/*!
 * FullCalendar v2.2.5
 * Docs & License: http://arshaw.com/fullcalendar/
 * (c) 2013 Adam Shaw
 */

(function(factory) {
	if (typeof define === 'function' && define.amd) {
		define([ 'jquery', 'moment' ], factory);
	}
	else {
		factory(jQuery, moment);
	}
})(function($, moment) {

    var defaults = {

	titleRangeSeparator: ' \u2014 ', // emphasized dash
	monthYearFormat: 'MMMM YYYY', // required for en. other languages rely on datepicker computable option

	defaultTimedEventDuration: '02:00:00',
	defaultAllDayEventDuration: { days: 1 },
	forceEventDuration: false,
	nextDayThreshold: '09:00:00', // 9am

	// display
	defaultView: 'month',
	aspectRatio: 1.35,
	header: {
		left: 'title',
		center: '',
		right: 'today prev,next'
	},
	weekends: true,
	weekNumbers: false,

	weekNumberTitle: 'W',
	weekNumberCalculation: 'local',
	
	//editable: false,
	
	// event ajax
	lazyFetching: true,
	startParam: 'start',
	endParam: 'end',
	timezoneParam: 'timezone',

	timezone: false,

	//allDayDefault: undefined,

	// locale
	isRTL: false,
	defaultButtonText: {
		prev: "prev",
		next: "next",
		prevYear: "prev year",
		nextYear: "next year",
		today: 'today',
		month: 'month',
		week: 'week',
		day: 'day'
	},

	buttonIcons: {
		prev: 'left-single-arrow',
		next: 'right-single-arrow',
		prevYear: 'left-double-arrow',
		nextYear: 'right-double-arrow'
	},
	
	// jquery-ui theming
	theme: false,
	themeButtonIcons: {
		prev: 'circle-triangle-w',
		next: 'circle-triangle-e',
		prevYear: 'seek-prev',
		nextYear: 'seek-next'
	},

	dragOpacity: .75,
	dragRevertDuration: 500,
	dragScroll: true,
	
	//selectable: false,
	unselectAuto: true,
	
	dropAccept: '*',

	eventLimit: false,
	eventLimitText: 'more',
	eventLimitClick: 'popover',
	dayPopoverFormat: 'LL',
	
	handleWindowResize: true,
	windowResizeDelay: 200 // milliseconds before an updateSize happens
	
};


var englishDefaults = {
	dayPopoverFormat: 'dddd, MMMM D'
};


// right-to-left defaults
var rtlDefaults = {
	header: {
		left: 'next,prev today',
		center: '',
		right: 'title'
	},
	buttonIcons: {
		prev: 'right-single-arrow',
		next: 'left-single-arrow',
		prevYear: 'right-double-arrow',
		nextYear: 'left-double-arrow'
	},
	themeButtonIcons: {
		prev: 'circle-triangle-e',
		next: 'circle-triangle-w',
		nextYear: 'seek-prev',
		prevYear: 'seek-next'
	}
};

    var fc = $.fullCalendar = { version: "2.2.5" };
var fcViews = fc.views = {};


$.fn.fullCalendar = function(options) {
	var args = Array.prototype.slice.call(arguments, 1); // for a possible method call
	var res = this; // what this function will return (this jQuery object by default)

	this.each(function(i, _element) { // loop each DOM element involved
		var element = $(_element);
		var calendar = element.data('fullCalendar'); // get the existing calendar object (if any)
		var singleRes; // the returned value of this single method call

		// a method call
		if (typeof options === 'string') {
			if (calendar && $.isFunction(calendar[options])) {
				singleRes = calendar[options].apply(calendar, args);
				if (!i) {
					res = singleRes; // record the first method call result
				}
				if (options === 'destroy') { // for the destroy method, must remove Calendar object data
					element.removeData('fullCalendar');
				}
			}
		}
		// a new calendar initialization
		else if (!calendar) { // don't initialize twice
			calendar = new Calendar(element, options);
			element.data('fullCalendar', calendar);
			calendar.render();
		}
	});
	
	return res;
};


// function for adding/overriding defaults
function setDefaults(d) {
	mergeOptions(defaults, d);
}


// Recursively combines option hash-objects.
// Better than `$.extend(true, ...)` because arrays are not traversed/copied.
//
// called like:
//     mergeOptions(target, obj1, obj2, ...)
//
function mergeOptions(target) {

	function mergeIntoTarget(name, value) {
		if ($.isPlainObject(value) && $.isPlainObject(target[name]) && !isForcedAtomicOption(name)) {
			// merge into a new object to avoid destruction
			target[name] = mergeOptions({}, target[name], value); // combine. `value` object takes precedence
		}
		else if (value !== undefined) { // only use values that are set and not undefined
			target[name] = value;
		}
	}

	for (var i=1; i<arguments.length; i++) {
		$.each(arguments[i], mergeIntoTarget);
	}

	return target;
}


// overcome sucky view-option-hash and option-merging behavior messing with options it shouldn't
function isForcedAtomicOption(name) {
	// Any option that ends in "Time" or "Duration" is probably a Duration,
	// and these will commonly be specified as plain objects, which we don't want to mess up.
	return /(Time|Duration)$/.test(name);
}
// FIX: find a different solution for view-option-hashes and have a whitelist
// for options that can be recursively merged.

    var langOptionHash = fc.langs = {}; // initialize and expose


// TODO: document the structure and ordering of a FullCalendar lang file
// TODO: rename everything "lang" to "locale", like what the moment project did


// Initialize jQuery UI datepicker translations while using some of the translations
// Will set this as the default language for datepicker.
fc.datepickerLang = function(langCode, dpLangCode, dpOptions) {

	// get the FullCalendar internal option hash for this language. create if necessary
	var fcOptions = langOptionHash[langCode] || (langOptionHash[langCode] = {});

	// transfer some simple options from datepicker to fc
	fcOptions.isRTL = dpOptions.isRTL;
	fcOptions.weekNumberTitle = dpOptions.weekHeader;

	// compute some more complex options from datepicker
	$.each(dpComputableOptions, function(name, func) {
		fcOptions[name] = func(dpOptions);
	});

	// is jQuery UI Datepicker is on the page?
	if ($.datepicker) {

		// Register the language data.
		// FullCalendar and MomentJS use language codes like "pt-br" but Datepicker
		// does it like "pt-BR" or if it doesn't have the language, maybe just "pt".
		// Make an alias so the language can be referenced either way.
		$.datepicker.regional[dpLangCode] =
			$.datepicker.regional[langCode] = // alias
				dpOptions;

		// Alias 'en' to the default language data. Do this every time.
		$.datepicker.regional.en = $.datepicker.regional[''];

		// Set as Datepicker's global defaults.
		$.datepicker.setDefaults(dpOptions);
	}
};


// Sets FullCalendar-specific translations. Will set the language as the global default.
fc.lang = function(langCode, newFcOptions) {
	var fcOptions;
	var momOptions;

	// get the FullCalendar internal option hash for this language. create if necessary
	fcOptions = langOptionHash[langCode] || (langOptionHash[langCode] = {});

	// provided new options for this language? merge them in
	if (newFcOptions) {
		mergeOptions(fcOptions, newFcOptions);
	}

	// compute language options that weren't defined.
	// always do this. newFcOptions can be undefined when initializing from i18n file,
	// so no way to tell if this is an initialization or a default-setting.
	momOptions = getMomentLocaleData(langCode); // will fall back to en
	$.each(momComputableOptions, function(name, func) {
		if (fcOptions[name] === undefined) {
			fcOptions[name] = func(momOptions, fcOptions);
		}
	});

	// set it as the default language for FullCalendar
	defaults.lang = langCode;
};


// NOTE: can't guarantee any of these computations will run because not every language has datepicker
// configs, so make sure there are English fallbacks for these in the defaults file.
var dpComputableOptions = {

	defaultButtonText: function(dpOptions) {
		return {
			// the translations sometimes wrongly contain HTML entities
			prev: stripHtmlEntities(dpOptions.prevText),
			next: stripHtmlEntities(dpOptions.nextText),
			today: stripHtmlEntities(dpOptions.currentText)
		};
	},

	// Produces format strings like "MMMM YYYY" -> "September 2014"
	monthYearFormat: function(dpOptions) {
		return dpOptions.showMonthAfterYear ?
			'YYYY[' + dpOptions.yearSuffix + '] MMMM' :
			'MMMM YYYY[' + dpOptions.yearSuffix + ']';
	}

};

var momComputableOptions = {

	// Produces format strings like "ddd MM/DD" -> "Fri 12/10"
	dayOfMonthFormat: function(momOptions, fcOptions) {
		var format = momOptions.longDateFormat('l'); // for the format like "M/D/YYYY"

		// strip the year off the edge, as well as other misc non-whitespace chars
		format = format.replace(/^Y+[^\w\s]*|[^\w\s]*Y+$/g, '');

		if (fcOptions.isRTL) {
			format += ' ddd'; // for RTL, add day-of-week to end
		}
		else {
			format = 'ddd ' + format; // for LTR, add day-of-week to beginning
		}
		return format;
	},

	// Produces format strings like "H(:mm)a" -> "6pm" or "6:30pm"
	smallTimeFormat: function(momOptions) {
		return momOptions.longDateFormat('LT')
			.replace(':mm', '(:mm)')
			.replace(/(\Wmm)$/, '($1)') // like above, but for foreign langs
			.replace(/\s*a$/i, 'a'); // convert AM/PM/am/pm to lowercase. remove any spaces beforehand
	},

	// Produces format strings like "H(:mm)t" -> "6p" or "6:30p"
	extraSmallTimeFormat: function(momOptions) {
		return momOptions.longDateFormat('LT')
			.replace(':mm', '(:mm)')
			.replace(/(\Wmm)$/, '($1)') // like above, but for foreign langs
			.replace(/\s*a$/i, 't'); // convert to AM/PM/am/pm to lowercase one-letter. remove any spaces beforehand
	},

	// Produces format strings like "H:mm" -> "6:30" (with no AM/PM)
	noMeridiemTimeFormat: function(momOptions) {
		return momOptions.longDateFormat('LT')
			.replace(/\s*a$/i, ''); // remove trailing AM/PM
	}

};


// Returns moment's internal locale data. If doesn't exist, returns English.
// Works with moment-pre-2.8
function getMomentLocaleData(langCode) {
	var func = moment.localeData || moment.langData;
	return func.call(moment, langCode) ||
		func.call(moment, 'en'); // the newer localData could return null, so fall back to en
}


// Initialize English by forcing computation of moment-derived options.
// Also, sets it as the default.
fc.lang('en', englishDefaults);

// exports
fc.intersectionToSeg = intersectionToSeg;
fc.applyAll = applyAll;
fc.debounce = debounce;


/* FullCalendar-specific DOM Utilities
----------------------------------------------------------------------------------------------------------------------*/


// Given the scrollbar widths of some other container, create borders/margins on rowEls in order to match the left
// and right space that was offset by the scrollbars. A 1-pixel border first, then margin beyond that.
function compensateScroll(rowEls, scrollbarWidths) {
	if (scrollbarWidths.left) {
		rowEls.css({
			'border-left-width': 1,
			'margin-left': scrollbarWidths.left - 1
		});
	}
	if (scrollbarWidths.right) {
		rowEls.css({
			'border-right-width': 1,
			'margin-right': scrollbarWidths.right - 1
		});
	}
}


// Undoes compensateScroll and restores all borders/margins
function uncompensateScroll(rowEls) {
	rowEls.css({
		'margin-left': '',
		'margin-right': '',
		'border-left-width': '',
		'border-right-width': ''
	});
}


// Make the mouse cursor express that an event is not allowed in the current area
function disableCursor() {
	$('body').addClass('fc-not-allowed');
}


// Returns the mouse cursor to its original look
function enableCursor() {
	$('body').removeClass('fc-not-allowed');
}


// Given a total available height to fill, have `els` (essentially child rows) expand to accomodate.
// By default, all elements that are shorter than the recommended height are expanded uniformly, not considering
// any other els that are already too tall. if `shouldRedistribute` is on, it considers these tall rows and 
// reduces the available height.
function distributeHeight(els, availableHeight, shouldRedistribute) {

	// *FLOORING NOTE*: we floor in certain places because zoom can give inaccurate floating-point dimensions,
	// and it is better to be shorter than taller, to avoid creating unnecessary scrollbars.

	var minOffset1 = Math.floor(availableHeight / els.length); // for non-last element
	var minOffset2 = Math.floor(availableHeight - minOffset1 * (els.length - 1)); // for last element *FLOORING NOTE*
	var flexEls = []; // elements that are allowed to expand. array of DOM nodes
	var flexOffsets = []; // amount of vertical space it takes up
	var flexHeights = []; // actual css height
	var usedHeight = 0;

	undistributeHeight(els); // give all elements their natural height

	// find elements that are below the recommended height (expandable).
	// important to query for heights in a single first pass (to avoid reflow oscillation).
	els.each(function(i, el) {
		var minOffset = i === els.length - 1 ? minOffset2 : minOffset1;
		var naturalOffset = $(el).outerHeight(true);

		if (naturalOffset < minOffset) {
			flexEls.push(el);
			flexOffsets.push(naturalOffset);
			flexHeights.push($(el).height());
		}
		else {
			// this element stretches past recommended height (non-expandable). mark the space as occupied.
			usedHeight += naturalOffset;
		}
	});

	// readjust the recommended height to only consider the height available to non-maxed-out rows.
	if (shouldRedistribute) {
		availableHeight -= usedHeight;
		minOffset1 = Math.floor(availableHeight / flexEls.length);
		minOffset2 = Math.floor(availableHeight - minOffset1 * (flexEls.length - 1)); // *FLOORING NOTE*
	}

	// assign heights to all expandable elements
	$(flexEls).each(function(i, el) {
		var minOffset = i === flexEls.length - 1 ? minOffset2 : minOffset1;
		var naturalOffset = flexOffsets[i];
		var naturalHeight = flexHeights[i];
		var newHeight = minOffset - (naturalOffset - naturalHeight); // subtract the margin/padding

		if (naturalOffset < minOffset) { // we check this again because redistribution might have changed things
			$(el).height(newHeight);
		}
	});
}


// Undoes distrubuteHeight, restoring all els to their natural height
function undistributeHeight(els) {
	els.height('');
}


// Given `els`, a jQuery set of <td> cells, find the cell with the largest natural width and set the widths of all the
// cells to be that width.
// PREREQUISITE: if you want a cell to take up width, it needs to have a single inner element w/ display:inline
function matchCellWidths(els) {
	var maxInnerWidth = 0;

	els.find('> *').each(function(i, innerEl) {
		var innerWidth = $(innerEl).outerWidth();
		if (innerWidth > maxInnerWidth) {
			maxInnerWidth = innerWidth;
		}
	});

	maxInnerWidth++; // sometimes not accurate of width the text needs to stay on one line. insurance

	els.width(maxInnerWidth);

	return maxInnerWidth;
}


// Turns a container element into a scroller if its contents is taller than the allotted height.
// Returns true if the element is now a scroller, false otherwise.
// NOTE: this method is best because it takes weird zooming dimensions into account
function setPotentialScroller(containerEl, height) {
	containerEl.height(height).addClass('fc-scroller');

	// are scrollbars needed?
	if (containerEl[0].scrollHeight - 1 > containerEl[0].clientHeight) { // !!! -1 because IE is often off-by-one :(
		return true;
	}

	unsetScroller(containerEl); // undo
	return false;
}


// Takes an element that might have been a scroller, and turns it back into a normal element.
function unsetScroller(containerEl) {
	containerEl.height('').removeClass('fc-scroller');
}


/* General DOM Utilities
----------------------------------------------------------------------------------------------------------------------*/


// borrowed from https://github.com/jquery/jquery-ui/blob/1.11.0/ui/core.js#L51
function getScrollParent(el) {
	var position = el.css('position'),
		scrollParent = el.parents().filter(function() {
			var parent = $(this);
			return (/(auto|scroll)/).test(
				parent.css('overflow') + parent.css('overflow-y') + parent.css('overflow-x')
			);
		}).eq(0);

	return position === 'fixed' || !scrollParent.length ? $(el[0].ownerDocument || document) : scrollParent;
}


// Given a container element, return an object with the pixel values of the left/right scrollbars.
// Left scrollbars might occur on RTL browsers (IE maybe?) but I have not tested.
// PREREQUISITE: container element must have a single child with display:block
function getScrollbarWidths(container) {
	var containerLeft = container.offset().left;
	var containerRight = containerLeft + container.width();
	var inner = container.children();
	var innerLeft = inner.offset().left;
	var innerRight = innerLeft + inner.outerWidth();

	return {
		left: innerLeft - containerLeft,
		right: containerRight - innerRight
	};
}


// Returns a boolean whether this was a left mouse click and no ctrl key (which means right click on Mac)
function isPrimaryMouseButton(ev) {
	return ev.which == 1 && !ev.ctrlKey;
}


/* FullCalendar-specific Misc Utilities
----------------------------------------------------------------------------------------------------------------------*/


// Creates a basic segment with the intersection of the two ranges. Returns undefined if no intersection.
// Expects all dates to be normalized to the same timezone beforehand.
// TODO: move to date section?
function intersectionToSeg(subjectRange, constraintRange) {
	var subjectStart = subjectRange.start;
	var subjectEnd = subjectRange.end;
	var constraintStart = constraintRange.start;
	var constraintEnd = constraintRange.end;
	var segStart, segEnd;
	var isStart, isEnd;

	if (subjectEnd > constraintStart && subjectStart < constraintEnd) { // in bounds at all?

		if (subjectStart >= constraintStart) {
			segStart = subjectStart.clone();
			isStart = true;
		}
		else {
			segStart = constraintStart.clone();
			isStart =  false;
		}

		if (subjectEnd <= constraintEnd) {
			segEnd = subjectEnd.clone();
			isEnd = true;
		}
		else {
			segEnd = constraintEnd.clone();
			isEnd = false;
		}

		return {
			start: segStart,
			end: segEnd,
			isStart: isStart,
			isEnd: isEnd
		};
	}
}


function smartProperty(obj, name) { // get a camel-cased/namespaced property of an object
	obj = obj || {};
	if (obj[name] !== undefined) {
		return obj[name];
	}
	var parts = name.split(/(?=[A-Z])/),
		i = parts.length - 1, res;
	for (; i>=0; i--) {
		res = obj[parts[i].toLowerCase()];
		if (res !== undefined) {
			return res;
		}
	}
	return obj['default'];
}


/* Date Utilities
----------------------------------------------------------------------------------------------------------------------*/

var dayIDs = [ 'sun', 'mon', 'tue', 'wed', 'thu', 'fri', 'sat' ];
var intervalUnits = [ 'year', 'month', 'week', 'day', 'hour', 'minute', 'second', 'millisecond' ];


// Diffs the two moments into a Duration where full-days are recorded first, then the remaining time.
// Moments will have their timezones normalized.
function diffDayTime(a, b) {
	return moment.duration({
		days: a.clone().stripTime().diff(b.clone().stripTime(), 'days'),
		ms: a.time() - b.time() // time-of-day from day start. disregards timezone
	});
}


// Diffs the two moments via their start-of-day (regardless of timezone). Produces whole-day durations.
function diffDay(a, b) {
	return moment.duration({
		days: a.clone().stripTime().diff(b.clone().stripTime(), 'days')
	});
}


// Computes the larges whole-unit period of time, as a duration object.
// For example, 48 hours will be {days:2} whereas 49 hours will be {hours:49}.
// Accepts start/end, a range object, or an original duration object.
/* (never used)
function computeIntervalDuration(start, end) {
	var durationInput = {};
	var i, unit;
	var val;

	for (i = 0; i < intervalUnits.length; i++) {
		unit = intervalUnits[i];
		val = computeIntervalAs(unit, start, end);
		if (val) {
			break;
		}
	}

	durationInput[unit] = val;
	return moment.duration(durationInput);
}
*/


// Computes the unit name of the largest whole-unit period of time.
// For example, 48 hours will be "days" wherewas 49 hours will be "hours".
// Accepts start/end, a range object, or an original duration object.
function computeIntervalUnit(start, end) {
	var i, unit;

	for (i = 0; i < intervalUnits.length; i++) {
		unit = intervalUnits[i];
		if (computeIntervalAs(unit, start, end)) {
			break;
		}
	}

	return unit; // will be "milliseconds" if nothing else matches
}


// Computes the number of units the interval is cleanly comprised of.
// If the given unit does not cleanly divide the interval a whole number of times, `false` is returned.
// Accepts start/end, a range object, or an original duration object.
function computeIntervalAs(unit, start, end) {
	var val;

	if (end != null) { // given start, end
		val = end.diff(start, unit, true);
	}
	else if (moment.isDuration(start)) { // given duration
		val = start.as(unit);
	}
	else { // given { start, end } range object
		val = start.end.diff(start.start, unit, true);
	}

	if (val >= 1 && isInt(val)) {
		return val;
	}

	return false;
}


function isNativeDate(input) {
	return  Object.prototype.toString.call(input) === '[object Date]' || input instanceof Date;
}


// Returns a boolean about whether the given input is a time string, like "06:40:00" or "06:00"
function isTimeString(str) {
	return /^\d+\:\d+(?:\:\d+\.?(?:\d{3})?)?$/.test(str);
}


/* General Utilities
----------------------------------------------------------------------------------------------------------------------*/

var hasOwnPropMethod = {}.hasOwnProperty;


// Create an object that has the given prototype. Just like Object.create
function createObject(proto) {
	var f = function() {};
	f.prototype = proto;
	return new f();
}


function copyOwnProps(src, dest) {
	for (var name in src) {
		if (hasOwnProp(src, name)) {
			dest[name] = src[name];
		}
	}
}


function hasOwnProp(obj, name) {
	return hasOwnPropMethod.call(obj, name);
}


// Is the given value a non-object non-function value?
function isAtomic(val) {
	return /undefined|null|boolean|number|string/.test($.type(val));
}


function applyAll(functions, thisObj, args) {
	if ($.isFunction(functions)) {
		functions = [ functions ];
	}
	if (functions) {
		var i;
		var ret;
		for (i=0; i<functions.length; i++) {
			ret = functions[i].apply(thisObj, args) || ret;
		}
		return ret;
	}
}


function firstDefined() {
	for (var i=0; i<arguments.length; i++) {
		if (arguments[i] !== undefined) {
			return arguments[i];
		}
	}
}


function htmlEscape(s) {
	return (s + '').replace(/&/g, '&amp;')
		.replace(/</g, '&lt;')
		.replace(/>/g, '&gt;')
		.replace(/'/g, '&#039;')
		.replace(/"/g, '&quot;')
		.replace(/\n/g, '<br />');
}


function stripHtmlEntities(text) {
	return text.replace(/&.*?;/g, '');
}


function capitaliseFirstLetter(str) {
	return str.charAt(0).toUpperCase() + str.slice(1);
}


function compareNumbers(a, b) { // for .sort()
	return a - b;
}


function isInt(n) {
	return n % 1 === 0;
}


// Returns a function, that, as long as it continues to be invoked, will not
// be triggered. The function will be called after it stops being called for
// N milliseconds.
// https://github.com/jashkenas/underscore/blob/1.6.0/underscore.js#L714
function debounce(func, wait) {
	var timeoutId;
	var args;
	var context;
	var timestamp; // of most recent call
	var later = function() {
		var last = +new Date() - timestamp;
		if (last < wait && last > 0) {
			timeoutId = setTimeout(later, wait - last);
		}
		else {
			timeoutId = null;
			func.apply(context, args);
			if (!timeoutId) {
				context = args = null;
			}
		}
	};

	return function() {
		context = this;
		args = arguments;
		timestamp = +new Date();
		if (!timeoutId) {
			timeoutId = setTimeout(later, wait);
		}
	};
}

    var ambigDateOfMonthRegex = /^\s*\d{4}-\d\d$/;
var ambigTimeOrZoneRegex =
	/^\s*\d{4}-(?:(\d\d-\d\d)|(W\d\d$)|(W\d\d-\d)|(\d\d\d))((T| )(\d\d(:\d\d(:\d\d(\.\d+)?)?)?)?)?$/;
var newMomentProto = moment.fn; // where we will attach our new methods
var oldMomentProto = $.extend({}, newMomentProto); // copy of original moment methods
var allowValueOptimization;
var setUTCValues; // function defined below
var setLocalValues; // function defined below


// Creating
// -------------------------------------------------------------------------------------------------

// Creates a new moment, similar to the vanilla moment(...) constructor, but with
// extra features (ambiguous time, enhanced formatting). When given an existing moment,
// it will function as a clone (and retain the zone of the moment). Anything else will
// result in a moment in the local zone.
fc.moment = function() {
	return makeMoment(arguments);
};

// Sames as fc.moment, but forces the resulting moment to be in the UTC timezone.
fc.moment.utc = function() {
	var mom = makeMoment(arguments, true);

	// Force it into UTC because makeMoment doesn't guarantee it
	// (if given a pre-existing moment for example)
	if (mom.hasTime()) { // don't give ambiguously-timed moments a UTC zone
		mom.utc();
	}

	return mom;
};

// Same as fc.moment, but when given an ISO8601 string, the timezone offset is preserved.
// ISO8601 strings with no timezone offset will become ambiguously zoned.
fc.moment.parseZone = function() {
	return makeMoment(arguments, true, true);
};

// Builds an enhanced moment from args. When given an existing moment, it clones. When given a
// native Date, or called with no arguments (the current time), the resulting moment will be local.
// Anything else needs to be "parsed" (a string or an array), and will be affected by:
//    parseAsUTC - if there is no zone information, should we parse the input in UTC?
//    parseZone - if there is zone information, should we force the zone of the moment?
function makeMoment(args, parseAsUTC, parseZone) {
	var input = args[0];
	var isSingleString = args.length == 1 && typeof input === 'string';
	var isAmbigTime;
	var isAmbigZone;
	var ambigMatch;
	var mom;

	if (moment.isMoment(input)) {
		mom = moment.apply(null, args); // clone it
		transferAmbigs(input, mom); // the ambig flags weren't transfered with the clone
	}
	else if (isNativeDate(input) || input === undefined) {
		mom = moment.apply(null, args); // will be local
	}
	else { // "parsing" is required
		isAmbigTime = false;
		isAmbigZone = false;

		if (isSingleString) {
			if (ambigDateOfMonthRegex.test(input)) {
				// accept strings like '2014-05', but convert to the first of the month
				input += '-01';
				args = [ input ]; // for when we pass it on to moment's constructor
				isAmbigTime = true;
				isAmbigZone = true;
			}
			else if ((ambigMatch = ambigTimeOrZoneRegex.exec(input))) {
				isAmbigTime = !ambigMatch[5]; // no time part?
				isAmbigZone = true;
			}
		}
		else if ($.isArray(input)) {
			// arrays have no timezone information, so assume ambiguous zone
			isAmbigZone = true;
		}
		// otherwise, probably a string with a format

		if (parseAsUTC || isAmbigTime) {
			mom = moment.utc.apply(moment, args);
		}
		else {
			mom = moment.apply(null, args);
		}

		if (isAmbigTime) {
			mom._ambigTime = true;
			mom._ambigZone = true; // ambiguous time always means ambiguous zone
		}
		else if (parseZone) { // let's record the inputted zone somehow
			if (isAmbigZone) {
				mom._ambigZone = true;
			}
			else if (isSingleString) {
				mom.zone(input); // if not a valid zone, will assign UTC
			}
		}
	}

	mom._fullCalendar = true; // flag for extended functionality

	return mom;
}


// A clone method that works with the flags related to our enhanced functionality.
// In the future, use moment.momentProperties
newMomentProto.clone = function() {
	var mom = oldMomentProto.clone.apply(this, arguments);

	// these flags weren't transfered with the clone
	transferAmbigs(this, mom);
	if (this._fullCalendar) {
		mom._fullCalendar = true;
	}

	return mom;
};


// Time-of-day
// -------------------------------------------------------------------------------------------------

// GETTER
// Returns a Duration with the hours/minutes/seconds/ms values of the moment.
// If the moment has an ambiguous time, a duration of 00:00 will be returned.
//
// SETTER
// You can supply a Duration, a Moment, or a Duration-like argument.
// When setting the time, and the moment has an ambiguous time, it then becomes unambiguous.
newMomentProto.time = function(time) {

	// Fallback to the original method (if there is one) if this moment wasn't created via FullCalendar.
	// `time` is a generic enough method name where this precaution is necessary to avoid collisions w/ other plugins.
	if (!this._fullCalendar) {
		return oldMomentProto.time.apply(this, arguments);
	}

	if (time == null) { // getter
		return moment.duration({
			hours: this.hours(),
			minutes: this.minutes(),
			seconds: this.seconds(),
			milliseconds: this.milliseconds()
		});
	}
	else { // setter

		this._ambigTime = false; // mark that the moment now has a time

		if (!moment.isDuration(time) && !moment.isMoment(time)) {
			time = moment.duration(time);
		}

		// The day value should cause overflow (so 24 hours becomes 00:00:00 of next day).
		// Only for Duration times, not Moment times.
		var dayHours = 0;
		if (moment.isDuration(time)) {
			dayHours = Math.floor(time.asDays()) * 24;
		}

		// We need to set the individual fields.
		// Can't use startOf('day') then add duration. In case of DST at start of day.
		return this.hours(dayHours + time.hours())
			.minutes(time.minutes())
			.seconds(time.seconds())
			.milliseconds(time.milliseconds());
	}
};

// Converts the moment to UTC, stripping out its time-of-day and timezone offset,
// but preserving its YMD. A moment with a stripped time will display no time
// nor timezone offset when .format() is called.
newMomentProto.stripTime = function() {
	var a;

	if (!this._ambigTime) {

		// get the values before any conversion happens
		a = this.toArray(); // array of y/m/d/h/m/s/ms

		this.utc(); // set the internal UTC flag (will clear the ambig flags)
		setUTCValues(this, a.slice(0, 3)); // set the year/month/date. time will be zero

		// Mark the time as ambiguous. This needs to happen after the .utc() call, which calls .zone(),
		// which clears all ambig flags. Same with setUTCValues with moment-timezone.
		this._ambigTime = true;
		this._ambigZone = true; // if ambiguous time, also ambiguous timezone offset
	}

	return this; // for chaining
};

// Returns if the moment has a non-ambiguous time (boolean)
newMomentProto.hasTime = function() {
	return !this._ambigTime;
};


// Timezone
// -------------------------------------------------------------------------------------------------

// Converts the moment to UTC, stripping out its timezone offset, but preserving its
// YMD and time-of-day. A moment with a stripped timezone offset will display no
// timezone offset when .format() is called.
newMomentProto.stripZone = function() {
	var a, wasAmbigTime;

	if (!this._ambigZone) {

		// get the values before any conversion happens
		a = this.toArray(); // array of y/m/d/h/m/s/ms
		wasAmbigTime = this._ambigTime;

		this.utc(); // set the internal UTC flag (will clear the ambig flags)
		setUTCValues(this, a); // will set the year/month/date/hours/minutes/seconds/ms

		if (wasAmbigTime) {
			// the above call to .utc()/.zone() unfortunately clears the ambig flags, so reassign
			this._ambigTime = true;
		}

		// Mark the zone as ambiguous. This needs to happen after the .utc() call, which calls .zone(),
		// which clears all ambig flags. Same with setUTCValues with moment-timezone.
		this._ambigZone = true;
	}

	return this; // for chaining
};

// Returns of the moment has a non-ambiguous timezone offset (boolean)
newMomentProto.hasZone = function() {
	return !this._ambigZone;
};

// this method implicitly marks a zone (will get called upon .utc() and .local())
newMomentProto.zone = function(tzo) {

	if (tzo != null) { // setter
		// these assignments needs to happen before the original zone method is called.
		// I forget why, something to do with a browser crash.
		this._ambigTime = false;
		this._ambigZone = false;
	}

	return oldMomentProto.zone.apply(this, arguments);
};

// this method implicitly marks a zone
newMomentProto.local = function() {
	var a = this.toArray(); // year,month,date,hours,minutes,seconds,ms as an array
	var wasAmbigZone = this._ambigZone;

	oldMomentProto.local.apply(this, arguments); // will clear ambig flags

	if (wasAmbigZone) {
		// If the moment was ambiguously zoned, the date fields were stored as UTC.
		// We want to preserve these, but in local time.
		setLocalValues(this, a);
	}

	return this; // for chaining
};


// Formatting
// -------------------------------------------------------------------------------------------------

newMomentProto.format = function() {
	if (this._fullCalendar && arguments[0]) { // an enhanced moment? and a format string provided?
		return formatDate(this, arguments[0]); // our extended formatting
	}
	if (this._ambigTime) {
		return oldMomentFormat(this, 'YYYY-MM-DD');
	}
	if (this._ambigZone) {
		return oldMomentFormat(this, 'YYYY-MM-DD[T]HH:mm:ss');
	}
	return oldMomentProto.format.apply(this, arguments);
};

newMomentProto.toISOString = function() {
	if (this._ambigTime) {
		return oldMomentFormat(this, 'YYYY-MM-DD');
	}
	if (this._ambigZone) {
		return oldMomentFormat(this, 'YYYY-MM-DD[T]HH:mm:ss');
	}
	return oldMomentProto.toISOString.apply(this, arguments);
};


// Querying
// -------------------------------------------------------------------------------------------------

// Is the moment within the specified range? `end` is exclusive.
// FYI, this method is not a standard Moment method, so always do our enhanced logic.
newMomentProto.isWithin = function(start, end) {
	var a = commonlyAmbiguate([ this, start, end ]);
	return a[0] >= a[1] && a[0] < a[2];
};

// When isSame is called with units, timezone ambiguity is normalized before the comparison happens.
// If no units specified, the two moments must be identically the same, with matching ambig flags.
newMomentProto.isSame = function(input, units) {
	var a;

