/** Returns all images contained in this album and all its albums. */
val Album.allImages: Collection<Image>
get() =
- images + albums.flatMap { it.allImages }
+ images + albums.flatMap(Album::allImages)
+
+/**
+ * Returns this album and all albums contained in this album (recursively).
+ * A child album is always listed after its parent.
+ */
+val Album.allAlbums: List<Album>
+ get() =
+ listOf(this) + albums.flatMap(Album::allAlbums)
+
+@get:JvmName("notEmpty")
+val notEmpty: (Album) -> Boolean = { album ->
+ album.allImages.let { images ->
+ images.isNotEmpty() && images.any(Image::isInserted)
+ }
+}