path: root/WebCore/rendering/RenderObject.h

/*
 * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
 *           (C) 2000 Antti Koivisto (koivisto@kde.org)
 *           (C) 2000 Dirk Mueller (mueller@kde.org)
 *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
 * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 *
 */

#ifndef RenderObject_h
#define RenderObject_h

#include "CachedResourceClient.h"
#include "FloatQuad.h"
#include "Document.h"
#include "RenderStyle.h"

namespace WebCore {

class AnimationController;
class HitTestResult;
class InlineBox;
class InlineFlowBox;
class RenderBlock;
class RenderFlow;
class RenderLayer;
class VisiblePosition;

/*
 *  The painting of a layer occurs in three distinct phases.  Each phase involves
 *  a recursive descent into the layer's render objects. The first phase is the background phase.
 *  The backgrounds and borders of all blocks are painted.  Inlines are not painted at all.
 *  Floats must paint above block backgrounds but entirely below inline content that can overlap them.
 *  In the foreground phase, all inlines are fully painted.  Inline replaced elements will get all
 *  three phases invoked on them during this phase.
 */

enum PaintPhase {
    PaintPhaseBlockBackground,
    PaintPhaseChildBlockBackground,
    PaintPhaseChildBlockBackgrounds,
    PaintPhaseFloat,
    PaintPhaseForeground,
    PaintPhaseOutline,
    PaintPhaseChildOutlines,
    PaintPhaseSelfOutline,
    PaintPhaseSelection,
    PaintPhaseCollapsedTableBorders,
    PaintPhaseTextClip,
    PaintPhaseMask
};

enum PaintRestriction {
    PaintRestrictionNone,
    PaintRestrictionSelectionOnly,
    PaintRestrictionSelectionOnlyBlackText
};

enum HitTestFilter {
    HitTestAll,
    HitTestSelf,
    HitTestDescendants
};

enum HitTestAction {
    HitTestBlockBackground,
    HitTestChildBlockBackground,
    HitTestChildBlockBackgrounds,
    HitTestFloat,
    HitTestForeground
};

// Values for verticalPosition.
const int PositionTop = -0x7fffffff;
const int PositionBottom = 0x7fffffff;
const int PositionUndefined = 0x80000000;

#if ENABLE(DASHBOARD_SUPPORT)
struct DashboardRegionValue {
    bool operator==(const DashboardRegionValue& o) const
    {
        return type == o.type && bounds == o.bounds && clip == o.clip && label == o.label;
    }
    bool operator!=(const DashboardRegionValue& o) const
    {
        return !(*this == o);
    }

    String label;
    IntRect bounds;
    IntRect clip;
    int type;
};
#endif

// Base class for all rendering tree objects.
class RenderObject : public CachedResourceClient {
    friend class RenderContainer;
    friend class RenderLayer;
    friend class RenderSVGContainer;
public:
    // Anonymous objects should pass the document as their node, and they will then automatically be
    // marked as anonymous in the constructor.
    RenderObject(Node*);
    virtual ~RenderObject();

    virtual const char* renderName() const { return "RenderObject"; }

    RenderObject* parent() const { return m_parent; }
    bool isDescendantOf(const RenderObject*) const;

    RenderObject* previousSibling() const { return m_previous; }
    RenderObject* nextSibling() const { return m_next; }

    virtual RenderObject* firstChild() const { return 0; }
    virtual RenderObject* lastChild() const { return 0; }

    RenderObject* nextInPreOrder() const;
    RenderObject* nextInPreOrder(RenderObject* stayWithin) const;
    RenderObject* nextInPreOrderAfterChildren() const;
    RenderObject* nextInPreOrderAfterChildren(RenderObject* stayWithin) const;
    RenderObject* previousInPreOrder() const;
    RenderObject* childAt(unsigned) const;

    RenderObject* firstLeafChild() const;
    RenderObject* lastLeafChild() const;

