https://aast.edu/template/50yrs-slider/js/jquery.mousewheel.js

1(function($) {
2
3var types = ['DOMMouseScroll', 'mousewheel'];
4
5if ($.event.fixHooks) {
6    for ( var i=types.length; i; ) {
7        $.event.fixHooks[ types[--i] ] = $.event.mouseHooks;
8    }
9}
10
11$.event.special.mousewheel = {
12    setup: function() {
13        if ( this.addEventListener ) {
14            for ( var i=types.length; i; ) {
15                this.addEventListener( types[--i], handler, false );
16            }
17        } else {
18            this.onmousewheel = handler;
19        }
20    },
21    
22    teardown: function() {
23        if ( this.removeEventListener ) {
24            for ( var i=types.length; i; ) {
25                this.removeEventListener( types[--i], handler, false );
26            }
27        } else {
28            this.onmousewheel = null;
29        }
30    }
31};
32
33$.fn.extend({
34    mousewheel: function(fn) {
35        return fn ? this.bind("mousewheel", fn) : this.trigger("mousewheel");
36    },
37    
38    unmousewheel: function(fn) {
39        return this.unbind("mousewheel", fn);
40    }
41});
42
43
44function handler(event) {
45    var orgEvent = event || window.event, args = [].slice.call( arguments, 1 ), delta = 0, returnValue = true, deltaX = 0, deltaY = 0;
46    event = $.event.fix(orgEvent);
47    event.type = "mousewheel";
48    
49    // Old school scrollwheel delta
50   if ( orgEvent.wheelDelta ) { delta = orgEvent.wheelDelta/120; }
51    if ( orgEvent.detail     ) { delta = -orgEvent.detail/3; }
52    
53    // New school multidimensional scroll (touchpads) deltas
54    deltaY = delta;
55    
56    // Gecko
57    if ( orgEvent.axis !== undefined && orgEvent.axis === orgEvent.HORIZONTAL_AXIS ) {
58        deltaY = 0;
59        deltaX = -1*delta;
60    }
61    
62    // Webkit
63    if ( orgEvent.wheelDeltaY !== undefined ) { deltaY = orgEvent.wheelDeltaY/120; }
64    if ( orgEvent.wheelDeltaX !== undefined ) { deltaX = -1*orgEvent.wheelDeltaX/120; }
65    
66    // Add event and delta to the front of the arguments
67    args.unshift(event, delta, deltaX, deltaY);
68    
69    return ($.event.dispatch || $.event.handle).apply(this, args);
70}
71
72})(jQuery);