1 /*
2 * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
3 * (C) 1999 Antti Koivisto (koivisto@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/animation/ActiveAnimations.h"
27 #include "core/rendering/RenderBoxModelObject.h"
28 #include "core/rendering/RenderOverflow.h"
29 #include "core/rendering/shapes/ShapeOutsideInfo.h"
30 #include "platform/scroll/ScrollTypes.h"
31
32 namespace WebCore {
33
34 struct PaintInfo;
35
36 enum SizeType { MainOrPreferredSize, MinSize, MaxSize };
37 enum AvailableLogicalHeightType { ExcludeMarginBorderPadding, IncludeMarginBorderPadding };
38 enum OverlayScrollbarSizeRelevancy { IgnoreOverlayScrollbarSize, IncludeOverlayScrollbarSize };
39 enum MarginDirection { BlockDirection, InlineDirection };
40
41 enum ShouldComputePreferred { ComputeActual, ComputePreferred };
42
43 enum ContentsClipBehavior { ForceContentsClip, SkipContentsClipIfPossible };
44
45 enum ScrollOffsetClamping {
46 ScrollOffsetUnclamped,
47 ScrollOffsetClamped
48 };
49
50 struct RenderBoxRareData {
51 WTF_MAKE_NONCOPYABLE(RenderBoxRareData); WTF_MAKE_FAST_ALLOCATED;
52 public:
RenderBoxRareDataRenderBoxRareData53 RenderBoxRareData()
54 : m_inlineBoxWrapper(0)
55 , m_overrideLogicalContentHeight(-1)
56 , m_overrideLogicalContentWidth(-1)
57 {
58 }
59
60 // For inline replaced elements, the inline box that owns us.
61 InlineBox* m_inlineBoxWrapper;
62
63 LayoutUnit m_overrideLogicalContentHeight;
64 LayoutUnit m_overrideLogicalContentWidth;
65 };
66
67
68 class RenderBox : public RenderBoxModelObject {
69 public:
70 explicit RenderBox(ContainerNode*);
71
72 // hasAutoZIndex only returns true if the element is positioned or a flex-item since
73 // position:static elements that are not flex-items get their z-index coerced to auto.
layerTypeRequired()74 virtual LayerType layerTypeRequired() const OVERRIDE
75 {
76 if (isPositioned() || createsGroup() || hasClipPath() || hasTransform() || hasHiddenBackface() || hasReflection() || style()->specifiesColumns() || !style()->hasAutoZIndex() || style()->shouldCompositeForCurrentAnimations())
77 return NormalLayer;
78 if (hasOverflowClip())
79 return OverflowClipLayer;
80
81 return NoLayer;
82 }
83
84 virtual bool backgroundIsKnownToBeOpaqueInRect(const LayoutRect& localRect) const OVERRIDE;
85
86 // Use this with caution! No type checking is done!
87 RenderBox* firstChildBox() const;
88 RenderBox* lastChildBox() const;
89
x()90 LayoutUnit x() const { return m_frameRect.x(); }
y()91 LayoutUnit y() const { return m_frameRect.y(); }
width()92 LayoutUnit width() const { return m_frameRect.width(); }
height()93 LayoutUnit height() const { return m_frameRect.height(); }
94
pixelSnappedWidth()95 int pixelSnappedWidth() const { return m_frameRect.pixelSnappedWidth(); }
pixelSnappedHeight()96 int pixelSnappedHeight() const { return m_frameRect.pixelSnappedHeight(); }
97
98 // These represent your location relative to your container as a physical offset.
99 // In layout related methods you almost always want the logical location (e.g. x() and y()).
top()100 LayoutUnit top() const { return topLeftLocation().y(); }
left()101 LayoutUnit left() const { return topLeftLocation().x(); }
102
setX(LayoutUnit x)103 void setX(LayoutUnit x) { m_frameRect.setX(x); }
setY(LayoutUnit y)104 void setY(LayoutUnit y) { m_frameRect.setY(y); }
setWidth(LayoutUnit width)105 void setWidth(LayoutUnit width) { m_frameRect.setWidth(width); }
setHeight(LayoutUnit height)106 void setHeight(LayoutUnit height) { m_frameRect.setHeight(height); }
107
logicalLeft()108 LayoutUnit logicalLeft() const { return style()->isHorizontalWritingMode() ? x() : y(); }
logicalRight()109 LayoutUnit logicalRight() const { return logicalLeft() + logicalWidth(); }
logicalTop()110 LayoutUnit logicalTop() const { return style()->isHorizontalWritingMode() ? y() : x(); }
logicalBottom()111 LayoutUnit logicalBottom() const { return logicalTop() + logicalHeight(); }
logicalWidth()112 LayoutUnit logicalWidth() const { return style()->isHorizontalWritingMode() ? width() : height(); }
logicalHeight()113 LayoutUnit logicalHeight() const { return style()->isHorizontalWritingMode() ? height() : width(); }
114
115 LayoutUnit constrainLogicalWidthByMinMax(LayoutUnit, LayoutUnit, RenderBlock*) const;
116 LayoutUnit constrainLogicalHeightByMinMax(LayoutUnit logicalHeight, LayoutUnit intrinsicContentHeight) const;
117 LayoutUnit constrainContentBoxLogicalHeightByMinMax(LayoutUnit logicalHeight, LayoutUnit intrinsicContentHeight) const;
118
pixelSnappedLogicalHeight()119 int pixelSnappedLogicalHeight() const { return style()->isHorizontalWritingMode() ? pixelSnappedHeight() : pixelSnappedWidth(); }
pixelSnappedLogicalWidth()120 int pixelSnappedLogicalWidth() const { return style()->isHorizontalWritingMode() ? pixelSnappedWidth() : pixelSnappedHeight(); }
121
setLogicalLeft(LayoutUnit left)122 void setLogicalLeft(LayoutUnit left)
123 {
124 if (style()->isHorizontalWritingMode())
125 setX(left);
126 else
127 setY(left);
128 }
setLogicalTop(LayoutUnit top)129 void setLogicalTop(LayoutUnit top)
130 {
131 if (style()->isHorizontalWritingMode())
132 setY(top);
133 else
134 setX(top);
135 }
setLogicalLocation(const LayoutPoint & location)136 void setLogicalLocation(const LayoutPoint& location)
137 {
138 if (style()->isHorizontalWritingMode())
139 setLocation(location);
140 else
141 setLocation(location.transposedPoint());
142 }
setLogicalWidth(LayoutUnit size)143 void setLogicalWidth(LayoutUnit size)
144 {
145 if (style()->isHorizontalWritingMode())
146 setWidth(size);
147 else
148 setHeight(size);
