def __init__(self, **kw): super(View, self).__init__(**kw) self.orientation='vertical' self._do_update=False progress=ProgressBar() progress.size_hint=(1., None) progress.height=3 self._progress=progress self.add_widget(progress) btn_0=Button(text='Pipe') btn_0.bind(on_press=self.on_press_pipe) self.add_widget(btn_0) btn_1=Button(text='Transcoder') btn_1.bind(on_press=self.on_press_transcoder) self.add_widget(btn_1)