owl.carousel.js

/**
 * Owl carousel
 * @version 2.3.4
 * @author Bartosz Wojciechowski
 * @author David Deutsch
 * @license The MIT License (MIT)
 * @todo Lazy Load Icon
 * @todo prevent animationend bubling
 * @todo itemsScaleUp
 * @todo Test Zepto
 * @todo stagePadding calculate wrong active classes
 */
;(function($, window, document, undefined) {

	/**
	 * Creates a carousel.
	 * @class The Owl Carousel.
	 * @public
	 * @param {HTMLElement|jQuery} element - The element to create the carousel for.
	 * @param {Object} [options] - The options
	 */
	function Owl(element, options) {

		/**
		 * Current settings for the carousel.
		 * @public
		 */
		this.settings = null;

		/**
		 * Current options set by the caller including defaults.
		 * @public
		 */
		this.options = $.extend({}, Owl.Defaults, options);

		/**
		 * Plugin element.
		 * @public
		 */
		this.$element = $(element);

		/**
		 * Proxied event handlers.
		 * @protected
		 */
		this._handlers = {};

		/**
		 * References to the running plugins of this carousel.
		 * @protected
		 */
		this._plugins = {};

		/**
		 * Currently suppressed events to prevent them from being retriggered.
		 * @protected
		 */
		this._supress = {};

		/**
		 * Absolute current position.
		 * @protected
		 */
		this._current = null;

		/**
		 * Animation speed in milliseconds.
		 * @protected
		 */
		this._speed = null;

		/**
		 * Coordinates of all items in pixel.
		 * @todo The name of this member is missleading.
		 * @protected
		 */
		this._coordinates = [];

		/**
		 * Current breakpoint.
		 * @todo Real media queries would be nice.
		 * @protected
		 */
		this._breakpoint = null;

		/**
		 * Current width of the plugin element.
		 */
		this._width = null;

		/**
		 * All real items.
		 * @protected
		 */
		this._items = [];

		/**
		 * All cloned items.
		 * @protected
		 */
		this._clones = [];

		/**
		 * Merge values of all items.
		 * @todo Maybe this could be part of a plugin.
		 * @protected
		 */
		this._mergers = [];

		/**
		 * Widths of all items.
		 */
		this._widths = [];

		/**
		 * Invalidated parts within the update process.
		 * @protected
		 */
		this._invalidated = {};

		/**
		 * Ordered list of workers for the update process.
		 * @protected
		 */
		this._pipe = [];

		/**
		 * Current state information for the drag operation.
		 * @todo #261
		 * @protected
		 */
		this._drag = {
			time: null,
			target: null,
			pointer: null,
			stage: {
				start: null,
				current: null
			},
			direction: null
		};

		/**
		 * Current state information and their tags.
		 * @type {Object}
		 * @protected
		 */
		this._states = {
			current: {},
			tags: {
				'initializing': [ 'busy' ],
				'animating': [ 'busy' ],
				'dragging': [ 'interacting' ]
			}
		};

		$.each([ 'onResize', 'onThrottledResize' ], $.proxy(function(i, handler) {
			this._handlers[handler] = $.proxy(this[handler], this);
		}, this));

		$.each(Owl.Plugins, $.proxy(function(key, plugin) {
			this._plugins[key.charAt(0).toLowerCase() + key.slice(1)]
				= new plugin(this);
		}, this));

		$.each(Owl.Workers, $.proxy(function(priority, worker) {
			this._pipe.push({
				'filter': worker.filter,
				'run': $.proxy(worker.run, this)
			});
		}, this));

		this.setup();
		this.initialize();
	}

	/**
	 * Default options for the carousel.
	 * @public
	 */
	Owl.Defaults = {
		items: 3,
		loop: false,
		center: false,
		rewind: false,
		checkVisibility: true,

		mouseDrag: true,
		touchDrag: true,
		pullDrag: true,
		freeDrag: false,

		margin: 0,
		stagePadding: 0,

		merge: false,
		mergeFit: true,
		autoWidth: false,

		startPosition: 0,
		rtl: false,

		smartSpeed: 250,
		fluidSpeed: false,
		dragEndSpeed: false,

		responsive: {},
		responsiveRefreshRate: 200,
		responsiveBaseElement: window,

		fallbackEasing: 'swing',
		slideTransition: '',

		info: false,

		nestedItemSelector: false,
		itemElement: 'div',
		stageElement: 'div',

		refreshClass: 'owl-refresh',
		loadedClass: 'owl-loaded',
		loadingClass: 'owl-loading',
		rtlClass: 'owl-rtl',
		responsiveClass: 'owl-responsive',
		dragClass: 'owl-drag',
		itemClass: 'owl-item',
		stageClass: 'owl-stage',
		stageOuterClass: 'owl-stage-outer',
		grabClass: 'owl-grab'
	};

	/**
	 * Enumeration for width.
	 * @public
	 * @readonly
	 * @enum {String}
	 */
	Owl.Width = {
		Default: 'default',
		Inner: 'inner',
		Outer: 'outer'
	};

	/**
	 * Enumeration for types.
	 * @public
	 * @readonly
	 * @enum {String}
	 */
	Owl.Type = {
		Event: 'event',
		State: 'state'
	};

	/**
	 * Contains all registered plugins.
	 * @public
	 */
	Owl.Plugins = {};

	/**
	 * List of workers involved in the update process.
	 */
	Owl.Workers = [ {
		filter: [ 'width', 'settings' ],
		run: function() {
			this._width = this.$element.width();
		}
	}, {
		filter: [ 'width', 'items', 'settings' ],
		run: function(cache) {
			cache.current = this._items && this._items[this.relative(this._current)];
		}
	}, {
		filter: [ 'items', 'settings' ],
		run: function() {
			this.$stage.children('.cloned').remove();
		}
	}, {
		filter: [ 'width', 'items', 'settings' ],
		run: function(cache) {
			var margin = this.settings.margin || '',
				grid = !this.settings.autoWidth,
				rtl = this.settings.rtl,
				css = {
					'width': 'auto',
					'margin-left': rtl ? margin : '',
					'margin-right': rtl ? '' : margin
				};