	// only do custom logic if this is an enhanced moment
	if (!this._fullCalendar) {
		return oldMomentProto.isSame.apply(this, arguments);
	}

	if (units) {
		a = commonlyAmbiguate([ this, input ], true); // normalize timezones but don't erase times
		return oldMomentProto.isSame.call(a[0], a[1], units);
	}
	else {
		input = fc.moment.parseZone(input); // normalize input
		return oldMomentProto.isSame.call(this, input) &&
			Boolean(this._ambigTime) === Boolean(input._ambigTime) &&
			Boolean(this._ambigZone) === Boolean(input._ambigZone);
	}
};

// Make these query methods work with ambiguous moments
$.each([
	'isBefore',
	'isAfter'
], function(i, methodName) {
	newMomentProto[methodName] = function(input, units) {
		var a;

		// only do custom logic if this is an enhanced moment
		if (!this._fullCalendar) {
			return oldMomentProto[methodName].apply(this, arguments);
		}

		a = commonlyAmbiguate([ this, input ]);
		return oldMomentProto[methodName].call(a[0], a[1], units);
	};
});


// Misc Internals
// -------------------------------------------------------------------------------------------------

// given an array of moment-like inputs, return a parallel array w/ moments similarly ambiguated.
// for example, of one moment has ambig time, but not others, all moments will have their time stripped.
// set `preserveTime` to `true` to keep times, but only normalize zone ambiguity.
// returns the original moments if no modifications are necessary.
function commonlyAmbiguate(inputs, preserveTime) {
	var anyAmbigTime = false;
	var anyAmbigZone = false;
	var len = inputs.length;
	var moms = [];
	var i, mom;

	// parse inputs into real moments and query their ambig flags
	for (i = 0; i < len; i++) {
		mom = inputs[i];
		if (!moment.isMoment(mom)) {
			mom = fc.moment.parseZone(mom);
		}
		anyAmbigTime = anyAmbigTime || mom._ambigTime;
		anyAmbigZone = anyAmbigZone || mom._ambigZone;
		moms.push(mom);
	}

	// strip each moment down to lowest common ambiguity
	// use clones to avoid modifying the original moments
	for (i = 0; i < len; i++) {
		mom = moms[i];
		if (!preserveTime && anyAmbigTime && !mom._ambigTime) {
			moms[i] = mom.clone().stripTime();
		}
		else if (anyAmbigZone && !mom._ambigZone) {
			moms[i] = mom.clone().stripZone();
		}
	}

	return moms;
}

// Transfers all the flags related to ambiguous time/zone from the `src` moment to the `dest` moment
function transferAmbigs(src, dest) {
	if (src._ambigTime) {
		dest._ambigTime = true;
	}
	else if (dest._ambigTime) {
		dest._ambigTime = false;
	}

	if (src._ambigZone) {
		dest._ambigZone = true;
	}
	else if (dest._ambigZone) {
		dest._ambigZone = false;
	}
}


// Sets the year/month/date/etc values of the moment from the given array.
// Inefficient because it calls each individual setter.
function setMomentValues(mom, a) {
	mom.year(a[0] || 0)
		.month(a[1] || 0)
		.date(a[2] || 0)
		.hours(a[3] || 0)
		.minutes(a[4] || 0)
		.seconds(a[5] || 0)
		.milliseconds(a[6] || 0);
}

// Can we set the moment's internal date directly?
allowValueOptimization = '_d' in moment() && 'updateOffset' in moment;

// Utility function. Accepts a moment and an array of the UTC year/month/date/etc values to set.
// Assumes the given moment is already in UTC mode.
setUTCValues = allowValueOptimization ? function(mom, a) {
	// simlate what moment's accessors do
	mom._d.setTime(Date.UTC.apply(Date, a));
	moment.updateOffset(mom, false); // keepTime=false
} : setMomentValues;

// Utility function. Accepts a moment and an array of the local year/month/date/etc values to set.
// Assumes the given moment is already in local mode.
setLocalValues = allowValueOptimization ? function(mom, a) {
	// simlate what moment's accessors do
	mom._d.setTime(+new Date( // FYI, there is now way to apply an array of args to a constructor
		a[0] || 0,
		a[1] || 0,
		a[2] || 0,
		a[3] || 0,
		a[4] || 0,
		a[5] || 0,
		a[6] || 0
	));
	moment.updateOffset(mom, false); // keepTime=false
} : setMomentValues;

// Single Date Formatting
// -------------------------------------------------------------------------------------------------


// call this if you want Moment's original format method to be used
function oldMomentFormat(mom, formatStr) {
	return oldMomentProto.format.call(mom, formatStr); // oldMomentProto defined in moment-ext.js
}


// Formats `date` with a Moment formatting string, but allow our non-zero areas and
// additional token.
function formatDate(date, formatStr) {
	return formatDateWithChunks(date, getFormatStringChunks(formatStr));
}


function formatDateWithChunks(date, chunks) {
	var s = '';
	var i;

	for (i=0; i<chunks.length; i++) {
		s += formatDateWithChunk(date, chunks[i]);
	}

	return s;
}


// addition formatting tokens we want recognized
var tokenOverrides = {
	t: function(date) { // "a" or "p"
		return oldMomentFormat(date, 'a').charAt(0);
	},
	T: function(date) { // "A" or "P"
		return oldMomentFormat(date, 'A').charAt(0);
	}
};


function formatDateWithChunk(date, chunk) {
	var token;
	var maybeStr;

	if (typeof chunk === 'string') { // a literal string
		return chunk;
	}
	else if ((token = chunk.token)) { // a token, like "YYYY"
		if (tokenOverrides[token]) {
			return tokenOverrides[token](date); // use our custom token
		}
		return oldMomentFormat(date, token);
	}
	else if (chunk.maybe) { // a grouping of other chunks that must be non-zero
		maybeStr = formatDateWithChunks(date, chunk.maybe);
		if (maybeStr.match(/[1-9]/)) {
			return maybeStr;
		}
	}

	return '';
}


// Date Range Formatting
// -------------------------------------------------------------------------------------------------
// TODO: make it work with timezone offset

// Using a formatting string meant for a single date, generate a range string, like
// "Sep 2 - 9 2013", that intelligently inserts a separator where the dates differ.
// If the dates are the same as far as the format string is concerned, just return a single
// rendering of one date, without any separator.
function formatRange(date1, date2, formatStr, separator, isRTL) {
	var localeData;

	date1 = fc.moment.parseZone(date1);
	date2 = fc.moment.parseZone(date2);

	localeData = (date1.localeData || date1.lang).call(date1); // works with moment-pre-2.8

	// Expand localized format strings, like "LL" -> "MMMM D YYYY"
	formatStr = localeData.longDateFormat(formatStr) || formatStr;
	// BTW, this is not important for `formatDate` because it is impossible to put custom tokens
	// or non-zero areas in Moment's localized format strings.

	separator = separator || ' - ';

	return formatRangeWithChunks(
		date1,
		date2,
		getFormatStringChunks(formatStr),
		separator,
		isRTL
	);
}
fc.formatRange = formatRange; // expose


function formatRangeWithChunks(date1, date2, chunks, separator, isRTL) {
	var chunkStr; // the rendering of the chunk
	var leftI;
	var leftStr = '';
	var rightI;
	var rightStr = '';
	var middleI;
	var middleStr1 = '';
	var middleStr2 = '';
	var middleStr = '';

	// Start at the leftmost side of the formatting string and continue until you hit a token
	// that is not the same between dates.
	for (leftI=0; leftI<chunks.length; leftI++) {
		chunkStr = formatSimilarChunk(date1, date2, chunks[leftI]);
		if (chunkStr === false) {
			break;
		}
		leftStr += chunkStr;
	}

	// Similarly, start at the rightmost side of the formatting string and move left
	for (rightI=chunks.length-1; rightI>leftI; rightI--) {
		chunkStr = formatSimilarChunk(date1, date2, chunks[rightI]);
		if (chunkStr === false) {
			break;
		}
		rightStr = chunkStr + rightStr;
	}

	// The area in the middle is different for both of the dates.
	// Collect them distinctly so we can jam them together later.
	for (middleI=leftI; middleI<=rightI; middleI++) {
		middleStr1 += formatDateWithChunk(date1, chunks[middleI]);
		middleStr2 += formatDateWithChunk(date2, chunks[middleI]);
	}

	if (middleStr1 || middleStr2) {
		if (isRTL) {
			middleStr = middleStr2 + separator + middleStr1;
		}
		else {
			middleStr = middleStr1 + separator + middleStr2;
		}
	}

	return leftStr + middleStr + rightStr;
}


var similarUnitMap = {
	Y: 'year',
	M: 'month',
	D: 'day', // day of month
	d: 'day', // day of week
	// prevents a separator between anything time-related...
	A: 'second', // AM/PM
	a: 'second', // am/pm
	T: 'second', // A/P
	t: 'second', // a/p
	H: 'second', // hour (24)
	h: 'second', // hour (12)
	m: 'second', // minute
	s: 'second' // second
};
// TODO: week maybe?


// Given a formatting chunk, and given that both dates are similar in the regard the
// formatting chunk is concerned, format date1 against `chunk`. Otherwise, return `false`.
function formatSimilarChunk(date1, date2, chunk) {
	var token;
	var unit;

	if (typeof chunk === 'string') { // a literal string
		return chunk;
	}
	else if ((token = chunk.token)) {
		unit = similarUnitMap[token.charAt(0)];
		// are the dates the same for this unit of measurement?
		if (unit && date1.isSame(date2, unit)) {
			return oldMomentFormat(date1, token); // would be the same if we used `date2`
			// BTW, don't support custom tokens
		}
	}

	return false; // the chunk is NOT the same for the two dates
	// BTW, don't support splitting on non-zero areas
}


// Chunking Utils
// -------------------------------------------------------------------------------------------------


var formatStringChunkCache = {};


function getFormatStringChunks(formatStr) {
	if (formatStr in formatStringChunkCache) {
		return formatStringChunkCache[formatStr];
	}
	return (formatStringChunkCache[formatStr] = chunkFormatString(formatStr));
}


// Break the formatting string into an array of chunks
function chunkFormatString(formatStr) {
	var chunks = [];
	var chunker = /\[([^\]]*)\]|\(([^\)]*)\)|(LT|(\w)\4*o?)|([^\w\[\(]+)/g; // TODO: more descrimination
	var match;

	while ((match = chunker.exec(formatStr))) {
		if (match[1]) { // a literal string inside [ ... ]
			chunks.push(match[1]);
		}
		else if (match[2]) { // non-zero formatting inside ( ... )
			chunks.push({ maybe: chunkFormatString(match[2]) });
		}
		else if (match[3]) { // a formatting token
			chunks.push({ token: match[3] });
		}
		else if (match[5]) { // an unenclosed literal string
			chunks.push(match[5]);
		}
	}

	return chunks;
}

    fc.Class = Class; // export

// class that all other classes will inherit from
function Class() { }

// called upon a class to create a subclass
Class.extend = function(members) {
	var superClass = this;
	var subClass;

	members = members || {};

	// ensure a constructor for the subclass, forwarding all arguments to the super-constructor if it doesn't exist
	if (hasOwnProp(members, 'constructor')) {
		subClass = members.constructor;
	}
	if (typeof subClass !== 'function') {
		subClass = members.constructor = function() {
			superClass.apply(this, arguments);
		};
	}

	// build the base prototype for the subclass, which is an new object chained to the superclass's prototype
	subClass.prototype = createObject(superClass.prototype);

	// copy each member variable/method onto the the subclass's prototype
	copyOwnProps(members, subClass.prototype);

	// copy over all class variables/methods to the subclass, such as `extend` and `mixin`
	copyOwnProps(superClass, subClass);

	return subClass;
};

// adds new member variables/methods to the class's prototype.
// can be called with another class, or a plain object hash containing new members.
Class.mixin = function(members) {
	copyOwnProps(members.prototype || members, this.prototype);
};
    /* A rectangular panel that is absolutely positioned over other content
------------------------------------------------------------------------------------------------------------------------
Options:
	- className (string)
	- content (HTML string or jQuery element set)
	- parentEl
	- top
	- left
	- right (the x coord of where the right edge should be. not a "CSS" right)
	- autoHide (boolean)
	- show (callback)
	- hide (callback)
*/

var Popover = Class.extend({

	isHidden: true,
	options: null,
	el: null, // the container element for the popover. generated by this object
	documentMousedownProxy: null, // document mousedown handler bound to `this`
	margin: 10, // the space required between the popover and the edges of the scroll container


	constructor: function(options) {
		this.options = options || {};
	},


	// Shows the popover on the specified position. Renders it if not already
	show: function() {
		if (this.isHidden) {
			if (!this.el) {
				this.render();
			}
			this.el.show();
			this.position();
			this.isHidden = false;
			this.trigger('show');
		}
	},


	// Hides the popover, through CSS, but does not remove it from the DOM
	hide: function() {
		if (!this.isHidden) {
			this.el.hide();
			this.isHidden = true;
			this.trigger('hide');
		}
	},


	// Creates `this.el` and renders content inside of it
	render: function() {
		var _this = this;
		var options = this.options;

		this.el = $('<div class="fc-popover"/>')
			.addClass(options.className || '')
			.css({
				// position initially to the top left to avoid creating scrollbars
				top: 0,
				left: 0
			})
			.append(options.content)
			.appendTo(options.parentEl);

		// when a click happens on anything inside with a 'fc-close' className, hide the popover
		this.el.on('click', '.fc-close', function() {
			_this.hide();
		});

		if (options.autoHide) {
			$(document).on('mousedown', this.documentMousedownProxy = $.proxy(this, 'documentMousedown'));
		}
	},


	// Triggered when the user clicks *anywhere* in the document, for the autoHide feature
	documentMousedown: function(ev) {
		// only hide the popover if the click happened outside the popover
		if (this.el && !$(ev.target).closest(this.el).length) {
			this.hide();
		}
	},


	// Hides and unregisters any handlers
	destroy: function() {
		this.hide();

		if (this.el) {
			this.el.remove();
			this.el = null;
		}

		$(document).off('mousedown', this.documentMousedownProxy);
	},


	// Positions the popover optimally, using the top/left/right options
	position: function() {
		var options = this.options;
		var origin = this.el.offsetParent().offset();
		var width = this.el.outerWidth();
		var height = this.el.outerHeight();
		var windowEl = $(window);
		var viewportEl = getScrollParent(this.el);
		var viewportTop;
		var viewportLeft;
		var viewportOffset;
		var top; // the "position" (not "offset") values for the popover
		var left; //

		// compute top and left
		top = options.top || 0;
		if (options.left !== undefined) {
			left = options.left;
		}
		else if (options.right !== undefined) {
			left = options.right - width; // derive the left value from the right value
		}
		else {
			left = 0;
		}

		if (viewportEl.is(window) || viewportEl.is(document)) { // normalize getScrollParent's result
			viewportEl = windowEl;
			viewportTop = 0; // the window is always at the top left
			viewportLeft = 0; // (and .offset() won't work if called here)
		}
		else {
			viewportOffset = viewportEl.offset();
			viewportTop = viewportOffset.top;
			viewportLeft = viewportOffset.left;
		}

		// if the window is scrolled, it causes the visible area to be further down
		viewportTop += windowEl.scrollTop();
		viewportLeft += windowEl.scrollLeft();

		// constrain to the view port. if constrained by two edges, give precedence to top/left
		if (options.viewportConstrain !== false) {
			top = Math.min(top, viewportTop + viewportEl.outerHeight() - height - this.margin);
			top = Math.max(top, viewportTop + this.margin);
			left = Math.min(left, viewportLeft + viewportEl.outerWidth() - width - this.margin);
			left = Math.max(left, viewportLeft + this.margin);
		}

		this.el.css({
			top: top - origin.top,
			left: left - origin.left
		});
	},


	// Triggers a callback. Calls a function in the option hash of the same name.
	// Arguments beyond the first `name` are forwarded on.
	// TODO: better code reuse for this. Repeat code
	trigger: function(name) {
		if (this.options[name]) {
			this.options[name].apply(this, Array.prototype.slice.call(arguments, 1));
		}
	}

});

    /* A "coordinate map" converts pixel coordinates into an associated cell, which has an associated date
------------------------------------------------------------------------------------------------------------------------
Common interface:

	CoordMap.prototype = {
		build: function() {},
		getCell: function(x, y) {}
	};

*/

/* Coordinate map for a grid component
----------------------------------------------------------------------------------------------------------------------*/

var GridCoordMap = Class.extend({

	grid: null, // reference to the Grid
	rowCoords: null, // array of {top,bottom} objects
	colCoords: null, // array of {left,right} objects

	containerEl: null, // container element that all coordinates are constrained to. optionally assigned
	minX: null,
	maxX: null, // exclusive
	minY: null,
	maxY: null, // exclusive


	constructor: function(grid) {
		this.grid = grid;
	},


	// Queries the grid for the coordinates of all the cells
	build: function() {
		this.rowCoords = this.grid.computeRowCoords();
		this.colCoords = this.grid.computeColCoords();
		this.computeBounds();
	},


	// Clears the coordinates data to free up memory
	clear: function() {
		this.rowCoords = null;
		this.colCoords = null;
	},


	// Given a coordinate of the document, gets the associated cell. If no cell is underneath, returns null
	getCell: function(x, y) {
		var rowCoords = this.rowCoords;
		var colCoords = this.colCoords;
		var hitRow = null;
		var hitCol = null;
		var i, coords;
		var cell;

		if (this.inBounds(x, y)) {

			for (i = 0; i < rowCoords.length; i++) {
				coords = rowCoords[i];
				if (y >= coords.top && y < coords.bottom) {
					hitRow = i;
					break;
				}
			}

			for (i = 0; i < colCoords.length; i++) {
				coords = colCoords[i];
				if (x >= coords.left && x < coords.right) {
					hitCol = i;
					break;
				}
			}

			if (hitRow !== null && hitCol !== null) {
				cell = this.grid.getCell(hitRow, hitCol);
				cell.grid = this.grid; // for DragListener's isCellsEqual. dragging between grids
				return cell;
			}
		}

		return null;
	},


	// If there is a containerEl, compute the bounds into min/max values
	computeBounds: function() {
		var containerOffset;

		if (this.containerEl) {
			containerOffset = this.containerEl.offset();
			this.minX = containerOffset.left;
			this.maxX = containerOffset.left + this.containerEl.outerWidth();
			this.minY = containerOffset.top;
			this.maxY = containerOffset.top + this.containerEl.outerHeight();
		}
	},


	// Determines if the given coordinates are in bounds. If no `containerEl`, always true
	inBounds: function(x, y) {
		if (this.containerEl) {
			return x >= this.minX && x < this.maxX && y >= this.minY && y < this.maxY;
		}
		return true;
	}

});


/* Coordinate map that is a combination of multiple other coordinate maps
----------------------------------------------------------------------------------------------------------------------*/

var ComboCoordMap = Class.extend({

	coordMaps: null, // an array of CoordMaps


	constructor: function(coordMaps) {
		this.coordMaps = coordMaps;
	},


	// Builds all coordMaps
	build: function() {
		var coordMaps = this.coordMaps;
		var i;

		for (i = 0; i < coordMaps.length; i++) {
			coordMaps[i].build();
		}
	},


	// Queries all coordMaps for the cell underneath the given coordinates, returning the first result
	getCell: function(x, y) {
		var coordMaps = this.coordMaps;
		var cell = null;
		var i;

		for (i = 0; i < coordMaps.length && !cell; i++) {
			cell = coordMaps[i].getCell(x, y);
		}

		return cell;
	},


	// Clears all coordMaps
	clear: function() {
		var coordMaps = this.coordMaps;
		var i;

		for (i = 0; i < coordMaps.length; i++) {
			coordMaps[i].clear();
		}
	}

});

    /* Tracks mouse movements over a CoordMap and raises events about which cell the mouse is over.
----------------------------------------------------------------------------------------------------------------------*/
// TODO: very useful to have a handler that gets called upon cellOut OR when dragging stops (for cleanup)

var DragListener = Class.extend({

	coordMap: null,
	options: null,

	isListening: false,
	isDragging: false,

	// the cell the mouse was over when listening started
	origCell: null,

	// the cell the mouse is over
	cell: null,

	// coordinates of the initial mousedown
	mouseX0: null,
	mouseY0: null,

	// handler attached to the document, bound to the DragListener's `this`
	mousemoveProxy: null,
	mouseupProxy: null,

	scrollEl: null,
	scrollBounds: null, // { top, bottom, left, right }
	scrollTopVel: null, // pixels per second
	scrollLeftVel: null, // pixels per second
	scrollIntervalId: null, // ID of setTimeout for scrolling animation loop
	scrollHandlerProxy: null, // this-scoped function for handling when scrollEl is scrolled

	scrollSensitivity: 30, // pixels from edge for scrolling to start
	scrollSpeed: 200, // pixels per second, at maximum speed
	scrollIntervalMs: 50, // millisecond wait between scroll increment


	constructor: function(coordMap, options) {
		this.coordMap = coordMap;
		this.options = options || {};
	},


	// Call this when the user does a mousedown. Will probably lead to startListening
	mousedown: function(ev) {
		if (isPrimaryMouseButton(ev)) {

			ev.preventDefault(); // prevents native selection in most browsers

			this.startListening(ev);

			// start the drag immediately if there is no minimum distance for a drag start
			if (!this.options.distance) {
				this.startDrag(ev);
			}
		}
	},


	// Call this to start tracking mouse movements
	startListening: function(ev) {
		var scrollParent;
		var cell;

		if (!this.isListening) {

			// grab scroll container and attach handler
			if (ev && this.options.scroll) {
				scrollParent = getScrollParent($(ev.target));
				if (!scrollParent.is(window) && !scrollParent.is(document)) {
					this.scrollEl = scrollParent;

					// scope to `this`, and use `debounce` to make sure rapid calls don't happen
					this.scrollHandlerProxy = debounce($.proxy(this, 'scrollHandler'), 100);
					this.scrollEl.on('scroll', this.scrollHandlerProxy);
				}
			}

			this.computeCoords(); // relies on `scrollEl`

			// get info on the initial cell and its coordinates
			if (ev) {
				cell = this.getCell(ev);
				this.origCell = cell;

				this.mouseX0 = ev.pageX;
				this.mouseY0 = ev.pageY;
			}

			$(document)
				.on('mousemove', this.mousemoveProxy = $.proxy(this, 'mousemove'))
				.on('mouseup', this.mouseupProxy = $.proxy(this, 'mouseup'))
				.on('selectstart', this.preventDefault); // prevents native selection in IE<=8

			this.isListening = true;
			this.trigger('listenStart', ev);
		}
	},


	// Recomputes the drag-critical positions of elements
	computeCoords: function() {
		this.coordMap.build();
		this.computeScrollBounds();
	},


	// Called when the user moves the mouse
	mousemove: function(ev) {
		var minDistance;
		var distanceSq; // current distance from mouseX0/mouseY0, squared

		if (!this.isDragging) { // if not already dragging...
			// then start the drag if the minimum distance criteria is met
			minDistance = this.options.distance || 1;
			distanceSq = Math.pow(ev.pageX - this.mouseX0, 2) + Math.pow(ev.pageY - this.mouseY0, 2);
			if (distanceSq >= minDistance * minDistance) { // use pythagorean theorem
				this.startDrag(ev);
			}
		}

		if (this.isDragging) {
			this.drag(ev); // report a drag, even if this mousemove initiated the drag
		}
	},


	// Call this to initiate a legitimate drag.
	// This function is called internally from this class, but can also be called explicitly from outside
	startDrag: function(ev) {
		var cell;

		if (!this.isListening) { // startDrag must have manually initiated
			this.startListening();
		}

		if (!this.isDragging) {
			this.isDragging = true;
			this.trigger('dragStart', ev);

			// report the initial cell the mouse is over
			// especially important if no min-distance and drag starts immediately
			cell = this.getCell(ev); // this might be different from this.origCell if the min-distance is large
			if (cell) {
				this.cellOver(cell);
			}
		}
	},


	// Called while the mouse is being moved and when we know a legitimate drag is taking place
	drag: function(ev) {
		var cell;

		if (this.isDragging) {
			cell = this.getCell(ev);

			if (!isCellsEqual(cell, this.cell)) { // a different cell than before?
				if (this.cell) {
					this.cellOut();
				}
				if (cell) {
					this.cellOver(cell);
				}
			}

			this.dragScroll(ev); // will possibly cause scrolling
		}
	},


	// Called when a the mouse has just moved over a new cell
	cellOver: function(cell) {
		this.cell = cell;
		this.trigger('cellOver', cell, isCellsEqual(cell, this.origCell));
	},


	// Called when the mouse has just moved out of a cell
	cellOut: function() {
		if (this.cell) {
			this.trigger('cellOut', this.cell);
			this.cell = null;
		}
	},


	// Called when the user does a mouseup
	mouseup: function(ev) {
		this.stopDrag(ev);
		this.stopListening(ev);
	},


	// Called when the drag is over. Will not cause listening to stop however.
	// A concluding 'cellOut' event will NOT be triggered.
	stopDrag: function(ev) {
		if (this.isDragging) {
			this.stopScrolling();
			this.trigger('dragStop', ev);
			this.isDragging = false;
		}
	},


	// Call this to stop listening to the user's mouse events
	stopListening: function(ev) {
		if (this.isListening) {

			// remove the scroll handler if there is a scrollEl
			if (this.scrollEl) {
				this.scrollEl.off('scroll', this.scrollHandlerProxy);
				this.scrollHandlerProxy = null;
			}

			$(document)
				.off('mousemove', this.mousemoveProxy)
				.off('mouseup', this.mouseupProxy)
				.off('selectstart', this.preventDefault);

			this.mousemoveProxy = null;
			this.mouseupProxy = null;

			this.isListening = false;
			this.trigger('listenStop', ev);

			this.origCell = this.cell = null;
			this.coordMap.clear();
		}
	},


	// Gets the cell underneath the coordinates for the given mouse event
	getCell: function(ev) {
		return this.coordMap.getCell(ev.pageX, ev.pageY);
	},


	// Triggers a callback. Calls a function in the option hash of the same name.
	// Arguments beyond the first `name` are forwarded on.
	trigger: function(name) {
		if (this.options[name]) {
			this.options[name].apply(this, Array.prototype.slice.call(arguments, 1));
		}
	},


	// Stops a given mouse event from doing it's native browser action. In our case, text selection.
	preventDefault: function(ev) {
		ev.preventDefault();
	},


	/* Scrolling
	------------------------------------------------------------------------------------------------------------------*/


	// Computes and stores the bounding rectangle of scrollEl
	computeScrollBounds: function() {
		var el = this.scrollEl;
		var offset;

		if (el) {
			offset = el.offset();
			this.scrollBounds = {
				top: offset.top,
				left: offset.left,
				bottom: offset.top + el.outerHeight(),
				right: offset.left + el.outerWidth()
			};
		}
	},


	// Called when the dragging is in progress and scrolling should be updated
	dragScroll: function(ev) {
		var sensitivity = this.scrollSensitivity;
		var bounds = this.scrollBounds;
		var topCloseness, bottomCloseness;
		var leftCloseness, rightCloseness;
		var topVel = 0;
		var leftVel = 0;

		if (bounds) { // only scroll if scrollEl exists

			// compute closeness to edges. valid range is from 0.0 - 1.0
			topCloseness = (sensitivity - (ev.pageY - bounds.top)) / sensitivity;
			bottomCloseness = (sensitivity - (bounds.bottom - ev.pageY)) / sensitivity;
			leftCloseness = (sensitivity - (ev.pageX - bounds.left)) / sensitivity;
			rightCloseness = (sensitivity - (bounds.right - ev.pageX)) / sensitivity;

			// translate vertical closeness into velocity.
			// mouse must be completely in bounds for velocity to happen.
			if (topCloseness >= 0 && topCloseness <= 1) {
				topVel = topCloseness * this.scrollSpeed * -1; // negative. for scrolling up
			}
			else if (bottomCloseness >= 0 && bottomCloseness <= 1) {
				topVel = bottomCloseness * this.scrollSpeed;
			}

			// translate horizontal closeness into velocity
			if (leftCloseness >= 0 && leftCloseness <= 1) {
				leftVel = leftCloseness * this.scrollSpeed * -1; // negative. for scrolling left
			}
			else if (rightCloseness >= 0 && rightCloseness <= 1) {
				leftVel = rightCloseness * this.scrollSpeed;
			}
		}

		this.setScrollVel(topVel, leftVel);
	},


	// Sets the speed-of-scrolling for the scrollEl
	setScrollVel: function(topVel, leftVel) {

		this.scrollTopVel = topVel;
		this.scrollLeftVel = leftVel;

		this.constrainScrollVel(); // massages into realistic values

		// if there is non-zero velocity, and an animation loop hasn't already started, then START
		if ((this.scrollTopVel || this.scrollLeftVel) && !this.scrollIntervalId) {
			this.scrollIntervalId = setInterval(
				$.proxy(this, 'scrollIntervalFunc'), // scope to `this`
				this.scrollIntervalMs
			);
		}
	},


	// Forces scrollTopVel and scrollLeftVel to be zero if scrolling has already gone all the way
	constrainScrollVel: function() {
		var el = this.scrollEl;

		if (this.scrollTopVel < 0) { // scrolling up?
			if (el.scrollTop() <= 0) { // already scrolled all the way up?
				this.scrollTopVel = 0;
			}
		}
		else if (this.scrollTopVel > 0) { // scrolling down?
			if (el.scrollTop() + el[0].clientHeight >= el[0].scrollHeight) { // already scrolled all the way down?
				this.scrollTopVel = 0;
			}
		}

		if (this.scrollLeftVel < 0) { // scrolling left?
			if (el.scrollLeft() <= 0) { // already scrolled all the left?
				this.scrollLeftVel = 0;
			}
		}
		else if (this.scrollLeftVel > 0) { // scrolling right?
			if (el.scrollLeft() + el[0].clientWidth >= el[0].scrollWidth) { // already scrolled all the way right?
				this.scrollLeftVel = 0;
			}
		}
	},


	// This function gets called during every iteration of the scrolling animation loop
	scrollIntervalFunc: function() {
		var el = this.scrollEl;
		var frac = this.scrollIntervalMs / 1000; // considering animation frequency, what the vel should be mult'd by

		// change the value of scrollEl's scroll
		if (this.scrollTopVel) {
			el.scrollTop(el.scrollTop() + this.scrollTopVel * frac);
		}
		if (this.scrollLeftVel) {
			el.scrollLeft(el.scrollLeft() + this.scrollLeftVel * frac);
		}

		this.constrainScrollVel(); // since the scroll values changed, recompute the velocities

		// if scrolled all the way, which causes the vels to be zero, stop the animation loop
		if (!this.scrollTopVel && !this.scrollLeftVel) {
			this.stopScrolling();
		}
	},


	// Kills any existing scrolling animation loop
	stopScrolling: function() {
		if (this.scrollIntervalId) {
			clearInterval(this.scrollIntervalId);
			this.scrollIntervalId = null;

			// when all done with scrolling, recompute positions since they probably changed
			this.computeCoords();
		}
	},


	// Get called when the scrollEl is scrolled (NOTE: this is delayed via debounce)
	scrollHandler: function() {
		// recompute all coordinates, but *only* if this is *not* part of our scrolling animation
		if (!this.scrollIntervalId) {
			this.computeCoords();
		}
	}

});


// Returns `true` if the cells are identically equal. `false` otherwise.
// They must have the same row, col, and be from the same grid.
// Two null values will be considered equal, as two "out of the grid" states are the same.
function isCellsEqual(cell1, cell2) {

	if (!cell1 && !cell2) {
		return true;
	}

	if (cell1 && cell2) {
		return cell1.grid === cell2.grid &&
			cell1.row === cell2.row &&
			cell1.col === cell2.col;
	}

	return false;
}

    /* Creates a clone of an element and lets it track the mouse as it moves
----------------------------------------------------------------------------------------------------------------------*/

var MouseFollower = Class.extend({

	options: null,

	sourceEl: null, // the element that will be cloned and made to look like it is dragging
	el: null, // the clone of `sourceEl` that will track the mouse
	parentEl: null, // the element that `el` (the clone) will be attached to

	// the initial position of el, relative to the offset parent. made to match the initial offset of sourceEl
	top0: null,
	left0: null,

	// the initial position of the mouse
	mouseY0: null,
	mouseX0: null,

	// the number of pixels the mouse has moved from its initial position
	topDelta: null,
	leftDelta: null,

	mousemoveProxy: null, // document mousemove handler, bound to the MouseFollower's `this`

	isFollowing: false,
	isHidden: false,
	isAnimating: false, // doing the revert animation?

	constructor: function(sourceEl, options) {
		this.options = options = options || {};
		this.sourceEl = sourceEl;
		this.parentEl = options.parentEl ? $(options.parentEl) : sourceEl.parent(); // default to sourceEl's parent
	},


	// Causes the element to start following the mouse
	start: function(ev) {
		if (!this.isFollowing) {
			this.isFollowing = true;

			this.mouseY0 = ev.pageY;
			this.mouseX0 = ev.pageX;
			this.topDelta = 0;
			this.leftDelta = 0;

			if (!this.isHidden) {
				this.updatePosition();
			}

			$(document).on('mousemove', this.mousemoveProxy = $.proxy(this, 'mousemove'));
		}
	},


	// Causes the element to stop following the mouse. If shouldRevert is true, will animate back to original position.
	// `callback` gets invoked when the animation is complete. If no animation, it is invoked immediately.
	stop: function(shouldRevert, callback) {
		var _this = this;
		var revertDuration = this.options.revertDuration;

		function complete() {
			this.isAnimating = false;
			_this.destroyEl();

			this.top0 = this.left0 = null; // reset state for future updatePosition calls

			if (callback) {
				callback();
			}
		}

		if (this.isFollowing && !this.isAnimating) { // disallow more than one stop animation at a time
			this.isFollowing = false;

