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1 /*
2  * Copyright (C) 2003, 2009 Apple Inc. All rights reserved.
3  *
4  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
5  *
6  * Other contributors:
7  *   Robert O'Callahan <roc+@cs.cmu.edu>
8  *   David Baron <dbaron@fas.harvard.edu>
9  *   Christian Biesinger <cbiesinger@web.de>
10  *   Randall Jesup <rjesup@wgate.com>
11  *   Roland Mainz <roland.mainz@informatik.med.uni-giessen.de>
12  *   Josh Soref <timeless@mac.com>
13  *   Boris Zbarsky <bzbarsky@mit.edu>
14  *
15  * This library is free software; you can redistribute it and/or
16  * modify it under the terms of the GNU Lesser General Public
17  * License as published by the Free Software Foundation; either
18  * version 2.1 of the License, or (at your option) any later version.
19  *
20  * This library is distributed in the hope that it will be useful,
21  * but WITHOUT ANY WARRANTY; without even the implied warranty of
22  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
23  * Lesser General Public License for more details.
24  *
25  * You should have received a copy of the GNU Lesser General Public
26  * License along with this library; if not, write to the Free Software
27  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
28  *
29  * Alternatively, the contents of this file may be used under the terms
30  * of either the Mozilla Public License Version 1.1, found at
31  * http://www.mozilla.org/MPL/ (the "MPL") or the GNU General Public
32  * License Version 2.0, found at http://www.fsf.org/copyleft/gpl.html
33  * (the "GPL"), in which case the provisions of the MPL or the GPL are
34  * applicable instead of those above.  If you wish to allow use of your
35  * version of this file only under the terms of one of those two
36  * licenses (the MPL or the GPL) and not to allow others to use your
37  * version of this file under the LGPL, indicate your decision by
38  * deletingthe provisions above and replace them with the notice and
39  * other provisions required by the MPL or the GPL, as the case may be.
40  * If you do not delete the provisions above, a recipient may use your
41  * version of this file under any of the LGPL, the MPL or the GPL.
42  */
43 
44 #ifndef RenderLayer_h
45 #define RenderLayer_h
46 
47 #include "PaintInfo.h"
48 #include "RenderBox.h"
49 #include "ScrollBehavior.h"
50 #include "ScrollableArea.h"
51 #include <wtf/OwnPtr.h>
52 
53 namespace WebCore {
54 
55 class HitTestRequest;
56 class HitTestResult;
57 class HitTestingTransformState;
58 class RenderMarquee;
59 class RenderReplica;
60 class RenderScrollbarPart;
61 class RenderStyle;
62 class RenderView;
63 class Scrollbar;
64 class TransformationMatrix;
65 
66 #if USE(ACCELERATED_COMPOSITING)
67 class RenderLayerBacking;
68 class RenderLayerCompositor;
69 #endif
70 
71 class ClipRects {
72 public:
ClipRects()73     ClipRects()
74         : m_refCnt(0)
75         , m_fixed(false)
76     {
77     }
78 
ClipRects(const IntRect & r)79     ClipRects(const IntRect& r)
80         : m_overflowClipRect(r)
81         , m_fixedClipRect(r)
82         , m_posClipRect(r)
83         , m_refCnt(0)
84         , m_fixed(false)
85     {
86     }
87 
ClipRects(const ClipRects & other)88     ClipRects(const ClipRects& other)
89         : m_overflowClipRect(other.overflowClipRect())
90         , m_fixedClipRect(other.fixedClipRect())
91         , m_posClipRect(other.posClipRect())
92         , m_refCnt(0)
93         , m_fixed(other.fixed())
94     {
95     }
96 
reset(const IntRect & r)97     void reset(const IntRect& r)
98     {
99         m_overflowClipRect = r;
100         m_fixedClipRect = r;
101         m_posClipRect = r;
102         m_fixed = false;
103     }
104 
overflowClipRect()105     const IntRect& overflowClipRect() const { return m_overflowClipRect; }
setOverflowClipRect(const IntRect & r)106     void setOverflowClipRect(const IntRect& r) { m_overflowClipRect = r; }
107 
fixedClipRect()108     const IntRect& fixedClipRect() const { return m_fixedClipRect; }
setFixedClipRect(const IntRect & r)109     void setFixedClipRect(const IntRect&r) { m_fixedClipRect = r; }
110 
posClipRect()111     const IntRect& posClipRect() const { return m_posClipRect; }
setPosClipRect(const IntRect & r)112     void setPosClipRect(const IntRect& r) { m_posClipRect = r; }
113 
fixed()114     bool fixed() const { return m_fixed; }
setFixed(bool fixed)115     void setFixed(bool fixed) { m_fixed = fixed; }
116 
ref()117     void ref() { m_refCnt++; }
deref(RenderArena * renderArena)118     void deref(RenderArena* renderArena) { if (--m_refCnt == 0) destroy(renderArena); }
119 
120     void destroy(RenderArena*);
121 
122     // Overloaded new operator.
