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      1 /*
      2  * Copyright (C) 1999 Lars Knoll (knoll (at) kde.org)
      3  *           (C) 1999 Antti Koivisto (koivisto (at) kde.org)
      4  *           (C) 2007 David Smith (catfish.man (at) gmail.com)
      5  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
      6  *
      7  * This library is free software; you can redistribute it and/or
      8  * modify it under the terms of the GNU Library General Public
      9  * License as published by the Free Software Foundation; either
     10  * version 2 of the License, or (at your option) any later version.
     11  *
     12  * This library is distributed in the hope that it will be useful,
     13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
     14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     15  * Library General Public License for more details.
     16  *
     17  * You should have received a copy of the GNU Library General Public License
     18  * along with this library; see the file COPYING.LIB.  If not, write to
     19  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
     20  * Boston, MA 02110-1301, USA.
     21  */
     22 
     23 #ifndef RenderBlock_h
     24 #define RenderBlock_h
     25 
     26 #include "GapRects.h"
     27 #include "RenderBox.h"
     28 #include "RenderLineBoxList.h"
     29 #include "RootInlineBox.h"
     30 #include <wtf/OwnPtr.h>
     31 #include <wtf/ListHashSet.h>
     32 
     33 namespace WebCore {
     34 
     35 class BidiContext;
     36 class ColumnInfo;
     37 class InlineIterator;
     38 class LayoutStateMaintainer;
     39 class LazyLineBreakIterator;
     40 class LineWidth;
     41 class RenderInline;
     42 
     43 struct BidiRun;
     44 struct PaintInfo;
     45 
     46 template <class Iterator, class Run> class BidiResolver;
     47 template <class Run> class BidiRunList;
     48 template <class Iterator> struct MidpointState;
     49 typedef BidiResolver<InlineIterator, BidiRun> InlineBidiResolver;
     50 typedef MidpointState<InlineIterator> LineMidpointState;
     51 
     52 enum CaretType { CursorCaret, DragCaret };
     53 
     54 class RenderBlock : public RenderBox {
     55 public:
     56     RenderBlock(Node*);
     57     virtual ~RenderBlock();
     58 
     59     const RenderObjectChildList* children() const { return &m_children; }
     60     RenderObjectChildList* children() { return &m_children; }
     61 
     62     virtual void destroy();
     63     bool beingDestroyed() const { return m_beingDestroyed; }
     64 
     65     // These two functions are overridden for inline-block.
     66     virtual int lineHeight(bool firstLine, LineDirectionMode, LinePositionMode = PositionOnContainingLine) const;
     67     virtual int baselinePosition(FontBaseline, bool firstLine, LineDirectionMode, LinePositionMode = PositionOnContainingLine) const;
     68 
     69     RenderLineBoxList* lineBoxes() { return &m_lineBoxes; }
     70     const RenderLineBoxList* lineBoxes() const { return &m_lineBoxes; }
     71 
     72     InlineFlowBox* firstLineBox() const { return m_lineBoxes.firstLineBox(); }
     73     InlineFlowBox* lastLineBox() const { return m_lineBoxes.lastLineBox(); }
     74 
     75     void deleteLineBoxTree();
     76 
     77     virtual void addChild(RenderObject* newChild, RenderObject* beforeChild = 0);
     78     virtual void removeChild(RenderObject*);
     79 
     80     virtual void layoutBlock(bool relayoutChildren, int pageLogicalHeight = 0);
     81 
     82     void insertPositionedObject(RenderBox*);
     83     void removePositionedObject(RenderBox*);
     84     void removePositionedObjects(RenderBlock*);
     85 
     86     typedef ListHashSet<RenderBox*, 4> PositionedObjectsListHashSet;
     87     PositionedObjectsListHashSet* positionedObjects() const { return m_positionedObjects.get(); }
     88 
     89     void addPercentHeightDescendant(RenderBox*);
     90     static void removePercentHeightDescendant(RenderBox*);
     91     HashSet<RenderBox*>* percentHeightDescendants() const;
     92 
     93     RootInlineBox* createAndAppendRootInlineBox();
     94 
     95     bool generatesLineBoxesForInlineChild(RenderObject*, bool isLineEmpty = true, bool previousLineBrokeCleanly = true);
     96 
     97     void markAllDescendantsWithFloatsForLayout(RenderBox* floatToRemove = 0, bool inLayout = true);
     98     void markSiblingsWithFloatsForLayout();
     99     void markPositionedObjectsForLayout();
    100     virtual void markForPaginationRelayoutIfNeeded();
    101 
    102     bool containsFloats() { return m_floatingObjects && !m_floatingObjects->set().isEmpty(); }
    103     bool containsFloat(RenderBox*);
    104 
    105     int availableLogicalWidthForLine(int position, bool firstLine) const;
    106     int logicalRightOffsetForLine(int position, bool firstLine) const { return logicalRightOffsetForLine(position, logicalRightOffsetForContent(), firstLine); }
    107     int logicalLeftOffsetForLine(int position, bool firstLine) const { return logicalLeftOffsetForLine(position, logicalLeftOffsetForContent(), firstLine); }
    108     int startOffsetForLine(int position, bool firstLine) const { return style()->isLeftToRightDirection() ? logicalLeftOffsetForLine(position, firstLine) : logicalRightOffsetForLine(position, firstLine); }
    109 
    110     virtual VisiblePosition positionForPoint(const IntPoint&);
    111 
    112     // Block flows subclass availableWidth to handle multi column layout (shrinking the width available to children when laying out.)
