/**
 * 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 && $.support ? 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 );