add extension for adding enum values

Pilz.UI.Telerik/Extensions/RadListDataItemCollectionExtensions.cs

@@ -0,0 +1,37 @@
+using Telerik.WinControls.UI;
+
+namespace Pilz.UI.Telerik.Extensions;
+
+public static class RadListDataItemCollectionExtensions
+{
+    public static IEnumerable<RadListDataItem> AddEnumValues<T>(this RadListDataItemCollection @this) where T : struct, Enum
+    {
+        return AddEnumValues<T>(@this, false);
+    }
+
+    public static IEnumerable<RadListDataItem> AddEnumValues<T>(this RadListDataItemCollection @this, bool clearCollection) where T : struct, Enum
+    {
+        return AddEnumValues<T>(@this, clearCollection, null, null);
+    }
+
+    public static IEnumerable<RadListDataItem> AddEnumValues<T>(this RadListDataItemCollection @this, bool clearCollection, Func<T, bool>? filter, Func<T, string?>? format) where T : struct, Enum
+    {
+        var values = Enum.GetValues<T>();
+        var items = new List<RadListDataItem>();
+
+        format ??= v => Enum.GetName(v);
+
+        if (clearCollection)
+            @this.Clear();
+
+        foreach (var value in values)
+        {
+            if (filter is null || filter(value))
+                items.Add(new(format(value), value));
+        }
+
+        @this.AddRange(items);
+
+        return items;
+    }
+}