/*
 * Copyright (C) 1999-2004 <a href="mailto:mandarax@jbdietrich.com">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;


import java.util.Collection;

/**
 * Event fired to notify listeners that a knowledge base has changed.
 * @author <A HREF="mailto:mandarax@jbdietrich.com">Jens Dietrich</A>
 * @version 3.3.1 <9 August 2004>
 * @since 1.0
 */
public class KnowledgeBaseChangeEvent extends java.util.EventObject {

    public static int  UNKNOWN         = -1;
    public static int  CLAUSE_MOVED    = 0;
    public static int  CLAUSE_REMOVED  = 1;
    public static int  CLAUSE_ADDED    = 2;
    private Collection affectedClauses = null;
    private int        type            = UNKNOWN;

    /**
     * Constructor.
     * @param source java.lang.Object
     * @param aType int
     */
    public KnowledgeBaseChangeEvent(Object source, int aType) {
        super (source);

        type            = aType;
        affectedClauses = new java.util.Vector ();
    }

    /**
     * Constructor.
     * @param aSource java.lang.Object
     * @param aType int
     * @param clause java.lang.Object
     */
    public KnowledgeBaseChangeEvent(Object aSource, int aType,
                                    Object clause) {
        this (aSource, aType);

        affectedClauses = new java.util.Vector (1);

        affectedClauses.add (clause);
    }

    /**
     * Constructor.
     * @param aSource java.lang.Object
     * @param aType int
     * @param clauses java.util.Collection
     */
    public KnowledgeBaseChangeEvent(Object aSource, int aType,
                                    Collection clauses) {
        this (aSource, aType);

        affectedClauses = clauses;
    }

    /**
     * Get the clauses affected by the change.
     * @return java.util.Collection
     */
    public Collection getAffectedClauses() {
        return affectedClauses;
    }

    /**
     * Get the type.
     * @return int
     */
    public int getType() {
        return type;
    }
}
