<el-tabs
      class="customer-tab"
      type="card"
      @tab-click="jump"
      v-model="tabName"
    >
      <el-tab-pane
        v-for="(tab, index) in tabs"
        :name="tab.refName"
        :key="index"
        :label="tab.name"
      ></el-tab-pane>
    </el-tabs>
    <div
      class="scroll-content"
      @scroll="onScroll"
      :style="
        'overflow-x: hidden; overflow-y: auto;height:' + contentStyleObj.height
      "
    >
      <!-- 用戶管理 -->
      <div :ref="tabs[0].refName" class="scroll-item">
        <div class="line-name">
          <h2>{{ tabs[0].name }}</h2>
        </div>
        <div>
          <p
            style="height: 40px"
            v-for="item in [
              0, 1, 2, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,
            ]"
            :key="item"
          >
            待發(fā)貨符合規(guī)范化如故
          </p>
        </div>
      </div>
      <!-- 配置管理 -->
      <div :ref="tabs[1].refName" class="scroll-item">
          <div class="line-name">
          <h2>{{ tabs[1].name }}</h2>
        </div>
        <div>
          <p
            style="height: 40px"
            v-for="item in [
              0, 1, 2, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,
            ]"
            :key="item"
          >
            新能說出的基本功發(fā)到你DNF不得發(fā)布
          </p>
        </div>
      </div>
      <!-- 角色管理 -->
      <div
        :ref="tabs[2].refName"
        class="scroll-item"
        style="padding-top: 1rem; top: 5px"
      >
      <div class="line-name">
          <h2>{{ tabs[2].name }}</h2>
        </div>
        <div>
          <p
            v-for="item in [
              0, 1, 2, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,
            ]"
            :key="item"
          >
            新水泥廠劇場版
          </p>
        </div>
      </div>
      <!-- 角色管理2 -->
      <div
        :ref="tabs[3].refName"
        class="scroll-item"
        style="padding-top: 1rem; top: 5px"
      >
      <div class="line-name">
          <h2>{{ tabs[3].name }}</h2>
        </div>
        <div>
          <p
            v-for="item in [
              0, 1, 2, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,
            ]"
            :key="item"
          >
            新水泥廠劇場版
          </p>
        </div>
      </div>
    </div>

<script>
export default {
  name: 'index',
  props: {},
  components: {},
  data() {
    return {
      tabIndex: '0',
      contentStyleObj: {
        height: '100px',
      },
      tabName: 'setOneRef',
      tabs: [
        {
          name: '用戶管理',
          refName: 'setOneRef',
        },
        {
          name: '配置管理',
          refName: 'setTwoRef',
        },
        {
          name: '角色管理',
          refName: 'setThreeRef',
        },
        {
          name: '角色管理2',
          refName: 'setFourRef',
        },
      ],
    }
  },
  computed: {},
  watch: {},
  created() {
    this.getHight()
    window.addEventListener('resize', this.getHight)
  },
  destroyed() {
    window.removeEventListener('resize', this.getHight)
  },
  methods: {
    // tab click
    jump(tab, event) {
      let target = document.querySelector('.scroll-content')
      let scrollItems = document.querySelectorAll('.scroll-item')
      // 判斷滾動條是否滾動到底部
      if (target.scrollHeight <= target.scrollTop + target.clientHeight) {
        this.tabIndex = tab.index.toString()
      }
      let totalY = scrollItems[tab.index].offsetTop - scrollItems[0].offsetTop // 錨點元素距離其offsetParent(這里是body)頂部的距離(待滾動的距離)
      let distance = document.querySelector('.scroll-content').scrollTop // 滾動條距離滾動區(qū)域頂部的距離
      // let distance = document.body.scrollTop || document.documentElement.scrollTop || window.pageYOffset // 滾動條距離滾動區(qū)域頂部的距離(滾動區(qū)域為窗口)
      // 滾動動畫實現(xiàn), 使用setTimeout的遞歸實現(xiàn)平滑滾動，將距離細分為50小段，10ms滾動一次
      // 計算每一小段的距離
      let step = totalY / 50
      if (totalY > distance) {
        smoothDown(document.querySelector('.scroll-content'))
      } else {
        let newTotal = distance - totalY
        step = newTotal / 50
        smoothUp(document.querySelector('.scroll-content'))
      }

      // 參數(shù)element為滾動區(qū)域
      function smoothDown(element) {
        if (distance < totalY) {
          distance += step
          element.scrollTop = distance
          setTimeout(smoothDown.bind(this, element), 10)
        } else {
          element.scrollTop = totalY
        }
      }

      // 參數(shù)element為滾動區(qū)域
      function smoothUp(element) {
        if (distance > totalY) {
          distance -= step
          element.scrollTop = distance
          setTimeout(smoothUp.bind(this, element), 10)
        } else {
          element.scrollTop = totalY
        }
      }
    },
    // 滾動條滾動
    onScroll(e) {
      let scrollItems = document.querySelectorAll('.scroll-item')
      for (let i = scrollItems.length - 1; i >= 0; i--) {
        // 判斷滾動條滾動距離是否大于當前滾動項可滾動距離
        let judge =
          e.target.scrollTop >=
          scrollItems[i].offsetTop - scrollItems[0].offsetTop - 400
        if (judge) {
          this.tabIndex = i.toString()
          // 找對應的tab-name值
          this.tabName = this.tabs[this.tabIndex].refName
          break
        }
      }
    },
    getHight() {
      this.contentStyleObj.height = window.innerHeight - 190 + 'px'
    },
  },
}
</script>

<style lang="scss" scoped>
::v-deep.customer-tab {
  width: 100%;
  height: 50px;
  background-color:#f5f7fa;
  padding: 4px;
}
::v-deep.el-tabs--card > .el-tabs__header {
  border-bottom: none;
  margin: 0;
  .el-tabs__nav {
    width: 100%;
    display: flex;
    justify-content: space-around;
    border: none;
    .el-tabs__item {
      width: 25%;
      text-align: center;
      border: none;
    }
    .is-active {
      border-radius: 4px;
      background-color: #005BD9;
      color: #fff;
    }
  }
}
</style>