1/*
2 * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
3 *           (C) 2000 Antti Koivisto (koivisto@kde.org)
4 *           (C) 2000 Dirk Mueller (mueller@kde.org)
5 *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
6 * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2012 Apple Inc. All rights reserved.
7 * Copyright (C) 2009 Google Inc. All rights reserved.
8 *
9 * This library is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Library General Public
11 * License as published by the Free Software Foundation; either
12 * version 2 of the License, or (at your option) any later version.
13 *
14 * This library is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17 * Library General Public License for more details.
18 *
19 * You should have received a copy of the GNU Library General Public License
20 * along with this library; see the file COPYING.LIB.  If not, write to
21 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
22 * Boston, MA 02110-1301, USA.
23 *
24 */
25
26#ifndef RenderObject_h
27#define RenderObject_h
28
29#include "CachedImageClient.h"
30#include "DocumentStyleSheetCollection.h"
31#include "Element.h"
32#include "FloatQuad.h"
33#include "LayoutRect.h"
34#include "PaintPhase.h"
35#include "RenderObjectChildList.h"
36#include "RenderStyle.h"
37#include "ScrollBehavior.h"
38#include "StyleInheritedData.h"
39#include "TextAffinity.h"
40#include <wtf/HashSet.h>
41
42namespace WebCore {
43
44class AffineTransform;
45class AnimationController;
46class Cursor;
47class Document;
48class HitTestLocation;
49class HitTestResult;
50class InlineBox;
51class Path;
52class Position;
53class PseudoStyleRequest;
54class RenderBoxModelObject;
55class RenderInline;
56class RenderBlock;
57class RenderFlowThread;
58class RenderGeometryMap;
59class RenderLayer;
60class RenderLayerModelObject;
61class RenderNamedFlowThread;
62class RenderTheme;
63class TransformState;
64class VisiblePosition;
65#if ENABLE(SVG)
66class RenderSVGResourceContainer;
67#endif
68
69struct PaintInfo;
70
71enum CursorDirective {
72    SetCursorBasedOnStyle,
73    SetCursor,
74    DoNotSetCursor
75};
76
77enum HitTestFilter {
78    HitTestAll,
79    HitTestSelf,
80    HitTestDescendants
81};
82
83enum HitTestAction {
84    HitTestBlockBackground,
85    HitTestChildBlockBackground,
86    HitTestChildBlockBackgrounds,
87    HitTestFloat,
88    HitTestForeground
89};
90
91// Sides used when drawing borders and outlines. The values should run clockwise from top.
92enum BoxSide {
93    BSTop,
94    BSRight,
95    BSBottom,
96    BSLeft
97};
98
99enum MarkingBehavior {
100    MarkOnlyThis,
101    MarkContainingBlockChain,
102};
103
104enum MapCoordinatesMode {
105    IsFixed = 1 << 0,
106    UseTransforms = 1 << 1,
107    ApplyContainerFlip = 1 << 2
108};
109typedef unsigned MapCoordinatesFlags;
110
111const int caretWidth = 1;
112
113#if ENABLE(DASHBOARD_SUPPORT) || ENABLE(DRAGGABLE_REGION)
114struct AnnotatedRegionValue {
115    bool operator==(const AnnotatedRegionValue& o) const
116    {
117#if ENABLE(DASHBOARD_SUPPORT)
118        return type == o.type && bounds == o.bounds && clip == o.clip && label == o.label;
119#else // ENABLE(DRAGGABLE_REGION)
120        return draggable == o.draggable && bounds == o.bounds;
121#endif
122    }
123    bool operator!=(const AnnotatedRegionValue& o) const
124    {
125        return !(*this == o);
126    }
127
128    LayoutRect bounds;
129#if ENABLE(DASHBOARD_SUPPORT)
130    String label;
131    LayoutRect clip;
132    int type;
133#else // ENABLE(DRAGGABLE_REGION)
134    bool draggable;
135#endif
136};
137#endif
138
139typedef WTF::HashSet<const RenderObject*> RenderObjectAncestorLineboxDirtySet;
140
141#ifndef NDEBUG
142const int showTreeCharacterOffset = 39;
143#endif
144
145// Base class for all rendering tree objects.
146class RenderObject : public CachedImageClient {
147    friend class RenderBlock;
148    friend class RenderLayer;
149    friend class RenderObjectChildList;
150public:
151    // Anonymous objects should pass the document as their node, and they will then automatically be
152    // marked as anonymous in the constructor.
153    explicit RenderObject(Node*);
154    virtual ~RenderObject();
155
156    RenderTheme* theme() const;
157
158    virtual const char* renderName() const = 0;
159
160    RenderObject* parent() const { return m_parent; }
161    bool isDescendantOf(const RenderObject*) const;
162
163    RenderObject* previousSibling() const { return m_previous; }
164    RenderObject* nextSibling() const { return m_next; }
165
166    // FIXME: These should be renamed slowFirstChild, slowLastChild, etc.
167    // to discourage their use. The virtualChildren() call inside these
168    // can be slow for hot code paths.
169    // Currently, some subclasses like RenderBlock, override these NON-virtual
170    // functions to make these fast when we already have a more specific pointer type.
171    RenderObject* firstChild() const
172    {
173        if (const RenderObjectChildList* children = virtualChildren())
174            return children->firstChild();
175        return 0;
176    }
177    RenderObject* lastChild() const
178    {
179        if (const RenderObjectChildList* children = virtualChildren())
180            return children->lastChild();
181        return 0;
182    }
183
184    virtual RenderObjectChildList* virtualChildren() { return 0; }
185    virtual const RenderObjectChildList* virtualChildren() const { return 0; }
186
187    RenderObject* nextInPreOrder() const;
188    RenderObject* nextInPreOrder(const RenderObject* stayWithin) const;
189    RenderObject* nextInPreOrderAfterChildren() const;
190    RenderObject* nextInPreOrderAfterChildren(const RenderObject* stayWithin) const;
191    RenderObject* previousInPreOrder() const;
192    RenderObject* previousInPreOrder(const RenderObject* stayWithin) const;
193    RenderObject* childAt(unsigned) const;
194
195    RenderObject* firstLeafChild() const;
196    RenderObject* lastLeafChild() const;
197
198    // The following six functions are used when the render tree hierarchy changes to make sure layers get
199    // properly added and removed.  Since containership can be implemented by any subclass, and since a hierarchy
200    // can contain a mixture of boxes and other object types, these functions need to be in the base class.
201    RenderLayer* enclosingLayer() const;
202    void addLayers(RenderLayer* parentLayer);
203    void removeLayers(RenderLayer* parentLayer);
204    void moveLayers(RenderLayer* oldParent, RenderLayer* newParent);
205    RenderLayer* findNextLayer(RenderLayer* parentLayer, RenderObject* startPoint, bool checkParent = true);
206
207    // Scrolling is a RenderBox concept, however some code just cares about recursively scrolling our enclosing ScrollableArea(s).
208    bool scrollRectToVisible(const LayoutRect&, const ScrollAlignment& alignX = ScrollAlignment::alignCenterIfNeeded, const ScrollAlignment& alignY = ScrollAlignment::alignCenterIfNeeded);
209
210    // Convenience function for getting to the nearest enclosing box of a RenderObject.
211    RenderBox* enclosingBox() const;
212    RenderBoxModelObject* enclosingBoxModelObject() const;
213
214    // Function to return our enclosing flow thread if we are contained inside one. This
215    // function follows the containing block chain.
216    RenderFlowThread* flowThreadContainingBlock() const
217    {
218        if (flowThreadState() == NotInsideFlowThread)
219            return 0;
220        return locateFlowThreadContainingBlock();
221    }
222
223    RenderNamedFlowThread* renderNamedFlowThreadWrapper() const;
224
225    virtual bool isEmpty() const { return firstChild() == 0; }
226
227#ifndef NDEBUG
228    void setHasAXObject(bool flag) { m_hasAXObject = flag; }
229    bool hasAXObject() const { return m_hasAXObject; }
230
231    // Helper class forbidding calls to setNeedsLayout() during its lifetime.
