/*
 * Copyright 2009 Sun Microsystems, Inc.  All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Sun designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Sun in the LICENSE file that accompanied this code.
 *
 * This code 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
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 */
package com.sun.nio.sctp;

/**
 * Notification emitted when an association has either opened or closed.
 *
 * @since 1.7
 */
public abstract class AssociationChangeNotification
    implements Notification
{
    /**
     * Defines the type of change event that happened to the association.
     *
     * @since 1.7
     */
    public enum AssocChangeEvent
    {
        /**
         * A new association is now ready and data may be exchanged with this peer.
         */
        COMM_UP,

        /**
         * The association has failed. A series of SCTP send failed notifications
         * will follow this notification, one for each outstanding message.
         */
       COMM_LOST,

        /**
         * SCTP has detected that the peer has restarted.
         */
       RESTART,

        /**
         * The association has gracefully closed.
         */
       SHUTDOWN,

        /**
         * The association failed to setup. If a message was sent on a {@link
         * SctpMultiChannel} in non-blocking mode, an
         * SCTP send failed notification will follow this notification for the
         * outstanding message.
         */
       CANT_START
    }

    /**
     * Initializes a new instance of this class.
     */
    protected AssociationChangeNotification() {}

    /**
     * Returns the association that this notification is applicable to.
     *
     * @return  The association whose state has changed, or {@code null} if
     *          there is no association, that is {@linkplain
     *          AssocChangeEvent#CANT_START CANT_START}
     */
    public abstract Association association();

    /**
     * Returns the type of change event.
     *
     * @return  The event
     */
    public abstract AssocChangeEvent event();
}