			$(document).off('mousemove', this.mousemoveProxy);

			if (shouldRevert && revertDuration && !this.isHidden) { // do a revert animation?
				this.isAnimating = true;
				this.el.animate({
					top: this.top0,
					left: this.left0
				}, {
					duration: revertDuration,
					complete: complete
				});
			}
			else {
				complete();
			}
		}
	},


	// Gets the tracking element. Create it if necessary
	getEl: function() {
		var el = this.el;

		if (!el) {
			this.sourceEl.width(); // hack to force IE8 to compute correct bounding box
			el = this.el = this.sourceEl.clone()
				.css({
					position: 'absolute',
					visibility: '', // in case original element was hidden (commonly through hideEvents())
					display: this.isHidden ? 'none' : '', // for when initially hidden
					margin: 0,
					right: 'auto', // erase and set width instead
					bottom: 'auto', // erase and set height instead
					width: this.sourceEl.width(), // explicit height in case there was a 'right' value
					height: this.sourceEl.height(), // explicit width in case there was a 'bottom' value
					opacity: this.options.opacity || '',
					zIndex: this.options.zIndex
				})
				.appendTo(this.parentEl);
		}

		return el;
	},


	// Removes the tracking element if it has already been created
	destroyEl: function() {
		if (this.el) {
			this.el.remove();
			this.el = null;
		}
	},


	// Update the CSS position of the tracking element
	updatePosition: function() {
		var sourceOffset;
		var origin;

		this.getEl(); // ensure this.el

		// make sure origin info was computed
		if (this.top0 === null) {
			this.sourceEl.width(); // hack to force IE8 to compute correct bounding box
			sourceOffset = this.sourceEl.offset();
			origin = this.el.offsetParent().offset();
			this.top0 = sourceOffset.top - origin.top;
			this.left0 = sourceOffset.left - origin.left;
		}

		this.el.css({
			top: this.top0 + this.topDelta,
			left: this.left0 + this.leftDelta
		});
	},


	// Gets called when the user moves the mouse
	mousemove: function(ev) {
		this.topDelta = ev.pageY - this.mouseY0;
		this.leftDelta = ev.pageX - this.mouseX0;

		if (!this.isHidden) {
			this.updatePosition();
		}
	},


	// Temporarily makes the tracking element invisible. Can be called before following starts
	hide: function() {
		if (!this.isHidden) {
			this.isHidden = true;
			if (this.el) {
				this.el.hide();
			}
		}
	},


	// Show the tracking element after it has been temporarily hidden
	show: function() {
		if (this.isHidden) {
			this.isHidden = false;
			this.updatePosition();
			this.getEl().show();
		}
	}

});

    /* A utility class for rendering <tr> rows.
----------------------------------------------------------------------------------------------------------------------*/
// It leverages methods of the subclass and the View to determine custom rendering behavior for each row "type"
// (such as highlight rows, day rows, helper rows, etc).

var RowRenderer = Class.extend({

	view: null, // a View object
	isRTL: null, // shortcut to the view's isRTL option
	cellHtml: '<td/>', // plain default HTML used for a cell when no other is available


	constructor: function(view) {
		this.view = view;
		this.isRTL = view.opt('isRTL');
	},


	// Renders the HTML for a row, leveraging custom cell-HTML-renderers based on the `rowType`.
	// Also applies the "intro" and "outro" cells, which are specified by the subclass and views.
	// `row` is an optional row number.
	rowHtml: function(rowType, row) {
		var renderCell = this.getHtmlRenderer('cell', rowType);
		var rowCellHtml = '';
		var col;
		var cell;

		row = row || 0;

		for (col = 0; col < this.colCnt; col++) {
			cell = this.getCell(row, col);
			rowCellHtml += renderCell(cell);
		}

		rowCellHtml = this.bookendCells(rowCellHtml, rowType, row); // apply intro and outro

		return '<tr>' + rowCellHtml + '</tr>';
	},


	// Applies the "intro" and "outro" HTML to the given cells.
	// Intro means the leftmost cell when the calendar is LTR and the rightmost cell when RTL. Vice-versa for outro.
	// `cells` can be an HTML string of <td>'s or a jQuery <tr> element
	// `row` is an optional row number.
	bookendCells: function(cells, rowType, row) {
		var intro = this.getHtmlRenderer('intro', rowType)(row || 0);
		var outro = this.getHtmlRenderer('outro', rowType)(row || 0);
		var prependHtml = this.isRTL ? outro : intro;
		var appendHtml = this.isRTL ? intro : outro;

		if (typeof cells === 'string') {
			return prependHtml + cells + appendHtml;
		}
		else { // a jQuery <tr> element
			return cells.prepend(prependHtml).append(appendHtml);
		}
	},


	// Returns an HTML-rendering function given a specific `rendererName` (like cell, intro, or outro) and a specific
	// `rowType` (like day, eventSkeleton, helperSkeleton), which is optional.
	// If a renderer for the specific rowType doesn't exist, it will fall back to a generic renderer.
	// We will query the View object first for any custom rendering functions, then the methods of the subclass.
	getHtmlRenderer: function(rendererName, rowType) {
		var view = this.view;
		var generalName; // like "cellHtml"
		var specificName; // like "dayCellHtml". based on rowType
		var provider; // either the View or the RowRenderer subclass, whichever provided the method
		var renderer;

		generalName = rendererName + 'Html';
		if (rowType) {
			specificName = rowType + capitaliseFirstLetter(rendererName) + 'Html';
		}

		if (specificName && (renderer = view[specificName])) {
			provider = view;
		}
		else if (specificName && (renderer = this[specificName])) {
			provider = this;
		}
		else if ((renderer = view[generalName])) {
			provider = view;
		}
		else if ((renderer = this[generalName])) {
			provider = this;
		}

		if (typeof renderer === 'function') {
			return function() {
				return renderer.apply(provider, arguments) || ''; // use correct `this` and always return a string
			};
		}

		// the rendered can be a plain string as well. if not specified, always an empty string.
		return function() {
			return renderer || '';
		};
	}

});

    /* An abstract class comprised of a "grid" of cells that each represent a specific datetime
----------------------------------------------------------------------------------------------------------------------*/

var Grid = fc.Grid = RowRenderer.extend({

	start: null, // the date of the first cell
	end: null, // the date after the last cell

	rowCnt: 0, // number of rows
	colCnt: 0, // number of cols
	rowData: null, // array of objects, holding misc data for each row
	colData: null, // array of objects, holding misc data for each column

	el: null, // the containing element
	coordMap: null, // a GridCoordMap that converts pixel values to datetimes
	elsByFill: null, // a hash of jQuery element sets used for rendering each fill. Keyed by fill name.

	documentDragStartProxy: null, // binds the Grid's scope to documentDragStart (in DayGrid.events)

	// derived from options
	colHeadFormat: null, // TODO: move to another class. not applicable to all Grids
	eventTimeFormat: null,
	displayEventEnd: null,


	constructor: function() {
		RowRenderer.apply(this, arguments); // call the super-constructor

		this.coordMap = new GridCoordMap(this);
		this.elsByFill = {};
		this.documentDragStartProxy = $.proxy(this, 'documentDragStart');
	},


	// Renders the grid into the `el` element.
	// Subclasses should override and call this super-method when done.
	render: function() {
		this.bindHandlers();
	},


	// Called when the grid's resources need to be cleaned up
	destroy: function() {
		this.unbindHandlers();
	},


	/* Options
	------------------------------------------------------------------------------------------------------------------*/


	// Generates the format string used for the text in column headers, if not explicitly defined by 'columnFormat'
	// TODO: move to another class. not applicable to all Grids
	computeColHeadFormat: function() {
		// subclasses must implement if they want to use headHtml()
	},


	// Generates the format string used for event time text, if not explicitly defined by 'timeFormat'
	computeEventTimeFormat: function() {
		return this.view.opt('smallTimeFormat');
	},


	// Determines whether events should have their end times displayed, if not explicitly defined by 'displayEventEnd'
	computeDisplayEventEnd: function() {
		return false;
	},


	/* Dates
	------------------------------------------------------------------------------------------------------------------*/


	// Tells the grid about what period of time to display. Grid will subsequently compute dates for cell system.
	setRange: function(range) {
		var view = this.view;

		this.start = range.start.clone();
		this.end = range.end.clone();

		this.rowData = [];
		this.colData = [];
		this.updateCells();

		// Populate option-derived settings. Look for override first, then compute if necessary.
		this.colHeadFormat = view.opt('columnFormat') || this.computeColHeadFormat();
		this.eventTimeFormat = view.opt('timeFormat') || this.computeEventTimeFormat();
		this.displayEventEnd = view.opt('displayEventEnd');
		if (this.displayEventEnd == null) {
			this.displayEventEnd = this.computeDisplayEventEnd();
		}
	},


	// Responsible for setting rowCnt/colCnt and any other row/col data
	updateCells: function() {
		// subclasses must implement
	},


	// Converts a range with an inclusive `start` and an exclusive `end` into an array of segment objects
	rangeToSegs: function(range) {
		// subclasses must implement
	},


	/* Cells
	------------------------------------------------------------------------------------------------------------------*/
	// NOTE: columns are ordered left-to-right


	// Gets an object containing row/col number, misc data, and range information about the cell.
	// Accepts row/col values, an object with row/col properties, or a single-number offset from the first cell.
	getCell: function(row, col) {
		var cell;

		if (col == null) {
			if (typeof row === 'number') { // a single-number offset
				col = row % this.colCnt;
				row = Math.floor(row / this.colCnt);
			}
			else { // an object with row/col properties
				col = row.col;
				row = row.row;
			}
		}

		cell = { row: row, col: col };

		$.extend(cell, this.getRowData(row), this.getColData(col));
		$.extend(cell, this.computeCellRange(cell));

		return cell;
	},


	// Given a cell object with index and misc data, generates a range object
	computeCellRange: function(cell) {
		// subclasses must implement
	},


	// Retrieves misc data about the given row
	getRowData: function(row) {
		return this.rowData[row] || {};
	},


	// Retrieves misc data baout the given column
	getColData: function(col) {
		return this.colData[col] || {};
	},


	// Retrieves the element representing the given row
	getRowEl: function(row) {
		// subclasses should implement if leveraging the default getCellDayEl() or computeRowCoords()
	},


	// Retrieves the element representing the given column
	getColEl: function(col) {
		// subclasses should implement if leveraging the default getCellDayEl() or computeColCoords()
	},


	// Given a cell object, returns the element that represents the cell's whole-day
	getCellDayEl: function(cell) {
		return this.getColEl(cell.col) || this.getRowEl(cell.row);
	},


	/* Cell Coordinates
	------------------------------------------------------------------------------------------------------------------*/


	// Computes the top/bottom coordinates of all rows.
	// By default, queries the dimensions of the element provided by getRowEl().
	computeRowCoords: function() {
		var items = [];
		var i, el;
		var item;

		for (i = 0; i < this.rowCnt; i++) {
			el = this.getRowEl(i);
			item = {
				top: el.offset().top
			};
			if (i > 0) {
				items[i - 1].bottom = item.top;
			}
			items.push(item);
		}
		item.bottom = item.top + el.outerHeight();

		return items;
	},


	// Computes the left/right coordinates of all rows.
	// By default, queries the dimensions of the element provided by getColEl().
	computeColCoords: function() {
		var items = [];
		var i, el;
		var item;

		for (i = 0; i < this.colCnt; i++) {
			el = this.getColEl(i);
			item = {
				left: el.offset().left
			};
			if (i > 0) {
				items[i - 1].right = item.left;
			}
			items.push(item);
		}
		item.right = item.left + el.outerWidth();

		return items;
	},


	/* Handlers
	------------------------------------------------------------------------------------------------------------------*/


	// Attaches handlers to DOM
	bindHandlers: function() {
		var _this = this;

		// attach a handler to the grid's root element.
		// we don't need to clean up in unbindHandlers or destroy, because when jQuery removes the element from the
		// DOM it automatically unregisters the handlers.
		this.el.on('mousedown', function(ev) {
			if (
				!$(ev.target).is('.fc-event-container *, .fc-more') && // not an an event element, or "more.." link
				!$(ev.target).closest('.fc-popover').length // not on a popover (like the "more.." events one)
			) {
				_this.dayMousedown(ev);
			}
		});

		// attach event-element-related handlers. in Grid.events
		// same garbage collection note as above.
		this.bindSegHandlers();

		$(document).on('dragstart', this.documentDragStartProxy); // jqui drag
	},


	// Unattaches handlers from the DOM
	unbindHandlers: function() {
		$(document).off('dragstart', this.documentDragStartProxy); // jqui drag
	},


	// Process a mousedown on an element that represents a day. For day clicking and selecting.
	dayMousedown: function(ev) {
		var _this = this;
		var view = this.view;
		var isSelectable = view.opt('selectable');
		var dayClickCell; // null if invalid dayClick
		var selectionRange; // null if invalid selection

		// this listener tracks a mousedown on a day element, and a subsequent drag.
		// if the drag ends on the same day, it is a 'dayClick'.
		// if 'selectable' is enabled, this listener also detects selections.
		var dragListener = new DragListener(this.coordMap, {
			//distance: 5, // needs more work if we want dayClick to fire correctly
			scroll: view.opt('dragScroll'),
			dragStart: function() {
				view.unselect(); // since we could be rendering a new selection, we want to clear any old one
			},
			cellOver: function(cell, isOrig) {
				var origCell = dragListener.origCell;
				if (origCell) { // click needs to have started on a cell
					dayClickCell = isOrig ? cell : null; // single-cell selection is a day click
					if (isSelectable) {
						selectionRange = _this.computeSelection(origCell, cell);
						if (selectionRange) {
							_this.renderSelection(selectionRange);
						}
						else {
							disableCursor();
						}
					}
				}
			},
			cellOut: function(cell) {
				dayClickCell = null;
				selectionRange = null;
				_this.destroySelection();
				enableCursor();
			},
			listenStop: function(ev) {
				if (dayClickCell) {
					view.trigger('dayClick', _this.getCellDayEl(dayClickCell), dayClickCell.start, ev);
				}
				if (selectionRange) {
					// the selection will already have been rendered. just report it
					view.reportSelection(selectionRange, ev);
				}
				enableCursor();
			}
		});

		dragListener.mousedown(ev); // start listening, which will eventually initiate a dragStart
	},


	/* Event Helper
	------------------------------------------------------------------------------------------------------------------*/
	// TODO: should probably move this to Grid.events, like we did event dragging / resizing


	// Renders a mock event over the given range.
	// The range's end can be null, in which case the mock event that is rendered will have a null end time.
	// `sourceSeg` is the internal segment object involved in the drag. If null, something external is dragging.
	renderRangeHelper: function(range, sourceSeg) {
		var fakeEvent;

		fakeEvent = sourceSeg ? createObject(sourceSeg.event) : {}; // mask the original event object if possible
		fakeEvent.start = range.start.clone();
		fakeEvent.end = range.end ? range.end.clone() : null;
		fakeEvent.allDay = null; // force it to be freshly computed by normalizeEventDateProps
		this.view.calendar.normalizeEventDateProps(fakeEvent);

		// this extra className will be useful for differentiating real events from mock events in CSS
		fakeEvent.className = (fakeEvent.className || []).concat('fc-helper');

		// if something external is being dragged in, don't render a resizer
		if (!sourceSeg) {
			fakeEvent.editable = false;
		}

		this.renderHelper(fakeEvent, sourceSeg); // do the actual rendering
	},


	// Renders a mock event
	renderHelper: function(event, sourceSeg) {
		// subclasses must implement
	},


	// Unrenders a mock event
	destroyHelper: function() {
		// subclasses must implement
	},


	/* Selection
	------------------------------------------------------------------------------------------------------------------*/


	// Renders a visual indication of a selection. Will highlight by default but can be overridden by subclasses.
	renderSelection: function(range) {
		this.renderHighlight(range);
	},


	// Unrenders any visual indications of a selection. Will unrender a highlight by default.
	destroySelection: function() {
		this.destroyHighlight();
	},


	// Given the first and last cells of a selection, returns a range object.
	// Will return something falsy if the selection is invalid (when outside of selectionConstraint for example).
	// Subclasses can override and provide additional data in the range object. Will be passed to renderSelection().
	computeSelection: function(firstCell, lastCell) {
		var dates = [
			firstCell.start,
			firstCell.end,
			lastCell.start,
			lastCell.end
		];
		var range;

		dates.sort(compareNumbers); // sorts chronologically. works with Moments

		range = {
			start: dates[0].clone(),
			end: dates[3].clone()
		};

		if (!this.view.calendar.isSelectionRangeAllowed(range)) {
			return null;
		}

		return range;
	},


	/* Highlight
	------------------------------------------------------------------------------------------------------------------*/


	// Renders an emphasis on the given date range. `start` is inclusive. `end` is exclusive.
	renderHighlight: function(range) {
		this.renderFill('highlight', this.rangeToSegs(range));
	},


	// Unrenders the emphasis on a date range
	destroyHighlight: function() {
		this.destroyFill('highlight');
	},


	// Generates an array of classNames for rendering the highlight. Used by the fill system.
	highlightSegClasses: function() {
		return [ 'fc-highlight' ];
	},


	/* Fill System (highlight, background events, business hours)
	------------------------------------------------------------------------------------------------------------------*/


	// Renders a set of rectangles over the given segments of time.
	// Returns a subset of segs, the segs that were actually rendered.
	// Responsible for populating this.elsByFill. TODO: better API for expressing this requirement
	renderFill: function(type, segs) {
		// subclasses must implement
	},


	// Unrenders a specific type of fill that is currently rendered on the grid
	destroyFill: function(type) {
		var el = this.elsByFill[type];

		if (el) {
			el.remove();
			delete this.elsByFill[type];
		}
	},


	// Renders and assigns an `el` property for each fill segment. Generic enough to work with different types.
	// Only returns segments that successfully rendered.
	// To be harnessed by renderFill (implemented by subclasses).
	// Analagous to renderFgSegEls.
	renderFillSegEls: function(type, segs) {
		var _this = this;
		var segElMethod = this[type + 'SegEl'];
		var html = '';
		var renderedSegs = [];
		var i;

		if (segs.length) {

			// build a large concatenation of segment HTML
			for (i = 0; i < segs.length; i++) {
				html += this.fillSegHtml(type, segs[i]);
			}

			// Grab individual elements from the combined HTML string. Use each as the default rendering.
			// Then, compute the 'el' for each segment.
			$(html).each(function(i, node) {
				var seg = segs[i];
				var el = $(node);

				// allow custom filter methods per-type
				if (segElMethod) {
					el = segElMethod.call(_this, seg, el);
				}

				if (el) { // custom filters did not cancel the render
					el = $(el); // allow custom filter to return raw DOM node

					// correct element type? (would be bad if a non-TD were inserted into a table for example)
					if (el.is(_this.fillSegTag)) {
						seg.el = el;
						renderedSegs.push(seg);
					}
				}
			});
		}

		return renderedSegs;
	},


	fillSegTag: 'div', // subclasses can override


	// Builds the HTML needed for one fill segment. Generic enought o work with different types.
	fillSegHtml: function(type, seg) {
		var classesMethod = this[type + 'SegClasses']; // custom hooks per-type
		var stylesMethod = this[type + 'SegStyles']; //
		var classes = classesMethod ? classesMethod.call(this, seg) : [];
		var styles = stylesMethod ? stylesMethod.call(this, seg) : ''; // a semi-colon separated CSS property string

		return '<' + this.fillSegTag +
			(classes.length ? ' class="' + classes.join(' ') + '"' : '') +
			(styles ? ' style="' + styles + '"' : '') +
			' />';
	},


	/* Generic rendering utilities for subclasses
	------------------------------------------------------------------------------------------------------------------*/


	// Renders a day-of-week header row.
	// TODO: move to another class. not applicable to all Grids
	headHtml: function() {
		return '' +
			'<div class="fc-row ' + this.view.widgetHeaderClass + '">' +
				'<table>' +
					'<thead>' +
						this.rowHtml('head') + // leverages RowRenderer
					'</thead>' +
				'</table>' +
			'</div>';
	},


	// Used by the `headHtml` method, via RowRenderer, for rendering the HTML of a day-of-week header cell
	// TODO: move to another class. not applicable to all Grids
	headCellHtml: function(cell) {
		var view = this.view;
		var date = cell.start;

		return '' +
			'<th class="fc-day-header ' + view.widgetHeaderClass + ' fc-' + dayIDs[date.day()] + '">' +
				htmlEscape(date.format(this.colHeadFormat)) +
			'</th>';
	},


	// Renders the HTML for a single-day background cell
	bgCellHtml: function(cell) {
		var view = this.view;
		var date = cell.start;
		var classes = this.getDayClasses(date);

		classes.unshift('fc-day', view.widgetContentClass);

		return '<td class="' + classes.join(' ') + '"' +
			' data-date="' + date.format('YYYY-MM-DD') + '"' + // if date has a time, won't format it
			'></td>';
	},


	// Computes HTML classNames for a single-day cell
	getDayClasses: function(date) {
		var view = this.view;
		var today = view.calendar.getNow().stripTime();
		var classes = [ 'fc-' + dayIDs[date.day()] ];

		if (
			view.name === 'month' &&
			date.month() != view.intervalStart.month()
		) {
			classes.push('fc-other-month');
		}

		if (date.isSame(today, 'day')) {
			classes.push(
				'fc-today',
				view.highlightStateClass
			);
		}
		else if (date < today) {
			classes.push('fc-past');
		}
		else {
			classes.push('fc-future');
		}

		return classes;
	}

});

    /* Event-rendering and event-interaction methods for the abstract Grid class
----------------------------------------------------------------------------------------------------------------------*/

Grid.mixin({

	mousedOverSeg: null, // the segment object the user's mouse is over. null if over nothing
	isDraggingSeg: false, // is a segment being dragged? boolean
	isResizingSeg: false, // is a segment being resized? boolean
	segs: null, // the event segments currently rendered in the grid


	// Renders the given events onto the grid
	renderEvents: function(events) {
		var segs = this.eventsToSegs(events);
		var bgSegs = [];
		var fgSegs = [];
		var i, seg;

		for (i = 0; i < segs.length; i++) {
			seg = segs[i];

			if (isBgEvent(seg.event)) {
				bgSegs.push(seg);
			}
			else {
				fgSegs.push(seg);
			}
		}

		// Render each different type of segment.
		// Each function may return a subset of the segs, segs that were actually rendered.
		bgSegs = this.renderBgSegs(bgSegs) || bgSegs;
		fgSegs = this.renderFgSegs(fgSegs) || fgSegs;

		this.segs = bgSegs.concat(fgSegs);
	},


	// Unrenders all events currently rendered on the grid
	destroyEvents: function() {
		this.triggerSegMouseout(); // trigger an eventMouseout if user's mouse is over an event

		this.destroyFgSegs();
		this.destroyBgSegs();

		this.segs = null;
	},


	// Retrieves all rendered segment objects currently rendered on the grid
	getEventSegs: function() {
		return this.segs || [];
	},


	/* Foreground Segment Rendering
	------------------------------------------------------------------------------------------------------------------*/


	// Renders foreground event segments onto the grid. May return a subset of segs that were rendered.
	renderFgSegs: function(segs) {
		// subclasses must implement
	},


	// Unrenders all currently rendered foreground segments
	destroyFgSegs: function() {
		// subclasses must implement
	},


	// Renders and assigns an `el` property for each foreground event segment.
	// Only returns segments that successfully rendered.
	// A utility that subclasses may use.
	renderFgSegEls: function(segs, disableResizing) {
		var view = this.view;
		var html = '';
		var renderedSegs = [];
		var i;

		if (segs.length) { // don't build an empty html string

			// build a large concatenation of event segment HTML
			for (i = 0; i < segs.length; i++) {
				html += this.fgSegHtml(segs[i], disableResizing);
			}

			// Grab individual elements from the combined HTML string. Use each as the default rendering.
			// Then, compute the 'el' for each segment. An el might be null if the eventRender callback returned false.
			$(html).each(function(i, node) {
				var seg = segs[i];
				var el = view.resolveEventEl(seg.event, $(node));

				if (el) {
					el.data('fc-seg', seg); // used by handlers
					seg.el = el;
					renderedSegs.push(seg);
				}
			});
		}

		return renderedSegs;
	},


	// Generates the HTML for the default rendering of a foreground event segment. Used by renderFgSegEls()
	fgSegHtml: function(seg, disableResizing) {
		// subclasses should implement
	},


	/* Background Segment Rendering
	------------------------------------------------------------------------------------------------------------------*/


	// Renders the given background event segments onto the grid.
	// Returns a subset of the segs that were actually rendered.
	renderBgSegs: function(segs) {
		return this.renderFill('bgEvent', segs);
	},


	// Unrenders all the currently rendered background event segments
	destroyBgSegs: function() {
		this.destroyFill('bgEvent');
	},


	// Renders a background event element, given the default rendering. Called by the fill system.
	bgEventSegEl: function(seg, el) {
		return this.view.resolveEventEl(seg.event, el); // will filter through eventRender
	},


	// Generates an array of classNames to be used for the default rendering of a background event.
	// Called by the fill system.
	bgEventSegClasses: function(seg) {
		var event = seg.event;
		var source = event.source || {};

		return [ 'fc-bgevent' ].concat(
			event.className,
			source.className || []
		);
	},


	// Generates a semicolon-separated CSS string to be used for the default rendering of a background event.
	// Called by the fill system.
	// TODO: consolidate with getEventSkinCss?
	bgEventSegStyles: function(seg) {
		var view = this.view;
		var event = seg.event;
		var source = event.source || {};
		var eventColor = event.color;
		var sourceColor = source.color;
		var optionColor = view.opt('eventColor');
		var backgroundColor =
			event.backgroundColor ||
			eventColor ||
			source.backgroundColor ||
			sourceColor ||
			view.opt('eventBackgroundColor') ||
			optionColor;

		if (backgroundColor) {
			return 'background-color:' + backgroundColor;
		}

		return '';
	},


	// Generates an array of classNames to be used for the rendering business hours overlay. Called by the fill system.
	businessHoursSegClasses: function(seg) {
		return [ 'fc-nonbusiness', 'fc-bgevent' ];
	},


	/* Handlers
	------------------------------------------------------------------------------------------------------------------*/


	// Attaches event-element-related handlers to the container element and leverage bubbling
	bindSegHandlers: function() {
		var _this = this;
		var view = this.view;

		$.each(
			{
				mouseenter: function(seg, ev) {
					_this.triggerSegMouseover(seg, ev);
				},
				mouseleave: function(seg, ev) {
					_this.triggerSegMouseout(seg, ev);
				},
				click: function(seg, ev) {
					return view.trigger('eventClick', this, seg.event, ev); // can return `false` to cancel
				},
				mousedown: function(seg, ev) {
					if ($(ev.target).is('.fc-resizer') && view.isEventResizable(seg.event)) {
						_this.segResizeMousedown(seg, ev);
					}
					else if (view.isEventDraggable(seg.event)) {
						_this.segDragMousedown(seg, ev);
					}
				}
			},
			function(name, func) {
				// attach the handler to the container element and only listen for real event elements via bubbling
				_this.el.on(name, '.fc-event-container > *', function(ev) {
					var seg = $(this).data('fc-seg'); // grab segment data. put there by View::renderEvents

					// only call the handlers if there is not a drag/resize in progress
					if (seg && !_this.isDraggingSeg && !_this.isResizingSeg) {
						return func.call(this, seg, ev); // `this` will be the event element
					}
				});
			}
		);
	},


	// Updates internal state and triggers handlers for when an event element is moused over
	triggerSegMouseover: function(seg, ev) {
		if (!this.mousedOverSeg) {
			this.mousedOverSeg = seg;
			this.view.trigger('eventMouseover', seg.el[0], seg.event, ev);
		}
	},


	// Updates internal state and triggers handlers for when an event element is moused out.
	// Can be given no arguments, in which case it will mouseout the segment that was previously moused over.
	triggerSegMouseout: function(seg, ev) {
		ev = ev || {}; // if given no args, make a mock mouse event

		if (this.mousedOverSeg) {
			seg = seg || this.mousedOverSeg; // if given no args, use the currently moused-over segment
			this.mousedOverSeg = null;
			this.view.trigger('eventMouseout', seg.el[0], seg.event, ev);
		}
	},


	/* Event Dragging
	------------------------------------------------------------------------------------------------------------------*/


	// Called when the user does a mousedown on an event, which might lead to dragging.
	// Generic enough to work with any type of Grid.
	segDragMousedown: function(seg, ev) {
		var _this = this;
		var view = this.view;
		var el = seg.el;
		var event = seg.event;
		var dropLocation;

		// A clone of the original element that will move with the mouse
		var mouseFollower = new MouseFollower(seg.el, {
			parentEl: view.el,
			opacity: view.opt('dragOpacity'),
			revertDuration: view.opt('dragRevertDuration'),
			zIndex: 2 // one above the .fc-view
		});

		// Tracks mouse movement over the *view's* coordinate map. Allows dragging and dropping between subcomponents
		// of the view.
		var dragListener = new DragListener(view.coordMap, {
			distance: 5,
			scroll: view.opt('dragScroll'),
			listenStart: function(ev) {
				mouseFollower.hide(); // don't show until we know this is a real drag
				mouseFollower.start(ev);
			},
			dragStart: function(ev) {
				_this.triggerSegMouseout(seg, ev); // ensure a mouseout on the manipulated event has been reported
				_this.isDraggingSeg = true;
				view.hideEvent(event); // hide all event segments. our mouseFollower will take over
				view.trigger('eventDragStart', el[0], event, ev, {}); // last argument is jqui dummy
			},
			cellOver: function(cell, isOrig) {
				var origCell = seg.cell || dragListener.origCell; // starting cell could be forced (DayGrid.limit)

				dropLocation = _this.computeEventDrop(origCell, cell, event);
				if (dropLocation) {
					if (view.renderDrag(dropLocation, seg)) { // have the subclass render a visual indication
						mouseFollower.hide(); // if the subclass is already using a mock event "helper", hide our own
					}
					else {
						mouseFollower.show();
					}
					if (isOrig) {
						dropLocation = null; // needs to have moved cells to be a valid drop
					}
				}
				else {
					// have the helper follow the mouse (no snapping) with a warning-style cursor
					mouseFollower.show();
					disableCursor();
				}
			},
			cellOut: function() { // called before mouse moves to a different cell OR moved out of all cells
				dropLocation = null;
				view.destroyDrag(); // unrender whatever was done in renderDrag
				mouseFollower.show(); // show in case we are moving out of all cells
				enableCursor();
			},
			dragStop: function(ev) {
				// do revert animation if hasn't changed. calls a callback when finished (whether animation or not)
				mouseFollower.stop(!dropLocation, function() {
					_this.isDraggingSeg = false;
					view.destroyDrag();
					view.showEvent(event);
					view.trigger('eventDragStop', el[0], event, ev, {}); // last argument is jqui dummy

					if (dropLocation) {
						view.reportEventDrop(event, dropLocation, el, ev);
					}
				});
				enableCursor();
			},
			listenStop: function() {
				mouseFollower.stop(); // put in listenStop in case there was a mousedown but the drag never started
			}
		});

		dragListener.mousedown(ev); // start listening, which will eventually lead to a dragStart
	},


	// Given the cell an event drag began, and the cell event was dropped, calculates the new start/end/allDay
	// values for the event. Subclasses may override and set additional properties to be used by renderDrag.
	// A falsy returned value indicates an invalid drop.
	computeEventDrop: function(startCell, endCell, event) {
		var dragStart = startCell.start;
		var dragEnd = endCell.start;
		var delta;
		var newStart;
		var newEnd;
		var newAllDay;
		var dropLocation;

		if (dragStart.hasTime() === dragEnd.hasTime()) {
			delta = diffDayTime(dragEnd, dragStart);
			newStart = event.start.clone().add(delta);
			if (event.end === null) { // do we need to compute an end?
				newEnd = null;
			}
			else {
				newEnd = event.end.clone().add(delta);
			}
			newAllDay = event.allDay; // keep it the same
		}
		else {
			// if switching from day <-> timed, start should be reset to the dropped date, and the end cleared
			newStart = dragEnd.clone();
			newEnd = null; // end should be cleared
			newAllDay = !dragEnd.hasTime();
		}

		dropLocation = {
			start: newStart,
			end: newEnd,
			allDay: newAllDay
		};

		if (!this.view.calendar.isEventRangeAllowed(dropLocation, event)) {
			return null;
		}

		return dropLocation;
	},


	/* External Element Dragging
	------------------------------------------------------------------------------------------------------------------*/


	// Called when a jQuery UI drag is initiated anywhere in the DOM
	documentDragStart: function(ev, ui) {
		var view = this.view;
		var el;
		var accept;

		if (view.opt('droppable')) { // only listen if this setting is on
			el = $(ev.target);

			// Test that the dragged element passes the dropAccept selector or filter function.
			// FYI, the default is "*" (matches all)
			accept = view.opt('dropAccept');
			if ($.isFunction(accept) ? accept.call(el[0], el) : el.is(accept)) {

				this.startExternalDrag(el, ev, ui);
			}
		}
	},


	// Called when a jQuery UI drag starts and it needs to be monitored for cell dropping
	startExternalDrag: function(el, ev, ui) {
		var _this = this;
		var meta = getDraggedElMeta(el); // extra data about event drop, including possible event to create
		var dragListener;
		var dropLocation; // a null value signals an unsuccessful drag

		// listener that tracks mouse movement over date-associated pixel regions
		dragListener = new DragListener(this.coordMap, {
			cellOver: function(cell) {
				dropLocation = _this.computeExternalDrop(cell, meta);
				if (dropLocation) {
					_this.renderDrag(dropLocation); // called without a seg parameter
				}
				else { // invalid drop cell
					disableCursor();
				}
			},
			cellOut: function() {
				dropLocation = null; // signal unsuccessful
				_this.destroyDrag();
				enableCursor();
			}
		});

