var app = angular.module('app', []);

app.directive('yaTree', function() {

    return {
        restrict: 'A',
        transclude: 'element',
        priority: 1000,
        terminal: true,
        compile: function(tElement, tAttrs, transclude) {

            var repeatExpr, childExpr, rootExpr, childrenExpr;

            repeatExpr = tAttrs.yaTree.match(/^(.*) in ((?:.*\.)?(.*)) at (.*)$/);
            childExpr = repeatExpr[1];
            rootExpr = repeatExpr[2];
            childrenExpr = repeatExpr[3];
            branchExpr = repeatExpr[4];

            return function link(scope, element, attrs) {

                var rootElement = element[0].parentNode,
                    cache = [];

                // Reverse lookup object to avoid re-rendering elements


                function lookup(child) {
                    var i = cache.length;
                    while (i--) {
                        if (cache[i].scope[childExpr] === child) {
                            return cache.splice(i, 1)[0];
                        }
                    }
                }

                scope.$watch(rootExpr, function(root) {
                    var currentCache = [];

                    // Recurse the data structure
                    (function walk(children, parentNode, parentScope, depth) {

                        var i = 0,
                            n = children.length,
                            last = n - 1,
                            cursor, child, cached, childScope, grandchildren;

                        // Iterate the children at the current level
                        for (; i < n; ++i) {

                            // We will compare the cached element to the element in
                            // at the destination index. If it does not match, then
                            // the cached element is being moved into this position.
                            cursor = parentNode.childNodes[i];

                            child = children[i];

                            // See if this child has been previously rendered
                            // using a reverse lookup by object reference
                            cached = lookup(child);

                            // If the parentScope no longer matches, we've moved.
                            // We'll have to transclude again so that scopes
                            // and controllers are properly inherited
                            if (cached && cached.parentScope !== parentScope) {
                                cache.push(cached);
                                cached = null;
                            }

                            // If it has not, render a new element and prepare its scope
                            // We also cache a reference to its branch node which will
                            // be used as the parentNode in the next level of recursion
                            if (!cached) {
                                transclude(parentScope.$new(), function(clone, childScope) {

                                    childScope[childExpr] = child;

                                    cached = {
                                        scope: childScope,
                                        parentScope: parentScope,
                                        element: clone[0],
                                        branch: clone.find(branchExpr)[0]
                                    };

                                    // This had to happen during transclusion so inherited
                                    // controllers, among other things, work properly
                                    if (!cursor) parentNode.appendChild(cached.element);
                                    else parentNode.insertBefore(cached.element, cursor);


                                });
                            } else if (cached.element !== cursor) {
                                if (!cursor) parentNode.appendChild(cached.element);
                                else parentNode.insertBefore(cached.element, cursor);

                            }

                            // Lets's set some scope values
                            childScope = cached.scope;

                            // Store the current depth on the scope in case you want
                            // to use it (for good or evil, no judgment).
                            childScope.$depth = depth;

                            // Emulate some ng-repeat values
                            childScope.$index = i;
                            childScope.$first = (i === 0);
                            childScope.$last = (i === last);
                            childScope.$middle = !(childScope.$first || childScope.$last);

                            // Push the object onto the new cache which will replace
                            // the old cache at the end of the walk.
                            currentCache.push(cached);

                            // If the child has children of its own, recurse 'em.
                            grandchildren = child[childrenExpr];
                            if (grandchildren && grandchildren.length) {
                                walk(grandchildren, cached.branch, childScope, depth + 1);
                            }
                        }
                    })(root, rootElement, scope, 0);

                    // Cleanup objects which have been removed.
                    // Remove DOM elements and destroy scopes to prevent memory leaks.
                    i = cache.length;

                    while (i--) {
                        cached = cache[i];
                        if (cached.scope) {
                            cached.scope.$destroy();
                        }
                        if (cached.element) {
                            cached.element.parentNode.removeChild(cached.element);
                        }
                    }

                    // Replace previous cache.
                    cache = currentCache;

                }, true);
            };
        }
    };
});

app.directive('uiNestedSortable', ['$parse', function($parse) {

    'use strict';

    var eventTypes = 'Create Start Sort Change BeforeStop Stop Update Receive Remove Over Out Activate Deactivate'.split(' ');

    return {
        restrict: 'A',
        link: function(scope, element, attrs) {

            var options = attrs.uiNestedSortable ? $parse(attrs.uiNestedSortable)(scope) : {};

            angular.forEach(eventTypes, function(eventType) {

                var attr = attrs['uiNestedSortable' + eventType],
                    callback;

                if (attr) {
                    callback = $parse(attr);
                    options[eventType.charAt(0).toLowerCase() + eventType.substr(1)] = function(event, ui) {
                        scope.$apply(function() {