    113     virtual int availableLogicalWidth() const;
    114 
    115     IntPoint flipForWritingModeIncludingColumns(const IntPoint&) const;
    116     void flipForWritingModeIncludingColumns(IntRect&) const;
    117 
    118     RootInlineBox* firstRootBox() const { return static_cast<RootInlineBox*>(firstLineBox()); }
    119     RootInlineBox* lastRootBox() const { return static_cast<RootInlineBox*>(lastLineBox()); }
    120 
    121     bool containsNonZeroBidiLevel() const;
    122 
    123     GapRects selectionGapRectsForRepaint(RenderBoxModelObject* repaintContainer);
    124     IntRect logicalLeftSelectionGap(RenderBlock* rootBlock, const IntPoint& rootBlockPhysicalPosition, const IntSize& offsetFromRootBlock,
    125                                     RenderObject* selObj, int logicalLeft, int logicalTop, int logicalHeight, const PaintInfo*);
    126     IntRect logicalRightSelectionGap(RenderBlock* rootBlock, const IntPoint& rootBlockPhysicalPosition, const IntSize& offsetFromRootBlock,
    127                                      RenderObject* selObj, int logicalRight, int logicalTop, int logicalHeight, const PaintInfo*);
    128     void getSelectionGapInfo(SelectionState, bool& leftGap, bool& rightGap);
    129     IntRect logicalRectToPhysicalRect(const IntPoint& physicalPosition, const IntRect& logicalRect);
    130 
    131     // Helper methods for computing line counts and heights for line counts.
    132     RootInlineBox* lineAtIndex(int);
    133     int lineCount();
    134     int heightForLineCount(int);
    135     void clearTruncation();
    136 
    137     void adjustRectForColumns(IntRect&) const;
    138     virtual void adjustForColumns(IntSize&, const IntPoint&) const;
    139 
    140     void addContinuationWithOutline(RenderInline*);
    141     bool paintsContinuationOutline(RenderInline*);
    142 
    143     virtual RenderBoxModelObject* virtualContinuation() const { return continuation(); }
    144     bool isAnonymousBlockContinuation() const { return continuation() && isAnonymousBlock(); }
    145     RenderInline* inlineElementContinuation() const;
    146     RenderBlock* blockElementContinuation() const;
    147 
    148     using RenderBoxModelObject::continuation;
    149     using RenderBoxModelObject::setContinuation;
    150 
    151     // This function is a convenience helper for creating an anonymous block that inherits its
    152     // style from this RenderBlock.
    153     RenderBlock* createAnonymousBlock(bool isFlexibleBox = false) const;
    154     RenderBlock* createAnonymousColumnsBlock() const;
    155     RenderBlock* createAnonymousColumnSpanBlock() const;
    156     RenderBlock* createAnonymousBlockWithSameTypeAs(RenderBlock* otherAnonymousBlock) const;
    157 
    158     static void appendRunsForObject(BidiRunList<BidiRun>&, int start, int end, RenderObject*, InlineBidiResolver&);
    159     static bool requiresLineBox(const InlineIterator&, bool isLineEmpty = true, bool previousLineBrokeCleanly = true);
    160 
    161     ColumnInfo* columnInfo() const;
    162     int columnGap() const;
    163 
    164     // These two functions take the ColumnInfo* to avoid repeated lookups of the info in the global HashMap.
    165     unsigned columnCount(ColumnInfo*) const;
    166     IntRect columnRectAt(ColumnInfo*, unsigned) const;
    167 
    168     int paginationStrut() const { return m_rareData ? m_rareData->m_paginationStrut : 0; }
    169     void setPaginationStrut(int);
    170 
    171     // The page logical offset is the object's offset from the top of the page in the page progression
    172     // direction (so an x-offset in vertical text and a y-offset for horizontal text).
    173     int pageLogicalOffset() const { return m_rareData ? m_rareData->m_pageLogicalOffset : 0; }
    174     void setPageLogicalOffset(int);
    175 
    176     // Accessors for logical width/height and margins in the containing block's block-flow direction.
    177     enum ApplyLayoutDeltaMode { ApplyLayoutDelta, DoNotApplyLayoutDelta };
    178     int logicalWidthForChild(RenderBox* child) { return isHorizontalWritingMode() ? child->width() : child->height(); }
    179     int logicalHeightForChild(RenderBox* child) { return isHorizontalWritingMode() ? child->height() : child->width(); }
    180     int logicalTopForChild(RenderBox* child) { return isHorizontalWritingMode() ? child->y() : child->x(); }
    181     void setLogicalLeftForChild(RenderBox* child, int logicalLeft, ApplyLayoutDeltaMode = DoNotApplyLayoutDelta);
    182     void setLogicalTopForChild(RenderBox* child, int logicalTop, ApplyLayoutDeltaMode = DoNotApplyLayoutDelta);
    183     int marginBeforeForChild(RenderBoxModelObject* child) const;
    184     int marginAfterForChild(RenderBoxModelObject* child) const;
    185     int marginStartForChild(RenderBoxModelObject* child) const;
    186     int marginEndForChild(RenderBoxModelObject* child) const;
    187     void setMarginStartForChild(RenderBox* child, int);
    188     void setMarginEndForChild(RenderBox* child, int);
    189     void setMarginBeforeForChild(RenderBox* child, int);
    190     void setMarginAfterForChild(RenderBox* child, int);
    191     int collapsedMarginBeforeForChild(RenderBox* child) const;
    192     int collapsedMarginAfterForChild(RenderBox* child) const;
    193 
    194     virtual void updateFirstLetter();
    195 
    196     class MarginValues {
    197     public:
    198         MarginValues(int beforePos, int beforeNeg, int afterPos, int afterNeg)
    199             : m_positiveMarginBefore(beforePos)
    200             , m_negativeMarginBefore(beforeNeg)
    201             , m_positiveMarginAfter(afterPos)
    202             , m_negativeMarginAfter(afterNeg)
    203         { }
    204 
    205         int positiveMarginBefore() const { return m_positiveMarginBefore; }
    206         int negativeMarginBefore() const { return m_negativeMarginBefore; }
    207         int positiveMarginAfter() const { return m_positiveMarginAfter; }
    208         int negativeMarginAfter() const { return m_negativeMarginAfter; }
    209 
    210         void setPositiveMarginBefore(int pos) { m_positiveMarginBefore = pos; }
    211         void setNegativeMarginBefore(int neg) { m_negativeMarginBefore = neg; }
    212         void setPositiveMarginAfter(int pos) { m_positiveMarginAfter = pos; }
    213         void setNegativeMarginAfter(int neg) { m_negativeMarginAfter = neg; }
    214 
    215     private:
    216         int m_positiveMarginBefore;
    217         int m_negativeMarginBefore;
    218         int m_positiveMarginAfter;
    219         int m_negativeMarginAfter;
    220     };
    221     MarginValues marginValuesForChild(RenderBox* child);
    222 
    223     virtual void scrollbarsChanged(bool /*horizontalScrollbarChanged*/, bool /*verticalScrollbarChanged*/) { };
    224 
    225     int logicalRightOffsetForContent() const { return isHorizontalWritingMode() ? borderLeft() + paddingLeft() + availableLogicalWidth() : borderTop() + paddingTop() + availableLogicalWidth(); }
    226     int logicalLeftOffsetForContent() const { return isHorizontalWritingMode() ? borderLeft() + paddingLeft() : borderTop() + paddingTop(); }
    227 
    228 protected:
    229     // These functions are only used internally to manipulate the render tree structure via remove/insert/appendChildNode.
