cc/layers/ui_resource_layer.h

// Copyright 2013 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CC_LAYERS_UI_RESOURCE_LAYER_H_
#define CC_LAYERS_UI_RESOURCE_LAYER_H_

#include <memory>

#include "cc/cc_export.h"
#include "cc/layers/layer.h"
#include "cc/resources/ui_resource_client.h"
#include "third_party/skia/include/core/SkBitmap.h"
#include "ui/gfx/geometry/rect.h"

namespace cc {

class LayerTreeHost;

class CC_EXPORT UIResourceLayer : public Layer {
 public:
  static scoped_refptr<UIResourceLayer> Create();

  UIResourceLayer(const UIResourceLayer&) = delete;
  UIResourceLayer& operator=(const UIResourceLayer&) = delete;

  void SetLayerTreeHost(LayerTreeHost* host) override;

  // Sets the resource. If they don't exist already, the shared UI resource and
  // ID are generated and cached in a map in the associated UIResourceManager.
  // This resource will be released when all references of SkPixelRefs outside
  // the associated UIResourceManager's map are dropped
  void SetBitmap(const SkBitmap& skbitmap);

  // An alternative way of setting the resource where an ID is used directly. If
  // you use this method, you are responsible for updating the ID if the layer
  // moves between compositors.
  void SetUIResourceId(UIResourceId resource_id);

  // Sets a UV transform to be used at draw time. Defaults to (0, 0) and (1, 1).
  void SetUV(const gfx::PointF& top_left, const gfx::PointF& bottom_right);


 protected:
  UIResourceLayer();
  ~UIResourceLayer() override;

  void PushDirtyPropertiesTo(
      LayerImpl* layer,
      uint8_t dirty_flag,
      const CommitState& commit_state,
      const ThreadUnsafeCommitState& unsafe_state) override;

  bool HasDrawableContent() const override;

  UIResourceId resource_id() const { return resource_id_.Read(*this); }

 private:
  std::unique_ptr<LayerImpl> CreateLayerImpl(
      LayerTreeImpl* tree_impl) const override;
  void RecreateUIResourceIdFromBitmap();
  void SetUIResourceIdInternal(UIResourceId resource_id);

  // The resource ID will be zero when it's unset or when there's no associated
  // LayerTreeHost.
  ProtectedSequenceReadable<UIResourceId> resource_id_;
  ProtectedSequenceForbidden<SkBitmap> bitmap_;

  ProtectedSequenceReadable<gfx::PointF> uv_top_left_;
  ProtectedSequenceReadable<gfx::PointF> uv_bottom_right_;
};

}  // namespace cc

#endif  // CC_LAYERS_UI_RESOURCE_LAYER_H_