1 /*
2  *  Copyright 2015 The WebRTC project authors. All Rights Reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 
11 #ifndef PC_MEDIA_STREAM_OBSERVER_H_
12 #define PC_MEDIA_STREAM_OBSERVER_H_
13 
14 #include "api/media_stream_interface.h"
15 #include "api/scoped_refptr.h"
16 #include "rtc_base/third_party/sigslot/sigslot.h"
17 
18 namespace webrtc {
19 
20 // Helper class which will listen for changes to a stream and emit the
21 // corresponding signals.
22 class MediaStreamObserver : public ObserverInterface {
23  public:
24   explicit MediaStreamObserver(MediaStreamInterface* stream);
25   ~MediaStreamObserver() override;
26 
stream()27   const MediaStreamInterface* stream() const { return stream_; }
28 
29   void OnChanged() override;
30 
31   sigslot::signal2<AudioTrackInterface*, MediaStreamInterface*>
32       SignalAudioTrackAdded;
33   sigslot::signal2<AudioTrackInterface*, MediaStreamInterface*>
34       SignalAudioTrackRemoved;
35   sigslot::signal2<VideoTrackInterface*, MediaStreamInterface*>
36       SignalVideoTrackAdded;
37   sigslot::signal2<VideoTrackInterface*, MediaStreamInterface*>
38       SignalVideoTrackRemoved;
39 
40  private:
41   rtc::scoped_refptr<MediaStreamInterface> stream_;
42   AudioTrackVector cached_audio_tracks_;
43   VideoTrackVector cached_video_tracks_;
44 };
45 
46 }  // namespace webrtc
47 
48 #endif  // PC_MEDIA_STREAM_OBSERVER_H_
49