Bug 811927 - Allow conversion of nsDisplayBackgroundImage into ImageLayers. r=roc

layout/base/FrameLayerBuilder.cpp

@@ -368,7 +368,7 @@ protected:
      * supports being optimized to an ImageLayer (TYPE_RASTER only) returns
      * an ImageContainer for the image.
      */
-    already_AddRefed<ImageContainer> CanOptimizeImageLayer();
+    already_AddRefed<ImageContainer> CanOptimizeImageLayer(nsDisplayListBuilder* aBuilder);
 
     /**
      * The region of visible content in the layer, relative to the
@@ -1525,13 +1525,13 @@ ContainerState::ThebesLayerData::UpdateCommonClipCount(
 }
 
 already_AddRefed<ImageContainer>
-ContainerState::ThebesLayerData::CanOptimizeImageLayer()
+ContainerState::ThebesLayerData::CanOptimizeImageLayer(nsDisplayListBuilder* aBuilder)
 {
   if (!mImage) {
     return nullptr;
   }
 
-  return mImage->GetContainer();
+  return mImage->GetContainer(aBuilder);
 }
 
 void
@@ -1543,7 +1543,7 @@ ContainerState::PopThebesLayerData()
   ThebesLayerData* data = mThebesLayerDataStack[lastIndex];
 
   nsRefPtr<Layer> layer;
-  nsRefPtr<ImageContainer> imageContainer = data->CanOptimizeImageLayer();
+  nsRefPtr<ImageContainer> imageContainer = data->CanOptimizeImageLayer(mBuilder);
 
   if ((data->mIsSolidColorInVisibleRegion || imageContainer) &&
       data->mLayer->GetValidRegion().IsEmpty()) {
@@ -1735,8 +1735,7 @@ ContainerState::ThebesLayerData::Accumulate(ContainerState* aState,
    * we are the first visible item in the ThebesLayerData object.
    */
   if (mVisibleRegion.IsEmpty() &&
-      (aItem->GetType() == nsDisplayItem::TYPE_IMAGE ||
-       aItem->GetType() == nsDisplayItem::TYPE_XUL_IMAGE)) {
+      aItem->SupportsOptimizingToImage()) {
     mImage = static_cast<nsDisplayImageContainer*>(aItem);
   } else {
     mImage = nullptr;

layout/base/nsDisplayList.cpp

@@ -1470,7 +1470,7 @@ nsDisplayBackgroundImage::nsDisplayBackgroundImage(nsDisplayListBuilder* aBuilde
                                                    uint32_t aLayer,
                                                    bool aIsThemed,
                                                    const nsStyleBackground* aBackgroundStyle)
-  : nsDisplayItem(aBuilder, aFrame)
+  : nsDisplayImageContainer(aBuilder, aFrame)
   , mBackgroundStyle(aBackgroundStyle)
   , mLayer(aLayer)
   , mIsThemed(aIsThemed)
@@ -1711,7 +1711,7 @@ nsDisplayBackgroundImage::TryOptimizeToImageLayer(nsDisplayListBuilder* aBuilder
 
   nsImageRenderer* imageRenderer = &state.mImageRenderer;
   // We only care about images here, not gradients.
-  if (imageRenderer->IsRasterImage())
+  if (!imageRenderer->IsRasterImage())
     return false;
 
   nsRefPtr<ImageContainer> imageContainer = imageRenderer->GetContainer();
@@ -1737,6 +1737,18 @@ nsDisplayBackgroundImage::TryOptimizeToImageLayer(nsDisplayListBuilder* aBuilder
   return true;
 }
 
