org.geotoolkit.image.io.plugin
Class TextRecordImageReader.Spi

Object
  IIOServiceProvider
      ImageReaderWriterSpi
          ImageReaderSpi
              SpatialImageReader.Spi
                  StreamImageReader.Spi
                      TextImageReader.Spi
                          TextRecordImageReader.Spi

All Implemented Interfaces:

RegisterableService

Enclosing class:

TextRecordImageReader

public static class TextRecordImageReader.Spi
extends TextImageReader.Spi

Service provider interface (SPI) for TextRecordImageReaders. This SPI provides necessary implementation for creating default TextRecordImageReader using default locale and character set. The default constructor initializes the fields to the values listed below:

Field	Value
ImageReaderWriterSpi.names	"records"
ImageReaderWriterSpi.MIMETypes	"text/plain"
ImageReaderWriterSpi.pluginClassName	"org.geotoolkit.image.io.plugin.TextRecordImageReader"
IIOServiceProvider.vendorName	"Geotoolkit.org"
IIOServiceProvider.version	Version.GEOTOOLKIT
xColumn	0
yColumn	1
gridTolerance	May vary.
See super-class javadoc for remaining fields

Subclasses can set some fields at construction time in order to tune the reader to a particular environment, e.g.:

public final class CLSImageReaderSpi extends TextRecordImageReader.Spi {
    public CLSImageReaderSpi() {
        names      = new String[] {"CLS"};
        MIMETypes  = new String[] {"text/x-records-CLS"};
        vendorName = "Institut de Recherche pour le Développement";
        version    = "1.0";
        locale     = Locale.US;
        charset    = Charset.forName("ISO-8859-1"); // ISO-LATIN-1
        padValue   = -9999;
    }
}

Note: fields vendorName and version are only informatives.

There is no need to override any method in this example. However, developers can gain more control by creating subclasses of TextRecordImageReader and Spi.

Since:

3.08 (derived from 2.1)

Version:

3.08

Author:

Martin Desruisseaux (IRD, Geomatys)

Module:

coverage/geotk-coverageio (download)

View source code for this class

Field Summary

protected float	gridTolerance A tolerance factor during decoding, between 0 and 1.
protected int	xColumn 0-based column number for x values.
protected int	yColumn 0-based column number for y values.

Fields inherited from class TextImageReader.Spi

charset, locale, padValue

Fields inherited from class ImageReaderSpi

inputTypes, STANDARD_INPUT_TYPE, writerSpiNames

Fields inherited from class ImageReaderWriterSpi

extraImageMetadataFormatClassNames, extraImageMetadataFormatNames, extraStreamMetadataFormatClassNames, extraStreamMetadataFormatNames, MIMETypes, names, nativeImageMetadataFormatClassName, nativeImageMetadataFormatName, nativeStreamMetadataFormatClassName, nativeStreamMetadataFormatName, pluginClassName, suffixes, supportsStandardImageMetadataFormat, supportsStandardStreamMetadataFormat

Fields inherited from class IIOServiceProvider

vendorName, version

Constructor Summary

TextRecordImageReader.Spi()
Constructs a default TextRecordImageReader.Spi.

Method Summary

ImageReader	createReaderInstance(Object extension) Returns an instance of the ImageReader implementation associated with this service provider.
String	getDescription(Locale locale) Returns a brief, human-readable description of this service provider and its associated implementation.
protected boolean	isValidColumnCount(int count) Invoked by isValidColumnCount(int) for determining if the given number of columns is valid.
protected boolean	isValidContent(double[][] rows) Returns true if the content of the first few rows seems valid, or false otherwise.
void	onRegistration(ServiceRegistry registry, Class<?> category) Invoked when this Service Provider is registered.

Methods inherited from class TextImageReader.Spi

canDecodeInput, canDecodeInput, isValidHeader

Methods inherited from class SpatialImageReader.Spi

getImageMetadataFormat, getStreamMetadataFormat

Methods inherited from class ImageReaderSpi

createReaderInstance, getImageWriterSpiNames, getInputTypes, isOwnReader

Methods inherited from class ImageReaderWriterSpi

getExtraImageMetadataFormatNames, getExtraStreamMetadataFormatNames, getFileSuffixes, getFormatNames, getMIMETypes, getNativeImageMetadataFormatName, getNativeStreamMetadataFormatName, getPluginClassName, isStandardImageMetadataFormatSupported, isStandardStreamMetadataFormatSupported

Methods inherited from class IIOServiceProvider

getVendorName, getVersion, onDeregistration

Methods inherited from class Object

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

Field Detail

xColumn

protected int xColumn

0-based column number for x values. The default value is 0.

See Also:

TextRecordImageReader.getColumnX(int)

yColumn

protected int yColumn

0-based column number for y values. The default value is 1.

See Also:

TextRecordImageReader.getColumnY(int)

gridTolerance

protected float gridTolerance

A tolerance factor during decoding, between 0 and 1. During decoding, the image reader computes cell's width and height (i.e. the smallest non-null difference between ordinates in a given column: x for cell's width and y for cell's height). Then, it checks if every coordinate points fall on a grid having this cell's size. If a point depart from more than gridTolerance percent of cell's width or height, an exception is thrown.

gridTolerance should be a small number like 1E-5f or 1E-3f. The later is more tolerant than the former.

Constructor Detail

TextRecordImageReader.Spi

public TextRecordImageReader.Spi()

Constructs a default TextRecordImageReader.Spi. The fields are initialized as documented in the class javadoc. Subclasses can modify those values if desired.

For efficiency reasons, the above fields are initialized to shared arrays. Subclasses can assign new arrays, but should not modify the default array content.

Method Detail

getDescription

public String getDescription(Locale locale)

Returns a brief, human-readable description of this service provider and its associated implementation. The resulting string should be localized for the supplied locale, if possible.

Specified by:

getDescription in class IIOServiceProvider

Parameters:

locale - A Locale for which the return value should be localized.

Returns:

A String containing a description of this service provider.

createReaderInstance

public ImageReader createReaderInstance(Object extension)
                                 throws IOException

Returns an instance of the ImageReader implementation associated with this service provider.

Specified by:

createReaderInstance in class ImageReaderSpi

Parameters:

extension - An optional extension object, which may be null.

Returns:

An image reader instance.

Throws:

IOException - if the attempt to instantiate the reader fails.

isValidContent

protected boolean isValidContent(double[][] rows)

Returns true if the content of the first few rows seems valid, or false otherwise. The default implementation performs the same check than the super-class, and additionaly checks if the (x, y) values seem distributed on a regular grid.

Overrides:

isValidContent in class TextImageReader.Spi

Parameters:

rows - The first few rows.

Returns:

true if the given rows seem to have a valid content.

isValidColumnCount

protected boolean isValidColumnCount(int count)

Invoked by isValidColumnCount(int) for determining if the given number of columns is valid. Note that this is the number of columns in the data file, not to be confused with the image width.

Overrides:

isValidColumnCount in class TextImageReader.Spi

Parameters:

count - The number of columns in the first few line of rows.

Returns:

true if the given number of columns seems to be valid.

Since:

3.07

onRegistration

public void onRegistration(ServiceRegistry registry,
                           Class<?> category)

Invoked when this Service Provider is registered. This method sets the ordering of this TextRecordImageReader.Spi before TextMatrixImageReader.Spi, because the later is generic enough for claiming to be able to read records file.

Specified by:

onRegistration in interface RegisterableService

Overrides:

onRegistration in class IIOServiceProvider

Parameters:

registry - The registry where is service is registered.

category - The category for which this service is registered.