149 }
setLogicalHeight(LayoutUnit size)150 void setLogicalHeight(LayoutUnit size)
151 {
152 if (style()->isHorizontalWritingMode())
153 setHeight(size);
154 else
155 setWidth(size);
156 }
setLogicalSize(const LayoutSize & size)157 void setLogicalSize(const LayoutSize& size)
158 {
159 if (style()->isHorizontalWritingMode())
160 setSize(size);
161 else
162 setSize(size.transposedSize());
163 }
164
location()165 LayoutPoint location() const { return m_frameRect.location(); }
locationOffset()166 LayoutSize locationOffset() const { return LayoutSize(x(), y()); }
size()167 LayoutSize size() const { return m_frameRect.size(); }
pixelSnappedSize()168 IntSize pixelSnappedSize() const { return m_frameRect.pixelSnappedSize(); }
169
setLocation(const LayoutPoint & location)170 void setLocation(const LayoutPoint& location) { m_frameRect.setLocation(location); }
171
setSize(const LayoutSize & size)172 void setSize(const LayoutSize& size) { m_frameRect.setSize(size); }
move(LayoutUnit dx,LayoutUnit dy)173 void move(LayoutUnit dx, LayoutUnit dy) { m_frameRect.move(dx, dy); }
174
frameRect()175 LayoutRect frameRect() const { return m_frameRect; }
pixelSnappedFrameRect()176 IntRect pixelSnappedFrameRect() const { return pixelSnappedIntRect(m_frameRect); }
setFrameRect(const LayoutRect & rect)177 void setFrameRect(const LayoutRect& rect) { m_frameRect = rect; }
178
borderBoxRect()179 LayoutRect borderBoxRect() const { return LayoutRect(LayoutPoint(), size()); }
paddingBoxRect()180 LayoutRect paddingBoxRect() const { return LayoutRect(borderLeft(), borderTop(), contentWidth() + paddingLeft() + paddingRight(), contentHeight() + paddingTop() + paddingBottom()); }
pixelSnappedBorderBoxRect()181 IntRect pixelSnappedBorderBoxRect() const { return IntRect(IntPoint(), m_frameRect.pixelSnappedSize()); }
borderBoundingBox()182 virtual IntRect borderBoundingBox() const OVERRIDE FINAL { return pixelSnappedBorderBoxRect(); }
183
184 // The content area of the box (excludes padding - and intrinsic padding for table cells, etc... - and border).
contentBoxRect()185 LayoutRect contentBoxRect() const { return LayoutRect(borderLeft() + paddingLeft(), borderTop() + paddingTop(), contentWidth(), contentHeight()); }
186 // The content box in absolute coords. Ignores transforms.
187 IntRect absoluteContentBox() const;
188 // The content box converted to absolute coords (taking transforms into account).
189 FloatQuad absoluteContentQuad() const;
190
191 // This returns the content area of the box (excluding padding and border). The only difference with contentBoxRect is that computedCSSContentBoxRect
192 // does include the intrinsic padding in the content box as this is what some callers expect (like getComputedStyle).
computedCSSContentBoxRect()193 LayoutRect computedCSSContentBoxRect() const { return LayoutRect(borderLeft() + computedCSSPaddingLeft(), borderTop() + computedCSSPaddingTop(), clientWidth() - computedCSSPaddingLeft() - computedCSSPaddingRight(), clientHeight() - computedCSSPaddingTop() - computedCSSPaddingBottom()); }
194
195 virtual void addFocusRingRects(Vector<IntRect>&, const LayoutPoint& additionalOffset, const RenderLayerModelObject* paintContainer = 0) OVERRIDE;
196
197 // Use this with caution! No type checking is done!
198 RenderBox* previousSiblingBox() const;
199 RenderBox* nextSiblingBox() const;
200 RenderBox* parentBox() const;
201
202 bool canResize() const;
203
204 // Visual and layout overflow are in the coordinate space of the box. This means that they aren't purely physical directions.
205 // For horizontal-tb and vertical-lr they will match physical directions, but for horizontal-bt and vertical-rl, the top/bottom and left/right
206 // respectively are flipped when compared to their physical counterparts. For example minX is on the left in vertical-lr,
207 // but it is on the right in vertical-rl.
208 LayoutRect noOverflowRect() const;
layoutOverflowRect()209 LayoutRect layoutOverflowRect() const { return m_overflow ? m_overflow->layoutOverflowRect() : noOverflowRect(); }
pixelSnappedLayoutOverflowRect()210 IntRect pixelSnappedLayoutOverflowRect() const { return pixelSnappedIntRect(layoutOverflowRect()); }
maxLayoutOverflow()211 LayoutSize maxLayoutOverflow() const { return LayoutSize(layoutOverflowRect().maxX(), layoutOverflowRect().maxY()); }
logicalLeftLayoutOverflow()212 LayoutUnit logicalLeftLayoutOverflow() const { return style()->isHorizontalWritingMode() ? layoutOverflowRect().x() : layoutOverflowRect().y(); }
logicalRightLayoutOverflow()213 LayoutUnit logicalRightLayoutOverflow() const { return style()->isHorizontalWritingMode() ? layoutOverflowRect().maxX() : layoutOverflowRect().maxY(); }
214
visualOverflowRect()215 virtual LayoutRect visualOverflowRect() const { return m_overflow ? m_overflow->visualOverflowRect() : borderBoxRect(); }
logicalLeftVisualOverflow()216 LayoutUnit logicalLeftVisualOverflow() const { return style()->isHorizontalWritingMode() ? visualOverflowRect().x() : visualOverflowRect().y(); }
logicalRightVisualOverflow()217 LayoutUnit logicalRightVisualOverflow() const { return style()->isHorizontalWritingMode() ? visualOverflowRect().maxX() : visualOverflowRect().maxY(); }
218
219 LayoutRect overflowRectForPaintRejection() const;
220
contentsVisualOverflowRect()221 LayoutRect contentsVisualOverflowRect() const { return m_overflow ? m_overflow->contentsVisualOverflowRect() : LayoutRect(); }
222
223 void addLayoutOverflow(const LayoutRect&);
224 void addVisualOverflow(const LayoutRect&);
225
226 // Clipped by the contents clip, if one exists.
