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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  * Copyright (C) 2003, 2006, 2007 Apple Inc. All rights reserved.
      5  *
      6  * This library is free software; you can redistribute it and/or
      7  * modify it under the terms of the GNU Library General Public
      8  * License as published by the Free Software Foundation; either
      9  * version 2 of the License, or (at your option) any later version.
     10  *
     11  * This library is distributed in the hope that it will be useful,
     12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
     13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     14  * Library General Public License for more details.
     15  *
     16  * You should have received a copy of the GNU Library General Public License
     17  * along with this library; see the file COPYING.LIB.  If not, write to
     18  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
     19  * Boston, MA 02110-1301, USA.
     20  *
     21  */
     22 
     23 #ifndef RenderBox_h
     24 #define RenderBox_h
     25 
     26 #include "core/rendering/RenderBoxModelObject.h"
     27 #include "core/rendering/RenderOverflow.h"
     28 #include "core/rendering/shapes/ShapeOutsideInfo.h"
     29 #include "platform/scroll/ScrollTypes.h"
     30 
     31 namespace WebCore {
     32 
     33 class RenderBoxRegionInfo;
     34 class RenderRegion;
     35 struct PaintInfo;
     36 
     37 enum SizeType { MainOrPreferredSize, MinSize, MaxSize };
     38 enum AvailableLogicalHeightType { ExcludeMarginBorderPadding, IncludeMarginBorderPadding };
     39 enum OverlayScrollbarSizeRelevancy { IgnoreOverlayScrollbarSize, IncludeOverlayScrollbarSize };
     40 
     41 enum ShouldComputePreferred { ComputeActual, ComputePreferred };
     42 
     43 enum ContentsClipBehavior { ForceContentsClip, SkipContentsClipIfPossible };
     44 
     45 enum ScrollOffsetClamping {
     46     ScrollOffsetUnclamped,
     47     ScrollOffsetClamped
     48 };
     49 
     50 class RenderBox : public RenderBoxModelObject {
     51 public:
     52     explicit RenderBox(ContainerNode*);
     53     virtual ~RenderBox();
     54 
     55     // hasAutoZIndex only returns true if the element is positioned or a flex-item since
     56     // position:static elements that are not flex-items get their z-index coerced to auto.
     57     virtual bool requiresLayer() const OVERRIDE { return isRoot() || isPositioned() || createsGroup() || hasClipPath() || hasOverflowClip() || hasTransform() || hasHiddenBackface() || hasReflection() || style()->specifiesColumns() || !style()->hasAutoZIndex(); }
     58 
     59     virtual bool backgroundIsKnownToBeOpaqueInRect(const LayoutRect& localRect) const OVERRIDE;
     60 
     61     // Use this with caution! No type checking is done!
     62     RenderBox* firstChildBox() const;
     63     RenderBox* lastChildBox() const;
     64 
     65     LayoutUnit x() const { return m_frameRect.x(); }
     66     LayoutUnit y() const { return m_frameRect.y(); }
     67     LayoutUnit width() const { return m_frameRect.width(); }
     68     LayoutUnit height() const { return m_frameRect.height(); }
     69 
     70     int pixelSnappedWidth() const { return m_frameRect.pixelSnappedWidth(); }
     71     int pixelSnappedHeight() const { return m_frameRect.pixelSnappedHeight(); }
     72 
     73     // These represent your location relative to your container as a physical offset.
     74     // In layout related methods you almost always want the logical location (e.g. x() and y()).
     75     LayoutUnit top() const { return topLeftLocation().y(); }
     76     LayoutUnit left() const { return topLeftLocation().x(); }
     77 
     78     void setX(LayoutUnit x) { m_frameRect.setX(x); }
     79     void setY(LayoutUnit y) { m_frameRect.setY(y); }
     80     void setWidth(LayoutUnit width) { m_frameRect.setWidth(width); }
     81     void setHeight(LayoutUnit height) { m_frameRect.setHeight(height); }
     82 
     83     LayoutUnit logicalLeft() const { return style()->isHorizontalWritingMode() ? x() : y(); }
     84     LayoutUnit logicalRight() const { return logicalLeft() + logicalWidth(); }
     85     LayoutUnit logicalTop() const { return style()->isHorizontalWritingMode() ? y() : x(); }
     86     LayoutUnit logicalBottom() const { return logicalTop() + logicalHeight(); }
     87     LayoutUnit logicalWidth() const { return style()->isHorizontalWritingMode() ? width() : height(); }
     88     LayoutUnit logicalHeight() const { return style()->isHorizontalWritingMode() ? height() : width(); }
     89 
     90     LayoutUnit constrainLogicalWidthInRegionByMinMax(LayoutUnit, LayoutUnit, RenderBlock*, RenderRegion* = 0) const;
     91     LayoutUnit constrainLogicalHeightByMinMax(LayoutUnit logicalHeight, LayoutUnit intrinsicContentHeight) const;
     92     LayoutUnit constrainContentBoxLogicalHeightByMinMax(LayoutUnit logicalHeight, LayoutUnit intrinsicContentHeight) const;
     93 
     94     int pixelSnappedLogicalHeight() const { return style()->isHorizontalWritingMode() ? pixelSnappedHeight() : pixelSnappedWidth(); }
     95     int pixelSnappedLogicalWidth() const { return style()->isHorizontalWritingMode() ? pixelSnappedWidth() : pixelSnappedHeight(); }
     96 
     97     void setLogicalLeft(LayoutUnit left)
     98     {
     99         if (style()->isHorizontalWritingMode())
    100             setX(left);
    101         else
    102             setY(left);
    103     }
    104     void setLogicalTop(LayoutUnit top)
    105     {
    106         if (style()->isHorizontalWritingMode())
    107             setY(top);
    108         else
    109             setX(top);
    110     }
    111     void setLogicalLocation(const LayoutPoint& location)
    112     {
    113         if (style()->isHorizontalWritingMode())
    114             setLocation(location);
    115         else
    116             setLocation(location.transposedPoint());
