render_object.h

It is WEB browser core module with source code. Very good!

    bool isReplaced() const { return m_replaced; } // a "replaced" element (see CSS)
    bool shouldPaintBackgroundOrBorder() const { return m_paintBackground; }
    bool needsLayout() const   { return m_needsLayout || m_normalChildNeedsLayout || m_posChildNeedsLayout; }
    bool selfNeedsLayout() const { return m_needsLayout; }
    bool posChildNeedsLayout() const { return m_posChildNeedsLayout; }
    bool normalChildNeedsLayout() const { return m_normalChildNeedsLayout; }
    bool minMaxKnown() const{ return m_minMaxKnown; }
    bool recalcMinMax() const { return m_recalcMinMax; }
    bool isSelectionBorder() const;

    bool hasOverflowClip() const { return m_hasOverflowClip; }
    bool hasAutoScrollbars() const { return hasOverflowClip() &&
        (style()->overflow() == OAUTO || style()->overflow() == OOVERLAY); }
    bool scrollsOverflow() const { return hasOverflowClip() &&
        (style()->overflow() == OSCROLL || hasAutoScrollbars()); }
    bool includeScrollbarSize() const { return hasOverflowClip() &&
        (style()->overflow() == OSCROLL || style()->overflow() == OAUTO); }

    RenderStyle* getPseudoStyle(RenderStyle::PseudoId pseudo, RenderStyle* parentStyle = 0) const;

    void updateDragState(bool dragOn);

    RenderCanvas* canvas() const;

    // don't even think about making this method virtual!
    DOM::NodeImpl* element() const { return m_isAnonymous ? 0 : m_node; }
    DOM::DocumentImpl* document() const { return m_node->getDocument(); }
    void setNode(DOM::NodeImpl* node) { m_node = node; }
    DOM::NodeImpl* node() const { return m_node; }

   /**
     * returns the object containing this one. can be different from parent for
     * positioned elements
     */
    RenderObject *container() const;

    virtual void markAllDescendantsWithFloatsForLayout(RenderObject* floatToRemove = 0);
    void markContainingBlocksForLayout();
    void setNeedsLayout(bool b, bool markParents = true);
    void setChildNeedsLayout(bool b, bool markParents = true);
    void setMinMaxKnown(bool b=true) {
	m_minMaxKnown = b;
	if ( !b ) {
	    RenderObject *o = this;
	    RenderObject *root = this;
	    while( o ) { // ### && !o->m_recalcMinMax ) {
		o->m_recalcMinMax = true;
		root = o;
		o = o->m_parent;
	    }
	}
    }

    void setNeedsLayoutAndMinMaxRecalc() {
        setMinMaxKnown(false);
        setNeedsLayout(true);
    }

    void setPositioned(bool b=true)  { m_positioned = b;  }
    void setRelPositioned(bool b=true) { m_relPositioned = b; }
    void setFloating(bool b=true) { m_floating = b; }
    void setInline(bool b=true) { m_inline = b; }
    void setMouseInside(bool b=true) { m_mouseInside = b; }
    void setShouldPaintBackgroundOrBorder(bool b=true) { m_paintBackground = b; }
    void setRenderText() { m_isText = true; }
    void setReplaced(bool b=true) { m_replaced = b; }
    void setHasOverflowClip(bool b = true) { m_hasOverflowClip = b; }

    void scheduleRelayout();

    void updateBackgroundImages(RenderStyle* oldStyle);

    virtual InlineBox* createInlineBox(bool makePlaceHolderBox, bool isRootLineBox, bool isOnlyRun=false);
    virtual void dirtyLineBoxes(bool fullLayout, bool isRootLineBox=false);

    // For inline replaced elements, this function returns the inline box that owns us.  Enables
    // the replaced RenderObject to quickly determine what line it is contained on and to easily
    // iterate over structures on the line.
    virtual InlineBox* inlineBoxWrapper() const;
    virtual void setInlineBoxWrapper(InlineBox* b);
    void deleteLineBoxWrapper();

    virtual InlineBox *inlineBox(long offset=0, EAffinity affinity = UPSTREAM);

    // for discussion of lineHeight see CSS2 spec
    virtual short lineHeight( bool firstLine, bool isRootLineBox=false ) const;
    // for the vertical-align property of inline elements
    // the difference between this objects baseline position and the lines baseline position.
    virtual short verticalPositionHint( bool firstLine ) const;
    // the offset of baseline from the top of the object.
    virtual short baselinePosition( bool firstLine, bool isRootLineBox=false ) const;

