dispose method

Implementation

@override
void dispose() async {
  super.dispose();
  clearStateChangeListener();
  if (_eventSubscription != null) {
    _eventSubscription!.cancel();
    _eventSubscription = null;
  }
  if (isScanning) {
    await BleAPI.instance.stopScan();
  }
  if (_timer != null && _timer!.isActive) {
    _timer!.cancel();
    _timer = null;
  }
}