jquery-ui/ui/ui.sortable.js

/*
 * jQuery UI Sortable
 *
 * Copyright (c) 2008 Paul Bakaus
 * Dual licensed under the MIT (MIT-LICENSE.txt)
 * and GPL (GPL-LICENSE.txt) licenses.
 * 
 * http://docs.jquery.com/UI/Sortables
 *
 * Depends:
 *	ui.core.js
 *
 * Revision: $Id: ui.sortable.js 5433 2008-05-04 20:07:17Z joern.zaefferer $
 */
(function($) {

function contains(a, b) { 
    var safari2 = $.browser.safari && $.browser.version < 522; 
    if (a.contains && !safari2) { 
        return a.contains(b); 
    } 
    if (a.compareDocumentPosition) 
        return !!(a.compareDocumentPosition(b) & 16); 
    while (b = b.parentNode) 
          if (b == a) return true; 
    return false; 
};

$.widget("ui.sortable", $.extend($.ui.mouse, {
	init: function() {

		var o = this.options;
		this.containerCache = {};
		this.element.addClass("ui-sortable");
	
		//Get the items
		this.refresh();

		//Let's determine if the items are floating
		this.floating = this.items.length ? (/left|right/).test(this.items[0].item.css('float')) : false;
		
		//Let's determine the parent's offset
		if(!(/(relative|absolute|fixed)/).test(this.element.css('position'))) this.element.css('position', 'relative');
		this.offset = this.element.offset();

		//Initialize mouse events for interaction
		this.mouseInit();
		
	},
	plugins: {},
	ui: function(inst) {
		return {
			helper: (inst || this)["helper"],
			placeholder: (inst || this)["placeholder"] || $([]),
			position: (inst || this)["position"],
			absolutePosition: (inst || this)["positionAbs"],
			options: this.options,
			element: this.element,
			item: (inst || this)["currentItem"],
			sender: inst ? inst.element : null
		};		
	},
	propagate: function(n,e,inst, noPropagation) {
		$.ui.plugin.call(this, n, [e, this.ui(inst)]);
		if(!noPropagation) this.element.triggerHandler(n == "sort" ? n : "sort"+n, [e, this.ui(inst)], this.options[n]);
	},
	serialize: function(o) {

		var items = ($.isFunction(this.options.items) ? this.options.items.call(this.element) : $(this.options.items, this.element)).not('.ui-sortable-helper'); //Only the items of the sortable itself
		var str = []; o = o || {};
		
		items.each(function() {
			var res = ($(this).attr(o.attribute || 'id') || '').match(o.expression || (/(.+)[-=_](.+)/));
			if(res) str.push((o.key || res[1])+'[]='+(o.key ? res[1] : res[2]));
		});
		
		return str.join('&');
		
	},
	toArray: function(attr) {
		
		var items = ($.isFunction(this.options.items) ? this.options.items.call(this.element) : $(this.options.items, this.element)).not('.ui-sortable-helper'); //Only the items of the sortable itself
		var ret = [];

		items.each(function() { ret.push($(this).attr(attr || '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;

		if(this.options.tolerance == "pointer" || (this.options.tolerance == "guess" && this.helperProportions[this.floating ? 'width' : 'height'] > item[this.floating ? 'width' : 'height'])) {
			return (y1 + this.offset.click.top > t && y1 + this.offset.click.top < b && x1 + this.offset.click.left > l && x1 + this.offset.click.left < r);
		} 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
		
