| /******************************************************************************* |
| * Copyright (C) 2007 The University of Manchester |
| * |
| * Modifications to the initial code base are copyright of their |
| * respective authors, or their employers as appropriate. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public License |
| * as published by the Free Software Foundation; either version 2.1 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 |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 |
| ******************************************************************************/ |
| package net.sf.taverna.t2.lang.observer; |
| |
| import static org.junit.Assert.*; |
| |
| import java.util.List; |
| |
| import net.sf.taverna.t2.lang.observer.MultiCaster; |
| import net.sf.taverna.t2.lang.observer.Observable; |
| import net.sf.taverna.t2.lang.observer.Observer; |
| |
| import org.junit.Test; |
| |
| public class ObserverTest { |
| |
| @Test |
| public void registerObserver() throws Exception { |
| MyObservable observable = new MyObservable(); |
| MyObserver observer1 = new MyObserver(); |
| MyObserver observer2 = new MyObserver(); |
| |
| observable.triggerEvent(); // don't notify, but increase count |
| assertNull(observer1.lastMessage); |
| observable.addObserver(observer1); |
| assertNull(observer1.lastMessage); |
| assertNull(observer2.lastMessage); |
| assertNull(observer1.lastSender); |
| assertNull(observer2.lastSender); |
| observable.triggerEvent(); |
| assertEquals("This is message 1", observer1.lastMessage); |
| assertSame(observable, observer1.lastSender); |
| assertNull(observer2.lastSender); |
| |
| observable.addObserver(observer2); |
| assertNull(observer2.lastMessage); |
| observable.triggerEvent(); |
| assertEquals("This is message 2", observer1.lastMessage); |
| assertEquals("This is message 2", observer2.lastMessage); |
| assertSame(observable, observer1.lastSender); |
| assertSame(observable, observer2.lastSender); |
| |
| MyObservable otherObservable = new MyObservable(); |
| otherObservable.addObserver(observer2); |
| otherObservable.triggerEvent(); |
| // New instance, should start from 0 |
| assertEquals("This is message 0", observer2.lastMessage); |
| assertSame(otherObservable, observer2.lastSender); |
| |
| // observer1 unchanged |
| assertEquals("This is message 2", observer1.lastMessage); |
| assertSame(observable, observer1.lastSender); |
| |
| } |
| |
| @Test |
| public void concurrencyTest() { |
| MyObservable observable = new MyObservable(); |
| MyObserver dummyObserver = new MyObserver(); |
| SelvRemovingObserver selfRemoving = new SelvRemovingObserver(); |
| observable.addObserver(dummyObserver); |
| observable.addObserver(selfRemoving); |
| assertEquals(2, observable.getObservers().size()); |
| observable.triggerEvent(); |
| |
| |
| } |
| |
| public class MyObservable implements Observable<String> { |
| |
| private int counter = 0; |
| MultiCaster<String> multiCaster = new MultiCaster<String>(this); |
| |
| public void addObserver(Observer<String> observer) { |
| multiCaster.addObserver(observer); |
| } |
| |
| public void removeObserver(Observer<String> observer) { |
| multiCaster.removeObserver(observer); |
| } |
| |
| public void triggerEvent() { |
| multiCaster.notify("This is message " + counter++); |
| } |
| |
| public List<Observer<String>> getObservers() { |
| return multiCaster.getObservers(); |
| } |
| } |
| |
| public class MyObserver implements Observer<String> { |
| String lastMessage = null; |
| Observable<String> lastSender = null; |
| |
| public void notify(Observable<String> sender, String message) { |
| lastSender = sender; |
| lastMessage = message; |
| } |
| } |
| |
| public class SelvRemovingObserver implements Observer<String> { |
| |
| public int called=0; |
| |
| public void notify(Observable<String> sender, String message) { |
| called++; |
| if (called > 1) { |
| fail("Did not remove itself"); |
| } |
| sender.removeObserver(this); |
| } |
| |
| } |
| |
| } |