Related
The Project: I have setup a scroll function that should scroll to the next item within a container div when clicked "up" or "down." It is leveraging the window.requestAnimationFrame() method for the loop and calling element.scrollTo on each iteration.
The reason I made this is to allow for custom duration, as the "behavior: 'smooth'" setting is a set speed, and I would like to keep the css scroll-snap functionality so it needs to be within a container(So window.scrollTo() is not possible, although that seems to work across browsers).
The Problem: This works perfectly in Safari, but for some reason the .scrollTo() function is not moving the scroll view in Chrome and Firefox.
What I've Tried:
I have tried setting element.scrollTop instead of calling element.scrollTo() with the same outcome.
I read somewhere that Chrome's performance is too quick for certain loops, so I surrounded the element.scrollTo() with a setTimeout(()=>{},1) with varying durations. This did not work either.
My Code: The code is viewable in Codepen.io here
HTML:
<div class="scroll-wrap">
<div id="item-1" class="scroll-item blue">
<h1>1</h1>
<div class="scroll-up"></div>
<div class="scroll-down"></div>
</div>
<div id="item-2" class="scroll-item green">
<h1>2</h1>
<div class="scroll-up"></div>
<div class="scroll-down"></div>
</div>
<div id="item-3" class="scroll-item red">
<h1>3</h1>
<div class="scroll-up"></div>
<div class="scroll-down"></div>
</div>
</div>
JS:
const scrollUps = document.querySelectorAll('.scroll-up')
const scrollDowns = document.querySelectorAll('.scroll-down')
// options...
options = {
scrollWrap: document.querySelector('.scroll-wrap'), // scroll container.
duration: 300, // Pixels per second. The smaller the number the longer the duration.
easing: 'easeInOutSine', // can be easeOutSine, easeInOutSine, easeInOutQuint.
}
// RAF shim from ... http://www.paulirish.com/2011/requestanimationframe-for-smart-animating/
window.requestAnimFrame = (function(){
return window.requestAnimationFrame ||
window.webkitRequestAnimationFrame ||
window.mozRequestAnimationFrame ||
function( callback ){
window.setTimeout(callback, 1000 / 60);
};
})();
// Click Scroll function
function scrollToY(currentPosition, scrollTargetY) {
// currentPostion: the current scrollY property of the view within the scroll container
// scrollTargetY: the target scrollY property of the window
// speed: time in pixels per second
// easing: easing equation to use
var scrollY = currentPosition,
scrollTargetY = scrollTargetY || 0,
speed = options.duration || 2000,
easing = options.easing || 'easeOutSine',
currentTime = 0;
// *For speed in pixels per second...
// min time .1, max time 5 seconds
var time = Math.max(.1, Math.min(Math.abs(scrollY - scrollTargetY) / speed, 5));
// easing equations from https://github.com/danro/easing-js/blob/master/easing.js
const PI_D2 = Math.PI / 2,
easingEquations = {
easeOutSine: function (pos) {
return Math.sin(pos * (Math.PI / 2));
},
easeInOutSine: function (pos) {
return (-0.5 * (Math.cos(Math.PI * pos) - 1));
},
easeInOutQuint: function (pos) {
if ((pos /= 0.5) < 1) {
return 0.5 * Math.pow(pos, 5);
}
return 0.5 * (Math.pow((pos - 2), 5) + 2);
}
};
// animation loop
function tick() {
currentTime += 1 / 60;
const p = currentTime / time;
const t = easingEquations[easing](p);
if (p < 1) {
requestAnimFrame(tick);
const newPosition = scrollY + ((scrollTargetY - scrollY) * t)
setTimeout(()=>{
options.scrollWrap.scrollTo(0, newPosition);
// console.log('scroll:', options.scrollWrap.scrollTop);
},1)
} else {
// console.log('scroll done');
options.scrollWrap.scrollTo(0, scrollTargetY);
}
}
// call it once to get started
tick();
}
// set clickable areas...
Array.from(scrollUps).forEach(btn => {
btn.addEventListener('click', (e) => {
// Get Parent of button...
const parent = e.target.parentElement
// Get destination element...
const destId = `item-${Number(parent.id.split('-')[1]) - 1}`
const dest = document.getElementById(destId)
// call scroll function if destination exists...
if(dest) {
const destDistanceToTop = dest.offsetTop
scrollToY(parent.offsetTop, destDistanceToTop)
}
})
})
Array.from(scrollDowns).forEach(btn => {
btn.addEventListener('click', (e) => {
const parent = e.target.parentElement
const destId = `item-${Number(parent.id.split('-')[1]) + 1}`
const dest = document.getElementById(destId)
if(dest) {
const destDistanceToTop = dest.offsetTop
// console.log(destDistanceToTop, parent.offsetTop)
scrollToY(parent.offsetTop, destDistanceToTop)
}
})
})
This is due to the scroll-snap in CSS. It won't work along with requestAnimationFrame (for some reason).
I removed the scroll-snap from your CSS and it seems to work just fine without it.
I have a strange issue which I can only replicate on Microsoft browsers (Edge and IE11 tested).
<style>
body {
height: 5000px;
width: 5000px;
}
</style>
<p>Click the button to scroll the document window to 1000 pixels.</p>
<button onclick="scrollWin()">Click me to scroll!</button>
<script>
function scrollWin() {
window.scrollTo({
left: 1000,
top: 1000,
behavior:"smooth"
});
}
</script>
This code correctly scrolls the window 1000px to the left and down, with a smooth behaviour in Chrome and Firefox. However, on Edge and IE, it does not move at all.
As mentioned before, the Scroll Behavior specification has only been implemented in Chrome, Firefox and Opera.
Here's a one-liner to detect support for the behavior property in ScrollOptions:
const supportsNativeSmoothScroll = 'scrollBehavior' in document.documentElement.style;
And here's a simple implementation for cross-browser smooth scrolling: https://gist.github.com/eyecatchup/d210786daa23fd57db59634dd231f341
Maybe not a true answer in the sense of the word, but I have solved this problem by using this helpful polyfill: https://github.com/iamdustan/smoothscroll which works really well across all browsers.
Example page for pollyfill: http://iamdustan.com/smoothscroll/
Many thanks to the author.
You can detect support for the behavior option in scrollTo using this snippet:
function testSupportsSmoothScroll () {
var supports = false
try {
var div = document.createElement('div')
div.scrollTo({
top: 0,
get behavior () {
supports = true
return 'smooth'
}
})
} catch (err) {}
return supports
}
Tested in Chrome, Firefox, Safari, and Edge, and seems to work correctly. If supports is false, you fall back to a polyfill.
Indeed, they don't support this variant, MDN articles should be updated.
One way to polyfill this method is to run the scroll method in a requestAnimationFrame powered loop. Nothing too fancy here.
The main problem that arises is how to detect when this variant is not supported. actually #nlawson's answer tackles this problem perfectly...
For this, we can use the fact that a call to Window#scroll will fire a ScrollEvent if the viewPort actually did scroll.
This means we can set up an asynchronous test that will:
Attach an event handler to the ScrollEvent,
Call a first time scroll(left , top) variant to be sure the Event will fire,
Overwrite this call with a second one using the options variant.
In the event handler, if we aren't at the correct scroll position, this means we need to attach our polyfill.
So the caveat of this test is that it is an asynchronous test. But since you need to actually wait for the document has loaded before calling this method, I guess in 99% of cases it will be ok.