    230     // Since they are typically called only to move objects around within anonymous blocks (which only have layers in
    231     // the case of column spans), the default for fullRemoveInsert is false rather than true.
    232     void moveChildTo(RenderBlock* to, RenderObject* child, bool fullRemoveInsert = false)
    233     {
    234         return moveChildTo(to, child, 0, fullRemoveInsert);
    235     }
    236     void moveChildTo(RenderBlock* to, RenderObject* child, RenderObject* beforeChild, bool fullRemoveInsert = false);
    237     void moveAllChildrenTo(RenderBlock* to, bool fullRemoveInsert = false)
    238     {
    239         return moveAllChildrenTo(to, 0, fullRemoveInsert);
    240     }
    241     void moveAllChildrenTo(RenderBlock* to, RenderObject* beforeChild, bool fullRemoveInsert = false)
    242     {
    243         return moveChildrenTo(to, firstChild(), 0, beforeChild, fullRemoveInsert);
    244     }
    245     // Move all of the kids from |startChild| up to but excluding |endChild|.  0 can be passed as the endChild to denote
    246     // that all the kids from |startChild| onwards should be added.
    247     void moveChildrenTo(RenderBlock* to, RenderObject* startChild, RenderObject* endChild, bool fullRemoveInsert = false)
    248     {
    249         return moveChildrenTo(to, startChild, endChild, 0, fullRemoveInsert);
    250     }
    251     void moveChildrenTo(RenderBlock* to, RenderObject* startChild, RenderObject* endChild, RenderObject* beforeChild, bool fullRemoveInsert = false);
    252 
    253     int maxPositiveMarginBefore() const { return m_rareData ? m_rareData->m_margins.positiveMarginBefore() : RenderBlockRareData::positiveMarginBeforeDefault(this); }
    254     int maxNegativeMarginBefore() const { return m_rareData ? m_rareData->m_margins.negativeMarginBefore() : RenderBlockRareData::negativeMarginBeforeDefault(this); }
    255     int maxPositiveMarginAfter() const { return m_rareData ? m_rareData->m_margins.positiveMarginAfter() : RenderBlockRareData::positiveMarginAfterDefault(this); }
    256     int maxNegativeMarginAfter() const { return m_rareData ? m_rareData->m_margins.negativeMarginAfter() : RenderBlockRareData::negativeMarginAfterDefault(this); }
    257 
    258     void setMaxMarginBeforeValues(int pos, int neg);
    259     void setMaxMarginAfterValues(int pos, int neg);
    260 
    261     void initMaxMarginValues()
    262     {
    263         if (m_rareData) {
    264             m_rareData->m_margins = MarginValues(RenderBlockRareData::positiveMarginBeforeDefault(this) , RenderBlockRareData::negativeMarginBeforeDefault(this),
    265                                                  RenderBlockRareData::positiveMarginAfterDefault(this), RenderBlockRareData::negativeMarginAfterDefault(this));
    266             m_rareData->m_paginationStrut = 0;
    267         }
    268     }
    269 
    270     virtual void layout();
    271 
    272     void layoutPositionedObjects(bool relayoutChildren);
    273 
    274     virtual void paint(PaintInfo&, int tx, int ty);
    275     virtual void paintObject(PaintInfo&, int tx, int ty);
    276 
    277     int logicalRightOffsetForLine(int position, int fixedOffset, bool applyTextIndent = true, int* logicalHeightRemaining = 0) const;
    278     int logicalLeftOffsetForLine(int position, int fixedOffset, bool applyTextIndent = true, int* logicalHeightRemaining = 0) const;
    279 
    280     virtual ETextAlign textAlignmentForLine(bool endsWithSoftBreak) const;
    281     virtual void adjustInlineDirectionLineBounds(int /* expansionOpportunityCount */, float& /* logicalLeft */, float& /* logicalWidth */) const { }
    282 
    283     virtual bool nodeAtPoint(const HitTestRequest&, HitTestResult&, int x, int y, int tx, int ty, HitTestAction);
    284 
    285     virtual void computePreferredLogicalWidths();
    286 
    287     virtual int firstLineBoxBaseline() const;
    288     virtual int lastLineBoxBaseline() const;
    289 
    290     virtual void updateHitTestResult(HitTestResult&, const IntPoint&);
    291 
    292     // Delay update scrollbar until finishDelayRepaint() will be
    293     // called. This function is used when a flexbox is laying out its
    294     // descendant. If multiple calls are made to startDelayRepaint(),
    295     // finishDelayRepaint() will do nothing until finishDelayRepaint()
    296     // is called the same number of times.
