/*!

* 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 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. // 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 }

}; });