Implement elementsFromPoint

Source/core/page/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 846 matching lines @@
 
 bool EventHandler::panScrollInProgress() const
 {
     return autoscrollController() && autoscrollController()->panScrollInProgress();
 }
 
 HitTestResult EventHandler::hitTestResultAtPoint(const LayoutPoint& point, HitTestRequest::HitTestRequestType hitType, const LayoutSize& padding)
 {
     TRACE_EVENT0("blink", "EventHandler::hitTestResultAtPoint");
 
+    ASSERT((hitType & HitTestRequest::ListBased) || padding.isEmpty());
+
     // We always send hitTestResultAtPoint to the main frame if we have one,
     // otherwise we might hit areas that are obscured by higher frames.
     if (m_frame->page()) {
         LocalFrame* mainFrame = m_frame->localFrameRoot();
         if (mainFrame && m_frame != mainFrame) {
             FrameView* frameView = m_frame->view();
             FrameView* mainView = mainFrame->view();
             if (frameView && mainView) {
                 IntPoint mainFramePoint = mainView->rootViewToContents(frameView->contentsToRootView(roundedIntPoint(point)));
                 return mainFrame->eventHandler().hitTestResultAtPoint(mainFramePoint, hitType, padding);
@@ skipping 1707 matching lines @@
     // scrollbars being untouchable.
     if (result.scrollbar()) {
         targetNode = 0;
         return false;
     }
 
     IntPoint touchCenter = m_frame->view()->contentsToWindow(result.roundedPointInMainFrame());
     IntRect touchRect = m_frame->view()->contentsToWindow(result.hitTestLocation().boundingBox());
 
     WillBeHeapVector<RefPtrWillBeMember<Node>, 11> nodes;
-    copyToVector(result.rectBasedTestResult(), nodes);
+    copyToVector(result.listBasedTestResult(), nodes);
 
     // FIXME: the explicit Vector conversion copies into a temporary and is wasteful.
     return findBestClickableCandidate(targetNode, targetPoint, touchCenter, touchRect, WillBeHeapVector<RefPtrWillBeMember<Node>> (nodes));
 }
 
 bool EventHandler::bestContextMenuNodeForHitTestResult(const HitTestResult& result, IntPoint& targetPoint, Node*& targetNode)
 {
     ASSERT(result.isRectBasedTest());
     IntPoint touchCenter = m_frame->view()->contentsToWindow(result.roundedPointInMainFrame());
     IntRect touchRect = m_frame->view()->contentsToWindow(result.hitTestLocation().boundingBox());
     WillBeHeapVector<RefPtrWillBeMember<Node>, 11> nodes;
-    copyToVector(result.rectBasedTestResult(), nodes);
+    copyToVector(result.listBasedTestResult(), nodes);
 
     // FIXME: the explicit Vector conversion copies into a temporary and is wasteful.
     return findBestContextMenuCandidate(targetNode, targetPoint, touchCenter, touchRect, WillBeHeapVector<RefPtrWillBeMember<Node>>(nodes));
 }
 
 bool EventHandler::bestZoomableAreaForTouchPoint(const IntPoint& touchCenter, const IntSize& touchRadius, IntRect& targetArea, Node*& targetNode)
 {
     IntPoint hitTestPoint = m_frame->view()->windowToContents(touchCenter);
-    HitTestResult result = hitTestResultAtPoint(hitTestPoint, HitTestRequest::ReadOnly | HitTestRequest::Active, LayoutSize(touchRadius));
+
+    HitTestRequest::HitTestRequestType hitType = HitTestRequest::ReadOnly | HitTestRequest::Active;
+    if (!touchRadius.isEmpty())
+        hitType |= HitTestRequest::ListBased;

[Rick Byers, 2015/02/20 20:02:24]

This function it intended to be used only with a non-empty radius (seems weird
to add logic that results in working on an empty list when radius is 0). 
Perhaps just bail out early on zero radius?  We could assert non-zero except I
believe clusterFuzz will fuzz calls to window.internals APIs (at least I know it
fuzzes calls to eventSender).

