--- /dev/null
+/**
+ * Sone - Album.kt - Copyright © 2019–2020 David ‘Bombe’ Roden
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package net.pterodactylus.sone.data
+
+/** Returns all images contained in this album and all its albums. */
+val Album.allImages: Collection<Image>
+ get() =
+ 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)
+ }
+}