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 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
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 */

package java.beans;

import java.util.EventObject;

/**
 * A "PropertyChange" event gets delivered whenever a bean changes a "bound"
 * or "constrained" property. A PropertyChangeEvent object is sent as an
 * argument to the PropertyChangeListener and VetoableChangeListener methods.
 * <P>
 * Normally PropertyChangeEvents are accompanied by the name and the old
 * and new value of the changed property. If the new value is a primitive
 * type (such as int or boolean) it must be wrapped as the
 * corresponding java.lang.* Object type (such as Integer or Boolean).
 * <P>
 * Null values may be provided for the old and the new values if their
 * true values are not known.
 * <P>
 * An event source may send a null object as the name to indicate that an
 * arbitrary set of if its properties have changed. In this case the
 * old and new values should also be null.
 */
public class PropertyChangeEvent extends EventObject {
 private static final long serialVersionUID = 7042693688939648123L;

 /**
 * Constructs a new {@code PropertyChangeEvent}.
 *
 * @param source the bean that fired the event
 * @param propertyName the programmatic name of the property that was changed
 * @param oldValue the old value of the property
 * @param newValue the new value of the property
 *
 * @throws IllegalArgumentException if {@code source} is {@code null}
 */
 public PropertyChangeEvent(Object source, String propertyName,
 Object oldValue, Object newValue) {
 super(source);
 this.propertyName = propertyName;
 this.newValue = newValue;
 this.oldValue = oldValue;
 }

 /**
 * Gets the programmatic name of the property that was changed.
 *
 * @return The programmatic name of the property that was changed.
 * May be null if multiple properties have changed.
 */
 public String getPropertyName() {
 return propertyName;
 }

 /**
 * Gets the new value for the property, expressed as an Object.
 *
 * @return The new value for the property, expressed as an Object.
 * May be null if multiple properties have changed.
 */
 public Object getNewValue() {
 return newValue;
 }

 /**
 * Gets the old value for the property, expressed as an Object.
 *
 * @return The old value for the property, expressed as an Object.
 * May be null if multiple properties have changed.
 */
 public Object getOldValue() {
 return oldValue;
 }

 /**
 * Sets the propagationId object for the event.
 *
 * @param propagationId The propagationId object for the event.
 */
 public void setPropagationId(Object propagationId) {
 this.propagationId = propagationId;
 }

 /**
 * The "propagationId" field is reserved for future use. In Beans 1.0
 * the sole requirement is that if a listener catches a PropertyChangeEvent
 * and then fires a PropertyChangeEvent of its own, then it should
 * make sure that it propagates the propagationId field from its
 * incoming event to its outgoing event.
 *
 * @return the propagationId object associated with a bound/constrained
 * property update.
 */
 public Object getPropagationId() {
 return propagationId;
 }

 /**
 * name of the property that changed. May be null, if not known.
 * @serial
 */
 private String propertyName;

 /**
 * New value for property. May be null if not known.
 * @serial
 */
 private Object newValue;

 /**
 * Previous value for property. May be null if not known.
 * @serial
 */
 private Object oldValue;

 /**
 * Propagation ID. May be null.
 * @serial
 * @see #getPropagationId
 */
 private Object propagationId;

 /**
 * Returns a string representation of the object.
 *
 * @return a string representation of the object
 *
 * @since 1.7
 */
 public String toString() {
 StringBuilder sb = new StringBuilder(getClass().getName());
 sb.append("[propertyName=").append(getPropertyName());
 appendTo(sb);
 sb.append("; oldValue=").append(getOldValue());
 sb.append("; newValue=").append(getNewValue());
 sb.append("; propagationId=").append(getPropagationId());
 sb.append("; source=").append(getSource());
 return sb.append("]").toString();
 }

 void appendTo(StringBuilder sb) {
 }
}