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;
021import java.util.Arrays;
022
023import org.apache.commons.imaging.ImagingException;
024import org.apache.commons.imaging.formats.tiff.TiffField;
025import org.apache.commons.imaging.formats.tiff.constants.TiffDirectoryType;
026import org.apache.commons.imaging.formats.tiff.fieldtypes.AbstractFieldType;
027
028/**
029 * Windows XP onwards store some tags using UTF-16LE, but the field type is byte - here we deal with this.
030 */
031public class TagInfoXpString extends TagInfo {
032    public TagInfoXpString(final String name, final int tag, final TiffDirectoryType directoryType) {
033        super(name, tag, AbstractFieldType.BYTE, LENGTH_UNKNOWN, directoryType);
034    }
035
036    @Override
037    public byte[] encodeValue(final AbstractFieldType abstractFieldType, final Object value, final ByteOrder byteOrder) throws ImagingException {
038        if (!(value instanceof String)) {
039            throw new ImagingException("Text value not String", value);
040        }
041        final String s = (String) value;
042        final byte[] bytes = s.getBytes(StandardCharsets.UTF_16LE);
043        return Arrays.copyOf(bytes, bytes.length + 2);
044    }
045
046    @Override
047    public String getValue(final TiffField entry) throws ImagingException {
048        if (entry.getFieldType() != AbstractFieldType.BYTE) {
049            throw new ImagingException("Text field not encoded as bytes.");
050        }
051        final byte[] bytes = entry.getByteArrayValue();
052        final int length;
053        if (bytes.length >= 2 && bytes[bytes.length - 1] == 0 && bytes[bytes.length - 2] == 0) {
054            length = bytes.length - 2;
055        } else {
056            length = bytes.length;
057        }
058        return new String(bytes, 0, length, StandardCharsets.UTF_16LE);
059    }
060}