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.imaging.formats.png.chunks;
018
019import java.nio.charset.StandardCharsets;
020import java.util.logging.Level;
021import java.util.logging.Logger;
022
023import org.apache.commons.imaging.ImagingException;
024import org.apache.commons.imaging.common.BinaryFunctions;
025import org.apache.commons.imaging.formats.png.AbstractPngText;
026
027public final class PngChunkText extends AbstractPngTextChunk {
028
029    private static final Logger LOGGER = Logger.getLogger(PngChunkText.class.getName());
030
031    private final String keyword;
032    private final String text;
033
034    /**
035     * Constructs a new instance.
036     *
037     * @param length    chunk length.
038     * @param chunkType chunk type.
039     * @param crc       CRC computed over the chunk type and chunk data (but not the length).
040     * @param bytes     chunk data bytes.
041     * @throws ImagingException Thrown on a parsing error.
042     * @throws NullPointerException if {@code bytes} is null.
043     */
044    public PngChunkText(final int length, final int chunkType, final int crc, final byte[] bytes) throws ImagingException {
045        super(length, chunkType, crc, bytes);
046        final int index = BinaryFunctions.indexOf0(bytes, "PNG tEXt chunk keyword is not terminated.");
047        keyword = new String(bytes, 0, index, StandardCharsets.ISO_8859_1);
048        final int textLength = bytes.length - (index + 1);
049        text = new String(bytes, index + 1, textLength, StandardCharsets.ISO_8859_1);
050        if (LOGGER.isLoggable(Level.FINEST)) {
051            LOGGER.finest("Keyword: " + keyword);
052            LOGGER.finest("Text: " + text);
053        }
054    }
055
056    @Override
057    public AbstractPngText getContents() {
058        return new AbstractPngText.Text(keyword, text);
059    }
060
061    /**
062     * @return the keyword.
063     */
064    @Override
065    public String getKeyword() {
066        return keyword;
067    }
068
069    /**
070     * @return the text.
071     */
072    @Override
073    public String getText() {
074        return text;
075    }
076
077}