+ return new ArrayList<Image>(Collections2.filter(Collections2.transform(imageIds, new Function<String, Image>() {
+
+ @Override
+ @SuppressWarnings("synthetic-access")
+ public Image apply(String imageId) {
+ return images.get(imageId);
+ }
+ }), Predicates.notNull()));
+ }
+
+ /**
+ * Adds the given image to this album.
+ *
+ * @param image
+ * The image to add
+ */
+ public void addImage(Image image) {
+ checkNotNull(image, "image must not be null");
+ checkNotNull(image.getSone(), "image must have an owner");
+ checkArgument(image.getSone().equals(sone), "image must belong to the same Sone as this album");
+ if (image.getAlbum() != null) {
+ image.getAlbum().removeImage(image);
+ }
+ image.setAlbum(this);
+ if (imageIds.isEmpty() && (albumImage == null)) {
+ albumImage = image.getId();
+ }
+ if (!imageIds.contains(image.getId())) {
+ imageIds.add(image.getId());
+ images.put(image.getId(), image);
+ }
+ }
+
+ /**
+ * Removes the given image from this album.
+ *
+ * @param image
+ * The image to remove
+ */
+ public void removeImage(Image image) {
+ checkNotNull(image, "image must not be null");
+ checkNotNull(image.getSone(), "image must have an owner");
+ checkArgument(image.getSone().equals(sone), "image must belong to the same Sone as this album");
+ imageIds.remove(image.getId());
+ images.remove(image.getId());
+ if (image.getId().equals(albumImage)) {
+ if (images.isEmpty()) {
+ albumImage = null;
+ } else {
+ albumImage = images.values().iterator().next().getId();
+ }
+ }
+ }
+
+ /**
+ * Moves the given image up in this album’s images. If the image is already
+ * the first image, nothing happens.
+ *
+ * @param image
+ * The image to move up
+ * @return The image that the given image swapped the place with, or
+ * <code>null</code> if the image did not change its place
+ */
+ public Image moveImageUp(Image image) {
+ checkNotNull(image, "image must not be null");
+ checkNotNull(image.getSone(), "image must have an owner");
+ checkArgument(image.getSone().equals(sone), "image must belong to the same Sone as this album");
+ checkArgument(image.getAlbum().equals(this), "image must belong to this album");
+ int oldIndex = imageIds.indexOf(image.getId());
+ if (oldIndex <= 0) {
+ return null;
+ }
+ imageIds.remove(image.getId());
+ imageIds.add(oldIndex - 1, image.getId());
+ return images.get(imageIds.get(oldIndex));
+ }
+
+ /**
+ * Moves the given image down in this album’s images. If the image is
+ * already the last image, nothing happens.
+ *
+ * @param image
+ * The image to move down
+ * @return The image that the given image swapped the place with, or
+ * <code>null</code> if the image did not change its place
+ */
+ public Image moveImageDown(Image image) {
+ checkNotNull(image, "image must not be null");
+ checkNotNull(image.getSone(), "image must have an owner");
+ checkArgument(image.getSone().equals(sone), "image must belong to the same Sone as this album");
+ checkArgument(image.getAlbum().equals(this), "image must belong to this album");
+ int oldIndex = imageIds.indexOf(image.getId());
+ if ((oldIndex == -1) || (oldIndex >= (imageIds.size() - 1))) {
+ return null;
+ }
+ imageIds.remove(image.getId());
+ imageIds.add(oldIndex + 1, image.getId());
+ return images.get(imageIds.get(oldIndex));
+ }
+
+ /**
+ * Returns the album image of this album, or {@code null} if no album image
+ * has been set.
+ *
+ * @return The image to show when this album is listed
+ */
+ public Image getAlbumImage() {
+ if (albumImage == null) {
+ return null;
+ }
+ return Optional.fromNullable(images.get(albumImage)).or(images.values().iterator().next());
+ }
+
+ /**
+ * Sets the ID of the album image.
+ *
+ * @param id
+ * The ID of the album image
+ * @return This album
+ */
+ public Album setAlbumImage(String id) {
+ this.albumImage = id;
+ return this;
+ }
+
+ /**
+ * Returns whether this album contains any other albums or images.
+ *
+ * @return {@code true} if this album is empty, {@code false} otherwise
+ */
+ public boolean isEmpty() {
+ return albums.isEmpty() && images.isEmpty();
+ }
+
+ /**
+ * Returns the parent album of this album.
+ *
+ * @return The parent album of this album, or {@code null} if this album
+ * does not have a parent
+ */
+ public Album getParent() {
+ return parent;