    117     }
    118     void setLogicalWidth(LayoutUnit size)
    119     {
    120         if (style()->isHorizontalWritingMode())
    121             setWidth(size);
    122         else
    123             setHeight(size);
    124     }
    125     void setLogicalHeight(LayoutUnit size)
    126     {
    127         if (style()->isHorizontalWritingMode())
    128             setHeight(size);
    129         else
    130             setWidth(size);
    131     }
    132     void setLogicalSize(const LayoutSize& size)
    133     {
    134         if (style()->isHorizontalWritingMode())
    135             setSize(size);
    136         else
    137             setSize(size.transposedSize());
    138     }
    139 
    140     LayoutPoint location() const { return m_frameRect.location(); }
    141     LayoutSize locationOffset() const { return LayoutSize(x(), y()); }
    142     LayoutSize size() const { return m_frameRect.size(); }
    143     IntSize pixelSnappedSize() const { return m_frameRect.pixelSnappedSize(); }
    144 
    145     void setLocation(const LayoutPoint& location) { m_frameRect.setLocation(location); }
    146 
    147     void setSize(const LayoutSize& size) { m_frameRect.setSize(size); }
    148     void move(LayoutUnit dx, LayoutUnit dy) { m_frameRect.move(dx, dy); }
    149 
    150     LayoutRect frameRect() const { return m_frameRect; }
    151     IntRect pixelSnappedFrameRect() const { return pixelSnappedIntRect(m_frameRect); }
    152     void setFrameRect(const LayoutRect& rect) { m_frameRect = rect; }
    153 
    154     LayoutRect borderBoxRect() const { return LayoutRect(LayoutPoint(), size()); }
    155     LayoutRect paddingBoxRect() const { return LayoutRect(borderLeft(), borderTop(), contentWidth() + paddingLeft() + paddingRight(), contentHeight() + paddingTop() + paddingBottom()); }
    156     IntRect pixelSnappedBorderBoxRect() const { return IntRect(IntPoint(), m_frameRect.pixelSnappedSize()); }
    157     virtual IntRect borderBoundingBox() const OVERRIDE FINAL { return pixelSnappedBorderBoxRect(); }
    158 
    159     // The content area of the box (excludes padding - and intrinsic padding for table cells, etc... - and border).
    160     LayoutRect contentBoxRect() const { return LayoutRect(borderLeft() + paddingLeft(), borderTop() + paddingTop(), contentWidth(), contentHeight()); }
    161     // The content box in absolute coords. Ignores transforms.
    162     IntRect absoluteContentBox() const;
    163     // The content box converted to absolute coords (taking transforms into account).
    164     FloatQuad absoluteContentQuad() const;
    165 
    166     // This returns the content area of the box (excluding padding and border). The only difference with contentBoxRect is that computedCSSContentBoxRect
    167     // does include the intrinsic padding in the content box as this is what some callers expect (like getComputedStyle).
    168     LayoutRect computedCSSContentBoxRect() const { return LayoutRect(borderLeft() + computedCSSPaddingLeft(), borderTop() + computedCSSPaddingTop(), clientWidth() - computedCSSPaddingLeft() - computedCSSPaddingRight(), clientHeight() - computedCSSPaddingTop() - computedCSSPaddingBottom()); }
    169 
    170     // Bounds of the outline box in absolute coords. Respects transforms
    171     virtual LayoutRect outlineBoundsForRepaint(const RenderLayerModelObject* /*repaintContainer*/, const RenderGeometryMap*) const OVERRIDE FINAL;
    172     virtual void addFocusRingRects(Vector<IntRect>&, const LayoutPoint& additionalOffset, const RenderLayerModelObject* paintContainer = 0) OVERRIDE;
    173 
    174     // Use this with caution! No type checking is done!
    175     RenderBox* previousSiblingBox() const;
    176     RenderBox* nextSiblingBox() const;
    177     RenderBox* parentBox() const;
    178 
    179     bool canResize() const;
    180 
    181     // Visual and layout overflow are in the coordinate space of the box.  This means that they aren't purely physical directions.
    182     // For horizontal-tb and vertical-lr they will match physical directions, but for horizontal-bt and vertical-rl, the top/bottom and left/right
    183     // respectively are flipped when compared to their physical counterparts.  For example minX is on the left in vertical-lr,
    184     // but it is on the right in vertical-rl.
    185     LayoutRect noOverflowRect() const;
    186     LayoutRect layoutOverflowRect() const { return m_overflow ? m_overflow->layoutOverflowRect() : noOverflowRect(); }
    187     IntRect pixelSnappedLayoutOverflowRect() const { return pixelSnappedIntRect(layoutOverflowRect()); }
    188     LayoutSize maxLayoutOverflow() const { return LayoutSize(layoutOverflowRect().maxX(), layoutOverflowRect().maxY()); }
    189     LayoutUnit logicalLeftLayoutOverflow() const { return style()->isHorizontalWritingMode() ? layoutOverflowRect().x() : layoutOverflowRect().y(); }
    190     LayoutUnit logicalRightLayoutOverflow() const { return style()->isHorizontalWritingMode() ? layoutOverflowRect().maxX() : layoutOverflowRect().maxY(); }
    191 
    192     virtual LayoutRect visualOverflowRect() const { return m_overflow ? m_overflow->visualOverflowRect() : borderBoxRect(); }
    193     LayoutUnit logicalLeftVisualOverflow() const { return style()->isHorizontalWritingMode() ? visualOverflowRect().x() : visualOverflowRect().y(); }
    194     LayoutUnit logicalRightVisualOverflow() const { return style()->isHorizontalWritingMode() ? visualOverflowRect().maxX() : visualOverflowRect().maxY(); }
    195 
    196     LayoutRect overflowRectForPaintRejection() const;
    197 
    198     LayoutRect contentsVisualOverflowRect() const { return m_overflow ? m_overflow->contentsVisualOverflowRect() : LayoutRect(); }
    199 
    200     void addLayoutOverflow(const LayoutRect&);
    201     void addVisualOverflow(const LayoutRect&);
    202 
    203     // Clipped by the contents clip, if one exists.
