services/gfx/compositor/renderer_state.h

// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef SERVICES_GFX_COMPOSITOR_RENDERER_STATE_H_
#define SERVICES_GFX_COMPOSITOR_RENDERER_STATE_H_

#include <memory>
#include <string>

#include "base/macros.h"
#include "base/memory/weak_ptr.h"
#include "mojo/services/gfx/composition/cpp/formatting.h"
#include "mojo/services/gfx/composition/interfaces/compositor.mojom.h"
#include "services/gfx/compositor/backend/output.h"
#include "services/gfx/compositor/graph/snapshot.h"
#include "services/gfx/compositor/scene_state.h"

namespace compositor {

class Snapshot;

// Describes the state of a particular renderer.
// This object is owned by the CompositorEngine that created it.
class RendererState {
 public:
  RendererState(uint32_t id, const std::string& label);
  ~RendererState();

  base::WeakPtr<RendererState> GetWeakPtr() {
    return weak_factory_.GetWeakPtr();
  }

  // Sets the associated renderer implementation and takes ownership of it.
  void set_renderer_impl(mojo::gfx::composition::Renderer* impl) {
    renderer_impl_.reset(impl);
  }

  // The underlying backend output.
  void set_output(std::unique_ptr<Output> output) {
    output_ = std::move(output);
  }
  Output* output() { return output_.get(); }

  // Gets the root scene, may be null if none set yet.
  SceneState* root_scene() { return root_scene_; }
  uint32_t root_scene_version() { return root_scene_version_; }
  const mojo::Rect& root_scene_viewport() { return root_scene_viewport_; }

  // Sets the root scene and clears the current frame and cached dependencies.
  // If different, invalidates the snapshot and returns true.
  bool SetRootScene(SceneState* scene,
                    uint32_t version,
                    const mojo::Rect& viewport);

  // The currently composited frame, may be null if none.
  const std::shared_ptr<RenderFrame>& frame() { return frame_; }

  // The current scene graph snapshot, may be null if none.
  const std::unique_ptr<Snapshot>& snapshot() { return snapshot_; }

  // Returns true if the renderer has a snapshot and it is valid.
  // This implies that |frame()| is also non-null.
  bool valid() { return snapshot_ && snapshot_->valid(); }

  // Sets the snapshot, or null if none.
  // If the snapshot is valid, updates |frame()| to point to the snapshot's
  // new frame, otherwise leaves it alone.
  // Returns true if the snapshot is valid.
  bool SetSnapshot(std::unique_ptr<Snapshot> snapshot);

  const std::string& label() { return label_; }
  std::string FormattedLabel();

 private:
  std::unique_ptr<Output> output_;
  const uint32_t id_;
  const std::string label_;
  std::string formatted_label_cache_;

  std::unique_ptr<mojo::gfx::composition::Renderer> renderer_impl_;

  SceneState* root_scene_ = nullptr;
  uint32_t root_scene_version_ = mojo::gfx::composition::kSceneVersionNone;
  mojo::Rect root_scene_viewport_;

  std::shared_ptr<RenderFrame> frame_;
  std::unique_ptr<Snapshot> snapshot_;

  base::WeakPtrFactory<RendererState> weak_factory_;

  DISALLOW_COPY_AND_ASSIGN(RendererState);
};

std::ostream& operator<<(std::ostream& os, RendererState* renderer_state);

}  // namespace compositor

#endif  // SERVICES_GFX_COMPOSITOR_RENDERER_STATE_H_