1/*
2 * Copyright (C) 2009, 2010 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27
28#include "RenderLayerCompositor.h"
29
30#include "CSSAnimationController.h"
31#include "CSSPropertyNames.h"
32#include "CanvasRenderingContext.h"
33#include "Chrome.h"
34#include "ChromeClient.h"
35#include "DocumentTimeline.h"
36#include "Frame.h"
37#include "FrameView.h"
38#include "FullscreenManager.h"
39#include "GraphicsLayer.h"
40#include "HTMLCanvasElement.h"
41#include "HTMLIFrameElement.h"
42#include "HTMLNames.h"
43#include "HitTestResult.h"
44#include "InspectorInstrumentation.h"
45#include "LayerOverlapMap.h"
46#include "Logging.h"
47#include "NodeList.h"
48#include "Page.h"
49#include "PageOverlayController.h"
50#include "RenderEmbeddedObject.h"
51#include "RenderFragmentedFlow.h"
52#include "RenderFullScreen.h"
53#include "RenderGeometryMap.h"
54#include "RenderIFrame.h"
55#include "RenderLayerBacking.h"
56#include "RenderReplica.h"
57#include "RenderVideo.h"
58#include "RenderView.h"
59#include "RuntimeEnabledFeatures.h"
60#include "ScrollingConstraints.h"
61#include "ScrollingCoordinator.h"
62#include "Settings.h"
63#include "TiledBacking.h"
64#include "TransformState.h"
65#include <wtf/HexNumber.h>
66#include <wtf/MemoryPressureHandler.h>
67#include <wtf/SetForScope.h>
68#include <wtf/text/CString.h>
69#include <wtf/text/StringBuilder.h>
70#include <wtf/text/StringConcatenateNumbers.h>
71#include <wtf/text/TextStream.h>
72
73#if PLATFORM(IOS_FAMILY)
74#include "LegacyTileCache.h"
75#include "RenderScrollbar.h"
76#endif
77
78#if PLATFORM(MAC)
79#include "LocalDefaultSystemAppearance.h"
80#endif
81
82#if ENABLE(TREE_DEBUGGING)
83#include "RenderTreeAsText.h"
84#endif
85
86#if ENABLE(3D_TRANSFORMS)
87// This symbol is used to determine from a script whether 3D rendering is enabled (via 'nm').
88WEBCORE_EXPORT bool WebCoreHas3DRendering = true;
89#endif
90
91#if !PLATFORM(MAC) && !PLATFORM(IOS_FAMILY)
92#define USE_COMPOSITING_FOR_SMALL_CANVASES 1
93#endif
94
95namespace WebCore {
96
97#if !USE(COMPOSITING_FOR_SMALL_CANVASES)
98static const int canvasAreaThresholdRequiringCompositing = 50 * 100;
99#endif
100// During page loading delay layer flushes up to this many seconds to allow them coalesce, reducing workload.
101#if PLATFORM(IOS_FAMILY)
102static const Seconds throttledLayerFlushInitialDelay { 500_ms };
103static const Seconds throttledLayerFlushDelay { 1.5_s };
104#else
105static const Seconds throttledLayerFlushInitialDelay { 500_ms };
106static const Seconds throttledLayerFlushDelay { 500_ms };
107#endif
108
109using namespace HTMLNames;
110
111struct ScrollingTreeState {
112 Optional<ScrollingNodeID> parentNodeID;
113 size_t nextChildIndex { 0 };
114};
115
116struct RenderLayerCompositor::OverlapExtent {
117 LayoutRect bounds;
118 bool extentComputed { false };
119 bool hasTransformAnimation { false };
120 bool animationCausesExtentUncertainty { false };
121
122 bool knownToBeHaveExtentUncertainty() const { return extentComputed && animationCausesExtentUncertainty; }
123};
124
125struct RenderLayerCompositor::CompositingState {
126 CompositingState(RenderLayer* compAncestor, bool testOverlap = true)
127 : compositingAncestor(compAncestor)
128 , testingOverlap(testOverlap)
129 {
130 }
131
132 CompositingState stateForPaintOrderChildren(RenderLayer& layer) const
133 {
134 UNUSED_PARAM(layer);
135 CompositingState childState(compositingAncestor);
136 if (layer.isStackingContext())
137 childState.stackingContextAncestor = &layer;
138 else
139 childState.stackingContextAncestor = stackingContextAncestor;
140
141 childState.backingSharingAncestor = backingSharingAncestor;
142 childState.subtreeIsCompositing = false;
143 childState.testingOverlap = testingOverlap;
144 childState.fullPaintOrderTraversalRequired = fullPaintOrderTraversalRequired;
145 childState.descendantsRequireCompositingUpdate = descendantsRequireCompositingUpdate;
146 childState.ancestorHasTransformAnimation = ancestorHasTransformAnimation;
147#if ENABLE(CSS_COMPOSITING)
148 childState.hasNotIsolatedCompositedBlendingDescendants = false; // FIXME: should this only be reset for stacking contexts?
149#endif
150#if !LOG_DISABLED
151 childState.depth = depth + 1;
152#endif
153 return childState;
154 }
155
156 void updateWithDescendantStateAndLayer(const CompositingState& childState, const RenderLayer& layer, const OverlapExtent& layerExtent, bool isUnchangedSubtree = false)
157 {
158 // Subsequent layers in the parent stacking context also need to composite.
159 subtreeIsCompositing |= childState.subtreeIsCompositing | layer.isComposited();
160 if (!isUnchangedSubtree)
161 fullPaintOrderTraversalRequired |= childState.fullPaintOrderTraversalRequired;
162
163 // Turn overlap testing off for later layers if it's already off, or if we have an animating transform.
164 // Note that if the layer clips its descendants, there's no reason to propagate the child animation to the parent layers. That's because
165 // we know for sure the animation is contained inside the clipping rectangle, which is already added to the overlap map.
166 auto canReenableOverlapTesting = [&layer]() {
167 return layer.isComposited() && RenderLayerCompositor::clipsCompositingDescendants(layer);
168 };
169 if ((!childState.testingOverlap && !canReenableOverlapTesting()) || layerExtent.knownToBeHaveExtentUncertainty())
170 testingOverlap = false;
171
172#if ENABLE(CSS_COMPOSITING)
173 if ((layer.isComposited() && layer.hasBlendMode()) || (layer.hasNotIsolatedCompositedBlendingDescendants() && !layer.isolatesCompositedBlending()))
174 hasNotIsolatedCompositedBlendingDescendants = true;
175#endif
176 }
177
178 bool hasNonRootCompositedAncestor() const
179 {
180 return compositingAncestor && !compositingAncestor->isRenderViewLayer();
181 }
182
183 RenderLayer* compositingAncestor;
184 RenderLayer* backingSharingAncestor { nullptr };
185 RenderLayer* stackingContextAncestor { nullptr };
186 bool subtreeIsCompositing { false };
187 bool testingOverlap { true };
188 bool fullPaintOrderTraversalRequired { false };
189 bool descendantsRequireCompositingUpdate { false };
190 bool ancestorHasTransformAnimation { false };
191#if ENABLE(CSS_COMPOSITING)
192 bool hasNotIsolatedCompositedBlendingDescendants { false };
193#endif
194#if !LOG_DISABLED
195 unsigned depth { 0 };
196#endif
197};
198
199class RenderLayerCompositor::BackingSharingState {
200 WTF_MAKE_NONCOPYABLE(BackingSharingState);
201public:
202 BackingSharingState() = default;
203
204 RenderLayer* backingProviderCandidate() const { return m_backingProviderCandidate; };
205
206 void appendSharingLayer(RenderLayer& layer)
207 {
208 LOG_WITH_STREAM(Compositing, stream << &layer << " appendSharingLayer " << &layer << " for backing provider " << m_backingProviderCandidate);
209 m_backingSharingLayers.append(makeWeakPtr(layer));
210 }
211
212 void updateBeforeDescendantTraversal(RenderLayer&, bool willBeComposited);
213 void updateAfterDescendantTraversal(RenderLayer&, RenderLayer* stackingContextAncestor);
214
215private:
216 void layerWillBeComposited(RenderLayer&);
217
218 void startBackingSharingSequence(RenderLayer& candidateLayer, RenderLayer* candidateStackingContext);
219 void endBackingSharingSequence();
220
221 RenderLayer* m_backingProviderCandidate { nullptr };
222 RenderLayer* m_backingProviderStackingContext { nullptr };
223 Vector<WeakPtr<RenderLayer>> m_backingSharingLayers;
224};
225
226void RenderLayerCompositor::BackingSharingState::startBackingSharingSequence(RenderLayer& candidateLayer, RenderLayer* candidateStackingContext)
227{
228 ASSERT(!m_backingProviderCandidate);
229 ASSERT(m_backingSharingLayers.isEmpty());
230
231 m_backingProviderCandidate = &candidateLayer;
232 m_backingProviderStackingContext = candidateStackingContext;
233}
234
235void RenderLayerCompositor::BackingSharingState::endBackingSharingSequence()
236{
237 if (m_backingProviderCandidate) {
238 m_backingProviderCandidate->backing()->setBackingSharingLayers(WTFMove(m_backingSharingLayers));
239 m_backingSharingLayers.clear();
240 }
241
242 m_backingProviderCandidate = nullptr;
243}
244
245void RenderLayerCompositor::BackingSharingState::updateBeforeDescendantTraversal(RenderLayer& layer, bool willBeComposited)
246{
247 layer.setBackingProviderLayer(nullptr);
248
249 // A layer that composites resets backing-sharing, since subsequent layers need to composite to overlap it.
250 if (willBeComposited) {
251 m_backingSharingLayers.removeAll(&layer);
252 LOG_WITH_STREAM(Compositing, stream << "Pre-descendant compositing of " << &layer << ", ending sharing sequence for " << m_backingProviderCandidate << " with " << m_backingSharingLayers.size() << " sharing layers");
253 endBackingSharingSequence();
254 }
255}
256
257void RenderLayerCompositor::BackingSharingState::updateAfterDescendantTraversal(RenderLayer& layer, RenderLayer* stackingContextAncestor)
258{
259 if (layer.isComposited()) {
260 // If this layer is being composited, clean up sharing-related state.
261 layer.disconnectFromBackingProviderLayer();
262 m_backingSharingLayers.removeAll(&layer);
263 }
264
265 if (m_backingProviderCandidate && &layer == m_backingProviderStackingContext) {
266 LOG_WITH_STREAM(Compositing, stream << "End of stacking context for backing provider " << m_backingProviderCandidate << ", ending sharing sequence with " << m_backingSharingLayers.size() << " sharing layers");
267 endBackingSharingSequence();
268 } else if (!m_backingProviderCandidate && layer.isComposited()) {
269 LOG_WITH_STREAM(Compositing, stream << "Post-descendant compositing of " << &layer << ", ending sharing sequence for " << m_backingProviderCandidate << " with " << m_backingSharingLayers.size() << " sharing layers");
270 endBackingSharingSequence();
271 startBackingSharingSequence(layer, stackingContextAncestor);
272 }
273
274 if (&layer != m_backingProviderCandidate && layer.isComposited())
275 layer.backing()->clearBackingSharingLayers();
276}
277
278#if !LOG_DISABLED
279static inline bool compositingLogEnabled()
280{
281 return LogCompositing.state == WTFLogChannelState::On;
282}
283
284static inline bool layersLogEnabled()
285{
286 return LogLayers.state == WTFLogChannelState::On;
287}
288#endif
289
290RenderLayerCompositor::RenderLayerCompositor(RenderView& renderView)
291 : m_renderView(renderView)
292 , m_updateCompositingLayersTimer(*this, &RenderLayerCompositor::updateCompositingLayersTimerFired)
293 , m_layerFlushTimer(*this, &RenderLayerCompositor::layerFlushTimerFired)
294{
295#if PLATFORM(IOS_FAMILY)
296 if (m_renderView.frameView().platformWidget())
297 m_legacyScrollingLayerCoordinator = std::make_unique<LegacyWebKitScrollingLayerCoordinator>(page().chrome().client(), isMainFrameCompositor());
298#endif
299}
300
301RenderLayerCompositor::~RenderLayerCompositor()
302{
303 // Take care that the owned GraphicsLayers are deleted first as their destructors may call back here.
304 GraphicsLayer::unparentAndClear(m_rootContentsLayer);
305
306 GraphicsLayer::unparentAndClear(m_clipLayer);
307 GraphicsLayer::unparentAndClear(m_scrollContainerLayer);
308 GraphicsLayer::unparentAndClear(m_scrolledContentsLayer);
309
310 GraphicsLayer::unparentAndClear(m_overflowControlsHostLayer);
311
312 GraphicsLayer::unparentAndClear(m_layerForHorizontalScrollbar);
313 GraphicsLayer::unparentAndClear(m_layerForVerticalScrollbar);
314 GraphicsLayer::unparentAndClear(m_layerForScrollCorner);
315
316#if ENABLE(RUBBER_BANDING)
317 GraphicsLayer::unparentAndClear(m_layerForOverhangAreas);
318 GraphicsLayer::unparentAndClear(m_contentShadowLayer);
319 GraphicsLayer::unparentAndClear(m_layerForTopOverhangArea);
320 GraphicsLayer::unparentAndClear(m_layerForBottomOverhangArea);
321 GraphicsLayer::unparentAndClear(m_layerForHeader);
322 GraphicsLayer::unparentAndClear(m_layerForFooter);
323#endif
324
325 ASSERT(m_rootLayerAttachment == RootLayerUnattached);
326}
327
328void RenderLayerCompositor::enableCompositingMode(bool enable /* = true */)
329{
330 if (enable != m_compositing) {
331 m_compositing = enable;
332
333 if (m_compositing) {
334 ensureRootLayer();
335 notifyIFramesOfCompositingChange();
336 } else
337 destroyRootLayer();
338
339
340 m_renderView.layer()->setNeedsPostLayoutCompositingUpdate();
341 }
342}
343
344void RenderLayerCompositor::cacheAcceleratedCompositingFlags()
345{
346 auto& settings = m_renderView.settings();
347 bool hasAcceleratedCompositing = settings.acceleratedCompositingEnabled();
348
349 // We allow the chrome to override the settings, in case the page is rendered
350 // on a chrome that doesn't allow accelerated compositing.
351 if (hasAcceleratedCompositing) {
352 m_compositingTriggers = page().chrome().client().allowedCompositingTriggers();
353 hasAcceleratedCompositing = m_compositingTriggers;
354 }
355
356 bool showDebugBorders = settings.showDebugBorders();
357 bool showRepaintCounter = settings.showRepaintCounter();
358 bool acceleratedDrawingEnabled = settings.acceleratedDrawingEnabled();
359 bool displayListDrawingEnabled = settings.displayListDrawingEnabled();
360
361 // forceCompositingMode for subframes can only be computed after layout.
362 bool forceCompositingMode = m_forceCompositingMode;
363 if (isMainFrameCompositor())
364 forceCompositingMode = m_renderView.settings().forceCompositingMode() && hasAcceleratedCompositing;
365
366 if (hasAcceleratedCompositing != m_hasAcceleratedCompositing || showDebugBorders != m_showDebugBorders || showRepaintCounter != m_showRepaintCounter || forceCompositingMode != m_forceCompositingMode) {
367 if (auto* rootLayer = m_renderView.layer()) {
368 rootLayer->setNeedsCompositingConfigurationUpdate();
369 rootLayer->setDescendantsNeedUpdateBackingAndHierarchyTraversal();
370 }
371 }
372
373 bool debugBordersChanged = m_showDebugBorders != showDebugBorders;
374 m_hasAcceleratedCompositing = hasAcceleratedCompositing;
375 m_forceCompositingMode = forceCompositingMode;
376 m_showDebugBorders = showDebugBorders;
377 m_showRepaintCounter = showRepaintCounter;
378 m_acceleratedDrawingEnabled = acceleratedDrawingEnabled;
379 m_displayListDrawingEnabled = displayListDrawingEnabled;
380
381 if (debugBordersChanged) {
382 if (m_layerForHorizontalScrollbar)
383 m_layerForHorizontalScrollbar->setShowDebugBorder(m_showDebugBorders);
384
385 if (m_layerForVerticalScrollbar)
386 m_layerForVerticalScrollbar->setShowDebugBorder(m_showDebugBorders);
387
388 if (m_layerForScrollCorner)
389 m_layerForScrollCorner->setShowDebugBorder(m_showDebugBorders);
390 }
391
392 if (updateCompositingPolicy())
393 rootRenderLayer().setDescendantsNeedCompositingRequirementsTraversal();
394}
395
396void RenderLayerCompositor::cacheAcceleratedCompositingFlagsAfterLayout()
397{
398 cacheAcceleratedCompositingFlags();
399
400 if (isMainFrameCompositor())
401 return;
402
403 RequiresCompositingData queryData;
404 bool forceCompositingMode = m_hasAcceleratedCompositing && m_renderView.settings().forceCompositingMode() && requiresCompositingForScrollableFrame(queryData);
405 if (forceCompositingMode != m_forceCompositingMode) {
406 m_forceCompositingMode = forceCompositingMode;
407 rootRenderLayer().setDescendantsNeedCompositingRequirementsTraversal();
408 }
409}
410
411bool RenderLayerCompositor::updateCompositingPolicy()
412{
413 if (!usesCompositing())
414 return false;
415
416 auto currentPolicy = m_compositingPolicy;
417 if (page().compositingPolicyOverride()) {
418 m_compositingPolicy = page().compositingPolicyOverride().value();
419 return m_compositingPolicy != currentPolicy;
420 }
421
422 auto memoryPolicy = MemoryPressureHandler::currentMemoryUsagePolicy();
423 m_compositingPolicy = memoryPolicy == WTF::MemoryUsagePolicy::Unrestricted ? CompositingPolicy::Normal : CompositingPolicy::Conservative;
424 return m_compositingPolicy != currentPolicy;
425}
426
427bool RenderLayerCompositor::canRender3DTransforms() const
428{
429 return hasAcceleratedCompositing() && (m_compositingTriggers & ChromeClient::ThreeDTransformTrigger);
430}
431
432void RenderLayerCompositor::willRecalcStyle()
433{
434 cacheAcceleratedCompositingFlags();
435}
436
437bool RenderLayerCompositor::didRecalcStyleWithNoPendingLayout()
438{
439 return updateCompositingLayers(CompositingUpdateType::AfterStyleChange);
440}
441
442void RenderLayerCompositor::customPositionForVisibleRectComputation(const GraphicsLayer* graphicsLayer, FloatPoint& position) const
443{
444 if (graphicsLayer != m_scrolledContentsLayer.get())
445 return;
446
447 FloatPoint scrollPosition = -position;
448
449 if (m_renderView.frameView().scrollBehaviorForFixedElements() == StickToDocumentBounds)
450 scrollPosition = m_renderView.frameView().constrainScrollPositionForOverhang(roundedIntPoint(scrollPosition));
451
452 position = -scrollPosition;
453}
454
455void RenderLayerCompositor::notifyFlushRequired(const GraphicsLayer* layer)
456{
457 scheduleLayerFlush(layer->canThrottleLayerFlush());
458}
459
460void RenderLayerCompositor::scheduleLayerFlush(bool canThrottle)
461{
462 ASSERT(!m_flushingLayers);
463
464 if (canThrottle)
465 startInitialLayerFlushTimerIfNeeded();
466
467 if (canThrottle && isThrottlingLayerFlushes())
468 m_hasPendingLayerFlush = true;
469 else {
470 m_hasPendingLayerFlush = false;
471 page().renderingUpdateScheduler().scheduleRenderingUpdate();
472 }
473}
474
475FloatRect RenderLayerCompositor::visibleRectForLayerFlushing() const
476{
477 const FrameView& frameView = m_renderView.frameView();
478#if PLATFORM(IOS_FAMILY)
479 return frameView.exposedContentRect();
480#else
481 // Having a m_scrolledContentsLayer indicates that we're doing scrolling via GraphicsLayers.
482 FloatRect visibleRect = m_scrolledContentsLayer ? FloatRect({ }, frameView.sizeForVisibleContent()) : frameView.visibleContentRect();
483
484 if (frameView.viewExposedRect())
485 visibleRect.intersect(frameView.viewExposedRect().value());
486
487 return visibleRect;
488#endif
489}
490
491void RenderLayerCompositor::flushPendingLayerChanges(bool isFlushRoot)
492{
493 // FrameView::flushCompositingStateIncludingSubframes() flushes each subframe,
494 // but GraphicsLayer::flushCompositingState() will cross frame boundaries
495 // if the GraphicsLayers are connected (the RootLayerAttachedViaEnclosingFrame case).
496 // As long as we're not the root of the flush, we can bail.
497 if (!isFlushRoot && rootLayerAttachment() == RootLayerAttachedViaEnclosingFrame)
498 return;
499
500 if (rootLayerAttachment() == RootLayerUnattached) {
501#if PLATFORM(IOS_FAMILY)
502 startLayerFlushTimerIfNeeded();
503#endif
504 m_shouldFlushOnReattach = true;
505 return;
506 }
507
508 auto& frameView = m_renderView.frameView();
509 AnimationUpdateBlock animationUpdateBlock(&frameView.frame().animation());
510
511 ASSERT(!m_flushingLayers);
512 {
513 SetForScope<bool> flushingLayersScope(m_flushingLayers, true);
514
515 if (auto* rootLayer = rootGraphicsLayer()) {
516 FloatRect visibleRect = visibleRectForLayerFlushing();
517 LOG_WITH_STREAM(Compositing, stream << "\nRenderLayerCompositor " << this << " flushPendingLayerChanges (is root " << isFlushRoot << ") visible rect " << visibleRect);
518 rootLayer->flushCompositingState(visibleRect);
519 }
520
521 ASSERT(m_flushingLayers);
522
523#if ENABLE(TREE_DEBUGGING)
524 if (layersLogEnabled()) {
525 LOG(Layers, "RenderLayerCompositor::flushPendingLayerChanges");
526 showGraphicsLayerTree(m_rootContentsLayer.get());
527 }
528#endif
529 }
530
531#if PLATFORM(IOS_FAMILY)
532 updateScrollCoordinatedLayersAfterFlushIncludingSubframes();
533
534 if (isFlushRoot)
535 page().chrome().client().didFlushCompositingLayers();
536#endif
537
538 ++m_layerFlushCount;
539 startLayerFlushTimerIfNeeded();
540}
541
542#if PLATFORM(IOS_FAMILY)
543void RenderLayerCompositor::updateScrollCoordinatedLayersAfterFlushIncludingSubframes()
544{
545 updateScrollCoordinatedLayersAfterFlush();
546
547 auto& frame = m_renderView.frameView().frame();
548 for (Frame* subframe = frame.tree().firstChild(); subframe; subframe = subframe->tree().traverseNext(&frame)) {
549 auto* view = subframe->contentRenderer();
550 if (!view)
551 continue;
552
553 view->compositor().updateScrollCoordinatedLayersAfterFlush();
554 }
555}
556
557void RenderLayerCompositor::updateScrollCoordinatedLayersAfterFlush()
558{
559 if (m_legacyScrollingLayerCoordinator) {
560 m_legacyScrollingLayerCoordinator->registerAllViewportConstrainedLayers(*this);
561 m_legacyScrollingLayerCoordinator->registerScrollingLayersNeedingUpdate();
562 }
563}
564#endif
565
566void RenderLayerCompositor::didChangePlatformLayerForLayer(RenderLayer& layer, const GraphicsLayer*)
567{
568#if PLATFORM(IOS_FAMILY)
569 if (m_legacyScrollingLayerCoordinator)
570 m_legacyScrollingLayerCoordinator->didChangePlatformLayerForLayer(layer);
571#endif
572
573 auto* scrollingCoordinator = this->scrollingCoordinator();
574 if (!scrollingCoordinator)
575 return;
576
577 auto* backing = layer.backing();
578 if (auto nodeID = backing->scrollingNodeIDForRole(ScrollCoordinationRole::Scrolling))
579 updateScrollingNodeLayers(nodeID, layer, *scrollingCoordinator);
580
581 if (auto nodeID = backing->scrollingNodeIDForRole(ScrollCoordinationRole::ViewportConstrained))
582 scrollingCoordinator->setNodeLayers(nodeID, { backing->graphicsLayer() });
583
584 if (auto nodeID = backing->scrollingNodeIDForRole(ScrollCoordinationRole::FrameHosting))
585 scrollingCoordinator->setNodeLayers(nodeID, { backing->graphicsLayer() });
586
587 if (auto nodeID = backing->scrollingNodeIDForRole(ScrollCoordinationRole::Positioning))
588 scrollingCoordinator->setNodeLayers(nodeID, { backing->graphicsLayer() });
589}
590
591void RenderLayerCompositor::didPaintBacking(RenderLayerBacking*)
592{
593 auto& frameView = m_renderView.frameView();
594 frameView.setLastPaintTime(MonotonicTime::now());
595 if (frameView.milestonesPendingPaint())
596 frameView.firePaintRelatedMilestonesIfNeeded();
597}
598
599void RenderLayerCompositor::didChangeVisibleRect()
600{
601 auto* rootLayer = rootGraphicsLayer();
602 if (!rootLayer)
603 return;
604
605 FloatRect visibleRect = visibleRectForLayerFlushing();
606 bool requiresFlush = rootLayer->visibleRectChangeRequiresFlush(visibleRect);
607 LOG_WITH_STREAM(Compositing, stream << "RenderLayerCompositor::didChangeVisibleRect " << visibleRect << " requiresFlush " << requiresFlush);
608 if (requiresFlush)
609 scheduleLayerFlush();
610}
611
612void RenderLayerCompositor::notifyFlushBeforeDisplayRefresh(const GraphicsLayer*)
613{
614 if (!m_layerUpdater) {
615 PlatformDisplayID displayID = page().chrome().displayID();
616 m_layerUpdater = std::make_unique<GraphicsLayerUpdater>(*this, displayID);
617 }
618
619 m_layerUpdater->scheduleUpdate();
620}
621
622void RenderLayerCompositor::flushLayersSoon(GraphicsLayerUpdater&)
623{
624 scheduleLayerFlush(true);
625}
626
627void RenderLayerCompositor::layerTiledBackingUsageChanged(const GraphicsLayer* graphicsLayer, bool usingTiledBacking)
628{
629 if (usingTiledBacking) {
630 ++m_layersWithTiledBackingCount;
631 graphicsLayer->tiledBacking()->setIsInWindow(page().isInWindow());
632 } else {
633 ASSERT(m_layersWithTiledBackingCount > 0);
634 --m_layersWithTiledBackingCount;
635 }
636}
637
638void RenderLayerCompositor::scheduleCompositingLayerUpdate()
639{
640 if (!m_updateCompositingLayersTimer.isActive())
641 m_updateCompositingLayersTimer.startOneShot(0_s);
642}
643
644void RenderLayerCompositor::updateCompositingLayersTimerFired()
645{
646 updateCompositingLayers(CompositingUpdateType::AfterLayout);
647}
648
649void RenderLayerCompositor::cancelCompositingLayerUpdate()
650{
651 m_updateCompositingLayersTimer.stop();
652}
653
654static Optional<ScrollingNodeID> frameHostingNodeForFrame(Frame& frame)
655{
656 if (!frame.document() || !frame.view())
657 return { };
658
659 // Find the frame's enclosing layer in our render tree.
