1 /*
2 Copyright (C) 1997 Martin Jones (mjones@kde.org)
3 (C) 1998 Waldo Bastian (bastian@kde.org)
4 (C) 1998, 1999 Torben Weis (weis@kde.org)
5 (C) 1999 Lars Knoll (knoll@kde.org)
6 (C) 1999 Antti Koivisto (koivisto@kde.org)
7 Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple 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 #ifndef FrameView_h
26 #define FrameView_h
27
28 #include "core/rendering/PaintPhase.h"
29 #include "platform/RuntimeEnabledFeatures.h"
30 #include "platform/geometry/LayoutRect.h"
31 #include "platform/graphics/Color.h"
32 #include "platform/scroll/ScrollView.h"
33 #include "wtf/Forward.h"
34 #include "wtf/OwnPtr.h"
35 #include "wtf/text/WTFString.h"
36
37 namespace WebCore {
38
39 class AXObjectCache;
40 class DocumentLifecycle;
41 class Cursor;
42 class Element;
43 class FloatSize;
44 class HTMLFrameOwnerElement;
45 class LocalFrame;
46 class KURL;
47 class Node;
48 class Page;
49 class RenderBox;
50 class RenderEmbeddedObject;
51 class RenderObject;
52 class RenderScrollbarPart;
53 class RenderStyle;
54 class RenderView;
55 class RenderWidget;
56
57 typedef unsigned long long DOMTimeStamp;
58
59 class FrameView FINAL : public ScrollView {
60 public:
61 friend class RenderView;
62 friend class Internals;
63
64 static PassRefPtr<FrameView> create(LocalFrame*);
65 static PassRefPtr<FrameView> create(LocalFrame*, const IntSize& initialSize);
66
67 virtual ~FrameView();
68
69 virtual HostWindow* hostWindow() const OVERRIDE;
70
71 virtual void invalidateRect(const IntRect&) OVERRIDE;
72 virtual void setFrameRect(const IntRect&) OVERRIDE;
73
74 virtual bool scheduleAnimation() OVERRIDE;
75
frame()76 LocalFrame& frame() const { return *m_frame; }
77 Page* page() const;
78
79 RenderView* renderView() const;
80
81 virtual void setCanHaveScrollbars(bool) OVERRIDE;
82
83 virtual PassRefPtr<Scrollbar> createScrollbar(ScrollbarOrientation) OVERRIDE;
84
85 virtual void setContentsSize(const IntSize&) OVERRIDE;
86 IntPoint clampOffsetAtScale(const IntPoint& offset, float scale) const;
87
88 void layout(bool allowSubtree = true);
89 bool didFirstLayout() const;
90 void scheduleRelayout();
91 void scheduleRelayoutOfSubtree(RenderObject*);
92 bool layoutPending() const;
93 bool isInPerformLayout() const;
94
setCanInvalidatePaintDuringPerformLayout(bool b)95 void setCanInvalidatePaintDuringPerformLayout(bool b) { m_canInvalidatePaintDuringPerformLayout = b; }
canInvalidatePaintDuringPerformLayout()96 bool canInvalidatePaintDuringPerformLayout() const { return m_canInvalidatePaintDuringPerformLayout; }
97
98 RenderObject* layoutRoot(bool onlyDuringLayout = false) const;
clearLayoutSubtreeRoot()99 void clearLayoutSubtreeRoot() { m_layoutSubtreeRoot = 0; }
layoutCount()100 int layoutCount() const { return m_layoutCount; }
101
102 bool needsLayout() const;
103 void setNeedsLayout();
104
105 // Methods for getting/setting the size Blink should use to layout the contents.
106 IntSize layoutSize(IncludeScrollbarsInRect = ExcludeScrollbars) const;
107 void setLayoutSize(const IntSize&);
108
109 // If this is set to false, the layout size will need to be explicitly set by the owner.
