path: root/ui/jquery.ui.sortable.js

/*!
 * jQuery UI Sortable @VERSION
 * http://jqueryui.com
 *
 * Copyright 2012 jQuery Foundation and other contributors
 * Released under the MIT license.
 * http://jquery.org/license
 *
 * http://api.jqueryui.com/sortable/
 *
 * Depends:
 *	jquery.ui.core.js
 *	jquery.ui.mouse.js
 *	jquery.ui.widget.js
 */
(function( $, undefined ) {

$.widget("ui.sortable", $.ui.mouse, {
	version: "@VERSION",
	widgetEventPrefix: "sort",
	ready: false,
	options: {
		appendTo: "parent",
		axis: false,
		connectWith: false,
		containment: false,
		cursor: 'auto',
		cursorAt: false,
		dropOnEmpty: true,
		forcePlaceholderSize: false,
		forceHelperSize: false,
		grid: false,
		handle: false,
		helper: "original",
		items: '> *',
		opacity: false,
		placeholder: false,
		revert: false,
		scroll: true,
		scrollSensitivity: 20,
		scrollSpeed: 20,
		scope: "default",
		tolerance: "intersect",
		zIndex: 1000
	},
	_create: function() {

		var o = this.options;
		this.containerCache = {};
		this.element.addClass("ui-sortable");

		//Get the items
		this.refresh();

		//Let's determine if the items are being displayed horizontally
		this.floating = this.items.length ? o.axis === 'x' || (/left|right/).test(this.items[0].item.css('float')) || (/inline|table-cell/).test(this.items[0].item.css('display')) : false;

		//Let's determine the parent's offset
		this.offset = this.element.offset();

		//Initialize mouse events for interaction
		this._mouseInit();

		//We're ready to go
		this.ready = true

	},

	_destroy: function() {
		this.element
			.removeClass("ui-sortable ui-sortable-disabled");
		this._mouseDestroy();

		for ( var i = this.items.length - 1; i >= 0; i-- )
			this.items[i].item.removeData(this.widgetName + "-item");

		return this;
	},

	_setOption: function(key, value){
		if ( key === "disabled" ) {
			this.options[ key ] = value;

			this.widget().toggleClass( "ui-sortable-disabled", !!value );
		} else {
			// Don't call widget base _setOption for disable as it adds ui-state-disabled class
			$.Widget.prototype._setOption.apply(this, arguments);
		}
	},

	_mouseCapture: function(event, overrideHandle) {
		var that = this;

		if (this.reverting) {
			return false;
		}

		if(this.options.disabled || this.options.type == 'static') return false;

		//We have to refresh the items data once first
		this._refreshItems(event);

		//Find out if the clicked node (or one of its parents) is a actual item in this.items
		var currentItem = null, nodes = $(event.target).parents().each(function() {
			if($.data(this, that.widgetName + '-item') == that) {
				currentItem = $(this);
				return false;
			}
		});
		if($.data(event.target, that.widgetName + '-item') == that) currentItem = $(event.target);

		if(!currentItem) return false;
		if(this.options.handle && !overrideHandle) {
			var validHandle = false;

			$(this.options.handle, currentItem).find("*").andSelf().each(function() { if(this == event.target) validHandle = true; });
			if(!validHandle) return false;
		}

		this.currentItem = currentItem;
		this._removeCurrentsFromItems();
		return true;

	},

	_mouseStart: function(event, overrideHandle, noActivation) {

		var o = this.options;
		this.currentContainer = this;

		//We only need to call refreshPositions, because the refreshItems call has been moved to mouseCapture
		this.refreshPositions();

		//Create and append the visible helper
		this.helper = this._createHelper(event);

		//Cache the helper size
		this._cacheHelperProportions();

		/*
		 * - Position generation -
		 * This block generates everything position related - it's the core of draggables.
		 */

		//Cache the margins of the original element
		this._cacheMargins();

		//Get the next scrolling parent
		this.scrollParent = this.helper.scrollParent();

		//The element's absolute position on the page minus margins
		this.offset = this.currentItem.offset();
		this.offset = {
			top: this.offset.top - this.margins.top,
			left: this.offset.left - this.margins.left
		};

		$.extend(this.offset, {
			click: { //Where the click happened, relative to the element
				left: event.pageX - this.offset.left,
				top: event.pageY - this.offset.top
			},
			parent: this._getParentOffset(),
			relative: this._getRelativeOffset() //This is a relative to absolute position minus the actual position calculation - only used for relative positioned helper
		});

		// Only after we got the offset, we can change the helper's position to absolute
		// TODO: Still need to figure out a way to make relative sorting possible
		this.helper.css("position", "absolute");
		this.cssPosition = this.helper.css("position");

		//Generate the original position
		this.originalPosition = this._generatePosition(event);
		this.originalPageX = event.pageX;
		this.originalPageY = event.pageY;

		//Adjust the mouse offset relative to the helper if 'cursorAt' is supplied
		(o.cursorAt && this._adjustOffsetFromHelper(o.cursorAt));

		//Cache the former DOM position
		this.domPosition = { prev: this.currentItem.prev()[0], parent: this.currentItem.parent()[0] };

