SuperView Element Prototype

by Станислав Некрасов

HTML

<script src="https://fonts.googleapis.com/css2?family=Montserrat:wght@400;700&amp;display=swap"></script>
<div class="super-view"></div>

CSS

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  padding: 10px;
}

.super-view {
  background: #f6f6f6;
  box-shadow: 1px 1px 4px 0 #0008;
  border-radius: 5px;
  width: 150px;
  height: 200px;
  padding: 5px;
  overflow: auto;
}

.num-block {
  background: #fff;
  text-align: center;
  height: 50px;
  font-family: Montserrat, sans-serif;
  font-weight: bold;
  font-size: 32px;
  line-height: 50px;
  border-radius: 5px;
  box-shadow: 1px 1px 2px 0 #0003;
}

.num-block:not(:last-child) {
  margin-bottom: 5px;
}

JavaScript

(function (superView) {
	"use strict";
  function createNumBlock(st) {
  	let element = document.createElement('div');
    element.classList.add('num-block');
   	element.textContent = st.value;
    return element;
  }
  
  async function first(e) {
  	
  }
  
  async function last(e) {
  	
  }
  
  class Struct {
    constructor (value) {
      this.value = value;
    }
    async prev () {
      let prevSt = new Struct(this.value - 1);
      this.prev = async () => prevSt;
      prevSt.next = async () => this;
      return prevSt;
    }
    async next () {
      let nextSt = new Struct(this.value + 1);
      nextSt.prev = async () => this;
      this.next = async () => nextSt;
      return nextSt;
    }
  } 
  
  let struct = new Struct(0);
  
  superView.addEventListener('scroll', function (event) {
  	first(this);
  	last(this);
    
    while (true) {
    	let box = this.firstChild.getBoundingClientRect();
    	this.firstChild.remove();
    }
  });
  
  (async function () {
    for (;struct.value != 10; struct = await struct.next()) {
      superView.append(createNumBlock(struct));
    }
  })();
})(document.querySelector('.super-view'));