public BasemapGalleryController(MapView mapView)
        {
            _mapView = mapView;

            _basemapGalleryView = new BasemapGalleryView { ViewModel = { mapView = mapView } };

            var owner = Window.GetWindow(mapView);

            if (owner != null)
            {
                _basemapGalleryView.Owner = owner;
            }

            InitializeArcGISPortal();

            Mediator.Register(Constants.ACTION_UPDATE_BASEMAP, DoUpdateBasemap);
        }
        public BasemapGalleryController(MapView mapView)
        {
            _mapView = mapView;

            _basemapGalleryView = new BasemapGalleryView { PlacementTarget = mapView, ViewModel = { mapView = mapView } };

            var owner = Window.GetWindow(mapView);

            if (owner != null)
            {
                owner.LocationChanged += (sender, e) =>
                {
                    _basemapGalleryView.HorizontalOffset += 1;
                    _basemapGalleryView.HorizontalOffset -= 1;
                };
            }

            InitializeArcGISPortal();

            Mediator.Register(Constants.ACTION_UPDATE_BASEMAP, DoUpdateBasemap);
        }