
diff --git a/third_party/WebKit/Source/core/input/EventHandler.cpp b/third_party/WebKit/Source/core/input/EventHandler.cpp
index bad5b0dc36e3628c3abf728963fe111b80484d2d..dd44bd04e2ddfa67201299d3c7bca64e10a72212 100644
--- a/third_party/WebKit/Source/core/input/EventHandler.cpp
+++ b/third_party/WebKit/Source/core/input/EventHandler.cpp
@@ -215,6 +215,7 @@ EventHandler::EventHandler(LocalFrame* frame)
     , m_longTapShouldInvokeContextMenu(false)
     , m_activeIntervalTimer(this, &EventHandler::activeIntervalTimerFired)
     , m_lastShowPressTimestamp(0)
+    , m_suppressMouseEventsFromGestures(false)
 {
 }
 
@@ -281,6 +282,7 @@ void EventHandler::clear()
     m_longTapShouldInvokeContextMenu = false;
     m_dragStartPos = LayoutPoint();
     m_mouseDown = PlatformMouseEvent();
+    m_suppressMouseEventsFromGestures = false;
 }
 
 WebInputEventResult EventHandler::mergeEventResult(
@@ -1809,6 +1811,8 @@ WebInputEventResult EventHandler::handleGestureEventInFrame(const GestureEventWi
     }
 
     switch (gestureEvent.type()) {
+    case PlatformEvent::GestureTapDown:
+        return handleGestureTapDown(targetedEvent);
     case PlatformEvent::GestureTap:
         return handleGestureTap(targetedEvent);
     case PlatformEvent::GestureShowPress:
@@ -1819,7 +1823,6 @@ WebInputEventResult EventHandler::handleGestureEventInFrame(const GestureEventWi
         return handleGestureLongTap(targetedEvent);
     case PlatformEvent::GestureTwoFingerTap:
         return sendContextMenuEventForGesture(targetedEvent);
-    case PlatformEvent::GestureTapDown:
     case PlatformEvent::GesturePinchBegin:
     case PlatformEvent::GesturePinchEnd:
     case PlatformEvent::GesturePinchUpdate:
@@ -1840,6 +1843,13 @@ WebInputEventResult EventHandler::handleGestureScrollEvent(const PlatformGesture
     return m_scrollManager.handleGestureScrollEvent(gestureEvent);
 }
 
+WebInputEventResult EventHandler::handleGestureTapDown(const GestureEventWithHitTestResults& targetedEvent)
+{
+    m_suppressMouseEventsFromGestures =
+        m_pointerEventManager.primaryPointerdownCanceled(targetedEvent.event().uniqueTouchEventId());
+    return WebInputEventResult::NotHandled;
+}
+
 WebInputEventResult EventHandler::handleGestureTap(const GestureEventWithHitTestResults& targetedEvent)
 {
     FrameView* frameView(m_frame->view());
@@ -1856,12 +1866,15 @@ WebInputEventResult EventHandler::handleGestureTap(const GestureEventWithHitTest
     // co-ordinates outside the target's bounds.
     IntPoint adjustedPoint = frameView->rootFrameToContents(gestureEvent.position());
 
-    unsigned modifiers = gestureEvent.getModifiers();
-    PlatformMouseEvent fakeMouseMove(gestureEvent.position(), gestureEvent.globalPosition(),
-        NoButton, PlatformEvent::MouseMoved, /* clickCount */ 0,
-        static_cast<PlatformEvent::Modifiers>(modifiers),
-        PlatformMouseEvent::FromTouch, gestureEvent.timestamp(), WebPointerProperties::PointerType::Mouse);
-    dispatchMouseEvent(EventTypeNames::mousemove, currentHitTest.innerNode(), 0, fakeMouseMove);
+    const unsigned modifiers = gestureEvent.getModifiers();
+
+    if (!m_suppressMouseEventsFromGestures) {
+        PlatformMouseEvent fakeMouseMove(gestureEvent.position(), gestureEvent.globalPosition(),
+            NoButton, PlatformEvent::MouseMoved, /* clickCount */ 0,
+            static_cast<PlatformEvent::Modifiers>(modifiers),
+            PlatformMouseEvent::FromTouch, gestureEvent.timestamp(), WebPointerProperties::PointerType::Mouse);
+        dispatchMouseEvent(EventTypeNames::mousemove, currentHitTest.innerNode(), 0, fakeMouseMove);
+    }
 