		// gets called, only once, when jqui drag is finished
		$(document).one('dragstop', function(ev, ui) {
			_this.destroyDrag();
			enableCursor();

			if (dropLocation) { // element was dropped on a valid date/time cell
				_this.view.reportExternalDrop(meta, dropLocation, el, ev, ui);
			}
		});

		dragListener.startDrag(ev); // start listening immediately
	},


	// Given a cell to be dropped upon, and misc data associated with the jqui drag (guaranteed to be a plain object),
	// returns start/end dates for the event that would result from the hypothetical drop. end might be null.
	// Returning a null value signals an invalid drop cell.
	computeExternalDrop: function(cell, meta) {
		var dropLocation = {
			start: cell.start.clone(),
			end: null
		};

		// if dropped on an all-day cell, and element's metadata specified a time, set it
		if (meta.startTime && !dropLocation.start.hasTime()) {
			dropLocation.start.time(meta.startTime);
		}

		if (meta.duration) {
			dropLocation.end = dropLocation.start.clone().add(meta.duration);
		}

		if (!this.view.calendar.isExternalDropRangeAllowed(dropLocation, meta.eventProps)) {
			return null;
		}

		return dropLocation;
	},



	/* Drag Rendering (for both events and an external elements)
	------------------------------------------------------------------------------------------------------------------*/


	// Renders a visual indication of an event or external element being dragged.
	// `dropLocation` contains hypothetical start/end/allDay values the event would have if dropped. end can be null.
	// `seg` is the internal segment object that is being dragged. If dragging an external element, `seg` is null.
	// A truthy returned value indicates this method has rendered a helper element.
	renderDrag: function(dropLocation, seg) {
		// subclasses must implement
	},


	// Unrenders a visual indication of an event or external element being dragged
	destroyDrag: function() {
		// subclasses must implement
	},


	/* Resizing
	------------------------------------------------------------------------------------------------------------------*/


	// Called when the user does a mousedown on an event's resizer, which might lead to resizing.
	// Generic enough to work with any type of Grid.
	segResizeMousedown: function(seg, ev) {
		var _this = this;
		var view = this.view;
		var calendar = view.calendar;
		var el = seg.el;
		var event = seg.event;
		var start = event.start;
		var oldEnd = calendar.getEventEnd(event);
		var newEnd; // falsy if invalid resize
		var dragListener;

		function destroy() { // resets the rendering to show the original event
			_this.destroyEventResize();
			view.showEvent(event);
			enableCursor();
		}

		// Tracks mouse movement over the *grid's* coordinate map
		dragListener = new DragListener(this.coordMap, {
			distance: 5,
			scroll: view.opt('dragScroll'),
			dragStart: function(ev) {
				_this.triggerSegMouseout(seg, ev); // ensure a mouseout on the manipulated event has been reported
				_this.isResizingSeg = true;
				view.trigger('eventResizeStart', el[0], event, ev, {}); // last argument is jqui dummy
			},
			cellOver: function(cell) {
				newEnd = cell.end;

				if (!newEnd.isAfter(start)) { // was end moved before start?
					newEnd = start.clone().add( // make the event span a single slot
						diffDayTime(cell.end, cell.start) // assumes all slot durations are the same
					);
				}

				if (newEnd.isSame(oldEnd)) {
					newEnd = null;
				}
				else if (!calendar.isEventRangeAllowed({ start: start, end: newEnd }, event)) {
					newEnd = null;
					disableCursor();
				}
				else {
					_this.renderEventResize({ start: start, end: newEnd }, seg);
					view.hideEvent(event);
				}
			},
			cellOut: function() { // called before mouse moves to a different cell OR moved out of all cells
				newEnd = null;
				destroy();
			},
			dragStop: function(ev) {
				_this.isResizingSeg = false;
				destroy();
				view.trigger('eventResizeStop', el[0], event, ev, {}); // last argument is jqui dummy

				if (newEnd) { // valid date to resize to?
					view.reportEventResize(event, newEnd, el, ev);
				}
			}
		});

		dragListener.mousedown(ev); // start listening, which will eventually lead to a dragStart
	},


	// Renders a visual indication of an event being resized.
	// `range` has the updated dates of the event. `seg` is the original segment object involved in the drag.
	renderEventResize: function(range, seg) {
		// subclasses must implement
	},


	// Unrenders a visual indication of an event being resized.
	destroyEventResize: function() {
		// subclasses must implement
	},


	/* Rendering Utils
	------------------------------------------------------------------------------------------------------------------*/


	// Compute the text that should be displayed on an event's element.
	// `range` can be the Event object itself, or something range-like, with at least a `start`.
	// The `timeFormat` options and the grid's default format is used, but `formatStr` can override.
	getEventTimeText: function(range, formatStr) {

		formatStr = formatStr || this.eventTimeFormat;

		if (range.end && this.displayEventEnd) {
			return this.view.formatRange(range, formatStr);
		}
		else {
			return range.start.format(formatStr);
		}
	},


	// Generic utility for generating the HTML classNames for an event segment's element
	getSegClasses: function(seg, isDraggable, isResizable) {
		var event = seg.event;
		var classes = [
			'fc-event',
			seg.isStart ? 'fc-start' : 'fc-not-start',
			seg.isEnd ? 'fc-end' : 'fc-not-end'
		].concat(
			event.className,
			event.source ? event.source.className : []
		);

		if (isDraggable) {
			classes.push('fc-draggable');
		}
		if (isResizable) {
			classes.push('fc-resizable');
		}

		return classes;
	},


	// Utility for generating a CSS string with all the event skin-related properties
	getEventSkinCss: function(event) {
		var view = this.view;
		var source = event.source || {};
		var eventColor = event.color;
		var sourceColor = source.color;
		var optionColor = view.opt('eventColor');
		var backgroundColor =
			event.backgroundColor ||
			eventColor ||
			source.backgroundColor ||
			sourceColor ||
			view.opt('eventBackgroundColor') ||
			optionColor;
		var borderColor =
			event.borderColor ||
			eventColor ||
			source.borderColor ||
			sourceColor ||
			view.opt('eventBorderColor') ||
			optionColor;
		var textColor =
			event.textColor ||
			source.textColor ||
			view.opt('eventTextColor');
		var statements = [];
		if (backgroundColor) {
			statements.push('background-color:' + backgroundColor);
		}
		if (borderColor) {
			statements.push('border-color:' + borderColor);
		}
		if (textColor) {
			statements.push('color:' + textColor);
		}
		return statements.join(';');
	},


	/* Converting events -> ranges -> segs
	------------------------------------------------------------------------------------------------------------------*/


	// Converts an array of event objects into an array of event segment objects.
	// A custom `rangeToSegsFunc` may be given for arbitrarily slicing up events.
	eventsToSegs: function(events, rangeToSegsFunc) {
		var eventRanges = this.eventsToRanges(events);
		var segs = [];
		var i;

		for (i = 0; i < eventRanges.length; i++) {
			segs.push.apply(
				segs,
				this.eventRangeToSegs(eventRanges[i], rangeToSegsFunc)
			);
		}

		return segs;
	},


	// Converts an array of events into an array of "range" objects.
	// A "range" object is a plain object with start/end properties denoting the time it covers. Also an event property.
	// For "normal" events, this will be identical to the event's start/end, but for "inverse-background" events,
	// will create an array of ranges that span the time *not* covered by the given event.
	eventsToRanges: function(events) {
		var _this = this;
		var eventsById = groupEventsById(events);
		var ranges = [];

		// group by ID so that related inverse-background events can be rendered together
		$.each(eventsById, function(id, eventGroup) {
			if (eventGroup.length) {
				ranges.push.apply(
					ranges,
					isInverseBgEvent(eventGroup[0]) ?
						_this.eventsToInverseRanges(eventGroup) :
						_this.eventsToNormalRanges(eventGroup)
				);
			}
		});

		return ranges;
	},


	// Converts an array of "normal" events (not inverted rendering) into a parallel array of ranges
	eventsToNormalRanges: function(events) {
		var calendar = this.view.calendar;
		var ranges = [];
		var i, event;
		var eventStart, eventEnd;

		for (i = 0; i < events.length; i++) {
			event = events[i];

			// make copies and normalize by stripping timezone
			eventStart = event.start.clone().stripZone();
			eventEnd = calendar.getEventEnd(event).stripZone();

			ranges.push({
				event: event,
				start: eventStart,
				end: eventEnd,
				eventStartMS: +eventStart,
				eventDurationMS: eventEnd - eventStart
			});
		}

		return ranges;
	},


	// Converts an array of events, with inverse-background rendering, into an array of range objects.
	// The range objects will cover all the time NOT covered by the events.
	eventsToInverseRanges: function(events) {
		var view = this.view;
		var viewStart = view.start.clone().stripZone(); // normalize timezone
		var viewEnd = view.end.clone().stripZone(); // normalize timezone
		var normalRanges = this.eventsToNormalRanges(events); // will give us normalized dates we can use w/o copies
		var inverseRanges = [];
		var event0 = events[0]; // assign this to each range's `.event`
		var start = viewStart; // the end of the previous range. the start of the new range
		var i, normalRange;

		// ranges need to be in order. required for our date-walking algorithm
		normalRanges.sort(compareNormalRanges);

		for (i = 0; i < normalRanges.length; i++) {
			normalRange = normalRanges[i];

			// add the span of time before the event (if there is any)
			if (normalRange.start > start) { // compare millisecond time (skip any ambig logic)
				inverseRanges.push({
					event: event0,
					start: start,
					end: normalRange.start
				});
			}

			start = normalRange.end;
		}

		// add the span of time after the last event (if there is any)
		if (start < viewEnd) { // compare millisecond time (skip any ambig logic)
			inverseRanges.push({
				event: event0,
				start: start,
				end: viewEnd
			});
		}

		return inverseRanges;
	},


	// Slices the given event range into one or more segment objects.
	// A `rangeToSegsFunc` custom slicing function can be given.
	eventRangeToSegs: function(eventRange, rangeToSegsFunc) {
		var segs;
		var i, seg;

		if (rangeToSegsFunc) {
			segs = rangeToSegsFunc(eventRange);
		}
		else {
			segs = this.rangeToSegs(eventRange); // defined by the subclass
		}

		for (i = 0; i < segs.length; i++) {
			seg = segs[i];
			seg.event = eventRange.event;
			seg.eventStartMS = eventRange.eventStartMS;
			seg.eventDurationMS = eventRange.eventDurationMS;
		}

		return segs;
	}

});


/* Utilities
----------------------------------------------------------------------------------------------------------------------*/


function isBgEvent(event) { // returns true if background OR inverse-background
	var rendering = getEventRendering(event);
	return rendering === 'background' || rendering === 'inverse-background';
}


function isInverseBgEvent(event) {
	return getEventRendering(event) === 'inverse-background';
}


function getEventRendering(event) {
	return firstDefined((event.source || {}).rendering, event.rendering);
}


function groupEventsById(events) {
	var eventsById = {};
	var i, event;

	for (i = 0; i < events.length; i++) {
		event = events[i];
		(eventsById[event._id] || (eventsById[event._id] = [])).push(event);
	}

	return eventsById;
}


// A cmp function for determining which non-inverted "ranges" (see above) happen earlier
function compareNormalRanges(range1, range2) {
	return range1.eventStartMS - range2.eventStartMS; // earlier ranges go first
}


// A cmp function for determining which segments should take visual priority
// DOES NOT WORK ON INVERTED BACKGROUND EVENTS because they have no eventStartMS/eventDurationMS
function compareSegs(seg1, seg2) {
	return seg1.eventStartMS - seg2.eventStartMS || // earlier events go first
		seg2.eventDurationMS - seg1.eventDurationMS || // tie? longer events go first
		seg2.event.allDay - seg1.event.allDay || // tie? put all-day events first (booleans cast to 0/1)
		(seg1.event.title || '').localeCompare(seg2.event.title); // tie? alphabetically by title
}

fc.compareSegs = compareSegs; // export


/* External-Dragging-Element Data
----------------------------------------------------------------------------------------------------------------------*/

// Require all HTML5 data-* attributes used by FullCalendar to have this prefix.
// A value of '' will query attributes like data-event. A value of 'fc' will query attributes like data-fc-event.
fc.dataAttrPrefix = '';

// Given a jQuery element that might represent a dragged FullCalendar event, returns an intermediate data structure
// to be used for Event Object creation.
// A defined `.eventProps`, even when empty, indicates that an event should be created.
function getDraggedElMeta(el) {
	var prefix = fc.dataAttrPrefix;
	var eventProps; // properties for creating the event, not related to date/time
	var startTime; // a Duration
	var duration;
	var stick;

	if (prefix) { prefix += '-'; }
	eventProps = el.data(prefix + 'event') || null;

	if (eventProps) {
		if (typeof eventProps === 'object') {
			eventProps = $.extend({}, eventProps); // make a copy
		}
		else { // something like 1 or true. still signal event creation
			eventProps = {};
		}

		// pluck special-cased date/time properties
		startTime = eventProps.start;
		if (startTime == null) { startTime = eventProps.time; } // accept 'time' as well
		duration = eventProps.duration;
		stick = eventProps.stick;
		delete eventProps.start;
		delete eventProps.time;
		delete eventProps.duration;
		delete eventProps.stick;
	}

	// fallback to standalone attribute values for each of the date/time properties
	if (startTime == null) { startTime = el.data(prefix + 'start'); }
	if (startTime == null) { startTime = el.data(prefix + 'time'); } // accept 'time' as well
	if (duration == null) { duration = el.data(prefix + 'duration'); }
	if (stick == null) { stick = el.data(prefix + 'stick'); }

	// massage into correct data types
	startTime = startTime != null ? moment.duration(startTime) : null;
	duration = duration != null ? moment.duration(duration) : null;
	stick = Boolean(stick);

	return { eventProps: eventProps, startTime: startTime, duration: duration, stick: stick };
}


    /* A component that renders a grid of whole-days that runs horizontally. There can be multiple rows, one per week.
----------------------------------------------------------------------------------------------------------------------*/

var DayGrid = Grid.extend({

	numbersVisible: false, // should render a row for day/week numbers? set by outside view. TODO: make internal
	bottomCoordPadding: 0, // hack for extending the hit area for the last row of the coordinate grid
	breakOnWeeks: null, // should create a new row for each week? set by outside view

	cellDates: null, // flat chronological array of each cell's dates
	dayToCellOffsets: null, // maps days offsets from grid's start date, to cell offsets

	rowEls: null, // set of fake row elements
	dayEls: null, // set of whole-day elements comprising the row's background
	helperEls: null, // set of cell skeleton elements for rendering the mock event "helper"


	// Renders the rows and columns into the component's `this.el`, which should already be assigned.
	// isRigid determins whether the individual rows should ignore the contents and be a constant height.
	// Relies on the view's colCnt and rowCnt. In the future, this component should probably be self-sufficient.
	render: function(isRigid) {
		var view = this.view;
		var rowCnt = this.rowCnt;
		var colCnt = this.colCnt;
		var cellCnt = rowCnt * colCnt;
		var html = '';
		var row;
		var i, cell;

		for (row = 0; row < rowCnt; row++) {
			html += this.dayRowHtml(row, isRigid);
		}
		this.el.html(html);

		this.rowEls = this.el.find('.fc-row');
		this.dayEls = this.el.find('.fc-day');

		// trigger dayRender with each cell's element
		for (i = 0; i < cellCnt; i++) {
			cell = this.getCell(i);
			view.trigger('dayRender', null, cell.start, this.dayEls.eq(i));
		}

		Grid.prototype.render.call(this); // call the super-method
	},


	destroy: function() {
		this.destroySegPopover();
		Grid.prototype.destroy.call(this); // call the super-method
	},


	// Generates the HTML for a single row. `row` is the row number.
	dayRowHtml: function(row, isRigid) {
		var view = this.view;
		var classes = [ 'fc-row', 'fc-week', view.widgetContentClass ];

		if (isRigid) {
			classes.push('fc-rigid');
		}

		return '' +
			'<div class="' + classes.join(' ') + '">' +
				'<div class="fc-bg">' +
					'<table>' +
						this.rowHtml('day', row) + // leverages RowRenderer. calls dayCellHtml()
					'</table>' +
				'</div>' +
				'<div class="fc-content-skeleton">' +
					'<table>' +
						(this.numbersVisible ?
							'<thead>' +
								this.rowHtml('number', row) + // leverages RowRenderer. View will define render method
							'</thead>' :
							''
							) +
					'</table>' +
				'</div>' +
			'</div>';
	},


	// Renders the HTML for a whole-day cell. Will eventually end up in the day-row's background.
	// We go through a 'day' row type instead of just doing a 'bg' row type so that the View can do custom rendering
	// specifically for whole-day rows, whereas a 'bg' might also be used for other purposes (TimeGrid bg for example).
	dayCellHtml: function(cell) {
		return this.bgCellHtml(cell);
	},


	/* Options
	------------------------------------------------------------------------------------------------------------------*/


	// Computes a default column header formatting string if `colFormat` is not explicitly defined
	computeColHeadFormat: function() {
		if (this.rowCnt > 1) { // more than one week row. day numbers will be in each cell
			return 'ddd'; // "Sat"
		}
		else if (this.colCnt > 1) { // multiple days, so full single date string WON'T be in title text
			return this.view.opt('dayOfMonthFormat'); // "Sat 12/10"
		}
		else { // single day, so full single date string will probably be in title text
			return 'dddd'; // "Saturday"
		}
	},


	// Computes a default event time formatting string if `timeFormat` is not explicitly defined
	computeEventTimeFormat: function() {
		return this.view.opt('extraSmallTimeFormat'); // like "6p" or "6:30p"
	},


	// Computes a default `displayEventEnd` value if one is not expliclty defined
	computeDisplayEventEnd: function() {
		return this.colCnt == 1; // we'll likely have space if there's only one day
	},


	/* Cell System
	------------------------------------------------------------------------------------------------------------------*/


	// Initializes row/col information
	updateCells: function() {
		var cellDates;
		var firstDay;
		var rowCnt;
		var colCnt;

		this.updateCellDates(); // populates cellDates and dayToCellOffsets
		cellDates = this.cellDates;

		if (this.breakOnWeeks) {
			// count columns until the day-of-week repeats
			firstDay = cellDates[0].day();
			for (colCnt = 1; colCnt < cellDates.length; colCnt++) {
				if (cellDates[colCnt].day() == firstDay) {
					break;
				}
			}
			rowCnt = Math.ceil(cellDates.length / colCnt);
		}
		else {
			rowCnt = 1;
			colCnt = cellDates.length;
		}

		this.rowCnt = rowCnt;
		this.colCnt = colCnt;
	},


	// Populates cellDates and dayToCellOffsets
	updateCellDates: function() {
		var view = this.view;
		var date = this.start.clone();
		var dates = [];
		var offset = -1;
		var offsets = [];

		while (date.isBefore(this.end)) { // loop each day from start to end
			if (view.isHiddenDay(date)) {
				offsets.push(offset + 0.5); // mark that it's between offsets
			}
			else {
				offset++;
				offsets.push(offset);
				dates.push(date.clone());
			}
			date.add(1, 'days');
		}

		this.cellDates = dates;
		this.dayToCellOffsets = offsets;
	},


	// Given a cell object, generates a range object
	computeCellRange: function(cell) {
		var colCnt = this.colCnt;
		var index = cell.row * colCnt + (this.isRTL ? colCnt - cell.col - 1 : cell.col);
		var start = this.cellDates[index].clone();
		var end = start.clone().add(1, 'day');

		return { start: start, end: end };
	},


	// Retrieves the element representing the given row
	getRowEl: function(row) {
		return this.rowEls.eq(row);
	},


	// Retrieves the element representing the given column
	getColEl: function(col) {
		return this.dayEls.eq(col);
	},


	// Gets the whole-day element associated with the cell
	getCellDayEl: function(cell) {
		return this.dayEls.eq(cell.row * this.colCnt + cell.col);
	},


	// Overrides Grid's method for when row coordinates are computed
	computeRowCoords: function() {
		var rowCoords = Grid.prototype.computeRowCoords.call(this); // call the super-method

		// hack for extending last row (used by AgendaView)
		rowCoords[rowCoords.length - 1].bottom += this.bottomCoordPadding;

		return rowCoords;
	},


	/* Dates
	------------------------------------------------------------------------------------------------------------------*/


	// Slices up a date range by row into an array of segments
	rangeToSegs: function(range) {
		var isRTL = this.isRTL;
		var rowCnt = this.rowCnt;
		var colCnt = this.colCnt;
		var segs = [];
		var first, last; // inclusive cell-offset range for given range
		var row;
		var rowFirst, rowLast; // inclusive cell-offset range for current row
		var isStart, isEnd;
		var segFirst, segLast; // inclusive cell-offset range for segment
		var seg;

		range = this.view.computeDayRange(range); // make whole-day range, considering nextDayThreshold
		first = this.dateToCellOffset(range.start);
		last = this.dateToCellOffset(range.end.subtract(1, 'days')); // offset of inclusive end date

		for (row = 0; row < rowCnt; row++) {
			rowFirst = row * colCnt;
			rowLast = rowFirst + colCnt - 1;

			// intersect segment's offset range with the row's
			segFirst = Math.max(rowFirst, first);
			segLast = Math.min(rowLast, last);

			// deal with in-between indices
			segFirst = Math.ceil(segFirst); // in-between starts round to next cell
			segLast = Math.floor(segLast); // in-between ends round to prev cell

			if (segFirst <= segLast) { // was there any intersection with the current row?

				// must be matching integers to be the segment's start/end
				isStart = segFirst === first;
				isEnd = segLast === last;

				// translate offsets to be relative to start-of-row
				segFirst -= rowFirst;
				segLast -= rowFirst;

				seg = { row: row, isStart: isStart, isEnd: isEnd };
				if (isRTL) {
					seg.leftCol = colCnt - segLast - 1;
					seg.rightCol = colCnt - segFirst - 1;
				}
				else {
					seg.leftCol = segFirst;
					seg.rightCol = segLast;
				}
				segs.push(seg);
			}
		}

		return segs;
	},


	// Given a date, returns its chronolocial cell-offset from the first cell of the grid.
	// If the date lies between cells (because of hiddenDays), returns a floating-point value between offsets.
	// If before the first offset, returns a negative number.
	// If after the last offset, returns an offset past the last cell offset.
	// Only works for *start* dates of cells. Will not work for exclusive end dates for cells.
	dateToCellOffset: function(date) {
		var offsets = this.dayToCellOffsets;
		var day = date.diff(this.start, 'days');

		if (day < 0) {
			return offsets[0] - 1;
		}
		else if (day >= offsets.length) {
			return offsets[offsets.length - 1] + 1;
		}
		else {
			return offsets[day];
		}
	},


	/* Event Drag Visualization
	------------------------------------------------------------------------------------------------------------------*/
	// TODO: move to DayGrid.event, similar to what we did with Grid's drag methods


	// Renders a visual indication of an event or external element being dragged.
	// The dropLocation's end can be null. seg can be null. See Grid::renderDrag for more info.
	renderDrag: function(dropLocation, seg) {
		var opacity;

		// always render a highlight underneath
		this.renderHighlight(
			this.view.calendar.ensureVisibleEventRange(dropLocation) // needs to be a proper range
		);

		// if a segment from the same calendar but another component is being dragged, render a helper event
		if (seg && !seg.el.closest(this.el).length) {

			this.renderRangeHelper(dropLocation, seg);

			opacity = this.view.opt('dragOpacity');
			if (opacity !== undefined) {
				this.helperEls.css('opacity', opacity);
			}

			return true; // a helper has been rendered
		}
	},


	// Unrenders any visual indication of a hovering event
	destroyDrag: function() {
		this.destroyHighlight();
		this.destroyHelper();
	},


	/* Event Resize Visualization
	------------------------------------------------------------------------------------------------------------------*/


	// Renders a visual indication of an event being resized
	renderEventResize: function(range, seg) {
		this.renderHighlight(range);
		this.renderRangeHelper(range, seg);
	},


	// Unrenders a visual indication of an event being resized
	destroyEventResize: function() {
		this.destroyHighlight();
		this.destroyHelper();
	},


	/* Event Helper
	------------------------------------------------------------------------------------------------------------------*/


	// Renders a mock "helper" event. `sourceSeg` is the associated internal segment object. It can be null.
	renderHelper: function(event, sourceSeg) {
		var helperNodes = [];
		var segs = this.eventsToSegs([ event ]);
		var rowStructs;

		segs = this.renderFgSegEls(segs); // assigns each seg's el and returns a subset of segs that were rendered
		rowStructs = this.renderSegRows(segs);

		// inject each new event skeleton into each associated row
		this.rowEls.each(function(row, rowNode) {
			var rowEl = $(rowNode); // the .fc-row
			var skeletonEl = $('<div class="fc-helper-skeleton"><table/></div>'); // will be absolutely positioned
			var skeletonTop;

			// If there is an original segment, match the top position. Otherwise, put it at the row's top level
			if (sourceSeg && sourceSeg.row === row) {
				skeletonTop = sourceSeg.el.position().top;
			}
			else {
				skeletonTop = rowEl.find('.fc-content-skeleton tbody').position().top;
			}

			skeletonEl.css('top', skeletonTop)
				.find('table')
					.append(rowStructs[row].tbodyEl);

			rowEl.append(skeletonEl);
			helperNodes.push(skeletonEl[0]);
		});

		this.helperEls = $(helperNodes); // array -> jQuery set
	},


	// Unrenders any visual indication of a mock helper event
	destroyHelper: function() {
		if (this.helperEls) {
			this.helperEls.remove();
			this.helperEls = null;
		}
	},


	/* Fill System (highlight, background events, business hours)
	------------------------------------------------------------------------------------------------------------------*/


	fillSegTag: 'td', // override the default tag name


	// Renders a set of rectangles over the given segments of days.
	// Only returns segments that successfully rendered.
	renderFill: function(type, segs) {
		var nodes = [];
		var i, seg;
		var skeletonEl;

		segs = this.renderFillSegEls(type, segs); // assignes `.el` to each seg. returns successfully rendered segs

		for (i = 0; i < segs.length; i++) {
			seg = segs[i];
			skeletonEl = this.renderFillRow(type, seg);
			this.rowEls.eq(seg.row).append(skeletonEl);
			nodes.push(skeletonEl[0]);
		}

		this.elsByFill[type] = $(nodes);

		return segs;
	},


	// Generates the HTML needed for one row of a fill. Requires the seg's el to be rendered.
	renderFillRow: function(type, seg) {
		var colCnt = this.colCnt;
		var startCol = seg.leftCol;
		var endCol = seg.rightCol + 1;
		var skeletonEl;
		var trEl;

		skeletonEl = $(
			'<div class="fc-' + type.toLowerCase() + '-skeleton">' +
				'<table><tr/></table>' +
			'</div>'
		);
		trEl = skeletonEl.find('tr');

		if (startCol > 0) {
			trEl.append('<td colspan="' + startCol + '"/>');
		}

		trEl.append(
			seg.el.attr('colspan', endCol - startCol)
		);

		if (endCol < colCnt) {
			trEl.append('<td colspan="' + (colCnt - endCol) + '"/>');
		}

		this.bookendCells(trEl, type);

		return skeletonEl;
	}

});

    /* Event-rendering methods for the DayGrid class
----------------------------------------------------------------------------------------------------------------------*/

DayGrid.mixin({

	rowStructs: null, // an array of objects, each holding information about a row's foreground event-rendering


	// Unrenders all events currently rendered on the grid
	destroyEvents: function() {
		this.destroySegPopover(); // removes the "more.." events popover
		Grid.prototype.destroyEvents.apply(this, arguments); // calls the super-method
	},


	// Retrieves all rendered segment objects currently rendered on the grid
	getEventSegs: function() {
		return Grid.prototype.getEventSegs.call(this) // get the segments from the super-method
			.concat(this.popoverSegs || []); // append the segments from the "more..." popover
	},


	// Renders the given background event segments onto the grid
	renderBgSegs: function(segs) {

		// don't render timed background events
		var allDaySegs = $.grep(segs, function(seg) {
			return seg.event.allDay;
		});

		return Grid.prototype.renderBgSegs.call(this, allDaySegs); // call the super-method
	},


	// Renders the given foreground event segments onto the grid
	renderFgSegs: function(segs) {
		var rowStructs;

		// render an `.el` on each seg
		// returns a subset of the segs. segs that were actually rendered
		segs = this.renderFgSegEls(segs);

		rowStructs = this.rowStructs = this.renderSegRows(segs);

		// append to each row's content skeleton
		this.rowEls.each(function(i, rowNode) {
			$(rowNode).find('.fc-content-skeleton > table').append(
				rowStructs[i].tbodyEl
			);
		});

		return segs; // return only the segs that were actually rendered
	},


	// Unrenders all currently rendered foreground event segments
	destroyFgSegs: function() {
		var rowStructs = this.rowStructs || [];
		var rowStruct;

		while ((rowStruct = rowStructs.pop())) {
			rowStruct.tbodyEl.remove();
		}

		this.rowStructs = null;
	},


	// Uses the given events array to generate <tbody> elements that should be appended to each row's content skeleton.
	// Returns an array of rowStruct objects (see the bottom of `renderSegRow`).
	// PRECONDITION: each segment shoud already have a rendered and assigned `.el`
	renderSegRows: function(segs) {
		var rowStructs = [];
		var segRows;
		var row;

		segRows = this.groupSegRows(segs); // group into nested arrays

		// iterate each row of segment groupings
		for (row = 0; row < segRows.length; row++) {
			rowStructs.push(
				this.renderSegRow(row, segRows[row])
			);
		}

		return rowStructs;
	},


	// Builds the HTML to be used for the default element for an individual segment
	fgSegHtml: function(seg, disableResizing) {
		var view = this.view;
		var event = seg.event;
		var isDraggable = view.isEventDraggable(event);
		var isResizable = !disableResizing && event.allDay && seg.isEnd && view.isEventResizable(event);
		var classes = this.getSegClasses(seg, isDraggable, isResizable);
		var skinCss = this.getEventSkinCss(event);
		var timeHtml = '';
		var titleHtml;

		classes.unshift('fc-day-grid-event');

		// Only display a timed events time if it is the starting segment
		if (!event.allDay && seg.isStart) {
			timeHtml = '<span class="fc-time">' + htmlEscape(this.getEventTimeText(event)) + '</span>';
		}

		titleHtml =
			'<span class="fc-title">' +
				(htmlEscape(event.title || '') || '&nbsp;') + // we always want one line of height
			'</span>';
		
		return '<a class="' + classes.join(' ') + '"' +
				(event.url ?
					' href="' + htmlEscape(event.url) + '"' :
					''
					) +
				(skinCss ?
					' style="' + skinCss + '"' :
					''
					) +
			'>' +
				'<div class="fc-content">' +
					(this.isRTL ?
						titleHtml + ' ' + timeHtml : // put a natural space in between
						timeHtml + ' ' + titleHtml   //
						) +
				'</div>' +
				(isResizable ?
					'<div class="fc-resizer"/>' :
					''
					) +
			'</a>';
	},


	// Given a row # and an array of segments all in the same row, render a <tbody> element, a skeleton that contains
	// the segments. Returns object with a bunch of internal data about how the render was calculated.
	renderSegRow: function(row, rowSegs) {
		var colCnt = this.colCnt;
		var segLevels = this.buildSegLevels(rowSegs); // group into sub-arrays of levels
		var levelCnt = Math.max(1, segLevels.length); // ensure at least one level
		var tbody = $('<tbody/>');
		var segMatrix = []; // lookup for which segments are rendered into which level+col cells
		var cellMatrix = []; // lookup for all <td> elements of the level+col matrix
		var loneCellMatrix = []; // lookup for <td> elements that only take up a single column
		var i, levelSegs;
		var col;
		var tr;
		var j, seg;
		var td;

		// populates empty cells from the current column (`col`) to `endCol`
		function emptyCellsUntil(endCol) {
			while (col < endCol) {
				// try to grab a cell from the level above and extend its rowspan. otherwise, create a fresh cell
				td = (loneCellMatrix[i - 1] || [])[col];
				if (td) {
					td.attr(
						'rowspan',
						parseInt(td.attr('rowspan') || 1, 10) + 1
					);
				}
				else {
					td = $('<td/>');
					tr.append(td);
				}
				cellMatrix[i][col] = td;
				loneCellMatrix[i][col] = td;
				col++;
			}
		}

		for (i = 0; i < levelCnt; i++) { // iterate through all levels
			levelSegs = segLevels[i];
			col = 0;
			tr = $('<tr/>');

			segMatrix.push([]);
			cellMatrix.push([]);
			loneCellMatrix.push([]);

			// levelCnt might be 1 even though there are no actual levels. protect against this.
			// this single empty row is useful for styling.
			if (levelSegs) {
				for (j = 0; j < levelSegs.length; j++) { // iterate through segments in level
					seg = levelSegs[j];

					emptyCellsUntil(seg.leftCol);

					// create a container that occupies or more columns. append the event element.
					td = $('<td class="fc-event-container"/>').append(seg.el);
					if (seg.leftCol != seg.rightCol) {
						td.attr('colspan', seg.rightCol - seg.leftCol + 1);
					}
					else { // a single-column segment
						loneCellMatrix[i][col] = td;
					}

					while (col <= seg.rightCol) {
						cellMatrix[i][col] = td;
						segMatrix[i][col] = seg;
						col++;
					}

					tr.append(td);
				}
			}

			emptyCellsUntil(colCnt); // finish off the row
			this.bookendCells(tr, 'eventSkeleton');
			tbody.append(tr);
		}

		return { // a "rowStruct"
			row: row, // the row number
			tbodyEl: tbody,
			cellMatrix: cellMatrix,
			segMatrix: segMatrix,
			segLevels: segLevels,
			segs: rowSegs
		};
	},


