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.html.internal;
018
019import org.apache.wicket.markup.MarkupStream;
020import org.apache.wicket.request.Response;
021import org.apache.wicket.request.cycle.RequestCycle;
022import org.apache.wicket.response.StringResponse;
023
024/**
025 * Utility class that buffers output and maintains markup stream index
026 * 
027 * @author igor.vaynberg
028 */
029public abstract class ResponseBufferZone
030{
031        private final RequestCycle cycle;
032        private final MarkupStream stream;
033
034        public ResponseBufferZone(RequestCycle cycle, MarkupStream stream)
035        {
036                this.cycle = cycle;
037                this.stream = stream;
038        }
039
040        public CharSequence execute()
041        {
042                final int originalStreamPos = stream.getCurrentIndex();
043
044                final Response original = cycle.getResponse();
045
046                final StringResponse buffer = new StringResponse();
047                cycle.setResponse(buffer);
048                try
049                {
050                        executeInsideBufferedZone();
051                        return buffer.getBuffer();
052                }
053                finally
054                {
055                        cycle.setResponse(original);
056                        stream.setCurrentIndex(originalStreamPos);
057                }
058        }
059
060        protected abstract void executeInsideBufferedZone();
061}