content/renderer/media/media_stream_impl.h

// Copyright (c) 2012 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.

#ifndef CONTENT_RENDERER_MEDIA_MEDIA_STREAM_IMPL_H_
#define CONTENT_RENDERER_MEDIA_MEDIA_STREAM_IMPL_H_

#include <string>
#include <vector>

#include "base/basictypes.h"
#include "base/compiler_specific.h"
#include "base/memory/ref_counted.h"
#include "base/memory/scoped_ptr.h"
#include "base/memory/scoped_vector.h"
#include "base/memory/weak_ptr.h"
#include "base/threading/non_thread_safe.h"
#include "content/common/content_export.h"
#include "content/public/renderer/render_view_observer.h"
#include "content/renderer/media/media_stream_client.h"
#include "content/renderer/media/media_stream_dispatcher_eventhandler.h"
#include "third_party/WebKit/public/platform/WebMediaStream.h"
#include "third_party/WebKit/public/platform/WebMediaStreamSource.h"
#include "third_party/WebKit/public/platform/WebVector.h"
#include "third_party/WebKit/public/web/WebUserMediaClient.h"
#include "third_party/WebKit/public/web/WebUserMediaRequest.h"
#include "third_party/libjingle/source/talk/app/webrtc/mediastreaminterface.h"

namespace content {
class MediaStreamAudioRenderer;
class MediaStreamDependencyFactory;
class MediaStreamDispatcher;
class MediaStreamSourceExtraData;
class WebRtcAudioRenderer;
class WebRtcLocalAudioRenderer;

// MediaStreamImpl is a delegate for the Media Stream API messages used by
// WebKit. It ties together WebKit, native PeerConnection in libjingle and
// MediaStreamManager (via MediaStreamDispatcher and MediaStreamDispatcherHost)
// in the browser process. It must be created, called and destroyed on the
// render thread.
// MediaStreamImpl have weak pointers to a MediaStreamDispatcher.
class CONTENT_EXPORT MediaStreamImpl
    : public RenderViewObserver,
      NON_EXPORTED_BASE(public WebKit::WebUserMediaClient),
      NON_EXPORTED_BASE(public MediaStreamClient),
      public MediaStreamDispatcherEventHandler,
      public base::SupportsWeakPtr<MediaStreamImpl>,
      NON_EXPORTED_BASE(public base::NonThreadSafe) {
 public:
  MediaStreamImpl(
      RenderView* render_view,
      MediaStreamDispatcher* media_stream_dispatcher,
      MediaStreamDependencyFactory* dependency_factory);
  virtual ~MediaStreamImpl();

  // WebKit::WebUserMediaClient implementation
  virtual void requestUserMedia(
      const WebKit::WebUserMediaRequest& user_media_request) OVERRIDE;
  virtual void cancelUserMediaRequest(
      const WebKit::WebUserMediaRequest& user_media_request) OVERRIDE;

  // MediaStreamClient implementation.
  virtual bool IsMediaStream(const GURL& url) OVERRIDE;
  virtual scoped_refptr<VideoFrameProvider> GetVideoFrameProvider(
      const GURL& url,
      const base::Closure& error_cb,
      const VideoFrameProvider::RepaintCB& repaint_cb) OVERRIDE;
  virtual scoped_refptr<MediaStreamAudioRenderer>
      GetAudioRenderer(const GURL& url) OVERRIDE;

  // MediaStreamDispatcherEventHandler implementation.
  virtual void OnStreamGenerated(
      int request_id,
      const std::string& label,
      const StreamDeviceInfoArray& audio_array,
      const StreamDeviceInfoArray& video_array) OVERRIDE;
  virtual void OnStreamGenerationFailed(int request_id) OVERRIDE;
  virtual void OnStopGeneratedStream(const std::string& label) OVERRIDE;
  virtual void OnDevicesEnumerated(
      int request_id,
      const StreamDeviceInfoArray& device_array) OVERRIDE;
  virtual void OnDevicesEnumerationFailed(int request_id) OVERRIDE;
  virtual void OnDeviceOpened(
      int request_id,
      const std::string& label,
      const StreamDeviceInfo& device_info) OVERRIDE;
  virtual void OnDeviceOpenFailed(int request_id) OVERRIDE;

  // RenderViewObserver OVERRIDE
  virtual void FrameDetached(WebKit::WebFrame* frame) OVERRIDE;
  virtual void FrameWillClose(WebKit::WebFrame* frame) OVERRIDE;

 protected:
  void OnLocalSourceStop(const WebKit::WebMediaStreamSource& source);

  void OnLocalMediaStreamStop(const std::string& label);

  // Callback function triggered when all native (libjingle) versions of the
  // underlying media sources have been created and started.
  // |web_stream| is a raw pointer to the web_stream in
  // UserMediaRequests::web_stream for which the underlying sources have been
  // created.
  void OnCreateNativeSourcesComplete(
      WebKit::WebMediaStream* web_stream,
      bool request_succeeded);

