/*!
 * jQuery UI Draggable @VERSION
 * http://jqueryui.com
 *
 * Copyright 2012 jQuery Foundation and other contributors
 * Dual licensed under the MIT or GPL Version 2 licenses.
 * http://jquery.org/license
 *
 * http://docs.jquery.com/UI/Draggable
 *
 * Depends:
 *	jquery.ui.core.js
 *	jquery.ui.interaction.js
 *	jquery.ui.widget.js
 */
(function( $, undefined ) {

// create a shallow copy of an object
function copy( obj ) {
	var prop,
		ret = {};
	for ( prop in obj ) {
		ret[ prop ] = obj[ prop ];
	}
	return ret;
}

$.widget( "ui.draggable", $.ui.interaction, {
	version: "@VERSION",
	widgetEventPrefix: "drag",

	options: {
		appendTo: null,
		exclude: "input,textarea,button,select,option",
		handle: null,
		helper: false,

		// callbacks
		beforeStart: null,
		drag: null,
		start: null,
		stop: null
	},

	// dragEl: element being dragged (original or helper)
	// position: final CSS position of dragEl
	// offset: offset of dragEl
	// originalPosition: CSS position before drag start
	// originalOffset: offset before drag start
	// originalPointer: pageX/Y at drag start (offset of pointer)
	// startPosition: CSS position at drag start (after beforeStart)
	// startOffset: offset at drag start (after beforeStart)
	// tempPosition: overridable CSS position of dragEl
	// overflowOffset: offset of scroll parent
	// overflow: object containing width and height keys of scroll parent
	// domPosition: object containing original parent and index when using
	// appendTo option without a helper
	// dragDimensions: saved off width and height used for various options

	_create: function() {
		this._super();

		this.scrollSensitivity = 20;
		this.scrollSpeed = 5;

		// Static position elements can't be moved with top/left
		if ( this.element.css( "position" ) === "static" ) {
			this.element.css( "position", "relative" );
		}

		this.element.addClass( "ui-draggable" );
	},

	/** interaction interface **/

	_isValidTarget: function( element ) {
		var handle = this.options.handle ? element.is( this.options.handle ) : true,
			exclude = this.options.exclude ? element.is( this.options.exclude ) : false;

		return ( handle && !exclude );
	},

	_start: function( event, pointerPosition ) {
		var offset, startCssLeft, startCssTop, startPosition, startOffset;

		// Reset
		this.dragDimensions = null;

		// The actual dragging element, should always be a jQuery object
		this.dragEl = ( this.options.helper === true || typeof this.options.helper === "function" ) ?
			this._createHelper( pointerPosition ) :
			this.element;

		// _createHelper() ensures that helpers are in the correct position
		// in the DOM, but we need to handle appendTo when there is no helper
		if ( this.options.appendTo && this.dragEl === this.element ) {
			this.domPosition = {
				parent: this.element.parent(),
				index: this.element.index()
			};
			offset = this.dragEl.offset();
			this.dragEl
				.appendTo( this._appendToEl() )
				.offset( offset );
		}

		this.cssPosition = this.dragEl.css( "position" );
		this.scrollParent = this.element.scrollParent();

		// Cache starting positions
		this.originalPosition = this.startPosition = this._getPosition();
		this.originalOffset = this.startOffset = this.dragEl.offset();
		this.originalPointer = pointerPosition;

		// If not already cached within _createHelper
		if ( !this.dragDimensions ) {
			this._cacheDragDimensions( this.dragEl );
		}

		// Cache current position and offset
		this.position = copy( this.startPosition );
		this.offset = copy( this.startOffset );

		// Cache the offset of scrollParent, if required for _handleScrolling
		if ( this.scrollParent[0] !== this.document[0] && this.scrollParent[0].tagName !== "HTML" ) {
			this.overflowOffset = this.scrollParent.offset();
		}

		this.overflow = {
			height: this.scrollParent[0] === this.document[0] ?
				this.window.height() : this.scrollParent.height(),
			width: this.scrollParent[0] === this.document[0] ?
				this.window.width() : this.scrollParent.width()
		};

		this._preparePosition( pointerPosition );