232    class SetLayoutNeededForbiddenScope {
233    public:
234        explicit SetLayoutNeededForbiddenScope(RenderObject*, bool isForbidden = true);
235        ~SetLayoutNeededForbiddenScope();
236    private:
237        RenderObject* m_renderObject;
238        bool m_preexistingForbidden;
239    };
240#endif
241
242    // Obtains the nearest enclosing block (including this block) that contributes a first-line style to our inline
243    // children.
244    virtual RenderBlock* firstLineBlock() const;
245
246    // Called when an object that was floating or positioned becomes a normal flow object
247    // again.  We have to make sure the render tree updates as needed to accommodate the new
248    // normal flow object.
249    void handleDynamicFloatPositionChange();
250    void removeAnonymousWrappersForInlinesIfNecessary();
251
252    // RenderObject tree manipulation
253    //////////////////////////////////////////
254    virtual bool canHaveChildren() const { return virtualChildren(); }
255    virtual bool canHaveGeneratedChildren() const;
256    virtual bool isChildAllowed(RenderObject*, RenderStyle*) const { return true; }
257    virtual void addChild(RenderObject* newChild, RenderObject* beforeChild = 0);
258    virtual void addChildIgnoringContinuation(RenderObject* newChild, RenderObject* beforeChild = 0) { return addChild(newChild, beforeChild); }
259    virtual void removeChild(RenderObject*);
260    virtual bool createsAnonymousWrapper() const { return false; }
261    //////////////////////////////////////////
262
263protected:
264    //////////////////////////////////////////
265    // Helper functions. Dangerous to use!
266    void setPreviousSibling(RenderObject* previous) { m_previous = previous; }
267    void setNextSibling(RenderObject* next) { m_next = next; }
268    void setParent(RenderObject* parent)
269    {
270        m_parent = parent;
271
272        // Only update if our flow thread state is different from our new parent and if we're not a RenderFlowThread.
273        // A RenderFlowThread is always considered to be inside itself, so it never has to change its state
274        // in response to parent changes.
275        FlowThreadState newState = parent ? parent->flowThreadState() : NotInsideFlowThread;
276        if (newState != flowThreadState() && !isRenderFlowThread())
277            setFlowThreadStateIncludingDescendants(newState);
278    }
279
280    //////////////////////////////////////////
281private:
282#ifndef NDEBUG
283    bool isSetNeedsLayoutForbidden() const { return m_setNeedsLayoutForbidden; }
284    void setNeedsLayoutIsForbidden(bool flag) { m_setNeedsLayoutForbidden = flag; }
285#endif
286
287    void addAbsoluteRectForLayer(LayoutRect& result);
288    void setLayerNeedsFullRepaint();
289    void setLayerNeedsFullRepaintForPositionedMovementLayout();
290
291public:
292#ifndef NDEBUG
293    void showTreeForThis() const;
294    void showRenderTreeForThis() const;
295    void showLineTreeForThis() const;
296
297    void showRenderObject() const;
298    // We don't make printedCharacters an optional parameter so that
299    // showRenderObject can be called from gdb easily.
300    void showRenderObject(int printedCharacters) const;
301    void showRenderTreeAndMark(const RenderObject* markedObject1 = 0, const char* markedLabel1 = 0, const RenderObject* markedObject2 = 0, const char* markedLabel2 = 0, int depth = 0) const;
302#endif
303
304    static RenderObject* createObject(Element*, RenderStyle*);
305
306    // Overloaded new operator.  Derived classes must override operator new
307    // in order to allocate out of the RenderArena.
308    void* operator new(size_t, RenderArena*);
309
310    // Overridden to prevent the normal delete from being called.
311    void operator delete(void*, size_t);
312
313private:
314    // The normal operator new is disallowed on all render objects.
315    void* operator new(size_t) throw();
316
317public:
318    RenderArena* renderArena() const { return document()->renderArena(); }
319
320    bool isPseudoElement() const { return node() && node()->isPseudoElement(); }
321
322    virtual bool isBR() const { return false; }
323    virtual bool isBlockFlow() const { return false; }
324    virtual bool isBoxModelObject() const { return false; }
325    virtual bool isCounter() const { return false; }
326#if ENABLE(DIALOG_ELEMENT)
327    virtual bool isDialog() const { return false; }
328#endif
329    virtual bool isQuote() const { return false; }
330
331#if ENABLE(DETAILS_ELEMENT)
332    virtual bool isDetailsMarker() const { return false; }
333#endif
334    virtual bool isEmbeddedObject() const { return false; }
335    virtual bool isFieldset() const { return false; }
336    virtual bool isFileUploadControl() const { return false; }
337    virtual bool isFrame() const { return false; }
338    virtual bool isFrameSet() const { return false; }
339    virtual bool isImage() const { return false; }
340    virtual bool isInlineBlockOrInlineTable() const { return false; }
341    virtual bool isLayerModelObject() const { return false; }
342    virtual bool isListBox() const { return false; }
343    virtual bool isListItem() const { return false; }
344    virtual bool isListMarker() const { return false; }
345    virtual bool isMedia() const { return false; }
346    virtual bool isMenuList() const { return false; }
347#if ENABLE(METER_ELEMENT)
348    virtual bool isMeter() const { return false; }
349#endif
350    virtual bool isSnapshottedPlugIn() const { return false; }
351#if ENABLE(PROGRESS_ELEMENT)
352    virtual bool isProgress() const { return false; }
353#endif
354    virtual bool isRenderBlock() const { return false; }
355    virtual bool isRenderButton() const { return false; }
356    virtual bool isRenderIFrame() const { return false; }
357    virtual bool isRenderImage() const { return false; }
358    virtual bool isRenderInline() const { return false; }
359    virtual bool isRenderPart() const { return false; }
360    virtual bool isRenderRegion() const { return false; }
361    virtual bool isRenderView() const { return false; }
362    virtual bool isReplica() const { return false; }
363
364    virtual bool isRuby() const { return false; }
365    virtual bool isRubyBase() const { return false; }
366    virtual bool isRubyRun() const { return false; }
367    virtual bool isRubyText() const { return false; }
368
369    virtual bool isSlider() const { return false; }
370    virtual bool isSliderThumb() const { return false; }
371    virtual bool isTable() const { return false; }
372    virtual bool isTableCell() const { return false; }
373    virtual bool isRenderTableCol() const { return false; }
374    virtual bool isTableCaption() const { return false; }
375    virtual bool isTableRow() const { return false; }
376    virtual bool isTableSection() const { return false; }
377    virtual bool isTextControl() const { return false; }
378    virtual bool isTextArea() const { return false; }
379    virtual bool isTextField() const { return false; }
380    virtual bool isVideo() const { return false; }
381    virtual bool isWidget() const { return false; }
382    virtual bool isCanvas() const { return false; }
383#if ENABLE(FULLSCREEN_API)
384    virtual bool isRenderFullScreen() const { return false; }
385    virtual bool isRenderFullScreenPlaceholder() const { return false; }
386#endif
387
388    virtual bool isRenderGrid() const { return false; }
389
390    virtual bool isRenderFlowThread() const { return false; }
391    virtual bool isRenderNamedFlowThread() const { return false; }
392    bool isInFlowRenderFlowThread() const { return isRenderFlowThread() && !isOutOfFlowPositioned(); }
393    bool isOutOfFlowRenderFlowThread() const { return isRenderFlowThread() && isOutOfFlowPositioned(); }
394
395    virtual bool isRenderMultiColumnBlock() const { return false; }
396    virtual bool isRenderMultiColumnSet() const { return false; }
397
398    virtual bool isRenderScrollbarPart() const { return false; }
399
400    bool isRoot() const { return document()->documentElement() == m_node; }
401    bool isBody() const;
402    bool isHR() const;
403    bool isLegend() const;
404
405    bool isHTMLMarquee() const;
406
407    bool isTablePart() const { return isTableCell() || isRenderTableCol() || isTableCaption() || isTableRow() || isTableSection(); }
408
409    inline bool isBeforeContent() const;
410    inline bool isAfterContent() const;
411    inline bool isBeforeOrAfterContent() const;
412    static inline bool isBeforeContent(const RenderObject* obj) { return obj && obj->isBeforeContent(); }
413    static inline bool isAfterContent(const RenderObject* obj) { return obj && obj->isAfterContent(); }
414    static inline bool isBeforeOrAfterContent(const RenderObject* obj) { return obj && obj->isBeforeOrAfterContent(); }
415
416    bool hasCounterNodeMap() const { return m_bitfields.hasCounterNodeMap(); }
417    void setHasCounterNodeMap(bool hasCounterNodeMap) { m_bitfields.setHasCounterNodeMap(hasCounterNodeMap); }
418    bool everHadLayout() const { return m_bitfields.everHadLayout(); }
419
420    bool childrenInline() const { return m_bitfields.childrenInline(); }
421    void setChildrenInline(bool b) { m_bitfields.setChildrenInline(b); }
422    bool hasColumns() const { return m_bitfields.hasColumns(); }
423    void setHasColumns(bool b = true) { m_bitfields.setHasColumns(b); }
424
425    bool ancestorLineBoxDirty() const { return s_ancestorLineboxDirtySet && s_ancestorLineboxDirtySet->contains(this); }
426    void setAncestorLineBoxDirty(bool b = true)
427    {
428        if (b) {
429            if (!s_ancestorLineboxDirtySet)
430                s_ancestorLineboxDirtySet = new RenderObjectAncestorLineboxDirtySet;
431            s_ancestorLineboxDirtySet->add(this);
432            setNeedsLayout(true);
433        } else if (s_ancestorLineboxDirtySet) {
434            s_ancestorLineboxDirtySet->remove(this);
435            if (s_ancestorLineboxDirtySet->isEmpty()) {
436                delete s_ancestorLineboxDirtySet;
437                s_ancestorLineboxDirtySet = 0;
438            }
439        }
440    }
441
442    enum FlowThreadState {
443        NotInsideFlowThread = 0,
444        InsideOutOfFlowThread = 1,
445        InsideInFlowThread = 2,
446    };
447
448    void setFlowThreadStateIncludingDescendants(FlowThreadState);
449
450    FlowThreadState flowThreadState() const { return m_bitfields.flowThreadState(); }
451    void setFlowThreadState(FlowThreadState state) { m_bitfields.setFlowThreadState(state); }
452
453    virtual bool requiresForcedStyleRecalcPropagation() const { return false; }
454
455#if ENABLE(MATHML)
456    virtual bool isRenderMathMLBlock() const { return false; }
457#endif // ENABLE(MATHML)
458
459#if ENABLE(SVG)
460    // FIXME: Until all SVG renders can be subclasses of RenderSVGModelObject we have
461    // to add SVG renderer methods to RenderObject with an ASSERT_NOT_REACHED() default implementation.