227 void addContentsVisualOverflow(const LayoutRect&);
228
229 void addVisualEffectOverflow();
addOverflowFromChild(RenderBox * child)230 void addOverflowFromChild(RenderBox* child) { addOverflowFromChild(child, child->locationOffset()); }
231 void addOverflowFromChild(RenderBox* child, const LayoutSize& delta);
232 void clearLayoutOverflow();
clearAllOverflows()233 void clearAllOverflows() { m_overflow.clear(); }
234
235 void updateLayerTransformAfterLayout();
236
contentWidth()237 LayoutUnit contentWidth() const { return clientWidth() - paddingLeft() - paddingRight(); }
contentHeight()238 LayoutUnit contentHeight() const { return clientHeight() - paddingTop() - paddingBottom(); }
contentLogicalWidth()239 LayoutUnit contentLogicalWidth() const { return style()->isHorizontalWritingMode() ? contentWidth() : contentHeight(); }
contentLogicalHeight()240 LayoutUnit contentLogicalHeight() const { return style()->isHorizontalWritingMode() ? contentHeight() : contentWidth(); }
241
242 // IE extensions. Used to calculate offsetWidth/Height. Overridden by inlines (RenderFlow)
243 // to return the remaining width on a given line (and the height of a single line).
offsetWidth()244 virtual LayoutUnit offsetWidth() const OVERRIDE { return width(); }
offsetHeight()245 virtual LayoutUnit offsetHeight() const OVERRIDE { return height(); }
246
247 virtual int pixelSnappedOffsetWidth() const OVERRIDE FINAL;
248 virtual int pixelSnappedOffsetHeight() const OVERRIDE FINAL;
249
250 // More IE extensions. clientWidth and clientHeight represent the interior of an object
251 // excluding border and scrollbar. clientLeft/Top are just the borderLeftWidth and borderTopWidth.
clientLeft()252 LayoutUnit clientLeft() const { return borderLeft() + (style()->shouldPlaceBlockDirectionScrollbarOnLogicalLeft() ? verticalScrollbarWidth() : 0); }
clientTop()253 LayoutUnit clientTop() const { return borderTop(); }
254 LayoutUnit clientWidth() const;
255 LayoutUnit clientHeight() const;
clientLogicalWidth()256 LayoutUnit clientLogicalWidth() const { return style()->isHorizontalWritingMode() ? clientWidth() : clientHeight(); }
clientLogicalHeight()257 LayoutUnit clientLogicalHeight() const { return style()->isHorizontalWritingMode() ? clientHeight() : clientWidth(); }
clientLogicalBottom()258 LayoutUnit clientLogicalBottom() const { return borderBefore() + clientLogicalHeight(); }
clientBoxRect()259 LayoutRect clientBoxRect() const { return LayoutRect(clientLeft(), clientTop(), clientWidth(), clientHeight()); }
260
261 int pixelSnappedClientWidth() const;
262 int pixelSnappedClientHeight() const;
263
264 // scrollWidth/scrollHeight will be the same as clientWidth/clientHeight unless the
265 // object has overflow:hidden/scroll/auto specified and also has overflow.
266 // scrollLeft/Top return the current scroll position. These methods are virtual so that objects like
267 // textareas can scroll shadow content (but pretend that they are the objects that are
268 // scrolling).
269 virtual LayoutUnit scrollLeft() const;
270 virtual LayoutUnit scrollTop() const;
271 virtual LayoutUnit scrollWidth() const;
272 virtual LayoutUnit scrollHeight() const;
273 int pixelSnappedScrollWidth() const;
274 int pixelSnappedScrollHeight() const;
275 virtual void setScrollLeft(LayoutUnit);
276 virtual void setScrollTop(LayoutUnit);
277
278 void scrollToOffset(const IntSize&);
279 void scrollByRecursively(const IntSize& delta, ScrollOffsetClamping = ScrollOffsetUnclamped);
280 void scrollRectToVisible(const LayoutRect&, const ScrollAlignment& alignX, const ScrollAlignment& alignY);
281
marginTop()282 virtual LayoutUnit marginTop() const OVERRIDE { return m_marginBox.top(); }
marginBottom()283 virtual LayoutUnit marginBottom() const OVERRIDE { return m_marginBox.bottom(); }
marginLeft()284 virtual LayoutUnit marginLeft() const OVERRIDE { return m_marginBox.left(); }
marginRight()285 virtual LayoutUnit marginRight() const OVERRIDE { return m_marginBox.right(); }
setMarginTop(LayoutUnit margin)286 void setMarginTop(LayoutUnit margin) { m_marginBox.setTop(margin); }
setMarginBottom(LayoutUnit margin)287 void setMarginBottom(LayoutUnit margin) { m_marginBox.setBottom(margin); }
setMarginLeft(LayoutUnit margin)288 void setMarginLeft(LayoutUnit margin) { m_marginBox.setLeft(margin); }
setMarginRight(LayoutUnit margin)289 void setMarginRight(LayoutUnit margin) { m_marginBox.setRight(margin); }
290
marginLogicalLeft()291 LayoutUnit marginLogicalLeft() const { return m_marginBox.logicalLeft(style()->writingMode()); }
marginLogicalRight()292 LayoutUnit marginLogicalRight() const { return m_marginBox.logicalRight(style()->writingMode()); }
293
294 virtual LayoutUnit marginBefore(const RenderStyle* overrideStyle = 0) const OVERRIDE FINAL { return m_marginBox.before((overrideStyle ? overrideStyle : style())->writingMode()); }
295 virtual LayoutUnit marginAfter(const RenderStyle* overrideStyle = 0) const OVERRIDE FINAL { return m_marginBox.after((overrideStyle ? overrideStyle : style())->writingMode()); }
296 virtual LayoutUnit marginStart(const RenderStyle* overrideStyle = 0) const OVERRIDE FINAL
297 {
298 const RenderStyle* styleToUse = overrideStyle ? overrideStyle : style();
299 return m_marginBox.start(styleToUse->writingMode(), styleToUse->direction());
300 }
301 virtual LayoutUnit marginEnd(const RenderStyle* overrideStyle = 0) const OVERRIDE FINAL
302 {
303 const RenderStyle* styleToUse = overrideStyle ? overrideStyle : style();
304 return m_marginBox.end(styleToUse->writingMode(), styleToUse->direction());
305 }
306 void setMarginBefore(LayoutUnit value, const RenderStyle* overrideStyle = 0) { m_marginBox.setBefore((overrideStyle ? overrideStyle : style())->writingMode(), value); }
307 void setMarginAfter(LayoutUnit value, const RenderStyle* overrideStyle = 0) { m_marginBox.setAfter((overrideStyle ? overrideStyle : style())->writingMode(), value); }
308 void setMarginStart(LayoutUnit value, const RenderStyle* overrideStyle = 0)
309 {
310 const RenderStyle* styleToUse = overrideStyle ? overrideStyle : style();
311 m_marginBox.setStart(styleToUse->writingMode(), styleToUse->direction(), value);
312 }
313 void setMarginEnd(LayoutUnit value, const RenderStyle* overrideStyle = 0)
314 {
315 const RenderStyle* styleToUse = overrideStyle ? overrideStyle : style();
316 m_marginBox.setEnd(styleToUse->writingMode(), styleToUse->direction(), value);
317 }
318
319 // The following five functions are used to implement collapsing margins.
