renderblock.h

linux下开源浏览器WebKit的源码,市面上的很多商用浏览器都是移植自WebKit

/*
 * This file is part of the render object implementation for KHTML.
 *
 * Copyright (C) 1999 Lars Knoll ([e-mail])
 *           (C) 1999 Antti Koivisto ([e-mail])
 *           (C) 2007 David Smith ([e-mail])
 * 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 RenderBlock_h
#define RenderBlock_h

#include "DeprecatedPtrList.h"
#include "GapRects.h"
#include "RenderBox.h"
#include "RenderLineBoxList.h"
#include "RootInlineBox.h"
#include <wtf/ListHashSet.h>

namespace WebCore {

class InlineIterator;
class BidiRun;
class Position;
class RenderInline;
class RootInlineBox;

template <class Iterator, class Run> class BidiResolver;
typedef BidiResolver<InlineIterator, BidiRun> InlineBidiResolver;

enum CaretType { CursorCaret, DragCaret };

class RenderBlock : public RenderBox {
public:
    RenderBlock(Node*);
    virtual ~RenderBlock();

    virtual RenderObjectChildList* virtualChildren() { return children(); }
    virtual const RenderObjectChildList* virtualChildren() const { return children(); }
    const RenderObjectChildList* children() const { return &m_children; }
    RenderObjectChildList* children() { return &m_children; }

    virtual void destroy();

    virtual const char* renderName() const;

    // These two functions are overridden for inline-block.
    virtual int lineHeight(bool firstLine, bool isRootLineBox = false) const;
    virtual int baselinePosition(bool firstLine, bool isRootLineBox = false) const;

    virtual bool isRenderBlock() const { return true; }
    virtual bool isBlockFlow() const { return (!isInline() || isReplaced()) && !isTable(); }
    virtual bool isInlineBlockOrInlineTable() const { return isInline() && isReplaced(); }

    void makeChildrenNonInline(RenderObject* insertionPoint = 0);
    virtual void removeLeftoverAnonymousBlock(RenderBlock* child);

    RenderLineBoxList* lineBoxes() { return &m_lineBoxes; }
    const RenderLineBoxList* lineBoxes() const { return &m_lineBoxes; }

    InlineFlowBox* firstLineBox() const { return m_lineBoxes.firstLineBox(); }
    InlineFlowBox* lastLineBox() const { return m_lineBoxes.lastLineBox(); }

    void deleteLineBoxTree();
    virtual void dirtyLinesFromChangedChild(RenderObject* child) { m_lineBoxes.dirtyLinesFromChangedChild(this, child); }

    // The height (and width) of a block when you include 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;
    virtual int overflowWidth(bool includeInterior = true) const;
    virtual int overflowLeft(bool includeInterior = true) const;
    virtual int overflowTop(bool includeInterior = true) const;
    virtual IntRect overflowRect(bool includeInterior = true) const;
    virtual void setOverflowHeight(int h) { m_overflowHeight = h; }
    virtual void setOverflowWidth(int w) { m_overflowWidth = w; }

    void addVisualOverflow(const IntRect&);

    virtual bool isSelfCollapsingBlock() const;

    virtual int maxTopMargin(bool positive) const { return positive ? maxTopPosMargin() : maxTopNegMargin(); }
    virtual int maxBottomMargin(bool positive) const { return positive ? maxBottomPosMargin() : maxBottomNegMargin(); }

    int maxTopPosMargin() const { return m_maxMargin ? m_maxMargin->m_topPos : MaxMargin::topPosDefault(this); }
    int maxTopNegMargin() const { return m_maxMargin ? m_maxMargin->m_topNeg : MaxMargin::topNegDefault(this); }
    int maxBottomPosMargin() const { return m_maxMargin ? m_maxMargin->m_bottomPos : MaxMargin::bottomPosDefault(this); }
    int maxBottomNegMargin() const { return m_maxMargin ? m_maxMargin->m_bottomNeg : MaxMargin::bottomNegDefault(this); }
    void setMaxTopMargins(int pos, int neg);
    void setMaxBottomMargins(int pos, int neg);
    