	// Stacks a flat array of segments, which are all assumed to be in the same row, into subarrays of vertical levels.
	buildSegLevels: function(segs) {
		var levels = [];
		var i, seg;
		var j;

		// Give preference to elements with certain criteria, so they have
		// a chance to be closer to the top.
		segs.sort(compareSegs);
		
		for (i = 0; i < segs.length; i++) {
			seg = segs[i];

			// loop through levels, starting with the topmost, until the segment doesn't collide with other segments
			for (j = 0; j < levels.length; j++) {
				if (!isDaySegCollision(seg, levels[j])) {
					break;
				}
			}
			// `j` now holds the desired subrow index
			seg.level = j;

			// create new level array if needed and append segment
			(levels[j] || (levels[j] = [])).push(seg);
		}

		// order segments left-to-right. very important if calendar is RTL
		for (j = 0; j < levels.length; j++) {
			levels[j].sort(compareDaySegCols);
		}

		return levels;
	},


	// Given a flat array of segments, return an array of sub-arrays, grouped by each segment's row
	groupSegRows: function(segs) {
		var segRows = [];
		var i;

		for (i = 0; i < this.rowCnt; i++) {
			segRows.push([]);
		}

		for (i = 0; i < segs.length; i++) {
			segRows[segs[i].row].push(segs[i]);
		}

		return segRows;
	}

});


// Computes whether two segments' columns collide. They are assumed to be in the same row.
function isDaySegCollision(seg, otherSegs) {
	var i, otherSeg;

	for (i = 0; i < otherSegs.length; i++) {
		otherSeg = otherSegs[i];

		if (
			otherSeg.leftCol <= seg.rightCol &&
			otherSeg.rightCol >= seg.leftCol
		) {
			return true;
		}
	}

	return false;
}


// A cmp function for determining the leftmost event
function compareDaySegCols(a, b) {
	return a.leftCol - b.leftCol;
}

    /* Methods relate to limiting the number events for a given day on a DayGrid
----------------------------------------------------------------------------------------------------------------------*/
// NOTE: all the segs being passed around in here are foreground segs

DayGrid.mixin({

	segPopover: null, // the Popover that holds events that can't fit in a cell. null when not visible
	popoverSegs: null, // an array of segment objects that the segPopover holds. null when not visible


	destroySegPopover: function() {
		if (this.segPopover) {
			this.segPopover.hide(); // will trigger destruction of `segPopover` and `popoverSegs`
		}
	},


	// Limits the number of "levels" (vertically stacking layers of events) for each row of the grid.
	// `levelLimit` can be false (don't limit), a number, or true (should be computed).
	limitRows: function(levelLimit) {
		var rowStructs = this.rowStructs || [];
		var row; // row #
		var rowLevelLimit;

		for (row = 0; row < rowStructs.length; row++) {
			this.unlimitRow(row);

			if (!levelLimit) {
				rowLevelLimit = false;
			}
			else if (typeof levelLimit === 'number') {
				rowLevelLimit = levelLimit;
			}
			else {
				rowLevelLimit = this.computeRowLevelLimit(row);
			}

			if (rowLevelLimit !== false) {
				this.limitRow(row, rowLevelLimit);
			}
		}
	},


	// Computes the number of levels a row will accomodate without going outside its bounds.
	// Assumes the row is "rigid" (maintains a constant height regardless of what is inside).
	// `row` is the row number.
	computeRowLevelLimit: function(row) {
		var rowEl = this.rowEls.eq(row); // the containing "fake" row div
		var rowHeight = rowEl.height(); // TODO: cache somehow?
		var trEls = this.rowStructs[row].tbodyEl.children();
		var i, trEl;

		// Reveal one level <tr> at a time and stop when we find one out of bounds
		for (i = 0; i < trEls.length; i++) {
			trEl = trEls.eq(i).removeClass('fc-limited'); // get and reveal
			if (trEl.position().top + trEl.outerHeight() > rowHeight) {
				return i;
			}
		}

		return false; // should not limit at all
	},


	// Limits the given grid row to the maximum number of levels and injects "more" links if necessary.
	// `row` is the row number.
	// `levelLimit` is a number for the maximum (inclusive) number of levels allowed.
	limitRow: function(row, levelLimit) {
		var _this = this;
		var rowStruct = this.rowStructs[row];
		var moreNodes = []; // array of "more" <a> links and <td> DOM nodes
		var col = 0; // col #, left-to-right (not chronologically)
		var cell;
		var levelSegs; // array of segment objects in the last allowable level, ordered left-to-right
		var cellMatrix; // a matrix (by level, then column) of all <td> jQuery elements in the row
		var limitedNodes; // array of temporarily hidden level <tr> and segment <td> DOM nodes
		var i, seg;
		var segsBelow; // array of segment objects below `seg` in the current `col`
		var totalSegsBelow; // total number of segments below `seg` in any of the columns `seg` occupies
		var colSegsBelow; // array of segment arrays, below seg, one for each column (offset from segs's first column)
		var td, rowspan;
		var segMoreNodes; // array of "more" <td> cells that will stand-in for the current seg's cell
		var j;
		var moreTd, moreWrap, moreLink;

		// Iterates through empty level cells and places "more" links inside if need be
		function emptyCellsUntil(endCol) { // goes from current `col` to `endCol`
			while (col < endCol) {
				cell = _this.getCell(row, col);
				segsBelow = _this.getCellSegs(cell, levelLimit);
				if (segsBelow.length) {
					td = cellMatrix[levelLimit - 1][col];
					moreLink = _this.renderMoreLink(cell, segsBelow);
					moreWrap = $('<div/>').append(moreLink);
					td.append(moreWrap);
					moreNodes.push(moreWrap[0]);
				}
				col++;
			}
		}

		if (levelLimit && levelLimit < rowStruct.segLevels.length) { // is it actually over the limit?
			levelSegs = rowStruct.segLevels[levelLimit - 1];
			cellMatrix = rowStruct.cellMatrix;

			limitedNodes = rowStruct.tbodyEl.children().slice(levelLimit) // get level <tr> elements past the limit
				.addClass('fc-limited').get(); // hide elements and get a simple DOM-nodes array

			// iterate though segments in the last allowable level
			for (i = 0; i < levelSegs.length; i++) {
				seg = levelSegs[i];
				emptyCellsUntil(seg.leftCol); // process empty cells before the segment

				// determine *all* segments below `seg` that occupy the same columns
				colSegsBelow = [];
				totalSegsBelow = 0;
				while (col <= seg.rightCol) {
					cell = this.getCell(row, col);
					segsBelow = this.getCellSegs(cell, levelLimit);
					colSegsBelow.push(segsBelow);
					totalSegsBelow += segsBelow.length;
					col++;
				}

				if (totalSegsBelow) { // do we need to replace this segment with one or many "more" links?
					td = cellMatrix[levelLimit - 1][seg.leftCol]; // the segment's parent cell
					rowspan = td.attr('rowspan') || 1;
					segMoreNodes = [];

					// make a replacement <td> for each column the segment occupies. will be one for each colspan
					for (j = 0; j < colSegsBelow.length; j++) {
						moreTd = $('<td class="fc-more-cell"/>').attr('rowspan', rowspan);
						segsBelow = colSegsBelow[j];
						cell = this.getCell(row, seg.leftCol + j);
						moreLink = this.renderMoreLink(cell, [ seg ].concat(segsBelow)); // count seg as hidden too
						moreWrap = $('<div/>').append(moreLink);
						moreTd.append(moreWrap);
						segMoreNodes.push(moreTd[0]);
						moreNodes.push(moreTd[0]);
					}

					td.addClass('fc-limited').after($(segMoreNodes)); // hide original <td> and inject replacements
					limitedNodes.push(td[0]);
				}
			}

			emptyCellsUntil(this.colCnt); // finish off the level
			rowStruct.moreEls = $(moreNodes); // for easy undoing later
			rowStruct.limitedEls = $(limitedNodes); // for easy undoing later
		}
	},


	// Reveals all levels and removes all "more"-related elements for a grid's row.
	// `row` is a row number.
	unlimitRow: function(row) {
		var rowStruct = this.rowStructs[row];

		if (rowStruct.moreEls) {
			rowStruct.moreEls.remove();
			rowStruct.moreEls = null;
		}

		if (rowStruct.limitedEls) {
			rowStruct.limitedEls.removeClass('fc-limited');
			rowStruct.limitedEls = null;
		}
	},


	// Renders an <a> element that represents hidden event element for a cell.
	// Responsible for attaching click handler as well.
	renderMoreLink: function(cell, hiddenSegs) {
		var _this = this;
		var view = this.view;

		return $('<a class="fc-more"/>')
			.text(
				this.getMoreLinkText(hiddenSegs.length)
			)
			.on('click', function(ev) {
				var clickOption = view.opt('eventLimitClick');
				var date = cell.start;
				var moreEl = $(this);
				var dayEl = _this.getCellDayEl(cell);
				var allSegs = _this.getCellSegs(cell);

				// rescope the segments to be within the cell's date
				var reslicedAllSegs = _this.resliceDaySegs(allSegs, date);
				var reslicedHiddenSegs = _this.resliceDaySegs(hiddenSegs, date);

				if (typeof clickOption === 'function') {
					// the returned value can be an atomic option
					clickOption = view.trigger('eventLimitClick', null, {
						date: date,
						dayEl: dayEl,
						moreEl: moreEl,
						segs: reslicedAllSegs,
						hiddenSegs: reslicedHiddenSegs
					}, ev);
				}

				if (clickOption === 'popover') {
					_this.showSegPopover(cell, moreEl, reslicedAllSegs);
				}
				else if (typeof clickOption === 'string') { // a view name
					view.calendar.zoomTo(date, clickOption);
				}
			});
	},


	// Reveals the popover that displays all events within a cell
	showSegPopover: function(cell, moreLink, segs) {
		var _this = this;
		var view = this.view;
		var moreWrap = moreLink.parent(); // the <div> wrapper around the <a>
		var topEl; // the element we want to match the top coordinate of
		var options;

		if (this.rowCnt == 1) {
			topEl = view.el; // will cause the popover to cover any sort of header
		}
		else {
			topEl = this.rowEls.eq(cell.row); // will align with top of row
		}

		options = {
			className: 'fc-more-popover',
			content: this.renderSegPopoverContent(cell, segs),
			parentEl: this.el,
			top: topEl.offset().top,
			autoHide: true, // when the user clicks elsewhere, hide the popover
			viewportConstrain: view.opt('popoverViewportConstrain'),
			hide: function() {
				// destroy everything when the popover is hidden
				_this.segPopover.destroy();
				_this.segPopover = null;
				_this.popoverSegs = null;
			}
		};

		// Determine horizontal coordinate.
		// We use the moreWrap instead of the <td> to avoid border confusion.
		if (this.isRTL) {
			options.right = moreWrap.offset().left + moreWrap.outerWidth() + 1; // +1 to be over cell border
		}
		else {
			options.left = moreWrap.offset().left - 1; // -1 to be over cell border
		}

		this.segPopover = new Popover(options);
		this.segPopover.show();
	},


	// Builds the inner DOM contents of the segment popover
	renderSegPopoverContent: function(cell, segs) {
		var view = this.view;
		var isTheme = view.opt('theme');
		var title = cell.start.format(view.opt('dayPopoverFormat'));
		var content = $(
			'<div class="fc-header ' + view.widgetHeaderClass + '">' +
				'<span class="fc-close ' +
					(isTheme ? 'ui-icon ui-icon-closethick' : 'fc-icon fc-icon-x') +
				'"></span>' +
				'<span class="fc-title">' +
					htmlEscape(title) +
				'</span>' +
				'<div class="fc-clear"/>' +
			'</div>' +
			'<div class="fc-body ' + view.widgetContentClass + '">' +
				'<div class="fc-event-container"></div>' +
			'</div>'
		);
		var segContainer = content.find('.fc-event-container');
		var i;

		// render each seg's `el` and only return the visible segs
		segs = this.renderFgSegEls(segs, true); // disableResizing=true
		this.popoverSegs = segs;

		for (i = 0; i < segs.length; i++) {

			// because segments in the popover are not part of a grid coordinate system, provide a hint to any
			// grids that want to do drag-n-drop about which cell it came from
			segs[i].cell = cell;

			segContainer.append(segs[i].el);
		}

		return content;
	},


	// Given the events within an array of segment objects, reslice them to be in a single day
	resliceDaySegs: function(segs, dayDate) {

		// build an array of the original events
		var events = $.map(segs, function(seg) {
			return seg.event;
		});

		var dayStart = dayDate.clone().stripTime();
		var dayEnd = dayStart.clone().add(1, 'days');
		var dayRange = { start: dayStart, end: dayEnd };

		// slice the events with a custom slicing function
		return this.eventsToSegs(
			events,
			function(range) {
				var seg = intersectionToSeg(range, dayRange); // undefind if no intersection
				return seg ? [ seg ] : []; // must return an array of segments
			}
		);
	},


	// Generates the text that should be inside a "more" link, given the number of events it represents
	getMoreLinkText: function(num) {
		var opt = this.view.opt('eventLimitText');

		if (typeof opt === 'function') {
			return opt(num);
		}
		else {
			return '+' + num + ' ' + opt;
		}
	},


	// Returns segments within a given cell.
	// If `startLevel` is specified, returns only events including and below that level. Otherwise returns all segs.
	getCellSegs: function(cell, startLevel) {
		var segMatrix = this.rowStructs[cell.row].segMatrix;
		var level = startLevel || 0;
		var segs = [];
		var seg;

		while (level < segMatrix.length) {
			seg = segMatrix[level][cell.col];
			if (seg) {
				segs.push(seg);
			}
			level++;
		}

		return segs;
	}

});

    /* A component that renders one or more columns of vertical time slots
----------------------------------------------------------------------------------------------------------------------*/

var TimeGrid = Grid.extend({

	slotDuration: null, // duration of a "slot", a distinct time segment on given day, visualized by lines
	snapDuration: null, // granularity of time for dragging and selecting

	minTime: null, // Duration object that denotes the first visible time of any given day
	maxTime: null, // Duration object that denotes the exclusive visible end time of any given day

	axisFormat: null, // formatting string for times running along vertical axis

	dayEls: null, // cells elements in the day-row background
	slatEls: null, // elements running horizontally across all columns

	slatTops: null, // an array of top positions, relative to the container. last item holds bottom of last slot

	helperEl: null, // cell skeleton element for rendering the mock event "helper"

	businessHourSegs: null,


	constructor: function() {
		Grid.apply(this, arguments); // call the super-constructor
		this.processOptions();
	},


	// Renders the time grid into `this.el`, which should already be assigned.
	// Relies on the view's colCnt. In the future, this component should probably be self-sufficient.
	render: function() {
		this.el.html(this.renderHtml());
		this.dayEls = this.el.find('.fc-day');
		this.slatEls = this.el.find('.fc-slats tr');

		this.computeSlatTops();
		this.renderBusinessHours();
		Grid.prototype.render.call(this); // call the super-method
	},


	renderBusinessHours: function() {
		var events = this.view.calendar.getBusinessHoursEvents();
		this.businessHourSegs = this.renderFill('businessHours', this.eventsToSegs(events), 'bgevent');
	},


	// Renders the basic HTML skeleton for the grid
	renderHtml: function() {
		return '' +
			'<div class="fc-bg">' +
				'<table>' +
					this.rowHtml('slotBg') + // leverages RowRenderer, which will call slotBgCellHtml
				'</table>' +
			'</div>' +
			'<div class="fc-slats">' +
				'<table>' +
					this.slatRowHtml() +
				'</table>' +
			'</div>';
	},


	// Renders the HTML for a vertical background cell behind the slots.
	// This method is distinct from 'bg' because we wanted a new `rowType` so the View could customize the rendering.
	slotBgCellHtml: function(cell) {
		return this.bgCellHtml(cell);
	},


	// Generates the HTML for the horizontal "slats" that run width-wise. Has a time axis on a side. Depends on RTL.
	slatRowHtml: function() {
		var view = this.view;
		var isRTL = this.isRTL;
		var html = '';
		var slotNormal = this.slotDuration.asMinutes() % 15 === 0;
		var slotTime = moment.duration(+this.minTime); // wish there was .clone() for durations
		var slotDate; // will be on the view's first day, but we only care about its time
		var minutes;
		var axisHtml;

		// Calculate the time for each slot
		while (slotTime < this.maxTime) {
			slotDate = this.start.clone().time(slotTime); // will be in UTC but that's good. to avoid DST issues
			minutes = slotDate.minutes();

			axisHtml =
				'<td class="fc-axis fc-time ' + view.widgetContentClass + '" ' + view.axisStyleAttr() + '>' +
					((!slotNormal || !minutes) ? // if irregular slot duration, or on the hour, then display the time
						'<span>' + // for matchCellWidths
							htmlEscape(slotDate.format(this.axisFormat)) +
						'</span>' :
						''
						) +
				'</td>';

			html +=
				'<tr ' + (!minutes ? '' : 'class="fc-minor"') + '>' +
					(!isRTL ? axisHtml : '') +
					'<td class="' + view.widgetContentClass + '"/>' +
					(isRTL ? axisHtml : '') +
				"</tr>";

			slotTime.add(this.slotDuration);
		}

		return html;
	},


	/* Options
	------------------------------------------------------------------------------------------------------------------*/


	// Parses various options into properties of this object
	processOptions: function() {
		var view = this.view;
		var slotDuration = view.opt('slotDuration');
		var snapDuration = view.opt('snapDuration');

		slotDuration = moment.duration(slotDuration);
		snapDuration = snapDuration ? moment.duration(snapDuration) : slotDuration;

		this.slotDuration = slotDuration;
		this.snapDuration = snapDuration;

		this.minTime = moment.duration(view.opt('minTime'));
		this.maxTime = moment.duration(view.opt('maxTime'));

		this.axisFormat = view.opt('axisFormat') || view.opt('smallTimeFormat');
	},


	// Computes a default column header formatting string if `colFormat` is not explicitly defined
	computeColHeadFormat: function() {
		if (this.colCnt > 1) { // multiple days, so full single date string WON'T be in title text
			return this.view.opt('dayOfMonthFormat'); // "Sat 12/10"
		}
		else { // single day, so full single date string will probably be in title text
			return 'dddd'; // "Saturday"
		}
	},


	// Computes a default event time formatting string if `timeFormat` is not explicitly defined
	computeEventTimeFormat: function() {
		return this.view.opt('noMeridiemTimeFormat'); // like "6:30" (no AM/PM)
	},


	// Computes a default `displayEventEnd` value if one is not expliclty defined
	computeDisplayEventEnd: function() {
		return true;
	},


	/* Cell System
	------------------------------------------------------------------------------------------------------------------*/


	// Initializes row/col information
	updateCells: function() {
		var view = this.view;
		var colData = [];
		var date;

		date = this.start.clone();
		while (date.isBefore(this.end)) {
			colData.push({
				day: date.clone()
			});
			date.add(1, 'day');
			date = view.skipHiddenDays(date);
		}

		if (this.isRTL) {
			colData.reverse();
		}

		this.colData = colData;
		this.colCnt = colData.length;
		this.rowCnt = Math.ceil((this.maxTime - this.minTime) / this.snapDuration); // # of vertical snaps
	},


	// Given a cell object, generates a range object
	computeCellRange: function(cell) {
		var time = this.computeSnapTime(cell.row);
		var start = this.view.calendar.rezoneDate(cell.day).time(time);
		var end = start.clone().add(this.snapDuration);

		return { start: start, end: end };
	},


	// Retrieves the element representing the given column
	getColEl: function(col) {
		return this.dayEls.eq(col);
	},


	/* Dates
	------------------------------------------------------------------------------------------------------------------*/


	// Given a row number of the grid, representing a "snap", returns a time (Duration) from its start-of-day
	computeSnapTime: function(row) {
		return moment.duration(this.minTime + this.snapDuration * row);
	},


	// Slices up a date range by column into an array of segments
	rangeToSegs: function(range) {
		var colCnt = this.colCnt;
		var segs = [];
		var seg;
		var col;
		var colDate;
		var colRange;

		// normalize :(
		range = {
			start: range.start.clone().stripZone(),
			end: range.end.clone().stripZone()
		};

		for (col = 0; col < colCnt; col++) {
			colDate = this.colData[col].day; // will be ambig time/timezone
			colRange = {
				start: colDate.clone().time(this.minTime),
				end: colDate.clone().time(this.maxTime)
			};
			seg = intersectionToSeg(range, colRange); // both will be ambig timezone
			if (seg) {
				seg.col = col;
				segs.push(seg);
			}
		}

		return segs;
	},


	/* Coordinates
	------------------------------------------------------------------------------------------------------------------*/


	// Called when there is a window resize/zoom and we need to recalculate coordinates for the grid
	resize: function() {
		this.computeSlatTops();
		this.updateSegVerticals();
	},


	// Computes the top/bottom coordinates of each "snap" rows
	computeRowCoords: function() {
		var originTop = this.el.offset().top;
		var items = [];
		var i;
		var item;

		for (i = 0; i < this.rowCnt; i++) {
			item = {
				top: originTop + this.computeTimeTop(this.computeSnapTime(i))
			};
			if (i > 0) {
				items[i - 1].bottom = item.top;
			}
			items.push(item);
		}
		item.bottom = item.top + this.computeTimeTop(this.computeSnapTime(i));

		return items;
	},


	// Computes the top coordinate, relative to the bounds of the grid, of the given date.
	// A `startOfDayDate` must be given for avoiding ambiguity over how to treat midnight.
	computeDateTop: function(date, startOfDayDate) {
		return this.computeTimeTop(
			moment.duration(
				date.clone().stripZone() - startOfDayDate.clone().stripTime()
			)
		);
	},


	// Computes the top coordinate, relative to the bounds of the grid, of the given time (a Duration).
	computeTimeTop: function(time) {
		var slatCoverage = (time - this.minTime) / this.slotDuration; // floating-point value of # of slots covered
		var slatIndex;
		var slatRemainder;
		var slatTop;
		var slatBottom;

		// constrain. because minTime/maxTime might be customized
		slatCoverage = Math.max(0, slatCoverage);
		slatCoverage = Math.min(this.slatEls.length, slatCoverage);

		slatIndex = Math.floor(slatCoverage); // an integer index of the furthest whole slot
		slatRemainder = slatCoverage - slatIndex;
		slatTop = this.slatTops[slatIndex]; // the top position of the furthest whole slot

		if (slatRemainder) { // time spans part-way into the slot
			slatBottom = this.slatTops[slatIndex + 1];
			return slatTop + (slatBottom - slatTop) * slatRemainder; // part-way between slots
		}
		else {
			return slatTop;
		}
	},


	// Queries each `slatEl` for its position relative to the grid's container and stores it in `slatTops`.
	// Includes the the bottom of the last slat as the last item in the array.
	computeSlatTops: function() {
		var tops = [];
		var top;

		this.slatEls.each(function(i, node) {
			top = $(node).position().top;
			tops.push(top);
		});

		tops.push(top + this.slatEls.last().outerHeight()); // bottom of the last slat

		this.slatTops = tops;
	},


	/* Event Drag Visualization
	------------------------------------------------------------------------------------------------------------------*/


	// Renders a visual indication of an event being dragged over the specified date(s).
	// dropLocation's end might be null, as well as `seg`. See Grid::renderDrag for more info.
	// A returned value of `true` signals that a mock "helper" event has been rendered.
	renderDrag: function(dropLocation, seg) {
		var opacity;

		if (seg) { // if there is event information for this drag, render a helper event
			this.renderRangeHelper(dropLocation, seg);

			opacity = this.view.opt('dragOpacity');
			if (opacity !== undefined) {
				this.helperEl.css('opacity', opacity);
			}

			return true; // signal that a helper has been rendered
		}
		else {
			// otherwise, just render a highlight
			this.renderHighlight(
				this.view.calendar.ensureVisibleEventRange(dropLocation) // needs to be a proper range
			);
		}
	},


	// Unrenders any visual indication of an event being dragged
	destroyDrag: function() {
		this.destroyHelper();
		this.destroyHighlight();
	},


	/* Event Resize Visualization
	------------------------------------------------------------------------------------------------------------------*/


	// Renders a visual indication of an event being resized
	renderEventResize: function(range, seg) {
		this.renderRangeHelper(range, seg);
	},


	// Unrenders any visual indication of an event being resized
	destroyEventResize: function() {
		this.destroyHelper();
	},


	/* Event Helper
	------------------------------------------------------------------------------------------------------------------*/


	// Renders a mock "helper" event. `sourceSeg` is the original segment object and might be null (an external drag)
	renderHelper: function(event, sourceSeg) {
		var segs = this.eventsToSegs([ event ]);
		var tableEl;
		var i, seg;
		var sourceEl;

		segs = this.renderFgSegEls(segs); // assigns each seg's el and returns a subset of segs that were rendered
		tableEl = this.renderSegTable(segs);

		// Try to make the segment that is in the same row as sourceSeg look the same
		for (i = 0; i < segs.length; i++) {
			seg = segs[i];
			if (sourceSeg && sourceSeg.col === seg.col) {
				sourceEl = sourceSeg.el;
				seg.el.css({
					left: sourceEl.css('left'),
					right: sourceEl.css('right'),
					'margin-left': sourceEl.css('margin-left'),
					'margin-right': sourceEl.css('margin-right')
				});
			}
		}

		this.helperEl = $('<div class="fc-helper-skeleton"/>')
			.append(tableEl)
				.appendTo(this.el);
	},


	// Unrenders any mock helper event
	destroyHelper: function() {
		if (this.helperEl) {
			this.helperEl.remove();
			this.helperEl = null;
		}
	},


	/* Selection
	------------------------------------------------------------------------------------------------------------------*/


	// Renders a visual indication of a selection. Overrides the default, which was to simply render a highlight.
	renderSelection: function(range) {
		if (this.view.opt('selectHelper')) { // this setting signals that a mock helper event should be rendered
			this.renderRangeHelper(range);
		}
		else {
			this.renderHighlight(range);
		}
	},


	// Unrenders any visual indication of a selection
	destroySelection: function() {
		this.destroyHelper();
		this.destroyHighlight();
	},


	/* Fill System (highlight, background events, business hours)
	------------------------------------------------------------------------------------------------------------------*/


	// Renders a set of rectangles over the given time segments.
	// Only returns segments that successfully rendered.
	renderFill: function(type, segs, className) {
		var segCols;
		var skeletonEl;
		var trEl;
		var col, colSegs;
		var tdEl;
		var containerEl;
		var dayDate;
		var i, seg;

		if (segs.length) {

			segs = this.renderFillSegEls(type, segs); // assignes `.el` to each seg. returns successfully rendered segs
			segCols = this.groupSegCols(segs); // group into sub-arrays, and assigns 'col' to each seg

			className = className || type.toLowerCase();
			skeletonEl = $(
				'<div class="fc-' + className + '-skeleton">' +
					'<table><tr/></table>' +
				'</div>'
			);
			trEl = skeletonEl.find('tr');

			for (col = 0; col < segCols.length; col++) {
				colSegs = segCols[col];
				tdEl = $('<td/>').appendTo(trEl);

				if (colSegs.length) {
					containerEl = $('<div class="fc-' + className + '-container"/>').appendTo(tdEl);
					dayDate = this.colData[col].day;

					for (i = 0; i < colSegs.length; i++) {
						seg = colSegs[i];
						containerEl.append(
							seg.el.css({
								top: this.computeDateTop(seg.start, dayDate),
								bottom: -this.computeDateTop(seg.end, dayDate) // the y position of the bottom edge
							})
						);
					}
				}
			}

			this.bookendCells(trEl, type);

			this.el.append(skeletonEl);
			this.elsByFill[type] = skeletonEl;
		}

		return segs;
	}

});

    /* Event-rendering methods for the TimeGrid class
----------------------------------------------------------------------------------------------------------------------*/

TimeGrid.mixin({

	eventSkeletonEl: null, // has cells with event-containers, which contain absolutely positioned event elements


	// Renders the given foreground event segments onto the grid
	renderFgSegs: function(segs) {
		segs = this.renderFgSegEls(segs); // returns a subset of the segs. segs that were actually rendered

		this.el.append(
			this.eventSkeletonEl = $('<div class="fc-content-skeleton"/>')
				.append(this.renderSegTable(segs))
		);

		return segs; // return only the segs that were actually rendered
	},


	// Unrenders all currently rendered foreground event segments
	destroyFgSegs: function(segs) {
		if (this.eventSkeletonEl) {
			this.eventSkeletonEl.remove();
			this.eventSkeletonEl = null;
		}
	},


	// Renders and returns the <table> portion of the event-skeleton.
	// Returns an object with properties 'tbodyEl' and 'segs'.
	renderSegTable: function(segs) {
		var tableEl = $('<table><tr/></table>');
		var trEl = tableEl.find('tr');
		var segCols;
		var i, seg;
		var col, colSegs;
		var containerEl;

		segCols = this.groupSegCols(segs); // group into sub-arrays, and assigns 'col' to each seg

		this.computeSegVerticals(segs); // compute and assign top/bottom

		for (col = 0; col < segCols.length; col++) { // iterate each column grouping
			colSegs = segCols[col];
			placeSlotSegs(colSegs); // compute horizontal coordinates, z-index's, and reorder the array

			containerEl = $('<div class="fc-event-container"/>');

			// assign positioning CSS and insert into container
			for (i = 0; i < colSegs.length; i++) {
				seg = colSegs[i];
				seg.el.css(this.generateSegPositionCss(seg));

				// if the height is short, add a className for alternate styling
				if (seg.bottom - seg.top < 30) {
					seg.el.addClass('fc-short');
				}

				containerEl.append(seg.el);
			}

			trEl.append($('<td/>').append(containerEl));
		}

		this.bookendCells(trEl, 'eventSkeleton');

		return tableEl;
	},


	// Refreshes the CSS top/bottom coordinates for each segment element. Probably after a window resize/zoom.
	// Repositions business hours segs too, so not just for events. Maybe shouldn't be here.
	updateSegVerticals: function() {
		var allSegs = (this.segs || []).concat(this.businessHourSegs || []);
		var i;

		this.computeSegVerticals(allSegs);

		for (i = 0; i < allSegs.length; i++) {
			allSegs[i].el.css(
				this.generateSegVerticalCss(allSegs[i])
			);
		}
	},


	// For each segment in an array, computes and assigns its top and bottom properties
	computeSegVerticals: function(segs) {
		var i, seg;

		for (i = 0; i < segs.length; i++) {
			seg = segs[i];
			seg.top = this.computeDateTop(seg.start, seg.start);
			seg.bottom = this.computeDateTop(seg.end, seg.start);
		}
	},


	// Renders the HTML for a single event segment's default rendering
	fgSegHtml: function(seg, disableResizing) {
		var view = this.view;
		var event = seg.event;
		var isDraggable = view.isEventDraggable(event);
		var isResizable = !disableResizing && seg.isEnd && view.isEventResizable(event);
		var classes = this.getSegClasses(seg, isDraggable, isResizable);
		var skinCss = this.getEventSkinCss(event);
		var timeText;
		var fullTimeText; // more verbose time text. for the print stylesheet
		var startTimeText; // just the start time text

		classes.unshift('fc-time-grid-event');

		if (view.isMultiDayEvent(event)) { // if the event appears to span more than one day...
			// Don't display time text on segments that run entirely through a day.
			// That would appear as midnight-midnight and would look dumb.
			// Otherwise, display the time text for the *segment's* times (like 6pm-midnight or midnight-10am)
			if (seg.isStart || seg.isEnd) {
				timeText = this.getEventTimeText(seg);
				fullTimeText = this.getEventTimeText(seg, 'LT');
				startTimeText = this.getEventTimeText({ start: seg.start });
			}
		} else {
			// Display the normal time text for the *event's* times
			timeText = this.getEventTimeText(event);
			fullTimeText = this.getEventTimeText(event, 'LT');
			startTimeText = this.getEventTimeText({ start: event.start });
		}

		return '<a class="' + classes.join(' ') + '"' +
			(event.url ?
				' href="' + htmlEscape(event.url) + '"' :
				''
				) +
			(skinCss ?
				' style="' + skinCss + '"' :
				''
				) +
			'>' +
				'<div class="fc-content">' +
					(timeText ?
						'<div class="fc-time"' +
						' data-start="' + htmlEscape(startTimeText) + '"' +
						' data-full="' + htmlEscape(fullTimeText) + '"' +
						'>' +
							'<span>' + htmlEscape(timeText) + '</span>' +
						'</div>' :
						''
						) +
					(event.title ?
						'<div class="fc-title">' +
							htmlEscape(event.title) +
						'</div>' :
						''
						) +
				'</div>' +
				'<div class="fc-bg"/>' +
				(isResizable ?
					'<div class="fc-resizer"/>' :
					''
					) +
			'</a>';
	},


	// Generates an object with CSS properties/values that should be applied to an event segment element.
	// Contains important positioning-related properties that should be applied to any event element, customized or not.
	generateSegPositionCss: function(seg) {
		var shouldOverlap = this.view.opt('slotEventOverlap');
		var backwardCoord = seg.backwardCoord; // the left side if LTR. the right side if RTL. floating-point
		var forwardCoord = seg.forwardCoord; // the right side if LTR. the left side if RTL. floating-point
		var props = this.generateSegVerticalCss(seg); // get top/bottom first
		var left; // amount of space from left edge, a fraction of the total width
		var right; // amount of space from right edge, a fraction of the total width

		if (shouldOverlap) {
			// double the width, but don't go beyond the maximum forward coordinate (1.0)
			forwardCoord = Math.min(1, backwardCoord + (forwardCoord - backwardCoord) * 2);
		}

		if (this.isRTL) {
			left = 1 - forwardCoord;
			right = backwardCoord;
		}
		else {
			left = backwardCoord;
			right = 1 - forwardCoord;
		}

		props.zIndex = seg.level + 1; // convert from 0-base to 1-based
		props.left = left * 100 + '%';
		props.right = right * 100 + '%';

		if (shouldOverlap && seg.forwardPressure) {
			// add padding to the edge so that forward stacked events don't cover the resizer's icon
			props[this.isRTL ? 'marginLeft' : 'marginRight'] = 10 * 2; // 10 is a guesstimate of the icon's width
		}

		return props;
	},


	// Generates an object with CSS properties for the top/bottom coordinates of a segment element
	generateSegVerticalCss: function(seg) {
		return {
			top: seg.top,
			bottom: -seg.bottom // flipped because needs to be space beyond bottom edge of event container
		};
	},


