Java tutorial
/* * Sone - Album.java - Copyright 20112013 David 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; import static com.google.common.base.Optional.absent; import static com.google.common.base.Optional.fromNullable; import static com.google.common.base.Preconditions.checkArgument; import static com.google.common.base.Preconditions.checkNotNull; import static com.google.common.base.Preconditions.checkState; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.UUID; import com.google.common.base.Function; import com.google.common.base.Optional; import com.google.common.base.Predicates; import com.google.common.collect.Collections2; import com.google.common.hash.Hasher; import com.google.common.hash.Hashing; /** * Container for images that can also contain nested {@link AlbumImpl}s. * * @author <a href="mailto:bombe@pterodactylus.net">David Bombe Roden</a> */ public class AlbumImpl implements Album { /** The ID of this album. */ private final String id; /** The Sone this album belongs to. */ private Sone sone; /** Nested albums. */ private final List<Album> albums = new ArrayList<Album>(); /** The image IDs in order. */ private final List<String> imageIds = new ArrayList<String>(); /** The images in this album. */ private final Map<String, Image> images = new HashMap<String, Image>(); /** The parent album. */ private Album parent; /** The title of this album. */ private String title; /** The description of this album. */ private String description; /** The ID of the album picture. */ private String albumImage; /** Creates a new album with a random ID. */ public AlbumImpl() { this(UUID.randomUUID().toString()); } /** * Creates a new album with the given ID. * * @param id * The ID of the album */ public AlbumImpl(String id) { this.id = checkNotNull(id, "id must not be null"); } // // ACCESSORS // @Override public String getId() { return id; } @Override public Sone getSone() { return sone; } @Override public Album setSone(Sone sone) { checkNotNull(sone, "sone must not be null"); checkState((this.sone == null) || (this.sone.equals(sone)), "album owner must not already be set to some other Sone"); this.sone = sone; return this; } @Override public List<Album> getAlbums() { return new ArrayList<Album>(albums); } @Override public void addAlbum(Album album) { checkNotNull(album, "album must not be null"); checkArgument(album.getSone().equals(sone), "album must belong to the same Sone as this album"); album.setParent(this); if (!albums.contains(album)) { albums.add(album); } } @Override public void removeAlbum(Album album) { checkNotNull(album, "album must not be null"); checkArgument(album.getSone().equals(sone), "album must belong this albums Sone"); checkArgument(equals(album.getParent()), "album must belong to this album"); albums.remove(album); album.removeParent(); } @Override public Album moveAlbumUp(Album album) { checkNotNull(album, "album must not be null"); checkArgument(album.getSone().equals(sone), "album must belong to the same Sone as this album"); checkArgument(equals(album.getParent()), "album must belong to this album"); int oldIndex = albums.indexOf(album); if (oldIndex <= 0) { return null; } albums.remove(oldIndex); albums.add(oldIndex - 1, album); return albums.get(oldIndex); } @Override public Album moveAlbumDown(Album album) { checkNotNull(album, "album must not be null"); checkArgument(album.getSone().equals(sone), "album must belong to the same Sone as this album"); checkArgument(equals(album.getParent()), "album must belong to this album"); int oldIndex = albums.indexOf(album); if ((oldIndex < 0) || (oldIndex >= (albums.size() - 1))) { return null; } albums.remove(oldIndex); albums.add(oldIndex + 1, album); return albums.get(oldIndex); } @Override public List<Image> getImages() { 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())); } @Override 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); } } @Override 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(); } } } @Override 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)); } @Override 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)); } @Override public Image getAlbumImage() { if (albumImage == null) { return null; } return Optional.fromNullable(images.get(albumImage)).or(images.values().iterator().next()); } @Override public boolean isEmpty() { return albums.isEmpty() && images.isEmpty(); } @Override public boolean isRoot() { return parent == null; } @Override public Album getParent() { return parent; } @Override public Album setParent(Album parent) { this.parent = checkNotNull(parent, "parent must not be null"); return this; } @Override public Album removeParent() { this.parent = null; return this; } @Override public String getTitle() { return title; } @Override public String getDescription() { return description; } @Override public Modifier modify() throws IllegalStateException { // TODO: reenable check for local Sones return new Modifier() { private Optional<String> title = absent(); private Optional<String> description = absent(); private Optional<String> albumImage = absent(); @Override public Modifier setTitle(String title) { this.title = fromNullable(title); return this; } @Override public Modifier setDescription(String description) { this.description = fromNullable(description); return this; } @Override public Modifier setAlbumImage(String imageId) { this.albumImage = fromNullable(imageId); return this; } @Override public Album update() throws IllegalStateException { if (title.isPresent()) { AlbumImpl.this.title = title.get(); } if (description.isPresent()) { AlbumImpl.this.description = description.get(); } if (albumImage.isPresent()) { AlbumImpl.this.albumImage = albumImage.get(); } return AlbumImpl.this; } }; } // // FINGERPRINTABLE METHODS // @Override public String getFingerprint() { Hasher hash = Hashing.sha256().newHasher(); hash.putString("Album("); hash.putString("ID(").putString(id).putString(")"); hash.putString("Title(").putString(title).putString(")"); hash.putString("Description(").putString(description).putString(")"); if (albumImage != null) { hash.putString("AlbumImage(").putString(albumImage).putString(")"); } /* add nested albums. */ hash.putString("Albums("); for (Album album : albums) { hash.putString(album.getFingerprint()); } hash.putString(")"); /* add images. */ hash.putString("Images("); for (Image image : getImages()) { if (image.isInserted()) { hash.putString(image.getFingerprint()); } } hash.putString(")"); hash.putString(")"); return hash.hash().toString(); } // // OBJECT METHODS // @Override public int hashCode() { return id.hashCode(); } @Override public boolean equals(Object object) { if (!(object instanceof AlbumImpl)) { return false; } AlbumImpl album = (AlbumImpl) object; return id.equals(album.id); } }