BugFix: BasemapGallery loading demo data in production release (#579)

* Refactor basemap loading and add event handler

* Update BasemapGallery and BasemapGalleryItem classes

- In `BasemapGallery.Appearance.cs`, the visibility of `PART_LoadingScrim` Grid has been set to `False`.
- The `LoadBasemaps` method in `BasemapGallery.cs` and `BasemapGallery.Windows.cs` has been removed and its functionality has been moved to the `BasemapGallery_Loaded` method.
- In `BasemapGalleryItem.cs`, the `Equals` method has been updated to check for equality of `BaseLayers` count and existence of all layers in `Basemap` in the `other` object, in addition to the existing checks.

* Refactor BasemapGalleryItem equality logic

* Add cancellation support to BasemapGallery

* Unsubscribe from Loaded event in BasemapGallery

* Refactor basemap loading cancellation logic

* Refactor BasemapGalleryItem Equals logic

* Enhance layer comparison in BasemapGalleryItem

* Update src/Toolkit/Toolkit/UI/Controls/BasemapGallery/BasemapGalleryItem.cs

src/Toolkit/Toolkit.Maui/BasemapGallery/BasemapGallery.Appearance.cs

@@ -173,7 +173,7 @@ static BasemapGallery()
                                                     </Style>
                                                 </Grid.Resources>
                                         <CollectionView x:Name=""PART_InnerListView"" HorizontalOptions=""Fill"" VerticalOptions=""Fill"" SelectionMode=""Single"" BackgroundColor=""{{AppThemeBinding Light=#fff,Dark=#353535}}"" />
-                                        <Grid x:Name=""PART_LoadingScrim"">
+                                        <Grid x:Name=""PART_LoadingScrim"" IsVisible=""False"">
                                             <Grid BackgroundColor=""{{AppThemeBinding Light=White, Dark=Black}}"" Opacity=""0.3"" />
                                             <ActivityIndicator IsRunning=""True"" HorizontalOptions=""Center"" VerticalOptions=""Center"" />
                                         </Grid>

src/Toolkit/Toolkit.Maui/BasemapGallery/BasemapGallery.cs

@@ -41,9 +41,20 @@ public BasemapGallery()
         ListItemTemplate = DefaultListDataTemplate;
         GridItemTemplate = DefaultGridDataTemplate;
         ControlTemplate = DefaultControlTemplate;
-        _ = _controller.LoadFromDefaultPortal();
-    }
-
+        Loaded += BasemapGallery_Loaded;
+    }
+
+    private async void BasemapGallery_Loaded(object? sender, EventArgs e)
+    {
+        // Unsubscribe from the Loaded event to ensure this only runs once.
+        Loaded -= BasemapGallery_Loaded;
+
+        if (AvailableBasemaps is null)
+        {
+            await _controller.LoadFromDefaultPortal();
+        }
+    }
+
     private void HandleControllerPropertyChanged(object? sender, PropertyChangedEventArgs e)
     {
         switch (e.PropertyName)
@@ -185,7 +196,7 @@ public GeoModel? GeoModel
     public IList<BasemapGalleryItem>? AvailableBasemaps
     {
         get => GetValue(AvailableBasemapsProperty) as IList<BasemapGalleryItem>;
-        set => SetValue(AvailableBasemapsProperty, value);
+        set => SetValue(AvailableBasemapsProperty, value);
     }
 
     /// <summary>

src/Toolkit/Toolkit.UI.Controls/BasemapGallery/BasemapGallery.Windows.cs

@@ -45,7 +45,18 @@ public BasemapGallery()
             SizeChanged += BasemapGallerySizeChanged;
             AvailableBasemaps = new ObservableCollection<BasemapGalleryItem>();
             _controller.PropertyChanged += HandleControllerPropertyChanged;
-            _ = _controller.LoadFromDefaultPortal();
+            Loaded += BasemapGallery_Loaded;
+        }
+
+        private async void BasemapGallery_Loaded(object? sender, RoutedEventArgs e)
+        {
+            // Unsubscribe from the Loaded event to ensure this only runs once.
+            Loaded -= BasemapGallery_Loaded;
+
+            if (AvailableBasemaps is null)
+            {
+                await _controller.LoadFromDefaultPortal();
+            }
         }
 
         private void HandleControllerPropertyChanged(object? sender, PropertyChangedEventArgs e)

src/Toolkit/Toolkit/UI/Controls/BasemapGallery/BasemapGalleryController.cs

@@ -29,14 +29,17 @@ namespace Esri.ArcGISRuntime.Toolkit.Maui
 namespace Esri.ArcGISRuntime.Toolkit.UI
 #endif
 {
+#pragma warning disable CA1001 // Types that own disposable fields should be disposable
     internal class BasemapGalleryController : INotifyPropertyChanged
+#pragma warning restore CA1001 // Types that own disposable fields should be disposable
     {
         private ArcGISPortal? _portal;
         private bool _ignoreEventsFlag;
         private IList<BasemapGalleryItem>? _availableBasemaps;
         private GeoModel? _geoModel;
         private BasemapGalleryItem? _selectedBasemap;
         private bool _isLoading;
+        private CancellationTokenSource? _loadCancellationTokenSource;
 
         public bool IsLoading
         {
@@ -72,6 +75,7 @@ public IList<BasemapGalleryItem>? AvailableBasemaps
 