		//If the helper is not the original, hide the original so it's not playing any role during the drag, won't cause anything bad this way
		if(this.helper[0] != this.currentItem[0]) {
			this.currentItem.hide();
		}

		//Create the placeholder
		this._createPlaceholder();

		//Set a containment if given in the options
		if(o.containment)
			this._setContainment();

		if(o.cursor) { // cursor option
			if ($('body').css("cursor")) this._storedCursor = $('body').css("cursor");
			$('body').css("cursor", o.cursor);
		}

		if(o.opacity) { // opacity option
			if (this.helper.css("opacity")) this._storedOpacity = this.helper.css("opacity");
			this.helper.css("opacity", o.opacity);
		}

		if(o.zIndex) { // zIndex option
			if (this.helper.css("zIndex")) this._storedZIndex = this.helper.css("zIndex");
			this.helper.css("zIndex", o.zIndex);
		}

		//Prepare scrolling
		if(this.scrollParent[0] != document && this.scrollParent[0].tagName != 'HTML')
			this.overflowOffset = this.scrollParent.offset();

		//Call callbacks
		this._trigger("start", event, this._uiHash());

		//Recache the helper size
		if(!this._preserveHelperProportions)
			this._cacheHelperProportions();


		//Post 'activate' events to possible containers
		if(!noActivation) {
			 for (var i = this.containers.length - 1; i >= 0; i--) { this.containers[i]._trigger("activate", event, this._uiHash(this)); }
		}

		//Prepare possible droppables
		if($.ui.ddmanager)
			$.ui.ddmanager.current = this;

		if ($.ui.ddmanager && !o.dropBehaviour)
			$.ui.ddmanager.prepareOffsets(this, event);

		this.dragging = true;

		this.helper.addClass("ui-sortable-helper");
		this._mouseDrag(event); //Execute the drag once - this causes the helper not to be visible before getting its correct position
		return true;

	},

	_mouseDrag: function(event) {

		//Compute the helpers position
		this.position = this._generatePosition(event);
		this.positionAbs = this._convertPositionTo("absolute");

		if (!this.lastPositionAbs) {
			this.lastPositionAbs = this.positionAbs;
		}

		//Do scrolling
		if(this.options.scroll) {
			var o = this.options, scrolled = false;
			if(this.scrollParent[0] != document && this.scrollParent[0].tagName != 'HTML') {

				if((this.overflowOffset.top + this.scrollParent[0].offsetHeight) - event.pageY < o.scrollSensitivity)
					this.scrollParent[0].scrollTop = scrolled = this.scrollParent[0].scrollTop + o.scrollSpeed;
				else if(event.pageY - this.overflowOffset.top < o.scrollSensitivity)
					this.scrollParent[0].scrollTop = scrolled = this.scrollParent[0].scrollTop - o.scrollSpeed;

				if((this.overflowOffset.left + this.scrollParent[0].offsetWidth) - event.pageX < o.scrollSensitivity)
					this.scrollParent[0].scrollLeft = scrolled = this.scrollParent[0].scrollLeft + o.scrollSpeed;
				else if(event.pageX - this.overflowOffset.left < o.scrollSensitivity)
					this.scrollParent[0].scrollLeft = scrolled = this.scrollParent[0].scrollLeft - o.scrollSpeed;

			} else {

				if(event.pageY - $(document).scrollTop() < o.scrollSensitivity)
					scrolled = $(document).scrollTop($(document).scrollTop() - o.scrollSpeed);
				else if($(window).height() - (event.pageY - $(document).scrollTop()) < o.scrollSensitivity)
					scrolled = $(document).scrollTop($(document).scrollTop() + o.scrollSpeed);

				if(event.pageX - $(document).scrollLeft() < o.scrollSensitivity)
					scrolled = $(document).scrollLeft($(document).scrollLeft() - o.scrollSpeed);
				else if($(window).width() - (event.pageX - $(document).scrollLeft()) < o.scrollSensitivity)
					scrolled = $(document).scrollLeft($(document).scrollLeft() + o.scrollSpeed);

			}

			if(scrolled !== false && $.ui.ddmanager && !o.dropBehaviour)
				$.ui.ddmanager.prepareOffsets(this, event);
		}

		//Regenerate the absolute position used for position checks
		this.positionAbs = this._convertPositionTo("absolute");

		//Set the helper position
		if(!this.options.axis || this.options.axis != "y") this.helper[0].style.left = this.position.left+'px';
		if(!this.options.axis || this.options.axis != "x") this.helper[0].style.top = this.position.top+'px';

		//Rearrange
		for (var i = this.items.length - 1; i >= 0; i--) {

			//Cache variables and intersection, continue if no intersection
			var item = this.items[i], itemElement = item.item[0], intersection = this._intersectsWithPointer(item);
			if (!intersection) continue;

