<template>
 <div class="my-scroll" :class="[scrollState?'prohibit':'allow']" ref="myScroll" @scroll.passive="onScroll($event)" @touchmove="onScroll($event)" >
  <!-- top -->
  <div class="scroll-list">
   <slot name='scrollList'></slot>
   <div class="scroll-bottom">
    <div v-if="state==1">
     <i><img :src="Load"/></i>
     <p>加載中</p>
     </div>
    <div v-if="state==2">加載完成</div>
    <div v-if="state==3">沒有數(shù)據(jù)了</div>
   </div>
  </div>
 </div>
</template>
<script type="text/javascript">
import Load from '@/assets/Load.gif'
export default {
 name: 'myScroll',
 props: {
 'onPull': { // 加載回調
  type: Function,
  require: true
 },
 'scrollState': {// 是否可滑動
  type: Boolean,
  require: true
 },
 loaded: {
  type: Boolean,
  default() {
  return false
  }
 }
 },
 data() {
 return {
  Load,
  timeoutId: null,
  state: 0,
  myScroll: null
 }
 },
 methods: {
 /*
    * 加載中：1
    * 加載完成：2
    * 沒有更多：3
    */
 setState(index) { // 修改狀態(tài)
  this.state = index
  // console.log(this.state)
 },
 onScroll(e) {
  const _this = this
  const scrollTop = document.documentElement.scrollTop || document.body.scrollTop
  // console.log(window.innerHeight + scrollTop, this.myScroll.offsetHeight)
  if (!this.loaded && window.innerHeight + scrollTop - 50 >= this.myScroll.offsetHeight) {
  clearTimeout(this.timeoutId)
  _this.timeoutId = setTimeout(() => {
   _this.bottomCallback()
  }, 100)
  }
 },
 bottomCallback() { // 加載回調
  // console.log('回調', new Date().getTime())
  if (this.state != 3) {
  this.state = 1
  this.onPull()
  }
 }
 },
 mounted() {
 this.myScroll = this.$refs.myScroll // 獲取滑條dom
 }
}
</script>
<style lang="scss" scoped>
 .allow{
  overflow:hidden;
  height: auto;
 }
 .prohibit{
  max-width: 100%;
  max-height: 100%;
  height: 100%;
  overflow:hidden;
  overflow-y: scroll;
  -webkit-overflow-scrolling: touch;
  will-change: transform;
  transition: all 450ms;
  backface-visibility: hidden;
  perspective: 1000;
 }
 .my-scroll{
  position: relative;
   color: #999;
  .scroll-top{
   text-align: center;
   display:flex;
   position:absolute;
   top:0;
   left:0;
    width:100%;
    overflow: hidden;
  }
  .scroll-list{
   overflow:hidden;
   min-height: 100%;
  }
  .scroll-bottom{
   text-align: center;
   line-height: .8rem;
  div{
    display:flex;
     height:auto;
    width:100%;
    justify-content: center;
    align-items:center;
    flex-wrap: wrap;
    i{
     flex:1 0 100%;
     display:block;
     height: 0.4rem;
    }
    img{
     width:0.6rem;
    }
    p{
     flex:1 0 100%;
    }
   }
  }
 }
</style>

<template>
 <div id="app">
  <my-scroll class="scrolls" ref="myScroll" :on-pull="getList" :loaded="loaded" :scroll-state="scrollState">
   <div slot="scrollList">
   <div class="list" v-for="(item,index) in listData" :key="index">{{item.name}}</div>
   </div>
  </my-scroll>
 </div>
</template>
<script>
import myScroll from "./components/vue-scroll.vue";
import axios from 'axios'
export default {
 name: "app",
 data(){
 return{
  scrollState: true, // 是否可以滑動
  loaded: false,
  iPage: 1,
  listData:[],
  iPageSize: 10,
 }
 },
 methods: {
 getList(){
  this.$refs.myScroll.setState(1)
  let _this = this
  // ajax 請求
  axios.get('https://easy-mock.com/mock/5b90f971ce624c454133ee2d/scoll/datalist').then(function (response) {
   if (response.data.code == 200 && response.data.data.pagelist.length > 0 && !_this.loaded) {
    if (_this.iPage == 1) {
    _this.listData = response.data.data.pagelist
    } else {
    _this.listData.push(...response.data.data.pagelist)
    }
    _this.iPage++
    _this.$refs.myScroll.setState(2)
   } else {
    if (_this.iPage == 1) {
    _this.czListData = []
    }
    _this.loaded = true
    _this.$refs.myScroll.setState(3)
   } 
   })
   .catch(function (error) {
   console.log(error);
   });
  }

 },
 mounted () {
 this.getList() 
 },
 components: {
 myScroll
 }
};
</script>

<style scoped>
#app {
 font-family: "Avenir", Helvetica, Arial, sans-serif;
 -webkit-font-smoothing: antialiased;
 -moz-osx-font-smoothing: grayscale;
 text-align: center;
 color: #2c3e50;
 margin-top: 60px;
}
.scrolls{
 font-size:.24rem;
}
.list{
 height:.9rem;
 line-height: .9rem;
 margin-bottom:.1rem;
 border-bottom:1px solid #dedede;
 color:#999;
 font-size:.28rem;
}
</style>