Record changes to signal ID

Author: daviduhm

Assets/Scripts/Map/MapSignal.cs

@@ -9,6 +9,7 @@
 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
+using UnityEditor;
 using System.Linq;
 using Simulator.Utilities;
 using Simulator.Controllable;
@@ -37,7 +38,13 @@ public class MapSignal : MapData, IControllable, IMapType
         public string id
         {
             get { return _id; }
-            set { _id = value; }
+            set
+            {
+#if UNITY_EDITOR
+                Undo.RecordObject(this, "Changed signal ID");
+#endif
+                _id = value;
+            }
         }
 
         public string Key => UID;