Develop Reference

Scroll to bottom of page using Javascript or jquery with these conditions

I am trying to stimulate a web chat room for which the page needs to be:
Scrolled to bottom of the page after some interval if the user hasn't scrolled.
Stop scrolling if the user has scrolled.
Starts scrolling to bottom of page if user reaches a div #end
<script>
var scroll = 1;
function autoScrolling(scroll) {
if(scroll==1){
window.scrollTo(0,document.body.scrollHeight);
}
}
window.onscroll = function() {
setInterval(autoScrolling(0), 1000);
}
window.addEventListener("scroll", function() {
var elementTarget = document.getElementById("end");
if (window.scrollY > (elementTarget.offsetTop + elementTarget.offsetHeight)) {
scroll=1;
setInterval(autoScrolling(0), 1000);
}
});
</script>
I am applying this logic but it isn't working.

Try this,
var scrolled = false;
$(document).ready(function(){
//First requirement
window.setInterval(function(){
checkScroll();
}, 5000);
//Second requirement
window.onscroll = function() { setScroll()};
//Third requirement
$('#end').on('scroll', function() {
if($(this).scrollTop() + $(this).innerHeight() >= $(this)[0].scrollHeight) {
autoScroll();
}
})
})
function autoScroll(){
window.scrollTo(0,document.body.scrollHeight);
}
function setScroll(){
if (window.scrollY > (elementTarget.offsetTop + elementTarget.offsetHeight)) {
scroll=true;
}
}
}
function checkScroll(){
if(!scrolled)
autoScroll();
scrolled = false;
}

Toggle mobile navigation depending on scroll direction

I have this navigation for mobile that i want to hide/show depending on which direction the viewport gets scrolled in. So if scrolling down i want it to hide, and scrolling up i want it to show.
My current code looks like this. It just toggles on scroll top. Anyone?
$(function() {
$(window).on("scroll touchmove", function () {
$('.mobile-nav').toggleClass('tiny', $(document).scrollTop() > 0);
});
});

Maybe something like this:
var menu_height = 80;
var menu_visible = true;
var old_scroll = $(window).scrollTop();
function checkMenu() {
new_scroll = $(window).scrollTop();
if (old_scroll < new_scroll && new_scroll > 0) {
// Scroll down
if (menu_visible == true) {
toggleMenu();
}
} else if (old_scroll > new_scroll) {
// Scroll up
if (menu_visible != true) {
toggleMenu();
}
}
old_scroll = new_scroll;
}
function toggleMenu() {
if (menu_visible == true) {
// Hide
$('#menu').animate({top: '-='+menu_height+'px'}, 200, function(){ $(this).css('display', 'none') });
menu_visible = false;
} else {
// Show
menu_visible = true;
$('#menu').css('display', 'block').animate({top: '+='+menu_height+'px'}, 200);
}
}
$(document).ready(function() {
// Show / hide menu on scroll
setInterval(checkMenu, 100);
});
Codepen: http://codepen.io/anon/pen/dPGggg

Reposition DIV after scrolling

I have a navigation bar that repositions after scrolling down. It works with position:fixed, but while scrolling I want it to move up like all the other content that follow on the site . I the user stops scrolling it should reposition on top:
Heres a demo:
http://jsfiddle.net/gvjeyywa/7/
But I want it to be position:absolute (especially for the scrolling on the Ipad)
http://jsfiddle.net/gvjeyywa/5/
How do i let the JS overide my CSS? Here is my JS:
var isInAction = false;
var lastScrollTop = 0;
$(window).scroll(function(event){
var st = $(this).scrollTop();
if (st > lastScrollTop){
if (!isInAction){
isInAction = true;
$( "#navigation" ).animate({
top: "-" + $("#navigation").innerHeight() + "px"
}).delay(1000).animate({
top: "0px"
}, 800, function() {
isInAction = false;
});
}
}
lastScrollTop = st;
});