		}
		
	},
	intersectsWithEdge: 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;

		if(this.options.tolerance == "pointer" || (this.options.tolerance == "guess" && this.helperProportions[this.floating ? 'width' : 'height'] > item[this.floating ? 'width' : 'height'])) {

			if(!(y1 + this.offset.click.top > t && y1 + this.offset.click.top < b && x1 + this.offset.click.left > l && x1 + this.offset.click.left < r)) return false;
			
			if(this.floating) {
				if(x1 + this.offset.click.left > l && x1 + this.offset.click.left < l + item.width/2) return 2;
				if(x1 + this.offset.click.left > l+item.width/2 && x1 + this.offset.click.left < r) return 1;
			} else {
				if(y1 + this.offset.click.top > t && y1 + this.offset.click.top < t + item.height/2) return 2;
				if(y1 + this.offset.click.top > t+item.height/2 && y1 + this.offset.click.top < b) return 1;
			}

		} else {
		
			if (!(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 )) return false; // Top Half
			
			if(this.floating) {
				if(x2 > l && x1 < l) return 2; //Crosses left edge
				if(x1 < r && x2 > r) return 1; //Crosses right edge
			} else {
				if(y2 > t && y1 < t) return 1; //Crosses top edge
				if(y1 < b && y2 > b) return 2; //Crosses bottom edge
			}
		
		}
		
		return false;
		
	},
	refresh: function() {
		this.refreshItems();
		this.refreshPositions();
	},
	refreshItems: function() {
		
		this.items = [];
		this.containers = [this];
		var items = this.items;
		var queries = [$.isFunction(this.options.items) ? this.options.items.call(this.element) : $(this.options.items, this.element)];
		
		if(this.options.connectWith) {
			for (var i = this.options.connectWith.length - 1; i >= 0; i--){
				var cur = $(this.options.connectWith[i]);
				for (var j = cur.length - 1; j >= 0; j--){
					var inst = $.data(cur[j], 'sortable');
					if(inst && !inst.options.disabled) {
						queries.push($.isFunction(inst.options.items) ? inst.options.items.call(inst.element) : $(inst.options.items, inst.element));
						this.containers.push(inst);
					}
				};
			};
		}

		for (var i = queries.length - 1; i >= 0; i--){
			queries[i].each(function() {
				$.data(this, 'sortable-item', true); // Data for target checking (mouse manager)
				items.push({
					item: $(this),
					width: 0, height: 0,
					left: 0, top: 0
				});
			});
		};

	},
	refreshPositions: function(fast) {
		for (var i = this.items.length - 1; i >= 0; i--){
			var t = this.items[i].item;
			if(!fast) this.items[i].width = (this.options.toleranceElement ? $(this.options.toleranceElement, t) : t).outerWidth();
			if(!fast) this.items[i].height = (this.options.toleranceElement ? $(this.options.toleranceElement, t) : t).outerHeight();
			var p = (this.options.toleranceElement ? $(this.options.toleranceElement, t) : t).offset();
			this.items[i].left = p.left;
			this.items[i].top = p.top;
		};
		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();
		};
	},
	destroy: function() {
		this.element
			.removeClass("ui-sortable ui-sortable-disabled")
			.removeData("sortable")
			.unbind(".sortable");
		this.mouseDestroy();
		
		for ( var i = this.items.length - 1; i >= 0; i-- )
			this.items[i].item.removeData("sortable-item");
	},
	createPlaceholder: function(that) {
		
		var self = that || this, o = self.options;

		if(o.placeholder.constructor == String) {
			var className = o.placeholder;
			o.placeholder = {
				element: function() {
					return $('<div></div>').addClass(className)[0];
				},
				update: function(i, p) {
					p.css(i.offset()).css({ width: i.outerWidth(), height: i.outerHeight() });
				}
			};
		}
		
		self.placeholder = $(o.placeholder.element.call(self.element, self.currentItem)).appendTo('body').css({ position: 'absolute' });
		o.placeholder.update.call(self.element, self.currentItem, self.placeholder);
	},
	contactContainers: function(e) {
		for (var i = this.containers.length - 1; i >= 0; i--){

			if(this.intersectsWith(this.containers[i].containerCache)) {
				if(!this.containers[i].containerCache.over) {
					

