1/*
2 * libjingle
3 * Copyright 2015 Google Inc.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 *
8 *  1. Redistributions of source code must retain the above copyright notice,
9 *     this list of conditions and the following disclaimer.
10 *  2. Redistributions in binary form must reproduce the above copyright notice,
11 *     this list of conditions and the following disclaimer in the documentation
12 *     and/or other materials provided with the distribution.
13 *  3. The name of the author may not be used to endorse or promote products
14 *     derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
17 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
18 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
19 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28#include "talk/app/webrtc/mediastreamobserver.h"
29
30#include <algorithm>
31
32namespace webrtc {
33
34MediaStreamObserver::MediaStreamObserver(MediaStreamInterface* stream)
35    : stream_(stream),
36      cached_audio_tracks_(stream->GetAudioTracks()),
37      cached_video_tracks_(stream->GetVideoTracks()) {
38  stream_->RegisterObserver(this);
39}
40
41MediaStreamObserver::~MediaStreamObserver() {
42  stream_->UnregisterObserver(this);
43}
44
45void MediaStreamObserver::OnChanged() {
46  AudioTrackVector new_audio_tracks = stream_->GetAudioTracks();
47  VideoTrackVector new_video_tracks = stream_->GetVideoTracks();
48
49  // Find removed audio tracks.
50  for (const auto& cached_track : cached_audio_tracks_) {
51    auto it = std::find_if(
52        new_audio_tracks.begin(), new_audio_tracks.end(),
53        [cached_track](const AudioTrackVector::value_type& new_track) {
54          return new_track->id().compare(cached_track->id()) == 0;
55        });
56    if (it == new_audio_tracks.end()) {
57      SignalAudioTrackRemoved(cached_track.get(), stream_);
58    }
59  }
60
61  // Find added audio tracks.
62  for (const auto& new_track : new_audio_tracks) {
63    auto it = std::find_if(
64        cached_audio_tracks_.begin(), cached_audio_tracks_.end(),
65        [new_track](const AudioTrackVector::value_type& cached_track) {
66          return new_track->id().compare(cached_track->id()) == 0;
67        });
68    if (it == cached_audio_tracks_.end()) {
69      SignalAudioTrackAdded(new_track.get(), stream_);
70    }
71  }
72
73  // Find removed video tracks.
74  for (const auto& cached_track : cached_video_tracks_) {
75    auto it = std::find_if(
76        new_video_tracks.begin(), new_video_tracks.end(),
77        [cached_track](const VideoTrackVector::value_type& new_track) {
78          return new_track->id().compare(cached_track->id()) == 0;
79        });
80    if (it == new_video_tracks.end()) {
81      SignalVideoTrackRemoved(cached_track.get(), stream_);
82    }
83  }
84
85  // Find added video tracks.
86  for (const auto& new_track : new_video_tracks) {
87    auto it = std::find_if(
88        cached_video_tracks_.begin(), cached_video_tracks_.end(),
89        [new_track](const VideoTrackVector::value_type& cached_track) {
90          return new_track->id().compare(cached_track->id()) == 0;
91        });
92    if (it == cached_video_tracks_.end()) {
93      SignalVideoTrackAdded(new_track.get(), stream_);
94    }
95  }
96
97  cached_audio_tracks_ = new_audio_tracks;
98  cached_video_tracks_ = new_video_tracks;
99}
100
101}  // namespace webrtc
102