    297     static void startDelayUpdateScrollInfo();
    298     static void finishDelayUpdateScrollInfo();
    299 
    300     virtual void styleWillChange(StyleDifference, const RenderStyle* newStyle);
    301     virtual void styleDidChange(StyleDifference, const RenderStyle* oldStyle);
    302 
    303     virtual bool hasLineIfEmpty() const;
    304 
    305     bool simplifiedLayout();
    306     void simplifiedNormalFlowLayout();
    307 
    308     void computeOverflow(int oldClientAfterEdge, bool recomputeFloats = false);
    309     virtual void addOverflowFromChildren();
    310     void addOverflowFromFloats();
    311     void addOverflowFromPositionedObjects();
    312     void addOverflowFromBlockChildren();
    313     void addOverflowFromInlineChildren();
    314 
    315     virtual void addFocusRingRects(Vector<IntRect>&, int tx, int ty);
    316 
    317 #if ENABLE(SVG)
    318     // Only used by RenderSVGText, which explicitely overrides RenderBlock::layoutBlock(), do NOT use for anything else.
    319     void forceLayoutInlineChildren()
    320     {
    321         int repaintLogicalTop = 0;
    322         int repaintLogicalBottom = 0;
    323         layoutInlineChildren(true, repaintLogicalTop, repaintLogicalBottom);
    324     }
    325 #endif
    326 
    327 private:
    328     virtual RenderObjectChildList* virtualChildren() { return children(); }
    329     virtual const RenderObjectChildList* virtualChildren() const { return children(); }
    330 
    331     virtual const char* renderName() const;
    332 
    333     virtual bool isRenderBlock() const { return true; }
    334     virtual bool isBlockFlow() const { return (!isInline() || isReplaced()) && !isTable(); }
    335     virtual bool isInlineBlockOrInlineTable() const { return isInline() && isReplaced(); }
    336 
    337     void makeChildrenNonInline(RenderObject* insertionPoint = 0);
    338     virtual void removeLeftoverAnonymousBlock(RenderBlock* child);
    339 
    340     virtual void dirtyLinesFromChangedChild(RenderObject* child) { m_lineBoxes.dirtyLinesFromChangedChild(this, child); }
    341 
    342     void addChildToContinuation(RenderObject* newChild, RenderObject* beforeChild);
    343     void addChildIgnoringContinuation(RenderObject* newChild, RenderObject* beforeChild);
    344     void addChildToAnonymousColumnBlocks(RenderObject* newChild, RenderObject* beforeChild);
    345     virtual void addChildIgnoringAnonymousColumnBlocks(RenderObject* newChild, RenderObject* beforeChild = 0);
    346 
    347     virtual bool isSelfCollapsingBlock() const;
    348 
    349     virtual int collapsedMarginBefore() const { return maxPositiveMarginBefore() - maxNegativeMarginBefore(); }
    350     virtual int collapsedMarginAfter() const { return maxPositiveMarginAfter() - maxNegativeMarginAfter(); }
    351 
    352     virtual void repaintOverhangingFloats(bool paintAllDescendants);
    353 
    354     void layoutBlockChildren(bool relayoutChildren, int& maxFloatLogicalBottom);
    355     void layoutInlineChildren(bool relayoutChildren, int& repaintLogicalTop, int& repaintLogicalBottom);
    356     BidiRun* handleTrailingSpaces(BidiRunList<BidiRun>&, BidiContext*);
    357 
    358     virtual void borderFitAdjust(int& x, int& w) const; // Shrink the box in which the border paints if border-fit is set.
    359 
    360     virtual void updateBeforeAfterContent(PseudoId);
    361 
    362     virtual RootInlineBox* createRootInlineBox(); // Subclassed by SVG and Ruby.
    363 
    364     // Called to lay out the legend for a fieldset or the ruby text of a ruby run.
    365     virtual RenderObject* layoutSpecialExcludedChild(bool /*relayoutChildren*/) { return 0; }
    366 
    367     struct FloatWithRect {
    368         FloatWithRect(RenderBox* f)
    369             : object(f)
    370             , rect(IntRect(f->x() - f->marginLeft(), f->y() - f->marginTop(), f->width() + f->marginLeft() + f->marginRight(), f->height() + f->marginTop() + f->marginBottom()))
    371             , everHadLayout(f->m_everHadLayout)
    372         {
    373         }
    374 
    375         RenderBox* object;
    376         IntRect rect;
    377         bool everHadLayout;
    378     };
    379 
    380     struct FloatingObject {
    381         WTF_MAKE_NONCOPYABLE(FloatingObject); WTF_MAKE_FAST_ALLOCATED;
    382     public:
    383         // Note that Type uses bits so you can use FloatBoth as a mask to query for both left and right.
