static void OnUIModeChanged(DependencyObject obj, DependencyPropertyChangedEventArgs e)
        {
            ShortcutManager mgr = obj as ShortcutManager;

            if (mgr != null)
            {
                mgr.UpdateAdornerVisualStates();

                var handler = mgr.UIModeChanged;

                if (handler != null)
                {
                    handler(mgr, EventArgs.Empty);
                }
            }
        }
        static void OnAreShortcutAdornmentsVisibleChanged(DependencyObject obj, DependencyPropertyChangedEventArgs e)
        {
            ShortcutManager mgr = obj as ShortcutManager;

            if (mgr != null)
            {
                if (mgr.AreShortcutAdornmentsVisible)
                {
                    mgr.timer.Start();
                }
                else
                {
                    mgr.timer.Stop();
                }

                mgr.UpdateAdornerVisualStates();
            }
        }