Now to less burden the main doc, and since it is already an asynchronous test, we can even wrap this test inside an iframe, which gives us something like:
/* Polyfills the Window#scroll(options) & Window#scrollTo(options) */
(function ScrollPolyfill() {
// The asynchronous tester
// wrapped in an iframe (will not work in SO's StackSnippet®)
var iframe = document.createElement('iframe');
iframe.onload = function() {
var win = iframe.contentWindow;
// listen for a scroll event
win.addEventListener('scroll', function handler(e){
// when the scroll event fires, check that we did move
if(win.pageXOffset < 99) { // !== 0 should be enough, but better be safe
attachPolyfill();
}
// cleanup
document.body.removeChild(iframe);
});
// set up our document so we can scroll
var body = win.document.body;
body.style.width = body.style.height = '1000px';
win.scrollTo(10, 0); // force the event
win.scrollTo({left:100, behavior:'instant'}); // the one we actually test
};
// prepare our frame
iframe.src = "about:blank";
iframe.setAttribute('width', 1);
iframe.setAttribute('height', 1);
iframe.setAttribute('style', 'position:absolute;z-index:-1');
iframe.onerror = function() {
console.error('failed to load the frame, try in jsfiddle');
};
document.body.appendChild(iframe);
// The Polyfill
function attachPolyfill() {
var original = window.scroll, // keep the original method around
animating = false, // will keep our timer's id
dx = 0,
dy = 0,
target = null;
// override our methods
window.scrollTo = window.scroll = function polyfilledScroll(user_opts) {
// if we are already smooth scrolling, we need to stop the previous one
// whatever the current arguments are
if(animating) {
clearAnimationFrame(animating);
}
// not the object syntax, use the default
if(arguments.length === 2) {
return original.apply(this, arguments);
}
if(!user_opts || typeof user_opts !== 'object') {
throw new TypeError("value can't be converted to a dictionnary");
}
// create a clone to not mess the passed object
// and set missing entries
var opts = {
left: ('left' in user_opts) ? user_opts.left : window.pageXOffset,
top: ('top' in user_opts) ? user_opts.top : window.pageYOffset,
behavior: ('behavior' in user_opts) ? user_opts.behavior : 'auto',
};
if(opts.behavior !== 'instant' && opts.behavior !== 'smooth') {
// parse 'auto' based on CSS computed value of 'smooth-behavior' property
// But note that if the browser doesn't support this variant
// There are good chances it doesn't support the CSS property either...
opts.behavior = window.getComputedStyle(document.scrollingElement || document.body)
.getPropertyValue('scroll-behavior') === 'smooth' ?
'smooth' : 'instant';
}
if(opts.behavior === 'instant') {
// not smooth, just default to the original after parsing the oject
return original.call(this, opts.left, opts.top);
}
// update our direction
dx = (opts.left - window.pageXOffset) || 0;
dy = (opts.top - window.pageYOffset) || 0;
// going nowhere
if(!dx && !dy) {
return;
}
// save passed arguments
target = opts;
// save the rAF id
animating = anim();
};
// the animation loop
function anim() {
var freq = 16 / 300, // whole anim duration is approximately 300ms #60fps
posX, poxY;
if( // we already reached our goal on this axis ?
(dx <= 0 && window.pageXOffset <= +target.left) ||
(dx >= 0 && window.pageXOffset >= +target.left)
){
posX = +target.left;
}
else {
posX = window.pageXOffset + (dx * freq);
}
if(
(dy <= 0 && window.pageYOffset <= +target.top) ||
(dy >= 0 && window.pageYOffset >= +target.top)
){
posY = +target.top;
}
else {
posY = window.pageYOffset + (dx * freq);
}
// move to the new position
original.call(window, posX, posY);
// while we are not ok on both axis
if(posX !== +target.left || posY !== +target.top) {
requestAnimationFrame(anim);
}
else {
animating = false;
}
}
}
})();
Sorry for not providing a runable demo inside the answer directly, but StackSnippet®'s over-protected iframes don't allow us to access the content of an inner iframe on IE...
So instead, here is a link to a jsfiddle.
Post-scriptum:
Now comes to my mind that it might actually be possible to check for support in a synchronous way by checking for the CSS scroll-behavior support, but I'm not sure it really covers all UAs in the history...
Post-Post-scriptum:
Using #nlawson's detection we can now have a working snippet ;-)
/* Polyfills the Window#scroll(options) & Window#scrollTo(options) */
(function ScrollPolyfill() {
// The synchronous tester from #nlawson's answer
var supports = false
test_el = document.createElement('div'),
test_opts = {top:0};
// ES5 style for IE
Object.defineProperty(test_opts, 'behavior', {
get: function() {
supports = true;
}
});
try {
test_el.scrollTo(test_opts);
}catch(e){};
if(!supports) {
attachPolyfill();
}
function attachPolyfill() {
var original = window.scroll, // keep the original method around
animating = false, // will keep our timer's id
dx = 0,
dy = 0,
target = null;
// override our methods
window.scrollTo = window.scroll = function polyfilledScroll(user_opts) {
// if we are already smooth scrolling, we need to stop the previous one
// whatever the current arguments are
if(animating) {
clearAnimationFrame(animating);
}
// not the object syntax, use the default
if(arguments.length === 2) {
return original.apply(this, arguments);
}
if(!user_opts || typeof user_opts !== 'object') {
throw new TypeError("value can't be converted to a dictionnary");
}
// create a clone to not mess the passed object
// and set missing entries
var opts = {
left: ('left' in user_opts) ? user_opts.left : window.pageXOffset,
top: ('top' in user_opts) ? user_opts.top : window.pageYOffset,
behavior: ('behavior' in user_opts) ? user_opts.behavior : 'auto',
};
if(opts.behavior !== 'instant' && opts.behavior !== 'smooth') {
// parse 'auto' based on CSS computed value of 'smooth-behavior' property
// But note that if the browser doesn't support this variant
// There are good chances it doesn't support the CSS property either...
opts.behavior = window.getComputedStyle(document.scrollingElement || document.body)
.getPropertyValue('scroll-behavior') === 'smooth' ?
'smooth' : 'instant';
}
if(opts.behavior === 'instant') {
// not smooth, just default to the original after parsing the oject
return original.call(this, opts.left, opts.top);
}
// update our direction
dx = (opts.left - window.pageXOffset) || 0;
dy = (opts.top - window.pageYOffset) || 0;
// going nowhere
if(!dx && !dy) {
return;
}
// save passed arguments
target = opts;
// save the rAF id
animating = anim();
};
// the animation loop
function anim() {
var freq = 16 / 300, // whole anim duration is approximately 300ms #60fps
posX, poxY;
if( // we already reached our goal on this axis ?
(dx <= 0 && window.pageXOffset <= +target.left) ||
(dx >= 0 && window.pageXOffset >= +target.left)
){
posX = +target.left;
}
else {
posX = window.pageXOffset + (dx * freq);
}
if(
(dy <= 0 && window.pageYOffset <= +target.top) ||
(dy >= 0 && window.pageYOffset >= +target.top)
){
posY = +target.top;
}
else {
posY = window.pageYOffset + (dx * freq);
}
// move to the new position
original.call(window, posX, posY);
// while we are not ok on both axis
if(posX !== +target.left || posY !== +target.top) {
requestAnimationFrame(anim);
}
else {
animating = false;
}
}
}
})();
// OP's code,
// by the time you click the button, the polyfill should already be set up if needed
function scrollWin() {
window.scrollTo({
left: 1000,
top: 1000,
behavior: 'smooth'
});
}
body {
height: 5000px;
width: 5000px;
}
<p>Click the button to scroll the document window to 1000 pixels.</p>
<button onclick="scrollWin()">Click me to scroll!</button>
Unfortunately, there is no way for that method to work in these two browsers.
You can check open issues here and see that they have done nothing on this issue.
https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/15534521/
You can try to use Element.ScrollLeft and Element.ScrollTop property with Window.scrollTo().
Below is the example which is working with Edge and other browsers.
<html>
<style>
body {
height: 5000px;
width: 5000px;
}
</style>
<p>Click the button to scroll the document window to 1000 pixels.</p>
<button onclick="scrollWin(this)">Click me to scroll!</button>
<script>
function scrollWin(pos) {
window.scrollTo(pos.offsetTop+1000,pos.offsetLeft+1000);
}
</script>
</html>
Smooth behavior is not working with this code.
Reference:
Element.scrollLeft
Element.scrollTop
Regards
Deepak
The "smoothscroll" polyfill supports only "smooth" option. To support all options in scrollIntoViewOptions it's better to use seamless-scroll-polyfill (https://www.npmjs.com/package/seamless-scroll-polyfill)
Worked for me.
Here is a link with explanation https://github.com/Financial-Times/polyfill-library/issues/657
I have a strange issue which I can only replicate on Microsoft browsers (Edge and IE11 tested).
<style>
body {
height: 5000px;
width: 5000px;
}
</style>
<p>Click the button to scroll the document window to 1000 pixels.</p>
<button onclick="scrollWin()">Click me to scroll!</button>
<script>
function scrollWin() {
window.scrollTo({
left: 1000,
top: 1000,
behavior:"smooth"
});
}
</script>
This code correctly scrolls the window 1000px to the left and down, with a smooth behaviour in Chrome and Firefox. However, on Edge and IE, it does not move at all.
