(function (global, factory) {

typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
typeof define === 'function' && define.amd ? define(factory) :
(global.shuffle = factory());

}(this, (function () { 'use strict';

// Polyfill for creating CustomEvents on IE9/10/11

// code pulled from: // github.com/d4tocchini/customevent-polyfill // developer.mozilla.org/en-US/docs/Web/API/CustomEvent#Polyfill

try {

var ce = new window.CustomEvent('test');
ce.preventDefault();
if (ce.defaultPrevented !== true) {
    // IE has problems with .preventDefault() on custom events
    // http://stackoverflow.com/questions/23349191
    throw new Error('Could not prevent default');
}

} catch(e) {

var CustomEvent$1 = function(event, params) {
  var evt, origPrevent;
  params = params || {
    bubbles: false,
    cancelable: false,
    detail: undefined
  };

  evt = document.createEvent("CustomEvent");
  evt.initCustomEvent(event, params.bubbles, params.cancelable, params.detail);
  origPrevent = evt.preventDefault;
  evt.preventDefault = function () {
    origPrevent.call(this);
    try {
      Object.defineProperty(this, 'defaultPrevented', {
        get: function () {
          return true;
        }
      });
    } catch(e) {
      this.defaultPrevented = true;
    }
  };
  return evt;
};

CustomEvent$1.prototype = window.Event.prototype;
window.CustomEvent = CustomEvent$1; // expose definition to window

}

var proto = Element.prototype; var vendor = proto.matches

|| proto.matchesSelector
|| proto.webkitMatchesSelector
|| proto.mozMatchesSelector
|| proto.msMatchesSelector
|| proto.oMatchesSelector;

var index = match;

/**

* Match `el` to `selector`.
*
* @param {Element} el
* @param {String} selector
* @return {Boolean}
* @api public
*/

function match(el, selector) {

if (vendor) return vendor.call(el, selector);
var nodes = el.parentNode.querySelectorAll(selector);
for (var i = 0; i < nodes.length; i++) {
  if (nodes[i] == el) return true;
}
return false;

}

var commonjsGlobal = typeof window !== 'undefined' ? window : typeof global !== 'undefined' ? global : typeof self !== 'undefined' ? self : {};

function createCommonjsModule(fn, module) {

return module = { exports: {} }, fn(module, module.exports), module.exports;

}

var index$1 = createCommonjsModule(function (module) { 'use strict';

// there's 3 implementations written in increasing order of efficiency

// 1 - no Set type is defined function uniqNoSet(arr) {

var ret = [];

for (var i = 0; i < arr.length; i++) {
        if (ret.indexOf(arr[i]) === -1) {
                ret.push(arr[i]);
        }
}

return ret;

}

// 2 - a simple Set type is defined function uniqSet(arr) {

var seen = new Set();
return arr.filter(function (el) {
        if (!seen.has(el)) {
                seen.add(el);
                return true;
        }

        return false;
});

}

// 3 - a standard Set type is defined and it has a forEach method function uniqSetWithForEach(arr) {

var ret = [];

(new Set(arr)).forEach(function (el) {
        ret.push(el);
});

return ret;

}

// V8 currently has a broken implementation // github.com/joyent/node/issues/8449 function doesForEachActuallyWork() {

var ret = false;

(new Set([true])).forEach(function (el) {
        ret = el;
});

return ret === true;

}

if ('Set' in commonjsGlobal) {

if (typeof Set.prototype.forEach === 'function' && doesForEachActuallyWork()) {
        module.exports = uniqSetWithForEach;
} else {
        module.exports = uniqSet;
}

} else {

module.exports = uniqNoSet;

} });

var immutable = extend;

var hasOwnProperty = Object.prototype.hasOwnProperty;

function extend() {

var target = {};

for (var i = 0; i < arguments.length; i++) {
    var source = arguments[i];

    for (var key in source) {
        if (hasOwnProperty.call(source, key)) {
            target[key] = source[key];
        }
    }
}

return target

}

var index$2 = throttle;

/**

* Returns a new function that, when invoked, invokes `func` at most once per `wait` milliseconds.
*
* @param {Function} func Function to wrap.
* @param {Number} wait Number of milliseconds that must elapse between `func` invocations.
* @return {Function} A new function that wraps the `func` function passed in.
*/

function throttle (func, wait) {

var ctx, args, rtn, timeoutID; // caching
var last = 0;

return function throttled () {
  ctx = this;
  args = arguments;
  var delta = new Date() - last;
  if (!timeoutID)
    if (delta >= wait) call();
    else timeoutID = setTimeout(call, wait - delta);
  return rtn;
};

function call () {
  timeoutID = 0;
  last = +new Date();
  rtn = func.apply(ctx, args);
  ctx = null;
  args = null;
}

}

var index$3 = function parallel(fns, context, callback) {

if (!callback) {
  if (typeof context === 'function') {
    callback = context;
    context = null;
  } else {
    callback = noop;
  }
}

var pending = fns && fns.length;
if (!pending) return callback(null, []);

var finished = false;
var results = new Array(pending);

fns.forEach(context ? function (fn, i) {
  fn.call(context, maybeDone(i));
} : function (fn, i) {
  fn(maybeDone(i));
});

function maybeDone(i) {
  return function (err, result) {
    if (finished) return;

    if (err) {
      callback(err, results);
      finished = true;
      return
    }

    results[i] = result;

    if (!--pending) callback(null, results);
  }
}

};

function noop() {}

/**

* Always returns a numeric value, given a value. Logic from jQuery's `isNumeric`.
* @param {*} value Possibly numeric value.
* @return {number} `value` or zero if `value` isn't numeric.
*/

function getNumber(value) {

return parseFloat(value) || 0;

}

var classCallCheck = function (instance, Constructor) {

if (!(instance instanceof Constructor)) {
  throw new TypeError("Cannot call a class as a function");
}

};

var createClass = function () {

function defineProperties(target, props) {
  for (var i = 0; i < props.length; i++) {
    var descriptor = props[i];
    descriptor.enumerable = descriptor.enumerable || false;
    descriptor.configurable = true;
    if ("value" in descriptor) descriptor.writable = true;
    Object.defineProperty(target, descriptor.key, descriptor);
  }
}

return function (Constructor, protoProps, staticProps) {
  if (protoProps) defineProperties(Constructor.prototype, protoProps);
  if (staticProps) defineProperties(Constructor, staticProps);
  return Constructor;
};

