Develop Reference

Show hover card left right based on element left right?

My HTML has a div and when I hover the div a card will be displayed on the right side. When the div is in left side then this still show right side. When I reduce the browser width then this card partially show the detail.
How to automatically position using jquery.
var thisEl = $(this);
var offsets = thisEl.offset();
var thisElTopOffset = offsets.top;
var thisElLeftOffset = offsets.left;
This will show as i mentioned in the image. But i try to position the div to left when the elements are in right.
Code: I tried so far
allHoverCardTriggers.on({
click: function(event) {
event.preventDefault();
var thisEl = $(this);
cardTimer = setTimeout(function(){
var docWidth = $(document).width();
var rightSide = false;
//return user id
var userLink = thisEl.attr('href');
if($('.ViewProfilePage').length && $('img.lia-user-avatar-profile',thisEl).length){
var userLink = document.location.href;
} else if(thisEl.attr('href')=='#'){
return false;
}
var thisLen = (userLink).split('/');
thisUserID = (thisLen)[thisLen.length-1];
var thisCard = $('.profileCard[data-user='+thisUserID+']',cardWrapper);
var offsets = thisEl.offset();
var thisElTopOffset = offsets.top;
var thisElLeftOffset = offsets.left;
if(thisCard.length && $('.profileCard[data-user='+thisUserID+'] .preloader',cardWrapper).length<1)
{
$('.profileCard',cardWrapper).hide();
rightSide?thisCard.addClass('rightArrow'):thisCard.removeClass('rightArrow');
thisCard.delay(500).css({'top':thisElTopOffset,'left':thisElLeftOffset}).stop().show();
}
else
{
var ajaxReturn = '';
thisCard.remove();
//profile card wrapper markup
var rightArrowClass = rightSide?'rightArrow':'';
var profileCardHtml = '<div class="profileCard '+rightArrowClass+'" style="display:block;top:'+thisElTopOffset+'px;left:'+thisElLeftOffset+'px;" data-user="'+thisUserID+'"><div class="inner"><img src="/html/assets/feedback_loading_trans.gif" class="preloader" style="margin:80px auto;display:block;" /></div></div>';
$.when(
//get the background
$.ajax({
type: 'GET',
url: userApiUrl+thisUserID,
dataType: 'html',
success: function(data) {
$('.profileCard',cardWrapper).hide();
ajaxReturn = data;
}
})
)
.done(function(){
cardWrapper.append(profileCardHtml);
$('.profileCard[data-user='+thisUserID+']',cardWrapper).eq(0).empty().html(ajaxReturn);
if($('.profileCard[data-user='+thisUserID+'] .preloader',cardWrapper).length){
$('.profileCard[data-user='+thisUserID+'] .preloader',cardWrapper).parents('div.profileCard').remove();
}
})
.fail(function(){
// Hide if failed request
$('.profileCard',cardWrapper).hide();
});
}
}
},400);
},
mouseleave: function() {
clearTimeout(cardTimer);
if($('.profileCard[data-user='+thisUserID+']',cardWrapper).length){
$('.profileCard[data-user='+thisUserID+']',cardWrapper).delay(500).fadeOut('fast');
}
}
});
}

Here is a jQuery solution. Prior to displaying the popup, the script checks if the offset position of the trigger div plus the popup width falls beyond the screen width and adjusts the popup position accordingly.
hover = function(e) {
//var position = e.position();
var popup = $('.popup');
popup.attr('style', '');
if (e.offsetLeft + popup.outerWidth() > $( window ).width()) {
// adjust for screen width
popup.css({
right: $( window ).width() - e.offsetLeft - e.offsetWidth + 'px',
top: e.offsetTop - popup.outerHeight()
});
}
else {
// position normally
popup.css({
left: e.offsetLeft,
top: e.offsetTop - popup.outerHeight()
});
}
popup.show();
}
hide = function() {
$('.popup').hide();
}
.left-hover {
position:absolute;
left:20px;
top:80px;
border:1px solid black;
}
.right-hover {
position:absolute;
right:20px;
top:80px;
border:1px solid black;
}
.popup {
position:absolute;
display:none;
border:1px solid red;
width:100px;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="left-hover" onmouseover="hover(this)" onmouseout="hide()">Hover me</div>
<div class="right-hover" onmouseover="hover(this)" onmouseout="hide()">Hover me</div>
<div class="popup">My popup</div>

