/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2001-2008, 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.Date;
import java.util.HashMap;
import java.util.Map;
import org.opengis.metadata.extent.Extent;
import org.opengis.referencing.datum.Datum;
import org.opengis.util.InternationalString;
import org.geotools.referencing.AbstractIdentifiedObject;
import org.geotools.referencing.wkt.Formatter;
import org.geotools.util.Utilities;
import org.geotools.resources.Classes;
import org.geotools.resources.i18n.Vocabulary;
/**
* Specifies the relationship of a coordinate system to the earth, thus creating a {@linkplain
* org.opengis.referencing.crs.CoordinateReferenceSystem coordinate reference system}. A datum
* uses a parameter or set of parameters that determine the location of the origin of the coordinate
* reference system. Each datum subtype can be associated with only specific types of
* {@linkplain org.opengis.referencing.cs.AbstractCS coordinate systems}.
* <p>
* A datum can be defined as a set of real points on the earth that have coordinates.
* The definition of the datum may also include the temporal behavior (such as the
* rate of change of the orientation of the coordinate axes).
* <p>
* This class is conceptually <cite>abstract</cite>, even if it is technically possible to
* instantiate it. Typical applications should create instances of the most specific subclass with
* {@code Default} prefix instead. An exception to this rule may occurs when it is not possible to
* identify the exact type.
*
*
* @source $URL$
* @version $Id$
* @author Martin Desruisseaux (IRD)
*
* @since 2.1
*
* @see org.geotools.referencing.cs.AbstractCS
* @see org.geotools.referencing.crs.AbstractCRS
*/
public class AbstractDatum extends AbstractIdentifiedObject implements Datum {
/**
* Serial number for interoperability with different versions.
*/
private static final long serialVersionUID = -4894180465652474930L;
/**
* List of localizable properties. To be given to
* {@link AbstractIdentifiedObject} constructor.
*/
private static final String[] LOCALIZABLES = {ANCHOR_POINT_KEY, SCOPE_KEY};
/**
* Description, possibly including coordinates, of the point or points used to anchor the datum
* to the Earth. Also known as the "origin", especially for Engineering and Image Datums.
*/
private final InternationalString anchorPoint;
/**
* The time after which this datum definition is valid. This time may be precise
* (e.g. 1997 for IRTF97) or merely a year (e.g. 1983 for NAD83). If the time is
* not defined, then the value is {@link Long#MIN_VALUE}.
*/
private final long realizationEpoch;
/**
* Area or region in which this datum object is valid.
*/
private final Extent domainOfValidity;
/**
* Description of domain of usage, or limitations of usage, for which this
* datum object is valid.
*/
private final InternationalString scope;
/**
* 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 AbstractDatum(final Datum datum) {
super(datum);
final Date epoch = datum.getRealizationEpoch();
realizationEpoch = (epoch!=null) ? epoch.getTime() : Long.MIN_VALUE;
domainOfValidity = datum.getDomainOfValidity();
scope = datum.getScope();
anchorPoint = datum.getAnchorPoint();
}
/**
* Constructs a datum from a set of properties. The properties given in argument follow
* the same rules than for the {@linkplain AbstractIdentifiedObject#AbstractIdentifiedObject(Map)
* super-class constructor}. Additionally, the following properties are understood by this
* construtor:
* <br><br>
* <table border='1'>
* <tr bgcolor="#CCCCFF" class="TableHeadingColor">
* <th nowrap>Property name</th>
* <th nowrap>Value type</th>
* <th nowrap>Value given to</th>
* </tr>
* <tr>
* <td nowrap> {@link #ANCHOR_POINT_KEY "anchorPoint"} </td>
* <td nowrap> {@link InternationalString} or {@link String} </td>
* <td nowrap> {@link #getAnchorPoint}</td>
* </tr>
* <tr>
* <td nowrap> {@link #REALIZATION_EPOCH_KEY "realizationEpoch"} </td>
* <td nowrap> {@link Date} </td>
* <td nowrap> {@link #getRealizationEpoch}</td>
* </tr>
* <tr>
* <td nowrap> {@link #DOMAIN_OF_VALIDITY_KEY "domainOfValidity"} </td>
* <td nowrap> {@link Extent} </td>
* <td nowrap> {@link #getDomainOfValidity}</td>
* </tr>
* <tr>
* <td nowrap> {@link #SCOPE_KEY "scope"} </td>
* <td nowrap> {@link InternationalString} or {@link String} </td>
* <td nowrap> {@link #getScope}</td>
* </tr>
* </table>
*
* @param properties The properties to be given to the identified object.
*/
public AbstractDatum(final Map<String,?> properties) {
this(properties, new HashMap<String,Object>());
}
/**
* Work around for RFE #4093999 in Sun's bug database
* ("Relax constraint on placement of this()/super() call in constructors").