		// If user cancels beforeStart, don't allow dragging
		if ( this._trigger( "beforeStart", event,
				this._originalHash( pointerPosition ) ) === false ) {

			// domPosition needs to be undone even if beforeStart is stopped
			// Otherwise this.dragEl will remain in the element appendTo is set to
			this._resetDomPosition();
			return false;

		}

		// Save off the usual properties locally, so they can be reverted from start
		startCssLeft = this.dragEl.css("left");
		startCssTop = this.dragEl.css("top");
		startPosition = copy( this._getPosition() );
		startOffset = copy( this.offset );

		this._setCss();
		this.startPosition = this._getPosition();
		this.startOffset = this.dragEl.offset();

		// If user cancels on start, don't allow dragging
		if ( this._trigger( "start", event,
				this._fullHash( pointerPosition ) ) === false ) {
				// domPosition needs to be undone even if start is stopped
				// Otherwise this.dragEl will remain in the element appendTo is set to

				this.startPosition = startPosition;
				this.startOffset = startOffset;
				this.dragEl.css({
					left: startCssLeft,
					top: startCssTop
				});

				this._resetDomPosition();
				return false;
		}
		this._blockFrames();
	},

	_resetDomPosition: function() {

		// Nothing to do in this case
		if ( !this.domPosition ) {
			return;
		}

		var parent = this.domPosition.parent,
			next = parent.children().eq( this.domPosition.index );
		if ( next.length ) {
			next.before( this.element );
		} else {
			parent.append( this.element );
		}
		this.element.offset( this.offset );
		this.domPosition = null;

	},

	_move: function( event, pointerPosition ) {
		this._preparePosition( pointerPosition );

		// If user cancels drag, don't move the element
		if ( this._trigger( "drag", event, this._fullHash( pointerPosition ) ) === false ) {
			return false;
		}

		this._setCss();

		// Scroll the scrollParent, if needed
		this._handleScrolling( pointerPosition );
	},

	_stop: function( event, pointerPosition ) {
		this._preparePosition( pointerPosition );

		// If user cancels stop, leave helper there
		if ( this._trigger( "stop", event, this._fullHash( pointerPosition ) ) !== false ) {
			if ( this.options.helper ) {
				delete this.element.data( "uiDraggable" ).helper;
				this.dragEl.remove();
			}
			this._resetDomPosition();
		}

		this._unblockFrames();
	},

	/** internal **/

	_createHelper: function( pointerPosition ) {
		var helper,
			offset = this.element.offset(),
			xPos = (pointerPosition.x - offset.left) / this.element.outerWidth(),
			yPos = (pointerPosition.y - offset.top) / this.element.outerHeight();

		// clone
		if ( this.options.helper === true ) {
			helper = this.element.clone()
				.removeAttr( "id" )
				.find( "[id]" )
					.removeAttr( "id" )
				.end();
		} else {
			// TODO: figure out the signature for this; see #4957
			helper = $( this.options.helper() );
		}

		// Ensure the helper is in the DOM; obey the appendTo option if it exists
		if ( this.options.appendTo || !helper.closest( "body" ).length ) {
			helper.appendTo( this._appendToEl() || this.document[0].body );
		}

		this.element.data( "uiDraggable" ).helper = helper;

		this._cacheDragDimensions( helper );

		return helper
			// Helper must be absolute to function properly
			.css( "position", "absolute" )
			.offset({
				left: pointerPosition.x - this.dragDimensions.width * xPos,
				top: pointerPosition.y - this.dragDimensions.height * yPos
			});
	},

	_cacheDragDimensions: function( el) {
		this.dragDimensions = {
			width: el.outerWidth(),
			height: el.outerHeight()
		};
	},

	// TODO: Remove after 2.0, only used for backCompat
	_appendToEl: function() {
		return this.options.appendTo;
	},

