root/trunk/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 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 "Document.h"
#include "FloatQuad.h"
#include "RenderStyle.h"
#include "ScrollTypes.h"
#include "VisiblePosition.h"
#include <wtf/HashMap.h>

namespace WebCore {

class AffineTransform;
class AnimationController;
class Color;
class Document;
class Element;
class Event;
class FloatRect;
class FrameView;
class HTMLAreaElement;
class HitTestResult;
class InlineBox;
class InlineFlowBox;
class Position;
class RenderArena;
class RenderBlock;
class RenderFlow;
class RenderFrameSet;
class RenderLayer;
class RenderTable;
class RenderText;
class RenderView;
class String;

struct HitTestRequest;

/*
 *  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
};

enum VerticalPositionHint {
    PositionTop = -0x7fffffff,
    PositionBottom = 0x7fffffff,
    PositionUndefined = static_cast<int>(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

// FIXME: This should be a HashSequencedSet, but we don't have that data structure yet.
// This means the paint order of outlines will be wrong, although this is a minor issue.
typedef HashSet<RenderFlow*> RenderFlowSequencedSet;

// Base class for all rendering tree objects.
class RenderObject : public CachedResourceClient {
    friend class RenderContainer;
    friend class RenderSVGContainer;
    friend class RenderLayer;
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;

    virtual RenderLayer* layer() const { return 0; }
    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);
    virtual void positionChildLayers() { }
    virtual bool requiresLayer();

    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; }
#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 isInlineFlow() const { return false; }
    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* continuation() const;

#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 AffineTransform localTransform() const;
    virtual AffineTransform 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 isInline() const { return m_inline; }  // inline object
    bool isCompact() const { return style()->display() == COMPACT; } // compact 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 hasHorizontalBordersPaddingOrMargin() const { return hasHorizontalBordersOrPadding() || marginLeft() != 0 || marginRight() != 0; }
    bool hasHorizontalBordersOrPadding() const { return borderLeft() != 0 || borderRight() != 0 || paddingLeft() != 0 || paddingRight() != 0; }
                                                              
    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 hasAutoVerticalScrollbar() const { return hasOverflowClip() && (style()->overflowY() == OAUTO || style()->overflowY() == OOVERLAY); }
    bool hasAutoHorizontalScrollbar() const { return hasOverflowClip() && (style()->overflowX() == OAUTO || style()->overflowX() == OOVERLAY); }

    bool scrollsOverflow() const { return scrollsOverflowX() || scrollsOverflowY(); }
    bool scrollsOverflowX() const { return hasOverflowClip() && (style()->overflowX() == OSCROLL || hasAutoHorizontalScrollbar()); }
    bool scrollsOverflowY() const { return hasOverflowClip() && (style()->overflowY() == OSCROLL || hasAutoVerticalScrollbar()); }

    virtual int verticalScrollbarWidth() const;
    virtual int horizontalScrollbarHeight() const;
    
    bool hasTransform() const { return m_hasTransform; }
    bool hasMask() const { return style() && style()->hasMask(); }
    virtual IntRect maskClipRect() { return borderBox(); }

private:
    bool includeVerticalScrollbarSize() const { return hasOverflowClip() && (style()->overflowY() == OSCROLL || style()->overflowY() == OAUTO); }
    bool includeHorizontalScrollbarSize() const { return hasOverflowClip() && (style()->overflowX() == OSCROLL || style()->overflowX() == OAUTO); }

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;

    virtual void markAllDescendantsWithFloatsForLayout(RenderObject* floatToRemove = 0);
    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 setRenderText() { m_isText = 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, RenderFlowSequencedSet* 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
        RenderFlowSequencedSet* 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 paintOutline(GraphicsContext*, int tx, int ty, int w, int h, const RenderStyle*);
    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* box = 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() { }

    // Block flows subclass availableWidth to handle multi column layout (shrinking the width available to children when laying out.)
    virtual int availableWidth() const { return contentWidth(); }
    
    virtual int availableHeight() const { return 0; }

    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& point) { return positionForCoordinates(point.x(), point.y()); }

    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;