Fixed div on scroll

I'm trying to create a div which will get a class only on scrolling and when the value of scroll is 210. I have next code :
$(document).ready(function() {
var pageWidth = $(window).width();
if(pageWidth > 700){
var contentLeft = $('#content-left');
var height = 210;
$(window).scroll(function () {
if ($(window).scrollTop() < height) {
contentLeft.attr('class', 'content-left');
} else {
contentLeft.attr('class', 'content-left leftContentFixed');
}
});
}
});
I try to apply this only on desktops.
Thus, I do not need the class leftContentFixed if it's on a smartphone or tablet.
If I try something like :
$(document).ready(function() {
var pageWidth = $(window).width();
if(pageWidth > 700){
alert("Bigger than 700");
}else{
alert("Smaller than 700");
}
});
Than it works perfect, but with my code it isn't working. The class leftContentFixed is added although the screen is smaller than 700.
Any advice?

You need to check screen size on resize event and check for its value when user scrolls the page. You could create mobile variable and make it true/false depends on screen size, then in scroll callback check for its value and choose correct class.
$(document).ready(function() {
var pageWidth = $(window).width(),
height = 210,
contentLeft = $('.content-left'),
mobile = false;
$(window).on('load resize', function() {
pageWidth = $(this).width();
// Save mobile status
if (pageWidth > 700) {
mobile = false;
} else {
mobile = true
}
})
$(window).on('scroll', function() {
if ($(window).scrollTop() > height) {
// Set default class
var _class = 'content-left leftContentFixed';
// If mobile then modify class
if (mobile) {
_class = 'content-left';
}
contentLeft.attr('class', _class);
} else {
var _class = 'content-left';
contentLeft.attr('class', _class);
}
});
});
html {
height: 2000px
}
.content-left {
background: gold;
width: 50px;
height: 100px;
}
.content-left.leftContentFixed {
position: fixed;
top: 0;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="content-left"></div>

Animate/Ease an element to position when other elements disappear

Please take a look at this fiddle: http://jsfiddle.net/dhcyA/
Try clicking on a block. What I want is that when the other elements disapear, the selected block will animate/ease to his giving position instead of just jumping like it does now. Then the same animation repeats itself when clicking again on the box, but then back to place.
Maybe to keep in mind:
I'm using a reponsive design, which means those blocks can be vertical and horizontal after scaling the window.
Any redevisions on the fiddle or suggustions would be great!

Here is my solution.
On your existing markup, I added a wrapper division to calculate the position of boxes inside the wrapper. Like this
<div id="wrapper">
<div class="block">
<h2>I'm block 1</h2>
</div>
....
</div>
To maintain the fluidness of the block, I created a function to position the block on the wrapper. Here is the function for position of the blocks:
var reposition = function() {
wrapper = $("#wrapper");
console.log(wrapper.innerWidth());
pLeft = 0;
pTop = 0;
maxRowHeight = 0;
$(".block").each(function(){
if($(this).data('active')) {
$(this).data('top', pTop);
$(this).data('left', pLeft);
} else {
$(this).stop(0,0).animate({
'top' : pTop + 'px',
'left' : pLeft + 'px'
});
}
pLeft += $(this).outerWidth() + parseInt($(this).css('marginLeft'));
if($(this).height() > maxRowHeight) maxRowHeight = $(this).outerHeight() + parseInt($(this).css('marginTop')); //Find out the longest block on the row
if(pLeft + $(this).next().outerWidth() + parseInt($(this).next().css('marginLeft')) >= wrapper.innerWidth()) {
pLeft = 0;
pTop += maxRowHeight;
maxRowHeight = 0;
}
});
};
Finally, the script to toggle the block
$(".block").click(function() {
$(this).siblings().slideToggle('slow'); //Toggle other blocks
if(!$(this).data('active')){ //if the block is not active
$(this).data('left', $(this).position().left); //sets its left
$(this).data('top', $(this).position().top); // and top position
$(this).animate({ //animate at the top and bottom
top:0,
left:0
},'slow');
$(this).data('active',true);
}else{
$(this).animate({ //animate to its last known position
top:$(this).data('top'),
left:$(this).data('left')
},'slow');
$(this).data('active',false);
}
});
Demos
Demo[Full] (Resize this to see the fluidness maintained)
Demo[Full] (version showing variable heights)
Here is what this solutions gives:
Remembers the last position and gradually animate to/from this position
Block positions are calculated and animated on load and every resize
Repositioning happens on $(window).resize() thus maintaining the fluid nature of the block, despite the use of position absolute
Support variable heights
Minor change on existing markup & CSS
Also fixed two issues extended by Gaby
Accounts for each block margin independently
Recalculates the position of the element after resize

