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.jpeg;
  
  import com.drew.lang.annotations.NotNull;
  import com.drew.lang.annotations.Nullable;
  import com.drew.metadata.Directory;
  import com.drew.metadata.MetadataException;
  
  import java.util.HashMap;
  
  /**
   * Directory of tags and values for the SOF0 JPEG segment.  This segment holds basic metadata about the image.
   *
   * @author Darrell Silver https://www.darrellsilver.com and Drew Noakes https://drewnoakes.com
   */
  @SuppressWarnings("WeakerAccess")
  public class JpegDirectory extends Directory
  {
      public static final int TAG_COMPRESSION_TYPE = -3;
      /** This is in bits/sample, usually 8 (12 and 16 not supported by most software). */
      public static final int TAG_DATA_PRECISION = 0;
      /** The image's height.  Necessary for decoding the image, so it should always be there. */
      public static final int TAG_IMAGE_HEIGHT = 1;
      /** The image's width.  Necessary for decoding the image, so it should always be there. */
      public static final int TAG_IMAGE_WIDTH = 3;
      /**
       * Usually 1 = grey scaled, 3 = color YcbCr or YIQ, 4 = color CMYK
       * Each component TAG_COMPONENT_DATA_[1-4], has the following meaning:
       * component Id(1byte)(1 = Y, 2 = Cb, 3 = Cr, 4 = I, 5 = Q),
       * sampling factors (1byte) (bit 0-3 vertical., 4-7 horizontal.),
       * quantization table number (1 byte).
       * <p>
       * This info is from https://www.funducode.com/freec/Fileformats/format3/format3b.htm
       */
      public static final int TAG_NUMBER_OF_COMPONENTS = 5;
  
      // NOTE!  Component tag type int values must increment in steps of 1
  
      /** the first of a possible 4 color components.  Number of components specified in TAG_NUMBER_OF_COMPONENTS. */
      public static final int TAG_COMPONENT_DATA_1 = 6;
      /** the second of a possible 4 color components.  Number of components specified in TAG_NUMBER_OF_COMPONENTS. */
      public static final int TAG_COMPONENT_DATA_2 = 7;
      /** the third of a possible 4 color components.  Number of components specified in TAG_NUMBER_OF_COMPONENTS. */
      public static final int TAG_COMPONENT_DATA_3 = 8;
      /** the fourth of a possible 4 color components.  Number of components specified in TAG_NUMBER_OF_COMPONENTS. */
      public static final int TAG_COMPONENT_DATA_4 = 9;
  
      @NotNull
      private static final HashMap<Integer, String> _tagNameMap = new HashMap<Integer, String>();
  
      static {
          _tagNameMap.put(TAG_COMPRESSION_TYPE, "Compression Type");
          _tagNameMap.put(TAG_DATA_PRECISION, "Data Precision");
          _tagNameMap.put(TAG_IMAGE_WIDTH, "Image Width");
          _tagNameMap.put(TAG_IMAGE_HEIGHT, "Image Height");
          _tagNameMap.put(TAG_NUMBER_OF_COMPONENTS, "Number of Components");
          _tagNameMap.put(TAG_COMPONENT_DATA_1, "Component 1");
          _tagNameMap.put(TAG_COMPONENT_DATA_2, "Component 2");
          _tagNameMap.put(TAG_COMPONENT_DATA_3, "Component 3");
          _tagNameMap.put(TAG_COMPONENT_DATA_4, "Component 4");
      }
  
      public JpegDirectory()
      {
          this.setDescriptor(new JpegDescriptor(this));
      }
  
      @Override
      @NotNull
      public String getName()
      {
          return "JPEG";
      }
  
      @Override
      @NotNull
      protected HashMap<Integer, String> getTagNameMap()
      {
          return _tagNameMap;
      }
  
      /**
       * @param componentNumber The zero-based index of the component.  This number is normally between 0 and 3.
       *                        Use getNumberOfComponents for bounds-checking.
       * @return the JpegComponent having the specified number.
       */
      @Nullable
      public JpegComponent getComponent(int componentNumber)
      {
          int tagType = JpegDirectory.TAG_COMPONENT_DATA_1 + componentNumber;
          return (JpegComponent)getObject(tagType);
      }
  
      public int getImageWidth() throws MetadataException
      {
          return getInt(JpegDirectory.TAG_IMAGE_WIDTH);
      }
  
      public int getImageHeight() throws MetadataException
      {
          return getInt(JpegDirectory.TAG_IMAGE_HEIGHT);
      }
  
      public int getNumberOfComponents() throws MetadataException
      {
          return getInt(JpegDirectory.TAG_NUMBER_OF_COMPONENTS);
      }
  }
  