                     HandleAvailableBasemapsChanged();
                     PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(AvailableBasemaps)));
+                    _loadCancellationTokenSource?.Cancel();
                 }
             }
         }
@@ -227,10 +231,13 @@ private void HandleSelectedBasemapChanged()
         public async Task LoadFromDefaultPortal()
         {
             IsLoading = true;
+            _loadCancellationTokenSource = new CancellationTokenSource();
             try
             {
-                AvailableBasemaps = await PopulateFromDefaultList();
+                AvailableBasemaps = await PopulateFromDefaultList(_loadCancellationTokenSource.Token);
             }
+            catch (OperationCanceledException)
+            { }
             finally
             {
                 IsLoading = false;
@@ -305,11 +312,11 @@ private static async Task<bool> BasemapIsActuallyNotABasemap(Basemap input)
             return listOfBasemaps;
         }
 
-        private static async Task<IList<BasemapGalleryItem>> PopulateFromDefaultList()
+        private static async Task<IList<BasemapGalleryItem>> PopulateFromDefaultList(CancellationToken cancellationToken = default)
         {
-            ArcGISPortal defaultPortal = await ArcGISPortal.CreateAsync();
+            ArcGISPortal defaultPortal = await ArcGISPortal.CreateAsync(cancellationToken);
 
-            var results = await defaultPortal.GetDeveloperBasemapsAsync();
+            var results = await defaultPortal.GetDeveloperBasemapsAsync(cancellationToken);
 
             var listOfBasemaps = new List<BasemapGalleryItem>();
 

src/Toolkit/Toolkit/UI/Controls/BasemapGallery/BasemapGalleryItem.cs

@@ -246,9 +246,53 @@ internal bool EqualsBasemap(Basemap? other)
                 return false;
             }
 
-            return other == Basemap || other.Name == Basemap?.Name
-                                    || (other.Item?.ItemId != null && other.Item?.ItemId == Basemap?.Item?.ItemId)
-                                    || (other.Uri != null && other.Uri == Basemap?.Uri);
+            return other == Basemap || (other.Item?.ItemId != null && other.Item?.ItemId == Basemap?.Item?.ItemId)
+                                    || (other.Uri != null && other.Uri == Basemap?.Uri)
+                                    || AreBasemapsEqualByLayers(Basemap, other);
+        }
+
+        private static bool AreBasemapsEqualByLayers(Basemap? basemap1, Basemap? basemap2)
+        {
+            if (basemap1 == null || basemap2 == null) return false;
+
+            return LayersEqual(basemap1.BaseLayers, basemap2.BaseLayers)
+                && LayersEqual(basemap1.ReferenceLayers, basemap2.ReferenceLayers);
+        }
+
+        private static bool LayersEqual(LayerCollection layers1, LayerCollection layers2)
+        {
+            return layers1.Count == layers2.Count
+                && layers1.Zip(layers2, LayerEquals).All(equal => equal);
+        }
+
+        private static bool LayerEquals(Layer layer1, Layer layer2)
+        {
+            // This method can be extended to handle more specific layer comparisons if needed
+            if (layer1.GetType() != layer2.GetType()) return false;
+
+            return layer1 switch
+            {
+                AnnotationLayer annotationLayer => annotationLayer.Source == ((AnnotationLayer)layer2).Source,
+                ArcGISMapImageLayer arcGISMapImageLayer => arcGISMapImageLayer.Source == ((ArcGISMapImageLayer)layer2).Source,
+                ArcGISSceneLayer sceneLayer => sceneLayer.Source == ((ArcGISSceneLayer)layer2).Source,
+                ArcGISTiledLayer tiledLayer => tiledLayer.Source == ((ArcGISTiledLayer)layer2).Source,
+                ArcGISVectorTiledLayer vectorTiledLayer => vectorTiledLayer.Source == ((ArcGISVectorTiledLayer)layer2).Source,
+                BingMapsLayer imageServiceLayer => imageServiceLayer.Portal?.Uri == ((BingMapsLayer)layer2).Portal?.Uri,
+                DimensionLayer dimensionLayer => dimensionLayer.Source == ((DimensionLayer)layer2).Source,
+                FeatureCollectionLayer featureCollectionLayer => featureCollectionLayer.FeatureCollection == ((FeatureCollectionLayer)layer2).FeatureCollection,
+                GroupLayer groupLayer => groupLayer.Layers.Count == ((GroupLayer)layer2).Layers.Count && LayersEqual(groupLayer.Layers, ((GroupLayer)layer2).Layers),
+                IntegratedMeshLayer integratedMeshLayer => integratedMeshLayer.Source == ((IntegratedMeshLayer)layer2).Source,
+                KmlLayer kmlLayer => kmlLayer.Dataset?.Source == ((KmlLayer)layer2).Dataset?.Source,
+                Ogc3DTilesLayer ogc3DTilesLayer => ogc3DTilesLayer.Source == ((Ogc3DTilesLayer)layer2).Source,
+                OpenStreetMapLayer openStreetMapLayer => true, // OpenStreetMap layers are considered equal if types match
+                PointCloudLayer pointCloudLayer => pointCloudLayer.Source == ((PointCloudLayer)layer2).Source,
+                WebTiledLayer webTiledLayer => webTiledLayer.TemplateUri == ((WebTiledLayer)layer2).TemplateUri,
+                ServiceImageTiledLayer serviceImageTiledLayer => serviceImageTiledLayer.TileInfo == ((ServiceImageTiledLayer)layer2).TileInfo && serviceImageTiledLayer.FullExtent == ((ServiceImageTiledLayer)layer2).FullExtent,
+                SubtypeFeatureLayer subtypeFeatureLayer => subtypeFeatureLayer.FeatureTable == ((SubtypeFeatureLayer)layer2).FeatureTable,
+                WmsLayer wmsLayer => wmsLayer.Source == ((WmsLayer)layer2).Source,
+                WmtsLayer wmtsLayer => wmtsLayer.Source == ((WmtsLayer)layer2).Source,
+                _ => false,
+            };
         }
 
         /// <inheritdoc />