Cleanup: Remove LayoutRegion.

Source/core/layout/LayoutMultiColumnSet.h

 /*
  * Copyright (C) 2012 Apple Inc.  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.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 11 matching lines @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 
 #ifndef LayoutMultiColumnSet_h
 #define LayoutMultiColumnSet_h
 
 #include "core/CoreExport.h"
 #include "core/layout/LayoutMultiColumnFlowThread.h"
-#include "core/layout/LayoutRegion.h"
 #include "core/layout/MultiColumnFragmentainerGroup.h"
 #include "wtf/Vector.h"
 
 namespace blink {
 
 // A set of columns in a multicol container. A column set is inserted as an anonymous child of the
 // actual multicol container (i.e. the layoutObject whose style computes to non-auto column-count and/or
 // column-width), next to the flow thread. There'll be one column set for each contiguous run of
 // column content. The only thing that can interrupt a contiguous run of column content is a column
 // spanner, which means that if there are no spanners, there'll only be one column set.
 //
 // Since a spanner interrupts an otherwise contiguous run of column content, inserting one may
 // result in the creation of additional new column sets. A placeholder for the spanning layoutObject has
 // to be placed in between the column sets that come before and after the spanner, if there's
 // actually column content both before and after the spanner.
 //
 // A column set has no children on its own, but is merely used to slice a portion of the tall
 // "single-column" flow thread into actual columns visually, to convert from flow thread coordinates
 // to visual ones. It is in charge of both positioning columns correctly relatively to the parent
 // multicol container, and to calculate the correct translation for each column's contents, and to
 // paint any rules between them. LayoutMultiColumnSet objects are used for painting, hit testing,
 // and any other type of operation that requires mapping from flow thread coordinates to visual
 // coordinates.
 //
 // Columns are normally laid out in the inline progression direction, but if the multicol container
 // is inside another fragmentation context (e.g. paged media, or an another multicol container), we
 // may need to group the columns, so that we get one MultiColumnFragmentainerGroup for each outer
 // fragmentainer (page / column) that the inner multicol container lives in. Each fragmentainer
 // group has its own column height, but the column height is uniform within a group.
-class CORE_EXPORT LayoutMultiColumnSet : public LayoutRegion {
+class CORE_EXPORT LayoutMultiColumnSet : public LayoutBlockFlow {
 public:
     static LayoutMultiColumnSet* createAnonymous(LayoutFlowThread&, const ComputedStyle& parentStyle);
 
     const MultiColumnFragmentainerGroup& firstFragmentainerGroup() const { return m_fragmentainerGroups.first(); }
     const MultiColumnFragmentainerGroup& lastFragmentainerGroup() const { return m_fragmentainerGroups.last(); }
     MultiColumnFragmentainerGroup& fragmentainerGroupAtFlowThreadOffset(LayoutUnit);
     const MultiColumnFragmentainerGroup& fragmentainerGroupAtFlowThreadOffset(LayoutUnit) const;
     const MultiColumnFragmentainerGroup& fragmentainerGroupAtVisualPoint(const LayoutPoint&) const;
 
-    virtual bool isOfType(LayoutObjectType type) const override { return type == LayoutObjectLayoutMultiColumnSet || LayoutRegion::isOfType(type); }
+    virtual bool isOfType(LayoutObjectType type) const override { return type == LayoutObjectLayoutMultiColumnSet || LayoutBlockFlow::isOfType(type); }
+    virtual bool canHaveChildren() const override final { return false; }
 
-    virtual LayoutUnit pageLogicalWidth() const final { return flowThread()->logicalWidth(); }
-    virtual LayoutUnit pageLogicalHeight() const final;
+    // Return the width and height of a single column or page in the set.
+    LayoutUnit pageLogicalWidth() const { return flowThread()->logicalWidth(); }
+    LayoutUnit pageLogicalHeight() const;
+
+    LayoutFlowThread* flowThread() const { return m_flowThread; }
 