			!grid && this.$stage.children().css(css);

			cache.css = css;
		}
	}, {
		filter: [ 'width', 'items', 'settings' ],
		run: function(cache) {
			var width = (this.width() / this.settings.items).toFixed(3) - this.settings.margin,
				merge = null,
				iterator = this._items.length,
				grid = !this.settings.autoWidth,
				widths = [];

			cache.items = {
				merge: false,
				width: width
			};

			while (iterator--) {
				merge = this._mergers[iterator];
				merge = this.settings.mergeFit && Math.min(merge, this.settings.items) || merge;

				cache.items.merge = merge > 1 || cache.items.merge;

				widths[iterator] = !grid ? this._items[iterator].width() : width * merge;
			}

			this._widths = widths;
		}
	}, {
		filter: [ 'items', 'settings' ],
		run: function() {
			var clones = [],
				items = this._items,
				settings = this.settings,
				// TODO: Should be computed from number of min width items in stage
				view = Math.max(settings.items * 2, 4),
				size = Math.ceil(items.length / 2) * 2,
				repeat = settings.loop && items.length ? settings.rewind ? view : Math.max(view, size) : 0,
				append = '',
				prepend = '';

			repeat /= 2;

			while (repeat > 0) {
				// Switch to only using appended clones
				clones.push(this.normalize(clones.length / 2, true));
				append = append + items[clones[clones.length - 1]][0].outerHTML;
				clones.push(this.normalize(items.length - 1 - (clones.length - 1) / 2, true));
				prepend = items[clones[clones.length - 1]][0].outerHTML + prepend;
				repeat -= 1;
			}

			this._clones = clones;

			$(append).addClass('cloned').appendTo(this.$stage);
			$(prepend).addClass('cloned').prependTo(this.$stage);
		}
	}, {
		filter: [ 'width', 'items', 'settings' ],
		run: function() {
			var rtl = this.settings.rtl ? 1 : -1,
				size = this._clones.length + this._items.length,
				iterator = -1,
				previous = 0,
				current = 0,
				coordinates = [];

			while (++iterator < size) {
				previous = coordinates[iterator - 1] || 0;
				current = this._widths[this.relative(iterator)] + this.settings.margin;
				coordinates.push(previous + current * rtl);
			}

			this._coordinates = coordinates;
		}
	}, {
		filter: [ 'width', 'items', 'settings' ],
		run: function() {
			var padding = this.settings.stagePadding,
				coordinates = this._coordinates,
				css = {
					'width': Math.ceil(Math.abs(coordinates[coordinates.length - 1])) + padding * 2,
					'padding-left': padding || '',
					'padding-right': padding || ''
				};

			this.$stage.css(css);
		}
	}, {
		filter: [ 'width', 'items', 'settings' ],
		run: function(cache) {
			var iterator = this._coordinates.length,
				grid = !this.settings.autoWidth,
				items = this.$stage.children();

			if (grid && cache.items.merge) {
				while (iterator--) {
					cache.css.width = this._widths[this.relative(iterator)];
					items.eq(iterator).css(cache.css);
				}
			} else if (grid) {
				cache.css.width = cache.items.width;
				items.css(cache.css);
			}
		}
	}, {
		filter: [ 'items' ],
		run: function() {
			this._coordinates.length < 1 && this.$stage.removeAttr('style');
		}
	}, {
		filter: [ 'width', 'items', 'settings' ],
		run: function(cache) {
			cache.current = cache.current ? this.$stage.children().index(cache.current) : 0;
			cache.current = Math.max(this.minimum(), Math.min(this.maximum(), cache.current));
			this.reset(cache.current);
		}
	}, {
		filter: [ 'position' ],
		run: function() {
			this.animate(this.coordinates(this._current));
		}
	}, {
		filter: [ 'width', 'position', 'items', 'settings' ],
		run: function() {
			var rtl = this.settings.rtl ? 1 : -1,
				padding = this.settings.stagePadding * 2,
				begin = this.coordinates(this.current()) + padding,
				end = begin + this.width() * rtl,
				inner, outer, matches = [], i, n;

			for (i = 0, n = this._coordinates.length; i < n; i++) {
				inner = this._coordinates[i - 1] || 0;
				outer = Math.abs(this._coordinates[i]) + padding * rtl;

				if ((this.op(inner, '<=', begin) && (this.op(inner, '>', end)))
					|| (this.op(outer, '<', begin) && this.op(outer, '>', end))) {
					matches.push(i);
				}
			}

			this.$stage.children('.active').removeClass('active');
			this.$stage.children(':eq(' + matches.join('), :eq(') + ')').addClass('active');

			this.$stage.children('.center').removeClass('center');
			if (this.settings.center) {
				this.$stage.children().eq(this.current()).addClass('center');
			}
		}
	} ];

	/**
	 * Create the stage DOM element
	 */
	Owl.prototype.initializeStage = function() {
		this.$stage = this.$element.find('.' + this.settings.stageClass);

		// if the stage is already in the DOM, grab it and skip stage initialization
		if (this.$stage.length) {
			return;
		}

		this.$element.addClass(this.options.loadingClass);

		// create stage
		this.$stage = $('<' + this.settings.stageElement + '>', {
			"class": this.settings.stageClass
		}).wrap( $( '<div/>', {
			"class": this.settings.stageOuterClass
		}));

		// append stage
		this.$element.append(this.$stage.parent());
	};

	/**
	 * Create item DOM elements
	 */
	Owl.prototype.initializeItems = function() {
		var $items = this.$element.find('.owl-item');

		// if the items are already in the DOM, grab them and skip item initialization
		if ($items.length) {
			this._items = $items.get().map(function(item) {
				return $(item);
			});

			this._mergers = this._items.map(function() {
				return 1;
			});

			this.refresh();

			return;
		}

		// append content
		this.replace(this.$element.children().not(this.$stage.parent()));

		// check visibility
		if (this.isVisible()) {
			// update view
			this.refresh();
		} else {
			// invalidate width
			this.invalidate('width');
		}

		this.$element
			.removeClass(this.options.loadingClass)
			.addClass(this.options.loadedClass);
	};

