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.wicket.markup.repeater; 018 019import java.util.Iterator; 020 021import org.apache.wicket.model.IModel; 022import org.apache.wicket.util.io.IClusterable; 023 024 025/** 026 * Interface for item reuse strategies. 027 * <p> 028 * <u>Notice:</u> Child items will be rendered in the order they are provided by the returned 029 * iterator, so it is important that the strategy preserve this order 030 * </p> 031 * 032 * @author Igor Vaynberg (ivaynberg) 033 * 034 */ 035public interface IItemReuseStrategy extends IClusterable 036{ 037 038 /** 039 * Returns an iterator over items that will be added to the view. The iterator needs to return 040 * all the items because the old ones are removed prior to the new ones added. 041 * 042 * @param <T> 043 * type of Item 044 * 045 * @param factory 046 * implementation of IItemFactory 047 * @param newModels 048 * iterator over models for items 049 * @param existingItems 050 * iterator over child items 051 * @return iterator over items that will be added after all the old items are moved. 052 */ 053 <T> Iterator<Item<T>> getItems(IItemFactory<T> factory, Iterator<IModel<T>> newModels, 054 Iterator<Item<T>> existingItems); 055}