                            callback(scope, {
                                $event: event,
                                $ui: ui
                            });
                        });
                    };
                }

            });

            element.nestedSortable(options);

        }
    };
}]);

app.controller('TreeController', function($scope, $timeout) {

    $scope.selected = null;

    $scope.setSelected = function(child){
        $scope.selected = child;
        console.log(child);
    };

    $scope.pushToSelected = function(task){
        var target = (!!$scope.selected) ? $scope.selected.children : $scope.data.children;
        console.log(target);
        target.push(task);
    };

    $scope.data = {
        children: [
            {
                "TaskType": "Folder","minimized": true,
                "Name": "Engineering: Analysis \u0026 Configuration",
                "TotalHours": 569.03,
                "TotalCost": 77284.2000,
                "Id": 164,
                "SortOrder": 0,
                "ParentId": null,
                "children": [{
                    "TaskType": "Folder","minimized": true,
                    "Name": "Model Development",
                    "TotalHours": 1.80,
                    "TotalCost": 252.0000,
                    "Id": 270,
                    "SortOrder": 11,
                    "ParentId": 164,
                    "children": []
                }, {
                    "TaskType": "Folder","minimized": true,
                    "Name": "Model Checking",
                    "TotalHours": 0.02,
                    "TotalCost": 2.8000,
                    "Id": 1591,
                    "SortOrder": 12,
                    "ParentId": 164,
                    "children": [{
                        "TaskType": "Labor","minimized": true,
                        "TotalCost": 2.8000,
                        "TotalHours": 0.02,
                        "children": [],
                        "Name": "Check Model \u0026 TCC\u0027s (Per Bus)",
                        "Id": 1592,
                        "SortOrder": 1,
                        "ParentId": 1591
                    }]
                }]
            }
        ]
    };

    $scope.data2 = {
        children: [
            {
                "TaskType": "Labor",
                "Name": "New #1",
                "TotalHours": 569.03,
                "TotalCost": 77284.2000,
                "Id": 164,
                "SortOrder": 0,
                "ParentId": null,
                "children": []
            },
            {
                "TaskType": "Labor",
                "Name": "New #2",
                "TotalHours": 1.80,
                "TotalCost": 252.0000,
                "Id": 270,
                "SortOrder": 11,
                "ParentId": null,
                "children": []
            },
            {
                "TaskType": "Labor",
                "Name": "New #3",
                "TotalHours": 0.02,
                "TotalCost": 2.8000,
                "Id": 1591,
                "SortOrder": 12,
                "ParentId": null,
                "children": []
            }
        ]
    };

    $scope.options = {
        listType: 'ol',
        items: 'lis',
        doNotClear: true,
        placeholder: 'ui-state-highlightsss',
        forcePlaceholderSize: true,
        toleranceElement: '> div',
        startMin: true
    };

    $scope.toggleMinimized = function(child) {
        child.minimized = !child.minimized;
    };

    $scope.addChild = function(child) {
        child.children.push({
            title: '',
            children: []
        });
    };

    $scope.remove = function(child) {
        function walk(target) {
            var children = target.children,
                i;
            if (children) {
                i = children.length;
                while (i--) {
                    if (children[i] === child) {
                        return children.splice(i, 1);
                    } else {
                        walk(children[i])
                    }
                }
            }
        }
        walk($scope.data);
    };

    $scope.update = function(event, ui) {

        var root = event.target,
            item = ui.item,
            parent = item.parent(),
            target = (parent[0] === root) ? $scope.data : parent.scope().child,
            child = item.scope().child,
            index = item.index();

        if (!target)
            return;

        target.children || (target.children = []);

        function walk(target, child) {
            var children = target.children,
                i;
            if (children) {
                i = children.length;
                while (i--) {
                    if (children[i] === child) {
                        return children.splice(i, 1);
                    } else {
                        walk(children[i], child);
                    }
                }
            }
        }

        walk($scope.data, child);

        target.children.splice(index, 0, child);

        console.log(target.children);
    };

