I have a page with a lot of text that requires some amount of scrolling. I was able to get a button, when clicked, to shoot to the top of the page I am on. But when at the top of the page, I am wanting this button to switch to another link that goes to the homepage.
Bonus Points: How would I change the text to also switch from "top" to "home"? I have not tackled this hurdle because I figured my issue with switching the href would correlate to this obstacle.
JS:
window.onscroll = function() { scrollFunction() };
function scrollFunction() {
document.getElementById("scroll-to-top-button").classList.toggle("show");
window.onclick = function(event) {
if (document.body.scrollTop > 20 || document.documentElement.scrollTop > 20) {
window.location = "#top";
} else if(document.body.scrollTop = 0){
window.location.href = "https://homepage.html";
}
}
}
html:
<div class="fas fa-angle-up">top</div>
I have tried using window.scrollY instead of .scrollTop - but I have not touched scrolling elements prior to this. I am a little fuzzy with how to indicate if I have scrolled vs not scrolled. I do not know if my issue is because my if, else elements are not correct - or if it is something else?
Here's a small code snippet example to answer your question,
const anchor = document.querySelector('a')
window.addEventListener('scroll',() => {
if(window.scrollY > 100){
anchor.setAttribute('href', "#above")
anchor.innerText = "go above"
}else{
anchor.setAttribute('href', "#below")
anchor.innerText = "go below"
}
})
html{
scroll-behavior: smooth;
}
header{
background: white;
width: 100%
}
#above{
height:100vh;
width: 100%;
background: blue;
}
#below{
height: 100vh;
width: 100%;
background: green;
}
<header style="position:fixed">
go below
</header>
<section id="above"></section>
<section id="below"></section>
Here I am using setAttribute() to change the href attribute of anchor tag, and innerText to change that same anchor tag's text. I am using scrollY to check amount of window scrolled.
You could change the if(window.scrollY > 'change this value') according to your need
I have a fixed header with on my website at 65px tall. I have a secondary navigation about 3/4 down the page that I want to fix to the bottom of my header once scrolled to it.
I've used Josh Lee's answer on this post to get the functionality to work, however, because my header is fixed, the secondary navigation scrolls right past it and becomes fixed once it hits the top of the page.
Since it completely bypasses my header, how can I set an offset for the trigger so that it happens 65px from the top of the screen?
In my <head>:
<script>
function moveScroller() {
var move = function() {
var st = $(window).scrollTop();
var ot = $("#scroller-anchor").offset().top;
var s = $("#mydiv");
if(st > ot) {
s.css({
position: "fixed",
top: "65px"
});
} else {
if(st <= ot) {
s.css({
position: "relative",
top: ""
});
}
}
};
$(window).scroll(move);
move();
}
</script>
On my page:
<div id="scroller-anchor"></div>
<div id="mydiv" class="">
<ul class="wrap">
<li> ... </li>
<li> ... </li>
<li> ... </li>
<li> ... </li>
</ul>
</div>
<script type="text/javascript">
$(function() {
moveScroller();
});
</script>
I believe you will need to account for the space when you are checking when to change the position to fixed for example change ot variable to
var ot = $("#scroller-anchor").offset().top - 65;
I don't know if this could be considered the "correct" way of solving my problem, but it seemed to have worked for me... I added top:-65px to the scroller-anchor element.
<div id="scroller-anchor" style="top: -65px;"></div>
I have a very long article page that I want to help mobile users scroll on. For very long lists in mobile apps there's usually a alphabetical index that can help users jump to various places in the list. How do I implement something like that for a webapp?
If it helps my stack is angularjs / jquery / phonegap.
Just use angular's built-in $anchorScroll service.
See the live example in angular's official docs. Here are the important pieces of code:
In your view template:
<div id="scrollArea" ng-controller="ScrollCtrl">
<a ng-click="gotoBottom()">Go to bottom</a>
<a id="bottom"></a> You're at the bottom!
</div>
In your controller:
function ScrollCtrl($scope, $location, $anchorScroll) {
$scope.gotoBottom = function (){
// set the location.hash to the id of
// the element you wish to scroll to.
$location.hash('bottom');
// call $anchorScroll()
$anchorScroll();
};
}
iOS7 Style List Navigator
If you want something nice on the phone, I just wrote this iOS7 style list navigator. I think the way Apple solved the problem is very straightforward. So we steal it.