As mentioned before, the Scroll Behavior specification has only been implemented in Chrome, Firefox and Opera.
Here's a one-liner to detect support for the behavior property in ScrollOptions:
const supportsNativeSmoothScroll = 'scrollBehavior' in document.documentElement.style;
And here's a simple implementation for cross-browser smooth scrolling: https://gist.github.com/eyecatchup/d210786daa23fd57db59634dd231f341
Maybe not a true answer in the sense of the word, but I have solved this problem by using this helpful polyfill: https://github.com/iamdustan/smoothscroll which works really well across all browsers.
Example page for pollyfill: http://iamdustan.com/smoothscroll/
Many thanks to the author.
You can detect support for the behavior option in scrollTo using this snippet:
function testSupportsSmoothScroll () {
var supports = false
try {
var div = document.createElement('div')
div.scrollTo({
top: 0,
get behavior () {
supports = true
return 'smooth'
}
})
} catch (err) {}
return supports
}
Tested in Chrome, Firefox, Safari, and Edge, and seems to work correctly. If supports is false, you fall back to a polyfill.
Indeed, they don't support this variant, MDN articles should be updated.
One way to polyfill this method is to run the scroll method in a requestAnimationFrame powered loop. Nothing too fancy here.
The main problem that arises is how to detect when this variant is not supported. actually #nlawson's answer tackles this problem perfectly...
For this, we can use the fact that a call to Window#scroll will fire a ScrollEvent if the viewPort actually did scroll.
This means we can set up an asynchronous test that will:
Attach an event handler to the ScrollEvent,
Call a first time scroll(left , top) variant to be sure the Event will fire,
Overwrite this call with a second one using the options variant.
In the event handler, if we aren't at the correct scroll position, this means we need to attach our polyfill.
So the caveat of this test is that it is an asynchronous test. But since you need to actually wait for the document has loaded before calling this method, I guess in 99% of cases it will be ok.
Now to less burden the main doc, and since it is already an asynchronous test, we can even wrap this test inside an iframe, which gives us something like:
/* Polyfills the Window#scroll(options) & Window#scrollTo(options) */
(function ScrollPolyfill() {
// The asynchronous tester
// wrapped in an iframe (will not work in SO's StackSnippet®)
var iframe = document.createElement('iframe');
iframe.onload = function() {
var win = iframe.contentWindow;
// listen for a scroll event
win.addEventListener('scroll', function handler(e){
// when the scroll event fires, check that we did move
if(win.pageXOffset < 99) { // !== 0 should be enough, but better be safe
attachPolyfill();
}
// cleanup
document.body.removeChild(iframe);
});
// set up our document so we can scroll
var body = win.document.body;
body.style.width = body.style.height = '1000px';
win.scrollTo(10, 0); // force the event
win.scrollTo({left:100, behavior:'instant'}); // the one we actually test
};
// prepare our frame
iframe.src = "about:blank";
iframe.setAttribute('width', 1);
iframe.setAttribute('height', 1);
iframe.setAttribute('style', 'position:absolute;z-index:-1');
iframe.onerror = function() {
console.error('failed to load the frame, try in jsfiddle');
};
document.body.appendChild(iframe);
// The Polyfill
function attachPolyfill() {
var original = window.scroll, // keep the original method around
animating = false, // will keep our timer's id
dx = 0,
dy = 0,
target = null;
// override our methods
window.scrollTo = window.scroll = function polyfilledScroll(user_opts) {
// if we are already smooth scrolling, we need to stop the previous one
// whatever the current arguments are
if(animating) {
clearAnimationFrame(animating);
}
// not the object syntax, use the default
if(arguments.length === 2) {
return original.apply(this, arguments);
}
if(!user_opts || typeof user_opts !== 'object') {
throw new TypeError("value can't be converted to a dictionnary");
}
// create a clone to not mess the passed object
// and set missing entries
var opts = {
left: ('left' in user_opts) ? user_opts.left : window.pageXOffset,
top: ('top' in user_opts) ? user_opts.top : window.pageYOffset,
behavior: ('behavior' in user_opts) ? user_opts.behavior : 'auto',
};
if(opts.behavior !== 'instant' && opts.behavior !== 'smooth') {
// parse 'auto' based on CSS computed value of 'smooth-behavior' property
// But note that if the browser doesn't support this variant
// There are good chances it doesn't support the CSS property either...
opts.behavior = window.getComputedStyle(document.scrollingElement || document.body)
.getPropertyValue('scroll-behavior') === 'smooth' ?
'smooth' : 'instant';
}
if(opts.behavior === 'instant') {
// not smooth, just default to the original after parsing the oject
return original.call(this, opts.left, opts.top);
}
// update our direction
dx = (opts.left - window.pageXOffset) || 0;
dy = (opts.top - window.pageYOffset) || 0;
// going nowhere
if(!dx && !dy) {
return;
}
// save passed arguments
target = opts;
// save the rAF id
animating = anim();
};
// the animation loop
function anim() {
var freq = 16 / 300, // whole anim duration is approximately 300ms #60fps
posX, poxY;
if( // we already reached our goal on this axis ?
(dx <= 0 && window.pageXOffset <= +target.left) ||
(dx >= 0 && window.pageXOffset >= +target.left)
){
posX = +target.left;
}
else {
posX = window.pageXOffset + (dx * freq);
}
if(
(dy <= 0 && window.pageYOffset <= +target.top) ||
(dy >= 0 && window.pageYOffset >= +target.top)
){
posY = +target.top;
}
else {
posY = window.pageYOffset + (dx * freq);
}
// move to the new position
original.call(window, posX, posY);
// while we are not ok on both axis
if(posX !== +target.left || posY !== +target.top) {
requestAnimationFrame(anim);
}
else {
animating = false;
}
}
}
})();
Sorry for not providing a runable demo inside the answer directly, but StackSnippet®'s over-protected iframes don't allow us to access the content of an inner iframe on IE...
So instead, here is a link to a jsfiddle.
Post-scriptum:
Now comes to my mind that it might actually be possible to check for support in a synchronous way by checking for the CSS scroll-behavior support, but I'm not sure it really covers all UAs in the history...
Post-Post-scriptum:
Using #nlawson's detection we can now have a working snippet ;-)
/* Polyfills the Window#scroll(options) & Window#scrollTo(options) */
(function ScrollPolyfill() {
// The synchronous tester from #nlawson's answer
var supports = false
test_el = document.createElement('div'),
test_opts = {top:0};
// ES5 style for IE
Object.defineProperty(test_opts, 'behavior', {
get: function() {
supports = true;
}
});
try {
test_el.scrollTo(test_opts);
}catch(e){};
if(!supports) {
attachPolyfill();
}
function attachPolyfill() {
var original = window.scroll, // keep the original method around
animating = false, // will keep our timer's id
dx = 0,
dy = 0,
target = null;
// override our methods
window.scrollTo = window.scroll = function polyfilledScroll(user_opts) {
// if we are already smooth scrolling, we need to stop the previous one
// whatever the current arguments are
if(animating) {
clearAnimationFrame(animating);
}
// not the object syntax, use the default
if(arguments.length === 2) {
return original.apply(this, arguments);
}
if(!user_opts || typeof user_opts !== 'object') {
throw new TypeError("value can't be converted to a dictionnary");
}
// create a clone to not mess the passed object
// and set missing entries
var opts = {
left: ('left' in user_opts) ? user_opts.left : window.pageXOffset,
top: ('top' in user_opts) ? user_opts.top : window.pageYOffset,
behavior: ('behavior' in user_opts) ? user_opts.behavior : 'auto',
};
if(opts.behavior !== 'instant' && opts.behavior !== 'smooth') {
// parse 'auto' based on CSS computed value of 'smooth-behavior' property
// But note that if the browser doesn't support this variant
// There are good chances it doesn't support the CSS property either...
opts.behavior = window.getComputedStyle(document.scrollingElement || document.body)
.getPropertyValue('scroll-behavior') === 'smooth' ?