    $scope.isAllowed = function(placeholderEl, placeholderParentEl, itemEl){
        var item = angular.element(itemEl).scope().child;
        var hasParentScope = !!angular.element(placeholderParentEl).scope();
        return item.TaskType == "Folder" || hasParentScope;
    };

});
<!DOCTYPE html>
<html>

  <head>
    <meta charset="utf-8" />
    <title>AngularJS Plunker</title>
    <link rel="stylesheet" href="style.css" />
    <link data-require="jqueryui@*" data-semver="1.10.0" rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/jqueryui/1.10.0/css/smoothness/jquery-ui-1.10.0.custom.min.css" />
    <script data-require="jquery@*" data-semver="2.0.3" src="http://code.jquery.com/jquery-2.0.3.min.js"></script>
    <script data-require="jqueryui@*" data-semver="1.10.0" src="//cdnjs.cloudflare.com/ajax/libs/jqueryui/1.10.0/jquery-ui.js"></script>
    <script>document.write('<base href="' + document.location + '" />');</script>
    <script data-require="angular.js@1.1.x" src="https://ajax.googleapis.com/ajax/libs/angularjs/1.1.5/angular.js" data-semver="1.1.5"></script>
    <script src="nestedSortable.js"></script>
    <script src="app.js"></script>
  </head>

  <body>
    <div ng-app="app" ng-cloak>
        <div ng-controller="TreeController">
          <div ng-show="loading">Loading</div>
          <div><button ng-click="addChild(data)">+ New</button></div>
          <div class="live">
              <ol id="masterList"
                  ui-nested-sortable="{listType: 'ol',items: 'li',doNotClear: true,placeholder: 'ui-state-highlight',forcePlaceholderSize: true,toleranceElement: '> div', isAllowed: isAllowed, revert: true, connectWith: '#masterList, #pickList'}"
                  ui-nested-sortable-update="update($event, $ui)">
                  <li ya-tree="child in data.children at ol" ng-class="{minimized:child.minimized}">
                      <div>
                          <span ng-show="child.TaskType == 'Folder'">
                              <button class="toggle" ng-click="toggleMinimized(child)" ng-switch on="child.minimized"><span ng-switch-when="true">&#x25B6;</span><span ng-switch-default>&#x25BC;</span></button>
                          </span>
                          <div>{{child.TaskType + ' - ' + child.Name}}</div>
                          <div>{{child.TotalCost | currency}}</div>
                          <div>{{child.TotalHours + ' hrs'}}</div>
                          <span ng-show="child.TaskType == 'Folder'">
                              <button ng-click="addChild(child)">+</button>
                          </span>
                          <button ng-click="remove(child)">x</button>
                      </div>
                      <ol ng-class="{pregnant:child.children.length}"></ol>
                  </li>
              </ol>
          </div>
          <div class="shadow">
              <ol id="pickList"
                  ui-nested-sortable="{listType: 'ol',items: 'li',doNotClear: true,placeholder: 'ui-state-highlight',forcePlaceholderSize: true,toleranceElement: '> div', isAllowed: isAllowed, revert: true, connectWith: '#masterList, #pickList'}">
                  <li ya-tree="child in data2.children at ol">
                      <div>
                          <div>{{child.TaskType + ' - ' + child.Name}}</div>
                          <div>{{child.TotalCost | currency}}</div>
                          <div>{{child.TotalHours + ' hrs'}}</div>
                      </div>
                      <ol ng-class="{pregnant:child.children.length}"></ol>
                  </li>
              </ol>
          </div>
          <div>
              {{selected}}
          </div>
        </div>
    </div>
  </body>

</html>
/* Put your css in here */
[ng\:cloak],[ng-cloak],[data-ng-cloak],[x-ng-cloak],.ng-cloak,.x-ng-cloak {
    display:none;
}

ng\:form{
    display:block;
}

[ng-cloak] {
    display: none;
}

* {
    box-sizing: border-box;
}

body {
    font: 12px/16px helvetica, arial, sans-serif;
    background: #eee;
}

ol {
    margin: 4px 0;
    border: 0 none transparent;
    padding: 0;
    background: #eee;
}

li {
    list-style: none;
    margin: 1px;
    border: 1px solid #ddd;
    padding: 8px 0 4px 10px;
    background: #fff;
    border-right: none;
}

.ui-sortable li {
    cursor: move;
}

.live input,.shadow input {
    margin: 0;
    border: 1px solid #ddd;
    padding: 1px;
    font: inherit;
    font-weight: 700;
    height: 2em;
}

