gistfile1.txt

export function showInViewPort($el, tolarance, cb) {
  if (!$el || !$el[0]) { return cb && cb(); }
  tolarance = tolarance || 0;
  var $body = $(document.body);
  var topScrollAmount = $body.scrollTop();
  var viewPortHeight = $(window).height();
  var elY = $el.offset().top;
  var elBottomY = elY + $el.height();

  var topBounds = topScrollAmount + tolarance;
  var bottomBounds = topScrollAmount + viewPortHeight - tolarance;

  if (topBounds > elY) {
    $body.animate({ scrollTop: topScrollAmount - (topBounds - elY) }, 300, cb);
  } else if (bottomBounds < elBottomY) {
    $body.animate({ scrollTop: topScrollAmount + (elBottomY - bottomBounds) }, 300, cb);
  } else if (cb) {
    cb();
  }
}