<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
<style>
html,body{
margin: 0;
padding: 0;
}
#wrap{
width: 100%;
overflow: hidden;
background: #ccc;
}
#main{
width: 100%;
background: #ccc;
position: relative;
}
.page{
width:100%;
margin:0;
}
#page1{
background:#E4E6CE;
}
#page2{
background:#6CE26C;
}
#page3{
background:#BF4938;
}
#page4{
background:#2932E1;
}
</style>
</head>
<body>
<div id="wrap">
<div id="main">
<div id="page1" class="page"></div>
<div id="page2" class="page"></div>
<div id="page3" class="page"></div>
<div id="page4" class="page"></div>
</div>
</div>
<script>
var pages = document.getElementsByClassName("page");
var wrap = document.getElementById("wrap");
var len = document.documentElement.clientHeight;
var main = document.getElementById("main");
wrap.style.height = len + "px";
for(var i=0; i<pages.length; i++){
pages[i].style.height = len + "px";
}
if(navigator.userAgent.toLowerCase().indexOf("firefox") != -1){
document.addEventListener("DOMMouseScroll",scrollFun);
}else if(document.addEventListener){
document.addEventListener("mousewheel",scrollFun,false);
}else if(document.attachEvent){
document.attachEvent("onmousewheel",scrollFun);
}else{
document.onmousewheel = scrollFun;
}
var startTime = 0;
var endTime = 0;
var now = 0;
function scrollFun(e){
startTime = new Date().getTime();
var event = e || window.event;
var dir = event.detail || -event.wheelDelta;
if(startTime - endTime > 1000){
if(dir>0 && now > -3*len){
now -= len;
// main.style.top = now +"px";
transformScroll(false)
endTime = new Date().getTime();
}else if(dir<0 && now < 0){
now += len;
// main.style.top = now +"px";
transformScroll(true)
endTime = new Date().getTime();
}
}else{
event.preventDefault();
}
}
let current = main.style.top.slice(0,-2)
function transformScroll (bool) {
setTimeout(() => {
if (current !== now) {
if (bool) {
current += 50
current > now ? current = now : ''
} else {
current -= 50
current < now ? current = now : ''
}
main.style.top = current + 'px'
transformScroll(bool)
}
}, 20);
}
</script>
</body>
</html>
