listen method

  1. @protected
  2. @nonVirtual
void listen()

Starts message receiving.

Registers message sink in MessageSinkRegister.

If this Listener's message sink is already registered, it's automatically unregistered first.

Implementation

@protected
@nonVirtual
void listen() {
  if (_id != null) {
    cancel();
  }
  _messageStreamController = StreamController<Message>();
  _id = MessageSinkRegister()._add(
    _messageStreamController!.sink,
    onInitialMessage: onInitialMessage,
  );
  _messageSubscription = _messageStreamController!.stream.listen(onMessage);
}