I'm using JavaScript together with a css column-width layout to calculate breakpoints at each new column in the browser window. With each new column I also increase the page margins for which I calculate a second breakpoints so they fit.
I have everything fully working using root.classList.add(myCss) and root.classList.remove(myCss) but for the page margins I would prefer to update a single css variable --page-margins instead of adding and removing css margin classes if that's possible.
In the following sample when I load the page and two columns fit in the browser window the correct --page-margin should be 16 but the Chrome inspector shows 24. It looks like when the page loads, the matchMedia event checks each media query and if it doesn't match it sets the css variable --page-margins to (cols - 1) which I only need it to do if that event previously matched.
After the page has loaded if I increase and decrease the browser width everything works correctly. One way I could achieve this is with some kind of conditional "If event unmatches..."?
document.addEventListener('DOMContentLoaded', function() {
grid();
});
// The grid system
function grid() {
const root = document.documentElement;
const columnWidth = 239;
const columnGap = 1;
const columnMin = columnWidth + columnGap;
const scrollbar = 20;
let margins = parseInt(window.getComputedStyle(root).getPropertyValue('--page-margins'), 10);
// Page margins
const marginOne = 8;
const marginTwo = 16;
const marginThree = 24;
const marginFour = 32;
mediaQuery(2);
mediaQuery(3);
mediaQuery(4);
// Media queries for columns
function mediaQuery(cols) {
let marginStyles = window.matchMedia('(min-width: ' + columns(cols) + 'px)');
marginStyles.addEventListener('change', addMargins);
addMargins(marginStyles);
function addMargins(e) {
if (e.matches) {
root.style.setProperty('--page-margins', setMargins(cols) + 'px');
margins = parseInt(window.getComputedStyle(root).getPropertyValue('--page-margins'), 10);
}
else {
root.style.setProperty('--page-margins', setMargins((cols - 1)) + 'px');
margins = parseInt(window.getComputedStyle(root).getPropertyValue('--page-margins'), 10);
}
}
}
// Return the screen width (breakpoint) at num columns
function columns(num) {
setMargins(num);
let breakpoint = (columnMin * num) - columnGap + (padding * 2) + scrollbar;
return breakpoint;
}
// Set the margin for each column number
function setMargins(num) {
if (num == 4) {
padding = marginFour;
} else if (num == 3) {
padding = marginThree;
} else if (num == 2) {
padding = marginTwo;
} else {
padding = marginOne;
}
return padding;
}
}
I figured it out shortly after posting. I needed to nest a second conditional inside the event's else statement that checks the value of the css variable --page-margins. The variable margins is referenced elsewhere in the script so I'm updating it when the event matches and unmatches.
Everything works.
function addMargins(e) {
if (e.matches) {
root.style.setProperty('--page-margins', setMargins(cols) + 'px');
margins = parseInt(window.getComputedStyle(root).getPropertyValue('--page-margins'), 10);
}
else {
if (margins == setMargins(cols)) {
root.style.setProperty('--page-margins', setMargins((cols - 1)) + 'px');
margins = parseInt(window.getComputedStyle(root).getPropertyValue('--page-margins'), 10);
}
}
}
I have some HTML flipping cards with automatic flipping animations. I am trying to implement a feature such that when the user scrolls to the part where they see the flipping cards, start the flipping animation. If the user scrolls more such that the flipping cards are not visible anymore, stop the flipping animation.
