Refactored gamepad polling to support dynamic sources

device/gamepad/gamepad_data_fetcher_manager.h

+// Copyright 2016 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 DEVICE_GAMEPAD_GAMEPAD_DATA_FETCHER_MANAGER_H_
+#define DEVICE_GAMEPAD_GAMEPAD_DATA_FETCHER_MANAGER_H_
+
+#include <memory>
+#include <utility>
+#include <vector>
+
+#include "device/gamepad/gamepad_export.h"
+#include "device/gamepad/gamepad_provider.h"
+
+namespace device {
+
+class GamepadDataFetcherFactory;
+
+class DEVICE_GAMEPAD_EXPORT GamepadDataFetcherManager {
+ public:
+  ~GamepadDataFetcherManager();
+
+  // Returns the GamepadDataFetcherManager singleton.
+  static GamepadDataFetcherManager* GetInstance();
+
+  void AddFactory(GamepadDataFetcherFactory* factory);
+  void RemoveSourceFactory(GamepadSource source);
+
+  // Must be called on the providers polling thread
+  void InitializeProvider(GamepadProvider* provider);
+  void ClearProvider();
+
+ private:
+  GamepadDataFetcherManager();
+
+  void CreateDataFetcherFromFactory(GamepadDataFetcherFactory* factory);
+  void RemoveSourceDataFetcher(GamepadSource* source);
+
+  typedef std::vector<GamepadDataFetcherFactory*> FactoryVector;
+  FactoryVector factories_;
+
+  GamepadProvider* provider_;
+};
+
+}  // namespace device
+
+#endif  // DEVICE_GAMEPAD_GAMEPAD_DATA_FETCHER_MANAGER_H_