    // The following five functions are used when the render tree hierarchy changes to make sure layers get
    // properly added and removed.  Since containership can be implemented by any subclass, and since a hierarchy
    // can contain a mixture of boxes and other object types, these functions need to be in the base class.
    RenderLayer* enclosingLayer() const;
    void addLayers(RenderLayer* parentLayer, RenderObject* newObject);
    void removeLayers(RenderLayer* parentLayer);
    void moveLayers(RenderLayer* oldParent, RenderLayer* newParent);
    RenderLayer* findNextLayer(RenderLayer* parentLayer, RenderObject* startPoint, bool checkParent = true);

    // Convenience function for getting to the nearest enclosing box of a RenderObject.
    RenderBox* enclosingBox() const;
    
    virtual IntRect getOverflowClipRect(int /*tx*/, int /*ty*/) { return IntRect(0, 0, 0, 0); }
    virtual IntRect getClipRect(int /*tx*/, int /*ty*/) { return IntRect(0, 0, 0, 0); }
    bool hasClip() { return isPositioned() && style()->hasClip(); }

    virtual int getBaselineOfFirstLineBox() const { return -1; }
    virtual int getBaselineOfLastLineBox() const { return -1; }

    virtual bool isEmpty() const { return firstChild() == 0; }

    virtual bool isEdited() const { return false; }
    virtual void setEdited(bool) { }

#ifndef NDEBUG
    void setHasAXObject(bool flag) { m_hasAXObject = flag; }
    bool hasAXObject() const { return m_hasAXObject; }
    bool isSetNeedsLayoutForbidden() const { return m_setNeedsLayoutForbidden; }
    void setNeedsLayoutIsForbidden(bool flag) { m_setNeedsLayoutForbidden = flag; }
#endif

    // Obtains the nearest enclosing block (including this block) that contributes a first-line style to our inline
    // children.
    virtual RenderBlock* firstLineBlock() const;

    // Called when an object that was floating or positioned becomes a normal flow object
    // again.  We have to make sure the render tree updates as needed to accommodate the new
    // normal flow object.
    void handleDynamicFloatPositionChange();

    // This function is a convenience helper for creating an anonymous block that inherits its
    // style from this RenderObject.
    RenderBlock* createAnonymousBlock();

    // Whether or not a positioned element requires normal flow x/y to be computed
    // to determine its position.
    bool hasStaticX() const;
    bool hasStaticY() const;
    virtual void setStaticX(int /*staticX*/) { }
    virtual void setStaticY(int /*staticY*/) { }
    virtual int staticX() const { return 0; }
    virtual int staticY() const { return 0; }

    // RenderObject tree manipulation
    //////////////////////////////////////////
    virtual bool canHaveChildren() const;
    virtual bool isChildAllowed(RenderObject*, RenderStyle*) const { return true; }
    virtual void addChild(RenderObject* newChild, RenderObject* beforeChild = 0);
    virtual void removeChild(RenderObject*);
    virtual bool createsAnonymousWrapper() const { return false; }

    // raw tree manipulation
    virtual RenderObject* removeChildNode(RenderObject*, bool fullRemove = true);
    virtual void appendChildNode(RenderObject*, bool fullAppend = true);
    virtual void insertChildNode(RenderObject* child, RenderObject* before, bool fullInsert = true);
    // Designed for speed.  Don't waste time doing a bunch of work like layer updating and repainting when we know that our
    // change in parentage is not going to affect anything.
    virtual void moveChildNode(RenderObject*);
    //////////////////////////////////////////

protected:
    //////////////////////////////////////////
    // Helper functions. Dangerous to use!
    void setPreviousSibling(RenderObject* previous) { m_previous = previous; }
    void setNextSibling(RenderObject* next) { m_next = next; }
    void setParent(RenderObject* parent) { m_parent = parent; }
    //////////////////////////////////////////
private:
    void addAbsoluteRectForLayer(IntRect& result);

public:
#ifndef NDEBUG
    void showTreeForThis() const;
#endif

    static RenderObject* createObject(Node*, RenderStyle*);

    // Overloaded new operator.  Derived classes must override operator new
    // in order to allocate out of the RenderArena.
    void* operator new(size_t, RenderArena*) throw();