Below is the JavaScript codes:
function isScrolledIntoView(elem) {
var docViewTop = $(window).scrollTop();
var docViewBottom = docViewTop + $(window).height();
var elemTop = $(elem).offset().top;
var elemBottom = elemTop + $(elem).height();
return ((elemBottom <= docViewBottom) && (elemTop >= docViewTop));
}
// $(window).scroll(function() {
if (isScrolledIntoView(".flip-card")) {
console.log(true);
const cards = document.querySelectorAll('.flip-card');
const flip_delay = 2000;
/*
* function to flip the card forward (rotateY 180deg) or back (no rotation)
*/
const flipCard = (card, direction) => {
switch (direction) {
case 'forward':
card.children[0].classList.add("rotated");
break;
case 'back':
card.children[0].classList.remove("rotated");
break;
default:
card.children[0].classList.toggle("rotated");
}
};
/*
* function to check whether the automatic flip should skip the card
*/
const skipFlip = (cardIndex) => {
return cards[cardIndex].getAttribute('data-isHovered') || false;
}
cards.forEach((card, index) => {
card.addEventListener('mouseenter', (event) => {
/*
* onMouseEnter:
* 1. flip the card forward (comment the function call if you do not want a "flip on mouse over" behaviour)
* 2. add an attribute to prevent automatic flip
*/
flipCard(card, 'forward');
card.setAttribute('data-isHovered', true);
});
card.addEventListener('mouseleave', (event) => {
/*
* onMouseLeave
* 1. flip the card back (comment the function call if you do not want a "flip on mouse over" behaviour)
* 2. remove the attribute preventing the automatic flip
*/
flipCard(card, 'back');
card.removeAttribute('data-isHovered', false);
});
});
/*
* Automatically flip forward/back the cards one after the other, every 2 seconds
* unless a card is hovered by the mouse (in which case the card will
* stay in the same flipping position until the mouse moves out of it)
*/
let currCardIndex = 0;
window.setInterval(() => {
const prevCardIndex = (currCardIndex === 0 && cards.length - 1) || currCardIndex - 1;
if (!skipFlip(prevCardIndex)) {
flipCard(cards[prevCardIndex], 'back');
}
if (!skipFlip(currCardIndex)) {
flipCard(cards[currCardIndex], 'forward');
}
currCardIndex = currCardIndex === cards.length - 1 ? 0 : currCardIndex + 1;
}, flip_delay);
}
I tried to use the solution provided here: How to check if element is visible after scrolling? But it only detect if the element is in the viewport on page reload, I am trying to implement it on scrolling. I tried to use $(window).scroll(function() {, but it just piles up the flipping animation at every scroll.
Quite possibly a duplicate of:
How to check if element is visible after scrolling?
Extra:
Have you seen this? https://developer.mozilla.org/en-US/docs/Web/API/Element/scrollHeight#Determine_if_an_element_has_been_totally_scrolled
I have a webpage that when scrolled down, the text freezes when it reaches the last paragraph of text but the images keep on scrolling. I've got the implementation working but there is a lot of jank when scrolling with a mouse wheel, not so much if I click and drag the scroll bar.
Are there any optimizations I can make to this code to make work as intended or is there a different way to accomplish the same task?
window.addEventListener('scroll', function (e) {
window.requestAnimationFrame(keepTextStationary);
//keepTextStationary(); // Less janky, but still horrible
});
function keepTextStationary() {
var textRect = writtenContent.getBoundingClientRect();
var imageRec = images.getBoundingClientRect();
if (textRect.bottom < window.innerHeight && document.documentElement.scrollTop > 0) {
writtenContent.style.position = 'relative';
writtenContent.style.bottom = (225 - document.documentElement.scrollTop) + 'px';
if (imagesTop === undefined) {
imagesTop = imageRec.y;
}
} else {
writtenContent.style.bottom = (225 - document.documentElement.scrollTop) + 'px';
}
if (imageRec.y >= imagesTop) {
writtenContent.style.position = '';
}
}
Here is the site so you can see the problem.
https://bowerbankninow.azurewebsites.net/exhibitions/oscar-perry-the-pheasant
You are causing layout trashing every time you call getBoundingClientRect. Try debouncing your scroll events:
var lastScrollY = 0;
var ticking = false;
function keepTextStationary() {
var textRect = writtenContent.getBoundingClientRect();
var imageRec = images.getBoundingClientRect();
if (textRect.bottom < window.innerHeight && lastScrollY > 0) {
writtenContent.style.position = 'relative';
writtenContent.style.bottom = (225 - lastScrollY) + 'px';
if (imagesTop === undefined) {
imagesTop = imageRec.y;
}
} else {
writtenContent.style.bottom = (225 - lastScrollY) + 'px';
}
if (imageRec.y >= imagesTop) {
writtenContent.style.position = '';
}
ticking = false;
}
function onScroll() {
lastScrollY = document.documentElement.scrollTop;
requestTick();
}
function requestTick() {
if (!ticking) {
requestAnimationFrame(keepTextStationary);
ticking = true;
}
}
window.addEventListener('scroll', onScroll );
See this article for in-depth explanation: https://www.html5rocks.com/en/tutorials/speed/animations/
You dont.
Relocations / styling in javascript take place after the CSS has been loaded. Bad practise. What you can do, is make it animated to make it look less horrible.