}();

var Point = function () {

/**
 * Represents a coordinate pair.
 * @param {number} [x=0] X.
 * @param {number} [y=0] Y.
 */
function Point(x, y) {
  classCallCheck(this, Point);

  this.x = getNumber(x);
  this.y = getNumber(y);
}

/**
 * Whether two points are equal.
 * @param {Point} a Point A.
 * @param {Point} b Point B.
 * @return {boolean}
 */

createClass(Point, null, [{
  key: 'equals',
  value: function equals(a, b) {
    return a.x === b.x && a.y === b.y;
  }
}]);
return Point;

}();

var Classes = {

BASE: 'shuffle',
SHUFFLE_ITEM: 'shuffle-item',
VISIBLE: 'shuffle-item--visible',
HIDDEN: 'shuffle-item--hidden'

};

var id$1 = 0;

var ShuffleItem = function () {

function ShuffleItem(element) {
  classCallCheck(this, ShuffleItem);

  id$1 += 1;
  this.id = id$1;
  this.element = element;
  this.isVisible = true;
}

createClass(ShuffleItem, [{
  key: 'show',
  value: function show() {
    this.isVisible = true;
    this.element.classList.remove(Classes.HIDDEN);
    this.element.classList.add(Classes.VISIBLE);
  }
}, {
  key: 'hide',
  value: function hide() {
    this.isVisible = false;
    this.element.classList.remove(Classes.VISIBLE);
    this.element.classList.add(Classes.HIDDEN);
  }
}, {
  key: 'init',
  value: function init() {
    this.addClasses([Classes.SHUFFLE_ITEM, Classes.VISIBLE]);
    this.applyCss(ShuffleItem.Css.INITIAL);
    this.scale = ShuffleItem.Scale.VISIBLE;
    this.point = new Point();
  }
}, {
  key: 'addClasses',
  value: function addClasses(classes) {
    var _this = this;

    classes.forEach(function (className) {
      _this.element.classList.add(className);
    });
  }
}, {
  key: 'removeClasses',
  value: function removeClasses(classes) {
    var _this2 = this;

    classes.forEach(function (className) {
      _this2.element.classList.remove(className);
    });
  }
}, {
  key: 'applyCss',
  value: function applyCss(obj) {
    var _this3 = this;

    Object.keys(obj).forEach(function (key) {
      _this3.element.style[key] = obj[key];
    });
  }
}, {
  key: 'dispose',
  value: function dispose() {
    this.removeClasses([Classes.HIDDEN, Classes.VISIBLE, Classes.SHUFFLE_ITEM]);

    this.element.removeAttribute('style');
    this.element = null;
  }
}]);
return ShuffleItem;

}();

ShuffleItem.Css = {

INITIAL: {
  position: 'absolute',
  top: 0,
  left: 0,
  visibility: 'visible',
  'will-change': 'transform'
},
VISIBLE: {
  before: {
    opacity: 1,
    visibility: 'visible'
  },
  after: {}
},
HIDDEN: {
  before: {
    opacity: 0
  },
  after: {
    visibility: 'hidden'
  }
}

};

ShuffleItem.Scale = {

VISIBLE: 1,
HIDDEN: 0.001

};

var element = document.body || document.documentElement; var e$1 = document.createElement('div'); e$1.style.cssText = 'width:10px;padding:2px;box-sizing:border-box;'; element.appendChild(e$1);

var width = window.getComputedStyle(e$1, null).width; var ret = width === '10px';

element.removeChild(e$1);

/**

* Retrieve the computed style for an element, parsed as a float.
* @param {Element} element Element to get style for.
* @param {string} style Style property.
* @param {CSSStyleDeclaration} [styles] Optionally include clean styles to
*     use instead of asking for them again.
* @return {number} The parsed computed value or zero if that fails because IE
*     will return 'auto' when the element doesn't have margins instead of
*     the computed style.
*/

function getNumberStyle(element, style) {

var styles = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : window.getComputedStyle(element, null);

var value = getNumber(styles[style]);

// Support IE<=11 and W3C spec.
if (!ret && style === 'width') {
  value += getNumber(styles.paddingLeft) + getNumber(styles.paddingRight) + getNumber(styles.borderLeftWidth) + getNumber(styles.borderRightWidth);
} else if (!ret && style === 'height') {
  value += getNumber(styles.paddingTop) + getNumber(styles.paddingBottom) + getNumber(styles.borderTopWidth) + getNumber(styles.borderBottomWidth);
}

return value;

}

/**

* Fisher-Yates shuffle.
* http://stackoverflow.com/a/962890/373422
* https://bost.ocks.org/mike/shuffle/
* @param {Array} array Array to shuffle.
* @return {Array} Randomly sorted array.
*/

function randomize(array) {

var n = array.length;

while (n) {
  n -= 1;
  var i = Math.floor(Math.random() * (n + 1));
  var temp = array[i];
  array[i] = array[n];
  array[n] = temp;
}

return array;

}

var defaults$1 = {

// Use array.reverse() to reverse the results
reverse: false,

// Sorting function
by: null,

// If true, this will skip the sorting and return a randomized order in the array
randomize: false,

// Determines which property of each item in the array is passed to the
// sorting method.
key: 'element'

};

// You can return `undefined` from the `by` function to revert to DOM order. function sorter(arr, options) {

var opts = immutable(defaults$1, options);
var original = [].slice.call(arr);
var revert = false;

if (!arr.length) {
  return [];
}

if (opts.randomize) {
  return randomize(arr);
}

// Sort the elements by the opts.by function.
// If we don't have opts.by, default to DOM order
if (typeof opts.by === 'function') {
  arr.sort(function (a, b) {
    // Exit early if we already know we want to revert
    if (revert) {
      return 0;
    }

    var valA = opts.by(a[opts.key]);
    var valB = opts.by(b[opts.key]);