    384         enum Type { FloatLeft = 1, FloatRight = 2, FloatBoth = 3 };
    385 
    386         FloatingObject(Type type)
    387             : m_renderer(0)
    388             , m_originatingLine(0)
    389             , m_paginationStrut(0)
    390             , m_type(type)
    391             , m_shouldPaint(true)
    392             , m_isDescendant(false)
    393             , m_isPlaced(false)
    394         {
    395         }
    396 
    397         FloatingObject(Type type, const IntRect& frameRect)
    398             : m_renderer(0)
    399             , m_originatingLine(0)
    400             , m_frameRect(frameRect)
    401             , m_paginationStrut(0)
    402             , m_type(type)
    403             , m_shouldPaint(true)
    404             , m_isDescendant(false)
    405             , m_isPlaced(true)
    406         {
    407         }
    408 
    409         Type type() const { return static_cast<Type>(m_type); }
    410         RenderBox* renderer() const { return m_renderer; }
    411 
    412         bool isPlaced() const { return m_isPlaced; }
    413         void setIsPlaced(bool placed = true) { m_isPlaced = placed; }
    414 
    415         int x() const { ASSERT(isPlaced()); return m_frameRect.x(); }
    416         int maxX() const { ASSERT(isPlaced()); return m_frameRect.maxX(); }
    417         int y() const { ASSERT(isPlaced()); return m_frameRect.y(); }
    418         int maxY() const { ASSERT(isPlaced()); return m_frameRect.maxY(); }
    419         int width() const { return m_frameRect.width(); }
    420         int height() const { return m_frameRect.height(); }
    421 
    422         void setX(int x) { m_frameRect.setX(x); }
    423         void setY(int y) { m_frameRect.setY(y); }
    424         void setWidth(int width) { m_frameRect.setWidth(width); }
    425         void setHeight(int height) { m_frameRect.setHeight(height); }
    426 
    427         const IntRect& frameRect() const { ASSERT(isPlaced()); return m_frameRect; }
    428         void setFrameRect(const IntRect& frameRect) { m_frameRect = frameRect; }
    429 
    430         RenderBox* m_renderer;
    431         RootInlineBox* m_originatingLine;
    432         IntRect m_frameRect;
    433         int m_paginationStrut;
    434         unsigned m_type : 2; // Type (left or right aligned)
    435         bool m_shouldPaint : 1;
    436         bool m_isDescendant : 1;
    437         bool m_isPlaced : 1;
    438     };
    439 
    440     IntPoint flipFloatForWritingMode(const FloatingObject*, const IntPoint&) const;
    441 
    442     int logicalTopForFloat(const FloatingObject* child) const { return isHorizontalWritingMode() ? child->y() : child->x(); }
    443     int logicalBottomForFloat(const FloatingObject* child) const { return isHorizontalWritingMode() ? child->maxY() : child->maxX(); }
    444     int logicalLeftForFloat(const FloatingObject* child) const { return isHorizontalWritingMode() ? child->x() : child->y(); }
    445     int logicalRightForFloat(const FloatingObject* child) const { return isHorizontalWritingMode() ? child->maxX() : child->maxY(); }
    446     int logicalWidthForFloat(const FloatingObject* child) const { return isHorizontalWritingMode() ? child->width() : child->height(); }
    447     void setLogicalTopForFloat(FloatingObject* child, int logicalTop)
    448     {
    449         if (isHorizontalWritingMode())
    450             child->setY(logicalTop);
    451         else
    452             child->setX(logicalTop);
    453     }
    454     void setLogicalLeftForFloat(FloatingObject* child, int logicalLeft)
    455     {
    456         if (isHorizontalWritingMode())
    457             child->setX(logicalLeft);
    458         else
    459             child->setY(logicalLeft);
    460     }
    461     void setLogicalHeightForFloat(FloatingObject* child, int logicalHeight)
    462     {
    463         if (isHorizontalWritingMode())
    464             child->setHeight(logicalHeight);
    465         else
    466             child->setWidth(logicalHeight);
    467     }
    468     void setLogicalWidthForFloat(FloatingObject* child, int logicalWidth)
    469     {
    470         if (isHorizontalWritingMode())
    471             child->setWidth(logicalWidth);
    472         else
    473             child->setHeight(logicalWidth);
    474     }
    475 
    476     int xPositionForFloatIncludingMargin(const FloatingObject* child) const
    477     {
    478         if (isHorizontalWritingMode())
    479             return child->x() + child->renderer()->marginLeft();
    480         else
    481             return child->x() + marginBeforeForChild(child->renderer());
    482     }
    483 
    484     int yPositionForFloatIncludingMargin(const FloatingObject* child) const
    485     {
    486         if (isHorizontalWritingMode())
    487             return child->y() + marginBeforeForChild(child->renderer());
    488         else
    489             return child->y() + child->renderer()->marginTop();
    490     }
    491 
    492     // The following functions' implementations are in RenderBlockLineLayout.cpp.
    493     void checkFloatsInCleanLine(RootInlineBox*, Vector<FloatWithRect>&, size_t& floatIndex, bool& encounteredNewFloat, bool& dirtiedByFloat);
    494     RootInlineBox* determineStartPosition(bool& firstLine, bool& fullLayout, bool& previousLineBrokeCleanly,
    495                                           InlineBidiResolver&, Vector<FloatWithRect>& floats, unsigned& numCleanFloats,
    496                                           bool& useRepaintBounds, int& repaintTop, int& repaintBottom);
    497     RootInlineBox* determineEndPosition(RootInlineBox* startBox, Vector<FloatWithRect>& floats, size_t floatIndex, InlineIterator& cleanLineStart,
    498                                         BidiStatus& cleanLineBidiStatus, int& yPos);
    499     bool matchedEndLine(const InlineBidiResolver&, const InlineIterator& endLineStart, const BidiStatus& endLineStatus,
    500                         RootInlineBox*& endLine, int& endYPos, int& repaintBottom, int& repaintTop);
    501 
    502     void skipTrailingWhitespace(InlineIterator&, bool isLineEmpty, bool previousLineBrokeCleanly);
    503     void skipLeadingWhitespace(InlineBidiResolver&, bool isLineEmpty, bool previousLineBrokeCleanly, FloatingObject* lastFloatFromPreviousLine, LineWidth&);
    504     typedef std::pair<RenderText*, LazyLineBreakIterator> LineBreakIteratorInfo;
    505     InlineIterator findNextLineBreak(InlineBidiResolver&, bool firstLine, bool& isLineEmpty, LineBreakIteratorInfo&, bool& previousLineBrokeCleanly, bool& hyphenated,
    506                                      EClear*, FloatingObject* lastFloatFromPreviousLine, Vector<RenderBox*>& positionedObjects);
    507     RootInlineBox* constructLine(BidiRunList<BidiRun>&, bool firstLine, bool lastLine);
    508     InlineFlowBox* createLineBoxes(RenderObject*, bool firstLine, InlineBox* childBox);
    509 
    510     void computeInlineDirectionPositionsForLine(RootInlineBox*, bool firstLine, BidiRun* firstRun, BidiRun* trailingSpaceRun, bool reachedEnd, GlyphOverflowAndFallbackFontsMap&, VerticalPositionCache&);
    511     void computeBlockDirectionPositionsForLine(RootInlineBox*, BidiRun*, GlyphOverflowAndFallbackFontsMap&, VerticalPositionCache&);
    512     void deleteEllipsisLineBoxes();
    513     void checkLinesForTextOverflow();
    514 
    515     // Positions new floats and also adjust all floats encountered on the line if any of them
    516     // have to move to the next page/column.
    517     bool positionNewFloatOnLine(FloatingObject* newFloat, FloatingObject* lastFloatFromPreviousLine, LineWidth&);
    518     void appendFloatingObjectToLastLine(FloatingObject*);
    519 
    520     // End of functions defined in RenderBlockLineLayout.cpp.
