Rework compositor touch hit testing

Source/core/rendering/RenderObject.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2009 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
@@ skipping 111 matching lines @@
     bool operator!=(const AnnotatedRegionValue& o) const
     {
         return !(*this == o);
     }
 
     LayoutRect bounds;
     bool draggable;
 };
 
 typedef WTF::HashSet<const RenderObject*> RenderObjectAncestorLineboxDirtySet;
+typedef WTF::HashMap<const RenderLayer*, Vector<IntRect> > LayerHitTestRects;
 
 #ifndef NDEBUG
 const int showTreeCharacterOffset = 39;
 #endif
 
 // Base class for all rendering tree objects.
 class RenderObject : public CachedImageClient, public MemoryReporterTag {
     friend class RenderBlock;
     friend class RenderLayer;
     friend class RenderObjectChildList;
@@ skipping 791 matching lines @@
     virtual const RenderObject* pushMappingToContainer(const RenderLayerModelObject* ancestorToStopAt, RenderGeometryMap&) const;
     
     bool shouldUseTransformFromContainer(const RenderObject* container) const;
     void getTransformFromContainer(const RenderObject* container, const LayoutSize& offsetInContainer, TransformationMatrix&) const;
     
     // return true if this object requires a new stacking context
     bool createsGroup() const { return isTransparent() || hasMask() || hasFilter() || hasBlendMode(); } 
     
     virtual void addFocusRingRects(Vector<IntRect>&, const LayoutPoint& /* additionalOffset */, const RenderLayerModelObject* /* paintContainer */ = 0) { };
 
+    // Compute a list of hit-test rectangles per composited layer rooted at this renderer.
+    virtual void computeLayerHitTestRects(LayerHitTestRects&) const;
+
     LayoutRect absoluteOutlineBounds() const
     {
         return outlineBoundsForRepaint(0);
     }
 
     // Return the renderer whose background style is used to paint the root background. Should only be called on the renderer for which isRoot() is true.
     RenderObject* rendererForRootBackground();
 
     RespectImageOrientationEnum shouldRespectImageOrientation() const;
 
 protected:
     inline bool layerCreationAllowedForSubtree() const;
 
+    void enclosingCompositedLayerAndOffset(const RenderLayer**, LayoutPoint&) const;
+
     // Overrides should call the superclass at the end
     virtual void styleWillChange(StyleDifference, const RenderStyle* newStyle);
     // Overrides should call the superclass at the start
     virtual void styleDidChange(StyleDifference, const RenderStyle* oldStyle);
     void propagateStyleToAnonymousChildren(bool blockChildrenOnly = false);
 
     void drawLineForBoxSide(GraphicsContext*, int x1, int y1, int x2, int y2, BoxSide,
                             Color, EBorderStyle, int adjbw1, int adjbw2, bool antialias = false);
 
     void paintFocusRing(PaintInfo&, const LayoutPoint&, RenderStyle*);
     void paintOutline(PaintInfo&, const LayoutRect&);
     void addPDFURLRect(GraphicsContext*, const LayoutRect&);
     
     virtual LayoutRect viewRect() const;
 
     void adjustRectForOutlineAndShadow(LayoutRect&) const;
 
     void clearLayoutRootIfNeeded() const;
     virtual void willBeDestroyed();
     void arenaDelete(RenderArena*, void* objectBase);
 
     virtual bool canBeReplacedWithInlineRunIn() const;
 
     virtual void insertedIntoTree();
     virtual void willBeRemovedFromTree();
 
     void setDocumentForAnonymous(Document* document) { ASSERT(isAnonymous()); m_node = document; }
 
+    // Add hit-test rects for the render tree rooted at this node to the provided collection on a
+    // per-composited-layer basis. CurrentCompositedLayer must be the enclosing composited layer,
+    // and layerOffset is the current offset within this layer. Subclass implementations will add
+    // any offset for this renderer within it's container, so callers should provide only the
+    // offset of the container within it's layer.
+    virtual void addLayerHitTestRects(LayerHitTestRects&, const RenderLayer* currentCompositedLayer, const LayoutPoint& layerOffset) const;
+
+    // Add hit-test rects for this renderer only to the provided list. layerOffset is the offset of this renderer within
+    // the current composited layer that should be used for each result.
+    virtual void computeOwnHitTestRects(Vector<IntRect>&, const LayoutPoint& layerOffset) const { };
+
 private:
     RenderFlowThread* locateFlowThreadContainingBlock() const;
     void removeFromRenderFlowThread();
     void removeFromRenderFlowThreadRecursive(RenderFlowThread*);
 
     bool shouldRepaintForStyleDifference(StyleDifference) const;
     bool hasImmediateNonWhitespaceTextChild() const;
 
     RenderStyle* cachedFirstLineStyle() const;
     StyleDifference adjustStyleDifference(StyleDifference, unsigned contextSensitiveProperties) const;
@@ skipping 325 matching lines @@
 // Outside the WebCore namespace for ease of invocation from gdb.
 void showTree(const WebCore::RenderObject*);
 void showLineTree(const WebCore::RenderObject*);
 void showRenderTree(const WebCore::RenderObject* object1);
 // We don't make object2 an optional parameter so that showRenderTree
 // can be called from gdb easily.
 void showRenderTree(const WebCore::RenderObject* object1, const WebCore::RenderObject* object2);
 #endif
 
 #endif // RenderObject_h