    // If both values are undefined, use the DOM order
    if (valA === undefined && valB === undefined) {
      revert = true;
      return 0;
    }

    if (valA < valB || valA === 'sortFirst' || valB === 'sortLast') {
      return -1;
    }

    if (valA > valB || valA === 'sortLast' || valB === 'sortFirst') {
      return 1;
    }

    return 0;
  });
}

// Revert to the original array if necessary
if (revert) {
  return original;
}

if (opts.reverse) {
  arr.reverse();
}

return arr;

}

var transitions = {}; var eventName = 'transitionend'; var count = 0;

function uniqueId() {

count += 1;
return eventName + count;

}

function cancelTransitionEnd(id) {

if (transitions[id]) {
  transitions[id].element.removeEventListener(eventName, transitions[id].listener);
  transitions[id] = null;
  return true;
}

return false;

}

function onTransitionEnd(element, callback) {

var id = uniqueId();
var listener = function listener(evt) {
  if (evt.currentTarget === evt.target) {
    cancelTransitionEnd(id);
    callback(evt);
  }
};

element.addEventListener(eventName, listener);

transitions[id] = { element: element, listener: listener };

return id;

}

function arrayMax(array) {

return Math.max.apply(Math, array); // eslint-disable-line prefer-spread

}

function arrayMin(array) {

return Math.min.apply(Math, array); // eslint-disable-line prefer-spread

}

/**

* Determine the number of columns an items spans.
* @param {number} itemWidth Width of the item.
* @param {number} columnWidth Width of the column (includes gutter).
* @param {number} columns Total number of columns
* @param {number} threshold A buffer value for the size of the column to fit.
* @return {number}
*/

function getColumnSpan(itemWidth, columnWidth, columns, threshold) {

var columnSpan = itemWidth / columnWidth;

// If the difference between the rounded column span number and the
// calculated column span number is really small, round the number to
// make it fit.
if (Math.abs(Math.round(columnSpan) - columnSpan) < threshold) {
  // e.g. columnSpan = 4.0089945390298745
  columnSpan = Math.round(columnSpan);
}

// Ensure the column span is not more than the amount of columns in the whole layout.
return Math.min(Math.ceil(columnSpan), columns);

}

/**

* Retrieves the column set to use for placement.
* @param {number} columnSpan The number of columns this current item spans.
* @param {number} columns The total columns in the grid.
* @return {Array.<number>} An array of numbers represeting the column set.
*/

function getAvailablePositions(positions, columnSpan, columns) {

// The item spans only one column.
if (columnSpan === 1) {
  return positions;
}

// The item spans more than one column, figure out how many different
// places it could fit horizontally.
// The group count is the number of places within the positions this block
// could fit, ignoring the current positions of items.
// Imagine a 2 column brick as the second item in a 4 column grid with
// 10px height each. Find the places it would fit:
// [20, 10, 10, 0]
//  |   |   |
//  *   *   *
//
// Then take the places which fit and get the bigger of the two:
// max([20, 10]), max([10, 10]), max([10, 0]) = [20, 10, 0]
//
// Next, find the first smallest number (the short column).
// [20, 10, 0]
//          |
//          *
//
// And that's where it should be placed!
//
// Another example where the second column's item extends past the first:
// [10, 20, 10, 0] => [20, 20, 10] => 10
var available = [];

// For how many possible positions for this item there are.
for (var i = 0; i <= columns - columnSpan; i++) {
  // Find the bigger value for each place it could fit.
  available.push(arrayMax(positions.slice(i, i + columnSpan)));
}

return available;

}

/**

* Find index of short column, the first from the left where this item will go.
*
* @param {Array.<number>} positions The array to search for the smallest number.
* @param {number} buffer Optional buffer which is very useful when the height
*     is a percentage of the width.
* @return {number} Index of the short column.
*/

function getShortColumn(positions, buffer) {

var minPosition = arrayMin(positions);
for (var i = 0, len = positions.length; i < len; i++) {
  if (positions[i] >= minPosition - buffer && positions[i] <= minPosition + buffer) {
    return i;
  }
}

return 0;

}

/**

* Determine the location of the next item, based on its size.
* @param {Object} itemSize Object with width and height.
* @param {Array.<number>} positions Positions of the other current items.
* @param {number} gridSize The column width or row height.
* @param {number} total The total number of columns or rows.
* @param {number} threshold Buffer value for the column to fit.
* @param {number} buffer Vertical buffer for the height of items.
* @return {Point}
*/

function getItemPosition(_ref) {

var itemSize = _ref.itemSize,
    positions = _ref.positions,
    gridSize = _ref.gridSize,
    total = _ref.total,
    threshold = _ref.threshold,
    buffer = _ref.buffer;

var span = getColumnSpan(itemSize.width, gridSize, total, threshold);
var setY = getAvailablePositions(positions, span, total);
var shortColumnIndex = getShortColumn(setY, buffer);

// Position the item
var point = new Point(Math.round(gridSize * shortColumnIndex), Math.round(setY[shortColumnIndex]));

// Update the columns array with the new values for each column.
// e.g. before the update the columns could be [250, 0, 0, 0] for an item
// which spans 2 columns. After it would be [250, itemHeight, itemHeight, 0].
var setHeight = setY[shortColumnIndex] + itemSize.height;
for (var i = 0; i < span; i++) {
  positions[shortColumnIndex + i] = setHeight;
}

return point;

}

function toArray(arrayLike) {

return Array.prototype.slice.call(arrayLike);

}

function arrayIncludes(array, obj) {

return array.indexOf(obj) > -1;

}

// Used for unique instance variables var id = 0;

var Shuffle = function () {

/**
 * Categorize, sort, and filter a responsive grid of items.
 *
 * @param {Element} element An element which is the parent container for the grid items.
 * @param {Object} [options=Shuffle.options] Options object.
 * @constructor
 */
function Shuffle(element) {
  var options = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : {};
  classCallCheck(this, Shuffle);

  this.options = immutable(Shuffle.options, options);

  this.useSizer = false;
  this.lastSort = {};
  this.group = Shuffle.ALL_ITEMS;
  this.lastFilter = Shuffle.ALL_ITEMS;
  this.isEnabled = true;
  this.isDestroyed = false;
  this.isInitialized = false;
  this._transitions = [];
  this.isTransitioning = false;
  this._queue = [];

  var el = this._getElementOption(element);

  if (!el) {
    throw new TypeError('Shuffle needs to be initialized with an element.');
  }

  this.element = el;
  this.id = 'shuffle_' + id;
  id += 1;

  this._init();
  this.isInitialized = true;
}

createClass(Shuffle, [{
  key: '_init',
  value: function _init() {
    this.items = this._getItems();

    this.options.sizer = this._getElementOption(this.options.sizer);

    if (this.options.sizer) {
      this.useSizer = true;
    }

    // Add class and invalidate styles
    this.element.classList.add(Shuffle.Classes.BASE);