320 // All objects know their maximal positive and negative margins. The
321 // formula for computing a collapsed margin is |maxPosMargin| - |maxNegmargin|.
322 // For a non-collapsing box, such as a leaf element, this formula will simply return
323 // the margin of the element. Blocks override the maxMarginBefore and maxMarginAfter
324 // methods.
325 enum MarginSign { PositiveMargin, NegativeMargin };
isSelfCollapsingBlock()326 virtual bool isSelfCollapsingBlock() const { return false; }
collapsedMarginBefore()327 virtual LayoutUnit collapsedMarginBefore() const { return marginBefore(); }
collapsedMarginAfter()328 virtual LayoutUnit collapsedMarginAfter() const { return marginAfter(); }
329
330 virtual void absoluteRects(Vector<IntRect>&, const LayoutPoint& accumulatedOffset) const OVERRIDE;
331 virtual void absoluteQuads(Vector<FloatQuad>&, bool* wasFixed) const OVERRIDE;
332
333 int reflectionOffset() const;
334 // Given a rect in the object's coordinate space, returns the corresponding rect in the reflection.
335 LayoutRect reflectedRect(const LayoutRect&) const;
336
337 virtual void layout() OVERRIDE;
338 virtual void paint(PaintInfo&, const LayoutPoint&) OVERRIDE;
339 virtual bool nodeAtPoint(const HitTestRequest&, HitTestResult&, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, HitTestAction) OVERRIDE;
340
341 virtual LayoutUnit minPreferredLogicalWidth() const OVERRIDE;
342 virtual LayoutUnit maxPreferredLogicalWidth() const OVERRIDE;
343
344 // FIXME: We should rename these back to overrideLogicalHeight/Width and have them store
345 // the border-box height/width like the regular height/width accessors on RenderBox.
346 // Right now, these are different than contentHeight/contentWidth because they still
347 // include the scrollbar height/width.
348 LayoutUnit overrideLogicalContentWidth() const;
349 LayoutUnit overrideLogicalContentHeight() const;
350 bool hasOverrideHeight() const;
351 bool hasOverrideWidth() const;
352 void setOverrideLogicalContentHeight(LayoutUnit);
353 void setOverrideLogicalContentWidth(LayoutUnit);
354 void clearOverrideSize();
355 void clearOverrideLogicalContentHeight();
356 void clearOverrideLogicalContentWidth();
357
358 LayoutUnit overrideContainingBlockContentLogicalWidth() const;
359 LayoutUnit overrideContainingBlockContentLogicalHeight() const;
360 bool hasOverrideContainingBlockLogicalWidth() const;
361 bool hasOverrideContainingBlockLogicalHeight() const;
362 void setOverrideContainingBlockContentLogicalWidth(LayoutUnit);
363 void setOverrideContainingBlockContentLogicalHeight(LayoutUnit);
364 void clearContainingBlockOverrideSize();
365 void clearOverrideContainingBlockContentLogicalHeight();
366
367 virtual LayoutSize offsetFromContainer(const RenderObject*, const LayoutPoint&, bool* offsetDependsOnPoint = 0) const OVERRIDE;
368
369 LayoutUnit adjustBorderBoxLogicalWidthForBoxSizing(LayoutUnit width) const;
370 LayoutUnit adjustBorderBoxLogicalHeightForBoxSizing(LayoutUnit height) const;
371 LayoutUnit adjustContentBoxLogicalWidthForBoxSizing(LayoutUnit width) const;
372 LayoutUnit adjustContentBoxLogicalHeightForBoxSizing(LayoutUnit height) const;
373
374 struct ComputedMarginValues {
ComputedMarginValuesComputedMarginValues375 ComputedMarginValues() { }
376
377 LayoutUnit m_before;
378 LayoutUnit m_after;
379 LayoutUnit m_start;
380 LayoutUnit m_end;
381 };
382 struct LogicalExtentComputedValues {
LogicalExtentComputedValuesLogicalExtentComputedValues383 LogicalExtentComputedValues() { }
384
385 LayoutUnit m_extent;
386 LayoutUnit m_position;
387 ComputedMarginValues m_margins;
388 };
389 // Resolve auto margins in the chosen direction of the containing block so that objects can be pushed to the start, middle or end
390 // of the containing block.
391 void computeMarginsForDirection(MarginDirection forDirection, const RenderBlock* containingBlock, LayoutUnit containerWidth, LayoutUnit childWidth, LayoutUnit& marginStart, LayoutUnit& marginEnd, Length marginStartLength, Length marginStartEnd) const;
392
393 // Used to resolve margins in the containing block's block-flow direction.