123     void* operator new(size_t, RenderArena*) throw();
124 
125     // Overridden to prevent the normal delete from being called.
126     void operator delete(void*, size_t);
127 
128     bool operator==(const ClipRects& other) const
129     {
130         return m_overflowClipRect == other.overflowClipRect() &&
131                m_fixedClipRect == other.fixedClipRect() &&
132                m_posClipRect == other.posClipRect() &&
133                m_fixed == other.fixed();
134     }
135 
136     ClipRects& operator=(const ClipRects& other)
137     {
138         m_overflowClipRect = other.overflowClipRect();
139         m_fixedClipRect = other.fixedClipRect();
140         m_posClipRect = other.posClipRect();
141         m_fixed = other.fixed();
142         return *this;
143     }
144 
145 private:
146     // The normal operator new is disallowed on all render objects.
147     void* operator new(size_t) throw();
148 
149 private:
150     IntRect m_overflowClipRect;
151     IntRect m_fixedClipRect;
152     IntRect m_posClipRect;
153     unsigned m_refCnt : 31;
154     bool m_fixed : 1;
155 };
156 
157 class RenderLayer : public ScrollableArea {
158 public:
159     friend class RenderReplica;
160 
161     RenderLayer(RenderBoxModelObject*);
162     ~RenderLayer();
163 
renderer()164     RenderBoxModelObject* renderer() const { return m_renderer; }
renderBox()165     RenderBox* renderBox() const { return m_renderer && m_renderer->isBox() ? toRenderBox(m_renderer) : 0; }
parent()166     RenderLayer* parent() const { return m_parent; }
previousSibling()167     RenderLayer* previousSibling() const { return m_previous; }
nextSibling()168     RenderLayer* nextSibling() const { return m_next; }
firstChild()169     RenderLayer* firstChild() const { return m_first; }
lastChild()170     RenderLayer* lastChild() const { return m_last; }
171 
172     void addChild(RenderLayer* newChild, RenderLayer* beforeChild = 0);
173     RenderLayer* removeChild(RenderLayer*);
174 
175     void removeOnlyThisLayer();
176     void insertOnlyThisLayer();
177 
178     void repaintIncludingDescendants();
179 
180 #if USE(ACCELERATED_COMPOSITING)
181     // Indicate that the layer contents need to be repainted. Only has an effect
182     // if layer compositing is being used,
183     void setBackingNeedsRepaint();
184     void setBackingNeedsRepaintInRect(const IntRect& r); // r is in the coordinate space of the layer's render object
185     void repaintIncludingNonCompositingDescendants(RenderBoxModelObject* repaintContainer);
186 #endif
187 
188     void styleChanged(StyleDifference, const RenderStyle* oldStyle);
189 
marquee()190     RenderMarquee* marquee() const { return m_marquee; }
191 
isNormalFlowOnly()192     bool isNormalFlowOnly() const { return m_isNormalFlowOnly; }
193     bool isSelfPaintingLayer() const;
194 
195     bool requiresSlowRepaints() const;
196 
197     bool isTransparent() const;
198     RenderLayer* transparentPaintingAncestor();
199     void beginTransparencyLayers(GraphicsContext*, const RenderLayer* rootLayer, PaintBehavior);
200 
hasReflection()201     bool hasReflection() const { return renderer()->hasReflection(); }
isReflection()202     bool isReflection() const { return renderer()->isReplica(); }
reflection()203     RenderReplica* reflection() const { return m_reflection; }
204     RenderLayer* reflectionLayer() const;
205 
root()206     const RenderLayer* root() const
207     {
208         const RenderLayer* curr = this;
209         while (curr->parent())
210             curr = curr->parent();
211         return curr;
212     }
213 
x()214     int x() const { return m_x; }
y()215     int y() const { return m_y; }
setLocation(int x,int y)216     void setLocation(int x, int y)
217     {
218         m_x = x;
219         m_y = y;
220     }
221 
width()222     int width() const { return m_width; }
height()223     int height() const { return m_height; }
size()224     IntSize size() const { return IntSize(m_width, m_height); }
225 
226 #if PLATFORM(ANDROID)
227     void setWidth(int w);
228     void setHeight(int h);
229 #else
setWidth(int w)230     void setWidth(int w) { m_width = w; }
setHeight(int h)231     void setHeight(int h) { m_height = h; }
232 #endif
233 
234     int scrollWidth();
235     int scrollHeight();
236 
237     void panScrollFromPoint(const IntPoint&);
238 
239     // Scrolling methods for layers that can scroll their overflow.
