001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  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.apache.commons.flatfile;
018
019/**
020 * EntityCollection whose children are indexed.
021 * @version $Revision: 758023 $ $Date: 2009-03-24 16:09:19 -0500 (Tue, 24 Mar 2009) $
022 */
023public interface IndexedEntityCollection extends EntityCollection {
024    /**
025     * Get the size (# of child elements) of this IndexedEntityCollection.
026     * @return int
027     */
028    int size();
029
030    /**
031     * Get the child at the specified index.
032     * @param index int
033     * @return Entity
034     */
035    Entity getChild(int index);
036
037    /**
038     * Learn whether the size of this object can be set.
039     * @return boolean
040     */
041    boolean isSizable();
042
043    /**
044     * Set new size of this object.
045     * @param size to set
046     * @throws IllegalStateException if {@link #isSizable()} <code>== false</code>
047     */
048    void setSize(int size) throws IllegalStateException;
049}