Implement enable/disable in Observable

src/main/java/org/eclipse/basyx/submodel/observer/Observable.java

@@ -28,13 +28,14 @@
 
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.function.Consumer;
 
 /**
  * Generic implementation of an Observable. This class contains all common
  * operations an Observable is supposed to do. Java generics is used to specify
  * which type of Observable is required
  * 
- * @author haque
+ * @author haque, mateusmolina
  *
  * @param <T>
  *            can be Observers which extends IObserver
@@ -43,6 +44,8 @@ public class Observable<T extends IObserver> {
 
 	public Collection<T> observers = new ArrayList<T>();
 
+	private boolean notificationsEnabled = true;
+
 	/**
 	 * Adds an observer to the subscriber list
 	 * 
@@ -63,4 +66,35 @@ public void addObserver(T observer) {
 	public boolean removeObserver(T observer) {
 		return observers.remove(observer);
 	}
+
+	/**
+	 * Disables notification to all observers. After calling this method, observers
+	 * will not be notified of changes until {@link #enableNotifications()} is
+	 * called.
+	 */
+	public void disableNotifications() {
+		notificationsEnabled = false;
+	}
+
+	/**
+	 * Enables notification to all observers. After calling this method, observers
+	 * will again be notified of changes if they were previously disabled using
+	 * {@link #disableNotifications()}.
+	 */
+	public void enableNotifications() {
+		notificationsEnabled = true;
+	}
+
+	/**
+	 * Notifies all observers using the specified notification action if
+	 * notifications are enabled. If notifications are disabled, this method does
+	 * nothing.
+	 *
+	 * @param notificationAction
+	 *            The action to perform for each observer.
+	 */
+	protected void notifyAll(Consumer<T> notificationAction) {
+		if (notificationsEnabled)
+			observers.forEach(notificationAction);
+	}
 }

src/test/java/org/eclipse/basyx/testsuite/regression/submodel/observer/ObservableTest.java

@@ -0,0 +1,110 @@
+/*******************************************************************************
+* Copyright (C) 2023 the Eclipse BaSyx Authors
+* 
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+* 
+* SPDX-License-Identifier: MIT
+******************************************************************************/
+
+package org.eclipse.basyx.testsuite.regression.submodel.observer;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+
+import org.eclipse.basyx.submodel.observer.IObserver;
+import org.eclipse.basyx.submodel.observer.Observable;
+import org.junit.Before;
+import org.junit.Test;
+
+/**
+ * Test for Observable<?>
+ * 
+ * @author mateusmolina
+ */
+public class ObservableTest {
+
+	private MockObserver observer;
+	private MockObservable observable;
+
+	@Before
+	public void setUp() {
+		observable = new MockObservable();
+		observer = mock(MockObserver.class);
+		observable.addObserver(observer);
+	}
+
+	@Test
+	public void testAddObserver() {
+		assertEquals(1, observable.observers.size());
+	}
+
+	@Test
+	public void testRemoveObserver() {
+		observable.removeObserver(observer);
+
+		assertTrue(observable.observers.isEmpty());
+	}
+
+	@Test
+	public void testDefaultEnabled() {
+		observable.sendMockEvent();
+
+		verify(observer, times(1)).receiveEvent();
+	}
+
+	@Test
+	public void testDisableNotifications() {
+		observable.disableNotifications();
+
+		observable.sendMockEvent();
+
+		verify(observer, never()).receiveEvent();
+	}
+
+	@Test
+	public void testEnableNotifications() {
+		observable.disableNotifications();
+
+		observable.enableNotifications();
+
+		observable.sendMockEvent();
+
+		verify(observer, times(1)).receiveEvent();
+	}
+
+	private interface MockObserver extends IObserver {
+		public void receiveEvent();
+	}
+
+	private class MockObservable extends Observable<MockObserver> {
+		public MockObservable() {
+			super();
+		}
+
+		public void sendMockEvent() {
+			notifyAll(o -> o.receiveEvent());
+		}
+	}
+}