It's written considering that you won't probably scroll the body, because in the many designs I've seen for smartphones, scrolling a container allows you to have fixed headers and footers for Android < 4 without getting mad.
A word of warning: this code is really fresh and untested.
SEE DEMO AND CODE
CSS (extract)
#scrolling {
padding-top: 44px;
overflow: scroll;
-webkit-overflow-scroll: touch;
height: 100%;
}
.menu {
position: fixed;
right: 0;
font-size: 12px;
text-align: center;
display: inline-block;
z-index: 2;
top: 58px;
}
.list .divider {
position: -webkit-sticky; /* will stop the label when it reaches the header */
top: 44px;
}
HTML (extract)
<div id="scrolling">
<ul class="menu">
<li>A</li>
<li>B</li>
<li>C</li>
<!-- etc -->
</ul>
<ul class="list">
<li class="divider" id="a">A</li>
<li>Amelia Webster</li>
<li>Andrew WifKinson</li>
<!-- etc -->
Javascript (zepto/jquery)
$(function() {
$(window).on("touchstart touchmove mouseover click", ".menu a", function(e) {
e.preventDefault();
clearInterval(t);
var steps = 25;
var padding = 68;
var target = $( $(this).attr("href") ).next("li");
if ( target.length > 0 ) {
var scroller = $("#scrolling")[0];
var step = parseInt((target[0].offsetTop - padding - scroller.scrollTop)/steps);
var stepno = 0;
setInterval( function() {
if ( stepno++ <= steps ) {
scroller.scrollTop += step;
} else {
clearInterval(t)
}
}, 20);
};
});
});
It performs a basic check of link validity before attempting the scroll. You can change padding to your needs.
Also, you will notice that we are targeting the first element after the required target. This is because Safari seems to go nuts because of the sticky positioning.
This code uses jQuery/Zepto selectors for the sake of brevity and readability. But these libraries are not really needed to achieve the result. With just a little extra digitation you could easily go dependency-free.
http://codepen.io/frapporti/pen/GtaLD
You can use a toggleable sidebar like this one. Resize your browser to the width of the screen of a mobile phone to understand what I mean.
Then create a directive in angularjs to wrap jQuery's animate function to scroll to a specific part in the article. Like this:
angular.module('yourModule', [])
.directive('scrollTo', function() {
return {
restrict : 'EA',
link: function(scope , element, attr){
$('html, body').animate({
scrollTop: $( attr['href'] ).offset().top
}, 300);
}
};
});
where href will be an id of a specific section in the article. Then all you need to do is apply the directive to the links in the sidebar.
...
<li><a href="#section-1" scroll-to>Jump to section 1</a></li>
...
Hope this helps.
This might be what you're looking for http://www.designkode.com/alphascroll-jquery-mobile/
Haven't used it myself, but seems pretty simple to get going with.
I think something like this could work for you: http://codepen.io/aecend/pen/AsnIE. This is just a basic prototype I put together to answer but I could expand on the concept if needed. Basically, it creates a translucent bar on the right side of the screen, finds each of the headings for articles (which would need to be adapted to suit your needs) and places clickable/tappable anchors to jump to individual articles. When you click one, the page scrolls to that article. I have a few ideas to make this actually usable, but here's the proof of concept.
CSS
#scrollhelper {
position: fixed;
top: 0;
right: 0;
height: 100%;
width: 5%;
background-color: rgba(0,0,0,0.2);
overflow: hidden;
}
#scrollhelper .point {
position: absolute;
display: block;
width: 100%;
height: 10px;
margin: 0 auto;
background-color: rgba(0,0,255,0.5);
}
JavaScript
var articles;
function buildScrollHelp() {
var bodyHeight = $("body").height();
var viewHeight = window.innerHeight;
$("#scrollhelper").html("");
articles.each(function() {
var top = $(this).offset().top;
var element = document.createElement("a");
element.className = "point";
element.href = "#" + $(this).attr("id");
element.style.top = ((top / bodyHeight) * viewHeight) + "px";
$(element).on("click", function(e){
e.preventDefault();
$('html, body').animate({
scrollTop: $($(this).attr("href")).offset().top
}, 500);
});
$("#scrollhelper")[0].appendChild(element);
});
}
$(document).ready(function() {
articles = $("body").children("[id]");
$("body").append("<div id=\"scrollhelper\"></div>");
$(window).resize(function(){
buildScrollHelp();
});
buildScrollHelp();
});
I am creating my product pages by using the object tag code, but every time I click the "view" button, the next page is staying at the same position of previous page which I just viewed. How can I add functionality that will let me view from the top of page every time I click the "view" button?
