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
or GtkScale/GtkHScale/GtkVScale). GtkOrientable is more flexible in that
it allows the orientation to be changed at runtime, allowing the widgets
to 'flip'.
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 or 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.