	_getPosition: function() {
		var left, top, position,
			scrollTop = this.scrollParent.scrollTop(),
			scrollLeft = this.scrollParent.scrollLeft();

		// If fixed or absolute
		if ( this.cssPosition !== "relative" ) {
			position = this.dragEl.position();

			// Take into account scrollbar
			position.top -= scrollTop;
			position.left -= scrollLeft;

			return position;
		}

		// When using relative, css values are checked
		// Otherwise the position wouldn't account for padding on ancestors
		left = this.dragEl.css( "left" );
		top = this.dragEl.css( "top" );

		// Webkit will give back auto if there is no explicit value
		left = ( left === "auto" ) ? 0: parseInt( left, 10 );
		top = ( top === "auto" ) ? 0: parseInt( top, 10 );

		return {
			left: left - scrollLeft,
			top: top - scrollTop
		};
	},

	_handleScrolling: function( pointerPosition ) {
		var scrollTop = this.scrollParent.scrollTop(),
			scrollLeft = this.scrollParent.scrollLeft(),
			scrollSensitivity = this.scrollSensitivity,
			// overflowOffset is only set when scrollParent is not doc/html
			overflowLeft = this.overflowOffset ?
				this.overflowOffset.left :
				scrollLeft,
			overflowTop = this.overflowOffset ?
				this.overflowOffset.top :
				scrollTop,
			xRight = this.overflow.width + overflowLeft - pointerPosition.x,
			xLeft = pointerPosition.x- overflowLeft,
			yBottom = this.overflow.height + overflowTop - pointerPosition.y,
			yTop = pointerPosition.y - overflowTop;

		// Handle vertical scrolling
		if ( yBottom < scrollSensitivity ) {
			this.scrollParent.scrollTop( scrollTop +
				this._speed( scrollSensitivity - yBottom ) );
		} else if ( yTop < scrollSensitivity ) {
			this.scrollParent.scrollTop( scrollTop -
				this._speed( scrollSensitivity - yTop ) );
		}

		// Handle horizontal scrolling
		if ( xRight < scrollSensitivity ) {
			this.scrollParent.scrollLeft( scrollLeft +
				this._speed( scrollSensitivity - xRight ) );
		} else if ( xLeft < scrollSensitivity ) {
			this.scrollParent.scrollLeft( scrollLeft -
				this._speed( scrollSensitivity - xLeft ) );
		}
	},

	_speed: function( distance ) {
		return this.scrollSpeed + Math.round( distance / 2 );
	},

	// Uses event to determine new position of draggable, before any override from callbacks
	// TODO: handle absolute element inside relative parent like a relative element
	_preparePosition: function( pointerPosition ) {
		var leftDiff = pointerPosition.x - this.originalPointer.x,
			topDiff = pointerPosition.y - this.originalPointer.y,
			newLeft = leftDiff + this.startPosition.left,
			newTop = topDiff + this.startPosition.top;

		// Save off new values for .css() in various callbacks using this function
		this.position = {
			left: newLeft,
			top: newTop
		};

		// Save off values to compare user override against automatic coordinates
		this.tempPosition = {
			left: newLeft,
			top: newTop
		};

		// Refresh offset cache with new positions
		this.offset.left = this.startOffset.left + leftDiff;
		this.offset.top = this.startOffset.top + topDiff;
	},

	// Places draggable where event, or user via event/callback, indicates
	_setCss: function() {
		var newLeft = this.position.left,
			newTop = this.position.top;

		// User overriding left/top so shortcut math is no longer valid
		if ( this.tempPosition.left !== this.position.left ||
				this.tempPosition.top !== this.position.top ) {
			// Reset offset based on difference of expected and overridden values
			this.offset.left += newLeft - this.tempPosition.left;
			this.offset.top += newTop - this.tempPosition.top;
		}

