/*
	 * 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
	 */

	$.fn.stickyfloat = function(options, lockBottom) {
		var $obj 				= this;
		var parentPaddingTop 	= parseInt($obj.parent().css('padding-top'));
		var objectMarginTop 	= parseInt($obj.css('margin-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 + objectMarginTop - 275; //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 );
			}
		});
	};