    // Set initial css for each item
    this._initItems();

    // Bind resize events
    this._onResize = this._getResizeFunction();
    window.addEventListener('resize', this._onResize);

    // Get container css all in one request. Causes reflow
    var containerCss = window.getComputedStyle(this.element, null);
    var containerWidth = Shuffle.getSize(this.element).width;

    // Add styles to the container if it doesn't have them.
    this._validateStyles(containerCss);

    // We already got the container's width above, no need to cause another
    // reflow getting it again... Calculate the number of columns there will be
    this._setColumns(containerWidth);

    // Kick off!
    this.filter(this.options.group, this.options.initialSort);

    // The shuffle items haven't had transitions set on them yet so the user
    // doesn't see the first layout. Set them now that the first layout is done.
    // First, however, a synchronous layout must be caused for the previous
    // styles to be applied without transitions.
    this.element.offsetWidth; // eslint-disable-line no-unused-expressions
    this._setTransitions();
    this.element.style.transition = 'height ' + this.options.speed + 'ms ' + this.options.easing;
  }

  /**
   * Returns a throttled and proxied function for the resize handler.
   * @return {Function}
   * @private
   */

}, {
  key: '_getResizeFunction',
  value: function _getResizeFunction() {
    var resizeFunction = this._handleResize.bind(this);
    return this.options.throttle ? this.options.throttle(resizeFunction, this.options.throttleTime) : resizeFunction;
  }

  /**
   * Retrieve an element from an option.
   * @param {string|jQuery|Element} option The option to check.
   * @return {?Element} The plain element or null.
   * @private
   */

}, {
  key: '_getElementOption',
  value: function _getElementOption(option) {
    // If column width is a string, treat is as a selector and search for the
    // sizer element within the outermost container
    if (typeof option === 'string') {
      return this.element.querySelector(option);

      // Check for an element
    } else if (option && option.nodeType && option.nodeType === 1) {
      return option;

      // Check for jQuery object
    } else if (option && option.jquery) {
      return option[0];
    }

    return null;
  }

  /**
   * Ensures the shuffle container has the css styles it needs applied to it.
   * @param {Object} styles Key value pairs for position and overflow.
   * @private
   */

}, {
  key: '_validateStyles',
  value: function _validateStyles(styles) {
    // Position cannot be static.
    if (styles.position === 'static') {
      this.element.style.position = 'relative';
    }

    // Overflow has to be hidden.
    if (styles.overflow !== 'hidden') {
      this.element.style.overflow = 'hidden';
    }
  }

  /**
   * Filter the elements by a category.
   * @param {string} [category] Category to filter by. If it's given, the last
   *     category will be used to filter the items.
   * @param {Array} [collection] Optionally filter a collection. Defaults to
   *     all the items.
   * @return {!{visible: Array, hidden: Array}}
   * @private
   */

}, {
  key: '_filter',
  value: function _filter() {
    var category = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : this.lastFilter;
    var collection = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : this.items;

    var set$$1 = this._getFilteredSets(category, collection);

    // Individually add/remove hidden/visible classes
    this._toggleFilterClasses(set$$1);

    // Save the last filter in case elements are appended.
    this.lastFilter = category;

    // This is saved mainly because providing a filter function (like searching)
    // will overwrite the `lastFilter` property every time its called.
    if (typeof category === 'string') {
      this.group = category;
    }

    return set$$1;
  }

  /**
   * Returns an object containing the visible and hidden elements.
   * @param {string|Function} category Category or function to filter by.
   * @param {Array.<Element>} items A collection of items to filter.
   * @return {!{visible: Array, hidden: Array}}
   * @private
   */

}, {
  key: '_getFilteredSets',
  value: function _getFilteredSets(category, items) {
    var _this = this;

    var visible = [];
    var hidden = [];

    // category === 'all', add visible class to everything
    if (category === Shuffle.ALL_ITEMS) {
      visible = items;

      // Loop through each item and use provided function to determine
      // whether to hide it or not.
    } else {
      items.forEach(function (item) {
        if (_this._doesPassFilter(category, item.element)) {
          visible.push(item);
        } else {
          hidden.push(item);
        }
      });
    }

    return {
      visible: visible,
      hidden: hidden
    };
  }

  /**
   * Test an item to see if it passes a category.
   * @param {string|Function} category Category or function to filter by.
   * @param {Element} element An element to test.
   * @return {boolean} Whether it passes the category/filter.
   * @private
   */

}, {
  key: '_doesPassFilter',
  value: function _doesPassFilter(category, element) {
    if (typeof category === 'function') {
      return category.call(element, element, this);
    }

    // Check each element's data-groups attribute against the given category.
    var attr = element.getAttribute('data-' + Shuffle.FILTER_ATTRIBUTE_KEY);
    var keys = this.options.delimeter ? attr.split(this.options.delimeter) : JSON.parse(attr);

    function testCategory(category) {
      return arrayIncludes(keys, category);
    }

    if (Array.isArray(category)) {
      if (this.options.filterMode === Shuffle.FilterMode.ANY) {
        return category.some(testCategory);
      }
      return category.every(testCategory);
    }

    return arrayIncludes(keys, category);
  }

  /**
   * Toggles the visible and hidden class names.
   * @param {{visible, hidden}} Object with visible and hidden arrays.
   * @private
   */

}, {
  key: '_toggleFilterClasses',
  value: function _toggleFilterClasses(_ref) {
    var visible = _ref.visible,
        hidden = _ref.hidden;

    visible.forEach(function (item) {
      item.show();
    });

    hidden.forEach(function (item) {
      item.hide();
    });
  }

  /**
   * Set the initial css for each item
   * @param {Array.<ShuffleItem>} [items] Optionally specifiy at set to initialize.
   * @private
   */

