Function paint_floating_window_card 

pub fn paint_floating_window_card(
    scene: &mut Scene,
    transform: Affine,
    rect: Rect,
    theme: &Theme,
    content: impl FnOnce(&mut Scene, &Theme),
) -> Theme

A window card a person lifted off the desk, drawn in the shell’s floating material: the panel ground and hairline a menu stands on and the two-layer lift under it, so the window reads as standing over the desk rather than as another window on it. content is clipped to the card’s shape; the window’s own edge is stroked around it by the caller, outside that clip, where a focused window’s ring belongs. Returns the theme a child on the card paints with, as paint_window_card does.