    204     void addContentsVisualOverflow(const LayoutRect&);
    205 
    206     void addVisualEffectOverflow();
    207     void addOverflowFromChild(RenderBox* child) { addOverflowFromChild(child, child->locationOffset()); }
    208     void addOverflowFromChild(RenderBox* child, const LayoutSize& delta);
    209     void clearLayoutOverflow();
    210 
    211     void updateLayerTransform();
    212 
    213     LayoutUnit contentWidth() const { return clientWidth() - paddingLeft() - paddingRight(); }
    214     LayoutUnit contentHeight() const { return clientHeight() - paddingTop() - paddingBottom(); }
    215     LayoutUnit contentLogicalWidth() const { return style()->isHorizontalWritingMode() ? contentWidth() : contentHeight(); }
    216     LayoutUnit contentLogicalHeight() const { return style()->isHorizontalWritingMode() ? contentHeight() : contentWidth(); }
    217 
    218     // IE extensions. Used to calculate offsetWidth/Height.  Overridden by inlines (RenderFlow)
    219     // to return the remaining width on a given line (and the height of a single line).
    220     virtual LayoutUnit offsetWidth() const { return width(); }
    221     virtual LayoutUnit offsetHeight() const { return height(); }
    222 
    223     virtual int pixelSnappedOffsetWidth() const OVERRIDE FINAL;
    224     virtual int pixelSnappedOffsetHeight() const OVERRIDE FINAL;
    225 
    226     bool canDetermineWidthWithoutLayout() const;
    227     LayoutUnit fixedOffsetWidth() const;
    228 
    229     // More IE extensions.  clientWidth and clientHeight represent the interior of an object
    230     // excluding border and scrollbar.  clientLeft/Top are just the borderLeftWidth and borderTopWidth.
    231     LayoutUnit clientLeft() const { return borderLeft(); }
    232     LayoutUnit clientTop() const { return borderTop(); }
    233     LayoutUnit clientWidth() const;
    234     LayoutUnit clientHeight() const;
    235     LayoutUnit clientLogicalWidth() const { return style()->isHorizontalWritingMode() ? clientWidth() : clientHeight(); }
    236     LayoutUnit clientLogicalHeight() const { return style()->isHorizontalWritingMode() ? clientHeight() : clientWidth(); }
    237     LayoutUnit clientLogicalBottom() const { return borderBefore() + clientLogicalHeight(); }
    238     LayoutRect clientBoxRect() const { return LayoutRect(clientLeft(), clientTop(), clientWidth(), clientHeight()); }
    239 
    240     int pixelSnappedClientWidth() const;
    241     int pixelSnappedClientHeight() const;
    242 
    243     // scrollWidth/scrollHeight will be the same as clientWidth/clientHeight unless the
    244     // object has overflow:hidden/scroll/auto specified and also has overflow.
    245     // scrollLeft/Top return the current scroll position.  These methods are virtual so that objects like
    246     // textareas can scroll shadow content (but pretend that they are the objects that are
    247     // scrolling).
    248     virtual int scrollLeft() const;
    249     virtual int scrollTop() const;
    250     virtual int scrollWidth() const;
    251     virtual int scrollHeight() const;
    252     virtual void setScrollLeft(int);
    253     virtual void setScrollTop(int);
    254 
    255     void scrollToOffset(const IntSize&);
    256     void scrollByRecursively(const IntSize& delta, ScrollOffsetClamping = ScrollOffsetUnclamped);
    257     void scrollRectToVisible(const LayoutRect&, const ScrollAlignment& alignX, const ScrollAlignment& alignY);
    258 
    259     virtual LayoutUnit marginTop() const OVERRIDE { return m_marginBox.top(); }
    260     virtual LayoutUnit marginBottom() const OVERRIDE { return m_marginBox.bottom(); }
    261     virtual LayoutUnit marginLeft() const OVERRIDE { return m_marginBox.left(); }
    262     virtual LayoutUnit marginRight() const OVERRIDE { return m_marginBox.right(); }
    263     void setMarginTop(LayoutUnit margin) { m_marginBox.setTop(margin); }
    264     void setMarginBottom(LayoutUnit margin) { m_marginBox.setBottom(margin); }
    265     void setMarginLeft(LayoutUnit margin) { m_marginBox.setLeft(margin); }
    266     void setMarginRight(LayoutUnit margin) { m_marginBox.setRight(margin); }
    267 
    268     LayoutUnit marginLogicalLeft() const { return m_marginBox.logicalLeft(style()->writingMode()); }
    269     LayoutUnit marginLogicalRight() const { return m_marginBox.logicalRight(style()->writingMode()); }
    270 
    271     virtual LayoutUnit marginBefore(const RenderStyle* overrideStyle = 0) const OVERRIDE FINAL { return m_marginBox.before((overrideStyle ? overrideStyle : style())->writingMode()); }
    272     virtual LayoutUnit marginAfter(const RenderStyle* overrideStyle = 0) const OVERRIDE FINAL { return m_marginBox.after((overrideStyle ? overrideStyle : style())->writingMode()); }
    273     virtual LayoutUnit marginStart(const RenderStyle* overrideStyle = 0) const OVERRIDE FINAL
    274     {
    275         const RenderStyle* styleToUse = overrideStyle ? overrideStyle : style();
    276         return m_marginBox.start(styleToUse->writingMode(), styleToUse->direction());
    277     }
    278     virtual LayoutUnit marginEnd(const RenderStyle* overrideStyle = 0) const OVERRIDE FINAL
    279     {
    280         const RenderStyle* styleToUse = overrideStyle ? overrideStyle : style();
    281         return m_marginBox.end(styleToUse->writingMode(), styleToUse->direction());
    282     }
    283     void setMarginBefore(LayoutUnit value, const RenderStyle* overrideStyle = 0) { m_marginBox.setBefore((overrideStyle ? overrideStyle : style())->writingMode(), value); }
    284     void setMarginAfter(LayoutUnit value, const RenderStyle* overrideStyle = 0) { m_marginBox.setAfter((overrideStyle ? overrideStyle : style())->writingMode(), value); }
    285     void setMarginStart(LayoutUnit value, const RenderStyle* overrideStyle = 0)
    286     {
    287         const RenderStyle* styleToUse = overrideStyle ? overrideStyle : style();
    288         m_marginBox.setStart(styleToUse->writingMode(), styleToUse->direction(), value);
    289     }
    290     void setMarginEnd(LayoutUnit value, const RenderStyle* overrideStyle = 0)
    291     {
    292         const RenderStyle* styleToUse = overrideStyle ? overrideStyle : style();
    293         m_marginBox.setEnd(styleToUse->writingMode(), styleToUse->direction(), value);
    294     }
    295 
    296     // The following five functions are used to implement collapsing margins.