	/**
	 * Initializes the carousel.
	 * @protected
	 */
	Owl.prototype.initialize = function() {
		this.enter('initializing');
		this.trigger('initialize');

		this.$element.toggleClass(this.settings.rtlClass, this.settings.rtl);

		if (this.settings.autoWidth && !this.is('pre-loading')) {
			var imgs, nestedSelector, width;
			imgs = this.$element.find('img');
			nestedSelector = this.settings.nestedItemSelector ? '.' + this.settings.nestedItemSelector : undefined;
			width = this.$element.children(nestedSelector).width();

			if (imgs.length && width <= 0) {
				this.preloadAutoWidthImages(imgs);
			}
		}

		this.initializeStage();
		this.initializeItems();

		// register event handlers
		this.registerEventHandlers();

		this.leave('initializing');
		this.trigger('initialized');
	};

	/**
	 * @returns {Boolean} visibility of $element
	 *                    if you know the carousel will always be visible you can set `checkVisibility` to `false` to
	 *                    prevent the expensive browser layout forced reflow the $element.is(':visible') does
	 */
	Owl.prototype.isVisible = function() {
		return this.settings.checkVisibility
			? this.$element.is(':visible')
			: true;
	};

	/**
	 * Setups the current settings.
	 * @todo Remove responsive classes. Why should adaptive designs be brought into IE8?
	 * @todo Support for media queries by using `matchMedia` would be nice.
	 * @public
	 */
	Owl.prototype.setup = function() {
		var viewport = this.viewport(),
			overwrites = this.options.responsive,
			match = -1,
			settings = null;

		if (!overwrites) {
			settings = $.extend({}, this.options);
		} else {
			$.each(overwrites, function(breakpoint) {
				if (breakpoint <= viewport && breakpoint > match) {
					match = Number(breakpoint);
				}
			});

			settings = $.extend({}, this.options, overwrites[match]);
			if (typeof settings.stagePadding === 'function') {
				settings.stagePadding = settings.stagePadding();
			}
			delete settings.responsive;

			// responsive class
			if (settings.responsiveClass) {
				this.$element.attr('class',
					this.$element.attr('class').replace(new RegExp('(' + this.options.responsiveClass + '-)\\S+\\s', 'g'), '$1' + match)
				);
			}
		}

		this.trigger('change', { property: { name: 'settings', value: settings } });
		this._breakpoint = match;
		this.settings = settings;
		this.invalidate('settings');
		this.trigger('changed', { property: { name: 'settings', value: this.settings } });
	};

	/**
	 * Updates option logic if necessery.
	 * @protected
	 */
	Owl.prototype.optionsLogic = function() {
		if (this.settings.autoWidth) {
			this.settings.stagePadding = false;
			this.settings.merge = false;
		}
	};

	/**
	 * Prepares an item before add.
	 * @todo Rename event parameter `content` to `item`.
	 * @protected
	 * @returns {jQuery|HTMLElement} - The item container.
	 */
	Owl.prototype.prepare = function(item) {
		var event = this.trigger('prepare', { content: item });

		if (!event.data) {
			event.data = $('<' + this.settings.itemElement + '/>')
				.addClass(this.options.itemClass).append(item)
		}

		this.trigger('prepared', { content: event.data });

		return event.data;
	};

	/**
	 * Updates the view.
	 * @public
	 */
	Owl.prototype.update = function() {
		var i = 0,
			n = this._pipe.length,
			filter = $.proxy(function(p) { return this[p] }, this._invalidated),
			cache = {};

		while (i < n) {
			if (this._invalidated.all || $.grep(this._pipe[i].filter, filter).length > 0) {
				this._pipe[i].run(cache);
			}
			i++;
		}

		this._invalidated = {};

		!this.is('valid') && this.enter('valid');
	};

	/**
	 * Gets the width of the view.
	 * @public
	 * @param {Owl.Width} [dimension=Owl.Width.Default] - The dimension to return.
	 * @returns {Number} - The width of the view in pixel.
	 */
	Owl.prototype.width = function(dimension) {
		dimension = dimension || Owl.Width.Default;
		switch (dimension) {
			case Owl.Width.Inner:
			case Owl.Width.Outer:
				return this._width;
			default:
				return this._width - this.settings.stagePadding * 2 + this.settings.margin;
		}
	};

	/**
	 * Refreshes the carousel primarily for adaptive purposes.
	 * @public
	 */
	Owl.prototype.refresh = function() {
		this.enter('refreshing');
		this.trigger('refresh');

		this.setup();

		this.optionsLogic();

		this.$element.addClass(this.options.refreshClass);

		this.update();

		this.$element.removeClass(this.options.refreshClass);

		this.leave('refreshing');
		this.trigger('refreshed');
	};

	/**
	 * Checks window `resize` event.
	 * @protected
	 */
	Owl.prototype.onThrottledResize = function() {
		window.clearTimeout(this.resizeTimer);
		this.resizeTimer = window.setTimeout(this._handlers.onResize, this.settings.responsiveRefreshRate);
	};

	/**
	 * Checks window `resize` event.
	 * @protected
	 */
	Owl.prototype.onResize = function() {
		if (!this._items.length) {
			return false;
		}

		if (this._width === this.$element.width()) {
			return false;
		}

		if (!this.isVisible()) {
			return false;
		}

		this.enter('resizing');

		if (this.trigger('resize').isDefaultPrevented()) {
			this.leave('resizing');
			return false;
		}

		this.invalidate('width');

		this.refresh();

		this.leave('resizing');
		this.trigger('resized');
	};

