Show element when in viewport on scroll - javascript

I've been trying to show an element on scroll when it's in viewport and when no, hide it again. But no matter what I try, I can't make it work.
This is what I have so far, but the function is running just once, when the page is loaded and not when it's scrolled, so it doesn't update the value.
$(window).scroll(function() {
var top_of_element = $("#cont_quote blockquote").offset().top;
var bottom_of_element = $("#cont_quote blockquote").offset().top + $("#cont_quote blockquote").outerHeight();
var bottom_of_screen = $(window).scrollTop() + window.innerHeight;
var top_of_screen = $(window).scrollTop();
if((bottom_of_screen > top_of_element) && (top_of_screen < bottom_of_element)){
$('#cont_quote blockquote').animate({'opacity':'1'},1000);
}
else {
$('#cont_quote blockquote').animate({'opacity':'0'},1000);
}
});
<section id="cont_quote">
<article class="cont_q">
<blockquote>Lorem ipsum</blockquote>
</article>
</section>

In pure javascript, you could do something like this, which uses a lot less resources than a full on jQuery approach:
function inViewport( element ){
// Get the elements position relative to the viewport
var bb = element.getBoundingClientRect();
// Check if the element is outside the viewport
// Then invert the returned value because you want to know the opposite
return !(bb.top > innerHeight || bb.bottom < 0);
}
var myElement = document.querySelector( 'div' );
// Listen for the scroll event
document.addEventListener( 'scroll', event => {
// Check the viewport status
if( inViewport( myElement ) ){
myElement.style.background = 'red';
} else {
myElement.style.background = '';
}
})
body {
height: 400vh;
}
div {
width: 50vw;
height: 50vh;
position: absolute;
top: 125vh;
left: 25vw;
transition: background 4s;
border: 1px solid red;
}
<p>Scroll Down</p>
<div></div>
Here is a snippet with the opacity change:
function inViewport( element ){
// Get the elements position relative to the viewport
var bb = element.getBoundingClientRect();
// Check if the element is outside the viewport
// Then invert the returned value because you want to know the opposite
return !(bb.top > innerHeight || bb.bottom < 0);
}
var myElement = document.querySelector( 'div' );
// Listen for the scroll event
document.addEventListener( 'scroll', event => {
// Check the viewport status
if( inViewport( myElement ) ){
myElement.style.opacity = 1;
} else {
myElement.style.opacity = '';
}
})
body {
height: 400vh;
}
div {
width: 50vw;
height: 50vh;
position: absolute;
top: 125vh;
left: 25vw;
transition: opacity 1s;
opacity: .2;
background: blue;
}
<p>Scroll Down</p>
<div></div>
And here is a snippet showing you how to define where in the viewport it triggers, I just changed the innerHeight and 0 values to an object where you define the amount of pixels from the top it should be and the amount of pixels from the bottom. Don't forget to also add an event listener for resize, as these pixel based values will change if your viewport changes, so your myViewport object would need to be updated accordingly:
function inViewport( element, viewport = { top: 0, bottom: innerHeight } ){
// Get the elements position relative to the viewport
var bb = element.getBoundingClientRect();
// Check if the element is outside the viewport
// Then invert the returned value because you want to know the opposite
return !(bb.top > viewport.bottom || bb.bottom < viewport.top);
}
var myViewport = { top: innerHeight * .4, bottom: innerHeight * .6 };
var myElement = document.querySelector( 'div' );
// Listen for the scroll event
document.addEventListener( 'scroll', event => {
// Check the viewport status
if( inViewport( myElement, myViewport ) ){
myElement.style.opacity = 1;
} else {
myElement.style.opacity = '';
}
})
window.addEventListener( 'resize', event => {
// Update your viewport values
myViewport.top = innerHeight * .4;
myViewport.bottom = innerHeight * .6;
})
body {
height: 400vh;
}
div {
width: 50vw;
height: 50vh;
position: absolute;
top: 125vh;
left: 25vw;
transition: opacity 1s;
opacity: .2;
background: blue;
}
<p>Scroll Down</p>
<div></div>

Try using:
$(window).on('scroll mousewheel', function() {
And surround your function with:
$(document).ready(function(){
});

i tried to solve your problem by your code only. its working fine for me now. plz try this and let me know. also open your browser console to see if there is any js error.
$(window).scroll(function() {
var top_of_element = $("#cont_quote blockquote").offset().top;
var bottom_of_element = $("#cont_quote blockquote").offset().top + $("#cont_quote blockquote").outerHeight();
var bottom_of_screen = $(window).scrollTop() + window.innerHeight;
var top_of_screen = $(window).scrollTop();
if((bottom_of_screen > top_of_element) && (top_of_screen < bottom_of_element)){
$('#cont_quote blockquote').fadeIn(1000);
console.log('if cond');
} else {
$('#cont_quote blockquote').fadeOut(1000);
console.log('else cond');
}
});

