- /** Function that flattens the given album and all albums beneath it. */
- Function<Album, List<Album>> FLATTENER = new Function<Album, List<Album>>() {
-
- @Override
- @Nonnull
- public List<Album> apply(Album album) {
- if (album == null) {
- return emptyList();
- }
- List<Album> albums = new ArrayList<>();
- albums.add(album);
- for (Album subAlbum : album.getAlbums()) {
- albums.addAll(FluentIterable.from(ImmutableList.of(subAlbum)).transformAndConcat(FLATTENER).toList());
- }
- return albums;
- }
- };
-
- /** Function that transforms an album into the images it contains. */
- Function<Album, List<Image>> IMAGES = new Function<Album, List<Image>>() {
-
- @Override
- @Nonnull
- public List<Image> apply(Album album) {
- return (album != null) ? album.getImages() : Collections.<Image>emptyList();
- }
- };
-
- /**
- * Filter that removes all albums that do not have any images in any album
- * below it.
- */
- Predicate<Album> NOT_EMPTY = new Predicate<Album>() {
-
- @Override
- public boolean apply(Album album) {
- /* so, we flatten all albums below the given one and check whether at least one album… */
- return FluentIterable.from(asList(album)).transformAndConcat(FLATTENER).anyMatch(new Predicate<Album>() {
-
- @Override
- public boolean apply(Album album) {
- /* …contains any inserted images. */
- return !album.getImages().isEmpty() && FluentIterable.from(album.getImages()).allMatch(new Predicate<Image>() {
-
- @Override
- public boolean apply(Image input) {
- return input.isInserted();
- }
- });
- }
- });
- }
- };
-