'smooth' : 'instant';
}
if(opts.behavior === 'instant') {
// not smooth, just default to the original after parsing the oject
return original.call(this, opts.left, opts.top);
}
// update our direction
dx = (opts.left - window.pageXOffset) || 0;
dy = (opts.top - window.pageYOffset) || 0;
// going nowhere
if(!dx && !dy) {
return;
}
// save passed arguments
target = opts;
// save the rAF id
animating = anim();
};
// the animation loop
function anim() {
var freq = 16 / 300, // whole anim duration is approximately 300ms #60fps
posX, poxY;
if( // we already reached our goal on this axis ?
(dx <= 0 && window.pageXOffset <= +target.left) ||
(dx >= 0 && window.pageXOffset >= +target.left)
){
posX = +target.left;
}
else {
posX = window.pageXOffset + (dx * freq);
}
if(
(dy <= 0 && window.pageYOffset <= +target.top) ||
(dy >= 0 && window.pageYOffset >= +target.top)
){
posY = +target.top;
}
else {
posY = window.pageYOffset + (dx * freq);
}
// move to the new position
original.call(window, posX, posY);
// while we are not ok on both axis
if(posX !== +target.left || posY !== +target.top) {
requestAnimationFrame(anim);
}
else {
animating = false;
}
}
}
})();
// OP's code,
// by the time you click the button, the polyfill should already be set up if needed
function scrollWin() {
window.scrollTo({
left: 1000,
top: 1000,
behavior: 'smooth'
});
}
body {
height: 5000px;
width: 5000px;
}
<p>Click the button to scroll the document window to 1000 pixels.</p>
<button onclick="scrollWin()">Click me to scroll!</button>
Unfortunately, there is no way for that method to work in these two browsers.
You can check open issues here and see that they have done nothing on this issue.
https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/15534521/
You can try to use Element.ScrollLeft and Element.ScrollTop property with Window.scrollTo().
Below is the example which is working with Edge and other browsers.
<html>
<style>
body {
height: 5000px;
width: 5000px;
}
</style>
<p>Click the button to scroll the document window to 1000 pixels.</p>
<button onclick="scrollWin(this)">Click me to scroll!</button>
<script>
function scrollWin(pos) {
window.scrollTo(pos.offsetTop+1000,pos.offsetLeft+1000);
}
</script>
</html>
Smooth behavior is not working with this code.
Reference:
Element.scrollLeft
Element.scrollTop
Regards
Deepak
The "smoothscroll" polyfill supports only "smooth" option. To support all options in scrollIntoViewOptions it's better to use seamless-scroll-polyfill (https://www.npmjs.com/package/seamless-scroll-polyfill)
Worked for me.
Here is a link with explanation https://github.com/Financial-Times/polyfill-library/issues/657
I created a website with jQueryMobile for iOS and Android.
I don't want the document itself to scroll. Instead, just an area (a <div> element) should be scrollable (via css property overflow-y:scroll).
So I disabled document scrolling via:
$(document).bind("touchstart", function(e){
e.preventDefault();
});
$(document).bind("touchmove", function(e){
e.preventDefault();
});
But that will also disable scrolling for all other elements in the document, no matter if overflow:scroll is set or not.
How can I solve this?
How about this CSS only solution:
https://jsfiddle.net/Volker_E/jwGBy/24/
body gets position: fixed; and every other element you wish an overflow: scroll;.
Works on mobile Chrome (WebKit)/Firefox 19/Opera 12.
You'll also see my various attempts towards a jQuery solution. But as soon as you're binding touchmove/touchstart to document, it hinders scrolling in the child div no matter if unbinded or not.
Disclaimer: Solutions to this problem are in many ways basically not very nice UX-wise! You'll never know how big the viewport of your visitors exactly is or which font-size they are using (client user-agent style like), therefore it could easily be, that important content is hidden to them in your document.
Maybe I misunderstood the question, but if I'm correct:
You want not to be able to scroll except a certain element so you:
$(document).bind("touchmove", function(e){
e.preventDefault();
});
Prevent everything within the document.
Why don't you just stop the event bubbling on the element where you wish to scroll?
(PS: you don't have to prevent touchstart -> if you use touch start for selecting elements instead of clicks that is prevented as well, touch move is only needed because then it is actually tracing the movement)
$('#element').on('touchmove', function (e) {
e.stopPropagation();
});
Now on the element CSS
#element {
overflow-y: scroll; // (vertical)
overflow-x: hidden; // (horizontal)
}
If you are on a mobile device, you can even go a step further.
You can force hardware accelerated scrolling (though not all mobile browsers support this);
Browser Overflow scroll:
Android Browser Yes
Blackberry Browser Yes
Chrome for Mobile Yes
Firefox Mobile Yes
IE Mobile Yes
Opera Mini No
Opera Mobile Kinda
Safari Yes
#element.nativescroll {
-webkit-overflow-scrolling: touch;
}
normal:
<div id="element"></div>
native feel:
<div id="element" class="nativescroll"></div>
Finally, I got it to work. Really simple:
var $layer = $("#layer");
$layer.bind('touchstart', function (ev) {
var $this = $(this);
var layer = $layer.get(0);
if ($this.scrollTop() === 0) $this.scrollTop(1);
var scrollTop = layer.scrollTop;
var scrollHeight = layer.scrollHeight;
var offsetHeight = layer.offsetHeight;
var contentHeight = scrollHeight - offsetHeight;
if (contentHeight == scrollTop) $this.scrollTop(scrollTop-1);
});
Here is a solution I am using:
$scrollElement is the scroll element, $scrollMask is a div with style position: fixed; top: 0; bottom: 0;.
The z-index of $scrollMask is smaller than $scrollElement.
$scrollElement.on('touchmove touchstart', function (e) {
e.stopPropagation();
});
$scrollMask.on('touchmove', function(e) {
e.stopPropagation();
e.preventDefault();
});
I was looking for a solution that did not require calling out specific areas that should scroll. Piecing together a few resources, here is what worked for me:
// Detects if element has scroll bar
$.fn.hasScrollBar = function() {
return this.get(0).scrollHeight > this.outerHeight();
}
$(document).on("touchstart", function(e) {
var $scroller;
var $target = $(e.target);
// Get which element could have scroll bars
if($target.hasScrollBar()) {
$scroller = $target;
} else {
$scroller = $target
.parents()
.filter(function() {
return $(this).hasScrollBar();
})
.first()
;
}
// Prevent if nothing is scrollable
if(!$scroller.length) {
e.preventDefault();
} else {
var top = $scroller[0].scrollTop;
var totalScroll = $scroller[0].scrollHeight;
var currentScroll = top + $scroller[0].offsetHeight;
// If at container edge, add a pixel to prevent outer scrolling
if(top === 0) {
$scroller[0].scrollTop = 1;
} else if(currentScroll === totalScroll) {
$scroller[0].scrollTop = top - 1;
}
}
});
This code requires jQuery.
Sources:
this post
https://github.com/luster-io/prevent-overscroll
How can I check if a scrollbar is visible?
Jquery check if any parent div have scroll bar
Update
I needed a vanilla JavaScript version of this, so the following is a modified version. I implemented a margin-checker and something that explicitly allows input/textareas to be clickable (I was running into issues with this on the project I used it on...it may not be necessary for your project). Keep in mind this is ES6 code.
const preventScrolling = e => {
const shouldAllowEvent = element => {
// Must be an element that is not the document or body
if(!element || element === document || element === document.body) {
return false;
}
// Allow any input or textfield events
if(['INPUT', 'TEXTAREA'].indexOf(element.tagName) !== -1) {
return true;
}
// Get margin and outerHeight for final check
const styles = window.getComputedStyle(element);
const margin = parseFloat(styles['marginTop']) +
parseFloat(styles['marginBottom']);
const outerHeight = Math.ceil(element.offsetHeight + margin);
return (element.scrollHeight > outerHeight) && (margin >= 0);
};
let target = e.target;
// Get first element to allow event or stop
while(target !== null) {
if(shouldAllowEvent(target)) {
break;
}
target = target.parentNode;
}
// Prevent if no elements
if(!target) {
e.preventDefault();
} else {
const top = target.scrollTop;
const totalScroll = target.scrollHeight;
const currentScroll = top + target.offsetHeight;
// If at container edge, add a pixel to prevent outer scrolling
if(top === 0) {
target.scrollTop = 1;
} else if(currentScroll === totalScroll) {
target.scrollTop = top - 1;
}
}
};
document.addEventListener('touchstart', preventScrolling);
document.addEventListener('mousedown', preventScrolling);
In my case, I have a scrollable body and a scrollable floating menu over it. Both have to be scrollable, but I had to prevent body scrolling when "floating menu" (position:fixed) received touch events and was scrolling and it reached top or bottom. By default browser then started to scroll the body.
