| /* PropertyChangeEvent.java -- describes a change in a property |
| Copyright (C) 1998, 2000, 2002, 2005 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., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 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.EventObject; |
| |
| /** |
| * PropertyChangeEvents are fired in the PropertyChange and VetoableChange |
| * event classes. They represent the old and new values as well as the |
| * source Bean. If the old or new value is a primitive type, it must be |
| * wrapped in the appropriate wrapper type (java.lang.Integer for int, etc., |
| * etc.). |
| * |
| * <p>If the old or new values are unknown (although why that would be I do |
| * not know), they may be null. Also, if the set of properties itself has |
| * changed, the name should be null, and the old and new values may also be |
| * null. Right now Sun put in a propagationId, reserved for future use. Read |
| * the comments on the constructor and on setPropagationId for more |
| * information. |
| * |
| * @author John Keiser |
| * @author Eric Blake (ebb9@email.byu.edu) |
| * @since 1.1 |
| * @status udpated to 1.4 |
| */ |
| public class PropertyChangeEvent extends EventObject |
| { |
| /** |
| * Compatible with JDK 1.1+. |
| */ |
| private static final long serialVersionUID = 7042693688939648123L; |
| |
| /** |
| * The name of the property that changed, may be null. Package visible for |
| * use by PropertyChangeSupport. |
| * |
| * @serial the changed property name |
| */ |
| final String propertyName; |
| |
| /** |
| * The new value of the property, may be null. Package visible for use by |
| * PropertyChangeSupport. |
| * |
| * @serial the new property value |
| */ |
| final Object newValue; |
| |
| /** |
| * The old value of the property, may be null. Package visible for use by |
| * PropertyChangeSupport. |
| * |
| * @serial the old property value |
| */ |
| final Object oldValue; |
| |
| /** |
| * The propagation ID, reserved for future use. May be null. |
| * |
| * @see #getPropagationId() |
| * @serial the Propagation ID |
| */ |
| private Object propagationId; |
| |
| /** |
| * Create a new PropertyChangeEvent. Remember that if you received a |
| * PropertyChangeEvent and are sending a new one, you should also set the |
| * propagation ID from the old PropertyChangeEvent. |
| * |
| * @param source the Bean containing the property |
| * @param propertyName the property's name |
| * @param oldVal the old value of the property |
| * @param newVal the new value of the property |
| * @throws IllegalArgumentException if source is null |
| */ |
| public PropertyChangeEvent(Object source, String propertyName, |
| Object oldVal, Object newVal) |
| { |
| super(source); |
| this.propertyName = propertyName; |
| oldValue = oldVal; |
| newValue = newVal; |
| } |
| |
| /** |
| * Get the property name. May be null if multiple properties changed. |
| * |
| * @return the property name |
| */ |
| public String getPropertyName() |
| { |
| return propertyName; |
| } |
| |
| /** |
| * Get the property's new value. May be null if multiple properties changed. |
| * |
| * @return the property's new value |
| */ |
| public Object getNewValue() |
| { |
| return newValue; |
| } |
| |
| /** |
| * Get the property's old value. May be null if multiple properties changed. |
| * |
| * @return the property's old value |
| */ |
| public Object getOldValue() |
| { |
| return oldValue; |
| } |
| |
| /** |
| * Set the propagation ID. This is a way for the event to be passed from |
| * hand to hand and retain a little extra state. Right now it is unused, |
| * but it should be propagated anyway so that future versions of JavaBeans |
| * can use it, for God knows what. |
| * |
| * @param propagationId the propagation ID |
| * @see #getPropagationId() |
| */ |
| public void setPropagationId(Object propagationId) |
| { |
| this.propagationId = propagationId; |
| } |
| |
| /** |
| * Get the propagation ID. Right now, it is not used for anything. |
| * |
| * @return the propagation ID |
| * @see #setPropagationId(Object) |
| */ |
| public Object getPropagationId() |
| { |
| return propagationId; |
| } |
| |
| /** |
| * Utility method to rollback a change. |
| * |
| * @param event the event to rollback |
| * @return a new event with old and new swapped |
| */ |
| PropertyChangeEvent rollback() |
| { |
| PropertyChangeEvent result |
| = new PropertyChangeEvent(source, propertyName, newValue, oldValue); |
| result.propagationId = propagationId; |
| return result; |
| } |
| } // class PropertyChangeEvent |