New menu item implementation based directly on MenuItem/ToggleMenuFlyoutItem

MapUiTools/Shared/MapLayerMenuItem.cs

@@ -0,0 +1,90 @@
+using System;
+using System.Linq;
+using System.Threading.Tasks;
+#if WPF
+using System.Windows;
+using System.Windows.Markup;
+#elif UWP
+using Windows.UI.Xaml;
+using Windows.UI.Xaml.Markup;
+#elif WINUI
+using Microsoft.UI.Xaml;
+using Microsoft.UI.Xaml.Markup;
+#else
+using Avalonia.Metadata;
+using FrameworkElement = Avalonia.Controls.Control;
+#endif
+
+namespace MapControl.UiTools
+{
+#if WPF
+    [ContentProperty(nameof(MapLayer))]
+#elif UWP || WINUI
+    [ContentProperty(Name = nameof(MapLayer))]
+#endif
+    public class MapLayerMenuItem : MapMenuItem
+    {
+#if AVALONIA
+        [Content]
+#endif
+        public FrameworkElement MapLayer { get; set; }
+
+        public Func<Task<FrameworkElement>> MapLayerFactory { get; set; }
+
+        public MapLayerMenuItem()
+        {
+            Click += async (s, e) =>
+            {
+                if (DataContext is MapBase map)
+                {
+                    await Execute(map);
+
+                    foreach (var item in ParentMenuItems.OfType<MapLayerMenuItem>())
+                    {
+                        item.IsChecked = map.Children.Contains(item.MapLayer);
+                    }
+                }
+            };
+        }
+
+        public virtual async Task Execute(MapBase map)
+        {
+            map.MapLayer = MapLayer ?? (MapLayer = await MapLayerFactory.Invoke());
+            IsChecked = true;
+        }
+    }
+
+    public class MapOverlayMenuItem : MapLayerMenuItem
+    {
+        public override async Task Execute(MapBase map)
+        {
+            var layer = MapLayer ?? (MapLayer = await MapLayerFactory.Invoke());
+
+            if (map.Children.Contains(layer))
+            {
+                map.Children.Remove(layer);
+            }
+            else
+            {
+                var index = 1;
+
+                foreach (var itemLayer in ParentMenuItems?
+                    .OfType<MapOverlayMenuItem>()
+                    .Select(item => item.MapLayer)
+                    .Where(itemLayer => itemLayer != null))
+                {
+                    if (itemLayer == layer)
+                    {
+                        map.Children.Insert(index, itemLayer);
+                        break;
+                    }
+
+                    if (map.Children.Contains(itemLayer))
+                    {
+                        index++;
+                    }
+                }
+            }
+        }
+    }
+}