gobject:object, common-lisp:standard-object, common-lisp:t

gtk:app-chooser-widget, gtk:box, gtk:button-box, gtk:cell-area-box, gtk:cell-renderer-progress, gtk:cell-view, gtk:color-chooser-widget, gtk:color-selection, gtk:file-chooser-button, gtk:file-chooser-widget, gtk:flow-box, gtk:font-chooser-widget, gtk:grid, gtk:info-bar, gtk:level-bar, gtk:paned, gtk:progress-bar, gtk:range, gtk:recent-chooser-widget, gtk:scale, gtk:scale-button, gtk:scrollbar, gtk:separator, gtk:shortcuts-group, gtk:shortcuts-section, gtk:shortcuts-shortcut, gtk:spin-button, gtk:stack-switcher, gtk:statusbar, gtk:tool-palette, gtk:toolbar, gtk:volume-button

An interface for flippable widgets. The gtk:orientable 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. The gtk:orientable interface is more flexible in that it allows the orientation to be changed at runtime, allowing the widgets to "flip".