			// Only put the placeholder inside the current Container, skip all
			// items form other containers. This works because when moving
			// an item from one container to another the
			// currentContainer is switched before the placeholder is moved.
			//
			// Without this moving items in "sub-sortables" can cause the placeholder to jitter
			// beetween the outer and inner container.
			if (item.instance !== this.currentContainer) continue;

			if (itemElement != this.currentItem[0] //cannot intersect with itself
				&&	this.placeholder[intersection == 1 ? "next" : "prev"]()[0] != itemElement //no useless actions that have been done before
				&&	!$.contains(this.placeholder[0], itemElement) //no action if the item moved is the parent of the item checked
				&& (this.options.type == 'semi-dynamic' ? !$.contains(this.element[0], itemElement) : true)
				//&& itemElement.parentNode == this.placeholder[0].parentNode // only rearrange items within the same container
			) {

				this.direction = intersection == 1 ? "down" : "up";

				if (this.options.tolerance == "pointer" || this._intersectsWithSides(item)) {
					this._rearrange(event, item);
				} else {
					break;
				}

				this._trigger("change", event, this._uiHash());
				break;
			}
		}

		//Post events to containers
		this._contactContainers(event);

		//Interconnect with droppables
		if($.ui.ddmanager) $.ui.ddmanager.drag(this, event);

		//Call callbacks
		this._trigger('sort', event, this._uiHash());

		this.lastPositionAbs = this.positionAbs;
		return false;

	},

	_mouseStop: function(event, noPropagation) {

		if(!event) return;

		//If we are using droppables, inform the manager about the drop
		if ($.ui.ddmanager && !this.options.dropBehaviour)
			$.ui.ddmanager.drop(this, event);

		if(this.options.revert) {
			var that = this;
			var cur = this.placeholder.offset();

			this.reverting = true;

			$(this.helper).animate({
				left: cur.left - this.offset.parent.left - this.margins.left + (this.offsetParent[0] == document.body ? 0 : this.offsetParent[0].scrollLeft),
				top: cur.top - this.offset.parent.top - this.margins.top + (this.offsetParent[0] == document.body ? 0 : this.offsetParent[0].scrollTop)
			}, parseInt(this.options.revert, 10) || 500, function() {
				that._clear(event);
			});
		} else {
			this._clear(event, noPropagation);
		}

		return false;

	},

	cancel: function() {

		if(this.dragging) {

			this._mouseUp({ target: null });

			if(this.options.helper == "original")
				this.currentItem.css(this._storedCSS).removeClass("ui-sortable-helper");
			else
				this.currentItem.show();

			//Post deactivating events to containers
			for (var i = this.containers.length - 1; i >= 0; i--){
				this.containers[i]._trigger("deactivate", null, this._uiHash(this));
				if(this.containers[i].containerCache.over) {
					this.containers[i]._trigger("out", null, this._uiHash(this));
					this.containers[i].containerCache.over = 0;
				}
			}

		}

		if (this.placeholder) {
			//$(this.placeholder[0]).remove(); would have been the jQuery way - unfortunately, it unbinds ALL events from the original node!
			if(this.placeholder[0].parentNode) this.placeholder[0].parentNode.removeChild(this.placeholder[0]);
			if(this.options.helper != "original" && this.helper && this.helper[0].parentNode) this.helper.remove();

			$.extend(this, {
				helper: null,
				dragging: false,
				reverting: false,
				_noFinalSort: null
			});

			if(this.domPosition.prev) {
				$(this.domPosition.prev).after(this.currentItem);
			} else {
				$(this.domPosition.parent).prepend(this.currentItem);
			}
		}

		return this;

	},

	serialize: function(o) {

		var items = this._getItemsAsjQuery(o && o.connected);
		var str = []; o = o || {};

		$(items).each(function() {
			var res = ($(o.item || this).attr(o.attribute || 'id') || '').match(o.expression || (/(.+)[-=_](.+)/));
			if(res) str.push((o.key || res[1]+'[]')+'='+(o.key && o.expression ? res[1] : res[2]));
		});

		if(!str.length && o.key) {
			str.push(o.key + '=');
		}

		return str.join('&');

	},

	toArray: function(o) {

		var items = this._getItemsAsjQuery(o && o.connected);
		var ret = []; o = o || {};

		items.each(function() { ret.push($(o.item || this).attr(o.attribute || 'id') || ''); });
		return ret;

	},

	/* Be careful with the following core functions */
	_intersectsWith: function(item) {

		var x1 = this.positionAbs.left,
			x2 = x1 + this.helperProportions.width,
			y1 = this.positionAbs.top,
			y2 = y1 + this.helperProportions.height;

		var l = item.left,
			r = l + item.width,
			t = item.top,
			b = t + item.height;

		var dyClick = this.offset.click.top,
			dxClick = this.offset.click.left;

		var isOverElement = (y1 + dyClick) > t && (y1 + dyClick) < b && (x1 + dxClick) > l && (x1 + dxClick) < r;

		if(	   this.options.tolerance == "pointer"
			|| this.options.forcePointerForContainers
			|| (this.options.tolerance != "pointer" && this.helperProportions[this.floating ? 'width' : 'height'] > item[this.floating ? 'width' : 'height'])
		) {
			return isOverElement;
		} else {

			return (l < x1 + (this.helperProportions.width / 2) // Right Half
				&& x2 - (this.helperProportions.width / 2) < r // Left Half
				&& t < y1 + (this.helperProportions.height / 2) // Bottom Half
				&& y2 - (this.helperProportions.height / 2) < b ); // Top Half