240     void scrollByRecursively(int xDelta, int yDelta);
241 
scrolledContentOffset()242     IntSize scrolledContentOffset() const { return IntSize(scrollXOffset() + m_scrollLeftOverflow, scrollYOffset() + m_scrollTopOverflow); }
243 
scrollXOffset()244     int scrollXOffset() const { return m_scrollX + m_scrollOrigin.x(); }
scrollYOffset()245     int scrollYOffset() const { return m_scrollY + m_scrollOrigin.y(); }
246 
247     void scrollToOffset(int x, int y);
scrollToXOffset(int x)248     void scrollToXOffset(int x) { scrollToOffset(x, m_scrollY + m_scrollOrigin.y()); }
scrollToYOffset(int y)249     void scrollToYOffset(int y) { scrollToOffset(m_scrollX + m_scrollOrigin.x(), y); }
250     void scrollRectToVisible(const IntRect&, bool scrollToAnchor = false, const ScrollAlignment& alignX = ScrollAlignment::alignCenterIfNeeded, const ScrollAlignment& alignY = ScrollAlignment::alignCenterIfNeeded);
251 
252     IntRect getRectToExpose(const IntRect& visibleRect, const IntRect& exposeRect, const ScrollAlignment& alignX, const ScrollAlignment& alignY);
253 
254     void setHasHorizontalScrollbar(bool);
255     void setHasVerticalScrollbar(bool);
256 
257     PassRefPtr<Scrollbar> createScrollbar(ScrollbarOrientation);
258     void destroyScrollbar(ScrollbarOrientation);
259 
260     // ScrollableArea overrides
horizontalScrollbar()261     virtual Scrollbar* horizontalScrollbar() const { return m_hBar.get(); }
verticalScrollbar()262     virtual Scrollbar* verticalScrollbar() const { return m_vBar.get(); }
263 
264     int verticalScrollbarWidth(OverlayScrollbarSizeRelevancy = IgnoreOverlayScrollbarSize) const;
265     int horizontalScrollbarHeight(OverlayScrollbarSizeRelevancy = IgnoreOverlayScrollbarSize) const;
266 
267     bool hasOverflowControls() const;
268     bool isPointInResizeControl(const IntPoint& absolutePoint) const;
269     bool hitTestOverflowControls(HitTestResult&, const IntPoint& localPoint);
270     IntSize offsetFromResizeCorner(const IntPoint& absolutePoint) const;
271 
272     void paintOverflowControls(GraphicsContext*, int tx, int ty, const IntRect& damageRect, bool paintingOverlayControls = false);
273     void paintScrollCorner(GraphicsContext*, int tx, int ty, const IntRect& damageRect);
274     void paintResizer(GraphicsContext*, int tx, int ty, const IntRect& damageRect);
275 
276     void updateScrollInfoAfterLayout();
277 
278     bool scroll(ScrollDirection, ScrollGranularity, float multiplier = 1);
279     void autoscroll();
280 
281     void resize(const PlatformMouseEvent&, const IntSize&);
inResizeMode()282     bool inResizeMode() const { return m_inResizeMode; }
setInResizeMode(bool b)283     void setInResizeMode(bool b) { m_inResizeMode = b; }
284 
isRootLayer()285     bool isRootLayer() const { return renderer()->isRenderView(); }
286 
287 #if USE(ACCELERATED_COMPOSITING)
288     RenderLayerCompositor* compositor() const;
289 
290     // Notification from the renderer that its content changed (e.g. current frame of image changed).
291     // Allows updates of layer content without repainting.
292     enum ContentChangeType { ImageChanged, MaskImageChanged, CanvasChanged, VideoChanged, FullScreenChanged };
293     void contentChanged(ContentChangeType);
294 #endif
295 
296     // Returns true if the accelerated compositing is enabled
297     bool hasAcceleratedCompositing() const;
298 
299     bool canRender3DTransforms() const;
300 
301     void updateLayerPosition();
302 
303     enum UpdateLayerPositionsFlag {
304         CheckForRepaint = 1,
305         IsCompositingUpdateRoot = 1 << 1,
306         UpdateCompositingLayers = 1 << 2,
307         UpdatePagination = 1 << 3
308     };
309     typedef unsigned UpdateLayerPositionsFlags;
310     void updateLayerPositions(UpdateLayerPositionsFlags = CheckForRepaint | IsCompositingUpdateRoot | UpdateCompositingLayers, IntPoint* cachedOffset = 0);
311 
312     void updateTransform();
313 
relativePositionOffset(int & relX,int & relY)314     void relativePositionOffset(int& relX, int& relY) const { relX += m_relX; relY += m_relY; }
relativePositionOffset()315     IntSize relativePositionOffset() const { return IntSize(m_relX, m_relY); }
316 
317     void clearClipRectsIncludingDescendants();
318     void clearClipRects();
319 
320     void addBlockSelectionGapsBounds(const IntRect&);
321     void clearBlockSelectionGapsBounds();
322     void repaintBlockSelectionGaps();
323 
324     // Get the enclosing stacking context for this layer.  A stacking context is a layer
325     // that has a non-auto z-index.