					if(this.currentContainer != this.containers[i]) {
						
						//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 base = this.positionAbs[this.containers[i].floating ? 'left' : 'top'];
						for (var j = this.items.length - 1; j >= 0; j--) {
							if(!contains(this.containers[i].element[0], this.items[j].item[0])) continue;
							var cur = this.items[j][this.containers[i].floating ? 'left' : 'top'];
							if(Math.abs(cur - base) < dist) {
								dist = Math.abs(cur - base); itemWithLeastDistance = this.items[j];
							}
						}
						
						if(!itemWithLeastDistance && !this.options.dropOnEmpty) //Check if dropOnEmpty is enabled
							continue;
						
						//We also need to exchange the placeholder
						if(this.placeholder) this.placeholder.remove();
						if(this.containers[i].options.placeholder) {
							this.containers[i].createPlaceholder(this);
						} else {
							this.placeholder = null;;
						}
						
						
						itemWithLeastDistance ? this.rearrange(e, itemWithLeastDistance) : this.rearrange(e, null, this.containers[i].element);
						this.propagate("change", e); //Call plugins and callbacks
						this.containers[i].propagate("change", e, this); //Call plugins and callbacks
						this.currentContainer = this.containers[i];

					}
					
					this.containers[i].propagate("over", e, this);
					this.containers[i].containerCache.over = 1;
				}
			} else {
				if(this.containers[i].containerCache.over) {
					this.containers[i].propagate("out", e, this);
					this.containers[i].containerCache.over = 0;
				}
			}
			
		};			
	},
	mouseCapture: function(e, overrideHandle) {
		
		if(this.options.disabled || this.options.type == 'static') return false;

		//Find out if the clicked node (or one of its parents) is a actual item in this.items
		var currentItem = null, nodes = $(e.target).parents().each(function() {	
			if($.data(this, 'sortable-item')) {
				currentItem = $(this);
				return false;
			}
		});
		if($.data(e.target, 'sortable-item')) currentItem = $(e.target);
	
		if(!currentItem) return false;
		if(this.options.handle && !overrideHandle) {
			var validHandle = false;
			$(this.options.handle, currentItem).find("*").andSelf().each(function() { if(this == e.target) validHandle = true; });
			if(!validHandle) return false;
		}
			
		this.currentItem = currentItem;
		return true;	
			
	},
	mouseStart: function(e, overrideHandle, noActivation) {

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

		this.refresh();

		//Create and append the visible helper			
		this.helper = typeof o.helper == 'function' ? $(o.helper.apply(this.element[0], [e, this.currentItem])) : this.currentItem.clone();
		if(!this.helper.parents('body').length) this.helper.appendTo((o.appendTo != 'parent' ? o.appendTo : this.currentItem[0].parentNode)); //Add the helper to the DOM if that didn't happen already
		this.helper.css({ position: 'absolute', clear: 'both' }).addClass('ui-sortable-helper'); //Position it absolutely and add a helper class

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

		this.margins = {																				//Cache the margins
			left: (parseInt(this.currentItem.css("marginLeft"),10) || 0),
			top: (parseInt(this.currentItem.css("marginTop"),10) || 0)
		};		
	
		this.offset = this.currentItem.offset();														//The element's absolute position on the page
		this.offset = {																					//Substract the margins from the element's absolute offset
			top: this.offset.top - this.margins.top,
			left: this.offset.left - this.margins.left
		};
		
		this.offset.click = {																			//Where the click happened, relative to the element
			left: e.pageX - this.offset.left,
			top: e.pageY - this.offset.top
		};
		
		this.offsetParent = this.helper.offsetParent(); var po = this.offsetParent.offset();			//Get the offsetParent and cache its position

		this.offset.parent = {																			//Store its position plus border
			top: po.top + (parseInt(this.offsetParent.css("borderTopWidth"),10) || 0),
			left: po.left + (parseInt(this.offsetParent.css("borderLeftWidth"),10) || 0)
		};
	
