def text(self):
        """Get indent text as \t or string of spaces
        """
        if self.useTabs:
            return '\t'
        else:
            return ' ' * self.width
def getR(self):
        # x 分量與 y 分量
        x = self.p1.x - self.p2.x
        y = self.p1.y - self.p2.y
        return math.sqrt(x * x + y * y)