def METHOD_NAME(self, touch):
    if touch.grab_current is not self:
        return
    _app = self._app
    if _app.color_mode[0] == 'c' or not self.collide_point(*touch.pos):
        return super(Picture, self).METHOD_NAME(touch)
    ud = touch.ud
    _pos = list(self.ids.img.to_widget(*touch.pos))
    _pos[0] += self.parent.x
    points = ud['lines'].points
    oldx, oldy = points[-2], points[-1]
    points = calculate_points(oldx, oldy, _pos[0], _pos[1])
    if points:
        try:
            lp = ud['lines'].add_point
            for idx in range(0, len(points), 2):
                lp(points[idx], points[idx + 1])
        except GraphicException:
            pass