		this.originalPosition = this.generatePosition(e);												//Generate the original position
		this.helperProportions = { width: this.helper.outerWidth(), height: this.helper.outerHeight() };//Cache the helper size
		
		if(o.cursorAt) {
			if(o.cursorAt.left != undefined) this.offset.click.left = o.cursorAt.left;
			if(o.cursorAt.right != undefined) this.offset.click.left = this.helperProportions.width - o.cursorAt.right;
			if(o.cursorAt.top != undefined) this.offset.click.top = o.cursorAt.top;
			if(o.cursorAt.bottom != undefined) this.offset.click.top = this.helperProportions.height - o.cursorAt.bottom;
		}

		this.domPosition = this.currentItem.prev()[0];													//Cache the former DOM position

		/*
		 * - Position constraining -
		 * Here we prepare position constraining like grid and containment.
		 */	
		
		if(o.containment) {
			if(o.containment == 'parent') o.containment = this.helper[0].parentNode;
			if(o.containment == 'document' || o.containment == 'window') this.containment = [
				0 - this.offset.parent.left,
				0 - this.offset.parent.top,
				$(o.containment == 'document' ? document : window).width() - this.offset.parent.left - this.helperProportions.width - this.margins.left - (parseInt(this.element.css("marginRight"),10) || 0),
				($(o.containment == 'document' ? document : window).height() || document.body.parentNode.scrollHeight) - this.offset.parent.top - this.helperProportions.height - this.margins.top - (parseInt(this.element.css("marginBottom"),10) || 0)
			];

			if(!(/^(document|window|parent)$/).test(o.containment)) {
				var ce = $(o.containment)[0];
				var co = $(o.containment).offset();
				
				this.containment = [
					co.left + (parseInt($(ce).css("borderLeftWidth"),10) || 0) - this.offset.parent.left,
					co.top + (parseInt($(ce).css("borderTopWidth"),10) || 0) - this.offset.parent.top,
					co.left+Math.max(ce.scrollWidth,ce.offsetWidth) - (parseInt($(ce).css("borderLeftWidth"),10) || 0) - this.offset.parent.left - this.helperProportions.width - this.margins.left - (parseInt(this.currentItem.css("marginRight"),10) || 0),
					co.top+Math.max(ce.scrollHeight,ce.offsetHeight) - (parseInt($(ce).css("borderTopWidth"),10) || 0) - this.offset.parent.top - this.helperProportions.height - this.margins.top - (parseInt(this.currentItem.css("marginBottom"),10) || 0)
				];
			}
		}
		
		//If o.placeholder is used, create a new element at the given position with the class
		if(o.placeholder) this.createPlaceholder();
		
		//Call plugins and callbacks
		this.propagate("start", e);
		this.helperProportions = { width: this.helper.outerWidth(), height: this.helper.outerHeight() };//Recache the helper size

		if(this.options.placeholder != 'clone') this.currentItem.css('visibility', 'hidden'); //Set the original element visibility to hidden to still fill out the white space
		
		if(!noActivation) {
			 for (var i = this.containers.length - 1; i >= 0; i--) { this.containers[i].propagate("activate", e, this); } //Post 'activate' events to possible containers
		}
		
		//Prepare possible droppables
		if($.ui.ddmanager) $.ui.ddmanager.current = this;
		if ($.ui.ddmanager && !o.dropBehaviour) $.ui.ddmanager.prepareOffsets(this, e);

		this.dragging = true;

		this.mouseDrag(e); //Execute the drag once - this causes the helper not to be visible before getting its correct position
		return true;