    /*
     * Paint the object and its children, clipped by (x|y|w|h).
     * (tx|ty) is the calculated position of the parent
     */
    struct PaintInfo
    OOM_MODIFIED
    {
        PaintInfo(QPainter* _p, const QRect& _r, PaintAction _phase, RenderObject *_paintingRoot)
        : p(_p), r(_r), phase(_phase), paintingRoot(_paintingRoot), outlineObjects(0) {}
        ~PaintInfo() { delete outlineObjects; }
        QPainter* p;
        QRect     r;
        PaintAction phase;
        RenderObject *paintingRoot;      // used to draw just one element and its visual kids
        QPtrDict<RenderFlow>* outlineObjects; // used to list which outlines should be painted by a block with inline children
    };
    virtual void paint(PaintInfo& i, int tx, int ty);
    void paintBorder(QPainter *p, int _tx, int _ty, int w, int h, const RenderStyle* style, bool begin=true, bool end=true);
    void paintOutline(QPainter *p, int _tx, int _ty, int w, int h, const RenderStyle* style);

    // RenderBox implements this.
    virtual void paintBoxDecorations(PaintInfo& i, int _tx, int _ty) {};

    virtual void paintBackgroundExtended(QPainter *p, const QColor& c, const BackgroundLayer* bgLayer, int clipy, int cliph,
                                         int _tx, int _ty, int w, int height,
                                         int bleft, int bright) {};

    /*
     * This function calculates the minimum & maximum width that the object
     * can be set to.
     *
     * when the Element calls setMinMaxKnown(true), calcMinMaxWidth() will
     * be no longer called.
     *
     * when a element has a fixed size, m_minWidth and m_maxWidth should be
     * set to the same value. This has the special meaning that m_width,
     * contains the actual value.
     *
     * assumes calcMinMaxWidth has already been called for all children.
     */
    virtual void calcMinMaxWidth() { }

    /*
     * Does the min max width recalculations after changes.
     */
    void recalcMinMaxWidths();

    /*
     * Calculates the actual width of the object (only for non inline
     * objects)
     */
    virtual void calcWidth() {}

    /*
     * This function should cause the Element to calculate its
     * width and height and the layout of its content
     *
     * when the Element calls setNeedsLayout(false), layout() is no
     * longer called during relayouts, as long as there is no
     * style sheet change. When that occurs, m_needsLayout will be
     * set to true and the Element receives layout() calls
     * again.
     */
    virtual void layout() = 0;

    /* This function performs a layout only if one is needed. */
    void layoutIfNeeded() { if (needsLayout()) layout(); }

    // used for element state updates that can not be fixed with a
    // repaint and do not need a relayout
    virtual void updateFromElement() {};

    virtual int availableHeight() const { return 0; }

    // Whether or not the element shrinks to its max width (rather than filling the width
    // of a containing block).  HTML4 buttons, legends, and floating/compact elements do this.
    bool sizesToMaxWidth() const;

#if APPLE_CHANGES
    // Called recursively to update the absolute positions of all widgets.
    virtual void updateWidgetPositions();

    QValueList<DashboardRegionValue> computeDashboardRegions();
    void addDashboardRegions (QValueList<DashboardRegionValue>& regions);
    void collectDashboardRegions (QValueList<DashboardRegionValue>& regions);
#endif

    // does a query on the rendertree and finds the innernode
    // and overURL for the given position
    // if readonly == false, it will recalc hover styles accordingly
    class NodeInfo
    OOM_MODIFIED
    {
        friend class RenderLayer;
        friend class RenderImage;
        friend class RenderText;
        friend class RenderInline;
        friend class RenderObject;
        friend class RenderFrameSet;
        friend class DOM::HTMLAreaElementImpl;
    public:
        NodeInfo(bool readonly, bool active)
            : m_innerNode(0), m_innerNonSharedNode(0), m_innerURLElement(0), m_readonly(readonly), m_active(active)
            { }

        DOM::NodeImpl* innerNode() const { return m_innerNode; }
        DOM::NodeImpl* innerNonSharedNode() const { return m_innerNonSharedNode; }
        DOM::NodeImpl* URLElement() const { return m_innerURLElement; }
        bool readonly() const { return m_readonly; }
        bool active() const { return m_active; }

    private:
        void setInnerNode(DOM::NodeImpl* n) { m_innerNode = n; }
        void setInnerNonSharedNode(DOM::NodeImpl* n) { m_innerNonSharedNode = n; }
        void setURLElement(DOM::NodeImpl* n) { m_innerURLElement = n; }

