I'm trying to catch whether the mousewheel is triggered and whether it's scrolled up or down without actually scrolling the page (body has an overflow: hidden).
Any idea's how I can achieve this using jQuery or pure javascript?
$(window).scroll(function(){
if( /* scroll up */){ }
else { /* scroll down */ }
});
I rarely promote plugins but this one is just excellent (and relatively small in size) :
https://plugins.jquery.com/mousewheel/
It'll allow to do something like this :
$(window).mousewheel(function(turn, delta) {
if (delta == 1) // going up
else // going down
// all kinds of code
return false;
});
http://codepen.io/anon/pen/YPmjym?editors=001
Update - at this point the mousewheel plugin could be replaced with the wheel event if legacy browsers need not be supported:
$(window).on('wheel', function(e) {
var delta = e.originalEvent.deltaY;
if (delta > 0) // going down
else // going up
return false;
});
This disables the scrolling.
NOTE: Notice it only stops scrolling if you hover over the element.
$('#container').hover(function() {
$(document).bind('mousewheel DOMMouseScroll',function(){
console.log('Scroll!');
stopWheel();
});
}, function() {
$(document).unbind('mousewheel DOMMouseScroll');
});
function stopWheel(e){
if(!e){ /* IE7, IE8, Chrome, Safari */
e = window.event;
}
if(e.preventDefault) { /* Chrome, Safari, Firefox */
e.preventDefault();
}
e.returnValue = false; /* IE7, IE8 */
}
Quoted from amosrivera's answer
EDIT: To check which way it is scrolling.
var lastScrollTop = 0;
$(window).scroll(function(event){
var st = $(this).scrollTop();
if (st > lastScrollTop){
// downscroll code
} else {
// upscroll code
}
lastScrollTop = st;
});
On my site I have it so my scroll is locked:
body {
overflow: hidden;
height: 100%;
}
and on click of buttons it scrolls to a certain div, all the divs are beneath each other, I would like to know if it is possible to check if the user 'tries' to scroll down or up, while scroll is locked, so if they try scroll down with the mouse wheel, I want to know how to do this so I can scroll down or up to the next div.
Any help is appreciated.
This will tell you if they are scrolling down or up. Then you would have to deal with the transition by yourself.
But in any case, if you are looking for a more tested solution, I would encourage you to use an already existent plugin such as fullPage.js which will provide old browser compatibility, touch detection, a proper solution for trackpads and Apple laptops/Magic Mouse, resize support and a lot of other useful features.
addMouseWheelHandler();
function MouseWheelHandler(e) {
// cross-browser wheel delta
e = window.event || e;
var value = e.wheelDelta || -e.deltaY || -e.detail;
var delta = Math.max(-1, Math.min(1, value));
//scrolling down?
if (delta < 0) {
console.log("scrolling down");
}
//scrolling up?
else {
console.log("scrolling up");
}
return false;
}
function addMouseWheelHandler() {
if (document.addEventListener) {
document.addEventListener('mousewheel', MouseWheelHandler, false); //IE9, Chrome, Safari, Oper
document.addEventListener('wheel', MouseWheelHandler, false); //Firefox
} else {
document.attachEvent('onmousewheel', MouseWheelHandler); //IE 6/7/8
}
}
I'm using this bit of code to hide a menu bar when users scroll on a page. It works fine on Chrome 17.0.963.78 but keeps on flickering in and out on other browsers, namely I.E. firefox and safari ..
$(window).load(function(){
$(document).scroll(function(){
$('#inner_floating').fadeOut();
var scrollA = $('body').scrollTop();
setTimeout(function(){
if(scrollA == $('body').scrollTop()){
$('#inner_floating').fadeIn();
}
}, 100);
})
});
The problem is that your .scroll function is being called for every pixel (or mousewheel tick) scrolled, so the animations are being run many times consecutively.
Try something like this:
$(window).load(function(){
$(document).scroll(function(){
if($("#inner_floating:hidden").length == 0) {
$('#inner_floating').fadeOut();
}
var scrollA = $('body').scrollTop();
setTimeout(function(){
if(scrollA == $('body').scrollTop() && $("#inner_floating:hidden").length > 0){
$('#inner_floating').fadeIn();
}
}, 100);
})
});
This way the animation is only happening if necessary.
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'm creating a scrolling effect using JQuery and I'm wondering if it's possible to distinguish between the user scrolling vs. programmatically scrolling.
I have something like this:
$('#element').on('scroll',function(e){
$('#element').stop(true); // stop previous scrolling animation
$('#element').animate({ // start new scrolling animation (maybe different speed, different direction, etc)
scrollTop:...
});
});
However, this event is triggered during every step of the animation. How can I tell if this event was triggered by the user or by the animation?
Use a variable to determine when you are scrolling programmatically
Example:
var programScrolling = false;
$('#element').on('scroll',function(e){
if (programScrolling) {
return;
}
$('#element').stop(true); // stop scrolling animation
programScrolling = true;
$('#element').animate({
scrollTop:...
});
programScrolling = false;
});
Not sure if that is exactly what you want, but the concept should work.
I would make functions for different kinds of scrollings to detect them and call a scroll handler for all of them, like so:
JS Fiddle
$(window).bind('mousewheel DOMMouseScroll', function(event){
var direction;
if (event.originalEvent.wheelDelta > 0 || event.originalEvent.detail < 0) {
direction = 'up';
}
else {
direction = 'down';
}
scrollHandler(direction, 'mouseWheel');
event.preventDefault();
});
var scrollHandler = function(direction, origin) {
var height = $(document).scrollTop();
var movement = (direction == 'up') ? -100 : 100;
console.log(origin);
$('body').stop(true);
$('body').animate({
scrollTop: height + movement
}, 250);
};
Then you can do different stuff according to the origin of the event!
You could also check if the user scrolls to the same direction that the screen is scrolling and do something different, or whatever you want with the info passed by the mousewheel event.
Original mousewheel event function copied from THIS answer
I would suggest possibly using the .originalEvent method. The downside is, this is very browser dependent. See here. Hopefully the following helps:
$('#element').scroll(function(e){
var humanScroll = e.originalEvent === undefined;
if(humanScroll) {
$(this).stop(true);
}
})