/*
* 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.drew.metadata;
import com.drew.lang.annotations.NotNull;
import com.drew.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. 0x100E
).
*
* @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 Aperture
, or
* InteropVersion
.
*
* @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
* Exif
, GPS
or Interoperability
.
*
* @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: [FNumber] F2.8
.
*
* @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;
}
}