	// Given a flat array of segments, return an array of sub-arrays, grouped by each segment's col
	groupSegCols: function(segs) {
		var segCols = [];
		var i;

		for (i = 0; i < this.colCnt; i++) {
			segCols.push([]);
		}

		for (i = 0; i < segs.length; i++) {
			segCols[segs[i].col].push(segs[i]);
		}

		return segCols;
	}

});


// Given an array of segments that are all in the same column, sets the backwardCoord and forwardCoord on each.
// Also reorders the given array by date!
function placeSlotSegs(segs) {
	var levels;
	var level0;
	var i;

	segs.sort(compareSegs); // order by date
	levels = buildSlotSegLevels(segs);
	computeForwardSlotSegs(levels);

	if ((level0 = levels[0])) {

		for (i = 0; i < level0.length; i++) {
			computeSlotSegPressures(level0[i]);
		}

		for (i = 0; i < level0.length; i++) {
			computeSlotSegCoords(level0[i], 0, 0);
		}
	}
}


// Builds an array of segments "levels". The first level will be the leftmost tier of segments if the calendar is
// left-to-right, or the rightmost if the calendar is right-to-left. Assumes the segments are already ordered by date.
function buildSlotSegLevels(segs) {
	var levels = [];
	var i, seg;
	var j;

	for (i=0; i<segs.length; i++) {
		seg = segs[i];

		// go through all the levels and stop on the first level where there are no collisions
		for (j=0; j<levels.length; j++) {
			if (!computeSlotSegCollisions(seg, levels[j]).length) {
				break;
			}
		}

		seg.level = j;

		(levels[j] || (levels[j] = [])).push(seg);
	}

	return levels;
}


// For every segment, figure out the other segments that are in subsequent
// levels that also occupy the same vertical space. Accumulate in seg.forwardSegs
function computeForwardSlotSegs(levels) {
	var i, level;
	var j, seg;
	var k;

	for (i=0; i<levels.length; i++) {
		level = levels[i];

		for (j=0; j<level.length; j++) {
			seg = level[j];

			seg.forwardSegs = [];
			for (k=i+1; k<levels.length; k++) {
				computeSlotSegCollisions(seg, levels[k], seg.forwardSegs);
			}
		}
	}
}


// Figure out which path forward (via seg.forwardSegs) results in the longest path until
// the furthest edge is reached. The number of segments in this path will be seg.forwardPressure
function computeSlotSegPressures(seg) {
	var forwardSegs = seg.forwardSegs;
	var forwardPressure = 0;
	var i, forwardSeg;

	if (seg.forwardPressure === undefined) { // not already computed

		for (i=0; i<forwardSegs.length; i++) {
			forwardSeg = forwardSegs[i];

			// figure out the child's maximum forward path
			computeSlotSegPressures(forwardSeg);

			// either use the existing maximum, or use the child's forward pressure
			// plus one (for the forwardSeg itself)
			forwardPressure = Math.max(
				forwardPressure,
				1 + forwardSeg.forwardPressure
			);
		}

		seg.forwardPressure = forwardPressure;
	}
}


// Calculate seg.forwardCoord and seg.backwardCoord for the segment, where both values range
// from 0 to 1. If the calendar is left-to-right, the seg.backwardCoord maps to "left" and
// seg.forwardCoord maps to "right" (via percentage). Vice-versa if the calendar is right-to-left.
//
// The segment might be part of a "series", which means consecutive segments with the same pressure
// who's width is unknown until an edge has been hit. `seriesBackwardPressure` is the number of
// segments behind this one in the current series, and `seriesBackwardCoord` is the starting
// coordinate of the first segment in the series.
function computeSlotSegCoords(seg, seriesBackwardPressure, seriesBackwardCoord) {
	var forwardSegs = seg.forwardSegs;
	var i;

	if (seg.forwardCoord === undefined) { // not already computed

		if (!forwardSegs.length) {

			// if there are no forward segments, this segment should butt up against the edge
			seg.forwardCoord = 1;
		}
		else {

			// sort highest pressure first
			forwardSegs.sort(compareForwardSlotSegs);

			// this segment's forwardCoord will be calculated from the backwardCoord of the
			// highest-pressure forward segment.
			computeSlotSegCoords(forwardSegs[0], seriesBackwardPressure + 1, seriesBackwardCoord);
			seg.forwardCoord = forwardSegs[0].backwardCoord;
		}

		// calculate the backwardCoord from the forwardCoord. consider the series
		seg.backwardCoord = seg.forwardCoord -
			(seg.forwardCoord - seriesBackwardCoord) / // available width for series
			(seriesBackwardPressure + 1); // # of segments in the series

		// use this segment's coordinates to computed the coordinates of the less-pressurized
		// forward segments
		for (i=0; i<forwardSegs.length; i++) {
			computeSlotSegCoords(forwardSegs[i], 0, seg.forwardCoord);
		}
	}
}


// Find all the segments in `otherSegs` that vertically collide with `seg`.
// Append into an optionally-supplied `results` array and return.
function computeSlotSegCollisions(seg, otherSegs, results) {
	results = results || [];

	for (var i=0; i<otherSegs.length; i++) {
		if (isSlotSegCollision(seg, otherSegs[i])) {
			results.push(otherSegs[i]);
		}
	}

	return results;
}


// Do these segments occupy the same vertical space?
function isSlotSegCollision(seg1, seg2) {
	return seg1.bottom > seg2.top && seg1.top < seg2.bottom;
}


// A cmp function for determining which forward segment to rely on more when computing coordinates.
function compareForwardSlotSegs(seg1, seg2) {
	// put higher-pressure first
	return seg2.forwardPressure - seg1.forwardPressure ||
		// put segments that are closer to initial edge first (and favor ones with no coords yet)
		(seg1.backwardCoord || 0) - (seg2.backwardCoord || 0) ||
		// do normal sorting...
		compareSegs(seg1, seg2);
}

    /* An abstract class from which other views inherit from
----------------------------------------------------------------------------------------------------------------------*/

var View = fc.View = Class.extend({

	type: null, // subclass' view name (string)
	name: null, // deprecated. use `type` instead

	calendar: null, // owner Calendar object
	options: null, // view-specific options
	coordMap: null, // a CoordMap object for converting pixel regions to dates
	el: null, // the view's containing element. set by Calendar

	// range the view is actually displaying (moments)
	start: null,
	end: null, // exclusive

	// range the view is formally responsible for (moments)
	// may be different from start/end. for example, a month view might have 1st-31st, excluding padded dates
	intervalStart: null,
	intervalEnd: null, // exclusive

	intervalDuration: null, // the whole-unit duration that is being displayed
	intervalUnit: null, // name of largest unit being displayed, like "month" or "week"

	isSelected: false, // boolean whether a range of time is user-selected or not

	// subclasses can optionally use a scroll container
	scrollerEl: null, // the element that will most likely scroll when content is too tall
	scrollTop: null, // cached vertical scroll value

	// classNames styled by jqui themes
	widgetHeaderClass: null,
	widgetContentClass: null,
	highlightStateClass: null,

	// for date utils, computed from options
	nextDayThreshold: null,
	isHiddenDayHash: null,

	// document handlers, bound to `this` object
	documentMousedownProxy: null, // TODO: doesn't work with touch


	constructor: function(calendar, viewOptions, viewType) {
		this.calendar = calendar;
		this.options = viewOptions;
		this.type = this.name = viewType; // .name is deprecated

		this.nextDayThreshold = moment.duration(this.opt('nextDayThreshold'));
		this.initTheming();
		this.initHiddenDays();

		this.documentMousedownProxy = $.proxy(this, 'documentMousedown');

		this.initialize();
	},


	// A good place for subclasses to initialize member variables
	initialize: function() {
		// subclasses can implement
	},


	// Retrieves an option with the given name
	opt: function(name) {
		var val;

		val = this.options[name]; // look at view-specific options first
		if (val !== undefined) {
			return val;
		}

		val = this.calendar.options[name];
		if ($.isPlainObject(val) && !isForcedAtomicOption(name)) { // view-option-hashes are deprecated
			return smartProperty(val, this.type);
		}

		return val;
	},


	// Triggers handlers that are view-related. Modifies args before passing to calendar.
	trigger: function(name, thisObj) { // arguments beyond thisObj are passed along
		var calendar = this.calendar;

		return calendar.trigger.apply(
			calendar,
			[name, thisObj || this].concat(
				Array.prototype.slice.call(arguments, 2), // arguments beyond thisObj
				[ this ] // always make the last argument a reference to the view. TODO: deprecate
			)
		);
	},


	/* Dates
	------------------------------------------------------------------------------------------------------------------*/


	// Updates all internal dates to center around the given current date
	setDate: function(date) {
		this.setRange(this.computeRange(date));
	},


	// Updates all internal dates for displaying the given range.
	// Expects all values to be normalized (like what computeRange does).
	setRange: function(range) {
		$.extend(this, range);
	},


	// Given a single current date, produce information about what range to display.
	// Subclasses can override. Must return all properties.
	computeRange: function(date) {
		var intervalDuration = moment.duration(this.opt('duration') || this.constructor.duration || { days: 1 });
		var intervalUnit = computeIntervalUnit(intervalDuration);
		var intervalStart = date.clone().startOf(intervalUnit);
		var intervalEnd = intervalStart.clone().add(intervalDuration);
		var start, end;

		// normalize the range's time-ambiguity
		if (computeIntervalAs('days', intervalDuration)) { // whole-days?
			intervalStart.stripTime();
			intervalEnd.stripTime();
		}
		else { // needs to have a time?
			if (!intervalStart.hasTime()) {
				intervalStart = this.calendar.rezoneDate(intervalStart); // convert to current timezone, with 00:00
			}
			if (!intervalEnd.hasTime()) {
				intervalEnd = this.calendar.rezoneDate(intervalEnd); // convert to current timezone, with 00:00
			}
		}

		start = intervalStart.clone();
		start = this.skipHiddenDays(start);
		end = intervalEnd.clone();
		end = this.skipHiddenDays(end, -1, true); // exclusively move backwards

		return {
			intervalDuration: intervalDuration,
			intervalUnit: intervalUnit,
			intervalStart: intervalStart,
			intervalEnd: intervalEnd,
			start: start,
			end: end
		};
	},


	// Computes the new date when the user hits the prev button, given the current date
	computePrevDate: function(date) {
		return this.skipHiddenDays(
			date.clone().startOf(this.intervalUnit).subtract(this.intervalDuration), -1
		);
	},


	// Computes the new date when the user hits the next button, given the current date
	computeNextDate: function(date) {
		return this.skipHiddenDays(
			date.clone().startOf(this.intervalUnit).add(this.intervalDuration)
		);
	},


	/* Title and Date Formatting
	------------------------------------------------------------------------------------------------------------------*/


	// Computes what the title at the top of the calendar should be for this view
	computeTitle: function() {
		return this.formatRange(
			{ start: this.intervalStart, end: this.intervalEnd },
			this.opt('titleFormat') || this.computeTitleFormat(),
			this.opt('titleRangeSeparator')
		);
	},


	// Generates the format string that should be used to generate the title for the current date range.
	// Attempts to compute the most appropriate format if not explicitly specified with `titleFormat`.
	computeTitleFormat: function() {
		if (this.intervalUnit == 'year') {
			return 'YYYY';
		}
		else if (this.intervalUnit == 'month') {
			return this.opt('monthYearFormat'); // like "September 2014"
		}
		else if (this.intervalDuration.as('days') > 1) {
			return 'll'; // multi-day range. shorter, like "Sep 9 - 10 2014"
		}
		else {
			return 'LL'; // one day. longer, like "September 9 2014"
		}
	},


	// Utility for formatting a range. Accepts a range object, formatting string, and optional separator.
	// Displays all-day ranges naturally, with an inclusive end. Takes the current isRTL into account.
	formatRange: function(range, formatStr, separator) {
		var end = range.end;

		if (!end.hasTime()) { // all-day?
			end = end.clone().subtract(1); // convert to inclusive. last ms of previous day
		}

		return formatRange(range.start, end, formatStr, separator, this.opt('isRTL'));
	},


	/* Rendering
	------------------------------------------------------------------------------------------------------------------*/


	// Wraps the basic render() method with more View-specific logic. Called by the owner Calendar.
	renderView: function() {
		this.render();
		this.updateSize();
		this.initializeScroll();
		this.trigger('viewRender', this, this, this.el);

		// attach handlers to document. do it here to allow for destroy/rerender
		$(document).on('mousedown', this.documentMousedownProxy);
	},


	// Renders the view inside an already-defined `this.el`
	render: function() {
		// subclasses should implement
	},


	// Wraps the basic destroy() method with more View-specific logic. Called by the owner Calendar.
	destroyView: function() {
		this.unselect();
		this.destroyViewEvents();
		this.destroy();
		this.trigger('viewDestroy', this, this, this.el);

		$(document).off('mousedown', this.documentMousedownProxy);
	},


	// Clears the view's rendering
	destroy: function() {
		this.el.empty(); // removes inner contents but leaves the element intact
	},


	// Initializes internal variables related to theming
	initTheming: function() {
		var tm = this.opt('theme') ? 'ui' : 'fc';

		this.widgetHeaderClass = tm + '-widget-header';
		this.widgetContentClass = tm + '-widget-content';
		this.highlightStateClass = tm + '-state-highlight';
	},


	/* Dimensions
	------------------------------------------------------------------------------------------------------------------*/


	// Refreshes anything dependant upon sizing of the container element of the grid
	updateSize: function(isResize) {
		if (isResize) {
			this.recordScroll();
		}
		this.updateHeight();
		this.updateWidth();
	},


	// Refreshes the horizontal dimensions of the calendar
	updateWidth: function() {
		// subclasses should implement
	},


	// Refreshes the vertical dimensions of the calendar
	updateHeight: function() {
		var calendar = this.calendar; // we poll the calendar for height information

		this.setHeight(
			calendar.getSuggestedViewHeight(),
			calendar.isHeightAuto()
		);
	},


	// Updates the vertical dimensions of the calendar to the specified height.
	// if `isAuto` is set to true, height becomes merely a suggestion and the view should use its "natural" height.
	setHeight: function(height, isAuto) {
		// subclasses should implement
	},


	/* Scroller
	------------------------------------------------------------------------------------------------------------------*/


	// Given the total height of the view, return the number of pixels that should be used for the scroller.
	// By default, uses this.scrollerEl, but can pass this in as well.
	// Utility for subclasses.
	computeScrollerHeight: function(totalHeight, scrollerEl) {
		var both;
		var otherHeight; // cumulative height of everything that is not the scrollerEl in the view (header+borders)

		scrollerEl = scrollerEl || this.scrollerEl;
		both = this.el.add(scrollerEl);

		// fuckin IE8/9/10/11 sometimes returns 0 for dimensions. this weird hack was the only thing that worked
		both.css({
			position: 'relative', // cause a reflow, which will force fresh dimension recalculation
			left: -1 // ensure reflow in case the el was already relative. negative is less likely to cause new scroll
		});
		otherHeight = this.el.outerHeight() - scrollerEl.height(); // grab the dimensions
		both.css({ position: '', left: '' }); // undo hack

		return totalHeight - otherHeight;
	},


	// Sets the scroll value of the scroller to the initial pre-configured state prior to allowing the user to change it
	initializeScroll: function() {
	},


	// Called for remembering the current scroll value of the scroller.
	// Should be called before there is a destructive operation (like removing DOM elements) that might inadvertently
	// change the scroll of the container.
	recordScroll: function() {
		if (this.scrollerEl) {
			this.scrollTop = this.scrollerEl.scrollTop();
		}
	},


	// Set the scroll value of the scroller to the previously recorded value.
	// Should be called after we know the view's dimensions have been restored following some type of destructive
	// operation (like temporarily removing DOM elements).
	restoreScroll: function() {
		if (this.scrollTop !== null) {
			this.scrollerEl.scrollTop(this.scrollTop);
		}
	},


	/* Event Elements / Segments
	------------------------------------------------------------------------------------------------------------------*/


	// Wraps the basic renderEvents() method with more View-specific logic
	renderViewEvents: function(events) {
		this.renderEvents(events);

		this.eventSegEach(function(seg) {
			this.trigger('eventAfterRender', seg.event, seg.event, seg.el);
		});
		this.trigger('eventAfterAllRender');
	},


	// Renders the events onto the view.
	renderEvents: function() {
		// subclasses should implement
	},


	// Wraps the basic destroyEvents() method with more View-specific logic
	destroyViewEvents: function() {
		this.eventSegEach(function(seg) {
			this.trigger('eventDestroy', seg.event, seg.event, seg.el);
		});

		this.destroyEvents();
	},


	// Removes event elements from the view.
	destroyEvents: function() {
		// subclasses should implement
	},


	// Given an event and the default element used for rendering, returns the element that should actually be used.
	// Basically runs events and elements through the eventRender hook.
	resolveEventEl: function(event, el) {
		var custom = this.trigger('eventRender', event, event, el);

		if (custom === false) { // means don't render at all
			el = null;
		}
		else if (custom && custom !== true) {
			el = $(custom);
		}

		return el;
	},


	// Hides all rendered event segments linked to the given event
	showEvent: function(event) {
		this.eventSegEach(function(seg) {
			seg.el.css('visibility', '');
		}, event);
	},


	// Shows all rendered event segments linked to the given event
	hideEvent: function(event) {
		this.eventSegEach(function(seg) {
			seg.el.css('visibility', 'hidden');
		}, event);
	},


	// Iterates through event segments. Goes through all by default.
	// If the optional `event` argument is specified, only iterates through segments linked to that event.
	// The `this` value of the callback function will be the view.
	eventSegEach: function(func, event) {
		var segs = this.getEventSegs();
		var i;

		for (i = 0; i < segs.length; i++) {
			if (!event || segs[i].event._id === event._id) {
				func.call(this, segs[i]);
			}
		}
	},


	// Retrieves all the rendered segment objects for the view
	getEventSegs: function() {
		// subclasses must implement
		return [];
	},


	/* Event Drag-n-Drop
	------------------------------------------------------------------------------------------------------------------*/


	// Computes if the given event is allowed to be dragged by the user
	isEventDraggable: function(event) {
		var source = event.source || {};

		return firstDefined(
			event.startEditable,
			source.startEditable,
			this.opt('eventStartEditable'),
			event.editable,
			source.editable,
			this.opt('editable')
		);
	},


	// Must be called when an event in the view is dropped onto new location.
	// `dropLocation` is an object that contains the new start/end/allDay values for the event.
	reportEventDrop: function(event, dropLocation, el, ev) {
		var calendar = this.calendar;
		var mutateResult = calendar.mutateEvent(event, dropLocation);
		var undoFunc = function() {
			mutateResult.undo();
			calendar.reportEventChange();
		};

		this.triggerEventDrop(event, mutateResult.dateDelta, undoFunc, el, ev);
		calendar.reportEventChange(); // will rerender events
	},


	// Triggers event-drop handlers that have subscribed via the API
	triggerEventDrop: function(event, dateDelta, undoFunc, el, ev) {
		this.trigger('eventDrop', el[0], event, dateDelta, undoFunc, ev, {}); // {} = jqui dummy
	},


	/* External Element Drag-n-Drop
	------------------------------------------------------------------------------------------------------------------*/


	// Must be called when an external element, via jQuery UI, has been dropped onto the calendar.
	// `meta` is the parsed data that has been embedded into the dragging event.
	// `dropLocation` is an object that contains the new start/end/allDay values for the event.
	reportExternalDrop: function(meta, dropLocation, el, ev, ui) {
		var eventProps = meta.eventProps;
		var eventInput;
		var event;

		// Try to build an event object and render it. TODO: decouple the two
		if (eventProps) {
			eventInput = $.extend({}, eventProps, dropLocation);
			event = this.calendar.renderEvent(eventInput, meta.stick)[0]; // renderEvent returns an array
		}

		this.triggerExternalDrop(event, dropLocation, el, ev, ui);
	},


	// Triggers external-drop handlers that have subscribed via the API
	triggerExternalDrop: function(event, dropLocation, el, ev, ui) {

		// trigger 'drop' regardless of whether element represents an event
		this.trigger('drop', el[0], dropLocation.start, ev, ui);

		if (event) {
			this.trigger('eventReceive', null, event); // signal an external event landed
		}
	},


	/* Drag-n-Drop Rendering (for both events and external elements)
	------------------------------------------------------------------------------------------------------------------*/


	// Renders a visual indication of a event or external-element drag over the given drop zone.
	// If an external-element, seg will be `null`
	renderDrag: function(dropLocation, seg) {
		// subclasses must implement
	},


	// Unrenders a visual indication of an event or external-element being dragged.
	destroyDrag: function() {
		// subclasses must implement
	},


	/* Event Resizing
	------------------------------------------------------------------------------------------------------------------*/


	// Computes if the given event is allowed to be resize by the user
	isEventResizable: function(event) {
		var source = event.source || {};

		return firstDefined(
			event.durationEditable,
			source.durationEditable,
			this.opt('eventDurationEditable'),
			event.editable,
			source.editable,
			this.opt('editable')
		);
	},


	// Must be called when an event in the view has been resized to a new length
	reportEventResize: function(event, newEnd, el, ev) {
		var calendar = this.calendar;
		var mutateResult = calendar.mutateEvent(event, { end: newEnd });
		var undoFunc = function() {
			mutateResult.undo();
			calendar.reportEventChange();
		};

		this.triggerEventResize(event, mutateResult.durationDelta, undoFunc, el, ev);
		calendar.reportEventChange(); // will rerender events
	},


	// Triggers event-resize handlers that have subscribed via the API
	triggerEventResize: function(event, durationDelta, undoFunc, el, ev) {
		this.trigger('eventResize', el[0], event, durationDelta, undoFunc, ev, {}); // {} = jqui dummy
	},


	/* Selection
	------------------------------------------------------------------------------------------------------------------*/


	// Selects a date range on the view. `start` and `end` are both Moments.
	// `ev` is the native mouse event that begin the interaction.
	select: function(range, ev) {
		this.unselect(ev);
		this.renderSelection(range);
		this.reportSelection(range, ev);
	},


	// Renders a visual indication of the selection
	renderSelection: function(range) {
		// subclasses should implement
	},


	// Called when a new selection is made. Updates internal state and triggers handlers.
	reportSelection: function(range, ev) {
		this.isSelected = true;
		this.trigger('select', null, range.start, range.end, ev);
	},


	// Undoes a selection. updates in the internal state and triggers handlers.
	// `ev` is the native mouse event that began the interaction.
	unselect: function(ev) {
		if (this.isSelected) {
			this.isSelected = false;
			this.destroySelection();
			this.trigger('unselect', null, ev);
		}
	},


	// Unrenders a visual indication of selection
	destroySelection: function() {
		// subclasses should implement
	},


	// Handler for unselecting when the user clicks something and the 'unselectAuto' setting is on
	documentMousedown: function(ev) {
		var ignore;

		// is there a selection, and has the user made a proper left click?
		if (this.isSelected && this.opt('unselectAuto') && isPrimaryMouseButton(ev)) {

			// only unselect if the clicked element is not identical to or inside of an 'unselectCancel' element
			ignore = this.opt('unselectCancel');
			if (!ignore || !$(ev.target).closest(ignore).length) {
				this.unselect(ev);
			}
		}
	},


	/* Date Utils
	------------------------------------------------------------------------------------------------------------------*/


	// Initializes internal variables related to calculating hidden days-of-week
	initHiddenDays: function() {
		var hiddenDays = this.opt('hiddenDays') || []; // array of day-of-week indices that are hidden
		var isHiddenDayHash = []; // is the day-of-week hidden? (hash with day-of-week-index -> bool)
		var dayCnt = 0;
		var i;

		if (this.opt('weekends') === false) {
			hiddenDays.push(0, 6); // 0=sunday, 6=saturday
		}

		for (i = 0; i < 7; i++) {
			if (
				!(isHiddenDayHash[i] = $.inArray(i, hiddenDays) !== -1)
			) {
				dayCnt++;
			}
		}

		if (!dayCnt) {
			throw 'invalid hiddenDays'; // all days were hidden? bad.
		}

		this.isHiddenDayHash = isHiddenDayHash;
	},


	// Is the current day hidden?
	// `day` is a day-of-week index (0-6), or a Moment
	isHiddenDay: function(day) {
		if (moment.isMoment(day)) {
			day = day.day();
		}
		return this.isHiddenDayHash[day];
	},


	// Incrementing the current day until it is no longer a hidden day, returning a copy.
	// If the initial value of `date` is not a hidden day, don't do anything.
	// Pass `isExclusive` as `true` if you are dealing with an end date.
	// `inc` defaults to `1` (increment one day forward each time)
	skipHiddenDays: function(date, inc, isExclusive) {
		var out = date.clone();
		inc = inc || 1;
		while (
			this.isHiddenDayHash[(out.day() + (isExclusive ? inc : 0) + 7) % 7]
		) {
			out.add(inc, 'days');
		}
		return out;
	},


	// Returns the date range of the full days the given range visually appears to occupy.
	// Returns a new range object.
	computeDayRange: function(range) {
		var startDay = range.start.clone().stripTime(); // the beginning of the day the range starts
		var end = range.end;
		var endDay = null;
		var endTimeMS;

		if (end) {
			endDay = end.clone().stripTime(); // the beginning of the day the range exclusively ends
			endTimeMS = +end.time(); // # of milliseconds into `endDay`

			// If the end time is actually inclusively part of the next day and is equal to or
			// beyond the next day threshold, adjust the end to be the exclusive end of `endDay`.
			// Otherwise, leaving it as inclusive will cause it to exclude `endDay`.
			if (endTimeMS && endTimeMS >= this.nextDayThreshold) {
				endDay.add(1, 'days');
			}
		}

		// If no end was specified, or if it is within `startDay` but not past nextDayThreshold,
		// assign the default duration of one day.
		if (!end || endDay <= startDay) {
			endDay = startDay.clone().add(1, 'days');
		}

		return { start: startDay, end: endDay };
	},


	// Does the given event visually appear to occupy more than one day?
	isMultiDayEvent: function(event) {
		var range = this.computeDayRange(event); // event is range-ish

		return range.end.diff(range.start, 'days') > 1;
	}

});

    function Calendar(element, instanceOptions) {
	var t = this;



	// Build options object
	// -----------------------------------------------------------------------------------
	// Precedence (lowest to highest): defaults, rtlDefaults, langOptions, instanceOptions

	instanceOptions = instanceOptions || {};

	var options = mergeOptions({}, defaults, instanceOptions);
	var langOptions;

	// determine language options
	if (options.lang in langOptionHash) {
		langOptions = langOptionHash[options.lang];
	}
	else {
		langOptions = langOptionHash[defaults.lang];
	}

	if (langOptions) { // if language options exist, rebuild...
		options = mergeOptions({}, defaults, langOptions, instanceOptions);
	}

	if (options.isRTL) { // is isRTL, rebuild...
		options = mergeOptions({}, defaults, rtlDefaults, langOptions || {}, instanceOptions);
	}


	
	// Exports
	// -----------------------------------------------------------------------------------

	t.options = options;
	t.render = render;
	t.destroy = destroy;
	t.refetchEvents = refetchEvents;
	t.reportEvents = reportEvents;
	t.reportEventChange = reportEventChange;
	t.rerenderEvents = renderEvents; // `renderEvents` serves as a rerender. an API method
	t.changeView = changeView;
	t.select = select;
	t.unselect = unselect;
	t.prev = prev;
	t.next = next;
	t.prevYear = prevYear;
	t.nextYear = nextYear;
	t.today = today;
	t.gotoDate = gotoDate;
	t.incrementDate = incrementDate;
	t.zoomTo = zoomTo;
	t.getDate = getDate;
	t.getCalendar = getCalendar;
	t.getView = getView;
	t.option = option;
	t.trigger = trigger;
	t.isValidViewType = isValidViewType;
	t.getViewButtonText = getViewButtonText;



	// Language-data Internals
	// -----------------------------------------------------------------------------------
	// Apply overrides to the current language's data


	var localeData = createObject( // make a cheap copy
		getMomentLocaleData(options.lang) // will fall back to en
	);

	if (options.monthNames) {
		localeData._months = options.monthNames;
	}
	if (options.monthNamesShort) {
		localeData._monthsShort = options.monthNamesShort;
	}
	if (options.dayNames) {
		localeData._weekdays = options.dayNames;
	}
	if (options.dayNamesShort) {
		localeData._weekdaysShort = options.dayNamesShort;
	}
	if (options.firstDay != null) {
		var _week = createObject(localeData._week); // _week: { dow: # }
		_week.dow = options.firstDay;
		localeData._week = _week;
	}



	// Calendar-specific Date Utilities
	// -----------------------------------------------------------------------------------


	t.defaultAllDayEventDuration = moment.duration(options.defaultAllDayEventDuration);
	t.defaultTimedEventDuration = moment.duration(options.defaultTimedEventDuration);


	// Builds a moment using the settings of the current calendar: timezone and language.
	// Accepts anything the vanilla moment() constructor accepts.
	t.moment = function() {
		var mom;

		if (options.timezone === 'local') {
			mom = fc.moment.apply(null, arguments);

			// Force the moment to be local, because fc.moment doesn't guarantee it.
			if (mom.hasTime()) { // don't give ambiguously-timed moments a local zone
				mom.local();
			}
		}
		else if (options.timezone === 'UTC') {
			mom = fc.moment.utc.apply(null, arguments); // process as UTC
		}
		else {
			mom = fc.moment.parseZone.apply(null, arguments); // let the input decide the zone
		}

		if ('_locale' in mom) { // moment 2.8 and above
			mom._locale = localeData;
		}
		else { // pre-moment-2.8
			mom._lang = localeData;
		}

		return mom;
	};


	// Returns a boolean about whether or not the calendar knows how to calculate
	// the timezone offset of arbitrary dates in the current timezone.
	t.getIsAmbigTimezone = function() {
		return options.timezone !== 'local' && options.timezone !== 'UTC';
	};


	// Returns a copy of the given date in the current timezone of it is ambiguously zoned.
	// This will also give the date an unambiguous time.
	t.rezoneDate = function(date) {
		return t.moment(date.toArray());
	};


	// Returns a moment for the current date, as defined by the client's computer,
	// or overridden by the `now` option.
	t.getNow = function() {
		var now = options.now;
		if (typeof now === 'function') {
			now = now();
		}
		return t.moment(now);
	};


	// Calculates the week number for a moment according to the calendar's
	// `weekNumberCalculation` setting.
	t.calculateWeekNumber = function(mom) {
		var calc = options.weekNumberCalculation;

		if (typeof calc === 'function') {
			return calc(mom);
		}
		else if (calc === 'local') {
			return mom.week();
		}
		else if (calc.toUpperCase() === 'ISO') {
			return mom.isoWeek();
		}
	};


	// Get an event's normalized end date. If not present, calculate it from the defaults.
	t.getEventEnd = function(event) {
		if (event.end) {
			return event.end.clone();
		}
		else {
			return t.getDefaultEventEnd(event.allDay, event.start);
		}
	};


	// Given an event's allDay status and start date, return swhat its fallback end date should be.
	t.getDefaultEventEnd = function(allDay, start) { // TODO: rename to computeDefaultEventEnd
		var end = start.clone();

		if (allDay) {
			end.stripTime().add(t.defaultAllDayEventDuration);
		}
		else {
			end.add(t.defaultTimedEventDuration);
		}

		if (t.getIsAmbigTimezone()) {
			end.stripZone(); // we don't know what the tzo should be
		}

		return end;
	};


	// Produces a human-readable string for the given duration.
	// Side-effect: changes the locale of the given duration.
	function humanizeDuration(duration) {
		return (duration.locale || duration.lang).call(duration, options.lang) // works moment-pre-2.8
			.humanize();
	}


	
	// Imports
	// -----------------------------------------------------------------------------------


	EventManager.call(t, options);
	var isFetchNeeded = t.isFetchNeeded;
	var fetchEvents = t.fetchEvents;



	// Locals
	// -----------------------------------------------------------------------------------


	var _element = element[0];
	var header;
	var headerElement;
	var content;
	var tm; // for making theme classes
	var viewSpecCache = {};
	var currentView;
	var suggestedViewHeight;
	var windowResizeProxy; // wraps the windowResize function
	var ignoreWindowResize = 0;
	var date;
	var events = [];
	
	
	
	// Main Rendering
	// -----------------------------------------------------------------------------------


	if (options.defaultDate != null) {
		date = t.moment(options.defaultDate);
	}
	else {
		date = t.getNow();
	}
	
	
	function render(inc) {
		if (!content) {
			initialRender();
		}
		else if (elementVisible()) {
			// mainly for the public API
			calcSize();
			renderView(inc);
		}
	}
	
	
	function initialRender() {
		tm = options.theme ? 'ui' : 'fc';
		element.addClass('fc');

		if (options.isRTL) {
			element.addClass('fc-rtl');
		}
		else {
			element.addClass('fc-ltr');
		}

		if (options.theme) {
			element.addClass('ui-widget');
		}
		else {
			element.addClass('fc-unthemed');
		}

		content = $("<div class='fc-view-container'/>").prependTo(element);

		header = new Header(t, options);
		headerElement = header.render();
		if (headerElement) {
			element.prepend(headerElement);
		}

		changeView(options.defaultView);

		if (options.handleWindowResize) {
			windowResizeProxy = debounce(windowResize, options.windowResizeDelay); // prevents rapid calls
			$(window).resize(windowResizeProxy);
		}
	}
	
	
	function destroy() {

		if (currentView) {
			currentView.destroyView();
		}

		header.destroy();
		content.remove();
		element.removeClass('fc fc-ltr fc-rtl fc-unthemed ui-widget');