Why is pure CSS not an option ?
I'm building a onepager with a parallax intro. For the parallax effect I'm using the following piece of JS:
// Parallax
var layerBg = document.querySelector('.js-layer-bg');
var layerText = document.querySelector('.js-layer-text');
var sectionIntro = document.getElementById('section-intro');
var scrollPos = window.pageYOffset;
var layers = document.querySelectorAll('[data-type=\'parallax\']');
var parallax = function() {
for (var i = 0, len = layers.length; i < len; i++) {
var layer = layers[i];
var depth = layer.getAttribute('data-depth');
var movement = (scrollPos * depth) * -1;
var translate3d = 'translate3d(0, ' + movement + 'px, 0)';
layer.style['-webkit-transform'] = translate3d;
layer.style.transform = translate3d;
}
};
window.requestAnimationFrame(parallax);
window.addEventListener('scroll', function() {
// Parallax layers
scrollPos = window.pageYOffset;
window.requestAnimationFrame(parallax);
// Animate text layers
var vhScrolled = Math.round(window.pageYOffset / window.innerHeight * 100);
if (vhScrolled > 100 && layerText.classList.contains('is-hidden')) {
layerText.classList.remove('is-hidden');
} else if (vhScrolled <= 100 && !layerText.classList.contains('is-hidden')) {
layerText.classList.add('is-hidden');
}
});
Apart from this I'm animating a few other things on scroll using 2 libraries: ScrollMonitor and ScrollReveal. Nothing too special.
I've been developing this on Chrome and everything seems to be working smoothly enough. However, when I tested on Safari and especially Firefox, things got so laggy to the point of actually crashing my browser.
I really can't figure out what I am doing wrong and why performance is so different between browsers.
Hopefully you can help me out, thanks!
I'm not altogether certain about what's specifically causing the lag/choppiness issues, I seem to remember something similar in past projects. I'd look into any further image optimization to lower the weight of what's being rendered, that can make a huge difference. Otherwise, I've made a few suggestions for efficiency tweaks that might help it run a bit faster:
// Parallax
var layerBg = document.querySelector('.js-layer-bg');
var layerText = document.querySelector('.js-layer-text');
var sectionIntro = document.getElementById('section-intro');
var layers = document.querySelectorAll('[data-type=\'parallax\']');
var len = layers.length; // cache length
var layerarray = []; //create cache for depth attributes
var i = -1;
while(++i < len){
layerarray.push([layers[i], parseInt(layers[i].getAttribute('data-depth'))]); //create an array that stores each element alongside its depth attribute instead of requesting that attribute every time
}
var parallax = function() {
var scrollPos = window.pageYOffset; //define inside function instead of globally
var i = -1;
while(++i < len) { //while loop with cached length for minor speed gains
var layer = layerarray[i][0];
var depth = layerarray[i][1];
var movement = (scrollPos * depth) * -1;
var translate3d = ['translate3d(0, ', movement, 'px, 0)'].join(""); //join statement is much faster than string concatenation
layer.style['-webkit-transform'] = translate3d;
layer.style.transform = translate3d;
}
// Animate text layers
var vhScrolled = Math.round(scrollPos / window.innerHeight * 100);
if (vhScrolled > 100 && layerText.classList.contains('is-hidden')) {
layerText.classList.remove('is-hidden');
} else if (vhScrolled <= 100 && !layerText.classList.contains('is-hidden')) {
layerText.classList.add('is-hidden');
}
};
window.requestAnimationFrame(parallax);
window.addEventListener('scroll', function() {
// Parallax layers
window.requestAnimationFrame(parallax);
//moved text animation into the animationframe request
});
I want to have 4 buttons/links on the beginning of the page, and under them the content.
On the buttons I put this code:
Scroll to element 1
Scroll to element 2
Scroll to element 3
Scroll to element 4
And under links there will be content:
<h2 id="idElement1">Element1</h2>
content....
<h2 id="idElement2">Element2</h2>
content....
<h2 id="idElement3">Element3</h2>
content....
<h2 id="idElement4">Element4</h2>
content....
It is working now, but cannot make it look more smooth.
I used this code, but cannot get it to work.
$('html, body').animate({
scrollTop: $("#elementID").offset().top
}, 2000);
Any suggestions? Thank you.
