树图中设置了roam=true。我现在想要监听树图缩放,该如何做

描述:当前是关于Echarts图表中的 树图 示例。
 
            var data =  [{
    "children": [{
      "name": "aaa",
      "id": 10838,
      "count": 0,
      "level": 2,
      "desc": "11",
      "companyCode": 1000000000,
      "createTime": "2018-10-23"
    }, {
      "children": [{
        "name": "Java开发",
        "id": 10628,
        "count": 5,
        "level": 3,
        "desc": "",
        "companyCode": 1000000000,
        "createTime": "2018-06-27"
      }],
      "name": "研发中心",
      "id": 10627,
      "count": 9,
      "level": 2,
      "desc": "",
      "companyCode": 1000000000,
      "createTime": "2018-06-27"
    }, {
      "children": [{
        "name": "UI设计",
        "id": 10629,
        "count": 1,
        "level": 3,
        "desc": "",
        "companyCode": 1000000000,
        "createTime": "2018-06-27"
      }],
      "name": "产品部",
      "id": 10626,
      "count": 3,
      "level": 2,
      "desc": "",
      "companyCode": 1000000000,
      "createTime": "2018-06-27"
    }, {
      "children": [{
        "name": "商务一部",
        "id": 10573,
        "count": 1,
        "level": 3,
        "desc": "",
        "companyCode": 1000000000,
        "createTime": "2018-06-20"
      }],
      "name": "商务部",
      "id": 10443,
      "count": 1,
      "level": 2,
      "desc": "",
      "companyCode": 1000000000,
      "createTime": "2018-06-11"
    }, {
      "children": [{
        "name": "后勤组",
        "id": 10622,
        "count": 0,
        "level": 3,
        "desc": "",
        "companyCode": 1000000000,
        "createTime": "2018-06-27"
      }, {
        "children": [{
          "name": "招聘2组",
          "id": 10631,
          "count": 0,
          "level": 4,
          "desc": "1111@#$$%",
          "companyCode": 1000000000,
          "createTime": "2018-06-27"
        }, {
          "name": "招聘一组",
          "id": 10630,
          "count": 0,
          "level": 4,
          "desc": "",
          "companyCode": 1000000000,
          "createTime": "2018-06-27"
        }],
        "name": "招聘组",
        "id": 10621,
        "count": 0,
        "level": 3,
        "desc": "",
        "companyCode": 1000000000,
        "createTime": "2018-06-27"
      }],
      "name": "行政部",
      "id": 10407,
      "count": 0,
      "level": 2,
      "desc": "",
      "companyCode": 1000000000,
      "createTime": "2018-06-08"
    }, {
      "children": [{
        "name": "客服部",
        "id": 10625,
        "count": 0,
        "level": 3,
        "desc": "",
        "companyCode": 1000000000,
        "createTime": "2018-06-27"
      }, {
        "children": [{
          "children": [{
            "name": "B组",
            "id": 10633,
            "count": 0,
            "level": 5,
            "desc": "",
            "companyCode": 1000000000,
            "createTime": "2018-06-27"
          }],
          "name": "A组",
          "id": 10632,
          "count": 0,
          "level": 4,
          "desc": "",
          "companyCode": 1000000000,
          "createTime": "2018-06-27"
        }],
        "name": "运营二部",
        "id": 10624,
        "count": 0,
        "level": 3,
        "desc": "",
        "companyCode": 1000000000,
        "createTime": "2018-06-27"
      }, {
        "name": "运营一部",
        "id": 10623,
        "count": 2,
        "level": 3,
        "desc": "",
        "companyCode": 1000000000,
        "createTime": "2018-06-27"
      }],
      "name": "运营部",
      "id": 10398,
      "count": 6,
      "level": 2,
      "desc": "运营中心啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊顶顶顶顶顶顶顶顶顶顶顶顶顶顶顶顶顶顶顶呱呱呱呱呱呱呱呱呱呱呱呱呱呱呱古古怪怪哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈她她她她她她她她她她她她她她她她她她她斤",
      "companyCode": 1000000000,
      "createTime": "2018-06-07"
    }, {
      "name": "测试部",
      "id": 10392,
      "count": 5,
      "level": 2,
      "desc": "",
      "companyCode": 1000000000,
      "createTime": "2018-06-07"
    }, {
      "children": [{
        "name": "11",
        "id": 11001,
        "count": 0,
        "level": 3,
        "desc": "11",
        "companyCode": 1000000000,
        "createTime": "2019-11-13"
      }, {
        "children": [{
          "children": [{
            "name": "销售B",
            "id": 10572,
            "count": 13,
            "level": 5,
            "desc": "",
            "companyCode": 1000000000,
            "createTime": "2018-06-20"
          }],
          "name": "销售A",
          "id": 10571,
          "count": 14,
          "level": 4,
          "desc": "",
          "companyCode": 1000000000,
          "createTime": "2018-06-20"
        }],
        "name": "销售一组",
        "id": 10570,
        "count": 16,
        "level": 3,
        "desc": "",
        "companyCode": 1000000000,
        "createTime": "2018-06-20"
      }],
      "name": "销售部",
      "id": 10257,
      "count": 23,
      "level": 2,
      "desc": "销售部",
      "companyCode": 1000000000,
      "createTime": "2018-06-07"
    }],
    "name": "test公司",
    "id": 1,
    "count": 60,
    "level": 1,
    "companyCode": 1000000000,
    "createTime": "2018-05-26"
  }]

