+ @Override
+ public List<Album> getAlbums(Album parent) {
+ lock.readLock().lock();
+ try {
+ return from(albumChildren.get(parent.getId())).transformAndConcat(getAlbum()).toList();
+ } finally {
+ lock.readLock().unlock();
+ }
+ }
+
+ @Override
+ public void moveUp(Album album) {
+ lock.writeLock().lock();
+ try {
+ List<String> albums = albumChildren.get(album.getParent().getId());
+ int currentIndex = albums.indexOf(album.getId());
+ if (currentIndex == 0) {
+ return;
+ }
+ albums.remove(album.getId());
+ albums.add(currentIndex - 1, album.getId());
+ } finally {
+ lock.writeLock().unlock();
+ }
+ }
+
+ @Override
+ public void moveDown(Album album) {
+ lock.writeLock().lock();
+ try {
+ List<String> albums = albumChildren.get(album.getParent().getId());
+ int currentIndex = albums.indexOf(album.getId());
+ if (currentIndex == (albums.size() - 1)) {
+ return;
+ }
+ albums.remove(album.getId());
+ albums.add(currentIndex + 1, album.getId());
+ } finally {
+ lock.writeLock().unlock();
+ }
+ }
+