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 #include "pc/media_stream_observer.h"
12
13 #include <functional>
14 #include <string>
15 #include <utility>
16 #include <vector>
17
18 #include "absl/algorithm/container.h"
19
20 namespace webrtc {
21
MediaStreamObserver(MediaStreamInterface * stream,std::function<void (AudioTrackInterface *,MediaStreamInterface *)> audio_track_added_callback,std::function<void (AudioTrackInterface *,MediaStreamInterface *)> audio_track_removed_callback,std::function<void (VideoTrackInterface *,MediaStreamInterface *)> video_track_added_callback,std::function<void (VideoTrackInterface *,MediaStreamInterface *)> video_track_removed_callback)22 MediaStreamObserver::MediaStreamObserver(
23 MediaStreamInterface* stream,
24 std::function<void(AudioTrackInterface*, MediaStreamInterface*)>
25 audio_track_added_callback,
26 std::function<void(AudioTrackInterface*, MediaStreamInterface*)>
27 audio_track_removed_callback,
28 std::function<void(VideoTrackInterface*, MediaStreamInterface*)>
29 video_track_added_callback,
30 std::function<void(VideoTrackInterface*, MediaStreamInterface*)>
31 video_track_removed_callback)
32 : stream_(stream),
33 cached_audio_tracks_(stream->GetAudioTracks()),
34 cached_video_tracks_(stream->GetVideoTracks()),
35 audio_track_added_callback_(std::move(audio_track_added_callback)),
36 audio_track_removed_callback_(std::move(audio_track_removed_callback)),
37 video_track_added_callback_(std::move(video_track_added_callback)),
38 video_track_removed_callback_(std::move(video_track_removed_callback)) {
39 stream_->RegisterObserver(this);
40 }
41
~MediaStreamObserver()42 MediaStreamObserver::~MediaStreamObserver() {
43 stream_->UnregisterObserver(this);
44 }
45
OnChanged()46 void MediaStreamObserver::OnChanged() {
47 AudioTrackVector new_audio_tracks = stream_->GetAudioTracks();
48 VideoTrackVector new_video_tracks = stream_->GetVideoTracks();
49
50 // Find removed audio tracks.
51 for (const auto& cached_track : cached_audio_tracks_) {
52 if (absl::c_none_of(
53 new_audio_tracks,
54 [cached_track](const AudioTrackVector::value_type& new_track) {
55 return new_track->id() == cached_track->id();
56 })) {
57 audio_track_removed_callback_(cached_track.get(), stream_.get());
58 }
59 }
60
61 // Find added audio tracks.
62 for (const auto& new_track : new_audio_tracks) {
63 if (absl::c_none_of(
64 cached_audio_tracks_,
65 [new_track](const AudioTrackVector::value_type& cached_track) {
66 return new_track->id() == cached_track->id();
67 })) {
68 audio_track_added_callback_(new_track.get(), stream_.get());
69 }
70 }
71
72 // Find removed video tracks.
73 for (const auto& cached_track : cached_video_tracks_) {
74 if (absl::c_none_of(
75 new_video_tracks,
76 [cached_track](const VideoTrackVector::value_type& new_track) {
77 return new_track->id() == cached_track->id();
78 })) {
79 video_track_removed_callback_(cached_track.get(), stream_.get());
80 }
81 }
82
83 // Find added video tracks.
84 for (const auto& new_track : new_video_tracks) {
85 if (absl::c_none_of(
86 cached_video_tracks_,
87 [new_track](const VideoTrackVector::value_type& cached_track) {
88 return new_track->id() == cached_track->id();
89 })) {
90 video_track_added_callback_(new_track.get(), stream_.get());
91 }
92 }
93
94 cached_audio_tracks_ = new_audio_tracks;
95 cached_video_tracks_ = new_video_tracks;
96 }
97
98 } // namespace webrtc
99