326     RenderLayer* stackingContext() const;
327 #if ENABLE(COMPOSITED_FIXED_ELEMENTS)
isFixed()328     bool isFixed() const { return renderer()->isPositioned() && renderer()->style()->position() == FixedPosition; }
329     // If fixed elements are composited, they will be containing children
isStackingContext()330     bool isStackingContext() const {
331 #if ENABLE(ANDROID_OVERFLOW_SCROLL)
332       if (hasOverflowScroll())
333           return true;
334 #endif
335       return !hasAutoZIndex() || renderer()->isRenderView() || (isComposited() && isFixed());
336     }
337 #else
338 #if ENABLE(ANDROID_OVERFLOW_SCROLL)
isStackingContext()339     bool isStackingContext() const { return !hasAutoZIndex() || renderer()->isRenderView() || hasOverflowScroll(); }
340 #else
isStackingContext()341     bool isStackingContext() const { return !hasAutoZIndex() || renderer()->isRenderView() ; }
342 #endif
343 #endif
344 
345     void dirtyZOrderLists();
346     void dirtyStackingContextZOrderLists();
347     void updateZOrderLists();
posZOrderList()348     Vector<RenderLayer*>* posZOrderList() const { return m_posZOrderList; }
negZOrderList()349     Vector<RenderLayer*>* negZOrderList() const { return m_negZOrderList; }
350 
351     void dirtyNormalFlowList();
352     void updateNormalFlowList();
normalFlowList()353     Vector<RenderLayer*>* normalFlowList() const { return m_normalFlowList; }
354 
hasVisibleContent()355     bool hasVisibleContent() const { return m_hasVisibleContent; }
hasVisibleDescendant()356     bool hasVisibleDescendant() const { return m_hasVisibleDescendant; }
357     void setHasVisibleContent(bool);
358     void dirtyVisibleContentStatus();
359 
360     // Gets the nearest enclosing positioned ancestor layer (also includes
361     // the <html> layer and the root layer).
362     RenderLayer* enclosingPositionedAncestor() const;
363 
364     // The layer relative to which clipping rects for this layer are computed.
365     RenderLayer* clippingRoot() const;
366 
367 #if USE(ACCELERATED_COMPOSITING)
368     // Enclosing compositing layer; if includeSelf is true, may return this.
369     RenderLayer* enclosingCompositingLayer(bool includeSelf = true) const;
370     // Ancestor compositing layer, excluding this.
ancestorCompositingLayer()371     RenderLayer* ancestorCompositingLayer() const { return enclosingCompositingLayer(false); }
372 #endif
373 
374     void convertToLayerCoords(const RenderLayer* ancestorLayer, int& x, int& y) const;
375 
hasAutoZIndex()376     bool hasAutoZIndex() const { return renderer()->style()->hasAutoZIndex(); }
zIndex()377     int zIndex() const { return renderer()->style()->zIndex(); }
378 
379     // The two main functions that use the layer system.  The paint method
380     // paints the layers that intersect the damage rect from back to
381     // front.  The hitTest method looks for mouse events by walking
382     // layers that intersect the point from front to back.
383     void paint(GraphicsContext*, const IntRect& damageRect, PaintBehavior = PaintBehaviorNormal, RenderObject* paintingRoot = 0);
384     bool hitTest(const HitTestRequest&, HitTestResult&);
385     void paintOverlayScrollbars(GraphicsContext*, const IntRect& damageRect, PaintBehavior, RenderObject* paintingRoot);
386 
387     // This method figures out our layerBounds in coordinates relative to
388     // |rootLayer}.  It also computes our background and foreground clip rects
389     // for painting/event handling.
390     void calculateRects(const RenderLayer* rootLayer, const IntRect& paintDirtyRect, IntRect& layerBounds,
391                         IntRect& backgroundRect, IntRect& foregroundRect, IntRect& outlineRect, bool temporaryClipRects = false,
392                         OverlayScrollbarSizeRelevancy = IgnoreOverlayScrollbarSize) const;
393 
394     // Compute and cache clip rects computed with the given layer as the root
395     void updateClipRects(const RenderLayer* rootLayer, OverlayScrollbarSizeRelevancy = IgnoreOverlayScrollbarSize);
396     // Compute and return the clip rects. If useCached is true, will used previously computed clip rects on ancestors
397     // (rather than computing them all from scratch up the parent chain).
398     void calculateClipRects(const RenderLayer* rootLayer, ClipRects&, bool useCached = false, OverlayScrollbarSizeRelevancy = IgnoreOverlayScrollbarSize) const;
clipRects()399     ClipRects* clipRects() const { return m_clipRects; }
400 
401     IntRect childrenClipRect() const; // Returns the foreground clip rect of the layer in the document's coordinate space.
402     IntRect selfClipRect() const; // Returns the background clip rect of the layer in the document's coordinate space.
403 
404     bool intersectsDamageRect(const IntRect& layerBounds, const IntRect& damageRect, const RenderLayer* rootLayer) const;
405 
406     // Bounding box relative to some ancestor layer.
407     IntRect boundingBox(const RenderLayer* rootLayer) const;
408     // Bounding box in the coordinates of this layer.
