001/**
002 *
003 * Copyright the original author or authors
004 *
005 * Licensed under the Apache License, Version 2.0 (the "License");
006 * you may not use this file except in compliance with the License.
007 * You may obtain a copy of the License at
008 *
009 *     http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.jivesoftware.smackx.pubsub;
018
019import java.util.Collections;
020import java.util.List;
021
022/**
023 * Base class to represents events that are associated to subscriptions.
024 * 
025 * @author Robin Collier
026 */
027abstract public class SubscriptionEvent extends NodeEvent
028{
029    private List<String> subIds = Collections.emptyList();
030
031    /**
032     * Construct an event with no subscription id's.  This can 
033     * occur when there is only one subscription to a node.  The
034     * event may or may not report the subscription id along 
035     * with the event.
036     * 
037     * @param nodeId The id of the node the event came from
038     */
039    protected SubscriptionEvent(String nodeId)
040    {
041        super(nodeId);
042    }
043
044    /**
045     * Construct an event with multiple subscriptions.
046     * 
047     * @param nodeId The id of the node the event came from
048     * @param subscriptionIds The list of subscription id's
049     */
050    protected SubscriptionEvent(String nodeId, List<String> subscriptionIds)
051    {
052        super(nodeId);
053
054        if (subscriptionIds != null)
055            subIds = subscriptionIds;
056    }
057
058    /** 
059     * Get the subscriptions this event is associated with.
060     * 
061     * @return List of subscription id's
062     */
063    public List<String> getSubscriptions()
064    {
065        return Collections.unmodifiableList(subIds);
066    }
067
068    /**
069     * Set the list of subscription id's for this event.
070     * 
071     * @param subscriptionIds The list of subscription id's
072     */
073    protected void setSubscriptions(List<String> subscriptionIds)
074    {
075        if (subscriptionIds != null)
076            subIds = subscriptionIds;
077    }
078}