660 auto* ownerElement = frame.document()->ownerElement();
661 if (!ownerElement)
662 return { };
663
664 auto* frameRenderer = ownerElement->renderer();
665 if (!frameRenderer || !is<RenderWidget>(frameRenderer))
666 return { };
667
668 auto& widgetRenderer = downcast<RenderWidget>(*frameRenderer);
669 if (!widgetRenderer.hasLayer() || !widgetRenderer.layer()->isComposited()) {
670 LOG(Scrolling, "frameHostingNodeForFrame: frame renderer has no layer or is not composited.");
671 return { };
672 }
673
674 if (auto frameHostingNodeID = widgetRenderer.layer()->backing()->scrollingNodeIDForRole(ScrollCoordinationRole::FrameHosting))
675 return frameHostingNodeID;
676
677 return { };
678}
679
680// Returns true on a successful update.
681bool RenderLayerCompositor::updateCompositingLayers(CompositingUpdateType updateType, RenderLayer* updateRoot)
682{
683 LOG_WITH_STREAM(Compositing, stream << "RenderLayerCompositor " << this << " updateCompositingLayers " << updateType << " contentLayersCount " << m_contentLayersCount);
684
685#if ENABLE(TREE_DEBUGGING)
686 if (compositingLogEnabled())
687 showPaintOrderTree(m_renderView.layer());
688#endif
689
690 if (updateType == CompositingUpdateType::AfterStyleChange || updateType == CompositingUpdateType::AfterLayout)
691 cacheAcceleratedCompositingFlagsAfterLayout(); // Some flags (e.g. forceCompositingMode) depend on layout.
692
693 m_updateCompositingLayersTimer.stop();
694
695 ASSERT(m_renderView.document().pageCacheState() == Document::NotInPageCache);
696
697 // Compositing layers will be updated in Document::setVisualUpdatesAllowed(bool) if suppressed here.
698 if (!m_renderView.document().visualUpdatesAllowed())
699 return false;
700
701 // Avoid updating the layers with old values. Compositing layers will be updated after the layout is finished.
702 // This happens when m_updateCompositingLayersTimer fires before layout is updated.
703 if (m_renderView.needsLayout()) {
704 LOG_WITH_STREAM(Compositing, stream << "RenderLayerCompositor " << this << " updateCompositingLayers " << updateType << " - m_renderView.needsLayout, bailing ");
705 return false;
706 }
707
708 if (!m_compositing && (m_forceCompositingMode || (isMainFrameCompositor() && page().pageOverlayController().overlayCount())))
709 enableCompositingMode(true);
710
711 bool isPageScroll = !updateRoot || updateRoot == &rootRenderLayer();
712 updateRoot = &rootRenderLayer();
713
714 if (updateType == CompositingUpdateType::OnScroll || updateType == CompositingUpdateType::OnCompositedScroll) {
715 // We only get here if we didn't scroll on the scrolling thread, so this update needs to re-position viewport-constrained layers.
716 if (m_renderView.settings().acceleratedCompositingForFixedPositionEnabled() && isPageScroll) {
717 if (auto* viewportConstrainedObjects = m_renderView.frameView().viewportConstrainedObjects()) {
718 for (auto* renderer : *viewportConstrainedObjects) {
719 if (auto* layer = renderer->layer())
720 layer->setNeedsCompositingGeometryUpdate();
721 }
722 }
723 }
724
725 // Scrolling can affect overlap. FIXME: avoid for page scrolling.
726 updateRoot->setDescendantsNeedCompositingRequirementsTraversal();
727 }
728
729 if (updateType == CompositingUpdateType::AfterLayout) {
730 // Ensure that post-layout updates push new scroll position and viewport rects onto the root node.
731 rootRenderLayer().setNeedsScrollingTreeUpdate();
732 }
733
734 if (!updateRoot->hasDescendantNeedingCompositingRequirementsTraversal() && !m_compositing) {
735 LOG_WITH_STREAM(Compositing, stream << " no compositing work to do");
736 return true;
737 }
738
739 if (!updateRoot->needsAnyCompositingTraversal()) {
740 LOG_WITH_STREAM(Compositing, stream << " updateRoot has no dirty child and doesn't need update");
741 return true;
742 }
743
744 ++m_compositingUpdateCount;
745
746 AnimationUpdateBlock animationUpdateBlock(&m_renderView.frameView().frame().animation());
747
748 SetForScope<bool> postLayoutChange(m_inPostLayoutUpdate, true);
749
750#if !LOG_DISABLED
751 MonotonicTime startTime;
752 if (compositingLogEnabled()) {
753 ++m_rootLayerUpdateCount;
754 startTime = MonotonicTime::now();
755 }
756
757 if (compositingLogEnabled()) {
758 m_obligateCompositedLayerCount = 0;
759 m_secondaryCompositedLayerCount = 0;
760 m_obligatoryBackingStoreBytes = 0;
761 m_secondaryBackingStoreBytes = 0;
762
763 auto& frame = m_renderView.frameView().frame();
764 bool isMainFrame = isMainFrameCompositor();
765 LOG_WITH_STREAM(Compositing, stream << "\nUpdate " << m_rootLayerUpdateCount << " of " << (isMainFrame ? "main frame" : frame.tree().uniqueName().string().utf8().data()) << " - compositing policy is " << m_compositingPolicy);
766 }
767#endif
768
769 // FIXME: optimize root-only update.
770 if (updateRoot->hasDescendantNeedingCompositingRequirementsTraversal() || updateRoot->needsCompositingRequirementsTraversal()) {
771 CompositingState compositingState(updateRoot);
772 BackingSharingState backingSharingState;
773 LayerOverlapMap overlapMap;
774
775 bool descendantHas3DTransform = false;
776 computeCompositingRequirements(nullptr, rootRenderLayer(), overlapMap, compositingState, backingSharingState, descendantHas3DTransform);
777 }
778
779 LOG(Compositing, "\nRenderLayerCompositor::updateCompositingLayers - mid");
780#if ENABLE(TREE_DEBUGGING)
781 if (compositingLogEnabled())
782 showPaintOrderTree(m_renderView.layer());
783#endif
784
785 if (updateRoot->hasDescendantNeedingUpdateBackingOrHierarchyTraversal() || updateRoot->needsUpdateBackingOrHierarchyTraversal()) {
786 ScrollingTreeState scrollingTreeState = { 0, 0 };
787 if (!m_renderView.frame().isMainFrame())
788 scrollingTreeState.parentNodeID = frameHostingNodeForFrame(m_renderView.frame());
789
790 Vector<Ref<GraphicsLayer>> childList;
791 updateBackingAndHierarchy(*updateRoot, childList, scrollingTreeState);
792
793 // Host the document layer in the RenderView's root layer.
794 appendDocumentOverlayLayers(childList);
795 // Even when childList is empty, don't drop out of compositing mode if there are
796 // composited layers that we didn't hit in our traversal (e.g. because of visibility:hidden).
797 if (childList.isEmpty() && !needsCompositingForContentOrOverlays())
798 destroyRootLayer();
799 else if (m_rootContentsLayer)
800 m_rootContentsLayer->setChildren(WTFMove(childList));
801 }
802
803#if !LOG_DISABLED
804 if (compositingLogEnabled()) {
805 MonotonicTime endTime = MonotonicTime::now();
806 LOG(Compositing, "Total layers primary secondary obligatory backing (KB) secondary backing(KB) total backing (KB) update time (ms)\n");
807
808 LOG(Compositing, "%8d %11d %9d %20.2f %22.2f %22.2f %18.2f\n",
809 m_obligateCompositedLayerCount + m_secondaryCompositedLayerCount, m_obligateCompositedLayerCount,
810 m_secondaryCompositedLayerCount, m_obligatoryBackingStoreBytes / 1024, m_secondaryBackingStoreBytes / 1024, (m_obligatoryBackingStoreBytes + m_secondaryBackingStoreBytes) / 1024, (endTime - startTime).milliseconds());
811 }
812#endif
813
814 // FIXME: Only do if dirty.
815 updateRootLayerPosition();
816
817#if ENABLE(TREE_DEBUGGING)
818 if (compositingLogEnabled()) {
819 LOG(Compositing, "RenderLayerCompositor::updateCompositingLayers - post");
820 showPaintOrderTree(m_renderView.layer());
821 }
822#endif
823
824 InspectorInstrumentation::layerTreeDidChange(&page());
825
826 return true;
827}
828
829static bool backingProviderLayerCanIncludeLayer(const RenderLayer& sharedLayer, const RenderLayer& layer)
830{
831 // Disable sharing when painting shared layers doesn't work correctly.
832 if (layer.hasReflection())
833 return false;
834
835 return layer.ancestorLayerIsInContainingBlockChain(sharedLayer);
836}
837
838void RenderLayerCompositor::computeCompositingRequirements(RenderLayer* ancestorLayer, RenderLayer& layer, LayerOverlapMap& overlapMap, CompositingState& compositingState, BackingSharingState& backingSharingState, bool& descendantHas3DTransform)
839{
840 if (!layer.hasDescendantNeedingCompositingRequirementsTraversal()
841 && !layer.needsCompositingRequirementsTraversal()
842 && !compositingState.fullPaintOrderTraversalRequired
843 && !compositingState.descendantsRequireCompositingUpdate) {
844 traverseUnchangedSubtree(ancestorLayer, layer, overlapMap, compositingState, backingSharingState, descendantHas3DTransform);
845 return;
846 }
847
848 LOG_WITH_STREAM(Compositing, stream << TextStream::Repeat(compositingState.depth * 2, ' ') << &layer << (layer.isNormalFlowOnly() ? " n" : " s") << " computeCompositingRequirements (backing provider candidate " << backingSharingState.backingProviderCandidate() << ")");
849
850 // FIXME: maybe we can avoid updating all remaining layers in paint order.
851 compositingState.fullPaintOrderTraversalRequired |= layer.needsCompositingRequirementsTraversal();
852 compositingState.descendantsRequireCompositingUpdate |= layer.descendantsNeedCompositingRequirementsTraversal();
853
854 layer.updateDescendantDependentFlags();
855 layer.updateLayerListsIfNeeded();
856
857 layer.setHasCompositingDescendant(false);
858
859 // We updated compositing for direct reasons in layerStyleChanged(). Here, check for compositing that can only be evaluated after layout.
860 RequiresCompositingData queryData;
861 bool willBeComposited = layer.isComposited();
862 bool becameCompositedAfterDescendantTraversal = false;
863
864 if (layer.needsPostLayoutCompositingUpdate() || compositingState.fullPaintOrderTraversalRequired || compositingState.descendantsRequireCompositingUpdate) {
865 layer.setIndirectCompositingReason(IndirectCompositingReason::None);
866 willBeComposited = needsToBeComposited(layer, queryData);
867 }
868
869 compositingState.fullPaintOrderTraversalRequired |= layer.subsequentLayersNeedCompositingRequirementsTraversal();
870
871 OverlapExtent layerExtent;
872 // Use the fact that we're composited as a hint to check for an animating transform.
873 // FIXME: Maybe needsToBeComposited() should return a bitmask of reasons, to avoid the need to recompute things.
874 if (willBeComposited && !layer.isRenderViewLayer())
875 layerExtent.hasTransformAnimation = isRunningTransformAnimation(layer.renderer());
876
877 bool respectTransforms = !layerExtent.hasTransformAnimation;
878 overlapMap.geometryMap().pushMappingsToAncestor(&layer, ancestorLayer, respectTransforms);
879
880 IndirectCompositingReason compositingReason = compositingState.subtreeIsCompositing ? IndirectCompositingReason::Stacking : IndirectCompositingReason::None;
881 bool layerPaintsIntoProvidedBacking = false;
882 bool didPushOverlapContainer = false;
883
884 // If we know for sure the layer is going to be composited, don't bother looking it up in the overlap map
885 if (!willBeComposited && !overlapMap.isEmpty() && compositingState.testingOverlap) {
886 computeExtent(overlapMap, layer, layerExtent);
887
888 // If we're testing for overlap, we only need to composite if we overlap something that is already composited.
889 if (overlapMap.overlapsLayers(layerExtent.bounds)) {
890 if (backingSharingState.backingProviderCandidate() && canBeComposited(layer) && backingProviderLayerCanIncludeLayer(*backingSharingState.backingProviderCandidate(), layer)) {
891 backingSharingState.appendSharingLayer(layer);
892 LOG(Compositing, " layer %p can share with %p", &layer, backingSharingState.backingProviderCandidate());
893 compositingReason = IndirectCompositingReason::None;
894 layerPaintsIntoProvidedBacking = true;
895 } else
896 compositingReason = IndirectCompositingReason::Overlap;
897 } else
898 compositingReason = IndirectCompositingReason::None;
899 }
900
901#if ENABLE(VIDEO)
902 // Video is special. It's the only RenderLayer type that can both have
903 // RenderLayer children and whose children can't use its backing to render
904 // into. These children (the controls) always need to be promoted into their
905 // own layers to draw on top of the accelerated video.
906 if (compositingState.compositingAncestor && compositingState.compositingAncestor->renderer().isVideo())
907 compositingReason = IndirectCompositingReason::Overlap;
908#endif
909
910 if (compositingReason != IndirectCompositingReason::None)
911 layer.setIndirectCompositingReason(compositingReason);
912
913 // Check if the computed indirect reason will force the layer to become composited.
914 if (!willBeComposited && layer.mustCompositeForIndirectReasons() && canBeComposited(layer)) {
915 LOG_WITH_STREAM(Compositing, stream << "layer " << &layer << " compositing for indirect reason " << layer.indirectCompositingReason() << " (was sharing: " << layerPaintsIntoProvidedBacking << ")");
916 willBeComposited = true;
917 layerPaintsIntoProvidedBacking = false;
918 }
919
920 // The children of this layer don't need to composite, unless there is
921 // a compositing layer among them, so start by inheriting the compositing
922 // ancestor with subtreeIsCompositing set to false.
923 CompositingState currentState = compositingState.stateForPaintOrderChildren(layer);
924
925 auto layerWillComposite = [&] {
926 // This layer is going to be composited, so children can safely ignore the fact that there's an
927 // animation running behind this layer, meaning they can rely on the overlap map testing again.
928 currentState.testingOverlap = true;
929 // This layer now acts as the ancestor for kids.
930 currentState.compositingAncestor = &layer;
931 // Compositing turns off backing sharing.
932 currentState.backingSharingAncestor = nullptr;
933
934 if (layerPaintsIntoProvidedBacking) {
935 layerPaintsIntoProvidedBacking = false;
936 // layerPaintsIntoProvidedBacking was only true for layers that would otherwise composite because of overlap. If we can
937 // no longer share, put this this indirect reason back on the layer so that requiresOwnBackingStore() sees it.
938 layer.setIndirectCompositingReason(IndirectCompositingReason::Overlap);
939 LOG_WITH_STREAM(Compositing, stream << "layer " << &layer << " was sharing now will composite");
940 } else {
941 overlapMap.pushCompositingContainer();
942 didPushOverlapContainer = true;
943 LOG_WITH_STREAM(CompositingOverlap, stream << "layer " << &layer << " will composite, pushed container " << overlapMap);
944 }
945
946 willBeComposited = true;
947 };
948
949 auto layerWillCompositePostDescendants = [&] {
950 layerWillComposite();
951 currentState.subtreeIsCompositing = true;
952 becameCompositedAfterDescendantTraversal = true;
953 };
954
955 if (willBeComposited) {
956 layerWillComposite();
957
958 computeExtent(overlapMap, layer, layerExtent);
959 currentState.ancestorHasTransformAnimation |= layerExtent.hasTransformAnimation;
960 // Too hard to compute animated bounds if both us and some ancestor is animating transform.
961 layerExtent.animationCausesExtentUncertainty |= layerExtent.hasTransformAnimation && compositingState.ancestorHasTransformAnimation;
962 } else if (layerPaintsIntoProvidedBacking) {
963 currentState.backingSharingAncestor = &layer;
964 overlapMap.pushCompositingContainer();
965 didPushOverlapContainer = true;
966 LOG_WITH_STREAM(CompositingOverlap, stream << "layer " << &layer << " will share, pushed container " << overlapMap);
967 }
968
969 backingSharingState.updateBeforeDescendantTraversal(layer, willBeComposited);
970
971#if !ASSERT_DISABLED
972 LayerListMutationDetector mutationChecker(layer);
973#endif
974
975 bool anyDescendantHas3DTransform = false;
976 bool descendantsAddedToOverlap = currentState.hasNonRootCompositedAncestor();
977
978 for (auto* childLayer : layer.negativeZOrderLayers()) {
979 computeCompositingRequirements(&layer, *childLayer, overlapMap, currentState, backingSharingState, anyDescendantHas3DTransform);
980
981 // If we have to make a layer for this child, make one now so we can have a contents layer
982 // (since we need to ensure that the -ve z-order child renders underneath our contents).
983 if (!willBeComposited && currentState.subtreeIsCompositing) {
984 // make layer compositing
985 layer.setIndirectCompositingReason(IndirectCompositingReason::BackgroundLayer);
986 layerWillComposite();
987 }
988 }
989
990 for (auto* childLayer : layer.normalFlowLayers())
991 computeCompositingRequirements(&layer, *childLayer, overlapMap, currentState, backingSharingState, anyDescendantHas3DTransform);
992
993 for (auto* childLayer : layer.positiveZOrderLayers())
994 computeCompositingRequirements(&layer, *childLayer, overlapMap, currentState, backingSharingState, anyDescendantHas3DTransform);
995
996 // If we just entered compositing mode, the root will have become composited (as long as accelerated compositing is enabled).
997 if (layer.isRenderViewLayer()) {
998 if (usesCompositing() && m_hasAcceleratedCompositing)
999 willBeComposited = true;
1000 }
1001
1002#if ENABLE(CSS_COMPOSITING)
1003 bool isolatedCompositedBlending = layer.isolatesCompositedBlending();
1004 layer.setHasNotIsolatedCompositedBlendingDescendants(currentState.hasNotIsolatedCompositedBlendingDescendants);
1005 if (layer.isolatesCompositedBlending() != isolatedCompositedBlending) {
1006 // isolatedCompositedBlending affects the result of clippedByAncestor().
1007 layer.setChildrenNeedCompositingGeometryUpdate();
1008 }
1009
1010 ASSERT(!layer.hasNotIsolatedCompositedBlendingDescendants() || layer.hasNotIsolatedBlendingDescendants());
1011#endif
1012 // Now check for reasons to become composited that depend on the state of descendant layers.
1013 IndirectCompositingReason indirectCompositingReason;
1014 if (!willBeComposited && canBeComposited(layer)
1015 && requiresCompositingForIndirectReason(layer, compositingState.compositingAncestor, currentState.subtreeIsCompositing, anyDescendantHas3DTransform, layerPaintsIntoProvidedBacking, indirectCompositingReason)) {
1016 layer.setIndirectCompositingReason(indirectCompositingReason);
1017 layerWillCompositePostDescendants();
1018 }
1019
1020 if (layer.reflectionLayer()) {
1021 // FIXME: Shouldn't we call computeCompositingRequirements to handle a reflection overlapping with another renderer?
1022 layer.reflectionLayer()->setIndirectCompositingReason(willBeComposited ? IndirectCompositingReason::Stacking : IndirectCompositingReason::None);
1023 }
1024
1025 // Set the flag to say that this layer has compositing children.
1026 layer.setHasCompositingDescendant(currentState.subtreeIsCompositing);
1027
1028 // setHasCompositingDescendant() may have changed the answer to needsToBeComposited() when clipping, so test that now.
1029 bool isCompositedClippingLayer = canBeComposited(layer) && clipsCompositingDescendants(layer);
1030 if (isCompositedClippingLayer & !willBeComposited)
1031 layerWillCompositePostDescendants();
1032
1033 // If we're back at the root, and no other layers need to be composited, and the root layer itself doesn't need
1034 // to be composited, then we can drop out of compositing mode altogether. However, don't drop out of compositing mode
1035 // if there are composited layers that we didn't hit in our traversal (e.g. because of visibility:hidden).
1036 RequiresCompositingData rootLayerQueryData;
1037 if (layer.isRenderViewLayer() && !currentState.subtreeIsCompositing && !requiresCompositingLayer(layer, rootLayerQueryData) && !m_forceCompositingMode && !needsCompositingForContentOrOverlays()) {
1038 // Don't drop out of compositing on iOS, because we may flash. See <rdar://problem/8348337>.
1039#if !PLATFORM(IOS_FAMILY)
1040 enableCompositingMode(false);
1041 willBeComposited = false;
1042#endif
1043 }
1044
1045 ASSERT(willBeComposited == needsToBeComposited(layer, queryData));
1046
1047 // Create or destroy backing here. However, we can't update geometry because layers above us may become composited
1048 // during post-order traversal (e.g. for clipping).
1049 if (updateBacking(layer, queryData, CompositingChangeRepaintNow, willBeComposited ? BackingRequired::Yes : BackingRequired::No)) {
1050 layer.setNeedsCompositingLayerConnection();
1051 // Child layers need to get a geometry update to recompute their position.
1052 layer.setChildrenNeedCompositingGeometryUpdate();
1053 // The composited bounds of enclosing layers depends on which descendants are composited, so they need a geometry update.
1054 layer.setNeedsCompositingGeometryUpdateOnAncestors();
1055 }
1056
1057 // Update layer state bits.
1058 if (layer.reflectionLayer() && updateLayerCompositingState(*layer.reflectionLayer(), queryData, CompositingChangeRepaintNow))
1059 layer.setNeedsCompositingLayerConnection();
1060
1061 // FIXME: clarify needsCompositingPaintOrderChildrenUpdate. If a composited layer gets a new ancestor, it needs geometry computations.
1062 if (layer.needsCompositingPaintOrderChildrenUpdate()) {
1063 layer.setChildrenNeedCompositingGeometryUpdate();
1064 layer.setNeedsCompositingLayerConnection();
1065 }
1066
1067 layer.clearCompositingRequirementsTraversalState();
1068
1069 // Compute state passed to the caller.
1070 descendantHas3DTransform |= anyDescendantHas3DTransform || layer.has3DTransform();
1071 compositingState.updateWithDescendantStateAndLayer(currentState, layer, layerExtent);
1072 backingSharingState.updateAfterDescendantTraversal(layer, compositingState.stackingContextAncestor);
1073
1074 bool layerContributesToOverlap = (currentState.compositingAncestor && !currentState.compositingAncestor->isRenderViewLayer()) || currentState.backingSharingAncestor;
1075 updateOverlapMap(overlapMap, layer, layerExtent, didPushOverlapContainer, layerContributesToOverlap, becameCompositedAfterDescendantTraversal && !descendantsAddedToOverlap);
1076
1077 overlapMap.geometryMap().popMappingsToAncestor(ancestorLayer);
1078
1079 LOG_WITH_STREAM(Compositing, stream << TextStream::Repeat(compositingState.depth * 2, ' ') << &layer << " computeCompositingRequirements - willBeComposited " << willBeComposited << " (backing provider candidate " << backingSharingState.backingProviderCandidate() << ")");
1080}
1081
1082// We have to traverse unchanged layers to fill in the overlap map.
1083void RenderLayerCompositor::traverseUnchangedSubtree(RenderLayer* ancestorLayer, RenderLayer& layer, LayerOverlapMap& overlapMap, CompositingState& compositingState, BackingSharingState& backingSharingState, bool& descendantHas3DTransform)
1084{
1085 ASSERT(!compositingState.fullPaintOrderTraversalRequired);
1086 ASSERT(!layer.hasDescendantNeedingCompositingRequirementsTraversal());
1087 ASSERT(!layer.needsCompositingRequirementsTraversal());
1088
1089 LOG_WITH_STREAM(Compositing, stream << TextStream::Repeat(compositingState.depth * 2, ' ') << &layer << (layer.isNormalFlowOnly() ? " n" : " s") << " traverseUnchangedSubtree");
1090
1091 layer.updateDescendantDependentFlags();
1092 layer.updateLayerListsIfNeeded();
1093
1094 bool layerIsComposited = layer.isComposited();
1095 bool layerPaintsIntoProvidedBacking = false;
1096 bool didPushOverlapContainer = false;
1097
1098 OverlapExtent layerExtent;
1099 if (layerIsComposited && !layer.isRenderViewLayer())
1100 layerExtent.hasTransformAnimation = isRunningTransformAnimation(layer.renderer());
1101
1102 bool respectTransforms = !layerExtent.hasTransformAnimation;
1103 overlapMap.geometryMap().pushMappingsToAncestor(&layer, ancestorLayer, respectTransforms);
1104
1105 // If we know for sure the layer is going to be composited, don't bother looking it up in the overlap map
1106 if (!layerIsComposited && !overlapMap.isEmpty() && compositingState.testingOverlap)
1107 computeExtent(overlapMap, layer, layerExtent);
1108
1109 if (layer.paintsIntoProvidedBacking()) {
1110 ASSERT(backingSharingState.backingProviderCandidate());
1111 ASSERT(backingProviderLayerCanIncludeLayer(*backingSharingState.backingProviderCandidate(), layer));
1112 backingSharingState.appendSharingLayer(layer);
1113 layerPaintsIntoProvidedBacking = true;
1114 }
1115
1116 CompositingState currentState = compositingState.stateForPaintOrderChildren(layer);
1117
1118 if (layerIsComposited) {
1119 // This layer is going to be composited, so children can safely ignore the fact that there's an
1120 // animation running behind this layer, meaning they can rely on the overlap map testing again.
1121 currentState.testingOverlap = true;
1122 // This layer now acts as the ancestor for kids.
1123 currentState.compositingAncestor = &layer;
1124 currentState.backingSharingAncestor = nullptr;
1125 overlapMap.pushCompositingContainer();
1126 didPushOverlapContainer = true;
1127 LOG_WITH_STREAM(CompositingOverlap, stream << "unchangedSubtree: layer " << &layer << " will composite, pushed container " << overlapMap);
1128
1129 computeExtent(overlapMap, layer, layerExtent);
1130 currentState.ancestorHasTransformAnimation |= layerExtent.hasTransformAnimation;
1131 // Too hard to compute animated bounds if both us and some ancestor is animating transform.