    // Overridden to prevent the normal delete from being called.
    void operator delete(void*, size_t);

private:
    // The normal operator new is disallowed on all render objects.
    void* operator new(size_t) throw();

public:
    RenderArena* renderArena() const { return document()->renderArena(); }

    virtual bool isApplet() const { return false; }
    virtual bool isBR() const { return false; }
    virtual bool isBlockFlow() const { return false; }
    virtual bool isCounter() const { return false; }
    virtual bool isFieldset() const { return false; }
    virtual bool isFrame() const { return false; }
    virtual bool isFrameSet() const { return false; }
    virtual bool isImage() const { return false; }
    virtual bool isInlineBlockOrInlineTable() const { return false; }
    virtual bool isInlineContinuation() const;
    virtual bool isListBox() const { return false; }
    virtual bool isListItem() const { return false; }
    virtual bool isListMarker() const { return false; }
    virtual bool isMedia() const { return false; }
    virtual bool isMenuList() const { return false; }
    virtual bool isRenderBlock() const { return false; }
    virtual bool isRenderImage() const { return false; }
    virtual bool isRenderInline() const { return false; }
    virtual bool isRenderPart() const { return false; }
    virtual bool isRenderView() const { return false; }
    virtual bool isSlider() const { return false; }
    virtual bool isTable() const { return false; }
    virtual bool isTableCell() const { return false; }
    virtual bool isTableCol() const { return false; }
    virtual bool isTableRow() const { return false; }
    virtual bool isTableSection() const { return false; }
    virtual bool isTextArea() const { return false; }
    virtual bool isTextField() const { return false; }
    virtual bool isWidget() const { return false; }

    bool isRoot() const { return document()->documentElement() == node(); }
    bool isBody() const;
    bool isHR() const;

    bool isHTMLMarquee() const;

    virtual bool childrenInline() const { return false; }
    virtual void setChildrenInline(bool) { }

    virtual RenderFlow* virtualContinuation() const { return 0; }

#if ENABLE(SVG)
    virtual bool isSVGRoot() const { return false; }
    virtual bool isSVGContainer() const { return false; }
    virtual bool isSVGHiddenContainer() const { return false; }
    virtual bool isRenderPath() const { return false; }
    virtual bool isSVGText() const { return false; }

    virtual FloatRect relativeBBox(bool includeStroke = true) const;

    virtual TransformationMatrix localTransform() const;
    virtual TransformationMatrix absoluteTransform() const;
#endif

    virtual bool isEditable() const;

    bool isAnonymous() const { return m_isAnonymous; }
    void setIsAnonymous(bool b) { m_isAnonymous = b; }
    bool isAnonymousBlock() const
    {
        return m_isAnonymous && style()->display() == BLOCK && style()->styleType() == RenderStyle::NOPSEUDO && !isListMarker();
    }

    bool isFloating() const { return m_floating; }
    bool isPositioned() const { return m_positioned; } // absolute or fixed positioning
    bool isRelPositioned() const { return m_relPositioned; } // relative positioning
    bool isText() const  { return m_isText; }
    bool isBox() const { return m_isBox; }
    bool isInline() const { return m_inline; }  // inline object
    bool isRunIn() const { return style()->display() == RUN_IN; } // run-in object
    bool isDragging() const { return m_isDragging; }
    bool isReplaced() const { return m_replaced; } // a "replaced" element (see CSS)
    
    bool hasLayer() const { return m_hasLayer; }
    
    bool hasBoxDecorations() const { return m_paintBackground; }
    bool mustRepaintBackgroundOrBorder() const;
                                                              
    bool needsLayout() const { return m_needsLayout || m_normalChildNeedsLayout || m_posChildNeedsLayout || m_needsPositionedMovementLayout; }
    bool selfNeedsLayout() const { return m_needsLayout; }
    bool needsPositionedMovementLayout() const { return m_needsPositionedMovementLayout; }
    bool needsPositionedMovementLayoutOnly() const { return m_needsPositionedMovementLayout && !m_needsLayout && !m_normalChildNeedsLayout && !m_posChildNeedsLayout; }
    bool posChildNeedsLayout() const { return m_posChildNeedsLayout; }
    bool normalChildNeedsLayout() const { return m_normalChildNeedsLayout; }
    