[pdr., 2015/02/22 23:28:13]

Done

+
+    HitTestResult result = hitTestResultAtPoint(hitTestPoint, hitType, LayoutSize(touchRadius));
 
     IntRect touchRect(touchCenter - touchRadius, touchRadius + touchRadius);
     WillBeHeapVector<RefPtrWillBeMember<Node>, 11> nodes;
-    copyToVector(result.rectBasedTestResult(), nodes);
+    copyToVector(result.listBasedTestResult(), nodes);
 
     // FIXME: the explicit Vector conversion copies into a temporary and is wasteful.
     return findBestZoomableArea(targetNode, targetArea, touchCenter, touchRect, WillBeHeapVector<RefPtrWillBeMember<Node>>(nodes));
 }
 
 GestureEventWithHitTestResults EventHandler::targetGestureEvent(const PlatformGestureEvent& gestureEvent, bool readOnly)
 {
     TRACE_EVENT0("input", "EventHandler::targetGestureEvent");
 
     ASSERT(m_frame == m_frame->localFrameRoot());
@@ skipping 33 matching lines @@
 
 GestureEventWithHitTestResults EventHandler::hitTestResultForGestureEvent(const PlatformGestureEvent& gestureEvent, HitTestRequest::HitTestRequestType hitType)
 {
     // Perform the rect-based hit-test (or point-based if adjustment is disabled). Note that
     // we don't yet apply hover/active state here because we need to resolve touch adjustment
     // first so that we apply hover/active it to the final adjusted node.
     IntPoint hitTestPoint = m_frame->view()->windowToContents(gestureEvent.position());
     LayoutSize padding;
     if (shouldApplyTouchAdjustment(gestureEvent)) {
         padding = LayoutSize(gestureEvent.area());
-        padding.scale(1.f / 2);
+        if (!padding.isEmpty()) {
+            padding.scale(1.f / 2);
+            hitType |= HitTestRequest::ListBased;
+        }
     }
     HitTestResult hitTestResult = hitTestResultAtPoint(hitTestPoint, hitType | HitTestRequest::ReadOnly, padding);
 
     // Adjust the location of the gesture to the most likely nearby node, as appropriate for the
     // type of event.
     PlatformGestureEvent adjustedEvent = gestureEvent;
     applyTouchAdjustment(&adjustedEvent, &hitTestResult);
 
     // Do a new hit-test at the (adjusted) gesture co-ordinates. This is necessary because
     // rect-based hit testing and touch adjustment sometimes return a different node than
     // what a point-based hit test would return for the same point.
     // FIXME: Fix touch adjustment to avoid the need for a redundant hit test. http://crbug.com/398914
     if (shouldApplyTouchAdjustment(gestureEvent)) {
         LocalFrame* hitFrame = hitTestResult.innerNodeFrame();
         if (!hitFrame)
             hitFrame = m_frame;
-        hitTestResult = hitTestResultInFrame(hitFrame, hitFrame->view()->windowToContents(adjustedEvent.position()), hitType | HitTestRequest::ReadOnly);
+        hitTestResult = hitTestResultInFrame(hitFrame, hitFrame->view()->windowToContents(adjustedEvent.position()), (hitType | HitTestRequest::ReadOnly) & ~HitTestRequest::ListBased);
     }
 
     // If we did a rect-based hit test it must be resolved to the best single node by now to
     // ensure consumers don't accidentally use one of the other candidates.
     ASSERT(!hitTestResult.isRectBasedTest());
 
     return GestureEventWithHitTestResults(adjustedEvent, hitTestResult);
 }
 
 HitTestRequest::HitTestRequestType EventHandler::getHitTypeForGestureType(PlatformEvent::Type type)
@@ skipping 1196 matching lines @@
 unsigned EventHandler::accessKeyModifiers()
 {
 #if OS(MACOSX)
     return PlatformEvent::CtrlKey | PlatformEvent::AltKey;
 #else
     return PlatformEvent::AltKey;
 #endif
 }
 
 } // namespace blink