		$(window).unbind('resize', windowResizeProxy);
	}
	
	
	function elementVisible() {
		return element.is(':visible');
	}
	
	

	// View Rendering
	// -----------------------------------------------------------------------------------


	function changeView(viewType) {
		renderView(0, viewType);
	}


	// Renders a view because of a date change, view-type change, or for the first time
	function renderView(delta, viewType) {
		ignoreWindowResize++;

		// if viewType is changing, destroy the old view
		if (currentView && viewType && currentView.type !== viewType) {
			header.deactivateButton(currentView.type);
			freezeContentHeight(); // prevent a scroll jump when view element is removed
			if (currentView.start) { // rendered before?
				currentView.destroyView();
			}
			currentView.el.remove();
			currentView = null;
		}

		// if viewType changed, or the view was never created, create a fresh view
		if (!currentView && viewType) {
			currentView = instantiateView(viewType);
			currentView.el =  $("<div class='fc-view fc-" + viewType + "-view' />").appendTo(content);
			header.activateButton(viewType);
		}

		if (currentView) {

			// let the view determine what the delta means
			if (delta < 0) {
				date = currentView.computePrevDate(date);
			}
			else if (delta > 0) {
				date = currentView.computeNextDate(date);
			}

			// render or rerender the view
			if (
				!currentView.start || // never rendered before
				delta || // explicit date window change
				!date.isWithin(currentView.intervalStart, currentView.intervalEnd) // implicit date window change
			) {
				if (elementVisible()) {

					freezeContentHeight();
					if (currentView.start) { // rendered before?
						currentView.destroyView();
					}
					currentView.setDate(date);
					currentView.renderView();
					unfreezeContentHeight();

					// need to do this after View::render, so dates are calculated
					updateTitle();
					updateTodayButton();

					getAndRenderEvents();
				}
			}
		}

		unfreezeContentHeight(); // undo any lone freezeContentHeight calls
		ignoreWindowResize--;
	}



	// View Instantiation
	// -----------------------------------------------------------------------------------


	// Given a view name for a custom view or a standard view, creates a ready-to-go View object
	function instantiateView(viewType) {
		var spec = getViewSpec(viewType);

		return new spec['class'](t, spec.options, viewType);
	}


	// Gets information about how to create a view
	function getViewSpec(requestedViewType) {
		var allDefaultButtonText = options.defaultButtonText || {};
		var allButtonText = options.buttonText || {};
		var hash = options.views || {}; // the `views` option object
		var viewType = requestedViewType;
		var viewOptionsChain = [];
		var viewOptions;
		var viewClass;
		var duration, unit, unitIsSingle = false;
		var buttonText;

		if (viewSpecCache[requestedViewType]) {
			return viewSpecCache[requestedViewType];
		}

		function processSpecInput(input) {
			if (typeof input === 'function') {
				viewClass = input;
			}
			else if (typeof input === 'object') {
				$.extend(viewOptions, input);
			}
		}

		// iterate up a view's spec ancestor chain util we find a class to instantiate
		while (viewType && !viewClass) {
			viewOptions = {}; // only for this specific view in the ancestry
			processSpecInput(fcViews[viewType]); // $.fullCalendar.views, lower precedence
			processSpecInput(hash[viewType]); // options at initialization, higher precedence
			viewOptionsChain.unshift(viewOptions); // record older ancestors first
			viewType = viewOptions.type;
		}

		viewOptionsChain.unshift({}); // jQuery's extend needs at least one arg
		viewOptions = $.extend.apply($, viewOptionsChain); // combine all, newer ancestors overwritting old

		if (viewClass) {

			duration = viewOptions.duration || viewClass.duration;
			if (duration) {
				duration = moment.duration(duration);
				unit = computeIntervalUnit(duration);
				unitIsSingle = computeIntervalAs(unit, duration) === 1;
			}

			// options that are specified per the view's duration, like "week" or "day"
			if (unitIsSingle && hash[unit]) {
				viewOptions = $.extend({}, hash[unit], viewOptions); // lowest priority
			}

			// compute the final text for the button representing this view
			buttonText =
				allButtonText[requestedViewType] || // init options, like "agendaWeek"
				(unitIsSingle ? allButtonText[unit] : null) || // init options, like "week"
				allDefaultButtonText[requestedViewType] || // lang data, like "agendaWeek"
				(unitIsSingle ? allDefaultButtonText[unit] : null) || // lang data, like "week"
				viewOptions.buttonText ||
				viewClass.buttonText ||
				(duration ? humanizeDuration(duration) : null) ||
				requestedViewType;

			return (viewSpecCache[requestedViewType] = {
				'class': viewClass,
				options: viewOptions,
				buttonText: buttonText
			});
		}
	}


	// Returns a boolean about whether the view is okay to instantiate at some point
	function isValidViewType(viewType) {
		return Boolean(getViewSpec(viewType));
	}


	// Gets the text that should be displayed on a view's button in the header
	function getViewButtonText(viewType) {
		var spec = getViewSpec(viewType);

		if (spec) {
			return spec.buttonText;
		}
	}
	
	

	// Resizing
	// -----------------------------------------------------------------------------------


	t.getSuggestedViewHeight = function() {
		if (suggestedViewHeight === undefined) {
			calcSize();
		}
		return suggestedViewHeight;
	};


	t.isHeightAuto = function() {
		return options.contentHeight === 'auto' || options.height === 'auto';
	};
	
	
	function updateSize(shouldRecalc) {
		if (elementVisible()) {

			if (shouldRecalc) {
				_calcSize();
			}

			ignoreWindowResize++;
			currentView.updateSize(true); // isResize=true. will poll getSuggestedViewHeight() and isHeightAuto()
			ignoreWindowResize--;

			return true; // signal success
		}
	}


	function calcSize() {
		if (elementVisible()) {
			_calcSize();
		}
	}
	
	
	function _calcSize() { // assumes elementVisible
		if (typeof options.contentHeight === 'number') { // exists and not 'auto'
			suggestedViewHeight = options.contentHeight;
		}
		else if (typeof options.height === 'number') { // exists and not 'auto'
			suggestedViewHeight = options.height - (headerElement ? headerElement.outerHeight(true) : 0);
		}
		else {
			suggestedViewHeight = Math.round(content.width() / Math.max(options.aspectRatio, .5));
		}
	}
	
	
	function windowResize(ev) {
		if (
			!ignoreWindowResize &&
			ev.target === window && // so we don't process jqui "resize" events that have bubbled up
			currentView.start // view has already been rendered
		) {
			if (updateSize(true)) {
				currentView.trigger('windowResize', _element);
			}
		}
	}
	
	
	
	/* Event Fetching/Rendering
	-----------------------------------------------------------------------------*/
	// TODO: going forward, most of this stuff should be directly handled by the view


	function refetchEvents() { // can be called as an API method
		destroyEvents(); // so that events are cleared before user starts waiting for AJAX
		fetchAndRenderEvents();
	}


	function renderEvents() { // destroys old events if previously rendered
		if (elementVisible()) {
			freezeContentHeight();
			currentView.destroyViewEvents(); // no performance cost if never rendered
			currentView.renderViewEvents(events);
			unfreezeContentHeight();
		}
	}


	function destroyEvents() {
		freezeContentHeight();
		currentView.destroyViewEvents();
		unfreezeContentHeight();
	}
	

	function getAndRenderEvents() {
		if (!options.lazyFetching || isFetchNeeded(currentView.start, currentView.end)) {
			fetchAndRenderEvents();
		}
		else {
			renderEvents();
		}
	}


	function fetchAndRenderEvents() {
		fetchEvents(currentView.start, currentView.end);
			// ... will call reportEvents
			// ... which will call renderEvents
	}

	
	// called when event data arrives
	function reportEvents(_events) {
		events = _events;
		renderEvents();
	}


	// called when a single event's data has been changed
	function reportEventChange() {
		renderEvents();
	}



	/* Header Updating
	-----------------------------------------------------------------------------*/


	function updateTitle() {
		header.updateTitle(currentView.computeTitle());
	}


	function updateTodayButton() {
		var now = t.getNow();
		if (now.isWithin(currentView.intervalStart, currentView.intervalEnd)) {
			header.disableButton('today');
		}
		else {
			header.enableButton('today');
		}
	}
	


	/* Selection
	-----------------------------------------------------------------------------*/
	

	function select(start, end) {

		start = t.moment(start);
		if (end) {
			end = t.moment(end);
		}
		else if (start.hasTime()) {
			end = start.clone().add(t.defaultTimedEventDuration);
		}
		else {
			end = start.clone().add(t.defaultAllDayEventDuration);
		}

		currentView.select({ start: start, end: end }); // accepts a range
	}
	

	function unselect() { // safe to be called before renderView
		if (currentView) {
			currentView.unselect();
		}
	}
	
	
	
	/* Date
	-----------------------------------------------------------------------------*/
	
	
	function prev() {
		renderView(-1);
	}
	
	
	function next() {
		renderView(1);
	}
	
	
	function prevYear() {
		date.add(-1, 'years');
		renderView();
	}
	
	
	function nextYear() {
		date.add(1, 'years');
		renderView();
	}
	
	
	function today() {
		date = t.getNow();
		renderView();
	}
	
	
	function gotoDate(dateInput) {
		date = t.moment(dateInput);
		renderView();
	}
	
	
	function incrementDate(delta) {
		date.add(moment.duration(delta));
		renderView();
	}


	// Forces navigation to a view for the given date.
	// `viewType` can be a specific view name or a generic one like "week" or "day".
	function zoomTo(newDate, viewType) {
		var viewStr;
		var match;

		if (!viewType || !isValidViewType(viewType)) { // a general view name, or "auto"
			viewType = viewType || 'day';
			viewStr = header.getViewsWithButtons().join(' '); // space-separated string of all the views in the header

			// try to match a general view name, like "week", against a specific one, like "agendaWeek"
			match = viewStr.match(new RegExp('\\w+' + capitaliseFirstLetter(viewType)));

			// fall back to the day view being used in the header
			if (!match) {
				match = viewStr.match(/\w+Day/);
			}

			viewType = match ? match[0] : 'agendaDay'; // fall back to agendaDay
		}

		date = newDate;
		changeView(viewType);
	}
	
	
	function getDate() {
		return date.clone();
	}



	/* Height "Freezing"
	-----------------------------------------------------------------------------*/


	function freezeContentHeight() {
		content.css({
			width: '100%',
			height: content.height(),
			overflow: 'hidden'
		});
	}


	function unfreezeContentHeight() {
		content.css({
			width: '',
			height: '',
			overflow: ''
		});
	}
	
	
	
	/* Misc
	-----------------------------------------------------------------------------*/
	

	function getCalendar() {
		return t;
	}

	
	function getView() {
		return currentView;
	}
	
	
	function option(name, value) {
		if (value === undefined) {
			return options[name];
		}
		if (name == 'height' || name == 'contentHeight' || name == 'aspectRatio') {
			options[name] = value;
			updateSize(true); // true = allow recalculation of height
		}
	}
	
	
	function trigger(name, thisObj) {
		if (options[name]) {
			return options[name].apply(
				thisObj || _element,
				Array.prototype.slice.call(arguments, 2)
			);
		}
	}

}

    /* Top toolbar area with buttons and title
----------------------------------------------------------------------------------------------------------------------*/
// TODO: rename all header-related things to "toolbar"

function Header(calendar, options) {
	var t = this;
	
	// exports
	t.render = render;
	t.destroy = destroy;
	t.updateTitle = updateTitle;
	t.activateButton = activateButton;
	t.deactivateButton = deactivateButton;
	t.disableButton = disableButton;
	t.enableButton = enableButton;
	t.getViewsWithButtons = getViewsWithButtons;
	
	// locals
	var el = $();
	var viewsWithButtons = [];
	var tm;


	function render() {
		var sections = options.header;

		tm = options.theme ? 'ui' : 'fc';

		if (sections) {
			el = $("<div class='fc-toolbar'/>")
				.append(renderSection('left'))
				.append(renderSection('right'))
				.append(renderSection('center'))
				.append('<div class="fc-clear"/>');

			return el;
		}
	}
	
	
	function destroy() {
		el.remove();
	}
	
	
	function renderSection(position) {
		var sectionEl = $('<div class="fc-' + position + '"/>');
		var buttonStr = options.header[position];

		if (buttonStr) {
			$.each(buttonStr.split(' '), function(i) {
				var groupChildren = $();
				var isOnlyButtons = true;
				var groupEl;

				$.each(this.split(','), function(j, buttonName) {
					var buttonClick;
					var themeIcon;
					var normalIcon;
					var defaultText;
					var viewText; // highest priority
					var customText;
					var innerHtml;
					var classes;
					var button;

					if (buttonName == 'title') {
						groupChildren = groupChildren.add($('<h2>&nbsp;</h2>')); // we always want it to take up height
						isOnlyButtons = false;
					}
					else {
						if (calendar[buttonName]) { // a calendar method
							buttonClick = function() {
								calendar[buttonName]();
							};
						}
						else if (calendar.isValidViewType(buttonName)) { // a view type
							buttonClick = function() {
								calendar.changeView(buttonName);
							};
							viewsWithButtons.push(buttonName);
							viewText = calendar.getViewButtonText(buttonName);
						}
						if (buttonClick) {

							// smartProperty allows different text per view button (ex: "Agenda Week" vs "Basic Week")
							themeIcon = smartProperty(options.themeButtonIcons, buttonName);
							normalIcon = smartProperty(options.buttonIcons, buttonName);
							defaultText = smartProperty(options.defaultButtonText, buttonName); // from languages
							customText = smartProperty(options.buttonText, buttonName);

							if (viewText || customText) {
								innerHtml = htmlEscape(viewText || customText);
							}
							else if (themeIcon && options.theme) {
								innerHtml = "<span class='ui-icon ui-icon-" + themeIcon + "'></span>";
							}
							else if (normalIcon && !options.theme) {
								innerHtml = "<span class='fc-icon fc-icon-" + normalIcon + "'></span>";
							}
							else {
								innerHtml = htmlEscape(defaultText || buttonName);
							}

							classes = [
								'fc-' + buttonName + '-button',
								tm + '-button',
								tm + '-state-default'
							];

							button = $( // type="button" so that it doesn't submit a form
								'<button type="button" class="' + classes.join(' ') + '">' +
									innerHtml +
								'</button>'
								)
								.click(function() {
									// don't process clicks for disabled buttons
									if (!button.hasClass(tm + '-state-disabled')) {

										buttonClick();

										// after the click action, if the button becomes the "active" tab, or disabled,
										// it should never have a hover class, so remove it now.
										if (
											button.hasClass(tm + '-state-active') ||
											button.hasClass(tm + '-state-disabled')
										) {
											button.removeClass(tm + '-state-hover');
										}
									}
								})
								.mousedown(function() {
									// the *down* effect (mouse pressed in).
									// only on buttons that are not the "active" tab, or disabled
									button
										.not('.' + tm + '-state-active')
										.not('.' + tm + '-state-disabled')
										.addClass(tm + '-state-down');
								})
								.mouseup(function() {
									// undo the *down* effect
									button.removeClass(tm + '-state-down');
								})
								.hover(
									function() {
										// the *hover* effect.
										// only on buttons that are not the "active" tab, or disabled
										button
											.not('.' + tm + '-state-active')
											.not('.' + tm + '-state-disabled')
											.addClass(tm + '-state-hover');
									},
									function() {
										// undo the *hover* effect
										button
											.removeClass(tm + '-state-hover')
											.removeClass(tm + '-state-down'); // if mouseleave happens before mouseup
									}
								);

							groupChildren = groupChildren.add(button);
						}
					}
				});

				if (isOnlyButtons) {
					groupChildren
						.first().addClass(tm + '-corner-left').end()
						.last().addClass(tm + '-corner-right').end();
				}

				if (groupChildren.length > 1) {
					groupEl = $('<div/>');
					if (isOnlyButtons) {
						groupEl.addClass('fc-button-group');
					}
					groupEl.append(groupChildren);
					sectionEl.append(groupEl);
				}
				else {
					sectionEl.append(groupChildren); // 1 or 0 children
				}
			});
		}

		return sectionEl;
	}
	
	
	function updateTitle(text) {
		el.find('h2').text(text);
	}
	
	
	function activateButton(buttonName) {
		el.find('.fc-' + buttonName + '-button')
			.addClass(tm + '-state-active');
	}
	
	
	function deactivateButton(buttonName) {
		el.find('.fc-' + buttonName + '-button')
			.removeClass(tm + '-state-active');
	}
	
	
	function disableButton(buttonName) {
		el.find('.fc-' + buttonName + '-button')
			.attr('disabled', 'disabled')
			.addClass(tm + '-state-disabled');
	}
	
	
	function enableButton(buttonName) {
		el.find('.fc-' + buttonName + '-button')
			.removeAttr('disabled')
			.removeClass(tm + '-state-disabled');
	}


	function getViewsWithButtons() {
		return viewsWithButtons;
	}

}

    fc.sourceNormalizers = [];
fc.sourceFetchers = [];

var ajaxDefaults = {
	dataType: 'json',
	cache: false
};

var eventGUID = 1;


function EventManager(options) { // assumed to be a calendar
	var t = this;
	
	
	// exports
	t.isFetchNeeded = isFetchNeeded;
	t.fetchEvents = fetchEvents;
	t.addEventSource = addEventSource;
	t.removeEventSource = removeEventSource;
	t.updateEvent = updateEvent;
	t.renderEvent = renderEvent;
	t.removeEvents = removeEvents;
	t.clientEvents = clientEvents;
	t.mutateEvent = mutateEvent;
	t.normalizeEventDateProps = normalizeEventDateProps;
	t.ensureVisibleEventRange = ensureVisibleEventRange;
	
	
	// imports
	var trigger = t.trigger;
	var getView = t.getView;
	var reportEvents = t.reportEvents;
	
	
	// locals
	var stickySource = { events: [] };
	var sources = [ stickySource ];
	var rangeStart, rangeEnd;
	var currentFetchID = 0;
	var pendingSourceCnt = 0;
	var loadingLevel = 0;
	var cache = []; // holds events that have already been expanded


	$.each(
		(options.events ? [ options.events ] : []).concat(options.eventSources || []),
		function(i, sourceInput) {
			var source = buildEventSource(sourceInput);
			if (source) {
				sources.push(source);
			}
		}
	);
	
	
	
	/* Fetching
	-----------------------------------------------------------------------------*/
	
	
	function isFetchNeeded(start, end) {
		return !rangeStart || // nothing has been fetched yet?
			// or, a part of the new range is outside of the old range? (after normalizing)
			start.clone().stripZone() < rangeStart.clone().stripZone() ||
			end.clone().stripZone() > rangeEnd.clone().stripZone();
	}
	
	
	function fetchEvents(start, end) {
		rangeStart = start;
		rangeEnd = end;
		cache = [];
		var fetchID = ++currentFetchID;
		var len = sources.length;
		pendingSourceCnt = len;
		for (var i=0; i<len; i++) {
			fetchEventSource(sources[i], fetchID);
		}
	}
	
	
	function fetchEventSource(source, fetchID) {
		_fetchEventSource(source, function(eventInputs) {
			var isArraySource = $.isArray(source.events);
			var i, eventInput;
			var abstractEvent;

			if (fetchID == currentFetchID) {

				if (eventInputs) {
					for (i = 0; i < eventInputs.length; i++) {
						eventInput = eventInputs[i];

						if (isArraySource) { // array sources have already been convert to Event Objects
							abstractEvent = eventInput;
						}
						else {
							abstractEvent = buildEventFromInput(eventInput, source);
						}

						if (abstractEvent) { // not false (an invalid event)
							cache.push.apply(
								cache,
								expandEvent(abstractEvent) // add individual expanded events to the cache
							);
						}
					}
				}

				pendingSourceCnt--;
				if (!pendingSourceCnt) {
					reportEvents(cache);
				}
			}
		});
	}
	
	
	function _fetchEventSource(source, callback) {
		var i;
		var fetchers = fc.sourceFetchers;
		var res;

		for (i=0; i<fetchers.length; i++) {
			res = fetchers[i].call(
				t, // this, the Calendar object
				source,
				rangeStart.clone(),
				rangeEnd.clone(),
				options.timezone,
				callback
			);

			if (res === true) {
				// the fetcher is in charge. made its own async request
				return;
			}
			else if (typeof res == 'object') {
				// the fetcher returned a new source. process it
				_fetchEventSource(res, callback);
				return;
			}
		}

		var events = source.events;
		if (events) {
			if ($.isFunction(events)) {
				pushLoading();
				events.call(
					t, // this, the Calendar object
					rangeStart.clone(),
					rangeEnd.clone(),
					options.timezone,
					function(events) {
						callback(events);
						popLoading();
					}
				);
			}
			else if ($.isArray(events)) {
				callback(events);
			}
			else {
				callback();
			}
		}else{
			var url = source.url;
			if (url) {
				var success = source.success;
				var error = source.error;
				var complete = source.complete;

				// retrieve any outbound GET/POST $.ajax data from the options
				var customData;
				if ($.isFunction(source.data)) {
					// supplied as a function that returns a key/value object
					customData = source.data();
				}
				else {
					// supplied as a straight key/value object
					customData = source.data;
				}

				// use a copy of the custom data so we can modify the parameters
				// and not affect the passed-in object.
				var data = $.extend({}, customData || {});

				var startParam = firstDefined(source.startParam, options.startParam);
				var endParam = firstDefined(source.endParam, options.endParam);
				var timezoneParam = firstDefined(source.timezoneParam, options.timezoneParam);

				if (startParam) {
					data[startParam] = rangeStart.format();
				}
				if (endParam) {
					data[endParam] = rangeEnd.format();
				}
				if (options.timezone && options.timezone != 'local') {
					data[timezoneParam] = options.timezone;
				}

				pushLoading();
				$.ajax($.extend({}, ajaxDefaults, source, {
					data: data,
					success: function(events) {
						events = events || [];
						var res = applyAll(success, this, arguments);
						if ($.isArray(res)) {
							events = res;
						}
						callback(events);
					},
					error: function() {
						applyAll(error, this, arguments);
						callback();
					},
					complete: function() {
						applyAll(complete, this, arguments);
						popLoading();
					}
				}));
			}else{
				callback();
			}
		}
	}
	
	
	
	/* Sources
	-----------------------------------------------------------------------------*/
	

	function addEventSource(sourceInput) {
		var source = buildEventSource(sourceInput);
		if (source) {
			sources.push(source);
			pendingSourceCnt++;
			fetchEventSource(source, currentFetchID); // will eventually call reportEvents
		}
	}


	function buildEventSource(sourceInput) { // will return undefined if invalid source
		var normalizers = fc.sourceNormalizers;
		var source;
		var i;

		if ($.isFunction(sourceInput) || $.isArray(sourceInput)) {
			source = { events: sourceInput };
		}
		else if (typeof sourceInput === 'string') {
			source = { url: sourceInput };
		}
		else if (typeof sourceInput === 'object') {
			source = $.extend({}, sourceInput); // shallow copy
		}

		if (source) {

			// TODO: repeat code, same code for event classNames
			if (source.className) {
				if (typeof source.className === 'string') {
					source.className = source.className.split(/\s+/);
				}
				// otherwise, assumed to be an array
			}
			else {
				source.className = [];
			}

			// for array sources, we convert to standard Event Objects up front
			if ($.isArray(source.events)) {
				source.origArray = source.events; // for removeEventSource
				source.events = $.map(source.events, function(eventInput) {
					return buildEventFromInput(eventInput, source);
				});
			}

			for (i=0; i<normalizers.length; i++) {
				normalizers[i].call(t, source);
			}

			return source;
		}
	}


	function removeEventSource(source) {
		sources = $.grep(sources, function(src) {
			return !isSourcesEqual(src, source);
		});
		// remove all client events from that source
		cache = $.grep(cache, function(e) {
			return !isSourcesEqual(e.source, source);
		});
		reportEvents(cache);
	}


	function isSourcesEqual(source1, source2) {
		return source1 && source2 && getSourcePrimitive(source1) == getSourcePrimitive(source2);
	}


	function getSourcePrimitive(source) {
		return (
			(typeof source === 'object') ? // a normalized event source?
				(source.origArray || source.googleCalendarId || source.url || source.events) : // get the primitive
				null
		) ||
		source; // the given argument *is* the primitive
	}
	
	
	
	/* Manipulation
	-----------------------------------------------------------------------------*/


	// Only ever called from the externally-facing API
	function updateEvent(event) {

		// massage start/end values, even if date string values
		event.start = t.moment(event.start);
		if (event.end) {
			event.end = t.moment(event.end);
		}
		else {
			event.end = null;
		}

		mutateEvent(event, getMiscEventProps(event)); // will handle start/end/allDay normalization
		reportEvents(cache); // reports event modifications (so we can redraw)
	}


	// Returns a hash of misc event properties that should be copied over to related events.
	function getMiscEventProps(event) {
		var props = {};

		$.each(event, function(name, val) {
			if (isMiscEventPropName(name)) {
				if (val !== undefined && isAtomic(val)) { // a defined non-object
					props[name] = val;
				}
			}
		});

		return props;
	}

	// non-date-related, non-id-related, non-secret
	function isMiscEventPropName(name) {
		return !/^_|^(id|allDay|start|end)$/.test(name);
	}

	
	// returns the expanded events that were created
	function renderEvent(eventInput, stick) {
		var abstractEvent = buildEventFromInput(eventInput);
		var events;
		var i, event;

		if (abstractEvent) { // not false (a valid input)
			events = expandEvent(abstractEvent);

			for (i = 0; i < events.length; i++) {
				event = events[i];

				if (!event.source) {
					if (stick) {
						stickySource.events.push(event);
						event.source = stickySource;
					}
					cache.push(event);
				}
			}

			reportEvents(cache);

			return events;
		}

		return [];
	}
	
	
	function removeEvents(filter) {
		var eventID;
		var i;

		if (filter == null) { // null or undefined. remove all events
			filter = function() { return true; }; // will always match
		}
		else if (!$.isFunction(filter)) { // an event ID
			eventID = filter + '';
			filter = function(event) {
				return event._id == eventID;
			};
		}

		// Purge event(s) from our local cache
		cache = $.grep(cache, filter, true); // inverse=true

		// Remove events from array sources.
		// This works because they have been converted to official Event Objects up front.
		// (and as a result, event._id has been calculated).
		for (i=0; i<sources.length; i++) {
			if ($.isArray(sources[i].events)) {
				sources[i].events = $.grep(sources[i].events, filter, true);
			}
		}

		reportEvents(cache);
	}
	
	
	function clientEvents(filter) {
		if ($.isFunction(filter)) {
			return $.grep(cache, filter);
		}
		else if (filter != null) { // not null, not undefined. an event ID
			filter += '';
			return $.grep(cache, function(e) {
				return e._id == filter;
			});
		}
		return cache; // else, return all
	}
	
	
	
	/* Loading State
	-----------------------------------------------------------------------------*/
	
	
	function pushLoading() {
		if (!(loadingLevel++)) {
			trigger('loading', null, true, getView());
		}
	}
	
	
	function popLoading() {
		if (!(--loadingLevel)) {
			trigger('loading', null, false, getView());
		}
	}
	
	
	
	/* Event Normalization
	-----------------------------------------------------------------------------*/


	// Given a raw object with key/value properties, returns an "abstract" Event object.
	// An "abstract" event is an event that, if recurring, will not have been expanded yet.
	// Will return `false` when input is invalid.
	// `source` is optional
	function buildEventFromInput(input, source) {
		var out = {};
		var start, end;
		var allDay;

		if (options.eventDataTransform) {
			input = options.eventDataTransform(input);
		}
		if (source && source.eventDataTransform) {
			input = source.eventDataTransform(input);
		}

		// Copy all properties over to the resulting object.
		// The special-case properties will be copied over afterwards.
		$.extend(out, input);

		if (source) {
			out.source = source;
		}

		out._id = input._id || (input.id === undefined ? '_fc' + eventGUID++ : input.id + '');

		if (input.className) {
			if (typeof input.className == 'string') {
				out.className = input.className.split(/\s+/);
			}
			else { // assumed to be an array
				out.className = input.className;
			}
		}
		else {
			out.className = [];
		}

		start = input.start || input.date; // "date" is an alias for "start"
		end = input.end;

		// parse as a time (Duration) if applicable
		if (isTimeString(start)) {
			start = moment.duration(start);
		}
		if (isTimeString(end)) {
			end = moment.duration(end);
		}

		if (input.dow || moment.isDuration(start) || moment.isDuration(end)) {

			// the event is "abstract" (recurring) so don't calculate exact start/end dates just yet
			out.start = start ? moment.duration(start) : null; // will be a Duration or null
			out.end = end ? moment.duration(end) : null; // will be a Duration or null
			out._recurring = true; // our internal marker
		}
		else {

			if (start) {
				start = t.moment(start);
				if (!start.isValid()) {
					return false;
				}
			}

			if (end) {
				end = t.moment(end);
				if (!end.isValid()) {
					end = null; // let defaults take over
				}
			}

			allDay = input.allDay;
			if (allDay === undefined) { // still undefined? fallback to default
				allDay = firstDefined(
					source ? source.allDayDefault : undefined,
					options.allDayDefault
				);
				// still undefined? normalizeEventDateProps will calculate it
			}

			assignDatesToEvent(start, end, allDay, out);
		}

		return out;
	}


	// Normalizes and assigns the given dates to the given partially-formed event object.
	// NOTE: mutates the given start/end moments. does not make a copy.
	function assignDatesToEvent(start, end, allDay, event) {
		event.start = start;
		event.end = end;
		event.allDay = allDay;
		normalizeEventDateProps(event);
		backupEventDates(event);
	}


	// Ensures the allDay property exists.
	// Ensures the start/end dates are consistent with allDay and forceEventDuration.
	// Accepts an Event object, or a plain object with event-ish properties.
	// NOTE: Will modify the given object.
	function normalizeEventDateProps(props) {

		if (props.allDay == null) {
			props.allDay = !(props.start.hasTime() || (props.end && props.end.hasTime()));
		}

		if (props.allDay) {
			props.start.stripTime();
			if (props.end) {
				props.end.stripTime();
			}
		}
		else {
			if (!props.start.hasTime()) {
				props.start = t.rezoneDate(props.start); // will also give it a 00:00 time
			}
			if (props.end && !props.end.hasTime()) {
				props.end = t.rezoneDate(props.end); // will also give it a 00:00 time
			}
		}

		if (props.end && !props.end.isAfter(props.start)) {
			props.end = null;
		}

		if (!props.end) {
			if (options.forceEventDuration) {
				props.end = t.getDefaultEventEnd(props.allDay, props.start);
			}
			else {
				props.end = null;
			}
		}
	}


	// If `range` is a proper range with a start and end, returns the original object.
	// If missing an end, computes a new range with an end, computing it as if it were an event.
	// TODO: make this a part of the event -> eventRange system
	function ensureVisibleEventRange(range) {
		var allDay;

		if (!range.end) {

			allDay = range.allDay; // range might be more event-ish than we think
			if (allDay == null) {
				allDay = !range.start.hasTime();
			}

			range = {
				start: range.start,
				end: t.getDefaultEventEnd(allDay, range.start)
			};
		}
		return range;
	}


	// If the given event is a recurring event, break it down into an array of individual instances.
	// If not a recurring event, return an array with the single original event.
	// If given a falsy input (probably because of a failed buildEventFromInput call), returns an empty array.
	// HACK: can override the recurring window by providing custom rangeStart/rangeEnd (for businessHours).
	function expandEvent(abstractEvent, _rangeStart, _rangeEnd) {
		var events = [];
		var dowHash;
		var dow;
		var i;
		var date;
		var startTime, endTime;
		var start, end;
		var event;

		_rangeStart = _rangeStart || rangeStart;
		_rangeEnd = _rangeEnd || rangeEnd;

		if (abstractEvent) {
			if (abstractEvent._recurring) {

				// make a boolean hash as to whether the event occurs on each day-of-week
				if ((dow = abstractEvent.dow)) {
					dowHash = {};
					for (i = 0; i < dow.length; i++) {
						dowHash[dow[i]] = true;
					}
				}

				// iterate through every day in the current range
				date = _rangeStart.clone().stripTime(); // holds the date of the current day
				while (date.isBefore(_rangeEnd)) {

					if (!dowHash || dowHash[date.day()]) { // if everyday, or this particular day-of-week

						startTime = abstractEvent.start; // the stored start and end properties are times (Durations)
						endTime = abstractEvent.end; // "
						start = date.clone();
						end = null;

						if (startTime) {
							start = start.time(startTime);
						}
						if (endTime) {
							end = date.clone().time(endTime);
						}

						event = $.extend({}, abstractEvent); // make a copy of the original
						assignDatesToEvent(
							start, end,
							!startTime && !endTime, // allDay?
							event
						);
						events.push(event);
					}

					date.add(1, 'days');
				}
			}
			else {
				events.push(abstractEvent); // return the original event. will be a one-item array
			}
		}

		return events;
	}



	/* Event Modification Math
	-----------------------------------------------------------------------------------------*/


	// Modifies an event and all related events by applying the given properties.
	// Special date-diffing logic is used for manipulation of dates.
	// If `props` does not contain start/end dates, the updated values are assumed to be the event's current start/end.
	// All date comparisons are done against the event's pristine _start and _end dates.
	// Returns an object with delta information and a function to undo all operations.
	//
	function mutateEvent(event, props) {
		var miscProps = {};
		var clearEnd;
		var dateDelta;
		var durationDelta;
		var undoFunc;

		props = props || {};

