b.pack_start(w1, expand=not exr, fill=not exr)
        b.pack_start(w2, expand=exr, fill=exr)
        return b


    # Attach textual menu entry and callback
    @staticmethod
    def add_menu(menuwidget, label, action):
    def add_menu(menuwidget, label, action, insert=None):
        for where in list(menuwidget):
            m = gtk.MenuItem(label)
            m.connect("activate", action)
            m.show()
            if insert:
                where.insert(m, insert)
            else:
            where.add(m)
                where.add(m)
        

    # gtk.messagebox
    @staticmethod
    def msg(text, style=gtk.MESSAGE_INFO, buttons=gtk.BUTTONS_CLOSE):
        m = gtk.MessageDialog(None, 0, style, buttons, message_format=text)
        m.show()