[CSS Regions] Add new regionOversetChange event

Source/core/rendering/RenderFlowThread.h

 /*
  * Copyright (C) 2011 Adobe Systems Incorporated. All rights reserved.
  *
  * 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 108 matching lines @@
     void removeRenderBoxRegionInfo(RenderBox*);
     bool logicalWidthChangedInRegions(const RenderBlock*, LayoutUnit offsetFromLogicalTopOfFirstPage);
 
     LayoutUnit contentLogicalWidthOfFirstRegion() const;
     LayoutUnit contentLogicalHeightOfFirstRegion() const;
     LayoutUnit contentLogicalLeftOfFirstRegion() const;
     
     RenderRegion* firstRegion() const;
     RenderRegion* lastRegion() const;
 
+    bool previousRegionCountChanged() const { return m_previousRegionCount != m_regionList.size(); }
+    void updatePreviousRegionCount() { m_previousRegionCount = m_regionList.size(); }
+
     void setRegionRangeForBox(const RenderBox*, LayoutUnit offsetFromLogicalTopOfFirstPage);
     void getRegionRangeForBox(const RenderBox*, RenderRegion*& startRegion, RenderRegion*& endRegion) const;
 
     void clearRenderObjectCustomStyle(const RenderObject*,
         const RenderRegion* oldStartRegion = 0, const RenderRegion* oldEndRegion = 0,
         const RenderRegion* newStartRegion = 0, const RenderRegion* newEndRegion = 0);
     
-    void computeOverflowStateForRegions(LayoutUnit oldClientAfterEdge);
+    void computeOversetStateForRegions(LayoutUnit oldClientAfterEdge);
 
     bool overset() const { return m_overset; }
 
     // Check if the object is in region and the region is part of this flow thread.
     bool objectInFlowRegion(const RenderObject*, const RenderRegion*) const;
 
     void markAutoLogicalHeightRegionsForLayout();
 
     bool addForcedRegionBreak(LayoutUnit, RenderObject* breakChild, bool isBefore, LayoutUnit* offsetBreakAdjustment = 0);
     void applyBreakAfterContent(LayoutUnit);
@@ skipping 27 matching lines @@
     virtual void mapLocalToContainer(const RenderLayerModelObject* repaintContainer, TransformState&, MapCoordinatesFlags = ApplyContainerFlip, bool* wasFixed = 0) const OVERRIDE;
 
     void updateRegionsFlowThreadPortionRect(const RenderRegion* = 0);
     bool shouldRepaint(const LayoutRect&) const;
     bool regionInRange(const RenderRegion* targetRegion, const RenderRegion* startRegion, const RenderRegion* endRegion) const;
 
     LayoutRect computeRegionClippingRect(const LayoutPoint&, const LayoutRect&, const LayoutRect&) const;
 
     void setDispatchRegionLayoutUpdateEvent(bool value) { m_dispatchRegionLayoutUpdateEvent = value; }
     bool shouldDispatchRegionLayoutUpdateEvent() { return m_dispatchRegionLayoutUpdateEvent; }
+
+    void setDispatchRegionOversetChangeEvent(bool value) { m_dispatchRegionOversetChangeEvent = value; }
+    bool shouldDispatchRegionOversetChangeEvent() const { return m_dispatchRegionOversetChangeEvent; }
     
     // Override if the flow thread implementation supports dispatching events when the flow layout is updated (e.g. for named flows)
     virtual void dispatchRegionLayoutUpdateEvent() { m_dispatchRegionLayoutUpdateEvent = false; }
+    virtual void dispatchRegionOversetChangeEvent() { m_dispatchRegionOversetChangeEvent = false; }
 
     void initializeRegionsOverrideLogicalContentHeight(RenderRegion* = 0);
 
     virtual void autoGenerateRegionsToBlockOffset(LayoutUnit) { };
 
     RenderRegionList m_regionList;
+    unsigned short m_previousRegionCount;
 
     class RenderRegionRange {
     public:
         RenderRegionRange()
         {
             setRange(0, 0);
         }
 
         RenderRegionRange(RenderRegion* start, RenderRegion* end)
         {
@@ skipping 47 matching lines @@
     unsigned m_autoLogicalHeightRegionsCount;
 
     RegionIntervalTree m_regionIntervalTree;
 
     bool m_regionsInvalidated : 1;
     bool m_regionsHaveUniformLogicalWidth : 1;
     bool m_regionsHaveUniformLogicalHeight : 1;
     bool m_overset : 1;
     bool m_hasRegionsWithStyling : 1;
     bool m_dispatchRegionLayoutUpdateEvent : 1;
+    bool m_dispatchRegionOversetChangeEvent : 1;
     bool m_pageLogicalSizeChanged : 1;
     bool m_inConstrainedLayoutPhase : 1;
     bool m_needsTwoPhasesLayout : 1;
 };
 
 inline RenderFlowThread* toRenderFlowThread(RenderObject* object)
 {
     ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isRenderFlowThread());
     return static_cast<RenderFlowThread*>(object);
 }
@@ skipping 24 matching lines @@
 };
 
 template <> struct ValueToString<RenderRegion*> {
     static String string(const RenderRegion* value) { return String::format("%p", value); }
 };
 #endif
 
 } // namespace WebCore
 
 #endif // RenderFlowThread_h