MediaStreamDispatcher

content/renderer/media/media_stream_dispatcher.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.
+
+#ifndef CONTENT_RENDERER_MEDIA_MEDIA_STREAM_DISPATCHER_H_
+#define CONTENT_RENDERER_MEDIA_MEDIA_STREAM_DISPATCHER_H_
+
+#include <list>
+#include <map>
+#include <string>
+
+#include "base/basictypes.h"
+#include "base/message_loop.h"
+#include "content/common/media/media_stream_options.h"
+#include "content/renderer/media/media_stream_dispatcher_eventhandler.h"
+#include "content/renderer/render_view_observer.h"
+
+// MediaStreamDispatcher is a delegate for the Media Stream API messages.
+// MediaStreams are used by WebKit to open media devices such as Video Capture
+// and Audio input devices.
+// It's the complement of MediaStreamDispatcherHost (owned by
+// BrowserRenderProcessHost).
+class MediaStreamDispatcher : public RenderViewObserver {
+ public:
+  explicit MediaStreamDispatcher(RenderView* render_view);
+  virtual ~MediaStreamDispatcher();
+
+  // Request a new media stream to be created.
+  // This can be used either of WebKit or a plugin.
+  // Note: The event_handler must be valid for as long as the stream exists.
+  void GenerateStream(int request_id,
+                      MediaStreamDispatcherEventHandler* event_handler,
+                      media_stream::StreamOptions components,
+                      const std::string& security_origin);
+
+  // Stop a started stream. Label is the label provided in OnStreamGenerated.
+  void StopStream(const std::string& label);
+
+  // Check if the label is a valid stream.
+  bool IsStream(const std::string& label);
+  // Get the video session_id given a label. The label identifies a stream.
+  // index is the index in the video_device_array of the stream.
+  int video_session_id(const std::string& label, int index);
+  // Returns an audio session_id given a label and an index.
+  int audio_session_id(const std::string& label, int index);
+
+ private:
+  FRIEND_TEST_ALL_PREFIXES(MediaStreamDispatcherTest, Basic);
+  FRIEND_TEST_ALL_PREFIXES(MediaStreamDispatcherTest, TestFailure);
+
+  struct Request {
+    Request(MediaStreamDispatcherEventHandler* handler,
+            int request_id,
+            int ipc_request)
+        : handler(handler),
+          request_id(request_id),
+          ipc_request(ipc_request) {
+    }
+    MediaStreamDispatcherEventHandler* handler;
+    int request_id;
+    int ipc_request;
+  };
+
+  // Private class for keeping track of opened devices and who have
+  // opened it.
+  struct Stream {
+    MediaStreamDispatcherEventHandler* handler;
+    media_stream::StreamDeviceInfoArray audio_array;
+    media_stream::StreamDeviceInfoArray video_array;
+  };
+
+  // Messages from the browser.
+  virtual bool OnMessageReceived(const IPC::Message& message);
+  void OnStreamGenerated(
+      int request_id,
+      const std::string& label,
+      const media_stream::StreamDeviceInfoArray& audio_array,
+      const media_stream::StreamDeviceInfoArray& video_array);
+  void OnStreamGenerationFailed(int request_id);
+  void OnVideoDeviceFailed(const std::string& label, int index);
+  void OnAudioDeviceFailed(const std::string& label, int index);
+
+  int next_ipc_id_;
+  typedef std::map<std::string, Stream> LabelStreamMap;
+  LabelStreamMap label_stream_map_;
+
+  // List of calls made to GenerateStream that has not yet completed.
+  typedef std::list<Request> RequestList;
+  RequestList requests_;
+  MessageLoop* message_loop_;
+
+  DISALLOW_COPY_AND_ASSIGN(MediaStreamDispatcher);
+};
+
+#endif  // CONTENT_RENDERER_MEDIA_MEDIA_STREAM_DISPATCHER_H_