Make hit-test support clip-path references using svg clipPath

Source/core/layout/LayoutBlock.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 41 matching lines @@
 #include "core/layout/LayoutTextCombine.h"
 #include "core/layout/LayoutTextControl.h"
 #include "core/layout/LayoutTextFragment.h"
 #include "core/layout/LayoutTheme.h"
 #include "core/layout/LayoutView.h"
 #include "core/layout/TextAutosizer.h"
 #include "core/layout/line/GlyphOverflow.h"
 #include "core/layout/line/InlineIterator.h"
 #include "core/layout/line/InlineTextBox.h"
 #include "core/layout/shapes/ShapeOutsideInfo.h"
+#include "core/layout/svg/LayoutSVGResourceClipper.h"
 #include "core/page/Page.h"
 #include "core/paint/BlockPainter.h"
 #include "core/paint/BoxPainter.h"
 #include "core/paint/DeprecatedPaintLayer.h"
 #include "core/paint/LayoutObjectDrawingRecorder.h"
 #include "core/style/ComputedStyle.h"
 #include "core/style/ContentData.h"
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/geometry/FloatQuad.h"
 #include "platform/geometry/TransformState.h"
@@ skipping 1611 matching lines @@
     if (style()->clipPath()) {
         switch (style()->clipPath()->type()) {
         case ClipPathOperation::SHAPE: {
             ShapeClipPathOperation* clipPath = toShapeClipPathOperation(style()->clipPath());
             // FIXME: handle marginBox etc.
             if (!clipPath->path(borderBoxRect()).contains(FloatPoint(locationInContainer.point() - localOffset), clipPath->windRule()))
                 return false;
             break;
         }
         case ClipPathOperation::REFERENCE:
-            // FIXME: handle REFERENCE
+            ReferenceClipPathOperation* referenceClipPathOperation = toReferenceClipPathOperation(style()->clipPath());
+            Element* element = document().getElementById(referenceClipPathOperation->fragment());
+            if (element && isSVGClipPathElement(element) && element->layoutObject()) {

[fs, 2015/08/19 22:04:57]

Nit: The pointer-version of is...Element checks for null, so the explicit check
is redundant. Please drop.

[Yufeng Shen (Slow to review), 2015/08/20 20:17:21]

Done.

+                LayoutSVGResourceClipper* clipper = toLayoutSVGResourceClipper(toLayoutSVGResourceContainer(element->layoutObject()));
+                if (!clipper->hitTestClipContent(borderBoxRect(), FloatPoint(locationInContainer.point() - localOffset)))
+                    return false;
+            }
             break;
         }
     }
 
     // If we have clipping, then we can't have any spillout.
     bool useOverflowClip = hasOverflowClip() && !hasSelfPaintingLayer();
     bool useClip = (hasControlClip() || useOverflowClip);
     bool checkChildren = !useClip;
     if (!checkChildren) {
         if (hasControlClip()) {
@@ skipping 1214 matching lines @@
 void LayoutBlock::showLineTreeAndMark(const InlineBox* markedBox1, const char* markedLabel1, const InlineBox* markedBox2, const char* markedLabel2, const LayoutObject* obj) const
 {
     showLayoutObject();
     for (const RootInlineBox* root = firstRootBox(); root; root = root->nextRootBox())
         root->showLineTreeAndMark(markedBox1, markedLabel1, markedBox2, markedLabel2, obj, 1);
 }
 
 #endif
 
 } // namespace blink