(function(){

  function isElementInViewport(element) {
    var rect = element.getBoundingClientRect();
    if (
      rect.top >= 0 &&
      rect.left+rect.width/2 >= 0 &&
      rect.bottom <= (window.innerHeight || document.documentElement.clientHeight) + (element.offsetHeight * 0.75) &&
      rect.right-rect.width/2 <= (window.innerWidth || document.documentElement.clientWidth))
    {
      return 1;
    } else if (
      rect.left+rect.width/2 >= 0 &&
      rect.bottom <= (window.innerHeight || document.documentElement.clientHeight) &&
      rect.right-rect.width/2 <= (window.innerWidth || document.documentElement.clientWidth))
    {
      return 2;
    }
    return false;
  }

  function getAnimatedElements() {
    var animatedWrapper = document.querySelectorAll(".is-animated"),
      elements = [];

    for (var i = 0; i < animatedWrapper.length; i++)
    {
      var hasChildren = false;
      if (animatedWrapper[i].classList.contains("rs-columns") || animatedWrapper[i].classList.contains("animate-children"))
      {
        for (var j = 0; j < animatedWrapper[i].children.length; j++)
        {
          elements.push(animatedWrapper[i].children[j]);
        }
      } else if (!animatedWrapper[i].classList.contains("rs-columns"))
      {
        for (var j = 0; j < animatedWrapper[i].children.length; j++)
        {
          if (animatedWrapper[i].children[j].classList.contains("rs-columns"))
          {
            for (var k = 0; k < animatedWrapper[i].children[j].children.length; k++)
            {
              elements.push(animatedWrapper[i].children[j].children[k]);
              hasChildren = true;
            }
          }
        }
        if (!hasChildren)
        {
          elements.push(animatedWrapper[i]);
        }
      }
    }
    return elements;
  }

  var elements = getAnimatedElements();

  function callbackFunc() {
    var delay = 0;
    for (var i = 0; i < elements.length; i++)
    {
      if (elements[i].classList.contains('-in-view') === false && (hasDelay = isElementInViewport(elements[i])))
      {
        if (hasDelay === 1)
        {
          elements[i].style.transitionDelay = delay + 'ms';
          delay = delay + 125;
        }
        elements[i].classList.add("-in-view");
      }

      /* Else-Bedinung entfernen, um .visible nicht wieder zu löschen, wenn das Element den Viewport verlässt. */
      else if (Element.prototype.closest && elements[i].classList.contains('-in-view') === true && !isElementInViewport(elements[i]) && (elements[i].classList.contains('-reverse') || elements[i].closest('.is-animated').classList.contains('-reverse')))
      {
        elements[i].classList.remove("-in-view");
      }
    }
  }

  window.addEventListener("load", callbackFunc);
  window.addEventListener("scroll", callbackFunc);
})();