	/**
	 * Registers event handlers.
	 * @todo Check `msPointerEnabled`
	 * @todo #261
	 * @protected
	 */
	Owl.prototype.registerEventHandlers = function() {
		if ($.support.transition) {
			this.$stage.on($.support.transition.end + '.owl.core', $.proxy(this.onTransitionEnd, this));
		}

		if (this.settings.responsive !== false) {
			this.on(window, 'resize', this._handlers.onThrottledResize);
		}

		if (this.settings.mouseDrag) {
			this.$element.addClass(this.options.dragClass);
			this.$stage.on('mousedown.owl.core', $.proxy(this.onDragStart, this));
			this.$stage.on('dragstart.owl.core selectstart.owl.core', function() { return false });
		}

		if (this.settings.touchDrag){
			this.$stage.on('touchstart.owl.core', $.proxy(this.onDragStart, this));
			this.$stage.on('touchcancel.owl.core', $.proxy(this.onDragEnd, this));
		}
	};

	/**
	 * Handles `touchstart` and `mousedown` events.
	 * @todo Horizontal swipe threshold as option
	 * @todo #261
	 * @protected
	 * @param {Event} event - The event arguments.
	 */
	Owl.prototype.onDragStart = function(event) {
		var stage = null;

		if (event.which === 3) {
			return;
		}

		if ($.support.transform) {
			stage = this.$stage.css('transform').replace(/.*\(|\)| /g, '').split(',');
			stage = {
				x: stage[stage.length === 16 ? 12 : 4],
				y: stage[stage.length === 16 ? 13 : 5]
			};
		} else {
			stage = this.$stage.position();
			stage = {
				x: this.settings.rtl ?
					stage.left + this.$stage.width() - this.width() + this.settings.margin :
					stage.left,
				y: stage.top
			};
		}

		if (this.is('animating')) {
			$.support.transform ? this.animate(stage.x) : this.$stage.stop()
			this.invalidate('position');
		}

		this.$element.toggleClass(this.options.grabClass, event.type === 'mousedown');

		this.speed(0);

		this._drag.time = new Date().getTime();
		this._drag.target = $(event.target);
		this._drag.stage.start = stage;
		this._drag.stage.current = stage;
		this._drag.pointer = this.pointer(event);

		$(document).on('mouseup.owl.core touchend.owl.core', $.proxy(this.onDragEnd, this));

		$(document).one('mousemove.owl.core touchmove.owl.core', $.proxy(function(event) {
			var delta = this.difference(this._drag.pointer, this.pointer(event));

			$(document).on('mousemove.owl.core touchmove.owl.core', $.proxy(this.onDragMove, this));

			if (Math.abs(delta.x) < Math.abs(delta.y) && this.is('valid')) {
				return;
			}

			event.preventDefault();

			this.enter('dragging');
			this.trigger('drag');
		}, this));
	};

	/**
	 * Handles the `touchmove` and `mousemove` events.
	 * @todo #261
	 * @protected
	 * @param {Event} event - The event arguments.
	 */
	Owl.prototype.onDragMove = function(event) {
		var minimum = null,
			maximum = null,
			pull = null,
			delta = this.difference(this._drag.pointer, this.pointer(event)),
			stage = this.difference(this._drag.stage.start, delta);

		if (!this.is('dragging')) {
			return;
		}

		event.preventDefault();

		if (this.settings.loop) {
			minimum = this.coordinates(this.minimum());
			maximum = this.coordinates(this.maximum() + 1) - minimum;
			stage.x = (((stage.x - minimum) % maximum + maximum) % maximum) + minimum;
		} else {
			minimum = this.settings.rtl ? this.coordinates(this.maximum()) : this.coordinates(this.minimum());
			maximum = this.settings.rtl ? this.coordinates(this.minimum()) : this.coordinates(this.maximum());
			pull = this.settings.pullDrag ? -1 * delta.x / 5 : 0;
			stage.x = Math.max(Math.min(stage.x, minimum + pull), maximum + pull);
		}

		this._drag.stage.current = stage;

		this.animate(stage.x);
	};

	/**
	 * Handles the `touchend` and `mouseup` events.
	 * @todo #261
	 * @todo Threshold for click event
	 * @protected
	 * @param {Event} event - The event arguments.
	 */
	Owl.prototype.onDragEnd = function(event) {
		var delta = this.difference(this._drag.pointer, this.pointer(event)),
			stage = this._drag.stage.current,
			direction = delta.x > 0 ^ this.settings.rtl ? 'left' : 'right';

		$(document).off('.owl.core');

		this.$element.removeClass(this.options.grabClass);

		if (delta.x !== 0 && this.is('dragging') || !this.is('valid')) {
			this.speed(this.settings.dragEndSpeed || this.settings.smartSpeed);
			this.current(this.closest(stage.x, delta.x !== 0 ? direction : this._drag.direction));
			this.invalidate('position');
			this.update();

			this._drag.direction = direction;

			if (Math.abs(delta.x) > 3 || new Date().getTime() - this._drag.time > 300) {
				this._drag.target.one('click.owl.core', function() { return false; });
			}
		}

		if (!this.is('dragging')) {
			return;
		}

		this.leave('dragging');
		this.trigger('dragged');
	};

	/**
	 * Gets absolute position of the closest item for a coordinate.
	 * @todo Setting `freeDrag` makes `closest` not reusable. See #165.
	 * @protected
	 * @param {Number} coordinate - The coordinate in pixel.
	 * @param {String} direction - The direction to check for the closest item. Ether `left` or `right`.
	 * @return {Number} - The absolute position of the closest item.
	 */
	Owl.prototype.closest = function(coordinate, direction) {
		var position = -1,
			pull = 30,
			width = this.width(),
			coordinates = this.coordinates();

		if (!this.settings.freeDrag) {
			// check closest item
			$.each(coordinates, $.proxy(function(index, value) {
				// on a left pull, check on current index
				if (direction === 'left' && coordinate > value - pull && coordinate < value + pull) {
					position = index;
				// on a right pull, check on previous index
				// to do so, subtract width from value and set position = index + 1
				} else if (direction === 'right' && coordinate > value - width - pull && coordinate < value - width + pull) {
					position = index + 1;
				} else if (this.op(coordinate, '<', value)
					&& this.op(coordinate, '>', coordinates[index + 1] !== undefined ? coordinates[index + 1] : value - width)) {
					position = direction === 'left' ? index + 1 : index;
				}
				return position === -1;
			}, this));
		}

		if (!this.settings.loop) {
			// non loop boundries
			if (this.op(coordinate, '>', coordinates[this.minimum()])) {
				position = coordinate = this.minimum();
			} else if (this.op(coordinate, '<', coordinates[this.maximum()])) {
				position = coordinate = this.maximum();
			}
		}

		return position;
	};

