clausesetchangeevent.java

Mandarax是一个规则引擎的纯Java实现。它支持多类型的事实和基于反映的规则

/*
 * Copyright (C) 1999-2004 <A href="http://www-ist.massey.ac.nz/JBDietrich" target="_top">Jens Dietrich</a>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
package org.mandarax.kernel;


/**
 * Event fired to notify listeners that a clause set has changed.
 * @see org.mandarax.kernel.ClauseSetChangeListener
 * @author <A href="http://www-ist.massey.ac.nz/JBDietrich" target="_top">Jens Dietrich</A>
 * @version 3.4 <7 March 05>
 * @since 1.1
 */
public class ClauseSetChangeEvent extends java.util.EventObject {

    public static int OTHER        = -1;
    public static int KEY_CHANGED  = 0;
    public static int TERM_CHANGED = 1;
    private int       type         = OTHER;
    private Object    oldValue     = null;
    private Object    newValue     = null;

    /**
     * Constructor.
     * @param source the source of the event
     * @param oldVal the old value (e.g., the old key or the old terms)
     * @param newVal the new value
     * @param aType the type (one of the constants defined in this class)(
     */
    public ClauseSetChangeEvent(Object source, Object oldVal, Object newVal,int aType) {
        super (source);
        type     = aType;
        oldValue = oldVal;
        newValue = newVal;
    }

    /**
     * Get the new value.
     * @return the new value
     */
    public Object getNewValue() {
        return newValue;
    }

    /**
     * Get the old value.
     * @return the old value
     */
    public Object getOldValue() {
        return oldValue;
    }

    /**
     * Get the event type. Value should be one of the constants listet below.
     * @see ClauseSetChangeEvent#KEY_CHANGED
     * @see ClauseSetChangeEvent#TERM_CHANGED
     * @see ClauseSetChangeEvent#OTHER
     * @return the type of the event
     */
    public int getType() {
        return type;
    }
}