private void Focus_OnMouseLeave(object sender, MouseEventArgs e)
        {
            Cursor = null;
            FocusModel model = DataContext as FocusModel;

            if (model == null)
            {
                return;
            }
            if (model.IsWaiting)
            {
                return;
            }
            FocusGrid.ClearValue(EffectProperty);
        }
        private void Focus_PropertyChanged(object sender, PropertyChangedEventArgs e)
        {
            FocusModel model = DataContext as FocusModel;

            if (model == null)
            {
                return;
            }
            if (e.PropertyName == "IsWaiting")
            {
                FocusGrid.ClearValue(EffectProperty);
                if (model.IsWaiting)
                {
                    FocusGrid.Effect = new DropShadowEffect
                    {
                        Color       = Colors.OrangeRed,
                        BlurRadius  = 20,
                        Opacity     = 1,
                        ShadowDepth = 0
                    };
                }
            }
        }