	/**
	 * Animates the stage.
	 * @todo #270
	 * @public
	 * @param {Number} coordinate - The coordinate in pixels.
	 */
	Owl.prototype.animate = function(coordinate) {
		var animate = this.speed() > 0;

		this.is('animating') && this.onTransitionEnd();

		if (animate) {
			this.enter('animating');
			this.trigger('translate');
		}

		if ($.support.transform3d && $.support.transition) {
			this.$stage.css({
				transform: 'translate3d(' + coordinate + 'px,0px,0px)',
				transition: (this.speed() / 1000) + 's' + (
					this.settings.slideTransition ? ' ' + this.settings.slideTransition : ''
				)
			});
		} else if (animate) {
			this.$stage.animate({
				left: coordinate + 'px'
			}, this.speed(), this.settings.fallbackEasing, $.proxy(this.onTransitionEnd, this));
		} else {
			this.$stage.css({
				left: coordinate + 'px'
			});
		}
	};

	/**
	 * Checks whether the carousel is in a specific state or not.
	 * @param {String} state - The state to check.
	 * @returns {Boolean} - The flag which indicates if the carousel is busy.
	 */
	Owl.prototype.is = function(state) {
		return this._states.current[state] && this._states.current[state] > 0;
	};

	/**
	 * Sets the absolute position of the current item.
	 * @public
	 * @param {Number} [position] - The new absolute position or nothing to leave it unchanged.
	 * @returns {Number} - The absolute position of the current item.
	 */
	Owl.prototype.current = function(position) {
		if (position === undefined) {
			return this._current;
		}

		if (this._items.length === 0) {
			return undefined;
		}

		position = this.normalize(position);

		if (this._current !== position) {
			var event = this.trigger('change', { property: { name: 'position', value: position } });

			if (event.data !== undefined) {
				position = this.normalize(event.data);
			}

			this._current = position;

			this.invalidate('position');

			this.trigger('changed', { property: { name: 'position', value: this._current } });
		}

		return this._current;
	};

	/**
	 * Invalidates the given part of the update routine.
	 * @param {String} [part] - The part to invalidate.
	 * @returns {Array.<String>} - The invalidated parts.
	 */
	Owl.prototype.invalidate = function(part) {
		if ($.type(part) === 'string') {
			this._invalidated[part] = true;
			this.is('valid') && this.leave('valid');
		}
		return $.map(this._invalidated, function(v, i) { return i });
	};

	/**
	 * Resets the absolute position of the current item.
	 * @public
	 * @param {Number} position - The absolute position of the new item.
	 */
	Owl.prototype.reset = function(position) {
		position = this.normalize(position);

		if (position === undefined) {
			return;
		}

		this._speed = 0;
		this._current = position;

		this.suppress([ 'translate', 'translated' ]);

		this.animate(this.coordinates(position));

		this.release([ 'translate', 'translated' ]);
	};

	/**
	 * Normalizes an absolute or a relative position of an item.
	 * @public
	 * @param {Number} position - The absolute or relative position to normalize.
	 * @param {Boolean} [relative=false] - Whether the given position is relative or not.
	 * @returns {Number} - The normalized position.
	 */
	Owl.prototype.normalize = function(position, relative) {
		var n = this._items.length,
			m = relative ? 0 : this._clones.length;

		if (!this.isNumeric(position) || n < 1) {
			position = undefined;
		} else if (position < 0 || position >= n + m) {
			position = ((position - m / 2) % n + n) % n + m / 2;
		}

		return position;
	};

	/**
	 * Converts an absolute position of an item into a relative one.
	 * @public
	 * @param {Number} position - The absolute position to convert.
	 * @returns {Number} - The converted position.
	 */
	Owl.prototype.relative = function(position) {
		position -= this._clones.length / 2;
		return this.normalize(position, true);
	};

	/**
	 * Gets the maximum position for the current item.
	 * @public
	 * @param {Boolean} [relative=false] - Whether to return an absolute position or a relative position.
	 * @returns {Number}
	 */
	Owl.prototype.maximum = function(relative) {
		var settings = this.settings,
			maximum = this._coordinates.length,
			iterator,
			reciprocalItemsWidth,
			elementWidth;

		if (settings.loop) {
			maximum = this._clones.length / 2 + this._items.length - 1;
		} else if (settings.autoWidth || settings.merge) {
			iterator = this._items.length;
			if (iterator) {
				reciprocalItemsWidth = this._items[--iterator].width();
				elementWidth = this.$element.width();
				while (iterator--) {
					reciprocalItemsWidth += this._items[iterator].width() + this.settings.margin;
					if (reciprocalItemsWidth > elementWidth) {
						break;
					}
				}
			}
			maximum = iterator + 1;
		} else if (settings.center) {
			maximum = this._items.length - 1;
		} else {
			maximum = this._items.length - settings.items;
		}

		if (relative) {
			maximum -= this._clones.length / 2;
		}

		return Math.max(maximum, 0);
	};

	/**
	 * Gets the minimum position for the current item.
	 * @public
	 * @param {Boolean} [relative=false] - Whether to return an absolute position or a relative position.
	 * @returns {Number}
	 */
	Owl.prototype.minimum = function(relative) {
		return relative ? 0 : this._clones.length / 2;
	};

	/**
	 * Gets an item at the specified relative position.
	 * @public
	 * @param {Number} [position] - The relative position of the item.
	 * @return {jQuery|Array.<jQuery>} - The item at the given position or all items if no position was given.
	 */
	Owl.prototype.items = function(position) {
		if (position === undefined) {
			return this._items.slice();
		}

		position = this.normalize(position, true);
		return this._items[position];
	};