		// ensure new date-related values to compare against
		if (!props.start) {
			props.start = event.start.clone();
		}
		if (props.end === undefined) {
			props.end = event.end ? event.end.clone() : null;
		}
		if (props.allDay == null) { // is null or undefined?
			props.allDay = event.allDay;
		}

		normalizeEventDateProps(props); // massages start/end/allDay

		// clear the end date if explicitly changed to null
		clearEnd = event._end !== null && props.end === null;

		// compute the delta for moving the start and end dates together
		if (props.allDay) {
			dateDelta = diffDay(props.start, event._start); // whole-day diff from start-of-day
		}
		else {
			dateDelta = diffDayTime(props.start, event._start);
		}

		// compute the delta for moving the end date (after applying dateDelta)
		if (!clearEnd && props.end) {
			durationDelta = diffDayTime(
				// new duration
				props.end,
				props.start
			).subtract(diffDayTime(
				// subtract old duration
				event._end || t.getDefaultEventEnd(event._allDay, event._start),
				event._start
			));
		}

		// gather all non-date-related properties
		$.each(props, function(name, val) {
			if (isMiscEventPropName(name)) {
				if (val !== undefined) {
					miscProps[name] = val;
				}
			}
		});

		// apply the operations to the event and all related events
		undoFunc = mutateEvents(
			clientEvents(event._id), // get events with this ID
			clearEnd,
			props.allDay,
			dateDelta,
			durationDelta,
			miscProps
		);

		return {
			dateDelta: dateDelta,
			durationDelta: durationDelta,
			undo: undoFunc
		};
	}


	// Modifies an array of events in the following ways (operations are in order):
	// - clear the event's `end`
	// - convert the event to allDay
	// - add `dateDelta` to the start and end
	// - add `durationDelta` to the event's duration
	// - assign `miscProps` to the event
	//
	// Returns a function that can be called to undo all the operations.
	//
	// TODO: don't use so many closures. possible memory issues when lots of events with same ID.
	//
	function mutateEvents(events, clearEnd, allDay, dateDelta, durationDelta, miscProps) {
		var isAmbigTimezone = t.getIsAmbigTimezone();
		var undoFunctions = [];

		// normalize zero-length deltas to be null
		if (dateDelta && !dateDelta.valueOf()) { dateDelta = null; }
		if (durationDelta && !durationDelta.valueOf()) { durationDelta = null; }

		$.each(events, function(i, event) {
			var oldProps;
			var newProps;

			// build an object holding all the old values, both date-related and misc.
			// for the undo function.
			oldProps = {
				start: event.start.clone(),
				end: event.end ? event.end.clone() : null,
				allDay: event.allDay
			};
			$.each(miscProps, function(name) {
				oldProps[name] = event[name];
			});

			// new date-related properties. work off the original date snapshot.
			// ok to use references because they will be thrown away when backupEventDates is called.
			newProps = {
				start: event._start,
				end: event._end,
				allDay: event._allDay
			};

			if (clearEnd) {
				newProps.end = null;
			}

			newProps.allDay = allDay;

			normalizeEventDateProps(newProps); // massages start/end/allDay

			if (dateDelta) {
				newProps.start.add(dateDelta);
				if (newProps.end) {
					newProps.end.add(dateDelta);
				}
			}

			if (durationDelta) {
				if (!newProps.end) {
					newProps.end = t.getDefaultEventEnd(newProps.allDay, newProps.start);
				}
				newProps.end.add(durationDelta);
			}

			// if the dates have changed, and we know it is impossible to recompute the
			// timezone offsets, strip the zone.
			if (
				isAmbigTimezone &&
				!newProps.allDay &&
				(dateDelta || durationDelta)
			) {
				newProps.start.stripZone();
				if (newProps.end) {
					newProps.end.stripZone();
				}
			}

			$.extend(event, miscProps, newProps); // copy over misc props, then date-related props
			backupEventDates(event); // regenerate internal _start/_end/_allDay

			undoFunctions.push(function() {
				$.extend(event, oldProps);
				backupEventDates(event); // regenerate internal _start/_end/_allDay
			});
		});

		return function() {
			for (var i = 0; i < undoFunctions.length; i++) {
				undoFunctions[i]();
			}
		};
	}


	/* Business Hours
	-----------------------------------------------------------------------------------------*/

	t.getBusinessHoursEvents = getBusinessHoursEvents;


	// Returns an array of events as to when the business hours occur in the given view.
	// Abuse of our event system :(
	function getBusinessHoursEvents() {
		var optionVal = options.businessHours;
		var defaultVal = {
			className: 'fc-nonbusiness',
			start: '09:00',
			end: '17:00',
			dow: [ 1, 2, 3, 4, 5 ], // monday - friday
			rendering: 'inverse-background'
		};
		var view = t.getView();
		var eventInput;

		if (optionVal) {
			if (typeof optionVal === 'object') {
				// option value is an object that can override the default business hours
				eventInput = $.extend({}, defaultVal, optionVal);
			}
			else {
				// option value is `true`. use default business hours
				eventInput = defaultVal;
			}
		}

		if (eventInput) {
			return expandEvent(
				buildEventFromInput(eventInput),
				view.start,
				view.end
			);
		}

		return [];
	}


	/* Overlapping / Constraining
	-----------------------------------------------------------------------------------------*/

	t.isEventRangeAllowed = isEventRangeAllowed;
	t.isSelectionRangeAllowed = isSelectionRangeAllowed;
	t.isExternalDropRangeAllowed = isExternalDropRangeAllowed;


	function isEventRangeAllowed(range, event) {
		var source = event.source || {};
		var constraint = firstDefined(
			event.constraint,
			source.constraint,
			options.eventConstraint
		);
		var overlap = firstDefined(
			event.overlap,
			source.overlap,
			options.eventOverlap
		);

		range = ensureVisibleEventRange(range); // ensure a proper range with an end for isRangeAllowed

		return isRangeAllowed(range, constraint, overlap, event);
	}


	function isSelectionRangeAllowed(range) {
		return isRangeAllowed(range, options.selectConstraint, options.selectOverlap);
	}


	// when `eventProps` is defined, consider this an event.
	// `eventProps` can contain misc non-date-related info about the event.
	function isExternalDropRangeAllowed(range, eventProps) {
		var eventInput;
		var event;

		// note: very similar logic is in View's reportExternalDrop
		if (eventProps) {
			eventInput = $.extend({}, eventProps, range);
			event = expandEvent(buildEventFromInput(eventInput))[0];
		}

		if (event) {
			return isEventRangeAllowed(range, event);
		}
		else { // treat it as a selection

			range = ensureVisibleEventRange(range); // ensure a proper range with an end for isSelectionRangeAllowed

			return isSelectionRangeAllowed(range);
		}
	}


	// Returns true if the given range (caused by an event drop/resize or a selection) is allowed to exist
	// according to the constraint/overlap settings.
	// `event` is not required if checking a selection.
	function isRangeAllowed(range, constraint, overlap, event) {
		var constraintEvents;
		var anyContainment;
		var i, otherEvent;
		var otherOverlap;

		// normalize. fyi, we're normalizing in too many places :(
		range = {
			start: range.start.clone().stripZone(),
			end: range.end.clone().stripZone()
		};

		// the range must be fully contained by at least one of produced constraint events
		if (constraint != null) {

			// not treated as an event! intermediate data structure
			// TODO: use ranges in the future
			constraintEvents = constraintToEvents(constraint);

			anyContainment = false;
			for (i = 0; i < constraintEvents.length; i++) {
				if (eventContainsRange(constraintEvents[i], range)) {
					anyContainment = true;
					break;
				}
			}

			if (!anyContainment) {
				return false;
			}
		}

		for (i = 0; i < cache.length; i++) { // loop all events and detect overlap
			otherEvent = cache[i];

			// don't compare the event to itself or other related [repeating] events
			if (event && event._id === otherEvent._id) {
				continue;
			}

			// there needs to be an actual intersection before disallowing anything
			if (eventIntersectsRange(otherEvent, range)) {

				// evaluate overlap for the given range and short-circuit if necessary
				if (overlap === false) {
					return false;
				}
				else if (typeof overlap === 'function' && !overlap(otherEvent, event)) {
					return false;
				}

				// if we are computing if the given range is allowable for an event, consider the other event's
				// EventObject-specific or Source-specific `overlap` property
				if (event) {
					otherOverlap = firstDefined(
						otherEvent.overlap,
						(otherEvent.source || {}).overlap
						// we already considered the global `eventOverlap`
					);
					if (otherOverlap === false) {
						return false;
					}
					if (typeof otherOverlap === 'function' && !otherOverlap(event, otherEvent)) {
						return false;
					}
				}
			}
		}

		return true;
	}


	// Given an event input from the API, produces an array of event objects. Possible event inputs:
	// 'businessHours'
	// An event ID (number or string)
	// An object with specific start/end dates or a recurring event (like what businessHours accepts)
	function constraintToEvents(constraintInput) {

		if (constraintInput === 'businessHours') {
			return getBusinessHoursEvents();
		}

		if (typeof constraintInput === 'object') {
			return expandEvent(buildEventFromInput(constraintInput));
		}

		return clientEvents(constraintInput); // probably an ID
	}


	// Does the event's date range fully contain the given range?
	// start/end already assumed to have stripped zones :(
	function eventContainsRange(event, range) {
		var eventStart = event.start.clone().stripZone();
		var eventEnd = t.getEventEnd(event).stripZone();

		return range.start >= eventStart && range.end <= eventEnd;
	}


	// Does the event's date range intersect with the given range?
	// start/end already assumed to have stripped zones :(
	function eventIntersectsRange(event, range) {
		var eventStart = event.start.clone().stripZone();
		var eventEnd = t.getEventEnd(event).stripZone();

		return range.start < eventEnd && range.end > eventStart;
	}

}


// updates the "backup" properties, which are preserved in order to compute diffs later on.
function backupEventDates(event) {
	event._allDay = event.allDay;
	event._start = event.start.clone();
	event._end = event.end ? event.end.clone() : null;
}

    /* An abstract class for the "basic" views, as well as month view. Renders one or more rows of day cells.
----------------------------------------------------------------------------------------------------------------------*/
// It is a manager for a DayGrid subcomponent, which does most of the heavy lifting.
// It is responsible for managing width/height.

var BasicView = fcViews.basic = View.extend({

	dayGrid: null, // the main subcomponent that does most of the heavy lifting

	dayNumbersVisible: false, // display day numbers on each day cell?
	weekNumbersVisible: false, // display week numbers along the side?

	weekNumberWidth: null, // width of all the week-number cells running down the side

	headRowEl: null, // the fake row element of the day-of-week header


	initialize: function() {
		this.dayGrid = new DayGrid(this);
		this.coordMap = this.dayGrid.coordMap; // the view's date-to-cell mapping is identical to the subcomponent's
	},


	// Sets the display range and computes all necessary dates
	setRange: function(range) {
		View.prototype.setRange.call(this, range); // call the super-method

		this.dayGrid.breakOnWeeks = /year|month|week/.test(this.intervalUnit); // do before setRange
		this.dayGrid.setRange(range);
	},


	// Compute the value to feed into setRange. Overrides superclass.
	computeRange: function(date) {
		var range = View.prototype.computeRange.call(this, date); // get value from the super-method

		// year and month views should be aligned with weeks. this is already done for week
		if (/year|month/.test(range.intervalUnit)) {
			range.start.startOf('week');
			range.start = this.skipHiddenDays(range.start);

			// make end-of-week if not already
			if (range.end.weekday()) {
				range.end.add(1, 'week').startOf('week');
				range.end = this.skipHiddenDays(range.end, -1, true); // exclusively move backwards
			}
		}

		return range;
	},


	// Renders the view into `this.el`, which should already be assigned
	render: function() {

		this.dayNumbersVisible = this.dayGrid.rowCnt > 1; // TODO: make grid responsible
		this.weekNumbersVisible = this.opt('weekNumbers');
		this.dayGrid.numbersVisible = this.dayNumbersVisible || this.weekNumbersVisible;

		this.el.addClass('fc-basic-view').html(this.renderHtml());

		this.headRowEl = this.el.find('thead .fc-row');

		this.scrollerEl = this.el.find('.fc-day-grid-container');
		this.dayGrid.coordMap.containerEl = this.scrollerEl; // constrain clicks/etc to the dimensions of the scroller

		this.dayGrid.el = this.el.find('.fc-day-grid');
		this.dayGrid.render(this.hasRigidRows());
	},


	// Make subcomponents ready for cleanup
	destroy: function() {
		this.dayGrid.destroy();
		View.prototype.destroy.call(this); // call the super-method
	},


	// Builds the HTML skeleton for the view.
	// The day-grid component will render inside of a container defined by this HTML.
	renderHtml: function() {
		return '' +
			'<table>' +
				'<thead>' +
					'<tr>' +
						'<td class="' + this.widgetHeaderClass + '">' +
							this.dayGrid.headHtml() + // render the day-of-week headers
						'</td>' +
					'</tr>' +
				'</thead>' +
				'<tbody>' +
					'<tr>' +
						'<td class="' + this.widgetContentClass + '">' +
							'<div class="fc-day-grid-container">' +
								'<div class="fc-day-grid"/>' +
							'</div>' +
						'</td>' +
					'</tr>' +
				'</tbody>' +
			'</table>';
	},


	// Generates the HTML that will go before the day-of week header cells.
	// Queried by the DayGrid subcomponent when generating rows. Ordering depends on isRTL.
	headIntroHtml: function() {
		if (this.weekNumbersVisible) {
			return '' +
				'<th class="fc-week-number ' + this.widgetHeaderClass + '" ' + this.weekNumberStyleAttr() + '>' +
					'<span>' + // needed for matchCellWidths
						htmlEscape(this.opt('weekNumberTitle')) +
					'</span>' +
				'</th>';
		}
	},


	// Generates the HTML that will go before content-skeleton cells that display the day/week numbers.
	// Queried by the DayGrid subcomponent. Ordering depends on isRTL.
	numberIntroHtml: function(row) {
		if (this.weekNumbersVisible) {
			return '' +
				'<td class="fc-week-number" ' + this.weekNumberStyleAttr() + '>' +
					'<span>' + // needed for matchCellWidths
						this.calendar.calculateWeekNumber(this.dayGrid.getCell(row, 0).start) +
					'</span>' +
				'</td>';
		}
	},


	// Generates the HTML that goes before the day bg cells for each day-row.
	// Queried by the DayGrid subcomponent. Ordering depends on isRTL.
	dayIntroHtml: function() {
		if (this.weekNumbersVisible) {
			return '<td class="fc-week-number ' + this.widgetContentClass + '" ' +
				this.weekNumberStyleAttr() + '></td>';
		}
	},


	// Generates the HTML that goes before every other type of row generated by DayGrid. Ordering depends on isRTL.
	// Affects helper-skeleton and highlight-skeleton rows.
	introHtml: function() {
		if (this.weekNumbersVisible) {
			return '<td class="fc-week-number" ' + this.weekNumberStyleAttr() + '></td>';
		}
	},


	// Generates the HTML for the <td>s of the "number" row in the DayGrid's content skeleton.
	// The number row will only exist if either day numbers or week numbers are turned on.
	numberCellHtml: function(cell) {
		var date = cell.start;
		var classes;

		if (!this.dayNumbersVisible) { // if there are week numbers but not day numbers
			return '<td/>'; //  will create an empty space above events :(
		}

		classes = this.dayGrid.getDayClasses(date);
		classes.unshift('fc-day-number');

		return '' +
			'<td class="' + classes.join(' ') + '" data-date="' + date.format() + '">' +
				date.date() +
			'</td>';
	},


	// Generates an HTML attribute string for setting the width of the week number column, if it is known
	weekNumberStyleAttr: function() {
		if (this.weekNumberWidth !== null) {
			return 'style="width:' + this.weekNumberWidth + 'px"';
		}
		return '';
	},


	// Determines whether each row should have a constant height
	hasRigidRows: function() {
		var eventLimit = this.opt('eventLimit');
		return eventLimit && typeof eventLimit !== 'number';
	},


	/* Dimensions
	------------------------------------------------------------------------------------------------------------------*/


	// Refreshes the horizontal dimensions of the view
	updateWidth: function() {
		if (this.weekNumbersVisible) {
			// Make sure all week number cells running down the side have the same width.
			// Record the width for cells created later.
			this.weekNumberWidth = matchCellWidths(
				this.el.find('.fc-week-number')
			);
		}
	},


	// Adjusts the vertical dimensions of the view to the specified values
	setHeight: function(totalHeight, isAuto) {
		var eventLimit = this.opt('eventLimit');
		var scrollerHeight;

		// reset all heights to be natural
		unsetScroller(this.scrollerEl);
		uncompensateScroll(this.headRowEl);

		this.dayGrid.destroySegPopover(); // kill the "more" popover if displayed

		// is the event limit a constant level number?
		if (eventLimit && typeof eventLimit === 'number') {
			this.dayGrid.limitRows(eventLimit); // limit the levels first so the height can redistribute after
		}

		scrollerHeight = this.computeScrollerHeight(totalHeight);
		this.setGridHeight(scrollerHeight, isAuto);

		// is the event limit dynamically calculated?
		if (eventLimit && typeof eventLimit !== 'number') {
			this.dayGrid.limitRows(eventLimit); // limit the levels after the grid's row heights have been set
		}

		if (!isAuto && setPotentialScroller(this.scrollerEl, scrollerHeight)) { // using scrollbars?

			compensateScroll(this.headRowEl, getScrollbarWidths(this.scrollerEl));

			// doing the scrollbar compensation might have created text overflow which created more height. redo
			scrollerHeight = this.computeScrollerHeight(totalHeight);
			this.scrollerEl.height(scrollerHeight);

			this.restoreScroll();
		}
	},


	// Sets the height of just the DayGrid component in this view
	setGridHeight: function(height, isAuto) {
		if (isAuto) {
			undistributeHeight(this.dayGrid.rowEls); // let the rows be their natural height with no expanding
		}
		else {
			distributeHeight(this.dayGrid.rowEls, height, true); // true = compensate for height-hogging rows
		}
	},


	/* Events
	------------------------------------------------------------------------------------------------------------------*/


	// Renders the given events onto the view and populates the segments array
	renderEvents: function(events) {
		this.dayGrid.renderEvents(events);

		this.updateHeight(); // must compensate for events that overflow the row
	},


	// Retrieves all segment objects that are rendered in the view
	getEventSegs: function() {
		return this.dayGrid.getEventSegs();
	},


	// Unrenders all event elements and clears internal segment data
	destroyEvents: function() {
		this.recordScroll(); // removing events will reduce height and mess with the scroll, so record beforehand
		this.dayGrid.destroyEvents();

		// we DON'T need to call updateHeight() because:
		// A) a renderEvents() call always happens after this, which will eventually call updateHeight()
		// B) in IE8, this causes a flash whenever events are rerendered
	},


	/* Dragging (for both events and external elements)
	------------------------------------------------------------------------------------------------------------------*/


	// A returned value of `true` signals that a mock "helper" event has been rendered.
	renderDrag: function(dropLocation, seg) {
		return this.dayGrid.renderDrag(dropLocation, seg);
	},


	destroyDrag: function() {
		this.dayGrid.destroyDrag();
	},


	/* Selection
	------------------------------------------------------------------------------------------------------------------*/


	// Renders a visual indication of a selection
	renderSelection: function(range) {
		this.dayGrid.renderSelection(range);
	},


	// Unrenders a visual indications of a selection
	destroySelection: function() {
		this.dayGrid.destroySelection();
	}

});

    /* A month view with day cells running in rows (one-per-week) and columns
----------------------------------------------------------------------------------------------------------------------*/

setDefaults({
	fixedWeekCount: true
});

var MonthView = fcViews.month = BasicView.extend({

	// Produces information about what range to display
	computeRange: function(date) {
		var range = BasicView.prototype.computeRange.call(this, date); // get value from super-method

		if (this.isFixedWeeks()) {
			// ensure 6 weeks
			range.end.add(
				6 - range.end.diff(range.start, 'weeks'),
				'weeks'
			);
		}

		return range;
	},


	// Overrides the default BasicView behavior to have special multi-week auto-height logic
	setGridHeight: function(height, isAuto) {

		isAuto = isAuto || this.opt('weekMode') === 'variable'; // LEGACY: weekMode is deprecated

		// if auto, make the height of each row the height that it would be if there were 6 weeks
		if (isAuto) {
			height *= this.rowCnt / 6;
		}

		distributeHeight(this.dayGrid.rowEls, height, !isAuto); // if auto, don't compensate for height-hogging rows
	},


	isFixedWeeks: function() {
		var weekMode = this.opt('weekMode'); // LEGACY: weekMode is deprecated
		if (weekMode) {
			return weekMode === 'fixed'; // if any other type of weekMode, assume NOT fixed
		}

		return this.opt('fixedWeekCount');
	}

});

MonthView.duration = { months: 1 };

    /* A week view with simple day cells running horizontally
----------------------------------------------------------------------------------------------------------------------*/

fcViews.basicWeek = {
	type: 'basic',
	duration: { weeks: 1 }
};
    /* A view with a single simple day cell
----------------------------------------------------------------------------------------------------------------------*/

fcViews.basicDay = {
	type: 'basic',
	duration: { days: 1 }
};
    /* An abstract class for all agenda-related views. Displays one more columns with time slots running vertically.
----------------------------------------------------------------------------------------------------------------------*/
// Is a manager for the TimeGrid subcomponent and possibly the DayGrid subcomponent (if allDaySlot is on).
// Responsible for managing width/height.

setDefaults({
	allDaySlot: true,
	allDayText: 'all-day',
	scrollTime: '06:00:00',
	slotDuration: '00:30:00',
	minTime: '00:00:00',
	maxTime: '24:00:00',
	slotEventOverlap: true
});

var AGENDA_ALL_DAY_EVENT_LIMIT = 5;

fcViews.agenda = View.extend({ // AgendaView

	timeGrid: null, // the main time-grid subcomponent of this view
	dayGrid: null, // the "all-day" subcomponent. if all-day is turned off, this will be null

	axisWidth: null, // the width of the time axis running down the side

	noScrollRowEls: null, // set of fake row elements that must compensate when scrollerEl has scrollbars

	// when the time-grid isn't tall enough to occupy the given height, we render an <hr> underneath
	bottomRuleEl: null,
	bottomRuleHeight: null,


	initialize: function() {
		this.timeGrid = new TimeGrid(this);

		if (this.opt('allDaySlot')) { // should we display the "all-day" area?
			this.dayGrid = new DayGrid(this); // the all-day subcomponent of this view

			// the coordinate grid will be a combination of both subcomponents' grids
			this.coordMap = new ComboCoordMap([
				this.dayGrid.coordMap,
				this.timeGrid.coordMap
			]);
		}
		else {
			this.coordMap = this.timeGrid.coordMap;
		}
	},


	/* Rendering
	------------------------------------------------------------------------------------------------------------------*/


	// Sets the display range and computes all necessary dates
	setRange: function(range) {
		View.prototype.setRange.call(this, range); // call the super-method

		this.timeGrid.setRange(range);
		if (this.dayGrid) {
			this.dayGrid.setRange(range);
		}
	},


	// Renders the view into `this.el`, which has already been assigned
	render: function() {

		this.el.addClass('fc-agenda-view').html(this.renderHtml());

		// the element that wraps the time-grid that will probably scroll
		this.scrollerEl = this.el.find('.fc-time-grid-container');
		this.timeGrid.coordMap.containerEl = this.scrollerEl; // don't accept clicks/etc outside of this

		this.timeGrid.el = this.el.find('.fc-time-grid');
		this.timeGrid.render();

		// the <hr> that sometimes displays under the time-grid
		this.bottomRuleEl = $('<hr class="' + this.widgetHeaderClass + '"/>')
			.appendTo(this.timeGrid.el); // inject it into the time-grid

		if (this.dayGrid) {
			this.dayGrid.el = this.el.find('.fc-day-grid');
			this.dayGrid.render();

			// have the day-grid extend it's coordinate area over the <hr> dividing the two grids
			this.dayGrid.bottomCoordPadding = this.dayGrid.el.next('hr').outerHeight();
		}

		this.noScrollRowEls = this.el.find('.fc-row:not(.fc-scroller *)'); // fake rows not within the scroller
	},


	// Make subcomponents ready for cleanup
	destroy: function() {
		this.timeGrid.destroy();
		if (this.dayGrid) {
			this.dayGrid.destroy();
		}
		View.prototype.destroy.call(this); // call the super-method
	},


	// Builds the HTML skeleton for the view.
	// The day-grid and time-grid components will render inside containers defined by this HTML.
	renderHtml: function() {
		return '' +
			'<table>' +
				'<thead>' +
					'<tr>' +
						'<td class="' + this.widgetHeaderClass + '">' +
							this.timeGrid.headHtml() + // render the day-of-week headers
						'</td>' +
					'</tr>' +
				'</thead>' +
				'<tbody>' +
					'<tr>' +
						'<td class="' + this.widgetContentClass + '">' +
							(this.dayGrid ?
								'<div class="fc-day-grid"/>' +
								'<hr class="' + this.widgetHeaderClass + '"/>' :
								''
								) +
							'<div class="fc-time-grid-container">' +
								'<div class="fc-time-grid"/>' +
							'</div>' +
						'</td>' +
					'</tr>' +
				'</tbody>' +
			'</table>';
	},


	// Generates the HTML that will go before the day-of week header cells.
	// Queried by the TimeGrid subcomponent when generating rows. Ordering depends on isRTL.
	headIntroHtml: function() {
		var date;
		var weekNumber;
		var weekTitle;
		var weekText;

		if (this.opt('weekNumbers')) {
			date = this.timeGrid.getCell(0).start;
			weekNumber = this.calendar.calculateWeekNumber(date);
			weekTitle = this.opt('weekNumberTitle');

			if (this.opt('isRTL')) {
				weekText = weekNumber + weekTitle;
			}
			else {
				weekText = weekTitle + weekNumber;
			}

			return '' +
				'<th class="fc-axis fc-week-number ' + this.widgetHeaderClass + '" ' + this.axisStyleAttr() + '>' +
					'<span>' + // needed for matchCellWidths
						htmlEscape(weekText) +
					'</span>' +
				'</th>';
		}
		else {
			return '<th class="fc-axis ' + this.widgetHeaderClass + '" ' + this.axisStyleAttr() + '></th>';
		}
	},


	// Generates the HTML that goes before the all-day cells.
	// Queried by the DayGrid subcomponent when generating rows. Ordering depends on isRTL.
	dayIntroHtml: function() {
		return '' +
			'<td class="fc-axis ' + this.widgetContentClass + '" ' + this.axisStyleAttr() + '>' +
				'<span>' + // needed for matchCellWidths
					(this.opt('allDayHtml') || htmlEscape(this.opt('allDayText'))) +
				'</span>' +
			'</td>';
	},


	// Generates the HTML that goes before the bg of the TimeGrid slot area. Long vertical column.
	slotBgIntroHtml: function() {
		return '<td class="fc-axis ' + this.widgetContentClass + '" ' + this.axisStyleAttr() + '></td>';
	},


	// Generates the HTML that goes before all other types of cells.
	// Affects content-skeleton, helper-skeleton, highlight-skeleton for both the time-grid and day-grid.
	// Queried by the TimeGrid and DayGrid subcomponents when generating rows. Ordering depends on isRTL.
	introHtml: function() {
		return '<td class="fc-axis" ' + this.axisStyleAttr() + '></td>';
	},


	// Generates an HTML attribute string for setting the width of the axis, if it is known
	axisStyleAttr: function() {
		if (this.axisWidth !== null) {
			 return 'style="width:' + this.axisWidth + 'px"';
		}
		return '';
	},


	/* Dimensions
	------------------------------------------------------------------------------------------------------------------*/


	updateSize: function(isResize) {
		if (isResize) {
			this.timeGrid.resize();
		}
		View.prototype.updateSize.call(this, isResize);
	},


	// Refreshes the horizontal dimensions of the view
	updateWidth: function() {
		// make all axis cells line up, and record the width so newly created axis cells will have it
		this.axisWidth = matchCellWidths(this.el.find('.fc-axis'));
	},


	// Adjusts the vertical dimensions of the view to the specified values
	setHeight: function(totalHeight, isAuto) {
		var eventLimit;
		var scrollerHeight;

		if (this.bottomRuleHeight === null) {
			// calculate the height of the rule the very first time
			this.bottomRuleHeight = this.bottomRuleEl.outerHeight();
		}
		this.bottomRuleEl.hide(); // .show() will be called later if this <hr> is necessary

		// reset all dimensions back to the original state
		this.scrollerEl.css('overflow', '');
		unsetScroller(this.scrollerEl);
		uncompensateScroll(this.noScrollRowEls);

		// limit number of events in the all-day area
		if (this.dayGrid) {
			this.dayGrid.destroySegPopover(); // kill the "more" popover if displayed

			eventLimit = this.opt('eventLimit');
			if (eventLimit && typeof eventLimit !== 'number') {
				eventLimit = AGENDA_ALL_DAY_EVENT_LIMIT; // make sure "auto" goes to a real number
			}
			if (eventLimit) {
				this.dayGrid.limitRows(eventLimit);
			}
		}

		if (!isAuto) { // should we force dimensions of the scroll container, or let the contents be natural height?

			scrollerHeight = this.computeScrollerHeight(totalHeight);
			if (setPotentialScroller(this.scrollerEl, scrollerHeight)) { // using scrollbars?

				// make the all-day and header rows lines up
				compensateScroll(this.noScrollRowEls, getScrollbarWidths(this.scrollerEl));

				// the scrollbar compensation might have changed text flow, which might affect height, so recalculate
				// and reapply the desired height to the scroller.
				scrollerHeight = this.computeScrollerHeight(totalHeight);
				this.scrollerEl.height(scrollerHeight);

				this.restoreScroll();
			}
			else { // no scrollbars
				// still, force a height and display the bottom rule (marks the end of day)
				this.scrollerEl.height(scrollerHeight).css('overflow', 'hidden'); // in case <hr> goes outside
				this.bottomRuleEl.show();
			}
		}
	},


	// Sets the scroll value of the scroller to the initial pre-configured state prior to allowing the user to change it
	initializeScroll: function() {
		var _this = this;
		var scrollTime = moment.duration(this.opt('scrollTime'));
		var top = this.timeGrid.computeTimeTop(scrollTime);

		// zoom can give weird floating-point values. rather scroll a little bit further
		top = Math.ceil(top);

		if (top) {
			top++; // to overcome top border that slots beyond the first have. looks better
		}

		function scroll() {
			_this.scrollerEl.scrollTop(top);
		}

		scroll();
		setTimeout(scroll, 0); // overrides any previous scroll state made by the browser
	},


	/* Events
	------------------------------------------------------------------------------------------------------------------*/


	// Renders events onto the view and populates the View's segment array
	renderEvents: function(events) {
		var dayEvents = [];
		var timedEvents = [];
		var daySegs = [];
		var timedSegs;
		var i;

		// separate the events into all-day and timed
		for (i = 0; i < events.length; i++) {
			if (events[i].allDay) {
				dayEvents.push(events[i]);
			}
			else {
				timedEvents.push(events[i]);
			}
		}

		// render the events in the subcomponents
		timedSegs = this.timeGrid.renderEvents(timedEvents);
		if (this.dayGrid) {
			daySegs = this.dayGrid.renderEvents(dayEvents);
		}

		// the all-day area is flexible and might have a lot of events, so shift the height
		this.updateHeight();
	},


	// Retrieves all segment objects that are rendered in the view
	getEventSegs: function() {
		return this.timeGrid.getEventSegs().concat(
			this.dayGrid ? this.dayGrid.getEventSegs() : []
		);
	},


	// Unrenders all event elements and clears internal segment data
	destroyEvents: function() {

		// if destroyEvents is being called as part of an event rerender, renderEvents will be called shortly
		// after, so remember what the scroll value was so we can restore it.
		this.recordScroll();

		// destroy the events in the subcomponents
		this.timeGrid.destroyEvents();
		if (this.dayGrid) {
			this.dayGrid.destroyEvents();
		}

		// we DON'T need to call updateHeight() because:
		// A) a renderEvents() call always happens after this, which will eventually call updateHeight()
		// B) in IE8, this causes a flash whenever events are rerendered
	},


	/* Dragging (for events and external elements)
	------------------------------------------------------------------------------------------------------------------*/


	// A returned value of `true` signals that a mock "helper" event has been rendered.
	renderDrag: function(dropLocation, seg) {
		if (dropLocation.start.hasTime()) {
			return this.timeGrid.renderDrag(dropLocation, seg);
		}
		else if (this.dayGrid) {
			return this.dayGrid.renderDrag(dropLocation, seg);
		}
	},


	destroyDrag: function() {
		this.timeGrid.destroyDrag();
		if (this.dayGrid) {
			this.dayGrid.destroyDrag();
		}
	},


	/* Selection
	------------------------------------------------------------------------------------------------------------------*/


	// Renders a visual indication of a selection
	renderSelection: function(range) {
		if (range.start.hasTime() || range.end.hasTime()) {
			this.timeGrid.renderSelection(range);
		}
		else if (this.dayGrid) {
			this.dayGrid.renderSelection(range);
		}
	},


	// Unrenders a visual indications of a selection
	destroySelection: function() {
		this.timeGrid.destroySelection();
		if (this.dayGrid) {
			this.dayGrid.destroySelection();
		}
	}

});

    /* A week view with an all-day cell area at the top, and a time grid below
----------------------------------------------------------------------------------------------------------------------*/

fcViews.agendaWeek = {
	type: 'agenda',
	duration: { weeks: 1 }
};
    /* A day view with an all-day cell area at the top, and a time grid below
----------------------------------------------------------------------------------------------------------------------*/

fcViews.agendaDay = {
	type: 'agenda',
	duration: { days: 1 }
};
});