How to use the ginga.gw.Widgets.VBox function in ginga

def build_gui(self, container):

        vbox = Widgets.VBox()

        self.msg_font = self.fv.get_font('fixed', 12)

        vbox.add_widget(Widgets.Label("Output:"))
        tw = Widgets.TextArea(wrap=True, editable=False)
        tw.set_font(self.msg_font)
        tw.set_limit(self.histlimit)
        self.hist_w = tw

        vbox2 = Widgets.VBox()
        vbox2.add_widget(tw, stretch=1)
        vbox2.add_widget(Widgets.Label(''), stretch=0)

        vbox.add_widget(vbox2, stretch=1)

        vbox2 = Widgets.VBox()
        vbox2.add_widget(Widgets.Label("Type command here:"))
        self.cmd_w = Widgets.TextEntry()
        self.cmd_w.set_font(self.msg_font)
        vbox2.add_widget(self.cmd_w, stretch=0)
        self.cmd_w.add_callback('activated', self.exec_cmd_cb)
        vbox.add_widget(vbox2, stretch=0)

        btns = Widgets.HBox()
        btns.set_spacing(4)
        btns.set_border_width(4)

if options.num_cols is not None:
            cols = options.num_cols

        self.settings.add_defaults(columns=cols, zones=['UTC'],
                                   colors=colors)
        self.colors = self.settings.get('colors', colors)

        # now import our items
        from ginga.gw import Widgets, GwHelp

        self.app = Widgets.Application(logger=logger)
        self.app.add_callback('shutdown', self.quit)
        self.top = self.app.make_window("Clocks")
        self.top.add_callback('close', self.closed)

        vbox = Widgets.VBox()

        menubar = Widgets.Menubar()
        clockmenu = menubar.add_name('Clock')
        item = clockmenu.add_name("Quit")
        item.add_callback('activated', lambda *args: self.quit())
        vbox.add_widget(menubar, stretch=0)

        self.grid = Widgets.GridBox()
        self.grid.set_border_width(1)
        self.grid.set_spacing(2)
        vbox.add_widget(self.grid, stretch=1)

        hbox = Widgets.HBox()

        self.timezone_label = Widgets.Label('TimeZone')
        self.county_timezone = Widgets.ComboBox(editable=True)

def build_gui(self, container):
        assert iqcalc.have_scipy is True, \
            Exception("Please install python-scipy to use this plugin")

        vtop = Widgets.VBox()
        vtop.set_border_width(4)

        box, sw, orientation = Widgets.get_oriented_box(container)
        box.set_border_width(4)
        box.set_spacing(2)

        paned = Widgets.Splitter(orientation=orientation)
        self.w.splitter = paned

        nb = Widgets.TabWidget(tabpos='bottom')
        self.w.nb1 = nb
        paned.add_widget(Widgets.hadjust(nb, orientation))

        cm, im = self.fv.cm, self.fv.im

        di = Viewers.CanvasView(logger=self.logger)

def build_gui(self, container, future=None):
        vbox1 = Widgets.VBox()

        nb = Widgets.TabWidget(tabpos='bottom')
        self.w.nb = nb
        vbox1.add_widget(nb, stretch=1)

        vbox0 = Widgets.VBox()

        hbox = Widgets.HBox()
        hbox.set_spacing(4)
        vbox0.add_widget(hbox, stretch=1)

        vbox = Widgets.VBox()
        fr = Widgets.Frame(" Image Server ")
        fr.set_widget(vbox)
        hbox.add_widget(fr, stretch=0)

        captions = (('Server:', 'llabel'),
                    ('Server', 'combobox'),
                    ('Use DSS channel', 'checkbutton'),
                    ('Get Image', 'button'))
        w, b = Widgets.build_info(captions)
        self.w.update(b)

box, sw, orientation = Widgets.get_oriented_box(container)
        box.set_border_width(4)
        box.set_spacing(2)

        paned = Widgets.Splitter(orientation=orientation)
        self.w.splitter = paned

        self.plot = plots.Plot(logger=self.logger,
                               width=400, height=400)
        ax = self.plot.add_axis()
        ax.grid(True)
        w = Plot.PlotWidget(self.plot)
        w.resize(400, 400)
        paned.add_widget(Widgets.hadjust(w, orientation))

        vbox = Widgets.VBox()
        vbox.set_border_width(2)

