slble-attend/sl.ble_sys-attend/src-js/components/MapEditor/distanceToolEx.js

import * as maptalks from 'maptalks'

class DistanceToolEx extends maptalks.DistanceTool {
  constructor(options) {
    super(options)
    this._measureLayers = []
  }

  _measure(toMeasure) {
    const map = this.getMap()
    let length
    if (toMeasure instanceof maptalks.Geometry) {
      length = map.computeGeometryLength(toMeasure)
    } else if (Array.isArray(toMeasure)) {
      length = map.getProjection().measureLength(toMeasure)
    }
    this._lastMeasure = length
    let units
    if (this.options['language'] === 'zh-CN') {
      units = [' 米', ' 公里', ' 英尺', ' 英里']
    } else {
      units = [' m', ' km', ' feet', ' mile']
    }
    let content = ''
    if (this.options['metric']) {
      content += length < 1000 ? length.toFixed(3) + units[0] : (length / 1000).toFixed(2) + units[1]
    }
    if (this.options['imperial']) {
      length *= 3.2808399
      if (content.length > 0) {
        content += '\n'
      }
      content += length < 5280 ? length.toFixed(3) + units[2] : (length / 5280).toFixed(2) + units[3]
    }
    return content
  }
}

export default DistanceToolEx