1132 layerExtent.animationCausesExtentUncertainty |= layerExtent.hasTransformAnimation && compositingState.ancestorHasTransformAnimation;
1133 } else if (layerPaintsIntoProvidedBacking) {
1134 overlapMap.pushCompositingContainer();
1135 currentState.backingSharingAncestor = &layer;
1136 didPushOverlapContainer = true;
1137 LOG_WITH_STREAM(CompositingOverlap, stream << "unchangedSubtree: layer " << &layer << " will share, pushed container " << overlapMap);
1138 }
1139
1140 backingSharingState.updateBeforeDescendantTraversal(layer, layerIsComposited);
1141
1142#if !ASSERT_DISABLED
1143 LayerListMutationDetector mutationChecker(layer);
1144#endif
1145
1146 bool anyDescendantHas3DTransform = false;
1147
1148 for (auto* childLayer : layer.negativeZOrderLayers()) {
1149 traverseUnchangedSubtree(&layer, *childLayer, overlapMap, currentState, backingSharingState, anyDescendantHas3DTransform);
1150 if (currentState.subtreeIsCompositing)
1151 ASSERT(layerIsComposited);
1152 }
1153
1154 for (auto* childLayer : layer.normalFlowLayers())
1155 traverseUnchangedSubtree(&layer, *childLayer, overlapMap, currentState, backingSharingState, anyDescendantHas3DTransform);
1156
1157 for (auto* childLayer : layer.positiveZOrderLayers())
1158 traverseUnchangedSubtree(&layer, *childLayer, overlapMap, currentState, backingSharingState, anyDescendantHas3DTransform);
1159
1160 // Set the flag to say that this layer has compositing children.
1161 ASSERT(layer.hasCompositingDescendant() == currentState.subtreeIsCompositing);
1162 ASSERT_IMPLIES(canBeComposited(layer) && clipsCompositingDescendants(layer), layerIsComposited);
1163
1164 descendantHas3DTransform |= anyDescendantHas3DTransform || layer.has3DTransform();
1165
1166 ASSERT(!currentState.fullPaintOrderTraversalRequired);
1167 compositingState.updateWithDescendantStateAndLayer(currentState, layer, layerExtent, true);
1168 backingSharingState.updateAfterDescendantTraversal(layer, compositingState.stackingContextAncestor);
1169
1170 bool layerContributesToOverlap = (currentState.compositingAncestor && !currentState.compositingAncestor->isRenderViewLayer()) || currentState.backingSharingAncestor;
1171 updateOverlapMap(overlapMap, layer, layerExtent, didPushOverlapContainer, layerContributesToOverlap);
1172
1173 overlapMap.geometryMap().popMappingsToAncestor(ancestorLayer);
1174
1175 ASSERT(!layer.needsCompositingRequirementsTraversal());
1176}
1177
1178void RenderLayerCompositor::updateBackingAndHierarchy(RenderLayer& layer, Vector<Ref<GraphicsLayer>>& childLayersOfEnclosingLayer, ScrollingTreeState& scrollingTreeState, OptionSet<UpdateLevel> updateLevel, int depth)
1179{
1180 layer.updateDescendantDependentFlags();
1181 layer.updateLayerListsIfNeeded();
1182
1183 bool layerNeedsUpdate = !updateLevel.isEmpty();
1184 if (layer.descendantsNeedUpdateBackingAndHierarchyTraversal())
1185 updateLevel.add(UpdateLevel::AllDescendants);
1186
1187 ScrollingTreeState stateForDescendants = scrollingTreeState;
1188
1189 auto* layerBacking = layer.backing();
1190 if (layerBacking) {
1191 updateLevel.remove(UpdateLevel::CompositedChildren);
1192
1193 // We updated the composited bounds in RenderLayerBacking::updateAfterLayout(), but it may have changed
1194 // based on which descendants are now composited.
1195 if (layerBacking->updateCompositedBounds()) {
1196 layer.setNeedsCompositingGeometryUpdate();
1197 // Our geometry can affect descendants.
1198 updateLevel.add(UpdateLevel::CompositedChildren);
1199 }
1200
1201 if (layerNeedsUpdate || layer.needsCompositingConfigurationUpdate()) {
1202 if (layerBacking->updateConfiguration()) {
1203 layerNeedsUpdate = true; // We also need to update geometry.
1204 layer.setNeedsCompositingLayerConnection();
1205 }
1206
1207 layerBacking->updateDebugIndicators(m_showDebugBorders, m_showRepaintCounter);
1208 }
1209
1210 OptionSet<ScrollingNodeChangeFlags> scrollingNodeChanges = { ScrollingNodeChangeFlags::Layer };
1211 if (layerNeedsUpdate || layer.needsCompositingGeometryUpdate()) {
1212 layerBacking->updateGeometry();
1213 scrollingNodeChanges.add(ScrollingNodeChangeFlags::LayerGeometry);
1214 } else if (layer.needsScrollingTreeUpdate())
1215 scrollingNodeChanges.add(ScrollingNodeChangeFlags::LayerGeometry);
1216
1217 if (auto* reflection = layer.reflectionLayer()) {
1218 if (auto* reflectionBacking = reflection->backing()) {
1219 reflectionBacking->updateCompositedBounds();
1220 reflectionBacking->updateGeometry();
1221 reflectionBacking->updateAfterDescendants();
1222 }
1223 }
1224
1225 if (!layer.parent())
1226 updateRootLayerPosition();
1227
1228 // FIXME: do based on dirty flags. Need to do this for changes of geometry, configuration and hierarchy.
1229 // Need to be careful to do the right thing when a scroll-coordinated layer loses a scroll-coordinated ancestor.
1230 stateForDescendants.parentNodeID = updateScrollCoordinationForLayer(layer, scrollingTreeState, layerBacking->coordinatedScrollingRoles(), scrollingNodeChanges);
1231 stateForDescendants.nextChildIndex = 0;
1232
1233#if !LOG_DISABLED
1234 logLayerInfo(layer, "updateBackingAndHierarchy", depth);
1235#else
1236 UNUSED_PARAM(depth);
1237#endif
1238 }
1239
1240 if (layer.childrenNeedCompositingGeometryUpdate())
1241 updateLevel.add(UpdateLevel::CompositedChildren);
1242
1243 // If this layer has backing, then we are collecting its children, otherwise appending
1244 // to the compositing child list of an enclosing layer.
1245 Vector<Ref<GraphicsLayer>> layerChildren;
1246 auto& childList = layerBacking ? layerChildren : childLayersOfEnclosingLayer;
1247
1248 bool requireDescendantTraversal = layer.hasDescendantNeedingUpdateBackingOrHierarchyTraversal()
1249 || (layer.hasCompositingDescendant() && (!layerBacking || layer.needsCompositingLayerConnection() || !updateLevel.isEmpty()));
1250
1251 bool requiresChildRebuild = layerBacking && layer.needsCompositingLayerConnection() && !layer.hasCompositingDescendant();
1252
1253#if !ASSERT_DISABLED
1254 LayerListMutationDetector mutationChecker(layer);
1255#endif
1256
1257 auto appendForegroundLayerIfNecessary = [&] {
1258 // If a negative z-order child is compositing, we get a foreground layer which needs to get parented.
1259 if (layer.negativeZOrderLayers().size()) {
1260 if (layerBacking && layerBacking->foregroundLayer())
1261 childList.append(*layerBacking->foregroundLayer());
1262 }
1263 };
1264
1265 if (requireDescendantTraversal) {
1266 for (auto* renderLayer : layer.negativeZOrderLayers())
1267 updateBackingAndHierarchy(*renderLayer, childList, stateForDescendants, updateLevel, depth + 1);
1268
1269 appendForegroundLayerIfNecessary();
1270
1271 for (auto* renderLayer : layer.normalFlowLayers())
1272 updateBackingAndHierarchy(*renderLayer, childList, stateForDescendants, updateLevel, depth + 1);
1273
1274 for (auto* renderLayer : layer.positiveZOrderLayers())
1275 updateBackingAndHierarchy(*renderLayer, childList, stateForDescendants, updateLevel, depth + 1);
1276 } else if (requiresChildRebuild)
1277 appendForegroundLayerIfNecessary();
1278
1279 if (layerBacking) {
1280 if (requireDescendantTraversal || requiresChildRebuild) {
1281 bool parented = false;
1282 if (is<RenderWidget>(layer.renderer()))
1283 parented = parentFrameContentLayers(downcast<RenderWidget>(layer.renderer()));
1284
1285 if (!parented)
1286 layerBacking->parentForSublayers()->setChildren(WTFMove(layerChildren));
1287
1288 // If the layer has a clipping layer the overflow controls layers will be siblings of the clipping layer.
1289 // Otherwise, the overflow control layers are normal children.
1290 if (!layerBacking->hasClippingLayer() && !layerBacking->hasScrollingLayer()) {
1291 if (auto* overflowControlLayer = layerBacking->layerForHorizontalScrollbar())
1292 layerBacking->parentForSublayers()->addChild(*overflowControlLayer);
1293
1294 if (auto* overflowControlLayer = layerBacking->layerForVerticalScrollbar())
1295 layerBacking->parentForSublayers()->addChild(*overflowControlLayer);
1296
1297 if (auto* overflowControlLayer = layerBacking->layerForScrollCorner())
1298 layerBacking->parentForSublayers()->addChild(*overflowControlLayer);
1299 }
1300 }
1301
1302 childLayersOfEnclosingLayer.append(*layerBacking->childForSuperlayers());
1303
1304 layerBacking->updateAfterDescendants();
1305 }
1306
1307 layer.clearUpdateBackingOrHierarchyTraversalState();
1308}
1309
1310void RenderLayerCompositor::appendDocumentOverlayLayers(Vector<Ref<GraphicsLayer>>& childList)
1311{
1312 if (!isMainFrameCompositor() || !m_compositing)
1313 return;
1314
1315 if (!page().pageOverlayController().hasDocumentOverlays())
1316 return;
1317
1318 Ref<GraphicsLayer> overlayHost = page().pageOverlayController().layerWithDocumentOverlays();
1319 childList.append(WTFMove(overlayHost));
1320}
1321
1322bool RenderLayerCompositor::needsCompositingForContentOrOverlays() const
1323{
1324 return m_contentLayersCount + page().pageOverlayController().overlayCount();
1325}
1326
1327void RenderLayerCompositor::layerBecameComposited(const RenderLayer& layer)
1328{
1329 if (&layer != m_renderView.layer())
1330 ++m_contentLayersCount;
1331}
1332
1333void RenderLayerCompositor::layerBecameNonComposited(const RenderLayer& layer)
1334{
1335 // Inform the inspector that the given RenderLayer was destroyed.
1336 // FIXME: "destroyed" is a misnomer.
1337 InspectorInstrumentation::renderLayerDestroyed(&page(), layer);
1338
1339 if (&layer != m_renderView.layer()) {
1340 ASSERT(m_contentLayersCount > 0);
1341 --m_contentLayersCount;
1342 }
1343}
1344
1345#if !LOG_DISABLED
1346void RenderLayerCompositor::logLayerInfo(const RenderLayer& layer, const char* phase, int depth)
1347{
1348 if (!compositingLogEnabled())
1349 return;
1350
1351 auto* backing = layer.backing();
1352 RequiresCompositingData queryData;
1353 if (requiresCompositingLayer(layer, queryData) || layer.isRenderViewLayer()) {
1354 ++m_obligateCompositedLayerCount;
1355 m_obligatoryBackingStoreBytes += backing->backingStoreMemoryEstimate();
1356 } else {
1357 ++m_secondaryCompositedLayerCount;
1358 m_secondaryBackingStoreBytes += backing->backingStoreMemoryEstimate();
1359 }
1360
1361 LayoutRect absoluteBounds = backing->compositedBounds();
1362 absoluteBounds.move(layer.offsetFromAncestor(m_renderView.layer()));
1363
1364 StringBuilder logString;
1365 logString.append(makeString(pad(' ', 12 + depth * 2, hex(reinterpret_cast<uintptr_t>(&layer))), " id ", backing->graphicsLayer()->primaryLayerID(), " (", FormattedNumber::fixedWidth(absoluteBounds.x().toFloat(), 3), ',', FormattedNumber::fixedWidth(absoluteBounds.y().toFloat(), 3), '-', FormattedNumber::fixedWidth(absoluteBounds.maxX().toFloat(), 3), ',', FormattedNumber::fixedWidth(absoluteBounds.maxY().toFloat(), 3), ") ", FormattedNumber::fixedWidth(backing->backingStoreMemoryEstimate() / 1024, 2), "KB"));
1366
1367 if (!layer.renderer().style().hasAutoZIndex())
1368 logString.append(makeString(" z-index: ", layer.renderer().style().zIndex()));
1369
1370 logString.appendLiteral(" (");
1371 logString.append(logReasonsForCompositing(layer));
1372 logString.appendLiteral(") ");
1373
1374 if (backing->graphicsLayer()->contentsOpaque() || backing->paintsIntoCompositedAncestor() || backing->foregroundLayer() || backing->backgroundLayer()) {
1375 logString.append('[');
1376 bool prependSpace = false;
1377 if (backing->graphicsLayer()->contentsOpaque()) {
1378 logString.appendLiteral("opaque");
1379 prependSpace = true;
1380 }
1381
1382 if (backing->paintsIntoCompositedAncestor()) {
1383 if (prependSpace)
1384 logString.appendLiteral(", ");
1385 logString.appendLiteral("paints into ancestor");
1386 prependSpace = true;
1387 }
1388
1389 if (backing->foregroundLayer() || backing->backgroundLayer()) {
1390 if (prependSpace)
1391 logString.appendLiteral(", ");
1392 if (backing->foregroundLayer() && backing->backgroundLayer()) {
1393 logString.appendLiteral("+foreground+background");
1394 prependSpace = true;
1395 } else if (backing->foregroundLayer()) {
1396 logString.appendLiteral("+foreground");
1397 prependSpace = true;
1398 } else {
1399 logString.appendLiteral("+background");
1400 prependSpace = true;
1401 }
1402 }
1403
1404 if (backing->paintsSubpixelAntialiasedText()) {
1405 if (prependSpace)
1406 logString.appendLiteral(", ");
1407 logString.appendLiteral("texty");
1408 }
1409
1410 logString.appendLiteral("] ");
1411 }
1412
1413 logString.append(layer.name());
1414
1415 logString.appendLiteral(" - ");
1416 logString.append(phase);
1417
1418 LOG(Compositing, "%s", logString.toString().utf8().data());
1419}
1420#endif
1421
1422static bool clippingChanged(const RenderStyle& oldStyle, const RenderStyle& newStyle)
1423{
1424 return oldStyle.overflowX() != newStyle.overflowX() || oldStyle.overflowY() != newStyle.overflowY()
1425 || oldStyle.hasClip() != newStyle.hasClip() || oldStyle.clip() != newStyle.clip();
1426}
1427
1428static bool styleAffectsLayerGeometry(const RenderStyle& style)
1429{
1430 return style.hasClip() || style.clipPath() || style.hasBorderRadius();
1431}
1432
1433static bool recompositeChangeRequiresGeometryUpdate(const RenderStyle& oldStyle, const RenderStyle& newStyle)
1434{
1435 return oldStyle.transform() != newStyle.transform()
1436 || oldStyle.transformOriginX() != newStyle.transformOriginX()
1437 || oldStyle.transformOriginY() != newStyle.transformOriginY()
1438 || oldStyle.transformOriginZ() != newStyle.transformOriginZ()
1439 || oldStyle.transformStyle3D() != newStyle.transformStyle3D()
1440 || oldStyle.perspective() != newStyle.perspective()
1441 || oldStyle.perspectiveOriginX() != newStyle.perspectiveOriginX()
1442 || oldStyle.perspectiveOriginY() != newStyle.perspectiveOriginY()
1443 || oldStyle.backfaceVisibility() != newStyle.backfaceVisibility()
1444 || !arePointingToEqualData(oldStyle.clipPath(), newStyle.clipPath());
1445}
1446
1447void RenderLayerCompositor::layerStyleChanged(StyleDifference diff, RenderLayer& layer, const RenderStyle* oldStyle)
1448{
1449 if (diff == StyleDifference::Equal)
1450 return;
1451
1452 // Create or destroy backing here so that code that runs during layout can reliably use isComposited() (though this
1453 // is only true for layers composited for direct reasons).
1454 // Also, it allows us to avoid a tree walk in updateCompositingLayers() when no layer changed its compositing state.
1455 RequiresCompositingData queryData;
1456 queryData.layoutUpToDate = LayoutUpToDate::No;
1457
1458 bool layerChanged = updateBacking(layer, queryData, CompositingChangeRepaintNow);
1459 if (layerChanged) {
1460 layer.setChildrenNeedCompositingGeometryUpdate();
1461 layer.setNeedsCompositingLayerConnection();
1462 layer.setSubsequentLayersNeedCompositingRequirementsTraversal();
1463 // Ancestor layers that composited for indirect reasons (things listed in styleChangeMayAffectIndirectCompositingReasons()) need to get updated.
1464 // This could be optimized by only setting this flag on layers with the relevant styles.
1465 layer.setNeedsPostLayoutCompositingUpdateOnAncestors();
1466 }
1467
1468 if (queryData.reevaluateAfterLayout)
1469 layer.setNeedsPostLayoutCompositingUpdate();
1470
1471 if (diff >= StyleDifference::LayoutPositionedMovementOnly && hasContentCompositingLayers()) {
1472 layer.setNeedsPostLayoutCompositingUpdate();
1473 layer.setNeedsCompositingGeometryUpdate();
1474 }
1475
1476 auto* backing = layer.backing();
1477 if (!backing)
1478 return;
1479
1480 backing->updateConfigurationAfterStyleChange();
1481
1482 const auto& newStyle = layer.renderer().style();
1483
1484 if (diff >= StyleDifference::Repaint) {
1485 // Visibility change may affect geometry of the enclosing composited layer.
1486 if (oldStyle && oldStyle->visibility() != newStyle.visibility())
1487 layer.setNeedsCompositingGeometryUpdate();
1488
1489 // We'll get a diff of Repaint when things like clip-path change; these might affect layer or inner-layer geometry.
1490 if (layer.isComposited() && oldStyle) {
1491 if (styleAffectsLayerGeometry(*oldStyle) || styleAffectsLayerGeometry(newStyle))
1492 layer.setNeedsCompositingGeometryUpdate();
1493 }
1494 }
1495
1496 // This is necessary to get iframe layers hooked up in response to scheduleInvalidateStyleAndLayerComposition().
1497 if (diff == StyleDifference::RecompositeLayer && layer.isComposited() && is<RenderWidget>(layer.renderer()))
1498 layer.setNeedsCompositingConfigurationUpdate();
1499
1500 if (diff >= StyleDifference::RecompositeLayer && oldStyle && recompositeChangeRequiresGeometryUpdate(*oldStyle, newStyle)) {
1501 // FIXME: transform changes really need to trigger layout. See RenderElement::adjustStyleDifference().
1502 layer.setNeedsPostLayoutCompositingUpdate();
1503 layer.setNeedsCompositingGeometryUpdate();
1504 }
1505
1506 if (diff >= StyleDifference::Layout) {
1507 // FIXME: only set flags here if we know we have a composited descendant, but we might not know at this point.
1508 if (oldStyle && clippingChanged(*oldStyle, newStyle)) {
1509 if (layer.isStackingContext()) {
1510 layer.setNeedsPostLayoutCompositingUpdate(); // Layer needs to become composited if it has composited descendants.
1511 layer.setNeedsCompositingConfigurationUpdate(); // If already composited, layer needs to create/destroy clipping layer.
1512 } else {
1513 // Descendant (in containing block order) compositing layers need to re-evaluate their clipping,
1514 // but they might be siblings in z-order so go up to our stacking context.
1515 if (auto* stackingContext = layer.stackingContext())
1516 stackingContext->setDescendantsNeedUpdateBackingAndHierarchyTraversal();
1517 }
1518 }
1519
1520 // These properties trigger compositing if some descendant is composited.
1521 if (oldStyle && styleChangeMayAffectIndirectCompositingReasons(*oldStyle, newStyle))
1522 layer.setNeedsPostLayoutCompositingUpdate();
1523
1524 layer.setNeedsCompositingGeometryUpdate();
1525 }
1526}
1527
1528bool RenderLayerCompositor::needsCompositingUpdateForStyleChangeOnNonCompositedLayer(RenderLayer& layer, const RenderStyle* oldStyle) const
1529{
1530 // Needed for scroll bars.
1531 if (layer.isRenderViewLayer())
1532 return true;
1533
1534 if (!oldStyle)
1535 return false;
1536
1537 const RenderStyle& newStyle = layer.renderer().style();
1538 // Visibility change may affect geometry of the enclosing composited layer.
1539 if (oldStyle->visibility() != newStyle.visibility())
1540 return true;
1541
1542 // We don't have any direct reasons for this style change to affect layer composition. Test if it might affect things indirectly.
1543 if (styleChangeMayAffectIndirectCompositingReasons(*oldStyle, newStyle))
1544 return true;
1545
1546 return false;
1547}
1548
1549bool RenderLayerCompositor::canCompositeClipPath(const RenderLayer& layer)
1550{
1551 ASSERT(layer.isComposited());
1552 ASSERT(layer.renderer().style().clipPath());
1553
1554 if (layer.renderer().hasMask())
1555 return false;
1556
1557 auto& clipPath = *layer.renderer().style().clipPath();
1558 return (clipPath.type() != ClipPathOperation::Shape || clipPath.type() == ClipPathOperation::Shape) && GraphicsLayer::supportsLayerType(GraphicsLayer::Type::Shape);
1559}
1560
1561// FIXME: remove and never ask questions about reflection layers.
1562static RenderLayerModelObject& rendererForCompositingTests(const RenderLayer& layer)
1563{
1564 auto* renderer = &layer.renderer();
1565
1566 // The compositing state of a reflection should match that of its reflected layer.
1567 if (layer.isReflection())
1568 renderer = downcast<RenderLayerModelObject>(renderer->parent()); // The RenderReplica's parent is the object being reflected.
1569
1570 return *renderer;
1571}
1572
1573void RenderLayerCompositor::updateRootContentLayerClipping()
1574{
1575 m_rootContentsLayer->setMasksToBounds(!m_renderView.settings().backgroundShouldExtendBeyondPage());
1576}
1577
1578bool RenderLayerCompositor::updateBacking(RenderLayer& layer, RequiresCompositingData& queryData, CompositingChangeRepaint shouldRepaint, BackingRequired backingRequired)
1579{
1580 bool layerChanged = false;
1581 if (backingRequired == BackingRequired::Unknown)
1582 backingRequired = needsToBeComposited(layer, queryData) ? BackingRequired::Yes : BackingRequired::No;
1583 else {
1584 // Need to fetch viewportConstrainedNotCompositedReason, but without doing all the work that needsToBeComposited does.
1585 requiresCompositingForPosition(rendererForCompositingTests(layer), layer, queryData);
1586 }
1587
1588 if (backingRequired == BackingRequired::Yes) {
1589 layer.disconnectFromBackingProviderLayer();
1590
1591 enableCompositingMode();
1592
1593 if (!layer.backing()) {
1594 // If we need to repaint, do so before making backing
1595 if (shouldRepaint == CompositingChangeRepaintNow)
1596 repaintOnCompositingChange(layer); // wrong backing
1597
1598 layer.ensureBacking();
1599
1600 if (layer.isRenderViewLayer() && useCoordinatedScrollingForLayer(layer)) {
1601 auto& frameView = m_renderView.frameView();
1602 if (auto* scrollingCoordinator = this->scrollingCoordinator())
1603 scrollingCoordinator->frameViewRootLayerDidChange(frameView);
1604#if ENABLE(RUBBER_BANDING)
1605 updateLayerForHeader(frameView.headerHeight());
1606 updateLayerForFooter(frameView.footerHeight());
1607#endif
1608 updateRootContentLayerClipping();
1609
1610 if (auto* tiledBacking = layer.backing()->tiledBacking())
1611 tiledBacking->setTopContentInset(frameView.topContentInset());
1612 }
1613
1614 // This layer and all of its descendants have cached repaints rects that are relative to
1615 // the repaint container, so change when compositing changes; we need to update them here.
1616 if (layer.parent())
1617 layer.computeRepaintRectsIncludingDescendants();
1618
1619 layer.setNeedsCompositingGeometryUpdate();
1620 layer.setNeedsCompositingConfigurationUpdate();
1621 layer.setNeedsCompositingPaintOrderChildrenUpdate();
1622
1623 layerChanged = true;
1624 }
1625 } else {
1626 if (layer.backing()) {
1627 // If we're removing backing on a reflection, clear the source GraphicsLayer's pointer to
1628 // its replica GraphicsLayer. In practice this should never happen because reflectee and reflection
1629 // are both either composited, or not composited.
1630 if (layer.isReflection()) {
1631 auto* sourceLayer = downcast<RenderLayerModelObject>(*layer.renderer().parent()).layer();
1632 if (auto* backing = sourceLayer->backing()) {
1633 ASSERT(backing->graphicsLayer()->replicaLayer() == layer.backing()->graphicsLayer());
1634 backing->graphicsLayer()->setReplicatedByLayer(nullptr);
1635 }
1636 }
1637
1638 layer.clearBacking();
1639 layerChanged = true;
1640
1641 // This layer and all of its descendants have cached repaints rects that are relative to
1642 // the repaint container, so change when compositing changes; we need to update them here.
1643 layer.computeRepaintRectsIncludingDescendants();
1644
1645 // If we need to repaint, do so now that we've removed the backing
1646 if (shouldRepaint == CompositingChangeRepaintNow)
1647 repaintOnCompositingChange(layer);
1648 }
1649 }
1650
1651#if ENABLE(VIDEO)
1652 if (layerChanged && is<RenderVideo>(layer.renderer())) {
1653 // If it's a video, give the media player a chance to hook up to the layer.
1654 downcast<RenderVideo>(layer.renderer()).acceleratedRenderingStateChanged();
1655 }
1656#endif
1657
1658 if (layerChanged && is<RenderWidget>(layer.renderer())) {
1659 auto* innerCompositor = frameContentsCompositor(downcast<RenderWidget>(layer.renderer()));
1660 if (innerCompositor && innerCompositor->usesCompositing())
1661 innerCompositor->updateRootLayerAttachment();
1662 }
1663
1664 if (layerChanged)
1665 layer.clearClipRectsIncludingDescendants(PaintingClipRects);
1666
1667 // If a fixed position layer gained/lost a backing or the reason not compositing it changed,
1668 // the scrolling coordinator needs to recalculate whether it can do fast scrolling.
1669 if (layer.renderer().isFixedPositioned()) {
1670 if (layer.viewportConstrainedNotCompositedReason() != queryData.nonCompositedForPositionReason) {
1671 layer.setViewportConstrainedNotCompositedReason(queryData.nonCompositedForPositionReason);
1672 layerChanged = true;
1673 }
1674 if (layerChanged) {
1675 if (auto* scrollingCoordinator = this->scrollingCoordinator())
1676 scrollingCoordinator->frameViewFixedObjectsDidChange(m_renderView.frameView());
1677 }
1678 } else
1679 layer.setViewportConstrainedNotCompositedReason(RenderLayer::NoNotCompositedReason);
1680
1681 if (layer.backing())
1682 layer.backing()->updateDebugIndicators(m_showDebugBorders, m_showRepaintCounter);
1683
1684 return layerChanged;
1685}
1686
1687bool RenderLayerCompositor::updateLayerCompositingState(RenderLayer& layer, RequiresCompositingData& queryData, CompositingChangeRepaint shouldRepaint)
1688{
1689 bool layerChanged = updateBacking(layer, queryData, shouldRepaint);
1690
1691 // See if we need content or clipping layers. Methods called here should assume
1692 // that the compositing state of descendant layers has not been updated yet.