	/**
	 * Gets an item at the specified relative position.
	 * @public
	 * @param {Number} [position] - The relative position of the item.
	 * @return {jQuery|Array.<jQuery>} - The item at the given position or all items if no position was given.
	 */
	Owl.prototype.mergers = function(position) {
		if (position === undefined) {
			return this._mergers.slice();
		}

		position = this.normalize(position, true);
		return this._mergers[position];
	};

	/**
	 * Gets the absolute positions of clones for an item.
	 * @public
	 * @param {Number} [position] - The relative position of the item.
	 * @returns {Array.<Number>} - The absolute positions of clones for the item or all if no position was given.
	 */
	Owl.prototype.clones = function(position) {
		var odd = this._clones.length / 2,
			even = odd + this._items.length,
			map = function(index) { return index % 2 === 0 ? even + index / 2 : odd - (index + 1) / 2 };

		if (position === undefined) {
			return $.map(this._clones, function(v, i) { return map(i) });
		}

		return $.map(this._clones, function(v, i) { return v === position ? map(i) : null });
	};

	/**
	 * Sets the current animation speed.
	 * @public
	 * @param {Number} [speed] - The animation speed in milliseconds or nothing to leave it unchanged.
	 * @returns {Number} - The current animation speed in milliseconds.
	 */
	Owl.prototype.speed = function(speed) {
		if (speed !== undefined) {
			this._speed = speed;
		}

		return this._speed;
	};

	/**
	 * Gets the coordinate of an item.
	 * @todo The name of this method is missleanding.
	 * @public
	 * @param {Number} position - The absolute position of the item within `minimum()` and `maximum()`.
	 * @returns {Number|Array.<Number>} - The coordinate of the item in pixel or all coordinates.
	 */
	Owl.prototype.coordinates = function(position) {
		var multiplier = 1,
			newPosition = position - 1,
			coordinate;

		if (position === undefined) {
			return $.map(this._coordinates, $.proxy(function(coordinate, index) {
				return this.coordinates(index);
			}, this));
		}

		if (this.settings.center) {
			if (this.settings.rtl) {
				multiplier = -1;
				newPosition = position + 1;
			}

			coordinate = this._coordinates[position];
			coordinate += (this.width() - coordinate + (this._coordinates[newPosition] || 0)) / 2 * multiplier;
		} else {
			coordinate = this._coordinates[newPosition] || 0;
		}

		coordinate = Math.ceil(coordinate);

		return coordinate;
	};

	/**
	 * Calculates the speed for a translation.
	 * @protected
	 * @param {Number} from - The absolute position of the start item.
	 * @param {Number} to - The absolute position of the target item.
	 * @param {Number} [factor=undefined] - The time factor in milliseconds.
	 * @returns {Number} - The time in milliseconds for the translation.
	 */
	Owl.prototype.duration = function(from, to, factor) {
		if (factor === 0) {
			return 0;
		}

		return Math.min(Math.max(Math.abs(to - from), 1), 6) * Math.abs((factor || this.settings.smartSpeed));
	};

	/**
	 * Slides to the specified item.
	 * @public
	 * @param {Number} position - The position of the item.
	 * @param {Number} [speed] - The time in milliseconds for the transition.
	 */
	Owl.prototype.to = function(position, speed) {
		var current = this.current(),
			revert = null,
			distance = position - this.relative(current),
			direction = (distance > 0) - (distance < 0),
			items = this._items.length,
			minimum = this.minimum(),
			maximum = this.maximum();

		if (this.settings.loop) {
			if (!this.settings.rewind && Math.abs(distance) > items / 2) {
				distance += direction * -1 * items;
			}

			position = current + distance;
			revert = ((position - minimum) % items + items) % items + minimum;

			if (revert !== position && revert - distance <= maximum && revert - distance > 0) {
				current = revert - distance;
				position = revert;
				this.reset(current);
			}
		} else if (this.settings.rewind) {
			maximum += 1;
			position = (position % maximum + maximum) % maximum;
		} else {
			position = Math.max(minimum, Math.min(maximum, position));
		}

		this.speed(this.duration(current, position, speed));
		this.current(position);

		if (this.isVisible()) {
			this.update();
		}
	};

	/**
	 * Slides to the next item.
	 * @public
	 * @param {Number} [speed] - The time in milliseconds for the transition.
	 */
	Owl.prototype.next = function(speed) {
		speed = speed || false;
		this.to(this.relative(this.current()) + 1, speed);
	};

	/**
	 * Slides to the previous item.
	 * @public
	 * @param {Number} [speed] - The time in milliseconds for the transition.
	 */
	Owl.prototype.prev = function(speed) {
		speed = speed || false;
		this.to(this.relative(this.current()) - 1, speed);
	};

	/**
	 * Handles the end of an animation.
	 * @protected
	 * @param {Event} event - The event arguments.
	 */
	Owl.prototype.onTransitionEnd = function(event) {

		// if css2 animation then event object is undefined
		if (event !== undefined) {
			event.stopPropagation();

			// Catch only owl-stage transitionEnd event
			if ((event.target || event.srcElement || event.originalTarget) !== this.$stage.get(0)) {
				return false;
			}
		}

		this.leave('animating');
		this.trigger('translated');
	};

	/**
	 * Gets viewport width.
	 * @protected
	 * @return {Number} - The width in pixel.
	 */
	Owl.prototype.viewport = function() {
		var width;
		if (this.options.responsiveBaseElement !== window) {
			width = $(this.options.responsiveBaseElement).width();
		} else if (window.innerWidth) {
			width = window.innerWidth;
		} else if (document.documentElement && document.documentElement.clientWidth) {
			width = document.documentElement.clientWidth;
		} else {
			console.warn('Can not detect viewport width.');
		}
		return width;
	};