I really liked jimmont's answer, but unfortunatelly it did not work well on all devices and browsers, especially with a fast and long swipe.
I ended up using MOMENTUM SCROLLING USING JQUERY (hnldesign.nl) on floating menu, which prevents default browser scrolling and then animates scrolling itself. I include that code here for completeness:
/**
* jQuery inertial Scroller v1.5
* (c)2013 hnldesign.nl
* This work is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/4.0/.
**/
/*jslint browser: true*/
/*global $, jQuery*/
/* SETTINGS */
var i_v = {
i_touchlistener : '.inertialScroll', // element to monitor for touches, set to null to use document. Otherwise use quotes. Eg. '.myElement'. Note: if the finger leaves this listener while still touching, movement is stopped.
i_scrollElement : '.inertialScroll', // element (class) to be scrolled on touch movement
i_duration : window.innerHeight * 1.5, // (ms) duration of the inertial scrolling simulation. Devices with larger screens take longer durations (phone vs tablet is around 500ms vs 1500ms). This is a fixed value and does not influence speed and amount of momentum.
i_speedLimit : 1.2, // set maximum speed. Higher values will allow faster scroll (which comes down to a bigger offset for the duration of the momentum scroll) note: touch motion determines actual speed, this is just a limit.
i_handleY : true, // should scroller handle vertical movement on element?
i_handleX : true, // should scroller handle horizontal movement on element?
i_moveThreshold : 100, // (ms) determines if a swipe occurred: time between last updated movement # touchmove and time # touchend, if smaller than this value, trigger inertial scrolling
i_offsetThreshold : 30, // (px) determines, together with i_offsetThreshold if a swipe occurred: if calculated offset is above this threshold
i_startThreshold : 5, // (px) how many pixels finger needs to move before a direction (horizontal or vertical) is chosen. This will make the direction detection more accurate, but can introduce a delay when starting the swipe if set too high
i_acceleration : 0.5, // increase the multiplier by this value, each time the user swipes again when still scrolling. The multiplier is used to multiply the offset. Set to 0 to disable.
i_accelerationT : 250 // (ms) time between successive swipes that determines if the multiplier is increased (if lower than this value)
};
/* stop editing here */
//set some required vars
i_v.i_time = {};
i_v.i_elem = null;
i_v.i_elemH = null;
i_v.i_elemW = null;
i_v.multiplier = 1;
// Define easing function. This is based on a quartic 'out' curve. You can generate your own at http://www.timotheegroleau.com/Flash/experiments/easing_function_generator.htm
if ($.easing.hnlinertial === undefined) {
$.easing.hnlinertial = function (x, t, b, c, d) {
"use strict";
var ts = (t /= d) * t, tc = ts * t;
return b + c * (-1 * ts * ts + 4 * tc + -6 * ts + 4 * t);
};
}
$(i_v.i_touchlistener || document)
.on('touchstart touchmove touchend', function (e) {
"use strict";
//prevent default scrolling
e.preventDefault();
//store timeStamp for this event
i_v.i_time[e.type] = e.timeStamp;
})
.on('touchstart', function (e) {
"use strict";
this.tarElem = $(e.target);
this.elemNew = this.tarElem.closest(i_v.i_scrollElement).length > 0 ? this.tarElem.closest(i_v.i_scrollElement) : $(i_v.i_scrollElement).eq(0);
//dupecheck, optimizes code a bit for when the element selected is still the same as last time
this.sameElement = i_v.i_elem ? i_v.i_elem[0] == this.elemNew[0] : false;
//no need to redo these if element is unchanged
if (!this.sameElement) {
//set the element to scroll
i_v.i_elem = this.elemNew;
//get dimensions
i_v.i_elemH = i_v.i_elem.innerHeight();
i_v.i_elemW = i_v.i_elem.innerWidth();
//check element for applicable overflows and reevaluate settings
this.i_scrollableY = !!((i_v.i_elemH < i_v.i_elem.prop('scrollHeight') && i_v.i_handleY));
this.i_scrollableX = !!((i_v.i_elemW < i_v.i_elem.prop('scrollWidth') && i_v.i_handleX));
}
//get coordinates of touch event
this.pageY = e.originalEvent.touches[0].pageY;
this.pageX = e.originalEvent.touches[0].pageX;
if (i_v.i_elem.is(':animated') && (i_v.i_time.touchstart - i_v.i_time.touchend) < i_v.i_accelerationT) {
//user swiped while still animating, increase the multiplier for the offset
i_v.multiplier += i_v.i_acceleration;
} else {
//else reset multiplier
i_v.multiplier = 1;
}
i_v.i_elem
//stop any animations still running on element (this enables 'tap to stop')
.stop(true, false)
//store current scroll positions of element
.data('scrollTop', i_v.i_elem.scrollTop())
.data('scrollLeft', i_v.i_elem.scrollLeft());
})
.on('touchmove', function (e) {
"use strict";
//check if startThreshold is met
this.go = (Math.abs(this.pageX - e.originalEvent.touches[0].pageX) > i_v.i_startThreshold || Math.abs(this.pageY - e.originalEvent.touches[0].pageY) > i_v.i_startThreshold);
})
.on('touchmove touchend', function (e) {
"use strict";
//check if startThreshold is met
if (this.go) {
//set animpar1 to be array
this.animPar1 = {};
//handle events
switch (e.type) {
case 'touchmove':
this.vertical = Math.abs(this.pageX - e.originalEvent.touches[0].pageX) < Math.abs(this.pageY - e.originalEvent.touches[0].pageY); //find out in which direction we are scrolling
this.distance = this.vertical ? this.pageY - e.originalEvent.touches[0].pageY : this.pageX - e.originalEvent.touches[0].pageX; //determine distance between touches
this.acc = Math.abs(this.distance / (i_v.i_time.touchmove - i_v.i_time.touchstart)); //calculate acceleration during movement (crucial)
//determine which property to animate, reset animProp first for when no criteria is matched
this.animProp = null;
if (this.vertical && this.i_scrollableY) { this.animProp = 'scrollTop'; } else if (!this.vertical && this.i_scrollableX) { this.animProp = 'scrollLeft'; }
//set animation parameters
if (this.animProp) { this.animPar1[this.animProp] = i_v.i_elem.data(this.animProp) + this.distance; }
this.animPar2 = { duration: 0 };
break;
case 'touchend':
this.touchTime = i_v.i_time.touchend - i_v.i_time.touchmove; //calculate touchtime: the time between release and last movement
this.i_maxOffset = (this.vertical ? i_v.i_elemH : i_v.i_elemW) * i_v.i_speedLimit; //(re)calculate max offset
//calculate the offset (the extra pixels for the momentum effect
this.offset = Math.pow(this.acc, 2) * (this.vertical ? i_v.i_elemH : i_v.i_elemW);
this.offset = (this.offset > this.i_maxOffset) ? this.i_maxOffset : this.offset;
this.offset = (this.distance < 0) ? -i_v.multiplier * this.offset : i_v.multiplier * this.offset;
//if the touchtime is low enough, the offset is not null and the offset is above the offsetThreshold, (re)set the animation parameters to include momentum
if ((this.touchTime < i_v.i_moveThreshold) && this.offset !== 0 && Math.abs(this.offset) > (i_v.i_offsetThreshold)) {
if (this.animProp) { this.animPar1[this.animProp] = i_v.i_elem.data(this.animProp) + this.distance + this.offset; }
this.animPar2 = { duration: i_v.i_duration, easing : 'hnlinertial', complete: function () {
//reset multiplier
i_v.multiplier = 1;
}};
}
break;
}
// run the animation on the element
if ((this.i_scrollableY || this.i_scrollableX) && this.animProp) {
i_v.i_elem.stop(true, false).animate(this.animPar1, this.animPar2);
}
}
});
Another observation: I also tried various combinations of e.stopPropagation() on menu div and e.preventDefault() on window/body at touchmove event, but without success, I only managed to prevent scrolling I wanted and not scrolling I did not want. I also tried to have a div over whole document, with z-index between document and menu, visible only between touchstart and touchend, but it did not receive touchmove event (because it was under menu div).
