render_block.h

konqueror3 embedded版本, KDE环境下的当家浏览器的嵌入式版本源码包.

    void newLine();

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

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

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

    // 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;
        bool m_treatAsBlock : 1;

    public:
        RenderObject* compact() const { return m_compact; }
        RenderObject* block() const { return m_block; }
        void setTreatAsBlock(bool b) { m_treatAsBlock = b; }
        bool treatAsBlock() const { return m_treatAsBlock; }
        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; }
    };

    class PageBreakInfo {
        int m_pageBottom; // Next calculated page-break
        bool m_forcePageBreak : 1; // Must break before next block
        // ### to do better "page-break-after/before: avoid" this struct
        // should keep a pagebreakAvoid block and gather children in it
    public:
        PageBreakInfo(int pageBottom) : m_pageBottom(pageBottom), m_forcePageBreak(false) {};
        bool forcePageBreak() { return m_forcePageBreak; }
        void setForcePageBreak(bool b) { m_forcePageBreak = b; }
        int pageBottom() { return m_pageBottom; };
        void setPageBottom(int bottom) { m_pageBottom = bottom; }
    };

    virtual bool canClear(RenderObject *child, PageBreakLevel level);
    void clearPageBreak(RenderObject* child, int pageBottom);

    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, const MarginInfo& marginInfo, 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);
    void clearChildOfPageBreaks(RenderObject* child, PageBreakInfo &pageBreakInfo, MarginInfo &marginInfo);
    // End helper functions and structs used by layoutBlockChildren.

protected:
    // 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;

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

    bool m_childrenInline : 1;
    bool m_pre            : 1;
    bool m_firstLine      : 1; // used in inline layouting
    EClear m_clearStatus  : 2; // used during layuting of paragraphs
    bool m_avoidPageBreak : 1; // anonymous avoid page-break block
    bool m_topMarginQuirk : 1;
    bool m_bottomMarginQuirk : 1;

    short m_maxTopPosMargin;
    short m_maxTopNegMargin;
    short m_maxBottomPosMargin;
    short m_maxBottomNegMargin;

};

} // namespace

#endif // RENDER_BLOCK_H