Event.Wheeldelta Returns Undefined

event.wheelDelta returns undefined

The event object in a jQuery event handler does not reflect the real event. wheelDelta is a non-standard event property^{IE and Opera}, available through the originalEvent property of the jQuery event.

In jQuery 1.7+, the detail property is not available at the jQuery Event object. So, you should also use event.originalEvent.detail to for this property at the DOMMouseScroll event. This method is backwards-compatible with older jQuery versions.

event.originalEvent.wheelDelta

Demo: http://jsfiddle.net/eXQf3/22/

See also: http://api.jquery.com/category/events/event-object/

MouseWheel Event not working in IE?

Jquery doesn't pass along the IE event object. If you want the MS specific properties you have to use addeventlistener instead of on

Binding mousewheel returns undefined

I think you'll have to do a little bit more work to get it working in all browsers - or try the jquery-mousewheel extension

If the extension still does not work properly, you might try this modified version I created a while ago:

/* jquery.mousewheel.min.js
 * Copyright (c) 2009 Brandon Aaron (http://brandonaaron.net)
 * Dual licensed under the MIT (http://www.opensource.org/licenses/mit-license.php)
 * and GPL (http://www.opensource.org/licenses/gpl-license.php) licenses.
 * Thanks to: http://adomas.org/javascript-mouse-wheel/ for some pointers.
 * Thanks to: Mathias Bank(http://www.mathias-bank.de) for a scope bug fix.
 *
 * Version: 3.0.2
 * 
 * Requires: 1.2.2+
 */
(function(c) {
    var a = [ "DOMMouseScroll", "mousewheel" ];
    c.event.special.mousewheel = {
        setup : function() {
            if (this.addEventListener) {
                for ( var d = a.length; d;) {
                    this.addEventListener(a[--d], b, false)
                }
            } else {
                this.onmousewheel = b
            }
        },
        teardown : function() {
            if (this.removeEventListener) {
                for ( var d = a.length; d;) {
                    this.removeEventListener(a[--d], b, false)
                }
            } else {
                this.onmousewheel = null
            }
        }
    };
    c.fn.extend({
        mousewheel : function(d) {
            return d ? this.bind("mousewheel", d) : this.trigger("mousewheel")
        },
        unmousewheel : function(d) {
            return this.unbind("mousewheel", d)
        }
    });
    function b(f) {
        var d = [].slice.call(arguments, 1), g = 0, e = true;
        if (f.wheelDelta) {
            g = f.wheelDelta / 120
        }
        if (f.detail) {
            g = -f.detail / 3
        }
        // I had to move the following two lines down, probably because of jQuery update
        f = c.event.fix(f || window.event);
        f.type = "mousewheel";
        f.pageX = f.originalEvent.pageX;
        f.pageY = f.originalEvent.pageY;
        d.unshift(f, g);
        return c.event.handle.apply(this, d)
    }
})(jQuery);

I just tested it in Firefox and Chrome, but I don't know whether it works in other browsers. Usage:

$('element').mousewheel(function(e, delta) { alert(delta); });

Mouse Wheel event always returns less than 0 (down) in firefox? [JQuery]

Add this before you condition :

var theEvent = e.originalEvent.wheelDelta || e.originalEvent.detail*-1

And you condition

if ( theEvent /120 > 0)

*-1 is there because somehow, firefox reverse the scrolling value.

wheel event javascript give inconsistent values

event.wheelDelta is not defined in every browser, deprecated and should not been used anymore according to its Mozilla documention. You could use the values event.deltaX and event.deltaY. For further information, please refer to Mozilla wheel documentation.

I tested the following code in Google Chrome and Mozilla Firefox. The values are very different. Google Chrome always returns as event.deltaY the value 100 or -100. In Mozilla Firefox it always returns the values 3 or -3.

document.addEventListener('wheel', function(event) {
    console.log(event.deltaX, event.deltaY);
});

I would not rely onto the wheel value but rather listen to the scroll event like this is described on the Mozilla scroll documentation:

var lastKnownScrollPosition = 0;
var ticking = false;

function doSomething(scrollPosition) {
    console.log(scrollPosition);
}

window.addEventListener('scroll', function(e) {
    lastKnownScrollPosition = window.scrollY;
    if(!ticking) {
        window.requestAnimationFrame(function() {
            doSomething(lastKnownScrollPosition);
            ticking = false;
        });
    }
    ticking = true;
});

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