		}
	},

	_intersectsWithPointer: function(item) {

		var isOverElementHeight = (this.options.axis === 'x') || $.ui.isOverAxis(this.positionAbs.top + this.offset.click.top, item.top, item.height),
			isOverElementWidth = (this.options.axis === 'y') || $.ui.isOverAxis(this.positionAbs.left + this.offset.click.left, item.left, item.width),
			isOverElement = isOverElementHeight && isOverElementWidth,
			verticalDirection = this._getDragVerticalDirection(),
			horizontalDirection = this._getDragHorizontalDirection();

		if (!isOverElement)
			return false;

		return this.floating ?
			( ((horizontalDirection && horizontalDirection == "right") || verticalDirection == "down") ? 2 : 1 )
			: ( verticalDirection && (verticalDirection == "down" ? 2 : 1) );

	},

	_intersectsWithSides: function(item) {

		var isOverBottomHalf = $.ui.isOverAxis(this.positionAbs.top + this.offset.click.top, item.top + (item.height/2), item.height),
			isOverRightHalf = $.ui.isOverAxis(this.positionAbs.left + this.offset.click.left, item.left + (item.width/2), item.width),
			verticalDirection = this._getDragVerticalDirection(),
			horizontalDirection = this._getDragHorizontalDirection();

		if (this.floating && horizontalDirection) {
			return ((horizontalDirection == "right" && isOverRightHalf) || (horizontalDirection == "left" && !isOverRightHalf));
		} else {
			return verticalDirection && ((verticalDirection == "down" && isOverBottomHalf) || (verticalDirection == "up" && !isOverBottomHalf));
		}

	},

	_getDragVerticalDirection: function() {
		var delta = this.positionAbs.top - this.lastPositionAbs.top;
		return delta != 0 && (delta > 0 ? "down" : "up");
	},

	_getDragHorizontalDirection: function() {
		var delta = this.positionAbs.left - this.lastPositionAbs.left;
		return delta != 0 && (delta > 0 ? "right" : "left");
	},

	refresh: function(event) {
		this._refreshItems(event);
		this.refreshPositions();
		return this;
	},

	_connectWith: function() {
		var options = this.options;
		return options.connectWith.constructor == String
			? [options.connectWith]
			: options.connectWith;
	},

	_getItemsAsjQuery: function(connected) {

		var items = [];
		var queries = [];
		var connectWith = this._connectWith();

		if(connectWith && connected) {
			for (var i = connectWith.length - 1; i >= 0; i--){
				var cur = $(connectWith[i]);
				for (var j = cur.length - 1; j >= 0; j--){
					var inst = $.data(cur[j], this.widgetName);
					if(inst && inst != this && !inst.options.disabled) {
						queries.push([$.isFunction(inst.options.items) ? inst.options.items.call(inst.element) : $(inst.options.items, inst.element).not(".ui-sortable-helper").not('.ui-sortable-placeholder'), inst]);
					}
				};
			};
		}

		queries.push([$.isFunction(this.options.items) ? this.options.items.call(this.element, null, { options: this.options, item: this.currentItem }) : $(this.options.items, this.element).not(".ui-sortable-helper").not('.ui-sortable-placeholder'), this]);

		for (var i = queries.length - 1; i >= 0; i--){
			queries[i][0].each(function() {
				items.push(this);
			});
		};

		return $(items);

	},

	_removeCurrentsFromItems: function() {

		var list = this.currentItem.find(":data(" + this.widgetName + "-item)");

		this.items = $.grep(this.items, function (item) {
			for (var j=0; j < list.length; j++) {
				if(list[j] == item.item[0])
					return false;
			};
			return true;
		});

	},

	_refreshItems: function(event) {

		this.items = [];
		this.containers = [this];
		var items = this.items;
		var queries = [[$.isFunction(this.options.items) ? this.options.items.call(this.element[0], event, { item: this.currentItem }) : $(this.options.items, this.element), this]];
		var connectWith = this._connectWith();

		if(connectWith && this.ready) { //Shouldn't be run the first time through due to massive slow-down
			for (var i = connectWith.length - 1; i >= 0; i--){
				var cur = $(connectWith[i]);
				for (var j = cur.length - 1; j >= 0; j--){
					var inst = $.data(cur[j], this.widgetName);
					if(inst && inst != this && !inst.options.disabled) {
						queries.push([$.isFunction(inst.options.items) ? inst.options.items.call(inst.element[0], event, { item: this.currentItem }) : $(inst.options.items, inst.element), inst]);
						this.containers.push(inst);
					}
				};
			};
		}

		for (var i = queries.length - 1; i >= 0; i--) {
			var targetData = queries[i][1];
			var _queries = queries[i][0];

			for (var j=0, queriesLength = _queries.length; j < queriesLength; j++) {
				var item = $(_queries[j]);

				item.data(this.widgetName + '-item', targetData); // Data for target checking (mouse manager)

				items.push({
					item: item,
					instance: targetData,
					width: 0, height: 0,
					left: 0, top: 0
				});
			};
		};

	},

	refreshPositions: function(fast) {

		//This has to be redone because due to the item being moved out/into the offsetParent, the offsetParent's position will change
		if(this.offsetParent && this.helper) {
			this.offset.parent = this._getParentOffset();
		}

		for (var i = this.items.length - 1; i >= 0; i--){
			var item = this.items[i];

