code: def _onIdle(self, evt):
          'a GUI idle event'
          evt.Skip()
          FigureCanvasBase.idle_event(self, guiEvent=evtf _onIdle(self, evt):
          'a GUI idle event'
          evt.Skip()
          FigureCanvasBase.idle_event(self, guiEvent=evt)
docs: a GUI idle event