    bool prefWidthsDirty() const { return m_prefWidthsDirty; }

    bool isSelectionBorder() const;

    bool hasOverflowClip() const { return m_hasOverflowClip; }
    virtual bool hasControlClip() const { return false; }
    virtual IntRect controlClipRect(int /*tx*/, int /*ty*/) const { return IntRect(); }

    bool hasTransform() const { return m_hasTransform; }
    bool hasMask() const { return style() && style()->hasMask(); }

public:
    // The pseudo element style can be cached or uncached.  Use the cached method if the pseudo element doesn't respect
    // any pseudo classes (and therefore has no concept of changing state).
    RenderStyle* getCachedPseudoStyle(RenderStyle::PseudoId, RenderStyle* parentStyle = 0) const;
    PassRefPtr<RenderStyle> getUncachedPseudoStyle(RenderStyle::PseudoId, RenderStyle* parentStyle = 0) const;
    
    void updateDragState(bool dragOn);

    RenderView* view() const;

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

    bool hasOutlineAnnotation() const;
    bool hasOutline() const { return style()->hasOutline() || hasOutlineAnnotation(); }

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

    void markContainingBlocksForLayout(bool scheduleRelayout = true, RenderObject* newRoot = 0);
    void setNeedsLayout(bool b, bool markParents = true);
    void setChildNeedsLayout(bool b, bool markParents = true);
    void setNeedsPositionedMovementLayout();
    void setPrefWidthsDirty(bool, bool markParents = true);
    void invalidateContainerPrefWidths();
    virtual void invalidateCounters() { }
    
    void setNeedsLayoutAndPrefWidthsRecalc()
    {
        setNeedsLayout(true);
        setPrefWidthsDirty(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 setHasBoxDecorations(bool b = true) { m_paintBackground = b; }
    void setIsText() { m_isText = true; }
    void setIsBox() { m_isBox = true; }
    void setReplaced(bool b = true) { m_replaced = b; }
    void setHasOverflowClip(bool b = true) { m_hasOverflowClip = b; }
    void setHasLayer(bool b = true) { m_hasLayer = b; }
    void setHasTransform(bool b = true) { m_hasTransform = b; }
    void setHasReflection(bool b = true) { m_hasReflection = b; }

    void scheduleRelayout();

    void updateFillImages(const FillLayer*, const FillLayer*);
    void updateImage(StyleImage*, StyleImage*);

    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*);
    virtual void deleteLineBoxWrapper();

    // for discussion of lineHeight see CSS2 spec
    virtual int 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 int verticalPositionHint(bool firstLine) const;
    // the offset of baseline from the top of the object.
    virtual int 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 {
        PaintInfo(GraphicsContext* newContext, const IntRect& newRect, PaintPhase newPhase, bool newForceBlackText,
                  RenderObject* newPaintingRoot, ListHashSet<RenderFlow*>* newOutlineObjects)
            : context(newContext)
            , rect(newRect)
            , phase(newPhase)
            , forceBlackText(newForceBlackText)
            , paintingRoot(newPaintingRoot)
            , outlineObjects(newOutlineObjects)
        {
        }

        GraphicsContext* context;
        IntRect rect;
        PaintPhase phase;
        bool forceBlackText;
        RenderObject* paintingRoot; // used to draw just one element and its visual kids
        ListHashSet<RenderFlow*>* outlineObjects; // used to list outlines that should be painted by a block with inline children
    };

    virtual void paint(PaintInfo&, int tx, int ty);
    void paintBorder(GraphicsContext*, int tx, int ty, int w, int h, const RenderStyle*, bool begin = true, bool end = true);
    bool paintNinePieceImage(GraphicsContext*, int tx, int ty, int w, int h, const RenderStyle*, const NinePieceImage&, CompositeOperator = CompositeSourceOver);
    void paintBoxShadow(GraphicsContext*, int tx, int ty, int w, int h, const RenderStyle*, bool begin = true, bool end = true);

