struct BlockSelectionInfo {
        RenderBlock* m_block;
        GapRects m_rects;
        SelectionState m_state;

        BlockSelectionInfo() { m_block = 0; m_state = SelectionNone; }
        BlockSelectionInfo(RenderBlock* b) {
            m_block = b;
            m_state = m_block->selectionState();
            m_rects = m_block->selectionGapRects();
        }

        GapRects rects() const { return m_rects; }
        SelectionState state() const { return m_state; }
        RenderBlock* block() const { return m_block; }
    };

    virtual QRect selectionRect() { return selectionGapRects(); }
    GapRects selectionGapRects();
    virtual bool shouldPaintSelectionGaps() const;
    bool isSelectionRoot() const;
    GapRects fillSelectionGaps(RenderBlock* rootBlock, int blockX, int blockY, int tx, int ty,
                               int& lastTop, int& lastLeft, int& lastRight, const PaintInfo* i = 0);
    GapRects fillInlineSelectionGaps(RenderBlock* rootBlock, int blockX, int blockY, int tx, int ty,
                                     int& lastTop, int& lastLeft, int& lastRight, const PaintInfo* i);
    GapRects fillBlockSelectionGaps(RenderBlock* rootBlock, int blockX, int blockY, int tx, int ty,
                                    int& lastTop, int& lastLeft, int& lastRight, const PaintInfo* i);
    QRect fillVerticalSelectionGap(int lastTop, int lastLeft, int lastRight,
                                   int bottomY, RenderBlock* rootBlock, int blockX, int blockY, const PaintInfo* i);
    QRect fillLeftSelectionGap(RenderObject* selObj, int xPos, int yPos, int height, RenderBlock* rootBlock, int blockX, int blockY, int tx, int ty, const PaintInfo* i);
    QRect fillRightSelectionGap(RenderObject* selObj, int xPos, int yPos, int height, RenderBlock* rootBlock, int blockX, int blockY, int tx, int ty, const PaintInfo* i);
    QRect fillHorizontalSelectionGap(RenderObject* selObj, int xPos, int yPos, int width, int height, const PaintInfo* i);

    void getHorizontalSelectionGapInfo(SelectionState state, bool& leftGap, bool& rightGap);
    int leftSelectionOffset(RenderBlock* rootBlock, int y);
    int rightSelectionOffset(RenderBlock* rootBlock, int y);

#ifndef NDEBUG
    virtual void printTree(int indent=0) const;
    virtual void dump(QTextStream *stream, QString ind = "") const;
#endif

    // Helper methods for computing line counts and heights for line counts.
    RootInlineBox* lineAtIndex(int i);
    int lineCount();
    int heightForLineCount(int l);
    void clearTruncation();

protected:
    void newLine();

private:
    DOM::Position positionForBox(InlineBox *box, bool start=true) const;
    DOM::Position positionForRenderer(RenderObject *renderer, bool start=true) const;
    bool skipNonBreakingSpace(BidiIterator &it);

protected:
    struct FloatingObject {
        enum Type {
            FloatLeft,
            FloatRight
        };

        FloatingObject(Type _type) {
            node = 0;
            startY = 0;
            endY = 0;
            type = _type;
            left = 0;
            width = 0;
            noPaint = false;
        }

        RenderObject* node;
        int startY;
        int endY;
        int left;
        int width;
        Type type : 1; // left or right aligned
        bool noPaint : 1;
    };

    // The following helper functions and structs are used by layoutBlockChildren.
    class CompactInfo {
        // A compact child that needs to be collapsed into the margin of the following block.
        RenderObject* m_compact;

        // The block with the open margin that the compact child is going to place itself within.
        RenderObject* m_block;

    public:
        RenderObject* compact() const { return m_compact; }
        RenderObject* block() const { return m_block; }
        bool matches(RenderObject* child) const { return m_compact && m_block == child; }

        void clear() { set(0, 0);  }
        void set(RenderObject* c, RenderObject* b) { m_compact = c; m_block = b; }

        CompactInfo() { clear(); }
    };

    class MarginInfo {
        // Collapsing flags for whether we can collapse our margins with our children's margins.
        bool m_canCollapseWithChildren : 1;
        bool m_canCollapseTopWithChildren : 1;
        bool m_canCollapseBottomWithChildren : 1;

        // Whether or not we are a quirky container, i.e., do we collapse away top and bottom
        // margins in our container.  Table cells and the body are the common examples. We
        // also have a custom style property for Safari RSS to deal with TypePad blog articles.
        bool m_quirkContainer : 1;

        // This flag tracks whether we are still looking at child margins that can all collapse together at the beginning of a block.
        // They may or may not collapse with the top margin of the block (|m_canCollapseTopWithChildren| tells us that), but they will
        // always be collapsing with one another.  This variable can remain set to true through multiple iterations
        // as long as we keep encountering self-collapsing blocks.
        bool m_atTopOfBlock : 1;

        // This flag is set when we know we're examining bottom margins and we know we're at the bottom of the block.
        bool m_atBottomOfBlock : 1;