}, {
  key: '_initItems',
  value: function _initItems() {
    var items = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : this.items;

    items.forEach(function (item) {
      item.init();
    });
  }

  /**
   * Remove element reference and styles.
   * @private
   */

}, {
  key: '_disposeItems',
  value: function _disposeItems() {
    var items = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : this.items;

    items.forEach(function (item) {
      item.dispose();
    });
  }

  /**
   * Updates the visible item count.
   * @private
   */

}, {
  key: '_updateItemCount',
  value: function _updateItemCount() {
    this.visibleItems = this._getFilteredItems().length;
  }

  /**
   * Sets css transform transition on a group of elements. This is not executed
   * at the same time as `item.init` so that transitions don't occur upon
   * initialization of Shuffle.
   * @param {Array.<ShuffleItem>} items Shuffle items to set transitions on.
   * @private
   */

}, {
  key: '_setTransitions',
  value: function _setTransitions() {
    var items = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : this.items;

    var speed = this.options.speed;
    var easing = this.options.easing;

    var str = this.options.useTransforms ? 'transform ' + speed + 'ms ' + easing + ', opacity ' + speed + 'ms ' + easing : 'top ' + speed + 'ms ' + easing + ', left ' + speed + 'ms ' + easing + ', opacity ' + speed + 'ms ' + easing;

    items.forEach(function (item) {
      item.element.style.transition = str;
    });
  }
}, {
  key: '_getItems',
  value: function _getItems() {
    var _this2 = this;

    return toArray(this.element.children).filter(function (el) {
      return index(el, _this2.options.itemSelector);
    }).map(function (el) {
      return new ShuffleItem(el);
    });
  }

  /**
   * When new elements are added to the shuffle container, update the array of
   * items because that is the order `_layout` calls them.
   */

}, {
  key: '_updateItemsOrder',
  value: function _updateItemsOrder() {
    var children = this.element.children;
    this.items = sorter(this.items, {
      by: function by(element) {
        return Array.prototype.indexOf.call(children, element);
      }
    });
  }
}, {
  key: '_getFilteredItems',
  value: function _getFilteredItems() {
    return this.items.filter(function (item) {
      return item.isVisible;
    });
  }
}, {
  key: '_getConcealedItems',
  value: function _getConcealedItems() {
    return this.items.filter(function (item) {
      return !item.isVisible;
    });
  }

  /**
   * Returns the column size, based on column width and sizer options.
   * @param {number} containerWidth Size of the parent container.
   * @param {number} gutterSize Size of the gutters.
   * @return {number}
   * @private
   */

}, {
  key: '_getColumnSize',
  value: function _getColumnSize(containerWidth, gutterSize) {
    var size = void 0;

    // If the columnWidth property is a function, then the grid is fluid
    if (typeof this.options.columnWidth === 'function') {
      size = this.options.columnWidth(containerWidth);

      // columnWidth option isn't a function, are they using a sizing element?
    } else if (this.useSizer) {
      size = Shuffle.getSize(this.options.sizer).width;

      // if not, how about the explicitly set option?
    } else if (this.options.columnWidth) {
      size = this.options.columnWidth;

      // or use the size of the first item
    } else if (this.items.length > 0) {
      size = Shuffle.getSize(this.items[0].element, true).width;

      // if there's no items, use size of container
    } else {
      size = containerWidth;
    }

    // Don't let them set a column width of zero.
    if (size === 0) {
      size = containerWidth;
    }

    return size + gutterSize;
  }

  /**
   * Returns the gutter size, based on gutter width and sizer options.
   * @param {number} containerWidth Size of the parent container.
   * @return {number}
   * @private
   */

}, {
  key: '_getGutterSize',
  value: function _getGutterSize(containerWidth) {
    var size = void 0;
    if (typeof this.options.gutterWidth === 'function') {
      size = this.options.gutterWidth(containerWidth);
    } else if (this.useSizer) {
      size = getNumberStyle(this.options.sizer, 'marginLeft');
    } else {
      size = this.options.gutterWidth;
    }

    return size;
  }

  /**
   * Calculate the number of columns to be used. Gets css if using sizer element.
   * @param {number} [containerWidth] Optionally specify a container width if
   *    it's already available.
   */

}, {
  key: '_setColumns',
  value: function _setColumns() {
    var containerWidth = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : Shuffle.getSize(this.element).width;

    var gutter = this._getGutterSize(containerWidth);
    var columnWidth = this._getColumnSize(containerWidth, gutter);
    var calculatedColumns = (containerWidth + gutter) / columnWidth;

    // Widths given from getStyles are not precise enough...
    if (Math.abs(Math.round(calculatedColumns) - calculatedColumns) < this.options.columnThreshold) {
      // e.g. calculatedColumns = 11.998876
      calculatedColumns = Math.round(calculatedColumns);
    }

    this.cols = Math.max(Math.floor(calculatedColumns), 1);
    this.containerWidth = containerWidth;
    this.colWidth = columnWidth;
  }

  /**
   * Adjust the height of the grid
   */

}, {
  key: '_setContainerSize',
  value: function _setContainerSize() {
    this.element.style.height = this._getContainerSize() + 'px';
  }

  /**
   * Based on the column heights, it returns the biggest one.
   * @return {number}
   * @private
   */

}, {
  key: '_getContainerSize',
  value: function _getContainerSize() {
    return arrayMax(this.positions);
  }

  /**
   * Get the clamped stagger amount.
   * @param {number} index Index of the item to be staggered.
   * @return {number}
   */

}, {
  key: '_getStaggerAmount',
  value: function _getStaggerAmount(index$$1) {
    return Math.min(index$$1 * this.options.staggerAmount, this.options.staggerAmountMax);
  }

  /**
   * @return {boolean} Whether the event was prevented or not.
   */

}, {
  key: '_dispatch',
  value: function _dispatch(name) {
    var details = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : {};

    if (this.isDestroyed) {
      return false;
    }

    details.shuffle = this;
    return !this.element.dispatchEvent(new CustomEvent(name, {
      bubbles: true,
      cancelable: false,
      detail: details
    }));
  }

  /**
   * Zeros out the y columns array, which is used to determine item placement.
   * @private
   */