    // RenderBox implements this.
    virtual void paintBoxDecorations(PaintInfo&, int /*tx*/, int /*ty*/) { }
    virtual void paintMask(PaintInfo&, int /*tx*/, int /*ty*/) { }
    virtual void paintFillLayerExtended(const PaintInfo&, const Color&, const FillLayer*,
                                        int /*clipY*/, int /*clipH*/, int /*tx*/, int /*ty*/, int /*width*/, int /*height*/,
                                        InlineFlowBox* = 0, CompositeOperator = CompositeSourceOver) { }

    /*
     * 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(); }

    // Called when a positioned object moves but doesn't necessarily change size.  A simplified layout is attempted
    // that just updates the object's position. If the size does change, the object remains dirty.
    virtual void tryLayoutDoingPositionedMovementOnly() { }
    
    // used for element state updates that cannot be fixed with a
    // repaint and do not need a relayout
    virtual void updateFromElement() { }

    virtual void updateWidgetPosition();

#if ENABLE(DASHBOARD_SUPPORT)
    void addDashboardRegions(Vector<DashboardRegionValue>&);
    void collectDashboardRegions(Vector<DashboardRegionValue>&);
#endif

    bool hitTest(const HitTestRequest&, HitTestResult&, const IntPoint&, int tx, int ty, HitTestFilter = HitTestAll);
    virtual bool nodeAtPoint(const HitTestRequest&, HitTestResult&, int x, int y, int tx, int ty, HitTestAction);
    void updateHitTestResult(HitTestResult&, const IntPoint&);

    virtual VisiblePosition positionForCoordinates(int x, int y);
    VisiblePosition positionForPoint(const IntPoint&);

    virtual void dirtyLinesFromChangedChild(RenderObject*);

    // Called to update a style that is allowed to trigger animations.
    // FIXME: Right now this will typically be called only when updating happens from the DOM on explicit elements.
    // We don't yet handle generated content animation such as first-letter or before/after (we'll worry about this later).
    void setAnimatableStyle(PassRefPtr<RenderStyle>);

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

    // 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(PassRefPtr<RenderStyle>);

    // 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;

    // 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 /*overrideSize*/) { }

    // Convert the given local point to absolute coordinates
    // FIXME: Temporary. If useTransforms is true, take transforms into account. Eventually localToAbsolute() will always be transform-aware.
    virtual FloatPoint localToAbsolute(FloatPoint localPoint = FloatPoint(), bool fixed = false, bool useTransforms = false) const;
    virtual FloatPoint absoluteToLocal(FloatPoint, bool fixed = false, bool useTransforms = false) const;

    // Convert a local quad to absolute coordinates, taking transforms into account.
    FloatQuad localToAbsoluteQuad(const FloatQuad& quad, bool fixed = false) const
    {
        return localToContainerQuad(quad, 0, fixed);
    }
    // Convert a local quad into the coordinate system of container, taking transforms into account.
    virtual FloatQuad localToContainerQuad(const FloatQuad&, RenderBox* repaintContainer, bool fixed = false) const;

    // Return the offset from the container() renderer (excluding transforms)
    virtual IntSize offsetFromContainer(RenderObject*) const;

    virtual void addLineBoxRects(Vector<IntRect>&, unsigned startOffset = 0, unsigned endOffset = UINT_MAX, bool useSelectionHeight = false);
    
    virtual void absoluteRects(Vector<IntRect>&, int, int, bool = true) { }
    // FIXME: useTransforms should go away eventually
    IntRect absoluteBoundingBoxRect(bool useTransforms = false);

    // Build an array of quads in absolute coords for line boxes
    virtual void collectAbsoluteLineBoxQuads(Vector<FloatQuad>&, unsigned /*startOffset*/ = 0, unsigned /*endOffset*/ = UINT_MAX, bool /*useSelectionHeight*/ = false) { }
    virtual void absoluteQuads(Vector<FloatQuad>&, bool /*topLevel*/ = true) { }

