code: def set_widget(self, canvas):
          
          self.tkcanvas = canvas
  
          canvas.bind("<Configure>", self._resize_cb)
          width = canvas.winfo_width()
          height = canvas.winfo_height()
  
          # see reschedule_redraw() method
          self._defer_task = TkHelp.Timer(tkcanvas=canvas)
          self._defer_task.add_callback('expired',
                                        lambda timer: self.delayed_redraw())
          self.msgtask = TkHelp.Timer(tkcanvas=canvas)
          self.msgtask.add_callback('expired',
                                    lambda timer: self.onscreen_message(None))
  
          self.configure_window(width, height)
docs: Call this method with the Tkinter canvas that will be used
          for the display.