		// TODO: does this work with nested scrollable parents?
		if ( this.cssPosition !== "fixed" ) {
			newLeft += this.scrollParent.scrollLeft();
			newTop += this.scrollParent.scrollTop();
		}

		this.dragEl.css({
			left: newLeft,
			top: newTop
		});
	},

	_originalHash: function( pointerPosition ) {

		var ret = {
			position: this.position,
			offset: copy( this.offset ),
			pointer: copy( pointerPosition )
		};

		if ( this.options.helper ) {
			ret.helper = this.dragEl;
		}

		return ret;
	},

	_fullHash: function( pointerPosition ) {
		return $.extend( this._originalHash( pointerPosition ), {
			originalPosition: copy( this.originalPosition ),
			originalOffset: copy( this.originalOffset ),
			originalPointer: copy( this.originalPointer )
		});
	},

	_blockFrames: function() {

		this.iframeBlocks = this.document.find( "iframe" ).map(function() {
			var iframe = $( this ),
				iframeOffset = iframe.offset();

			return $( "<div>" )
				.css({
					position: "absolute",
					width: iframe.outerWidth(),
					height: iframe.outerHeight(),
					top: iframeOffset.top,
					left: iframeOffset.left
				})
				.appendTo( iframe.parent() )[0];
		});
	},

	_unblockFrames: function() {
		if ( this.iframeBlocks ) {
			this.iframeBlocks.remove();
			delete this.iframeBlocks;
		}
	},

	_destroy: function() {
		this.element.removeClass( "ui-draggable" );
		this._super();
	}
});

$.widget( "ui.draggable", $.ui.draggable, {
	// $.widget doesn't know how to handle redefinitions with a custom prefix
	// custom prefixes are going away anyway, so it's not worth fixing right now
	widgetEventPrefix: "drag",

	options: {
		containment: null
	},

	_create: function() {
		this._super();
		this._on({
			dragstart: "_setContainment",
			drag: "_contain"
		});
	},

	_setContainment: function( event, ui ) {
		var offset, left, top,
			container = this._getContainer();

		if ( !container ) {
			this.containment = null;
			return;
		}

		offset = container.offset();
		left = offset.left +
			(parseFloat( $.css( container[0], "borderLeftWidth", true ) ) || 0) +
			(parseFloat( $.css( container[0], "paddingLeft", true ) ) || 0);
		top = offset.top +
			(parseFloat( $.css( container[0], "borderTopWidth", true ) ) || 0) +
			(parseFloat( $.css( container[0], "paddingTop", true ) ) || 0);

		this.containment = {
			left: left,
			top: top,
			right: left + container.width(),
			bottom: top + container.height(),
			leftDiff: ui.originalOffset.left - ui.originalPosition.left,
			topDiff: ui.originalOffset.top - ui.originalPosition.top,
			width: this.dragDimensions.width,
			height: this.dragDimensions.height
		};
	},

	_contain: function( event, ui ) {
		var containment = this.containment;

		if ( !containment ) {
			return;
		}

		ui.position.left = Math.max( ui.position.left,
			containment.left - containment.leftDiff );
		ui.position.left = Math.min( ui.position.left,
			containment.right - containment.width - containment.leftDiff );

		ui.position.top = Math.max( ui.position.top,
			containment.top - containment.topDiff );
		ui.position.top = Math.min( ui.position.top,
			containment.bottom - containment.height - containment.topDiff );
	},

	_getContainer: function() {
		var container,
			containment = this.options.containment;

		if ( !containment ) {
			container = null;
		} else if ( containment === "parent" ) {
			container = this.element.parent();
		} else {
			container = $( containment );
			if ( !container.length ) {
				container = null;
			}
		}

		return container;
	}
});

})( jQuery );

// DEPRECATED
if ( $.uiBackCompat !== false ) {

	// appendTo 'parent' value
	$.widget( "ui.draggable", $.ui.draggable, {

		_appendToEl: function() {

			var el = this.options.appendTo;

			if ( el === "parent" ) {
				el = this.dragEl.parent();
			}

			return el;

		}

	});

	// helper 'original' or 'clone' value + helper return value
	$.widget( "ui.draggable", $.ui.draggable, {