    // the rect that will be painted if this object is passed as the paintingRoot
    IntRect paintingRootRect(IntRect& topLevelRect);

    virtual int minPrefWidth() const { return 0; }
    virtual int maxPrefWidth() const { return 0; }

    RenderStyle* style() const { return m_style.get(); }
    RenderStyle* firstLineStyle() const;
    RenderStyle* style(bool firstLine) const { return firstLine ? firstLineStyle() : style(); }

    void getTextDecorationColors(int decorations, Color& underline, Color& overline,
                                 Color& linethrough, bool quirksMode = false);

    enum BorderSide {
        BSTop,
        BSBottom,
        BSLeft,
        BSRight
    };

    void drawBorderArc(GraphicsContext*, int x, int y, float thickness, IntSize radius, int angleStart,
                       int angleSpan, BorderSide, Color, const Color& textcolor, EBorderStyle, bool firstCorner);
    void drawBorder(GraphicsContext*, int x1, int y1, int x2, int y2, BorderSide,
                    Color, const Color& textcolor, EBorderStyle, int adjbw1, int adjbw2);

    // Return the RenderBox in the container chain which is responsible for painting this object, or 0
    // if painting is root-relative. This is the container that should be passed to the 'forRepaint'
    // methods.
    RenderBox* containerForRepaint() const;
    
    // Repaint the entire object.  Called when, e.g., the color of a border changes, or when a border
    // style changes.
    void repaint(bool immediate = false);

    // Repaint a specific subrectangle within a given object.  The rect |r| is in the object's coordinate space.
    void repaintRectangle(const IntRect&, bool immediate = false);

    // Repaint only if our old bounds and new bounds are different.
    bool repaintAfterLayoutIfNeeded(const IntRect& oldBounds, const IntRect& oldOutlineBox);

    // Repaint only if the object moved.
    virtual void repaintDuringLayoutIfMoved(const IntRect& rect);

    // Called to repaint a block's floats.
    virtual void repaintOverhangingFloats(bool paintAllDescendants = false);

    bool checkForRepaintDuringLayout() const;

    // Returns the rect that should be repainted whenever this object changes.  The rect is in the view's
    // coordinate space.  This method deals with outlines and overflow.
    IntRect absoluteClippedOverflowRect()
    {
        return clippedOverflowRectForRepaint(0);
    }
    virtual IntRect clippedOverflowRectForRepaint(RenderBox* repaintContainer);
    
    IntRect rectWithOutlineForRepaint(RenderBox* repaintContainer, int outlineWidth);

    // Given a rect in the object's coordinate space, compute a rect suitable for repainting
    // that rect in view coordinates.
    void computeAbsoluteRepaintRect(IntRect& r, bool fixed = false)
    {
        return computeRectForRepaint(r, 0, fixed);
    }
    // Given a rect in the object's coordinate space, compute a rect suitable for repainting
    // that rect in the coordinate space of repaintContainer.
    virtual void computeRectForRepaint(IntRect&, RenderBox* repaintContainer, bool fixed = false);

    virtual unsigned int length() const { return 1; }

    bool isFloatingOrPositioned() const { return (isFloating() || isPositioned()); }
    virtual bool containsFloats() { return false; }
    virtual bool containsFloat(RenderObject*) { return false; }
    virtual bool hasOverhangingFloats() { return false; }

    virtual bool avoidsFloats() const;
    bool shrinkToAvoidFloats() const;

    // positioning of inline children (bidi)
    virtual void position(InlineBox*) { }

    bool isTransparent() const { return style()->opacity() < 1.0f; }
    float opacity() const { return style()->opacity(); }

    bool hasReflection() const { return m_hasReflection; }

    // Applied as a "slop" to dirty rect checks during the outline painting phase's dirty-rect checks.
    int maximalOutlineSize(PaintPhase) const;

    enum SelectionState {
        SelectionNone, // The object is not selected.
        SelectionStart, // The object either contains the start of a selection run or is the start of a run
        SelectionInside, // The object is fully encompassed by a selection run
        SelectionEnd, // The object either contains the end of a selection run or is the end of a run
        SelectionBoth // The object contains an entire run or is the sole selected object in that run
    };

