private void OnGUI()
{
EditorGUILayout.HelpBox("This spinner icon is drawn using the Spinner utility class.\nThe animation is updated using the Update() message of EditorWindow. But when it comes to a custom inspector script (by inheriting from Editor), you must override RequireConstantRepaint() to make the GUI be repainted each editor frame.", MessageType.Info);
EditorGUILayout.Space();
Rect rect = EditorGUILayout.GetControlRect(false, SPINNER_SIZE, GUILayout.Width(SPINNER_SIZE));
rect.x += SPINNER_OFFSET;
m_Spinner.DrawGUI(rect);
}