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Implementations of Coordinate Reference Systems (CRS),
conversion and transformation services derived from ISO 19111.
/*
* Geotoolkit.org - An Open Source Java GIS Toolkit
* http://www.geotoolkit.org
*
* (C) 2001-2011, Open Source Geospatial Foundation (OSGeo)
* (C) 2009-2011, Geomatys
*
* 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.geotoolkit.referencing.datum;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import javax.measure.unit.NonSI;
import javax.measure.unit.Unit;
import javax.measure.quantity.Angle;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;
import net.jcip.annotations.Immutable;
import org.opengis.referencing.datum.PrimeMeridian;
import org.geotoolkit.referencing.NamedIdentifier;
import org.geotoolkit.referencing.AbstractIdentifiedObject;
import org.geotoolkit.metadata.iso.citation.Citations;
import org.geotoolkit.io.wkt.Formatter;
import org.geotoolkit.util.ComparisonMode;
import org.geotoolkit.util.Utilities;
import org.geotoolkit.measure.Units;
import static org.geotoolkit.util.Utilities.hash;
import static org.geotoolkit.util.ArgumentChecks.ensureNonNull;
import static org.geotoolkit.internal.InternalUtilities.epsilonEqual;
/**
* A prime meridian defines the origin from which longitude values are determined.
* The {@link #getName name} initial value is "Greenwich", and that value shall be
* used when the {@linkplain #getGreenwichLongitude greenwich longitude} value is
* zero.
*
* @author Martin Desruisseaux (IRD, Geomatys)
* @author Cédric Briançon (Geomatys)
* @version 3.19
*
* @since 1.2
* @module
*/
@Immutable
@XmlRootElement(name = "PrimeMeridian")
public class DefaultPrimeMeridian extends AbstractIdentifiedObject implements PrimeMeridian {
/**
* Serial number for inter-operability with different versions.
*/
private static final long serialVersionUID = 541978454643213305L;;
/**
* The Greenwich meridian (EPSG:8901), with angular measurements in decimal degrees.
*/
public static final DefaultPrimeMeridian GREENWICH;
static {
final Map properties = new HashMap(4);
properties.put(NAME_KEY, "Greenwich");
properties.put(IDENTIFIERS_KEY, new NamedIdentifier(Citations.EPSG, "8901"));
GREENWICH = new DefaultPrimeMeridian(properties, 0, NonSI.DEGREE_ANGLE);
}
/**
* Longitude of the prime meridian measured from the Greenwich meridian, positive eastward.
*/
@XmlElement(required = true)
private final double greenwichLongitude;
/**
* The angular unit of the {@linkplain #getGreenwichLongitude Greenwich longitude}.
*/
private final Unit angularUnit;
/**
* Constructs a new object in which every attributes are set to a default value.
* This is not a valid object. This constructor is strictly
* reserved to JAXB, which will assign values to the fields using reflexion.
*/
private DefaultPrimeMeridian() {
this(GREENWICH);
}
/**
* Constructs a new prime meridian with the same values than the specified one.
* This copy constructor provides a way to convert an arbitrary implementation into a
* Geotk 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 meridian The prime meridian to copy.
*
* @since 2.2
*/
public DefaultPrimeMeridian(final PrimeMeridian meridian) {
super(meridian);
greenwichLongitude = meridian.getGreenwichLongitude();
angularUnit = meridian.getAngularUnit();
}
/**
* Constructs a prime meridian from a name. The {@code greenwichLongitude} value
* is assumed in {@linkplain NonSI#DEGREE_ANGLE decimal degrees}.
*
* @param name The datum name.
* @param greenwichLongitude The longitude value relative to the Greenwich Meridian.
*/
public DefaultPrimeMeridian(final String name, final double greenwichLongitude) {
this(name, greenwichLongitude, NonSI.DEGREE_ANGLE);
}
/**
* Constructs a prime meridian from a name.
*
* @param name The datum name.
* @param greenwichLongitude The longitude value relative to the Greenwich Meridian.
* @param angularUnit The angular unit of the longitude.
*/
public DefaultPrimeMeridian(final String name, final double greenwichLongitude,
final Unit angularUnit)
{
this(Collections.singletonMap(NAME_KEY, name), greenwichLongitude, angularUnit);
}
/**
* Constructs a prime meridian from a set of properties. The properties map is given
* unchanged to the {@linkplain AbstractIdentifiedObject#AbstractIdentifiedObject(Map)
* super-class constructor}.
*
* @param properties Set of properties. Should contains at least {@code "name"}.
* @param greenwichLongitude The longitude value relative to the Greenwich Meridian.
* @param angularUnit The angular unit of the longitude.
