<!--顶部小标题组件-->
<template>
  <div class="nav_container">
    <div class="iconBox" @click.prevent="change()">
      <i v-if="!isCollapse" class="el-icon-s-unfold" />
      <i v-else class="el-icon-s-fold" />
      <!-- <menu-unfold-outlined v-if="true" />
      <menu-fold-outlined  v-else/> -->
    </div>
    <div>
      <span v-for="(item, index) in list" :key="index" style="margin: 0 5px">
        <!-- <el-button size="small" @click="changeUrl(item.url)">{{ item.title }}</el-button> -->
        <el-tag :key="index" closable @click="changeUrl(item.url)" @close="handleClose(index)">
          {{ item.title }}
        </el-tag>
      </span>
    </div>
  </div>
</template>

<script>
export default {
  model: {
    prop: 'isCollapse',
    event: 'changeIsCollapse'
  },
  props: ['isCollapse'],
  data() {
    return {
      list: []
    }
  },
  watch: {
    $route: {
      handler: function(val, oldVal) {
        // 只判断后一条
        // 防止第一条监听不到
        const index = this.list.findIndex((item) => item.url === val.path)
        if (index != -1 || this.list.length > 10) {
          this.list.splice(index, 1) // 存在则删除
        }
        this.list.push({ url: val.fullPath, title: val.meta.title })
      },
      // 强制立即执行回调
      immediate: true,
      // 深度观察监听
      deep: true
    }
  },
  methods: {
    handleClose(index) {
      this.list.splice(index, 1)
    },
    changeUrl(url) {
      this.$router.push(url)
    },
    change() {
      console.log(!this.isCollapse)
      this.$emit('changeIsCollapse', !this.isCollapse)
    }
  }
}
</script>

<style lang="scss" scoped>
.nav_container {
  display: flex;
  padding: 0 10px;
  box-sizing: border-box;
  align-items: center;
  height: 40px;
  box-shadow: 0px 0px 20px 3px #999;
  position: relative;
  z-index: 1;

  .iconBox {
    // background: red;
    margin: 0 15px 0 0;
    height: 100%;
    width: 40px;
    text-align: center;
    line-height: 40px;
  }
}
</style>