C#/XAML workaround solution for an accordion-style grid menu

// A workaround for:
// https://stackoverflow.com/questions/70027679/why-does-the-ismouseover-trigger-not-work-for-a-grid-columndefinition
//---------------------------
// XAML PART:

<Grid x:Name="MainGrid">
    <Grid.ColumnDefinitions>
        <ColumnDefinition/>
        <ColumnDefinition/>
        <ColumnDefinition/>
        <ColumnDefinition/>
    </Grid.ColumnDefinitions>

    <Rectangle x:Name="Rect1" Fill="Blue"   Grid.Column="0" IsMouseDirectlyOverChanged="Rectangle_IsMouseDirectlyOverChanged"/>
    <Rectangle x:Name="Rect2" Fill="Red"    Grid.Column="1" IsMouseDirectlyOverChanged="Rectangle_IsMouseDirectlyOverChanged"/>
    <Rectangle x:Name="Rect3" Fill="Green"  Grid.Column="2" IsMouseDirectlyOverChanged="Rectangle_IsMouseDirectlyOverChanged"/>
    <Rectangle x:Name="Rect4" Fill="Yellow" Grid.Column="3" IsMouseDirectlyOverChanged="Rectangle_IsMouseDirectlyOverChanged"/>
</Grid>

//---------------------------
// CODE-BEHIND PART:

// Widths in star* unit type
private int _columnWidthWide = 2;
private int _columnWidthNarrow = 1;

private void Rectangle_IsMouseDirectlyOverChanged(object sender, DependencyPropertyChangedEventArgs e)
{
    var rect = sender as Rectangle;

    if ((bool)e.NewValue)
    {
        // On mouse enter
        GridLength columnWidthWide = new(_columnWidthWide, GridUnitType.Star);
        switch (rect.Name)
        {
            case "Rect1":
                MainGrid.ColumnDefinitions[0].Width = columnWidthWide;
                break;
            case "Rect2":
                MainGrid.ColumnDefinitions[1].Width = columnWidthWide;
                break;
            case "Rect3":
                MainGrid.ColumnDefinitions[2].Width = columnWidthWide;
                break;
            case "Rect4":
                MainGrid.ColumnDefinitions[3].Width = columnWidthWide;
                break;
            default:
                break;
        }
    }
    else
    {
        // On mouse leave
        GridLength columnWidthNarrow = new(_columnWidthNarrow, GridUnitType.Star);
        switch (rect.Name)
        {
            case "Rect1":
                MainGrid.ColumnDefinitions[0].Width = columnWidthNarrow;
                break;
            case "Rect2":
                MainGrid.ColumnDefinitions[1].Width = columnWidthNarrow;
                break;
            case "Rect3":
                MainGrid.ColumnDefinitions[2].Width = columnWidthNarrow;
                break;
            case "Rect4":
                MainGrid.ColumnDefinitions[3].Width = columnWidthNarrow;
                break;
            default:
                break;
        }
    }
}