     LayoutBlockFlow* multiColumnBlockFlow() const { return toLayoutBlockFlow(parent()); }
     LayoutMultiColumnFlowThread* multiColumnFlowThread() const
     {
         ASSERT_WITH_SECURITY_IMPLICATION(!flowThread() || flowThread()->isLayoutMultiColumnFlowThread());
         return static_cast<LayoutMultiColumnFlowThread*>(flowThread());
     }
 
     LayoutMultiColumnSet* nextSiblingMultiColumnSet() const;
     LayoutMultiColumnSet* previousSiblingMultiColumnSet() const;
 
     LayoutUnit logicalTopInFlowThread() const;
     LayoutUnit logicalBottomInFlowThread() const;
     LayoutUnit logicalHeightInFlowThread() const { return logicalBottomInFlowThread() - logicalTopInFlowThread(); }
+    LayoutRect flowThreadPortionRect() const;
+    LayoutRect flowThreadPortionOverflowRect() const;
+    LayoutRect overflowRectForFlowThreadPortion(const LayoutRect& flowThreadPortionRect, bool isFirstPortion, bool isLastPortion) const;
 
     // The used CSS value of column-count, i.e. how many columns there are room for without overflowing.
     unsigned usedColumnCount() const { return multiColumnFlowThread()->columnCount(); }
 
     bool heightIsAuto() const;
 
     // Find the column that contains the given block offset, and return the translation needed to
     // get from flow thread coordinates to visual coordinates.
     LayoutSize flowThreadTranslationAtOffset(LayoutUnit) const;
 
@@ skipping 28 matching lines @@
 
     // Layout of flow thread content that was to be rendered inside this column set has
     // finished. This happens at end of flow thread layout, and when advancing to the next column
     // set or spanner.
     void endFlow(LayoutUnit offsetInFlowThread);
 
     // Expand this set's flow thread portion rectangle to contain all trailing flow thread
     // overflow. Only to be called on the last set.
     void expandToEncompassFlowThreadContentsIfNeeded();
 
-    void attachRegion();
-    void detachRegion();
+    virtual void computeIntrinsicLogicalWidths(LayoutUnit& minLogicalWidth, LayoutUnit& maxLogicalWidth) const override final;
 
-    // The top of the nearest page inside the region. For LayoutRegions, this is just the logical top of the
-    // flow thread portion we contain. For sets, we have to figure out the top of the nearest column or
-    // page.
+    void attachToFlowThread();
+    void detachFromFlowThread();
+
+    // The top of the page nearest to the specified block offset. All in flowthread coordinates.
     LayoutUnit pageLogicalTopForOffset(LayoutUnit offset) const;
 
     void collectLayerFragments(DeprecatedPaintLayerFragments&, const LayoutRect& layerBoundingBox, const LayoutRect& dirtyRect);
 
     LayoutUnit columnGap() const;
 
     // The "CSS actual" value of column-count. This includes overflowing columns, if any.
     unsigned actualColumnCount() const;
 
     virtual const char* name() const override { return "LayoutMultiColumnSet"; }
 
 protected:
     LayoutMultiColumnSet(LayoutFlowThread*);
 
 private:
     virtual void insertedIntoTree() override final;
     virtual void willBeRemovedFromTree() override final;
 
     virtual bool isSelfCollapsingBlock() const override { return false; }
 
     virtual void computeLogicalHeight(LayoutUnit logicalHeight, LayoutUnit logicalTop, LogicalExtentComputedValues&) const override;
     virtual PositionWithAffinity positionForPoint(const LayoutPoint&) override;
 
     virtual void paintObject(const PaintInfo&, const LayoutPoint& paintOffset) override;
 
     virtual void addOverflowFromChildren() override;
 
-    virtual LayoutRect flowThreadPortionRect() const override;
-
     MultiColumnFragmentainerGroupList m_fragmentainerGroups;
+    LayoutFlowThread* m_flowThread;
 };
 
 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutMultiColumnSet, isLayoutMultiColumnSet());
 
 } // namespace blink
 
 #endif // LayoutMultiColumnSet_h