feat: initialize and setup demo.

demo/Ursa.Demo/ViewModels/EnumSelectorDemoViewModel.cs

@@ -0,0 +1,55 @@
+using System;
+using System.Collections.ObjectModel;
+using Avalonia.Animation;
+using Avalonia.Controls;
+using Avalonia.Data;
+using Avalonia.Input;
+using Avalonia.Interactivity;
+using Avalonia.Layout;
+using CommunityToolkit.Mvvm.ComponentModel;
+
+namespace Ursa.Demo.ViewModels;
+
+public class EnumSelectorDemoViewModel: ObservableObject
+{
+    public ObservableCollection<Type?> Types { get; set; }
+    
+    private Type? _selectedType;
+    public Type? SelectedType
+    {
+        get => _selectedType;
+        set
+        {
+            SetProperty(ref _selectedType, value);
+            Value = null;
+        }
+    }
+
+    private object? _value;
+    public object? Value
+    {
+        get => _value;
+        set => SetProperty(ref _value, value);
+    }
+    
+    public EnumSelectorDemoViewModel()
+    {
+        Types = new ObservableCollection<Type?>()
+        {
+            typeof(HorizontalAlignment),
+            typeof(VerticalAlignment),
+            typeof(Orientation),
+            typeof(Dock),
+            typeof(GridResizeDirection),
+            typeof(DayOfWeek),
+            typeof(FillMode),
+            typeof(IterationType),
+            typeof(BindingMode),
+            typeof(BindingPriority),
+            typeof(StandardCursorType),
+            typeof(Key),
+            typeof(KeyModifiers),
+            typeof(RoutingStrategies),
+        };
+    }
+}