    521 
    522     void paintFloats(PaintInfo&, int tx, int ty, bool preservePhase = false);
    523     void paintContents(PaintInfo&, int tx, int ty);
    524     void paintColumnContents(PaintInfo&, int tx, int ty, bool paintFloats = false);
    525     void paintColumnRules(PaintInfo&, int tx, int ty);
    526     void paintChildren(PaintInfo&, int tx, int ty);
    527     void paintEllipsisBoxes(PaintInfo&, int tx, int ty);
    528     void paintSelection(PaintInfo&, int tx, int ty);
    529     void paintCaret(PaintInfo&, int tx, int ty, CaretType);
    530 
    531     FloatingObject* insertFloatingObject(RenderBox*);
    532     void removeFloatingObject(RenderBox*);
    533     void removeFloatingObjectsBelow(FloatingObject*, int logicalOffset);
    534 
    535     // Called from lineWidth, to position the floats added in the last line.
    536     // Returns true if and only if it has positioned any floats.
    537     bool positionNewFloats();
    538 
    539     void clearFloats();
    540     int getClearDelta(RenderBox* child, int yPos);
    541 
    542     virtual bool avoidsFloats() const;
    543 
    544     bool hasOverhangingFloats() { return parent() && !hasColumns() && containsFloats() && lowestFloatLogicalBottom() > logicalHeight(); }
    545     bool hasOverhangingFloat(RenderBox*);
    546     void addIntrudingFloats(RenderBlock* prev, int xoffset, int yoffset);
    547     int addOverhangingFloats(RenderBlock* child, int xoffset, int yoffset, bool makeChildPaintOtherFloats);
    548 
    549     int lowestFloatLogicalBottom(FloatingObject::Type = FloatingObject::FloatBoth) const;
    550     int nextFloatLogicalBottomBelow(int) const;
    551 
    552     virtual bool hitTestColumns(const HitTestRequest&, HitTestResult&, int x, int y, int tx, int ty, HitTestAction);
    553     virtual bool hitTestContents(const HitTestRequest&, HitTestResult&, int x, int y, int tx, int ty, HitTestAction);
    554     bool hitTestFloats(const HitTestRequest&, HitTestResult&, int x, int y, int tx, int ty);
    555 
    556     virtual bool isPointInOverflowControl(HitTestResult&, int x, int y, int tx, int ty);
    557 
    558     void computeInlinePreferredLogicalWidths();
    559     void computeBlockPreferredLogicalWidths();
    560 
    561     // Obtains the nearest enclosing block (including this block) that contributes a first-line style to our inline
    562     // children.
    563     virtual RenderBlock* firstLineBlock() const;
    564 
    565     virtual IntRect rectWithOutlineForRepaint(RenderBoxModelObject* repaintContainer, int outlineWidth);
    566     virtual RenderStyle* outlineStyleForRepaint() const;
    567 
    568     virtual RenderObject* hoverAncestor() const;
    569     virtual void updateDragState(bool dragOn);
    570     virtual void childBecameNonInline(RenderObject* child);
    571 
    572     virtual IntRect selectionRectForRepaint(RenderBoxModelObject* repaintContainer, bool /*clipToVisibleContent*/)
    573     {
    574         return selectionGapRectsForRepaint(repaintContainer);
    575     }
    576     virtual bool shouldPaintSelectionGaps() const;
    577     bool isSelectionRoot() const;
    578     GapRects selectionGaps(RenderBlock* rootBlock, const IntPoint& rootBlockPhysicalPosition, const IntSize& offsetFromRootBlock,
    579                            int& lastLogicalTop, int& lastLogicalLeft, int& lastLogicalRight, const PaintInfo* = 0);
    580     GapRects inlineSelectionGaps(RenderBlock* rootBlock, const IntPoint& rootBlockPhysicalPosition, const IntSize& offsetFromRootBlock,
    581                            int& lastLogicalTop, int& lastLogicalLeft, int& lastLogicalRight, const PaintInfo*);
    582     GapRects blockSelectionGaps(RenderBlock* rootBlock, const IntPoint& rootBlockPhysicalPosition, const IntSize& offsetFromRootBlock,
    583                            int& lastLogicalTop, int& lastLogicalLeft, int& lastLogicalRight, const PaintInfo*);
    584     IntRect blockSelectionGap(RenderBlock* rootBlock, const IntPoint& rootBlockPhysicalPosition, const IntSize& offsetFromRootBlock,
    585                               int lastLogicalTop, int lastLogicalLeft, int lastLogicalRight, int logicalBottom, const PaintInfo*);
    586     int logicalLeftSelectionOffset(RenderBlock* rootBlock, int position);
    587     int logicalRightSelectionOffset(RenderBlock* rootBlock, int position);
    588 
    589     virtual void absoluteRects(Vector<IntRect>&, int tx, int ty);
    590     virtual void absoluteQuads(Vector<FloatQuad>&);
    591 
    592     int desiredColumnWidth() const;
    593     unsigned desiredColumnCount() const;
    594     void setDesiredColumnCountAndWidth(int count, int width);
    595 
    596     void paintContinuationOutlines(PaintInfo&, int tx, int ty);
    597 
    598     virtual IntRect localCaretRect(InlineBox*, int caretOffset, int* extraWidthToEndOfLine = 0);
    599 
    600     void adjustPointToColumnContents(IntPoint&) const;
    601     void adjustForBorderFit(int x, int& left, int& right) const; // Helper function for borderFitAdjust
    602 
    603     void markLinesDirtyInBlockRange(int logicalTop, int logicalBottom, RootInlineBox* highest = 0);
    604 
    605     void newLine(EClear);
    606 
    607     Position positionForBox(InlineBox*, bool start = true) const;
    608     VisiblePosition positionForPointWithInlineChildren(const IntPoint&);
    609 
    610     // Adjust tx and ty from painting offsets to the local coords of this renderer
    611     void offsetForContents(int& tx, int& ty) const;
    612 
    613     void calcColumnWidth();
    614     bool layoutColumns(bool hasSpecifiedPageLogicalHeight, int pageLogicalHeight, LayoutStateMaintainer&);
    615     void makeChildrenAnonymousColumnBlocks(RenderObject* beforeChild, RenderBlock* newBlockBox, RenderObject* newChild);
    616 
    617     bool expandsToEncloseOverhangingFloats() const;
    618 
    619     void updateScrollInfoAfterLayout();
    620 
    621     RenderObject* splitAnonymousBlocksAroundChild(RenderObject* beforeChild);
    622     void splitBlocks(RenderBlock* fromBlock, RenderBlock* toBlock, RenderBlock* middleBlock,
    623                      RenderObject* beforeChild, RenderBoxModelObject* oldCont);
    624     void splitFlow(RenderObject* beforeChild, RenderBlock* newBlockBox,
    625                    RenderObject* newChild, RenderBoxModelObject* oldCont);
    626     RenderBlock* clone() const;
    627     RenderBlock* continuationBefore(RenderObject* beforeChild);
    628     RenderBlock* containingColumnsBlock(bool allowAnonymousColumnBlock = true);
    629     RenderBlock* columnsBlockForSpanningElement(RenderObject* newChild);
    630 
    631     class MarginInfo {
    632         // Collapsing flags for whether we can collapse our margins with our children's margins.