        DOM::NodeImpl* m_innerNode;
        DOM::NodeImpl* m_innerNonSharedNode;
        DOM::NodeImpl* m_innerURLElement;
        bool m_readonly;
        bool m_active;
    };

    // Used to signal a specific subrect within an object that must be repainted after
    // layout is complete.
    struct RepaintInfo
    OOM_MODIFIED
    {
        RenderObject* m_object;
        QRect m_repaintRect;

        RepaintInfo(RenderObject* o, const QRect& r) :m_object(o), m_repaintRect(r) {}
    };

    bool hitTest(NodeInfo& info, int x, int y, int tx, int ty, HitTestFilter hitTestFilter = HitTestAll);
    virtual bool nodeAtPoint(NodeInfo& info, int x, int y, int tx, int ty,
                             HitTestAction hitTestAction);
    void setInnerNode(NodeInfo& info);

    virtual VisiblePosition positionForCoordinates(int x, int y);

    virtual void dirtyLinesFromChangedChild(RenderObject* child, bool adding = true);

    // Set the style of the object and update the state of the object accordingly.
    virtual void setStyle(RenderStyle* style);

    // Updates only the local style ptr of the object.  Does not update the state of the object,
    // and so only should be called when the style is known not to have changed (or from setStyle).
    void setStyleInternal(RenderStyle* style);

    // returns the containing block level element for this element.
    RenderBlock *containingBlock() const;

    // return just the width of the containing block
    virtual int containingBlockWidth() const;
    // return just the height of the containing block
    virtual int containingBlockHeight() const;

    // size of the content area (box size minus padding/border)
    virtual int contentWidth() const { return 0; }
    virtual int contentHeight() const { return 0; }

    // intrinsic extend of replaced elements. undefined otherwise
    virtual int intrinsicWidth() const { return 0; }
    virtual int intrinsicHeight() const { return 0; }

    // used by flexible boxes to impose a flexed width/height override
    virtual int overrideSize() const { return 0; }
    virtual int overrideWidth() const { return 0; }
    virtual int overrideHeight() const { return 0; }
    virtual void setOverrideSize(int s) {}

    // relative to parent node
    virtual void setPos( int /*xPos*/, int /*yPos*/ ) { }
    virtual void setWidth( int /*width*/ ) { }
    virtual void setHeight( int /*height*/ ) { }

    virtual int xPos() const { return 0; }
    virtual int yPos() const { return 0; }

    // calculate client position of box
    virtual bool absolutePosition(int &/*xPos*/, int &/*yPos*/, bool fixed = false);

    // width and height are without margins but include paddings and borders
    virtual int width() const { return 0; }
    virtual int height() const { return 0; }

    virtual QRect borderBox() const { return QRect(0, 0, width(), height()); }

    // The height of a block when you include normal flow overflow spillage out of the bottom
    // of the block (e.g., a <div style="height:25px"> that has a 100px tall image inside
    // it would have an overflow height of borderTop() + paddingTop() + 100px.
    virtual int overflowHeight(bool includeInterior=true) const { return height(); }
    virtual int overflowWidth(bool includeInterior=true) const { return width(); }
    virtual void setOverflowHeight(int) {}
    virtual void setOverflowWidth(int) {}
    virtual int overflowLeft(bool includeInterior=true) const { return 0; }
    virtual int overflowTop(bool includeInterior=true) const { return 0; }
    virtual QRect overflowRect(bool includeInterior=true) const { return borderBox(); }

    // IE extensions. Used to calculate offsetWidth/Height.  Overridden by inlines (render_flow)
    // to return the remaining width on a given line (and the height of a single line). -dwh
    virtual int offsetWidth() const { return width(); }
    virtual int offsetHeight() const { return height(); }

    // IE exxtensions.  Also supported by Gecko.  We override in render flow to get the
    // left and top correct. -dwh
    virtual int offsetLeft() const;
    virtual int offsetTop() const;
    virtual RenderObject* offsetParent() const;

    // More IE extensions.  clientWidth and clientHeight represent the interior of an object
    // excluding border and scrollbar.
    int clientWidth() const;
    int clientHeight() const;

    // scrollWidth/scrollHeight will be the same as clientWidth/clientHeight unless the
    // object has overflow:hidden/scroll/auto specified and also has overflow.
    int scrollWidth() const;
    int scrollHeight() const;

    virtual bool scroll(KWQScrollDirection direction, KWQScrollGranularity granularity, float multiplier=1.0);

    // The following seven functions are used to implement collapsing margins.
    // All objects know their maximal positive and negative margins.  The