content/browser/renderer_host/media/media_stream_provider.h

   1 // Copyright (c) 2012 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 // MediaStreamProvider is used to capture media of the types defined in
   6 // MediaStreamType. There is only one MediaStreamProvider instance per media
   7 // type and a MediaStreamProvider instance can have only one registered
   8 // listener.
   9 // The MediaStreamManager is expected to be called on Browser::IO thread and
  10 // the listener will be called on the same thread.
  11
  12 #ifndef CONTENT_BROWSER_RENDERER_HOST_MEDIA_MEDIA_STREAM_PROVIDER_H_
  13 #define CONTENT_BROWSER_RENDERER_HOST_MEDIA_MEDIA_STREAM_PROVIDER_H_
  14
  15 #include <list>
  16 #include <string>
  17
  18 #include "base/memory/ref_counted.h"
  19 #include "content/common/content_export.h"
  20 #include "content/common/media/media_stream_options.h"
  21
  22 namespace base {
  23 class MessageLoopProxy;
  24 }
  25
  26 namespace content {
  27
  28 enum MediaStreamProviderError {
  29   kMediaStreamOk = 0,
  30   kInvalidMediaStreamType,
  31   kInvalidSession,
  32   kUnknownSession,
  33   kDeviceNotAvailable,
  34   kDeviceAlreadyInUse,
  35   kUnknownError
  36 };
  37
  38 enum { kInvalidMediaCaptureSessionId = 0xFFFFFFFF };
  39
  40 // Callback class used by MediaStreamProvider.
  41 class CONTENT_EXPORT MediaStreamProviderListener {
  42  public:
  43   // Called by a MediaStreamProvider when a stream has been opened.
  44   virtual void Opened(MediaStreamType stream_type,
  45                       int capture_session_id) = 0;
  46
  47   // Called by a MediaStreamProvider when a stream has been closed.
  48   virtual void Closed(MediaStreamType stream_type,
  49                       int capture_session_id) = 0;
  50
  51   // Called by a MediaStreamProvider when available devices has been enumerated.
  52   virtual void DevicesEnumerated(MediaStreamType stream_type,
  53                                  const StreamDeviceInfoArray& devices) = 0;
  54
  55   // Called by a MediaStreamProvider when an error has occured.
  56   virtual void Error(MediaStreamType stream_type,
  57                      int capture_session_id,
  58                      MediaStreamProviderError error) = 0;
  59
  60  protected:
  61   virtual ~MediaStreamProviderListener() {}
  62 };
  63
  64 // Implemented by a manager class providing captured media.
  65 class CONTENT_EXPORT MediaStreamProvider
  66     : public base::RefCountedThreadSafe<MediaStreamProvider> {
  67  public:
  68   // Registers a listener and a device message loop.
  69   virtual void Register(MediaStreamProviderListener* listener,
  70                         base::MessageLoopProxy* device_thread_loop) = 0;
  71
  72   // Unregisters the previously registered listener.
  73   virtual void Unregister() = 0;
  74
  75   // Enumerates existing capture devices and calls |DevicesEnumerated|.
  76   virtual void EnumerateDevices(MediaStreamType stream_type) = 0;
  77
  78   // Opens the specified device. The device is not started and it is still
  79   // possible for other applications to open the device before the device is
  80   // started. |Opened| is called when the device is opened.
  81   // kInvalidMediaCaptureSessionId is returned on error.
  82   virtual int Open(const StreamDeviceInfo& device) = 0;
  83
  84   // Closes the specified device and calls |Closed| when done.
  85   virtual void Close(int capture_session_id) = 0;
  86
  87  protected:
  88   friend class base::RefCountedThreadSafe<MediaStreamProvider>;
  89   virtual ~MediaStreamProvider() {}
  90 };
  91
  92 }  // namespace content
  93
  94 #endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_MEDIA_STREAM_PROVIDER_H_