		_create: function() {

			var self = this,
				orig = this._originalHash;

			this._super();

			if ( this.options.helper === "original" ) {
				this.options.helper = false;
			}

			if ( this.options.helper === "clone" ) {
				this.options.helper = true;
			}

			this._originalHash = function() {

				var ret = orig.apply( self, arguments );

				if ( !ret.helper ) {
					ret.helper = self.element;
				}

				return ret;

			};

		},

		_setOption: function( key, value ) {

			if ( key !== "helper" ) {
				return this._super( key, value );
			}

			if ( value === "clone" ) {
				value = true;
			}

			if ( value === "original" ) {
				value = false;
			}

			this._super( key, value );

		}

	});

	// axis option
	$.widget( "ui.draggable", $.ui.draggable, {
		options: {
			axis: false
		},

		_create: function() {

			var self = this;

			this._super();

			// On drag, make sure top does not change so axis is locked
			this.element.on( "drag", function( event, ui ) {

				if ( self.options.axis === "x" ) {
					ui.position.top = ui.originalPosition.top;
				}

				if ( self.options.axis === "y" ) {
					ui.position.left = ui.originalPosition.left;
				}

			});

		}

	});

	// cancel option
	$.widget( "ui.draggable", $.ui.draggable, {
		options: {
			cancel: null
		},

		_create: function() {

			this._super();

			if ( this.options.cancel !== null ) {
				this.options.exclude = this.options.cancel;
			}

		},

		_setOption: function( key, value ) {

			if ( key !== "cancel" ) {
				return this._super( key, value );
			}

			this._super( key, value );
			this.options.exclude = this.options.cancel;

		}

	});

	// cursor option
	$.widget( "ui.draggable", $.ui.draggable, {
		options: {
			cursor: "auto"
		},

		_create: function() {

			var startCursor, self, body;

			this._super();

			self = this;
			body = $( this.document[0].body );

			// Cache original cursor to set back
			this.element.on( "dragbeforestart", function() {

				if ( self.options.cursor ) {
					startCursor = body[0].style.cursor;
					body.css( "cursor", self.options.cursor );
				}

			});

			// Set back cursor to whatever default was
			this.element.on( "dragstop", function() {

				if ( self.options.cursor ) {
					body.css( "cursor", startCursor );
				}

			});


		}

	});

	// cursorAt option
	$.widget( "ui.draggable", $.ui.draggable, {
		options: {
			cursorAt: false
		},

		_create: function() {

			var self = this;

			this._super();

			this.element.on( "dragbeforestart", function( event, ui ) {

				var cursorAt = self.options.cursorAt;

				// No need to continue
				if ( !cursorAt ) {
					return;
				}

				// support array and string position notation
				// TODO: Remove after 2.0, only used for backCompat
				if ( typeof cursorAt === "string" ) {
					cursorAt = cursorAt.split(" ");
				}
				if ( $.isArray( cursorAt ) ) {
					cursorAt = {
						left: +cursorAt[ 0 ],
						top: +cursorAt[ 1 ] || 0
					};
				}

				if ( "top" in cursorAt ) {
					ui.position.top += ui.pointer.y - ui.offset.top - cursorAt.top;
				}
				if ( "left" in cursorAt ) {
					ui.position.left += ui.pointer.x - ui.offset.left - cursorAt.left;
				}
				if ( "bottom" in cursorAt ) {
					ui.position.top += ui.pointer.y - ui.offset.top - self.dragDimensions.height + cursorAt.bottom;
				}
				if ( "right" in cursorAt ) {
					ui.position.left += ui.pointer.x - ui.offset.left - self.dragDimensions.width + cursorAt.right;
				}
			});

		}

	});

	// grid option
	$.widget( "ui.draggable", $.ui.draggable, {
		options: {
			grid: false
		},

		_create: function() {

			var self = this,
				currentX, currentY;

			this._super();

			this.element.on( "dragbeforestart", function( event, ui ) {

				if ( !self.options.grid ) {
					return;
				}

				// Save off the start position, which may be overwritten during drag
				currentX = ui.position.left;
				currentY = ui.position.top;