110 // E.g. WebViewImpl sets its mainFrame's layout size manually
setLayoutSizeFixedToFrameSize(bool isFixed)111 void setLayoutSizeFixedToFrameSize(bool isFixed) { m_layoutSizeFixedToFrameSize = isFixed; }
layoutSizeFixedToFrameSize()112 bool layoutSizeFixedToFrameSize() { return m_layoutSizeFixedToFrameSize; }
113
needsFullPaintInvalidation()114 bool needsFullPaintInvalidation() const { return m_doFullPaintInvalidation; }
115
116 void updateAcceleratedCompositingSettings();
117
118 void recalcOverflowAfterStyleChange();
119
120 bool hasCompositedContent() const;
121 bool isEnclosedInCompositingLayer() const;
122
123 void resetScrollbars();
124 void prepareForDetach();
125 void detachCustomScrollbars();
126 virtual void recalculateScrollbarOverlayStyle();
127
128 void clear();
129
130 bool isTransparent() const;
131 void setTransparent(bool isTransparent);
132
133 // True if the FrameView is not transparent, and the base background color is opaque.
134 bool hasOpaqueBackground() const;
135
136 Color baseBackgroundColor() const;
137 void setBaseBackgroundColor(const Color&);
138 void updateBackgroundRecursively(const Color&, bool);
139
140 void adjustViewSize();
141
142 virtual IntRect windowClipRect(IncludeScrollbarsInRect = ExcludeScrollbars) const OVERRIDE;
143 IntRect windowClipRectForFrameOwner(const HTMLFrameOwnerElement*) const;
144
145 virtual IntRect windowResizerRect() const OVERRIDE;
146
visibleContentScaleFactor()147 virtual float visibleContentScaleFactor() const OVERRIDE { return m_visibleContentScaleFactor; }
148 void setVisibleContentScaleFactor(float);
149
150 virtual float inputEventsScaleFactor() const OVERRIDE;
151 virtual IntSize inputEventsOffsetForEmulation() const OVERRIDE;
152 void setInputEventsTransformForEmulation(const IntSize&, float);
153
154 virtual void setScrollPosition(const IntPoint&) OVERRIDE;
155 virtual bool isRubberBandInProgress() const OVERRIDE;
156 void setScrollPositionNonProgrammatically(const IntPoint&);
157
158 // This is different than visibleContentRect() in that it ignores negative (or overly positive)
159 // offsets from rubber-banding, and it takes zooming into account.
160 LayoutRect viewportConstrainedVisibleContentRect() const;
161 void viewportConstrainedVisibleContentSizeChanged(bool widthChanged, bool heightChanged);
162
163 AtomicString mediaType() const;
164 void setMediaType(const AtomicString&);
165 void adjustMediaTypeForPrinting(bool printing);
166
167 void setCannotBlitToWindow();
168 void setIsOverlapped(bool);
isOverlapped()169 bool isOverlapped() const { return m_isOverlapped; }
170 void setContentIsOpaque(bool);
171
172 void addSlowRepaintObject();
173 void removeSlowRepaintObject();
hasSlowRepaintObjects()174 bool hasSlowRepaintObjects() const { return m_slowRepaintObjectCount; }
175
176 // Includes fixed- and sticky-position objects.
177 typedef HashSet<RenderObject*> ViewportConstrainedObjectSet;
178 void addViewportConstrainedObject(RenderObject*);
179 void removeViewportConstrainedObject(RenderObject*);
viewportConstrainedObjects()180 const ViewportConstrainedObjectSet* viewportConstrainedObjects() const { return m_viewportConstrainedObjects.get(); }
hasViewportConstrainedObjects()181 bool hasViewportConstrainedObjects() const { return m_viewportConstrainedObjects && m_viewportConstrainedObjects->size() > 0; }
182
183 void handleLoadCompleted();
184
185 void updateAnnotatedRegions();
186 void updateControlTints();
187
188 void restoreScrollbar();
189
190 void postLayoutTimerFired(Timer<FrameView>*);
191
192 bool wasScrolledByUser() const;
193 void setWasScrolledByUser(bool);
194
safeToPropagateScrollToParent()195 bool safeToPropagateScrollToParent() const { return m_safeToPropagateScrollToParent; }
setSafeToPropagateScrollToParent(bool isSafe)196 void setSafeToPropagateScrollToParent(bool isSafe) { m_safeToPropagateScrollToParent = isSafe; }
197
198 void addWidget(RenderWidget*);
199 void removeWidget(RenderWidget*);
200 void updateWidgetPositions();
201
202 void addWidgetToUpdate(RenderEmbeddedObject&);
203