			//We ignore calculating positions of all connected containers when we're not over them
			if(item.instance != this.currentContainer && this.currentContainer && item.item[0] != this.currentItem[0])
				continue;

			var t = this.options.toleranceElement ? $(this.options.toleranceElement, item.item) : item.item;

			if (!fast) {
				item.width = t.outerWidth();
				item.height = t.outerHeight();
			}

			var p = t.offset();
			item.left = p.left;
			item.top = p.top;
		};

		if(this.options.custom && this.options.custom.refreshContainers) {
			this.options.custom.refreshContainers.call(this);
		} else {
			for (var i = this.containers.length - 1; i >= 0; i--){
				var p = this.containers[i].element.offset();
				this.containers[i].containerCache.left = p.left;
				this.containers[i].containerCache.top = p.top;
				this.containers[i].containerCache.width	= this.containers[i].element.outerWidth();
				this.containers[i].containerCache.height = this.containers[i].element.outerHeight();
			};
		}

		return this;
	},

	_createPlaceholder: function(that) {
		that = that || this;
		var o = that.options;

		if(!o.placeholder || o.placeholder.constructor == String) {
			var className = o.placeholder;
			o.placeholder = {
				element: function() {

					var el = $(document.createElement(that.currentItem[0].nodeName))
						.addClass(className || that.currentItem[0].className+" ui-sortable-placeholder")
						.removeClass("ui-sortable-helper")[0];

					if(!className)
						el.style.visibility = "hidden";

					return el;
				},
				update: function(container, p) {

					// 1. If a className is set as 'placeholder option, we don't force sizes - the class is responsible for that
					// 2. The option 'forcePlaceholderSize can be enabled to force it even if a class name is specified
					if(className && !o.forcePlaceholderSize) return;

					//If the element doesn't have a actual height by itself (without styles coming from a stylesheet), it receives the inline height from the dragged item
					if(!p.height()) { p.height(that.currentItem.innerHeight() - parseInt(that.currentItem.css('paddingTop')||0, 10) - parseInt(that.currentItem.css('paddingBottom')||0, 10)); };
					if(!p.width()) { p.width(that.currentItem.innerWidth() - parseInt(that.currentItem.css('paddingLeft')||0, 10) - parseInt(that.currentItem.css('paddingRight')||0, 10)); };
				}
			};
		}

		//Create the placeholder
		that.placeholder = $(o.placeholder.element.call(that.element, that.currentItem));

		//Append it after the actual current item
		that.currentItem.after(that.placeholder);

		//Update the size of the placeholder (TODO: Logic to fuzzy, see line 316/317)
		o.placeholder.update(that, that.placeholder);

	},

	_contactContainers: function(event) {

		// get innermost container that intersects with item
		var innermostContainer = null, innermostIndex = null;


		for (var i = this.containers.length - 1; i >= 0; i--){

			// never consider a container that's located within the item itself
			if($.contains(this.currentItem[0], this.containers[i].element[0]))
				continue;

			if(this._intersectsWith(this.containers[i].containerCache)) {

				// if we've already found a container and it's more "inner" than this, then continue
				if(innermostContainer && $.contains(this.containers[i].element[0], innermostContainer.element[0]))
					continue;

				innermostContainer = this.containers[i];
				innermostIndex = i;

			} else {
				// container doesn't intersect. trigger "out" event if necessary
				if(this.containers[i].containerCache.over) {
					this.containers[i]._trigger("out", event, this._uiHash(this));
					this.containers[i].containerCache.over = 0;
				}
			}

		}

		// if no intersecting containers found, return
		if(!innermostContainer) return;

		// move the item into the container if it's not there already
		if(this.containers.length === 1) {
			this.containers[innermostIndex]._trigger("over", event, this._uiHash(this));
			this.containers[innermostIndex].containerCache.over = 1;
		} else {

			//When entering a new container, we will find the item with the least distance and append our item near it
			var dist = 10000; var itemWithLeastDistance = null;
			var posProperty = this.containers[innermostIndex].floating ? 'left' : 'top';
			var sizeProperty = this.containers[innermostIndex].floating ? 'width' : 'height';
			var base = this.positionAbs[posProperty] + this.offset.click[posProperty];
			for (var j = this.items.length - 1; j >= 0; j--) {
				if(!$.contains(this.containers[innermostIndex].element[0], this.items[j].item[0])) continue;
				if(this.items[j].item[0] == this.currentItem[0]) continue;
				var cur = this.items[j].item.offset()[posProperty];
				var nearBottom = false;
				if(Math.abs(cur - base) > Math.abs(cur + this.items[j][sizeProperty] - base)){
					nearBottom = true;
					cur += this.items[j][sizeProperty];
				}

				if(Math.abs(cur - base) < dist) {
					dist = Math.abs(cur - base); itemWithLeastDistance = this.items[j];
					this.direction = nearBottom ? "up": "down";
				}
			}

			if(!itemWithLeastDistance && !this.options.dropOnEmpty) //Check if dropOnEmpty is enabled
				return;

			this.currentContainer = this.containers[innermostIndex];
			itemWithLeastDistance ? this._rearrange(event, itemWithLeastDistance, null, true) : this._rearrange(event, null, this.containers[innermostIndex].element, true);
			this._trigger("change", event, this._uiHash());
			this.containers[innermostIndex]._trigger("change", event, this._uiHash(this));

