| /* | 
 |  *  Copyright 2011 The WebRTC project authors. All Rights Reserved. | 
 |  * | 
 |  *  Use of this source code is governed by a BSD-style license | 
 |  *  that can be found in the LICENSE file in the root of the source | 
 |  *  tree. An additional intellectual property rights grant can be found | 
 |  *  in the file PATENTS.  All contributing project authors may | 
 |  *  be found in the AUTHORS file in the root of the source tree. | 
 |  */ | 
 |  | 
 | #ifndef WEBRTC_API_MEDIASTREAMTRACK_H_ | 
 | #define WEBRTC_API_MEDIASTREAMTRACK_H_ | 
 |  | 
 | #include <string> | 
 |  | 
 | #include "webrtc/api/mediastreaminterface.h" | 
 | #include "webrtc/api/notifier.h" | 
 |  | 
 | namespace webrtc { | 
 |  | 
 | // MediaTrack implements the interface common to AudioTrackInterface and | 
 | // VideoTrackInterface. | 
 | template <typename T> | 
 | class MediaStreamTrack : public Notifier<T> { | 
 |  public: | 
 |   typedef typename T::TrackState TypedTrackState; | 
 |  | 
 |   std::string id() const override { return id_; } | 
 |   MediaStreamTrackInterface::TrackState state() const override { | 
 |     return state_; | 
 |   } | 
 |   bool enabled() const override { return enabled_; } | 
 |   bool set_enabled(bool enable) override { | 
 |     bool fire_on_change = (enable != enabled_); | 
 |     enabled_ = enable; | 
 |     if (fire_on_change) { | 
 |       Notifier<T>::FireOnChanged(); | 
 |     } | 
 |     return fire_on_change; | 
 |   } | 
 |  | 
 |  protected: | 
 |   explicit MediaStreamTrack(const std::string& id) | 
 |       : enabled_(true), id_(id), state_(MediaStreamTrackInterface::kLive) {} | 
 |  | 
 |   bool set_state(MediaStreamTrackInterface::TrackState new_state) { | 
 |     bool fire_on_change = (state_ != new_state); | 
 |     state_ = new_state; | 
 |     if (fire_on_change) | 
 |       Notifier<T>::FireOnChanged(); | 
 |     return true; | 
 |   } | 
 |  | 
 |  private: | 
 |   bool enabled_; | 
 |   std::string id_; | 
 |   MediaStreamTrackInterface::TrackState state_; | 
 | }; | 
 |  | 
 | }  // namespace webrtc | 
 |  | 
 | #endif  // WEBRTC_API_MEDIASTREAMTRACK_H_ |