Colorjar: Navigable collapsed list of posts

jquery.navigable_collapsed_list.js

/*  
 *
 * Navigable collapsed list of posts
 * Author: Tim Novinger
 * Email: [email protected]
 * #colorjar
 */ 

// ---------------------------------
// PREV/NEXT Content Navigation
// ---------------------------------
var $collapsed_content = $('.collapsed-content'),
    $navigation_links  = $collapsed_content.find('.the-navigation'),
    opacity            = 0.5;

// Initially show prev link faded out since we
// obviously can't go backwards at this point
$navigation_links.find('.previous').css('opacity', opacity);

// Bind events for prev/next links
$navigation_links.delegate('a.previous, a.next', 'click', function(e){
  e.preventDefault();

  var $currentLink = $(e.currentTarget),
      $current     = $collapsed_content.find('li.current'),
      $count       = $navigation_links.find('.count'),
      $prev        = $current.prev(),
      $next        = $current.next(),
      total        = parseInt(($collapsed_content.find('li').length - 1).toString(), 10),
      position     = parseInt($current.prop('id').match(/\d/)[0].toString(), 10),
      height       = parseInt($current.outerHeight(true), 10),
      delay        = 200;

  // Always reset the nav link opacity
  $navigation_links.find('a').css('opacity', 1.0);

  if ($currentLink.prop('class') == 'next')
  {
    if (position < total)
    {
      $currentLink.css('opacity', 1.0);
      $collapsed_content
        .find('li')
        .animate({ top:'-='+height }, delay, function(){
          $prev.removeClass('current');
          $current.removeClass('current');
          $next.addClass('current');
        });

      // Update the displayed count
      $count.text( position+2 );
    }

    // Fade out the nav item when we've
    // reached the last testimonial
    if (position >= (total - 1)) { $currentLink.css('opacity', opacity); }
  }
  else
  {
    if (position <= total && position != 0)
    {
      $currentLink.css('opacity', 1.0);
      $collapsed_content
        .find('li')
        .animate({ top:'+='+height }, delay, function(){
          $prev.addClass('current');
          $current.removeClass('current');
          $next.removeClass('current');
        });

      // Update the displayed count
      $count.text(position);
    }

    // Fade out the nav item when we've
    // reached the last testimonial
    if (position <= 1) { $currentLink.css('opacity', opacity); }
  }
});