I have a working script which adds a class to the body after scrolling 80px.
This works but I need it to work too after having already scrolled and then refreshing the page.
So maybe replace the scroll part by position?
// fixed header
$(function() {
$(window).scroll(function() {
var scroll = $(window).scrollTop();
if (scroll >= 80) {
$("body").addClass('fixed');
} else {
$("body").removeClass("fixed");
}
});
});
$(window).scroll will only fire once a scroll event occurs. If you want to check for the scroll position when the page loads, you should do this outside of the $(window).scroll callback, like this:
function updateScroll() {
if ($(window).scrollTop() >= 80) {
$("body").addClass('fixed');
} else {
$("body").removeClass("fixed");
}
}
$(function() {
$(window).scroll(updateScroll);
updateScroll();
});
you're right. you need to check the event and the initial value:
window.addEventListener('load', function() {
var scroll = $(window).scrollTop();
if (scroll >= 80) {
$("body").addClass('fixed');
}
//no removing needed cause refresh did it
});
window.onscroll = function () { scrollFunction() };
function scrollFunction() {
if (document.body.scrollTop > 100 || document.documentElement.scrollTop > 100) {
document.querySelector(".fixed-top").classList.add("headerFix");
} else {
document.querySelector(".fixed-top").classList.remove("headerFix");
}
}
Is there a way to get the mouse wheel events (not talking about scroll events) in jQuery?
$(document).ready(function(){
$('#foo').bind('mousewheel', function(e){
if(e.originalEvent.wheelDelta /120 > 0) {
console.log('scrolling up !');
}
else{
console.log('scrolling down !');
}
});
});
Binding to both mousewheel and DOMMouseScroll ended up working really well for me:
$(window).bind('mousewheel DOMMouseScroll', function(event){
if (event.originalEvent.wheelDelta > 0 || event.originalEvent.detail < 0) {
// scroll up
}
else {
// scroll down
}
});
This method is working in IE9+, Chrome 33, and Firefox 27.
Edit - Mar 2016
I decided to revisit this issue since it's been a while. The MDN page for the scroll event has a great way of retrieving the scroll position that makes use of requestAnimationFrame, which is highly preferable to my previous detection method. I modified their code to provide better compatibility in addition to scroll direction and position:
(function() {
var supportOffset = window.pageYOffset !== undefined,
lastKnownPos = 0,
ticking = false,
scrollDir,
currYPos;
function doSomething(scrollPos, scrollDir) {
// Your code goes here...
console.log('scroll pos: ' + scrollPos + ' | scroll dir: ' + scrollDir);
}
window.addEventListener('wheel', function(e) {
currYPos = supportOffset ? window.pageYOffset : document.body.scrollTop;
scrollDir = lastKnownPos > currYPos ? 'up' : 'down';
lastKnownPos = currYPos;
if (!ticking) {
window.requestAnimationFrame(function() {
doSomething(lastKnownPos, scrollDir);
ticking = false;
});
}
ticking = true;
});
})();
See the Pen Vanilla JS Scroll Tracking by Jesse Dupuy (#blindside85) on CodePen.
This code is currently working in Chrome v50, Firefox v44, Safari v9, and IE9+
References:
https://developer.mozilla.org/en-US/docs/Web/Events/scroll
https://developer.mozilla.org/en-US/docs/Web/Events/wheel
As of now in 2017, you can just write
$(window).on('wheel', function(event){
// deltaY obviously records vertical scroll, deltaX and deltaZ exist too.
// this condition makes sure it's vertical scrolling that happened
if(event.originalEvent.deltaY !== 0){
if(event.originalEvent.deltaY < 0){
// wheeled up
}
else {
// wheeled down
}
}
});
Works with current Firefox 51, Chrome 56, IE9+
There's a plugin that detects up/down mouse wheel and velocity over a region.
Answers talking about "mousewheel" event are refering to a deprecated event. The standard event is simply "wheel". See https://developer.mozilla.org/en-US/docs/Web/Reference/Events/wheel
This worked for me:)
//Firefox
$('#elem').bind('DOMMouseScroll', function(e){
if(e.originalEvent.detail > 0) {
//scroll down
console.log('Down');
}else {
//scroll up
console.log('Up');
}
//prevent page fom scrolling
return false;
});
//IE, Opera, Safari
$('#elem').bind('mousewheel', function(e){
if(e.originalEvent.wheelDelta < 0) {
//scroll down
console.log('Down');
}else {
//scroll up
console.log('Up');
}
//prevent page fom scrolling
return false;
});
from stackoverflow
Here is a vanilla solution. Can be used in jQuery if the event passed to the function is event.originalEvent which jQuery makes available as property of the jQuery event. Or if inside the callback function under we add before first line: event = event.originalEvent;.