     // Do a new hit-test in case the mousemove event changed the DOM.
     // Note that if the original hit test wasn't over an element (eg. was over a scrollbar) we
@@ -1889,8 +1902,10 @@ WebInputEventResult EventHandler::handleGestureTap(const GestureEventWithHitTest
     PlatformMouseEvent fakeMouseDown(gestureEvent.position(), gestureEvent.globalPosition(),
         LeftButton, PlatformEvent::MousePressed, gestureEvent.tapCount(),
         static_cast<PlatformEvent::Modifiers>(modifiers | PlatformEvent::LeftButtonDown),
-        PlatformMouseEvent::FromTouch,  gestureEvent.timestamp(), WebPointerProperties::PointerType::Mouse);
-    WebInputEventResult mouseDownEventResult = dispatchMouseEvent(EventTypeNames::mousedown, currentHitTest.innerNode(), gestureEvent.tapCount(), fakeMouseDown);
+        PlatformMouseEvent::FromTouch, gestureEvent.timestamp(), WebPointerProperties::PointerType::Mouse);
+    WebInputEventResult mouseDownEventResult = WebInputEventResult::NotHandled;

[Rick Byers, 2016/06/03 16:20:44]

Back to the earlier discussion - as written this means that if you cancel the
pointerdown, you have no way to avoid the logic in handleMouseFocus and
handleMousePressEvent.  I expect that's not what Edge does (spec says the
default action of pointerdown includes the default actions of mousedown), but I
guess it's not completely clear for the touch case.  Feel free to file a
separate bug if you like.

But I think it would also be fine (and likely more correct) to just initialize
mouseDownEventResult to HandledSuppressed.

Same for mouseup case below of course.

[mustaq, 2016/06/03 20:34:45]

Looks like we were thinking in opposite directions: by "minimal" I meant keeping
TE side-effects unchanged. Moved back to "maximal" suppression.

Also filed crbug.com/617255 because it's not clear to me what would, say,
not-focusing, mean for uncanceled TEs.

+    if (!m_suppressMouseEventsFromGestures)
+        mouseDownEventResult = dispatchMouseEvent(EventTypeNames::mousedown, currentHitTest.innerNode(), gestureEvent.tapCount(), fakeMouseDown);
     selectionController().initializeSelectionState();
     if (mouseDownEventResult == WebInputEventResult::NotHandled)
         mouseDownEventResult = handleMouseFocus(MouseEventWithHitTestResults(fakeMouseDown, currentHitTest), InputDeviceCapabilities::firesTouchEventsSourceCapabilities());
@@ -1912,11 +1927,14 @@ WebInputEventResult EventHandler::handleGestureTap(const GestureEventWithHitTest
         adjustedPoint = frameView->rootFrameToContents(gestureEvent.position());
         currentHitTest = hitTestResultInFrame(m_frame, adjustedPoint, hitType);
     }
+
     PlatformMouseEvent fakeMouseUp(gestureEvent.position(), gestureEvent.globalPosition(),
         LeftButton, PlatformEvent::MouseReleased, gestureEvent.tapCount(),
         static_cast<PlatformEvent::Modifiers>(modifiers),
-        PlatformMouseEvent::FromTouch,  gestureEvent.timestamp(), WebPointerProperties::PointerType::Mouse);
-    WebInputEventResult mouseUpEventResult = dispatchMouseEvent(EventTypeNames::mouseup, currentHitTest.innerNode(), gestureEvent.tapCount(), fakeMouseUp);
+        PlatformMouseEvent::FromTouch, gestureEvent.timestamp(), WebPointerProperties::PointerType::Mouse);
+    WebInputEventResult mouseUpEventResult = WebInputEventResult::NotHandled;
+    if (!m_suppressMouseEventsFromGestures)
+        mouseUpEventResult = dispatchMouseEvent(EventTypeNames::mouseup, currentHitTest.innerNode(), gestureEvent.tapCount(), fakeMouseUp);
 
     WebInputEventResult clickEventResult = WebInputEventResult::NotHandled;
     if (m_clickNode) {
@@ -1960,6 +1978,8 @@ WebInputEventResult EventHandler::handleGestureLongPress(const GestureEventWithH
 
     m_longTapShouldInvokeContextMenu = false;
     if (m_frame->settings() && m_frame->settings()->touchDragDropEnabled() && m_frame->view()) {
+        // TODO(mustaq): Suppressing long-tap MouseEvents could break
+        // drag-drop. Will do separately because of the risk. crbug.com/606938.
         PlatformMouseEvent mouseDownEvent(adjustedPoint, gestureEvent.globalPosition(), LeftButton, PlatformEvent::MousePressed, 1,
             static_cast<PlatformEvent::Modifiers>(modifiers | PlatformEvent::LeftButtonDown),
             PlatformMouseEvent::FromTouch, WTF::monotonicallyIncreasingTime(), WebPointerProperties::PointerType::Mouse);
@@ -3089,7 +3109,6 @@ HitTestResult EventHandler::hitTestResultInFrame(LocalFrame* frame, const Layout
 WebInputEventResult EventHandler::handleTouchEvent(const PlatformTouchEvent& event)
 {
     TRACE_EVENT0("blink", "EventHandler::handleTouchEvent");
-
     return m_pointerEventManager.handleTouchEvents(event);
 }