content: /*
   * Copyright 2002-2019 Drew Noakes and contributors
   *
   *    Licensed under the Apache License, Version 2.0 (the "License");
   *    you may not use this file except in compliance with the License.
   *    You may obtain a copy of the License at
   *
   *        https://www.apache.org/licenses/LICENSE-2.0
   *
   *    Unless required by applicable law or agreed to in writing, software
   *    distributed under the License is distributed on an "AS IS" BASIS,
   *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   *    See the License for the specific language governing permissions and
   *    limitations under the License.
   *
   * More information about this project is available at:
   *
   *    https://drewnoakes.com/code/exif/
   *    https://github.com/drewnoakes/metadata-extractor
   */
  
  package com.drew.metadata.exif;
  
  import com.drew.lang.annotations.NotNull;
  
  import java.util.HashMap;
  
  /**
   * One of several Exif directories.  Otherwise known as IFD1, this directory holds information about an embedded thumbnail image.
   *
   * @author Drew Noakes https://drewnoakes.com
   */
  @SuppressWarnings("WeakerAccess")
  public class ExifThumbnailDirectory extends ExifDirectoryBase
  {
      /**
       * The offset to thumbnail image bytes, relative to the start of the IFD.
       *
       * To obtain the offset relative to the start of the TIFF data stream, use
       * <code>getAdjustedThumbnailOffset</code>, which includes the value of
       * <code>getExifStartOffset</code>.
       */
      public static final int TAG_THUMBNAIL_OFFSET = 0x0201;
      /**
       * The size of the thumbnail image data in bytes.
       */
      public static final int TAG_THUMBNAIL_LENGTH = 0x0202;
  
      /**
       * @deprecated use {@link com.drew.metadata.exif.ExifDirectoryBase#TAG_COMPRESSION} instead.
       */
      @Deprecated
      public static final int TAG_THUMBNAIL_COMPRESSION = 0x0103;
  
      @NotNull
      private static final HashMap<Integer, String> _tagNameMap = new HashMap<Integer, String>();
  
      static
      {
          addExifTagNames(_tagNameMap);
  
          _tagNameMap.put(TAG_THUMBNAIL_OFFSET, "Thumbnail Offset");
          _tagNameMap.put(TAG_THUMBNAIL_LENGTH, "Thumbnail Length");
      }
  
      private final int _exifStartOffset;
  
      public ExifThumbnailDirectory(int exifStartOffset)
      {
          _exifStartOffset = exifStartOffset;
          this.setDescriptor(new ExifThumbnailDescriptor(this));
      }
  
      @Override
      @NotNull
      public String getName()
      {
          return "Exif Thumbnail";
      }
  
      @Override
      @NotNull
      protected HashMap<Integer, String> getTagNameMap()
      {
          return _tagNameMap;
      }
  
      /**
       * Gets the offset at which the Exif data stream commenced within any containing stream.
       */
      public int getExifStartOffset()
      {
          return _exifStartOffset;
      }
  
      /**
       * Returns the offset to thumbnail data within the outermost data stream.
       *
       * The value for <code>TagThumbnailOffset</code> is relative to the Exif data stream.
       * Generally, consumers of thumbnail data need this value relative to the outermost stream,
       * so that the thumbnail data may be extracted from that stream.
       *
       * This property adds the value of <code>ExifStartOffset</code> to this tag's value in order
       * to produce that value.
       *
       * Returns <code>null</code> when the tag is not defined in this directory.
       */
      public Integer getAdjustedThumbnailOffset()
      {
          Integer offset = this.getInteger(TAG_THUMBNAIL_OFFSET);
  
          if (offset == null) {
              return null;
          }
  
          return offset.intValue() + _exifStartOffset;
      }
  }
  