level fill area.
Specifically, when the value is [gtk.types.LevelBarMode.Continuous], [gtk.level_bar.LevelBar] will draw a single block representing the current value in that area; when the value is [gtk.types.LevelBarMode.Discrete], the widget will draw a succession of separate blocks filling the draw area, with the number of blocks being equal to the units separating the integral roundings of property@Gtk.LevelBar:min-value and property@Gtk.LevelBar:max-value.