Esempio n. 1
1
  /**
   * Given a master list and the new sub list, replace the items in the master list with the
   * matching items from the new sub list. This process works even if the length of the new sublist
   * is different.
   *
   * <p>For example, givn:
   *
   * <pre>
   * replace A by A':
   *   M=[A,B,C], S=[A'] => [A',B,C]
   *   M=[A,B,A,B,C], S=[A',A'] => [A',B,A',B,C]
   *
   * when list length is different:
   *   M=[A,A,B,C], S=[] => [B,C]
   *   M=[A,B,C], S=[A',A'] => [A',A',B,C]
   *   M=[B,C], S=[A',A'] => [B,C,A',A']
   * </pre>
   */
  private static List<Child> stitchList(
      List<Child> list, String name, List<? extends Child> newSubList) {
    List<Child> removed = new LinkedList<Child>();
    // to preserve order, try to put new itesm where old items are found.
    // if the new list is longer than the current list, we put all the extra
    // after the last item in the sequence. That is,
    // given [A,A,B,C] and [A',A',A'], we'll update the list to [A',A',A',B,C]
    // The 'last' variable remembers the insertion position.
    int last = list.size();

    ListIterator<Child> itr = list.listIterator();
    ListIterator<? extends Child> jtr = newSubList.listIterator();
    while (itr.hasNext()) {
      Child child = itr.next();
      if (child.name.equals(name)) {
        if (jtr.hasNext()) {
          itr.set(jtr.next()); // replace
          last = itr.nextIndex();
          removed.add(child);
        } else {
          itr.remove(); // remove
          removed.add(child);
        }
      }
    }

    // new list is longer than the current one
    if (jtr.hasNext()) list.addAll(last, newSubList.subList(jtr.nextIndex(), newSubList.size()));

    return removed;
  }