option = {
        calculable: false,
        tooltip: {
          trigger: 'item',
          triggerOn: 'click',
          position: 'inside',
          renderMode: 'html',
          // appendToBody: true,
          formatter: function (params) {
            that.echartNowClickData = params.data
            let html = '<div style="width:190px;height:90px;display:flex;justify-content: space-between; flex-direction: column;align-items:flex-end">' +
              '<span  style="pointer-events: all;display:block;width:29px;height:29px;border-radius: 50%;background: #1AA094;text-align:center;font-size: 18px;padding-top: 5px;" class="el-icon-plus"></span>' +
              '<sapn  style="pointer-events: all;display:block;width:29px;height:29px;border-radius: 50%;background: #1AA094;text-align:center;font-size: 18px;padding-top: 5px;" class="el-icon-edit-outline"></sapn>' +
              '<sapn  style="pointer-events: all;display:block;width:29px;height:29px;border-radius: 50%;background: #1AA094;text-align:center;font-size: 18px;padding-top: 5px;" class="el-icon-delete"></sapn>' +
              '</div>'
            return html
            // return '<div style="width:190px;height:90px">111</div>'
          }
        },
        toolbox: {
          show: true,
          feature: {
            dataZoom: {
              show: true
            }
          }
        },
        series: [
          {
            name: '树图',
            type: 'tree',
            orient: 'TB', // vertical horizontal
            rootLocation: { x: '50%', y: '15%' }, // 根节点位置  {x: 'center',y: 10}
            nodePadding: 20,
            layerPadding: 40,
            // symbol: 'rectangle',
            borderColor: 'black',
            symbolSize: [200, 100],
            symbol: 'rect',
            symbolKeepAspect: true,
            edgeShape: 'polyline',
            roam: true,
            initialTreeDepth: -1,
            left: '-50%',
            width: 3500,
            expandAndCollapse: false,
            itemStyle: {
              normal: {
                color: '#eeeeee', // 节点背景色
                'borderWidth': 1,
                'borderColor': '#b2d8d4',
                label: {
                  show: true,
                  position: 'inside',
                  lineHeight: 30,
                  textStyle: {
                    color: '#696969',
                    fontSize: 14
                    // fontWeight:  'bolder'
                  },
                  formatter: function (params) {
                    return params.data.name + '\n拥有人数' + params.data.count + '人\n' + params.data.createTime
                  }
                },
                lineStyle: {
                  color: '#7fcac3',
                  width: 1
                  // type: 'broken' // 'curve'|'broken'|'solid'|'dotted'|'dashed'
                }
              },
              emphasis: {
                label: {
                  show: false
                }
              }
            },
            data: data
          }
        ]
};