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+/* PropertyChangeListenerProxy.java -- adds a name to a property listener
+ Copyright (C) 2002 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath 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
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING. If not, write to the
+Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library. Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module. An independent module is a module which is not derived from
+or based on this library. If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so. If you do not wish to do so, delete this
+exception statement from your version. */
+
+
+package java.beans;
+
+import java.util.EventListenerProxy;
+
+/**
+ * This class provides an extension to <code>PropertyChangeListener</code> -
+ * associating a name with the listener. This can be used to filter the
+ * changes that one is interested in.
+ *
+ * @author Eric Blake <ebb9@email.byu.edu>
+ * @since 1.4
+ * @status udpated to 1.4
+ */
+public class PropertyChangeListenerProxy extends EventListenerProxy
+ implements PropertyChangeListener
+{
+ /**
+ * The name of the property to listen for. Package visible for use by
+ * PropertyChangeSupport.
+ */
+ final String propertyName;
+
+ /**
+ * Create a new proxy which filters property change events and only passes
+ * changes to the named property on to the delegate. A null propertyName
+ * or listener does not fail now, but may cause a NullPointerException down
+ * the road.
+ *
+ * @param propertyName the property's name to filter on
+ * @param listener the delegate listener
+ */
+ public PropertyChangeListenerProxy(String propertyName,
+ PropertyChangeListener listener)
+ {
+ super(listener);
+ this.propertyName = propertyName;
+ }
+
+ /**
+ * Forwards the event on to the delegate if the property name matches.
+ *
+ * @param event the event to pass on, if it meets the filter
+ * @throws NullPointerException if the delegate this was created with is null
+ */
+ public void propertyChange(PropertyChangeEvent event)
+ {
+ // Note: Sun does not filter, under the assumption that since
+ // PropertyChangeSupport unwraps proxys, this method should never be
+ // called by normal use of listeners.
+ String name = event == null ? null : event.getPropertyName();
+ if (name == null ? propertyName == null : name.equals(propertyName))
+ ((PropertyChangeListener) getListener()).propertyChange(event);
+ }
+
+ /**
+ * Gets the name of the property this proxy is filtering on.
+ *
+ * @return the property name
+ */
+ public String getPropertyName()
+ {
+ return propertyName;
+ }
+} // class PropertyChangeListenerProxy