animate.css jQuery extension using waypoints.js

jquery.animate.css.js

window.jQuery.fn.extend({
    animateCss: function (animationName, delay, offset) {
        var offset = typeof offset !== 'undefined' ?  offset : '70%';
        var delay = typeof delay !== 'undefined' ? delay : 0;
    var $this = $(this);
    $this.css('visibility', 'hidden');
    new Waypoint({
      element:this[0],
      handler:function(direction) {
                setTimeout(function() {
            $this.addClass('animated '+animationName).css('visibility', 'visible');
                }, delay);
      },
      offset: offset
    });
    }
});