Update RuntimeSet.cs

Author: Cory Leach

Runtime/RuntimeSets/RuntimeSet.cs

@@ -1,24 +1,29 @@
-using System.Collections;
-using System.Collections.Generic;
+using System.Collections.Generic;
 using UnityEngine;
+using UnityEngine.Events;
 
 namespace Gameframe.ScriptableObjects.RuntimeSets
 {
   public class RuntimeSet<T> : ScriptableObject
   {
+    public class RuntimeSetChangeEvent : UnityEvent<T> {}
 
-    List<T> items = new List<T>();
-    public List<T> Items => items;
+    private readonly List<T> _items = new List<T>();
+    public IReadOnlyList<T> Items => _items;
+
+    public RuntimeSetChangeEvent OnAdded { get; } = new RuntimeSetChangeEvent();
+    public RuntimeSetChangeEvent OnRemoved { get; } = new RuntimeSetChangeEvent();
 
     public void Add(T t)
     {
-      items.Add(t);
+      _items.Add(t);
+      OnAdded.Invoke(t);
     }
 
     public void Remove(T t)
     {
-      items.Remove(t);
+      _items.Remove(t);
+      OnRemoved.Invoke(t);
     }
-
   }
-}
+}