Controller that creates window

controller.py

class TKViewController(CementBaseController):

    class Meta:
        label = "tkview"
        stacked_on = 'base'
        stacked_type = 'nested'
        arguments = [
            (['dataset'],
             dict(help='dataset to show',
                  action='store', metavar='DATASET', nargs='?')
             ),
            (['-v', '--version'], dict(action='version', version=BANNER)),
        ]
        default_func = 'default'

    def list(self):

        print("list of available data")

    @expose(help="Tk Chart Viewer for Ranger charts", hide=True)
    def default(self):

        app = self.app

        if not app.pargs.dataset:
            print('No dataset was specified.')
            self.list()
            return

        data = app.database.get_dataset('superdata', app.pargs.dataset)

        model = SuperDataModel()
        model._setup(app, data)

        window = ChartView()
        window._setup(app, model)

        window.title('Tk SuperData View: {} ({})'.format(
            data.name))

        window.mainloop()