gtk:header-bar-subtitle (object)

object -- a gtk:header-bar widget
subtitle -- a string for the subtitle, or nil

The accessor for the subtitle slot gets or sets the subtitle of the header bar. The title should give a user an additional detail to help him identify the current view.

Note that the gtk:header-bar widget by default reserves room for the subtitle, even if none is currently set. If this is not desired, set the has-subtitle property to the false value.