X-Git-Url: https://git.pterodactylus.net/?a=blobdiff_plain;f=src%2Fnet%2Fpterodactylus%2Futil%2Fbeans%2FAbstractBean.java;h=b2da7324962fc4837db538da71205d703fdc0a44;hb=d6015942121ba0e43177da20c3559126e9c6dafe;hp=0438c6dbc3d6d98b5ac4bc58d34bff04adfacfd9;hpb=ce32d41fc7a9b72674d2bb42d0064293b38f06db;p=jSite2.git

diff --git a/src/net/pterodactylus/util/beans/AbstractBean.java b/src/net/pterodactylus/util/beans/AbstractBean.java
index 0438c6d..b2da732 100644
--- a/src/net/pterodactylus/util/beans/AbstractBean.java
+++ b/src/net/pterodactylus/util/beans/AbstractBean.java
@@ -29,9 +29,8 @@ import java.util.List;
  * Abstract bean super class that contains property change listener management.
  * 
  * @author David ‘Bombe’ Roden <bombe@freenetproject.org>
- * @version $Id$
  */
-public class AbstractBean {
+public abstract class AbstractBean {
 
 	/** Property change listeners. */
 	private final List<PropertyChangeListener> propertyChangeListeners = Collections.synchronizedList(new ArrayList<PropertyChangeListener>());
@@ -74,4 +73,40 @@ public class AbstractBean {
 
 	}
 
+	/**
+	 * Fires a property change event if the two values are not equal.
+	 * 
+	 * @param propertyName
+	 *            The name of the property
+	 * @param oldValue
+	 *            The old value of the property
+	 * @param newValue
+	 *            The new value of the property
+	 */
+	protected void fireIfPropertyChanged(String propertyName, Object oldValue, Object newValue) {
+		if (!equal(oldValue, newValue)) {
+			firePropertyChange(propertyName, oldValue, newValue);
+		}
+	}
+
+	//
+	// PRIVATE METHODS
+	//
+
+	/**
+	 * Compares the two objects and returns whether they are equal according to
+	 * {@link Object#equals(Object)}. This method takes <code>null</code>
+	 * into account as a valid value for an object.
+	 * 
+	 * @param first
+	 *            The first object
+	 * @param second
+	 *            The second object
+	 * @return <code>true</code> if the two objects are equal,
+	 *         <code>false</code> otherwise
+	 */
+	private boolean equal(Object first, Object second) {
+		return ((first == null) && (second == null)) || ((first != null) && first.equals(second)) || ((second != null) && second.equals(first));
+	}
+
 }