jquery.mousewheel.js 3.3 KB
/*! Copyright (c) 2013 Brandon Aaron (http://brandonaaron.net)
 * Licensed under the MIT License (LICENSE.txt).
 *
 * 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.
 * Thanks to: Seamus Leahy for adding deltaX and deltaY
 *
 * Version: 3.1.3
 *
 * Requires: 1.2.2+
 */

(function (factory) {
	if ( typeof define === 'function' && define.amd ) {
		// AMD. Register as an anonymous module.
		define(['jquery'], factory);
	} else if (typeof exports === 'object') {
		// Node/CommonJS style for Browserify
		module.exports = factory;
	} else {
		// Browser globals
		factory(jQuery);
	}
}(function ($) {

	var toFix = ['wheel', 'mousewheel', 'DOMMouseScroll', 'MozMousePixelScroll'];
	var toBind = 'onwheel' in document || document.documentMode >= 9 ? ['wheel'] : ['mousewheel', 'DomMouseScroll', 'MozMousePixelScroll'];
	var lowestDelta, lowestDeltaXY;

	if ( $.event.fixHooks ) {
		for ( var i = toFix.length; i; ) {
			$.event.fixHooks[ toFix[--i] ] = $.event.mouseHooks;
		}
	}

	$.event.special.mousewheel = {
		setup: function() {
			if ( this.addEventListener ) {
				for ( var i = toBind.length; i; ) {
					this.addEventListener( toBind[--i], handler, false );
				}
			} else {
				this.onmousewheel = handler;
			}
		},

		teardown: function() {
			if ( this.removeEventListener ) {
				for ( var i = toBind.length; i; ) {
					this.removeEventListener( toBind[--i], handler, false );
				}
			} else {
				this.onmousewheel = null;
			}
		}
	};

	$.fn.extend({
		mousewheel: function(fn) {
			return fn ? this.bind("mousewheel", fn) : this.trigger("mousewheel");
		},

		unmousewheel: function(fn) {
			return this.unbind("mousewheel", fn);
		}
	});


	function handler(event) {
		var orgEvent = event || window.event,
			args = [].slice.call(arguments, 1),
			delta = 0,
			deltaX = 0,
			deltaY = 0,
			absDelta = 0,
			absDeltaXY = 0,
			fn;
		event = $.event.fix(orgEvent);
		event.type = "mousewheel";

		// Old school scrollwheel delta
		if ( orgEvent.wheelDelta ) { delta = orgEvent.wheelDelta; }
		if ( orgEvent.detail )     { delta = orgEvent.detail * -1; }

		// New school wheel delta (wheel event)
		if ( orgEvent.deltaY ) {
			deltaY = orgEvent.deltaY * -1;
			delta  = deltaY;
		}
		if ( orgEvent.deltaX ) {
			deltaX = orgEvent.deltaX;
			delta  = deltaX * -1;
		}

		// Webkit
		if ( orgEvent.wheelDeltaY !== undefined ) { deltaY = orgEvent.wheelDeltaY; }
		if ( orgEvent.wheelDeltaX !== undefined ) { deltaX = orgEvent.wheelDeltaX * -1; }

		// Look for lowest delta to normalize the delta values
		absDelta = Math.abs(delta);
		if ( !lowestDelta || absDelta < lowestDelta ) { lowestDelta = absDelta; }
		absDeltaXY = Math.max(Math.abs(deltaY), Math.abs(deltaX));
		if ( !lowestDeltaXY || absDeltaXY < lowestDeltaXY ) { lowestDeltaXY = absDeltaXY; }

		// Get a whole value for the deltas
		fn = delta > 0 ? 'floor' : 'ceil';
		delta  = Math[fn](delta / lowestDelta);
		deltaX = Math[fn](deltaX / lowestDeltaXY);
		deltaY = Math[fn](deltaY / lowestDeltaXY);

		// Add event and delta to the front of the arguments
		args.unshift(event, delta, deltaX, deltaY);

		return ($.event.dispatch || $.event.handle).apply(this, args);
	}

}));