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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * published by the Free Software Foundation.  Oracle designates this
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 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
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 * 2 along with this work; if not, write to the Free Software Foundation,
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package javax.imageio.plugins.tiff;

import java.util.ArrayList;
import java.util.List;

A class containing the TIFF tags used to reference the Exif and GPS IFDs. This tag set should be added to the root tag set by means of the 
TIFFImageReadParam.addAllowedTagSet method if Exif support is desired. 
Since:
9/**
 * A class containing the TIFF tags used to reference the Exif and GPS IFDs.
 * This tag set should be added to the root tag set by means of the
 * {@link TIFFImageReadParam#addAllowedTagSet(TIFFTagSet)
 * TIFFImageReadParam.addAllowedTagSet} method if Exif
 * support is desired.
 *
 * @since 9
 */
public final class ExifParentTIFFTagSet extends TIFFTagSet {

    private static ExifParentTIFFTagSet theInstance = null;

    // 34665 - Exif IFD Pointer                   (LONG/1)
    
Tag pointing to the Exif IFD (type LONG). /** Tag pointing to the Exif IFD (type LONG). */
    public static final int TAG_EXIF_IFD_POINTER = 34665;

    
Tag pointing to a GPS info IFD (type LONG). /** Tag pointing to a GPS info IFD (type LONG). */
    public static final int TAG_GPS_INFO_IFD_POINTER = 34853;

    // To be inserted into parent (root) TIFFTagSet
    static class ExifIFDPointer extends TIFFTag {

        public ExifIFDPointer() {
            super("ExifIFDPointer",
                  TAG_EXIF_IFD_POINTER,
                  ExifTIFFTagSet.getInstance());
        }
    }

    // To be inserted into parent (root) TIFFTagSet
    static class GPSInfoIFDPointer extends TIFFTag {

        public GPSInfoIFDPointer() {
            super("GPSInfoIFDPointer",
                  TAG_GPS_INFO_IFD_POINTER,
                  ExifGPSTagSet.getInstance());
        }
    }

    private static List<TIFFTag> tags;

    private static void initTags() {
        tags = new ArrayList<TIFFTag>(1);
        tags.add(new ExifParentTIFFTagSet.ExifIFDPointer());
        tags.add(new ExifParentTIFFTagSet.GPSInfoIFDPointer());
    }

    private ExifParentTIFFTagSet() {
        super(tags);
    }

    
Returns a shared instance of an ExifParentTIFFTagSet. 
Returns:
an ExifParentTIFFTagSet instance./**
     * Returns a shared instance of an {@code ExifParentTIFFTagSet}.
     *
     * @return an {@code ExifParentTIFFTagSet} instance.
     */
    public synchronized static ExifParentTIFFTagSet getInstance() {
        if (theInstance == null) {
            initTags();
            theInstance = new ExifParentTIFFTagSet();
            tags = null;
        }
        return theInstance;
    }
}