共计 1936 个字符，预计需要花费 5 分钟才能阅读完成。
Math.easeInOutQuad = function (t, b, c, d) {
t /= d / 2
if (t < 1) {
return c / 2 * t * t + b}
t–
return -c / 2 (t (t – 2) – 1) + b
}
// requestAnimationFrame for Smart Animating http://goo.gl/sx5sts
var requestAnimFrame = (function () {
return window.requestAnimationFrame || window.webkitRequestAnimationFrame || window.mozRequestAnimationFrame || function (callback) {window.setTimeout(callback, 1000 / 60) }
})()
/**
- Because it’s so fucking difficult to detect the scrolling element, just move them all
- @param {number} amount
*/
function move(amount, domTarget) {
if (domTarget && document.querySelector(domTarget)) {
document.querySelector(domTarget).scrollTop = amount} else if (document.querySelector(‘.base’)) {
document.querySelector('.base').scrollTop = amount}
document.documentElement.scrollTop = amount
document.body.parentNode.scrollTop = amount
document.body.scrollTop = amount
}
function position(domTarget) {
if (domTarget && document.querySelector(domTarget)) {
return document.querySelector(domTarget).scrollTop || document.documentElement.scrollTop || document.body.parentNode.scrollTop || document.body.scrollTop}
return document.querySelector(‘.base’) && document.querySelector(‘.base’).scrollTop || document.documentElement.scrollTop || document.body.parentNode.scrollTop || document.body.scrollTop
}
/**
- @param {number} to
- @param {number} duration
- @param {Function} callback
*/
export function scrollTo(to, duration, callback, domTarget) {
const start = position(domTarget)
const change = to – start
const increment = 20
let currentTime = 0
duration = (typeof (duration) === ‘undefined’) ? 500 : duration
var animateScroll = function () {
// increment the time
currentTime += increment
// find the value with the quadratic in-out easing function
var val = Math.easeInOutQuad(currentTime, start, change, duration)
// move the document.body
move(val, domTarget)
// do the animation unless its over
if (currentTime < duration) {requestAnimFrame(animateScroll)
} else {if (callback && typeof (callback) === 'function') {
// the animation is done so lets callback
callback()}
}}
animateScroll()
}
// 代码中应用
// import {scrollTo} from “Tools/scroll-to”;
// scrollTo(0, 1600, ”, ‘.target’);