	},
	convertPositionTo: function(d, pos) {
		if(!pos) pos = this.position;
		var mod = d == "absolute" ? 1 : -1;
		return {
			top: (
				pos.top																	// the calculated relative position
				+ this.offset.parent.top * mod											// The offsetParent's offset without borders (offset + border)
				- (this.offsetParent[0] == document.body ? 0 : this.offsetParent[0].scrollTop) * mod	// The offsetParent's scroll position
				+ this.margins.top * mod												//Add the margin (you don't want the margin counting in intersection methods)
			),
			left: (
				pos.left																// the calculated relative position
				+ this.offset.parent.left * mod											// The offsetParent's offset without borders (offset + border)
				- (this.offsetParent[0] == document.body ? 0 : this.offsetParent[0].scrollLeft) * mod	// The offsetParent's scroll position
				+ this.margins.left * mod												//Add the margin (you don't want the margin counting in intersection methods)
			)
		};
	},
	generatePosition: function(e) {
		
		var o = this.options;
		var position = {
			top: (
				e.pageY																	// The absolute mouse position
				- this.offset.click.top													// Click offset (relative to the element)
				- this.offset.parent.top												// The offsetParent's offset without borders (offset + border)
				+ (this.offsetParent[0] == document.body ? 0 : this.offsetParent[0].scrollTop)	// The offsetParent's scroll position, not if the element is fixed
			),
			left: (
				e.pageX																	// The absolute mouse position
				- this.offset.click.left												// Click offset (relative to the element)
				- this.offset.parent.left												// The offsetParent's offset without borders (offset + border)
				+ (this.offsetParent[0] == document.body ? 0 : this.offsetParent[0].scrollLeft)	// The offsetParent's scroll position, not if the element is fixed
			)
		};
		
		if(!this.originalPosition) return position;										//If we are not dragging yet, we won't check for options
		
		/*
		 * - Position constraining -
		 * Constrain the position to a mix of grid, containment.
		 */
		if(this.containment) {
			if(position.left < this.containment[0]) position.left = this.containment[0];
			if(position.top < this.containment[1]) position.top = this.containment[1];
			if(position.left > this.containment[2]) position.left = this.containment[2];
			if(position.top > this.containment[3]) position.top = this.containment[3];
		}
		
		if(o.grid) {
			var top = this.originalPosition.top + Math.round((position.top - this.originalPosition.top) / o.grid[1]) * o.grid[1];
			position.top = this.containment ? (!(top < this.containment[1] || top > this.containment[3]) ? top : (!(top < this.containment[1]) ? top - o.grid[1] : top + o.grid[1])) : top;
			
			var left = this.originalPosition.left + Math.round((position.left - this.originalPosition.left) / o.grid[0]) * o.grid[0];
			position.left = this.containment ? (!(left < this.containment[0] || left > this.containment[2]) ? left : (!(left < this.containment[0]) ? left - o.grid[0] : left + o.grid[0])) : left;
		}
		
		return position;
	},
	mouseDrag: function(e) {


		//Compute the helpers position
		this.position = this.generatePosition(e);
		this.positionAbs = this.convertPositionTo("absolute");

		//Rearrange
		for (var i = this.items.length - 1; i >= 0; i--) {
			var intersection = this.intersectsWithEdge(this.items[i]);
			if(!intersection) continue;
			
			if(this.items[i].item[0] != this.currentItem[0] //cannot intersect with itself
				&&	this.currentItem[intersection == 1 ? "next" : "prev"]()[0] != this.items[i].item[0] //no useless actions that have been done before
				&&	!contains(this.currentItem[0], this.items[i].item[0]) //no action if the item moved is the parent of the item checked
				&& (this.options.type == 'semi-dynamic' ? !contains(this.element[0], this.items[i].item[0]) : true)
			) {
				
				this.direction = intersection == 1 ? "down" : "up";
				this.rearrange(e, this.items[i]);
				this.propagate("change", e); //Call plugins and callbacks
				break;
			}
		}
		
		//Post events to containers
		this.contactContainers(e);
		