<div id="container" class="clearfix"><!--! end of #sidebar -->
<div class="holder"></div>
<div id="content" class="defaults"><!-- navigation holder -->
<div id="title2">Office Section</div>
<!-- item container -->
<ul id="itemContainer">
<li>
<div id="product">
<div id="title">FuBang®</div>
<div class="imageOuter" style="margin:0">
<a class="image" href="officesection010.html">
<span class="rollover" ></span>
<img class="imgborder" src="product/officesection/010.jpg" width="165" height="165" />
</a>
</div><br />
<div id="text">Sofa </div><br />
<div id="button">
View Details
</div>
</div>
</li>
</ul>
<br />
<div id="title2"></div>
<div class="holder"></div>
</div>
</div> <!--! end of #content -->
</div> <!--! end of #container -->
When I click the "View Details" button at a specific position "x" here: http://postimg.org/image/vgs0lwhtr/
The next page shows the same position "x", but I want it to jump to the top of page:
http://postimg.org/image/vn80e2lph/
Using Javascript:
document.body.scrollTop = document.documentElement.scrollTop = 0;
Using jQuery:
$(function() {
$('body').scrollTop(0);
});
jQuery(document).ready(function($){
$(window).scroll(function(){
if ($(this).scrollTop() > 50) {
$('#backToTop').fadeIn('slow');
} else {
$('#backToTop').fadeOut('slow');
}
});
$('#backToTop').click(function(){
$("html, body").animate({ scrollTop: 0 }, 500);
//$("html, body").scrollTop(0); //For without animation
return false;
});
});
please refere this, may this help
Sometimes placing scroll to body doesn't work if your current content is generated through jQuery (as it was in my case). In such situation you can just do following.
$(function() {
$('html').scrollTop(0);
});
A small issue with Subhash's jQuery solution is that you must call this code within $(document).ready() in order for your $('body') selector to work. The ready event may not fire before parts of your page have been rendered to the screen.
An better approach is to simply modify the user's location as a work-around to this browser 'feature':
//Above all of your $(document).ready(...) code
document.location = "#";
Simple HTML solution for jumping between page parts
// Place a tag like this where you would like to go
// in your case at the top
<a name="top"></a>
// you will reach there by click of this link better use an image reach their by clicking on this we can also use an image, align in right
last
Back to top button, works in all browsers.To change the scroll speed simply change the x in counter -= x here x = 10
function scrollToTop(){
var myBody = document.body;
var id = setInterval(secondFunction,1);
var height = window.pageYOffset;
var counter = height;
function secondFunction(){
if(window.pageYOffset == 0){
clearInterval(id);
}
else {
if(!!navigator.userAgent.match(/Trident/g) || !!navigator.userAgent.match(/MSIE/g)){
counter -= 10;
counter--;
document.documentElement.scrollTop = counter;
}
else {
counter -= 10;
counter--;
myBody.scrollTop = counter;
}
}
}
}
body {
height: 5000px;
margin: 0;
padding: 0;
}
.backToTop {
position: fixed;
/* Fixed at page */
top: auto;
bottom: 20px;
left: auto;
right: 20px;
background-color: crimson;
color: white;
padding: 5px;
cursor: pointer;
}
header {
position: relative;
top: 0;
left: 0;
width: 100%;
height: 100px;
background-color: black;
}
<!-- back to top button -->
<span class="backToTop" onclick="scrollToTop()">TOP</span>
<!-- Header -->
<header>
</header>
Assign an id="#body" and tabindex in the <body> tag
<body id="#body" tabindex="1">
and use jquery focus()
$(function() {
$("#body").attr("tabindex",-1).focus();
}
You can use this method:
function gototop() {
if (window.scrollY>0) {
window.scrollTo(0,window.scrollY-20)
setTimeout("gototop()",10)
}
}
I have a scrolled div and I want to have an event when I click on it, it will force this div to scroll to view an element inside.
