src/third_party/WebKit/Source/core/rendering/compositing/GraphicsLayerTreeBuilder.cpp

   1 /*
   2  * Copyright (C) 2009, 2010 Apple Inc. All rights reserved.
   3  * Copyright (C) 2014 Google Inc. All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  15  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  17  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
  18  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  19  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  20  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  21  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  22  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  24  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  */
  26
  27 #include "config.h"
  28 #include "core/rendering/compositing/GraphicsLayerTreeBuilder.h"
  29
  30 #include "core/html/HTMLMediaElement.h"
  31 #include "core/html/HTMLVideoElement.h"
  32 #include "core/rendering/RenderLayer.h"
  33 #include "core/rendering/RenderLayerReflectionInfo.h"
  34 #include "core/rendering/RenderPart.h"
  35 #include "core/rendering/RenderView.h"
  36 #include "core/rendering/compositing/CompositedLayerMapping.h"
  37 #include "core/rendering/compositing/RenderLayerCompositor.h"
  38
  39 namespace blink {
  40
  41 GraphicsLayerTreeBuilder::GraphicsLayerTreeBuilder()
  42 {
  43 }
  44
  45 GraphicsLayerTreeBuilder::~GraphicsLayerTreeBuilder()
  46 {
  47 }
  48
  49 static bool shouldAppendLayer(const RenderLayer& layer)
  50 {
  51     if (!RuntimeEnabledFeatures::overlayFullscreenVideoEnabled())
  52         return true;
  53     Node* node = layer.renderer()->node();
  54     if (node && isHTMLVideoElement(*node)) {
  55         HTMLVideoElement* element = toHTMLVideoElement(node);
  56         // For WebRTC, video frame contains all the data and no hardware surface is used.
  57         // We should always append the layer in this case.
  58         if (element->isFullscreen() && !HTMLMediaElement::isMediaStreamURL(element->sourceURL().string()))
  59             return false;
  60     }
  61     return true;
  62 }
  63
  64 void GraphicsLayerTreeBuilder::rebuild(RenderLayer& layer, AncestorInfo info)
  65 {
  66     // Make the layer compositing if necessary, and set up clipping and content layers.
  67     // Note that we can only do work here that is independent of whether the descendant layers
  68     // have been processed. computeCompositingRequirements() will already have done the paint invalidation if necessary.
  69
  70     layer.stackingNode()->updateLayerListsIfNeeded();
  71
  72     const bool hasCompositedLayerMapping = layer.hasCompositedLayerMapping();
  73     CompositedLayerMapping* currentCompositedLayerMapping = layer.compositedLayerMapping();
  74
  75     // If this layer has a compositedLayerMapping, then that is where we place subsequent children GraphicsLayers.
  76     // Otherwise children continue to append to the child list of the enclosing layer.
  77     GraphicsLayerVector layerChildren;
  78     AncestorInfo infoForChildren(info);
  79     if (hasCompositedLayerMapping) {
  80         infoForChildren.childLayersOfEnclosingCompositedLayer = &layerChildren;
  81         infoForChildren.enclosingCompositedLayer = &layer;
  82     }
  83
  84 #if ENABLE(ASSERT)
  85     LayerListMutationDetector mutationChecker(layer.stackingNode());
  86 #endif
  87
  88     if (layer.stackingNode()->isStackingContext()) {
  89         RenderLayerStackingNodeIterator iterator(*layer.stackingNode(), NegativeZOrderChildren);
  90         while (RenderLayerStackingNode* curNode = iterator.next())
  91             rebuild(*curNode->layer(), infoForChildren);
  92
  93         // If a negative z-order child is compositing, we get a foreground layer which needs to get parented.
  94         if (hasCompositedLayerMapping && currentCompositedLayerMapping->foregroundLayer())
  95             infoForChildren.childLayersOfEnclosingCompositedLayer->append(currentCompositedLayerMapping->foregroundLayer());
  96     }
  97
  98     RenderLayerStackingNodeIterator iterator(*layer.stackingNode(), NormalFlowChildren | PositiveZOrderChildren);
  99     while (RenderLayerStackingNode* curNode = iterator.next())
 100         rebuild(*curNode->layer(), infoForChildren);
 101
 102     if (hasCompositedLayerMapping) {
 103         bool parented = false;
 104         if (layer.renderer()->isRenderPart())
 105             parented = RenderLayerCompositor::parentFrameContentLayers(toRenderPart(layer.renderer()));
 106
 107         if (!parented)
 108             currentCompositedLayerMapping->parentForSublayers()->setChildren(layerChildren);
 109
 110         // If the layer has a clipping layer the overflow controls layers will be siblings of the clipping layer.
 111         // Otherwise, the overflow control layers are normal children.
 112         // FIXME: Why isn't this handled in CLM updateInternalHierarchy?
 113         if (!currentCompositedLayerMapping->hasClippingLayer() && !currentCompositedLayerMapping->hasScrollingLayer()) {
 114             if (GraphicsLayer* overflowControlLayer = currentCompositedLayerMapping->layerForHorizontalScrollbar()) {
 115                 overflowControlLayer->removeFromParent();
 116                 currentCompositedLayerMapping->parentForSublayers()->addChild(overflowControlLayer);
 117             }
 118
 119             if (GraphicsLayer* overflowControlLayer = currentCompositedLayerMapping->layerForVerticalScrollbar()) {
 120                 overflowControlLayer->removeFromParent();
 121                 currentCompositedLayerMapping->parentForSublayers()->addChild(overflowControlLayer);
 122             }
 123
 124             if (GraphicsLayer* overflowControlLayer = currentCompositedLayerMapping->layerForScrollCorner()) {
 125                 overflowControlLayer->removeFromParent();
 126                 currentCompositedLayerMapping->parentForSublayers()->addChild(overflowControlLayer);
 127             }
 128         }
 129
 130         if (shouldAppendLayer(layer))
 131             info.childLayersOfEnclosingCompositedLayer->append(currentCompositedLayerMapping->childForSuperlayers());
 132     }
 133
 134     if (layer.scrollParent()
 135         && layer.scrollParent()->hasCompositedLayerMapping()
 136         && layer.scrollParent()->compositedLayerMapping()->needsToReparentOverflowControls()
 137         && layer.scrollParent()->scrollableArea()->topmostScrollChild() == &layer)
 138         info.childLayersOfEnclosingCompositedLayer->append(layer.scrollParent()->compositedLayerMapping()->detachLayerForOverflowControls(*info.enclosingCompositedLayer));
 139 }
 140
 141 }