Editor stuff

Assets/Plugins/com.unity.uiextensions/Runtime/Scripts/Utilities/ExtentionMethods.cs

@@ -0,0 +1,33 @@
+using System;
+
+namespace UnityEngine.UI.Extensions
+{
+    public static class ExtentionMethods
+    {
+        public static T GetOrAddComponent<T>(this GameObject child) where T : Component
+        {
+            T result = child.GetComponent<T>();
+            if (result == null)
+            {
+                result = child.AddComponent<T>();
+            }
+            return result;
+        }
+
+        public static bool IsPrefab(this GameObject gameObject)
+        {
+            if (gameObject == null)
+            {
+                throw new ArgumentNullException(nameof(gameObject));
+            }
+
+            return
+                !gameObject.scene.IsValid() &&
+                !gameObject.scene.isLoaded &&
+                gameObject.GetInstanceID() >= 0 &&
+                // I noticed that ones with IDs under 0 were objects I didn't recognize
+                !gameObject.hideFlags.HasFlag(HideFlags.HideInHierarchy);
+                    // I don't care about GameObjects *inside* prefabs, just the overall prefab.
+        }
+    }
+}