I wrote its JavasSript like this:
document.getElementById(chr).scrollIntoView(true);
but this scrolls all the page while scrolling the div itself.
How to fix that?
I want to say it like this:
MyContainerDiv.getElementById(chr).scrollIntoView(true);
You need to get the top offset of the element you'd like to scroll into view, relative to its parent (the scrolling div container):
var myElement = document.getElementById('element_within_div');
var topPos = myElement.offsetTop;
The variable topPos is now set to the distance between the top of the scrolling div and the element you wish to have visible (in pixels).
Now we tell the div to scroll to that position using scrollTop:
document.getElementById('scrolling_div').scrollTop = topPos;
If you're using the prototype JS framework, you'd do the same thing like this:
var posArray = $('element_within_div').positionedOffset();
$('scrolling_div').scrollTop = posArray[1];
Again, this will scroll the div so that the element you wish to see is exactly at the top (or if that's not possible, scrolled as far down as it can so it's visible).
You would have to find the position of the element in the DIV you want to scroll to, and set the scrollTop property.
divElem.scrollTop = 0;
Update:
Sample code to move up or down
function move_up() {
document.getElementById('divElem').scrollTop += 10;
}
function move_down() {
document.getElementById('divElem').scrollTop -= 10;
}
Method 1 - Smooth scrolling to an element inside an element
var box = document.querySelector('.box'),
targetElm = document.querySelector('.boxChild'); // <-- Scroll to here within ".box"
document.querySelector('button').addEventListener('click', function(){
scrollToElm( box, targetElm , 600 );
});
/////////////
function scrollToElm(container, elm, duration){
var pos = getRelativePos(elm);
scrollTo( container, pos.top , 2); // duration in seconds
}
function getRelativePos(elm){
var pPos = elm.parentNode.getBoundingClientRect(), // parent pos
cPos = elm.getBoundingClientRect(), // target pos
pos = {};
pos.top = cPos.top - pPos.top + elm.parentNode.scrollTop,
pos.right = cPos.right - pPos.right,
pos.bottom = cPos.bottom - pPos.bottom,
pos.left = cPos.left - pPos.left;
return pos;
}
function scrollTo(element, to, duration, onDone) {
var start = element.scrollTop,
change = to - start,
startTime = performance.now(),
val, now, elapsed, t;
function animateScroll(){
now = performance.now();
elapsed = (now - startTime)/1000;
t = (elapsed/duration);
element.scrollTop = start + change * easeInOutQuad(t);
if( t < 1 )
window.requestAnimationFrame(animateScroll);
else
onDone && onDone();
};
animateScroll();
}
function easeInOutQuad(t){ return t<.5 ? 2*t*t : -1+(4-2*t)*t };
.box{ width:80%; border:2px dashed; height:180px; overflow:auto; }
.boxChild{
margin:600px 0 300px;
width: 40px;
height:40px;
background:green;
}
<button>Scroll to element</button>
<div class='box'>
<div class='boxChild'></div>
</div>
Method 2 - Using Element.scrollIntoView:
Note that browser support isn't great for this one
var targetElm = document.querySelector('.boxChild'), // reference to scroll target
button = document.querySelector('button'); // button that triggers the scroll
// bind "click" event to a button
button.addEventListener('click', function(){
targetElm.scrollIntoView()
})
.box {
width: 80%;
border: 2px dashed;
height: 180px;
overflow: auto;
scroll-behavior: smooth; /* <-- for smooth scroll */
}
.boxChild {
margin: 600px 0 300px;
width: 40px;
height: 40px;
background: green;
}
<button>Scroll to element</button>
<div class='box'>
<div class='boxChild'></div>
</div>
Method 3 - Using CSS scroll-behavior:
.box {
width: 80%;
border: 2px dashed;
height: 180px;
overflow-y: scroll;
scroll-behavior: smooth; /* <--- */
}
#boxChild {
margin: 600px 0 300px;
width: 40px;
height: 40px;
background: green;
}
<a href='#boxChild'>Scroll to element</a>
<div class='box'>
<div id='boxChild'></div>
</div>
Native JS, Cross Browser, Smooth Scroll (Update 2020)
Setting ScrollTop does give the desired result but the scroll is very abrupt. Using jquery to have smooth scroll was not an option. So here's a native way to get the job done that supports all major browsers. Reference - caniuse
// get the "Div" inside which you wish to scroll (i.e. the container element)
const El = document.getElementById('xyz');
// Lets say you wish to scroll by 100px,
El.scrollTo({top: 100, behavior: 'smooth'});
// If you wish to scroll until the end of the container
El.scrollTo({top: El.scrollHeight, behavior: 'smooth'});
That's it!