  // This function is virtual for test purposes. A test can override this to
  // test requesting local media streams. The function notifies WebKit that the
  // |request| have completed and generated the MediaStream |stream|.
  virtual void CompleteGetUserMediaRequest(
      const WebKit::WebMediaStream& stream,
      WebKit::WebUserMediaRequest* request_info,
      bool request_succeeded);

  // Returns the WebKit representation of a MediaStream given an URL.
  // This is virtual for test purposes.
  virtual WebKit::WebMediaStream GetMediaStream(const GURL& url);

 private:
  // Structure for storing information about a WebKit request to create a
  // MediaStream.
  struct UserMediaRequestInfo {
    UserMediaRequestInfo(int request_id,
                         WebKit::WebFrame* frame,
                         const WebKit::WebUserMediaRequest& request,
                         bool enable_automatic_output_device_selection);
    ~UserMediaRequestInfo();
    int request_id;
    // True if MediaStreamDispatcher has generated the stream, see
    // OnStreamGenerated.
    bool generated;
    const bool enable_automatic_output_device_selection;
    WebKit::WebFrame* frame;  // WebFrame that requested the MediaStream.
    WebKit::WebMediaStream web_stream;
    WebKit::WebUserMediaRequest request;
    std::vector<WebKit::WebMediaStreamSource> sources;
  };
  typedef ScopedVector<UserMediaRequestInfo> UserMediaRequests;

  struct LocalStreamSource {
    LocalStreamSource(WebKit::WebFrame* frame,
                      const WebKit::WebMediaStreamSource& source)
        : frame(frame), source(source) {
    }
    // |frame| is the WebFrame that requested |source|. NULL in unit tests.
    // TODO(perkj): Change so that |frame| is not NULL in unit tests.
    WebKit::WebFrame* frame;
    WebKit::WebMediaStreamSource source;
  };
  typedef std::vector<LocalStreamSource> LocalStreamSources;

  // Creates a WebKit representation of stream sources based on
  // |devices| from the MediaStreamDispatcher.
  void CreateWebKitSourceVector(
      const std::string& label,
      const StreamDeviceInfoArray& devices,
      WebKit::WebMediaStreamSource::Type type,
      WebKit::WebFrame* frame,
      WebKit::WebVector<WebKit::WebMediaStreamSource>& webkit_sources);

  UserMediaRequestInfo* FindUserMediaRequestInfo(int request_id);
  UserMediaRequestInfo* FindUserMediaRequestInfo(
      WebKit::WebMediaStream* web_stream);
  UserMediaRequestInfo* FindUserMediaRequestInfo(
      const WebKit::WebUserMediaRequest& request);
  UserMediaRequestInfo* FindUserMediaRequestInfo(const std::string& label);
  void DeleteUserMediaRequestInfo(UserMediaRequestInfo* request);

  // Returns the source that use a device with |device.session_id|
  // and |device.device.id|. NULL if such source doesn't exist.
  const WebKit::WebMediaStreamSource* FindLocalSource(
      const StreamDeviceInfo& device) const;

  // Returns true if |source| exists in |user_media_requests_|
  bool FindSourceInRequests(const WebKit::WebMediaStreamSource& source) const;

  void StopLocalSource(const WebKit::WebMediaStreamSource& source,
                       bool notify_dispatcher);
  // Stops all local sources that don't exist in exist in
  // |user_media_requests_|.
  void StopUnreferencedSources(bool notify_dispatcher);

  scoped_refptr<VideoFrameProvider>
  CreateVideoFrameProvider(
      webrtc::MediaStreamInterface* stream,
      const base::Closure& error_cb,
      const VideoFrameProvider::RepaintCB& repaint_cb);
  scoped_refptr<WebRtcAudioRenderer> CreateRemoteAudioRenderer(
      webrtc::MediaStreamInterface* stream);
  scoped_refptr<WebRtcLocalAudioRenderer> CreateLocalAudioRenderer(
      webrtc::MediaStreamInterface* stream);

  // Returns a valid session id if a single capture device is currently open
  // (and then the matching session_id), otherwise -1.
  // This is used to pass on a session id to a webrtc audio renderer (either
  // local or remote), so that audio will be rendered to a matching output
  // device, should one exist.
  // Note that if there are more than one open capture devices the function
  // will not be able to pick an appropriate device and return false.
  bool GetAuthorizedDeviceInfoForAudioRenderer(
      int* session_id, int* output_sample_rate, int* output_buffer_size);

  // Weak ref to a MediaStreamDependencyFactory, owned by the RenderThread.
  // It's valid for the lifetime of RenderThread.
  MediaStreamDependencyFactory* dependency_factory_;

  // media_stream_dispatcher_ is a weak reference, owned by RenderView. It's
  // valid for the lifetime of RenderView.
  MediaStreamDispatcher* media_stream_dispatcher_;

  UserMediaRequests user_media_requests_;

  LocalStreamSources local_sources_;

  DISALLOW_COPY_AND_ASSIGN(MediaStreamImpl);
};

}  // namespace content

#endif  // CONTENT_RENDERER_MEDIA_MEDIA_STREAM_IMPL_H_