content: /*
   * Copyright 2002-2012 Drew Noakes
   *
   *    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
   *
   *        http://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:
   *
   *    http://drewnoakes.com/code/exif/
   *    http://code.google.com/p/metadata-extractor/
   */
  package com.almalence.util.exifreader.metadata;
  
  import com.almalence.util.exifreader.lang.annotations.NotNull;
  import com.almalence.util.exifreader.lang.annotations.Nullable;
  
  /**
   * Models a particular tag within a directory and provides methods for obtaining its value.  Note that a Tag instance is
   * specific to a particular metadata extraction and cannot be reused.
   *
   * @author Drew Noakes http://drewnoakes.com
   */
  public class Tag
  {
      private final int _tagType;
      @NotNull
      private final Directory _directory;
  
      public Tag(int tagType, @NotNull Directory directory)
      {
          _tagType = tagType;
          _directory = directory;
      }
  
      /**
       * Gets the tag type as an int
       *
       * @return the tag type as an int
       */
      public int getTagType()
      {
          return _tagType;
      }
  
      /**
       * Gets the tag type in hex notation as a String with padded leading
       * zeroes if necessary (i.e. <code>0x100E</code>).
       *
       * @return the tag type as a string in hexadecimal notation
       */
      @NotNull
      public String getTagTypeHex()
      {
          String hex = Integer.toHexString(_tagType);
          while (hex.length() < 4) 
          	hex = "0" + hex;
          return "0x" + hex;
      }
  
      /**
       * Get a description of the tag's value, considering enumerated values
       * and units.
       *
       * @return a description of the tag's value
       */
      @Nullable
      public String getDescription()
      {
          return _directory.getDescription(_tagType);
      }
  
      /**
       * Get the name of the tag, such as <code>Aperture</code>, or
       * <code>InteropVersion</code>.
       *
       * @return the tag's name
       */
      @NotNull
      public String getTagName()
      {
          return _directory.getTagName(_tagType);
      }
  
      /**
       * Get the name of the directory in which the tag exists, such as
       * <code>Exif</code>, <code>GPS</code> or <code>Interoperability</code>.
       *
       * @return name of the directory in which this tag exists
       */
      @NotNull
      public String getDirectoryName()
      {
          return _directory.getName();
      }
  
      /**
       * A basic representation of the tag's type and value.  EG: <code>[FNumber] F2.8</code>.
       *
       * @return the tag's type and value
       */
      @NotNull
      public String toString()
      {
          String description = getDescription();
          if (description==null)
              description = _directory.getString(getTagType()) + " (unable to formulate description)";
          return "[" + _directory.getName() + "] " + getTagName() + " - " + description;
      }
  }
  