Gtk.Bin

const Gtk = imports.gi.Gtk;

let bin = new Gtk.Bin();
  

The Gtk.Bin widget is a container with just one child. It is not very useful itself, but it is useful for deriving subclasses, since it provides common code needed for handling a single child widget.

Many GTK+ widgets are subclasses of Gtk.Bin, including Gtk.Window, Gtk.Button, Gtk.Frame, Gtk.HandleBox or Gtk.ScrolledWindow.