Add support for device-change notifications to MediaStreamDispatcher and MediaStreamDispatcherHost

content/renderer/media/media_stream_dispatcher.cc

 // 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.
 
 #include "content/renderer/media/media_stream_dispatcher.h"
 
 #include <stddef.h>
 
 #include "base/logging.h"
 #include "content/common/media/media_stream_messages.h"
@@ skipping 50 matching lines @@
   base::WeakPtr<MediaStreamDispatcherEventHandler> handler;
   StreamDeviceInfoArray audio_array;
   StreamDeviceInfoArray video_array;
 };
 
 MediaStreamDispatcher::MediaStreamDispatcher(RenderFrame* render_frame)
     : RenderFrameObserver(render_frame),
       next_ipc_id_(0) {
 }
 
-MediaStreamDispatcher::~MediaStreamDispatcher() {}
+MediaStreamDispatcher::~MediaStreamDispatcher() {
+  DCHECK(device_change_subscribers_.empty());
+}
 
 void MediaStreamDispatcher::GenerateStream(
     int request_id,
     const base::WeakPtr<MediaStreamDispatcherEventHandler>& event_handler,
     const StreamControls& controls,
     const url::Origin& security_origin) {
   DCHECK(thread_checker_.CalledOnValidThread());
   DVLOG(1) << "MediaStreamDispatcher::GenerateStream(" << request_id << ")";
 
   requests_.push_back(Request(event_handler, request_id, next_ipc_id_));
@@ skipping 120 matching lines @@
            << ", {label = " << label << "}";
 
   LabelStreamMap::iterator it = label_stream_map_.find(label);
   if (it == label_stream_map_.end())
     return;
   label_stream_map_.erase(it);
 
   Send(new MediaStreamHostMsg_CloseDevice(routing_id(), label));
 }
 
+void MediaStreamDispatcher::SubscribeToDeviceChangeNotifications(
+    const base::WeakPtr<MediaStreamDispatcherEventHandler>& event_handler,
+    const url::Origin& security_origin) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK(std::find_if(
+             device_change_subscribers_.begin(),
+             device_change_subscribers_.end(),
+             [&event_handler](
+                 const base::WeakPtr<MediaStreamDispatcherEventHandler>& item) {
+               return event_handler.get() == item.get();
+             }) == device_change_subscribers_.end());
+  DVLOG(1) << "MediaStreamDispatcher::SubscribeToDeviceChangeNotifications";
+
+  if (device_change_subscribers_.empty()) {
+    Send(new MediaStreamHostMsg_SubscribeToDeviceChangeNotifications(
+        routing_id(), security_origin));
+  }
+  device_change_subscribers_.push_back(event_handler);
+}
+
+void MediaStreamDispatcher::CancelDeviceChangeNotifications(
+    const base::WeakPtr<MediaStreamDispatcherEventHandler>& event_handler) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  DVLOG(1) << "MediaStreamDispatcher::SubscribeToDeviceChangeNotifications";
+  auto it = std::find_if(
+      device_change_subscribers_.begin(), device_change_subscribers_.end(),
+      [&event_handler](
+          const base::WeakPtr<MediaStreamDispatcherEventHandler>& item) {
+        return event_handler.get() == item.get();
+      });
+  CHECK(it != device_change_subscribers_.end());
+  device_change_subscribers_.erase(it);
+
+  if (device_change_subscribers_.empty())
+    Send(new MediaStreamHostMsg_CancelDeviceChangeNotifications(routing_id()));
+}
+
 void MediaStreamDispatcher::OnDestruct() {
   // Do not self-destruct. UserMediaClientImpl owns |this|.
 }
 
 bool MediaStreamDispatcher::Send(IPC::Message* message) {
   if (!RenderThread::Get()) {
     delete message;
     return false;
   }
 
   return RenderThread::Get()->Send(message);
 }
 
 bool MediaStreamDispatcher::OnMessageReceived(const IPC::Message& message) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(MediaStreamDispatcher, message)
     IPC_MESSAGE_HANDLER(MediaStreamMsg_StreamGenerated,
                         OnStreamGenerated)
     IPC_MESSAGE_HANDLER(MediaStreamMsg_StreamGenerationFailed,
                         OnStreamGenerationFailed)
     IPC_MESSAGE_HANDLER(MediaStreamMsg_DeviceStopped,
                         OnDeviceStopped)
     IPC_MESSAGE_HANDLER(MediaStreamMsg_DevicesEnumerated,
                         OnDevicesEnumerated)
     IPC_MESSAGE_HANDLER(MediaStreamMsg_DeviceOpened,
                         OnDeviceOpened)
     IPC_MESSAGE_HANDLER(MediaStreamMsg_DeviceOpenFailed,
                         OnDeviceOpenFailed)
+    IPC_MESSAGE_HANDLER(MediaStreamMsg_DevicesChanged, OnDevicesChanged)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
 }
 
 void MediaStreamDispatcher::OnStreamGenerated(
     int request_id,
     const std::string& label,
     const StreamDeviceInfoArray& audio_array,
     const StreamDeviceInfoArray& video_array) {
@@ skipping 121 matching lines @@
         request.handler->OnDeviceOpenFailed(request.request_id);
         DVLOG(1) << "MediaStreamDispatcher::OnDeviceOpenFailed("
                  << request.request_id << ")\n";
       }
       requests_.erase(it);
       break;
     }
   }
 }
 
+void MediaStreamDispatcher::OnDevicesChanged() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  for (auto event_handler : device_change_subscribers_) {
+    DCHECK(event_handler);
+    event_handler->OnDevicesChanged();
+  }
+}
+
 int MediaStreamDispatcher::audio_session_id(const std::string& label,
                                             int index) {
   DCHECK(thread_checker_.CalledOnValidThread());
   LabelStreamMap::iterator it = label_stream_map_.find(label);
   if (it == label_stream_map_.end() ||
       it->second.audio_array.size() <= static_cast<size_t>(index)) {
     return StreamDeviceInfo::kNoId;
   }
   return it->second.audio_array[index].session_id;
 }
 
 bool MediaStreamDispatcher::IsStream(const std::string& label) {
   DCHECK(thread_checker_.CalledOnValidThread());
   return label_stream_map_.find(label) != label_stream_map_.end();
 }
 
 int MediaStreamDispatcher::video_session_id(const std::string& label,
                                             int index) {
   DCHECK(thread_checker_.CalledOnValidThread());
   LabelStreamMap::iterator it = label_stream_map_.find(label);
   if (it == label_stream_map_.end() ||
       it->second.video_array.size() <= static_cast<size_t>(index)) {
     return StreamDeviceInfo::kNoId;
   }
   return it->second.video_array[index].session_id;
 }
 
 }  // namespace content