In the first look i think it's impossible but after some tries this code was created.
I spent long time to write this code and use several techniques and hope to be helpful.
Maybe there are simpler solutions too !!
var bitFlag = false;
var lastScrollTop = 0;
var timeoutId;
$navigation = $("#navigation");
$(window).scroll(function (event) {
var intWindowTop = $(window).scrollTop();
var intElementBottom = $navigation.offset().top + $navigation.innerHeight();
if (intWindowTop > lastScrollTop) {
if (!bitFlag) {
$navigation.css("position", "absolute").css("top", intWindowTop + "px");
bitFlag = true;
}
if (timeoutId) {
clearTimeout(timeoutId);
}
timeoutId = setTimeout(function () {
if (intWindowTop > intElementBottom) {
intDelayTime = setTimeout(function () {
$navigation.animate({
top: intWindowTop + "px"
}, 800);
}, 500);
}
}, 100);
} else {
$navigation.css("position", "fixed").css("top", "0px");
bitFlag = false;
}
lastScrollTop = intWindowTop;
});
The }, 500); section control Delay time in milliseconds and the }, 800); section control the slide down animation speed.
Check JSFiddle Demo

Force "overscrolling" at Chrome/Mac with javascript

When you get to the limit of document, you can keep scrolling and can see an background behing the document before it bounces back (overscrolling).
How can I force the window to overscroll like this with javascript?

This is not the ultimate solution since I think the animation is imperfect and it's really only for desktops, but it can at least get you started. What I have done is increase the height of the body for animation on scroll.
$(document).on('scroll mousewheel', function (e) {
//Check for mousewheel scrolling down (or not used at all)
if (!e.originalEvent || !e.originalEvent.wheelDeltaY
|| e.originalEvent.wheelDeltaY < 0) {
if ($(window).height() + $(this).scrollTop() == $(this).height()) {
//Prevent simultaneous triggering of the animation
if (!$("body").data('bouncing')) {
$("body").height(function (_, h) { return h + 15; })
.data('bouncing', true);
$("body, html").animate({
'scrollTop': '+=15'
}, 125).animate({
'scrollTop': '-=15'
}, {duration: 125, complete: function () {
$(this).height(function (_, h) { return h - 15; })
.data('bouncing', false);
}});
}
}
}
}).on('keydown', function (e) {
//The "down" arrow; still bounces when pressed at the bottom of the page
if (e.which == '40') {
$(this).trigger('scroll');
}
});

I've been playing with this version that imitates the effect using a div, that slides in and out of view at the bottom of the page. If you have a high res monitor, you may need to increase the height of the main div to test it.
<div id="main" style="background:#f5f5f5;height:1000px"></div>
<div id="overscroll" style="background:#666666;height:120px"></div>
<script type="text/javascript">
var $doc = $(document);
$doc.ready(function () {
var $wnd = $(window),
$oscroll = $('#overscroll'),
block = false;
$wnd.bind('scroll', function () {
if (!block) {
block = true;
var scrollTop = $wnd.scrollTop(),
wndHeight = $wnd.height(),
docHeight = $doc.height();
try {
if (scrollTop + (wndHeight + 120) > docHeight) {
$oscroll.slideUp('slow');
}
else if ($oscroll.css('display') === 'none'
&& (scrollTop + (wndHeight + 120) < docHeight)) {
$oscroll.slideDown();
}
} finally {
block = false;
}
}
});
});
</script>

Add class to element upon scroll

I'd like to add a class to an element when a user first scrolls away from the top of the page. If the user then scrolls back up and hits the top of the page I'd like that class removed.
Use of jQuery in the solution is fine.

try
$(window).scroll(function() {
$("id or class").removeClass("active");
var scroll = $(window).scrollTop();
if (scroll <= 500) {
$("#one").addClass("active");
}
else if (scroll <= 1000) {
$("#tow").addClass("active");
}
else {
$("#three").addClass("active");
}
}

So here is the solution you're looking for. Just customize it with your div tags.
$(document).ready(function () {
$(window).scroll(function(){
// get the height of #wrap
var h = $('#top').height();
var y = $(window).scrollTop();
if( y > (h*.25) ){
$("#sidef").fadeIn(1100);
} else {
$('#sidef').fadeOut(75);
}
});
});

var notAdded = true;
$(window).scroll(function(){
if( $(this).scrollTop() == 0){
$(elem).removeClass('classname');
notAdded = true;
}
else if(notAdded){
$(elem).addClass('classname');
notAdded = false;
}
});