Draw Script Fields to the Script and EditorScript of a Unity UGUI Editor Extension

ScriptNameEditor.cs

private void DrawScriptFields()
{
    EditorGUI.BeginDisabledGroup(true);

    MonoScript monoScript = (target as MonoBehaviour) != null
        ? MonoScript.FromMonoBehaviour((MonoBehaviour)target)
        : MonoScript.FromScriptableObject((ScriptableObject)target);
    EditorGUILayout.ObjectField("Script", monoScript, GetType(), false);

    MonoScript monoScript2 = MonoScript.FromScriptableObject((ScriptableObject)this);
    EditorGUILayout.ObjectField("EditorScript", monoScript2, GetType(), false);

    EditorGUI.EndDisabledGroup();
}