Adding support for MediaStream and PeerConnection functionality

content/renderer/media/peer_connection_handler.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_PEER_CONNECTION_HANDLER_H_
+#define CONTENT_RENDERER_MEDIA_PEER_CONNECTION_HANDLER_H_
+
+#include <string>
+
+#include "base/basictypes.h"
+#include "base/gtest_prod_util.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/message_loop_proxy.h"
+#include "third_party/libjingle/source/talk/app/webrtc/peerconnection.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebPeerConnectionHandler.h"
+
+namespace talk_base {
+class Thread;
+}
+
+class MediaStreamDependencyFactory;
+class MediaStreamImpl;
+
+// PeerConnectionHandler is a delegate for the PeerConnection API messages going
+// between WebKit and native PeerConnection in libjingle. It's owned by
+// MediaStreamImpl.
+class PeerConnectionHandler
+    : public WebKit::WebPeerConnectionHandler,
+      public webrtc::PeerConnectionObserver {
+ public:
+  PeerConnectionHandler(
+      WebKit::WebPeerConnectionHandlerClient* client,
+      MediaStreamImpl* msi,
+      MediaStreamDependencyFactory* dependency_factory,
+      talk_base::Thread* signaling_thread);
+  virtual ~PeerConnectionHandler();
+
+  // Set the video renderer for the specified stream.
+  virtual bool SetVideoRenderer(const std::string& stream_label,
+                                cricket::VideoRenderer* renderer);
+
+  // WebKit::WebPeerConnectionHandler implementation
+  virtual void initialize(
+      const WebKit::WebString& server_configuration,
+      const WebKit::WebSecurityOrigin& security_origin) OVERRIDE;
+  virtual void produceInitialOffer(
+      const WebKit::WebVector<WebKit::WebMediaStreamDescriptor>&
+          pending_add_streams) OVERRIDE;
+  virtual void handleInitialOffer(const WebKit::WebString& sdp) OVERRIDE;
+  virtual void processSDP(const WebKit::WebString& sdp) OVERRIDE;
+  virtual void processPendingStreams(
+      const WebKit::WebVector<WebKit::WebMediaStreamDescriptor>&
+          pending_add_streams,
+      const WebKit::WebVector<WebKit::WebMediaStreamDescriptor>&
+          pending_remove_streams) OVERRIDE;
+  virtual void sendDataStreamMessage(const char* data, size_t length) OVERRIDE;
+  virtual void stop() OVERRIDE;
+
+  // webrtc::PeerConnectionObserver implementation
+  virtual void OnSignalingMessage(const std::string& msg) OVERRIDE;
+  virtual void OnAddStream(const std::string& stream_id, bool video) OVERRIDE;
+  virtual void OnRemoveStream(
+      const std::string& stream_id,
+      bool video) OVERRIDE;
+
+ private:
+  FRIEND_TEST(PeerConnectionHandlerTest, Basic);
+
+  void AddStream(const std::string label);
+  void OnAddStreamCallback(const std::string& stream_label);
+  void OnRemoveStreamCallback(const std::string& stream_label);
+
+  // client_ is a weak pointer, and is valid until stop() has returned.
+  WebKit::WebPeerConnectionHandlerClient* client_;
+
+  // media_stream_impl_ is a weak pointer, and is valid for the lifetime of this
+  // class.
+  MediaStreamImpl* media_stream_impl_;
+
+  // dependency_factory_ is a weak pointer, and is valid for the lifetime of
+  // MediaStreamImpl.
+  MediaStreamDependencyFactory* dependency_factory_;
+
+  // native_peer_connection_ is the native PeerConnection object,
+  // it handles the ICE processing and media engine.
+  scoped_ptr<webrtc::PeerConnection> native_peer_connection_;
+
+  scoped_refptr<base::MessageLoopProxy> message_loop_proxy_;
+
+  talk_base::Thread* signaling_thread_;
+
+  // Currently, a stream in WebKit has audio and/or video and has one label.
+  // Local and remote streams have different labels.
+  // In native PeerConnection, a stream has audio or video (not both), and they
+  // have separate labels. A remote stream has the same label as the
+  // corresponding local stream. Hence the workarounds in the implementation to
+  // handle this. It could look like this:
+  // WebKit: Local, audio and video: label "foo".
+  //         Remote, audio and video: label "foo-remote".
+  // Libjingle: Local and remote, audio: label "foo-audio".
+  //            Local and remote, video: label "foo".
+  // TODO(grunell): This shall be removed or changed when native PeerConnection
+  // has been updated to closer follow the specification.
+  std::string local_label_;   // Label used in WebKit
+  std::string remote_label_;  // Label used in WebKit
+
+  // Call states. Possible transitions:
+  // NOT_STARTED -> INITIATING -> SENDING_AND_RECEIVING
+  // NOT_STARTED -> RECEIVING
+  // RECEIVING -> NOT_STARTED
+  // RECEIVING -> SENDING_AND_RECEIVING
+  // SENDING_AND_RECEIVING -> NOT_STARTED
+  // Note that when in state SENDING_AND_RECEIVING, the other side may or may
+  // not send media. Thus, this state does not necessarily mean full duplex.
+  // TODO(grunell): This shall be removed or changed when native PeerConnection
+  // has been updated to closer follow the specification.
+  enum CallState {
+    NOT_STARTED,
+    INITIATING,
+    RECEIVING,
+    SENDING_AND_RECEIVING
+  };
+  CallState call_state_;
+
+  DISALLOW_COPY_AND_ASSIGN(PeerConnectionHandler);
+};
+
+#endif  // CONTENT_RENDERER_MEDIA_PEER_CONNECTION_HANDLER_H_