    void initMaxMarginValues()
    {
        if (m_maxMargin) {
            m_maxMargin->m_topPos = MaxMargin::topPosDefault(this);
            m_maxMargin->m_topNeg = MaxMargin::topNegDefault(this);
            m_maxMargin->m_bottomPos = MaxMargin::bottomPosDefault(this);
            m_maxMargin->m_bottomNeg = MaxMargin::bottomNegDefault(this);
        }
    }

    virtual void addChild(RenderObject* newChild, RenderObject* beforeChild = 0);
    virtual void removeChild(RenderObject*);

    virtual void repaintOverhangingFloats(bool paintAllDescendants);

    virtual void layout();
    virtual void layoutBlock(bool relayoutChildren);
    void layoutBlockChildren(bool relayoutChildren, int& maxFloatBottom);
    void layoutInlineChildren(bool relayoutChildren, int& repaintTop, int& repaintBottom);

    void layoutPositionedObjects(bool relayoutChildren);
    void insertPositionedObject(RenderBox*);
    void removePositionedObject(RenderBox*);
    void removePositionedObjects(RenderBlock*);

    void addPercentHeightDescendant(RenderBox*);
    static void removePercentHeightDescendant(RenderBox*);

    virtual void positionListMarker() { }

    virtual void borderFitAdjust(int& x, int& w) const; // Shrink the box in which the border paints if border-fit is set.

    virtual void updateBeforeAfterContent(PseudoId);

    RootInlineBox* createRootInlineBox();

    // Called to lay out the legend for a fieldset.
    virtual RenderObject* layoutLegend(bool /*relayoutChildren*/) { return 0; }

    // the implementation of the following functions is in bidi.cpp
    struct FloatWithRect {
        FloatWithRect(RenderBox* f)
            : object(f)
            , rect(IntRect(f->x() - f->marginLeft(), f->y() - f->marginTop(), f->width() + f->marginLeft() + f->marginRight(), f->height() + f->marginTop() + f->marginBottom()))
        {
        }

        RenderBox* object;
        IntRect rect;
    };

    void bidiReorderLine(InlineBidiResolver&, const InlineIterator& end);
    RootInlineBox* determineStartPosition(bool& firstLine, bool& fullLayout, InlineBidiResolver&, Vector<FloatWithRect>& floats, unsigned& numCleanFloats);
    RootInlineBox* determineEndPosition(RootInlineBox* startBox, InlineIterator& cleanLineStart,
                                        BidiStatus& cleanLineBidiStatus,
                                        int& yPos);
    bool matchedEndLine(const InlineBidiResolver&, const InlineIterator& endLineStart, const BidiStatus& endLineStatus,
                        RootInlineBox*& endLine, int& endYPos, int& repaintBottom, int& repaintTop);
    bool generatesLineBoxesForInlineChild(RenderObject*);
    void skipTrailingWhitespace(InlineIterator&);
    int skipLeadingWhitespace(InlineBidiResolver&, bool firstLine);
    void fitBelowFloats(int widthToFit, bool firstLine, int& availableWidth);
    InlineIterator findNextLineBreak(InlineBidiResolver&, bool firstLine, EClear* clear = 0);
    RootInlineBox* constructLine(unsigned runCount, BidiRun* firstRun, BidiRun* lastRun, bool firstLine, bool lastLine, RenderObject* endObject);
    InlineFlowBox* createLineBoxes(RenderObject*, bool firstLine);
    void computeHorizontalPositionsForLine(RootInlineBox*, bool firstLine, BidiRun* firstRun, BidiRun* trailingSpaceRun, bool reachedEnd);
    void computeVerticalPositionsForLine(RootInlineBox*, BidiRun*);
    void checkLinesForOverflow();
    void deleteEllipsisLineBoxes();
    void checkLinesForTextOverflow();
    // end bidi.cpp functions

    virtual void paint(PaintInfo&, int tx, int ty);
    virtual void paintObject(PaintInfo&, int tx, int ty);
    void paintFloats(PaintInfo&, int tx, int ty, bool preservePhase = false);
    void paintContents(PaintInfo&, int tx, int ty);
    void paintColumnContents(PaintInfo&, int tx, int ty, bool paintFloats = false);
    void paintColumnRules(PaintInfo&, int tx, int ty);
    void paintChildren(PaintInfo&, int tx, int ty);
    void paintEllipsisBoxes(PaintInfo&, int tx, int ty);
    void paintSelection(PaintInfo&, int tx, int ty);
    void paintCaret(PaintInfo&, int tx, int ty, CaretType);

    void insertFloatingObject(RenderBox*);
    void removeFloatingObject(RenderBox*);