Final Update
Here is a full working solution (pretty straight forward in my opinion) with JS to set the positioning (a simple calculation) and CSS transitions for the rest..
Demo at http://jsfiddle.net/gaby/pYdKB/3/
It maintains the fluidity of float:left and works with any number of elements, and you can keep the :nth-child for the styling, and it will also work if you want to leave more than one element visible..
javascript
var wrapper = $('.wrapper'),
boxes = wrapper.children(),
boxWidth = boxes.first().outerWidth(true),
boxHeight = boxes.first().outerHeight(true);
function rePosition(){
var w = wrapper.width(),
breakat = Math.floor( w / boxWidth ); // calculate fluid layout, just like float:left
boxes
.filter(':not(.go)')
.each(function(i){
var matrixX = ((i)%breakat)+1,
matrixY = Math.ceil((i+1)/breakat);
$(this).css({
left:(matrixX-1) * boxWidth ,
top: (matrixY-1) * boxHeight
});
});
}
$('.box').click(function(){
$(this)
.siblings()
.toggleClass('go');// just add the go class, and let CSS handle the rest
rePosition(); // recalculate final positions and let CSS animate the boxes
});
$(window).resize(rePosition);
$(window).trigger('resize');
CSS
.wrapper{
position:relative;
}
.box{
width:200px;
height:100px;
position:absolute;
margin:5px;
cursor:pointer;
overflow:hidden;
text-align: center;
line-height: 100px;
-moz-transition-property: top,left,width,height;
-webkit-transition-property: top,left,width,height;
-ms-transition-property: top,left,width,height;
-o-transition-property: top,left,width,height;
transition-property: top,left,width,height;
-moz-transition-duration: 1s;
-webkit-transition-duration: 1s;
-ms-transition-duration: 1s;
-o-transition-duration: 1s;
transition-duration: 1s;
}
.go{
height:0;
width:0;
}
note: As #Athari correctly mentioned in the comments, you should include all browser prefixes for the widest support. (my initial answer only included moz / webkit and the standard)
Original Answer
You can not do it directly with your current HTML structure. The floated concept does not support it.
But if you can afford an extra wrapper, then it is no problem..
Just slide the contents of your extra wrapper element..
Put the float code on the wrapper element and use
$(document).ready(function() {
$(".block-wrapper").click(function() {
$(this).siblings().find('.block').slideToggle("slow");
});
});
Demo at http://jsfiddle.net/gaby/t8GNP/
Update #1
If you need to move the clicked element to the top left and back, then you cannot really do it with CSS.
You will need to manually position them (through JS), set CSS transitions (or jquery), and apply the new positions once you click.
Later on you might want more than one to remain visible and reposition as well..
So you might want to take a look at the great Isotope plugin which can handle this and a multitude of more situations/layouts

Here is my version:
http://jsfiddle.net/selbh/dhcyA/92/
(only javascript is changed, and it's responsive)
$(document).ready(function() {
$(".block").click(function() {
var $this = $(this);
var pos = $this.offset();
var $siblings = $(this).siblings().add(this);
var marginTop = $this.css('marginTop').replace(/[^-\d\.]/g, '');
var marginLeft = $this.css('marginLeft').replace(/[^-\d\.]/g, '');
var $clone = $this.clone();
$siblings.slideToggle("slow");
$clone.css({
position: 'absolute',
left: pos.left - marginLeft,
top: pos.top - marginTop,
'background-color': $this.css('background-color')
});
$('body').append($clone);
$this.css('opacity', 0);
$clone.animate({
'left': 0,
'top': 0
});
$clone.click(function() {
$siblings.slideToggle("slow", function() {
$clone.remove();
$this.css('opacity', 1);
});
$clone.animate({
left: pos.left - marginLeft,
top: pos.top - marginTop
});
});
});
});​