And here's a working snippet for the doubtful -
document.getElementById('btn').addEventListener('click', e => {
e.preventDefault();
// smooth scroll
document.getElementById('container').scrollTo({top: 175, behavior: 'smooth'});
});
/* just some styling for you to ignore */
.scrollContainer {
overflow-y: auto;
max-height: 100px;
position: relative;
border: 1px solid red;
width: 120px;
}
body {
padding: 10px;
}
.box {
margin: 5px;
background-color: yellow;
height: 25px;
display: flex;
align-items: center;
justify-content: center;
}
#goose {
background-color: lime;
}
<!-- Dummy html to be ignored -->
<div id="container" class="scrollContainer">
<div class="box">duck</div>
<div class="box">duck</div>
<div class="box">duck</div>
<div class="box">duck</div>
<div class="box">duck</div>
<div class="box">duck</div>
<div class="box">duck</div>
<div class="box">duck</div>
<div id="goose" class="box">goose</div>
<div class="box">duck</div>
<div class="box">duck</div>
<div class="box">duck</div>
<div class="box">duck</div>
</div>
<button id="btn">goose</button>
Update: As you can perceive in the comments, it seems that Element.scrollTo() is not supported in IE11. So if you don't care about IE11 (you really shouldn't, Microsoft is retiring IE11 in June 2022), feel free to use this in all your projects. Note that support exists for Edge! So you're not really leaving your Edge/Windows users behind ;)
Reference
To scroll an element into view of a div, only if needed, you can use this scrollIfNeeded function:
function scrollIfNeeded(element, container) {
if (element.offsetTop < container.scrollTop) {
container.scrollTop = element.offsetTop;
} else {
const offsetBottom = element.offsetTop + element.offsetHeight;
const scrollBottom = container.scrollTop + container.offsetHeight;
if (offsetBottom > scrollBottom) {
container.scrollTop = offsetBottom - container.offsetHeight;
}
}
}
document.getElementById('btn').addEventListener('click', ev => {
ev.preventDefault();
scrollIfNeeded(document.getElementById('goose'), document.getElementById('container'));
});
.scrollContainer {
overflow-y: auto;
max-height: 100px;
position: relative;
border: 1px solid red;
width: 120px;
}
body {
padding: 10px;
}
.box {
margin: 5px;
background-color: yellow;
height: 25px;
display: flex;
align-items: center;
justify-content: center;
}
#goose {
background-color: lime;
}
<div id="container" class="scrollContainer">
<div class="box">duck</div>
<div class="box">duck</div>
<div class="box">duck</div>
<div class="box">duck</div>
<div class="box">duck</div>
<div class="box">duck</div>
<div class="box">duck</div>
<div class="box">duck</div>
<div id="goose" class="box">goose</div>
<div class="box">duck</div>
<div class="box">duck</div>
<div class="box">duck</div>
<div class="box">duck</div>
</div>
<button id="btn">scroll to goose</button>
Code should be:
var divElem = document.getElementById('scrolling_div');
var chElem = document.getElementById('element_within_div');
var topPos = divElem.offsetTop;
divElem.scrollTop = topPos - chElem.offsetTop;
You want to scroll the difference between child top position and div's top position.
Get access to child elements using:
var divElem = document.getElementById('scrolling_div');
var numChildren = divElem.childNodes.length;
and so on....
If you are using jQuery, you could scroll with an animation using the following:
$(MyContainerDiv).animate({scrollTop: $(MyContainerDiv).scrollTop() + ($('element_within_div').offset().top - $(MyContainerDiv).offset().top)});
The animation is optional: you could also take the scrollTop value calculated above and put it directly in the container's scrollTop property.
We can resolve this problem without using JQuery and other libs.
