cayenne-server/src/main/java/org/apache/cayenne/graph/GraphEvent.java

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 *  regarding copyright ownership.  The ASF licenses this file
 *  to you under the Apache License, Version 2.0 (the
 *  "License"); you may not use this file except in compliance
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 *    https://www.apache.org/licenses/LICENSE-2.0
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package org.apache.cayenne.graph;

import org.apache.cayenne.event.CayenneEvent;

/**
 * An event indicating a change in the object graph. A change is expressed as a
 * GraphDiff, so the easiest way to process the event is the following:
 * 
 * <pre>
 *    GraphChangeHandler handler = ..;
 *    event.getDiff().apply(handler);
 * </pre>
 * 
 * @since 1.2
 */
public class GraphEvent extends CayenneEvent {

	private static final long serialVersionUID = -8954343713674462675L;
	
	protected GraphDiff diff;

	public GraphEvent(Object source, GraphDiff diff) {
		this(source, source, diff);
	}

	public GraphEvent(Object source, Object postedBy, GraphDiff diff) {
		super(source, postedBy, null);
		this.diff = diff;
	}

	public GraphDiff getDiff() {
		return diff;
	}
}