409     IntRect localBoundingBox() const;
410     // Bounding box relative to the root.
411     IntRect absoluteBoundingBox() const;
412 
413     void updateHoverActiveState(const HitTestRequest&, HitTestResult&);
414 
415     // Return a cached repaint rect, computed relative to the layer renderer's containerForRepaint.
repaintRect()416     IntRect repaintRect() const { return m_repaintRect; }
417     IntRect repaintRectIncludingDescendants() const;
418     void computeRepaintRects();
419     void updateRepaintRectsAfterScroll(bool fixed = false);
420     void setNeedsFullRepaint(bool f = true) { m_needsFullRepaint = f; }
421 
staticInlinePosition()422     int staticInlinePosition() const { return m_staticInlinePosition; }
staticBlockPosition()423     int staticBlockPosition() const { return m_staticBlockPosition; }
setStaticInlinePosition(int position)424     void setStaticInlinePosition(int position) { m_staticInlinePosition = position; }
setStaticBlockPosition(int position)425     void setStaticBlockPosition(int position) { m_staticBlockPosition = position; }
426 
hasTransform()427     bool hasTransform() const { return renderer()->hasTransform(); }
428     // Note that this transform has the transform-origin baked in.
transform()429     TransformationMatrix* transform() const { return m_transform.get(); }
430     // currentTransform computes a transform which takes accelerated animations into account. The
431     // resulting transform has transform-origin baked in. If the layer does not have a transform,
432     // returns the identity matrix.
433     TransformationMatrix currentTransform() const;
434     TransformationMatrix renderableTransform(PaintBehavior) const;
435 
436     // Get the perspective transform, which is applied to transformed sublayers.
437     // Returns true if the layer has a -webkit-perspective.
438     // Note that this transform has the perspective-origin baked in.
439     TransformationMatrix perspectiveTransform() const;
440     FloatPoint perspectiveOrigin() const;
preserves3D()441     bool preserves3D() const { return renderer()->style()->transformStyle3D() == TransformStyle3DPreserve3D; }
has3DTransform()442     bool has3DTransform() const { return m_transform && !m_transform->isAffine(); }
443 
444      // Overloaded new operator.  Derived classes must override operator new
445     // in order to allocate out of the RenderArena.
446     void* operator new(size_t, RenderArena*) throw();
447 
448     // Overridden to prevent the normal delete from being called.
449     void operator delete(void*, size_t);
450 
451 #if USE(ACCELERATED_COMPOSITING)
isComposited()452     bool isComposited() const { return m_backing != 0; }
453     bool hasCompositedMask() const;
backing()454     RenderLayerBacking* backing() const { return m_backing.get(); }
455     RenderLayerBacking* ensureBacking();
456     void clearBacking();
457     virtual GraphicsLayer* layerForHorizontalScrollbar() const;
458     virtual GraphicsLayer* layerForVerticalScrollbar() const;
459     virtual GraphicsLayer* layerForScrollCorner() const;
460 #else
isComposited()461     bool isComposited() const { return false; }
hasCompositedMask()462     bool hasCompositedMask() const { return false; }
463 #endif
464 
paintsWithTransparency(PaintBehavior paintBehavior)465     bool paintsWithTransparency(PaintBehavior paintBehavior) const
466     {
467         return isTransparent() && ((paintBehavior & PaintBehaviorFlattenCompositingLayers) || !isComposited());
468     }
469 
470     bool paintsWithTransform(PaintBehavior) const;
471 
containsDirtyOverlayScrollbars()472     bool containsDirtyOverlayScrollbars() const { return m_containsDirtyOverlayScrollbars; }
setContainsDirtyOverlayScrollbars(bool dirtyScrollbars)473     void setContainsDirtyOverlayScrollbars(bool dirtyScrollbars) { m_containsDirtyOverlayScrollbars = dirtyScrollbars; }
474 
475 #if ENABLE(ANDROID_OVERFLOW_SCROLL)
hasOverflowScroll()476     bool hasOverflowScroll() const { return m_hasOverflowScroll; }
477     bool hasOverflowParent() const;
478 #endif
479 #if PLATFORM(ANDROID)
intrinsicallyComposited()480     bool intrinsicallyComposited() const { return m_intrinsicallyComposited; }
setIntrinsicallyComposited(bool intrinsicallyComposited)481     void setIntrinsicallyComposited(bool intrinsicallyComposited) {
482         m_intrinsicallyComposited = intrinsicallyComposited;
483     }
484 #endif
485 
486 private:
487     // The normal operator new is disallowed on all render objects.