			});

			this.element.on( "drag", function( event, ui ) {

				if ( !self.options.grid ) {
					return;
				}

				// Save off the intended intervals
				var x = self.options.grid[0],
					y = self.options.grid[1];

				// If x is actually something, check that user is at least half way to next point
				if ( x ) {
					if ( ui.position.left - currentX >= x/2 ) {
						currentX = currentX + x;
					}	else if ( currentX - ui.position.left >= x/2 ) {
						currentX = currentX - x;
					}
				}

				// If y is actually something, check that user is at least half way to next point
				if ( y ) {
					if ( ui.position.top - currentY >= y/2 ) {
						currentY = currentY + y;
					} else if ( currentY - ui.position.top >= y/2 ) {
						currentY = currentY - y;
					}
				}

				// If there threshold wasn't crossed these variables wouldn't be changed
				// Otherwise this will now bump the draggable to the next spot on grid
				ui.position.left = currentX;
				ui.position.top = currentY;

			});

		}

	});

	// opacity option
	$.widget( "ui.draggable", $.ui.draggable, {
		options: {
			opacity: false
		},

		_create: function() {

			var self = this,
				originalOpacity;

			this._super();

			this.element.on( "dragstart", function() {

				// No need to continue
				if ( !self.options.opacity ) {
					return;
				}

				// Cache the original opacity of draggable element to reset later
				originalOpacity = self.dragEl.css( "opacity" );

				// Set draggable element to new opacity
				self.dragEl.css( "opacity", self.options.opacity );

			});

			this.element.on( "dragstop", function() {

				// No need to continue
				if ( !self.options.opacity ) {
					return;
				}

				// Reset opacity
				self.dragEl.css( "opacity", originalOpacity );

			});

		}

	});

	// TODO: handle droppables
	// revert + revertDuration options
	$.widget( "ui.draggable", $.ui.draggable, {
		options: {
			revert: false,
			revertDuration: 500
		},

		_create: function() {

			var self = this,
				originalLeft, originalTop, originalPosition;

			this._super();

			this.element.on( "dragbeforestart", function() {

				// No need to continue
				if ( !self.options.revert ) {
					return;
				}

				// Cache the original css of draggable element to reset later
				originalLeft = self.dragEl.css( "left" );
				originalTop = self.dragEl.css( "top" );
				originalPosition = self.dragEl.css( "position" );

			});

			this.element.on( "dragstop", function() {

				// No need to continue
				if ( !self.options.revert ) {
					return;
				}

				// Reset to before drag
				self.dragEl.animate({
					left: originalLeft,
					top: originalTop,
					position: originalPosition
				}, self.options.revertDuration );

			});

		}

	});

	// zIndex option
	$.widget( "ui.draggable", $.ui.draggable, {
		options: {
			zIndex: false
		},

		_create: function() {

			var self = this,
				originalZIndex;

			this._super();

			this.element.on( "dragstart", function() {

				// No need to continue
				if ( !self.options.zIndex ) {
					return;
				}

				// Cache the original zIndex of draggable element to reset later
				originalZIndex = self.dragEl.css( "z-index" );

				// Set draggable element to new zIndex
				self.dragEl.css( "z-index", self.options.zIndex );

			});

			this.element.on( "dragstop", function() {

				// No need to continue
				if ( !self.options.zIndex ) {
					return;
				}

				// Reset zIndex
				self.dragEl.css( "z-index", originalZIndex );

			});

		}

	});

	// TODO: need droppable working
	// scope option
	$.widget( "ui.draggable", $.ui.draggable, {
		options: {
			scope: "default"
		}
	});

	// scroll + scrollSensitivity + scrollSpeedType option
	$.widget( "ui.draggable", $.ui.draggable, {
		options: {
			scroll: true,
			scrollSpeed: null,
			scrollSensitivity: null
		},
		_create : function() {

			var self = this,
				handleScroll = this._handleScrolling,
				speed = this._speed;

			this._super();

			this._speed = function( distance ) {

				if ( self.options.scrollSpeed !== null ) {

					self.scrollSpeed = self.options.scrollSpeed;

