Data emitted from Observer does not trigger the Subscriber in Rx Java

Question

We have a scenario, where in we switch off the BLE Enabled device and then the Android App screen shall grey out. But when the switch off the BLE Enabled device, instead of Greying out, the screen remains freezes and UI does not respond

None of the methods like onNext(), onCompleted() and onError() in the subscriber are called after executing the Observable.

below is the Subscriber code:

private void subscribeToConnEvents() {
  Subscriber<ConnService.ConnEvent> subscriber = new Subscriber<ConnService.ConnEvent>() {
    @Override
    public void onCompleted() {
    }

    @Override
    public void onError(Throwable e) {
    }

    @Override
    public void onNext(ConnService.ConnEvent connEvent) {
    }
  };
  SerializedSubscriber<ConnService.ConnEvent> serializedSubscriber = new SerializedSubscriber<>(subscriber);
}

Below is the Observable code from which the subscriber shall be called:

In the Below Code the connectionStateSubject gets initialised in the Constructor

private SerializedSubject<ConnEvent, ConnEvent> connectionStateSubject;

public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
  super.onConnectionStateChange(gatt, status, newState);
  BluetoothDevice device = gatt.getDevice();
  String address = gatt.getDevice().getAddress();
  ConnectionEvent event = new ConnectionEvent();
  event.deviceAddress = address;
  if (newState == BluetoothProfile.STATE_DISCONNECTED) {
    event.status = ConnectionStatus.STATE_DISCONNECTED;
    connectionStateSubject.onNext(event);
  }
}

Answer 1

You need to have your Subscriber subscribe to the Subject. Something like -

serializedSubscriber.add(connectionStateSubject.subscribe())