/**
 * jQuery.ScrollTo
 * Copyright (c) 2007-2008 Ariel Flesler - aflesler(at)gmail(dot)com | http://flesler.blogspot.com
 * Dual licensed under MIT and GPL.
 * Date: 2/19/2008
 *
 * @projectDescription Easy element scrolling using jQuery.
 * http://flesler.blogspot.com/2007/10/jqueryscrollto.html
 * Tested with jQuery 1.2.1. On FF 2.0.0.11, IE 6, Opera 9.22 and Safari 3 beta. on Windows.
 *
 * @author Ariel Flesler
 * @version 1.3.3
 *
 * @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} settings Hash of settings, optional.
 *	 @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.
 *
 * @example jQuery('div').scrollTo( 340 );
 *
 * @example jQuery('div').scrollTo( '+=340px', { axis:'y' } );
 *
 * @example jQuery('div').scrollTo( 'p.paragraph:eq(2)', 500, { easing:'swing', queue:true, axis:'xy' } );
 *
 * @example var second_child = document.getElementById('container').firstChild.nextSibling;
 *			jQuery('#container').scrollTo( second_child, { duration:500, axis:'x', onAfter:function(){
 *				alert('scrolled!!');																   
 *			}});
 *
 * @example jQuery('div').scrollTo( { top: 300, left:'+=200' }, { offset:-20 } );
 *
 * Notes:
 *  - jQuery.scrollTo will make the whole window scroll, it accepts the same arguments as jQuery.fn.scrollTo.
 *	- If you are interested in animated anchor navigation, check http://jquery.com/plugins/project/LocalScroll.
 *	- The options margin, offset and over are ignored, if the target is not a jQuery object or a DOM element.
 *	- The option 'queue' won't be taken into account, if only 1 axis is given.
 */
var jQueryscrollTo = jQuery.scrollTo = function( target, duration, settings ){
    jQueryscrollTo.window().scrollTo( target, duration, settings );
};

jQueryscrollTo.defaults = {
    axis:'y',
    duration:1
};

//returns the element that needs to be animated to scroll the window
jQueryscrollTo.window = function(){
    return jQuery( jQuery.browser.safari ? 'body' : 'html' );
};

jQuery.fn.scrollTo = function( target, duration, settings ){
    if( typeof duration == 'object' ){
        settings = duration;
        duration = 0;
    }
    settings = jQuery.extend( {}, jQueryscrollTo.defaults, settings );
    duration = duration || settings.speed || settings.duration;//speed is still recognized for backwards compatibility
    settings.queue = settings.queue && settings.axis.length > 1;//make sure the settings are given right
    if( settings.queue )
        duration /= 2;//let's keep the overall speed, the same.
    settings.offset = both( settings.offset );
    settings.over = both( settings.over );

    return this.each(function(){
        var elem = this, jQueryelem = jQuery(elem),
        t = target, toff, attr = {},
        win = jQueryelem.is('html,body');
        switch( typeof t ){
            case 'number'://will pass the regex
            case 'string':
                if( /^([+-]=)?\d+(px)?jQuery/.test(t) ){
                    t = both( t );
                    break;//we are done
                }
                t = jQuery(t,this);// relative selector, no break!
            case 'object':
                if( t.is || t.style )//DOM/jQuery
                    toff = (t = jQuery(t)).offset();//get the real position of the target
        }
        jQuery.each( settings.axis.split(''), function( i, axis ){
            var Pos	= axis == 'x' ? 'Left' : 'Top',
            pos = Pos.toLowerCase(),
            key = 'scroll' + Pos,
            act = elem[key],
            Dim = axis == 'x' ? 'Width' : 'Height',
            dim = Dim.toLowerCase();

            if( toff ){//jQuery/DOM
                attr[key] = toff[pos] + ( win ? 0 : act - jQueryelem.offset()[pos] );

                if( settings.margin ){//if it's a dom element, reduce the margin
                    attr[key] -= parseInt(t.css('margin'+Pos)) || 0;
                    attr[key] -= parseInt(t.css('border'+Pos+'Width')) || 0;
                }
					
                attr[key] += settings.offset[pos] || 0;//add/deduct the offset
					
                if( settings.over[pos] )//scroll to a fraction of its width/height
                    attr[key] += t[dim]() * settings.over[pos];
            }else
                attr[key] = t[pos];//remove the unnecesary 'px'

            if( /^\d+jQuery/.test(attr[key]) )//number or 'number'
                attr[key] = attr[key] <= 0 ? 0 : Math.min( attr[key], max(Dim) );//check the limits

            if( !i && settings.queue ){//queueing each axis is required
                if( act != attr[key] )//don't waste time animating, if there's no need.
                    animate( settings.onAfterFirst );//intermediate animation
                delete attr[key];//don't animate this axis again in the next iteration.
            }
        });
        animate( settings.onAfter );

        function animate( callback ){
            jQueryelem.animate( attr, duration, settings.easing, callback && function(){
                callback.call(this, target);
            });
        };
        function max( Dim ){
            var el = win ? jQuery.browser.opera ? document.body : document.documentElement : elem;
            return el['scroll'+Dim] - el['client'+Dim];
        };
    });
};

function both( val ){
    return typeof val == 'object' ? val : {
        top:val,
        left:val
    };
};