Edit: and the fiddle: http://jsfiddle.net/WxJLx/2/
Super smoothly with requestAnimationFrame
For smoothly rendered scrolling animation one could use window.requestAnimationFrame() which performs better with rendering than regular setTimeout() solutions.
A basic example looks like this. Function step is called for browser's every animation frame and allows for better time management of repaints, and thus increasing performance.
function doScrolling(elementY, duration) {
var startingY = window.pageYOffset;
var diff = elementY - startingY;
var start;
// Bootstrap our animation - it will get called right before next frame shall be rendered.
window.requestAnimationFrame(function step(timestamp) {
if (!start) start = timestamp;
// Elapsed milliseconds since start of scrolling.
var time = timestamp - start;
// Get percent of completion in range [0, 1].
var percent = Math.min(time / duration, 1);
window.scrollTo(0, startingY + diff * percent);
// Proceed with animation as long as we wanted it to.
if (time < duration) {
window.requestAnimationFrame(step);
}
})
}
For element's Y position use functions in other answers or the one in my below-mentioned fiddle.
I set up a bit more sophisticated function with easing support and proper scrolling to bottom-most elements:
https://jsfiddle.net/s61x7c4e/
Question was asked 5 years ago and I was dealing with smooth scroll and felt giving a simple solution is worth it to those who are looking for. All the answers are good but here you go a simple one.
function smoothScroll(){
document.querySelector('.your_class or #id here').scrollIntoView({
behavior: 'smooth'
});
}
just call the smoothScroll function on onClick event on your source element.
DOCS: https://developer.mozilla.org/en-US/docs/Web/API/Element/scrollIntoView
Note: Please check compatibility here
3rd Party edit
Support for Element.scrollIntoView() in 2020 is this:
Region full + partial = sum full+partial Support
Asia 73.24% + 22.75% = 95.98%
North America 56.15% + 42.09% = 98.25%
India 71.01% + 20.13% = 91.14%
Europe 68.58% + 27.76% = 96.35%
Just made this javascript only solution below.
Simple usage:
EPPZScrollTo.scrollVerticalToElementById('signup_form', 20);
Engine object (you can fiddle with filter, fps values):
/**
*
* Created by Borbás Geri on 12/17/13
* Copyright (c) 2013 eppz! development, LLC.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
* The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
*/
var EPPZScrollTo =
{
/**
* Helpers.
*/
documentVerticalScrollPosition: function()
{
if (self.pageYOffset) return self.pageYOffset; // Firefox, Chrome, Opera, Safari.
if (document.documentElement && document.documentElement.scrollTop) return document.documentElement.scrollTop; // Internet Explorer 6 (standards mode).
if (document.body.scrollTop) return document.body.scrollTop; // Internet Explorer 6, 7 and 8.
return 0; // None of the above.
},
viewportHeight: function()
{ return (document.compatMode === "CSS1Compat") ? document.documentElement.clientHeight : document.body.clientHeight; },
documentHeight: function()
{ return (document.height !== undefined) ? document.height : document.body.offsetHeight; },
documentMaximumScrollPosition: function()
{ return this.documentHeight() - this.viewportHeight(); },
elementVerticalClientPositionById: function(id)
{
var element = document.getElementById(id);
var rectangle = element.getBoundingClientRect();
return rectangle.top;
},
/**
* Animation tick.
*/
scrollVerticalTickToPosition: function(currentPosition, targetPosition)
{
var filter = 0.2;
var fps = 60;
var difference = parseFloat(targetPosition) - parseFloat(currentPosition);
// Snap, then stop if arrived.
var arrived = (Math.abs(difference) <= 0.5);
if (arrived)
{
// Apply target.
scrollTo(0.0, targetPosition);
return;
}
// Filtered position.
currentPosition = (parseFloat(currentPosition) * (1.0 - filter)) + (parseFloat(targetPosition) * filter);
// Apply target.
scrollTo(0.0, Math.round(currentPosition));
// Schedule next tick.
setTimeout("EPPZScrollTo.scrollVerticalTickToPosition("+currentPosition+", "+targetPosition+")", (1000 / fps));
},
/**
* For public use.
*
* #param id The id of the element to scroll to.
* #param padding Top padding to apply above element.