204 virtual void paintContents(GraphicsContext*, const IntRect& damageRect) OVERRIDE;
205 void setPaintBehavior(PaintBehavior);
206 PaintBehavior paintBehavior() const;
207 bool isPainting() const;
hasEverPainted()208 bool hasEverPainted() const { return m_lastPaintTime; }
209 void setNodeToDraw(Node*);
210
211 virtual void paintOverhangAreas(GraphicsContext*, const IntRect& horizontalOverhangArea, const IntRect& verticalOverhangArea, const IntRect& dirtyRect) OVERRIDE;
212 virtual void paintScrollCorner(GraphicsContext*, const IntRect& cornerRect) OVERRIDE;
213 virtual void paintScrollbar(GraphicsContext*, Scrollbar*, const IntRect&) OVERRIDE;
214
215 Color documentBackgroundColor() const;
216
currentFrameTimeStamp()217 static double currentFrameTimeStamp() { return s_currentFrameTimeStamp; }
218
219 void updateLayoutAndStyleForPainting();
220 void updateLayoutAndStyleIfNeededRecursive();
221
222 void incrementVisuallyNonEmptyCharacterCount(unsigned);
223 void incrementVisuallyNonEmptyPixelCount(const IntSize&);
setIsVisuallyNonEmpty()224 void setIsVisuallyNonEmpty() { m_isVisuallyNonEmpty = true; }
225 void enableAutoSizeMode(bool enable, const IntSize& minSize, const IntSize& maxSize);
226
227 void forceLayout(bool allowSubtree = false);
228 void forceLayoutForPagination(const FloatSize& pageSize, const FloatSize& originalPageSize, float maximumShrinkFactor);
229
230 bool scrollToFragment(const KURL&);
231 bool scrollToAnchor(const String&);
232 void maintainScrollPositionAtAnchor(Node*);
233 void scrollElementToRect(Element*, const IntRect&);
234 void scrollContentsIfNeededRecursive();
235
236 // Methods to convert points and rects between the coordinate space of the renderer, and this view.
237 IntRect convertFromRenderer(const RenderObject&, const IntRect&) const;
238 IntRect convertToRenderer(const RenderObject&, const IntRect&) const;
239 IntPoint convertFromRenderer(const RenderObject&, const IntPoint&) const;
240 IntPoint convertToRenderer(const RenderObject&, const IntPoint&) const;
241
isFrameViewScrollCorner(RenderScrollbarPart * scrollCorner)242 bool isFrameViewScrollCorner(RenderScrollbarPart* scrollCorner) const { return m_scrollCorner == scrollCorner; }
243
244 bool isScrollable();
245
246 enum ScrollbarModesCalculationStrategy { RulesFromWebContentOnly, AnyRule };
247 void calculateScrollbarModesForLayoutAndSetViewportRenderer(ScrollbarMode& hMode, ScrollbarMode& vMode, ScrollbarModesCalculationStrategy = AnyRule);
248
249 virtual IntPoint lastKnownMousePosition() const OVERRIDE;
250 bool shouldSetCursor() const;
251
252 void setCursor(const Cursor&);
253
254 virtual bool scrollbarsCanBeActive() const OVERRIDE;
255
256 // FIXME: Remove this method once plugin loading is decoupled from layout.
257 void flushAnyPendingPostLayoutTasks();
258
259 virtual bool shouldSuspendScrollAnimations() const OVERRIDE;
260 virtual void scrollbarStyleChanged() OVERRIDE;
261
262 RenderBox* embeddedContentBox() const;
263
264 void setTracksPaintInvalidations(bool);
isTrackingPaintInvalidations()265 bool isTrackingPaintInvalidations() const { return m_isTrackingPaintInvalidations; }
266 void resetTrackedPaintInvalidations();
267 String trackedPaintInvalidationRectsAsText() const;
268
269 typedef HashSet<ScrollableArea*> ScrollableAreaSet;
270 void addScrollableArea(ScrollableArea*);
271 void removeScrollableArea(ScrollableArea*);
scrollableAreas()272 const ScrollableAreaSet* scrollableAreas() const { return m_scrollableAreas.get(); }
273
274 // With CSS style "resize:" enabled, a little resizer handle will appear at the bottom
275 // right of the object. We keep track of these resizer areas for checking if touches
276 // (implemented using Scroll gesture) are targeting the resizer.
277 typedef HashSet<RenderBox*> ResizerAreaSet;
278 void addResizerArea(RenderBox&);
279 void removeResizerArea(RenderBox&);
resizerAreas()280 const ResizerAreaSet* resizerAreas() const { return m_resizerAreas.get(); }
281
282 virtual void removeChild(Widget*) OVERRIDE;
283
284 // This function exists for ports that need to handle wheel events manually.
