Initial commit

Packages/com.unity.inputsystem/InputSystem/Editor/UITKAssetEditor/Views/VisualElementExtensions.cs

@@ -0,0 +1,22 @@
+#if UNITY_EDITOR
+using System;
+using UnityEngine.UIElements;
+
+namespace UnityEngine.InputSystem.Editor
+{
+    internal static class VisualElementExtensions
+    {
+        public static TElement Q<TElement>(this VisualElement visualElement, string name) where TElement : VisualElement
+        {
+            var element = UQueryExtensions.Q<TElement>(visualElement, name);
+            if (element == null)
+                throw new InvalidOperationException(
+                    $"Expected a visual element called '{name}' of type '{typeof(TElement)}' to exist " +
+                    $"but none was found.");
+
+            return element;
+        }
+    }
+}
+
+#endif