/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 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.xacml.geoxacml.cond;
import java.net.URISyntaxException;
import java.util.List;
import org.geotools.xacml.geoxacml.attr.GeometryAttribute;
import com.sun.xacml.EvaluationCtx;
import com.sun.xacml.attr.AttributeValue;
import com.sun.xacml.cond.EvaluationResult;
import com.sun.xacml.cond.Expression;
import com.vividsolutions.jts.geom.Geometry;
/**
* Calculates the convex hull
*
* @author Christian Mueller
*
*/
public class GeometryConvexHull extends GeometryConstructFunction {
public static final String NAME = NAME_PREFIX + "geometry-convex-hull";
public GeometryConvexHull() {
super(NAME, 0, new String[] { GeometryAttribute.identifier },
new boolean[] { false, false }, GeometryAttribute.identifier, false);
}
public EvaluationResult evaluate(List<? extends Expression> inputs, EvaluationCtx context) {
AttributeValue[] argValues = new AttributeValue[inputs.size()];
EvaluationResult result = evalArgs(inputs, context, argValues);
if (result != null)
return result;
GeometryAttribute geomAttr = (GeometryAttribute) (argValues[0]);
Geometry resultGeom = null;
try {
resultGeom = geomAttr.getGeometry().convexHull();
} catch (Throwable t) {
return exceptionError(t);
}
GeometryAttribute resultAttr = null;
try {
resultAttr = new GeometryAttribute(resultGeom, geomAttr.getSrsName(), null, null, null);
} catch (URISyntaxException e) {
// should not happend
}
return new EvaluationResult(resultAttr);
}
}