def METHOD_NAME(self, event):
    if event.is_dragging:
        dxy = event.pos - event.last_event.pos
        button = event.press_event.button
        if button == 1:
            self.points.transform.move(dxy)
        elif button == 2:
            center = event.press_event.pos
            self.points.transform.zoom(np.exp(dxy * (0.01, -0.01)), center)
        self.update()