1693 if (layer.backing() && layer.backing()->updateConfiguration())
1694 layerChanged = true;
1695
1696 return layerChanged;
1697}
1698
1699void RenderLayerCompositor::repaintOnCompositingChange(RenderLayer& layer)
1700{
1701 // If the renderer is not attached yet, no need to repaint.
1702 if (&layer.renderer() != &m_renderView && !layer.renderer().parent())
1703 return;
1704
1705 auto* repaintContainer = layer.renderer().containerForRepaint();
1706 if (!repaintContainer)
1707 repaintContainer = &m_renderView;
1708
1709 layer.repaintIncludingNonCompositingDescendants(repaintContainer);
1710 if (repaintContainer == &m_renderView) {
1711 // The contents of this layer may be moving between the window
1712 // and a GraphicsLayer, so we need to make sure the window system
1713 // synchronizes those changes on the screen.
1714 m_renderView.frameView().setNeedsOneShotDrawingSynchronization();
1715 }
1716}
1717
1718// This method assumes that layout is up-to-date, unlike repaintOnCompositingChange().
1719void RenderLayerCompositor::repaintInCompositedAncestor(RenderLayer& layer, const LayoutRect& rect)
1720{
1721 auto* compositedAncestor = layer.enclosingCompositingLayerForRepaint(ExcludeSelf);
1722 if (!compositedAncestor)
1723 return;
1724
1725 ASSERT(compositedAncestor->backing());
1726 LayoutRect repaintRect = rect;
1727 repaintRect.move(layer.offsetFromAncestor(compositedAncestor));
1728 compositedAncestor->setBackingNeedsRepaintInRect(repaintRect);
1729
1730 // The contents of this layer may be moving from a GraphicsLayer to the window,
1731 // so we need to make sure the window system synchronizes those changes on the screen.
1732 if (compositedAncestor->isRenderViewLayer())
1733 m_renderView.frameView().setNeedsOneShotDrawingSynchronization();
1734}
1735
1736// FIXME: remove.
1737void RenderLayerCompositor::layerWasAdded(RenderLayer&, RenderLayer&)
1738{
1739}
1740
1741void RenderLayerCompositor::layerWillBeRemoved(RenderLayer& parent, RenderLayer& child)
1742{
1743 if (parent.renderer().renderTreeBeingDestroyed())
1744 return;
1745
1746 if (child.isComposited())
1747 repaintInCompositedAncestor(child, child.backing()->compositedBounds()); // FIXME: do via dirty bits?
1748 else if (child.paintsIntoProvidedBacking()) {
1749 auto* backingProviderLayer = child.backingProviderLayer();
1750 // FIXME: Optimize this repaint.
1751 backingProviderLayer->setBackingNeedsRepaint();
1752 backingProviderLayer->backing()->removeBackingSharingLayer(child);
1753 } else
1754 return;
1755
1756 child.setNeedsCompositingLayerConnection();
1757}
1758
1759RenderLayer* RenderLayerCompositor::enclosingNonStackingClippingLayer(const RenderLayer& layer) const
1760{
1761 for (auto* parent = layer.parent(); parent; parent = parent->parent()) {
1762 if (parent->isStackingContext())
1763 return nullptr;
1764 if (parent->renderer().hasClipOrOverflowClip())
1765 return parent;
1766 }
1767 return nullptr;
1768}
1769
1770void RenderLayerCompositor::computeExtent(const LayerOverlapMap& overlapMap, const RenderLayer& layer, OverlapExtent& extent) const
1771{
1772 if (extent.extentComputed)
1773 return;
1774
1775 LayoutRect layerBounds;
1776 if (extent.hasTransformAnimation)
1777 extent.animationCausesExtentUncertainty = !layer.getOverlapBoundsIncludingChildrenAccountingForTransformAnimations(layerBounds);
1778 else
1779 layerBounds = layer.overlapBounds();
1780
1781 // In the animating transform case, we avoid double-accounting for the transform because
1782 // we told pushMappingsToAncestor() to ignore transforms earlier.
1783 extent.bounds = enclosingLayoutRect(overlapMap.geometryMap().absoluteRect(layerBounds));
1784
1785 // Empty rects never intersect, but we need them to for the purposes of overlap testing.
1786 if (extent.bounds.isEmpty())
1787 extent.bounds.setSize(LayoutSize(1, 1));
1788
1789
1790 RenderLayerModelObject& renderer = layer.renderer();
1791 if (renderer.isFixedPositioned() && renderer.container() == &m_renderView) {
1792 // Because fixed elements get moved around without re-computing overlap, we have to compute an overlap
1793 // rect that covers all the locations that the fixed element could move to.
1794 // FIXME: need to handle sticky too.
1795 extent.bounds = m_renderView.frameView().fixedScrollableAreaBoundsInflatedForScrolling(extent.bounds);
1796 }
1797
1798 extent.extentComputed = true;
1799}
1800
1801void RenderLayerCompositor::addToOverlapMap(LayerOverlapMap& overlapMap, const RenderLayer& layer, OverlapExtent& extent) const
1802{
1803 if (layer.isRenderViewLayer())
1804 return;
1805
1806 computeExtent(overlapMap, layer, extent);
1807
1808 LayoutRect clipRect = layer.backgroundClipRect(RenderLayer::ClipRectsContext(&rootRenderLayer(), AbsoluteClipRects)).rect(); // FIXME: Incorrect for CSS regions.
1809
1810 // On iOS, pageScaleFactor() is not applied by RenderView, so we should not scale here.
1811 if (!m_renderView.settings().delegatesPageScaling())
1812 clipRect.scale(pageScaleFactor());
1813 clipRect.intersect(extent.bounds);
1814 overlapMap.add(clipRect);
1815}
1816
1817void RenderLayerCompositor::addDescendantsToOverlapMapRecursive(LayerOverlapMap& overlapMap, const RenderLayer& layer, const RenderLayer* ancestorLayer) const
1818{
1819 if (!canBeComposited(layer))
1820 return;
1821
1822 // A null ancestorLayer is an indication that 'layer' has already been pushed.
1823 if (ancestorLayer) {
1824 overlapMap.geometryMap().pushMappingsToAncestor(&layer, ancestorLayer);
1825
1826 OverlapExtent layerExtent;
1827 addToOverlapMap(overlapMap, layer, layerExtent);
1828 }
1829
1830#if !ASSERT_DISABLED
1831 LayerListMutationDetector mutationChecker(const_cast<RenderLayer&>(layer));
1832#endif
1833
1834 for (auto* renderLayer : layer.negativeZOrderLayers())
1835 addDescendantsToOverlapMapRecursive(overlapMap, *renderLayer, &layer);
1836
1837 for (auto* renderLayer : layer.normalFlowLayers())
1838 addDescendantsToOverlapMapRecursive(overlapMap, *renderLayer, &layer);
1839
1840 for (auto* renderLayer : layer.positiveZOrderLayers())
1841 addDescendantsToOverlapMapRecursive(overlapMap, *renderLayer, &layer);
1842
1843 if (ancestorLayer)
1844 overlapMap.geometryMap().popMappingsToAncestor(ancestorLayer);
1845}
1846
1847void RenderLayerCompositor::updateOverlapMap(LayerOverlapMap& overlapMap, const RenderLayer& layer, OverlapExtent& layerExtent, bool didPushContainer, bool addLayerToOverlap, bool addDescendantsToOverlap) const
1848{
1849 if (addLayerToOverlap) {
1850 addToOverlapMap(overlapMap, layer, layerExtent);
1851 LOG_WITH_STREAM(CompositingOverlap, stream << "layer " << &layer << " contributes to overlap, added to map " << overlapMap);
1852 }
1853
1854 if (addDescendantsToOverlap) {
1855 // If this is the first non-root layer to composite, we need to add all the descendants we already traversed to the overlap map.
1856 addDescendantsToOverlapMapRecursive(overlapMap, layer);
1857 LOG_WITH_STREAM(CompositingOverlap, stream << "layer " << &layer << " composited post descendant traversal, added recursive " << overlapMap);
1858 }
1859
1860 if (didPushContainer) {
1861 overlapMap.popCompositingContainer();
1862 LOG_WITH_STREAM(CompositingOverlap, stream << "layer " << &layer << " is composited or shared, popped container " << overlapMap);
1863 }
1864}
1865
1866#if ENABLE(VIDEO)
1867bool RenderLayerCompositor::canAccelerateVideoRendering(RenderVideo& video) const
1868{
1869 if (!m_hasAcceleratedCompositing)
1870 return false;
1871
1872 return video.supportsAcceleratedRendering();
1873}
1874#endif
1875
1876void RenderLayerCompositor::frameViewDidChangeLocation(const IntPoint& contentsOffset)
1877{
1878 if (m_overflowControlsHostLayer)
1879 m_overflowControlsHostLayer->setPosition(contentsOffset);
1880}
1881
1882void RenderLayerCompositor::frameViewDidChangeSize()
1883{
1884 if (auto* layer = m_renderView.layer())
1885 layer->setNeedsCompositingGeometryUpdate();
1886
1887 if (m_scrolledContentsLayer) {
1888 updateScrollLayerClipping();
1889 frameViewDidScroll();
1890 updateOverflowControlsLayers();
1891
1892#if ENABLE(RUBBER_BANDING)
1893 if (m_layerForOverhangAreas) {
1894 auto& frameView = m_renderView.frameView();
1895 m_layerForOverhangAreas->setSize(frameView.frameRect().size());
1896 m_layerForOverhangAreas->setPosition(FloatPoint(0, frameView.topContentInset()));
1897 }
1898#endif
1899 }
1900}
1901
1902bool RenderLayerCompositor::hasCoordinatedScrolling() const
1903{
1904 auto* scrollingCoordinator = this->scrollingCoordinator();
1905 return scrollingCoordinator && scrollingCoordinator->coordinatesScrollingForFrameView(m_renderView.frameView());
1906}
1907
1908void RenderLayerCompositor::updateScrollLayerPosition()
1909{
1910 ASSERT(!hasCoordinatedScrolling());
1911 ASSERT(m_scrolledContentsLayer);
1912
1913 auto& frameView = m_renderView.frameView();
1914 IntPoint scrollPosition = frameView.scrollPosition();
1915
1916 m_scrolledContentsLayer->setPosition(FloatPoint(-scrollPosition.x(), -scrollPosition.y()));
1917
1918 if (auto* fixedBackgroundLayer = fixedRootBackgroundLayer())
1919 fixedBackgroundLayer->setPosition(frameView.scrollPositionForFixedPosition());
1920}
1921
1922void RenderLayerCompositor::updateScrollLayerClipping()
1923{
1924 auto* layerForClipping = this->layerForClipping();
1925 if (!layerForClipping)
1926 return;
1927
1928 layerForClipping->setSize(m_renderView.frameView().sizeForVisibleContent());
1929 layerForClipping->setPosition(positionForClipLayer());
1930}
1931
1932FloatPoint RenderLayerCompositor::positionForClipLayer() const
1933{
1934 auto& frameView = m_renderView.frameView();
1935
1936 return FloatPoint(
1937 frameView.shouldPlaceBlockDirectionScrollbarOnLeft() ? frameView.horizontalScrollbarIntrusion() : 0,
1938 FrameView::yPositionForInsetClipLayer(frameView.scrollPosition(), frameView.topContentInset()));
1939}
1940
1941void RenderLayerCompositor::frameViewDidScroll()
1942{
1943 if (!m_scrolledContentsLayer)
1944 return;
1945
1946 // If there's a scrolling coordinator that manages scrolling for this frame view,
1947 // it will also manage updating the scroll layer position.
1948 if (hasCoordinatedScrolling()) {
1949 // We have to schedule a flush in order for the main TiledBacking to update its tile coverage.
1950 scheduleLayerFlush();
1951 return;
1952 }
1953
1954 updateScrollLayerPosition();
1955}
1956
1957void RenderLayerCompositor::frameViewDidAddOrRemoveScrollbars()
1958{
1959 updateOverflowControlsLayers();
1960}
1961
1962void RenderLayerCompositor::frameViewDidLayout()
1963{
1964 if (auto* renderViewBacking = m_renderView.layer()->backing())
1965 renderViewBacking->adjustTiledBackingCoverage();
1966}
1967
1968void RenderLayerCompositor::rootLayerConfigurationChanged()
1969{
1970 auto* renderViewBacking = m_renderView.layer()->backing();
1971 if (renderViewBacking && renderViewBacking->isFrameLayerWithTiledBacking()) {
1972 m_renderView.layer()->setNeedsCompositingConfigurationUpdate();
1973 scheduleCompositingLayerUpdate();
1974 }
1975}
1976
1977String RenderLayerCompositor::layerTreeAsText(LayerTreeFlags flags)
1978{
1979 updateCompositingLayers(CompositingUpdateType::AfterLayout);
1980
1981 if (!m_rootContentsLayer)
1982 return String();
1983
1984 flushPendingLayerChanges(true);
1985 page().renderingUpdateScheduler().scheduleCompositingLayerFlush();
1986
1987 LayerTreeAsTextBehavior layerTreeBehavior = LayerTreeAsTextBehaviorNormal;
1988 if (flags & LayerTreeFlagsIncludeDebugInfo)
1989 layerTreeBehavior |= LayerTreeAsTextDebug;
1990 if (flags & LayerTreeFlagsIncludeVisibleRects)
1991 layerTreeBehavior |= LayerTreeAsTextIncludeVisibleRects;
1992 if (flags & LayerTreeFlagsIncludeTileCaches)
1993 layerTreeBehavior |= LayerTreeAsTextIncludeTileCaches;
1994 if (flags & LayerTreeFlagsIncludeRepaintRects)
1995 layerTreeBehavior |= LayerTreeAsTextIncludeRepaintRects;
1996 if (flags & LayerTreeFlagsIncludePaintingPhases)
1997 layerTreeBehavior |= LayerTreeAsTextIncludePaintingPhases;
1998 if (flags & LayerTreeFlagsIncludeContentLayers)
1999 layerTreeBehavior |= LayerTreeAsTextIncludeContentLayers;
2000 if (flags & LayerTreeFlagsIncludeAcceleratesDrawing)
2001 layerTreeBehavior |= LayerTreeAsTextIncludeAcceleratesDrawing;
2002 if (flags & LayerTreeFlagsIncludeBackingStoreAttached)
2003 layerTreeBehavior |= LayerTreeAsTextIncludeBackingStoreAttached;
2004 if (flags & LayerTreeFlagsIncludeRootLayerProperties)
2005 layerTreeBehavior |= LayerTreeAsTextIncludeRootLayerProperties;
2006 if (flags & LayerTreeFlagsIncludeEventRegion)
2007 layerTreeBehavior |= LayerTreeAsTextIncludeEventRegion;
2008
2009 // We skip dumping the scroll and clip layers to keep layerTreeAsText output
2010 // similar between platforms.
2011 String layerTreeText = m_rootContentsLayer->layerTreeAsText(layerTreeBehavior);
2012
2013 // Dump an empty layer tree only if the only composited layer is the main frame's tiled backing,
2014 // so that tests expecting us to drop out of accelerated compositing when there are no layers succeed.
2015 if (!hasContentCompositingLayers() && documentUsesTiledBacking() && !(layerTreeBehavior & LayerTreeAsTextIncludeTileCaches) && !(layerTreeBehavior & LayerTreeAsTextIncludeRootLayerProperties))
2016 layerTreeText = emptyString();
2017
2018 // The true root layer is not included in the dump, so if we want to report
2019 // its repaint rects, they must be included here.
2020 if (flags & LayerTreeFlagsIncludeRepaintRects)
2021 return m_renderView.frameView().trackedRepaintRectsAsText() + layerTreeText;
2022
2023 return layerTreeText;
2024}
2025
2026static RenderView* frameContentsRenderView(RenderWidget& renderer)
2027{
2028 if (auto* contentDocument = renderer.frameOwnerElement().contentDocument())
2029 return contentDocument->renderView();
2030
2031 return nullptr;
2032}
2033
2034RenderLayerCompositor* RenderLayerCompositor::frameContentsCompositor(RenderWidget& renderer)
2035{
2036 if (auto* view = frameContentsRenderView(renderer))
2037 return &view->compositor();
2038
2039 return nullptr;
2040}
2041
2042bool RenderLayerCompositor::parentFrameContentLayers(RenderWidget& renderer)
2043{
2044 auto* innerCompositor = frameContentsCompositor(renderer);
2045 if (!innerCompositor || !innerCompositor->usesCompositing() || innerCompositor->rootLayerAttachment() != RootLayerAttachedViaEnclosingFrame)
2046 return false;
2047
2048 auto* layer = renderer.layer();
2049 if (!layer->isComposited())
2050 return false;
2051
2052 auto* backing = layer->backing();
2053 auto* hostingLayer = backing->parentForSublayers();
2054 auto* rootLayer = innerCompositor->rootGraphicsLayer();
2055 if (hostingLayer->children().size() != 1 || hostingLayer->children()[0].ptr() != rootLayer) {
2056 hostingLayer->removeAllChildren();
2057 hostingLayer->addChild(*rootLayer);
2058 }
2059
2060 if (auto frameHostingNodeID = backing->scrollingNodeIDForRole(ScrollCoordinationRole::FrameHosting)) {
2061 auto* contentsRenderView = frameContentsRenderView(renderer);
2062 if (auto frameRootScrollingNodeID = contentsRenderView->frameView().scrollingNodeID()) {
2063 if (auto* scrollingCoordinator = this->scrollingCoordinator())
2064 scrollingCoordinator->insertNode(ScrollingNodeType::Subframe, frameRootScrollingNodeID, frameHostingNodeID, 0);
2065 }
2066 }
2067
2068 // FIXME: Why always return true and not just when the layers changed?
2069 return true;
2070}
2071
2072void RenderLayerCompositor::repaintCompositedLayers()
2073{
2074 recursiveRepaintLayer(rootRenderLayer());
2075}
2076
2077void RenderLayerCompositor::recursiveRepaintLayer(RenderLayer& layer)
2078{
2079 layer.updateLayerListsIfNeeded();
2080
2081 // FIXME: This method does not work correctly with transforms.
2082 if (layer.isComposited() && !layer.backing()->paintsIntoCompositedAncestor())
2083 layer.setBackingNeedsRepaint();
2084
2085#if !ASSERT_DISABLED
2086 LayerListMutationDetector mutationChecker(layer);
2087#endif
2088
2089 if (layer.hasCompositingDescendant()) {
2090 for (auto* renderLayer : layer.negativeZOrderLayers())
2091 recursiveRepaintLayer(*renderLayer);
2092
2093 for (auto* renderLayer : layer.positiveZOrderLayers())
2094 recursiveRepaintLayer(*renderLayer);
2095 }
2096
2097 for (auto* renderLayer : layer.normalFlowLayers())
2098 recursiveRepaintLayer(*renderLayer);
2099}
2100
2101RenderLayer& RenderLayerCompositor::rootRenderLayer() const
2102{
2103 return *m_renderView.layer();
2104}
2105
2106GraphicsLayer* RenderLayerCompositor::rootGraphicsLayer() const
2107{
2108 if (m_overflowControlsHostLayer)
2109 return m_overflowControlsHostLayer.get();
2110 return m_rootContentsLayer.get();
2111}
2112
2113void RenderLayerCompositor::setIsInWindow(bool isInWindow)
2114{
2115 LOG(Compositing, "RenderLayerCompositor %p setIsInWindow %d", this, isInWindow);
2116
2117 if (!usesCompositing())
2118 return;
2119
2120 if (auto* rootLayer = rootGraphicsLayer()) {
2121 GraphicsLayer::traverse(*rootLayer, [isInWindow](GraphicsLayer& layer) {
2122 layer.setIsInWindow(isInWindow);
2123 });
2124 }
2125
2126 if (isInWindow) {
2127 if (m_rootLayerAttachment != RootLayerUnattached)
2128 return;
2129
2130 RootLayerAttachment attachment = isMainFrameCompositor() ? RootLayerAttachedViaChromeClient : RootLayerAttachedViaEnclosingFrame;
2131 attachRootLayer(attachment);
2132#if PLATFORM(IOS_FAMILY)
2133 if (m_legacyScrollingLayerCoordinator) {
2134 m_legacyScrollingLayerCoordinator->registerAllViewportConstrainedLayers(*this);
2135 m_legacyScrollingLayerCoordinator->registerAllScrollingLayers();
2136 }
2137#endif
2138 } else {
2139 if (m_rootLayerAttachment == RootLayerUnattached)
2140 return;
2141
2142 detachRootLayer();
2143#if PLATFORM(IOS_FAMILY)
2144 if (m_legacyScrollingLayerCoordinator) {
2145 m_legacyScrollingLayerCoordinator->unregisterAllViewportConstrainedLayers();
2146 m_legacyScrollingLayerCoordinator->unregisterAllScrollingLayers();
2147 }
2148#endif
2149 }
2150}
2151
2152void RenderLayerCompositor::clearBackingForLayerIncludingDescendants(RenderLayer& layer)
2153{
2154 if (layer.isComposited())
2155 layer.clearBacking();
2156
2157 for (auto* childLayer = layer.firstChild(); childLayer; childLayer = childLayer->nextSibling())
2158 clearBackingForLayerIncludingDescendants(*childLayer);
2159}
2160
2161void RenderLayerCompositor::clearBackingForAllLayers()
2162{
2163 clearBackingForLayerIncludingDescendants(*m_renderView.layer());
2164}
2165
2166void RenderLayerCompositor::updateRootLayerPosition()
2167{
2168 if (m_rootContentsLayer) {
2169 m_rootContentsLayer->setSize(m_renderView.frameView().contentsSize());
2170 m_rootContentsLayer->setPosition(m_renderView.frameView().positionForRootContentLayer());
2171 m_rootContentsLayer->setAnchorPoint(FloatPoint3D());
2172 }
2173
2174 updateScrollLayerClipping();
2175
2176#if ENABLE(RUBBER_BANDING)
2177 if (m_contentShadowLayer && m_rootContentsLayer) {
2178 m_contentShadowLayer->setPosition(m_rootContentsLayer->position());
2179 m_contentShadowLayer->setSize(m_rootContentsLayer->size());
2180 }
2181
2182 updateLayerForTopOverhangArea(m_layerForTopOverhangArea != nullptr);
2183 updateLayerForBottomOverhangArea(m_layerForBottomOverhangArea != nullptr);
2184 updateLayerForHeader(m_layerForHeader != nullptr);
2185 updateLayerForFooter(m_layerForFooter != nullptr);
2186#endif
2187}
2188
2189bool RenderLayerCompositor::has3DContent() const
2190{
2191 return layerHas3DContent(rootRenderLayer());
2192}
2193
2194bool RenderLayerCompositor::needsToBeComposited(const RenderLayer& layer, RequiresCompositingData& queryData) const
2195{
2196 if (!canBeComposited(layer))
2197 return false;
2198
2199 return requiresCompositingLayer(layer, queryData) || layer.mustCompositeForIndirectReasons() || (usesCompositing() && layer.isRenderViewLayer());
2200}
2201
2202// Note: this specifies whether the RL needs a compositing layer for intrinsic reasons.
2203// Use needsToBeComposited() to determine if a RL actually needs a compositing layer.
2204// FIXME: is clipsCompositingDescendants() an intrinsic reason?
2205bool RenderLayerCompositor::requiresCompositingLayer(const RenderLayer& layer, RequiresCompositingData& queryData) const
2206{
2207 auto& renderer = rendererForCompositingTests(layer);
2208
2209 // The root layer always has a compositing layer, but it may not have backing.
2210 return requiresCompositingForTransform(renderer)
2211 || requiresCompositingForAnimation(renderer)
2212 || clipsCompositingDescendants(*renderer.layer())
2213 || requiresCompositingForPosition(renderer, *renderer.layer(), queryData)
2214 || requiresCompositingForCanvas(renderer)
2215 || requiresCompositingForFilters(renderer)
2216 || requiresCompositingForWillChange(renderer)
2217 || requiresCompositingForBackfaceVisibility(renderer)
2218 || requiresCompositingForVideo(renderer)
2219 || requiresCompositingForFrame(renderer, queryData)
2220 || requiresCompositingForPlugin(renderer, queryData)
2221 || requiresCompositingForEditableImage(renderer)
2222 || requiresCompositingForOverflowScrolling(*renderer.layer(), queryData);
2223}
2224
2225bool RenderLayerCompositor::canBeComposited(const RenderLayer& layer) const
2226{
2227 if (m_hasAcceleratedCompositing && layer.isSelfPaintingLayer()) {
2228 if (!layer.isInsideFragmentedFlow())
2229 return true;
2230
2231 // CSS Regions flow threads do not need to be composited as we use composited RenderFragmentContainers
2232 // to render the background of the RenderFragmentedFlow.
2233 if (layer.isRenderFragmentedFlow())
2234 return false;
2235
2236 return true;
2237 }
2238 return false;
2239}
2240
2241#if ENABLE(FULLSCREEN_API)
2242enum class FullScreenDescendant { Yes, No, NotApplicable };
2243static FullScreenDescendant isDescendantOfFullScreenLayer(const RenderLayer& layer)
2244{
2245 auto& document = layer.renderer().document();
2246
2247 if (!document.fullscreenManager().isFullscreen() || !document.fullscreenManager().fullscreenRenderer())
2248 return FullScreenDescendant::NotApplicable;
2249
2250 auto* fullScreenLayer = document.fullscreenManager().fullscreenRenderer()->layer();
2251 if (!fullScreenLayer) {
2252 ASSERT_NOT_REACHED();
2253 return FullScreenDescendant::NotApplicable;
2254 }
2255
2256 return layer.isDescendantOf(*fullScreenLayer) ? FullScreenDescendant::Yes : FullScreenDescendant::No;
2257}
2258#endif
2259
2260bool RenderLayerCompositor::requiresOwnBackingStore(const RenderLayer& layer, const RenderLayer* compositingAncestorLayer, const LayoutRect& layerCompositedBoundsInAncestor, const LayoutRect& ancestorCompositedBounds) const
2261{
2262 auto& renderer = layer.renderer();
2263
2264 if (compositingAncestorLayer
2265 && !(compositingAncestorLayer->backing()->graphicsLayer()->drawsContent()
2266 || compositingAncestorLayer->backing()->paintsIntoWindow()
2267 || compositingAncestorLayer->backing()->paintsIntoCompositedAncestor()))
2268 return true;
2269
2270 RequiresCompositingData queryData;
2271 if (layer.isRenderViewLayer()
2272 || layer.transform() // note: excludes perspective and transformStyle3D.
