Improves audio-routing in combination with BT in AppRTCMobile on Android

webrtc/examples/androidapp/src/org/appspot/apprtc/AppRTCBluetoothManager.java

 /*
  *  Copyright 2016 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 311 matching lines @@
       Log.e(TAG, "BT SCO connection fails - no headset available");
       return false;
     }
     // Start BT SCO channel and wait for ACTION_AUDIO_STATE_CHANGED.
     Log.d(TAG, "Starting Bluetooth SCO and waits for ACTION_AUDIO_STATE_CHANGED...");
     // The SCO connection establishment can take several seconds, hence we cannot rely on the
     // connection to be available when the method returns but instead register to receive the
     // intent ACTION_SCO_AUDIO_STATE_UPDATED and wait for the state to be SCO_AUDIO_STATE_CONNECTED.
     bluetoothState = State.SCO_CONNECTING;
     audioManager.startBluetoothSco();
+    audioManager.setBluetoothScoOn(true);
     scoConnectionAttempts++;
     startTimer();
-    Log.d(TAG, "startScoAudio done: BT state=" + bluetoothState);
+    Log.d(TAG, "startScoAudio done: BT state=" + bluetoothState + ", "
+            + "SCO is on: " + isScoOn());
     return true;
   }
 
   /** Stops Bluetooth SCO connection with remote device. */
   public void stopScoAudio() {
     ThreadUtils.checkIsOnMainThread();
     Log.d(TAG, "stopScoAudio: BT state=" + bluetoothState + ", "
             + "SCO is on: " + isScoOn());
     if (bluetoothState != State.SCO_CONNECTING && bluetoothState != State.SCO_CONNECTED) {
       return;
     }
     cancelTimer();
     audioManager.stopBluetoothSco();
+    audioManager.setBluetoothScoOn(false);
     bluetoothState = State.SCO_DISCONNECTING;
-    Log.d(TAG, "stopScoAudio done: BT state=" + bluetoothState);
+    Log.d(TAG, "stopScoAudio done: BT state=" + bluetoothState + ", "
+            + "SCO is on: " + isScoOn());
   }
 
   /**
    * Use the BluetoothHeadset proxy object (controls the Bluetooth Headset
    * Service via IPC) to update the list of connected devices for the HEADSET
    * profile. The internal state will change to HEADSET_UNAVAILABLE or to
    * HEADSET_AVAILABLE and |bluetoothDevice| will be mapped to the connected
    * device if available.
    */
   public void updateDevice() {
     if (bluetoothState == State.UNINITIALIZED || bluetoothHeadset == null) {
       return;
     }
     Log.d(TAG, "updateDevice");
     // Get connected devices for the headset profile. Returns the set of
     // devices which are in state STATE_CONNECTED. The BluetoothDevice class
     // is just a thin wrapper for a Bluetooth hardware address.
     List<BluetoothDevice> devices = bluetoothHeadset.getConnectedDevices();
     if (devices.isEmpty()) {
       bluetoothDevice = null;
       bluetoothState = State.HEADSET_UNAVAILABLE;
       Log.d(TAG, "No connected bluetooth headset");
     } else {
-      // Always use first device is list. Android only supports one device.
+      // Always use first device in list. Android only supports one device.
       bluetoothDevice = devices.get(0);
       bluetoothState = State.HEADSET_AVAILABLE;
       Log.d(TAG, "Connected bluetooth headset: "
               + "name=" + bluetoothDevice.getName() + ", "
               + "state=" + stateToString(bluetoothHeadset.getConnectionState(bluetoothDevice))
               + ", SCO audio=" + bluetoothHeadset.isAudioConnected(bluetoothDevice));
     }
     Log.d(TAG, "updateDevice done: BT state=" + bluetoothState);
   }
 
@@ skipping 127 matching lines @@
         return "TURNING_OFF";
       case BluetoothAdapter.STATE_TURNING_ON:
         // Indicates the local Bluetooth adapter is turning on. However local clients should wait
         // for STATE_ON before attempting to use the adapter.
         return  "TURNING_ON";
       default:
         return "INVALID";
     }
   }
 }