		 //Call plugins and callbacks
		this.propagate("sort", e);

		if(!this.options.axis || this.options.axis == "x") this.helper[0].style.left = this.position.left+'px';
		if(!this.options.axis || this.options.axis == "y") this.helper[0].style.top = this.position.top+'px';
		
		//Interconnect with droppables
		if($.ui.ddmanager) $.ui.ddmanager.drag(this, e);

		return false;
		
	},
	mouseStop: function(e, noPropagation) {

		//If we are using droppables, inform the manager about the drop
		if ($.ui.ddmanager && !this.options.dropBehaviour)
			$.ui.ddmanager.drop(this, e);
			
		if(this.options.revert) {
			var self = this;
			var cur = self.currentItem.offset();

			//Also animate the placeholder if we have one
			if(self.placeholder) self.placeholder.animate({ opacity: 'hide' }, (parseInt(this.options.revert, 10) || 500)-50);

			$(this.helper).animate({
				left: cur.left - this.offset.parent.left - self.margins.left + (this.offsetParent[0] == document.body ? 0 : this.offsetParent[0].scrollLeft),
				top: cur.top - this.offset.parent.top - self.margins.top + (this.offsetParent[0] == document.body ? 0 : this.offsetParent[0].scrollTop)
			}, parseInt(this.options.revert, 10) || 500, function() {
				self.propagate("stop", e, null, noPropagation);
				self.clear(e);
			});
		} else {
			this.propagate("stop", e, null, noPropagation);
			this.clear(e, noPropagation);
		}

		return false;
		
	},
	clear: function(e, noPropagation) {

		if(this.domPosition != this.currentItem.prev().not(".ui-sortable-helper")[0]) this.propagate("update", e, null, noPropagation); //Trigger update callback if the DOM position has changed
		if(!contains(this.element[0], this.currentItem[0])) { //Node was moved out of the current element
			if(this.domPosition == this.currentItem.prev().not(".ui-sortable-helper")[0]) this.propagate("update", e, null, noPropagation); //Trigger update callback, if it wasn't triggered before, because that is definitely an update
			this.propagate("remove", e, null, noPropagation);
			for (var i = this.containers.length - 1; i >= 0; i--){
				if(contains(this.containers[i].element[0], this.currentItem[0])) {
					this.containers[i].propagate("update", e, this, noPropagation);
					this.containers[i].propagate("receive", e, this, noPropagation);
				}
			};
		};
		
		//Post events to containers
		for (var i = this.containers.length - 1; i >= 0; i--){
			this.containers[i].propagate("deactivate", e, this, noPropagation);
			if(this.containers[i].containerCache.over) {
				this.containers[i].propagate("out", e, this);
				this.containers[i].containerCache.over = 0;
			}
		}
		
		this.dragging = false;
		if(this.cancelHelperRemoval) return false;
		$(this.currentItem).css('visibility', '');
		if(this.placeholder) this.placeholder.remove();
		this.helper.remove();
		
		return true;
		
	},
	rearrange: function(e, i, a) {
		a ? a.append(this.currentItem) : i.item[this.direction == 'down' ? 'before' : 'after'](this.currentItem);
		this.refreshPositions(true); //Precompute after each DOM insertion, NOT on mousemove
		if(this.options.placeholder) this.options.placeholder.update.call(this.element, this.currentItem, this.placeholder);
	}
}));

$.extend($.ui.sortable, {
	getter: "serialize toArray",
	defaults: {
		tolerance: "guess",
		distance: 0,
		delay: 0,
		cancel: ":input,button",
		items: '> *',
		zIndex: 1000,
		dropOnEmpty: true,
		appendTo: "parent"
	}
});

/*
 * Sortable Extensions
 */

$.ui.plugin.add("sortable", "cursor", {
	start: function(e, ui) {
		var t = $('body');
		if (t.css("cursor")) ui.options._cursor = t.css("cursor");
		t.css("cursor", ui.options.cursor);
	},
	stop: function(e, ui) {
		if (ui.options._cursor) $('body').css("cursor", ui.options._cursor);
	}
});

