动态添加时间范围，如何实现已选时间段的置灰效果？

<template>
  <el-table :data="tabledata">
    <el-table-column prop="starttime" label="开始时段"></el-table-column>
    <el-table-column prop="endtime" label="结束时段"></el-table-column>
    <el-table-column prop="remark" label="备注"></el-table-column>
    <el-table-column label="操作">
      <template slot-scope="scope">
        <el-button type="primary" @click="handleedit(scope.row)">编辑</el-button>
        <el-button type="danger" @click="handledelete(scope.row)">删除</el-button>
      </template>
    </el-table-column>
  </el-table>
</template>

<script>
import { reactive, ref } from 'vue';
import editdialog from './editdialog.vue';

export default {
  data() {
    return {
      tabledata: reactive([]),
    }
  },
  components: { editdialog },
  methods: {
    // 编辑时间范围
    handleedit(row) {
      this.$refs.editdialog.toggledialog(row);
    },

    // 删除时间范围
    handledelete(row) {
      this.tabledata = this.tabledata.filter(item => item !== row);
    },
  },
}
</script>

<template>
  <el-dialog :visible="visible" title="编辑时间范围" @close="handleClose">
    <el-form
      :model="formData"
      label-position="top"
      label-width="100px"
      class="edit-dialog-form"
    >
      <el-form-item label="开始时段">
        <el-time-picker v-model="formData.startTime" format="HH:mm"></el-time-picker>
      </el-form-item>
      <el-form-item label="结束时段">
        <el-time-picker v-model="formData.endTime" format="HH:mm"></el-time-picker>
      </el-form-item>
      <el-form-item label="备注">
        <el-input v-model="formData.remark" placeholder="请输入备注"></el-input>
      </el-form-item>
    </el-form>
    <div class="dialog-footer" slot="footer">
      <el-button @click="handleClose">取消</el-button>
      <el-button type="primary" @click="handleSave">保存</el-button>
    </div>
  </el-dialog>
</template>

<script>
import { ref } from 'vue';
import { validateTimeRange } from '@/utils/time';

export default {
  props: ['visible', 'row'],
  setup(props, { emit }) {
    const formData = ref(props.row ? Object.assign({}, props.row) : {});

    const handleClose = () => {
      emit('close');
    };

    const handleSave = () => {
      const isValid = validateTimeRange(formData.value);
      if (!isValid) {
        return;
      }

      emit('save', formData.value);
      handleClose();
    };

    return { formData, handleClose, handleSave };
  },
};
</script>