462    virtual bool isSVGRoot() const { return false; }
463    virtual bool isSVGContainer() const { return false; }
464    virtual bool isSVGTransformableContainer() const { return false; }
465    virtual bool isSVGViewportContainer() const { return false; }
466    virtual bool isSVGGradientStop() const { return false; }
467    virtual bool isSVGHiddenContainer() const { return false; }
468    virtual bool isSVGPath() const { return false; }
469    virtual bool isSVGShape() const { return false; }
470    virtual bool isSVGText() const { return false; }
471    virtual bool isSVGTextPath() const { return false; }
472    virtual bool isSVGInline() const { return false; }
473    virtual bool isSVGInlineText() const { return false; }
474    virtual bool isSVGImage() const { return false; }
475    virtual bool isSVGForeignObject() const { return false; }
476    virtual bool isSVGResourceContainer() const { return false; }
477    virtual bool isSVGResourceFilter() const { return false; }
478    virtual bool isSVGResourceFilterPrimitive() const { return false; }
479
480    bool hasAspectRatio() const { return isReplaced() && (isImage() || isVideo() || isCanvas()); }
481
482    virtual RenderSVGResourceContainer* toRenderSVGResourceContainer();
483
484    // FIXME: Those belong into a SVG specific base-class for all renderers (see above)
485    // Unfortunately we don't have such a class yet, because it's not possible for all renderers
486    // to inherit from RenderSVGObject -> RenderObject (some need RenderBlock inheritance for instance)
487    virtual void setNeedsTransformUpdate() { }
488    virtual void setNeedsBoundariesUpdate();
489    virtual bool needsBoundariesUpdate() { return false; }
490
491    // Per SVG 1.1 objectBoundingBox ignores clipping, masking, filter effects, opacity and stroke-width.
492    // This is used for all computation of objectBoundingBox relative units and by SVGLocatable::getBBox().
493    // NOTE: Markers are not specifically ignored here by SVG 1.1 spec, but we ignore them
494    // since stroke-width is ignored (and marker size can depend on stroke-width).
495    // objectBoundingBox is returned local coordinates.
496    // The name objectBoundingBox is taken from the SVG 1.1 spec.
497    virtual FloatRect objectBoundingBox() const;
498    virtual FloatRect strokeBoundingBox() const;
499
500    // Returns the smallest rectangle enclosing all of the painted content
501    // respecting clipping, masking, filters, opacity, stroke-width and markers
502    virtual FloatRect repaintRectInLocalCoordinates() const;
503
504    // This only returns the transform="" value from the element
505    // most callsites want localToParentTransform() instead.
506    virtual AffineTransform localTransform() const;
507
508    // Returns the full transform mapping from local coordinates to local coords for the parent SVG renderer
509    // This includes any viewport transforms and x/y offsets as well as the transform="" value off the element.
510    virtual const AffineTransform& localToParentTransform() const;
511
512    // SVG uses FloatPoint precise hit testing, and passes the point in parent
513    // coordinates instead of in repaint container coordinates.  Eventually the
514    // rest of the rendering tree will move to a similar model.
515    virtual bool nodeAtFloatPoint(const HitTestRequest&, HitTestResult&, const FloatPoint& pointInParent, HitTestAction);
516#endif
517
518    bool isAnonymous() const { return m_bitfields.isAnonymous(); }
519    bool isAnonymousBlock() const
520    {
521        // This function is kept in sync with anonymous block creation conditions in
522        // RenderBlock::createAnonymousBlock(). This includes creating an anonymous
523        // RenderBlock having a BLOCK or BOX display. Other classes such as RenderTextFragment
524        // are not RenderBlocks and will return false. See https://bugs.webkit.org/show_bug.cgi?id=56709.
525        return isAnonymous() && (style()->display() == BLOCK || style()->display() == BOX) && style()->styleType() == NOPSEUDO && isRenderBlock() && !isListMarker() && !isRenderFlowThread()
526#if ENABLE(FULLSCREEN_API)
527            && !isRenderFullScreen()
528            && !isRenderFullScreenPlaceholder()
529#endif
530#if ENABLE(MATHML)
531            && !isRenderMathMLBlock()
532#endif
533            ;
534    }
535    bool isAnonymousColumnsBlock() const { return style()->specifiesColumns() && isAnonymousBlock(); }
536    bool isAnonymousColumnSpanBlock() const { return style()->columnSpan() && isAnonymousBlock(); }
537    bool isElementContinuation() const { return node() && node()->renderer() != this; }
538    bool isInlineElementContinuation() const { return isElementContinuation() && isInline(); }
539    bool isBlockElementContinuation() const { return isElementContinuation() && !isInline(); }
540    virtual RenderBoxModelObject* virtualContinuation() const { return 0; }
541
542    bool isFloating() const { return m_bitfields.floating(); }
543
544    bool isOutOfFlowPositioned() const { return m_bitfields.isOutOfFlowPositioned(); } // absolute or fixed positioning
545    bool isInFlowPositioned() const { return m_bitfields.isRelPositioned() || m_bitfields.isStickyPositioned(); } // relative or sticky positioning
546    bool hasPaintOffset() const
547    {
548        bool positioned = isInFlowPositioned();
549#if ENABLE(CSS_SHAPES)
550        // Shape outside on a float can reposition the float in much the
551        // same way as relative positioning, so treat it as such.