I'm kind of sleepy(It's 2:30 AM here) so I leave the half done answer here to give you an idea (I did it in 30 minutes so I guess with 30 minutes more you can get something really nice)
http://jsfiddle.net/LuL2s/2/
The trick comes by the block-holder which make the ease animation and making a difference between when they appear and disappear
JS
$(document).ready(function() {
var open = true;
$(".block").click(function() {
var $this = $(this);
var count = 0;
if (open) {
$this.parent().siblings().children().slideToggle("slow", function(){
if (count++ == 2) {
$this.parent().siblings().animate({width: 'toggle', height:'toggle'});
}
});
} else {
$this.parent().siblings().animate({width: 'toggle', height:'toggle'}, function(){
if (count++ == 2) {
$this.parent().siblings().children().slideToggle("slow");
}
});
}
open = !open;
});
});
HTML
<div class="block-holder">
<div class="block">
<h2>I'm block 1</h2>
</div>
</div>
<div class="block-holder">
<div class="block">
<h2>I'm block 2</h2>
</div>
</div>
<div class="block-holder">
<div class="block">
<h2>I'm block 3</h2>
</div>
</div>
<div class="block-holder">
<div class="block">
<h2>I'm block 4</h2>
</div>
</div>
CSS
.block {
width: 100%;
height: 100%;
text-align: center;
line-height: 100px;
cursor: pointer;
}
.block-holder:nth-child(1) .block {
background: green;
}
.block-holder:nth-child(2) .block {
background: red;
}
.block-holder:nth-child(3) .block {
background: orange;
}
.block-holder:nth-child(4) .block {
background: pink;
}
.block-holder {
width: 200px;
height: 100px;
float: left;
margin: 20px;
}

Great Challenge!
New Version:
Here is a much better version as it makes the blocks stay in their rows. I added a css function so that your nth-child styles could be applied even in the rows. Even maintains same HTML Structure.
Demo: http://jsfiddle.net/MadLittleMods/fDDZB/23/
The jQuery for this new revision looks like:
$('.block').on('click', function() {
var block = $(this);
// Keep the blocks in line
makeRows($('body'));
$('.block').not(this).each(function() {
// If sibling on the same level, horizontal toggle
// We also want ignore the toggleMethod if it is shown because we might need to reassign
if (($(this).position().top == block.position().top && (($(this).data('toggle') == -1) || $(this).data('toggle') == null)) || ($(this).data('toggle') != -1 && $(this).data('toggleMethod') == 'side'))
{
$(this).data('toggleMethod', 'side');
// Hide block
if ($(this).data('toggle') == -1 || $(this).data('toggle') == null)
{
// Set properties for later use in show block
$(this).data('overflowBefore', $(this).css('overflow'));
$(this).css('overflow', 'hidden');
$(this).data('marginBefore', $(this).css('margin'));
var width = $(this).width();
$(this).animate({
width: 0,
margin: 0
}, function() {
$(this).data('toggle', width);
});
}
// Show block
else
{
$(this).css('overflow', $(this).data('overflowBefore'));
$(this).animate({
width: $(this).data('toggle'),
margin: $(this).data('marginBefore')
}, function() {
$(this).data('toggle', -1);
});
}
}
// Do a normal vertical toggle
else
{
$(this).data('toggleMethod', 'top');
$(this).slideToggle('slow');
}
});
});
// Make rows to make the blocks in line
function makeRows(container)
{
// Make rows so that the elements stay where they should
var containerWidth = container.width();
var currentRowWidth = 0;
// Add styles first so nothing gets messed up
container.children().each(function() {
var itemCSS = css($(this));
$(this).css(itemCSS);
});
// Now assemble the rows
container.children().each(function() {
var blockWidth = $(this).outerWidth() + parseInt($(this).css('margin-left')) + parseInt($(this).css('margin-right'));
if((currentRowWidth + blockWidth) < containerWidth)
{
currentRowWidth += blockWidth;
}
else
{
Array.prototype.reverse.call($(this).prevUntil('.row')).wrapAll('<div class="row"></div>');
$(this).prev().append('<div class="row_clear" style="clear: both;"></div>');
currentRowWidth = 0;
}
});
}
// Remove the rows added
function deleteRows()
{
var content = $('.row').contents()
$('.row').replaceWith(content);
$('.row_clear').remove();
}
$(window).resize(function() {
deleteRows();
});
// Functions courtesy of marknadal
// https://stackoverflow.com/a/5830517/796832
function css(a)
{
var sheets = document.styleSheets, o = {};
for(var i in sheets) {
var rules = sheets[i].rules || sheets[i].cssRules;
for(var r in rules) {
if(a.is(rules[r].selectorText)) {
o = $.extend(o, css2json(rules[r].style), css2json(a.attr('style')));
}
}
}
return o;
}
function css2json(css)
{
var s = {};
if(!css) return s;
if(css instanceof CSSStyleDeclaration) {
for(var i in css) {
if((css[i]).toLowerCase) {
s[(css[i]).toLowerCase()] = (css[css[i]]);
}
}
} else if(typeof css == "string") {
css = css.split("; ");
for (var i in css) {
var l = css[i].split(": ");
s[l[0].toLowerCase()] = (l[1]);
};
}
return s;
}
I added a makeRows and deleteRows functions so that the blocks would stay in their rows instead of getting smaller and moving into the row above. I call deleteRows whenever the window resizes so that it can maintain a responsive layout. Then if the blocks need to be toggled, I recreate the rows.
css and css2json functions are courtesy of marknadal
Old version:
I came up with a solution with .animate so that it could ease horizontally.
Here is a demo: http://jsfiddle.net/MadLittleMods/fDDZB/8/
The jQuery looks like:
$('.block').on('click', function() {
var block = $(this);
$(this).siblings().each(function() {
// If sibling on the same level, horizontal toggle
// We also want ignore the toggleMethod if it is shown because we might need to reassign
if (($(this).position().top == block.position().top && ($(this).data('toggle') == -1) || $(this).data('toggle') == null) || ($(this).data('toggle') != -1 && $(this).data('toggleMethod') == 'side'))
{
$(this).data('toggleMethod', 'side');
// Hide block
if ($(this).data('toggle') == -1 || $(this).data('toggle') == null)
{
// Set properties for later use in show block
$(this).data('overflowBefore', $(this).css('overflow'));
$(this).css('overflow', 'hidden');
$(this).data('marginBefore', $(this).css('margin'));
var width = $(this).width();
$(this).animate({
width: 0,
margin: 0
}, function() {
$(this).data('toggle', width);
});
}
// Show block
else
{
$(this).css('overflow', $(this).data('overflowBefore'));
$(this).animate({
width: $(this).data('toggle'),
margin: $(this).data('marginBefore')
}, function() {
$(this).data('toggle', -1);
});
}
}
// Do a normal vertical toggle
else
{
$(this).data('toggleMethod', 'top');
$(this).slideToggle('slow');
}
});
});​
The key was to separate the blocks that were toggled with .slideToggle and .animate because you have to apply the same when they show and hide.

