moveCtrl (num, dx, dy) {
    const { item } = this
    item['x' + num] += dx
    item['y' + num] += dy

    const pts = [
      item.x, item.y,
      item.x1, item.y1, item.x2, item.y2
    ]

    replacePathSegMethod(this.type, this.index, pts)
    this.update(true)
  }
@param {Integer} num
@param {Integer} dx
@param {Integer} dy
@returns {void}