    297     // All objects know their maximal positive and negative margins.  The
    298     // formula for computing a collapsed margin is |maxPosMargin| - |maxNegmargin|.
    299     // For a non-collapsing box, such as a leaf element, this formula will simply return
    300     // the margin of the element.  Blocks override the maxMarginBefore and maxMarginAfter
    301     // methods.
    302     enum MarginSign { PositiveMargin, NegativeMargin };
    303     virtual bool isSelfCollapsingBlock() const { return false; }
    304     virtual LayoutUnit collapsedMarginBefore() const { return marginBefore(); }
    305     virtual LayoutUnit collapsedMarginAfter() const { return marginAfter(); }
    306 
    307     virtual void absoluteRects(Vector<IntRect>&, const LayoutPoint& accumulatedOffset) const;
    308     virtual void absoluteQuads(Vector<FloatQuad>&, bool* wasFixed) const;
    309 
    310     LayoutRect reflectionBox() const;
    311     int reflectionOffset() const;
    312     // Given a rect in the object's coordinate space, returns the corresponding rect in the reflection.
    313     LayoutRect reflectedRect(const LayoutRect&) const;
    314 
    315     virtual void layout();
    316     virtual void paint(PaintInfo&, const LayoutPoint&);
    317     virtual bool nodeAtPoint(const HitTestRequest&, HitTestResult&, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, HitTestAction) OVERRIDE;
    318 
    319     virtual LayoutUnit minPreferredLogicalWidth() const;
    320     virtual LayoutUnit maxPreferredLogicalWidth() const;
    321 
    322     // FIXME: We should rename these back to overrideLogicalHeight/Width and have them store
    323     // the border-box height/width like the regular height/width accessors on RenderBox.
    324     // Right now, these are different than contentHeight/contentWidth because they still
    325     // include the scrollbar height/width.
    326     LayoutUnit overrideLogicalContentWidth() const;
    327     LayoutUnit overrideLogicalContentHeight() const;
    328     bool hasOverrideHeight() const;
    329     bool hasOverrideWidth() const;
    330     void setOverrideLogicalContentHeight(LayoutUnit);
    331     void setOverrideLogicalContentWidth(LayoutUnit);
    332     void clearOverrideSize();
    333     void clearOverrideLogicalContentHeight();
    334     void clearOverrideLogicalContentWidth();
    335 
    336     LayoutUnit overrideContainingBlockContentLogicalWidth() const;
    337     LayoutUnit overrideContainingBlockContentLogicalHeight() const;
    338     bool hasOverrideContainingBlockLogicalWidth() const;
    339     bool hasOverrideContainingBlockLogicalHeight() const;
    340     void setOverrideContainingBlockContentLogicalWidth(LayoutUnit);
    341     void setOverrideContainingBlockContentLogicalHeight(LayoutUnit);
    342     void clearContainingBlockOverrideSize();
    343     void clearOverrideContainingBlockContentLogicalHeight();
    344 
    345     virtual LayoutSize offsetFromContainer(RenderObject*, const LayoutPoint&, bool* offsetDependsOnPoint = 0) const;
    346 
    347     LayoutUnit adjustBorderBoxLogicalWidthForBoxSizing(LayoutUnit width) const;
    348     LayoutUnit adjustBorderBoxLogicalHeightForBoxSizing(LayoutUnit height) const;
    349     LayoutUnit adjustContentBoxLogicalWidthForBoxSizing(LayoutUnit width) const;
    350     LayoutUnit adjustContentBoxLogicalHeightForBoxSizing(LayoutUnit height) const;
    351 
    352     struct ComputedMarginValues {
    353         ComputedMarginValues() { }
    354 
    355         LayoutUnit m_before;
    356         LayoutUnit m_after;
    357         LayoutUnit m_start;
    358         LayoutUnit m_end;
    359     };
    360     struct LogicalExtentComputedValues {
    361         LogicalExtentComputedValues() { }
    362 
    363         LayoutUnit m_extent;
    364         LayoutUnit m_position;
    365         ComputedMarginValues m_margins;
    366     };
    367     // Resolve auto margins in the inline direction of the containing block so that objects can be pushed to the start, middle or end
    368     // of the containing block.
    369     void computeInlineDirectionMargins(RenderBlock* containingBlock, LayoutUnit containerWidth, LayoutUnit childWidth, LayoutUnit& marginStart, LayoutUnit& marginEnd) const;
    370 
    371     // Used to resolve margins in the containing block's block-flow direction.
    372     void computeBlockDirectionMargins(const RenderBlock* containingBlock, LayoutUnit& marginBefore, LayoutUnit& marginAfter) const;
    373     void computeAndSetBlockDirectionMargins(const RenderBlock* containingBlock);
    374 
    375     enum RenderBoxRegionInfoFlags { CacheRenderBoxRegionInfo, DoNotCacheRenderBoxRegionInfo };
    376     LayoutRect borderBoxRectInRegion(RenderRegion*, RenderBoxRegionInfoFlags = CacheRenderBoxRegionInfo) const;
    377     void clearRenderBoxRegionInfo();
    378     virtual LayoutUnit offsetFromLogicalTopOfFirstPage() const;
    379 
    380     void positionLineBox(InlineBox*);
    381 
    382     virtual InlineBox* createInlineBox();
    383     void dirtyLineBoxes(bool fullLayout);
    384 
    385     // For inline replaced elements, this function returns the inline box that owns us.  Enables
    386     // the replaced RenderObject to quickly determine what line it is contained on and to easily
    387     // iterate over structures on the line.