394 void computeAndSetBlockDirectionMargins(const RenderBlock* containingBlock);
395
396 virtual LayoutUnit offsetFromLogicalTopOfFirstPage() const;
397
398 void positionLineBox(InlineBox*);
399
400 virtual InlineBox* createInlineBox();
401 void dirtyLineBoxes(bool fullLayout);
402
403 // For inline replaced elements, this function returns the inline box that owns us. Enables
404 // the replaced RenderObject to quickly determine what line it is contained on and to easily
405 // iterate over structures on the line.
inlineBoxWrapper()406 InlineBox* inlineBoxWrapper() const { return m_rareData ? m_rareData->m_inlineBoxWrapper : 0; }
407 void setInlineBoxWrapper(InlineBox*);
408 void deleteLineBoxWrapper();
409
410 virtual LayoutRect clippedOverflowRectForPaintInvalidation(const RenderLayerModelObject* paintInvalidationContainer) const OVERRIDE;
411 virtual void mapRectToPaintInvalidationBacking(const RenderLayerModelObject* paintInvalidationContainer, LayoutRect&, bool fixed = false) const OVERRIDE;
412 void repaintDuringLayoutIfMoved(const LayoutRect&);
413 virtual void repaintOverhangingFloats(bool paintAllDescendants);
414
415 virtual LayoutUnit containingBlockLogicalWidthForContent() const OVERRIDE;
416 LayoutUnit containingBlockLogicalHeightForContent(AvailableLogicalHeightType) const;
417
418 LayoutUnit containingBlockAvailableLineWidth() const;
419 LayoutUnit perpendicularContainingBlockLogicalHeight() const;
420
421 virtual void updateLogicalWidth();
422 virtual void updateLogicalHeight();
423 virtual void computeLogicalHeight(LayoutUnit logicalHeight, LayoutUnit logicalTop, LogicalExtentComputedValues&) const;
424
425 void computeLogicalWidth(LogicalExtentComputedValues&) const;
426
stretchesToViewport()427 bool stretchesToViewport() const
428 {
429 return document().inQuirksMode() && style()->logicalHeight().isAuto() && !isFloatingOrOutOfFlowPositioned() && (isDocumentElement() || isBody()) && !isInline();
430 }
431
intrinsicSize()432 virtual LayoutSize intrinsicSize() const { return LayoutSize(); }
intrinsicLogicalWidth()433 LayoutUnit intrinsicLogicalWidth() const { return style()->isHorizontalWritingMode() ? intrinsicSize().width() : intrinsicSize().height(); }
intrinsicLogicalHeight()434 LayoutUnit intrinsicLogicalHeight() const { return style()->isHorizontalWritingMode() ? intrinsicSize().height() : intrinsicSize().width(); }
intrinsicContentLogicalHeight()435 virtual LayoutUnit intrinsicContentLogicalHeight() const { return m_intrinsicContentLogicalHeight; }
436
437 // Whether or not the element shrinks to its intrinsic width (rather than filling the width
438 // of a containing block). HTML4 buttons, <select>s, <input>s, legends, and floating/compact elements do this.
439 bool sizesLogicalWidthToFitContent(const Length& logicalWidth) const;
440
441 LayoutUnit shrinkLogicalWidthToAvoidFloats(LayoutUnit childMarginStart, LayoutUnit childMarginEnd, const RenderBlockFlow* cb) const;
442
443 LayoutUnit computeLogicalWidthUsing(SizeType, const Length& logicalWidth, LayoutUnit availableLogicalWidth, const RenderBlock* containingBlock) const;
444 LayoutUnit computeLogicalHeightUsing(const Length& height, LayoutUnit intrinsicContentHeight) const;
445 LayoutUnit computeContentLogicalHeight(const Length& height, LayoutUnit intrinsicContentHeight) const;
446 LayoutUnit computeContentAndScrollbarLogicalHeightUsing(const Length& height, LayoutUnit intrinsicContentHeight) const;
447 LayoutUnit computeReplacedLogicalWidthUsing(const Length& width) const;
448 LayoutUnit computeReplacedLogicalWidthRespectingMinMaxWidth(LayoutUnit logicalWidth, ShouldComputePreferred = ComputeActual) const;
449 LayoutUnit computeReplacedLogicalHeightUsing(const Length& height) const;
450 LayoutUnit computeReplacedLogicalHeightRespectingMinMaxHeight(LayoutUnit logicalHeight) const;
451
452 virtual LayoutUnit computeReplacedLogicalWidth(ShouldComputePreferred = ComputeActual) const;
453 virtual LayoutUnit computeReplacedLogicalHeight() const;
454
455 static bool percentageLogicalHeightIsResolvableFromBlock(const RenderBlock* containingBlock, bool outOfFlowPositioned);
456 LayoutUnit computePercentageLogicalHeight(const Length& height) const;
457
458 // Block flows subclass availableWidth/Height to handle multi column layout (shrinking the width/height available to children when laying out.)
availableLogicalWidth()459 virtual LayoutUnit availableLogicalWidth() const { return contentLogicalWidth(); }
460 virtual LayoutUnit availableLogicalHeight(AvailableLogicalHeightType) const;
461 LayoutUnit availableLogicalHeightUsing(const Length&, AvailableLogicalHeightType) const;
462
463 // There are a few cases where we need to refer specifically to the available physical width and available physical height.
464 // Relative positioning is one of those cases, since left/top offsets are physical.
