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resources/lib/jquery.ui/jquery.ui.sortable.js

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/*!
 * jQuery UI Sortable 1.9.2
 * 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: "1.9.2",
    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);