.ui-state-highlight {
    border: 1px solid #fc0;
    background: #ffe;
}

.live,.shadow {
    float: left;
    width: 45%;
    margin-right: 5%;
}

.shadow {
    opacity: 0.7;
}

.debug {
    clear: both;
}

.debug textarea {
    width: 100%;
    height: 40em;
    font: 10px/13px monospace;
}

textarea,input {
    outline: none;
}

.pregnant {
    border: 1px solid #ddd;
    border-right: none;
}

.minimized > ol > li {
    display: none;
}

.minimized > ol {
    border: 0 none transparent;
}

.toggle {
    border: 0 none transparent;
    background: transparent;
    width: 2em;
    color: #aaa;
}

button {
    cursor: pointer;
}

.selected {
  background: #FFFFD7;
}
/*
 * jQuery UI Nested Sortable
 * v 2.0 / 29 oct 2012
 * http://mjsarfatti.com/sandbox/nestedSortable
 *
 * Depends on:
 *   jquery.ui.sortable.js 1.10+
 *
 * Copyright (c) 2010-2013 Manuele J Sarfatti
 * Licensed under the MIT License
 * http://www.opensource.org/licenses/mit-license.php
 */

(function($) {

    function isOverAxis(x, reference, size) {
        return (x > reference) && (x < (reference + size));
    }

    $.widget("mjs.nestedSortable", $.extend({}, $.ui.sortable.prototype, {

        options: {
            doNotClear: false,
            expandOnHover: 700,
            isAllowed: function(placeholder, placeholderParent, originalItem) {
                return true;
            },
            isTree: false,
            listType: 'ol',
            maxLevels: 0,
            protectRoot: false,
            rootID: null,
            rtl: false,
            startCollapsed: false,
            tabSize: 20,

            branchClass: 'mjs-nestedSortable-branch',
            collapsedClass: 'mjs-nestedSortable-collapsed',
            disableNestingClass: 'mjs-nestedSortable-no-nesting',
            errorClass: 'mjs-nestedSortable-error',
            expandedClass: 'mjs-nestedSortable-expanded',
            hoveringClass: 'mjs-nestedSortable-hovering',
            leafClass: 'mjs-nestedSortable-leaf'
        },

        _create: function() {
            this.element.data('ui-sortable', this.element.data('mjs-nestedSortable'));

            // mjs - prevent browser from freezing if the HTML is not correct
            if (!this.element.is(this.options.listType)) throw new Error('nestedSortable: Please check that the listType option is set to your actual list type');

            // mjs - force 'intersect' tolerance method if we have a tree with expanding/collapsing functionality
            if (this.options.isTree && this.options.expandOnHover) {
                this.options.tolerance = 'intersect';
            }

            $.ui.sortable.prototype._create.apply(this, arguments);

            // mjs - prepare the tree by applying the right classes (the CSS is responsible for actual hide/show functionality)
            if (this.options.isTree) {
                var self = this;
                $(this.items).each(function() {
                    var $li = this.item;
                    if ($li.children(self.options.listType).length) {
                        $li.addClass(self.options.branchClass);
                        // expand/collapse class only if they have children
                        if (self.options.startCollapsed) $li.addClass(self.options.collapsedClass);
                        else $li.addClass(self.options.expandedClass);
                    } else {
                        $li.addClass(self.options.leafClass);
                    }
                })
            }
        },

        _destroy: function() {
            this.element.removeData("mjs-nestedSortable").removeData("ui-sortable");
            return $.ui.sortable.prototype._destroy.apply(this, arguments);
        },

        _mouseDrag: function(event) {
            var i, item, itemElement, intersection, o = this.options,
                scrolled = false;

            //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) {
                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");

            // mjs - find the top offset before rearrangement,
            var previousTopOffset = this.placeholder.offset().top;

            //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";
            }

            // mjs - check and reset hovering state at each cycle
            this.hovering = this.hovering || null;
            this.mouseentered = this.mouseentered || false;

            // mjs - let's start caching some variables
            var parentItem = (this.placeholder[0].parentNode.parentNode && $(this.placeholder[0].parentNode.parentNode).closest('.ui-sortable').length) ? $(this.placeholder[0].parentNode.parentNode) : null,
                level = this._getLevel(this.placeholder),
                childLevels = this._getChildLevels(this.helper);

            var newList = document.createElement(o.listType);