Here is a solution that uses jQuery for the events.
var stuff = {};
$('#scroller').on('touchstart',stuff,function(e){
e.data.max = this.scrollHeight - this.offsetHeight;
e.data.y = e.originalEvent.pageY;
}).on('touchmove',stuff,function(e){
var dy = e.data.y - e.originalEvent.pageY;
// if scrolling up and at the top, or down and at the bottom
if((dy < 0 && this.scrollTop < 1)||(dy > 0 && this.scrollTop >= e.data.max)){
e.preventDefault();
};
});
First position the innerScroller wherever you want on the screen and then fix outerScroller by setting it css to 'hidden'. When you want to restore it you can set it back to 'auto' or 'scroll', whichever you used previously.
Here is my implementation which works on touch devices and laptops.
function ScrollManager() {
let startYCoord;
function getScrollDiff(event) {
let delta = 0;
switch (event.type) {
case 'mousewheel':
delta = event.wheelDelta ? event.wheelDelta : -1 * event.deltaY;
break;
case 'touchstart':
startYCoord = event.touches[0].clientY;
break;
case 'touchmove': {
const yCoord = event.touches[0].clientY;
delta = yCoord - startYCoord;
startYCoord = yCoord;
break;
}
}
return delta;
}
function getScrollDirection(event) {
return getScrollDiff(event) >= 0 ? 'UP' : 'DOWN';
}
function blockScrollOutside(targetElement, event) {
const { target } = event;
const isScrollAllowed = targetElement.contains(target);
const isTouchStart = event.type === 'touchstart';
let doScrollBlock = !isTouchStart;
if (isScrollAllowed) {
const isScrollingUp = getScrollDirection(event) === 'UP';
const elementHeight = targetElement.scrollHeight - targetElement.offsetHeight;
doScrollBlock =
doScrollBlock &&
((isScrollingUp && targetElement.scrollTop <= 0) ||
(!isScrollingUp && targetElement.scrollTop >= elementHeight));
}
if (doScrollBlock) {
event.preventDefault();
}
}
return {
blockScrollOutside,
getScrollDirection,
};
}
const scrollManager = ScrollManager();
const testBlock = document.body.querySelector('.test');
function handleScroll(event) {
scrollManager.blockScrollOutside(testBlock, event);
}
window.addEventListener('scroll', handleScroll);
window.addEventListener('mousewheel', handleScroll);
window.addEventListener('touchstart', handleScroll);
window.addEventListener('touchmove', handleScroll);
.main {
border: 1px solid red;
height: 200vh;
}
.test {
border: 1px solid green;
height: 300px;
width: 300px;
overflow-y: auto;
position: absolute;
top: 100px;
left: 50%;
}
.content {
height: 100vh;
}
<div class="main">
<div class="test">
<div class="content"></div>
</div>
</div>
This is what worked for me for Android and IOS devices.
Imagine that we have a div class="backdrop"> element that we don't want to be scrolled, ever. But we want to be able to scroll over an element that is on top of this backdrop.
function handleTouchMove(event) {
const [backdrop] = document.getElementsByClassName('backdrop');
const isScrollingBackdrop = backdrop === event.target;
isScrollingBackdrop ? event.preventDefault() : event.stopPropagation();
}
window.addEventListener('touchmove', handleTouchMove, { passive: false });
So, we listen to the touchmove event, if we're scrolling over the backdrop, we prevent it. If we're scrolling over something else, we allow it but stop its propagation so it doesn't scroll also the backdrop.
Of course this is pretty basic and can be re-worked and expanded a lot, but this is what fixed my issue in a VueJs2 project.
Hope it helps! ;)
I was able to disable scrolling of the main document by adding css "overflow-y: hidden" on HTML.
It did not mess with positioning at all.
I'm coding up a page where I only want to use raw JavaScript code for UI without any interference of plugins or frameworks.
And now I'm struggling with finding a way to scroll over the page smoothly without jQuery.
Native browser smooth scrolling in JavaScript is like this:
// scroll to specific values,
// same as window.scroll() method.
// for scrolling a particular distance, use window.scrollBy().
window.scroll({
top: 2500,
left: 0,
behavior: 'smooth'
});
// scroll certain amounts from current position
window.scrollBy({
top: 100, // negative value acceptable
left: 0,
behavior: 'smooth'
});
// scroll to a certain element
document.querySelector('.hello').scrollIntoView({
behavior: 'smooth'
});
Try this smooth scrolling demo, or an algorithm like:
Get the current top location using self.pageYOffset
Get the position of element till where you want to scroll to: element.offsetTop
Do a for loop to reach there, which will be quite fast or use a timer to do smooth scroll till that position using window.scrollTo
See also the other popular answer to this question.
Andrew Johnson's original code:
function currentYPosition() {
// Firefox, Chrome, Opera, Safari
if (self.pageYOffset) return self.pageYOffset;
// Internet Explorer 6 - standards mode
if (document.documentElement && document.documentElement.scrollTop)
return document.documentElement.scrollTop;
// Internet Explorer 6, 7 and 8
if (document.body.scrollTop) return document.body.scrollTop;
return 0;
}
function elmYPosition(eID) {
var elm = document.getElementById(eID);
var y = elm.offsetTop;
var node = elm;
while (node.offsetParent && node.offsetParent != document.body) {
node = node.offsetParent;
y += node.offsetTop;
} return y;
}
function smoothScroll(eID) {
var startY = currentYPosition();
var stopY = elmYPosition(eID);
var distance = stopY > startY ? stopY - startY : startY - stopY;
if (distance < 100) {
scrollTo(0, stopY); return;
}
var speed = Math.round(distance / 100);
if (speed >= 20) speed = 20;
var step = Math.round(distance / 25);
var leapY = stopY > startY ? startY + step : startY - step;
var timer = 0;
if (stopY > startY) {
for ( var i=startY; i<stopY; i+=step ) {
setTimeout("window.scrollTo(0, "+leapY+")", timer * speed);
leapY += step; if (leapY > stopY) leapY = stopY; timer++;
} return;
}
for ( var i=startY; i>stopY; i-=step ) {
setTimeout("window.scrollTo(0, "+leapY+")", timer * speed);
leapY -= step; if (leapY < stopY) leapY = stopY; timer++;
}
}
Related links:
https://www.sitepoint.com/smooth-scrolling-vanilla-javascript/
https://github.com/zengabor/zenscroll/blob/dist/zenscroll.js
https://github.com/cferdinandi/smooth-scroll/blob/master/src/js/smooth-scroll.js
https://github.com/alicelieutier/smoothScroll/blob/master/smoothscroll.js
Algorithm
Scrolling an element requires changing its scrollTop value over time. For a given point in time, calculate a new scrollTop value. To animate smoothly, interpolate using a smooth-step algorithm.
Calculate scrollTop as follows:
var point = smooth_step(start_time, end_time, now);
var scrollTop = Math.round(start_top + (distance * point));
Where:
start_time is the time the animation started;
end_time is when the animation will end (start_time + duration);
start_top is the scrollTop value at the beginning; and
distance is the difference between the desired end value and the start value (target - start_top).
A robust solution should detect when animating is interrupted, and more. Read my post about Smooth Scrolling without jQuery for details.
Demo
See the JSFiddle.
Implementation
The code:
/**
Smoothly scroll element to the given target (element.scrollTop)
for the given duration
Returns a promise that's fulfilled when done, or rejected if
interrupted
*/
var smooth_scroll_to = function(element, target, duration) {
target = Math.round(target);
duration = Math.round(duration);
if (duration < 0) {
return Promise.reject("bad duration");
}
if (duration === 0) {
element.scrollTop = target;
return Promise.resolve();
}
var start_time = Date.now();
var end_time = start_time + duration;
var start_top = element.scrollTop;
var distance = target - start_top;
// based on http://en.wikipedia.org/wiki/Smoothstep
var smooth_step = function(start, end, point) {
if(point <= start) { return 0; }
if(point >= end) { return 1; }
var x = (point - start) / (end - start); // interpolation
return x*x*(3 - 2*x);
}
return new Promise(function(resolve, reject) {
// This is to keep track of where the element's scrollTop is
// supposed to be, based on what we're doing
var previous_top = element.scrollTop;
// This is like a think function from a game loop
var scroll_frame = function() {
if(element.scrollTop != previous_top) {
reject("interrupted");
return;
}
// set the scrollTop for this frame
var now = Date.now();
var point = smooth_step(start_time, end_time, now);
var frameTop = Math.round(start_top + (distance * point));
element.scrollTop = frameTop;
// check if we're done!
if(now >= end_time) {
resolve();
return;
}
// If we were supposed to scroll but didn't, then we
// probably hit the limit, so consider it done; not
// interrupted.
if(element.scrollTop === previous_top
&& element.scrollTop !== frameTop) {
resolve();
return;
}
previous_top = element.scrollTop;
// schedule next frame for execution
setTimeout(scroll_frame, 0);
}
// boostrap the animation process
setTimeout(scroll_frame, 0);
});
}
You can use the new Scroll Behaviour CSS Property.
for example, add the below line to your CSS.
html{
scroll-behavior:smooth;
}
and this will result in a native smooth scrolling feature.
see demo here
All modern browsers support the scroll-behavior property.
