/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2004-2008, Open Source Geospatial Foundation (OSGeo)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* This package contains documentation from OpenGIS specifications.
* OpenGIS consortium's work is fully acknowledged here.
*/
package org.geotools.referencing.datum;
import java.util.Collections;
import java.util.Map;
import org.opengis.referencing.datum.ImageDatum;
import org.opengis.referencing.datum.PixelInCell;
import org.geotools.referencing.AbstractIdentifiedObject;
import org.geotools.referencing.wkt.Formatter;
import org.geotools.util.Utilities;
/**
* Defines the origin of an image coordinate reference system. An image datum is used in a local
* context only. For an image datum, the anchor point is usually either the centre of the image
* or the corner of the image.
*
* @source $URL$
* @version $Id$
* @author Martin Desruisseaux (IRD)
*
* @since 2.1
*/
public class DefaultImageDatum extends AbstractDatum implements ImageDatum {
/**
* Serial number for interoperability with different versions.
*/
private static final long serialVersionUID = -4304193511244150936L;
/**
* Specification of the way the image grid is associated with the image data attributes.
*/
private final PixelInCell pixelInCell;
/**
* Constructs a new datum with the same values than the specified one.
* This copy constructor provides a way to wrap an arbitrary implementation into a
* Geotools one or a user-defined one (as a subclass), usually in order to leverage
* some implementation-specific API. This constructor performs a shallow copy,
* i.e. the properties are not cloned.
*
* @param datum The datum to copy.
*
* @since 2.2
*/
public DefaultImageDatum(final ImageDatum datum) {
super(datum);
pixelInCell = datum.getPixelInCell();
}
/**
* Constructs an image datum from a name.
*
* @param name The datum name.
* @param pixelInCell the way the image grid is associated with the image data attributes.
*/
public DefaultImageDatum(final String name, final PixelInCell pixelInCell) {
this(Collections.singletonMap(NAME_KEY, name), pixelInCell);
}
/**
* Constructs an image datum from a set of properties. The properties map is given
* unchanged to the {@linkplain AbstractDatum#AbstractDatum(Map) super-class constructor}.
*
* @param properties Set of properties. Should contains at least {@code "name"}.
* @param pixelInCell the way the image grid is associated with the image data attributes.
*/
public DefaultImageDatum(final Map<String,?> properties, final PixelInCell pixelInCell) {
super(properties);
this.pixelInCell = pixelInCell;
ensureNonNull("pixelInCell", pixelInCell);
}
/**
* Specification of the way the image grid is associated with the image data attributes.
*
* @return The way image grid is associated with image data attributes.
*/
public PixelInCell getPixelInCell() {
return pixelInCell;
}
/**
* Compare this datum with the specified object for equality.
*
* @param object The object to compare to {@code this}.
* @param compareMetadata {@code true} for performing a strict comparaison, or
* {@code false} for comparing only properties relevant to transformations.
* @return {@code true} if both objects are equal.
*/
@Override
public boolean equals(final AbstractIdentifiedObject object, final boolean compareMetadata) {
if (object == this) {
return true; // Slight optimization.
}
if (super.equals(object, compareMetadata)) {
final DefaultImageDatum that = (DefaultImageDatum) object;
return Utilities.equals(this.pixelInCell, that.pixelInCell);
}
return false;
}
/**
* Returns a hash value for this image datum. {@linkplain #getName Name},
* {@linkplain #getRemarks remarks} and the like are not taken in account. In
* other words, two image datums will return the same hash value if they
* are equal in the sense of
* <code>{@link #equals equals}(AbstractIdentifiedObject, <strong>false</strong>)</code>.
*
* @return The hash code value. This value doesn't need to be the same
* in past or future versions of this class.
*/
@Override
public int hashCode() {
return super.hashCode() ^ pixelInCell.hashCode();
}
/**
* Format the inner part of a
* <A HREF="http://geoapi.sourceforge.net/snapshot/javadoc/org/opengis/referencing/doc-files/WKT.html"><cite>Well
* Known Text</cite> (WKT)</A> element.
*
* <strong>Note:</strong> WKT of image datum is not yet part of OGC specification.
*
* @param formatter The formatter to use.
* @return The WKT element name.
*/
@Override
protected String formatWKT(final Formatter formatter) {
super.formatWKT(formatter);
formatter.append(pixelInCell);
formatter.setInvalidWKT(ImageDatum.class);
return "IMAGE_DATUM";
}
}