    633         bool m_canCollapseWithChildren : 1;
    634         bool m_canCollapseMarginBeforeWithChildren : 1;
    635         bool m_canCollapseMarginAfterWithChildren : 1;
    636 
    637         // Whether or not we are a quirky container, i.e., do we collapse away top and bottom
    638         // margins in our container.  Table cells and the body are the common examples. We
    639         // also have a custom style property for Safari RSS to deal with TypePad blog articles.
    640         bool m_quirkContainer : 1;
    641 
    642         // This flag tracks whether we are still looking at child margins that can all collapse together at the beginning of a block.
    643         // They may or may not collapse with the top margin of the block (|m_canCollapseTopWithChildren| tells us that), but they will
    644         // always be collapsing with one another.  This variable can remain set to true through multiple iterations
    645         // as long as we keep encountering self-collapsing blocks.
    646         bool m_atBeforeSideOfBlock : 1;
    647 
    648         // This flag is set when we know we're examining bottom margins and we know we're at the bottom of the block.
    649         bool m_atAfterSideOfBlock : 1;
    650 
    651         // These variables are used to detect quirky margins that we need to collapse away (in table cells
    652         // and in the body element).
    653         bool m_marginBeforeQuirk : 1;
    654         bool m_marginAfterQuirk : 1;
    655         bool m_determinedMarginBeforeQuirk : 1;
    656 
    657         // These flags track the previous maximal positive and negative margins.
    658         int m_positiveMargin;
    659         int m_negativeMargin;
    660 
    661     public:
    662         MarginInfo(RenderBlock* b, int beforeBorderPadding, int afterBorderPadding);
    663 
    664         void setAtBeforeSideOfBlock(bool b) { m_atBeforeSideOfBlock = b; }
    665         void setAtAfterSideOfBlock(bool b) { m_atAfterSideOfBlock = b; }
    666         void clearMargin() { m_positiveMargin = m_negativeMargin = 0; }
    667         void setMarginBeforeQuirk(bool b) { m_marginBeforeQuirk = b; }
    668         void setMarginAfterQuirk(bool b) { m_marginAfterQuirk = b; }
    669         void setDeterminedMarginBeforeQuirk(bool b) { m_determinedMarginBeforeQuirk = b; }
    670         void setPositiveMargin(int p) { m_positiveMargin = p; }
    671         void setNegativeMargin(int n) { m_negativeMargin = n; }
    672         void setPositiveMarginIfLarger(int p) { if (p > m_positiveMargin) m_positiveMargin = p; }
    673         void setNegativeMarginIfLarger(int n) { if (n > m_negativeMargin) m_negativeMargin = n; }
    674 
    675         void setMargin(int p, int n) { m_positiveMargin = p; m_negativeMargin = n; }
    676 
    677         bool atBeforeSideOfBlock() const { return m_atBeforeSideOfBlock; }
    678         bool canCollapseWithMarginBefore() const { return m_atBeforeSideOfBlock && m_canCollapseMarginBeforeWithChildren; }
    679         bool canCollapseWithMarginAfter() const { return m_atAfterSideOfBlock && m_canCollapseMarginAfterWithChildren; }
    680         bool canCollapseMarginBeforeWithChildren() const { return m_canCollapseMarginBeforeWithChildren; }
    681         bool canCollapseMarginAfterWithChildren() const { return m_canCollapseMarginAfterWithChildren; }
    682         bool quirkContainer() const { return m_quirkContainer; }
    683         bool determinedMarginBeforeQuirk() const { return m_determinedMarginBeforeQuirk; }
    684         bool marginBeforeQuirk() const { return m_marginBeforeQuirk; }
    685         bool marginAfterQuirk() const { return m_marginAfterQuirk; }
    686         int positiveMargin() const { return m_positiveMargin; }
    687         int negativeMargin() const { return m_negativeMargin; }
    688         int margin() const { return m_positiveMargin - m_negativeMargin; }
    689     };
    690 
    691     void layoutBlockChild(RenderBox* child, MarginInfo&, int& previousFloatLogicalBottom, int& maxFloatLogicalBottom);
    692     void adjustPositionedBlock(RenderBox* child, const MarginInfo&);
    693     void adjustFloatingBlock(const MarginInfo&);
    694     bool handleSpecialChild(RenderBox* child, const MarginInfo&);
    695     bool handleFloatingChild(RenderBox* child, const MarginInfo&);
    696     bool handlePositionedChild(RenderBox* child, const MarginInfo&);
    697     bool handleRunInChild(RenderBox* child);
    698     int collapseMargins(RenderBox* child, MarginInfo&);
    699     int clearFloatsIfNeeded(RenderBox* child, MarginInfo&, int oldTopPosMargin, int oldTopNegMargin, int yPos);
    700     int estimateLogicalTopPosition(RenderBox* child, const MarginInfo&);
    701     void determineLogicalLeftPositionForChild(RenderBox* child);
    702     void handleAfterSideOfBlock(int top, int bottom, MarginInfo&);
    703     void setCollapsedBottomMargin(const MarginInfo&);
    704     // End helper functions and structs used by layoutBlockChildren.
