1// Copyright 2014 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef CONTENT_RENDERER_MEDIA_MEDIA_STREAM_H_
6#define CONTENT_RENDERER_MEDIA_MEDIA_STREAM_H_
7
8#include <string>
9#include <vector>
10
11#include "base/callback.h"
12#include "base/compiler_specific.h"
13#include "base/threading/thread_checker.h"
14#include "content/common/content_export.h"
15#include "third_party/WebKit/public/platform/WebMediaStream.h"
16
17namespace webrtc {
18class MediaStreamInterface;
19}
20
21namespace content {
22
23// MediaStreamObserver can be used to get notifications of when a track is
24// added or removed from a MediaStream.
25class MediaStreamObserver {
26 public:
27  // TrackAdded is called |track| is added to the observed MediaStream.
28  virtual void TrackAdded(const blink::WebMediaStreamTrack& track)  = 0;
29  // TrackRemoved is called |track| is added to the observed MediaStream.
30  virtual void TrackRemoved(const blink::WebMediaStreamTrack& track) = 0;
31
32 protected:
33  virtual ~MediaStreamObserver() {}
34};
35
36// MediaStream is the Chrome representation of blink::WebMediaStream.
37// It is owned by blink::WebMediaStream as blink::WebMediaStream::ExtraData.
38// Its lifetime is the same as the blink::WebMediaStream instance it belongs to.
39class CONTENT_EXPORT MediaStream
40    : NON_EXPORTED_BASE(public blink::WebMediaStream::ExtraData) {
41 public:
42  // Constructor for local MediaStreams.
43  MediaStream(const blink::WebMediaStream& stream);
44
45  // Constructor for remote MediaStreams.
46  // TODO(xians): Remove once the audio renderer don't separate between local
47  // and remotely generated streams.
48  explicit MediaStream(webrtc::MediaStreamInterface* webrtc_stream);
49
50  virtual ~MediaStream();
51
52  // Returns an instance of MediaStream. This method will never return NULL.
53  static MediaStream* GetMediaStream(
54      const blink::WebMediaStream& stream);
55
56  // Returns a libjingle representation of a remote MediaStream.
57  // TODO(xians): Remove once the audio renderer don't separate between local
58  // and remotely generated streams.
59  static webrtc::MediaStreamInterface* GetAdapter(
60      const blink::WebMediaStream& stream);
61
62  // Adds an observer to this MediaStream. Its the callers responsibility to
63  // remove the observer before the destruction of the MediaStream.
64  void AddObserver(MediaStreamObserver* observer);
65  void RemoveObserver(MediaStreamObserver* observer);
66
67  // TODO(xians): Remove |is_local| once AudioTracks can be rendered the same
68  // way regardless if they are local or remote.
69  bool is_local() const { return is_local_; }
70
71  // Called by MediaStreamCenter when a track has been added to a stream stream.
72  bool AddTrack(const blink::WebMediaStreamTrack& track);
73
74  // Called by MediaStreamCenter when a track has been removed from |stream|.
75  bool RemoveTrack(const blink::WebMediaStreamTrack& track);
76
77 protected:
78  virtual webrtc::MediaStreamInterface* GetWebRtcAdapter(
79      const blink::WebMediaStream& stream);
80
81 private:
82  base::ThreadChecker thread_checker_;
83  const bool is_local_;
84  const std::string label_;
85  std::vector<MediaStreamObserver*> observers_;
86
87  // TODO(xians): Remove once the audio renderer don't separate between local
88  // and remotely generated streams.
89  scoped_refptr<webrtc::MediaStreamInterface> webrtc_media_stream_;
90
91  DISALLOW_COPY_AND_ASSIGN(MediaStream);
92};
93
94}  // namespace content
95
96#endif  // CONTENT_RENDERER_MEDIA_MEDIA_STREAM_H_
97