ranging method
Start ranging iBeacons with defined List
of Regions.
This will fires RangingResult whenever the iBeacons in range.
Implementation
Stream<RangingResult> ranging(List<Region> regions) {
if (_onRanging == null) {
final list = regions.map((region) => region.toJson).toList();
_onRanging = _rangingChannel
.receiveBroadcastStream(list)
.map((dynamic event) => RangingResult._from(event));
}
return _onRanging;
}