*/
scrollVerticalToElementById: function(id, padding)
{
var element = document.getElementById(id);
if (element == null)
{
console.warn('Cannot find element with id \''+id+'\'.');
return;
}
var targetPosition = this.documentVerticalScrollPosition() + this.elementVerticalClientPositionById(id) - padding;
var currentPosition = this.documentVerticalScrollPosition();
// Clamp.
var maximumScrollPosition = this.documentMaximumScrollPosition();
if (targetPosition > maximumScrollPosition) targetPosition = maximumScrollPosition;
// Start animation.
this.scrollVerticalTickToPosition(currentPosition, targetPosition);
}
};
Smooth scrolling - look ma no jQuery
Based on an article on itnewb.com i made a demo plunk to smoothly scroll without external libraries.
The javascript is quite simple. First a helper function to improve cross browser support to determine the current position.
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;
}
Then a function to determine the position of the destination element - the one where we would like to scroll to.
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;
}
And the core function to do the scrolling
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++;
}
return false;
}
To call it you just do the following. You create a link which points to another element by using the id as a reference for a destination anchor.
<a href="#anchor-2"
onclick="smoothScroll('anchor-2');">smooth scroll to the headline with id anchor-2<a/>
...
... some content
...
<h2 id="anchor-2">Anchor 2</h2>
Copyright
In the footer of itnewb.com the following is written: The techniques, effects and code demonstrated in ITNewb articles may be used for any purpose without attribution (although we recommend it) (2014-01-12)
You could also check this great Blog - with some very simple ways to achieve this :)
https://css-tricks.com/snippets/jquery/smooth-scrolling/
Like (from the blog)
// 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'
});
// Scroll to a certain element
document.querySelector('.hello').scrollIntoView({
behavior: 'smooth'
});
and you can also get the element "top" position like below (or some other way)
var e = document.getElementById(element);
var top = 0;
do {
top += e.offsetTop;
} while (e = e.offsetParent);
return top;
Why not use CSS scroll-behavior property
html {
scroll-behavior: smooth;
}
The browser support is also good
https://caniuse.com/#feat=css-scroll-behavior
For a more comprehensive list of methods for smooth scrolling, see my answer here.
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. To scroll to an element, just set the y-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:
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);
}
});
}
document.getElementById("toElement").addEventListener("click", function(e){
scrollToSmoothly(document.querySelector('div').offsetTop, 500 /* milliseconds */);
});
document.getElementById("backToTop").addEventListener("click", function(e){
scrollToSmoothly(0, 500);
});
<button id="toElement">Scroll To Element</button>
<div style="margin: 1000px 0px; text-align: center;">Div element
<button id="backToTop">Scroll back to top</button>
</div>
The SmoothScroll.js library can also be used, which supports scrolling to an element on the page in addition to more complex features such as smooth scrolling both vertically and horizontally, scrolling inside other container elements, different easing behaviors, scrolling relatively from the current position, and more.
document.getElementById("toElement").addEventListener("click", function(e){
smoothScroll({toElement: document.querySelector('div'), duration: 500});
});
document.getElementById("backToTop").addEventListener("click", function(e){
smoothScroll({yPos: 'start', duration: 500});
});
<script src="https://cdn.jsdelivr.net/gh/LieutenantPeacock/SmoothScroll#1.2.0/src/smoothscroll.min.js" integrity="sha384-UdJHYJK9eDBy7vML0TvJGlCpvrJhCuOPGTc7tHbA+jHEgCgjWpPbmMvmd/2bzdXU" crossorigin="anonymous"></script>
<button id="toElement">Scroll To Element</button>
<div style="margin: 1000px 0px; text-align: center;">Div element
<button id="backToTop">Scroll back to top</button>
</div>
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'
});
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'
});
I've been using this for a long time:
function scrollToItem(item) {
var diff=(item.offsetTop-window.scrollY)/8
if (Math.abs(diff)>1) {
window.scrollTo(0, (window.scrollY+diff))
clearTimeout(window._TO)
window._TO=setTimeout(scrollToItem, 30, item)
} else {
window.scrollTo(0, item.offsetTop)
}
}
usage:
scrollToItem(element) where element is document.getElementById('elementid') for example.
Variation of #tominko answer.