+already_AddRefed<ImageContainer>
+nsDisplayBackgroundImage::GetContainer(nsDisplayListBuilder *aBuilder)
+{
+  if (!TryOptimizeToImageLayer(aBuilder)) {
+    return nullptr;
+  }
+
+  nsRefPtr<ImageContainer> container = mImageContainer;
+
+  return container.forget();
+}
+
 LayerState
 nsDisplayBackgroundImage::GetLayerState(nsDisplayListBuilder* aBuilder,
                                         LayerManager* aManager,
@@ -1779,12 +1791,12 @@ nsDisplayBackgroundImage::BuildLayer(nsDisplayListBuilder* aBuilder,
 {
   nsRefPtr<ImageLayer> layer = aManager->CreateImageLayer();
   layer->SetContainer(mImageContainer);
-  ConfigureLayer(layer);
+  ConfigureLayer(layer, aParameters.mOffset);
   return layer.forget();
 }
 
 void
-nsDisplayBackgroundImage::ConfigureLayer(ImageLayer* aLayer)
+nsDisplayBackgroundImage::ConfigureLayer(ImageLayer* aLayer, const nsIntPoint& aOffset)
 {
   aLayer->SetFilter(nsLayoutUtils::GetGraphicsFilterForFrame(mFrame));
 
@@ -1792,7 +1804,7 @@ nsDisplayBackgroundImage::ConfigureLayer(ImageLayer* aLayer)
   NS_ASSERTION(imageSize.width != 0 && imageSize.height != 0, "Invalid image size!");
 
   gfxMatrix transform;
-  transform.Translate(mDestRect.TopLeft());
+  transform.Translate(mDestRect.TopLeft() + aOffset);
   transform.Scale(mDestRect.width/imageSize.width,
                   mDestRect.height/imageSize.height);
   aLayer->SetBaseTransform(gfx3DMatrix::From2D(transform));

layout/base/nsDisplayList.h

@@ -1087,6 +1087,8 @@ public:
   virtual bool CanUseAsyncAnimations(nsDisplayListBuilder* aBuilder) {
     return false;
   }
+  
+  virtual bool SupportsOptimizingToImage() { return false; }
 
 protected:
   friend class nsDisplayList;
@@ -1539,6 +1541,22 @@ private:
   nsDisplayList mLists[6];
 };
 
+
+class nsDisplayImageContainer : public nsDisplayItem {
+public:
+  typedef mozilla::layers::ImageContainer ImageContainer;
+  typedef mozilla::layers::ImageLayer ImageLayer;
+
+  nsDisplayImageContainer(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame)
+    : nsDisplayItem(aBuilder, aFrame)
+  {}
+
+  virtual already_AddRefed<ImageContainer> GetContainer(nsDisplayListBuilder* aBuilder) = 0;
+  virtual void ConfigureLayer(ImageLayer* aLayer, const nsIntPoint& aOffset) = 0;
+
+  virtual bool SupportsOptimizingToImage() { return true; }
+};
+
 /**
  * Use this class to implement not-very-frequently-used display items
  * that are not opaque, do not receive events, and are bounded by a frame's
@@ -1785,7 +1803,7 @@ private:
  * A display item to paint one background-image for a frame. Each background
  * image layer gets its own nsDisplayBackgroundImage.
  */
-class nsDisplayBackgroundImage : public nsDisplayItem {
+class nsDisplayBackgroundImage : public nsDisplayImageContainer {
 public:
   /**
    * aLayer signifies which background layer this item represents.
@@ -1850,14 +1868,17 @@ public:
    */
   bool RenderingMightDependOnPositioningAreaSizeChange();
 
-  virtual nsDisplayItemGeometry* AllocateGeometry(nsDisplayListBuilder* aBuilder)
+  virtual nsDisplayItemGeometry* AllocateGeometry(nsDisplayListBuilder* aBuilder) MOZ_OVERRIDE
   {
     return new nsDisplayBackgroundGeometry(this, aBuilder);
   }
 
   virtual void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
                                          const nsDisplayItemGeometry* aGeometry,
-                                         nsRegion* aInvalidRegion);
+                                         nsRegion* aInvalidRegion) MOZ_OVERRIDE;
+  
+  virtual already_AddRefed<ImageContainer> GetContainer(nsDisplayListBuilder *aBuilder) MOZ_OVERRIDE;
+  virtual void ConfigureLayer(ImageLayer* aLayer, const nsIntPoint& aOffset) MOZ_OVERRIDE;
 
