cc/trees/layer_tree_host_client.h

// Copyright 2012 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 CC_TREES_LAYER_TREE_HOST_CLIENT_H_
#define CC_TREES_LAYER_TREE_HOST_CLIENT_H_

#include "base/memory/ref_counted.h"
#include "base/memory/scoped_ptr.h"
#include "base/time/time.h"

namespace gfx {
class Vector2d;
}

namespace cc {
class ContextProvider;
class InputHandlerClient;
class OutputSurface;
struct BeginFrameArgs;

class LayerTreeHostClient {
 public:
  virtual void WillBeginMainFrame(int frame_id) = 0;
  // Marks finishing compositing-related tasks on the main thread. In threaded
  // mode, this corresponds to DidCommit().
  virtual void BeginMainFrame(const BeginFrameArgs& args) = 0;
  virtual void DidBeginMainFrame() = 0;
  virtual void Layout() = 0;
  virtual void ApplyViewportDeltas(const gfx::Vector2d& inner_delta,
                                   const gfx::Vector2d& outer_delta,
                                   float page_scale,
                                   float top_controls_delta) = 0;
  virtual void ApplyViewportDeltas(const gfx::Vector2d& scroll_delta,
                                   float page_scale,
                                   float top_controls_delta) = 0;
  // Request an OutputSurface from the client. When the client has one it should
  // call LayerTreeHost::SetOutputSurface.  If fallback is true, it should
  // attempt to create an OutputSurface that is guaranteed to initialize
  // correctly.
  virtual void RequestNewOutputSurface(bool fallback) = 0;
  virtual void DidInitializeOutputSurface() = 0;
  virtual void WillCommit() = 0;
  virtual void DidCommit() = 0;
  virtual void DidCommitAndDrawFrame() = 0;
  virtual void DidCompleteSwapBuffers() = 0;

  // TODO(simonhong): Makes this to pure virtual function when client
  // implementation is ready.
  virtual void SendBeginFramesToChildren(const BeginFrameArgs& args) {}

  // Requests that the client insert a rate limiting token in the shared main
  // thread context's command stream that will block if the context gets too far
  // ahead of the compositor's command stream. Only needed if the tree contains
  // a TextureLayer that calls SetRateLimitContext(true).
  virtual void RateLimitSharedMainThreadContext() {}

  // This hook is for testing.
  virtual void DidFailToInitializeOutputSurface() {}

 protected:
  virtual ~LayerTreeHostClient() {}
};

}  // namespace cc

#endif  // CC_TREES_LAYER_TREE_HOST_CLIENT_H_