285 // On Mac WebKit1 the underlying NSScrollView just does the scrolling, but on most other platforms
286 // we need this function in order to do the scroll ourselves.
287 bool wheelEvent(const PlatformWheelEvent&);
288
inProgrammaticScroll()289 bool inProgrammaticScroll() const { return m_inProgrammaticScroll; }
setInProgrammaticScroll(bool programmaticScroll)290 void setInProgrammaticScroll(bool programmaticScroll) { m_inProgrammaticScroll = programmaticScroll; }
291
setHasSoftwareFilters(bool hasSoftwareFilters)292 void setHasSoftwareFilters(bool hasSoftwareFilters) { m_hasSoftwareFilters = hasSoftwareFilters; }
hasSoftwareFilters()293 bool hasSoftwareFilters() const { return m_hasSoftwareFilters; }
294
295 virtual bool isActive() const OVERRIDE;
296
297 // DEPRECATED: Use viewportConstrainedVisibleContentRect() instead.
298 IntSize scrollOffsetForFixedPosition() const;
299
300 // Override scrollbar notifications to update the AXObject cache.
301 virtual void didAddScrollbar(Scrollbar*, ScrollbarOrientation) OVERRIDE;
302 virtual void willRemoveScrollbar(Scrollbar*, ScrollbarOrientation) OVERRIDE;
303
304 virtual bool shouldAttemptToScrollUsingFastPath() const OVERRIDE;
305 // FIXME: This should probably be renamed as the 'inSubtreeLayout' parameter
306 // passed around the FrameView layout methods can be true while this returns
307 // false.
isSubtreeLayout()308 bool isSubtreeLayout() const { return !!m_layoutSubtreeRoot; }
309
310 // Sets the tickmarks for the FrameView, overriding the default behavior
311 // which is to display the tickmarks corresponding to find results.
312 // If |m_tickmarks| is empty, the default behavior is restored.
setTickmarks(const Vector<IntRect> & tickmarks)313 void setTickmarks(const Vector<IntRect>& tickmarks) { m_tickmarks = tickmarks; }
314
315 // ScrollableArea interface
316 virtual void invalidateScrollbarRect(Scrollbar*, const IntRect&) OVERRIDE;
317 virtual void getTickmarks(Vector<IntRect>&) const OVERRIDE;
318 virtual void scrollTo(const IntSize&) OVERRIDE;
319 virtual IntRect scrollableAreaBoundingBox() const OVERRIDE;
320 virtual bool scrollAnimatorEnabled() const OVERRIDE;
321 virtual bool usesCompositedScrolling() const OVERRIDE;
322 virtual GraphicsLayer* layerForScrolling() const OVERRIDE;
323 virtual GraphicsLayer* layerForHorizontalScrollbar() const OVERRIDE;
324 virtual GraphicsLayer* layerForVerticalScrollbar() const OVERRIDE;
325 virtual GraphicsLayer* layerForScrollCorner() const OVERRIDE;
326
327 protected:
328 virtual void scrollContentsIfNeeded();
329 virtual bool scrollContentsFastPath(const IntSize& scrollDelta, const IntRect& rectToScroll, const IntRect& clipRect) OVERRIDE;
330 virtual void scrollContentsSlowPath(const IntRect& updateRect) OVERRIDE;
331
332 virtual bool isVerticalDocument() const OVERRIDE;
333 virtual bool isFlippedDocument() const OVERRIDE;
334
335 private:
336 explicit FrameView(LocalFrame*);
337
338 void reset();
339 void init();
340
341 virtual void frameRectsChanged() OVERRIDE;
isFrameView()342 virtual bool isFrameView() const OVERRIDE { return true; }
343
344 friend class RenderWidget;
345 bool useSlowRepaints(bool considerOverlap = true) const;
346 bool useSlowRepaintsIfNotOverlapped() const;
347
348 bool contentsInCompositedLayer() const;
349
350 void applyOverflowToViewportAndSetRenderer(RenderObject*, ScrollbarMode& hMode, ScrollbarMode& vMode);
351 void updateOverflowStatus(bool horizontalOverflow, bool verticalOverflow);
352
353 void updateCounters();
354 void autoSizeIfEnabled();
355 void forceLayoutParentViewIfNeeded();
356 void performPreLayoutTasks();
357 void performLayout(RenderObject* rootForThisLayout, bool inSubtreeLayout);
358 void scheduleOrPerformPostLayoutTasks();
359 void performPostLayoutTasks();
360
361 void invalidateTree(RenderObject* root);
362
363 void gatherDebugLayoutRects(RenderObject* layoutRoot);
364
365 DocumentLifecycle& lifecycle() const;
366
367 virtual void contentRectangleForPaintInvalidation(const IntRect&) OVERRIDE;
368 virtual void contentsResized() OVERRIDE;
369 virtual void scrollbarExistenceDidChange() OVERRIDE;
370
371 // Override ScrollView methods to do point conversion via renderers, in order to
372 // take transforms into account.