I wrote following code for this purpose:
You have similar structure ->
<div class="parent">
<div class="child-one">
</div>
<div class="child-two">
</div>
</div>
JS:
scrollToElement() {
var parentElement = document.querySelector('.parent');
var childElement = document.querySelector('.child-two');
parentElement.scrollTop = childElement.offsetTop - parentElement.offsetTop;
}
We can easily rewrite this method for passing parent and child as an arguments
Another example of using jQuery and animate.
var container = $('#container');
var element = $('#element');
container.animate({
scrollTop: container.scrollTop = container.scrollTop() + element.offset().top - container.offset().top
}, {
duration: 1000,
specialEasing: {
width: 'linear',
height: 'easeOutBounce'
},
complete: function (e) {
console.log("animation completed");
}
});
None of other answer fixed my issue.
I played around with scrollIntoView arguments and managed to found a solution. Setting inline to start and block to nearest prevents parent element (or entire page) to scroll:
document.getElementById(chr).scrollIntoView({
behavior: 'smooth',
block: 'nearest',
inline: 'start'
});
There are two facts :
1) Component scrollIntoView is not supported by safari.
2) JS framework jQuery can do the job like this:
parent = 'some parent div has css position==="fixed"' || 'html, body';
$(parent).animate({scrollTop: $(child).offset().top}, duration)
Here's a simple pure JavaScript solution that works for a target Number (value for scrollTop), target DOM element, or some special String cases:
/**
* target - target to scroll to (DOM element, scrollTop Number, 'top', or 'bottom'
* containerEl - DOM element for the container with scrollbars
*/
var scrollToTarget = function(target, containerEl) {
// Moved up here for readability:
var isElement = target && target.nodeType === 1,
isNumber = Object.prototype.toString.call(target) === '[object Number]';
if (isElement) {
containerEl.scrollTop = target.offsetTop;
} else if (isNumber) {
containerEl.scrollTop = target;
} else if (target === 'bottom') {
containerEl.scrollTop = containerEl.scrollHeight - containerEl.offsetHeight;
} else if (target === 'top') {
containerEl.scrollTop = 0;
}
};
And here are some examples of usage:
// Scroll to the top
var scrollableDiv = document.getElementById('scrollable_div');
scrollToTarget('top', scrollableDiv);
or
// Scroll to 200px from the top
var scrollableDiv = document.getElementById('scrollable_div');
scrollToTarget(200, scrollableDiv);
or
// Scroll to targetElement
var scrollableDiv = document.getElementById('scrollable_div');
var targetElement= document.getElementById('target_element');
scrollToTarget(targetElement, scrollableDiv);
given you have a div element you need to scroll inside, try this piece of code
document.querySelector('div').scroll(x,y)
this works with me inside a div with a scroll, this should work with you in case you pointed the mouse over this element and then tried to scroll down or up. If it manually works, it should work too
User Animated Scrolling
Here's an example of how to programmatically scroll a <div> horizontally, without JQuery. To scroll vertically, you would replace JavaScript's writes to scrollLeft with scrollTop, instead.
JSFiddle
https://jsfiddle.net/fNPvf/38536/
HTML
<!-- Left Button. -->
<div style="float:left;">
<!-- (1) Whilst it's pressed, increment the scroll. When we release, clear the timer to stop recursive scroll calls. -->
<input type="button" value="«" style="height: 100px;" onmousedown="scroll('scroller',3, 10);" onmouseup="clearTimeout(TIMER_SCROLL);"/>
</div>
<!-- Contents to scroll. -->
<div id="scroller" style="float: left; width: 100px; height: 100px; overflow: hidden;">
<!-- <3 -->
<img src="https://cdn.sstatic.net/Sites/stackoverflow/company/img/logos/so/so-logo.png?v=9c558ec15d8a" alt="image large" style="height: 100px" />
</div>
<!-- Right Button. -->
<div style="float:left;">
<!-- As (1). (Use a negative value of 'd' to decrease the scroll.) -->
<input type="button" value="»" style="height: 100px;" onmousedown="scroll('scroller',-3, 10);" onmouseup="clearTimeout(TIMER_SCROLL);"/>
</div>
JavaScript
// Declare the Shared Timer.
var TIMER_SCROLL;
/**
Scroll function.
#param id Unique id of element to scroll.
#param d Amount of pixels to scroll per sleep.
#param del Size of the sleep (ms).*/
function scroll(id, d, del){
// Scroll the element.
document.getElementById(id).scrollLeft += d;
// Perform a delay before recursing this function again.