}, {
  key: '_resetCols',
  value: function _resetCols() {
    var i = this.cols;
    this.positions = [];
    while (i) {
      i -= 1;
      this.positions.push(0);
    }
  }

  /**
   * Loops through each item that should be shown and calculates the x, y position.
   * @param {Array.<ShuffleItem>} items Array of items that will be shown/layed
   *     out in order in their array.
   */

}, {
  key: '_layout',
  value: function _layout(items) {
    var _this3 = this;

    var count = 0;
    items.forEach(function (item) {
      var currPos = item.point;
      var currScale = item.scale;
      var itemSize = Shuffle.getSize(item.element, true);
      var pos = _this3._getItemPosition(itemSize);

      function callback() {
        item.element.style.transitionDelay = '';
        item.applyCss(ShuffleItem.Css.VISIBLE.after);
      }

      // If the item will not change its position, do not add it to the render
      // queue. Transitions don't fire when setting a property to the same value.
      if (Point.equals(currPos, pos) && currScale === ShuffleItem.Scale.VISIBLE) {
        item.applyCss(ShuffleItem.Css.VISIBLE.before);
        callback();
        return;
      }

      item.point = pos;
      item.scale = ShuffleItem.Scale.VISIBLE;

      // Use xtend here to clone the object so that the `before` object isn't
      // modified when the transition delay is added.
      var styles = immutable(ShuffleItem.Css.VISIBLE.before);
      styles.transitionDelay = _this3._getStaggerAmount(count) + 'ms';

      _this3._queue.push({
        item: item,
        styles: styles,
        callback: callback
      });

      count += 1;
    });
  }

  /**
   * Determine the location of the next item, based on its size.
   * @param {{width: number, height: number}} itemSize Object with width and height.
   * @return {Point}
   * @private
   */

}, {
  key: '_getItemPosition',
  value: function _getItemPosition(itemSize) {
    return getItemPosition({
      itemSize: itemSize,
      positions: this.positions,
      gridSize: this.colWidth,
      total: this.cols,
      threshold: this.options.columnThreshold,
      buffer: this.options.buffer
    });
  }

  /**
   * Hides the elements that don't match our filter.
   * @param {Array.<ShuffleItem>} collection Collection to shrink.
   * @private
   */

}, {
  key: '_shrink',
  value: function _shrink() {
    var _this4 = this;

    var collection = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : this._getConcealedItems();

    var count = 0;
    collection.forEach(function (item) {
      function callback() {
        item.applyCss(ShuffleItem.Css.HIDDEN.after);
      }

      // Continuing would add a transitionend event listener to the element, but
      // that listener would not execute because the transform and opacity would
      // stay the same.
      // The callback is executed here because it is not guaranteed to be called
      // after the transitionend event because the transitionend could be
      // canceled if another animation starts.
      if (item.scale === ShuffleItem.Scale.HIDDEN) {
        item.applyCss(ShuffleItem.Css.HIDDEN.before);
        callback();
        return;
      }

      item.scale = ShuffleItem.Scale.HIDDEN;

      var styles = immutable(ShuffleItem.Css.HIDDEN.before);
      styles.transitionDelay = _this4._getStaggerAmount(count) + 'ms';

      _this4._queue.push({
        item: item,
        styles: styles,
        callback: callback
      });

      count += 1;
    });
  }

  /**
   * Resize handler.
   * @private
   */

}, {
  key: '_handleResize',
  value: function _handleResize() {
    // If shuffle is disabled, destroyed, don't do anything
    if (!this.isEnabled || this.isDestroyed) {
      return;
    }

    // Will need to check height in the future if it's layed out horizontaly
    var containerWidth = Shuffle.getSize(this.element).width;

    // containerWidth hasn't changed, don't do anything
    if (containerWidth === this.containerWidth) {
      return;
    }

    this.update();
  }

  /**
   * Returns styles which will be applied to the an item for a transition.
   * @param {Object} obj Transition options.
   * @return {!Object} Transforms for transitions, left/top for animate.
   * @private
   */

}, {
  key: '_getStylesForTransition',
  value: function _getStylesForTransition(_ref2) {
    var item = _ref2.item,
        styles = _ref2.styles;

    if (!styles.transitionDelay) {
      styles.transitionDelay = '0ms';
    }

    var x = item.point.x;
    var y = item.point.y;

    if (this.options.useTransforms) {
      styles.transform = 'translate(' + x + 'px, ' + y + 'px) scale(' + item.scale + ')';
    } else {
      styles.left = x + 'px';
      styles.top = y + 'px';
    }

    return styles;
  }

  /**
   * Listen for the transition end on an element and execute the itemCallback
   * when it finishes.
   * @param {Element} element Element to listen on.
   * @param {Function} itemCallback Callback for the item.
   * @param {Function} done Callback to notify `parallel` that this one is done.
   */

}, {
  key: '_whenTransitionDone',
  value: function _whenTransitionDone(element, itemCallback, done) {
    var id = onTransitionEnd(element, function (evt) {
      itemCallback();
      done(null, evt);
    });

    this._transitions.push(id);
  }

  /**
   * Return a function which will set CSS styles and call the `done` function
   * when (if) the transition finishes.
   * @param {Object} opts Transition object.
   * @return {Function} A function to be called with a `done` function.
   */

}, {
  key: '_getTransitionFunction',
  value: function _getTransitionFunction(opts) {
    var _this5 = this;

    return function (done) {
      opts.item.applyCss(_this5._getStylesForTransition(opts));
      _this5._whenTransitionDone(opts.item.element, opts.callback, done);
    };
  }

  /**
   * Execute the styles gathered in the style queue. This applies styles to elements,
   * triggering transitions.
   * @private
   */

}, {
  key: '_processQueue',
  value: function _processQueue() {
    if (this.isTransitioning) {
      this._cancelMovement();
    }

    var hasSpeed = this.options.speed > 0;
    var hasQueue = this._queue.length > 0;

    if (hasQueue && hasSpeed && this.isInitialized) {
      this._startTransitions(this._queue);
    } else if (hasQueue) {
      this._styleImmediately(this._queue);
      this._dispatchLayout();

      // A call to layout happened, but none of the newly visible items will
      // change position or the transition duration is zero, which will not trigger
      // the transitionend event.
    } else {
      this._dispatchLayout();
    }