2273 || requiresCompositingForAnimation(renderer)
2274 || requiresCompositingForPosition(renderer, layer, queryData)
2275 || requiresCompositingForCanvas(renderer)
2276 || requiresCompositingForFilters(renderer)
2277 || requiresCompositingForWillChange(renderer)
2278 || requiresCompositingForBackfaceVisibility(renderer)
2279 || requiresCompositingForVideo(renderer)
2280 || requiresCompositingForFrame(renderer, queryData)
2281 || requiresCompositingForPlugin(renderer, queryData)
2282 || requiresCompositingForEditableImage(renderer)
2283 || requiresCompositingForOverflowScrolling(layer, queryData)
2284 || needsContentsCompositingLayer(layer)
2285 || renderer.isTransparent()
2286 || renderer.hasMask()
2287 || renderer.hasReflection()
2288 || renderer.hasFilter()
2289 || renderer.hasBackdropFilter())
2290 return true;
2291
2292 if (layer.mustCompositeForIndirectReasons()) {
2293 IndirectCompositingReason reason = layer.indirectCompositingReason();
2294 return reason == IndirectCompositingReason::Overlap
2295 || reason == IndirectCompositingReason::OverflowScrollPositioning
2296 || reason == IndirectCompositingReason::Stacking
2297 || reason == IndirectCompositingReason::BackgroundLayer
2298 || reason == IndirectCompositingReason::GraphicalEffect
2299 || reason == IndirectCompositingReason::Preserve3D; // preserve-3d has to create backing store to ensure that 3d-transformed elements intersect.
2300 }
2301
2302 if (!ancestorCompositedBounds.contains(layerCompositedBoundsInAncestor))
2303 return true;
2304
2305 if (layer.isComposited() && layer.backing()->hasBackingSharingLayers())
2306 return true;
2307
2308 return false;
2309}
2310
2311OptionSet<CompositingReason> RenderLayerCompositor::reasonsForCompositing(const RenderLayer& layer) const
2312{
2313 OptionSet<CompositingReason> reasons;
2314
2315 if (!layer.isComposited())
2316 return reasons;
2317
2318 RequiresCompositingData queryData;
2319
2320 auto& renderer = rendererForCompositingTests(layer);
2321
2322 if (requiresCompositingForTransform(renderer))
2323 reasons.add(CompositingReason::Transform3D);
2324
2325 if (requiresCompositingForVideo(renderer))
2326 reasons.add(CompositingReason::Video);
2327 else if (requiresCompositingForCanvas(renderer))
2328 reasons.add(CompositingReason::Canvas);
2329 else if (requiresCompositingForPlugin(renderer, queryData))
2330 reasons.add(CompositingReason::Plugin);
2331 else if (requiresCompositingForFrame(renderer, queryData))
2332 reasons.add(CompositingReason::IFrame);
2333 else if (requiresCompositingForEditableImage(renderer))
2334 reasons.add(CompositingReason::EmbeddedView);
2335
2336 if ((canRender3DTransforms() && renderer.style().backfaceVisibility() == BackfaceVisibility::Hidden))
2337 reasons.add(CompositingReason::BackfaceVisibilityHidden);
2338
2339 if (clipsCompositingDescendants(*renderer.layer()))
2340 reasons.add(CompositingReason::ClipsCompositingDescendants);
2341
2342 if (requiresCompositingForAnimation(renderer))
2343 reasons.add(CompositingReason::Animation);
2344
2345 if (requiresCompositingForFilters(renderer))
2346 reasons.add(CompositingReason::Filters);
2347
2348 if (requiresCompositingForWillChange(renderer))
2349 reasons.add(CompositingReason::WillChange);
2350
2351 if (requiresCompositingForPosition(renderer, *renderer.layer(), queryData))
2352 reasons.add(renderer.isFixedPositioned() ? CompositingReason::PositionFixed : CompositingReason::PositionSticky);
2353
2354 if (requiresCompositingForOverflowScrolling(*renderer.layer(), queryData))
2355 reasons.add(CompositingReason::OverflowScrolling);
2356
2357 switch (renderer.layer()->indirectCompositingReason()) {
2358 case IndirectCompositingReason::None:
2359 break;
2360 case IndirectCompositingReason::Stacking:
2361 reasons.add(CompositingReason::Stacking);
2362 break;
2363 case IndirectCompositingReason::OverflowScrollPositioning:
2364 reasons.add(CompositingReason::OverflowScrollPositioning);
2365 break;
2366 case IndirectCompositingReason::Overlap:
2367 reasons.add(CompositingReason::Overlap);
2368 break;
2369 case IndirectCompositingReason::BackgroundLayer:
2370 reasons.add(CompositingReason::NegativeZIndexChildren);
2371 break;
2372 case IndirectCompositingReason::GraphicalEffect:
2373 if (renderer.hasTransform())
2374 reasons.add(CompositingReason::TransformWithCompositedDescendants);
2375
2376 if (renderer.isTransparent())
2377 reasons.add(CompositingReason::OpacityWithCompositedDescendants);
2378
2379 if (renderer.hasMask())
2380 reasons.add(CompositingReason::MaskWithCompositedDescendants);
2381
2382 if (renderer.hasReflection())
2383 reasons.add(CompositingReason::ReflectionWithCompositedDescendants);
2384
2385 if (renderer.hasFilter() || renderer.hasBackdropFilter())
2386 reasons.add(CompositingReason::FilterWithCompositedDescendants);
2387
2388#if ENABLE(CSS_COMPOSITING)
2389 if (layer.isolatesCompositedBlending())
2390 reasons.add(CompositingReason::IsolatesCompositedBlendingDescendants);
2391
2392 if (layer.hasBlendMode())
2393 reasons.add(CompositingReason::BlendingWithCompositedDescendants);
2394#endif
2395 break;
2396 case IndirectCompositingReason::Perspective:
2397 reasons.add(CompositingReason::Perspective);
2398 break;
2399 case IndirectCompositingReason::Preserve3D:
2400 reasons.add(CompositingReason::Preserve3D);
2401 break;
2402 }
2403
2404 if (usesCompositing() && renderer.layer()->isRenderViewLayer())
2405 reasons.add(CompositingReason::Root);
2406
2407 return reasons;
2408}
2409
2410#if !LOG_DISABLED
2411const char* RenderLayerCompositor::logReasonsForCompositing(const RenderLayer& layer)
2412{
2413 OptionSet<CompositingReason> reasons = reasonsForCompositing(layer);
2414
2415 if (reasons & CompositingReason::Transform3D)
2416 return "3D transform";
2417
2418 if (reasons & CompositingReason::Video)
2419 return "video";
2420
2421 if (reasons & CompositingReason::Canvas)
2422 return "canvas";
2423
2424 if (reasons & CompositingReason::Plugin)
2425 return "plugin";
2426
2427 if (reasons & CompositingReason::IFrame)
2428 return "iframe";
2429
2430 if (reasons & CompositingReason::BackfaceVisibilityHidden)
2431 return "backface-visibility: hidden";
2432
2433 if (reasons & CompositingReason::ClipsCompositingDescendants)
2434 return "clips compositing descendants";
2435
2436 if (reasons & CompositingReason::Animation)
2437 return "animation";
2438
2439 if (reasons & CompositingReason::Filters)
2440 return "filters";
2441
2442 if (reasons & CompositingReason::PositionFixed)
2443 return "position: fixed";
2444
2445 if (reasons & CompositingReason::PositionSticky)
2446 return "position: sticky";
2447
2448 if (reasons & CompositingReason::OverflowScrolling)
2449 return "async overflow scrolling";
2450
2451 if (reasons & CompositingReason::Stacking)
2452 return "stacking";
2453
2454 if (reasons & CompositingReason::Overlap)
2455 return "overlap";
2456
2457 if (reasons & CompositingReason::NegativeZIndexChildren)
2458 return "negative z-index children";
2459
2460 if (reasons & CompositingReason::TransformWithCompositedDescendants)
2461 return "transform with composited descendants";
2462
2463 if (reasons & CompositingReason::OpacityWithCompositedDescendants)
2464 return "opacity with composited descendants";
2465
2466 if (reasons & CompositingReason::MaskWithCompositedDescendants)
2467 return "mask with composited descendants";
2468
2469 if (reasons & CompositingReason::ReflectionWithCompositedDescendants)
2470 return "reflection with composited descendants";
2471
2472 if (reasons & CompositingReason::FilterWithCompositedDescendants)
2473 return "filter with composited descendants";
2474
2475#if ENABLE(CSS_COMPOSITING)
2476 if (reasons & CompositingReason::BlendingWithCompositedDescendants)
2477 return "blending with composited descendants";
2478
2479 if (reasons & CompositingReason::IsolatesCompositedBlendingDescendants)
2480 return "isolates composited blending descendants";
2481#endif
2482
2483 if (reasons & CompositingReason::Perspective)
2484 return "perspective";
2485
2486 if (reasons & CompositingReason::Preserve3D)
2487 return "preserve-3d";
2488
2489 if (reasons & CompositingReason::Root)
2490 return "root";
2491
2492 return "";
2493}
2494#endif
2495
2496// Return true if the given layer has some ancestor in the RenderLayer hierarchy that clips,
2497// up to the enclosing compositing ancestor. This is required because compositing layers are parented
2498// according to the z-order hierarchy, yet clipping goes down the renderer hierarchy.
2499// Thus, a RenderLayer can be clipped by a RenderLayer that is an ancestor in the renderer hierarchy,
2500// but a sibling in the z-order hierarchy.
2501// FIXME: can we do this without a tree walk?
2502bool RenderLayerCompositor::clippedByAncestor(RenderLayer& layer) const
2503{
2504 ASSERT(layer.isComposited());
2505 if (!layer.parent())
2506 return false;
2507
2508 // On first pass in WK1, the root may not have become composited yet.
2509 auto* compositingAncestor = layer.ancestorCompositingLayer();
2510 if (!compositingAncestor)
2511 return false;
2512
2513 // If the compositingAncestor clips, that will be taken care of by clipsCompositingDescendants(),
2514 // so we only care about clipping between its first child that is our ancestor (the computeClipRoot),
2515 // and layer. The exception is when the compositingAncestor isolates composited blending children,
2516 // in this case it is not allowed to clipsCompositingDescendants() and each of its children
2517 // will be clippedByAncestor()s, including the compositingAncestor.
2518 auto* computeClipRoot = compositingAncestor;
2519 if (!compositingAncestor->isolatesCompositedBlending()) {
2520 computeClipRoot = nullptr;
2521 auto* parent = &layer;
2522 while (parent) {
2523 auto* next = parent->parent();
2524 if (next == compositingAncestor) {
2525 computeClipRoot = parent;
2526 break;
2527 }
2528 parent = next;
2529 }
2530
2531 if (!computeClipRoot || computeClipRoot == &layer)
2532 return false;
2533 }
2534
2535 return !layer.backgroundClipRect(RenderLayer::ClipRectsContext(computeClipRoot, TemporaryClipRects)).isInfinite(); // FIXME: Incorrect for CSS regions.
2536}
2537
2538// Return true if the given layer is a stacking context and has compositing child
2539// layers that it needs to clip. In this case we insert a clipping GraphicsLayer
2540// into the hierarchy between this layer and its children in the z-order hierarchy.
2541bool RenderLayerCompositor::clipsCompositingDescendants(const RenderLayer& layer)
2542{
2543 return layer.hasCompositingDescendant() && layer.renderer().hasClipOrOverflowClip() && !layer.isolatesCompositedBlending();
2544}
2545
2546bool RenderLayerCompositor::requiresCompositingForAnimation(RenderLayerModelObject& renderer) const
2547{
2548 if (!(m_compositingTriggers & ChromeClient::AnimationTrigger))
2549 return false;
2550
2551 if (auto* element = renderer.element()) {
2552 if (auto* timeline = element->document().existingTimeline()) {
2553 if (timeline->runningAnimationsForElementAreAllAccelerated(*element))
2554 return true;
2555 }
2556 }
2557
2558 if (RuntimeEnabledFeatures::sharedFeatures().webAnimationsCSSIntegrationEnabled())
2559 return false;
2560
2561 auto& animController = renderer.animation();
2562 return (animController.isRunningAnimationOnRenderer(renderer, CSSPropertyOpacity)
2563 && (usesCompositing() || (m_compositingTriggers & ChromeClient::AnimatedOpacityTrigger)))
2564 || animController.isRunningAnimationOnRenderer(renderer, CSSPropertyFilter)
2565#if ENABLE(FILTERS_LEVEL_2)
2566 || animController.isRunningAnimationOnRenderer(renderer, CSSPropertyWebkitBackdropFilter)
2567#endif
2568 || animController.isRunningAnimationOnRenderer(renderer, CSSPropertyTransform);
2569}
2570
2571bool RenderLayerCompositor::requiresCompositingForTransform(RenderLayerModelObject& renderer) const
2572{
2573 if (!(m_compositingTriggers & ChromeClient::ThreeDTransformTrigger))
2574 return false;
2575
2576 // Note that we ask the renderer if it has a transform, because the style may have transforms,
2577 // but the renderer may be an inline that doesn't suppport them.
2578 if (!renderer.hasTransform())
2579 return false;
2580
2581 switch (m_compositingPolicy) {
2582 case CompositingPolicy::Normal:
2583 return renderer.style().transform().has3DOperation();
2584 case CompositingPolicy::Conservative:
2585 // Continue to allow pages to avoid the very slow software filter path.
2586 if (renderer.style().transform().has3DOperation() && renderer.hasFilter())
2587 return true;
2588 return renderer.style().transform().isRepresentableIn2D() ? false : true;
2589 }
2590 return false;
2591}
2592
2593bool RenderLayerCompositor::requiresCompositingForBackfaceVisibility(RenderLayerModelObject& renderer) const
2594{
2595 if (!(m_compositingTriggers & ChromeClient::ThreeDTransformTrigger))
2596 return false;
2597
2598 if (renderer.style().backfaceVisibility() != BackfaceVisibility::Hidden)
2599 return false;
2600
2601 if (renderer.layer()->has3DTransformedAncestor())
2602 return true;
2603
2604 // FIXME: workaround for webkit.org/b/132801
2605 auto* stackingContext = renderer.layer()->stackingContext();
2606 if (stackingContext && stackingContext->renderer().style().transformStyle3D() == TransformStyle3D::Preserve3D)
2607 return true;
2608
2609 return false;
2610}
2611
2612bool RenderLayerCompositor::requiresCompositingForVideo(RenderLayerModelObject& renderer) const
2613{
2614 if (!(m_compositingTriggers & ChromeClient::VideoTrigger))
2615 return false;
2616
2617#if ENABLE(VIDEO)
2618 if (!is<RenderVideo>(renderer))
2619 return false;
2620
2621 auto& video = downcast<RenderVideo>(renderer);
2622 if ((video.requiresImmediateCompositing() || video.shouldDisplayVideo()) && canAccelerateVideoRendering(video))
2623 return true;
2624#else
2625 UNUSED_PARAM(renderer);
2626#endif
2627 return false;
2628}
2629
2630bool RenderLayerCompositor::requiresCompositingForCanvas(RenderLayerModelObject& renderer) const
2631{
2632 if (!(m_compositingTriggers & ChromeClient::CanvasTrigger))
2633 return false;
2634
2635 if (!renderer.isCanvas())
2636 return false;
2637
2638 bool isCanvasLargeEnoughToForceCompositing = true;
2639#if !USE(COMPOSITING_FOR_SMALL_CANVASES)
2640 auto* canvas = downcast<HTMLCanvasElement>(renderer.element());
2641 auto canvasArea = canvas->size().area<RecordOverflow>();
2642 isCanvasLargeEnoughToForceCompositing = !canvasArea.hasOverflowed() && canvasArea.unsafeGet() >= canvasAreaThresholdRequiringCompositing;
2643#endif
2644
2645 CanvasCompositingStrategy compositingStrategy = canvasCompositingStrategy(renderer);
2646 if (compositingStrategy == CanvasAsLayerContents)
2647 return true;
2648
2649 if (m_compositingPolicy == CompositingPolicy::Normal)
2650 return compositingStrategy == CanvasPaintedToLayer && isCanvasLargeEnoughToForceCompositing;
2651
2652 return false;
2653}
2654
2655bool RenderLayerCompositor::requiresCompositingForFilters(RenderLayerModelObject& renderer) const
2656{
2657#if ENABLE(FILTERS_LEVEL_2)
2658 if (renderer.hasBackdropFilter())
2659 return true;
2660#endif
2661
2662 if (!(m_compositingTriggers & ChromeClient::FilterTrigger))
2663 return false;
2664
2665 return renderer.hasFilter();
2666}
2667
2668bool RenderLayerCompositor::requiresCompositingForWillChange(RenderLayerModelObject& renderer) const
2669{
2670 if (!renderer.style().willChange() || !renderer.style().willChange()->canTriggerCompositing())
2671 return false;
2672
2673#if ENABLE(FULLSCREEN_API)
2674 // FIXME: does this require layout?
2675 if (renderer.layer() && isDescendantOfFullScreenLayer(*renderer.layer()) == FullScreenDescendant::No)
2676 return false;
2677#endif
2678
2679 if (m_compositingPolicy == CompositingPolicy::Conservative)
2680 return false;
2681
2682 if (is<RenderBox>(renderer))
2683 return true;
2684
2685 return renderer.style().willChange()->canTriggerCompositingOnInline();
2686}
2687
2688bool RenderLayerCompositor::requiresCompositingForPlugin(RenderLayerModelObject& renderer, RequiresCompositingData& queryData) const
2689{
2690 if (!(m_compositingTriggers & ChromeClient::PluginTrigger))
2691 return false;
2692
2693 bool isCompositedPlugin = is<RenderEmbeddedObject>(renderer) && downcast<RenderEmbeddedObject>(renderer).allowsAcceleratedCompositing();
2694 if (!isCompositedPlugin)
2695 return false;
2696
2697 auto& pluginRenderer = downcast<RenderWidget>(renderer);
2698 if (pluginRenderer.style().visibility() != Visibility::Visible)
2699 return false;
2700
2701 // If we can't reliably know the size of the plugin yet, don't change compositing state.
2702 if (queryData.layoutUpToDate == LayoutUpToDate::No) {
2703 queryData.reevaluateAfterLayout = true;
2704 return pluginRenderer.isComposited();
2705 }
2706
2707 // Don't go into compositing mode if height or width are zero, or size is 1x1.
2708 IntRect contentBox = snappedIntRect(pluginRenderer.contentBoxRect());
2709 return (contentBox.height() * contentBox.width() > 1);
2710}
2711
2712bool RenderLayerCompositor::requiresCompositingForEditableImage(RenderLayerModelObject& renderer) const
2713{
2714 if (!renderer.isRenderImage())
2715 return false;
2716
2717 auto& image = downcast<RenderImage>(renderer);
2718 if (!image.isEditableImage())
2719 return false;
2720
2721 return true;
2722}
2723
2724bool RenderLayerCompositor::requiresCompositingForFrame(RenderLayerModelObject& renderer, RequiresCompositingData& queryData) const
2725{
2726 if (!is<RenderWidget>(renderer))
2727 return false;
2728
2729 auto& frameRenderer = downcast<RenderWidget>(renderer);
2730 if (frameRenderer.style().visibility() != Visibility::Visible)
2731 return false;
2732
2733 if (!frameRenderer.requiresAcceleratedCompositing())
2734 return false;
2735
2736 if (queryData.layoutUpToDate == LayoutUpToDate::No) {
2737 queryData.reevaluateAfterLayout = true;
2738 return frameRenderer.isComposited();
2739 }
2740
2741 // Don't go into compositing mode if height or width are zero.
2742 return !snappedIntRect(frameRenderer.contentBoxRect()).isEmpty();
2743}
2744
2745bool RenderLayerCompositor::requiresCompositingForScrollableFrame(RequiresCompositingData& queryData) const
2746{
2747 if (isMainFrameCompositor())
2748 return false;
2749
2750#if PLATFORM(MAC) || PLATFORM(IOS_FAMILY)
2751 if (!m_renderView.settings().asyncFrameScrollingEnabled())
2752 return false;
2753#endif
2754
2755 if (!(m_compositingTriggers & ChromeClient::ScrollableNonMainFrameTrigger))
2756 return false;
2757
2758 if (queryData.layoutUpToDate == LayoutUpToDate::No) {
2759 queryData.reevaluateAfterLayout = true;
2760 return m_renderView.isComposited();
2761 }
2762
2763 return m_renderView.frameView().isScrollable();
2764}
2765
2766bool RenderLayerCompositor::requiresCompositingForPosition(RenderLayerModelObject& renderer, const RenderLayer& layer, RequiresCompositingData& queryData) const
2767{
2768 // position:fixed elements that create their own stacking context (e.g. have an explicit z-index,
2769 // opacity, transform) can get their own composited layer. A stacking context is required otherwise
2770 // z-index and clipping will be broken.
2771 if (!renderer.isPositioned())
2772 return false;
2773
2774#if ENABLE(FULLSCREEN_API)
2775 if (isDescendantOfFullScreenLayer(layer) == FullScreenDescendant::No)
2776 return false;
2777#endif
2778
2779 auto position = renderer.style().position();
2780 bool isFixed = renderer.isFixedPositioned();
2781 if (isFixed && !layer.isStackingContext())
2782 return false;
2783
2784 bool isSticky = renderer.isInFlowPositioned() && position == PositionType::Sticky;
2785 if (!isFixed && !isSticky)
2786 return false;
2787
2788 // FIXME: acceleratedCompositingForFixedPositionEnabled should probably be renamed acceleratedCompositingForViewportConstrainedPositionEnabled().
2789 if (!m_renderView.settings().acceleratedCompositingForFixedPositionEnabled())
2790 return false;
2791
2792 if (isSticky)
2793 return isAsyncScrollableStickyLayer(layer);
2794
2795 if (queryData.layoutUpToDate == LayoutUpToDate::No) {
2796 queryData.reevaluateAfterLayout = true;
2797 return layer.isComposited();
2798 }
2799
2800 auto container = renderer.container();
2801 ASSERT(container);
2802
2803 // Don't promote fixed position elements that are descendants of a non-view container, e.g. transformed elements.
2804 // They will stay fixed wrt the container rather than the enclosing frame.j
2805 if (container != &m_renderView) {
2806 queryData.nonCompositedForPositionReason = RenderLayer::NotCompositedForNonViewContainer;
2807 return false;
2808 }
2809
2810 bool paintsContent = layer.isVisuallyNonEmpty() || layer.hasVisibleDescendant();
2811 if (!paintsContent) {
2812 queryData.nonCompositedForPositionReason = RenderLayer::NotCompositedForNoVisibleContent;
2813 return false;
2814 }
2815
2816 bool intersectsViewport = fixedLayerIntersectsViewport(layer);
2817 if (!intersectsViewport) {
2818 queryData.nonCompositedForPositionReason = RenderLayer::NotCompositedForBoundsOutOfView;
2819 LOG_WITH_STREAM(Compositing, stream << "Layer " << &layer << " is outside the viewport");
2820 return false;
2821 }
2822
2823 return true;
2824}
2825
2826bool RenderLayerCompositor::requiresCompositingForOverflowScrolling(const RenderLayer& layer, RequiresCompositingData& queryData) const
2827{
2828 if (!layer.canUseCompositedScrolling())
2829 return false;
2830
2831 if (queryData.layoutUpToDate == LayoutUpToDate::No) {
2832 queryData.reevaluateAfterLayout = true;
2833 return layer.isComposited();
2834 }
2835
2836 return layer.hasCompositedScrollableOverflow();
2837}
2838
2839// FIXME: why doesn't this handle the clipping cases?
2840bool RenderLayerCompositor::requiresCompositingForIndirectReason(const RenderLayer& layer, const RenderLayer* compositingAncestor, bool hasCompositedDescendants, bool has3DTransformedDescendants, bool paintsIntoProvidedBacking, IndirectCompositingReason& reason) const
2841{
2842 // When a layer has composited descendants, some effects, like 2d transforms, filters, masks etc must be implemented
2843 // via compositing so that they also apply to those composited descendants.
2844 auto& renderer = layer.renderer();
2845 if (hasCompositedDescendants && (layer.isolatesCompositedBlending() || layer.transform() || renderer.createsGroup() || renderer.hasReflection())) {
2846 reason = IndirectCompositingReason::GraphicalEffect;
2847 return true;
2848 }
2849
2850 // A layer with preserve-3d or perspective only needs to be composited if there are descendant layers that
2851 // will be affected by the preserve-3d or perspective.
2852 if (has3DTransformedDescendants) {
2853 if (renderer.style().transformStyle3D() == TransformStyle3D::Preserve3D) {
2854 reason = IndirectCompositingReason::Preserve3D;
2855 return true;
2856 }
2857
2858 if (renderer.style().hasPerspective()) {
2859 reason = IndirectCompositingReason::Perspective;
2860 return true;
2861 }
2862 }
2863
2864 if (!paintsIntoProvidedBacking && renderer.isAbsolutelyPositioned() && compositingAncestor && layer.hasCompositedScrollingAncestor()) {
2865 if (layerContainingBlockCrossesCoordinatedScrollingBoundary(layer, *compositingAncestor)) {
2866 reason = IndirectCompositingReason::OverflowScrollPositioning;
2867 return true;
2868 }
2869 }
2870
2871 reason = IndirectCompositingReason::None;
2872 return false;
2873}
2874
2875bool RenderLayerCompositor::styleChangeMayAffectIndirectCompositingReasons(const RenderStyle& oldStyle, const RenderStyle& newStyle)
2876{
2877 if (RenderElement::createsGroupForStyle(newStyle) != RenderElement::createsGroupForStyle(oldStyle))
2878 return true;
2879 if (newStyle.isolation() != oldStyle.isolation())
2880 return true;
2881 if (newStyle.hasTransform() != oldStyle.hasTransform())
2882 return true;
2883 if (newStyle.boxReflect() != oldStyle.boxReflect())
2884 return true;
2885 if (newStyle.transformStyle3D() != oldStyle.transformStyle3D())
2886 return true;
2887 if (newStyle.hasPerspective() != oldStyle.hasPerspective())
2888 return true;
2889
2890 return false;
2891}
2892
2893bool RenderLayerCompositor::isAsyncScrollableStickyLayer(const RenderLayer& layer, const RenderLayer** enclosingAcceleratedOverflowLayer) const
2894{
2895 ASSERT(layer.renderer().isStickilyPositioned());
2896
2897 auto* enclosingOverflowLayer = layer.enclosingOverflowClipLayer(ExcludeSelf);
2898
2899 if (enclosingOverflowLayer && enclosingOverflowLayer->hasCompositedScrollableOverflow()) {
2900 if (enclosingAcceleratedOverflowLayer)
2901 *enclosingAcceleratedOverflowLayer = enclosingOverflowLayer;
2902 return true;
2903 }
2904
2905 // If the layer is inside normal overflow, it's not async-scrollable.
2906 if (enclosingOverflowLayer)
2907 return false;
2908
2909 // No overflow ancestor, so see if the frame supports async scrolling.
2910 if (hasCoordinatedScrolling())
2911 return true;
2912
2913#if PLATFORM(IOS_FAMILY)
2914 // iOS WK1 has fixed/sticky support in the main frame via WebFixedPositionContent.
2915 return isMainFrameCompositor();
2916#else
2917 return false;
2918#endif
2919}
2920
2921bool RenderLayerCompositor::isViewportConstrainedFixedOrStickyLayer(const RenderLayer& layer) const
2922{
2923 if (layer.renderer().isStickilyPositioned())
2924 return isAsyncScrollableStickyLayer(layer);
2925
2926 if (!layer.renderer().isFixedPositioned())
2927 return false;
2928
2929 // FIXME: Handle fixed inside of a transform, which should not behave as fixed.
