/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2006-2008, 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.
*/
package org.geotools.referencing.factory.epsg;
// OpenGIS dependencies
import org.opengis.metadata.citation.Citation;
import org.opengis.referencing.FactoryException;
import org.opengis.referencing.cs.CSAuthorityFactory;
import org.opengis.referencing.crs.CRSAuthorityFactory;
import org.opengis.referencing.datum.DatumAuthorityFactory;
import org.opengis.referencing.operation.CoordinateOperationAuthorityFactory;
// Geotools dependencies
import org.geotools.factory.Hints;
import org.geotools.factory.GeoTools;
import org.geotools.factory.FactoryRegistryException;
import org.geotools.factory.FactoryNotFoundException;
import org.geotools.referencing.ReferencingFactoryFinder;
import org.geotools.referencing.factory.AbstractAuthorityFactory;
import org.geotools.referencing.factory.DeferredAuthorityFactory;
import org.geotools.referencing.factory.OrderedAxisAuthorityFactory;
import org.geotools.metadata.iso.citation.Citations;
/**
* An EPSG authority factory using (<var>longitude</var>, <var>latitude</var>) axis order.
* This factory wraps a {@link ThreadedEpsgFactory} into an {@link OrderedAxisAuthorityFactory}
* when first needed.
* <p>
* Users don't need to create explicitly an instance of this class. Instead, one can get
* an instance using the following code:
*
* <blockquote><pre>
* Hints hints = new Hints({@linkplain Hints#FORCE_LONGITUDE_FIRST_AXIS_ORDER}, Boolean.TRUE);
* CRSAuthorityFactory factory = {@linkplain ReferencingFactoryFinder}.getCRSAuthorityFactory("EPSG", hints);
* </pre></blockquote>
*
* @since 2.3
*
*
* @source $URL$
* @version $Id$
* @author Martin Desruisseaux
*
* @see OrderedAxisAuthorityFactory
* @see Hints#FORCE_LONGITUDE_FIRST_AXIS_ORDER
* @tutorial http://docs.codehaus.org/display/GEOTOOLS/The+axis+order+issue
*/
public class LongitudeFirstFactory extends DeferredAuthorityFactory implements CRSAuthorityFactory,
CSAuthorityFactory, CoordinateOperationAuthorityFactory, DatumAuthorityFactory
{
/*
* Implementation note: in theory the DatumAuthorityFactory interface is useless here, since
* "axis order" doesn't make any sense for them. However if we do not register this class for
* the DatumAuthorityFactory as well, user will get a FactoryNotFoundException when asking for
* a factory with the FORCE_LONGITUDE_FIRST_AXIS_ORDER hint set.
*/
/**
* The {@linkplain System#getProperty(String) system property} key for setting the default
* {@link Hints#FORCE_LONGITUDE_FIRST_AXIS_ORDER FORCE_LONGITUDE_FIRST_AXIS_ORDER} hint value.
* This setting can provide a transition path for projects expecting a (<var>longitude</var>,
* <var>latitude</var>) axis order on a system-wide level. Application developpers can set the
* default value as below:
*
* <blockquote><pre>
* System.setProperty(SYSTEM_DEFAULT_KEY, "true");
* </pre></blockquote>
*
* Note that this system property applies mostly to the default EPSG factory. Most other
* factories ({@code "CRS"}, {@code "AUTO"}, <cite>etc.</cite>) don't need this property
* since they use (<var>longitude</var>, <var>latitude</var>) axis order by design.
*
* @see Hints#FORCE_LONGITUDE_FIRST_AXIS_ORDER
*
* @deprecated Moved to {@link GeoTools#FORCE_LONGITUDE_FIRST_AXIS_ORDER}.
*/
public static final String SYSTEM_DEFAULT_KEY = GeoTools.FORCE_LONGITUDE_FIRST_AXIS_ORDER;
/**
* Creates a default factory. The
* {@link Hints#FORCE_LONGITUDE_FIRST_AXIS_ORDER FORCE_LONGITUDE_FIRST_AXIS_ORDER}
* hint is always set to {@link Boolean#TRUE TRUE}. The
* {@link Hints#FORCE_STANDARD_AXIS_DIRECTIONS FORCE_STANDARD_AXIS_DIRECTIONS} and
* {@link Hints#FORCE_STANDARD_AXIS_UNITS FORCE_STANDARD_AXIS_UNITS} hints are set
* to {@link Boolean#FALSE FALSE} by default. A different value for those two hints
* can be specified using the {@linkplain LongitudeFirstFactory(Hints) constructor
* below}.