    // Remove everything in the style queue
    this._queue.length = 0;
  }

  /**
   * Wait for each transition to finish, the emit the layout event.
   * @param {Array.<Object>} transitions Array of transition objects.
   */

}, {
  key: '_startTransitions',
  value: function _startTransitions(transitions) {
    var _this6 = this;

    // Set flag that shuffle is currently in motion.
    this.isTransitioning = true;

    // Create an array of functions to be called.
    var callbacks = transitions.map(function (obj) {
      return _this6._getTransitionFunction(obj);
    });

    index$3(callbacks, this._movementFinished.bind(this));
  }
}, {
  key: '_cancelMovement',
  value: function _cancelMovement() {
    // Remove the transition end event for each listener.
    this._transitions.forEach(cancelTransitionEnd);

    // Reset the array.
    this._transitions.length = 0;

    // Show it's no longer active.
    this.isTransitioning = false;
  }

  /**
   * Apply styles without a transition.
   * @param {Array.<Object>} objects Array of transition objects.
   * @private
   */

}, {
  key: '_styleImmediately',
  value: function _styleImmediately(objects) {
    var _this7 = this;

    if (objects.length) {
      var elements = objects.map(function (obj) {
        return obj.item.element;
      });

      Shuffle._skipTransitions(elements, function () {
        objects.forEach(function (obj) {
          obj.item.applyCss(_this7._getStylesForTransition(obj));
          obj.callback();
        });
      });
    }
  }
}, {
  key: '_movementFinished',
  value: function _movementFinished() {
    this._transitions.length = 0;
    this.isTransitioning = false;
    this._dispatchLayout();
  }
}, {
  key: '_dispatchLayout',
  value: function _dispatchLayout() {
    this._dispatch(Shuffle.EventType.LAYOUT);
  }

  /**
   * The magic. This is what makes the plugin 'shuffle'
   * @param {string|Function|Array.<string>} [category] Category to filter by.
   *     Can be a function, string, or array of strings.
   * @param {Object} [sortObj] A sort object which can sort the visible set
   */

}, {
  key: 'filter',
  value: function filter(category, sortObj) {
    if (!this.isEnabled) {
      return;
    }

    if (!category || category && category.length === 0) {
      category = Shuffle.ALL_ITEMS; // eslint-disable-line no-param-reassign
    }

    this._filter(category);

    // Shrink each hidden item
    this._shrink();

    // How many visible elements?
    this._updateItemCount();

    // Update transforms on visible elements so they will animate to their new positions.
    this.sort(sortObj);
  }

  /**
   * Gets the visible elements, sorts them, and passes them to layout.
   * @param {Object} opts the options object for the sorted plugin
   */

}, {
  key: 'sort',
  value: function sort() {
    var opts = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : this.lastSort;

    if (!this.isEnabled) {
      return;
    }

    this._resetCols();

    var items = this._getFilteredItems();
    items = sorter(items, opts);

    this._layout(items);

    // `_layout` always happens after `_shrink`, so it's safe to process the style
    // queue here with styles from the shrink method.
    this._processQueue();

    // Adjust the height of the container.
    this._setContainerSize();

    this.lastSort = opts;
  }

  /**
   * Reposition everything.
   * @param {boolean} isOnlyLayout If true, column and gutter widths won't be
   *     recalculated.
   */

}, {
  key: 'update',
  value: function update(isOnlyLayout) {
    if (this.isEnabled) {
      if (!isOnlyLayout) {
        // Get updated colCount
        this._setColumns();
      }

      // Layout items
      this.sort();
    }
  }

  /**
   * Use this instead of `update()` if you don't need the columns and gutters updated
   * Maybe an image inside `shuffle` loaded (and now has a height), which means calculations
   * could be off.
   */

}, {
  key: 'layout',
  value: function layout() {
    this.update(true);
  }

  /**
   * New items have been appended to shuffle. Mix them in with the current
   * filter or sort status.
   * @param {Array.<Element>} newItems Collection of new items.
   */

}, {
  key: 'add',
  value: function add(newItems) {
    var items = index$1(newItems).map(function (el) {
      return new ShuffleItem(el);
    });

    // Add classes and set initial positions.
    this._initItems(items);

    // Add transition to each item.
    this._setTransitions(items);

    // Update the list of items.
    this.items = this.items.concat(items);
    this._updateItemsOrder();
    this.filter(this.lastFilter);
  }

  /**
   * Disables shuffle from updating dimensions and layout on resize
   */

}, {
  key: 'disable',
  value: function disable() {
    this.isEnabled = false;
  }

  /**
   * Enables shuffle again
   * @param {boolean} [isUpdateLayout=true] if undefined, shuffle will update columns and gutters
   */

}, {
  key: 'enable',
  value: function enable(isUpdateLayout) {
    this.isEnabled = true;
    if (isUpdateLayout !== false) {
      this.update();
    }
  }

  /**
   * Remove 1 or more shuffle items
   * @param {Array.<Element>} elements An array containing one or more
   *     elements in shuffle
   * @return {Shuffle} The shuffle object
   */

}, {
  key: 'remove',
  value: function remove(elements) {
    var _this8 = this;

    if (!elements.length) {
      return;
    }

    var collection = index$1(elements);

    var oldItems = collection.map(function (element) {
      return _this8.getItemByElement(element);
    }).filter(function (item) {
      return !!item;
    });

    var handleLayout = function handleLayout() {
      _this8.element.removeEventListener(Shuffle.EventType.LAYOUT, handleLayout);
      _this8._disposeItems(oldItems);

      // Remove the collection in the callback
      collection.forEach(function (element) {
        element.parentNode.removeChild(element);
      });

      _this8._dispatch(Shuffle.EventType.REMOVED, { collection: collection });
    };

    // Hide collection first.
    this._toggleFilterClasses({
      visible: [],
      hidden: oldItems
    });

    this._shrink(oldItems);

    this.sort();

    // Update the list of items here because `remove` could be called again
    // with an item that is in the process of being removed.
    this.items = this.items.filter(function (item) {
      return !arrayIncludes(oldItems, item);
    });
    this._updateItemCount();

    this.element.addEventListener(Shuffle.EventType.LAYOUT, handleLayout);
  }

  /**
   * Retrieve a shuffle item by its element.
   * @param {Element} element Element to look for.
   * @return {?ShuffleItem} A shuffle item or null if it's not found.
   */