488     void* operator new(size_t) throw();
489 
setNextSibling(RenderLayer * next)490     void setNextSibling(RenderLayer* next) { m_next = next; }
setPreviousSibling(RenderLayer * prev)491     void setPreviousSibling(RenderLayer* prev) { m_previous = prev; }
492     void setParent(RenderLayer* parent);
setFirstChild(RenderLayer * first)493     void setFirstChild(RenderLayer* first) { m_first = first; }
setLastChild(RenderLayer * last)494     void setLastChild(RenderLayer* last) { m_last = last; }
495 
renderBoxX()496     int renderBoxX() const { return renderer()->isBox() ? toRenderBox(renderer())->x() : 0; }
renderBoxY()497     int renderBoxY() const { return renderer()->isBox() ? toRenderBox(renderer())->y() : 0; }
498 
499     void collectLayers(Vector<RenderLayer*>*&, Vector<RenderLayer*>*&);
500 
501     void updateLayerListsIfNeeded();
502     void updateCompositingAndLayerListsIfNeeded();
503 
504     enum PaintLayerFlag {
505         PaintLayerHaveTransparency = 1,
506         PaintLayerAppliedTransform = 1 << 1,
507         PaintLayerTemporaryClipRects = 1 << 2,
508         PaintLayerPaintingReflection = 1 << 3,
509         PaintLayerPaintingOverlayScrollbars = 1 << 4
510     };
511 
512     typedef unsigned PaintLayerFlags;
513 
514     void paintLayer(RenderLayer* rootLayer, GraphicsContext*, const IntRect& paintDirtyRect,
515                     PaintBehavior, RenderObject* paintingRoot, OverlapTestRequestMap* = 0,
516                     PaintLayerFlags = 0);
517     void paintList(Vector<RenderLayer*>*, RenderLayer* rootLayer, GraphicsContext* p,
518                    const IntRect& paintDirtyRect, PaintBehavior,
519                    RenderObject* paintingRoot, OverlapTestRequestMap*,
520                    PaintLayerFlags);
521     void paintPaginatedChildLayer(RenderLayer* childLayer, RenderLayer* rootLayer, GraphicsContext*,
522                                   const IntRect& paintDirtyRect, PaintBehavior,
523                                   RenderObject* paintingRoot, OverlapTestRequestMap*,
524                                   PaintLayerFlags);
525     void paintChildLayerIntoColumns(RenderLayer* childLayer, RenderLayer* rootLayer, GraphicsContext*,
526                                     const IntRect& paintDirtyRect, PaintBehavior,
527                                     RenderObject* paintingRoot, OverlapTestRequestMap*,
528                                     PaintLayerFlags, const Vector<RenderLayer*>& columnLayers, size_t columnIndex);
529 
530     RenderLayer* hitTestLayer(RenderLayer* rootLayer, RenderLayer* containerLayer, const HitTestRequest& request, HitTestResult& result,
531                               const IntRect& hitTestRect, const IntPoint& hitTestPoint, bool appliedTransform,
532                               const HitTestingTransformState* transformState = 0, double* zOffset = 0);
533     RenderLayer* hitTestList(Vector<RenderLayer*>*, RenderLayer* rootLayer, const HitTestRequest& request, HitTestResult& result,
534                              const IntRect& hitTestRect, const IntPoint& hitTestPoint,
535                              const HitTestingTransformState* transformState, double* zOffsetForDescendants, double* zOffset,
536                              const HitTestingTransformState* unflattenedTransformState, bool depthSortDescendants);
537     RenderLayer* hitTestPaginatedChildLayer(RenderLayer* childLayer, RenderLayer* rootLayer, const HitTestRequest& request, HitTestResult& result,
538                                             const IntRect& hitTestRect, const IntPoint& hitTestPoint,
539                                             const HitTestingTransformState* transformState, double* zOffset);
540     RenderLayer* hitTestChildLayerColumns(RenderLayer* childLayer, RenderLayer* rootLayer, const HitTestRequest& request, HitTestResult& result,
541                                           const IntRect& hitTestRect, const IntPoint& hitTestPoint,
542                                           const HitTestingTransformState* transformState, double* zOffset,
543                                           const Vector<RenderLayer*>& columnLayers, size_t columnIndex);
544 
545     PassRefPtr<HitTestingTransformState> createLocalTransformState(RenderLayer* rootLayer, RenderLayer* containerLayer,
546                             const IntRect& hitTestRect, const IntPoint& hitTestPoint,
547                             const HitTestingTransformState* containerTransformState) const;
548 
549     bool hitTestContents(const HitTestRequest&, HitTestResult&, const IntRect& layerBounds, const IntPoint& hitTestPoint, HitTestFilter) const;
550 
551     void computeScrollDimensions(bool* needHBar = 0, bool* needVBar = 0);
552 
553     bool shouldBeNormalFlowOnly() const;
554 
555     // ScrollableArea interface
556     virtual int scrollSize(ScrollbarOrientation orientation) const;
557     virtual void setScrollOffset(const IntPoint&);
558     virtual int scrollPosition(Scrollbar*) const;
559     virtual void invalidateScrollbarRect(Scrollbar*, const IntRect&);
560     virtual void invalidateScrollCornerRect(const IntRect&);
561     virtual bool isActive() const;
562     virtual bool isScrollCornerVisible() const;
563     virtual IntRect scrollCornerRect() const;
564     virtual IntRect convertFromScrollbarToContainingView(const Scrollbar*, const IntRect&) const;
565     virtual IntRect convertFromContainingViewToScrollbar(const Scrollbar*, const IntRect&) const;
566     virtual IntPoint convertFromScrollbarToContainingView(const Scrollbar*, const IntPoint&) const;
567     virtual IntPoint convertFromContainingViewToScrollbar(const Scrollbar*, const IntPoint&) const;
568     virtual IntSize contentsSize() const;
569     virtual int visibleHeight() const;
570     virtual int visibleWidth() const;
571     virtual IntPoint currentMousePosition() const;
572     virtual bool shouldSuspendScrollAnimations() const;
573 
574     // Rectangle encompassing the scroll corner and resizer rect.