   static nsRegion GetInsideClipRegion(nsDisplayItem* aItem, nsPresContext* aPresContext, uint8_t aClip,
                                       const nsRect& aRect, bool* aSnap);
@@ -1869,7 +1890,6 @@ protected:
   bool IsSingleFixedPositionImage(nsDisplayListBuilder* aBuilder,
                                   const nsRect& aClipRect,
                                   gfxRect* aDestRect);
-  void ConfigureLayer(ImageLayer* aLayer);
 
   // Cache the result of nsCSSRendering::FindBackground. Always null if
   // mIsThemed is true or if FindBackground returned false.
@@ -2865,17 +2885,4 @@ public:
   nscoord mRightEdge; // length from the right side
 };
 
-class nsDisplayImageContainer : public nsDisplayItem {
-public:
-  typedef mozilla::layers::ImageContainer ImageContainer;
-  typedef mozilla::layers::ImageLayer ImageLayer;
-
-  nsDisplayImageContainer(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame)
-    : nsDisplayItem(aBuilder, aFrame)
-  {}
-
-  virtual already_AddRefed<ImageContainer> GetContainer() = 0;
-  virtual void ConfigureLayer(ImageLayer* aLayer, const nsIntPoint& aOffset) = 0;
-};
-
 #endif /*NSDISPLAYLIST_H_*/

layout/generic/nsCanvasFrame.h

@@ -184,6 +184,10 @@ public:
 
   virtual void Paint(nsDisplayListBuilder* aBuilder,
                      nsRenderingContext* aCtx) MOZ_OVERRIDE;
+ 
+  // We still need to paint a background color as well as an image for this item, 
+  // so we can't support this yet.
+  virtual bool SupportsOptimizingToImage() { return false; }
 
   void SetExtraBackgroundColor(nscolor aColor)
   {

layout/generic/nsImageFrame.cpp

@@ -1229,7 +1229,7 @@ nsDisplayImage::Paint(nsDisplayListBuilder* aBuilder,
 }
 
 already_AddRefed<ImageContainer>
-nsDisplayImage::GetContainer()
+nsDisplayImage::GetContainer(nsDisplayListBuilder* aBuilder)
 {
   nsRefPtr<ImageContainer> container;
   nsresult rv = mImage->GetImageContainer(getter_AddRefs(container));

layout/generic/nsImageFrame.h

@@ -370,7 +370,7 @@ public:
    * Returns an ImageContainer for this image if the image type
    * supports it (TYPE_RASTER only).
    */
-  virtual already_AddRefed<ImageContainer> GetContainer() MOZ_OVERRIDE;
+  virtual already_AddRefed<ImageContainer> GetContainer(nsDisplayListBuilder* aBuilder) MOZ_OVERRIDE;
 
   gfxRect GetDestRect();
 

layout/xul/base/src/nsImageBoxFrame.cpp

@@ -388,7 +388,7 @@ nsDisplayXULImage::ConfigureLayer(ImageLayer* aLayer, const nsIntPoint& aOffset)
 }
 
 already_AddRefed<ImageContainer>
-nsDisplayXULImage::GetContainer()
+nsDisplayXULImage::GetContainer(nsDisplayListBuilder* aBuilder)
 {
   return static_cast<nsImageBoxFrame*>(mFrame)->GetContainer();
 }

layout/xul/base/src/nsImageBoxFrame.h

@@ -130,7 +130,7 @@ public:
   }
 #endif
 
-  virtual already_AddRefed<ImageContainer> GetContainer() MOZ_OVERRIDE;
+  virtual already_AddRefed<ImageContainer> GetContainer(nsDisplayListBuilder* aBuilder) MOZ_OVERRIDE;
   virtual void ConfigureLayer(ImageLayer* aLayer, const nsIntPoint& aOffset) MOZ_OVERRIDE;
   virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap)
   {