}, {
  key: 'getItemByElement',
  value: function getItemByElement(element) {
    for (var i = this.items.length - 1; i >= 0; i--) {
      if (this.items[i].element === element) {
        return this.items[i];
      }
    }

    return null;
  }

  /**
   * Destroys shuffle, removes events, styles, and classes
   */

}, {
  key: 'destroy',
  value: function destroy() {
    this._cancelMovement();
    window.removeEventListener('resize', this._onResize);

    // Reset container styles
    this.element.classList.remove('shuffle');
    this.element.removeAttribute('style');

    // Reset individual item styles
    this._disposeItems();

    // Null DOM references
    this.items = null;
    this.options.sizer = null;
    this.element = null;
    this._transitions = null;

    // Set a flag so if a debounced resize has been triggered,
    // it can first check if it is actually isDestroyed and not doing anything
    this.isDestroyed = true;
  }

  /**
   * Returns the outer width of an element, optionally including its margins.
   *
   * There are a few different methods for getting the width of an element, none of
   * which work perfectly for all Shuffle's use cases.
   *
   * 1. getBoundingClientRect() `left` and `right` properties.
   *   - Accounts for transform scaled elements, making it useless for Shuffle
   *   elements which have shrunk.
   * 2. The `offsetWidth` property.
   *   - This value stays the same regardless of the elements transform property,
   *   however, it does not return subpixel values.
   * 3. getComputedStyle()
   *   - This works great Chrome, Firefox, Safari, but IE<=11 does not include
   *   padding and border when box-sizing: border-box is set, requiring a feature
   *   test and extra work to add the padding back for IE and other browsers which
   *   follow the W3C spec here.
   *
   * @param {Element} element The element.
   * @param {boolean} [includeMargins] Whether to include margins. Default is false.
   * @return {{width: number, height: number}} The width and height.
   */

}], [{
  key: 'getSize',
  value: function getSize(element, includeMargins) {
    // Store the styles so that they can be used by others without asking for it again.
    var styles = window.getComputedStyle(element, null);
    var width = getNumberStyle(element, 'width', styles);
    var height = getNumberStyle(element, 'height', styles);

    if (includeMargins) {
      var marginLeft = getNumberStyle(element, 'marginLeft', styles);
      var marginRight = getNumberStyle(element, 'marginRight', styles);
      var marginTop = getNumberStyle(element, 'marginTop', styles);
      var marginBottom = getNumberStyle(element, 'marginBottom', styles);
      width += marginLeft + marginRight;
      height += marginTop + marginBottom;
    }

    return {
      width: width,
      height: height
    };
  }

  /**
   * Change a property or execute a function which will not have a transition
   * @param {Array.<Element>} elements DOM elements that won't be transitioned.
   * @param {Function} callback A function which will be called while transition
   *     is set to 0ms.
   * @private
   */

}, {
  key: '_skipTransitions',
  value: function _skipTransitions(elements, callback) {
    var zero = '0ms';

    // Save current duration and delay.
    var data = elements.map(function (element) {
      var style = element.style;
      var duration = style.transitionDuration;
      var delay = style.transitionDelay;

      // Set the duration to zero so it happens immediately
      style.transitionDuration = zero;
      style.transitionDelay = zero;

      return {
        duration: duration,
        delay: delay
      };
    });

    callback();

    // Cause reflow.
    elements[0].offsetWidth; // eslint-disable-line no-unused-expressions

    // Put the duration back
    elements.forEach(function (element, i) {
      element.style.transitionDuration = data[i].duration;
      element.style.transitionDelay = data[i].delay;
    });
  }
}]);
return Shuffle;

}();

Shuffle.ShuffleItem = ShuffleItem;

Shuffle.ALL_ITEMS = 'all'; Shuffle.FILTER_ATTRIBUTE_KEY = 'groups';

/**

* @enum {string}
*/

Shuffle.EventType = {

LAYOUT: 'shuffle:layout',
REMOVED: 'shuffle:removed'

};

/** @enum {string} */ Shuffle.Classes = Classes;

/**

* @enum {string}
*/

Shuffle.FilterMode = {

ANY: 'any',
ALL: 'all'

};

// Overrideable options Shuffle.options = {

// Initial filter group.
group: Shuffle.ALL_ITEMS,

// Transition/animation speed (milliseconds).
speed: 250,

// CSS easing function to use.
easing: 'ease',

// e.g. '.picture-item'.
itemSelector: '*',

// Element or selector string. Use an element to determine the size of columns
// and gutters.
sizer: null,

// A static number or function that tells the plugin how wide the gutters
// between columns are (in pixels).
gutterWidth: 0,

// A static number or function that returns a number which tells the plugin
// how wide the columns are (in pixels).
columnWidth: 0,

// If your group is not json, and is comma delimeted, you could set delimeter
// to ','.
delimeter: null,

// Useful for percentage based heights when they might not always be exactly
// the same (in pixels).
buffer: 0,

// Reading the width of elements isn't precise enough and can cause columns to
// jump between values.
columnThreshold: 0.01,

// Shuffle can be isInitialized with a sort object. It is the same object
// given to the sort method.
initialSort: null,

// By default, shuffle will throttle resize events. This can be changed or
// removed.
throttle: index$2,

// How often shuffle can be called on resize (in milliseconds).
throttleTime: 300,

// Transition delay offset for each item in milliseconds.
staggerAmount: 15,

// Maximum stagger delay in milliseconds.
staggerAmountMax: 250,

// Whether to use transforms or absolute positioning.
useTransforms: true,

// Affects using an array with filter. e.g. `filter(['one', 'two'])`. With "any",
// the element passes the test if any of its groups are in the array. With "all",
// the element only passes if all groups are in the array.
filterMode: Shuffle.FilterMode.ANY

};

// Expose for testing. Hack at your own risk. Shuffle.__Point = Point; Shuffle.__sorter = sorter; Shuffle.__getColumnSpan = getColumnSpan; Shuffle.__getAvailablePositions = getAvailablePositions; Shuffle.__getShortColumn = getShortColumn;

return Shuffle;

}))); //# sourceMappingURL=shuffle.js.map