Rework compositor touch hit testing

Source/core/rendering/RenderLayerModelObject.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
  *           (C) 2005, 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2010, 2012 Google Inc. 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
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */
 
 #include "config.h"
 #include "core/rendering/RenderLayerModelObject.h"
 
 #include "core/rendering/RenderLayer.h"
+#include "core/rendering/RenderLayerBacking.h"
 #include "core/rendering/RenderView.h"
 
 using namespace std;
 
 namespace WebCore {
 
 bool RenderLayerModelObject::s_wasFloating = false;
 bool RenderLayerModelObject::s_hadLayer = false;
 bool RenderLayerModelObject::s_hadTransform = false;
 bool RenderLayerModelObject::s_layerWasSelfPainting = false;
@@ skipping 143 matching lines @@
     }
 }
 
 void RenderLayerModelObject::reportMemoryUsage(MemoryObjectInfo* memoryObjectInfo) const
 {
     MemoryClassInfo info(memoryObjectInfo, this, PlatformMemoryTypes::Rendering);
     RenderObject::reportMemoryUsage(memoryObjectInfo);
     info.addWeakPointer(m_layer);
 }
 
+void RenderLayerModelObject::addLayerHitTestRects(LayerHitTestRects& rects, const RenderLayer* currentCompositedLayer, const LayoutPoint& layerOffset) const
+{
+    // If we have a self painting layer then our current layer/offset is irrelevant.
+    // TODO: I don't think this is quite the right approach in the general case.
+    // Rather than update the offset, we probably need to map quads from one layer space
+    // to another, taking into account transforms (eg. scale) and clips (eg. overflow).
+    LayoutPoint adjustedLayerOffset = layerOffset;
+    if (hasSelfPaintingLayer())
+        enclosingCompositedLayerAndOffset(&currentCompositedLayer, adjustedLayerOffset);
+
+    RenderObject::addLayerHitTestRects(rects, currentCompositedLayer, adjustedLayerOffset);
+}
+
 } // namespace WebCore