Description The GtkOrientable interface is implemented by all widgets that can be oriented horizontally or vertically. Historically, such widgets have been realized as subclasses of a common base class (e.g GtkBox/GtkHBox/GtkVBox and GtkScale/GtkHScale/GtkVScale). GtkOrientable is more flexible in that it allows the orientation to be changed at runtime, allowing the widgets to 'flip'. GtkOrientable was introduced in GTK+ 2.16.