30 lines
688 B
JavaScript
30 lines
688 B
JavaScript
|
// https://gist.github.com/andjosh/6764939
|
||
|
|
export const scrollTo = (element, to, duration) => {
|
||
|
|
var start = element.scrollTop,
|
||
|
|
change = to - start,
|
||
|
|
currentTime = 0,
|
||
|
|
increment = 20
|
||
|
|
|
||
|
|
var animateScroll = function () {
|
||
|
|
currentTime += increment
|
||
|
|
var val = Math.easeInOutQuad(currentTime, start, change, duration)
|
||
|
|
element.scrollTop = val
|
||
|
|
if (currentTime < duration) {
|
||
|
|
setTimeout(animateScroll, increment)
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
animateScroll()
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
//t = current time
|
||
|
|
//b = start value
|
||
|
|
//c = change in value
|
||
|
|
//d = duration
|
||
|
|
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
|
||
|
|
}
|