MediaWiki:Gadget-jquery.mousewheel.js

/*! Copyright (c) 2013 Brandon Aaron (http://brandon.aaron.sh) * Licensed under the MIT License (LICENSE.txt). * * Version: 3.1.11 * * Requires: jQuery 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'], toBind = ( 'onwheel' in document || document.documentMode >= 9 ) ? ['wheel'] : ['mousewheel', 'DomMouseScroll', 'MozMousePixelScroll'], slice = Array.prototype.slice, nullLowestDeltaTimeout, lowestDelta;

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

var special = $.event.special.mousewheel = { version: '3.1.11',

setup: function { if ( this.addEventListener ) { for ( var i = toBind.length; i; ) { this.addEventListener( toBind[--i], handler, false ); }           } else { this.onmousewheel = handler; }           // Store the line height and page height for this particular element $.data(this, 'mousewheel-line-height', special.getLineHeight(this)); $.data(this, 'mousewheel-page-height', special.getPageHeight(this)); },

teardown: function { if ( this.removeEventListener ) { for ( var i = toBind.length; i; ) { this.removeEventListener( toBind[--i], handler, false ); }           } else { this.onmousewheel = null; }           // Clean up the data we added to the element $.removeData(this, 'mousewheel-line-height'); $.removeData(this, 'mousewheel-page-height'); },

getLineHeight: function(elem) { var $parent = $(elem)['offsetParent' in $.fn ? 'offsetParent' : 'parent']; if (!$parent.length) { $parent = $('body'); }           return parseInt($parent.css('fontSize'), 10); },

getPageHeight: function(elem) { return $(elem).height; },

settings: { adjustOldDeltas: true, // see shouldAdjustOldDeltas below normalizeOffset: true // calls getBoundingClientRect for each event }   };

$.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, offsetX   = 0, offsetY   = 0; event = $.event.fix(orgEvent); event.type = 'mousewheel';

// Old school scrollwheel delta if ( 'detail'     in orgEvent ) { deltaY = orgEvent.detail * -1;      } if ( 'wheelDelta' in orgEvent ) { deltaY = orgEvent.wheelDelta;       } if ( 'wheelDeltaY' in orgEvent ) { deltaY = orgEvent.wheelDeltaY;     } if ( 'wheelDeltaX' in orgEvent ) { deltaX = orgEvent.wheelDeltaX * -1; }

// Firefox < 17 horizontal scrolling related to DOMMouseScroll event if ( 'axis' in orgEvent && orgEvent.axis === orgEvent.HORIZONTAL_AXIS ) { deltaX = deltaY * -1; deltaY = 0; }

// Set delta to be deltaY or deltaX if deltaY is 0 for backwards compatabilitiy delta = deltaY === 0 ? deltaX : deltaY;

// New school wheel delta (wheel event) if ( 'deltaY' in orgEvent ) { deltaY = orgEvent.deltaY * -1; delta = deltaY; }       if ( 'deltaX' in orgEvent ) { deltaX = orgEvent.deltaX; if ( deltaY === 0 ) { delta = deltaX * -1; } }

// No change actually happened, no reason to go any further if ( deltaY === 0 && deltaX === 0 ) { return; }

// Need to convert lines and pages to pixels if we aren't already in pixels // There are three delta modes: //  * deltaMode 0 is by pixels, nothing to do        //   * deltaMode 1 is by lines //  * deltaMode 2 is by pages if ( orgEvent.deltaMode === 1 ) { var lineHeight = $.data(this, 'mousewheel-line-height'); delta *= lineHeight; deltaY *= lineHeight; deltaX *= lineHeight; } else if ( orgEvent.deltaMode === 2 ) { var pageHeight = $.data(this, 'mousewheel-page-height'); delta *= pageHeight; deltaY *= pageHeight; deltaX *= pageHeight; }

// Store lowest absolute delta to normalize the delta values absDelta = Math.max( Math.abs(deltaY), Math.abs(deltaX) );

if ( !lowestDelta || absDelta < lowestDelta ) { lowestDelta = absDelta;

// Adjust older deltas if necessary if ( shouldAdjustOldDeltas(orgEvent, absDelta) ) { lowestDelta /= 40; }       }

// Adjust older deltas if necessary if ( shouldAdjustOldDeltas(orgEvent, absDelta) ) { // Divide all the things by 40! delta /= 40; deltaX /= 40; deltaY /= 40; }

// Get a whole, normalized value for the deltas delta = Math[ delta  >= 1 ? 'floor' : 'ceil' ](delta / lowestDelta); deltaX = Math[ deltaX >= 1 ? 'floor' : 'ceil' ](deltaX / lowestDelta); deltaY = Math[ deltaY >= 1 ? 'floor' : 'ceil' ](deltaY / lowestDelta);

// Normalise offsetX and offsetY properties if ( special.settings.normalizeOffset && this.getBoundingClientRect ) { var boundingRect = this.getBoundingClientRect; offsetX = event.clientX - boundingRect.left; offsetY = event.clientY - boundingRect.top; }

// Add information to the event object event.deltaX = deltaX; event.deltaY = deltaY; event.deltaFactor = lowestDelta; event.offsetX = offsetX; event.offsetY = offsetY; // Go ahead and set deltaMode to 0 since we converted to pixels // Although this is a little odd since we overwrite the deltaX/Y // properties with normalized deltas. event.deltaMode = 0;

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

// Clearout lowestDelta after sometime to better // handle multiple device types that give different // a different lowestDelta // Ex: trackpad = 3 and mouse wheel = 120 if (nullLowestDeltaTimeout) { clearTimeout(nullLowestDeltaTimeout); } nullLowestDeltaTimeout = setTimeout(nullLowestDelta, 200);

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

function nullLowestDelta { lowestDelta = null; }

function shouldAdjustOldDeltas(orgEvent, absDelta) { // If this is an older event and the delta is divisable by 120, // then we are assuming that the browser is treating this as an       // older mouse wheel event and that we should divide the deltas // by 40 to try and get a more usable deltaFactor. // Side note, this actually impacts the reported scroll distance // in older browsers and can cause scrolling to be slower than native. // Turn this off by setting $.event.special.mousewheel.settings.adjustOldDeltas to false. return special.settings.adjustOldDeltas && orgEvent.type === 'mousewheel' && absDelta % 120 === 0; }

}));