def live_input_point(self, new_pt, clear_ahead_secs=0.01):
    (x, y) = new_pt
    exist = self.points_between(x, (x + clear_ahead_secs))
    for pt in exist:
        self.remove_point(pt)
    self.insert_pt(new_pt)
    dispatcher.send('points changed', sender=self)
def live_input_point(self, new_pt, clear_ahead_secs=0.01):
    (x, y) = new_pt
    exist = self.points_between(x, (x + clear_ahead_secs))
    for pt in exist:
        self.remove_point(pt)
    self.insert_pt(new_pt)
    dispatcher.send('points changed', sender=self)