Related

Fade in opacity on fixed div during scroll up

I'm trying to make a fixed div fade in when the page scrolls. Using the code bellow for another div class and it works perfectly, however this fades out and I need to reverse it so the div fades in.
var turn = document.getElementById('turn');
window.addEventListener('scroll', function(e) {
// http://stackoverflow.com/a/28633515/962603
var scroll = window.pageYOffset || document.documentElement.scrollTop ||
document.body.scrollTop || 0;
turn.style.opacity = Math.max(0.1, Math.min(1, -scroll / 400 + 2));
});
I have tried swapping the min and max value but doesn't seem to work. Thanks!
Example with fixed div and fade in opacity during scroll:
var turn = document.getElementById('turn');
updateOpacity(turn, 0);
window.addEventListener('scroll', function(e) {
var limit = document.body.scrollHeight - window.innerHeight;
var scroll = window.pageYOffset ||
document.documentElement.scrollTop ||
document.body.scrollTop || 0;
updateOpacity(turn, scroll / limit);
randomFontColor(turn); // optional
});
function updateOpacity(element, opacity) {
element.style.opacity = opacity;
}
function randomFontColor(element) {
var randColor = Math.floor(Math.random() * 9999).toString();
var hexColor = "#" + randColor.padStart(6, 'FF');
element.style.color = hexColor;
}
body {
height: 2600px;
}
#turn {
left: 6%;
width: 88%;
position: fixed;
}
.highlight {
color: yellow;
line-height: 42px;
background: black;
font-weight: bold;
text-align: center;
}
<div id="turn" class="highlight">
Fixed top div with Fade in Effect on Scroll
</div>

How to console log when offsetLeft reach a number of pixels

I'm creating a simple game: drag en element far enough (200px) The console logs fine, when I drag the element 200px the console reads 200px, but I still get the wrong message.(not there yet)..
function far_enough() {
console.log('You have moved the box ' + el.offsetLeft + 'pixels');
if(el.offsetleft == 200){
console.log('200px great!');
} else {
console.log('not there yet!');
}
}
}
To answer your question, element.offsetLeft can return a decimal value. This means that it may return 200.01px instead of 200px exactly. This is what's causing your code to not work. A simple work-around is simply to use Math.round(element.offsetLeft) to return an integer value. However, even when using this, there's a chance that the offsetLeft does not return 200px exactly, especially when you drag the element too fast (the browser does not repaint for each pixel moved). Another solution is to use a range like from 200px to 250px.
I suppose that you're using position: absolute and manipulating left CSS property to cause the element to be draggable. However, moving elements with transform is better than using position. I highly suggest reading this article on why.
As you're moving your element using transform now, the offsetLeft value of the element never changes. Therefore, you can alternatively get the rendered box position using getBoundingClientRect(). Here's an example using a getBoundingClientRect(), which returns a left value relative to the viewport.
const draggable = document.querySelector('#draggable')
function farEnough() {
const box = draggable.getBoundingClientRect()
// Get center of box; move center of box by 200px to return true
let center = box.left + (box.right - box.left) / 2
if (center >= 200 && center <= 300) return true
else return false
}
let dragging = false
let dragStartX = null
let dragStartY = null
let draggableMovedX = null
let draggableMovedY = null
function dragHandler(e) {
dragging = true
dragStartX = e.clientX
dragStartY = e.clientY
}
function moveHandler(e) {
if (dragging) {
let moveX = e.clientX - dragStartX + draggableMovedX
let moveY = e.clientY - dragStartY + draggableMovedY
draggable.style.transform = `translate(${moveX}px, ${moveY}px)`
if (farEnough()) {
draggable.removeEventListener('mousedown', dragHandler)
window.removeEventListener('mousemove', moveHandler)
window.removeEventListener('mouseup', leaveHandler)
dragging = false
dragStartX = null
dragStartY = null
// 175px so that the center of the box is exactly at 200px from the left
draggable.style.transform = `translate(175px, ${moveY}px)`
console.log('You did it! You moved it 200px to the right!')
}
}
}
function leaveHandler(e) {
dragging = false
dragStartX = null
dragStartY = null
const box = draggable.getBoundingClientRect()
draggableMovedX = box.left
draggableMovedY = box.top
}
draggable.addEventListener('mousedown', dragHandler)
window.addEventListener('mousemove', moveHandler)
window.addEventListener('mouseup', leaveHandler)
body,
html {
width: 100%;
height: 100%;
position: relative;
margin: 0;
}
#draggable {
width: 50px;
height: 50px;
border-radius: 5px;
background: #121212;
cursor: grab;
}
#draggable:active {
cursor: grabbing;
}
#line {
position: absolute;
top: 0;
left: 200px;
width: 2px;
height: 100%;
background: red;
transform: translateX(-50%);
}
<div id="draggable"></div>
<div id="line"></div>
try
function far_enough()
{
let leftOffset = el.offsetLeft;
console.log('You have moved the box ' + leftOffset + 'pixels');
if (leftOffset == 200)
{
console.log('200px great!');
}
else
{
console.log('not there yet!');
}
}