Read More about Scroll behavior
I've made an example without jQuery here : http://codepen.io/sorinnn/pen/ovzdq
/**
by Nemes Ioan Sorin - not an jQuery big fan
therefore this script is for those who love the old clean coding style
#id = the id of the element who need to bring into view
Note : this demo scrolls about 12.700 pixels from Link1 to Link3
*/
(function()
{
window.setTimeout = window.setTimeout; //
})();
var smoothScr = {
iterr : 30, // set timeout miliseconds ..decreased with 1ms for each iteration
tm : null, //timeout local variable
stopShow: function()
{
clearTimeout(this.tm); // stopp the timeout
this.iterr = 30; // reset milisec iterator to original value
},
getRealTop : function (el) // helper function instead of jQuery
{
var elm = el;
var realTop = 0;
do
{
realTop += elm.offsetTop;
elm = elm.offsetParent;
}
while(elm);
return realTop;
},
getPageScroll : function() // helper function instead of jQuery
{
var pgYoff = window.pageYOffset || document.body.scrollTop || document.documentElement.scrollTop;
return pgYoff;
},
anim : function (id) // the main func
{
this.stopShow(); // for click on another button or link
var eOff, pOff, tOff, scrVal, pos, dir, step;
eOff = document.getElementById(id).offsetTop; // element offsetTop
tOff = this.getRealTop(document.getElementById(id).parentNode); // terminus point
pOff = this.getPageScroll(); // page offsetTop
if (pOff === null || isNaN(pOff) || pOff === 'undefined') pOff = 0;
scrVal = eOff - pOff; // actual scroll value;
if (scrVal > tOff)
{
pos = (eOff - tOff - pOff);
dir = 1;
}
if (scrVal < tOff)
{
pos = (pOff + tOff) - eOff;
dir = -1;
}
if(scrVal !== tOff)
{
step = ~~((pos / 4) +1) * dir;
if(this.iterr > 1) this.iterr -= 1;
else this.itter = 0; // decrease the timeout timer value but not below 0
window.scrollBy(0, step);
this.tm = window.setTimeout(function()
{
smoothScr.anim(id);
}, this.iterr);
}
if(scrVal === tOff)
{
this.stopShow(); // reset function values
return;
}
}
}
Modern browsers has support for CSS "scroll-behavior: smooth" property. So, we even don't need any Javascript at all for this. Just add this for the "html" element, and use usual anchors and links.
scroll-behavior MDN docs
I recently set out to solve this problem in a situation where jQuery wasn't an option, so I'm logging my solution here just for posterity.
var scroll = (function() {
var elementPosition = function(a) {
return function() {
return a.getBoundingClientRect().top;
};
};
var scrolling = function( elementID ) {
var el = document.getElementById( elementID ),
elPos = elementPosition( el ),
duration = 400,
increment = Math.round( Math.abs( elPos() )/40 ),
time = Math.round( duration/increment ),
prev = 0,
E;
function scroller() {
E = elPos();
if (E === prev) {
return;
} else {
prev = E;
}
increment = (E > -20 && E < 20) ? ((E > - 5 && E < 5) ? 1 : 5) : increment;
if (E > 1 || E < -1) {
if (E < 0) {
window.scrollBy( 0,-increment );
} else {
window.scrollBy( 0,increment );
}
setTimeout(scroller, time);
} else {
el.scrollTo( 0,0 );
}
}
scroller();
};
return {
To: scrolling
}
})();
/* usage */
scroll.To('elementID');
The scroll() function uses the Revealing Module Pattern to pass the target element's id to its scrolling() function, via scroll.To('id'), which sets the values used by the scroller() function.
Breakdown
In scrolling():
el : the target DOM object
elPos : returns a function via elememtPosition() which gives the position of the target element relative to the top of the page each time it's called.
duration : transition time in milliseconds.
increment : divides the starting position of the target element into 40 steps.
time : sets the timing of each step.
prev : the target element's previous position in scroller().
E : holds the target element's position in scroller().
The actual work is done by the scroller() function which continues to call itself (via setTimeout()) until the target element is at the top of the page or the page can scroll no more.
Each time scroller() is called it checks the current position of the target element (held in variable E) and if that is > 1 OR < -1 and if the page is still scrollable shifts the window by increment pixels - up or down depending if E is a positive or negative value. When E is neither > 1 OR < -1, or E === prev the function stops. I added the DOMElement.scrollTo() method on completion just to make sure the target element was bang on the top of the window (not that you'd notice it being out by a fraction of a pixel!).
The if statement on line 2 of scroller() checks to see if the page is scrolling (in cases where the target might be towards the bottom of the page and the page can scroll no further) by checking E against its previous position (prev).
The ternary condition below it reduce the increment value as E approaches zero. This stops the page overshooting one way and then bouncing back to overshoot the other, and then bouncing back to overshoot the other again, ping-pong style, to infinity and beyond.
If your page is more that c.4000px high you might want to increase the values in the ternary expression's first condition (here at +/-20) and/or the divisor which sets the increment value (here at 40).
Playing about with duration, the divisor which sets increment, and the values in the ternary condition of scroller() should allow you to tailor the function to suit your page.
JSFiddle
N.B.Tested in up-to-date versions of Firefox and Chrome on Lubuntu, and Firefox, Chrome and IE on Windows8.
I've made something like this.
I have no idea if its working in IE8.
Tested in IE9, Mozilla, Chrome, Edge.
function scroll(toElement, speed) {
var windowObject = window;
var windowPos = windowObject.pageYOffset;
var pointer = toElement.getAttribute('href').slice(1);
var elem = document.getElementById(pointer);
var elemOffset = elem.offsetTop;
var counter = setInterval(function() {
windowPos;
if (windowPos > elemOffset) { // from bottom to top
windowObject.scrollTo(0, windowPos);
windowPos -= speed;
if (windowPos <= elemOffset) { // scrolling until elemOffset is higher than scrollbar position, cancel interval and set scrollbar to element position
clearInterval(counter);
windowObject.scrollTo(0, elemOffset);
}
} else { // from top to bottom
windowObject.scrollTo(0, windowPos);
windowPos += speed;
if (windowPos >= elemOffset) { // scroll until scrollbar is lower than element, cancel interval and set scrollbar to element position
clearInterval(counter);
windowObject.scrollTo(0, elemOffset);
}
}
}, 1);
}
//call example
var navPointer = document.getElementsByClassName('nav__anchor');
for (i = 0; i < navPointer.length; i++) {
navPointer[i].addEventListener('click', function(e) {
scroll(this, 18);
e.preventDefault();
});
}
Description
pointer—get element and chceck if it has attribute "href" if yes,
get rid of "#"
elem—pointer variable without "#"
elemOffset—offset of "scroll to" element from the top of the page
You can use
document.querySelector('your-element').scrollIntoView({behavior: 'smooth'});
If you want to scroll top the top of the page, you can just place an empty element in the top, and smooth scroll to that one.
With using the following smooth scrolling is working fine:
html {
scroll-behavior: smooth;
}
<script>
var set = 0;
function animatescroll(x, y) {
if (set == 0) {
var val72 = 0;
var val73 = 0;
var setin = 0;
set = 1;
var interval = setInterval(function() {
if (setin == 0) {
val72++;
val73 += x / 1000;
if (val72 == 1000) {
val73 = 0;
interval = clearInterval(interval);
}
document.getElementById(y).scrollTop = val73;
}
}, 1);
}
}
</script>
x = scrollTop
y = id of the div that is used to scroll
Note:
For making the body to scroll give the body an ID.
