com.drew.metadata
Class TagDescriptor<T extends Directory>

java.lang.Object
  com.drew.metadata.TagDescriptor<T>

Direct Known Subclasses:

AdobeJpegDescriptor, CanonMakernoteDescriptor, CasioType1MakernoteDescriptor, CasioType2MakernoteDescriptor, DefaultTagDescriptor, ExifIFD0Descriptor, ExifInteropDescriptor, ExifSubIFDDescriptor, ExifThumbnailDescriptor, FujifilmMakernoteDescriptor, GpsDescriptor, IccDescriptor, IptcDescriptor, JfifDescriptor, JpegCommentDescriptor, JpegDescriptor, KodakMakernoteDescriptor, KyoceraMakernoteDescriptor, NikonType1MakernoteDescriptor, NikonType2MakernoteDescriptor, OlympusMakernoteDescriptor, PanasonicMakernoteDescriptor, PentaxMakernoteDescriptor, PhotoshopDescriptor, PsdHeaderDescriptor, SigmaMakernoteDescriptor, SonyType1MakernoteDescriptor, SonyType6MakernoteDescriptor, XmpDescriptor

public abstract class TagDescriptor<T extends Directory>
extends Object

Abstract base class for all tag descriptor classes. Implementations are responsible for providing the human-readable string representation of tag values stored in a directory. The directory is provided to the tag descriptor via its constructor.

Author:

Drew Noakes http://drewnoakes.com

Field Summary

protected T

_directory

Constructor Summary

TagDescriptor(T directory)

Method Summary

static String	convertBytesToVersionString(int[] components, int majorDigits) Takes a series of 4 bytes from the specified offset, and converts these to a well-known version number, where possible.
String	getDescription(int tagType) Returns a descriptive value of the the specified tag for this image.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

_directory

protected final T extends Directory _directory

Constructor Detail

TagDescriptor

public TagDescriptor(T directory)

Method Detail

getDescription

public String getDescription(int tagType)

Returns a descriptive value of the the specified tag for this image. Where possible, known values will be substituted here in place of the raw tokens actually kept in the metadata segment. If no substitution is available, the value provided by getString(tagType) will be returned.

Parameters:

tagType - the tag to find a description for

Returns:

a description of the image's value for the specified tag, or null if the tag hasn't been defined.

convertBytesToVersionString

public static String convertBytesToVersionString(int[] components,
                                                 int majorDigits)

Takes a series of 4 bytes from the specified offset, and converts these to a well-known version number, where possible.

Two different formats are processed:

• [30 32 31 30] -> 2.10
• [0 1 0 0] -> 1.00

Parameters:

components - the four version values

majorDigits - the number of components to be

Returns:

the version as a string of form "2.10" or null if the argument cannot be converted