addOffsetValue

Adds a new offset marker on @self at the position specified by @value.

When the bar value is in the interval topped by @value (or between @value and property@Gtk.LevelBar:max-value in case the offset is the last one on the bar) a style class named level-@name will be applied when rendering the level bar fill.

If another offset marker named @name exists, its value will be replaced by @value.

Parameters