canShowPosition method
Implementation
@override
Future<bool> canShowPosition(int zoomLevel, List<LatLng> position) async {
final bound = controller.getBounds();
final ne = bound.getNorthEast();
final sw = bound.getSouthWest();
return !position.any((point) =>
point.latitude > ne.getLat() ||
point.latitude < sw.getLat() ||
point.longitude > ne.getLng() ||
point.longitude < sw.getLng());
}