/// <summary>
 /// Open the exhibitdetails page.
 /// </summary>
 /// <param name="item"></param>
 private void NavigateToExhibitDetails(ExhibitsOverviewListItemViewModel item)
 {
     if (item != null)
     {
         Navigation.PushAsync(new ExhibitDetailsViewModel(item.Exhibit));
     }
 }
        public ExhibitsOverviewViewModel(ExhibitSet set)
        {
            if (set != null)
            {
                DisplayedExhibitSet = set;
                ExhibitsList        = new ObservableCollection <ExhibitsOverviewListItemViewModel>();
                foreach (Exhibit exhibit in set)
                {
                    var listItem = new ExhibitsOverviewListItemViewModel(exhibit);
                    ExhibitsList.Add(listItem);
                }
            }
            ItemTappedCommand = new Command(item => NavigateToExhibitDetails(item as ExhibitsOverviewListItemViewModel));
            DisplayDistances  = false;


            locationManager      = IoCManager.Resolve <ILocationManager> ();
            nearbyExhibitManager = IoCManager.Resolve <INearbyExhibitManager> ();
            nearbyRouteManager   = IoCManager.Resolve <INearbyRouteManager>();
        }