/*

 * jQuery UI Position 1.8.1

 *

 * Copyright (c) 2010 AUTHORS.txt (http://jqueryui.com/about)

 * Dual licensed under the MIT (MIT-LICENSE.txt)

 * and GPL (GPL-LICENSE.txt) licenses.

 *

 * http://docs.jquery.com/UI/Position

 */

(function( $ ) {

$.ui = $.ui || {};

var horizontalPositions = /left|center|right/,

	horizontalDefault = "center",

	verticalPositions = /top|center|bottom/,

	verticalDefault = "center",

	_position = $.fn.position,

	_offset = $.fn.offset;

$.fn.position = function( options ) {

	if ( !options || !options.of ) {

		return _position.apply( this, arguments );

	}

	// make a copy, we don't want to modify arguments

	options = $.extend( {}, options );

	var target = $( options.of ),

		collision = ( options.collision || "flip" ).split( " " ),

		offset = options.offset ? options.offset.split( " " ) : [ 0, 0 ],

		targetWidth,

		targetHeight,

		basePosition;

	if ( options.of.nodeType === 9 ) {

		targetWidth = target.width();

		targetHeight = target.height();

		basePosition = { top: 0, left: 0 };

	} else if ( options.of.scrollTo && options.of.document ) {

		targetWidth = target.width();

		targetHeight = target.height();

		basePosition = { top: target.scrollTop(), left: target.scrollLeft() };

	} else if ( options.of.preventDefault ) {

		// force left top to allow flipping

		options.at = "left top";

		targetWidth = targetHeight = 0;

		basePosition = { top: options.of.pageY, left: options.of.pageX };

	} else {

		targetWidth = target.outerWidth();

		targetHeight = target.outerHeight();

		basePosition = target.offset();

	}

	// force my and at to have valid horizontal and veritcal positions

	// if a value is missing or invalid, it will be converted to center 

	$.each( [ "my", "at" ], function() {

		var pos = ( options[this] || "" ).split( " " );

		if ( pos.length === 1) {

			pos = horizontalPositions.test( pos[0] ) ?

				pos.concat( [verticalDefault] ) :

				verticalPositions.test( pos[0] ) ?

					[ horizontalDefault ].concat( pos ) :

					[ horizontalDefault, verticalDefault ];

		}

		pos[ 0 ] = horizontalPositions.test( pos[0] ) ? pos[ 0 ] : horizontalDefault;

		pos[ 1 ] = verticalPositions.test( pos[1] ) ? pos[ 1 ] : verticalDefault;

		options[ this ] = pos;

	});

	// normalize collision option

	if ( collision.length === 1 ) {

		collision[ 1 ] = collision[ 0 ];

	}

	// normalize offset option

	offset[ 0 ] = parseInt( offset[0], 10 ) || 0;

	if ( offset.length === 1 ) {

		offset[ 1 ] = offset[ 0 ];

	}

	offset[ 1 ] = parseInt( offset[1], 10 ) || 0;

	if ( options.at[0] === "right" ) {

		basePosition.left += targetWidth;

	} else if (options.at[0] === horizontalDefault ) {

		basePosition.left += targetWidth / 2;

	}

	if ( options.at[1] === "bottom" ) {

		basePosition.top += targetHeight;

	} else if ( options.at[1] === verticalDefault ) {

		basePosition.top += targetHeight / 2;

	}

	basePosition.left += offset[ 0 ];

	basePosition.top += offset[ 1 ];

	return this.each(function() {

		var elem = $( this ),

			elemWidth = elem.outerWidth(),

			elemHeight = elem.outerHeight(),

			position = $.extend( {}, basePosition );

		if ( options.my[0] === "right" ) {

			position.left -= elemWidth;

		} else if ( options.my[0] === horizontalDefault ) {

			position.left -= elemWidth / 2;

		}

		if ( options.my[1] === "bottom" ) {

			position.top -= elemHeight;

		} else if ( options.my[1] === verticalDefault ) {

			position.top -= elemHeight / 2;

		}

		// prevent fractions (see #5280)

		position.left = parseInt( position.left );

		position.top = parseInt( position.top );

		$.each( [ "left", "top" ], function( i, dir ) {

			if ( $.ui.position[ collision[i] ] ) {

				$.ui.position[ collision[i] ][ dir ]( position, {

					targetWidth: targetWidth,

					targetHeight: targetHeight,

					elemWidth: elemWidth,

					elemHeight: elemHeight,

					offset: offset,

					my: options.my,

					at: options.at

				});

			}

		});

		if ( $.fn.bgiframe ) {

			elem.bgiframe();

		}

		elem.offset( $.extend( position, { using: options.using } ) );

	});

};

$.ui.position = {

	fit: {

		left: function( position, data ) {

			var win = $( window ),

				over = position.left + data.elemWidth - win.width() - win.scrollLeft();

			position.left = over > 0 ? position.left - over : Math.max( 0, position.left );

		},

		top: function( position, data ) {

			var win = $( window ),

				over = position.top + data.elemHeight - win.height() - win.scrollTop();

			position.top = over > 0 ? position.top - over : Math.max( 0, position.top );

		}

	},

	flip: {

		left: function( position, data ) {

			if ( data.at[0] === "center" ) {

				return;

			}

			var win = $( window ),

				over = position.left + data.elemWidth - win.width() - win.scrollLeft(),

				myOffset = data.my[ 0 ] === "left" ?

					-data.elemWidth :

					data.my[ 0 ] === "right" ?

						data.elemWidth :

						0,

				offset = -2 * data.offset[ 0 ];

			position.left += position.left < 0 ?

				myOffset + data.targetWidth + offset :

				over > 0 ?

					myOffset - data.targetWidth + offset :

					0;

		},

		top: function( position, data ) {

			if ( data.at[1] === "center" ) {

				return;

			}

			var win = $( window ),

				over = position.top + data.elemHeight - win.height() - win.scrollTop(),

				myOffset = data.my[ 1 ] === "top" ?

					-data.elemHeight :

					data.my[ 1 ] === "bottom" ?

						data.elemHeight :

						0,

				atOffset = data.at[ 1 ] === "top" ?

					data.targetHeight :

					-data.targetHeight,

				offset = -2 * data.offset[ 1 ];

			position.top += position.top < 0 ?

				myOffset + data.targetHeight + offset :

				over > 0 ?

					myOffset + atOffset + offset :

					0;

		}

	}

};

// offset setter from jQuery 1.4

if ( !$.offset.setOffset ) {

	$.offset.setOffset = function( elem, options ) {

		// set position first, in-case top/left are set even on static elem

		if ( /static/.test( $.curCSS( elem, "position" ) ) ) {

			elem.style.position = "relative";

		}

		var curElem   = $( elem ),

			curOffset = curElem.offset(),

			curTop    = parseInt( $.curCSS( elem, "top",  true ), 10 ) || 0,

			curLeft   = parseInt( $.curCSS( elem, "left", true ), 10)  || 0,

			props     = {

				top:  (options.top  - curOffset.top)  + curTop,

				left: (options.left - curOffset.left) + curLeft

			};

		if ( 'using' in options ) {

			options.using.call( elem, props );

		} else {

			curElem.css( props );

		}

	};

	$.fn.offset = function( options ) {

		var elem = this[ 0 ];

		if ( !elem || !elem.ownerDocument ) { return null; }

		if ( options ) { 

			return this.each(function() {

				$.offset.setOffset( this, options );

			});

		}

		return _offset.call( this );

	};

}

}( jQuery ));