A little smoother animation and resolved problem with infinite invoked setTimeout(), when some elements can't allign to top of viewport.
function scrollToItem(item) {
var diff=(item.offsetTop-window.scrollY)/20;
if(!window._lastDiff){
window._lastDiff = 0;
}
console.log('test')
if (Math.abs(diff)>2) {
window.scrollTo(0, (window.scrollY+diff))
clearTimeout(window._TO)
if(diff !== window._lastDiff){
window._lastDiff = diff;
window._TO=setTimeout(scrollToItem, 15, item);
}
} else {
console.timeEnd('test');
window.scrollTo(0, item.offsetTop)
}
}
you can use this plugin. Does exactly what you want.
http://flesler.blogspot.com/2007/10/jqueryscrollto.html
If one need to scroll to an element inside a div there is my solution based on Andrzej Sala's answer:
function scroolTo(element, duration) {
if (!duration) {
duration = 700;
}
if (!element.offsetParent) {
element.scrollTo();
}
var startingTop = element.offsetParent.scrollTop;
var elementTop = element.offsetTop;
var dist = elementTop - startingTop;
var start;
window.requestAnimationFrame(function step(timestamp) {
if (!start)
start = timestamp;
var time = timestamp - start;
var percent = Math.min(time / duration, 1);
element.offsetParent.scrollTo(0, startingTop + dist * percent);
// Proceed with animation as long as we wanted it to.
if (time < duration) {
window.requestAnimationFrame(step);
}
})
}
Why not use this easy way
Native JS
document.querySelector(".layout").scrollIntoView({
behavior: "smooth",
});
Smooth scrolling with jQuery.ScrollTo
To use the jQuery ScrollTo plugin you have to do the following
Create links where href points to another elements.id
create the elements you want to scroll to
reference jQuery and the scrollTo Plugin
Make sure to add a click event handler for each link that should do smooth scrolling
Creating the links
<h1>Smooth Scrolling with the jQuery Plugin .scrollTo</h1>
<div id="nav-list">
Scroll to element 1
Scroll to element 2
Scroll to element 3
Scroll to element 4
</div>
Creating the target elements here only the first two are displayed the other headings are set up the same way. To see another example i added a link back to the navigation a.toNav
<h2 id="idElement1">Element1</h2>
....
<h2 id="idElement1">Element1</h2>
...
<a class="toNav" href="#nav-list">Scroll to Nav-List</a>
Setting the references to the scripts. Your path to the files may be different.
<script src="./jquery-1.8.3.min.js"></script>
<script src="./jquery.scrollTo-1.4.3.1-min.js"></script>
Wiring it all up
The code below is borrowed from jQuery easing plugin
jQuery(function ($) {
$.easing.elasout = function (x, t, b, c, d) {
var s = 1.70158; var p = 0; var a = c;
if (t == 0) return b;
if ((t /= d) == 1) return b + c;
if (!p) p = d * .3;
if (a < Math.abs(c)) {
a = c; var s = p / 4;
} else var s = p / (2 * Math.PI) * Math.asin(c / a);
// line breaks added to avoid scroll bar
return a * Math.pow(2, -10 * t) * Math.sin((t * d - s)
* (2 * Math.PI) / p) + c + b;
};
// important reset all scrollable panes to (0,0)
$('div.pane').scrollTo(0);
$.scrollTo(0); // Reset the screen to (0,0)
// adding a click handler for each link
// within the div with the id nav-list
$('#nav-list a').click(function () {
$.scrollTo(this.hash, 1500, {
easing: 'elasout'
});
return false;
});
// adding a click handler for the link at the bottom
$('a.toNav').click(function () {
var scrollTargetId = this.hash;
$.scrollTo(scrollTargetId, 1500, {
easing: 'elasout'
});
return false;
});
});
Fully working demo on plnkr.co
You may take a look at the soucre code for the demo.
Update May 2014
Based on another question i came across another solution from kadaj. Here jQuery animate is used to scroll to an element inside a <div style=overflow-y: scroll>
$(document).ready(function () {
$('.navSection').on('click', function (e) {
debugger;
var elemId = ""; //eg: #nav2
switch (e.target.id) {
case "nav1":
elemId = "#s1";
break;
case "nav2":
elemId = "#s2";
break;
case "nav3":
elemId = "#s3";
break;
case "nav4":
elemId = "#s4";
break;
}
$('.content').animate({
scrollTop: $(elemId).parent().scrollTop()
+ $(elemId).offset().top
- $(elemId).parent().offset().top
}, {
duration: 1000,
specialEasing: { width: 'linear'
, height: 'easeOutBounce' },
complete: function (e) {
//console.log("animation completed");
}
});
e.preventDefault();
});
});