This code normalizes the wheel speed/amount and is positive for what would be a forward scroll in a typical mouse, and negative in a backward mouse wheel movement.
Demo: http://jsfiddle.net/BXhzD/
var wheel = document.getElementById('wheel');
function report(ammout) {
wheel.innerHTML = 'wheel ammout: ' + ammout;
}
function callback(event) {
var normalized;
if (event.wheelDelta) {
normalized = (event.wheelDelta % 120 - 0) == -0 ? event.wheelDelta / 120 : event.wheelDelta / 12;
} else {
var rawAmmount = event.deltaY ? event.deltaY : event.detail;
normalized = -(rawAmmount % 3 ? rawAmmount * 10 : rawAmmount / 3);
}
report(normalized);
}
var event = 'onwheel' in document ? 'wheel' : 'onmousewheel' in document ? 'mousewheel' : 'DOMMouseScroll';
window.addEventListener(event, callback);
There is also a plugin for jQuery, which is more verbose in the code and some extra sugar: https://github.com/brandonaaron/jquery-mousewheel
This is working in each IE, Firefox and Chrome's latest versions.
$(document).ready(function(){
$('#whole').bind('DOMMouseScroll mousewheel', function(e){
if(e.originalEvent.wheelDelta > 0 || e.originalEvent.detail < 0) {
alert("up");
}
else{
alert("down");
}
});
});
I was stuck in this issue today and found this code is working fine for me
$('#content').on('mousewheel', function(event) {
//console.log(event.deltaX, event.deltaY, event.deltaFactor);
if(event.deltaY > 0) {
console.log('scroll up');
} else {
console.log('scroll down');
}
});
use this code
knob.bind('mousewheel', function(e){
if(e.originalEvent.wheelDelta < 0) {
moveKnob('down');
} else {
moveKnob('up');
}
return false;
});
The plugin that #DarinDimitrov posted, jquery-mousewheel, is broken with jQuery 3+. It would be more advisable to use jquery-wheel which works with jQuery 3+.
If you don't want to go the jQuery route, MDN highly cautions using the mousewheel event as it's nonstandard and unsupported in many places. It instead says that you should use the wheel event as you get much more specificity over exactly what the values you're getting mean. It's supported by most major browsers.
my combination looks like this. it fades out and fades in on each scroll down/up. otherwise you have to scroll up to the header, for fading the header in.
var header = $("#header");
$('#content-container').bind('mousewheel', function(e){
if(e.originalEvent.wheelDelta > 0) {
if (header.data('faded')) {
header.data('faded', 0).stop(true).fadeTo(800, 1);
}
}
else{
if (!header.data('faded')) header.data('faded', 1).stop(true).fadeTo(800, 0);
}
});
the above one is not optimized for touch/mobile, I think this one does it better for all mobile:
var iScrollPos = 0;
var header = $("#header");
$('#content-container').scroll(function () {
var iCurScrollPos = $(this).scrollTop();
if (iCurScrollPos > iScrollPos) {
if (!header.data('faded')) header.data('faded', 1).stop(true).fadeTo(800, 0);
} else {
//Scrolling Up
if (header.data('faded')) {
header.data('faded', 0).stop(true).fadeTo(800, 1);
}
}
iScrollPos = iCurScrollPos;
});
If using mentioned jquery mousewheel plugin, then what about to use the 2nd argument of event handler function - delta:
$('#my-element').on('mousewheel', function(event, delta) {
if(delta > 0) {
console.log('scroll up');
}
else {
console.log('scroll down');
}
});
I think many key things are a bit all over the place and I needed to read all the answers to make my code work as I wanted, so I will post my findings in just one place:
You should use "wheel" event over the other deprecated or browser specific events.
Many people here is getting something wrong: the opposite of x>0 is x<=0 and the opposite of x<0 is x>=0, many of the answers in here will trigger scrolling down or up incorrectly when x=0 (horizontal scrolling).
Someone was asking how to put sensitivity on it, for this you can use setTimeout() with like 50 ms of delay that changes some helper flag isWaiting=false and you protect yourself with if(isWaiting) then don't do anything. When it fires you manually change isWaiting=true and just below this line you start the setTimeout again who will later change isWaiting=false after 50 ms.