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

                //Cache variables and intersection, continue if no intersection
                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;
                }

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

                    // mjs - we are intersecting an element: trigger the mouseenter event and store this state
                    if (!this.mouseentered) {
                        $(itemElement).mouseenter();
                        this.mouseentered = true;
                    }

                    // mjs - if the element has children and they are hidden, show them after a delay (CSS responsible)
                    if (o.isTree && $(itemElement).hasClass(o.collapsedClass) && o.expandOnHover) {
                        if (!this.hovering) {
                            $(itemElement).addClass(o.hoveringClass);
                            var self = this;
                            this.hovering = window.setTimeout(function() {
                                $(itemElement).removeClass(o.collapsedClass).addClass(o.expandedClass);
                                self.refreshPositions();
                                self._trigger("expand", event, self._uiHash());
                            }, o.expandOnHover);
                        }
                    }

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

                    // mjs - rearrange the elements and reset timeouts and hovering state
                    if (this.options.tolerance == "pointer" || this._intersectsWithSides(item)) {
                        $(itemElement).mouseleave();
                        this.mouseentered = false;
                        $(itemElement).removeClass(o.hoveringClass);
                        this.hovering && window.clearTimeout(this.hovering);
                        this.hovering = null;

                        // mjs - do not switch container if it's a root item and 'protectRoot' is true
                        // or if it's not a root item but we are trying to make it root
                        if (o.protectRoot && !(this.currentItem[0].parentNode == this.element[0] // it's a root item
                                && itemElement.parentNode != this.element[0]) // it's intersecting a non-root item
                        ) {
                            if (this.currentItem[0].parentNode != this.element[0] && itemElement.parentNode == this.element[0]) {

                                if (!$(itemElement).children(o.listType).length) {
                                    itemElement.appendChild(newList);
                                    o.isTree && $(itemElement).removeClass(o.leafClass).addClass(o.branchClass + ' ' + o.expandedClass);
                                }

                                var a = this.direction === "down" ? $(itemElement).prev().children(o.listType) : $(itemElement).children(o.listType);
                                if (a[0] !== undefined) {
                                    this._rearrange(event, null, a);
                                }

                            } else {
                                this._rearrange(event, item);
                            }
                        } else if (!o.protectRoot) {
                            this._rearrange(event, item);
                        }
                    } else {
                        break;
                    }

                    // Clear emtpy ul's/ol's
                    this._clearEmpty(itemElement);

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

            // mjs - to find the previous sibling in the list, keep backtracking until we hit a valid list item.
            var previousItem = this.placeholder[0].previousSibling ? $(this.placeholder[0].previousSibling) : null;
            if (previousItem != null) {
                while (previousItem[0].nodeName.toLowerCase() != 'li' || previousItem[0] == this.currentItem[0] || previousItem[0] == this.helper[0]) {
                    if (previousItem[0].previousSibling) {
                        previousItem = $(previousItem[0].previousSibling);
                    } else {
                        previousItem = null;
                        break;
                    }
                }
            }

            // mjs - to find the next sibling in the list, keep stepping forward until we hit a valid list item.
            var nextItem = this.placeholder[0].nextSibling ? $(this.placeholder[0].nextSibling) : null;
            if (nextItem != null) {
                while (nextItem[0].nodeName.toLowerCase() != 'li' || nextItem[0] == this.currentItem[0] || nextItem[0] == this.helper[0]) {
                    if (nextItem[0].nextSibling) {
                        nextItem = $(nextItem[0].nextSibling);
                    } else {
                        nextItem = null;
                        break;
                    }
                }
            }

            this.beyondMaxLevels = 0;

            // mjs - if the item is moved to the left, send it one level up but only if it's at the bottom of the list
            if (parentItem != null
                //&& nextItem == null
                && !(o.protectRoot && parentItem[0].parentNode == this.element[0]) && (o.rtl && (this.positionAbs.left + this.helper.outerWidth() > parentItem.offset().left + parentItem.outerWidth()) || !o.rtl && (this.positionAbs.left < parentItem.offset().left))) {

