/**
 * ueberwacht das "scroll" Event des window-Objektes und scrollt das reader-Icon
 *
 * @author Steve Rohrlack <steve.rohrlack@digitalwert.de>
 * @copyright 2011 digitalwert
 * @requires Mootools 1.2
 */
window.addEvent('domready', function(drEv) {
  if($$('.reader-container')[0]) {
    var reader = $$('.reader-container .reader')[0];
    var fx = new Fx.Tween(reader);
    var documentHeight = $('wrap').getDimensions().height;
    var topPosition = (documentHeight - 454) * -1;

    fx.start('top', topPosition);

    window.addEvent('scroll', function(sEv) {
      documentHeight = $('wrap').getDimensions().height;
      var scrollOffset = $$('body')[0].getScroll().y;

      //scrollen ab 407px Scrollhöhe
      if(scrollOffset > 407) {
        fx.cancel();
        fx.start('top', (documentHeight - scrollOffset - 170) * -1);
      } else {
        fx.cancel();
        fx.start('top', topPosition);
      }
    });
  }
});