Add and Remove class on window scroll [duplicate]

So basically I'd like to remove the class from 'header' after the user scrolls down a little and add another class to change it's look.
Trying to figure out the simplest way of doing this but I can't make it work.
$(window).scroll(function() {
var scroll = $(window).scrollTop();
if (scroll <= 500) {
$(".clearheader").removeClass("clearHeader").addClass("darkHeader");
}
}
CSS
.clearHeader{
height: 200px;
background-color: rgba(107,107,107,0.66);
position: fixed;
top:200;
width: 100%;
}
.darkHeader { height: 100px; }
.wrapper {
height:2000px;
}
HTML
<header class="clearHeader"> </header>
<div class="wrapper"> </div>
I'm sure I'm doing something very elementary wrong.
$(window).scroll(function() {
var scroll = $(window).scrollTop();
//>=, not <=
if (scroll >= 500) {
//clearHeader, not clearheader - caps H
$(".clearHeader").addClass("darkHeader");
}
}); //missing );
Fiddle
Also, by removing the clearHeader class, you're removing the position:fixed; from the element as well as the ability of re-selecting it through the $(".clearHeader") selector. I'd suggest not removing that class and adding a new CSS class on top of it for styling purposes.
And if you want to "reset" the class addition when the users scrolls back up:
$(window).scroll(function() {
var scroll = $(window).scrollTop();
if (scroll >= 500) {
$(".clearHeader").addClass("darkHeader");
} else {
$(".clearHeader").removeClass("darkHeader");
}
});
Fiddle
edit: Here's version caching the header selector - better performance as it won't query the DOM every time you scroll and you can safely remove/add any class to the header element without losing the reference:
$(function() {
//caches a jQuery object containing the header element
var header = $(".clearHeader");
$(window).scroll(function() {
var scroll = $(window).scrollTop();
if (scroll >= 500) {
header.removeClass('clearHeader').addClass("darkHeader");
} else {
header.removeClass("darkHeader").addClass('clearHeader');
}
});
});
Fiddle
Pure javascript
Here's javascript-only example of handling classes during scrolling.
const navbar = document.getElementById('navbar')
// OnScroll event handler
const onScroll = () => {
// Get scroll value
const scroll = document.documentElement.scrollTop
// If scroll value is more than 0 - add class
if (scroll > 0) {
navbar.classList.add("scrolled");
} else {
navbar.classList.remove("scrolled")
}
}
// Use the function
window.addEventListener('scroll', onScroll)
#navbar {
position: fixed;
top: 0;
left: 0;
right: 0;
width: 100%;
height: 60px;
background-color: #89d0f7;
box-shadow: 0px 5px 0px rgba(0, 0, 0, 0);
transition: box-shadow 500ms;
}
#navbar.scrolled {
box-shadow: 0px 5px 10px rgba(0, 0, 0, 0.25);
}
#content {
height: 3000px;
margin-top: 60px;
}
<!-- Optional - lodash library, used for throttlin onScroll handler-->
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.15/lodash.js"></script>
<header id="navbar"></header>
<div id="content"></div>
Some improvements
You'd probably want to throttle handling scroll events, more so as handler logic gets more complex, in that case throttle from lodash lib comes in handy.
And if you're doing spa, keep in mind that you need to clear event listeners with removeEventListener once they're not needed (eg during onDestroy lifecycle hook of your component, like destroyed() for Vue, or maybe return function of useEffect hook for React).
Example throttling with lodash:
// Throttling onScroll handler at 100ms with lodash
const throttledOnScroll = _.throttle(onScroll, 100, {})
// Use
window.addEventListener('scroll', throttledOnScroll)
Add some transition effect to it if you like:
http://jsbin.com/boreme/17/edit?html,css,js
.clearHeader {
height:50px;
background:lightblue;
position:fixed;
top:0;
left:0;
width:100%;
-webkit-transition: background 2s; /* For Safari 3.1 to 6.0 */
transition: background 2s;
}
.clearHeader.darkHeader {
background:#000;
}
Its my code
jQuery(document).ready(function(e) {
var WindowHeight = jQuery(window).height();
var load_element = 0;
//position of element
var scroll_position = jQuery('.product-bottom').offset().top;
var screen_height = jQuery(window).height();
var activation_offset = 0;
var max_scroll_height = jQuery('body').height() + screen_height;
var scroll_activation_point = scroll_position - (screen_height * activation_offset);
jQuery(window).on('scroll', function(e) {
var y_scroll_pos = window.pageYOffset;
var element_in_view = y_scroll_pos > scroll_activation_point;
var has_reached_bottom_of_page = max_scroll_height <= y_scroll_pos && !element_in_view;
if (element_in_view || has_reached_bottom_of_page) {
jQuery('.product-bottom').addClass("change");
} else {
jQuery('.product-bottom').removeClass("change");
}
});
});
Its working Fine
Is this value intended? if (scroll <= 500) { ... This means it's happening from 0 to 500, and not 500 and greater. In the original post you said "after the user scrolls down a little"
In a similar case, I wanted to avoid always calling addClass or removeClass due to performance issues. I've split the scroll handler function into two individual functions, used according to the current state. I also added a debounce functionality according to this article: https://developers.google.com/web/fundamentals/performance/rendering/debounce-your-input-handlers
var $header = jQuery( ".clearHeader" );
var appScroll = appScrollForward;
var appScrollPosition = 0;
var scheduledAnimationFrame = false;
function appScrollReverse() {
scheduledAnimationFrame = false;
if ( appScrollPosition > 500 )
return;
$header.removeClass( "darkHeader" );
appScroll = appScrollForward;
}
function appScrollForward() {
scheduledAnimationFrame = false;
if ( appScrollPosition < 500 )
return;
$header.addClass( "darkHeader" );
appScroll = appScrollReverse;
}
function appScrollHandler() {
appScrollPosition = window.pageYOffset;
if ( scheduledAnimationFrame )
return;
scheduledAnimationFrame = true;
requestAnimationFrame( appScroll );
}
jQuery( window ).scroll( appScrollHandler );
Maybe someone finds this helpful.
For Android mobile $(window).scroll(function() and $(document).scroll(function() may or may not work. So instead use the following.
jQuery(document.body).scroll(function() {
var scroll = jQuery(document.body).scrollTop();
if (scroll >= 300) {
//alert();
header.addClass("sticky");
} else {
header.removeClass('sticky');
}
});
This code worked for me. Hope it will help you.
This is based of of #shahzad-yousuf's answer, but I only needed to compress a menu when the user scrolled down. I used the reference point of the top container rolling "off screen" to initiate the "squish"
<script type="text/javascript">
$(document).ready(function (e) {
//position of element
var scroll_position = $('div.mainContainer').offset().top;
var scroll_activation_point = scroll_position;
$(window).on('scroll', function (e) {
var y_scroll_pos = window.pageYOffset;
var element_in_view = scroll_activation_point < y_scroll_pos;
if (element_in_view) {
$('body').addClass("toolbar-compressed ");
$('div.toolbar').addClass("toolbar-compressed ");
} else {
$('body').removeClass("toolbar-compressed ");
$('div.toolbar').removeClass("toolbar-compressed ");
}
});
}); </script>

