openlayermap/src/supermap/common/commontypes/geometry/Polygon.js

openlayer Map Component for Vue 2.0

import {SuperMap} from '../../SuperMap'
import {Collection} from './Collection'
import './Point'
import './LineString'
import './LinearRing'

/**
 * @class SuperMap.Geometry.Polygon
 * @classdesc  多边形几何对象类。
 * @category BaseTypes Geometry
 * @extends {SuperMap.Geometry.Collection}
 * @param components - {Array<SuperMap.Geometry.LinearRing>} 用来生成多边形的线环数组。
 * @example
 * var points =[new SuperMap.Geometry.Point(0,4010338),
 *      new SuperMap.Geometry.Point(1063524,4010338),
 *      new SuperMap.Geometry.Point(1063524,3150322),
 *      new SuperMap.Geometry.Point(0,3150322)
 *  ],
 *  var linearRings = new SuperMap.Geometry.LinearRing(points),
 *  var  region = new SuperMap.Geometry.Polygon([linearRings])
 */
export class Polygon extends Collection {
  constructor (components) {
    super(components)
        /**
         * @member SuperMap.Geometry.Polygon.prototype.componentTypes -{Array<string>}
         * @description components存储的的几何对象所支持的几何类型数组,为空表示类型不受限制。
         * @readonly
         * @default ["{@link SuperMap.Geometry.LinearRing}"]
         */
    this.componentTypes = ['SuperMap.Geometry.LinearRing']
    this.CLASS_NAME = 'SuperMap.Geometry.Polygon'
  }

    /**
     * @function SuperMap.Geometry.Polygon.prototype.getArea
     * @description 获得区域面积，从区域的外部口径减去计此区域内部口径算所得的面积。
     * @returns {float} 几何对象的面积。
     */
  getArea () {
    var area = 0.0
    if (this.components && (this.components.length > 0)) {
      area += Math.abs(this.components[0].getArea())
      for (var i = 1, len = this.components.length; i < len; i++) {
        area -= Math.abs(this.components[i].getArea())
      }
    }
    return area
  }
}

SuperMap.Geometry.Polygon = Polygon