<template>
  <scroll-view ref="scroll" @scroll="onScroll" class="page" bounces="false">
    <view class="content-item">
      <text class="text">向上滑动页面，体验元素吸顶效果。</text>
    </view>
    <view v-for="(item,index) in list" :key="index" class="content-item">
      <text class="text">first content-{{item}}</text>
    </view>

    <view ref="sticky" class="search">
      <view style="flex-direction: row;">
        <image src="/static/template/scroll-fold-nav/search.png" style="width: 15px;" mode="widthFix"></image>
        <text class="search-tip-text">请输入你要搜索的内容</text>
      </view>
      <text class="search-btn">搜索</text>
    </view>

    <view v-for="(item,index) in list" :key="index" class="content-item">
      <text class="text">second content-{{item}}</text>
    </view>

    <view v-for="(item,index) in list" :key="index" class="content-item">
      <text class="text">second content-{{item}}</text>
    </view>

  </scroll-view>
</template>

<script>
  export default {
    data() {
      return {
        list: ['1', '2', '3', '4', '5', '6', '7', '8', '9', '10', '11', '12', '13', '14', '15'],
        stickyTop: 0,
        stickyTran: 0,
        scrollTop: 0,
        stickyNode: null as UniElement | null
      }
    },
    methods: {
      onScroll(e : ScrollEvent) {
        if (e.detail.scrollTop > this.stickyTop) {
          let stickyTran = e.detail.scrollTop - this.stickyTop;
          if (stickyTran != this.stickyTran) {
            this.stickyNode?.style?.setProperty('transform', 'translateY(' + stickyTran + 'px)');
          }
          this.stickyTran = stickyTran;
        } else {
          this.stickyNode?.style?.setProperty('transform', '');
          this.stickyTran = 0;
        }
      },
      back() {
        uni.navigateBack({
          success(result) {
            console.log('navigateBack success', result.errMsg)
          },
          fail(error) {
            console.log('navigateBack fail', error.errMsg)
          },
          complete(result) {
            console.log('navigateBack complete', result.errMsg)
          },
        })
      },
      async calcStickyTop() {
        this.stickyNode = this.$refs['sticky'] as UniElement;
        // let rect = this.stickyNode?.getBoundingClientRect();
        // this.stickyTop = rect?.top;
        //this.stickyTop = this.stickyNode?.getBoundingClientRect()?.top;
        const stickyRect = await (this.$refs['sticky'] as UniElement).getBoundingClientRectAsync()!;
        const scrollRect = await (this.$refs['scroll'] as UniElement).getBoundingClientRectAsync()!;
        this.stickyTop = stickyRect.top - scrollRect.top;
        console.log(stickyRect, scrollRect);
      }
    },
    onLoad() {
    },
    onReady() {
      this.calcStickyTop()
    }
  }
</script>

<style>
  .page {
    flex: 1;
    padding: 0 15px;
    background-color: #f5f5f5;
  }

  .content-item {
    padding: 15px;
    margin: 5px 0;
    background-color: #fff;
    border-radius: 5px;

  }

  .text {
    font-size: 14px;
    color: #666;
    line-height: 20px;
  }

  .search {
    background-color: #FFFFFF;
    border: 1px solid #fbdf0d;
    height: 35px;
    border-radius: 100px;
    margin: 0 12px;
    padding: 8px;
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
    z-index: 100;
  }

  .search-tip-text {
    font-size: 12px;
    color: #666;
  }

  .search-btn {
    font-size: 12px;
    background-color: #ff6900;
    color: #FFF;
    padding: 5px 8px;
    border-radius: 100px;
  }
</style>