    // The current selection state for an object.  For blocks, the state refers to the state of the leaf
    // descendants (as described above in the SelectionState enum declaration).
    virtual SelectionState selectionState() const { return SelectionNone; }

    // Sets the selection state for an object.
    virtual void setSelectionState(SelectionState state) { if (parent()) parent()->setSelectionState(state); }

    // A single rectangle that encompasses all of the selected objects within this object.  Used to determine the tightest
    // possible bounding box for the selection.
    virtual IntRect selectionRect(bool) { return IntRect(); }

    // Whether or not an object can be part of the leaf elements of the selection.
    virtual bool canBeSelectionLeaf() const { return false; }

    // Whether or not a block has selected children.
    virtual bool hasSelectedChildren() const { return false; }

    // Obtains the selection colors that should be used when painting a selection.
    Color selectionBackgroundColor() const;
    Color selectionForegroundColor() const;

    // Whether or not a given block needs to paint selection gaps.
    virtual bool shouldPaintSelectionGaps() const { return false; }

    // This struct is used when the selection changes to cache the old and new state of the selection for each RenderObject.
    struct SelectionInfo {
        SelectionInfo()
            : m_object(0)
            , m_state(SelectionNone)
        {
        }

        SelectionInfo(RenderObject* o, bool clipToVisibleContent)
            : m_object(o)
            , m_rect(o->needsLayout() ? IntRect() : o->selectionRect(clipToVisibleContent))
            , m_state(o->selectionState())
        {
        }

        RenderObject* object() const { return m_object; }
        IntRect rect() const { return m_rect; }
        SelectionState state() const { return m_state; }

        RenderObject* m_object;
        IntRect m_rect;
        SelectionState m_state;
    };

    Node* draggableNode(bool dhtmlOK, bool uaOK, int x, int y, bool& dhtmlWillDrag) const;

    /**
     * Returns the local coordinates of the caret within this render object.
     * @param caretOffset zero-based offset determining position within the render object.
     * @param extraWidthToEndOfLine optional out arg to give extra width to end of line -
     * useful for character range rect computations
     */
    virtual IntRect localCaretRect(InlineBox*, int caretOffset, int* extraWidthToEndOfLine = 0);

    virtual int lowestPosition(bool /*includeOverflowInterior*/ = true, bool /*includeSelf*/ = true) const { return 0; }
    virtual int rightmostPosition(bool /*includeOverflowInterior*/ = true, bool /*includeSelf*/ = true) const { return 0; }
    virtual int leftmostPosition(bool /*includeOverflowInterior*/ = true, bool /*includeSelf*/ = true) const { return 0; }

    virtual void calcVerticalMargins() { }
    void removeFromObjectLists();

    // When performing a global document tear-down, the renderer of the document is cleared.  We use this
    // as a hook to detect the case of document destruction and don't waste time doing unnecessary work.
    bool documentBeingDestroyed() const;

    virtual void destroy();

    // Virtual function helpers for CSS3 Flexible Box Layout
    virtual bool isFlexibleBox() const { return false; }
    virtual bool isFlexingChildren() const { return false; }
    virtual bool isStretchingChildren() const { return false; }

    virtual int caretMinOffset() const;
    virtual int caretMaxOffset() const;
    virtual unsigned caretMaxRenderedOffset() const;

    virtual int previousOffset(int current) const;
    virtual int nextOffset(int current) const;

    virtual void imageChanged(CachedImage*, const IntRect* = 0);
    virtual void imageChanged(WrappedImagePtr, const IntRect* = 0) { }
    virtual bool willRenderImage(CachedImage*);

    virtual void selectionStartEnd(int& spos, int& epos) const;