			//Update the placeholder
			this.options.placeholder.update(this.currentContainer, this.placeholder);

			this.containers[innermostIndex]._trigger("over", event, this._uiHash(this));
			this.containers[innermostIndex].containerCache.over = 1;
		}


	},

	_createHelper: function(event) {

		var o = this.options;
		var helper = $.isFunction(o.helper) ? $(o.helper.apply(this.element[0], [event, this.currentItem])) : (o.helper == 'clone' ? this.currentItem.clone() : this.currentItem);

		if(!helper.parents('body').length) //Add the helper to the DOM if that didn't happen already
			$(o.appendTo != 'parent' ? o.appendTo : this.currentItem[0].parentNode)[0].appendChild(helper[0]);

		if(helper[0] == this.currentItem[0])
			this._storedCSS = { width: this.currentItem[0].style.width, height: this.currentItem[0].style.height, position: this.currentItem.css("position"), top: this.currentItem.css("top"), left: this.currentItem.css("left") };

		if(helper[0].style.width == '' || o.forceHelperSize) helper.width(this.currentItem.width());
		if(helper[0].style.height == '' || o.forceHelperSize) helper.height(this.currentItem.height());

		return helper;

	},

	_adjustOffsetFromHelper: function(obj) {
		if (typeof obj == 'string') {
			obj = obj.split(' ');
		}
		if ($.isArray(obj)) {
			obj = {left: +obj[0], top: +obj[1] || 0};
		}
		if ('left' in obj) {
			this.offset.click.left = obj.left + this.margins.left;
		}
		if ('right' in obj) {
			this.offset.click.left = this.helperProportions.width - obj.right + this.margins.left;
		}
		if ('top' in obj) {
			this.offset.click.top = obj.top + this.margins.top;
		}
		if ('bottom' in obj) {
			this.offset.click.top = this.helperProportions.height - obj.bottom + this.margins.top;
		}
	},

	_getParentOffset: function() {


		//Get the offsetParent and cache its position
		this.offsetParent = this.helper.offsetParent();
		var po = this.offsetParent.offset();

		// This is a special case where we need to modify a offset calculated on start, since the following happened:
		// 1. The position of the helper is absolute, so it's position is calculated based on the next positioned parent
		// 2. The actual offset parent is a child of the scroll parent, and the scroll parent isn't the document, which means that
		//    the scroll is included in the initial calculation of the offset of the parent, and never recalculated upon drag
		if(this.cssPosition == 'absolute' && this.scrollParent[0] != document && $.contains(this.scrollParent[0], this.offsetParent[0])) {
			po.left += this.scrollParent.scrollLeft();
			po.top += this.scrollParent.scrollTop();
		}

		if((this.offsetParent[0] == document.body) //This needs to be actually done for all browsers, since pageX/pageY includes this information
		|| (this.offsetParent[0].tagName && this.offsetParent[0].tagName.toLowerCase() == 'html' && $.ui.ie)) //Ugly IE fix
			po = { top: 0, left: 0 };

		return {
			top: po.top + (parseInt(this.offsetParent.css("borderTopWidth"),10) || 0),
			left: po.left + (parseInt(this.offsetParent.css("borderLeftWidth"),10) || 0)
		};

	},

	_getRelativeOffset: function() {

		if(this.cssPosition == "relative") {
			var p = this.currentItem.position();
			return {
				top: p.top - (parseInt(this.helper.css("top"),10) || 0) + this.scrollParent.scrollTop(),
				left: p.left - (parseInt(this.helper.css("left"),10) || 0) + this.scrollParent.scrollLeft()
			};
		} else {
			return { top: 0, left: 0 };
		}

	},

	_cacheMargins: function() {
		this.margins = {
			left: (parseInt(this.currentItem.css("marginLeft"),10) || 0),
			top: (parseInt(this.currentItem.css("marginTop"),10) || 0)
		};
	},

	_cacheHelperProportions: function() {
		this.helperProportions = {
			width: this.helper.outerWidth(),
			height: this.helper.outerHeight()
		};
	},

	_setContainment: function() {

		var o = this.options;
		if(o.containment == 'parent') o.containment = this.helper[0].parentNode;
		if(o.containment == 'document' || o.containment == 'window') this.containment = [
			0 - this.offset.relative.left - this.offset.parent.left,
			0 - this.offset.relative.top - this.offset.parent.top,
			$(o.containment == 'document' ? document : window).width() - this.helperProportions.width - this.margins.left,
			($(o.containment == 'document' ? document : window).height() || document.body.parentNode.scrollHeight) - this.helperProportions.height - this.margins.top
		];

		if(!(/^(document|window|parent)$/).test(o.containment)) {
			var ce = $(o.containment)[0];
			var co = $(o.containment).offset();
			var over = ($(ce).css("overflow") != 'hidden');

			this.containment = [
				co.left + (parseInt($(ce).css("borderLeftWidth"),10) || 0) + (parseInt($(ce).css("paddingLeft"),10) || 0) - this.margins.left,
				co.top + (parseInt($(ce).css("borderTopWidth"),10) || 0) + (parseInt($(ce).css("paddingTop"),10) || 0) - this.margins.top,
				co.left+(over ? Math.max(ce.scrollWidth,ce.offsetWidth) : ce.offsetWidth) - (parseInt($(ce).css("borderLeftWidth"),10) || 0) - (parseInt($(ce).css("paddingRight"),10) || 0) - this.helperProportions.width - this.margins.left,
				co.top+(over ? Math.max(ce.scrollHeight,ce.offsetHeight) : ce.offsetHeight) - (parseInt($(ce).css("borderTopWidth"),10) || 0) - (parseInt($(ce).css("paddingBottom"),10) || 0) - this.helperProportions.height - this.margins.top
			];
		}

