Function getChild

Sortable.js:355–369

* Gets nth child of el, ignoring hidden children, sortable's elements (does not ignore clone if it's visible) * and non-draggable elements * @param {HTMLElement} el The parent element * @param {Number} childNum The index of the child * @param {Object} options Parent S

(el, childNum, options, includeDragEl)

   * @return {HTMLElement}          The child at index childNum, or null if not found
   */
  function getChild(el, childNum, options, includeDragEl) {
    var currentChild = 0,
      i = 0,
      children = el.children;
    while (i < children.length) {
      if (children[i].style.display !== 'none' && children[i] !== Sortable.ghost && (includeDragEl || children[i] !== Sortable.dragged) && closest(children[i], options.draggable, el, false)) {
        if (currentChild === childNum) {
          return children[i];
        }
        currentChild++;
      }
      i++;
    }
    return null;
  }

  /**
   * Gets the last child in the el, ignoring ghostEl or invisible elements (clones)