    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.tiff.taginfos;
    018
    019import java.nio.ByteOrder;
    020import java.nio.charset.StandardCharsets;
    021
    022import org.apache.commons.imaging.ImageWriteException;
    023import org.apache.commons.imaging.formats.tiff.constants.TiffDirectoryType;
    024import org.apache.commons.imaging.formats.tiff.fieldtypes.FieldType;
    025
    026public class TagInfoAscii extends TagInfo {
    027    public TagInfoAscii(final String name, final int tag, final int length,
    028            final TiffDirectoryType directoryType) {
    029        super(name, tag, FieldType.ASCII, length, directoryType);
    030    }
    031
    032    public String[] getValue(final ByteOrder byteOrder, final byte[] bytes) {
    033        int nullCount = 0;
    034        for (int i = 0; i < bytes.length - 1; i++) {
    035            if (bytes[i] == 0) {
    036                nullCount++;
    037            }
    038        }
    039        final String[] strings = new String[nullCount + 1];
    040        int stringsAdded = 0;
    041        strings[0] = ""; // if we have a 0 length string
    042        int nextStringPos = 0;
    043        // According to the Exiftool FAQ, http://www.metadataworkinggroup.org
    044        // specifies that the TIFF ASCII fields are actually UTF-8.
    045        // Exiftool however allows you to configure the charset used.
    046        for (int i = 0; i < bytes.length; i++) {
    047            if (bytes[i] == 0) {
    048                final String string = new String(bytes, nextStringPos, i
    049                        - nextStringPos, StandardCharsets.UTF_8);
    050                strings[stringsAdded++] = string;
    051                nextStringPos = i + 1;
    052            }
    053        }
    054        if (nextStringPos < bytes.length) {
    055            // Buggy file, string wasn't null terminated
    056            final String string = new String(bytes, nextStringPos, bytes.length
    057                    - nextStringPos, StandardCharsets.UTF_8);
    058            strings[stringsAdded++] = string;
    059        }
    060        return strings;
    061    }
    062
    063    public byte[] encodeValue(final ByteOrder byteOrder, final String... values)
    064            throws ImageWriteException {
    065        return FieldType.ASCII.writeData(values, byteOrder);
    066    }
    067}