552        positioned = positioned || isFloatingWithShapeOutside();
553#endif
554        return positioned;
555    }
556    bool isRelPositioned() const { return m_bitfields.isRelPositioned(); } // relative positioning
557    bool isStickyPositioned() const { return m_bitfields.isStickyPositioned(); }
558    bool isPositioned() const { return m_bitfields.isPositioned(); }
559
560    bool isText() const  { return m_bitfields.isText(); }
561    bool isBox() const { return m_bitfields.isBox(); }
562    bool isInline() const { return m_bitfields.isInline(); } // inline object
563    bool isRunIn() const { return style()->display() == RUN_IN; } // run-in object
564    bool isDragging() const { return m_bitfields.isDragging(); }
565    bool isReplaced() const { return m_bitfields.isReplaced(); } // a "replaced" element (see CSS)
566    bool isHorizontalWritingMode() const { return m_bitfields.horizontalWritingMode(); }
567
568    bool hasLayer() const { return m_bitfields.hasLayer(); }
569
570    enum BoxDecorationState {
571        NoBoxDecorations,
572        HasBoxDecorationsAndBackgroundObscurationStatusInvalid,
573        HasBoxDecorationsAndBackgroundIsKnownToBeObscured,
574        HasBoxDecorationsAndBackgroundMayBeVisible,
575    };
576    bool hasBoxDecorations() const { return m_bitfields.boxDecorationState() != NoBoxDecorations; }
577    bool backgroundIsKnownToBeObscured();
578    bool borderImageIsLoadedAndCanBeRendered() const;
579    bool mustRepaintBackgroundOrBorder() const;
580    bool hasBackground() const { return style()->hasBackground(); }
581    bool hasEntirelyFixedBackground() const;
582
583    bool needsLayout() const
584    {
585        return m_bitfields.needsLayout() || m_bitfields.normalChildNeedsLayout() || m_bitfields.posChildNeedsLayout()
586            || m_bitfields.needsSimplifiedNormalFlowLayout() || m_bitfields.needsPositionedMovementLayout();
587    }
588
589    bool selfNeedsLayout() const { return m_bitfields.needsLayout(); }
590    bool needsPositionedMovementLayout() const { return m_bitfields.needsPositionedMovementLayout(); }
591    bool needsPositionedMovementLayoutOnly() const
592    {
593        return m_bitfields.needsPositionedMovementLayout() && !m_bitfields.needsLayout() && !m_bitfields.normalChildNeedsLayout()
594            && !m_bitfields.posChildNeedsLayout() && !m_bitfields.needsSimplifiedNormalFlowLayout();
595    }
596
597    bool posChildNeedsLayout() const { return m_bitfields.posChildNeedsLayout(); }
598    bool needsSimplifiedNormalFlowLayout() const { return m_bitfields.needsSimplifiedNormalFlowLayout(); }
599    bool normalChildNeedsLayout() const { return m_bitfields.normalChildNeedsLayout(); }
600
601    bool preferredLogicalWidthsDirty() const { return m_bitfields.preferredLogicalWidthsDirty(); }
602
603    bool isSelectionBorder() const;
604
605    bool hasClip() const { return isOutOfFlowPositioned() && style()->hasClip(); }
606    bool hasOverflowClip() const { return m_bitfields.hasOverflowClip(); }
607    bool hasClipOrOverflowClip() const { return hasClip() || hasOverflowClip(); }
608
609    bool hasTransform() const { return m_bitfields.hasTransform(); }
610    bool hasMask() const { return style() && style()->hasMask(); }
611    bool hasClipPath() const { return style() && style()->clipPath(); }
612    bool hasHiddenBackface() const { return style() && style()->backfaceVisibility() == BackfaceVisibilityHidden; }
613
614#if ENABLE(CSS_FILTERS)
615    bool hasFilter() const { return style() && style()->hasFilter(); }
616#else
617    bool hasFilter() const { return false; }
618#endif
619
620#if ENABLE(CSS_COMPOSITING)
621    bool hasBlendMode() const { return style() && style()->hasBlendMode(); }
622#else
623    bool hasBlendMode() const { return false; }
624#endif
625
626    inline bool preservesNewline() const;
627
628    // The pseudo element style can be cached or uncached.  Use the cached method if the pseudo element doesn't respect
629    // any pseudo classes (and therefore has no concept of changing state).
630    RenderStyle* getCachedPseudoStyle(PseudoId, RenderStyle* parentStyle = 0) const;
631    PassRefPtr<RenderStyle> getUncachedPseudoStyle(const PseudoStyleRequest&, RenderStyle* parentStyle = 0, RenderStyle* ownStyle = 0) const;
632
633    virtual void updateDragState(bool dragOn);
634
635    RenderView* view() const { return document()->renderView(); };
636
637    // Returns true if this renderer is rooted, and optionally returns the hosting view (the root of the hierarchy).
638    bool isRooted(RenderView** = 0) const;
639
640    Node* node() const { return isAnonymous() ? 0 : m_node; }
641    Node* nonPseudoNode() const { return isPseudoElement() ? 0 : node(); }
642
643    // FIXME: Why does RenderWidget need this?
644    void clearNode() { m_node = 0; }
645
646    // Returns the styled node that caused the generation of this renderer.
647    // This is the same as node() except for renderers of :before and :after
648    // pseudo elements for which their parent node is returned.
649    Node* generatingNode() const { return isPseudoElement() ? node()->parentOrShadowHostNode() : node(); }
650
651    Document* document() const { return m_node->document(); }
652    Frame* frame() const { return document()->frame(); }
653
654    bool hasOutlineAnnotation() const;
655    bool hasOutline() const { return style()->hasOutline() || hasOutlineAnnotation(); }
656
657    // Returns the object containing this one. Can be different from parent for positioned elements.
658    // If repaintContainer and repaintContainerSkipped are not null, on return *repaintContainerSkipped
659    // is true if the renderer returned is an ancestor of repaintContainer.
660    RenderObject* container(const RenderLayerModelObject* repaintContainer = 0, bool* repaintContainerSkipped = 0) const;
661
662    virtual RenderObject* hoverAncestor() const;
663
664    RenderBoxModelObject* offsetParent() const;
665
666    void markContainingBlocksForLayout(bool scheduleRelayout = true, RenderObject* newRoot = 0);
667    void setNeedsLayout(bool needsLayout, MarkingBehavior = MarkContainingBlockChain);
668    void setChildNeedsLayout(bool childNeedsLayout, MarkingBehavior = MarkContainingBlockChain);
669    void setNeedsPositionedMovementLayout(const RenderStyle* oldStyle);
670    void setNeedsSimplifiedNormalFlowLayout();
671    void setPreferredLogicalWidthsDirty(bool, MarkingBehavior = MarkContainingBlockChain);
672    void invalidateContainerPreferredLogicalWidths();
673
674    void setNeedsLayoutAndPrefWidthsRecalc()
675    {
676        setNeedsLayout(true);
677        setPreferredLogicalWidthsDirty(true);
678    }
679
680    void setPositionState(EPosition position)
681    {
682        ASSERT((position != AbsolutePosition && position != FixedPosition) || isBox());
683        m_bitfields.setPositionedState(position);
684    }
685    void clearPositionedState() { m_bitfields.clearPositionedState(); }
686
687    void setFloating(bool b = true) { m_bitfields.setFloating(b); }
688    void setInline(bool b = true) { m_bitfields.setIsInline(b); }
689
690    void setHasBoxDecorations(bool = true);
691    void invalidateBackgroundObscurationStatus();
692    virtual bool computeBackgroundIsKnownToBeObscured() { return false; }
693
694    void setIsText() { m_bitfields.setIsText(true); }
695    void setIsBox() { m_bitfields.setIsBox(true); }
696    void setReplaced(bool b = true) { m_bitfields.setIsReplaced(b); }
697    void setHorizontalWritingMode(bool b = true) { m_bitfields.setHorizontalWritingMode(b); }
698    void setHasOverflowClip(bool b = true) { m_bitfields.setHasOverflowClip(b); }
699    void setHasLayer(bool b = true) { m_bitfields.setHasLayer(b); }
700    void setHasTransform(bool b = true) { m_bitfields.setHasTransform(b); }
701    void setHasReflection(bool b = true) { m_bitfields.setHasReflection(b); }
702
703    void scheduleRelayout();
704
705    void updateFillImages(const FillLayer*, const FillLayer*);
706    void updateImage(StyleImage*, StyleImage*);
707
708    virtual void paint(PaintInfo&, const LayoutPoint&);
709
710    // Recursive function that computes the size and position of this object and all its descendants.
