content/renderer/media/media_stream.h

   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
  17 namespace webrtc {
  18 class MediaStreamInterface;
  19 }
  20
  21 namespace content {
  22
  23 // MediaStreamObserver can be used to get notifications of when a track is
  24 // added or removed from a MediaStream.
  25 class 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.
  39 class 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_