    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}