    RenderObject* paintingRootForChildren(PaintInfo& paintInfo) const
    {
        // if we're the painting root, kids draw normally, and see root of 0
        return (!paintInfo.paintingRoot || paintInfo.paintingRoot == this) ? 0 : paintInfo.paintingRoot;
    }

    bool shouldPaintWithinRoot(PaintInfo& paintInfo) const
    {
        return !paintInfo.paintingRoot || paintInfo.paintingRoot == this;
    }
#ifdef ANDROID_LAYOUT
    virtual bool hasChildTable() const { return false; }
#endif

    bool hasOverrideSize() const { return m_hasOverrideSize; }
    void setHasOverrideSize(bool b) { m_hasOverrideSize = b; }
    
    void remove() { if (parent()) parent()->removeChild(this); }

    void invalidateVerticalPosition() { m_verticalPosition = PositionUndefined; }
    
    virtual void removeLeftoverAnonymousBlock(RenderBlock* child);
    
    virtual void capsLockStateMayHaveChanged() { }

    AnimationController* animation() const;

    bool visibleToHitTesting() const { return style()->visibility() == VISIBLE && style()->pointerEvents() != PE_NONE; }
    
    virtual void addFocusRingRects(GraphicsContext*, int /*tx*/, int /*ty*/) { };

    IntRect absoluteOutlineBounds() const
    {
        return outlineBoundsForRepaint(0);
    }

protected:
    // Overrides should call the superclass at the end
    virtual void styleWillChange(RenderStyle::Diff, const RenderStyle* newStyle);
    // Overrides should call the superclass at the start
    virtual void styleDidChange(RenderStyle::Diff, const RenderStyle* oldStyle);
    
    virtual void printBoxDecorations(GraphicsContext*, int /*x*/, int /*y*/, int /*w*/, int /*h*/, int /*tx*/, int /*ty*/) { }

    void paintOutline(GraphicsContext*, int tx, int ty, int w, int h, const RenderStyle*);
    void addPDFURLRect(GraphicsContext*, const IntRect&);

    virtual IntRect viewRect() const;

    int getVerticalPosition(bool firstLine) const;

    void adjustRectForOutlineAndShadow(IntRect&) const;

    void arenaDelete(RenderArena*, void* objectBase);

    virtual IntRect outlineBoundsForRepaint(RenderBox* /*repaintContainer*/) const { return IntRect(); }

private:
    RefPtr<RenderStyle> m_style;

    Node* m_node;

    RenderObject* m_parent;
    RenderObject* m_previous;
    RenderObject* m_next;

#ifndef NDEBUG
    bool m_hasAXObject;
    bool m_setNeedsLayoutForbidden : 1;
#endif
    mutable int m_verticalPosition;

    bool m_needsLayout               : 1;
    bool m_needsPositionedMovementLayout :1;
    bool m_normalChildNeedsLayout    : 1;
    bool m_posChildNeedsLayout       : 1;
    bool m_prefWidthsDirty           : 1;
    bool m_floating                  : 1;

    bool m_positioned                : 1;
    bool m_relPositioned             : 1;
    bool m_paintBackground           : 1; // if the box has something to paint in the
                                          // background painting phase (background, border, etc)

    bool m_isAnonymous               : 1;
    bool m_isText                    : 1;
    bool m_isBox                     : 1;
    bool m_inline                    : 1;
    bool m_replaced                  : 1;
    bool m_isDragging                : 1;

    bool m_hasLayer                  : 1;
    bool m_hasOverflowClip           : 1;
    bool m_hasTransform              : 1;
    bool m_hasReflection             : 1;

    bool m_hasOverrideSize           : 1;
    
public:
    bool m_hasCounterNodeMap         : 1;
    bool m_everHadLayout             : 1;

private:
    // Store state between styleWillChange and styleDidChange
    static bool s_affectsParentBlock;
};

} // namespace WebCore

#ifndef NDEBUG
// Outside the WebCore namespace for ease of invocation from gdb.
void showTree(const WebCore::RenderObject*);
#endif

#endif // RenderObject_h