	/**
	 * Replaces the current content.
	 * @public
	 * @param {HTMLElement|jQuery|String} content - The new content.
	 */
	Owl.prototype.replace = function(content) {
		this.$stage.empty();
		this._items = [];

		if (content) {
			content = (content instanceof jQuery) ? content : $(content);
		}

		if (this.settings.nestedItemSelector) {
			content = content.find('.' + this.settings.nestedItemSelector);
		}

		content.filter(function() {
			return this.nodeType === 1;
		}).each($.proxy(function(index, item) {
			item = this.prepare(item);
			this.$stage.append(item);
			this._items.push(item);
			this._mergers.push(item.find('[data-merge]').addBack('[data-merge]').attr('data-merge') * 1 || 1);
		}, this));

		this.reset(this.isNumeric(this.settings.startPosition) ? this.settings.startPosition : 0);

		this.invalidate('items');
	};

	/**
	 * Adds an item.
	 * @todo Use `item` instead of `content` for the event arguments.
	 * @public
	 * @param {HTMLElement|jQuery|String} content - The item content to add.
	 * @param {Number} [position] - The relative position at which to insert the item otherwise the item will be added to the end.
	 */
	Owl.prototype.add = function(content, position) {
		var current = this.relative(this._current);

		position = position === undefined ? this._items.length : this.normalize(position, true);
		content = content instanceof jQuery ? content : $(content);

		this.trigger('add', { content: content, position: position });

		content = this.prepare(content);

		if (this._items.length === 0 || position === this._items.length) {
			this._items.length === 0 && this.$stage.append(content);
			this._items.length !== 0 && this._items[position - 1].after(content);
			this._items.push(content);
			this._mergers.push(content.find('[data-merge]').addBack('[data-merge]').attr('data-merge') * 1 || 1);
		} else {
			this._items[position].before(content);
			this._items.splice(position, 0, content);
			this._mergers.splice(position, 0, content.find('[data-merge]').addBack('[data-merge]').attr('data-merge') * 1 || 1);
		}

		this._items[current] && this.reset(this._items[current].index());

		this.invalidate('items');

		this.trigger('added', { content: content, position: position });
	};

	/**
	 * Removes an item by its position.
	 * @todo Use `item` instead of `content` for the event arguments.
	 * @public
	 * @param {Number} position - The relative position of the item to remove.
	 */
	Owl.prototype.remove = function(position) {
		position = this.normalize(position, true);

		if (position === undefined) {
			return;
		}

		this.trigger('remove', { content: this._items[position], position: position });

		this._items[position].remove();
		this._items.splice(position, 1);
		this._mergers.splice(position, 1);

		this.invalidate('items');

		this.trigger('removed', { content: null, position: position });
	};

	/**
	 * Preloads images with auto width.
	 * @todo Replace by a more generic approach
	 * @protected
	 */
	Owl.prototype.preloadAutoWidthImages = function(images) {
		images.each($.proxy(function(i, element) {
			this.enter('pre-loading');
			element = $(element);
			$(new Image()).one('load', $.proxy(function(e) {
				element.attr('src', e.target.src);
				element.css('opacity', 1);
				this.leave('pre-loading');
				!this.is('pre-loading') && !this.is('initializing') && this.refresh();
			}, this)).attr('src', element.attr('src') || element.attr('data-src') || element.attr('data-src-retina'));
		}, this));
	};

	/**
	 * Destroys the carousel.
	 * @public
	 */
	Owl.prototype.destroy = function() {

		this.$element.off('.owl.core');
		this.$stage.off('.owl.core');
		$(document).off('.owl.core');

		if (this.settings.responsive !== false) {
			window.clearTimeout(this.resizeTimer);
			this.off(window, 'resize', this._handlers.onThrottledResize);
		}

		for (var i in this._plugins) {
			this._plugins[i].destroy();
		}

		this.$stage.children('.cloned').remove();

		this.$stage.unwrap();
		this.$stage.children().contents().unwrap();
		this.$stage.children().unwrap();
		this.$stage.remove();
		this.$element
			.removeClass(this.options.refreshClass)
			.removeClass(this.options.loadingClass)
			.removeClass(this.options.loadedClass)
			.removeClass(this.options.rtlClass)
			.removeClass(this.options.dragClass)
			.removeClass(this.options.grabClass)
			.attr('class', this.$element.attr('class').replace(new RegExp(this.options.responsiveClass + '-\\S+\\s', 'g'), ''))
			.removeData('owl.carousel');
	};

	/**
	 * Operators to calculate right-to-left and left-to-right.
	 * @protected
	 * @param {Number} [a] - The left side operand.
	 * @param {String} [o] - The operator.
	 * @param {Number} [b] - The right side operand.
	 */
	Owl.prototype.op = function(a, o, b) {
		var rtl = this.settings.rtl;
		switch (o) {
			case '<':
				return rtl ? a > b : a < b;
			case '>':
				return rtl ? a < b : a > b;
			case '>=':
				return rtl ? a <= b : a >= b;
			case '<=':
				return rtl ? a >= b : a <= b;
			default:
				break;
		}
	};

	/**
	 * Attaches to an internal event.
	 * @protected
	 * @param {HTMLElement} element - The event source.
	 * @param {String} event - The event name.
	 * @param {Function} listener - The event handler to attach.
	 * @param {Boolean} capture - Wether the event should be handled at the capturing phase or not.
	 */
	Owl.prototype.on = function(element, event, listener, capture) {
		if (element.addEventListener) {
			element.addEventListener(event, listener, capture);
		} else if (element.attachEvent) {
			element.attachEvent('on' + event, listener);
		}
	};

	/**
	 * Detaches from an internal event.
	 * @protected
	 * @param {HTMLElement} element - The event source.
	 * @param {String} event - The event name.
	 * @param {Function} listener - The attached event handler to detach.
	 * @param {Boolean} capture - Wether the attached event handler was registered as a capturing listener or not.
	 */
	Owl.prototype.off = function(element, event, listener, capture) {
		if (element.removeEventListener) {
			element.removeEventListener(event, listener, capture);
		} else if (element.detachEvent) {
			element.detachEvent('on' + event, listener);
		}
	};

