PointerEvents for long-press: fix double firing & canceling MEs

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

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/input/GestureManager.h"
 
 #include "core/dom/Document.h"
 #include "core/editing/SelectionController.h"
 #include "core/events/GestureEvent.h"
 #include "core/frame/FrameHost.h"
@@ skipping 86 matching lines @@
         return handleGestureTapDown(targetedEvent);
     case PlatformEvent::GestureTap:
         return handleGestureTap(targetedEvent);
     case PlatformEvent::GestureShowPress:
         return handleGestureShowPress();
     case PlatformEvent::GestureLongPress:
         return handleGestureLongPress(targetedEvent);
     case PlatformEvent::GestureLongTap:
         return handleGestureLongTap(targetedEvent);
     case PlatformEvent::GestureTwoFingerTap:
-        return m_frame->eventHandler().sendContextMenuEventForGesture(targetedEvent);
+        return handleGestureTwoFingerTap(targetedEvent);
     case PlatformEvent::GesturePinchBegin:
     case PlatformEvent::GesturePinchEnd:
     case PlatformEvent::GesturePinchUpdate:
     case PlatformEvent::GestureTapDownCancel:
     case PlatformEvent::GestureTapUnconfirmed:
         break;
     default:
         NOTREACHED();
     }
 
@@ skipping 141 matching lines @@
         m_longTapShouldInvokeContextMenu = true;
         return WebInputEventResult::HandledSystem;
     }
     IntPoint hitTestPoint = m_frame->view()->rootFrameToContents(gestureEvent.position());
     HitTestResult result = m_frame->eventHandler().hitTestResultAtPoint(hitTestPoint);
     if (m_selectionController->handleGestureLongPress(gestureEvent, result)) {
         m_frame->eventHandler().focusDocumentView();
         return WebInputEventResult::HandledSystem;
     }
 
-    return m_frame->eventHandler().sendContextMenuEventForGesture(targetedEvent);
+    return sendContextMenuEventForGesture(targetedEvent);
 }
 
 WebInputEventResult GestureManager::handleGestureLongTap(const GestureEventWithHitTestResults& targetedEvent)
 {
 #if !OS(ANDROID)
     if (m_longTapShouldInvokeContextMenu) {
         m_longTapShouldInvokeContextMenu = false;
-        return m_frame->eventHandler().sendContextMenuEventForGesture(targetedEvent);
+        return sendContextMenuEventForGesture(targetedEvent);
     }
 #endif
     return WebInputEventResult::NotHandled;
 }
 
+WebInputEventResult GestureManager::handleGestureTwoFingerTap(const GestureEventWithHitTestResults& targetedEvent)
+{
+    return sendContextMenuEventForGesture(targetedEvent);
+}
+
+WebInputEventResult GestureManager::sendContextMenuEventForGesture(const GestureEventWithHitTestResults& targetedEvent)
+{
+    const PlatformGestureEvent& gestureEvent = targetedEvent.event();
+    unsigned modifiers = gestureEvent.getModifiers();
+
+    if (!m_suppressMouseEventsFromGestures) {
+        // Send MouseMoved event prior to handling (https://crbug.com/485290).
+        PlatformMouseEvent fakeMouseMove(gestureEvent.position(), gestureEvent.globalPosition(),
+            NoButton, PlatformEvent::MouseMoved, /* clickCount */ 0,
+            static_cast<PlatformEvent::Modifiers>(modifiers),
+            PlatformMouseEvent::FromTouch, gestureEvent.timestamp(), WebPointerProperties::PointerType::Mouse);
+
+        m_frame->eventHandler().dispatchMouseEvent(EventTypeNames::mousemove, targetedEvent.hitTestResult().innerNode(), 0, fakeMouseMove);
+    }
+
+    PlatformEvent::EventType eventType = PlatformEvent::MousePressed;
+    if (m_frame->settings() && m_frame->settings()->showContextMenuOnMouseUp())
+        eventType = PlatformEvent::MouseReleased;
+
+    // To simulate right-click behavior, we send a right mouse down and then
+    // context menu event.
+    // TODO(crbug.com/579564): Maybe we should not send mouse down at all
+    PlatformMouseEvent mouseEvent(targetedEvent.event().position(), targetedEvent.event().globalPosition(), RightButton, eventType, 1,
+        static_cast<PlatformEvent::Modifiers>(modifiers | PlatformEvent::RightButtonDown),
+        PlatformMouseEvent::FromTouch, WTF::monotonicallyIncreasingTime(), WebPointerProperties::PointerType::Mouse);
+
+    if (!m_suppressMouseEventsFromGestures && m_frame->view()) {
+        MouseEventWithHitTestResults mev(mouseEvent, targetedEvent.hitTestResult());

[dtapuska, 2016/07/18 21:16:31]

Is it safe to reuse the hit test result here? The other code in EventHandler
doesn't. What if the DOM mutates do to the mouse move? What about targeting
scrollbars on the two finger tap?

[mustaq, 2016/07/19 15:50:27]

Brought back the hittest, got distracted by the fixme comment.
I followed Rick's suggestion here which makes more sense to me: keeping only
the minimal effects of mouse for gestures. Do you think we should call
passMousePressEventToScrollbar() for all affected gestures (long-press,
long-tap & two-finger tap)?

[mustaq, 2016/07/19 15:52:32]

Note that we don't passMousePressEventToScrollbar() on GestureTap.

[mustaq, 2016/07/20 15:54:41]

Bad news: the cherry-picking of DOM events is causing a regression in CrOS:
long-press menu doesn't appear until touch-release.

I will go back to a minimal fix as in Patch1 (except that I will use the
"FromTouch" value in the PlatformMouseEvent instead of a bool param), to have
the fix landed before the hackatahon next week.

+        WebInputEventResult eventResult = m_frame->eventHandler().dispatchMouseEvent(EventTypeNames::mousedown, mev.innerNode(), /* clickCount */ 0, mouseEvent);
+
+        if (eventResult == WebInputEventResult::NotHandled) {
+            InputDeviceCapabilities* sourceCapabilities = mouseEvent.getSyntheticEventType() == PlatformMouseEvent::FromTouch ? InputDeviceCapabilities::firesTouchEventsSourceCapabilities() : InputDeviceCapabilities::doesntFireTouchEventsSourceCapabilities();
+            eventResult = m_frame->eventHandler().handleMouseFocus(mev, sourceCapabilities);
+        }
+
+        if (eventResult == WebInputEventResult::NotHandled)
+            m_frame->eventHandler().handleMousePressEvent(mev);
+    }
+
+    return m_frame->eventHandler().sendContextMenuEvent(mouseEvent);
+    // We do not need to send a corresponding mouse release because in case of
+    // right-click, the context menu takes capture and consumes all events.
+}
+
 WebInputEventResult GestureManager::handleGestureShowPress()
 {
     m_lastShowPressTimestamp = WTF::monotonicallyIncreasingTime();
 
     FrameView* view = m_frame->view();
     if (!view)
         return WebInputEventResult::NotHandled;
     if (ScrollAnimatorBase* scrollAnimator = view->existingScrollAnimator())
         scrollAnimator->cancelAnimation();
     const FrameView::ScrollableAreaSet* areas = view->scrollableAreas();
@@ skipping 14 matching lines @@
 
     return &m_frame->page()->frameHost();
 }
 
 double GestureManager::getLastShowPressTimestamp() const
 {
     return m_lastShowPressTimestamp;
 }
 
 } // namespace blink