Adding MediaStreamManager.

content/browser/renderer_host/media/media_stream_manager.h

+// Copyright (c) 2011 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.
+
+// MediaStreamManager is used to open media capture devices (video supported
+// now). Call flow:
+// 1. GenerateStream is called when a render process wants to use a capture
+//    device.
+// 2. MediaStreamManager will ask MediaStreamDeviceSettings for permission to
+//    use devices and for which device to use.
+// 3. MediaStreamDeviceSettings will request list(s) of available devices, the
+//    requests will be relayed to the corresponding media device manager and the
+//    result will be given to MediaStreamDeviceSettings.
+// 4. MediaStreamDeviceSettings will, by using user settings, pick devices which
+//    devices to use and let MediaStreamManager know the result.
+// 5. MediaStreamManager will call the proper media device manager to open the
+//    device and let the MediaStreamRequester know it has been done.
+
+#ifndef CONTENT_BROWSER_RENDERER_HOST_MEDIA_MEDIA_STREAM_MANAGER_H_
+#define CONTENT_BROWSER_RENDERER_HOST_MEDIA_MEDIA_STREAM_MANAGER_H_
+
+#include <list>
+#include <string>
+#include <vector>
+
+#include "base/lazy_instance.h"
+#include "base/memory/ref_counted.h"
+#include "content/browser/renderer_host/media/media_stream_provider.h"
+#include "content/browser/renderer_host/media/media_stream_settings_requester.h"
+#include "content/common/media/media_stream_options.h"
+
+namespace media_stream {
+
+class MediaStreamDeviceSettings;
+class MediaStreamRequester;
+class VideoCaptureManager;
+
+// MediaStreamManager is used to generate and close new media devices, not to
+// start the media flow.
+// The classes requesting new media streams are answered using
+// MediaStreamManager::Listener.
+class MediaStreamManager : public MediaStreamProviderListener,
+                           public SettingsRequester {
+ public:
+  typedef MediaStreamManager* (AccessorMethod)();
+  static MediaStreamManager* Get();
+  virtual ~MediaStreamManager();
+
+  // Used to access VideoCaptuerManager.
+  VideoCaptureManager* GetVideoCaptureManager();
+
+  // GenerateStream opens new media devices according to |components|. The
+  // request is identified using |label|, which is pointing to an already
+  // created std::string.
+  void GenerateStream(MediaStreamRequester* requester, int render_process_id,
+                      int render_view_id, const StreamOptions& options,
+                      const std::string& security_origin, std::string* label);
+
+  // Cancels all non-finished GenerateStream request, i.e. request for which
+  // StreamGenerated hasn't been called.
+  void CancelRequests(MediaStreamRequester* requester);
+
+  // Closes generated stream.
+  void StopGeneratedStream(const std::string& label);
+
+  // Implements MediaStreamProviderListener.
+  virtual void Opened(MediaStreamType stream_type, int capture_session_id);
+  virtual void Closed(MediaStreamType stream_type, int capture_session_id);
+  virtual void DevicesEnumerated(MediaStreamType stream_type,
+                                 const StreamDeviceInfoArray& devices);
+  virtual void Error(MediaStreamType stream_type, int capture_session_id,
+                     MediaStreamProviderError error);
+
+  // Implements SettingsRequester.
+  virtual void GetDevices(const std::string& label,
+                          MediaStreamType stream_type);
+  virtual void DevicesAccepted(const std::string& label,
+                               const StreamDeviceInfoArray& devices);
+  virtual void SettingsError(const std::string& label);
+
+  // Used by unit test to make sure fake devices are used instead of a real
+  // devices, which is needed for server based testing.
+  void UseFakeDevice();
+
+ private:
+  // Contains all data needed to keep track of requests.
+  struct DeviceRequest {
+    DeviceRequest(MediaStreamRequester* requester,
+                  const StreamOptions& request_options)
+        : requester(requester),
+          options(request_options),
+          state(kNumMediaStreamTypes, kNotRequested) {
+      DCHECK(requester);
+    }
+
+    enum RequestState {
+      kNotRequested = 0,
+      kRequested,
+      kOpening,
+      kDone,
+      kError
+    };
+
+    MediaStreamRequester* requester;
+    std::string label;
+    StreamOptions options;
+    std::vector<RequestState> state;
+    StreamDeviceInfoArray audio_devices;
+    StreamDeviceInfoArray video_devices;
+  };
+
+  // Helpers.
+  bool RequestDone(const MediaStreamManager::DeviceRequest& request) const;
+  MediaStreamProvider* GetDeviceManager(MediaStreamType stream_type) const;
+
+  // Private constructor to enforce singleton.
+  friend struct base::DefaultLazyInstanceTraits<MediaStreamManager>;
+  MediaStreamManager();
+
+  VideoCaptureManager* video_capture_manager_;
+  // TODO(mflodman) Add AudioInputManager.
+
+  // Keeps track of device types currently being enumerated to not enumerate
+  // when not necessary.
+  std::vector<bool> enumeration_in_progress_;
+
+  // All non-closed request.
+  typedef std::list<DeviceRequest> DeviceRequestList;
+  DeviceRequestList requests_;
+
+  MediaStreamDeviceSettings* device_settings_;
+
+  DISALLOW_COPY_AND_ASSIGN(MediaStreamManager);
+};
+
+}  // namespace media_stream
+
+#endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_MEDIA_STREAM_MANAGER_H_