/*
* 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.List;
import org.geotools.factory.CommonFactoryFinder;
import org.geotools.filter.capability.FunctionNameImpl;
import org.geotools.geometry.DirectPosition1D;
import org.geotools.geometry.DirectPosition2D;
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.geometry.DirectPosition;
import org.opengis.referencing.FactoryException;
import org.opengis.referencing.NoSuchAuthorityCodeException;
import org.opengis.referencing.crs.CoordinateReferenceSystem;
/**
* This function converts double values to DirectPosition 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 (optional, only for 2D)
* </ol>
*
* @author Rini Angreani (CSIRO Earth Science and Resource Engineering)
*
*
*
*
* @source $URL$
*/
public class ToDirectPositionFunction implements Function {
private final List<Expression> parameters;
private final Literal fallback;
private static final String USAGE = "Usage: toDirectPosition('SRS_NAME'(optional), srsName(optional), point 1, point 2(optional))";
public static final FunctionName NAME = new FunctionNameImpl("toDirectPosition",
FunctionNameImpl.parameter("return", DirectPosition.class), FunctionNameImpl.parameter(
"parameter", Object.class, 1, 4));
private static FilterFactory2 ff = CommonFactoryFinder.getFilterFactory2(null);
public static final Expression SRS_NAME = ff.literal("SRS_NAME");
public ToDirectPositionFunction() {
this(new ArrayList<Expression>(), null);
}
public ToDirectPositionFunction(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, DirectPosition.class);
}
@SuppressWarnings("unchecked")
public <T> T evaluate(Object object, Class<T> context) {
Expression param1 = parameters.get(0);
CoordinateReferenceSystem crs = null;
DirectPosition geom;
if (param1.equals(SRS_NAME)) {
// must be followed by srsName expression, and at least 1 point
if (parameters.size() < 3 || parameters.size() > 4) {
throw new IllegalArgumentException(
"Wrong number of parameters toDirectPosition function: "
+ parameters.toString() + ". " + USAGE);
}
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 toDirectPosition function: "
+ srsName + ". Cause: " + e.getMessage());
} catch (FactoryException e) {
throw new RuntimeException("Unable to decode SRS name. Cause: " + e.getMessage());
}
if (parameters.size() == 3) {
// 1D
geom = new DirectPosition1D(crs);
} else {
// 2D
geom = new DirectPosition2D(crs);
geom.setOrdinate(1, parameters.get(3).evaluate(object, Double.class));
}
geom.setOrdinate(0, parameters.get(2).evaluate(object, Double.class));
} else {
// should only have points, 1 for 1D, 2 for 2D
if (parameters.size() > 2) {
throw new IllegalArgumentException(
"Too many parameters for toDirectPosition function: "
+ parameters.toString() + ". " + USAGE);
}
if (parameters.size() == 1) {
// 1D
geom = new DirectPosition1D();
} else {
// 2D
geom = new DirectPosition2D();
geom.setOrdinate(1, parameters.get(1).evaluate(object, Double.class));
}
geom.setOrdinate(0, param1.evaluate(object, Double.class));
}
return (T) geom;
}
}