*/
public LongitudeFirstFactory() {
this(null);
}
/**
* Creates a factory from the specified set of hints.
*
* @param userHints An optional set of hints, or {@code null} for the default values.
*/
public LongitudeFirstFactory(final Hints userHints) {
super(userHints, ThreadedEpsgFactory.PRIORITY + relativePriority());
// See comment in createBackingStore() method body.
hints.put(Hints.FORCE_LONGITUDE_FIRST_AXIS_ORDER, Boolean.TRUE);
put(userHints, Hints.FORCE_STANDARD_AXIS_DIRECTIONS);
put(userHints, Hints.FORCE_STANDARD_AXIS_UNITS);
}
/**
* Stores a value from the specified hints.
*/
private void put(final Hints userHints, final Hints.Key key) {
Object value = null;
if (userHints != null) {
value = userHints.get(key);
}
if (value == null) {
value = Boolean.FALSE;
}
hints.put(key, value);
}
/**
* Returns the priority to use relative to the {@link ThreadedEpsgFactory} priority. The default
* priority should be lower, except if the <code>{@value #SYSTEM_DEFAULT_KEY}</code> system
* property is set to {@code true}.
*
* @deprecated Not needed anymore since {@link GeoTools#getDefaultHints}.
*/
private static int relativePriority() {
try {
if (Boolean.getBoolean(GeoTools.FORCE_LONGITUDE_FIRST_AXIS_ORDER)) {
return +7;
}
} catch (SecurityException e) {
// Fall back on default value.
}
return -7;
}
/**
* Returns the authority for this EPSG database.
* This authority will contains the database version in the {@linkplain Citation#getEdition
* edition} attribute, together with the {@linkplain Citation#getEditionDate edition date}.
*/
public Citation getAuthority() {
final Citation authority = super.getAuthority();
return (authority!=null) ? authority : Citations.EPSG;
}
/**
* Returns the factory instance (usually {@link ThreadedEpsgFactory})
* to be used as the backing store.
*
* @throws FactoryException If no suitable factory instance was found.
*/
protected AbstractAuthorityFactory createBackingStore() throws FactoryException {
/*
* Set the hints for the backing store to fetch. I'm not sure that we should request a
* org.geotools.referencing.factory.epsg.ThreadedEpsgFactory implementation; for now we are
* making this requirement mostly as a safety in order to get an implementation that is
* known to work, but we could relax that in a future version. AbstractAuthorityFactory
* is the minimal class required with current OrderedAxisAuthorityFactory API.
*
* The really important hints are the FORCE_*_AXIS_* handled by this class, which MUST
* be set to FALSE. This is especially important for FORCE_LONGITUDE_FIRST_AXIS_ORDER,
* which must be set to a different value than the value set by the constructor in order
* to prevent LongitudeFirstFactory to fetch itself. The other hints must also be set to
* false since forcing axis directions / units is handled by OrderedAxisAuthorityFactory
* and we don't want the backing store to interfer with that.
*/
final Hints backingStoreHints;
backingStoreHints = new Hints(Hints.CRS_AUTHORITY_FACTORY, ThreadedEpsgFactory.class);
backingStoreHints.put(Hints.FORCE_LONGITUDE_FIRST_AXIS_ORDER, Boolean.FALSE);
backingStoreHints.put(Hints.FORCE_STANDARD_AXIS_DIRECTIONS, Boolean.FALSE);
backingStoreHints.put(Hints.FORCE_STANDARD_AXIS_UNITS, Boolean.FALSE);
final AbstractAuthorityFactory factory;
try {
factory = (AbstractAuthorityFactory)
ReferencingFactoryFinder.getCRSAuthorityFactory("EPSG", backingStoreHints);
} catch (FactoryNotFoundException exception) {
throw new org.geotools.referencing.factory.FactoryNotFoundException(exception);
} catch (FactoryRegistryException exception) {
throw new FactoryException(exception);
}
return new OrderedAxisAuthorityFactory(factory, new Hints(hints), null);
}
}