    388     InlineBox* inlineBoxWrapper() const { return m_inlineBoxWrapper; }
    389     void setInlineBoxWrapper(InlineBox*);
    390     void deleteLineBoxWrapper();
    391 
    392     virtual LayoutRect clippedOverflowRectForRepaint(const RenderLayerModelObject* repaintContainer) const OVERRIDE;
    393     virtual void computeRectForRepaint(const RenderLayerModelObject* repaintContainer, LayoutRect&, bool fixed = false) const OVERRIDE;
    394     void repaintDuringLayoutIfMoved(const LayoutRect&);
    395     virtual void repaintOverhangingFloats(bool paintAllDescendants);
    396 
    397     virtual LayoutUnit containingBlockLogicalWidthForContent() const;
    398     LayoutUnit containingBlockLogicalHeightForContent(AvailableLogicalHeightType) const;
    399 
    400     LayoutUnit containingBlockLogicalWidthForContentInRegion(RenderRegion*) const;
    401     LayoutUnit containingBlockAvailableLineWidthInRegion(RenderRegion*) const;
    402     LayoutUnit perpendicularContainingBlockLogicalHeight() const;
    403 
    404     virtual void updateLogicalWidth();
    405     virtual void updateLogicalHeight();
    406     virtual void computeLogicalHeight(LayoutUnit logicalHeight, LayoutUnit logicalTop, LogicalExtentComputedValues&) const;
    407 
    408     RenderBoxRegionInfo* renderBoxRegionInfo(RenderRegion*, RenderBoxRegionInfoFlags = CacheRenderBoxRegionInfo) const;
    409     void computeLogicalWidthInRegion(LogicalExtentComputedValues&, RenderRegion* = 0) const;
    410 
    411     bool stretchesToViewport() const
    412     {
    413         return document().inQuirksMode() && style()->logicalHeight().isAuto() && !isFloatingOrOutOfFlowPositioned() && (isRoot() || isBody()) && !document().shouldDisplaySeamlesslyWithParent() && !isInline();
    414     }
    415 
    416     virtual LayoutSize intrinsicSize() const { return LayoutSize(); }
    417     LayoutUnit intrinsicLogicalWidth() const { return style()->isHorizontalWritingMode() ? intrinsicSize().width() : intrinsicSize().height(); }
    418     LayoutUnit intrinsicLogicalHeight() const { return style()->isHorizontalWritingMode() ? intrinsicSize().height() : intrinsicSize().width(); }
    419 
    420     // Whether or not the element shrinks to its intrinsic width (rather than filling the width
    421     // of a containing block).  HTML4 buttons, <select>s, <input>s, legends, and floating/compact elements do this.
    422     bool sizesLogicalWidthToFitContent(SizeType) const;
    423 
    424     LayoutUnit shrinkLogicalWidthToAvoidFloats(LayoutUnit childMarginStart, LayoutUnit childMarginEnd, const RenderBlockFlow* cb, RenderRegion*) const;
    425 
    426     LayoutUnit computeLogicalWidthInRegionUsing(SizeType, Length logicalWidth, LayoutUnit availableLogicalWidth, const RenderBlock* containingBlock, RenderRegion*) const;
    427     LayoutUnit computeLogicalHeightUsing(const Length& height, LayoutUnit intrinsicContentHeight) const;
    428     LayoutUnit computeContentLogicalHeight(const Length& height, LayoutUnit intrinsicContentHeight) const;
    429     LayoutUnit computeContentAndScrollbarLogicalHeightUsing(const Length& height, LayoutUnit intrinsicContentHeight) const;
    430     LayoutUnit computeReplacedLogicalWidthUsing(Length width) const;
    431     LayoutUnit computeReplacedLogicalWidthRespectingMinMaxWidth(LayoutUnit logicalWidth, ShouldComputePreferred  = ComputeActual) const;
    432     LayoutUnit computeReplacedLogicalHeightUsing(Length height) const;
    433     LayoutUnit computeReplacedLogicalHeightRespectingMinMaxHeight(LayoutUnit logicalHeight) const;
    434 
    435     virtual LayoutUnit computeReplacedLogicalWidth(ShouldComputePreferred  = ComputeActual) const;
    436     virtual LayoutUnit computeReplacedLogicalHeight() const;
    437 
    438     static bool percentageLogicalHeightIsResolvableFromBlock(const RenderBlock* containingBlock, bool outOfFlowPositioned);
    439     LayoutUnit computePercentageLogicalHeight(const Length& height) const;
    440 
    441     // Block flows subclass availableWidth/Height to handle multi column layout (shrinking the width/height available to children when laying out.)
    442     virtual LayoutUnit availableLogicalWidth() const { return contentLogicalWidth(); }
    443     virtual LayoutUnit availableLogicalHeight(AvailableLogicalHeightType) const;
    444     LayoutUnit availableLogicalHeightUsing(const Length&, AvailableLogicalHeightType) const;
    445 
    446     // There are a few cases where we need to refer specifically to the available physical width and available physical height.
    447     // Relative positioning is one of those cases, since left/top offsets are physical.
