/// <reference path="jquery-1.3.2-vsdoc.js" />

/*
* stickyfloat - jQuery plugin for verticaly floating anything in a constrained area
* 
* Example: jQuery('#menu').stickyfloat({duration: 400});
* parameters:
* 		duration 	- the duration of the animation
*		startOffset - the amount of scroll offset after it the animations kicks in
*		offsetY		- the offset from the top when the object is animated
*		lockBottom	- 'true' by default, set to false if you don't want your floating box to stop at parent's bottom
* $Version: 05.16.2009 r1
* Copyright (c) 2009 Yair Even-Or
* vsync.design@gmail.com
*/

;(function($) {
	$.fn.stickyFloat = function(options, lockBottom) {
		var $obj = this;
		var parentPaddingTop = parseInt($obj.parent().css('padding-top'));
		var startOffset = $obj.parent().offset().top;
		var opts = $.extend({ startOffset: startOffset, offsetY: parentPaddingTop, duration: 200, lockBottom: true }, options);

		$obj.css({ position: 'absolute' });

		if (opts.lockBottom) {
			var bottomPos = $obj.parent().height() - $obj.height() + parentPaddingTop; //get the maximum scrollTop value
			if (bottomPos < 0)
				bottomPos = 0;
		}

		$(window).scroll(function() {
			$obj.stop(); // stop all calculations on scroll event

			var pastStartOffset = $(document).scrollTop() > opts.startOffset; // check if the window was scrolled down more than the start offset declared.
			var objFartherThanTopPos = $obj.offset().top > startOffset; // check if the object is at it's top position (starting point)
			var objBiggerThanWindow = $obj.outerHeight() < $(window).height(); // if the window size is smaller than the Obj size, then do not animate.

			// if window scrolled down more than startOffset OR obj position is greater than
			// the top position possible (+ offsetY) AND window size must be bigger than Obj size
			if ((pastStartOffset || objFartherThanTopPos) && objBiggerThanWindow) {
				var newpos = ($(document).scrollTop() - startOffset + opts.offsetY);
				if (newpos > bottomPos)
					newpos = bottomPos;
				if ($(document).scrollTop() < opts.startOffset) // if window scrolled < starting offset, then reset Obj position (opts.offsetY);
					newpos = parentPaddingTop;

				$obj.animate({ top: newpos }, opts.duration);
			}
		});
	};
})(jQuery);