711    virtual void layout();
712
713    /* This function performs a layout only if one is needed. */
714    void layoutIfNeeded() { if (needsLayout()) layout(); }
715
716    // used for element state updates that cannot be fixed with a
717    // repaint and do not need a relayout
718    virtual void updateFromElement() { }
719
720#if ENABLE(DASHBOARD_SUPPORT) || ENABLE(DRAGGABLE_REGION)
721    virtual void addAnnotatedRegions(Vector<AnnotatedRegionValue>&);
722    void collectAnnotatedRegions(Vector<AnnotatedRegionValue>&);
723#endif
724
725    bool isComposited() const;
726
727    bool hitTest(const HitTestRequest&, HitTestResult&, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, HitTestFilter = HitTestAll);
728    virtual void updateHitTestResult(HitTestResult&, const LayoutPoint&);
729    virtual bool nodeAtPoint(const HitTestRequest&, HitTestResult&, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, HitTestAction);
730
731    virtual VisiblePosition positionForPoint(const LayoutPoint&);
732    VisiblePosition createVisiblePosition(int offset, EAffinity);
733    VisiblePosition createVisiblePosition(const Position&);
734
735    virtual void dirtyLinesFromChangedChild(RenderObject*);
736
737    // Called to update a style that is allowed to trigger animations.
738    // FIXME: Right now this will typically be called only when updating happens from the DOM on explicit elements.
739    // We don't yet handle generated content animation such as first-letter or before/after (we'll worry about this later).
740    void setAnimatableStyle(PassRefPtr<RenderStyle>);
741
742    // Set the style of the object and update the state of the object accordingly.
743    virtual void setStyle(PassRefPtr<RenderStyle>);
744
745    // Set the style of the object if it's generated content.
746    void setPseudoStyle(PassRefPtr<RenderStyle>);
747
748    // Updates only the local style ptr of the object.  Does not update the state of the object,
749    // and so only should be called when the style is known not to have changed (or from setStyle).
750    void setStyleInternal(PassRefPtr<RenderStyle> style) { m_style = style; }
751
752    // returns the containing block level element for this element.
753    RenderBlock* containingBlock() const;
754
755    bool canContainFixedPositionObjects() const
756    {
757        return isRenderView() || (hasTransform() && isRenderBlock())
758#if ENABLE(SVG)
759                || isSVGForeignObject()
760#endif
761                || isOutOfFlowRenderFlowThread();
762    }
763
764    // Convert the given local point to absolute coordinates
765    // FIXME: Temporary. If UseTransforms is true, take transforms into account. Eventually localToAbsolute() will always be transform-aware.
766    FloatPoint localToAbsolute(const FloatPoint& localPoint = FloatPoint(), MapCoordinatesFlags = 0) const;
767    FloatPoint absoluteToLocal(const FloatPoint&, MapCoordinatesFlags = 0) const;
768
769    // Convert a local quad to absolute coordinates, taking transforms into account.
770    FloatQuad localToAbsoluteQuad(const FloatQuad& quad, MapCoordinatesFlags mode = 0, bool* wasFixed = 0) const
771    {
772        return localToContainerQuad(quad, 0, mode, wasFixed);
773    }
774    // Convert an absolute quad to local coordinates.
775    FloatQuad absoluteToLocalQuad(const FloatQuad&, MapCoordinatesFlags mode = 0) const;
776
777    // Convert a local quad into the coordinate system of container, taking transforms into account.
778    FloatQuad localToContainerQuad(const FloatQuad&, const RenderLayerModelObject* repaintContainer, MapCoordinatesFlags = 0, bool* wasFixed = 0) const;
779    FloatPoint localToContainerPoint(const FloatPoint&, const RenderLayerModelObject* repaintContainer, MapCoordinatesFlags = 0, bool* wasFixed = 0) const;
780
781    // Return the offset from the container() renderer (excluding transforms). In multi-column layout,
782    // different offsets apply at different points, so return the offset that applies to the given point.
783    virtual LayoutSize offsetFromContainer(RenderObject*, const LayoutPoint&, bool* offsetDependsOnPoint = 0) const;
784    // Return the offset from an object up the container() chain. Asserts that none of the intermediate objects have transforms.
785    LayoutSize offsetFromAncestorContainer(RenderObject*) const;
786
787    virtual void absoluteRects(Vector<IntRect>&, const LayoutPoint&) const { }
788
789    // FIXME: useTransforms should go away eventually
790    IntRect absoluteBoundingBoxRect(bool useTransform = true) const;
791    IntRect absoluteBoundingBoxRectIgnoringTransforms() const { return absoluteBoundingBoxRect(false); }
792
793    // Build an array of quads in absolute coords for line boxes
794    virtual void absoluteQuads(Vector<FloatQuad>&, bool* /*wasFixed*/ = 0) const { }
795
796    virtual void absoluteFocusRingQuads(Vector<FloatQuad>&);
797
798    static FloatRect absoluteBoundingBoxRectForRange(const Range*);
799
800    // the rect that will be painted if this object is passed as the paintingRoot
801    LayoutRect paintingRootRect(LayoutRect& topLevelRect);
802
803    virtual LayoutUnit minPreferredLogicalWidth() const { return 0; }
804    virtual LayoutUnit maxPreferredLogicalWidth() const { return 0; }
805
806    RenderStyle* style() const { return m_style.get(); }
807    RenderStyle* firstLineStyle() const { return document()->styleSheetCollection()->usesFirstLineRules() ? cachedFirstLineStyle() : style(); }
808    RenderStyle* style(bool firstLine) const { return firstLine ? firstLineStyle() : style(); }
809
810    // Used only by Element::pseudoStyleCacheIsInvalid to get a first line style based off of a
811    // given new style, without accessing the cache.
812    PassRefPtr<RenderStyle> uncachedFirstLineStyle(RenderStyle*) const;
813
814    // Anonymous blocks that are part of of a continuation chain will return their inline continuation's outline style instead.
815    // This is typically only relevant when repainting.
816    virtual RenderStyle* outlineStyleForRepaint() const { return style(); }
817
818    virtual CursorDirective getCursor(const LayoutPoint&, Cursor&) const;
819
820    void getTextDecorationColors(int decorations, Color& underline, Color& overline, Color& linethrough, bool quirksMode = false, bool firstlineStyle = false);
821
822    // Return the RenderLayerModelObject in the container chain which is responsible for painting this object, or 0
823    // if painting is root-relative. This is the container that should be passed to the 'forRepaint'
824    // methods.
825    RenderLayerModelObject* containerForRepaint() const;
826    // Actually do the repaint of rect r for this object which has been computed in the coordinate space
827    // of repaintContainer. If repaintContainer is 0, repaint via the view.
828    void repaintUsingContainer(const RenderLayerModelObject* repaintContainer, const IntRect&, bool immediate = false) const;
829
830    // Repaint the entire object.  Called when, e.g., the color of a border changes, or when a border
831    // style changes.
832    void repaint(bool immediate = false) const;
833
834    // Repaint a specific subrectangle within a given object.  The rect |r| is in the object's coordinate space.
835    void repaintRectangle(const LayoutRect&, bool immediate = false) const;
836
837    // Repaint only if our old bounds and new bounds are different. The caller may pass in newBounds and newOutlineBox if they are known.
838    bool repaintAfterLayoutIfNeeded(const RenderLayerModelObject* repaintContainer, const LayoutRect& oldBounds, const LayoutRect& oldOutlineBox, const LayoutRect* newBoundsPtr = 0, const LayoutRect* newOutlineBoxPtr = 0);
839
840    bool checkForRepaintDuringLayout() const;
841
842    // Returns the rect that should be repainted whenever this object changes.  The rect is in the view's
843    // coordinate space.  This method deals with outlines and overflow.
844    LayoutRect absoluteClippedOverflowRect() const
845    {
846        return clippedOverflowRectForRepaint(0);
847    }
848    IntRect pixelSnappedAbsoluteClippedOverflowRect() const;
849    virtual LayoutRect clippedOverflowRectForRepaint(const RenderLayerModelObject* repaintContainer) const;
850    virtual LayoutRect rectWithOutlineForRepaint(const RenderLayerModelObject* repaintContainer, LayoutUnit outlineWidth) const;
851    virtual LayoutRect outlineBoundsForRepaint(const RenderLayerModelObject* /*repaintContainer*/, const RenderGeometryMap* = 0) const { return LayoutRect(); }
852
853    // Given a rect in the object's coordinate space, compute a rect suitable for repainting
854    // that rect in view coordinates.
