gecko/layout/base/FrameLayerBuilder.h

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#ifndef FRAMELAYERBUILDER_H_
#define FRAMELAYERBUILDER_H_

#include "Layers.h"

class nsDisplayListBuilder;
class nsDisplayList;
class nsDisplayItem;
class nsIFrame;
class nsRect;
class nsIntRegion;
class gfxContext;

namespace mozilla {

class FrameLayerBuilder {
public:
  typedef mozilla::layers::Layer Layer;
  typedef mozilla::layers::ThebesLayer ThebesLayer;
  typedef mozilla::layers::LayerManager LayerManager;

  /**
   * Get a container layer for a display item that contains a child
   * list, either reusing an existing one or creating a new one.
   * aContainer may be null, in which case we construct a root layer.
   */
  already_AddRefed<Layer> GetContainerLayerFor(nsDisplayListBuilder* aBuilder,
                                               LayerManager* aManager,
                                               nsDisplayItem* aContainer,
                                               const nsDisplayList& aChildren);

  /**
   * Get a retained layer for a leaf display item. Returns null if no
   * layer is available, in which case the caller will probably need to
   * create one.
   */
  Layer* GetLeafLayerFor(nsDisplayListBuilder* aBuilder,
                         LayerManager* aManager,
                         nsDisplayItem* aItem);

  /**
   * Call this during invalidation if aFrame has
   * the NS_FRAME_HAS_CONTAINER_LAYER state bit. Only the nearest
   * ancestor frame of the damaged frame that has
   * NS_FRAME_HAS_CONTAINER_LAYER needs to be invalidated this way.
   */
  static void InvalidateThebesLayerContents(nsIFrame* aFrame,
                                            const nsRect& aRect);

  /**
   * This callback must be provided to EndTransaction. The callback data
   * must be the nsDisplayListBuilder containing this FrameLayerBuilder.
   */
  static void DrawThebesLayer(ThebesLayer* aLayer,
                              gfxContext* aContext,
                              const nsIntRegion& aRegionToDraw,
                              const nsIntRegion& aRegionToInvalidate,
                              void* aCallbackData);
};

}

#endif /* FRAMELAYERBUILDER_H_ */