        // If our last normal flow child was a self-collapsing block that cleared a float,
        // we track it in this variable.
        bool m_selfCollapsingBlockClearedFloat : 1;

        // These variables are used to detect quirky margins that we need to collapse away (in table cells
        // and in the body element).
        bool m_topQuirk : 1;
        bool m_bottomQuirk : 1;
        bool m_determinedTopQuirk : 1;

        // These flags track the previous maximal positive and negative margins.
        int m_posMargin;
        int m_negMargin;

    public:
        MarginInfo(RenderBlock* b, int top, int bottom);

        void setAtTopOfBlock(bool b) { m_atTopOfBlock = b; }
        void setAtBottomOfBlock(bool b) { m_atBottomOfBlock = b; }
        void clearMargin() { m_posMargin = m_negMargin = 0; }
        void setSelfCollapsingBlockClearedFloat(bool b) { m_selfCollapsingBlockClearedFloat = b; }
        void setTopQuirk(bool b) { m_topQuirk = b; }
        void setBottomQuirk(bool b) { m_bottomQuirk = b; }
        void setDeterminedTopQuirk(bool b) { m_determinedTopQuirk = b; }
        void setPosMargin(int p) { m_posMargin = p; }
        void setNegMargin(int n) { m_negMargin = n; }
        void setPosMarginIfLarger(int p) { if (p > m_posMargin) m_posMargin = p; }
        void setNegMarginIfLarger(int n) { if (n > m_negMargin) m_negMargin = n; }

        void setMargin(int p, int n) { m_posMargin = p; m_negMargin = n; }

        bool atTopOfBlock() const { return m_atTopOfBlock; }
        bool canCollapseWithTop() const { return m_atTopOfBlock && m_canCollapseTopWithChildren; }
        bool canCollapseWithBottom() const { return m_atBottomOfBlock && m_canCollapseBottomWithChildren; }
        bool canCollapseTopWithChildren() const { return m_canCollapseTopWithChildren; }
        bool canCollapseBottomWithChildren() const { return m_canCollapseBottomWithChildren; }
        bool selfCollapsingBlockClearedFloat() const { return m_selfCollapsingBlockClearedFloat; }
        bool quirkContainer() const { return m_quirkContainer; }
        bool determinedTopQuirk() const { return m_determinedTopQuirk; }
        bool topQuirk() const { return m_topQuirk; }
        bool bottomQuirk() const { return m_bottomQuirk; }
        int posMargin() const { return m_posMargin; }
        int negMargin() const { return m_negMargin; }
        int margin() const { return m_posMargin - m_negMargin; }
    };

    void adjustPositionedBlock(RenderObject* child, const MarginInfo& marginInfo);
    void adjustFloatingBlock(const MarginInfo& marginInfo);
    RenderObject* handleSpecialChild(RenderObject* child, const MarginInfo& marginInfo, CompactInfo& compactInfo, bool& handled);
    RenderObject* handleFloatingChild(RenderObject* child, const MarginInfo& marginInfo, bool& handled);
    RenderObject* handlePositionedChild(RenderObject* child, const MarginInfo& marginInfo, bool& handled);
    RenderObject* handleCompactChild(RenderObject* child, CompactInfo& compactInfo, bool& handled);
    RenderObject* handleRunInChild(RenderObject* child, bool& handled);
    void collapseMargins(RenderObject* child, MarginInfo& marginInfo, int yPosEstimate);
    void clearFloatsIfNeeded(RenderObject* child, MarginInfo& marginInfo, int oldTopPosMargin, int oldTopNegMargin);
    void insertCompactIfNeeded(RenderObject* child, CompactInfo& compactInfo);
    int estimateVerticalPosition(RenderObject* child, const MarginInfo& info);
    void determineHorizontalPosition(RenderObject* child);
    void handleBottomOfBlock(int top, int bottom, MarginInfo& marginInfo);
    void setCollapsedBottomMargin(const MarginInfo& marginInfo);
    // End helper functions and structs used by layoutBlockChildren.

protected:
    QPtrList<FloatingObject>* m_floatingObjects;
    QPtrList<RenderObject>* m_positionedObjects;

    bool m_childrenInline : 1;
    bool m_pre            : 1;
    bool m_firstLine      : 1;
    EClear m_clearStatus  : 2;
    bool m_topMarginQuirk : 1;
    bool m_bottomMarginQuirk : 1;
    bool m_hasMarkupTruncation : 1;
    SelectionState m_selectionState : 3;

    int m_maxTopPosMargin;
    int m_maxTopNegMargin;
    int m_maxBottomPosMargin;
    int m_maxBottomNegMargin;

    // How much content overflows out of our block vertically or horizontally (all we support
    // for now is spillage out of the bottom and the right, which are the common cases).
    // XXX Generalize to work with top and left as well.
    int m_overflowHeight;
    int m_overflowWidth;

    // Left and top overflow.  Does not affect scrolling dimensions, but we do at least use it
    // when dirty rect checking and hit testing.
    int m_overflowLeft;
    int m_overflowTop;
};

}; // namespace

#ifdef __WINSCW__
#pragma enumsalwaysint reset
#endif

#endif // RENDER_BLOCK_H