title: How to disabled the other legends when clicking the first legend in echarts
body: <p>Here's the code: </p>
  
  <pre><code>option = {
      title: {
          text: '堆叠区域图'
      },
      tooltip: {
          trigger: 'axis',
          axisPointer: {
              type: 'cross',
              label: {
                  backgroundColor: '#6a7985'
              }
          }
      },
      legend: {
          data: ['邮件营销', '联盟广告', '视频广告', '直接访问', '搜索引擎'],
          selected: {
              '邮件营销': false
          }
      },
      toolbox: {
          feature: {
              saveAsImage: {}
          }
      },
      grid: {
          left: '3%',
          right: '4%',
          bottom: '3%',
          containLabel: true
      },
      xAxis: [
          {
              type: 'category',
              boundaryGap: false,
              data: ['周一', '周二', '周三', '周四', '周五', '周六', '周日']
          }
      ],
      yAxis: [
          {
              type: 'value'
          }
      ],
      series: [
          {
              name: '邮件营销',
              type: 'line',
              stack: '总量',
              areaStyle: {},
              data: [120, 132, 101, 134, 90, 230, 210]
          },
          {
              name: '联盟广告',
              type: 'line',
              stack: '总量',
              areaStyle: {},
              data: [220, 182, 191, 234, 290, 330, 310]
          },
          {
              name: '视频广告',
              type: 'line',
              stack: '总量',
              areaStyle: {},
              data: [150, 232, 201, 154, 190, 330, 410]
          },
          {
              name: '直接访问',
              type: 'line',
              stack: '总量',
              areaStyle: {},
              data: [320, 332, 301, 334, 390, 330, 320]
          },
          {
              name: '搜索引擎',
              type: 'line',
              stack: '总量',
              label: {
                  normal: {
                      show: true,
                      position: 'top'
                  }
              },
              areaStyle: {},
              data: [820, 932, 901, 934, 1290, 1330, 1320]
          }
      ]
  };
  </code></pre>
  
  <p>What I want to do is when I click the <code>邮件营销</code> it should show the series and disabled/hide all the other legend except the <code>邮件营销</code> that I clicked. 
  <a href="https://i.stack.imgur.com/vOgcV.png" rel="nofollow noreferrer">enter image description here</a></p>
  
  <p>and when I click the other legend the <code>邮件营销</code> will disabled/hide the series and it will show the series that I clicked.
  <a href="https://i.stack.imgur.com/aQk4i.png" rel="nofollow noreferrer">enter image description here</a></p>
  
  <p>but when I clicked the <code>邮件营销</code> again it will hide/disabled the other legends.</p>