    448     LayoutUnit availableWidth() const { return style()->isHorizontalWritingMode() ? availableLogicalWidth() : availableLogicalHeight(IncludeMarginBorderPadding); }
    449     LayoutUnit availableHeight() const { return style()->isHorizontalWritingMode() ? availableLogicalHeight(IncludeMarginBorderPadding) : availableLogicalWidth(); }
    450 
    451     virtual int verticalScrollbarWidth() const;
    452     int horizontalScrollbarHeight() const;
    453     int instrinsicScrollbarLogicalWidth() const;
    454     int scrollbarLogicalHeight() const { return style()->isHorizontalWritingMode() ? horizontalScrollbarHeight() : verticalScrollbarWidth(); }
    455     virtual bool scroll(ScrollDirection, ScrollGranularity, float multiplier = 1);
    456     bool canBeScrolledAndHasScrollableArea() const;
    457     virtual bool canBeProgramaticallyScrolled() const;
    458     virtual void autoscroll(const IntPoint&);
    459     bool autoscrollInProgress() const;
    460     bool canAutoscroll() const;
    461     IntSize calculateAutoscrollDirection(const IntPoint& windowPoint) const;
    462     static RenderBox* findAutoscrollable(RenderObject*);
    463     virtual void stopAutoscroll() { }
    464     virtual void panScroll(const IntPoint&);
    465 
    466     bool hasAutoVerticalScrollbar() const { return hasOverflowClip() && (style()->overflowY() == OAUTO || style()->overflowY() == OOVERLAY); }
    467     bool hasAutoHorizontalScrollbar() const { return hasOverflowClip() && (style()->overflowX() == OAUTO || style()->overflowX() == OOVERLAY); }
    468     bool scrollsOverflow() const { return scrollsOverflowX() || scrollsOverflowY(); }
    469 
    470     bool hasScrollableOverflowX() const { return scrollsOverflowX() && scrollWidth() != clientWidth(); }
    471     bool hasScrollableOverflowY() const { return scrollsOverflowY() && scrollHeight() != clientHeight(); }
    472     virtual bool scrollsOverflowX() const { return hasOverflowClip() && (style()->overflowX() == OSCROLL || hasAutoHorizontalScrollbar()); }
    473     virtual bool scrollsOverflowY() const { return hasOverflowClip() && (style()->overflowY() == OSCROLL || hasAutoVerticalScrollbar()); }
    474     bool usesCompositedScrolling() const;
    475 
    476     // Elements such as the <input> field override this to specify that they are scrollable
    477     // outside the context of the CSS overflow style
    478     virtual bool isIntristicallyScrollable(ScrollbarOrientation orientation) const { return false; }
    479 
    480     bool hasUnsplittableScrollingOverflow() const;
    481     bool isUnsplittableForPagination() const;
    482 
    483     virtual LayoutRect localCaretRect(InlineBox*, int caretOffset, LayoutUnit* extraWidthToEndOfLine = 0);
    484 
    485     virtual LayoutRect overflowClipRect(const LayoutPoint& location, RenderRegion*, OverlayScrollbarSizeRelevancy = IgnoreOverlayScrollbarSize);
    486     LayoutRect clipRect(const LayoutPoint& location, RenderRegion*);
    487     virtual bool hasControlClip() const { return false; }
    488     virtual LayoutRect controlClipRect(const LayoutPoint&) const { return LayoutRect(); }
    489     bool pushContentsClip(PaintInfo&, const LayoutPoint& accumulatedOffset, ContentsClipBehavior);
    490     void popContentsClip(PaintInfo&, PaintPhase originalPhase, const LayoutPoint& accumulatedOffset);
    491 
    492     virtual void paintObject(PaintInfo&, const LayoutPoint&) { ASSERT_NOT_REACHED(); }
    493     virtual void paintBoxDecorations(PaintInfo&, const LayoutPoint&);
    494     virtual void paintMask(PaintInfo&, const LayoutPoint&);
    495     virtual void paintClippingMask(PaintInfo&, const LayoutPoint&);
    496     virtual void imageChanged(WrappedImagePtr, const IntRect* = 0);
    497 
    498     // Called when a positioned object moves but doesn't necessarily change size.  A simplified layout is attempted
    499     // that just updates the object's position. If the size does change, the object remains dirty.
    500     bool tryLayoutDoingPositionedMovementOnly()
    501     {
    502         LayoutUnit oldWidth = width();
    503         updateLogicalWidth();
    504         // If we shrink to fit our width may have changed, so we still need full layout.
    505         if (oldWidth != width())
    506             return false;
    507         updateLogicalHeight();
    508         return true;
    509     }
    510 
    511     LayoutRect maskClipRect();
    512 
    513     virtual PositionWithAffinity positionForPoint(const LayoutPoint&) OVERRIDE;
    514 
    515     void removeFloatingOrPositionedChildFromBlockLists();
    516 
    517     RenderLayer* enclosingFloatPaintingLayer() const;
    518 
    519     virtual int firstLineBoxBaseline() const { return -1; }
    520     virtual int inlineBlockBaseline(LineDirectionMode) const { return -1; } // Returns -1 if we should skip this box when computing the baseline of an inline-block.
    521 
    522     bool shrinkToAvoidFloats() const;
    523     virtual bool avoidsFloats() const;
    524 
    525     virtual void markForPaginationRelayoutIfNeeded(SubtreeLayoutScope&) { }
    526 
    527     bool isWritingModeRoot() const { return !parent() || parent()->style()->writingMode() != style()->writingMode(); }
    528 
    529     bool isDeprecatedFlexItem() const { return !isInline() && !isFloatingOrOutOfFlowPositioned() && parent() && parent()->isDeprecatedFlexibleBox(); }
    530     bool isFlexItemIncludingDeprecated() const { return !isInline() && !isFloatingOrOutOfFlowPositioned() && parent() && parent()->isFlexibleBoxIncludingDeprecated(); }
    531 
    532     virtual LayoutUnit lineHeight(bool firstLine, LineDirectionMode, LinePositionMode = PositionOnContainingLine) const;
    533     virtual int baselinePosition(FontBaseline, bool firstLine, LineDirectionMode, LinePositionMode = PositionOnContainingLine) const OVERRIDE;
    534 
    535     virtual LayoutUnit offsetLeft() const OVERRIDE;
    536     virtual LayoutUnit offsetTop() const OVERRIDE;
    537 
    538     LayoutPoint flipForWritingModeForChild(const RenderBox* child, const LayoutPoint&) const;
    539     LayoutUnit flipForWritingMode(LayoutUnit position) const; // The offset is in the block direction (y for horizontal writing modes, x for vertical writing modes).
    540     LayoutPoint flipForWritingMode(const LayoutPoint&) const;
    541     LayoutPoint flipForWritingModeIncludingColumns(const LayoutPoint&) const;
    542     LayoutSize flipForWritingMode(const LayoutSize&) const;
    543     void flipForWritingMode(LayoutRect&) const;
    544     FloatPoint flipForWritingMode(const FloatPoint&) const;
    545     void flipForWritingMode(FloatRect&) const;
    546     // These represent your location relative to your container as a physical offset.