	},

	_convertPositionTo: function(d, pos) {

		if(!pos) pos = this.position;
		var mod = d == "absolute" ? 1 : -1;
		var o = this.options, scroll = this.cssPosition == 'absolute' && !(this.scrollParent[0] != document && $.contains(this.scrollParent[0], this.offsetParent[0])) ? this.offsetParent : this.scrollParent, scrollIsRootNode = (/(html|body)/i).test(scroll[0].tagName);

		return {
			top: (
				pos.top																	// The absolute mouse position
				+ this.offset.relative.top * mod										// Only for relative positioned nodes: Relative offset from element to offset parent
				+ this.offset.parent.top * mod											// The offsetParent's offset without borders (offset + border)
				- ( ( this.cssPosition == 'fixed' ? -this.scrollParent.scrollTop() : ( scrollIsRootNode ? 0 : scroll.scrollTop() ) ) * mod)
			),
			left: (
				pos.left																// The absolute mouse position
				+ this.offset.relative.left * mod										// Only for relative positioned nodes: Relative offset from element to offset parent
				+ this.offset.parent.left * mod											// The offsetParent's offset without borders (offset + border)
				- ( ( this.cssPosition == 'fixed' ? -this.scrollParent.scrollLeft() : scrollIsRootNode ? 0 : scroll.scrollLeft() ) * mod)
			)
		};

	},

	_generatePosition: function(event) {

		var o = this.options, scroll = this.cssPosition == 'absolute' && !(this.scrollParent[0] != document && $.contains(this.scrollParent[0], this.offsetParent[0])) ? this.offsetParent : this.scrollParent, scrollIsRootNode = (/(html|body)/i).test(scroll[0].tagName);

		// This is another very weird special case that only happens for relative elements:
		// 1. If the css position is relative
		// 2. and the scroll parent is the document or similar to the offset parent
		// we have to refresh the relative offset during the scroll so there are no jumps
		if(this.cssPosition == 'relative' && !(this.scrollParent[0] != document && this.scrollParent[0] != this.offsetParent[0])) {
			this.offset.relative = this._getRelativeOffset();
		}

		var pageX = event.pageX;
		var pageY = event.pageY;

		/*
		 * - Position constraining -
		 * Constrain the position to a mix of grid, containment.
		 */

		if(this.originalPosition) { //If we are not dragging yet, we won't check for options

			if(this.containment) {
				if(event.pageX - this.offset.click.left < this.containment[0]) pageX = this.containment[0] + this.offset.click.left;
				if(event.pageY - this.offset.click.top < this.containment[1]) pageY = this.containment[1] + this.offset.click.top;
				if(event.pageX - this.offset.click.left > this.containment[2]) pageX = this.containment[2] + this.offset.click.left;
				if(event.pageY - this.offset.click.top > this.containment[3]) pageY = this.containment[3] + this.offset.click.top;
			}

			if(o.grid) {
				var top = this.originalPageY + Math.round((pageY - this.originalPageY) / o.grid[1]) * o.grid[1];
				pageY = this.containment ? (!(top - this.offset.click.top < this.containment[1] || top - this.offset.click.top > this.containment[3]) ? top : (!(top - this.offset.click.top < this.containment[1]) ? top - o.grid[1] : top + o.grid[1])) : top;

				var left = this.originalPageX + Math.round((pageX - this.originalPageX) / o.grid[0]) * o.grid[0];
				pageX = this.containment ? (!(left - this.offset.click.left < this.containment[0] || left - this.offset.click.left > this.containment[2]) ? left : (!(left - this.offset.click.left < this.containment[0]) ? left - o.grid[0] : left + o.grid[0])) : left;
			}

		}

		return {
			top: (
				pageY																// The absolute mouse position
				- this.offset.click.top													// Click offset (relative to the element)
				- this.offset.relative.top												// Only for relative positioned nodes: Relative offset from element to offset parent
				- this.offset.parent.top												// The offsetParent's offset without borders (offset + border)
				+ ( ( this.cssPosition == 'fixed' ? -this.scrollParent.scrollTop() : ( scrollIsRootNode ? 0 : scroll.scrollTop() ) ))
			),
			left: (
				pageX																// The absolute mouse position
				- this.offset.click.left												// Click offset (relative to the element)
				- this.offset.relative.left												// Only for relative positioned nodes: Relative offset from element to offset parent
				- this.offset.parent.left												// The offsetParent's offset without borders (offset + border)
				+ ( ( this.cssPosition == 'fixed' ? -this.scrollParent.scrollLeft() : scrollIsRootNode ? 0 : scroll.scrollLeft() ))
			)
		};