Is it possible to proof an div element of visibility inside a "overflow-x:scroll" div-container ?

I am currently trying to figure out how to get the information of how much percent is visbile of a div inside a overflow-x:scroll container. I also need to know if it comes from the right or from the left ? Is this possible somehow ?
This might be helpfull. You could edit the code from the answer to that question to check if the element was scrolled in from the right or the left.
Check if element is visible after scrolling
To calculate the percentage visable you just need to compare child's size to the parent's size and what the 'left' offset of the child is.
(I might add a code example later)
EDIT
I made a small example that show how you can detect the visible percentage of that child inside an "overflow-x:scroll" div-container and if the child comes from left or right.
<style>
#parent {
overflow-x:scroll;
width: 300px;
height:120px;
border: solid 1px #000;
}
#child {
width: 200px;
height: 100px;
background:#FF0;
margin-left: 200px;
}
#scrollPane {
width: 800px;
}
</style>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js"></script>
<script>
$(document).ready(function(){
$("#button").click(function(){
alert(percantageVisible() + "% of the child is visible");
});
});
function percantageVisible()
{
var parent = $("#parent");
var parentLeftOffset = parent.offset().left;
var parentRightOffset = parentLeftOffset + parent.width();
var child = $("#child");
var childLeftOffset = child.offset().left;
var childRightOffset = childLeftOffset + child.width();
if(childLeftOffset < parentLeftOffset && childRightOffset > parentLeftOffset && childRightOffset < parentRightOffset){
// percentage from the left
var width = child.width();
var hiddenWidth = Math.abs(childLeftOffset - parentLeftOffset);
var visibleWidth = width - hiddenWidth;
return visibleWidth/(width/100);
}
else if(childRightOffset > parentRightOffset && childLeftOffset < parentRightOffset && childLeftOffset > parentLeftOffset ){
// percentage from the right
var width = child.width();
var hiddenWidth = Math.abs(parentRightOffset -childRightOffset);
var visibleWidth = width - hiddenWidth;
return visibleWidth/(width/100);
}
else if (childLeftOffset > parentLeftOffset && childRightOffset < parentRightOffset){
// all visible
return 100;
}
else{
// invisible
return 0;
}
}
</script>
<div id="parent">
<div id="scrollPane">
<div id="child"> </div>
</div>
</div>
<button id="button">check percentage</button>
Hope this helps

How can I make a div stick to the top of the screen once it's been scrolled to?

