render_object.h

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

/*
 * This file is part of the html renderer for KDE.
 *
 * Copyright (C) 2000-2003 Lars Knoll ([e-mail])
 *           (C) 2000 Antti Koivisto ([e-mail])
 *           (C) 2000-2003 Dirk Mueller ([e-mail])
 *           (C) 2002-2003 Apple Computer, Inc.
 *           (C) 2004 Allan Sandfeld Jensen
 *
 * 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 render_object_h
#define render_object_h

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

#include <kdebug.h>
#include <kglobal.h>

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

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

#ifndef NDEBUG
#define KHTMLAssert( x ) if( !(x) ) { \
    const RenderObject *o = this; while( o->parent() ) o = o->parent(); \
    o->printTree(); \
    qDebug(" this object = %p, %s", (void*) this, kdBacktrace().latin1() ); \
    assert( x ); \
}
#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;

typedef enum {
    PageBreakNormal = 0, // all rules apply
    PageBreakHarder = 1, // page-break-inside: avoid is ignored
    PageBreakForced = 2  // page-break-after/before: avoid, orphans and widows ignored
} PageBreakLevel;

inline PageBreakLevel operator| (PageBreakLevel a, PageBreakLevel b) {
    if (a == PageBreakForced || b == PageBreakForced)
        return PageBreakForced;
    if (a == PageBreakHarder || b == PageBreakHarder)
        return PageBreakHarder;
    return PageBreakNormal;
}

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

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

/**
 * Base Class for all rendering tree objects.
 */
class RenderObject : public CachedObjectClient
{
    RenderObject(const RenderObject&);
    RenderObject& operator=(const RenderObject&);
public:

    RenderObject(DOM::NodeImpl* node);
    virtual ~RenderObject();

    RenderObject *parent() const { return m_parent; }

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

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

    virtual bool childAllowed() const { return false; }

    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() const {
        return isRoot() || (!isTableCell() && (isPositioned() || isRelPositioned() || hasOverflowClip()));
    }

    // ### rename to overflowClipRect and clipRect
    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() const { return isPositioned() &&  style()->hasClip(); }
    bool hasOverflowClip() const { return style()->hidesOverflow(); }

    virtual int getBaselineOfFirstLineBox() { return -1; } // Tables and blocks implement this.
    virtual InlineFlowBox* getFirstLineBox() { return 0; } // Tables and blocks implement this.

    // Whether or not a positioned element requires normal flow x/y to be computed
    // to determine its position.
    bool hasStaticX() const;
    bool hasStaticY() const;

    // Linear tree traversal
    RenderObject *objectBelow() const;
    RenderObject *objectAbove() const;

    // Returns if an object has counter-increment or counter-reset
    bool hasCounter(const QString& counter) const;
    // Calculates the value of the counter
    CounterNode* getCounter(const QString& counter, bool view = false, bool counters = false);
    // Detaches all counterNodes
    void detachCounters();


protected:
    // Helper functions for counter-cache
    void insertCounter(const QString& counter, CounterNode* value);
    CounterNode* lookupCounter(const QString& counter) const;

public:
    //////////////////////////////////////////
    // RenderObject tree manipulation
    virtual void addChild(RenderObject *newChild, RenderObject *beforeChild = 0);
    void removeChild(RenderObject *oldChild);

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

    //////////////////////////////////////////
    // 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; }
    //////////////////////////////////////////

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

public:
    RenderArena* renderArena() const;
    virtual RenderFlow* continuation() const { return 0; }
    virtual bool isInlineContinuation() const { return false; }


    bool isRoot() const { return m_isRoot && !m_isAnonymous; }
    void setIsRoot(bool b) { m_isRoot = b; }
    bool isHR() 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 bool isBox() const { return false; }
    virtual bool isRenderReplaced() const { return false; }

    virtual bool isCounter() const { return false; }
    virtual bool isQuote() const { return false; }
    virtual bool isListItem() const { return false; }
    virtual bool isListMarker() const { return false; }
    virtual bool isCanvas() const { return false; }
    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 isBody() const { return false; }
    virtual bool isFormElement() const { return false; }
    virtual bool isFrameSet() const { return false; }
    virtual bool isApplet() const { return false; }

    bool isHTMLMarquee() const;

    bool isAnonymous() const { return m_isAnonymous; }
    void setIsAnonymous(bool b) { m_isAnonymous = b; }
    bool isAnonymousBlock() const { return isAnonymous() && style()->display() == BLOCK && node()->isDocumentNode(); }