Raise the loading priority of in-viewport images.

Source/core/rendering/RenderBlock.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 14 matching lines @@
 #include "core/rendering/RenderBlock.h"
 
 #include "HTMLNames.h"
 #include "core/accessibility/AXObjectCache.h"
 #include "core/dom/Document.h"
 #include "core/dom/Element.h"
 #include "core/events/OverflowEvent.h"
 #include "core/dom/shadow/ShadowRoot.h"
 #include "core/editing/Editor.h"
 #include "core/editing/FrameSelection.h"
+#include "core/fetch/ResourceLoadPriorityOptimizer.h"
 #include "core/frame/Frame.h"
 #include "core/frame/FrameView.h"
 #include "core/page/Page.h"
 #include "core/page/Settings.h"
 #include "core/rendering/FastTextAutosizer.h"
 #include "core/rendering/GraphicsContextAnnotator.h"
 #include "core/rendering/HitTestLocation.h"
 #include "core/rendering/HitTestResult.h"
 #include "core/rendering/InlineIterator.h"
 #include "core/rendering/InlineTextBox.h"
 #include "core/rendering/LayoutRectRecorder.h"
 #include "core/rendering/LayoutRepainter.h"
 #include "core/rendering/PaintInfo.h"
 #include "core/rendering/RenderCombineText.h"
 #include "core/rendering/RenderDeprecatedFlexibleBox.h"
 #include "core/rendering/RenderFlexibleBox.h"
 #include "core/rendering/RenderInline.h"
 #include "core/rendering/RenderLayer.h"
 #include "core/rendering/RenderMarquee.h"
 #include "core/rendering/RenderNamedFlowThread.h"
 #include "core/rendering/RenderRegion.h"
 #include "core/rendering/RenderTableCell.h"
 #include "core/rendering/RenderTextFragment.h"
 #include "core/rendering/RenderTheme.h"
 #include "core/rendering/RenderView.h"
 #include "core/rendering/shapes/ShapeOutsideInfo.h"
+#include "core/rendering/style/ContentData.h"
+#include "core/rendering/style/RenderStyle.h"
 #include "platform/geometry/FloatQuad.h"
 #include "platform/geometry/TransformState.h"
 #include "platform/graphics/GraphicsContextStateSaver.h"
 #include "wtf/StdLibExtras.h"
 #include "wtf/TemporaryChange.h"
 
 using namespace std;
 using namespace WTF;
 using namespace Unicode;
 
@@ skipping 91 matching lines @@
                 continue;
             HashSet<RenderBlock*>* containerSet = it->value.get();
             ASSERT(containerSet->contains(block));
             containerSet->remove(block);
             if (containerSet->isEmpty())
                 containerMap->remove(it);
         }
     }
 }
 
+static void appendImageIfNotNull(Vector<ImageResource*>& imageResources, const StyleImage* styleImage)
+{
+    if (styleImage && styleImage->cachedImage())
+        imageResources.append(styleImage->cachedImage());
+}
+
+static void appendLayers(Vector<ImageResource*>& images, const FillLayer* styleLayer)
+{
+    for (const FillLayer* layer = styleLayer; layer; layer = layer->next()) {
+        appendImageIfNotNull(images, layer->image());
+    }
+}
+
 RenderBlock::~RenderBlock()
 {
     if (hasColumns())
         gColumnInfoMap->take(this);
     if (gPercentHeightDescendantsMap)
         removeBlockFromDescendantAndContainerMaps(this, gPercentHeightDescendantsMap, gPercentHeightContainerMap);
     if (gPositionedDescendantsMap)
         removeBlockFromDescendantAndContainerMaps(this, gPositionedDescendantsMap, gPositionedContainerMap);
 }
 
@@ skipping 1063 matching lines @@
         return;
 
     // It's safe to check for control clip here, since controls can never be table cells.
     // If we have a lightweight clip, there can never be any overflow from children.
     if (hasControlClip() && m_overflow)
         clearLayoutOverflow();
 
     invalidateBackgroundObscurationStatus();
 }
 
+void RenderBlock::didLayout(ResourceLoadPriorityOptimizer& optimizer)
+{
+    RenderBox::didLayout(optimizer);
+    updateStyleImageLoadingPriorities(optimizer);
+}
+
+void RenderBlock::didScroll(ResourceLoadPriorityOptimizer& optimizer)
+{
+    RenderBox::didScroll(optimizer);
+    updateStyleImageLoadingPriorities(optimizer);
+}
+
+void RenderBlock::updateStyleImageLoadingPriorities(ResourceLoadPriorityOptimizer& optimizer)
+{
+    RenderStyle* blockStyle = style();
+    if (!blockStyle)
+        return;
+
+    Vector<ImageResource*> images;
+
+    appendLayers(images, blockStyle->backgroundLayers());
+    appendLayers(images, blockStyle->maskLayers());
+
+    const ContentData* contentData = blockStyle->contentData();
+    if (contentData && contentData->isImage()) {
+        const ImageContentData* imageContentData = static_cast<const ImageContentData*>(contentData);
+        appendImageIfNotNull(images, imageContentData->image());
+    }
+    if (blockStyle->boxReflect())
+        appendImageIfNotNull(images, blockStyle->boxReflect()->mask().image());
+    appendImageIfNotNull(images, blockStyle->listStyleImage());
+    appendImageIfNotNull(images, blockStyle->borderImageSource());
+    appendImageIfNotNull(images, blockStyle->maskBoxImageSource());
+
+    if (images.isEmpty())
+        return;
+
+    LayoutRect viewBounds = viewRect();
+    LayoutRect objectBounds = absoluteContentBox();
+    // The object bounds might be empty right now, so intersects will fail since it doesn't deal
+    // with empty rects. Use LayoutRect::contains in that case.
+    bool isVisible;
+    if (!objectBounds.isEmpty())
+        isVisible =  viewBounds.intersects(objectBounds);
+    else
+        isVisible = viewBounds.contains(objectBounds);
+
+    ResourceLoadPriorityOptimizer::VisibilityStatus status = isVisible ?
+        ResourceLoadPriorityOptimizer::Visible : ResourceLoadPriorityOptimizer::NotVisible;
+
+    for (Vector<ImageResource*>::iterator it = images.begin(), end = images.end(); it != end; ++it)
+        optimizer.notifyImageResourceVisibility(*it, status);
+}
+
 void RenderBlock::relayoutShapeDescendantIfMoved(RenderBlock* child, LayoutSize offset)
 {
     LayoutUnit left = isHorizontalWritingMode() ? offset.width() : offset.height();
     if (!left || !child || child->shapeInsideInfo() || !layoutShapeInsideInfo())
         return;
     // Propagate layout markers only up to the child, as we are still in the middle
     // of a layout pass
     child->setNormalChildNeedsLayout(true);
     child->markShapeInsideDescendantsForLayout();
     child->layoutIfNeeded();
@@ skipping 4469 matching lines @@
 void RenderBlock::showLineTreeAndMark(const InlineBox* markedBox1, const char* markedLabel1, const InlineBox* markedBox2, const char* markedLabel2, const RenderObject* obj) const
 {
     showRenderObject();
     for (const RootInlineBox* root = firstRootBox(); root; root = root->nextRootBox())
         root->showLineTreeAndMark(markedBox1, markedLabel1, markedBox2, markedLabel2, obj, 1);
 }
 
 #endif
 
 } // namespace WebCore