/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2009-2011, 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.filter.expression;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.geotools.factory.CommonFactoryFinder;
import org.geotools.filter.capability.FunctionNameImpl;
import org.geotools.referencing.CRS;
import org.opengis.filter.FilterFactory2;
import org.opengis.filter.capability.FunctionName;
import org.opengis.filter.expression.Expression;
import org.opengis.filter.expression.ExpressionVisitor;
import org.opengis.filter.expression.Function;
import org.opengis.filter.expression.Literal;
import org.opengis.referencing.FactoryException;
import org.opengis.referencing.NoSuchAuthorityCodeException;
import org.opengis.referencing.crs.CoordinateReferenceSystem;
import com.vividsolutions.jts.geom.Coordinate;
import com.vividsolutions.jts.geom.GeometryFactory;
import com.vividsolutions.jts.geom.Point;
import com.vividsolutions.jts.geom.PrecisionModel;
/**
* This function converts double values to a 2D Point geometry type. This is needed when the data
* store doesn't have geometry type columns. This function expects:
* <ol>
* <li>Literal: SRS_NAME (optional)
* <li>Expression: expression of SRS_NAME if SRS_NAME is defined
* <li>Expression: name of column pointing to first double value
* <li>Expression: name of column pointing to second double value
* <li>Expression: expression of gml:id (optional)
* </ol>
*
* @author Rini Angreani (CSIRO Earth Science and Resource Engineering)
*
*
*
* @source $URL$
*/
public class ToPointFunction implements Function {
private final List<Expression> parameters;
private final Literal fallback;
private static final String USAGE = "Usage: toPoint('SRS_NAME'(optional), srsName(optional), point 1, point 2, gml:id(optional))";
public static final FunctionName NAME = new FunctionNameImpl("toPoint",
FunctionNameImpl.parameter("return", Point.class), FunctionNameImpl.parameter(
"parameter", Object.class, 2, 5));
private static FilterFactory2 ff = CommonFactoryFinder.getFilterFactory2(null);
public static final Expression GML_ID = ff.literal("gml:id");
public ToPointFunction() {
this(new ArrayList<Expression>(), null);
}
public ToPointFunction(List<Expression> parameters, Literal fallback) {
this.parameters = parameters;
this.fallback = fallback;
}
public String getName() {
return NAME.getName();
}
public FunctionName getFunctionName() {
return NAME;
}
public List<Expression> getParameters() {
return Collections.unmodifiableList(parameters);
}
public Literal getFallbackValue() {
return fallback;
}
public Object accept(ExpressionVisitor visitor, Object extraData) {
return visitor.visit(this, extraData);
}
public Object evaluate(Object object) {
return evaluate(object, Point.class);
}
@SuppressWarnings("unchecked")
public <T> T evaluate(Object object, Class<T> context) {
Point point;
Expression param1 = parameters.get(0);
if (param1.equals(ToDirectPositionFunction.SRS_NAME)) {
if (parameters.size() > 5 || parameters.size() < 4) {
throw new IllegalArgumentException(
"Wrong number of parameters for toPoint function: " + parameters.toString()
+ ". " + USAGE);
}
CoordinateReferenceSystem crs = null;
String srsName = parameters.get(1).evaluate(object, String.class);
try {
crs = CRS.decode((String) srsName);
} catch (NoSuchAuthorityCodeException e) {
throw new IllegalArgumentException(
"Invalid or unsupported SRS name detected for toPoint function: " + srsName
+ ". Cause: " + e.getMessage());
} catch (FactoryException e) {
throw new RuntimeException("Unable to decode SRS name. Cause: " + e.getMessage());
}
GeometryFactory fac = new GeometryFactory(new PrecisionModel());
point = fac.createPoint(new Coordinate(
parameters.get(2).evaluate(object, Double.class), parameters.get(3).evaluate(
object, Double.class)));
// set attributes
String gmlId = null;
if (parameters.size() == 5) {
gmlId = parameters.get(4).evaluate(object, String.class);
}
setUserData(point, crs, gmlId);
} else {
if (parameters.size() > 3 || parameters.size() < 2) {
throw new IllegalArgumentException(
"Wrong number of parameters for toPoint function: " + parameters.toString()
+ ". " + USAGE);
}
GeometryFactory fac = new GeometryFactory();
point = fac.createPoint(new Coordinate(param1.evaluate(object, Double.class),
parameters.get(1).evaluate(object, Double.class)));
if (parameters.size() == 3) {
String gmlId = parameters.get(2).evaluate(object, String.class);
setUserData(point, null, gmlId);
}
}
return (T) point;
}
/**
* Set point attributes into its user data to be encoded in Geoserver: gml:id, srsName,
* srsDimension, axisLabels and uomLabels.
*
* @param point
* The point object
* @param crs
* Coordinate System object
* @param srsName
* srs name
* @param gmlId
* gml:id value
*/
private void setUserData(Point geom, CoordinateReferenceSystem crs, String gmlId) {
Map<Object, Object> userData = new HashMap<Object, Object>();
if (gmlId != null) {
userData.put("gml:id", gmlId);
}
if (crs != null) {
userData.put(CoordinateReferenceSystem.class, crs);
}
geom.setUserData(userData);
}
}