availableWidth()465 LayoutUnit availableWidth() const { return style()->isHorizontalWritingMode() ? availableLogicalWidth() : availableLogicalHeight(IncludeMarginBorderPadding); }
availableHeight()466 LayoutUnit availableHeight() const { return style()->isHorizontalWritingMode() ? availableLogicalHeight(IncludeMarginBorderPadding) : availableLogicalWidth(); }
467
468 virtual int verticalScrollbarWidth() const;
469 int horizontalScrollbarHeight() const;
470 int instrinsicScrollbarLogicalWidth() const;
scrollbarLogicalHeight()471 int scrollbarLogicalHeight() const { return style()->isHorizontalWritingMode() ? horizontalScrollbarHeight() : verticalScrollbarWidth(); }
472 virtual bool scroll(ScrollDirection, ScrollGranularity, float delta = 1);
473 bool canBeScrolledAndHasScrollableArea() const;
474 virtual bool canBeProgramaticallyScrolled() const;
475 virtual void autoscroll(const IntPoint&);
476 bool autoscrollInProgress() const;
477 bool canAutoscroll() const;
478 IntSize calculateAutoscrollDirection(const IntPoint& windowPoint) const;
479 static RenderBox* findAutoscrollable(RenderObject*);
stopAutoscroll()480 virtual void stopAutoscroll() { }
481 virtual void panScroll(const IntPoint&);
482
hasAutoVerticalScrollbar()483 bool hasAutoVerticalScrollbar() const { return hasOverflowClip() && (style()->overflowY() == OAUTO || style()->overflowY() == OOVERLAY); }
hasAutoHorizontalScrollbar()484 bool hasAutoHorizontalScrollbar() const { return hasOverflowClip() && (style()->overflowX() == OAUTO || style()->overflowX() == OOVERLAY); }
scrollsOverflow()485 bool scrollsOverflow() const { return scrollsOverflowX() || scrollsOverflowY(); }
486
hasScrollableOverflowX()487 bool hasScrollableOverflowX() const { return scrollsOverflowX() && pixelSnappedScrollWidth() != pixelSnappedClientWidth(); }
hasScrollableOverflowY()488 bool hasScrollableOverflowY() const { return scrollsOverflowY() && pixelSnappedScrollHeight() != pixelSnappedClientHeight(); }
scrollsOverflowX()489 virtual bool scrollsOverflowX() const { return hasOverflowClip() && (style()->overflowX() == OSCROLL || hasAutoHorizontalScrollbar()); }
scrollsOverflowY()490 virtual bool scrollsOverflowY() const { return hasOverflowClip() && (style()->overflowY() == OSCROLL || hasAutoVerticalScrollbar()); }
491 bool usesCompositedScrolling() const;
492
493 // Elements such as the <input> field override this to specify that they are scrollable
494 // outside the context of the CSS overflow style
isIntristicallyScrollable(ScrollbarOrientation orientation)495 virtual bool isIntristicallyScrollable(ScrollbarOrientation orientation) const { return false; }
496
497 bool hasUnsplittableScrollingOverflow() const;
498 bool isUnsplittableForPagination() const;
499
500 virtual LayoutRect localCaretRect(InlineBox*, int caretOffset, LayoutUnit* extraWidthToEndOfLine = 0) OVERRIDE;
501
502 virtual LayoutRect overflowClipRect(const LayoutPoint& location, OverlayScrollbarSizeRelevancy = IgnoreOverlayScrollbarSize);
503 LayoutRect clipRect(const LayoutPoint& location);
hasControlClip()504 virtual bool hasControlClip() const { return false; }
controlClipRect(const LayoutPoint &)505 virtual LayoutRect controlClipRect(const LayoutPoint&) const { return LayoutRect(); }
506 bool pushContentsClip(PaintInfo&, const LayoutPoint& accumulatedOffset, ContentsClipBehavior);
507 void popContentsClip(PaintInfo&, PaintPhase originalPhase, const LayoutPoint& accumulatedOffset);
508
paintObject(PaintInfo &,const LayoutPoint &)509 virtual void paintObject(PaintInfo&, const LayoutPoint&) { ASSERT_NOT_REACHED(); }
510 virtual void paintBoxDecorations(PaintInfo&, const LayoutPoint&);
511 virtual void paintMask(PaintInfo&, const LayoutPoint&);
512 virtual void paintClippingMask(PaintInfo&, const LayoutPoint&);
513 virtual void imageChanged(WrappedImagePtr, const IntRect* = 0) OVERRIDE;
514
515 // Called when a positioned object moves but doesn't necessarily change size. A simplified layout is attempted
516 // that just updates the object's position. If the size does change, the object remains dirty.
tryLayoutDoingPositionedMovementOnly()517 bool tryLayoutDoingPositionedMovementOnly()
518 {
519 LayoutUnit oldWidth = width();
520 updateLogicalWidth();
521 // If we shrink to fit our width may have changed, so we still need full layout.
522 if (oldWidth != width())
523 return false;
524 updateLogicalHeight();
525 return true;
526 }
527
528 virtual PositionWithAffinity positionForPoint(const LayoutPoint&) OVERRIDE;
529
530 void removeFloatingOrPositionedChildFromBlockLists();
531
532 RenderLayer* enclosingFloatPaintingLayer() const;
533
firstLineBoxBaseline()534 virtual int firstLineBoxBaseline() const { return -1; }
inlineBlockBaseline(LineDirectionMode)535 virtual int inlineBlockBaseline(LineDirectionMode) const { return -1; } // Returns -1 if we should skip this box when computing the baseline of an inline-block.
536
537 bool shrinkToAvoidFloats() const;
538 virtual bool avoidsFloats() const;
539
540 virtual void markForPaginationRelayoutIfNeeded(SubtreeLayoutScope&);
541
isWritingModeRoot()542 bool isWritingModeRoot() const { return !parent() || parent()->style()->writingMode() != style()->writingMode(); }
543
isDeprecatedFlexItem()544 bool isDeprecatedFlexItem() const { return !isInline() && !isFloatingOrOutOfFlowPositioned() && parent() && parent()->isDeprecatedFlexibleBox(); }
isFlexItemIncludingDeprecated()545 bool isFlexItemIncludingDeprecated() const { return !isInline() && !isFloatingOrOutOfFlowPositioned() && parent() && parent()->isFlexibleBoxIncludingDeprecated(); }
546
547 virtual LayoutUnit lineHeight(bool firstLine, LineDirectionMode, LinePositionMode = PositionOnContainingLine) const OVERRIDE;
548 virtual int baselinePosition(FontBaseline, bool firstLine, LineDirectionMode, LinePositionMode = PositionOnContainingLine) const OVERRIDE;
549
550 virtual LayoutUnit offsetLeft() const OVERRIDE;
551 virtual LayoutUnit offsetTop() const OVERRIDE;
552
553 LayoutPoint flipForWritingModeForChild(const RenderBox* child, const LayoutPoint&) const;
554 LayoutUnit flipForWritingMode(LayoutUnit position) const; // The offset is in the block direction (y for horizontal writing modes, x for vertical writing modes).
555 LayoutPoint flipForWritingMode(const LayoutPoint&) const;
556 LayoutPoint flipForWritingModeIncludingColumns(const LayoutPoint&) const;
557 LayoutSize flipForWritingMode(const LayoutSize&) const;
558 void flipForWritingMode(LayoutRect&) const;
559 FloatPoint flipForWritingMode(const FloatPoint&) const;
560 void flipForWritingMode(FloatRect&) const;
561 // These represent your location relative to your container as a physical offset.
562 // In layout related methods you almost always want the logical location (e.g. x() and y()).