    705 
    706     // Pagination routines.
    707     int nextPageLogicalTop(int logicalOffset) const; // Returns the top of the next page following logicalOffset.
    708     int applyBeforeBreak(RenderBox* child, int logicalOffset); // If the child has a before break, then return a new yPos that shifts to the top of the next page/column.
    709     int applyAfterBreak(RenderBox* child, int logicalOffset, MarginInfo& marginInfo); // If the child has an after break, then return a new offset that shifts to the top of the next page/column.
    710     int adjustForUnsplittableChild(RenderBox* child, int logicalOffset, bool includeMargins = false); // If the child is unsplittable and can't fit on the current page, return the top of the next page/column.
    711     void adjustLinePositionForPagination(RootInlineBox*, int& deltaOffset); // Computes a deltaOffset value that put a line at the top of the next page if it doesn't fit on the current page.
    712 
    713     struct FloatingObjectHashFunctions {
    714         static unsigned hash(FloatingObject* key) { return DefaultHash<RenderBox*>::Hash::hash(key->m_renderer); }
    715         static bool equal(FloatingObject* a, FloatingObject* b) { return a->m_renderer == b->m_renderer; }
    716         static const bool safeToCompareToEmptyOrDeleted = true;
    717     };
    718     struct FloatingObjectHashTranslator {
    719         static unsigned hash(RenderBox* key) { return DefaultHash<RenderBox*>::Hash::hash(key); }
    720         static bool equal(FloatingObject* a, RenderBox* b) { return a->m_renderer == b; }
    721     };
    722     typedef ListHashSet<FloatingObject*, 4, FloatingObjectHashFunctions> FloatingObjectSet;
    723     typedef FloatingObjectSet::const_iterator FloatingObjectSetIterator;
    724     class FloatingObjects {
    725     public:
    726         FloatingObjects()
    727             : m_leftObjectsCount(0)
    728             , m_rightObjectsCount(0)
    729         {
    730         }
    731 
    732         void clear();
    733         void increaseObjectsCount(FloatingObject::Type);
    734         void decreaseObjectsCount(FloatingObject::Type);
    735         bool hasLeftObjects() const { return m_leftObjectsCount > 0; }
    736         bool hasRightObjects() const { return m_rightObjectsCount > 0; }
    737         FloatingObjectSet& set() { return m_set; }
    738 
    739     private:
    740         FloatingObjectSet m_set;
    741         unsigned m_leftObjectsCount;
    742         unsigned m_rightObjectsCount;
    743     };
    744     OwnPtr<FloatingObjects> m_floatingObjects;
    745 
    746     typedef PositionedObjectsListHashSet::const_iterator Iterator;
    747     OwnPtr<PositionedObjectsListHashSet> m_positionedObjects;
    748 
    749     // Allocated only when some of these fields have non-default values
    750     struct RenderBlockRareData {
    751         WTF_MAKE_NONCOPYABLE(RenderBlockRareData); WTF_MAKE_FAST_ALLOCATED;
    752     public:
    753         RenderBlockRareData(const RenderBlock* block)
    754             : m_margins(positiveMarginBeforeDefault(block), negativeMarginBeforeDefault(block), positiveMarginAfterDefault(block), negativeMarginAfterDefault(block))
    755             , m_paginationStrut(0)
    756             , m_pageLogicalOffset(0)
    757         {
    758         }
    759 
    760         static int positiveMarginBeforeDefault(const RenderBlock* block)
    761         {
    762             return std::max(block->marginBefore(), 0);
    763         }
    764 
    765         static int negativeMarginBeforeDefault(const RenderBlock* block)
    766         {
    767             return std::max(-block->marginBefore(), 0);
    768         }
    769         static int positiveMarginAfterDefault(const RenderBlock* block)
    770         {
    771             return std::max(block->marginAfter(), 0);
    772         }
    773         static int negativeMarginAfterDefault(const RenderBlock* block)
    774         {
    775             return std::max(-block->marginAfter(), 0);
    776         }
    777 
    778         MarginValues m_margins;
    779         int m_paginationStrut;
    780         int m_pageLogicalOffset;
    781      };
    782 
    783     OwnPtr<RenderBlockRareData> m_rareData;
    784 
    785     RenderObjectChildList m_children;
    786     RenderLineBoxList m_lineBoxes;   // All of the root line boxes created for this block flow.  For example, <div>Hello<br>world.</div> will have two total lines for the <div>.
    787 
    788     mutable int m_lineHeight : 31;
    789     bool m_beingDestroyed : 1;
    790 
    791     // RenderRubyBase objects need to be able to split and merge, moving their children around
    792     // (calling moveChildTo, moveAllChildrenTo, and makeChildrenNonInline).
    793     friend class RenderRubyBase;
    794     friend class LineWidth; // Needs to know FloatingObject
    795 
    796 private:
    797     // Used to store state between styleWillChange and styleDidChange
    798     static bool s_canPropagateFloatIntoSibling;
    799 };
    800 
    801 inline RenderBlock* toRenderBlock(RenderObject* object)
    802 {
    803     ASSERT(!object || object->isRenderBlock());
    804     return static_cast<RenderBlock*>(object);
    805 }
    806 
    807 inline const RenderBlock* toRenderBlock(const RenderObject* object)
    808 {
    809     ASSERT(!object || object->isRenderBlock());
    810     return static_cast<const RenderBlock*>(object);
    811 }
    812 
    813 // This will catch anyone doing an unnecessary cast.
    814 void toRenderBlock(const RenderBlock*);
    815 
    816 } // namespace WebCore
    817 
    818 #endif // RenderBlock_h
    819