Sets the subtitle of the GtkHeaderBar. The title should give a user
an additional detail to help him identify the current view.
Note that GtkHeaderBar always reserves room for the subtitle, even
if none is currently set. If this is not desired, use
gtk_header_bar_set_custom_title() to place your own label in the
title position. To achieve the same style, use the "title" style
class.
Sets the subtitle of the GtkHeaderBar. The title should give a user an additional detail to help him identify the current view. Note that GtkHeaderBar always reserves room for the subtitle, even if none is currently set. If this is not desired, use gtk_header_bar_set_custom_title() to place your own label in the title position. To achieve the same style, use the "title" style class.