I would like to create a div, that is situated beneath a block of content but that once the page has been scrolled enough to contact its top boundary, becomes fixed in place and scrolls with the page.
You could use simply css, positioning your element as fixed:
.fixedElement {
background-color: #c0c0c0;
position:fixed;
top:0;
width:100%;
z-index:100;
}
Edit: You should have the element with position absolute, once the scroll offset has reached the element, it should be changed to fixed, and the top position should be set to zero.
You can detect the top scroll offset of the document with the scrollTop function:
$(window).scroll(function(e){
var $el = $('.fixedElement');
var isPositionFixed = ($el.css('position') == 'fixed');
if ($(this).scrollTop() > 200 && !isPositionFixed){
$el.css({'position': 'fixed', 'top': '0px'});
}
if ($(this).scrollTop() < 200 && isPositionFixed){
$el.css({'position': 'static', 'top': '0px'});
}
});
When the scroll offset reached 200, the element will stick to the top of the browser window, because is placed as fixed.
You've seen this example on Google Code's issue page and (only recently) on Stack Overflow's edit page.
CMS's answer doesn't revert the positioning when you scroll back up. Here's the shamelessly stolen code from Stack Overflow:
function moveScroller() {
var $anchor = $("#scroller-anchor");
var $scroller = $('#scroller');
var move = function() {
var st = $(window).scrollTop();
var ot = $anchor.offset().top;
if(st > ot) {
$scroller.css({
position: "fixed",
top: "0px"
});
} else {
$scroller.css({
position: "relative",
top: ""
});
}
};
$(window).scroll(move);
move();
}
<div id="sidebar" style="width:270px;">
<div id="scroller-anchor"></div>
<div id="scroller" style="margin-top:10px; width:270px">
Scroller Scroller Scroller
</div>
</div>
<script type="text/javascript">
$(function() {
moveScroller();
});
</script>
And a simple live demo.
A nascent, script-free alternative is position: sticky, which is supported in Chrome, Firefox, and Safari. See the article on HTML5Rocks and demo, and Mozilla docs.
As of January 2017 and the release of Chrome 56, most browsers in common use support the position: sticky property in CSS.
#thing_to_stick {
position: sticky;
top: 0px;
}
does the trick for me in Firefox and Chrome.
In Safari you still need to use position: -webkit-sticky.
Polyfills are available for Internet Explorer and Edge; https://github.com/wilddeer/stickyfill seems to be a good one.
And here's how without jquery (UPDATE: see other answers where you can now do this with CSS only)
var startProductBarPos=-1;
window.onscroll=function(){
var bar = document.getElementById('nav');
if(startProductBarPos<0)startProductBarPos=findPosY(bar);
if(pageYOffset>startProductBarPos){
bar.style.position='fixed';
bar.style.top=0;
}else{
bar.style.position='relative';
}
};
function findPosY(obj) {
var curtop = 0;
if (typeof (obj.offsetParent) != 'undefined' && obj.offsetParent) {
while (obj.offsetParent) {
curtop += obj.offsetTop;
obj = obj.offsetParent;
}
curtop += obj.offsetTop;
}
else if (obj.y)
curtop += obj.y;
return curtop;
}
* {margin:0;padding:0;}
.nav {
border: 1px red dashed;
background: #00ffff;
text-align:center;
padding: 21px 0;
margin: 0 auto;
z-index:10;
width:100%;
left:0;
right:0;
}
.header {
text-align:center;
padding: 65px 0;
border: 1px red dashed;
}
.content {
padding: 500px 0;
text-align:center;
border: 1px red dashed;
}
.footer {
padding: 100px 0;
text-align:center;
background: #777;
border: 1px red dashed;
}
<header class="header">This is a Header</header>
<div id="nav" class="nav">Main Navigation</div>
<div class="content">Hello World!</div>
<footer class="footer">This is a Footer</footer>
I had the same problem as you and ended up making a jQuery plugin to take care of it. It actually solves all the problems people have listed here, plus it adds a couple of optional features too.
Options
stickyPanelSettings = {
// Use this to set the top margin of the detached panel.
topPadding: 0,
// This class is applied when the panel detaches.
afterDetachCSSClass: "",
// When set to true the space where the panel was is kept open.
savePanelSpace: false,
// Event fires when panel is detached
// function(detachedPanel, panelSpacer){....}
onDetached: null,
// Event fires when panel is reattached
// function(detachedPanel){....}
onReAttached: null,
// Set this using any valid jquery selector to
// set the parent of the sticky panel.
// If set to null then the window object will be used.
parentSelector: null
};
https://github.com/donnyv/sticky-panel
demo: http://htmlpreview.github.io/?https://github.com/donnyv/sticky-panel/blob/master/jquery.stickyPanel/Main.htm
The simplest solution (without js) :
demo
.container {
position: relative;
}
.sticky-div {