        # for statistics line
        self.w.stats1 = Widgets.Label('')
        vbox.add_widget(self.w.stats1)

        captions = (('Cut Low:', 'label', 'Cut Low', 'entry'),
                    ('Cut High:', 'label', 'Cut High', 'entry',
                     'Cut Levels', 'button'),
                    ('Auto Levels', 'button'),
                    ('Log Histogram', 'checkbutton',
                     'Plot By Cuts', 'checkbutton'),
                    ('NumBins:', 'label', 'NumBins', 'entry'),
                    ('Full Image', 'button'),
                    )

def add_viewer(self, name, settings, workspace=None):

        vbox = Widgets.VBox()
        vbox.set_border_width(1)
        vbox.set_spacing(0)

        if not workspace:
            workspace = self.main_wsname
        w = self.ds.get_nb(workspace)

        size = (700, 700)
        if isinstance(w, Widgets.MDIWidget) and w.true_mdi:
            size = (300, 300)

        # build image viewer & widget
        fi = self.build_viewpane(settings, size=size)

        # add scrollbar support
        scr_val = settings.setdefault('scrollbars', None)

def show_help_text(self, name, help_txt, wsname='right'):
        """
        Show help text in a closeable tab window.  The title of the
        window is set from ``name`` prefixed with 'HELP:'
        """
        tabname = 'HELP: {}'.format(name)
        group = 1
        tabnames = self.ds.get_tabnames(group)
        if tabname in tabnames:
            # tab is already up somewhere
            return

        vbox = Widgets.VBox()
        vbox.set_margins(4, 4, 4, 4)
        vbox.set_spacing(2)

        msg_font = self.get_font('fixed', 12)
        tw = Widgets.TextArea(wrap=False, editable=False)
        tw.set_font(msg_font)
        tw.set_text(help_txt)
        vbox.add_widget(tw, stretch=1)

        btns = Widgets.HBox()
        btns.set_border_width(4)
        btns.set_spacing(3)

        def _close_cb(w):
            self.ds.remove_tab(tabname)

plname = pInfo.name
        lname = pInfo.name.lower()
        if lname in self.active:
            if alreadyOpenOk:
                self.set_focus(pInfo.name)
                return
            raise PluginManagerError("Plugin %s is already active." % (
                plname))

        # Raise tab with GUI
        pInfo.tabname = pInfo.spec.get('tab', plname)
        vbox = None
        had_error = False
        try:
            if hasattr(pInfo.obj, 'build_gui'):
                vbox = Widgets.VBox()

                # attach size of workspace to container so plugin
                # can plan for how to configure itself
                wd, ht = self.ds.get_ws_size(pInfo.spec.ws)
                vbox.size = (wd, ht)

                if future:
                    pInfo.obj.build_gui(vbox, future=future)
                else:
                    pInfo.obj.build_gui(vbox)

        except Exception as e:
            errstr = "Plugin UI failed to initialize: %s" % (
                str(e))
            self.logger.error(errstr)
            try:

w.set_widget(Widgets.Label("Framed content"))
    vbox.add_widget(w)

elif wname == 'expander':
    w = Widgets.Expander(title="Expander Title")
    w.set_widget(Widgets.Label("Expander content"))
    vbox.add_widget(w)

elif wname == 'hbox':
    w = Widgets.HBox()
    w.add_widget(Widgets.Label("Item 1"), stretch=0)
    w.add_widget(Widgets.Label("Item 2"), stretch=1)
    vbox.add_widget(w)

elif wname == 'vbox':
    w = Widgets.VBox()
    w.add_widget(Widgets.Label("Item 1"), stretch=0)
    w.add_widget(Widgets.Label("Item 2"), stretch=1)
    vbox.add_widget(w)

elif wname == 'splitter':
    w = Widgets.Splitter(orientation='horizontal')
    w.add_widget(Widgets.Label('Content of Pane 1'))
    w.add_widget(Widgets.Label('Content of Pane 2'))
    vbox.add_widget(w, stretch=1)

elif wname == 'scrollarea':
    w = Widgets.ScrollArea()
    img = Widgets.Image()
    img.load_file(os.path.join(icondir, 'ginga-512x512.png'))
    w.set_widget(img)
    vbox.add_widget(w, stretch=1)