    547     // In layout related methods you almost always want the logical location (e.g. x() and y()).
    548     LayoutPoint topLeftLocation() const;
    549     LayoutSize topLeftLocationOffset() const;
    550 
    551     LayoutRect logicalVisualOverflowRectForPropagation(RenderStyle*) const;
    552     LayoutRect visualOverflowRectForPropagation(RenderStyle*) const;
    553     LayoutRect logicalLayoutOverflowRectForPropagation(RenderStyle*) const;
    554     LayoutRect layoutOverflowRectForPropagation(RenderStyle*) const;
    555 
    556     bool hasRenderOverflow() const { return m_overflow; }
    557     bool hasVisualOverflow() const { return m_overflow && !borderBoxRect().contains(m_overflow->visualOverflowRect()); }
    558 
    559     virtual bool needsPreferredWidthsRecalculation() const;
    560     virtual void computeIntrinsicRatioInformation(FloatSize& /* intrinsicSize */, double& /* intrinsicRatio */, bool& /* isPercentageIntrinsicSize */) const { }
    561 
    562     IntSize scrolledContentOffset() const;
    563     LayoutSize cachedSizeForOverflowClip() const;
    564     void applyCachedClipAndScrollOffsetForRepaint(LayoutRect& paintRect) const;
    565 
    566     virtual bool hasRelativeDimensions() const;
    567     virtual bool hasRelativeLogicalHeight() const;
    568 
    569     bool hasHorizontalLayoutOverflow() const
    570     {
    571         if (!m_overflow)
    572             return false;
    573 
    574         LayoutRect layoutOverflowRect = m_overflow->layoutOverflowRect();
    575         LayoutRect noOverflowRect = this->noOverflowRect();
    576         return layoutOverflowRect.x() < noOverflowRect.x() || layoutOverflowRect.maxX() > noOverflowRect.maxX();
    577     }
    578 
    579     bool hasVerticalLayoutOverflow() const
    580     {
    581         if (!m_overflow)
    582             return false;
    583 
    584         LayoutRect layoutOverflowRect = m_overflow->layoutOverflowRect();
    585         LayoutRect noOverflowRect = this->noOverflowRect();
    586         return layoutOverflowRect.y() < noOverflowRect.y() || layoutOverflowRect.maxY() > noOverflowRect.maxY();
    587     }
    588 
    589     virtual RenderBox* createAnonymousBoxWithSameTypeAs(const RenderObject*) const
    590     {
    591         ASSERT_NOT_REACHED();
    592         return 0;
    593     }
    594 
    595     bool hasSameDirectionAs(const RenderBox* object) const { return style()->direction() == object->style()->direction(); }
    596 
    597     ShapeOutsideInfo* shapeOutsideInfo() const
    598     {
    599         return ShapeOutsideInfo::isEnabledFor(this) ? ShapeOutsideInfo::info(this) : 0;
    600     }
    601 
    602     void markShapeOutsideDependentsForLayout()
    603     {
    604         if (isFloating())
    605             removeFloatingOrPositionedChildFromBlockLists();
    606     }
    607 
    608 protected:
    609     virtual void willBeDestroyed();
    610 
    611     virtual void styleWillChange(StyleDifference, const RenderStyle* newStyle);
    612     virtual void styleDidChange(StyleDifference, const RenderStyle* oldStyle);
    613     virtual void updateFromStyle() OVERRIDE;
    614 
    615     LayoutRect backgroundPaintedExtent() const;
    616     virtual bool foregroundIsKnownToBeOpaqueInRect(const LayoutRect& localRect, unsigned maxDepthToTest) const;
    617     virtual bool computeBackgroundIsKnownToBeObscured() OVERRIDE;
    618 
    619     virtual void paintBackgroundWithBorderAndBoxShadow(PaintInfo&, const LayoutRect&, BackgroundBleedAvoidance);
    620     void paintBackground(const PaintInfo&, const LayoutRect&, BackgroundBleedAvoidance = BackgroundBleedNone);
    621 
    622     void paintFillLayer(const PaintInfo&, const Color&, const FillLayer*, const LayoutRect&, BackgroundBleedAvoidance, CompositeOperator, RenderObject* backgroundObject);
    623     void paintFillLayers(const PaintInfo&, const Color&, const FillLayer*, const LayoutRect&, BackgroundBleedAvoidance = BackgroundBleedNone, CompositeOperator = CompositeSourceOver, RenderObject* backgroundObject = 0);
    624 
    625     void paintMaskImages(const PaintInfo&, const LayoutRect&);
    626     void paintBoxDecorationsWithRect(PaintInfo&, const LayoutPoint&, const LayoutRect&);
    627 
    628     BackgroundBleedAvoidance determineBackgroundBleedAvoidance(GraphicsContext*) const;
    629     bool backgroundHasOpaqueTopLayer() const;
    630 
    631     void computePositionedLogicalWidth(LogicalExtentComputedValues&, RenderRegion* = 0) const;
    632 
    633     LayoutUnit computeIntrinsicLogicalWidthUsing(Length logicalWidthLength, LayoutUnit availableLogicalWidth, LayoutUnit borderAndPadding) const;
    634     LayoutUnit computeIntrinsicLogicalContentHeightUsing(Length logicalHeightLength, LayoutUnit intrinsicContentHeight, LayoutUnit borderAndPadding) const;
    635 
    636     virtual bool shouldComputeSizeAsReplaced() const { return isReplaced() && !isInlineBlockOrInlineTable(); }
    637 
    638     virtual void mapLocalToContainer(const RenderLayerModelObject* repaintContainer, TransformState&, MapCoordinatesFlags = ApplyContainerFlip, bool* wasFixed = 0) const OVERRIDE;
    639     virtual void mapAbsoluteToLocalPoint(MapCoordinatesFlags, TransformState&) const;
    640 
    641     void paintRootBoxFillLayers(const PaintInfo&);
    642 
    643     RenderObject* splitAnonymousBoxesAroundChild(RenderObject* beforeChild);
    644 
    645     virtual void addLayerHitTestRects(LayerHitTestRects&, const RenderLayer* currentCompositedLayer, const LayoutPoint& layerOffset, const LayoutRect& containerRect) const OVERRIDE;
    646     virtual void computeSelfHitTestRects(Vector<LayoutRect>&, const LayoutPoint& layerOffset) const OVERRIDE;
    647 
    648 private:
    649     void updateShapeOutsideInfoAfterStyleChange(const RenderStyle&, const RenderStyle* oldStyle);
    650     void updateGridPositionAfterStyleChange(const RenderStyle*);
    651 
    652     bool autoWidthShouldFitContent() const;
    653     void shrinkToFitWidth(const LayoutUnit availableSpace, const LayoutUnit logicalLeftValue, const LayoutUnit bordersPlusPadding, LogicalExtentComputedValues&) const;
    654 
    655     // Returns true if we did a full repaint
    656     bool repaintLayerRectsForImage(WrappedImagePtr image, const FillLayer* layers, bool drawingBackground);
    657 
    658     bool skipContainingBlockForPercentHeightCalculation(const RenderBox* containingBlock) const;
    659 
    660     LayoutUnit containingBlockLogicalWidthForPositioned(const RenderBoxModelObject* containingBlock, RenderRegion* = 0, bool checkForPerpendicularWritingMode = true) const;
    661     LayoutUnit containingBlockLogicalHeightForPositioned(const RenderBoxModelObject* containingBlock, bool checkForPerpendicularWritingMode = true) const;
    662 
    663     LayoutUnit viewLogicalHeightForPercentages() const;
    664 
    665     void computePositionedLogicalHeight(LogicalExtentComputedValues&) const;
    666     void computePositionedLogicalWidthUsing(Length logicalWidth, const RenderBoxModelObject* containerBlock, TextDirection containerDirection,
    667                                             LayoutUnit containerLogicalWidth, LayoutUnit bordersPlusPadding,
    668                                             Length logicalLeft, Length logicalRight, Length marginLogicalLeft, Length marginLogicalRight,
    669                                             LogicalExtentComputedValues&) const;
    670     void computePositionedLogicalHeightUsing(Length logicalHeightLength, const RenderBoxModelObject* containerBlock,
    671                                              LayoutUnit containerLogicalHeight, LayoutUnit bordersPlusPadding, LayoutUnit logicalHeight,
    672                                              Length logicalTop, Length logicalBottom, Length marginLogicalTop, Length marginLogicalBottom,
    673                                              LogicalExtentComputedValues&) const;
    674 
    675     void computePositionedLogicalHeightReplaced(LogicalExtentComputedValues&) const;
    676     void computePositionedLogicalWidthReplaced(LogicalExtentComputedValues&) const;
    677 
    678     LayoutUnit fillAvailableMeasure(LayoutUnit availableLogicalWidth) const;
    679     LayoutUnit fillAvailableMeasure(LayoutUnit availableLogicalWidth, LayoutUnit& marginStart, LayoutUnit& marginEnd) const;
    680 
    681     virtual void computeIntrinsicLogicalWidths(LayoutUnit& minLogicalWidth, LayoutUnit& maxLogicalWidth) const;
    682 
    683     // This function calculates the minimum and maximum preferred widths for an object.
    684     // These values are used in shrink-to-fit layout systems.
    685     // These include tables, positioned objects, floats and flexible boxes.
    686     virtual void computePreferredLogicalWidths() { clearPreferredLogicalWidthsDirty(); }
    687 
    688     virtual LayoutRect frameRectForStickyPositioning() const OVERRIDE FINAL { return frameRect(); }
    689 
    690 private:
    691     // The width/height of the contents + borders + padding.  The x/y location is relative to our container (which is not always our parent).
    692     LayoutRect m_frameRect;
    693 
    694 protected:
    695     LayoutBoxExtent m_marginBox;
    696 
    697     // The preferred logical width of the element if it were to break its lines at every possible opportunity.
    698     LayoutUnit m_minPreferredLogicalWidth;
    699 
    700     // The preferred logical width of the element if it never breaks any lines at all.
    701     LayoutUnit m_maxPreferredLogicalWidth;
    702 
    703     // Our intrinsic height, used for min-height: min-content etc. Maintained by
    704     // updateLogicalHeight. This is logicalHeight() before it is clamped to
    705     // min/max.
    706     LayoutUnit m_intrinsicContentLogicalHeight;
    707 
    708     // For inline replaced elements, the inline box that owns us.
    709     InlineBox* m_inlineBoxWrapper;
    710 
    711     // Our overflow information.
    712     OwnPtr<RenderOverflow> m_overflow;
    713 };
    714 
    715 DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderBox, isBox());
    716 
    717 inline RenderBox* RenderBox::previousSiblingBox() const
    718 {
    719     return toRenderBox(previousSibling());
    720 }
    721 
    722 inline RenderBox* RenderBox::nextSiblingBox() const
    723 {
    724     return toRenderBox(nextSibling());
    725 }
    726 
    727 inline RenderBox* RenderBox::parentBox() const
    728 {
    729     return toRenderBox(parent());
    730 }
    731 
    732 inline RenderBox* RenderBox::firstChildBox() const
    733 {
    734     return toRenderBox(firstChild());
    735 }
    736 
    737 inline RenderBox* RenderBox::lastChildBox() const
    738 {
    739     return toRenderBox(lastChild());
    740 }
    741 
    742 inline void RenderBox::setInlineBoxWrapper(InlineBox* boxWrapper)
    743 {
    744     if (boxWrapper) {
    745         ASSERT(!m_inlineBoxWrapper);
    746         // m_inlineBoxWrapper should already be 0. Deleting it is a safeguard against security issues.
    747         // Otherwise, there will two line box wrappers keeping the reference to this renderer, and
    748         // only one will be notified when the renderer is getting destroyed. The second line box wrapper
    749         // will keep a stale reference.
    750         if (UNLIKELY(m_inlineBoxWrapper != 0))
    751             deleteLineBoxWrapper();
    752     }
    753 
    754     m_inlineBoxWrapper = boxWrapper;
    755 }
    756 
    757 } // namespace WebCore
    758 
    759 #endif // RenderBox_h
    760