*/
private AbstractDatum(final Map<String,?> properties, final Map<String,Object> subProperties) {
super(properties, subProperties, LOCALIZABLES);
final Date realizationEpoch;
anchorPoint = (InternationalString) subProperties.get(ANCHOR_POINT_KEY );
realizationEpoch = (Date) subProperties.get(REALIZATION_EPOCH_KEY );
domainOfValidity = (Extent) subProperties.get(DOMAIN_OF_VALIDITY_KEY);
scope = (InternationalString) subProperties.get(SCOPE_KEY );
this.realizationEpoch = (realizationEpoch != null) ?
realizationEpoch.getTime() : Long.MIN_VALUE;
}
/**
* Same convenience method than {@link org.geotools.cs.AbstractCS#name} except that we get
* the unlocalized name (usually in English locale), because the name is part of the elements
* compared by the {@link #equals} method.
*/
static Map<String,Object> name(final int key) {
final Map<String,Object> properties = new HashMap<String,Object>(4);
final InternationalString name = Vocabulary.formatInternational(key);
properties.put(NAME_KEY, name.toString(null)); // "null" required for unlocalized version.
properties.put(ALIAS_KEY, name);
return properties;
}
/**
* Description, possibly including coordinates, of the point or points used to anchor the datum
* to the Earth. Also known as the "origin", especially for Engineering and Image Datums.
*
* <ul>
* <li>For a geodetic datum, this point is also known as the fundamental point, which is
* traditionally the point where the relationship between geoid and ellipsoid is defined.
* In some cases, the "fundamental point" may consist of a number of points. In those
* cases, the parameters defining the geoid/ellipsoid relationship have then been averaged
* for these points, and the averages adopted as the datum definition.</li>
*
* <li>For an engineering datum, the anchor point may be a physical point, or it may be a
* point with defined coordinates in another CRS.</li>
*
* <li>For an image datum, the anchor point is usually either the centre of the image or the
* corner of the image.</li>
*
* <li>For a temporal datum, this attribute is not defined. Instead of the anchor point,
* a temporal datum carries a separate time origin of type {@link Date}.</li>
* </ul>
*/
public InternationalString getAnchorPoint() {
return anchorPoint;
}
/**
* The time after which this datum definition is valid. This time may be precise (e.g. 1997
* for IRTF97) or merely a year (e.g. 1983 for NAD83). In the latter case, the epoch usually
* refers to the year in which a major recalculation of the geodetic control network, underlying
* the datum, was executed or initiated. An old datum can remain valid after a new datum is
* defined. Alternatively, a datum may be superseded by a later datum, in which case the
* realization epoch for the new datum defines the upper limit for the validity of the
* superseded datum.
*/
public Date getRealizationEpoch() {
return (realizationEpoch!=Long.MIN_VALUE) ? new Date(realizationEpoch) : null;
}
/**
* Area or region or timeframe in which this datum is valid.
*
* @since 2.4
*/
public Extent getDomainOfValidity() {
return domainOfValidity;
}
/**
* Area or region in which this datum object is valid.
*
* @deprecated Renamed {@link #getDomainOfValidity}.
*/
public Extent getValidArea() {
return domainOfValidity;
}
/**
* Description of domain of usage, or limitations of usage, for which this
* datum object is valid.
*/
public InternationalString getScope() {
return scope;
}
/**
* Gets the type of the datum as an enumerated code. Datum type was provided
* for all kind of datum in the legacy OGC 01-009 specification. In the new
* OGC 03-73 (ISO 19111) specification, datum type is provided only for
* vertical datum. Nevertheless, we keep this method around since it is
* needed for WKT formatting. Note that we returns the datum type ordinal
* value, not the code list object.
*/
int getLegacyDatumType() {
return 0;
}
/**
* Compares the specified object with this datum 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 (super.equals(object, compareMetadata)) {
if (!compareMetadata) {
/*
* Tests for name, since datum with different name have completly
* different meaning. We don't perform this comparaison if the user
* asked for metadata comparaison, because in such case the names
* have already been compared by the subclass.
*/
return nameMatches(object.getName().getCode()) ||
object.nameMatches(getName().getCode());
}
final AbstractDatum that = (AbstractDatum) object;
return this.realizationEpoch == that.realizationEpoch &&
Utilities.equals(this.domainOfValidity, that.domainOfValidity) &&
Utilities.equals(this.anchorPoint, that.anchorPoint) &&
Utilities.equals(this.scope, that.scope);
}
return false;
}
/**
* 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.
*
* Note: All subclasses will override this method, but only {@link DefaultGeodeticDatum} will
* <strong>not</strong> invokes this parent method, because horizontal datum do not write
* the datum type.
*
* @param formatter The formatter to use.
* @return The WKT element name.
*/
@Override
protected String formatWKT(final Formatter formatter) {
formatter.append(getLegacyDatumType());
return Classes.getShortClassName(this);
}
}