Here is my solution. Works in most browsers
document.getElementById("scrollHere").scrollIntoView({behavior: "smooth"});
Docs
document.getElementById("end").scrollIntoView({behavior: "smooth"});
body {margin: 0px; display: block; height: 100%; background-image: linear-gradient(red, yellow);}
.start {display: block; margin: 100px 10px 1000px 0px;}
.end {display: block; margin: 0px 0px 100px 0px;}
<div class="start">Start</div>
<div class="end" id="end">End</div>
There are many different methods for smooth scrolling in JavaScript. The most common ones are listed below.
To scroll to a certain position in an exact amount of time, window.requestAnimationFrame can be put to use, calculating the appropriate current position each time. setTimeout can be used to a similar effect when requestAnimationFrame is not supported. (To scroll to a specific element with the function below, just set the position to element.offsetTop.)
/*
#param pos: the y-position to scroll to (in pixels)
#param time: the exact amount of time the scrolling will take (in milliseconds)
*/
function scrollToSmoothly(pos, time) {
var currentPos = window.pageYOffset;
var start = null;
if(time == null) time = 500;
pos = +pos, time = +time;
window.requestAnimationFrame(function step(currentTime) {
start = !start ? currentTime : start;
var progress = currentTime - start;
if (currentPos < pos) {
window.scrollTo(0, ((pos - currentPos) * progress / time) + currentPos);
} else {
window.scrollTo(0, currentPos - ((currentPos - pos) * progress / time));
}
if (progress < time) {
window.requestAnimationFrame(step);
} else {
window.scrollTo(0, pos);
}
});
}
Demo:
/*
#param time: the exact amount of time the scrolling will take (in milliseconds)
#param pos: the y-position to scroll to (in pixels)
*/
function scrollToSmoothly(pos, time) {
var currentPos = window.pageYOffset;
var start = null;
if(time == null) time = 500;
pos = +pos, time = +time;
window.requestAnimationFrame(function step(currentTime) {
start = !start ? currentTime : start;
var progress = currentTime - start;
if (currentPos < pos) {
window.scrollTo(0, ((pos - currentPos) * progress / time) + currentPos);
} else {
window.scrollTo(0, currentPos - ((currentPos - pos) * progress / time));
}
if (progress < time) {
window.requestAnimationFrame(step);
} else {
window.scrollTo(0, pos);
}
});
}
<button onClick="scrollToSmoothly(document.querySelector('div').offsetTop, 300)">
Scroll To Div (300ms)
</button>
<button onClick="scrollToSmoothly(document.querySelector('div').offsetTop, 200)">
Scroll To Div (200ms)
</button>
<button onClick="scrollToSmoothly(document.querySelector('div').offsetTop, 100)">
Scroll To Div (100ms)
</button>
<button onClick="scrollToSmoothly(document.querySelector('div').offsetTop, 50)">
Scroll To Div (50ms)
</button>
<button onClick="scrollToSmoothly(document.querySelector('div').offsetTop, 1000)">
Scroll To Div (1000ms)
</button>
<div style="margin: 500px 0px;">
DIV<p/>
<button onClick="scrollToSmoothly(0, 500)">
Back To Top
</button>
<button onClick="scrollToSmoothly(document.body.scrollHeight)">
Scroll To Bottom
</button>
</div>
<div style="margin: 500px 0px;">
</div>
<button style="margin-top: 100px;" onClick="scrollToSmoothly(500, 3000)">
Scroll To y-position 500px (3000ms)
</button>
For more complex cases, the SmoothScroll.js library can be used, which handles smooth scrolling both vertically and horizontally, scrolling inside other container elements, different easing behaviors, scrolling relatively from the current position, and more.
var easings = document.getElementById("easings");
for(var key in smoothScroll.easing){
if(smoothScroll.easing.hasOwnProperty(key)){
var option = document.createElement('option');
option.text = option.value = key;
easings.add(option);
}
}
document.getElementById('to-bottom').addEventListener('click', function(e){
smoothScroll({yPos: 'end', easing: easings.value, duration: 2000});
});
document.getElementById('to-top').addEventListener('click', function(e){
smoothScroll({yPos: 'start', easing: easings.value, duration: 2000});
});
<script src="https://cdn.jsdelivr.net/gh/LieutenantPeacock/SmoothScroll#1.2.0/src/smoothscroll.min.js" integrity="sha384-UdJHYJK9eDBy7vML0TvJGlCpvrJhCuOPGTc7tHbA+jHEgCgjWpPbmMvmd/2bzdXU" crossorigin="anonymous"></script>
<!-- Taken from one of the library examples -->
Easing: <select id="easings"></select>
<button id="to-bottom">Scroll To Bottom</button>
<br>
<button id="to-top" style="margin-top: 5000px;">Scroll To Top</button>
Alternatively, you can pass an options object to window.scroll which scrolls to a specific x and y position and window.scrollBy which scrolls a certain amount from the current position:
// Scroll to specific values
// scrollTo is the same
window.scroll({
top: 2500,
left: 0,
behavior: 'smooth'
});
// Scroll certain amounts from current position
window.scrollBy({
top: 100, // could be negative value
left: 0,
behavior: 'smooth'
});
Demo:
<button onClick="scrollToDiv()">Scroll To Element</button>
<div style="margin: 500px 0px;">Div</div>
<script>
function scrollToDiv(){
var elem = document.querySelector("div");
window.scroll({
top: elem.offsetTop,
left: 0,
behavior: 'smooth'
});
}
</script>
If you only need to scroll to an element, not a specific position in the document, you can use Element.scrollIntoView with behavior set to smooth.
document.getElementById("elemID").scrollIntoView({
behavior: 'smooth'
});
Demo:
<button onClick="scrollToDiv()">Scroll To Element</button>
<div id="myDiv" style="margin: 500px 0px;">Div</div>
<script>
function scrollToDiv(){
document.getElementById("myDiv").scrollIntoView({
behavior: 'smooth'
});
}
</script>
Modern browsers support the scroll-behavior CSS property, which can be used to make scrolling in the document smooth (without the need for JavaScript). Anchor tags can be used for this by giving the anchor tag a href of # plus the id of the element to scroll to). You can also set the scroll-behavior property for a specific container like a div to make its contents scroll smoothly.
Demo:
html, body{
scroll-behavior: smooth;
}
Scroll To Element
<div id="elem" style="margin: 500px 0px;">Div</div>
Here's my variation:
let MenuItem = function ( _menuItem ) {
// I had a sticky header, so its height had to be taken into account when scrolling
let _header = document.querySelector('.site-header');
let _scrollToBlock = function( e, menuItem ) {
let id = menuItem.getAttribute('href'), // the href attribute stores the id of the block to which the scroll will be
headerHeight = _header.offsetHeight; // determine the height of the header
id = id.replace(/#/, ''); // remove the # sign from the id block
let elem = document.getElementById( id ), // define the element to which we will scroll
top = elem.getBoundingClientRect().top + window.scrollY - headerHeight; // determine the height of the scroll
window.scroll({
top: top,
left: 0,
behavior: 'smooth'
});
},
_addEvents = function() {
_menuItem.addEventListener('click', function (e){
e.preventDefault(); // Disable redirect on click
_scrollToBlock(e, _menuItem);
});
},
_init = function() {
_addEvents();
};
_init();
};
// Initialize the class MenuItem to all links with class .menu__item
document.querySelectorAll('.menu__item').forEach( function(item) {
new MenuItem(item);
} );
Here's the code that worked for me.
`$('a[href*="#"]')
.not('[href="#"]')
.not('[href="#0"]')
.click(function(event) {
if (
location.pathname.replace(/^\//, '') == this.pathname.replace(/^\//, '')
&&
location.hostname == this.hostname
) {
var target = $(this.hash);
target = target.length ? target : $('[name=' + this.hash.slice(1) + ']');
if (target.length) {
event.preventDefault();
$('html, body').animate({
scrollTop: target.offset().top
}, 1000, function() {
var $target = $(target);
$target.focus();
if ($target.is(":focus")) {
return false;
} else {
$target.attr('tabindex','-1');
$target.focus();
};
});
}
}
});
`