/**

 * jQuery.ScrollTo

 * Copyright (c) 2007-2008 Ariel Flesler - aflesler(at)gmail(dot)com | http://flesler.blogspot.com

 * Dual licensed under MIT and GPL.

 * Date: 9/11/2008

 *

 * @projectDescription Easy element scrolling using jQuery.

 * http://flesler.blogspot.com/2007/10/jqueryscrollto.html

 * Tested with jQuery 1.2.6. On FF 2/3, IE 6/7, Opera 9.2/5 and Safari 3. on Windows.

 *

 * @author Ariel Flesler

 * @version 1.4

 *

 * @id jQuery.scrollTo

 * @id jQuery.fn.scrollTo

 * @param {String, Number, DOMElement, jQuery, Object} target Where to scroll the matched elements.

 *	  The different options for target are:

 *		- A number position (will be applied to all axes).

 *		- A string position ('44', '100px', '+=90', etc ) will be applied to all axes

 *		- A jQuery/DOM element ( logically, child of the element to scroll )

 *		- A string selector, that will be relative to the element to scroll ( 'li:eq(2)', etc )

 *		- A hash { top:x, left:y }, x and y can be any kind of number/string like above.

 * @param {Number} duration The OVERALL length of the animation, this argument can be the settings object instead.

 * @param {Object,Function} settings Optional set of settings or the onAfter callback.

 *	 @option {String} axis Which axis must be scrolled, use 'x', 'y', 'xy' or 'yx'.

 *	 @option {Number} duration The OVERALL length of the animation.

 *	 @option {String} easing The easing method for the animation.

 *	 @option {Boolean} margin If true, the margin of the target element will be deducted from the final position.

 *	 @option {Object, Number} offset Add/deduct from the end position. One number for both axes or { top:x, left:y }.

 *	 @option {Object, Number} over Add/deduct the height/width multiplied by 'over', can be { top:x, left:y } when using both axes.

 *	 @option {Boolean} queue If true, and both axis are given, the 2nd axis will only be animated after the first one ends.

 *	 @option {Function} onAfter Function to be called after the scrolling ends. 

 *	 @option {Function} onAfterFirst If queuing is activated, this function will be called after the first scrolling ends.

 * @return {jQuery} Returns the same jQuery object, for chaining.

 *

 * @desc Scroll to a fixed position

 * @example $('div').scrollTo( 340 );

 *

 * @desc Scroll relatively to the actual position

 * @example $('div').scrollTo( '+=340px', { axis:'y' } );

 *

 * @dec Scroll using a selector (relative to the scrolled element)

 * @example $('div').scrollTo( 'p.paragraph:eq(2)', 500, { easing:'swing', queue:true, axis:'xy' } );

 *

 * @ Scroll to a DOM element (same for jQuery object)

 * @example var second_child = document.getElementById('container').firstChild.nextSibling;

 *			$('#container').scrollTo( second_child, { duration:500, axis:'x', onAfter:function(){

 *				alert('scrolled!!');																   

 *			}});

 *

 * @desc Scroll on both axes, to different values

 * @example $('div').scrollTo( { top: 300, left:'+=200' }, { axis:'xy', offset:-20 } );

 */

;(function( $ ){

	

	var $scrollTo = $.scrollTo = function( target, duration, settings ){

		$(window).scrollTo( target, duration, settings );

	};



	$scrollTo.defaults = {

		axis:'y',

		duration:1

	};



	// Returns the element that needs to be animated to scroll the window.

	// Kept for backwards compatibility (specially for localScroll & serialScroll)

	$scrollTo.window = function( scope ){

		return $(window).scrollable();

	};



	// Hack, hack, hack... stay away!

	// Returns the real elements to scroll (supports window/iframes, documents and regular nodes)

	$.fn.scrollable = function(){

		return this.map(function(){

			// Just store it, we might need it

			var win = this.parentWindow || this.defaultView,

				// If it's a document, get its iframe or the window if it's THE document

				elem = this.nodeName == '#document' ? win.frameElement || win : this,

				// Get the corresponding document

				doc = elem.contentDocument || (elem.contentWindow || elem).document,

				isWin = elem.setInterval;



			return elem.nodeName == 'IFRAME' || isWin && $.browser.safari ? doc.body

				: isWin ? doc.documentElement

				: this;

		});

	};



	$.fn.scrollTo = function( target, duration, settings ){

		if( typeof duration == 'object' ){

			settings = duration;

			duration = 0;

		}

		if( typeof settings == 'function' )

			settings = { onAfter:settings };

			

		settings = $.extend( {}, $scrollTo.defaults, settings );

		// Speed is still recognized for backwards compatibility

		duration = duration || settings.speed || settings.duration;

		// Make sure the settings are given right

		settings.queue = settings.queue && settings.axis.length > 1;

		

		if( settings.queue )

			// Let's keep the overall duration

			duration /= 2;

		settings.offset = both( settings.offset );

		settings.over = both( settings.over );



		return this.scrollable().each(function(){

			var elem = this,

				$elem = $(elem),

				targ = target, toff, attr = {},

				win = $elem.is('html,body');



			switch( typeof targ ){

				// A number will pass the regex

				case 'number':

				case 'string':

					if( /^([+-]=)?\d+(px)?$/.test(targ) ){

						targ = both( targ );

						// We are done

						break;

					}

					// Relative selector, no break!

					targ = $(targ,this);

				case 'object':

					// DOMElement / jQuery

					if( targ.is || targ.style )

						// Get the real position of the target 

						toff = (targ = $(targ)).offset();

			}

			$.each( settings.axis.split(''), function( i, axis ){

				var Pos	= axis == 'x' ? 'Left' : 'Top',

					pos = Pos.toLowerCase(),

					key = 'scroll' + Pos,

					old = elem[key],

					Dim = axis == 'x' ? 'Width' : 'Height',

					dim = Dim.toLowerCase();



				if( toff ){// jQuery / DOMElement

					attr[key] = toff[pos] + ( win ? 0 : old - $elem.offset()[pos] );



					// If it's a dom element, reduce the margin

					if( settings.margin ){

						attr[key] -= parseInt(targ.css('margin'+Pos)) || 0;

						attr[key] -= parseInt(targ.css('border'+Pos+'Width')) || 0;

					}

					

					attr[key] += settings.offset[pos] || 0;

					

					if( settings.over[pos] )

						// Scroll to a fraction of its width/height

						attr[key] += targ[dim]() * settings.over[pos];

				}else

					attr[key] = targ[pos];



				// Number or 'number'

				if( /^\d+$/.test(attr[key]) )

					// Check the limits

					attr[key] = attr[key] <= 0 ? 0 : Math.min( attr[key], max(Dim) );



				// Queueing axes

				if( !i && settings.queue ){

					// Don't waste time animating, if there's no need.

					if( old != attr[key] )

						// Intermediate animation

						animate( settings.onAfterFirst );

					// Don't animate this axis again in the next iteration.

					delete attr[key];

				}

			});			

			animate( settings.onAfter );			



			function animate( callback ){

				$elem.animate( attr, duration, settings.easing, callback && function(){

					callback.call(this, target, settings);

				});

			};

			function max( Dim ){

				var attr ='scroll'+Dim,

					doc = elem.ownerDocument;

				

				return win

						? Math.max( doc.documentElement[attr], doc.body[attr]  )

						: elem[attr];

			};

		}).end();

	};



	function both( val ){

		return typeof val == 'object' ? val : { top:val, left:val };

	};



})( jQuery );