                parentItem.after(this.placeholder[0]);
                if (o.isTree && parentItem.children(o.listItem).children('li:visible:not(.ui-sortable-helper)').length < 1) {
                    parentItem.removeClass(this.options.branchClass + ' ' + this.options.expandedClass).addClass(this.options.leafClass);
                }
                this._clearEmpty(parentItem[0]);
                this._trigger("change", event, this._uiHash());
            }
            // mjs - if the item is below a sibling and is moved to the right, make it a child of that sibling
            else if (previousItem != null && !previousItem.hasClass(o.disableNestingClass) && (previousItem.children(o.listType).length && previousItem.children(o.listType).is(':visible') || !previousItem.children(o.listType).length) && !(o.protectRoot && this.currentItem[0].parentNode == this.element[0]) && (o.rtl && (this.positionAbs.left + this.helper.outerWidth() < previousItem.offset().left + previousItem.outerWidth() - o.tabSize) || !o.rtl && (this.positionAbs.left > previousItem.offset().left + o.tabSize))) {

                this._isAllowed(previousItem, level, level + childLevels + 1);

                if (!previousItem.children(o.listType).length) {
                    previousItem[0].appendChild(newList);
                    o.isTree && previousItem.removeClass(o.leafClass).addClass(o.branchClass + ' ' + o.expandedClass);
                }

                // mjs - if this item is being moved from the top, add it to the top of the list.
                if (previousTopOffset && (previousTopOffset <= previousItem.offset().top)) {
                    previousItem.children(o.listType).prepend(this.placeholder);
                }
                // mjs - otherwise, add it to the bottom of the list.
                else {
                    previousItem.children(o.listType)[0].appendChild(this.placeholder[0]);
                }

                this._trigger("change", event, this._uiHash());
            } else {
                this._isAllowed(parentItem, level, level + childLevels);
            }

            //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) {

            // mjs - if the item is in a position not allowed, send it back
            if (this.beyondMaxLevels) {

                this.placeholder.removeClass(this.options.errorClass);

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

                this._trigger("revert", event, this._uiHash());

            }


            // mjs - clear the hovering timeout, just to be sure
            $('.' + this.options.hoveringClass).mouseleave().removeClass(this.options.hoveringClass);
            this.mouseentered = false;
            this.hovering && window.clearTimeout(this.hovering);
            this.hovering = null;

            $.ui.sortable.prototype._mouseStop.apply(this, arguments);

        },

        // mjs - this function is slightly modified to make it easier to hover over a collapsed element and have it expand
        _intersectsWithSides: function(item) {

            var half = this.options.isTree ? .8 : .5;

            var isOverBottomHalf = isOverAxis(this.positionAbs.top + this.offset.click.top, item.top + (item.height * half), item.height),
                isOverTopHalf = isOverAxis(this.positionAbs.top + this.offset.click.top, item.top - (item.height * half), item.height),
                isOverRightHalf = 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" && isOverTopHalf));
            }

        },

        _contactContainers: function(event) {

            if (this.options.protectRoot && this.currentItem[0].parentNode == this.element[0]) {
                return;
            }

            $.ui.sortable.prototype._contactContainers.apply(this, arguments);

        },

        _clear: function(event, noPropagation) {

            $.ui.sortable.prototype._clear.apply(this, arguments);

            // mjs - clean last empty ul/ol
            for (var i = this.items.length - 1; i >= 0; i--) {
                var item = this.items[i].item[0];
                this._clearEmpty(item);
            }

        },

        serialize: function(options) {

            var o = $.extend({}, this.options, options),
                items = this._getItemsAsjQuery(o && o.connected),
                str = [];

            $(items).each(function() {
                var res = ($(o.item || this).attr(o.attribute || 'id') || '').match(o.expression || (/(.+)[-=_](.+)/)),
                    pid = ($(o.item || this).parent(o.listType).parent(o.items).attr(o.attribute || 'id') || '').match(o.expression || (/(.+)[-=_](.+)/));

                if (res) {
                    str.push(((o.key || res[1]) + '[' + (o.key && o.expression ? res[1] : res[2]) + ']') + '=' + (pid ? (o.key && o.expression ? pid[1] : pid[2]) : o.rootID));
                }
            });

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

            return str.join('&');

        },

        toHierarchy: function(options) {

            var o = $.extend({}, this.options, options),
                sDepth = o.startDepthCount || 0,
                ret = [];

