1 /*******************************************************************************
2 * Copyright (c) 2007, 2010 Association for Decentralized Information Management
4 * All rights reserved. This program and the accompanying materials
5 * are made available under the terms of the Eclipse Public License v1.0
6 * which accompanies this distribution, and is available at
7 * http://www.eclipse.org/legal/epl-v10.html
10 * VTT Technical Research Centre of Finland - initial API and implementation
11 *******************************************************************************/
12 package org.simantics.db.common.procedure.single;
14 import java.util.Collection;
15 import java.util.HashSet;
17 import org.simantics.db.Disposable;
18 import org.simantics.db.procedure.Listener;
19 import org.simantics.db.procedure.SetListener;
21 abstract public class SingleSetListener<T> implements Listener<Collection<T>>, SetListener<T>, Disposable {
23 private boolean disposed = false;
25 private Collection<T> previous = null;
27 public void add(T result) {};
28 public void remove(T result) {};
31 public void execute(Collection<T> result) {
33 if(result == null) result = new HashSet<T>();
35 if(previous == null) {
37 for(T t : result) add(t);
41 HashSet<T> added = new HashSet<T>(result);
42 added.removeAll(previous);
43 HashSet<T> removed = new HashSet<T>(previous);
44 removed.removeAll(result);
46 for(T t : added) add(t);
47 for(T t : removed) remove(t);
55 public void dispose() {
60 public boolean isDisposed() {