Added implementation of RemoteMediaStreams.

content/renderer/media/remote_media_stream_impl.cc

+// Copyright (c) 2013 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.
+
+#include "content/renderer/media/remote_media_stream_impl.h"
+
+#include <string>
+
+#include "base/logging.h"
+#include "base/utf_string_conversions.h"
+#include "content/renderer/media/media_stream_extra_data.h"
+#include "third_party/WebKit/Source/Platform/chromium/public/WebString.h"
+
+namespace content {
+
+// RemoteMediaStreamTrackObserver is responsible for listening on change
+// notification on a remote webrtc MediaStreamTrack and notify WebKit.
+class RemoteMediaStreamTrackObserver
+    : NON_EXPORTED_BASE(public webrtc::ObserverInterface),
+      NON_EXPORTED_BASE(public base::NonThreadSafe) {
+ public:
+  RemoteMediaStreamTrackObserver(
+      webrtc::MediaStreamTrackInterface* webrtc_track,
+      const WebKit::WebMediaStreamTrack& webkit_track);
+  virtual ~RemoteMediaStreamTrackObserver();
+
+  webrtc::MediaStreamTrackInterface* observered_track() {
+    return webrtc_track_;
+  }
+  const WebKit::WebMediaStreamTrack& webkit_track() { return webkit_track_; }
+
+ private:
+  // webrtc::ObserverInterface implementation.
+  virtual void OnChanged() OVERRIDE;
+
+  webrtc::MediaStreamTrackInterface::TrackState state_;
+  scoped_refptr<webrtc::MediaStreamTrackInterface> webrtc_track_;
+  WebKit::WebMediaStreamTrack webkit_track_;
+
+  DISALLOW_COPY_AND_ASSIGN(RemoteMediaStreamTrackObserver);
+};
+
+}  // namespace content
+
+namespace {
+
+void InitializeWebkitTrack(webrtc::MediaStreamTrackInterface* track,
+                           WebKit::WebMediaStreamTrack* webkit_track,
+                           WebKit::WebMediaStreamSource::Type type) {
+  WebKit::WebMediaStreamSource webkit_source;
+  WebKit::WebString webkit_track_id(UTF8ToUTF16(track->id()));
+
+  webkit_source.initialize(webkit_track_id, type, webkit_track_id);
+  webkit_track->initialize(webkit_track_id, webkit_source);
+}
+
+content::RemoteMediaStreamTrackObserver* FindTrackObserver(
+    webrtc::MediaStreamTrackInterface* track,
+    const ScopedVector<content::RemoteMediaStreamTrackObserver>& observers) {
+  ScopedVector<content::RemoteMediaStreamTrackObserver>::const_iterator it =
+      observers.begin();
+  for (; it != observers.end(); ++it) {
+    if ((*it)->observered_track() == track)
+      return *it;
+  }
+  return NULL;
+}
+
+} // namespace anonymous
+
+namespace content {
+
+RemoteMediaStreamTrackObserver::RemoteMediaStreamTrackObserver(
+    webrtc::MediaStreamTrackInterface* webrtc_track,
+    const WebKit::WebMediaStreamTrack& webkit_track)
+    : state_(webrtc_track->state()),
+      webrtc_track_(webrtc_track),
+      webkit_track_(webkit_track) {
+  webrtc_track->RegisterObserver(this);
+}
+
+RemoteMediaStreamTrackObserver::~RemoteMediaStreamTrackObserver() {
+  webrtc_track_->UnregisterObserver(this);
+}
+
+void RemoteMediaStreamTrackObserver::OnChanged() {
+  DCHECK(CalledOnValidThread());
+
+  webrtc::MediaStreamTrackInterface::TrackState state = webrtc_track_->state();
+  if (state == state_)
+    return;
+
+  state_ = state;
+  switch (state) {
+    case webrtc::MediaStreamTrackInterface::kInitializing:
+      // Ignore the kInitializing state since there is no match in
+      // WebMediaStreamSource::ReadyState.
+      break;
+    case webrtc::MediaStreamTrackInterface::kLive:
+      webkit_track_.source().setReadyState(
+          WebKit::WebMediaStreamSource::ReadyStateLive);
+      break;
+    case webrtc::MediaStreamTrackInterface::kEnded:
+      webkit_track_.source().setReadyState(
+          WebKit::WebMediaStreamSource::ReadyStateEnded);
+      break;
+    default:
+      NOTREACHED();
+      break;
+  }
+}
+
+RemoteMediaStreamImpl::RemoteMediaStreamImpl(
+    webrtc::MediaStreamInterface* webrtc_stream)
+    : webrtc_stream_(webrtc_stream) {
+  webrtc_stream_->RegisterObserver(this);
+
+  webrtc::AudioTrackVector webrtc_audio_tracks =
+      webrtc_stream_->GetAudioTracks();
+  WebKit::WebVector<WebKit::WebMediaStreamTrack> webkit_audio_tracks(
+      webrtc_audio_tracks.size());
+
+  // Initialize WebKit audio tracks.