575     IntRect scrollCornerAndResizerRect() const;
576 
disconnectFromPage()577     virtual void disconnectFromPage() { m_page = 0; }
578 
579     // NOTE: This should only be called by the overriden setScrollOffset from ScrollableArea.
580     void scrollTo(int x, int y);
581 
582     IntSize scrollbarOffset(const Scrollbar*) const;
583 
584     void updateOverflowStatus(bool horizontalOverflow, bool verticalOverflow);
585 
586     void childVisibilityChanged(bool newVisibility);
587     void dirtyVisibleDescendantStatus();
588     void updateVisibilityStatus();
589 
590     // This flag is computed by RenderLayerCompositor, which knows more about 3d hierarchies than we do.
setHas3DTransformedDescendant(bool b)591     void setHas3DTransformedDescendant(bool b) { m_has3DTransformedDescendant = b; }
has3DTransformedDescendant()592     bool has3DTransformedDescendant() const { return m_has3DTransformedDescendant; }
593 
594     void dirty3DTransformedDescendantStatus();
595     // Both updates the status, and returns true if descendants of this have 3d.
596     bool update3DTransformedDescendantStatus();
597 
598     Node* enclosingElement() const;
599 
600     void createReflection();
601     void removeReflection();
602 
603     void updateReflectionStyle();
paintingInsideReflection()604     bool paintingInsideReflection() const { return m_paintingInsideReflection; }
setPaintingInsideReflection(bool b)605     void setPaintingInsideReflection(bool b) { m_paintingInsideReflection = b; }
606 
607     void parentClipRects(const RenderLayer* rootLayer, ClipRects&, bool temporaryClipRects = false, OverlayScrollbarSizeRelevancy = IgnoreOverlayScrollbarSize) const;
608     IntRect backgroundClipRect(const RenderLayer* rootLayer, bool temporaryClipRects, OverlayScrollbarSizeRelevancy = IgnoreOverlayScrollbarSize) const;
609 
610     RenderLayer* enclosingTransformedAncestor() const;
611 
612     // Convert a point in absolute coords into layer coords, taking transforms into account
613     IntPoint absoluteToContents(const IntPoint&) const;
614 
615     void positionOverflowControls(int tx, int ty);
616     void updateScrollCornerStyle();
617     void updateResizerStyle();
618 
619     void updatePagination();
isPaginated()620     bool isPaginated() const { return m_isPaginated; }
621 
622 #if USE(ACCELERATED_COMPOSITING)
hasCompositingDescendant()623     bool hasCompositingDescendant() const { return m_hasCompositingDescendant; }
setHasCompositingDescendant(bool b)624     void setHasCompositingDescendant(bool b)  { m_hasCompositingDescendant = b; }
625 
mustOverlapCompositedLayers()626     bool mustOverlapCompositedLayers() const { return m_mustOverlapCompositedLayers; }
setMustOverlapCompositedLayers(bool b)627     void setMustOverlapCompositedLayers(bool b) { m_mustOverlapCompositedLayers = b; }
628 #if ENABLE(COMPOSITED_FIXED_ELEMENTS)
shouldComposite()629     bool shouldComposite() { return m_shouldComposite; }
setShouldComposite(bool b)630     void setShouldComposite(bool b) { m_shouldComposite = b; }
631 #endif
632 #endif
633 
634     void updateContentsScale(float);
635 
636     friend class RenderLayerBacking;
637     friend class RenderLayerCompositor;
638     friend class RenderBoxModelObject;
639 
640     // Only safe to call from RenderBoxModelObject::destroyLayer(RenderArena*)
641     void destroy(RenderArena*);
642 
643     int overflowTop() const;
644     int overflowBottom() const;
645     int overflowLeft() const;
646     int overflowRight() const;
647 
648 protected:
649     RenderBoxModelObject* m_renderer;
650 
651     RenderLayer* m_parent;
652     RenderLayer* m_previous;
653     RenderLayer* m_next;
654     RenderLayer* m_first;
655     RenderLayer* m_last;
656 
657     IntRect m_repaintRect; // Cached repaint rects. Used by layout.
658     IntRect m_outlineBox;
659 
660     // Our current relative position offset.
661     int m_relX;
662     int m_relY;
663 
664     // Our (x,y) coordinates are in our parent layer's coordinate space.