	/**
	 * Triggers a public event.
	 * @todo Remove `status`, `relatedTarget` should be used instead.
	 * @protected
	 * @param {String} name - The event name.
	 * @param {*} [data=null] - The event data.
	 * @param {String} [namespace=carousel] - The event namespace.
	 * @param {String} [state] - The state which is associated with the event.
	 * @param {Boolean} [enter=false] - Indicates if the call enters the specified state or not.
	 * @returns {Event} - The event arguments.
	 */
	Owl.prototype.trigger = function(name, data, namespace, state, enter) {
		var status = {
			item: { count: this._items.length, index: this.current() }
		}, handler = $.camelCase(
			$.grep([ 'on', name, namespace ], function(v) { return v })
				.join('-').toLowerCase()
		), event = $.Event(
			[ name, 'owl', namespace || 'carousel' ].join('.').toLowerCase(),
			$.extend({ relatedTarget: this }, status, data)
		);

		if (!this._supress[name]) {
			$.each(this._plugins, function(name, plugin) {
				if (plugin.onTrigger) {
					plugin.onTrigger(event);
				}
			});

			this.register({ type: Owl.Type.Event, name: name });
			this.$element.trigger(event);

			if (this.settings && typeof this.settings[handler] === 'function') {
				this.settings[handler].call(this, event);
			}
		}

		return event;
	};

	/**
	 * Enters a state.
	 * @param name - The state name.
	 */
	Owl.prototype.enter = function(name) {
		$.each([ name ].concat(this._states.tags[name] || []), $.proxy(function(i, name) {
			if (this._states.current[name] === undefined) {
				this._states.current[name] = 0;
			}

			this._states.current[name]++;
		}, this));
	};

	/**
	 * Leaves a state.
	 * @param name - The state name.
	 */
	Owl.prototype.leave = function(name) {
		$.each([ name ].concat(this._states.tags[name] || []), $.proxy(function(i, name) {
			this._states.current[name]--;
		}, this));
	};

	/**
	 * Registers an event or state.
	 * @public
	 * @param {Object} object - The event or state to register.
	 */
	Owl.prototype.register = function(object) {
		if (object.type === Owl.Type.Event) {
			if (!$.event.special[object.name]) {
				$.event.special[object.name] = {};
			}

			if (!$.event.special[object.name].owl) {
				var _default = $.event.special[object.name]._default;
				$.event.special[object.name]._default = function(e) {
					if (_default && _default.apply && (!e.namespace || e.namespace.indexOf('owl') === -1)) {
						return _default.apply(this, arguments);
					}
					return e.namespace && e.namespace.indexOf('owl') > -1;
				};
				$.event.special[object.name].owl = true;
			}
		} else if (object.type === Owl.Type.State) {
			if (!this._states.tags[object.name]) {
				this._states.tags[object.name] = object.tags;
			} else {
				this._states.tags[object.name] = this._states.tags[object.name].concat(object.tags);
			}

			this._states.tags[object.name] = $.grep(this._states.tags[object.name], $.proxy(function(tag, i) {
				return $.inArray(tag, this._states.tags[object.name]) === i;
			}, this));
		}
	};

	/**
	 * Suppresses events.
	 * @protected
	 * @param {Array.<String>} events - The events to suppress.
	 */
	Owl.prototype.suppress = function(events) {
		$.each(events, $.proxy(function(index, event) {
			this._supress[event] = true;
		}, this));
	};

	/**
	 * Releases suppressed events.
	 * @protected
	 * @param {Array.<String>} events - The events to release.
	 */
	Owl.prototype.release = function(events) {
		$.each(events, $.proxy(function(index, event) {
			delete this._supress[event];
		}, this));
	};

	/**
	 * Gets unified pointer coordinates from event.
	 * @todo #261
	 * @protected
	 * @param {Event} - The `mousedown` or `touchstart` event.
	 * @returns {Object} - Contains `x` and `y` coordinates of current pointer position.
	 */
	Owl.prototype.pointer = function(event) {
		var result = { x: null, y: null };

		event = event.originalEvent || event || window.event;

		event = event.touches && event.touches.length ?
			event.touches[0] : event.changedTouches && event.changedTouches.length ?
				event.changedTouches[0] : event;

		if (event.pageX) {
			result.x = event.pageX;
			result.y = event.pageY;
		} else {
			result.x = event.clientX;
			result.y = event.clientY;
		}

		return result;
	};

	/**
	 * Determines if the input is a Number or something that can be coerced to a Number
	 * @protected
	 * @param {Number|String|Object|Array|Boolean|RegExp|Function|Symbol} - The input to be tested
	 * @returns {Boolean} - An indication if the input is a Number or can be coerced to a Number
	 */
	Owl.prototype.isNumeric = function(number) {
		return !isNaN(parseFloat(number));
	};

	/**
	 * Gets the difference of two vectors.
	 * @todo #261
	 * @protected
	 * @param {Object} - The first vector.
	 * @param {Object} - The second vector.
	 * @returns {Object} - The difference.
	 */
	Owl.prototype.difference = function(first, second) {
		return {
			x: first.x - second.x,
			y: first.y - second.y
		};
	};

	/**
	 * The jQuery Plugin for the Owl Carousel
	 * @todo Navigation plugin `next` and `prev`
	 * @public
	 */
	$.fn.owlCarousel = function(option) {
		var args = Array.prototype.slice.call(arguments, 1);

		return this.each(function() {
			var $this = $(this),
				data = $this.data('owl.carousel');

			if (!data) {
				data = new Owl(this, typeof option == 'object' && option);
				$this.data('owl.carousel', data);

				$.each([
					'next', 'prev', 'to', 'destroy', 'refresh', 'replace', 'add', 'remove'
				], function(i, event) {
					data.register({ type: Owl.Type.Event, name: event });
					data.$element.on(event + '.owl.carousel.core', $.proxy(function(e) {
						if (e.namespace && e.relatedTarget !== this) {
							this.suppress([ event ]);
							data[event].apply(this, [].slice.call(arguments, 1));
							this.release([ event ]);
						}
					}, data));
				});
			}

			if (typeof option == 'string' && option.charAt(0) !== '_') {
				data[option].apply(data, args);
			}
		});
	};

	/**
	 * The constructor for the jQuery Plugin
	 * @public
	 */
	$.fn.owlCarousel.Constructor = Owl;

})(window.Zepto || window.jQuery, window, document);