private void RefreshPolygonUsers() { if (SelectedPolygon != null) { if (SelectedPolygon.PolygonTagTypeEquals(PolygonTagType.Hexagon)) { var friends = _layerService.UsersInsidePolygonTagBrief(SelectedPolygon.ExtractPolygonTag().Tag); SelectedUsers = new ObservableCollection <UserInfoBriefViewCellModel>(friends); } else if (SelectedPolygon.PolygonTagTypeEquals(PolygonTagType.Zone)) { //TODO: read friends inside of Zone from webapi var friends = _layerService.UsersInsideZone(SelectedPolygon.ExtractPolygonTag().Tag); SelectedUsers = new ObservableCollection <UserInfoBriefViewCellModel>(friends); } else { SelectedUsers.Clear(); } PolygonUsersVisible = SelectedUsers.Count > 0; } else { SelectedUsers.Clear(); PolygonUsersVisible = false; } }