*/
public DefaultPrimeMeridian(final Map properties, final double greenwichLongitude,
final Unit angularUnit)
{
super(properties);
ensureNonNull("angularUnit", angularUnit);
this.greenwichLongitude = greenwichLongitude;
this.angularUnit = Units.ensureAngular(angularUnit);
}
/**
* Returns a Geotk prime meridian implementation with the same values than the given arbitrary
* implementation. If the given object is {@code null}, then this method returns {@code null}.
* Otherwise if the given object is already a Geotk implementation, then the given object is
* returned unchanged. Otherwise a new Geotk implementation is created and initialized to the
* attribute values of the given object.
*
* @param object The object to get as a Geotk implementation, or {@code null} if none.
* @return A Geotk implementation containing the values of the given object (may be the
* given object itself), or {@code null} if the argument was null.
*
* @since 3.18
*/
public static DefaultPrimeMeridian castOrCopy(final PrimeMeridian object) {
return (object == null) || (object instanceof DefaultPrimeMeridian)
? (DefaultPrimeMeridian) object : new DefaultPrimeMeridian(object);
}
/**
* @deprecated Renamed {@link #castOrCopy castOrCopy}.
* @param object The object to get as a Geotk implementation, or {@code null} if none.
* @return The given object as a Geotk implementation.
*/
@Deprecated
public static DefaultPrimeMeridian wrap(final PrimeMeridian object) {
return castOrCopy(object);
}
/**
* Longitude of the prime meridian measured from the Greenwich meridian, positive eastward.
* The {@code greenwichLongitude} initial value is zero, and that value shall be used
* when the {@linkplain #getName meridian name} value is "Greenwich".
*
* @return The prime meridian Greenwich longitude, in {@linkplain #getAngularUnit angular unit}.
*/
@Override
public double getGreenwichLongitude() {
return greenwichLongitude;
}
/**
* Returns the longitude value relative to the Greenwich Meridian, expressed in the specified
* units. This convenience method makes it easier to obtain longitude in decimal degrees
* ({@code getGreenwichLongitude(NonSI.DEGREE_ANGLE)}), regardless of the underlying
* angular units of this prime meridian.
*
* @param targetUnit The unit in which to express longitude.
* @return The Greenwich longitude in the given units.
*/
public double getGreenwichLongitude(final Unit targetUnit) {
return getAngularUnit().getConverterTo(targetUnit).convert(getGreenwichLongitude());
}
/**
* Returns the angular unit of the {@linkplain #getGreenwichLongitude Greenwich longitude}.
*/
@Override
public Unit getAngularUnit() {
return angularUnit;
}
/**
* Compare this prime meridian with the specified object for equality.
*
* @param object The object to compare to {@code this}.
* @param mode {@link ComparisonMode#STRICT STRICT} for performing a strict comparison, or
* {@link ComparisonMode#IGNORE_METADATA IGNORE_METADATA} for comparing only properties
* relevant to transformations.
* @return {@code true} if both objects are equal.
*/
@Override
public boolean equals(final Object object, final ComparisonMode mode) {
if (object == this) {
return true; // Slight optimization.
}
if (super.equals(object, mode)) {
switch (mode) {
case STRICT: {
final DefaultPrimeMeridian that = (DefaultPrimeMeridian) object;
return Utilities.equals(this.greenwichLongitude, that.greenwichLongitude) &&
Utilities.equals(this.angularUnit, that.angularUnit);
}
case BY_CONTRACT: {
final PrimeMeridian that = (PrimeMeridian) object;
return Utilities.equals(getGreenwichLongitude(), that.getGreenwichLongitude()) &&
Utilities.equals(getAngularUnit(), that.getAngularUnit());
}
default: {
final DefaultPrimeMeridian that = castOrCopy((PrimeMeridian) object);
return epsilonEqual(this.getGreenwichLongitude(NonSI.DEGREE_ANGLE),
that.getGreenwichLongitude(NonSI.DEGREE_ANGLE), mode);
/*
* Note: if mode==IGNORE_METADATA, we relax the unit check because EPSG uses
* sexagesimal degrees for the Greenwich meridian. Requirying the same
* unit prevent Geodetic.isWGS84(...) method to recognize EPSG's WGS84.
*/
}
}
}
return false;
}
/**
* {@inheritDoc}
*/
@Override
protected int computeHashCode() {
return hash(greenwichLongitude, super.computeHashCode());
}
/**
* Formats the inner part of a
* Well
* Known Text (WKT) element.
*
* @param formatter The formatter to use.
* @return The WKT element name, which is {@code "PRIMEM"}.
*/
@Override
public String formatWKT(final Formatter formatter) {
Unit context = formatter.getAngularUnit();
if (context == null) {
// If the PrimeMeridian is written inside a "GEOGCS",
// then OpenGIS say that it must be written into the
// unit of the enclosing geographic coordinate system.
// Otherwise, default to decimal degrees.
context = NonSI.DEGREE_ANGLE;
}
formatter.append(getGreenwichLongitude(context));
return "PRIMEM";
}
}