Connection API

To determine if your app is running on Android Auto or Android Automotive OS, use the CarConnection API to retrieve connection information at runtime. For example:

1. In your car app's Session, initialize a CarConnection and subscribe to LiveData updates:

   Kotlin

   CarConnection(carContext).type.observe(this, ::onConnectionStateUpdated)
   

   Java

   new CarConnection(getCarContext()).getType().observe(this, this::onConnectionStateUpdated);
   

2. In the observer, react to changes in the connection state:

   Kotlin

   fun onConnectionStateUpdated(connectionState: Int) {
     val message = when(connectionState) {
       CarConnection.CONNECTION_TYPE_NOT_CONNECTED -> "Not connected to a head unit"
       CarConnection.CONNECTION_TYPE_NATIVE -> "Connected to Android Automotive OS"
       CarConnection.CONNECTION_TYPE_PROJECTION -> "Connected to Android Auto"
       else -> "Unknown car connection type"
     }
     CarToast.makeText(carContext, message, CarToast.LENGTH_SHORT).show()
   }
   

   Java

   private void onConnectionStateUpdated(int connectionState) {
     String message;
     switch(connectionState) {
       case CarConnection.CONNECTION_TYPE_NOT_CONNECTED:
         message = "Not connected to a head unit";
         break;
       case CarConnection.CONNECTION_TYPE_NATIVE:
         message = "Connected to Android Automotive OS";
         break;
       case CarConnection.CONNECTION_TYPE_PROJECTION:
         message = "Connected to Android Auto";
         break;
       default:
         message = "Unknown car connection type";
         break;
     }
     CarToast.makeText(getCarContext(), message, CarToast.LENGTH_SHORT).show();
   }