position: sticky;
top: 0;
}
<div class="container">
<h1>
relative container & sticky div
</h1>
<div class="sticky-div"> this row is sticky</div>
<div>
content
</div>
</div>
This is how i did it with jquery. This was all cobbled together from various answers on stack overflow. This solution caches the selectors for faster performance and also solves the "jumping" issue when the sticky div becomes sticky.
Check it out on jsfiddle: http://jsfiddle.net/HQS8s/
CSS:
.stick {
position: fixed;
top: 0;
}
JS:
$(document).ready(function() {
// Cache selectors for faster performance.
var $window = $(window),
$mainMenuBar = $('#mainMenuBar'),
$mainMenuBarAnchor = $('#mainMenuBarAnchor');
// Run this on scroll events.
$window.scroll(function() {
var window_top = $window.scrollTop();
var div_top = $mainMenuBarAnchor.offset().top;
if (window_top > div_top) {
// Make the div sticky.
$mainMenuBar.addClass('stick');
$mainMenuBarAnchor.height($mainMenuBar.height());
}
else {
// Unstick the div.
$mainMenuBar.removeClass('stick');
$mainMenuBarAnchor.height(0);
}
});
});
As Josh Lee and Colin 't Hart have said, you could optionally just use position: sticky; top: 0; applying to the div that you want the scrolling at...
Plus, the only thing you will have to do is copy this into the top of your page or format it to fit into an external CSS sheet:
<style>
#sticky_div's_name_here { position: sticky; top: 0; }
</style>
Just replace #sticky_div's_name_here with the name of your div, i.e. if your div was <div id="example"> you would put #example { position: sticky; top: 0; }.
Here is another option:
JAVASCRIPT
var initTopPosition= $('#myElementToStick').offset().top;
$(window).scroll(function(){
if($(window).scrollTop() > initTopPosition)
$('#myElementToStick').css({'position':'fixed','top':'0px'});
else
$('#myElementToStick').css({'position':'absolute','top':initTopPosition+'px'});
});
Your #myElementToStick should start with position:absolute CSS property.
Here's one more version to try for those having issues with the others. It pulls together the techniques discussed in this duplicate question, and generates the required helper DIVs dynamically so no extra HTML is required.
CSS:
.sticky { position:fixed; top:0; }
JQuery:
function make_sticky(id) {
var e = $(id);
var w = $(window);
$('<div/>').insertBefore(id);
$('<div/>').hide().css('height',e.outerHeight()).insertAfter(id);
var n = e.next();
var p = e.prev();
function sticky_relocate() {
var window_top = w.scrollTop();
var div_top = p.offset().top;
if (window_top > div_top) {
e.addClass('sticky');
n.show();
} else {
e.removeClass('sticky');
n.hide();
}
}
w.scroll(sticky_relocate);
sticky_relocate();
}
To make an element sticky, do:
make_sticky('#sticky-elem-id');
When the element becomes sticky, the code manages the position of the remaining content to keep it from jumping into the gap left by the sticky element. It also returns the sticky element to its original non-sticky position when scrolling back above it.
My solution is a little verbose, but it handles variable positioning from the left edge for centered layouts.
// Ensurs that a element (usually a div) stays on the screen
// aElementToStick = The jQuery selector for the element to keep visible
global.makeSticky = function (aElementToStick) {
var $elementToStick = $(aElementToStick);
var top = $elementToStick.offset().top;
var origPosition = $elementToStick.css('position');
function positionFloater(a$Win) {
// Set the original position to allow the browser to adjust the horizontal position
$elementToStick.css('position', origPosition);
// Test how far down the page is scrolled
var scrollTop = a$Win.scrollTop();
// If the page is scrolled passed the top of the element make it stick to the top of the screen
if (top < scrollTop) {
// Get the horizontal position
var left = $elementToStick.offset().left;
// Set the positioning as fixed to hold it's position
$elementToStick.css('position', 'fixed');
// Reuse the horizontal positioning
$elementToStick.css('left', left);
// Hold the element at the top of the screen
$elementToStick.css('top', 0);
}
}
// Perform initial positioning
positionFloater($(window));
// Reposition when the window resizes
$(window).resize(function (e) {
positionFloater($(this));
});
// Reposition when the window scrolls
$(window).scroll(function (e) {
positionFloater($(this));
});
};
Here is an extended version to Josh Lee's answer. If you want the div to be on sidebar to the right, and float within a range (i.e., you need to specify top and bottom anchor positions). It also fixes a bug when you view this on mobile devices (you need to check left scroll position otherwise the div will move off screen).
function moveScroller() {
var move = function() {
var st = $(window).scrollTop();