2930 for (auto* stackingContext = layer.stackingContext(); stackingContext; stackingContext = stackingContext->stackingContext()) {
2931 if (stackingContext->isComposited() && stackingContext->renderer().isFixedPositioned())
2932 return false;
2933 }
2934
2935 return true;
2936}
2937
2938bool RenderLayerCompositor::fixedLayerIntersectsViewport(const RenderLayer& layer) const
2939{
2940 ASSERT(layer.renderer().isFixedPositioned());
2941
2942 // Fixed position elements that are invisible in the current view don't get their own layer.
2943 // FIXME: We shouldn't have to check useFixedLayout() here; one of the viewport rects needs to give the correct answer.
2944 LayoutRect viewBounds;
2945 if (m_renderView.frameView().useFixedLayout())
2946 viewBounds = m_renderView.unscaledDocumentRect();
2947 else
2948 viewBounds = m_renderView.frameView().rectForFixedPositionLayout();
2949
2950 LayoutRect layerBounds = layer.calculateLayerBounds(&layer, LayoutSize(), { RenderLayer::UseLocalClipRectIfPossible, RenderLayer::IncludeFilterOutsets, RenderLayer::UseFragmentBoxesExcludingCompositing,
2951 RenderLayer::ExcludeHiddenDescendants, RenderLayer::DontConstrainForMask, RenderLayer::IncludeCompositedDescendants });
2952 // Map to m_renderView to ignore page scale.
2953 FloatRect absoluteBounds = layer.renderer().localToContainerQuad(FloatRect(layerBounds), &m_renderView).boundingBox();
2954 return viewBounds.intersects(enclosingIntRect(absoluteBounds));
2955}
2956
2957bool RenderLayerCompositor::useCoordinatedScrollingForLayer(const RenderLayer& layer) const
2958{
2959 if (layer.isRenderViewLayer() && hasCoordinatedScrolling())
2960 return true;
2961
2962 if (auto* scrollingCoordinator = this->scrollingCoordinator())
2963 return scrollingCoordinator->coordinatesScrollingForOverflowLayer(layer);
2964
2965 return false;
2966}
2967
2968static RenderLayer* enclosingCompositedScrollingLayer(const RenderLayer& layer, const RenderLayer& intermediateLayer, bool& sawIntermediateLayer)
2969{
2970 const auto* currLayer = &layer;
2971 while (currLayer) {
2972 if (currLayer == &intermediateLayer)
2973 sawIntermediateLayer = true;
2974
2975 if (currLayer->hasCompositedScrollableOverflow())
2976 return const_cast<RenderLayer*>(currLayer);
2977
2978 currLayer = currLayer->parent();
2979 }
2980
2981 return nullptr;
2982}
2983
2984// Return true if overflowScrollLayer is in layer's containing block chain.
2985static bool isScrolledByOverflowScrollLayer(const RenderLayer& layer, const RenderLayer& overflowScrollLayer)
2986{
2987 bool containingBlockCanSkipLayers = layer.renderer().isAbsolutelyPositioned();
2988
2989 for (const auto* currLayer = layer.parent(); currLayer; currLayer = currLayer->parent()) {
2990 bool inContainingBlockChain = true;
2991 if (containingBlockCanSkipLayers) {
2992 inContainingBlockChain = currLayer->renderer().canContainAbsolutelyPositionedObjects();
2993 if (inContainingBlockChain)
2994 containingBlockCanSkipLayers = currLayer->renderer().isAbsolutelyPositioned();
2995 }
2996
2997 if (currLayer == &overflowScrollLayer)
2998 return inContainingBlockChain;
2999 }
3000
3001 return false;
3002}
3003
3004static bool isNonScrolledLayerInsideScrolledCompositedAncestor(const RenderLayer& layer, const RenderLayer& compositedAncestor, const RenderLayer& scrollingAncestor)
3005{
3006 bool ancestorMovedByScroller = &compositedAncestor == &scrollingAncestor || isScrolledByOverflowScrollLayer(compositedAncestor, scrollingAncestor);
3007 bool layerMovedByScroller = isScrolledByOverflowScrollLayer(layer, scrollingAncestor);
3008
3009 return ancestorMovedByScroller && !layerMovedByScroller;
3010}
3011
3012bool RenderLayerCompositor::layerContainingBlockCrossesCoordinatedScrollingBoundary(const RenderLayer& layer, const RenderLayer& compositedAncestor)
3013{
3014 bool compositedAncestorIsInsideScroller = false;
3015 auto* scrollingAncestor = enclosingCompositedScrollingLayer(layer, compositedAncestor, compositedAncestorIsInsideScroller);
3016 if (!scrollingAncestor) {
3017 ASSERT_NOT_REACHED(); // layer.hasCompositedScrollingAncestor() should guarantee we have one.
3018 return false;
3019 }
3020
3021 if (!compositedAncestorIsInsideScroller)
3022 return false;
3023
3024 return isNonScrolledLayerInsideScrolledCompositedAncestor(layer, compositedAncestor, *scrollingAncestor);
3025}
3026
3027static void collectStationaryLayerRelatedOverflowNodes(const RenderLayer& layer, const RenderLayer& /*compositedAncestor*/, Vector<ScrollingNodeID>& scrollingNodes)
3028{
3029 ASSERT(layer.isComposited());
3030
3031 auto appendOverflowLayerNodeID = [&scrollingNodes] (const RenderLayer& overflowLayer) {
3032 ASSERT(overflowLayer.isComposited());
3033 auto scrollingNodeID = overflowLayer.backing()->scrollingNodeIDForRole(ScrollCoordinationRole::Scrolling);
3034 if (scrollingNodeID)
3035 scrollingNodes.append(scrollingNodeID);
3036 else
3037 LOG(Scrolling, "Layer %p doesn't have scrolling node ID yet", &overflowLayer);
3038 };
3039
3040 ASSERT(layer.renderer().isAbsolutelyPositioned());
3041 bool containingBlockCanSkipLayers = true;
3042
3043 for (const auto* currLayer = layer.parent(); currLayer; currLayer = currLayer->parent()) {
3044 bool inContainingBlockChain = true;
3045 if (containingBlockCanSkipLayers) {
3046 inContainingBlockChain = currLayer->renderer().canContainAbsolutelyPositionedObjects();
3047 if (inContainingBlockChain)
3048 containingBlockCanSkipLayers = currLayer->renderer().isAbsolutelyPositioned();
3049 }
3050
3051 if (currLayer->hasCompositedScrollableOverflow()) {
3052 appendOverflowLayerNodeID(*currLayer);
3053 break;
3054 }
3055 }
3056}
3057
3058
3059ScrollPositioningBehavior RenderLayerCompositor::computeCoordinatedPositioningForLayer(const RenderLayer& layer) const
3060{
3061 if (layer.isRenderViewLayer())
3062 return ScrollPositioningBehavior::None;
3063
3064 if (layer.renderer().isFixedPositioned())
3065 return ScrollPositioningBehavior::None;
3066
3067 if (!layer.hasCompositedScrollingAncestor())
3068 return ScrollPositioningBehavior::None;
3069
3070 auto* scrollingCoordinator = this->scrollingCoordinator();
3071 if (!scrollingCoordinator)
3072 return ScrollPositioningBehavior::None;
3073
3074 auto* compositedAncestor = layer.ancestorCompositingLayer();
3075 if (!compositedAncestor) {
3076 ASSERT_NOT_REACHED();
3077 return ScrollPositioningBehavior::None;
3078 }
3079
3080 bool compositedAncestorIsInsideScroller = false;
3081 auto* scrollingAncestor = enclosingCompositedScrollingLayer(layer, *compositedAncestor, compositedAncestorIsInsideScroller);
3082 if (!scrollingAncestor) {
3083 ASSERT_NOT_REACHED(); // layer.hasCompositedScrollingAncestor() should guarantee we have one.
3084 return ScrollPositioningBehavior::None;
3085 }
3086
3087 // There are two cases we have to deal with here:
3088 // 1. There's a composited overflow:scroll in the parent chain between the renderer and its containing block, and the layer's
3089 // composited (z-order) ancestor is inside the scroller or is the scroller. In this case, we have to compensate for scroll position
3090 // changes to make the positioned layer stay in the same place. This only applies to position:absolute (since we handle fixed elsewhere).
3091 if (layer.renderer().isAbsolutelyPositioned()) {
3092 if (compositedAncestorIsInsideScroller && isNonScrolledLayerInsideScrolledCompositedAncestor(layer, *compositedAncestor, *scrollingAncestor))
3093 return ScrollPositioningBehavior::Stationary;
3094 }
3095
3096 // 2. The layer's containing block is the overflow or inside the overflow:scroll, but its z-order ancestor is
3097 // outside the overflow:scroll. In that case, we have to move the layer via the scrolling tree to make
3098 // it move along with the overflow scrolling.
3099 if (!compositedAncestorIsInsideScroller && isScrolledByOverflowScrollLayer(layer, *scrollingAncestor))
3100 return ScrollPositioningBehavior::Moves;
3101
3102 return ScrollPositioningBehavior::None;
3103}
3104
3105static Vector<ScrollingNodeID> collectRelatedCoordinatedScrollingNodes(const RenderLayer& layer, ScrollPositioningBehavior positioningBehavior)
3106{
3107 Vector<ScrollingNodeID> overflowNodeData;
3108
3109 switch (positioningBehavior) {
3110 case ScrollPositioningBehavior::Moves: {
3111 // Collect all the composited scrollers between this layer and its composited ancestor.
3112 auto* compositedAncestor = layer.ancestorCompositingLayer();
3113 for (const auto* currLayer = layer.parent(); currLayer != compositedAncestor; currLayer = currLayer->parent()) {
3114 if (currLayer->hasCompositedScrollableOverflow()) {
3115 auto scrollingNodeID = currLayer->isComposited() ? currLayer->backing()->scrollingNodeIDForRole(ScrollCoordinationRole::Scrolling) : 0;
3116 if (scrollingNodeID)
3117 overflowNodeData.append(scrollingNodeID);
3118 else
3119 LOG(Scrolling, "Layer %p isn't composited or doesn't have scrolling node ID yet", &layer);
3120 }
3121 }
3122 break;
3123 }
3124 case ScrollPositioningBehavior::Stationary: {
3125 ASSERT(layer.renderer().isAbsolutelyPositioned());
3126 // Collect all the composited scrollers between this layer and its composited ancestor.
3127 auto* compositedAncestor = layer.ancestorCompositingLayer();
3128 if (!compositedAncestor)
3129 return overflowNodeData;
3130 collectStationaryLayerRelatedOverflowNodes(layer, *compositedAncestor, overflowNodeData);
3131 break;
3132 }
3133 case ScrollPositioningBehavior::None:
3134 ASSERT_NOT_REACHED();
3135 break;
3136 }
3137
3138 return overflowNodeData;
3139}
3140
3141bool RenderLayerCompositor::isLayerForIFrameWithScrollCoordinatedContents(const RenderLayer& layer) const
3142{
3143 if (!is<RenderWidget>(layer.renderer()))
3144 return false;
3145
3146 auto* contentDocument = downcast<RenderWidget>(layer.renderer()).frameOwnerElement().contentDocument();
3147 if (!contentDocument)
3148 return false;
3149
3150 auto* view = contentDocument->renderView();
3151 if (!view)
3152 return false;
3153
3154 if (auto* scrollingCoordinator = this->scrollingCoordinator())
3155 return scrollingCoordinator->coordinatesScrollingForFrameView(view->frameView());
3156
3157 return false;
3158}
3159
3160bool RenderLayerCompositor::isRunningTransformAnimation(RenderLayerModelObject& renderer) const
3161{
3162 if (!(m_compositingTriggers & ChromeClient::AnimationTrigger))
3163 return false;
3164
3165 if (RuntimeEnabledFeatures::sharedFeatures().webAnimationsCSSIntegrationEnabled()) {
3166 if (auto* element = renderer.element()) {
3167 if (auto* timeline = element->document().existingTimeline())
3168 return timeline->isRunningAnimationOnRenderer(renderer, CSSPropertyTransform);
3169 }
3170 return false;
3171 }
3172 return renderer.animation().isRunningAnimationOnRenderer(renderer, CSSPropertyTransform);
3173}
3174
3175// If an element has negative z-index children, those children render in front of the
3176// layer background, so we need an extra 'contents' layer for the foreground of the layer object.
3177bool RenderLayerCompositor::needsContentsCompositingLayer(const RenderLayer& layer) const
3178{
3179 return layer.hasNegativeZOrderLayers();
3180}
3181
3182bool RenderLayerCompositor::requiresScrollLayer(RootLayerAttachment attachment) const
3183{
3184 auto& frameView = m_renderView.frameView();
3185
3186 // This applies when the application UI handles scrolling, in which case RenderLayerCompositor doesn't need to manage it.
3187 if (frameView.delegatesScrolling() && isMainFrameCompositor())
3188 return false;
3189
3190 // We need to handle our own scrolling if we're:
3191 return !m_renderView.frameView().platformWidget() // viewless (i.e. non-Mac, or Mac in WebKit2)
3192 || attachment == RootLayerAttachedViaEnclosingFrame; // a composited frame on Mac
3193}
3194
3195void paintScrollbar(Scrollbar* scrollbar, GraphicsContext& context, const IntRect& clip)
3196{
3197 if (!scrollbar)
3198 return;
3199
3200 context.save();
3201 const IntRect& scrollbarRect = scrollbar->frameRect();
3202 context.translate(-scrollbarRect.location());
3203 IntRect transformedClip = clip;
3204 transformedClip.moveBy(scrollbarRect.location());
3205 scrollbar->paint(context, transformedClip);
3206 context.restore();
3207}
3208
3209void RenderLayerCompositor::paintContents(const GraphicsLayer* graphicsLayer, GraphicsContext& context, GraphicsLayerPaintingPhase, const FloatRect& clip, GraphicsLayerPaintBehavior)
3210{
3211#if PLATFORM(MAC)
3212 LocalDefaultSystemAppearance localAppearance(m_renderView.useDarkAppearance());
3213#endif
3214
3215 IntRect pixelSnappedRectForIntegralPositionedItems = snappedIntRect(LayoutRect(clip));
3216 if (graphicsLayer == layerForHorizontalScrollbar())
3217 paintScrollbar(m_renderView.frameView().horizontalScrollbar(), context, pixelSnappedRectForIntegralPositionedItems);
3218 else if (graphicsLayer == layerForVerticalScrollbar())
3219 paintScrollbar(m_renderView.frameView().verticalScrollbar(), context, pixelSnappedRectForIntegralPositionedItems);
3220 else if (graphicsLayer == layerForScrollCorner()) {
3221 const IntRect& scrollCorner = m_renderView.frameView().scrollCornerRect();
3222 context.save();
3223 context.translate(-scrollCorner.location());
3224 IntRect transformedClip = pixelSnappedRectForIntegralPositionedItems;
3225 transformedClip.moveBy(scrollCorner.location());
3226 m_renderView.frameView().paintScrollCorner(context, transformedClip);
3227 context.restore();
3228 }
3229}
3230
3231bool RenderLayerCompositor::supportsFixedRootBackgroundCompositing() const
3232{
3233 auto* renderViewBacking = m_renderView.layer()->backing();
3234 return renderViewBacking && renderViewBacking->isFrameLayerWithTiledBacking();
3235}
3236
3237bool RenderLayerCompositor::needsFixedRootBackgroundLayer(const RenderLayer& layer) const
3238{
3239 if (!layer.isRenderViewLayer())
3240 return false;
3241
3242 if (m_renderView.settings().fixedBackgroundsPaintRelativeToDocument())
3243 return false;
3244
3245 return supportsFixedRootBackgroundCompositing() && m_renderView.rootBackgroundIsEntirelyFixed();
3246}
3247
3248GraphicsLayer* RenderLayerCompositor::fixedRootBackgroundLayer() const
3249{
3250 // Get the fixed root background from the RenderView layer's backing.
3251 auto* viewLayer = m_renderView.layer();
3252 if (!viewLayer)
3253 return nullptr;
3254
3255 if (viewLayer->isComposited() && viewLayer->backing()->backgroundLayerPaintsFixedRootBackground())
3256 return viewLayer->backing()->backgroundLayer();
3257
3258 return nullptr;
3259}
3260
3261void RenderLayerCompositor::resetTrackedRepaintRects()
3262{
3263 if (auto* rootLayer = rootGraphicsLayer()) {
3264 GraphicsLayer::traverse(*rootLayer, [](GraphicsLayer& layer) {
3265 layer.resetTrackedRepaints();
3266 });
3267 }
3268}
3269
3270float RenderLayerCompositor::deviceScaleFactor() const
3271{
3272 return m_renderView.document().deviceScaleFactor();
3273}
3274
3275float RenderLayerCompositor::pageScaleFactor() const
3276{
3277 return page().pageScaleFactor();
3278}
3279
3280float RenderLayerCompositor::zoomedOutPageScaleFactor() const
3281{
3282 return page().zoomedOutPageScaleFactor();
3283}
3284
3285float RenderLayerCompositor::contentsScaleMultiplierForNewTiles(const GraphicsLayer*) const
3286{
3287#if PLATFORM(IOS_FAMILY)
3288 LegacyTileCache* tileCache = nullptr;
3289 if (auto* frameView = page().mainFrame().view())
3290 tileCache = frameView->legacyTileCache();
3291
3292 if (!tileCache)
3293 return 1;
3294
3295 return tileCache->tileControllerShouldUseLowScaleTiles() ? 0.125 : 1;
3296#else
3297 return 1;
3298#endif
3299}
3300
3301bool RenderLayerCompositor::documentUsesTiledBacking() const
3302{
3303 auto* layer = m_renderView.layer();
3304 if (!layer)
3305 return false;
3306
3307 auto* backing = layer->backing();
3308 if (!backing)
3309 return false;
3310
3311 return backing->isFrameLayerWithTiledBacking();
3312}
3313
3314bool RenderLayerCompositor::isMainFrameCompositor() const
3315{
3316 return m_renderView.frameView().frame().isMainFrame();
3317}
3318
3319bool RenderLayerCompositor::shouldCompositeOverflowControls() const
3320{
3321 auto& frameView = m_renderView.frameView();
3322
3323 if (!frameView.managesScrollbars())
3324 return false;
3325
3326 if (documentUsesTiledBacking())
3327 return true;
3328
3329 if (m_overflowControlsHostLayer && isMainFrameCompositor())
3330 return true;
3331
3332#if !USE(COORDINATED_GRAPHICS)
3333 if (!frameView.hasOverlayScrollbars())
3334 return false;
3335#endif
3336
3337 return true;
3338}
3339
3340bool RenderLayerCompositor::requiresHorizontalScrollbarLayer() const
3341{
3342 return shouldCompositeOverflowControls() && m_renderView.frameView().horizontalScrollbar();
3343}
3344
3345bool RenderLayerCompositor::requiresVerticalScrollbarLayer() const
3346{
3347 return shouldCompositeOverflowControls() && m_renderView.frameView().verticalScrollbar();
3348}
3349
3350bool RenderLayerCompositor::requiresScrollCornerLayer() const
3351{
3352 return shouldCompositeOverflowControls() && m_renderView.frameView().isScrollCornerVisible();
3353}
3354
3355#if ENABLE(RUBBER_BANDING)
3356bool RenderLayerCompositor::requiresOverhangAreasLayer() const
3357{
3358 if (!isMainFrameCompositor())
3359 return false;
3360
3361 // We do want a layer if we're using tiled drawing and can scroll.
3362 if (documentUsesTiledBacking() && m_renderView.frameView().hasOpaqueBackground() && !m_renderView.frameView().prohibitsScrolling())
3363 return true;
3364
3365 return false;
3366}
3367
3368bool RenderLayerCompositor::requiresContentShadowLayer() const
3369{
3370 if (!isMainFrameCompositor())
3371 return false;
3372
3373#if PLATFORM(COCOA)
3374 if (viewHasTransparentBackground())
3375 return false;
3376
3377 // If the background is going to extend, then it doesn't make sense to have a shadow layer.
3378 if (m_renderView.settings().backgroundShouldExtendBeyondPage())
3379 return false;
3380
3381 // On Mac, we want a content shadow layer if we're using tiled drawing and can scroll.
3382 if (documentUsesTiledBacking() && !m_renderView.frameView().prohibitsScrolling())
3383 return true;
3384#endif
3385
3386 return false;
3387}
3388
3389GraphicsLayer* RenderLayerCompositor::updateLayerForTopOverhangArea(bool wantsLayer)
3390{
3391 if (!isMainFrameCompositor())
3392 return nullptr;
3393
3394 if (!wantsLayer) {
3395 GraphicsLayer::unparentAndClear(m_layerForTopOverhangArea);
3396 return nullptr;
3397 }
3398
3399 if (!m_layerForTopOverhangArea) {
3400 m_layerForTopOverhangArea = GraphicsLayer::create(graphicsLayerFactory(), *this);
3401 m_layerForTopOverhangArea->setName("top overhang");
3402 m_scrolledContentsLayer->addChildBelow(*m_layerForTopOverhangArea, m_rootContentsLayer.get());
3403 }
3404
3405 return m_layerForTopOverhangArea.get();
3406}
3407
3408GraphicsLayer* RenderLayerCompositor::updateLayerForBottomOverhangArea(bool wantsLayer)
3409{
3410 if (!isMainFrameCompositor())
3411 return nullptr;
3412
3413 if (!wantsLayer) {
3414 GraphicsLayer::unparentAndClear(m_layerForBottomOverhangArea);
3415 return nullptr;
3416 }
3417
3418 if (!m_layerForBottomOverhangArea) {
3419 m_layerForBottomOverhangArea = GraphicsLayer::create(graphicsLayerFactory(), *this);
3420 m_layerForBottomOverhangArea->setName("bottom overhang");
3421 m_scrolledContentsLayer->addChildBelow(*m_layerForBottomOverhangArea, m_rootContentsLayer.get());
3422 }
3423
3424 m_layerForBottomOverhangArea->setPosition(FloatPoint(0, m_rootContentsLayer->size().height() + m_renderView.frameView().headerHeight()
3425 + m_renderView.frameView().footerHeight() + m_renderView.frameView().topContentInset()));
3426 return m_layerForBottomOverhangArea.get();
3427}
3428
3429GraphicsLayer* RenderLayerCompositor::updateLayerForHeader(bool wantsLayer)
3430{
3431 if (!isMainFrameCompositor())
3432 return nullptr;
3433
3434 if (!wantsLayer) {
3435 if (m_layerForHeader) {
3436 GraphicsLayer::unparentAndClear(m_layerForHeader);
3437
3438 // The ScrollingTree knows about the header layer, and the position of the root layer is affected
3439 // by the header layer, so if we remove the header, we need to tell the scrolling tree.
3440 if (auto* scrollingCoordinator = this->scrollingCoordinator())
3441 scrollingCoordinator->frameViewRootLayerDidChange(m_renderView.frameView());
3442 }
3443 return nullptr;
3444 }
3445
3446 if (!m_layerForHeader) {
3447 m_layerForHeader = GraphicsLayer::create(graphicsLayerFactory(), *this);
3448 m_layerForHeader->setName("header");
3449 m_scrolledContentsLayer->addChildAbove(*m_layerForHeader, m_rootContentsLayer.get());
3450 m_renderView.frameView().addPaintPendingMilestones(DidFirstFlushForHeaderLayer);
3451 }
3452
3453 m_layerForHeader->setPosition(FloatPoint(0,
3454 FrameView::yPositionForHeaderLayer(m_renderView.frameView().scrollPosition(), m_renderView.frameView().topContentInset())));
3455 m_layerForHeader->setAnchorPoint(FloatPoint3D());
3456 m_layerForHeader->setSize(FloatSize(m_renderView.frameView().visibleWidth(), m_renderView.frameView().headerHeight()));
3457
3458 if (auto* scrollingCoordinator = this->scrollingCoordinator())
3459 scrollingCoordinator->frameViewRootLayerDidChange(m_renderView.frameView());
3460
3461 page().chrome().client().didAddHeaderLayer(*m_layerForHeader);
3462
3463 return m_layerForHeader.get();
3464}
3465
3466GraphicsLayer* RenderLayerCompositor::updateLayerForFooter(bool wantsLayer)
3467{
3468 if (!isMainFrameCompositor())
3469 return nullptr;
3470
3471 if (!wantsLayer) {
3472 if (m_layerForFooter) {
3473 GraphicsLayer::unparentAndClear(m_layerForFooter);
3474
3475 // The ScrollingTree knows about the footer layer, and the total scrollable size is affected
3476 // by the footer layer, so if we remove the footer, we need to tell the scrolling tree.
3477 if (auto* scrollingCoordinator = this->scrollingCoordinator())
3478 scrollingCoordinator->frameViewRootLayerDidChange(m_renderView.frameView());
3479 }
3480 return nullptr;
3481 }
3482
3483 if (!m_layerForFooter) {
3484 m_layerForFooter = GraphicsLayer::create(graphicsLayerFactory(), *this);
3485 m_layerForFooter->setName("footer");
3486 m_scrolledContentsLayer->addChildAbove(*m_layerForFooter, m_rootContentsLayer.get());
3487 }
3488
3489 float totalContentHeight = m_rootContentsLayer->size().height() + m_renderView.frameView().headerHeight() + m_renderView.frameView().footerHeight();
3490 m_layerForFooter->setPosition(FloatPoint(0, FrameView::yPositionForFooterLayer(m_renderView.frameView().scrollPosition(),
3491 m_renderView.frameView().topContentInset(), totalContentHeight, m_renderView.frameView().footerHeight())));
3492 m_layerForFooter->setAnchorPoint(FloatPoint3D());
3493 m_layerForFooter->setSize(FloatSize(m_renderView.frameView().visibleWidth(), m_renderView.frameView().footerHeight()));
3494
3495 if (auto* scrollingCoordinator = this->scrollingCoordinator())
3496 scrollingCoordinator->frameViewRootLayerDidChange(m_renderView.frameView());
3497
3498 page().chrome().client().didAddFooterLayer(*m_layerForFooter);
3499
3500 return m_layerForFooter.get();
3501}
3502
3503#endif
3504
3505bool RenderLayerCompositor::viewHasTransparentBackground(Color* backgroundColor) const
3506{
3507 if (m_renderView.frameView().isTransparent()) {
3508 if (backgroundColor)
3509 *backgroundColor = Color(); // Return an invalid color.
3510 return true;
3511 }
3512
3513 Color documentBackgroundColor = m_renderView.frameView().documentBackgroundColor();
3514 if (!documentBackgroundColor.isValid())
3515 documentBackgroundColor = m_renderView.frameView().baseBackgroundColor();
3516
3517 ASSERT(documentBackgroundColor.isValid());
3518
3519 if (backgroundColor)
3520 *backgroundColor = documentBackgroundColor;
3521
3522 return !documentBackgroundColor.isOpaque();
3523}
3524
3525// We can't rely on getting layerStyleChanged() for a style change that affects the root background, because the style change may
3526// be on the body which has no RenderLayer.
