Function paint_row_selection 

pub fn paint_row_selection(
    scene: &mut Scene,
    transform: Affine,
    rect: Rect,
    state: SelectionState,
    ground: AlphaColor<Srgb>,
    theme: &Theme,
)

Paint the selection of one row of a list: the hover or active lift of ground (selection_tier_on) on rect with the item radius (radii.item), and nothing for an idle row. A row is a lift with primary ink and nothing else: no hue, no border, no leading bar.

rect is the row’s outer rect: the column’s content edge grown by row_bleed. NavList, TreeView, super::paint_nav_row, ListRow, VirtualList and DataTable all paint through here, and a painted app’s own rows do too.