2 * jQuery Mousewheel 3.1.13
4 * Copyright jQuery Foundation and other contributors
5 * Released under the MIT license
6 * http://jquery.org/license
10 if ( typeof define === 'function' && define.amd ) {
11 // AMD. Register as an anonymous module.
12 define(['jquery'], factory);
13 } else if (typeof exports === 'object') {
14 // Node/CommonJS style for Browserify
15 module.exports = factory;
22 var toFix = ['wheel', 'mousewheel', 'DOMMouseScroll', 'MozMousePixelScroll'],
23 toBind = ( 'onwheel' in document || document.documentMode >= 9 ) ?
24 ['wheel'] : ['mousewheel', 'DomMouseScroll', 'MozMousePixelScroll'],
25 slice = Array.prototype.slice,
26 nullLowestDeltaTimeout, lowestDelta;
28 if ( $.event.fixHooks ) {
29 for ( var i = toFix.length; i; ) {
30 $.event.fixHooks[ toFix[--i] ] = $.event.mouseHooks;
34 var special = $.event.special.mousewheel = {
38 if ( this.addEventListener ) {
39 for ( var i = toBind.length; i; ) {
40 this.addEventListener( toBind[--i], handler, false );
43 this.onmousewheel = handler;
45 // Store the line height and page height for this particular element
46 $.data(this, 'mousewheel-line-height', special.getLineHeight(this));
47 $.data(this, 'mousewheel-page-height', special.getPageHeight(this));
50 teardown: function() {
51 if ( this.removeEventListener ) {
52 for ( var i = toBind.length; i; ) {
53 this.removeEventListener( toBind[--i], handler, false );
56 this.onmousewheel = null;
58 // Clean up the data we added to the element
59 $.removeData(this, 'mousewheel-line-height');
60 $.removeData(this, 'mousewheel-page-height');
63 getLineHeight: function(elem) {
65 $parent = $elem['offsetParent' in $.fn ? 'offsetParent' : 'parent']();
66 if (!$parent.length) {
69 return parseInt($parent.css('fontSize'), 10) || parseInt($elem.css('fontSize'), 10) || 16;
72 getPageHeight: function(elem) {
73 return $(elem).height();
77 adjustOldDeltas: true, // see shouldAdjustOldDeltas() below
78 normalizeOffset: true // calls getBoundingClientRect for each event
83 mousewheel: function(fn) {
84 return fn ? this.bind('mousewheel', fn) : this.trigger('mousewheel');
87 unmousewheel: function(fn) {
88 return this.unbind('mousewheel', fn);
93 function handler(event) {
94 var orgEvent = event || window.event,
95 args = slice.call(arguments, 1),
102 event = $.event.fix(orgEvent);
103 event.type = 'mousewheel';
105 // Old school scrollwheel delta
106 if ( 'detail' in orgEvent ) { deltaY = orgEvent.detail * -1; }
107 if ( 'wheelDelta' in orgEvent ) { deltaY = orgEvent.wheelDelta; }
108 if ( 'wheelDeltaY' in orgEvent ) { deltaY = orgEvent.wheelDeltaY; }
109 if ( 'wheelDeltaX' in orgEvent ) { deltaX = orgEvent.wheelDeltaX * -1; }
111 // Firefox < 17 horizontal scrolling related to DOMMouseScroll event
112 if ( 'axis' in orgEvent && orgEvent.axis === orgEvent.HORIZONTAL_AXIS ) {
113 deltaX = deltaY * -1;
117 // Set delta to be deltaY or deltaX if deltaY is 0 for backwards compatabilitiy
118 delta = deltaY === 0 ? deltaX : deltaY;
120 // New school wheel delta (wheel event)
121 if ( 'deltaY' in orgEvent ) {
122 deltaY = orgEvent.deltaY * -1;
125 if ( 'deltaX' in orgEvent ) {
126 deltaX = orgEvent.deltaX;
127 if ( deltaY === 0 ) { delta = deltaX * -1; }
130 // No change actually happened, no reason to go any further
131 if ( deltaY === 0 && deltaX === 0 ) { return; }
133 // Need to convert lines and pages to pixels if we aren't already in pixels
134 // There are three delta modes:
135 // * deltaMode 0 is by pixels, nothing to do
136 // * deltaMode 1 is by lines
137 // * deltaMode 2 is by pages
138 if ( orgEvent.deltaMode === 1 ) {
139 var lineHeight = $.data(this, 'mousewheel-line-height');
141 deltaY *= lineHeight;
142 deltaX *= lineHeight;
143 } else if ( orgEvent.deltaMode === 2 ) {
144 var pageHeight = $.data(this, 'mousewheel-page-height');
146 deltaY *= pageHeight;
147 deltaX *= pageHeight;
150 // Store lowest absolute delta to normalize the delta values
151 absDelta = Math.max( Math.abs(deltaY), Math.abs(deltaX) );
153 if ( !lowestDelta || absDelta < lowestDelta ) {
154 lowestDelta = absDelta;
156 // Adjust older deltas if necessary
157 if ( shouldAdjustOldDeltas(orgEvent, absDelta) ) {
162 // Adjust older deltas if necessary
163 if ( shouldAdjustOldDeltas(orgEvent, absDelta) ) {
164 // Divide all the things by 40!
170 // Get a whole, normalized value for the deltas
171 delta = Math[ delta >= 1 ? 'floor' : 'ceil' ](delta / lowestDelta);
172 deltaX = Math[ deltaX >= 1 ? 'floor' : 'ceil' ](deltaX / lowestDelta);
173 deltaY = Math[ deltaY >= 1 ? 'floor' : 'ceil' ](deltaY / lowestDelta);
175 // Normalise offsetX and offsetY properties
176 if ( special.settings.normalizeOffset && this.getBoundingClientRect ) {
177 var boundingRect = this.getBoundingClientRect();
178 offsetX = event.clientX - boundingRect.left;
179 offsetY = event.clientY - boundingRect.top;
182 // Add information to the event object
183 event.deltaX = deltaX;
184 event.deltaY = deltaY;
185 event.deltaFactor = lowestDelta;
186 event.offsetX = offsetX;
187 event.offsetY = offsetY;
188 // Go ahead and set deltaMode to 0 since we converted to pixels
189 // Although this is a little odd since we overwrite the deltaX/Y
190 // properties with normalized deltas.
193 // Add event and delta to the front of the arguments
194 args.unshift(event, delta, deltaX, deltaY);
196 // Clearout lowestDelta after sometime to better
197 // handle multiple device types that give different
198 // a different lowestDelta
199 // Ex: trackpad = 3 and mouse wheel = 120
200 if (nullLowestDeltaTimeout) { clearTimeout(nullLowestDeltaTimeout); }
201 nullLowestDeltaTimeout = setTimeout(nullLowestDelta, 200);
203 return ($.event.dispatch || $.event.handle).apply(this, args);
206 function nullLowestDelta() {
210 function shouldAdjustOldDeltas(orgEvent, absDelta) {
211 // If this is an older event and the delta is divisable by 120,
212 // then we are assuming that the browser is treating this as an
213 // older mouse wheel event and that we should divide the deltas
214 // by 40 to try and get a more usable deltaFactor.
215 // Side note, this actually impacts the reported scroll distance
216 // in older browsers and can cause scrolling to be slower than native.
217 // Turn this off by setting $.event.special.mousewheel.settings.adjustOldDeltas to false.
218 return special.settings.adjustOldDeltas && orgEvent.type === 'mousewheel' && absDelta % 120 === 0;