+  size_t i = 0;
+  for (; i < webrtc_audio_tracks.size(); ++i) {
+    webrtc::AudioTrackInterface* audio_track = webrtc_audio_tracks[i];
+    DCHECK(audio_track);
+    InitializeWebkitTrack(audio_track,  &webkit_audio_tracks[i],
+                          WebKit::WebMediaStreamSource::TypeAudio);
+    audio_track_observers_.push_back(
+        new RemoteMediaStreamTrackObserver(audio_track,
+                                           webkit_audio_tracks[i]));
+  }
+
+  // Initialize WebKit video tracks.
+  webrtc::VideoTrackVector webrtc_video_tracks =
+        webrtc_stream_->GetVideoTracks();
+  WebKit::WebVector<WebKit::WebMediaStreamTrack> webkit_video_tracks(
+       webrtc_video_tracks.size());
+  for (i = 0; i < webrtc_video_tracks.size(); ++i) {
+    webrtc::VideoTrackInterface* video_track = webrtc_video_tracks[i];
+    DCHECK(video_track);
+    InitializeWebkitTrack(video_track,  &webkit_video_tracks[i],
+                          WebKit::WebMediaStreamSource::TypeVideo);
+    video_track_observers_.push_back(
+        new RemoteMediaStreamTrackObserver(video_track,
+                                           webkit_video_tracks[i]));
+  }
+
+  webkit_stream_.initialize(UTF8ToUTF16(webrtc_stream->label()),
+                            webkit_audio_tracks, webkit_video_tracks);
+  webkit_stream_.setExtraData(new MediaStreamExtraData(webrtc_stream, false));
+}
+
+RemoteMediaStreamImpl::~RemoteMediaStreamImpl() {
+  webrtc_stream_->UnregisterObserver(this);
+}
+
+void RemoteMediaStreamImpl::OnChanged() {
+  // Find removed audio tracks.
+  ScopedVector<RemoteMediaStreamTrackObserver>::iterator audio_it =
+      audio_track_observers_.begin();
+  while (audio_it != audio_track_observers_.end()) {
+    std::string track_id = (*audio_it)->observered_track()->id();
+    if (webrtc_stream_->FindAudioTrack(track_id) == NULL) {
+       webkit_stream_.removeTrack((*audio_it)->webkit_track());
+       audio_it = audio_track_observers_.erase(audio_it);
+    } else {
+      ++audio_it;
+    }
+  }
+
+  // Find removed video tracks.
+  ScopedVector<RemoteMediaStreamTrackObserver>::iterator video_it =
+      video_track_observers_.begin();
+  while (video_it != video_track_observers_.end()) {
+    std::string track_id = (*video_it)->observered_track()->id();
+    if (webrtc_stream_->FindVideoTrack(track_id) == NULL) {
+      webkit_stream_.removeTrack((*video_it)->webkit_track());
+      video_it = video_track_observers_.erase(video_it);
+    } else {
+      ++video_it;
+    }
+  }
+
+  // Find added audio tracks.
+  webrtc::AudioTrackVector webrtc_audio_tracks =
+      webrtc_stream_->GetAudioTracks();
+  for (webrtc::AudioTrackVector::iterator it = webrtc_audio_tracks.begin();
+       it != webrtc_audio_tracks.end(); ++it) {
+    if (!FindTrackObserver(*it, audio_track_observers_)) {
+      WebKit::WebMediaStreamTrack new_track;
+      InitializeWebkitTrack(*it, &new_track,
+                            WebKit::WebMediaStreamSource::TypeAudio);
+      audio_track_observers_.push_back(
+          new RemoteMediaStreamTrackObserver(*it, new_track));
+      webkit_stream_.addTrack(new_track);
+    }
+  }
+
+  // Find added video tracks.
+  webrtc::VideoTrackVector webrtc_video_tracks =
+      webrtc_stream_->GetVideoTracks();
+  for (webrtc::VideoTrackVector::iterator it = webrtc_video_tracks.begin();
+       it != webrtc_video_tracks.end(); ++it) {
+    if (!FindTrackObserver(*it, video_track_observers_)) {
+      WebKit::WebMediaStreamTrack new_track;
+      InitializeWebkitTrack(*it, &new_track,
+                            WebKit::WebMediaStreamSource::TypeVideo);
+      video_track_observers_.push_back(
+          new RemoteMediaStreamTrackObserver(*it, new_track));
+      webkit_stream_.addTrack(new_track);
+    }
+  }
+}
+
+}  // namespace content