855    void computeAbsoluteRepaintRect(LayoutRect& r, bool fixed = false) const
856    {
857        computeRectForRepaint(0, r, fixed);
858    }
859    // Given a rect in the object's coordinate space, compute a rect suitable for repainting
860    // that rect in the coordinate space of repaintContainer.
861    virtual void computeRectForRepaint(const RenderLayerModelObject* repaintContainer, LayoutRect&, bool fixed = false) const;
862    virtual void computeFloatRectForRepaint(const RenderLayerModelObject* repaintContainer, FloatRect& repaintRect, bool fixed = false) const;
863
864    // If multiple-column layout results in applying an offset to the given point, add the same
865    // offset to the given size.
866    virtual void adjustForColumns(LayoutSize&, const LayoutPoint&) const { }
867    LayoutSize offsetForColumns(const LayoutPoint& point) const
868    {
869        LayoutSize offset;
870        adjustForColumns(offset, point);
871        return offset;
872    }
873
874    virtual unsigned int length() const { return 1; }
875
876    bool isFloatingOrOutOfFlowPositioned() const { return (isFloating() || isOutOfFlowPositioned()); }
877    bool isFloatingWithShapeOutside() const { return isBox() && isFloating() && style()->shapeOutside(); }
878
879    bool isTransparent() const { return style()->opacity() < 1.0f; }
880    float opacity() const { return style()->opacity(); }
881
882    bool hasReflection() const { return m_bitfields.hasReflection(); }
883
884    // Applied as a "slop" to dirty rect checks during the outline painting phase's dirty-rect checks.
885    int maximalOutlineSize(PaintPhase) const;
886
887    enum SelectionState {
888        SelectionNone, // The object is not selected.
889        SelectionStart, // The object either contains the start of a selection run or is the start of a run
890        SelectionInside, // The object is fully encompassed by a selection run
891        SelectionEnd, // The object either contains the end of a selection run or is the end of a run
892        SelectionBoth // The object contains an entire run or is the sole selected object in that run
893    };
894
895    // The current selection state for an object.  For blocks, the state refers to the state of the leaf
896    // descendants (as described above in the SelectionState enum declaration).
897    SelectionState selectionState() const { return m_bitfields.selectionState(); }
898    virtual void setSelectionState(SelectionState state) { m_bitfields.setSelectionState(state); }
899    inline void setSelectionStateIfNeeded(SelectionState);
900    bool canUpdateSelectionOnRootLineBoxes();
901
902    // A single rectangle that encompasses all of the selected objects within this object.  Used to determine the tightest
903    // possible bounding box for the selection.
904    LayoutRect selectionRect(bool clipToVisibleContent = true) { return selectionRectForRepaint(0, clipToVisibleContent); }
905    virtual LayoutRect selectionRectForRepaint(const RenderLayerModelObject* /*repaintContainer*/, bool /*clipToVisibleContent*/ = true) { return LayoutRect(); }
906
907    virtual bool canBeSelectionLeaf() const { return false; }
908    bool hasSelectedChildren() const { return selectionState() != SelectionNone; }
909
910    // Obtains the selection colors that should be used when painting a selection.
911    Color selectionBackgroundColor() const;
912    Color selectionForegroundColor() const;
913    Color selectionEmphasisMarkColor() const;
914
915    // Whether or not a given block needs to paint selection gaps.
916    virtual bool shouldPaintSelectionGaps() const { return false; }
917
918    /**
919     * Returns the local coordinates of the caret within this render object.
920     * @param caretOffset zero-based offset determining position within the render object.
921     * @param extraWidthToEndOfLine optional out arg to give extra width to end of line -
922     * useful for character range rect computations
923     */
924    virtual LayoutRect localCaretRect(InlineBox*, int caretOffset, LayoutUnit* extraWidthToEndOfLine = 0);
925
926    // When performing a global document tear-down, the renderer of the document is cleared.  We use this
927    // as a hook to detect the case of document destruction and don't waste time doing unnecessary work.
928    bool documentBeingDestroyed() const;
929
930    void destroyAndCleanupAnonymousWrappers();
931    virtual void destroy();
932
933    // Virtual function helpers for the deprecated Flexible Box Layout (display: -webkit-box).
934    virtual bool isDeprecatedFlexibleBox() const { return false; }
935    virtual bool isStretchingChildren() const { return false; }
936
937    // Virtual function helper for the new FlexibleBox Layout (display: -webkit-flex).
938    virtual bool isFlexibleBox() const { return false; }
939
940    bool isFlexibleBoxIncludingDeprecated() const
941    {
942        return isFlexibleBox() || isDeprecatedFlexibleBox();
943    }
944
945    virtual bool isCombineText() const { return false; }
946
947    virtual int caretMinOffset() const;
948    virtual int caretMaxOffset() const;
949
950    virtual int previousOffset(int current) const;
951    virtual int previousOffsetForBackwardDeletion(int current) const;
952    virtual int nextOffset(int current) const;
953
954    virtual void imageChanged(CachedImage*, const IntRect* = 0);
955    virtual void imageChanged(WrappedImagePtr, const IntRect* = 0) { }
956    virtual bool willRenderImage(CachedImage*);
957
958    void selectionStartEnd(int& spos, int& epos) const;
959
960    void remove() { if (parent()) parent()->removeChild(this); }
961
962    AnimationController* animation() const;
963
964    bool visibleToHitTesting() const { return style()->visibility() == VISIBLE && style()->pointerEvents() != PE_NONE; }
965
966    // Map points and quads through elements, potentially via 3d transforms. You should never need to call these directly; use
967    // localToAbsolute/absoluteToLocal methods instead.
968    virtual void mapLocalToContainer(const RenderLayerModelObject* repaintContainer, TransformState&, MapCoordinatesFlags = ApplyContainerFlip, bool* wasFixed = 0) const;
969    virtual void mapAbsoluteToLocalPoint(MapCoordinatesFlags, TransformState&) const;
970
971    // Pushes state onto RenderGeometryMap about how to map coordinates from this renderer to its container, or ancestorToStopAt (whichever is encountered first).
972    // Returns the renderer which was mapped to (container or ancestorToStopAt).
973    virtual const RenderObject* pushMappingToContainer(const RenderLayerModelObject* ancestorToStopAt, RenderGeometryMap&) const;
974
975    bool shouldUseTransformFromContainer(const RenderObject* container) const;
976    void getTransformFromContainer(const RenderObject* container, const LayoutSize& offsetInContainer, TransformationMatrix&) const;
977
978    // return true if this object requires a new stacking context
979    bool createsGroup() const { return isTransparent() || hasMask() || hasFilter() || hasBlendMode(); }
980
981    virtual void addFocusRingRects(Vector<IntRect>&, const LayoutPoint&) { };
982
983    LayoutRect absoluteOutlineBounds() const
984    {
985        return outlineBoundsForRepaint(0);
986    }
987
988    // Return the renderer whose background style is used to paint the root background. Should only be called on the renderer for which isRoot() is true.