            $(this.element).children(o.items).each(function() {
                var level = _recursiveItems(this);
                ret.push(level);
            });

            return ret;

            function _recursiveItems(item) {
                var id = ($(item).attr(o.attribute || 'id') || '').match(o.expression || (/(.+)[-=_](.+)/));
                if (id) {
                    var currentItem = {
                        "id": id[2]
                    };
                    if ($(item).children(o.listType).children(o.items).length > 0) {
                        currentItem.children = [];
                        $(item).children(o.listType).children(o.items).each(function() {
                            var level = _recursiveItems(this);
                            currentItem.children.push(level);
                        });
                    }
                    return currentItem;
                }
            }
        },

        toArray: function(options) {

            var o = $.extend({}, this.options, options),
                sDepth = o.startDepthCount || 0,
                ret = [],
                left = 1;

            if (!o.excludeRoot) {
                ret.push({
                    "item_id": o.rootID,
                    "parent_id": null,
                    "depth": sDepth,
                    "left": left,
                    "right": ($(o.items, this.element).length + 1) * 2
                });
                left++
            }

            $(this.element).children(o.items).each(function() {
                left = _recursiveArray(this, sDepth + 1, left);
            });

            ret = ret.sort(function(a, b) {
                return (a.left - b.left);
            });

            return ret;

            function _recursiveArray(item, depth, left) {

                var right = left + 1,
                    id, pid;

                if ($(item).children(o.listType).children(o.items).length > 0) {
                    depth++;
                    $(item).children(o.listType).children(o.items).each(function() {
                        right = _recursiveArray($(this), depth, right);
                    });
                    depth--;
                }

                id = ($(item).attr(o.attribute || 'id')).match(o.expression || (/(.+)[-=_](.+)/));

                if (depth === sDepth + 1) {
                    pid = o.rootID;
                } else {
                    var parentItem = ($(item).parent(o.listType).parent(o.items).attr(o.attribute || 'id')).match(o.expression || (/(.+)[-=_](.+)/));
                    pid = parentItem[2];
                }

                if (id) {
                    ret.push({
                        "item_id": id[2],
                        "parent_id": pid,
                        "depth": depth,
                        "left": left,
                        "right": right
                    });
                }

                left = right + 1;
                return left;
            }

        },

        _clearEmpty: function(item) {
            var o = this.options;

            var emptyList = $(item).children(o.listType);

            if (emptyList.length && !emptyList.children().length && !o.doNotClear) {
                o.isTree && $(item).removeClass(o.branchClass + ' ' + o.expandedClass).addClass(o.leafClass);
                emptyList.remove();
            } else if (o.isTree && emptyList.length && emptyList.children().length && emptyList.is(':visible')) {
                $(item).removeClass(o.leafClass).addClass(o.branchClass + ' ' + o.expandedClass);
            } else if (o.isTree && emptyList.length && emptyList.children().length && !emptyList.is(':visible')) {
                $(item).removeClass(o.leafClass).addClass(o.branchClass + ' ' + o.collapsedClass);
            }

        },

        _getLevel: function(item) {

            var level = 1;

            if (this.options.listType) {
                var list = item.closest(this.options.listType);
                while (list && list.length > 0 && !list.is('.ui-sortable')) {
                    level++;
                    list = list.parent().closest(this.options.listType);
                }
            }

            return level;
        },

        _getChildLevels: function(parent, depth) {
            var self = this,
                o = this.options,
                result = 0;
            depth = depth || 0;

            $(parent).children(o.listType).children(o.items).each(function(index, child) {
                result = Math.max(self._getChildLevels(child, depth + 1), result);
            });

            return depth ? result + 1 : result;
        },

        _isAllowed: function(parentItem, level, levels) {
            var o = this.options,
                maxLevels = this.placeholder.closest('.ui-sortable').nestedSortable('option', 'maxLevels'); // this takes into account the maxLevels set to the recipient list
            // mjs - is the root protected?
            // mjs - are we nesting too deep?
            if (!o.isAllowed(this.placeholder, parentItem, this.currentItem)) {
                this.placeholder.addClass(o.errorClass);
                if (maxLevels < levels && maxLevels != 0) {
                    this.beyondMaxLevels = levels - maxLevels;
                } else {
                    this.beyondMaxLevels = 1;
                }
            } else {
                if (maxLevels < levels && maxLevels != 0) {
                    this.placeholder.addClass(o.errorClass);
                    this.beyondMaxLevels = levels - maxLevels;
                } else {
                    this.placeholder.removeClass(o.errorClass);
                    this.beyondMaxLevels = 0;
                }
            }
        }

    }));

    $.mjs.nestedSortable.prototype.options = $.extend({}, $.ui.sortable.prototype.options, $.mjs.nestedSortable.prototype.options);
})(jQuery);