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,
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  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/rendering/RenderLayer.h"
  32 #include "core/rendering/RenderLayerReflectionInfo.h"
  33 #include "core/rendering/RenderPart.h"
  34 #include "core/rendering/RenderView.h"
  35 #include "core/rendering/compositing/CompositedLayerMapping.h"
  36 #include "core/rendering/compositing/RenderLayerCompositor.h"
  37
  38 namespace blink {
  39
  40 GraphicsLayerTreeBuilder::GraphicsLayerTreeBuilder()
  41 {
  42 }
  43
  44 GraphicsLayerTreeBuilder::~GraphicsLayerTreeBuilder()
  45 {
  46 }
  47
  48 static bool shouldAppendLayer(const RenderLayer& layer)
  49 {
  50     if (!RuntimeEnabledFeatures::overlayFullscreenVideoEnabled())
  51         return true;
  52     Node* node = layer.renderer()->node();
  53     if (node && isHTMLMediaElement(*node) && toHTMLMediaElement(node)->isFullscreen())
  54         return false;
  55     return true;
  56 }
  57
  58 void GraphicsLayerTreeBuilder::rebuild(RenderLayer& layer, AncestorInfo info)
  59 {
  60     // Make the layer compositing if necessary, and set up clipping and content layers.
  61     // Note that we can only do work here that is independent of whether the descendant layers
  62     // have been processed. computeCompositingRequirements() will already have done the paint invalidation if necessary.
  63
  64     layer.stackingNode()->updateLayerListsIfNeeded();
  65
  66     const bool hasCompositedLayerMapping = layer.hasCompositedLayerMapping();
  67     CompositedLayerMapping* currentCompositedLayerMapping = layer.compositedLayerMapping();
  68
  69     // If this layer has a compositedLayerMapping, then that is where we place subsequent children GraphicsLayers.
  70     // Otherwise children continue to append to the child list of the enclosing layer.
  71     GraphicsLayerVector layerChildren;
  72     AncestorInfo infoForChildren(info);
  73     if (hasCompositedLayerMapping) {
  74         infoForChildren.childLayersOfEnclosingCompositedLayer = &layerChildren;
  75         infoForChildren.enclosingCompositedLayer = &layer;
  76     }
  77
  78 #if ENABLE(ASSERT)
  79     LayerListMutationDetector mutationChecker(layer.stackingNode());
  80 #endif
  81
  82     if (layer.stackingNode()->isStackingContext()) {
  83         RenderLayerStackingNodeIterator iterator(*layer.stackingNode(), NegativeZOrderChildren);
  84         while (RenderLayerStackingNode* curNode = iterator.next())
  85             rebuild(*curNode->layer(), infoForChildren);
  86
  87         // If a negative z-order child is compositing, we get a foreground layer which needs to get parented.
  88         if (hasCompositedLayerMapping && currentCompositedLayerMapping->foregroundLayer())
  89             infoForChildren.childLayersOfEnclosingCompositedLayer->append(currentCompositedLayerMapping->foregroundLayer());
  90     }
  91
  92     RenderLayerStackingNodeIterator iterator(*layer.stackingNode(), NormalFlowChildren | PositiveZOrderChildren);
  93     while (RenderLayerStackingNode* curNode = iterator.next())
  94         rebuild(*curNode->layer(), infoForChildren);
  95
  96     if (hasCompositedLayerMapping) {
  97         bool parented = false;
  98         if (layer.renderer()->isRenderPart())
  99             parented = RenderLayerCompositor::parentFrameContentLayers(toRenderPart(layer.renderer()));
 100
 101         if (!parented)
 102             currentCompositedLayerMapping->parentForSublayers()->setChildren(layerChildren);
 103
 104         // If the layer has a clipping layer the overflow controls layers will be siblings of the clipping layer.
 105         // Otherwise, the overflow control layers are normal children.
 106         // FIXME: Why isn't this handled in CLM updateInternalHierarchy?
 107         if (!currentCompositedLayerMapping->hasClippingLayer() && !currentCompositedLayerMapping->hasScrollingLayer()) {
 108             if (GraphicsLayer* overflowControlLayer = currentCompositedLayerMapping->layerForHorizontalScrollbar()) {
 109                 overflowControlLayer->removeFromParent();
 110                 currentCompositedLayerMapping->parentForSublayers()->addChild(overflowControlLayer);
 111             }
 112
 113             if (GraphicsLayer* overflowControlLayer = currentCompositedLayerMapping->layerForVerticalScrollbar()) {
 114                 overflowControlLayer->removeFromParent();
 115                 currentCompositedLayerMapping->parentForSublayers()->addChild(overflowControlLayer);
 116             }
 117
 118             if (GraphicsLayer* overflowControlLayer = currentCompositedLayerMapping->layerForScrollCorner()) {
 119                 overflowControlLayer->removeFromParent();
 120                 currentCompositedLayerMapping->parentForSublayers()->addChild(overflowControlLayer);
 121             }
 122         }
 123
 124         if (shouldAppendLayer(layer))
 125             info.childLayersOfEnclosingCompositedLayer->append(currentCompositedLayerMapping->childForSuperlayers());
 126     }
 127
 128     if (layer.scrollParent()
 129         && layer.scrollParent()->hasCompositedLayerMapping()
 130         && layer.scrollParent()->compositedLayerMapping()->needsToReparentOverflowControls()
 131         && layer.scrollParent()->scrollableArea()->topmostScrollChild() == &layer)
 132         info.childLayersOfEnclosingCompositedLayer->append(layer.scrollParent()->compositedLayerMapping()->detachLayerForOverflowControls(*info.enclosingCompositedLayer));
 133 }
 134
 135 }