	},

	_rearrange: function(event, i, a, hardRefresh) {

		a ? a[0].appendChild(this.placeholder[0]) : i.item[0].parentNode.insertBefore(this.placeholder[0], (this.direction == 'down' ? i.item[0] : i.item[0].nextSibling));

		//Various things done here to improve the performance:
		// 1. we create a setTimeout, that calls refreshPositions
		// 2. on the instance, we have a counter variable, that get's higher after every append
		// 3. on the local scope, we copy the counter variable, and check in the timeout, if it's still the same
		// 4. this lets only the last addition to the timeout stack through
		this.counter = this.counter ? ++this.counter : 1;
		var counter = this.counter;

		this._delay(function() {
			if(counter == this.counter) this.refreshPositions(!hardRefresh); //Precompute after each DOM insertion, NOT on mousemove
		});

	},

	_clear: function(event, noPropagation) {

		this.reverting = false;
		// We delay all events that have to be triggered to after the point where the placeholder has been removed and
		// everything else normalized again
		var delayedTriggers = [];

		// We first have to update the dom position of the actual currentItem
		// Note: don't do it if the current item is already removed (by a user), or it gets reappended (see #4088)
		if(!this._noFinalSort && this.currentItem.parent().length) this.placeholder.before(this.currentItem);
		this._noFinalSort = null;

		if(this.helper[0] == this.currentItem[0]) {
			for(var i in this._storedCSS) {
				if(this._storedCSS[i] == 'auto' || this._storedCSS[i] == 'static') this._storedCSS[i] = '';
			}
			this.currentItem.css(this._storedCSS).removeClass("ui-sortable-helper");
		} else {
			this.currentItem.show();
		}

		if(this.fromOutside && !noPropagation) delayedTriggers.push(function(event) { this._trigger("receive", event, this._uiHash(this.fromOutside)); });
		if((this.fromOutside || this.domPosition.prev != this.currentItem.prev().not(".ui-sortable-helper")[0] || this.domPosition.parent != this.currentItem.parent()[0]) && !noPropagation) delayedTriggers.push(function(event) { this._trigger("update", event, this._uiHash()); }); //Trigger update callback if the DOM position has changed

		// Check if the items Container has Changed and trigger appropriate
		// events.
		if (this !== this.currentContainer) {
			if(!noPropagation) {
				delayedTriggers.push(function(event) { this._trigger("remove", event, this._uiHash()); });
				delayedTriggers.push((function(c) { return function(event) { c._trigger("receive", event, this._uiHash(this)); };  }).call(this, this.currentContainer));
				delayedTriggers.push((function(c) { return function(event) { c._trigger("update", event, this._uiHash(this));  }; }).call(this, this.currentContainer));
			}
		}


		//Post events to containers
		for (var i = this.containers.length - 1; i >= 0; i--){
			if(!noPropagation) delayedTriggers.push((function(c) { return function(event) { c._trigger("deactivate", event, this._uiHash(this)); };  }).call(this, this.containers[i]));
			if(this.containers[i].containerCache.over) {
				delayedTriggers.push((function(c) { return function(event) { c._trigger("out", event, this._uiHash(this)); };  }).call(this, this.containers[i]));
				this.containers[i].containerCache.over = 0;
			}
		}

		//Do what was originally in plugins
		if(this._storedCursor) $('body').css("cursor", this._storedCursor); //Reset cursor
		if(this._storedOpacity) this.helper.css("opacity", this._storedOpacity); //Reset opacity
		if(this._storedZIndex) this.helper.css("zIndex", this._storedZIndex == 'auto' ? '' : this._storedZIndex); //Reset z-index

		this.dragging = false;
		if(this.cancelHelperRemoval) {
			if(!noPropagation) {
				this._trigger("beforeStop", event, this._uiHash());
				for (var i=0; i < delayedTriggers.length; i++) { delayedTriggers[i].call(this, event); }; //Trigger all delayed events
				this._trigger("stop", event, this._uiHash());
			}

			this.fromOutside = false;
			return false;
		}

		if(!noPropagation) this._trigger("beforeStop", event, this._uiHash());

		//$(this.placeholder[0]).remove(); would have been the jQuery way - unfortunately, it unbinds ALL events from the original node!
		this.placeholder[0].parentNode.removeChild(this.placeholder[0]);

		if(this.helper[0] != this.currentItem[0]) this.helper.remove(); this.helper = null;

		if(!noPropagation) {
			for (var i=0; i < delayedTriggers.length; i++) { delayedTriggers[i].call(this, event); }; //Trigger all delayed events
			this._trigger("stop", event, this._uiHash());
		}

		this.fromOutside = false;
		return true;

	},

	_trigger: function() {
		if ($.Widget.prototype._trigger.apply(this, arguments) === false) {
			this.cancel();
		}
	},

	_uiHash: function(_inst) {
		var inst = _inst || this;
		return {
			helper: inst.helper,
			placeholder: inst.placeholder || $([]),
			position: inst.position,
			originalPosition: inst.originalPosition,
			offset: inst.positionAbs,
			item: inst.currentItem,
			sender: _inst ? _inst.element : null
		};
	}

});

})(jQuery);