var sl = $(window).scrollLeft();
var ot = $("#scroller-anchor-top").offset().top;
var ol = $("#scroller-anchor-top").offset().left;
var bt = $("#scroller-anchor-bottom").offset().top;
var s = $("#scroller");
if(st > ot) {
if (st < bt - 280) //280px is the approx. height for the sticky div
{
s.css({
position: "fixed",
top: "0px",
left: ol-sl
});
}
else
{
s.css({
position: "fixed",
top: bt-st-280,
left: ol-sl
});
}
} else {
s.css({
position: "relative",
top: "",
left: ""
});
}
};
$(window).scroll(move);
move();
}
I came across this when searching for the same thing. I know it's an old question but I thought I'd offer a more recent answer.
Scrollorama has a 'pin it' feature which is just what I was looking for.
http://johnpolacek.github.io/scrollorama/
The info provided to answer this other question may be of help to you, Evan:
Check if element is visible after scrolling
You basically want to modify the style of the element to set it to fixed only after having verified that the document.body.scrollTop value is equal to or greater than the top of your element.
The accepted answer works but doesn't move back to previous position if you scroll above it. It is always stuck to the top after being placed there.
$(window).scroll(function(e) {
$el = $('.fixedElement');
if ($(this).scrollTop() > 42 && $el.css('position') != 'fixed') {
$('.fixedElement').css( 'position': 'fixed', 'top': '0px');
} else if ($(this).scrollTop() < 42 && $el.css('position') != 'relative') {
$('.fixedElement').css( 'relative': 'fixed', 'top': '42px');
//this was just my previous position/formating
}
});
jleedev's response whould work, but I wasn't able to get it to work. His example page also didn't work (for me).
You can add 3 extra rows so when the user scroll back to the top, the div will stick on its old place:
Here is the code:
if ($(this).scrollTop() < 200 && $el.css('position') == 'fixed'){
$('.fixedElement').css({'position': 'relative', 'top': '200px'});
}
I have links setup in a div so it is a vertical list of letter and number links.
#links {
float:left;
font-size:9pt;
margin-left:0.5em;
margin-right:1em;
position:fixed;
text-align:center;
width:0.8em;
}
I then setup this handy jQuery function to save the loaded position and then change the position to fixed when scrolling beyond that position.
NOTE: this only works if the links are visible on page load!!
var listposition=false;
jQuery(function(){
try{
///// stick the list links to top of page when scrolling
listposition = jQuery('#links').css({'position': 'static', 'top': '0px'}).position();
console.log(listposition);
$(window).scroll(function(e){
$top = $(this).scrollTop();
$el = jQuery('#links');
//if(typeof(console)!='undefined'){
// console.log(listposition.top,$top);
//}
if ($top > listposition.top && $el.css('position') != 'fixed'){
$el.css({'position': 'fixed', 'top': '0px'});
}
else if ($top < listposition.top && $el.css('position') == 'fixed'){
$el.css({'position': 'static'});
}
});
} catch(e) {
alert('Please vendor admin#mydomain.com (Myvendor JavaScript Issue)');
}
});
In javascript you can do:
var element = document.getElementById("myid");
element.style.position = "fixed";
element.style.top = "0%";
Here's an example that uses jquery-visible plugin: http://jsfiddle.net/711p4em4/.
HTML:
<div class = "wrapper">
<header>Header</header>
<main>
<nav>Stick to top</nav>
Content
</main>
<footer>Footer</footer>
</div>
CSS:
* {
margin: 0;
padding: 0;
}
body {
background-color: #e2e2e2;
}
.wrapper > header,
.wrapper > footer {
font: 20px/2 Sans-Serif;
text-align: center;
background-color: #0040FF;
color: #fff;
}
.wrapper > main {
position: relative;
height: 500px;
background-color: #5e5e5e;
font: 20px/500px Sans-Serif;
color: #fff;
text-align: center;
padding-top: 40px;
}
.wrapper > main > nav {
position: absolute;
top: 0;
left: 0;
right: 0;
font: 20px/2 Sans-Serif;
color: #fff;
text-align: center;
background-color: #FFBF00;
}
.wrapper > main > nav.fixed {
position: fixed;
top: 0;
left: 0;
right: 0;
}
JS (include jquery-visible plugin):
(function($){
/**
* Copyright 2012, Digital Fusion
* Licensed under the MIT license.
* http://teamdf.com/jquery-plugins/license/
*
* #author Sam Sehnert
* #desc A small plugin that checks whether elements are within
* the user visible viewport of a web browser.
* only accounts for vertical position, not horizontal.
*/
var $w = $(window);
$.fn.visible = function(partial,hidden,direction){
if (this.length < 1)
return;
var $t = this.length > 1 ? this.eq(0) : this,
t = $t.get(0),
vpWidth = $w.width(),
vpHeight = $w.height(),
direction = (direction) ? direction : 'both',
clientSize = hidden === true ? t.offsetWidth * t.offsetHeight : true;
if (typeof t.getBoundingClientRect === 'function'){