665     int m_x;
666     int m_y;
667 
668     // The layer's width/height
669     int m_width;
670     int m_height;
671 
672     // Our scroll offsets if the view is scrolled.
673     int m_scrollX;
674     int m_scrollY;
675 
676     int m_scrollLeftOverflow;
677     int m_scrollTopOverflow;
678 
679     // The width/height of our scrolled area.
680     int m_scrollWidth;
681     int m_scrollHeight;
682 
683     // For layers with overflow, we have a pair of scrollbars.
684     RefPtr<Scrollbar> m_hBar;
685     RefPtr<Scrollbar> m_vBar;
686 
687     // Keeps track of whether the layer is currently resizing, so events can cause resizing to start and stop.
688     bool m_inResizeMode;
689 
690     // For layers that establish stacking contexts, m_posZOrderList holds a sorted list of all the
691     // descendant layers within the stacking context that have z-indices of 0 or greater
692     // (auto will count as 0).  m_negZOrderList holds descendants within our stacking context with negative
693     // z-indices.
694     Vector<RenderLayer*>* m_posZOrderList;
695     Vector<RenderLayer*>* m_negZOrderList;
696 
697     // This list contains child layers that cannot create stacking contexts.  For now it is just
698     // overflow layers, but that may change in the future.
699     Vector<RenderLayer*>* m_normalFlowList;
700 
701     ClipRects* m_clipRects;      // Cached clip rects used when painting and hit testing.
702 #ifndef NDEBUG
703     const RenderLayer* m_clipRectsRoot;   // Root layer used to compute clip rects.
704 #endif
705 
706     bool m_scrollDimensionsDirty : 1;
707     bool m_zOrderListsDirty : 1;
708     bool m_normalFlowListDirty: 1;
709     bool m_isNormalFlowOnly : 1;
710 
711     bool m_usedTransparency : 1; // Tracks whether we need to close a transparent layer, i.e., whether
712                                  // we ended up painting this layer or any descendants (and therefore need to
713                                  // blend).
714     bool m_paintingInsideReflection : 1;  // A state bit tracking if we are painting inside a replica.
715     bool m_inOverflowRelayout : 1;
716     bool m_needsFullRepaint : 1;
717 
718     bool m_overflowStatusDirty : 1;
719     bool m_horizontalOverflow : 1;
720     bool m_verticalOverflow : 1;
721     bool m_visibleContentStatusDirty : 1;
722     bool m_hasVisibleContent : 1;
723     bool m_visibleDescendantStatusDirty : 1;
724     bool m_hasVisibleDescendant : 1;
725 
726     bool m_isPaginated : 1; // If we think this layer is split by a multi-column ancestor, then this bit will be set.
727 
728     bool m_3DTransformedDescendantStatusDirty : 1;
729     bool m_has3DTransformedDescendant : 1;  // Set on a stacking context layer that has 3D descendants anywhere
730                                             // in a preserves3D hierarchy. Hint to do 3D-aware hit testing.
731 #if USE(ACCELERATED_COMPOSITING)
732     bool m_hasCompositingDescendant : 1; // In the z-order tree.
733     bool m_mustOverlapCompositedLayers : 1;
734 #if ENABLE(COMPOSITED_FIXED_ELEMENTS)
735     bool m_shouldComposite : 1;
736 #endif
737 #endif
738 #if PLATFORM(ANDROID)
739     bool m_intrinsicallyComposited : 1;
740 #endif
741 
742     bool m_containsDirtyOverlayScrollbars : 1;
743 #if ENABLE(ANDROID_OVERFLOW_SCROLL)
744     bool m_hasOverflowScroll : 1;
745 #endif
746 
747     IntPoint m_cachedOverlayScrollbarOffset;
748 
749     RenderMarquee* m_marquee; // Used by layers with overflow:marquee
750 
751     // Cached normal flow values for absolute positioned elements with static left/top values.
752     int m_staticInlinePosition;
753     int m_staticBlockPosition;
754 
755     OwnPtr<TransformationMatrix> m_transform;
756 
757     // May ultimately be extended to many replicas (with their own paint order).
758     RenderReplica* m_reflection;
759 
760     // Renderers to hold our custom scroll corner and resizer.
761     RenderScrollbarPart* m_scrollCorner;
762     RenderScrollbarPart* m_resizer;
763 
764 private:
765     IntRect m_blockSelectionGapsBounds;
766 
767 #if USE(ACCELERATED_COMPOSITING)
768     OwnPtr<RenderLayerBacking> m_backing;
769 #endif
770 
771     Page* m_page;
772 };
773 
774 } // namespace WebCore
775 
776 #ifndef NDEBUG
777 // Outside the WebCore namespace for ease of invocation from gdb.
778 void showLayerTree(const WebCore::RenderLayer*);
779 void showLayerTree(const WebCore::RenderObject*);
780 #endif
781 
782 #endif // RenderLayer_h
783