TIMER_SCROLL = setTimeout("scroll('"+id+"',"+d+", "+del+");", del);
}
Credit to Dux.
Auto Animated Scrolling
In addition, here are functions for scrolling a <div> fully to the left and right. The only thing we change here is we make a check to see if the full extension of the scroll has been utilised before making a recursive call to scroll again.
JSFiddle
https://jsfiddle.net/0nLc2fhh/1/
HTML
<!-- Left Button. -->
<div style="float:left;">
<!-- (1) Whilst it's pressed, increment the scroll. When we release, clear the timer to stop recursive scroll calls. -->
<input type="button" value="«" style="height: 100px;" onclick="scrollFullyLeft('scroller',3, 10);"/>
</div>
<!-- Contents to scroll. -->
<div id="scroller" style="float: left; width: 100px; height: 100px; overflow: hidden;">
<!-- <3 -->
<img src="https://cdn.sstatic.net/Sites/stackoverflow/company/img/logos/so/so-logo.png?v=9c558ec15d8a" alt="image large" style="height: 100px" />
</div>
<!-- Right Button. -->
<div style="float:left;">
<!-- As (1). (Use a negative value of 'd' to decrease the scroll.) -->
<input type="button" value="»" style="height: 100px;" onclick="scrollFullyRight('scroller',3, 10);"/>
</div>
JavaScript
// Declare the Shared Timer.
var TIMER_SCROLL;
/**
Scroll fully left function; completely scrolls a <div> to the left, as far as it will go.
#param id Unique id of element to scroll.
#param d Amount of pixels to scroll per sleep.
#param del Size of the sleep (ms).*/
function scrollFullyLeft(id, d, del){
// Fetch the element.
var el = document.getElementById(id);
// Scroll the element.
el.scrollLeft += d;
// Have we not finished scrolling yet?
if(el.scrollLeft < (el.scrollWidth - el.clientWidth)) {
TIMER_SCROLL = setTimeout("scrollFullyLeft('"+id+"',"+d+", "+del+");", del);
}
}
/**
Scroll fully right function; completely scrolls a <div> to the right, as far as it will go.
#param id Unique id of element to scroll.
#param d Amount of pixels to scroll per sleep.
#param del Size of the sleep (ms).*/
function scrollFullyRight(id, d, del){
// Fetch the element.
var el = document.getElementById(id);
// Scroll the element.
el.scrollLeft -= d;
// Have we not finished scrolling yet?
if(el.scrollLeft > 0) {
TIMER_SCROLL = setTimeout("scrollFullyRight('"+id+"',"+d+", "+del+");", del);
}
}
This is what has finally served me
/** Set parent scroll to show element
* #param element {object} The HTML object to show
* #param parent {object} The HTML object where the element is shown */
var scrollToView = function(element, parent) {
//Algorithm: Accumulate the height of the previous elements and add half the height of the parent
var offsetAccumulator = 0;
parent = $(parent);
parent.children().each(function() {
if(this == element) {
return false; //brake each loop
}
offsetAccumulator += $(this).innerHeight();
});
parent.scrollTop(offsetAccumulator - parent.innerHeight()/2);
}
I needed to scroll a dynamically loading element on a page so my solution was a little more involved.
This will work on static elements that are not lazy loading data and data being dynamically loaded.
const smoothScrollElement = async (selector: string, scrollBy = 12, prevCurrPos = 0) => {
const wait = (timeout: number) => new Promise(resolve => setTimeout(resolve, timeout));
const el = document.querySelector(selector) as HTMLElement;
let positionToScrollTo = el.scrollHeight;
let currentPosition = Math.floor(el.scrollTop) || 0;
let pageYOffset = (el.clientHeight + currentPosition);
if (positionToScrollTo == pageYOffset) {
await wait(1000);
}
if ((prevCurrPos > 0 && currentPosition <= prevCurrPos) !== true) {
setTimeout(async () => {
el.scrollBy(0, scrollBy);
await smoothScrollElement(selector, scrollBy, currentPosition);
}, scrollBy);
}
};
browser does scrolling automatically to an element that gets focus, so what you can also do it to wrap the element that you need to be scrolled to into <a>...</a> and then when you need scroll just set the focus on that a