Changing to default when you go away from Beacon

[MapiFer]

Hi,

I want to thank you for this great plugin. I'm using it with great success, but I have a little problem: I have a text that said "Unknow" while I'm away from any becon, and said some area name when I listen some beacon. The problem was that when I go away after chnge the text from Unknow to the area name, it keep as that area until I find another beacon. I want it to chnge back to unknow if there are no beacons near.

I change my code and now it works as I want, when I go away the text come back to Unknow. My problem now is that when I'm near a becon, it dont keep the text even if I don´t move, it start to change from Unknow to Area Name. This is my code, hope someone can tell me what I'm doing wrong:

    _streamRanging = flutterBeacon.ranging(regions).listen((result) {
      if (result != null && mounted) {

        _regionBeacons[result.region] = result.beacons;
        _beacons.clear();
        if (result.beacons.length == 0 && globals.Minor != 0){
          setState(() {
            globals.Minor = 0;
            globals.Ubicado = "Desconocida";
            globals.codArea = '0';
            globals.Sucio = false;
            globals.Limpio = false;
          });
        }
        _regionBeacons.values.forEach((list) {
          _beacons.addAll(list);
          if (_beacons[0].minor != globals.Minor){
            globals.Minor = _beacons[0].minor;
            BuscarArea(globals.Minor);
          }
          _beacons.sort(_compareParameters);
        });
      }
    });

[alann-maulana]

Hi @MapiFer

This is like my current issue from my project within past few months ago, this is happen especially in Android. I am solving it by saving the last detected timestamp of a beacon, then adding some threshold constant. So I will remove the beacon from a List only when the last detected timestamp past the threshold.

import 'package:flutter_beacon/flutter_beacon.dart' as fb;

// equal to 15 seconds
const kThresholdLastDetected = 15000;

class MyBeacon {
  MyBeacon(this._beacon, {DateTime lastTimestamp})
      : _lastTimestamp = lastTimestamp ?? DateTime.now();

  fb.Beacon _beacon;
  fb.Beacon get beacon => _beacon;

  DateTime _lastTimestamp;
  DateTime get lastTimestamp => _lastTimestamp;

  bool needToRemoved(DateTime timestamp) =>
      timestamp.millisecondsSinceEpoch - _lastTimestamp.millisecondsSinceEpoch >
      kThresholdLastDetected;

  void updateBeaconIfEqual(fb.Beacon beacon) {
    if (_beacon.proximityUUID == beacon.proximityUUID &&
        _beacon.major == beacon.major &&
        _beacon.minor == beacon.minor) {
      _beacon = beacon;
      _lastTimestamp = DateTime.now();
    }
  }
}

Call updateBeaconIfEqual after getting a ranging result on each beacon found. Then iterate again and call needToRemoved to check if there are some beacon needs to remove from list.

Hope it can help.

[MapiFer]

that ws great, it totally works for me.