373 virtual IntRect convertToContainingView(const IntRect&) const OVERRIDE;
374 virtual IntRect convertFromContainingView(const IntRect&) const OVERRIDE;
375 virtual IntPoint convertToContainingView(const IntPoint&) const OVERRIDE;
376 virtual IntPoint convertFromContainingView(const IntPoint&) const OVERRIDE;
377
378 void sendResizeEventIfNeeded();
379
380 void updateScrollableAreaSet();
381
382 virtual void notifyPageThatContentAreaWillPaint() const OVERRIDE;
383
384 void scheduleUpdateWidgetsIfNecessary();
385 void updateWidgetsTimerFired(Timer<FrameView>*);
386 bool updateWidgets();
387
388 void scrollToAnchor();
389 void scrollPositionChanged();
390 void didScrollTimerFired(Timer<FrameView>*);
391
392 void updateLayersAndCompositingAfterScrollIfNeeded();
393 void updateFixedElementPaintInvalidationRectsAfterScroll();
394
395 bool hasCustomScrollbars() const;
396 bool shouldUseCustomScrollbars(Element*& customScrollbarElement, LocalFrame*& customScrollbarFrame);
397
398 virtual void updateScrollCorner() OVERRIDE;
399
400 FrameView* parentFrameView() const;
401
402 AXObjectCache* axObjectCache() const;
403 void removeFromAXObjectCache();
404
405 void setLayoutSizeInternal(const IntSize&);
406
paintInvalidationIsAllowed()407 bool paintInvalidationIsAllowed() const
408 {
409 if (!RuntimeEnabledFeatures::repaintAfterLayoutEnabled())
410 return true;
411
412 return !isInPerformLayout() || canInvalidatePaintDuringPerformLayout();
413 }
414
415 static double s_currentFrameTimeStamp; // used for detecting decoded resource thrash in the cache
416 static bool s_inPaintContents;
417
418 LayoutSize m_size;
419
420 typedef HashSet<RefPtr<RenderEmbeddedObject> > EmbeddedObjectSet;
421 EmbeddedObjectSet m_widgetUpdateSet;
422
423 // FIXME: These are just "children" of the FrameView and should be RefPtr<Widget> instead.
424 HashSet<RefPtr<RenderWidget> > m_widgets;
425
426 RefPtr<LocalFrame> m_frame;
427
428 bool m_doFullPaintInvalidation;
429
430 bool m_canHaveScrollbars;
431 bool m_cannotBlitToWindow;
432 bool m_isOverlapped;
433 bool m_contentIsOpaque;
434 unsigned m_slowRepaintObjectCount;
435
436 bool m_hasPendingLayout;
437 RenderObject* m_layoutSubtreeRoot;
438
439 bool m_layoutSchedulingEnabled;
440 bool m_inPerformLayout;
441 bool m_canInvalidatePaintDuringPerformLayout;
442 bool m_inSynchronousPostLayout;
443 int m_layoutCount;
444 unsigned m_nestedLayoutCount;
445 Timer<FrameView> m_postLayoutTasksTimer;
446 Timer<FrameView> m_updateWidgetsTimer;
447 bool m_firstLayoutCallbackPending;
448
449 bool m_firstLayout;
450 bool m_isTransparent;
451 Color m_baseBackgroundColor;
452 IntSize m_lastViewportSize;
453 float m_lastZoomFactor;
454
455 AtomicString m_mediaType;
456 AtomicString m_mediaTypeWhenNotPrinting;
457
458 bool m_overflowStatusDirty;
459 bool m_horizontalOverflow;
460 bool m_verticalOverflow;
461 RenderObject* m_viewportRenderer;
462
463 bool m_wasScrolledByUser;
464 bool m_inProgrammaticScroll;
465 bool m_safeToPropagateScrollToParent;
466
467 double m_lastPaintTime;
468
469 bool m_isTrackingPaintInvalidations; // Used for testing.
