Gamepad API: add support for connection events

content/renderer/gamepad_shared_memory_reader.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_GAMEPAD_SHARED_MEMORY_READER_H_
 #define CONTENT_RENDERER_GAMEPAD_SHARED_MEMORY_READER_H_
 
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/shared_memory.h"
+#include "content/common/gamepad_messages.h"
+#include "ipc/ipc_channel_proxy.h"
 #include "third_party/WebKit/public/platform/WebGamepads.h"
 
 namespace content {
 
 struct GamepadHardwareBuffer;
 
-class GamepadSharedMemoryReader {
+class GamepadSharedMemoryReader : public IPC::ChannelProxy::MessageFilter {
  public:
-  GamepadSharedMemoryReader();
+  GamepadSharedMemoryReader(
+      const scoped_refptr<base::MessageLoopProxy>& io_message_loop);
+  void SampleGamepads(blink::WebGamepads&);
+  void SetGamepadListener(blink::WebGamepadListener* listener);
+
+ protected:
   virtual ~GamepadSharedMemoryReader();
-  void SampleGamepads(blink::WebGamepads&);
 
  private:
+  bool EnsurePollingStarted();
+
+  // IPC::ChannelProxy::MessageFilter override. Called on |io_message_loop|.
+  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
+
+  // Called when a gamepad is connected to the system
+  void OnGamepadConnected(const GamepadConnectionEventMessageParams& params);
+
+  // Called when a gamepad is disconnected from the system
+  void OnGamepadDisconnected(const GamepadConnectionEventMessageParams& params);
+
+  void DispatchGamepadConnected(int index, const blink::WebGamepad& gamepad);
+  void DispatchGamepadDisconnected(int index, const blink::WebGamepad& gamepad);
+
+  // Message loop on which IPC calls are driven.
+  const scoped_refptr<base::MessageLoopProxy> io_message_loop_;
+
+  // Main thread's message loop.
+  scoped_refptr<base::MessageLoopProxy> main_message_loop_;
+
   base::SharedMemoryHandle renderer_shared_memory_handle_;
   scoped_ptr<base::SharedMemory> renderer_shared_memory_;
   GamepadHardwareBuffer* gamepad_hardware_buffer_;
+  blink::WebGamepadListener* gamepad_listener_;
 
+  bool is_polling_;
   bool ever_interacted_with_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_GAMEPAD_SHARED_MEMORY_READER_H_