From ccdb2ab4b84f960ec67561227692f6e694a7f260 Mon Sep 17 00:00:00 2001
From: =?utf8?q?David=20=E2=80=98Bombe=E2=80=99=20Roden?=
 <bombe@pterodactylus.net>
Date: Thu, 19 Apr 2012 16:01:02 +0200
Subject: [PATCH] Add artist implementation that lazily loads referenced
 objects.

---
 .../demoscenemusic/data/DataManager.java           | 24 ++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/src/main/java/net/pterodactylus/demoscenemusic/data/DataManager.java b/src/main/java/net/pterodactylus/demoscenemusic/data/DataManager.java
index e6d58bf..5183226 100644
--- a/src/main/java/net/pterodactylus/demoscenemusic/data/DataManager.java
+++ b/src/main/java/net/pterodactylus/demoscenemusic/data/DataManager.java
@@ -23,7 +23,9 @@ import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashSet;
 import java.util.List;
+import java.util.concurrent.Callable;
 
+import net.pterodactylus.util.collection.Memoizer;
 import net.pterodactylus.util.database.Database;
 import net.pterodactylus.util.database.DatabaseException;
 import net.pterodactylus.util.database.Field;
@@ -181,4 +183,26 @@ public class DataManager {
 
 	}
 
+	private class LazyArtist extends DefaultArtist {
+
+		private final Memoizer<Void> tracks = new Memoizer<Void>(new Callable<Void>() {
+			public Void call() throws DatabaseException {
+				if (!hasValue("tracks")) {
+					value("tracks", Collection.class).set(getTracksByArtist(id()));
+				}
+				return null;
+			}
+		});
+
+		public LazyArtist(String id) {
+			super(id);
+		}
+
+		public Collection<Track> tracks() {
+			tracks.get();
+			return value("tracks", Collection.class).get();
+		}
+
+	}
+
 }
-- 
2.7.4