Reset drag state variables on mouse up

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 418 matching lines @@
 {
     selectionController().updateSelectionForMouseDrag(m_mousePressNode.get(), m_dragStartPos, m_lastKnownMousePosition);
 }
 
 WebInputEventResult EventHandler::handleMouseReleaseEvent(const MouseEventWithHitTestResults& event)
 {
     AutoscrollController* controller = m_scrollManager.autoscrollController();
     if (controller && controller->autoscrollInProgress())
         m_scrollManager.stopAutoscroll();
 
-    // Used to prevent mouseMoveEvent from initiating a drag before
-    // the mouse is pressed again.
-    m_mousePressed = false;
-    m_capturesDragging = false;
-    m_mouseDownMayStartDrag = false;
-    m_mouseDownMayStartAutoscroll = false;
-
     return selectionController().handleMouseReleaseEvent(event, m_dragStartPos) ? WebInputEventResult::HandledSystem : WebInputEventResult::NotHandled;
 }
 
 #if OS(WIN)
 
 void EventHandler::startPanScrolling(LayoutObject* layoutObject)
 {
     if (!layoutObject->isBox())
         return;
     AutoscrollController* controller = m_scrollManager.autoscrollController();
@@ skipping 749 matching lines @@
                 event->stopPropagation();
 
             clickEventResult = toWebInputEventResult(clickTargetNode->dispatchEvent(event));
         }
     }
 
     m_scrollManager.clearResizeScrollableArea(false);
 
     if (eventResult == WebInputEventResult::NotHandled)
         eventResult = handleMouseReleaseEvent(mev);
+    clearDragHeuristicState();
 
     invalidateClick();
 
     return mergeEventResult(clickEventResult, eventResult);
 }
 
 WebInputEventResult EventHandler::dispatchDragEvent(const AtomicString& eventType, Node* dragTarget, const PlatformMouseEvent& event, DataTransfer* dataTransfer)
 {
     FrameView* view = m_frame->view();
 
@@ skipping 157 matching lines @@
     if (targetIsFrame(m_dragTarget.get(), targetFrame)) {
         if (targetFrame)
             result = targetFrame->eventHandler().performDragAndDrop(event, dataTransfer);
     } else if (m_dragTarget.get()) {
         result = dispatchDragEvent(EventTypeNames::drop, m_dragTarget.get(), event, dataTransfer);
     }
     clearDragState();
     return result;
 }
 
+void EventHandler::clearDragHeuristicState()
+{
+    // Used to prevent mouseMoveEvent from initiating a drag before
+    // the mouse is pressed again.
+    m_mousePressed = false;
+    m_capturesDragging = false;
+    m_mouseDownMayStartDrag = false;
+    m_mouseDownMayStartAutoscroll = false;
+}
+
 void EventHandler::clearDragState()
 {
     m_scrollManager.stopAutoscroll();
     m_dragTarget = nullptr;
     m_capturingMouseEventsNode = nullptr;
     m_shouldOnlyFireDragOverEvent = false;
 }
 
 void EventHandler::setCapturingMouseEventsNode(Node* n)
 {
@@ skipping 465 matching lines @@
             // because commonAncestor() will exit early if their documents are different.
             m_clickNode->updateDistribution();
             Node* clickTargetNode = currentHitTest.innerNode()->commonAncestor(*m_clickNode, parentForClickEvent);
             clickEventResult = dispatchMouseEvent(EventTypeNames::click, clickTargetNode, gestureEvent.tapCount(), fakeMouseUp);
         }
         m_clickNode = nullptr;
     }
 
     if (mouseUpEventResult == WebInputEventResult::NotHandled)
         mouseUpEventResult = handleMouseReleaseEvent(MouseEventWithHitTestResults(fakeMouseUp, currentHitTest));
+    clearDragHeuristicState();
 
     WebInputEventResult eventResult = mergeEventResult(mergeEventResult(mouseDownEventResult, mouseUpEventResult), clickEventResult);
     if (eventResult == WebInputEventResult::NotHandled && tappedNode && m_frame->page()) {
         bool domTreeChanged = preDispatchDomTreeVersion != m_frame->document()->domTreeVersion();
         bool styleChanged = preDispatchStyleVersion != m_frame->document()->styleVersion();
 
         IntPoint tappedPositionInViewport = frameHost()->visualViewport().rootFrameToViewport(tappedPosition);
         m_frame->chromeClient().showUnhandledTapUIIfNeeded(tappedPositionInViewport, tappedNode, domTreeChanged || styleChanged);
     }
     return eventResult;
@@ skipping 963 matching lines @@
 
 FrameHost* EventHandler::frameHost() const
 {
     if (!m_frame->page())
         return nullptr;
 
     return &m_frame->page()->frameHost();
 }
 
 } // namespace blink