989    RenderObject* rendererForRootBackground();
990
991    RespectImageOrientationEnum shouldRespectImageOrientation() const;
992
993protected:
994    inline bool layerCreationAllowedForSubtree() const;
995
996    // Overrides should call the superclass at the end
997    virtual void styleWillChange(StyleDifference, const RenderStyle* newStyle);
998    // Overrides should call the superclass at the start
999    virtual void styleDidChange(StyleDifference, const RenderStyle* oldStyle);
1000    void propagateStyleToAnonymousChildren(bool blockChildrenOnly = false);
1001
1002    void drawLineForBoxSide(GraphicsContext*, int x1, int y1, int x2, int y2, BoxSide,
1003                            Color, EBorderStyle, int adjbw1, int adjbw2, bool antialias = false);
1004
1005    void paintFocusRing(GraphicsContext*, const LayoutPoint&, RenderStyle*);
1006    void paintOutline(GraphicsContext*, const LayoutRect&);
1007    void addPDFURLRect(GraphicsContext*, const LayoutRect&);
1008
1009    virtual LayoutRect viewRect() const;
1010
1011    void adjustRectForOutlineAndShadow(LayoutRect&) const;
1012
1013    void clearLayoutRootIfNeeded() const;
1014    virtual void willBeDestroyed();
1015    void arenaDelete(RenderArena*, void* objectBase);
1016
1017    virtual bool canBeReplacedWithInlineRunIn() const;
1018
1019    virtual void insertedIntoTree();
1020    virtual void willBeRemovedFromTree();
1021
1022    void setDocumentForAnonymous(Document* document) { ASSERT(isAnonymous()); m_node = document; }
1023
1024private:
1025    RenderFlowThread* locateFlowThreadContainingBlock() const;
1026    void removeFromRenderFlowThread();
1027    void removeFromRenderFlowThreadRecursive(RenderFlowThread*);
1028
1029    bool shouldRepaintForStyleDifference(StyleDifference) const;
1030    bool hasImmediateNonWhitespaceTextChild() const;
1031
1032    RenderStyle* cachedFirstLineStyle() const;
1033    StyleDifference adjustStyleDifference(StyleDifference, unsigned contextSensitiveProperties) const;
1034
1035    Color selectionColor(int colorProperty) const;
1036
1037#ifndef NDEBUG
1038    void checkBlockPositionedObjectsNeedLayout();
1039#endif
1040
1041    RefPtr<RenderStyle> m_style;
1042
1043    Node* m_node;
1044
1045    RenderObject* m_parent;
1046    RenderObject* m_previous;
1047    RenderObject* m_next;
1048
1049    static RenderObjectAncestorLineboxDirtySet* s_ancestorLineboxDirtySet;
1050
1051#ifndef NDEBUG
1052    bool m_hasAXObject             : 1;
1053    bool m_setNeedsLayoutForbidden : 1;
1054#endif
1055
1056#define ADD_BOOLEAN_BITFIELD(name, Name) \
1057    private:\
1058        unsigned m_##name : 1;\
1059    public:\
1060        bool name() const { return m_##name; }\
1061        void set##Name(bool name) { m_##name = name; }\
1062
1063    class RenderObjectBitfields {
1064        enum PositionedState {
1065            IsStaticallyPositioned = 0,
1066            IsRelativelyPositioned = 1,
1067            IsOutOfFlowPositioned = 2,
1068            IsStickyPositioned = 3
1069        };
1070
1071    public:
1072        RenderObjectBitfields(Node* node)
1073            : m_needsLayout(false)
1074            , m_needsPositionedMovementLayout(false)
1075            , m_normalChildNeedsLayout(false)
1076            , m_posChildNeedsLayout(false)
1077            , m_needsSimplifiedNormalFlowLayout(false)
1078            , m_preferredLogicalWidthsDirty(false)
1079            , m_floating(false)
1080            , m_isAnonymous(!node)
1081            , m_isText(false)
1082            , m_isBox(false)
1083            , m_isInline(true)
1084            , m_isReplaced(false)
1085            , m_horizontalWritingMode(true)
1086            , m_isDragging(false)
1087            , m_hasLayer(false)
1088            , m_hasOverflowClip(false)
1089            , m_hasTransform(false)
1090            , m_hasReflection(false)
1091            , m_hasCounterNodeMap(false)
1092            , m_everHadLayout(false)
1093            , m_childrenInline(false)
1094            , m_hasColumns(false)
1095            , m_positionedState(IsStaticallyPositioned)
1096            , m_selectionState(SelectionNone)
1097            , m_flowThreadState(NotInsideFlowThread)
1098            , m_boxDecorationState(NoBoxDecorations)
1099        {
1100        }
1101
1102        // 31 bits have been used here. There is one bit available.
1103        ADD_BOOLEAN_BITFIELD(needsLayout, NeedsLayout);
1104        ADD_BOOLEAN_BITFIELD(needsPositionedMovementLayout, NeedsPositionedMovementLayout);
1105        ADD_BOOLEAN_BITFIELD(normalChildNeedsLayout, NormalChildNeedsLayout);
1106        ADD_BOOLEAN_BITFIELD(posChildNeedsLayout, PosChildNeedsLayout);
1107        ADD_BOOLEAN_BITFIELD(needsSimplifiedNormalFlowLayout, NeedsSimplifiedNormalFlowLayout);
1108        ADD_BOOLEAN_BITFIELD(preferredLogicalWidthsDirty, PreferredLogicalWidthsDirty);
1109        ADD_BOOLEAN_BITFIELD(floating, Floating);
1110
1111        ADD_BOOLEAN_BITFIELD(isAnonymous, IsAnonymous);
1112        ADD_BOOLEAN_BITFIELD(isText, IsText);
1113        ADD_BOOLEAN_BITFIELD(isBox, IsBox);
1114        ADD_BOOLEAN_BITFIELD(isInline, IsInline);
1115        ADD_BOOLEAN_BITFIELD(isReplaced, IsReplaced);
1116        ADD_BOOLEAN_BITFIELD(horizontalWritingMode, HorizontalWritingMode);
1117        ADD_BOOLEAN_BITFIELD(isDragging, IsDragging);
1118
1119        ADD_BOOLEAN_BITFIELD(hasLayer, HasLayer);
1120        ADD_BOOLEAN_BITFIELD(hasOverflowClip, HasOverflowClip); // Set in the case of overflow:auto/scroll/hidden
1121        ADD_BOOLEAN_BITFIELD(hasTransform, HasTransform);
1122        ADD_BOOLEAN_BITFIELD(hasReflection, HasReflection);
1123
1124        ADD_BOOLEAN_BITFIELD(hasCounterNodeMap, HasCounterNodeMap);
1125        ADD_BOOLEAN_BITFIELD(everHadLayout, EverHadLayout);
1126
1127        // from RenderBlock
1128        ADD_BOOLEAN_BITFIELD(childrenInline, ChildrenInline);
1129        ADD_BOOLEAN_BITFIELD(hasColumns, HasColumns);
1130
1131    private:
1132        unsigned m_positionedState : 2; // PositionedState
1133        unsigned m_selectionState : 3; // SelectionState
1134        unsigned m_flowThreadState : 2; // FlowThreadState
1135        unsigned m_boxDecorationState : 2; // BoxDecorationState
1136
1137    public:
1138        bool isOutOfFlowPositioned() const { return m_positionedState == IsOutOfFlowPositioned; }
1139        bool isRelPositioned() const { return m_positionedState == IsRelativelyPositioned; }
1140        bool isStickyPositioned() const { return m_positionedState == IsStickyPositioned; }
1141        bool isPositioned() const { return m_positionedState != IsStaticallyPositioned; }
1142
1143        void setPositionedState(int positionState)
1144        {
1145            // This mask maps FixedPosition and AbsolutePosition to IsOutOfFlowPositioned, saving one bit.
1146            m_positionedState = static_cast<PositionedState>(positionState & 0x3);
1147        }
1148        void clearPositionedState() { m_positionedState = StaticPosition; }
1149
1150        ALWAYS_INLINE SelectionState selectionState() const { return static_cast<SelectionState>(m_selectionState); }
1151        ALWAYS_INLINE void setSelectionState(SelectionState selectionState) { m_selectionState = selectionState; }
1152
1153        ALWAYS_INLINE FlowThreadState flowThreadState() const { return static_cast<FlowThreadState>(m_flowThreadState); }
1154        ALWAYS_INLINE void setFlowThreadState(FlowThreadState flowThreadState) { m_flowThreadState = flowThreadState; }
1155
1156        ALWAYS_INLINE BoxDecorationState boxDecorationState() const { return static_cast<BoxDecorationState>(m_boxDecorationState); }
1157        ALWAYS_INLINE void setBoxDecorationState(BoxDecorationState boxDecorationState) { m_boxDecorationState = boxDecorationState; }
1158    };
1159
1160#undef ADD_BOOLEAN_BITFIELD
1161
1162    RenderObjectBitfields m_bitfields;
1163
1164    void setNeedsPositionedMovementLayout(bool b) { m_bitfields.setNeedsPositionedMovementLayout(b); }
1165    void setNormalChildNeedsLayout(bool b) { m_bitfields.setNormalChildNeedsLayout(b); }
1166    void setPosChildNeedsLayout(bool b) { m_bitfields.setPosChildNeedsLayout(b); }
1167    void setNeedsSimplifiedNormalFlowLayout(bool b) { m_bitfields.setNeedsSimplifiedNormalFlowLayout(b); }
1168    void setIsDragging(bool b) { m_bitfields.setIsDragging(b); }
1169    void setEverHadLayout(bool b) { m_bitfields.setEverHadLayout(b); }
1170
1171private:
1172    // Store state between styleWillChange and styleDidChange
1173    static bool s_affectsParentBlock;
1174    static bool s_noLongerAffectsParentBlock;
1175};
1176
1177inline bool RenderObject::documentBeingDestroyed() const
1178{
1179    return !document()->renderer();
1180}
1181
1182inline bool RenderObject::isBeforeContent() const
1183{
1184    if (style()->styleType() != BEFORE)
1185        return false;
1186    // Text nodes don't have their own styles, so ignore the style on a text node.