// Use this native browser method, if available.
var rec = t.getBoundingClientRect(),
tViz = rec.top >= 0 && rec.top < vpHeight,
bViz = rec.bottom > 0 && rec.bottom <= vpHeight,
lViz = rec.left >= 0 && rec.left < vpWidth,
rViz = rec.right > 0 && rec.right <= vpWidth,
vVisible = partial ? tViz || bViz : tViz && bViz,
hVisible = partial ? lViz || rViz : lViz && rViz;
if(direction === 'both')
return clientSize && vVisible && hVisible;
else if(direction === 'vertical')
return clientSize && vVisible;
else if(direction === 'horizontal')
return clientSize && hVisible;
} else {
var viewTop = $w.scrollTop(),
viewBottom = viewTop + vpHeight,
viewLeft = $w.scrollLeft(),
viewRight = viewLeft + vpWidth,
offset = $t.offset(),
_top = offset.top,
_bottom = _top + $t.height(),
_left = offset.left,
_right = _left + $t.width(),
compareTop = partial === true ? _bottom : _top,
compareBottom = partial === true ? _top : _bottom,
compareLeft = partial === true ? _right : _left,
compareRight = partial === true ? _left : _right;
if(direction === 'both')
return !!clientSize && ((compareBottom <= viewBottom) && (compareTop >= viewTop)) && ((compareRight <= viewRight) && (compareLeft >= viewLeft));
else if(direction === 'vertical')
return !!clientSize && ((compareBottom <= viewBottom) && (compareTop >= viewTop));
else if(direction === 'horizontal')
return !!clientSize && ((compareRight <= viewRight) && (compareLeft >= viewLeft));
}
};
})(jQuery);
$(function() {
$(window).scroll(function() {
$(".wrapper > header").visible(true) ?
$(".wrapper > main > nav").removeClass("fixed") :
$(".wrapper > main > nav").addClass("fixed");
});
});
I used some of the work above to create this tech. I improved it a bit and thought I would share my work. Hope this helps.
jsfiddle Code
function scrollErrorMessageToTop() {
var flash_error = jQuery('#flash_error');
var flash_position = flash_error.position();
function lockErrorMessageToTop() {
var place_holder = jQuery("#place_holder");
if (jQuery(this).scrollTop() > flash_position.top && flash_error.attr("position") != "fixed") {
flash_error.css({
'position': 'fixed',
'top': "0px",
"width": flash_error.width(),
"z-index": "1"
});
place_holder.css("display", "");
} else {
flash_error.css('position', '');
place_holder.css("display", "none");
}
}
if (flash_error.length > 0) {
lockErrorMessageToTop();
jQuery("#flash_error").after(jQuery("<div id='place_holder'>"));
var place_holder = jQuery("#place_holder");
place_holder.css({
"height": flash_error.height(),
"display": "none"
});
jQuery(window).scroll(function(e) {
lockErrorMessageToTop();
});
}
}
scrollErrorMessageToTop();​
This is a little bit more dynamic of a way to do the scroll. It does need some work and I will at some point turn this into a pluging but but this is what I came up with after hour of work.
Not an exact solution but a great alternative to consider
this CSS ONLY Top of screen scroll bar. Solved all the problem with ONLY CSS, NO JavaScript, NO JQuery, No Brain work (lol).
Enjoy my fiddle :D all the codes are included in there :)
CSS
#menu {
position: fixed;
height: 60px;
width: 100%;
top: 0;
left: 0;
border-top: 5px solid #a1cb2f;
background: #fff;
-moz-box-shadow: 0 2px 3px 0px rgba(0, 0, 0, 0.16);
-webkit-box-shadow: 0 2px 3px 0px rgba(0, 0, 0, 0.16);
box-shadow: 0 2px 3px 0px rgba(0, 0, 0, 0.16);
z-index: 999999;
}
.w {
width: 900px;
margin: 0 auto;
margin-bottom: 40px;
}<br type="_moz">
Put the content long enough so you can see the effect here :)
Oh, and the reference is in there as well, for the fact he deserve his credit
CSS ONLY Top of screen scroll bar
sticky till the footer hits the div:
function stickyCostSummary() {
var stickySummary = $('.sticky-cost-summary');
var scrollCostSummaryDivPosition = $(window).scrollTop();
var footerHeight = $('#footer').height();
var documentHeight = $(document).height();
var costSummaryHeight = stickySummary.height();
var headerHeight = 83;
var footerMargin = 10;
var scrollHeight = 252;
var footerPosition = $('#footer').offset().top;
if (scrollCostSummaryDivPosition > scrollHeight && scrollCostSummaryDivPosition <= (documentHeight - footerHeight - costSummaryHeight - headerHeight - footerMargin)) {
stickySummary.removeAttr('style');
stickySummary.addClass('fixed');
} else if (scrollCostSummaryDivPosition > (documentHeight - footerHeight - costSummaryHeight - headerHeight - footerMargin)) {
stickySummary.removeClass('fixed');
stickySummary.css({
"position" : "absolute",
"top" : (documentHeight - footerHeight - costSummaryHeight - headerHeight - footerMargin - scrollHeight) + "px"
});
} else {
stickySummary.removeClass('fixed');
stickySummary.css({
"position" : "absolute",
"top" : "0"
});
}
}
$window.scroll(stickyCostSummary);

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