Add/remove class with jquery based on vertical scroll?

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>

use jQuery to expand/collapse text

I want to cut off text based on a fixed height.When the text is cut off, a "more" link is used to expand to text. When the text is expanded, a "less" link is used to collapse the text. I wrote the js as this:
$(document).ready(function () {
// line height in 'px'
var maxheight=218;
var showText = "More";
var hideText = "Less";
$('.textContainer_Truncate').each(function () {
var text = $(this);
if (text.height() > maxheight){
text.css({ 'overflow': 'hidden','height': maxheight + 'px' });
var link = $('' + showText + '');
var linkDiv = $('<div></div>');
linkDiv.append(link);
$(this).after(linkDiv);
link.click(function (event) {
event.preventDefault();
if (text.css('height') == 'auto') {
$(this).html(showText);
text.css('height', maxheight + 'px');
} else {
$(this).html(hideText);
text.css('height', 'auto');
}
});
}
});
});
The html code is:
<div class="textContainer_Truncate">
<p>content</p>
</div>
My problem is that the "more" link works but the "less" doesn't. That is, when more is clicked, the text is expanded but it won't go back when the less is clicked.What's wrong here?
Thanks

It's just a small error, this:
if (text.css('height') == 'auto') {
should be this:
if (text.height() > maxheight) {
FIDDLE

I believe you are looking this one
http://jsfiddle.net/rbUst/
$(".act").click(function() {
var val = $(this).text();
if (val == "More") {
$("div").css('height', '200px');
$(this).text("less");
} else {
$("div").css('height', '20');
$(this).text("More");
}
return false;
});
div {
background-color: #CCA;
height: 20px;
overflow: hidden;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js"></script>
More
<div>This fskdljfl sflsdajfsadf
<br />fsdafsdfsadfsdf dfjsadf slfkjsf</div>
above is the live example..