					// Undo calculation that makes things go faster as distance increases
					distance = 0;
				}

				return speed.call( self, distance );

			};

			// Wrap member function to check for ability to scroll
			this._handleScrolling = function( pointerPosition ) {

				if ( !self.options.scroll ) {
					return;
				}

				if ( self.options.scrollSensitivity !== null ) {
					self.scrollSensitivity = self.options.scrollSensitivity;
				}

				handleScroll.call( self, pointerPosition );

			};

		}

	});

	// stack option
	$.widget( "ui.draggable", $.ui.draggable, {
		options: {
			stack: false
		},

		_create: function() {

			var self = this;

			this._super();

			this.element.on( "dragbeforestart", function() {

				var stack = self.options.stack,
					group, min;

				if ( !self.options.stack ) {
					return;
				}

				group = $.makeArray( $(stack) ).sort(function(a,b) {

					var aZIndex = parseInt( $(a).css("zIndex"), 10 ),
						bZIndex = parseInt( $(b).css("zIndex"), 10 );

					return ( aZIndex || 0) -  ( bZIndex|| 0);
				});

				if (!group.length) {
					return;
				}

				min = parseInt(group[0].style.zIndex, 10) || 0;

				$(group).each(function(i) {
					this.style.zIndex = min + i;
				});

				self.element[0].style.zIndex = min + group.length;

			});

		}

	});

	// snap snapMode snapTolerance options
	// mainly copy-pasted from 1.9 since the code is so "insane" didn't want to reverse-engineer into sanity
	$.widget( "ui.draggable", $.ui.draggable, {
		options: {
			snap: false,
			snapMode: "both",
			snapTolerance: 20
		},

		_create: function() {

			var inst = this,
				snapElements;

			this._super();

			this.element.on( "dragstart", function() {

				// Nothing to do
				if ( !inst.options.snap ) {
					return;
				}

				// Reset snapElements on every start in case there have been changes
				snapElements = [];

				// Select either all draggable elements, or the selector that was passed in
				$( inst.options.snap === true ? ":data(ui-draggable)" : inst.options.snap ).each(function() {

					var el = $(this),
						offset = el.offset();

					// Don't add this draggable to list of elements for snapping
					if( this === inst.element[0] ) {
						return;
					}

					// Save off elements dimensions for later
					snapElements.push({
						item: this,
						width: el.outerWidth(),
						height: el.outerHeight(),
						top: offset.top,
						left: offset.left
					});

				});

				inst.margins = {
					left: (parseInt(inst.element.css("marginLeft"),10) || 0),
					top: (parseInt(inst.element.css("marginTop"),10) || 0),
					right: (parseInt(inst.element.css("marginRight"),10) || 0),
					bottom: (parseInt(inst.element.css("marginBottom"),10) || 0)
				};

			});

			this.element.on( "drag", function( event, ui ) {

				// Nothing to do
				if ( !inst.options.snap ) {
					return;
				}

				var ts, bs, ls, rs, l, r, t, b, i, first,
					o = inst.options,
					d = o.snapTolerance,
					x1 = ui.offset.left, x2 = x1 + inst.dragDimensions.width,
					y1 = ui.offset.top, y2 = y1 + inst.dragDimensions.height;

				for (i = snapElements.length - 1; i >= 0; i--){

					l = snapElements[i].left;
					r = l + snapElements[i].width;
					t = snapElements[i].top;
					b = t + snapElements[i].height;