470 Vector<IntRect> m_trackedPaintInvalidationRects;
471
472 RefPtrWillBePersistent<Node> m_nodeToDraw;
473 PaintBehavior m_paintBehavior;
474 bool m_isPainting;
475
476 unsigned m_visuallyNonEmptyCharacterCount;
477 unsigned m_visuallyNonEmptyPixelCount;
478 bool m_isVisuallyNonEmpty;
479 bool m_firstVisuallyNonEmptyLayoutCallbackPending;
480
481 RefPtrWillBePersistent<Node> m_maintainScrollPositionAnchor;
482
483 // Renderer to hold our custom scroll corner.
484 RenderScrollbarPart* m_scrollCorner;
485
486 // If true, automatically resize the frame view around its content.
487 bool m_shouldAutoSize;
488 bool m_inAutoSize;
489 // True if autosize has been run since m_shouldAutoSize was set.
490 bool m_didRunAutosize;
491 // The lower bound on the size when autosizing.
492 IntSize m_minAutoSize;
493 // The upper bound on the size when autosizing.
494 IntSize m_maxAutoSize;
495
496 OwnPtr<ScrollableAreaSet> m_scrollableAreas;
497 OwnPtr<ResizerAreaSet> m_resizerAreas;
498 OwnPtr<ViewportConstrainedObjectSet> m_viewportConstrainedObjects;
499
500 bool m_hasSoftwareFilters;
501
502 float m_visibleContentScaleFactor;
503 IntSize m_inputEventsOffsetForEmulation;
504 float m_inputEventsScaleFactorForEmulation;
505
506 IntSize m_layoutSize;
507 bool m_layoutSizeFixedToFrameSize;
508
509 Timer<FrameView> m_didScrollTimer;
510
511 Vector<IntRect> m_tickmarks;
512 };
513
incrementVisuallyNonEmptyCharacterCount(unsigned count)514 inline void FrameView::incrementVisuallyNonEmptyCharacterCount(unsigned count)
515 {
516 if (m_isVisuallyNonEmpty)
517 return;
518 m_visuallyNonEmptyCharacterCount += count;
519 // Use a threshold value to prevent very small amounts of visible content from triggering didFirstVisuallyNonEmptyLayout.
520 // The first few hundred characters rarely contain the interesting content of the page.
521 static const unsigned visualCharacterThreshold = 200;
522 if (m_visuallyNonEmptyCharacterCount > visualCharacterThreshold)
523 setIsVisuallyNonEmpty();
524 }
525
incrementVisuallyNonEmptyPixelCount(const IntSize & size)526 inline void FrameView::incrementVisuallyNonEmptyPixelCount(const IntSize& size)
527 {
528 if (m_isVisuallyNonEmpty)
529 return;
530 m_visuallyNonEmptyPixelCount += size.width() * size.height();
531 // Use a threshold value to prevent very small amounts of visible content from triggering didFirstVisuallyNonEmptyLayout
532 static const unsigned visualPixelThreshold = 32 * 32;
533 if (m_visuallyNonEmptyPixelCount > visualPixelThreshold)
534 setIsVisuallyNonEmpty();
535 }
536
537 DEFINE_TYPE_CASTS(FrameView, Widget, widget, widget->isFrameView(), widget.isFrameView());
538
539 class AllowPaintInvalidationScope {
540 public:
AllowPaintInvalidationScope(FrameView * view)541 explicit AllowPaintInvalidationScope(FrameView* view)
542 : m_view(view)
543 , m_originalValue(view ? view->canInvalidatePaintDuringPerformLayout() : false)
544 {
545 if (!m_view)
546 return;
547
548 m_view->setCanInvalidatePaintDuringPerformLayout(true);
549 }
550
~AllowPaintInvalidationScope()551 ~AllowPaintInvalidationScope()
552 {
553 if (!m_view)
554 return;
555
556 m_view->setCanInvalidatePaintDuringPerformLayout(m_originalValue);
557 }
558 private:
559 FrameView* m_view;
560 bool m_originalValue;
561 };
562
563 } // namespace WebCore
564
565 #endif // FrameView_h
566