Add TernaryExtension

StabilityMatrix.Avalonia/MarkupExtensions/TernaryExtension.cs

@@ -0,0 +1,42 @@
+using System;
+using System.Globalization;
+using Avalonia.Data;
+using Avalonia.Data.Converters;
+using Avalonia.Markup.Xaml;
+using Avalonia.Markup.Xaml.MarkupExtensions;
+
+namespace StabilityMatrix.Avalonia.MarkupExtensions;
+
+/// <summary>
+/// https://github.com/AvaloniaUI/Avalonia/discussions/7408
+/// </summary>
+/// <example>
+/// <code>{e:Ternary SomeProperty, True=1, False=0}</code>
+/// </example>
+public class TernaryExtension : MarkupExtension
+{
+    public string Path { get; set; }
+
+    public Type Type { get; set; }
+
+    public object? True { get; set; }
+
+    public object? False { get; set; }
+
+    public override object ProvideValue(IServiceProvider serviceProvider)
+    {
+        var cultureInfo = CultureInfo.GetCultureInfo("en-US");
+        var binding = new ReflectionBindingExtension(Path)
+        {
+            Mode = BindingMode.OneWay,
+            Converter = new FuncValueConverter<bool, object?>(
+                isTrue =>
+                    isTrue
+                        ? Convert.ChangeType(True, Type, cultureInfo.NumberFormat)
+                        : Convert.ChangeType(False, Type, cultureInfo.NumberFormat)
+            )
+        };
+
+        return binding.ProvideValue(serviceProvider);
+    }
+}