3527void RenderLayerCompositor::rootOrBodyStyleChanged(RenderElement& renderer, const RenderStyle* oldStyle)
3528{
3529 if (!usesCompositing())
3530 return;
3531
3532 Color oldBackgroundColor;
3533 if (oldStyle)
3534 oldBackgroundColor = oldStyle->visitedDependentColorWithColorFilter(CSSPropertyBackgroundColor);
3535
3536 if (oldBackgroundColor != renderer.style().visitedDependentColorWithColorFilter(CSSPropertyBackgroundColor))
3537 rootBackgroundColorOrTransparencyChanged();
3538
3539 bool hadFixedBackground = oldStyle && oldStyle->hasEntirelyFixedBackground();
3540 if (hadFixedBackground != renderer.style().hasEntirelyFixedBackground())
3541 rootLayerConfigurationChanged();
3542}
3543
3544void RenderLayerCompositor::rootBackgroundColorOrTransparencyChanged()
3545{
3546 if (!usesCompositing())
3547 return;
3548
3549 Color backgroundColor;
3550 bool isTransparent = viewHasTransparentBackground(&backgroundColor);
3551
3552 Color extendedBackgroundColor = m_renderView.settings().backgroundShouldExtendBeyondPage() ? backgroundColor : Color();
3553
3554 bool transparencyChanged = m_viewBackgroundIsTransparent != isTransparent;
3555 bool backgroundColorChanged = m_viewBackgroundColor != backgroundColor;
3556 bool extendedBackgroundColorChanged = m_rootExtendedBackgroundColor != extendedBackgroundColor;
3557
3558 if (!transparencyChanged && !backgroundColorChanged && !extendedBackgroundColorChanged)
3559 return;
3560
3561 LOG(Compositing, "RenderLayerCompositor %p rootBackgroundColorOrTransparencyChanged. isTransparent=%d", this, isTransparent);
3562
3563 m_viewBackgroundIsTransparent = isTransparent;
3564 m_viewBackgroundColor = backgroundColor;
3565 m_rootExtendedBackgroundColor = extendedBackgroundColor;
3566
3567 if (extendedBackgroundColorChanged) {
3568 page().chrome().client().pageExtendedBackgroundColorDidChange(m_rootExtendedBackgroundColor);
3569
3570#if ENABLE(RUBBER_BANDING)
3571 if (m_layerForOverhangAreas) {
3572 m_layerForOverhangAreas->setBackgroundColor(m_rootExtendedBackgroundColor);
3573
3574 if (!m_rootExtendedBackgroundColor.isValid())
3575 m_layerForOverhangAreas->setCustomAppearance(GraphicsLayer::CustomAppearance::ScrollingOverhang);
3576 }
3577#endif
3578 }
3579
3580 rootLayerConfigurationChanged();
3581}
3582
3583void RenderLayerCompositor::updateOverflowControlsLayers()
3584{
3585#if ENABLE(RUBBER_BANDING)
3586 if (requiresOverhangAreasLayer()) {
3587 if (!m_layerForOverhangAreas) {
3588 m_layerForOverhangAreas = GraphicsLayer::create(graphicsLayerFactory(), *this);
3589 m_layerForOverhangAreas->setName("overhang areas");
3590 m_layerForOverhangAreas->setDrawsContent(false);
3591
3592 float topContentInset = m_renderView.frameView().topContentInset();
3593 IntSize overhangAreaSize = m_renderView.frameView().frameRect().size();
3594 overhangAreaSize.setHeight(overhangAreaSize.height() - topContentInset);
3595 m_layerForOverhangAreas->setSize(overhangAreaSize);
3596 m_layerForOverhangAreas->setPosition(FloatPoint(0, topContentInset));
3597 m_layerForOverhangAreas->setAnchorPoint(FloatPoint3D());
3598
3599 if (m_renderView.settings().backgroundShouldExtendBeyondPage())
3600 m_layerForOverhangAreas->setBackgroundColor(m_renderView.frameView().documentBackgroundColor());
3601 else
3602 m_layerForOverhangAreas->setCustomAppearance(GraphicsLayer::CustomAppearance::ScrollingOverhang);
3603
3604 // We want the overhang areas layer to be positioned below the frame contents,
3605 // so insert it below the clip layer.
3606 m_overflowControlsHostLayer->addChildBelow(*m_layerForOverhangAreas, layerForClipping());
3607 }
3608 } else
3609 GraphicsLayer::unparentAndClear(m_layerForOverhangAreas);
3610
3611 if (requiresContentShadowLayer()) {
3612 if (!m_contentShadowLayer) {
3613 m_contentShadowLayer = GraphicsLayer::create(graphicsLayerFactory(), *this);
3614 m_contentShadowLayer->setName("content shadow");
3615 m_contentShadowLayer->setSize(m_rootContentsLayer->size());
3616 m_contentShadowLayer->setPosition(m_rootContentsLayer->position());
3617 m_contentShadowLayer->setAnchorPoint(FloatPoint3D());
3618 m_contentShadowLayer->setCustomAppearance(GraphicsLayer::CustomAppearance::ScrollingShadow);
3619
3620 m_scrolledContentsLayer->addChildBelow(*m_contentShadowLayer, m_rootContentsLayer.get());
3621 }
3622 } else
3623 GraphicsLayer::unparentAndClear(m_contentShadowLayer);
3624#endif
3625
3626 if (requiresHorizontalScrollbarLayer()) {
3627 if (!m_layerForHorizontalScrollbar) {
3628 m_layerForHorizontalScrollbar = GraphicsLayer::create(graphicsLayerFactory(), *this);
3629 m_layerForHorizontalScrollbar->setCanDetachBackingStore(false);
3630 m_layerForHorizontalScrollbar->setShowDebugBorder(m_showDebugBorders);
3631 m_layerForHorizontalScrollbar->setName("horizontal scrollbar container");
3632#if PLATFORM(COCOA) && USE(CA)
3633 m_layerForHorizontalScrollbar->setAcceleratesDrawing(acceleratedDrawingEnabled());
3634#endif
3635 m_overflowControlsHostLayer->addChild(*m_layerForHorizontalScrollbar);
3636
3637 if (auto* scrollingCoordinator = this->scrollingCoordinator())
3638 scrollingCoordinator->scrollableAreaScrollbarLayerDidChange(m_renderView.frameView(), HorizontalScrollbar);
3639 }
3640 } else if (m_layerForHorizontalScrollbar) {
3641 GraphicsLayer::unparentAndClear(m_layerForHorizontalScrollbar);
3642
3643 if (auto* scrollingCoordinator = this->scrollingCoordinator())
3644 scrollingCoordinator->scrollableAreaScrollbarLayerDidChange(m_renderView.frameView(), HorizontalScrollbar);
3645 }
3646
3647 if (requiresVerticalScrollbarLayer()) {
3648 if (!m_layerForVerticalScrollbar) {
3649 m_layerForVerticalScrollbar = GraphicsLayer::create(graphicsLayerFactory(), *this);
3650 m_layerForVerticalScrollbar->setCanDetachBackingStore(false);
3651 m_layerForVerticalScrollbar->setShowDebugBorder(m_showDebugBorders);
3652 m_layerForVerticalScrollbar->setName("vertical scrollbar container");
3653#if PLATFORM(COCOA) && USE(CA)
3654 m_layerForVerticalScrollbar->setAcceleratesDrawing(acceleratedDrawingEnabled());
3655#endif
3656 m_overflowControlsHostLayer->addChild(*m_layerForVerticalScrollbar);
3657
3658 if (auto* scrollingCoordinator = this->scrollingCoordinator())
3659 scrollingCoordinator->scrollableAreaScrollbarLayerDidChange(m_renderView.frameView(), VerticalScrollbar);
3660 }
3661 } else if (m_layerForVerticalScrollbar) {
3662 GraphicsLayer::unparentAndClear(m_layerForVerticalScrollbar);
3663
3664 if (auto* scrollingCoordinator = this->scrollingCoordinator())
3665 scrollingCoordinator->scrollableAreaScrollbarLayerDidChange(m_renderView.frameView(), VerticalScrollbar);
3666 }
3667
3668 if (requiresScrollCornerLayer()) {
3669 if (!m_layerForScrollCorner) {
3670 m_layerForScrollCorner = GraphicsLayer::create(graphicsLayerFactory(), *this);
3671 m_layerForScrollCorner->setCanDetachBackingStore(false);
3672 m_layerForScrollCorner->setShowDebugBorder(m_showDebugBorders);
3673 m_layerForScrollCorner->setName("scroll corner");
3674#if PLATFORM(COCOA) && USE(CA)
3675 m_layerForScrollCorner->setAcceleratesDrawing(acceleratedDrawingEnabled());
3676#endif
3677 m_overflowControlsHostLayer->addChild(*m_layerForScrollCorner);
3678 }
3679 } else
3680 GraphicsLayer::unparentAndClear(m_layerForScrollCorner);
3681
3682 m_renderView.frameView().positionScrollbarLayers();
3683}
3684
3685void RenderLayerCompositor::ensureRootLayer()
3686{
3687 RootLayerAttachment expectedAttachment = isMainFrameCompositor() ? RootLayerAttachedViaChromeClient : RootLayerAttachedViaEnclosingFrame;
3688 if (expectedAttachment == m_rootLayerAttachment)
3689 return;
3690
3691 if (!m_rootContentsLayer) {
3692 m_rootContentsLayer = GraphicsLayer::create(graphicsLayerFactory(), *this);
3693 m_rootContentsLayer->setName("content root");
3694 IntRect overflowRect = snappedIntRect(m_renderView.layoutOverflowRect());
3695 m_rootContentsLayer->setSize(FloatSize(overflowRect.maxX(), overflowRect.maxY()));
3696 m_rootContentsLayer->setPosition(FloatPoint());
3697
3698#if PLATFORM(IOS_FAMILY)
3699 // Page scale is applied above this on iOS, so we'll just say that our root layer applies it.
3700 auto& frame = m_renderView.frameView().frame();
3701 if (frame.isMainFrame())
3702 m_rootContentsLayer->setAppliesPageScale();
3703#endif
3704
3705 // Need to clip to prevent transformed content showing outside this frame
3706 updateRootContentLayerClipping();
3707 }
3708
3709 if (requiresScrollLayer(expectedAttachment)) {
3710 if (!m_overflowControlsHostLayer) {
3711 ASSERT(!m_scrolledContentsLayer);
3712 ASSERT(!m_clipLayer);
3713
3714 // Create a layer to host the clipping layer and the overflow controls layers.
3715 m_overflowControlsHostLayer = GraphicsLayer::create(graphicsLayerFactory(), *this);
3716 m_overflowControlsHostLayer->setName("overflow controls host");
3717
3718 m_scrolledContentsLayer = GraphicsLayer::create(graphicsLayerFactory(), *this);
3719 m_scrolledContentsLayer->setName("scrolled contents");
3720 m_scrolledContentsLayer->setAnchorPoint({ });
3721
3722#if PLATFORM(IOS_FAMILY)
3723 if (m_renderView.settings().asyncFrameScrollingEnabled()) {
3724 m_scrollContainerLayer = GraphicsLayer::create(graphicsLayerFactory(), *this, GraphicsLayer::Type::ScrollContainer);
3725
3726 m_scrollContainerLayer->setName("scroll container");
3727 m_scrollContainerLayer->setMasksToBounds(true);
3728 m_scrollContainerLayer->setAnchorPoint({ });
3729
3730 m_scrollContainerLayer->addChild(*m_scrolledContentsLayer);
3731 m_overflowControlsHostLayer->addChild(*m_scrollContainerLayer);
3732 }
3733#endif
3734 if (!m_scrollContainerLayer) {
3735 m_clipLayer = GraphicsLayer::create(graphicsLayerFactory(), *this);
3736 m_clipLayer->setName("frame clipping");
3737 m_clipLayer->setMasksToBounds(true);
3738 m_clipLayer->setAnchorPoint({ });
3739
3740 m_clipLayer->addChild(*m_scrolledContentsLayer);
3741 m_overflowControlsHostLayer->addChild(*m_clipLayer);
3742 }
3743
3744 m_scrolledContentsLayer->addChild(*m_rootContentsLayer);
3745
3746 updateScrollLayerClipping();
3747 updateOverflowControlsLayers();
3748
3749 if (hasCoordinatedScrolling())
3750 scheduleLayerFlush(true);
3751 else
3752 updateScrollLayerPosition();
3753 }
3754 } else {
3755 if (m_overflowControlsHostLayer) {
3756 GraphicsLayer::unparentAndClear(m_overflowControlsHostLayer);
3757 GraphicsLayer::unparentAndClear(m_clipLayer);
3758 GraphicsLayer::unparentAndClear(m_scrollContainerLayer);
3759 GraphicsLayer::unparentAndClear(m_scrolledContentsLayer);
3760 }
3761 }
3762
3763 // Check to see if we have to change the attachment
3764 if (m_rootLayerAttachment != RootLayerUnattached)
3765 detachRootLayer();
3766
3767 attachRootLayer(expectedAttachment);
3768}
3769
3770void RenderLayerCompositor::destroyRootLayer()
3771{
3772 if (!m_rootContentsLayer)
3773 return;
3774
3775 detachRootLayer();
3776
3777#if ENABLE(RUBBER_BANDING)
3778 GraphicsLayer::unparentAndClear(m_layerForOverhangAreas);
3779#endif
3780
3781 if (m_layerForHorizontalScrollbar) {
3782 GraphicsLayer::unparentAndClear(m_layerForHorizontalScrollbar);
3783 if (auto* scrollingCoordinator = this->scrollingCoordinator())
3784 scrollingCoordinator->scrollableAreaScrollbarLayerDidChange(m_renderView.frameView(), HorizontalScrollbar);
3785 if (auto* horizontalScrollbar = m_renderView.frameView().verticalScrollbar())
3786 m_renderView.frameView().invalidateScrollbar(*horizontalScrollbar, IntRect(IntPoint(0, 0), horizontalScrollbar->frameRect().size()));
3787 }
3788
3789 if (m_layerForVerticalScrollbar) {
3790 GraphicsLayer::unparentAndClear(m_layerForVerticalScrollbar);
3791 if (auto* scrollingCoordinator = this->scrollingCoordinator())
3792 scrollingCoordinator->scrollableAreaScrollbarLayerDidChange(m_renderView.frameView(), VerticalScrollbar);
3793 if (auto* verticalScrollbar = m_renderView.frameView().verticalScrollbar())
3794 m_renderView.frameView().invalidateScrollbar(*verticalScrollbar, IntRect(IntPoint(0, 0), verticalScrollbar->frameRect().size()));
3795 }
3796
3797 if (m_layerForScrollCorner) {
3798 GraphicsLayer::unparentAndClear(m_layerForScrollCorner);
3799 m_renderView.frameView().invalidateScrollCorner(m_renderView.frameView().scrollCornerRect());
3800 }
3801
3802 if (m_overflowControlsHostLayer) {
3803 GraphicsLayer::unparentAndClear(m_overflowControlsHostLayer);
3804 GraphicsLayer::unparentAndClear(m_clipLayer);
3805 GraphicsLayer::unparentAndClear(m_scrollContainerLayer);
3806 GraphicsLayer::unparentAndClear(m_scrolledContentsLayer);
3807 }
3808 ASSERT(!m_scrolledContentsLayer);
3809 GraphicsLayer::unparentAndClear(m_rootContentsLayer);
3810
3811 m_layerUpdater = nullptr;
3812}
3813
3814void RenderLayerCompositor::attachRootLayer(RootLayerAttachment attachment)
3815{
3816 if (!m_rootContentsLayer)
3817 return;
3818
3819 LOG(Compositing, "RenderLayerCompositor %p attachRootLayer %d", this, attachment);
3820
3821 switch (attachment) {
3822 case RootLayerUnattached:
3823 ASSERT_NOT_REACHED();
3824 break;
3825 case RootLayerAttachedViaChromeClient: {
3826 auto& frame = m_renderView.frameView().frame();
3827 page().chrome().client().attachRootGraphicsLayer(frame, rootGraphicsLayer());
3828 break;
3829 }
3830 case RootLayerAttachedViaEnclosingFrame: {
3831 // The layer will get hooked up via RenderLayerBacking::updateConfiguration()
3832 // for the frame's renderer in the parent document.
3833 if (auto* ownerElement = m_renderView.document().ownerElement())
3834 ownerElement->scheduleInvalidateStyleAndLayerComposition();
3835 break;
3836 }
3837 }
3838
3839 m_rootLayerAttachment = attachment;
3840 rootLayerAttachmentChanged();
3841
3842 if (m_shouldFlushOnReattach) {
3843 scheduleLayerFlush();
3844 m_shouldFlushOnReattach = false;
3845 }
3846}
3847
3848void RenderLayerCompositor::detachRootLayer()
3849{
3850 if (!m_rootContentsLayer || m_rootLayerAttachment == RootLayerUnattached)
3851 return;
3852
3853 switch (m_rootLayerAttachment) {
3854 case RootLayerAttachedViaEnclosingFrame: {
3855 // The layer will get unhooked up via RenderLayerBacking::updateConfiguration()
3856 // for the frame's renderer in the parent document.
3857 if (m_overflowControlsHostLayer)
3858 m_overflowControlsHostLayer->removeFromParent();
3859 else
3860 m_rootContentsLayer->removeFromParent();
3861
3862 if (auto* ownerElement = m_renderView.document().ownerElement())
3863 ownerElement->scheduleInvalidateStyleAndLayerComposition();
3864
3865 if (auto frameRootScrollingNodeID = m_renderView.frameView().scrollingNodeID()) {
3866 if (auto* scrollingCoordinator = this->scrollingCoordinator())
3867 scrollingCoordinator->unparentNode(frameRootScrollingNodeID);
3868 }
3869 break;
3870 }
3871 case RootLayerAttachedViaChromeClient: {
3872 auto& frame = m_renderView.frameView().frame();
3873 page().chrome().client().attachRootGraphicsLayer(frame, nullptr);
3874 }
3875 break;
3876 case RootLayerUnattached:
3877 break;
3878 }
3879
3880 m_rootLayerAttachment = RootLayerUnattached;
3881 rootLayerAttachmentChanged();
3882}
3883
3884void RenderLayerCompositor::updateRootLayerAttachment()
3885{
3886 ensureRootLayer();
3887}
3888
3889void RenderLayerCompositor::rootLayerAttachmentChanged()
3890{
3891 // The document-relative page overlay layer (which is pinned to the main frame's layer tree)
3892 // is moved between different RenderLayerCompositors' layer trees, and needs to be
3893 // reattached whenever we swap in a new RenderLayerCompositor.
3894 if (m_rootLayerAttachment == RootLayerUnattached)
3895 return;
3896
3897 auto& frame = m_renderView.frameView().frame();
3898
3899 // The attachment can affect whether the RenderView layer's paintsIntoWindow() behavior,
3900 // so call updateDrawsContent() to update that.
3901 auto* layer = m_renderView.layer();
3902 if (auto* backing = layer ? layer->backing() : nullptr)
3903 backing->updateDrawsContent();
3904
3905 if (!frame.isMainFrame())
3906 return;
3907
3908 Ref<GraphicsLayer> overlayHost = page().pageOverlayController().layerWithDocumentOverlays();
3909 m_rootContentsLayer->addChild(WTFMove(overlayHost));
3910}
3911
3912void RenderLayerCompositor::notifyIFramesOfCompositingChange()
3913{
3914 // Compositing affects the answer to RenderIFrame::requiresAcceleratedCompositing(), so
3915 // we need to schedule a style recalc in our parent document.
3916 if (auto* ownerElement = m_renderView.document().ownerElement())
3917 ownerElement->scheduleInvalidateStyleAndLayerComposition();
3918}
3919
3920bool RenderLayerCompositor::layerHas3DContent(const RenderLayer& layer) const
3921{
3922 const RenderStyle& style = layer.renderer().style();
3923
3924 if (style.transformStyle3D() == TransformStyle3D::Preserve3D || style.hasPerspective() || style.transform().has3DOperation())
3925 return true;
3926
3927 const_cast<RenderLayer&>(layer).updateLayerListsIfNeeded();
3928
3929#if !ASSERT_DISABLED
3930 LayerListMutationDetector mutationChecker(const_cast<RenderLayer&>(layer));
3931#endif
3932
3933 for (auto* renderLayer : layer.negativeZOrderLayers()) {
3934 if (layerHas3DContent(*renderLayer))
3935 return true;
3936 }
3937
3938 for (auto* renderLayer : layer.positiveZOrderLayers()) {
3939 if (layerHas3DContent(*renderLayer))
3940 return true;
3941 }
3942
3943 for (auto* renderLayer : layer.normalFlowLayers()) {
3944 if (layerHas3DContent(*renderLayer))
3945 return true;
3946 }
3947
3948 return false;
3949}
3950
3951void RenderLayerCompositor::deviceOrPageScaleFactorChanged()
3952{
3953 // Page scale will only be applied at to the RenderView and sublayers, but the device scale factor
3954 // needs to be applied at the level of rootGraphicsLayer().
3955 if (auto* rootLayer = rootGraphicsLayer())
3956 rootLayer->noteDeviceOrPageScaleFactorChangedIncludingDescendants();
3957}
3958
3959void RenderLayerCompositor::removeFromScrollCoordinatedLayers(RenderLayer& layer)
3960{
3961#if PLATFORM(IOS_FAMILY)
3962 if (m_legacyScrollingLayerCoordinator)
3963 m_legacyScrollingLayerCoordinator->removeLayer(layer);
3964#endif
3965
3966 detachScrollCoordinatedLayer(layer, { ScrollCoordinationRole::Scrolling, ScrollCoordinationRole::ViewportConstrained, ScrollCoordinationRole::FrameHosting, ScrollCoordinationRole::Positioning });
3967}
3968
3969FixedPositionViewportConstraints RenderLayerCompositor::computeFixedViewportConstraints(RenderLayer& layer) const
3970{
3971 ASSERT(layer.isComposited());
3972
3973 auto* graphicsLayer = layer.backing()->graphicsLayer();
3974
3975 FixedPositionViewportConstraints constraints;
3976 constraints.setLayerPositionAtLastLayout(graphicsLayer->position());
3977 constraints.setViewportRectAtLastLayout(m_renderView.frameView().rectForFixedPositionLayout());
3978 constraints.setAlignmentOffset(graphicsLayer->pixelAlignmentOffset());
3979
3980 const RenderStyle& style = layer.renderer().style();
3981 if (!style.left().isAuto())
3982 constraints.addAnchorEdge(ViewportConstraints::AnchorEdgeLeft);
3983
3984 if (!style.right().isAuto())
3985 constraints.addAnchorEdge(ViewportConstraints::AnchorEdgeRight);
3986
3987 if (!style.top().isAuto())
3988 constraints.addAnchorEdge(ViewportConstraints::AnchorEdgeTop);
3989
3990 if (!style.bottom().isAuto())
3991 constraints.addAnchorEdge(ViewportConstraints::AnchorEdgeBottom);
3992
3993 // If left and right are auto, use left.
3994 if (style.left().isAuto() && style.right().isAuto())
3995 constraints.addAnchorEdge(ViewportConstraints::AnchorEdgeLeft);
3996
3997 // If top and bottom are auto, use top.
3998 if (style.top().isAuto() && style.bottom().isAuto())
3999 constraints.addAnchorEdge(ViewportConstraints::AnchorEdgeTop);
4000
4001 return constraints;
4002}
4003
4004StickyPositionViewportConstraints RenderLayerCompositor::computeStickyViewportConstraints(RenderLayer& layer) const
4005{
4006 ASSERT(layer.isComposited());
4007
4008 auto& renderer = downcast<RenderBoxModelObject>(layer.renderer());
4009
4010 StickyPositionViewportConstraints constraints;
4011 renderer.computeStickyPositionConstraints(constraints, renderer.constrainingRectForStickyPosition());
4012
4013 auto* graphicsLayer = layer.backing()->graphicsLayer();
4014 constraints.setLayerPositionAtLastLayout(graphicsLayer->position());
4015 constraints.setStickyOffsetAtLastLayout(renderer.stickyPositionOffset());
4016 constraints.setAlignmentOffset(graphicsLayer->pixelAlignmentOffset());
4017
4018 return constraints;
4019}
4020
4021static inline ScrollCoordinationRole scrollCoordinationRoleForNodeType(ScrollingNodeType nodeType)
4022{
4023 switch (nodeType) {
4024 case ScrollingNodeType::MainFrame:
4025 case ScrollingNodeType::Subframe:
4026 case ScrollingNodeType::Overflow:
4027 return ScrollCoordinationRole::Scrolling;
4028 case ScrollingNodeType::FrameHosting:
4029 return ScrollCoordinationRole::FrameHosting;
4030 case ScrollingNodeType::Fixed:
4031 case ScrollingNodeType::Sticky:
4032 return ScrollCoordinationRole::ViewportConstrained;
4033 case ScrollingNodeType::Positioned:
4034 return ScrollCoordinationRole::Positioning;
4035 }
4036 ASSERT_NOT_REACHED();
4037 return ScrollCoordinationRole::Scrolling;
4038}
4039
4040ScrollingNodeID RenderLayerCompositor::attachScrollingNode(RenderLayer& layer, ScrollingNodeType nodeType, ScrollingTreeState& treeState)
4041{
4042 auto* scrollingCoordinator = this->scrollingCoordinator();
4043 auto* backing = layer.backing();
4044 // Crash logs suggest that backing can be null here, but we don't know how: rdar://problem/18545452.
4045 ASSERT(backing);
4046 if (!backing)
4047 return 0;
4048
4049 ASSERT(treeState.parentNodeID || nodeType == ScrollingNodeType::Subframe);
4050 ASSERT_IMPLIES(nodeType == ScrollingNodeType::MainFrame, !treeState.parentNodeID.value());
4051
4052 ScrollCoordinationRole role = scrollCoordinationRoleForNodeType(nodeType);
4053 ScrollingNodeID nodeID = backing->scrollingNodeIDForRole(role);
4054 if (!nodeID)
4055 nodeID = scrollingCoordinator->uniqueScrollingNodeID();
4056
4057 LOG_WITH_STREAM(Scrolling, stream << "RenderLayerCompositor " << this << " attachScrollingNode " << nodeID << " (layer " << backing->graphicsLayer()->primaryLayerID() << ") type " << nodeType << " parent " << treeState.parentNodeID.valueOr(0));
4058
4059 if (nodeType == ScrollingNodeType::Subframe && !treeState.parentNodeID)
4060 nodeID = scrollingCoordinator->createNode(nodeType, nodeID);
4061 else {
4062 auto newNodeID = scrollingCoordinator->insertNode(nodeType, nodeID, treeState.parentNodeID.valueOr(0), treeState.nextChildIndex);
4063 if (newNodeID != nodeID) {
4064 // We'll get a new nodeID if the type changed (and not if the node is new).
