xref: /external/apache-harmony/luni/src/test/api/common/org/apache/harmony/luni/tests/java/util/ObservableTest.java

/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

package org.apache.harmony.luni.tests.java.util;

import java.util.Observable;
import java.util.Observer;
import java.util.Vector;

public class ObservableTest extends junit.framework.TestCase {

	static class TestObserver implements Observer {
		public Vector objv = new Vector();

		int updateCount = 0;

		public void update(Observable observed, Object arg) {
			++updateCount;
			objv.add(arg);
		}

		public int updateCount() {
			return updateCount;
		}

	}

	static class DeleteTestObserver implements Observer {
		int updateCount = 0;

		boolean deleteAll = false;

		public DeleteTestObserver(boolean all) {
			deleteAll = all;
		}

		public void update(Observable observed, Object arg) {
			++updateCount;
			if (deleteAll)
				observed.deleteObservers();
			else
				observed.deleteObserver(this);
		}

		public int updateCount() {
			return updateCount;
		}

	}

	static class TestObservable extends Observable {
		public void doChange() {
			setChanged();
		}
	}

	Observer observer;

	TestObservable observable;

	/**
	 * @tests java.util.Observable#Observable()
	 */
	public void test_Constructor() {
		// Test for method java.util.Observable()
                Observable ov = new Observable();
                assertTrue("Wrong initial values.", !ov.hasChanged());
                assertEquals("Wrong initial values.", 0, ov.countObservers());
	}

	/**
	 * @tests java.util.Observable#addObserver(java.util.Observer)
	 */
	public void test_addObserverLjava_util_Observer() {
		// Test for method void
		// java.util.Observable.addObserver(java.util.Observer)
		TestObserver test = new TestObserver();
		observable.addObserver(test);
		assertEquals("Failed to add observer", 1, observable.countObservers());
		observable.addObserver(test);
		assertEquals("Duplicate observer", 1, observable.countObservers());

		Observable o = new Observable();
		try {
			o.addObserver(null);
			fail("Expected adding a null observer to throw a NPE.");
		} catch (NullPointerException ex) {
			// expected;
		}
	}

	/**
	 * @tests java.util.Observable#countObservers()
	 */
	public void test_countObservers() {
		// Test for method int java.util.Observable.countObservers()
		assertEquals("New observable had > 0 observers", 0, observable
				.countObservers());
		observable.addObserver(new TestObserver());
		assertEquals("Observable with observer returned other than 1", 1, observable
				.countObservers());
	}

	/**
	 * @tests java.util.Observable#deleteObserver(java.util.Observer)
	 */
	public void test_deleteObserverLjava_util_Observer() {
		// Test for method void
		// java.util.Observable.deleteObserver(java.util.Observer)
		observable.addObserver(observer = new TestObserver());
		observable.deleteObserver(observer);
		assertEquals("Failed to delete observer",
				0, observable.countObservers());

	}

	/**
	 * @tests java.util.Observable#deleteObservers()
	 */
	public void test_deleteObservers() {
		// Test for method void java.util.Observable.deleteObservers()
		observable.addObserver(new TestObserver());
		observable.addObserver(new TestObserver());
		observable.addObserver(new TestObserver());
		observable.addObserver(new TestObserver());
		observable.addObserver(new TestObserver());
		observable.addObserver(new TestObserver());
		observable.addObserver(new TestObserver());
		observable.addObserver(new TestObserver());
		observable.deleteObservers();
		assertEquals("Failed to delete observers",
				0, observable.countObservers());
	}

	/**
	 * @tests java.util.Observable#hasChanged()
	 */
	public void test_hasChanged() {
		// TODO : Implement test
	}

	/**
	 * @tests java.util.Observable#notifyObservers()
	 */
	public void test_notifyObservers() {
		// Test for method void java.util.Observable.notifyObservers()
		observable.addObserver(observer = new TestObserver());
		observable.notifyObservers();
		assertEquals("Notified when unchnaged", 0, ((TestObserver) observer)
				.updateCount());
		((TestObservable) observable).doChange();
		observable.notifyObservers();
		assertEquals("Failed to notify",
				1, ((TestObserver) observer).updateCount());

		DeleteTestObserver observer1, observer2;
		observable.deleteObservers();
		observable.addObserver(observer1 = new DeleteTestObserver(false));
		observable.addObserver(observer2 = new DeleteTestObserver(false));
		observable.doChange();
		observable.notifyObservers();
		assertTrue("Failed to notify all", observer1.updateCount() == 1
				&& observer2.updateCount() == 1);
		assertEquals("Failed to delete all", 0, observable.countObservers());

		observable.addObserver(observer1 = new DeleteTestObserver(false));
		observable.addObserver(observer2 = new DeleteTestObserver(false));
		observable.doChange();
		observable.notifyObservers();
		assertTrue("Failed to notify all 2", observer1.updateCount() == 1
				&& observer2.updateCount() == 1);
		assertEquals("Failed to delete all 2", 0, observable.countObservers());
	}

	/**
	 * @tests java.util.Observable#notifyObservers(java.lang.Object)
	 */
	public void test_notifyObserversLjava_lang_Object() {
		// Test for method void
		// java.util.Observable.notifyObservers(java.lang.Object)
		Object obj;
		observable.addObserver(observer = new TestObserver());
		observable.notifyObservers();
		assertEquals("Notified when unchanged", 0, ((TestObserver) observer)
				.updateCount());
		((TestObservable) observable).doChange();
		observable.notifyObservers(obj = new Object());
		assertEquals("Failed to notify",
				1, ((TestObserver) observer).updateCount());
		assertTrue("Failed to pass Object arg", ((TestObserver) observer).objv
				.elementAt(0).equals(obj));
	}

	/**
	 * Sets up the fixture, for example, open a network connection. This method
	 * is called before a test is executed.
	 */
	protected void setUp() {
		observable = new TestObservable();
	}

	/**
	 * Tears down the fixture, for example, close a network connection. This
	 * method is called after a test is executed.
	 */
	protected void tearDown() {
	}
}