563 LayoutPoint topLeftLocation() const;
564 LayoutSize topLeftLocationOffset() const;
565
566 LayoutRect logicalVisualOverflowRectForPropagation(RenderStyle*) const;
567 LayoutRect visualOverflowRectForPropagation(RenderStyle*) const;
568 LayoutRect logicalLayoutOverflowRectForPropagation(RenderStyle*) const;
569 LayoutRect layoutOverflowRectForPropagation(RenderStyle*) const;
570
hasRenderOverflow()571 bool hasRenderOverflow() const { return m_overflow; }
hasVisualOverflow()572 bool hasVisualOverflow() const { return m_overflow && !borderBoxRect().contains(m_overflow->visualOverflowRect()); }
573
574 virtual bool needsPreferredWidthsRecalculation() const;
computeIntrinsicRatioInformation(FloatSize &,double &)575 virtual void computeIntrinsicRatioInformation(FloatSize& /* intrinsicSize */, double& /* intrinsicRatio */) const { }
576
577 IntSize scrolledContentOffset() const;
578 LayoutSize cachedSizeForOverflowClip() const;
579 void applyCachedClipAndScrollOffsetForRepaint(LayoutRect& paintRect) const;
580
581 virtual bool hasRelativeLogicalHeight() const;
582
hasHorizontalLayoutOverflow()583 bool hasHorizontalLayoutOverflow() const
584 {
585 if (!m_overflow)
586 return false;
587
588 LayoutRect layoutOverflowRect = m_overflow->layoutOverflowRect();
589 LayoutRect noOverflowRect = this->noOverflowRect();
590 return layoutOverflowRect.x() < noOverflowRect.x() || layoutOverflowRect.maxX() > noOverflowRect.maxX();
591 }
592
hasVerticalLayoutOverflow()593 bool hasVerticalLayoutOverflow() const
594 {
595 if (!m_overflow)
596 return false;
597
598 LayoutRect layoutOverflowRect = m_overflow->layoutOverflowRect();
599 LayoutRect noOverflowRect = this->noOverflowRect();
600 return layoutOverflowRect.y() < noOverflowRect.y() || layoutOverflowRect.maxY() > noOverflowRect.maxY();
601 }
602
createAnonymousBoxWithSameTypeAs(const RenderObject *)603 virtual RenderBox* createAnonymousBoxWithSameTypeAs(const RenderObject*) const
604 {
605 ASSERT_NOT_REACHED();
606 return 0;
607 }
608
hasSameDirectionAs(const RenderBox * object)609 bool hasSameDirectionAs(const RenderBox* object) const { return style()->direction() == object->style()->direction(); }
610
shapeOutsideInfo()611 ShapeOutsideInfo* shapeOutsideInfo() const
612 {
613 return ShapeOutsideInfo::isEnabledFor(*this) ? ShapeOutsideInfo::info(*this) : 0;
614 }
615
markShapeOutsideDependentsForLayout()616 void markShapeOutsideDependentsForLayout()
617 {
618 if (isFloating())
619 removeFloatingOrPositionedChildFromBlockLists();
620 }
621
622 virtual void invalidateTreeAfterLayout(const RenderLayerModelObject&) OVERRIDE;
623
624 protected:
625 virtual void willBeDestroyed() OVERRIDE;
626
627 virtual void styleWillChange(StyleDifference, const RenderStyle& newStyle) OVERRIDE;
628 virtual void styleDidChange(StyleDifference, const RenderStyle* oldStyle) OVERRIDE;
629 virtual void updateFromStyle() OVERRIDE;
630
631 // Returns false if it could not cheaply compute the extent (e.g. fixed background), in which case the returned rect may be incorrect.
632 bool getBackgroundPaintedExtent(LayoutRect&) const;
633 virtual bool foregroundIsKnownToBeOpaqueInRect(const LayoutRect& localRect, unsigned maxDepthToTest) const;
634 virtual bool computeBackgroundIsKnownToBeObscured() OVERRIDE;
635
636 void paintBackgroundWithBorderAndBoxShadow(PaintInfo&, const LayoutRect&, BackgroundBleedAvoidance);
637 void paintBackground(const PaintInfo&, const LayoutRect&, BackgroundBleedAvoidance = BackgroundBleedNone);
638
639 void paintFillLayer(const PaintInfo&, const Color&, const FillLayer*, const LayoutRect&, BackgroundBleedAvoidance, CompositeOperator, RenderObject* backgroundObject);
640 void paintFillLayers(const PaintInfo&, const Color&, const FillLayer*, const LayoutRect&, BackgroundBleedAvoidance = BackgroundBleedNone, CompositeOperator = CompositeSourceOver, RenderObject* backgroundObject = 0);
641
642 void paintMaskImages(const PaintInfo&, const LayoutRect&);
643 void paintBoxDecorationsWithRect(PaintInfo&, const LayoutPoint&, const LayoutRect&);
644
645 BackgroundBleedAvoidance determineBackgroundBleedAvoidance(GraphicsContext*) const;
646 bool backgroundHasOpaqueTopLayer() const;
647
648 void computePositionedLogicalWidth(LogicalExtentComputedValues&) const;
649
650 LayoutUnit computeIntrinsicLogicalWidthUsing(const Length& logicalWidthLength, LayoutUnit availableLogicalWidth, LayoutUnit borderAndPadding) const;
651 LayoutUnit computeIntrinsicLogicalContentHeightUsing(const Length& logicalHeightLength, LayoutUnit intrinsicContentHeight, LayoutUnit borderAndPadding) const;
652
shouldComputeSizeAsReplaced()653 virtual bool shouldComputeSizeAsReplaced() const { return isReplaced() && !isInlineBlockOrInlineTable(); }
654
655 virtual void mapLocalToContainer(const RenderLayerModelObject* repaintContainer, TransformState&, MapCoordinatesFlags = ApplyContainerFlip, bool* wasFixed = 0) const OVERRIDE;
656 virtual void mapAbsoluteToLocalPoint(MapCoordinatesFlags, TransformState&) const OVERRIDE;
657
658 void paintRootBoxFillLayers(const PaintInfo&);
659
660 RenderObject* splitAnonymousBoxesAroundChild(RenderObject* beforeChild);
661
662 virtual void addLayerHitTestRects(LayerHitTestRects&, const RenderLayer* currentCompositedLayer, const LayoutPoint& layerOffset, const LayoutRect& containerRect) const OVERRIDE;
663 virtual void computeSelfHitTestRects(Vector<LayoutRect>&, const LayoutPoint& layerOffset) const OVERRIDE;
664