4065 scrollingCoordinator->unparentChildrenAndDestroyNode(nodeID);
4066 m_scrollingNodeToLayerMap.remove(nodeID);
4067 }
4068 nodeID = newNodeID;
4069 }
4070
4071 ASSERT(nodeID);
4072 if (!nodeID)
4073 return 0;
4074
4075 backing->setScrollingNodeIDForRole(nodeID, role);
4076 m_scrollingNodeToLayerMap.add(nodeID, &layer);
4077
4078 ++treeState.nextChildIndex;
4079 return nodeID;
4080}
4081
4082void RenderLayerCompositor::detachScrollCoordinatedLayerWithRole(RenderLayer& layer, ScrollingCoordinator& scrollingCoordinator, ScrollCoordinationRole role)
4083{
4084 auto nodeID = layer.backing()->scrollingNodeIDForRole(role);
4085 if (!nodeID)
4086 return;
4087
4088 auto childNodes = scrollingCoordinator.childrenOfNode(nodeID);
4089 for (auto childNodeID : childNodes) {
4090 // FIXME: The child might be in a child frame. Need to do something that crosses frame boundaries.
4091 if (auto* layer = m_scrollingNodeToLayerMap.get(childNodeID))
4092 layer->setNeedsScrollingTreeUpdate();
4093 }
4094
4095 m_scrollingNodeToLayerMap.remove(nodeID);
4096}
4097
4098void RenderLayerCompositor::detachScrollCoordinatedLayer(RenderLayer& layer, OptionSet<ScrollCoordinationRole> roles)
4099{
4100 auto* backing = layer.backing();
4101 if (!backing)
4102 return;
4103
4104 auto* scrollingCoordinator = this->scrollingCoordinator();
4105
4106 if (roles.contains(ScrollCoordinationRole::Scrolling))
4107 detachScrollCoordinatedLayerWithRole(layer, *scrollingCoordinator, ScrollCoordinationRole::Scrolling);
4108
4109 if (roles.contains(ScrollCoordinationRole::FrameHosting))
4110 detachScrollCoordinatedLayerWithRole(layer, *scrollingCoordinator, ScrollCoordinationRole::FrameHosting);
4111
4112 if (roles.contains(ScrollCoordinationRole::ViewportConstrained))
4113 detachScrollCoordinatedLayerWithRole(layer, *scrollingCoordinator, ScrollCoordinationRole::ViewportConstrained);
4114
4115 if (roles.contains(ScrollCoordinationRole::Positioning))
4116 detachScrollCoordinatedLayerWithRole(layer, *scrollingCoordinator, ScrollCoordinationRole::Positioning);
4117
4118 backing->detachFromScrollingCoordinator(roles);
4119}
4120
4121ScrollingNodeID RenderLayerCompositor::updateScrollCoordinationForLayer(RenderLayer& layer, ScrollingTreeState& treeState, OptionSet<ScrollCoordinationRole> roles, OptionSet<ScrollingNodeChangeFlags> changes)
4122{
4123 bool isViewportConstrained = roles.contains(ScrollCoordinationRole::ViewportConstrained);
4124#if PLATFORM(IOS_FAMILY)
4125 if (m_legacyScrollingLayerCoordinator) {
4126 if (isViewportConstrained)
4127 m_legacyScrollingLayerCoordinator->addViewportConstrainedLayer(layer);
4128 else
4129 m_legacyScrollingLayerCoordinator->removeViewportConstrainedLayer(layer);
4130 }
4131#endif
4132
4133 // GraphicsLayers need to know whether they are viewport-constrained.
4134 layer.backing()->setIsScrollCoordinatedWithViewportConstrainedRole(isViewportConstrained);
4135
4136 if (!hasCoordinatedScrolling()) {
4137 // If this frame isn't coordinated, it cannot contain any scrolling tree nodes.
4138 return 0;
4139 }
4140
4141 auto newNodeID = treeState.parentNodeID.valueOr(0);
4142
4143 ScrollingTreeState childTreeState;
4144 ScrollingTreeState* currentTreeState = &treeState;
4145
4146 // If is fixed or sticky, it's the parent scrolling node for scrolling/frame hosting.
4147 if (roles.contains(ScrollCoordinationRole::ViewportConstrained)) {
4148 newNodeID = updateScrollingNodeForViewportConstrainedRole(layer, *currentTreeState, changes);
4149 // ViewportConstrained nodes are the parent of same-layer scrolling nodes, so adjust the ScrollingTreeState.
4150 childTreeState.parentNodeID = newNodeID;
4151 currentTreeState = &childTreeState;
4152 } else
4153 detachScrollCoordinatedLayer(layer, ScrollCoordinationRole::ViewportConstrained);
4154
4155 // If there's a positioning node, it's the parent scrolling node for scrolling/frame hosting.
4156 if (roles.contains(ScrollCoordinationRole::Positioning)) {
4157 newNodeID = updateScrollingNodeForPositioningRole(layer, *currentTreeState, changes);
4158 childTreeState.parentNodeID = newNodeID;
4159 currentTreeState = &childTreeState;
4160 } else
4161 detachScrollCoordinatedLayer(layer, ScrollCoordinationRole::Positioning);
4162
4163 if (roles.contains(ScrollCoordinationRole::Scrolling))
4164 newNodeID = updateScrollingNodeForScrollingRole(layer, *currentTreeState, changes);
4165 else
4166 detachScrollCoordinatedLayer(layer, ScrollCoordinationRole::Scrolling);
4167
4168 if (roles.contains(ScrollCoordinationRole::FrameHosting))
4169 newNodeID = updateScrollingNodeForFrameHostingRole(layer, *currentTreeState, changes);
4170 else
4171 detachScrollCoordinatedLayer(layer, ScrollCoordinationRole::FrameHosting);
4172
4173 return newNodeID;
4174}
4175
4176ScrollingNodeID RenderLayerCompositor::updateScrollingNodeForViewportConstrainedRole(RenderLayer& layer, ScrollingTreeState& treeState, OptionSet<ScrollingNodeChangeFlags> changes)
4177{
4178 auto* scrollingCoordinator = this->scrollingCoordinator();
4179
4180 auto nodeType = ScrollingNodeType::Fixed;
4181 if (layer.renderer().style().position() == PositionType::Sticky)
4182 nodeType = ScrollingNodeType::Sticky;
4183 else
4184 ASSERT(layer.renderer().isFixedPositioned());
4185
4186 auto newNodeID = attachScrollingNode(layer, nodeType, treeState);
4187 if (!newNodeID) {
4188 ASSERT_NOT_REACHED();
4189 return treeState.parentNodeID.valueOr(0);
4190 }
4191
4192 LOG_WITH_STREAM(Compositing, stream << "Registering ViewportConstrained " << nodeType << " node " << newNodeID << " (layer " << layer.backing()->graphicsLayer()->primaryLayerID() << ") as child of " << treeState.parentNodeID.valueOr(0));
4193
4194 if (changes & ScrollingNodeChangeFlags::Layer)
4195 scrollingCoordinator->setNodeLayers(newNodeID, { layer.backing()->graphicsLayer() });
4196
4197 if (changes & ScrollingNodeChangeFlags::LayerGeometry) {
4198 switch (nodeType) {
4199 case ScrollingNodeType::Fixed:
4200 scrollingCoordinator->setViewportConstraintedNodeConstraints(newNodeID, computeFixedViewportConstraints(layer));
4201 break;
4202 case ScrollingNodeType::Sticky:
4203 scrollingCoordinator->setViewportConstraintedNodeConstraints(newNodeID, computeStickyViewportConstraints(layer));
4204 break;
4205 default:
4206 break;
4207 }
4208 }
4209
4210 return newNodeID;
4211}
4212
4213LayoutRect RenderLayerCompositor::rootParentRelativeScrollableRect() const
4214{
4215 auto& frameView = m_renderView.frameView();
4216
4217 if (m_renderView.frame().isMainFrame())
4218 return frameView.frameRect();
4219
4220 return LayoutRect({ }, LayoutSize(frameView.size()));
4221}
4222
4223LayoutRect RenderLayerCompositor::parentRelativeScrollableRect(const RenderLayer& layer, const RenderLayer* ancestorLayer) const
4224{
4225 // FIXME: ancestorLayer needs to be always non-null, so should become a reference.
4226 if (!ancestorLayer)
4227 return LayoutRect({ }, LayoutSize(layer.visibleSize()));
4228
4229 LayoutRect scrollableRect;
4230 if (is<RenderBox>(layer.renderer()))
4231 scrollableRect = downcast<RenderBox>(layer.renderer()).paddingBoxRect();
4232
4233 auto offset = layer.convertToLayerCoords(ancestorLayer, scrollableRect.location()); // FIXME: broken for columns.
4234 scrollableRect.setLocation(offset);
4235 return scrollableRect;
4236}
4237
4238void RenderLayerCompositor::updateScrollingNodeLayers(ScrollingNodeID nodeID, RenderLayer& layer, ScrollingCoordinator& scrollingCoordinator)
4239{
4240 if (layer.isRenderViewLayer()) {
4241 FrameView& frameView = m_renderView.frameView();
4242 scrollingCoordinator.setNodeLayers(nodeID, { nullptr,
4243 scrollContainerLayer(), scrolledContentsLayer(),
4244 fixedRootBackgroundLayer(), clipLayer(), rootContentsLayer(),
4245 frameView.layerForHorizontalScrollbar(), frameView.layerForVerticalScrollbar() });
4246 } else {
4247 auto& backing = *layer.backing();
4248 scrollingCoordinator.setNodeLayers(nodeID, { backing.graphicsLayer(),
4249 backing.scrollContainerLayer(), backing.scrolledContentsLayer(),
4250 nullptr, nullptr, nullptr,
4251 layer.layerForHorizontalScrollbar(), layer.layerForVerticalScrollbar() });
4252 }
4253}
4254
4255ScrollingNodeID RenderLayerCompositor::updateScrollingNodeForScrollingRole(RenderLayer& layer, ScrollingTreeState& treeState, OptionSet<ScrollingNodeChangeFlags> changes)
4256{
4257 auto* scrollingCoordinator = this->scrollingCoordinator();
4258
4259 ScrollingNodeID newNodeID = 0;
4260
4261 if (layer.isRenderViewLayer()) {
4262 FrameView& frameView = m_renderView.frameView();
4263 ASSERT_UNUSED(frameView, scrollingCoordinator->coordinatesScrollingForFrameView(frameView));
4264
4265 newNodeID = attachScrollingNode(*m_renderView.layer(), m_renderView.frame().isMainFrame() ? ScrollingNodeType::MainFrame : ScrollingNodeType::Subframe, treeState);
4266
4267 if (!newNodeID) {
4268 ASSERT_NOT_REACHED();
4269 return treeState.parentNodeID.valueOr(0);
4270 }
4271
4272 if (changes & ScrollingNodeChangeFlags::Layer)
4273 updateScrollingNodeLayers(newNodeID, layer, *scrollingCoordinator);
4274
4275 if (changes & ScrollingNodeChangeFlags::LayerGeometry) {
4276 scrollingCoordinator->setRectRelativeToParentNode(newNodeID, rootParentRelativeScrollableRect());
4277 scrollingCoordinator->setScrollingNodeScrollableAreaGeometry(newNodeID, frameView);
4278 scrollingCoordinator->setFrameScrollingNodeState(newNodeID, frameView);
4279 }
4280 } else {
4281 newNodeID = attachScrollingNode(layer, ScrollingNodeType::Overflow, treeState);
4282 if (!newNodeID) {
4283 ASSERT_NOT_REACHED();
4284 return treeState.parentNodeID.valueOr(0);
4285 }
4286
4287 if (changes & ScrollingNodeChangeFlags::Layer)
4288 updateScrollingNodeLayers(newNodeID, layer, *scrollingCoordinator);
4289
4290 if (changes & ScrollingNodeChangeFlags::LayerGeometry && treeState.parentNodeID) {
4291 RenderLayer* scrollingAncestorLayer = m_scrollingNodeToLayerMap.get(treeState.parentNodeID.value());
4292 scrollingCoordinator->setRectRelativeToParentNode(newNodeID, parentRelativeScrollableRect(layer, scrollingAncestorLayer));
4293 scrollingCoordinator->setScrollingNodeScrollableAreaGeometry(newNodeID, layer);
4294 }
4295 }
4296
4297 return newNodeID;
4298}
4299
4300ScrollingNodeID RenderLayerCompositor::updateScrollingNodeForFrameHostingRole(RenderLayer& layer, ScrollingTreeState& treeState, OptionSet<ScrollingNodeChangeFlags> changes)
4301{
4302 auto* scrollingCoordinator = this->scrollingCoordinator();
4303
4304 auto newNodeID = attachScrollingNode(layer, ScrollingNodeType::FrameHosting, treeState);
4305 if (!newNodeID) {
4306 ASSERT_NOT_REACHED();
4307 return treeState.parentNodeID.valueOr(0);
4308 }
4309
4310 if (changes & ScrollingNodeChangeFlags::Layer)
4311 scrollingCoordinator->setNodeLayers(newNodeID, { layer.backing()->graphicsLayer() });
4312
4313 if (changes & ScrollingNodeChangeFlags::LayerGeometry && treeState.parentNodeID) {
4314 RenderLayer* scrollingAncestorLayer = m_scrollingNodeToLayerMap.get(treeState.parentNodeID.value());
4315 scrollingCoordinator->setRectRelativeToParentNode(newNodeID, parentRelativeScrollableRect(layer, scrollingAncestorLayer));
4316 }
4317
4318 return newNodeID;
4319}
4320
4321ScrollingNodeID RenderLayerCompositor::updateScrollingNodeForPositioningRole(RenderLayer& layer, ScrollingTreeState& treeState, OptionSet<ScrollingNodeChangeFlags> changes)
4322{
4323 auto* scrollingCoordinator = this->scrollingCoordinator();
4324
4325 auto newNodeID = attachScrollingNode(layer, ScrollingNodeType::Positioned, treeState);
4326 if (!newNodeID) {
4327 ASSERT_NOT_REACHED();
4328 return treeState.parentNodeID.valueOr(0);
4329 }
4330
4331 if (changes & ScrollingNodeChangeFlags::Layer) {
4332 auto& backing = *layer.backing();
4333 scrollingCoordinator->setNodeLayers(newNodeID, { backing.graphicsLayer() });
4334 }
4335
4336 if (changes & ScrollingNodeChangeFlags::LayerGeometry && treeState.parentNodeID) {
4337 // Would be nice to avoid calling computeCoordinatedPositioningForLayer() again.
4338 auto positioningBehavior = computeCoordinatedPositioningForLayer(layer);
4339 auto relatedNodeIDs = collectRelatedCoordinatedScrollingNodes(layer, positioningBehavior);
4340 scrollingCoordinator->setRelatedOverflowScrollingNodes(newNodeID, WTFMove(relatedNodeIDs));
4341
4342 auto* graphicsLayer = layer.backing()->graphicsLayer();
4343 LayoutConstraints constraints;
4344 constraints.setAlignmentOffset(graphicsLayer->pixelAlignmentOffset());
4345 constraints.setLayerPositionAtLastLayout(graphicsLayer->position());
4346 constraints.setScrollPositioningBehavior(positioningBehavior);
4347 scrollingCoordinator->setPositionedNodeGeometry(newNodeID, constraints);
4348 }
4349
4350 return newNodeID;
4351}
4352
4353ScrollableArea* RenderLayerCompositor::scrollableAreaForScrollLayerID(ScrollingNodeID nodeID) const
4354{
4355 if (!nodeID)
4356 return nullptr;
4357
4358 return m_scrollingNodeToLayerMap.get(nodeID);
4359}
4360
4361void RenderLayerCompositor::willRemoveScrollingLayerWithBacking(RenderLayer& layer, RenderLayerBacking& backing)
4362{
4363 if (scrollingCoordinator())
4364 return;
4365
4366#if PLATFORM(IOS_FAMILY)
4367 ASSERT(m_renderView.document().pageCacheState() == Document::NotInPageCache);
4368 if (m_legacyScrollingLayerCoordinator)
4369 m_legacyScrollingLayerCoordinator->removeScrollingLayer(layer, backing);
4370#else
4371 UNUSED_PARAM(layer);
4372 UNUSED_PARAM(backing);
4373#endif
4374}
4375
4376// FIXME: This should really be called from the updateBackingAndHierarchy.
4377void RenderLayerCompositor::didAddScrollingLayer(RenderLayer& layer)
4378{
4379 if (scrollingCoordinator())
4380 return;
4381
4382#if PLATFORM(IOS_FAMILY)
4383 ASSERT(m_renderView.document().pageCacheState() == Document::NotInPageCache);
4384 if (m_legacyScrollingLayerCoordinator)
4385 m_legacyScrollingLayerCoordinator->addScrollingLayer(layer);
4386#else
4387 UNUSED_PARAM(layer);
4388#endif
4389}
4390
4391void RenderLayerCompositor::windowScreenDidChange(PlatformDisplayID displayID)
4392{
4393 if (m_layerUpdater)
4394 m_layerUpdater->screenDidChange(displayID);
4395}
4396
4397ScrollingCoordinator* RenderLayerCompositor::scrollingCoordinator() const
4398{
4399 return page().scrollingCoordinator();
4400}
4401
4402GraphicsLayerFactory* RenderLayerCompositor::graphicsLayerFactory() const
4403{
4404 return page().chrome().client().graphicsLayerFactory();
4405}
4406
4407void RenderLayerCompositor::setLayerFlushThrottlingEnabled(bool enabled)
4408{
4409 m_layerFlushThrottlingEnabled = enabled;
4410 if (m_layerFlushThrottlingEnabled)
4411 return;
4412 m_layerFlushTimer.stop();
4413 if (!m_hasPendingLayerFlush)
4414 return;
4415 scheduleLayerFlush();
4416}
4417
4418void RenderLayerCompositor::disableLayerFlushThrottlingTemporarilyForInteraction()
4419{
4420 if (m_layerFlushThrottlingTemporarilyDisabledForInteraction)
4421 return;
4422 m_layerFlushThrottlingTemporarilyDisabledForInteraction = true;
4423}
4424
4425bool RenderLayerCompositor::isThrottlingLayerFlushes() const
4426{
4427 if (!m_layerFlushThrottlingEnabled)
4428 return false;
4429 if (!m_layerFlushTimer.isActive())
4430 return false;
4431 if (m_layerFlushThrottlingTemporarilyDisabledForInteraction)
4432 return false;
4433 return true;
4434}
4435
4436void RenderLayerCompositor::startLayerFlushTimerIfNeeded()
4437{
4438 m_layerFlushThrottlingTemporarilyDisabledForInteraction = false;
4439 m_layerFlushTimer.stop();
4440 if (!m_layerFlushThrottlingEnabled)
4441 return;
4442 m_layerFlushTimer.startOneShot(throttledLayerFlushDelay);
4443}
4444
4445void RenderLayerCompositor::startInitialLayerFlushTimerIfNeeded()
4446{
4447 if (!m_layerFlushThrottlingEnabled)
4448 return;
4449 if (m_layerFlushTimer.isActive())
4450 return;
4451 m_layerFlushTimer.startOneShot(throttledLayerFlushInitialDelay);
4452}
4453
4454void RenderLayerCompositor::layerFlushTimerFired()
4455{
4456 if (!m_hasPendingLayerFlush)
4457 return;
4458 scheduleLayerFlush();
4459}
4460
4461#if USE(REQUEST_ANIMATION_FRAME_DISPLAY_MONITOR)
4462RefPtr<DisplayRefreshMonitor> RenderLayerCompositor::createDisplayRefreshMonitor(PlatformDisplayID displayID) const
4463{
4464 if (auto monitor = page().chrome().client().createDisplayRefreshMonitor(displayID))
4465 return monitor;
4466
4467 return DisplayRefreshMonitor::createDefaultDisplayRefreshMonitor(displayID);
4468}
4469#endif
4470
4471#if ENABLE(CSS_SCROLL_SNAP)
4472void RenderLayerCompositor::updateScrollSnapPropertiesWithFrameView(const FrameView& frameView) const
4473{
4474 if (auto* coordinator = scrollingCoordinator())
4475 coordinator->updateScrollSnapPropertiesWithFrameView(frameView);
4476}
4477#endif
4478
4479Page& RenderLayerCompositor::page() const
4480{
4481 return m_renderView.page();
4482}
4483
4484TextStream& operator<<(TextStream& ts, CompositingUpdateType updateType)
4485{
4486 switch (updateType) {
4487 case CompositingUpdateType::AfterStyleChange: ts << "after style change"; break;
4488 case CompositingUpdateType::AfterLayout: ts << "after layout"; break;
4489 case CompositingUpdateType::OnScroll: ts << "on scroll"; break;
4490 case CompositingUpdateType::OnCompositedScroll: ts << "on composited scroll"; break;
4491 }
4492 return ts;
4493}
4494
4495TextStream& operator<<(TextStream& ts, CompositingPolicy compositingPolicy)
4496{
4497 switch (compositingPolicy) {
4498 case CompositingPolicy::Normal: ts << "normal"; break;
4499 case CompositingPolicy::Conservative: ts << "conservative"; break;
4500 }
4501 return ts;
4502}
4503
4504#if PLATFORM(IOS_FAMILY)
4505typedef HashMap<PlatformLayer*, std::unique_ptr<ViewportConstraints>> LayerMap;
4506typedef HashMap<PlatformLayer*, PlatformLayer*> StickyContainerMap;
4507
4508void LegacyWebKitScrollingLayerCoordinator::registerAllViewportConstrainedLayers(RenderLayerCompositor& compositor)
4509{
4510 if (!m_coordinateViewportConstrainedLayers)
4511 return;
4512
4513 LayerMap layerMap;
4514 StickyContainerMap stickyContainerMap;
4515
4516 for (auto* layer : m_viewportConstrainedLayers) {
4517 ASSERT(layer->isComposited());
4518
4519 std::unique_ptr<ViewportConstraints> constraints;
4520 if (layer->renderer().isStickilyPositioned()) {
4521 constraints = std::make_unique<StickyPositionViewportConstraints>(compositor.computeStickyViewportConstraints(*layer));
4522 const RenderLayer* enclosingTouchScrollableLayer = nullptr;
4523 if (compositor.isAsyncScrollableStickyLayer(*layer, &enclosingTouchScrollableLayer) && enclosingTouchScrollableLayer) {
4524 ASSERT(enclosingTouchScrollableLayer->isComposited());
4525 // what
4526 stickyContainerMap.add(layer->backing()->graphicsLayer()->platformLayer(), enclosingTouchScrollableLayer->backing()->scrollContainerLayer()->platformLayer());
4527 }
4528 } else if (layer->renderer().isFixedPositioned())
4529 constraints = std::make_unique<FixedPositionViewportConstraints>(compositor.computeFixedViewportConstraints(*layer));
4530 else
4531 continue;
4532
4533 layerMap.add(layer->backing()->graphicsLayer()->platformLayer(), WTFMove(constraints));
4534 }
4535
4536 m_chromeClient.updateViewportConstrainedLayers(layerMap, stickyContainerMap);
4537}
4538
4539void LegacyWebKitScrollingLayerCoordinator::unregisterAllViewportConstrainedLayers()
4540{
4541 if (!m_coordinateViewportConstrainedLayers)
4542 return;
4543
4544 LayerMap layerMap;
4545 m_chromeClient.updateViewportConstrainedLayers(layerMap, { });
4546}
4547
4548void LegacyWebKitScrollingLayerCoordinator::updateScrollingLayer(RenderLayer& layer)
4549{
4550 auto* backing = layer.backing();
4551 ASSERT(backing);
4552
4553 bool allowHorizontalScrollbar = !layer.horizontalScrollbarHiddenByStyle();
4554 bool allowVerticalScrollbar = !layer.verticalScrollbarHiddenByStyle();
4555 m_chromeClient.addOrUpdateScrollingLayer(layer.renderer().element(), backing->scrollContainerLayer()->platformLayer(), backing->scrolledContentsLayer()->platformLayer(),
4556 layer.reachableTotalContentsSize(), allowHorizontalScrollbar, allowVerticalScrollbar);
4557}
4558
4559void LegacyWebKitScrollingLayerCoordinator::registerAllScrollingLayers()
4560{
4561 for (auto* layer : m_scrollingLayers)
4562 updateScrollingLayer(*layer);
4563}
4564
4565void LegacyWebKitScrollingLayerCoordinator::registerScrollingLayersNeedingUpdate()
4566{
4567 for (auto* layer : m_scrollingLayersNeedingUpdate)
4568 updateScrollingLayer(*layer);
4569
4570 m_scrollingLayersNeedingUpdate.clear();
4571}
4572
4573void LegacyWebKitScrollingLayerCoordinator::unregisterAllScrollingLayers()
4574{
4575 for (auto* layer : m_scrollingLayers) {
4576 auto* backing = layer->backing();
4577 ASSERT(backing);
4578 m_chromeClient.removeScrollingLayer(layer->renderer().element(), backing->scrollContainerLayer()->platformLayer(), backing->scrolledContentsLayer()->platformLayer());
4579 }
4580}
4581
4582void LegacyWebKitScrollingLayerCoordinator::addScrollingLayer(RenderLayer& layer)
4583{
4584 m_scrollingLayers.add(&layer);
4585 m_scrollingLayersNeedingUpdate.add(&layer);
4586}
4587
4588void LegacyWebKitScrollingLayerCoordinator::removeScrollingLayer(RenderLayer& layer, RenderLayerBacking& backing)
4589{
4590 m_scrollingLayersNeedingUpdate.remove(&layer);
4591 if (m_scrollingLayers.remove(&layer)) {
4592 auto* scrollContainerLayer = backing.scrollContainerLayer()->platformLayer();
4593 auto* scrolledContentsLayer = backing.scrolledContentsLayer()->platformLayer();
4594 m_chromeClient.removeScrollingLayer(layer.renderer().element(), scrollContainerLayer, scrolledContentsLayer);
4595 }
4596}
4597
4598void LegacyWebKitScrollingLayerCoordinator::removeLayer(RenderLayer& layer)
4599{
4600 removeScrollingLayer(layer, *layer.backing());
4601
4602 // We'll put the new set of layers to the client via registerAllViewportConstrainedLayers() at flush time.
4603 m_viewportConstrainedLayers.remove(&layer);
4604}
4605
4606void LegacyWebKitScrollingLayerCoordinator::addViewportConstrainedLayer(RenderLayer& layer)
4607{
4608 m_viewportConstrainedLayers.add(&layer);
4609}
4610
4611void LegacyWebKitScrollingLayerCoordinator::removeViewportConstrainedLayer(RenderLayer& layer)
4612{
4613 m_viewportConstrainedLayers.remove(&layer);
4614}
4615
4616void LegacyWebKitScrollingLayerCoordinator::didChangePlatformLayerForLayer(RenderLayer& layer)
4617{
4618 if (m_scrollingLayers.contains(&layer))
4619 m_scrollingLayersNeedingUpdate.add(&layer);
4620}
4621
4622#endif
4623
4624} // namespace WebCore
4625
4626#if ENABLE(TREE_DEBUGGING)
4627void showGraphicsLayerTreeForCompositor(WebCore::RenderLayerCompositor& compositor)
4628{
4629 showGraphicsLayerTree(compositor.rootGraphicsLayer());
4630}
4631#endif
4632