Implement elementsFromPoint

Source/core/page/EventHandler.cpp

Index: Source/core/page/EventHandler.cpp
diff --git a/Source/core/page/EventHandler.cpp b/Source/core/page/EventHandler.cpp
index 850bdba7fad1bcaa7d325a5bc7ea2e38d98a7b02..84eb2b6520809f90b47a33216197fe7aac3242ea 100644
--- a/Source/core/page/EventHandler.cpp
+++ b/Source/core/page/EventHandler.cpp
@@ -889,6 +889,9 @@ HitTestResult EventHandler::hitTestResultAtPoint(const LayoutPoint& point, HitTe
     if (!m_frame->contentRenderer() || !m_frame->view() || !m_frame->view()->didFirstLayout())
         return result;
 
+    if (padding.width() || padding.height())
+        hitType |= HitTestRequest::ListBased;

[Rick Byers, 2015/02/04 10:34:03]

Perhaps we should require callers to opt-in to list-based explicitly and enforce
it with ASSERTs?  It's kind of subtle that you get list behavior by providing a
width/height (I was certainly confused by that originally).  I don't think there
are many places to update (mainly EventHandler::hitTestResultForGestureEvent,
the TouchDisambiguation case you already updated, and possibly the testing path
via Internals.cpp).

[pdr., 2015/02/17 04:10:13]

Added back! I took this out thinking it would be easier to review, but that was
dumb of me.

+
     // hitTestResultAtPoint is specifically used to hitTest into all frames, thus it always allows child frame content.
     HitTestRequest request(hitType | HitTestRequest::AllowChildFrameContent);
     m_frame->contentRenderer()->hitTest(request, result);
@@ -2600,7 +2603,7 @@ bool EventHandler::bestClickableNodeForHitTestResult(const HitTestResult& result
     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));
@@ -2612,7 +2615,7 @@ bool EventHandler::bestContextMenuNodeForHitTestResult(const HitTestResult& resu
     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));
@@ -2625,7 +2628,7 @@ bool EventHandler::bestZoomableAreaForTouchPoint(const IntPoint& touchCenter, co
 
     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));
@@ -2696,7 +2699,7 @@ GestureEventWithHitTestResults EventHandler::hitTestResultForGestureEvent(const
         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