Input event filtering and compositor thread setup.

content/renderer/gpu/compositor_thread.h

+// Copyright (c) 2011 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 CONTENT_RENDERER_GPU_COMPOSITOR_THREAD_H_
+#define CONTENT_RENDERER_GPU_COMPOSITOR_THREAD_H_
+
+#include <map>
+
+#include "base/memory/linked_ptr.h"
+#include "ipc/ipc_channel_proxy.h"
+#include "webkit/glue/webthread_impl.h"
+
+namespace WebKit {
+class WebInputEvent;
+}
+
+class InputEventFilter;
+
+// The CompositorThread class manages the background thread for the compositor.
+// The CompositorThread instance can be assumed to outlive the background
+// thread it manages.
+class CompositorThread {
+ public:
+  // |main_listener| refers to the central IPC message listener that lives on
+  // the main thread, where all incoming IPC messages are first handled.
+  explicit CompositorThread(IPC::Channel::Listener* main_listener);
+  ~CompositorThread();
+
+  // This MessageFilter should be added to allow input events to be redirected
+  // to the compositor's thread.
+  IPC::ChannelProxy::MessageFilter* GetMessageFilter() const;
+
+  // Callable from the main thread or the compositor's thread.
+  void AddCompositor(int routing_id, int compositor_id);
+
+ private:
+  // Callback only from the compositor's thread.
+  void RemoveCompositor(int routing_id);
+
+  // Called from the compositor's thread.
+  void HandleInputEvent(int routing_id,
+                        const WebKit::WebInputEvent* input_event);
+
+  class CompositorWrapper;
+  friend class CompositorWrapper;
+
+  typedef std::map<int,  // routing_id
+                   linked_ptr<CompositorWrapper> > CompositorMap;
+  CompositorMap compositors_;
+
+  webkit_glue::WebThreadImpl thread_;
+  scoped_refptr<InputEventFilter> filter_;
+};
+
+#endif  // CONTENT_RENDERER_GPU_COMPOSITOR_THREAD_H_