$.ui.plugin.add("sortable", "zIndex", {
	start: function(e, ui) {
		var t = ui.helper;
		if(t.css("zIndex")) ui.options._zIndex = t.css("zIndex");
		t.css('zIndex', ui.options.zIndex);
	},
	stop: function(e, ui) {
		if(ui.options._zIndex) $(ui.helper).css('zIndex', ui.options._zIndex);
	}
});

$.ui.plugin.add("sortable", "opacity", {
	start: function(e, ui) {
		var t = ui.helper;
		if(t.css("opacity")) ui.options._opacity = t.css("opacity");
		t.css('opacity', ui.options.opacity);
	},
	stop: function(e, ui) {
		if(ui.options._opacity) $(ui.helper).css('opacity', ui.options._opacity);
	}
});

$.ui.plugin.add("sortable", "scroll", {
	start: function(e, ui) {
		var o = ui.options;
		var i = $(this).data("sortable");
		o.scrollSensitivity	= o.scrollSensitivity || 20;
		o.scrollSpeed		= o.scrollSpeed || 20;
	
		i.overflowY = function(el) {
			do { if(/auto|scroll/.test(el.css('overflow')) || (/auto|scroll/).test(el.css('overflow-y'))) return el; el = el.parent(); } while (el[0].parentNode);
			return $(document);
		}(i.currentItem);
		i.overflowX = function(el) {
			do { if(/auto|scroll/.test(el.css('overflow')) || (/auto|scroll/).test(el.css('overflow-x'))) return el; el = el.parent(); } while (el[0].parentNode);
			return $(document);
		}(i.currentItem);
		
		if(i.overflowY[0] != document && i.overflowY[0].tagName != 'HTML') i.overflowYOffset = i.overflowY.offset();
		if(i.overflowX[0] != document && i.overflowX[0].tagName != 'HTML') i.overflowXOffset = i.overflowX.offset();
		
	},
	sort: function(e, ui) {
		
		var o = ui.options;
		var i = $(this).data("sortable");
		
		if(i.overflowY[0] != document && i.overflowY[0].tagName != 'HTML') {
			if((i.overflowYOffset.top + i.overflowY[0].offsetHeight) - e.pageY < o.scrollSensitivity)
				i.overflowY[0].scrollTop = i.overflowY[0].scrollTop + o.scrollSpeed;
			if(e.pageY - i.overflowYOffset.top < o.scrollSensitivity)
				i.overflowY[0].scrollTop = i.overflowY[0].scrollTop - o.scrollSpeed;
		} else {
			if(e.pageY - $(document).scrollTop() < o.scrollSensitivity)
				$(document).scrollTop($(document).scrollTop() - o.scrollSpeed);
			if($(window).height() - (e.pageY - $(document).scrollTop()) < o.scrollSensitivity)
				$(document).scrollTop($(document).scrollTop() + o.scrollSpeed);
		}
		
		if(i.overflowX[0] != document && i.overflowX[0].tagName != 'HTML') {
			if((i.overflowXOffset.left + i.overflowX[0].offsetWidth) - e.pageX < o.scrollSensitivity)
				i.overflowX[0].scrollLeft = i.overflowX[0].scrollLeft + o.scrollSpeed;
			if(e.pageX - i.overflowXOffset.left < o.scrollSensitivity)
				i.overflowX[0].scrollLeft = i.overflowX[0].scrollLeft - o.scrollSpeed;
		} else {
			if(e.pageX - $(document).scrollLeft() < o.scrollSensitivity)
				$(document).scrollLeft($(document).scrollLeft() - o.scrollSpeed);
			if($(window).width() - (e.pageX - $(document).scrollLeft()) < o.scrollSensitivity)
				$(document).scrollLeft($(document).scrollLeft() + o.scrollSpeed);
		}
		
	}
});

})(jQuery);