draw.rs

fn draw(&self, printer: &Printer) {
    // If the background is dirty draw a new background
    if self.dirty {
        for y in 0..printer.size.y {
            printer.with_color(ColorStyle::background(), |printer| {
                printer.print_hline((0,y), printer.size.x, " ");
            });
        }

        // set background as clean, so we don't need to do this every frame
        self.dirty = false;
    }
    
    ...
}