render_object.h

khtml在gtk上的移植版本

/*
 * This file is part of the html renderer for KDE.
 *
 * Copyright (C) 2000 Lars Knoll ([e-mail])
 *           (C) 2000 Antti Koivisto ([e-mail])
 *           (C) 2000 Dirk Mueller ([e-mail])
 * Copyright (C) 2003 Apple Computer, Inc.
 *
 * 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., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 */
#ifndef render_object_h
#define render_object_h

#include <qcolor.h>
#include <qrect.h>
#include <assert.h>

#include "misc/khtmllayout.h"
#include "misc/loader_client.h"
#include "misc/helper.h"
#include "rendering/render_style.h"
#include "khtml_events.h"
#include "xml/dom_docimpl.h"

class QPainter;
class QTextStream;
class CSSStyle;
class KHTMLView;
class RenderArena;

#ifndef NDEBUG
#define KHTMLAssert( x ) if( !(x) ) { \
    const RenderObject *o = this; while( o->parent() ) o = o->parent(); \
    o->printTree(); \
    qDebug(" this object = %p", this ); \
    assert( false ); \
}
#else
#define KHTMLAssert( x )
#endif

/*
 *	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.
 */

typedef enum {
    PaintActionElementBackground = 0,
    PaintActionChildBackground,
    PaintActionChildBackgrounds,
    PaintActionFloat,
    PaintActionForeground,
    PaintActionOutline,
    PaintActionSelection,
    PaintActionCollapsedTableBorders
} PaintAction;

typedef enum {
    HitTestAll = 0,
    HitTestSelfOnly = 1,
    HitTestChildrenOnly = 2
} HitTestAction;

namespace DOM {
    class HTMLAreaElementImpl;
    class DOMString;
    class DocumentImpl;
    class ElementImpl;
    class EventImpl;
    class Position;
};

namespace khtml {
    class RenderFlow;
    class RenderBlock;
    class RenderStyle;
    class RenderTable;
    class CachedObject;
    class RenderCanvas;
    class RenderText;
    class RenderFrameSet;
    class RenderLayer;
    class InlineBox;
    class InlineFlowBox;
    class CollapsedBorderValue;

/**
 * Base Class for all rendering tree objects.
 */
class RenderObject : public CachedObjectClient
{
public:
    // Anonymous objects should pass the document as their node, and they will then automatically be
    // marked as anonymous in the constructor.
    RenderObject(DOM::NodeImpl* node);
    virtual ~RenderObject();

    RenderObject *parent() const { return m_parent; }
    bool hasAncestor(const RenderObject *obj) 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 *nextRenderer() const; 
    RenderObject *previousRenderer() const; 

    RenderObject *nextEditable() const; 
    RenderObject *previousEditable() const; 

    RenderObject *firstLeafChild() const;
    RenderObject *lastLeafChild() const;
    
    virtual RenderLayer* layer() const { return 0; }
    RenderLayer* enclosingLayer();
    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 QRect getOverflowClipRect(int tx, int ty) { return QRect(0,0,0,0); }
    virtual QRect getClipRect(int tx, int ty) { return QRect(0,0,0,0); }
    bool hasClip() { return isPositioned() &&  style()->hasClip(); }
    
    virtual int getBaselineOfFirstLineBox() const { return -1; } 
    
    // Obtains the nearest enclosing block (including this block) that contributes a first-line style to our inline
    // children.
    virtual RenderBlock* firstLineBlock() const;
    virtual void updateFirstLetter();
    
    // 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) {};
    
    // RenderObject tree manipulation
    //////////////////////////////////////////
    virtual bool canHaveChildren() const;
    virtual void addChild(RenderObject *newChild, RenderObject *beforeChild = 0);
    virtual void removeChild(RenderObject *oldChild);

    // raw tree manipulation
    virtual RenderObject* removeChildNode(RenderObject* child);
    virtual void appendChildNode(RenderObject* child);
    virtual void insertChildNode(RenderObject* child, RenderObject* before);
    //////////////////////////////////////////

private:
    //////////////////////////////////////////
    // 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; }
    //////////////////////////////////////////
    
    QRect absoluteBoundingBoxRect();
    void addAbsoluteRectForLayer(QRect& result);

public:
    virtual const char *renderName() const { return "RenderObject"; }
#ifndef NDEBUG
    QString information() const;
    virtual void printTree(int indent=0) const;
    virtual void dump(QTextStream *stream, QString ind = "") const;
#endif

    static RenderObject *createObject(DOM::NodeImpl* node, RenderStyle* style);

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

    // Overridden to prevent the normal delete from being called.
    void operator delete(void* ptr, size_t sz);
        
private:
    // The normal operator new is disallowed on all render objects.
    void* operator new(size_t sz) throw();
    
public:
    RenderArena* renderArena() const;
    
    // some helper functions...
    virtual bool isRenderBlock() const { return false; }
    virtual bool isRenderInline() const { return false; }
    virtual bool isInlineFlow() const { return false; }
    virtual bool isBlockFlow() const { return false; }
    virtual bool isInlineBlockOrInlineTable() const { return false; }
    virtual bool childrenInline() const { return false; }
    virtual void setChildrenInline(bool b) { };

    virtual RenderFlow* continuation() const;
    virtual bool isInlineContinuation() const;
    
    virtual bool isListItem() const { return false; }
    virtual bool isListMarker() const { return false; }
    virtual bool isCanvas() const { return false; }
    bool isRoot() const;
    bool isBody() const;
    bool isHR() const;
    virtual bool isBR() const { return false; }
    virtual bool isTableCell() const { return false; }
    virtual bool isTableRow() const { return false; }
    virtual bool isTableSection() const { return false; }
    virtual bool isTableCol() const { return false; }
    virtual bool isTable() const { return false; }
    virtual bool isWidget() const { return false; }
    virtual bool isFormElement() const { return false; }
    virtual bool isImage() const { return false; }
    virtual bool isTextArea() const { return false; }
    virtual bool isFrameSet() const { return false; }
    virtual bool isApplet() const { return false; }
    
    virtual bool isEditable() const;

    bool isHTMLMarquee() 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 mouseInside() const;
    bool isDragging() const;
    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 isSelectionBorder() const { return m_isSelectionBorder; }
    bool recalcMinMax() const { return m_recalcMinMax; }