Function paint_emoji 

pub fn paint_emoji(
    ctx: &mut PaintCtx<'_>,
    rect: Rect,
    emoji: &str,
    style: &TextStyle,
    ink: AlphaColor<Srgb>,
)

Draw emoji in rect: a workspace emoji’s picture, its :name: in style and ink while it has none, or the Unicode emoji centred and sized to the rect.