
( function( $ ) {
	
	$.scrollFollow = function ( box, options )
	{ 
		
		box = $( box );
		
		
		var position = box.css( 'position' );
		
		function ani()
		{		
			
			
			box.queue( [ ] );
		
			
			var viewportHeight = parseInt( $( window ).height() );	
			var pageScroll =  parseInt( $( document ).scrollTop() );
			var parentTop =  parseInt( box.cont.offset().top );
			var parentHeight = parseInt( box.cont.attr( 'offsetHeight' ) );
			var boxHeight = parseInt( box.attr( 'offsetHeight' ) + ( parseInt( box.css( 'marginTop' ) ) || 0 ) + ( parseInt( box.css( 'marginBottom' ) ) || 0 ) );
			var aniTop;
			
			
			if ( isActive )
			{
				
				if ( options.relativeTo == 'top' )
				{
					
					if ( box.initialOffsetTop >= ( pageScroll + options.offset ) )
					{
						aniTop = box.initialTop;
					}
					else
					{
						aniTop = Math.min( ( Math.max( ( -parentTop ), ( pageScroll - box.initialOffsetTop + box.initialTop ) ) + options.offset ), ( parentHeight - boxHeight - box.paddingAdjustment ) );
					}
				}
				
				else if ( options.relativeTo == 'bottom' )
				{
					
					if ( ( box.initialOffsetTop + boxHeight ) >= ( pageScroll + options.offset + viewportHeight ) )
					{
						aniTop = box.initialTop;
					}
					else
					{
						aniTop = Math.min( ( pageScroll + viewportHeight - boxHeight - options.offset ), ( parentHeight - boxHeight ) );
					}
				}
				
				
				
				if ( ( new Date().getTime() - box.lastScroll ) >= ( options.delay - 20 ) )
				{
					box.animate(
						{
							top: aniTop
						}, options.speed, options.easing
					);
				}
			}
		};
		
		
		var isActive = true;
		
		if ( $.cookie != undefined )
		{
			if( $.cookie( 'scrollFollowSetting' + box.attr( 'id' ) ) == 'false' )
			{
				var isActive = false;
				
				$( '#' + options.killSwitch ).text( options.offText )
					.toggle( 
						function ()
						{
							isActive = true;
							
							$( this ).text( options.onText );
							
							$.cookie( 'scrollFollowSetting' + box.attr( 'id' ), true, { expires: 365, path: '/'} );
							
							ani();
						},
						function ()
						{
							isActive = false;
							
							$( this ).text( options.offText );
							
							box.animate(
								{
									top: box.initialTop
								}, options.speed, options.easing
							);	
							
							$.cookie( 'scrollFollowSetting' + box.attr( 'id' ), false, { expires: 365, path: '/'} );
						}
					);
			}
			else
			{
				$( '#' + options.killSwitch ).text( options.onText )
					.toggle( 
						function ()
						{
							isActive = false;
							
							$( this ).text( options.offText );
							
							box.animate(
								{
									top: box.initialTop
								}, 0
							);	
							
							$.cookie( 'scrollFollowSetting' + box.attr( 'id' ), false, { expires: 365, path: '/'} );
						},
						function ()
						{
							isActive = true;
							
							$( this ).text( options.onText );
							
							$.cookie( 'scrollFollowSetting' + box.attr( 'id' ), true, { expires: 365, path: '/'} );
							
							ani();
						}
					);
			}
		}
		
		
		
		if ( options.container == '')
		{
			box.cont = box.parent();
		}
		else
		{
			box.cont = $( '#' + options.container );
		}
		
		
		box.initialOffsetTop =  parseInt( box.offset().top );
		box.initialTop = parseInt( box.css( 'top' ) ) || 0;
		
		
		if ( box.css( 'position' ) == 'relative' )
		{
			box.paddingAdjustment = parseInt( box.cont.css( 'paddingTop' ) ) + parseInt( box.cont.css( 'paddingBottom' ) );
		}
		else
		{
			box.paddingAdjustment = 0;
		}
		
		
		$( window ).scroll( function ()
			{
				
				$.fn.scrollFollow.interval = setTimeout( function(){ ani();} , options.delay );
				
				
				box.lastScroll = new Date().getTime();
			}
		);
		
		
		$( window ).resize( function ()
			{
				
				$.fn.scrollFollow.interval = setTimeout( function(){ ani();} , options.delay );
				
				
				box.lastScroll = new Date().getTime();
			}
		);

		
		box.lastScroll = 0;
		
		ani();
	};
	
	$.fn.scrollFollow = function ( options )
	{
		options = options || {};
		options.relativeTo = options.relativeTo || 'top';
		options.speed = options.speed || 500;
		options.offset = options.offset || 0;
		options.easing = options.easing || 'swing';
		options.container = options.container || this.parent().attr( 'id' );
		options.killSwitch = options.killSwitch || 'killSwitch';
		options.onText = options.onText || 'Turn Slide Off';
		options.offText = options.offText || 'Turn Slide On';
		options.delay = options.delay || 0;
		
		this.each( function() 
			{
				new $.scrollFollow( this, options );
			}
		);
		
		return this;
	};
})( jQuery );