					//Yes, I know, this is insane ;)
					if(!((l-d < x1 && x1 < r+d && t-d < y1 && y1 < b+d) || (l-d < x1 && x1 < r+d && t-d < y2 && y2 < b+d) || (l-d < x2 && x2 < r+d && t-d < y1 && y1 < b+d) || (l-d < x2 && x2 < r+d && t-d < y2 && y2 < b+d))) {
						if(snapElements[i].snapping) {
							(inst.options.snap.release && inst.options.snap.release.call(inst.element, event, $.extend(inst._uiHash(), { snapItem: snapElements[i].item })));
						}
						snapElements[i].snapping = false;
						continue;
					}

					if(o.snapMode !== "inner") {
						ts = Math.abs(t - y2) <= d;
						bs = Math.abs(b - y1) <= d;
						ls = Math.abs(l - x2) <= d;
						rs = Math.abs(r - x1) <= d;
						if(ts) {
							ui.position.top = inst._convertPositionTo("relative", { top: t - inst.dragDimensions.height, left: 0 }).top - inst.margins.top;
						}
						if(bs) {
							ui.position.top = inst._convertPositionTo("relative", { top: b, left: 0 }).top - inst.margins.top;
						}
						if(ls) {
							ui.position.left = inst._convertPositionTo("relative", { top: 0, left: l - inst.dragDimensions.width }).left - inst.margins.left;
						}
						if(rs) {
							ui.position.left = inst._convertPositionTo("relative", { top: 0, left: r }).left - inst.margins.left;
						}
					}

					first = (ts || bs || ls || rs);

					if(o.snapMode !== "outer") {
						ts = Math.abs(t - y1) <= d;
						bs = Math.abs(b - y2) <= d;
						ls = Math.abs(l - x1) <= d;
						rs = Math.abs(r - x2) <= d;
						if(ts) {
							ui.position.top = inst._convertPositionTo("relative", { top: t, left: 0 }).top - inst.margins.top;
						}
						if(bs) {
							ui.position.top = inst._convertPositionTo("relative", { top: b - inst.dragDimensions.height, left: 0 }).top - inst.margins.top;
						}
						if(ls) {
							ui.position.left = inst._convertPositionTo("relative", { top: 0, left: l }).left - inst.margins.left;
						}
						if(rs) {
							ui.position.left = inst._convertPositionTo("relative", { top: 0, left: r - inst.dragDimensions.width }).left - inst.margins.left;
						}
					}

					if(!snapElements[i].snapping && (ts || bs || ls || rs || first)) {
						(inst.options.snap.snap && inst.options.snap.snap.call(inst.element, event, $.extend(inst._uiHash(), { snapItem: snapElements[i].item })));
					}
					snapElements[i].snapping = (ts || bs || ls || rs || first);

				}
			});


		},

		_convertPositionTo: function(d, pos) {

			if(!pos) {
				pos = this.position;
			}

			var mod = d === "absolute" ? 1 : -1,
				offset = {},
				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);

			$.extend(offset, {
				parent: this._getParentOffset(),
				relative: this._getRelativeOffset() //This is a relative to absolute position minus the actual position calculation - only used for relative positioned helper
			});

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

		},

		_getParentOffset: function() {

			//Get the offsetParent and cache its position
			this.offsetParent = this.dragEl.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();
			}

			//This needs to be actually done for all browsers, since pageX/pageY includes this information
			//Ugly IE fix
			if((this.offsetParent[0] === document.body) ||
				(this.offsetParent[0].tagName && this.offsetParent[0].tagName.toLowerCase() === "html" && $.ui.ie)) {
				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.element.position();
				return {
					top: p.top - (parseInt(this.dragEl.css("top"),10) || 0) + this.scrollParent.scrollTop(),
					left: p.left - (parseInt(this.dragEl.css("left"),10) || 0) + this.scrollParent.scrollLeft()
				};
			}

			return { top: 0, left: 0 };

		}

	});

	// refreshPositions option
	$.widget( "ui.draggable", $.ui.draggable, {
		options: {
			refreshPositions: false
		},

		_create: function() {

			var self = this,
				drops;

			this._super();

			this.element.on( "dragstart", function() {
				drops = $(":data(ui-sortable)");
			});

			// On drag, make sure top does not change so axis is locked
			this.element.on( "drag", function() {

				if ( self.options.refreshPositions !== true ) {
					return;
				}

				drops.each( function() {
					$(this).sortable("refreshPositions");
				});


			});

		}

	});


}