updateIntrinsicContentLogicalHeight(LayoutUnit intrinsicContentLogicalHeight)665 void updateIntrinsicContentLogicalHeight(LayoutUnit intrinsicContentLogicalHeight) const { m_intrinsicContentLogicalHeight = intrinsicContentLogicalHeight; }
666
667 private:
668 void updateShapeOutsideInfoAfterStyleChange(const RenderStyle&, const RenderStyle* oldStyle);
669 void updateGridPositionAfterStyleChange(const RenderStyle*);
670
671 bool autoWidthShouldFitContent() const;
672 void shrinkToFitWidth(const LayoutUnit availableSpace, const LayoutUnit logicalLeftValue, const LayoutUnit bordersPlusPadding, LogicalExtentComputedValues&) const;
673
674 // Returns true if we did a full repaint
675 bool repaintLayerRectsForImage(WrappedImagePtr image, const FillLayer* layers, bool drawingBackground);
676
677 bool skipContainingBlockForPercentHeightCalculation(const RenderBox* containingBlock) const;
678
679 LayoutUnit containingBlockLogicalWidthForPositioned(const RenderBoxModelObject* containingBlock, bool checkForPerpendicularWritingMode = true) const;
680 LayoutUnit containingBlockLogicalHeightForPositioned(const RenderBoxModelObject* containingBlock, bool checkForPerpendicularWritingMode = true) const;
681
682 void computePositionedLogicalHeight(LogicalExtentComputedValues&) const;
683 void computePositionedLogicalWidthUsing(Length logicalWidth, const RenderBoxModelObject* containerBlock, TextDirection containerDirection,
684 LayoutUnit containerLogicalWidth, LayoutUnit bordersPlusPadding,
685 const Length& logicalLeft, const Length& logicalRight, const Length& marginLogicalLeft,
686 const Length& marginLogicalRight, LogicalExtentComputedValues&) const;
687 void computePositionedLogicalHeightUsing(Length logicalHeightLength, const RenderBoxModelObject* containerBlock,
688 LayoutUnit containerLogicalHeight, LayoutUnit bordersPlusPadding, LayoutUnit logicalHeight,
689 const Length& logicalTop, const Length& logicalBottom, const Length& marginLogicalTop,
690 const Length& marginLogicalBottom, LogicalExtentComputedValues&) const;
691
692 void computePositionedLogicalHeightReplaced(LogicalExtentComputedValues&) const;
693 void computePositionedLogicalWidthReplaced(LogicalExtentComputedValues&) const;
694
695 LayoutUnit fillAvailableMeasure(LayoutUnit availableLogicalWidth) const;
696 LayoutUnit fillAvailableMeasure(LayoutUnit availableLogicalWidth, LayoutUnit& marginStart, LayoutUnit& marginEnd) const;
697
698 virtual void computeIntrinsicLogicalWidths(LayoutUnit& minLogicalWidth, LayoutUnit& maxLogicalWidth) const;
699
700 // This function calculates the minimum and maximum preferred widths for an object.
701 // These values are used in shrink-to-fit layout systems.
702 // These include tables, positioned objects, floats and flexible boxes.
computePreferredLogicalWidths()703 virtual void computePreferredLogicalWidths() { clearPreferredLogicalWidthsDirty(); }
704
frameRectForStickyPositioning()705 virtual LayoutRect frameRectForStickyPositioning() const OVERRIDE FINAL { return frameRect(); }
706
ensureRareData()707 RenderBoxRareData& ensureRareData()
708 {
709 if (!m_rareData)
710 m_rareData = adoptPtr(new RenderBoxRareData());
711 return *m_rareData.get();
712 }
713
714 private:
715 // The width/height of the contents + borders + padding. The x/y location is relative to our container (which is not always our parent).
716 LayoutRect m_frameRect;
717
718 // Our intrinsic height, used for min-height: min-content etc. Maintained by
719 // updateLogicalHeight. This is logicalHeight() before it is clamped to
720 // min/max.
721 mutable LayoutUnit m_intrinsicContentLogicalHeight;
722
723 protected:
724 LayoutBoxExtent m_marginBox;
725
726 // The preferred logical width of the element if it were to break its lines at every possible opportunity.
727 LayoutUnit m_minPreferredLogicalWidth;
728
729 // The preferred logical width of the element if it never breaks any lines at all.
730 LayoutUnit m_maxPreferredLogicalWidth;
731
732 // Our overflow information.
733 OwnPtr<RenderOverflow> m_overflow;
734
735 private:
736 OwnPtr<RenderBoxRareData> m_rareData;
737 };
738
739 DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderBox, isBox());
740
previousSiblingBox()741 inline RenderBox* RenderBox::previousSiblingBox() const
742 {
743 return toRenderBox(previousSibling());
744 }
745
nextSiblingBox()746 inline RenderBox* RenderBox::nextSiblingBox() const
747 {
748 return toRenderBox(nextSibling());
749 }
750
parentBox()751 inline RenderBox* RenderBox::parentBox() const
752 {
753 return toRenderBox(parent());
754 }
755
firstChildBox()756 inline RenderBox* RenderBox::firstChildBox() const
757 {
758 return toRenderBox(slowFirstChild());
759 }
760
lastChildBox()761 inline RenderBox* RenderBox::lastChildBox() const
762 {
763 return toRenderBox(slowLastChild());
764 }
765
setInlineBoxWrapper(InlineBox * boxWrapper)766 inline void RenderBox::setInlineBoxWrapper(InlineBox* boxWrapper)
767 {
768 if (boxWrapper) {
769 ASSERT(!inlineBoxWrapper());
770 // m_inlineBoxWrapper should already be 0. Deleting it is a safeguard against security issues.
771 // Otherwise, there will two line box wrappers keeping the reference to this renderer, and
772 // only one will be notified when the renderer is getting destroyed. The second line box wrapper
773 // will keep a stale reference.
774 if (UNLIKELY(inlineBoxWrapper() != 0))
775 deleteLineBoxWrapper();
776 }
777
778 ensureRareData().m_inlineBoxWrapper = boxWrapper;
779 }
780
781 } // namespace WebCore
782
783 #endif // RenderBox_h
784