public void DrawParameters(Rect rect, HelmController controller, SerializedObject serialized) { GUI.BeginGroup(rect); DrawParameterList(controller, serialized, rect.width); Rect buttonRect = new Rect(rect.width / 4, 0, rect.width / 2, addButtonHeight); if (GUI.Button(buttonRect, "Add Parameter Control")) { Undo.RecordObject(controller, "Add Parameter Control"); controller.AddEmptyParameter(); } GUI.EndGroup(); }