1187    if (isText() && !isBR())
1188        return false;
1189    return true;
1190}
1191
1192inline bool RenderObject::isAfterContent() const
1193{
1194    if (style()->styleType() != AFTER)
1195        return false;
1196    // Text nodes don't have their own styles, so ignore the style on a text node.
1197    if (isText() && !isBR())
1198        return false;
1199    return true;
1200}
1201
1202inline bool RenderObject::isBeforeOrAfterContent() const
1203{
1204    return isBeforeContent() || isAfterContent();
1205}
1206
1207inline void RenderObject::setNeedsLayout(bool needsLayout, MarkingBehavior markParents)
1208{
1209    bool alreadyNeededLayout = m_bitfields.needsLayout();
1210    m_bitfields.setNeedsLayout(needsLayout);
1211    if (needsLayout) {
1212        ASSERT(!isSetNeedsLayoutForbidden());
1213        if (!alreadyNeededLayout) {
1214            if (markParents == MarkContainingBlockChain)
1215                markContainingBlocksForLayout();
1216            if (hasLayer())
1217                setLayerNeedsFullRepaint();
1218        }
1219    } else {
1220        setEverHadLayout(true);
1221        setPosChildNeedsLayout(false);
1222        setNeedsSimplifiedNormalFlowLayout(false);
1223        setNormalChildNeedsLayout(false);
1224        setNeedsPositionedMovementLayout(false);
1225        setAncestorLineBoxDirty(false);
1226#ifndef NDEBUG
1227        checkBlockPositionedObjectsNeedLayout();
1228#endif
1229    }
1230}
1231
1232inline void RenderObject::setChildNeedsLayout(bool childNeedsLayout, MarkingBehavior markParents)
1233{
1234    bool alreadyNeededLayout = normalChildNeedsLayout();
1235    setNormalChildNeedsLayout(childNeedsLayout);
1236    if (childNeedsLayout) {
1237        ASSERT(!isSetNeedsLayoutForbidden());
1238        if (!alreadyNeededLayout && markParents == MarkContainingBlockChain)
1239            markContainingBlocksForLayout();
1240    } else {
1241        setPosChildNeedsLayout(false);
1242        setNeedsSimplifiedNormalFlowLayout(false);
1243        setNormalChildNeedsLayout(false);
1244        setNeedsPositionedMovementLayout(false);
1245    }
1246}
1247
1248inline void RenderObject::setNeedsPositionedMovementLayout(const RenderStyle* oldStyle)
1249{
1250    bool alreadyNeededLayout = needsPositionedMovementLayout();
1251    setNeedsPositionedMovementLayout(true);
1252    ASSERT(!isSetNeedsLayoutForbidden());
1253    if (!alreadyNeededLayout) {
1254        markContainingBlocksForLayout();
1255        if (hasLayer()) {
1256            if (oldStyle && m_style->diffRequiresRepaint(oldStyle))
1257                setLayerNeedsFullRepaint();
1258            else
1259                setLayerNeedsFullRepaintForPositionedMovementLayout();
1260        }
1261    }
1262}
1263
1264inline void RenderObject::setNeedsSimplifiedNormalFlowLayout()
1265{
1266    bool alreadyNeededLayout = needsSimplifiedNormalFlowLayout();
1267    setNeedsSimplifiedNormalFlowLayout(true);
1268    ASSERT(!isSetNeedsLayoutForbidden());
1269    if (!alreadyNeededLayout) {
1270        markContainingBlocksForLayout();
1271        if (hasLayer())
1272            setLayerNeedsFullRepaint();
1273    }
1274}
1275
1276inline bool RenderObject::preservesNewline() const
1277{
1278#if ENABLE(SVG)
1279    if (isSVGInlineText())
1280        return false;
1281#endif
1282
1283    return style()->preserveNewline();
1284}
1285
1286inline bool RenderObject::layerCreationAllowedForSubtree() const
1287{
1288#if ENABLE(SVG)
1289    RenderObject* parentRenderer = parent();
1290    while (parentRenderer) {
1291        if (parentRenderer->isSVGHiddenContainer())
1292            return false;
1293        parentRenderer = parentRenderer->parent();
1294    }
1295#endif
1296
1297    return true;
1298}
1299
1300inline void RenderObject::setSelectionStateIfNeeded(SelectionState state)
1301{
1302    if (selectionState() == state)
1303        return;
1304
1305    setSelectionState(state);
1306}
1307
1308inline void RenderObject::setHasBoxDecorations(bool b)
1309{
1310    if (!b) {
1311        m_bitfields.setBoxDecorationState(NoBoxDecorations);
1312        return;
1313    }
1314    if (hasBoxDecorations())
1315        return;
1316    m_bitfields.setBoxDecorationState(HasBoxDecorationsAndBackgroundObscurationStatusInvalid);
1317}
1318
1319inline void RenderObject::invalidateBackgroundObscurationStatus()
1320{
1321    if (!hasBoxDecorations())
1322        return;
1323    m_bitfields.setBoxDecorationState(HasBoxDecorationsAndBackgroundObscurationStatusInvalid);
1324}
1325
1326inline bool RenderObject::backgroundIsKnownToBeObscured()
1327{
1328    if (m_bitfields.boxDecorationState() == HasBoxDecorationsAndBackgroundObscurationStatusInvalid) {
1329        BoxDecorationState boxDecorationState = computeBackgroundIsKnownToBeObscured() ? HasBoxDecorationsAndBackgroundIsKnownToBeObscured : HasBoxDecorationsAndBackgroundMayBeVisible;
1330        m_bitfields.setBoxDecorationState(boxDecorationState);
1331    }
1332    return m_bitfields.boxDecorationState() == HasBoxDecorationsAndBackgroundIsKnownToBeObscured;
1333}
1334
1335inline int adjustForAbsoluteZoom(int value, RenderObject* renderer)
1336{
1337    return adjustForAbsoluteZoom(value, renderer->style());
1338}
1339
1340#if ENABLE(SUBPIXEL_LAYOUT)
1341inline LayoutUnit adjustLayoutUnitForAbsoluteZoom(LayoutUnit value, RenderObject* renderer)
1342{
1343    return adjustLayoutUnitForAbsoluteZoom(value, renderer->style());
1344}
1345#endif
1346
1347inline void adjustFloatQuadForAbsoluteZoom(FloatQuad& quad, RenderObject* renderer)
1348{
1349    float zoom = renderer->style()->effectiveZoom();
1350    if (zoom != 1)
1351        quad.scale(1 / zoom, 1 / zoom);
1352}
1353
1354inline void adjustFloatRectForAbsoluteZoom(FloatRect& rect, RenderObject* renderer)
1355{
1356    float zoom = renderer->style()->effectiveZoom();
1357    if (zoom != 1)
1358        rect.scale(1 / zoom, 1 / zoom);
1359}
1360
1361} // namespace WebCore
1362
1363#ifndef NDEBUG
1364// Outside the WebCore namespace for ease of invocation from gdb.
1365void showTree(const WebCore::RenderObject*);
1366void showLineTree(const WebCore::RenderObject*);
1367void showRenderTree(const WebCore::RenderObject* object1);
1368// We don't make object2 an optional parameter so that showRenderTree
1369// can be called from gdb easily.
1370void showRenderTree(const WebCore::RenderObject* object1, const WebCore::RenderObject* object2);
1371#endif
1372
1373#endif // RenderObject_h
1374