    // Called from lineWidth, to position the floats added in the last line.
    // Returns ture if and only if it has positioned any floats.
    bool positionNewFloats();
    void clearFloats();
    int getClearDelta(RenderBox* child, int yPos);
    void markAllDescendantsWithFloatsForLayout(RenderBox* floatToRemove = 0, bool inLayout = true);
    void markPositionedObjectsForLayout();

    bool containsFloats() { return m_floatingObjects && !m_floatingObjects->isEmpty(); }
    bool containsFloat(RenderObject*);

    virtual bool avoidsFloats() const;

    bool hasOverhangingFloats() { return parent() && !hasColumns() && floatBottom() > height(); }
    void addIntrudingFloats(RenderBlock* prev, int xoffset, int yoffset);
    int addOverhangingFloats(RenderBlock* child, int xoffset, int yoffset, bool makeChildPaintOtherFloats);

    int nextFloatBottomBelow(int) const;
    int floatBottom() const;
    inline int leftBottom();
    inline int rightBottom();
    IntRect floatRect() const;

    int lineWidth(int y, bool firstLine) const;
    virtual int lowestPosition(bool includeOverflowInterior = true, bool includeSelf = true) const;
    virtual int rightmostPosition(bool includeOverflowInterior = true, bool includeSelf = true) const;
    virtual int leftmostPosition(bool includeOverflowInterior = true, bool includeSelf = true) const;

    int rightOffset() const;
    int rightRelOffset(int y, int fixedOffset, bool applyTextIndent = true, int* heightRemaining = 0) const;
    int rightOffset(int y, bool firstLine) const { return rightRelOffset(y, rightOffset(), firstLine); }

    int leftOffset() const;
    int leftRelOffset(int y, int fixedOffset, bool applyTextIndent = true, int* heightRemaining = 0) const;
    int leftOffset(int y, bool firstLine) const { return leftRelOffset(y, leftOffset(), firstLine); }

    virtual bool nodeAtPoint(const HitTestRequest&, HitTestResult&, int x, int y, int tx, int ty, HitTestAction);
    virtual bool hitTestColumns(const HitTestRequest&, HitTestResult&, int x, int y, int tx, int ty, HitTestAction);
    virtual bool hitTestContents(const HitTestRequest&, HitTestResult&, int x, int y, int tx, int ty, HitTestAction);

    virtual bool isPointInOverflowControl(HitTestResult&, int x, int y, int tx, int ty);

    virtual VisiblePosition positionForPoint(const IntPoint&);
    
    // Block flows subclass availableWidth to handle multi column layout (shrinking the width available to children when laying out.)
    virtual int availableWidth() const;
    
    virtual void calcPrefWidths();
    void calcInlinePrefWidths();
    void calcBlockPrefWidths();

    virtual int firstLineBoxBaseline() const;
    virtual int lastLineBoxBaseline() const;

    RootInlineBox* firstRootBox() const { return static_cast<RootInlineBox*>(firstLineBox()); }
    RootInlineBox* lastRootBox() const { return static_cast<RootInlineBox*>(lastLineBox()); }

    bool containsNonZeroBidiLevel() const;

    // 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();

    bool inRootBlockContext() const;

    virtual IntRect rectWithOutlineForRepaint(RenderBoxModelObject* repaintContainer, int outlineWidth);
    virtual RenderStyle* outlineStyleForRepaint() const;
    
    virtual RenderObject* hoverAncestor() const;
    virtual void updateDragState(bool dragOn);
    virtual void updateHitTestResult(HitTestResult&, const IntPoint&);