/**
* 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: 'xy',
        duration: 1,
        queue: true
    };

    // 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);