I got same problem recently where
$(window).mousewheel was returning undefined
What I did was $(window).on('mousewheel', function() {});
Further to process it I am using:
function (event) {
var direction = null,
key;
if (event.type === 'mousewheel') {
if (yourFunctionForGetMouseWheelDirection(event) > 0) {
direction = 'up';
} else {
direction = 'down';
}
}
}
I was trying this jQuery example
(function ($) {
$(document).ready(function(){
// hide .navbar first
// $(".masthead").hide();
$(".masthead").css("background-color","inherit");
// fade in .navbar
$(function () {
$(window).scroll(function () {
// set distance user needs to scroll before we fadeIn navbar
if ($(this).scrollTop() > 600) {
$('.masthead').fadeIn();
$(".masthead").css("background-color","black");
} else if($(this).scrollTop === 0){
$('.masthead').fadeIn();
} else {
$('.masthead').fadeOut();
}
});
});
});
}(jQuery));
It shows the menu/navbar when I run the page and disapears when I start scrolling and after 700 pixels navbar is displayed again with black background, I expected it to fade in again after I come back to the top.
if($(this).scrollTop === 0){
$('.masthead').fadeIn();
}
But it have not worked. How do scrollTop() work then? I have also tried to set scrollTop < 10, but with no success. How do I make it work when I'm back at 10 pixels or zero?
You're comparing the function body to 0, not the actual results of the function (the scroll value), so this:
if($(this).scrollTop === 0){
$('.masthead').fadeIn();
}
should become this:
if($(this).scrollTop() === 0){
$('.masthead').fadeIn();
}
TL;DR
It's scrollTop vs. scrollTop().
I have a jQuery scroll function set up, that when the user scroll beyond 94px the .fixed-header-wrap fades in and there's a class change etc too. This function isn't working on IE browsers though, and the .fixed-header-wrap is showing on document load and not fading out / in etc. My markup below:
//Header Colour Scroll Function
var scroller = true;
$(window).scroll(function () {
if ($(".sector-menu").css('display') == 'none') {
if ($(this).scrollTop() > 94 && scroller) {
$('.fixed-header-wrap').addClass('header-shadow');
$(".fixed-header-wrap").fadeIn('fast');
$('.header-logo').fadeIn('slow');
$('.header-wrap').addClass('header-blue');
scroller = false;
} else if ($(this).scrollTop() < 94 && !scroller) {
$(".fixed-header-wrap").removeClass('header-shadow');
$(".fixed-header-wrap").fadeOut('fast');
$('.header-logo').fadeOut('fast');
$('.header-wrap').removeClass('header-blue');
scroller = true;
}
} else {
if ($(this).scrollTop() > 94 && scroller) {
$('.fixed-header-wrap').addClass('header-shadow');
$(".fixed-header-wrap").fadeIn('fast');
$('.header-wrap').addClass('header-blue');
scroller = false;
} else if ($(this).scrollTop() < 94 && !scroller) {
$(".fixed-header-wrap").removeClass('header-shadow');
$(".fixed-header-wrap").fadeOut('fast');
scroller = true;
}
}
});
Is there any reason for this or changes that can be made to make the desired effect work across all browsers?
Try changing $(window).scroll() to $('html,body').scroll(). It worked for me in a previous project... Let me know if it works.
I used the following function to scroll my document to specific point when user tries to scroll on the page. For this I used following code:
$(window).scroll(function(){
if ($(this).scrollTop() > 100) {
$("html, body").animate({scrollTop: 700}, 500);
return false;
}
});
I want to know if there are event listeners for the mousewheel actions or not. When using this I can not actually scroll back up to the top of the document, because the scroll of mouse re-invokes the function and it pulls down the document again.
Also, if there is an alternative way, please let me know.
Can I do this using CSS only for cases where JS may be disabled by the user/client?
EDIT:
After your short explanation I (hopefully) understand what do you want.
I made a function with position states:
header, content, unresolved
and I reused your scrolling function with state condition.
(function() {
var pagePosition = "header";
$(window).scroll(function(){
if ($(this).scrollTop() > 0 && pagePosition == "header") {
pagePosition = "unresolved";
$("html, body").animate({scrollTop: 700}, 500, function() {
pagePosition = "content";
});
return false;
} else if ($(this).scrollTop() < 700 && pagePosition == "content") {
pagePosition = "unresolved";
$("html, body").animate({scrollTop: 0}, 500, function() {
pagePosition = "header";
});
return false;
}
});
})();