Application: gvSIG desktop

/* gvSIG. Geographic Information System of the Valencian Government

 *

 * Copyright (C) 2007-2008 Infrastructures and Transports Department

 * of the Valencian Government (CIT)

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version 2

 * of the License, or (at your option) any later version.

 *

 * This program 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 General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,

 * MA  02110-1301, USA.

 *

 */

/*

 * AUTHORS (In addition to CIT):

 * 2008 IVER T.I. S.A.   {{Task}}

 */

package org.gvsig.fmap.data.vectorial.expressionevaluator.functions;

import org.gvsig.fmap.geom.Geometry;

import org.gvsig.fmap.geom.operation.GeometryOperationException;

import org.gvsig.fmap.geom.operation.GeometryOperationNotSupportedException;

import org.gvsig.fmap.geom.operation.fromwkt.FromWKT;

import org.gvsig.fmap.geom.operation.fromwkt.FromWKTGeometryOperationContext;

import org.gvsig.fmap.geom.primitive.NullGeometry;

import org.medfoster.sqljep.ASTFunNode;

import org.medfoster.sqljep.JepRuntime;

import org.medfoster.sqljep.ParseException;

import org.medfoster.sqljep.function.PostfixCommand;

public class GeomFromText extends PostfixCommand {

        private static Geometry nullGeometry = new NullGeometry();

        public static final String NAME = "GeomFromText";

        private static String lastTextGeometry="";

        private static String lastSRS="";

        private static Geometry lastGeometry=null;

        final public int getNumberOfParameters() {

                return 2;

        }

        /*

         * (non-Javadoc)

         *

         * @see org.medfoster.sqljep.function.PostfixCommand#evaluate(org.medfoster.sqljep.ASTFunNode,

         *      org.medfoster.sqljep.JepRuntime)

         */

        public void evaluate(ASTFunNode node, JepRuntime runtime)

                        throws ParseException {

                node.childrenAccept(runtime.ev, null);

                String srs = (String) runtime.stack.pop();

                String text = (String) runtime.stack.pop();

                runtime.stack.push(geometryFromText(text, srs));

        }

        private static Object geometryFromText(String text, String srs)

                        throws ParseException {

                if (!lastTextGeometry.equals(text) || !lastSRS.equals(srs)) {

                        try {

                                lastGeometry = (Geometry) nullGeometry.invokeOperation(

                                                FromWKT.CODE,

                                                new FromWKTGeometryOperationContext(text,srs)

                                        );

                        } catch (GeometryOperationNotSupportedException e) {

                                throw new ParseException(NAME, e);

                        } catch (GeometryOperationException e) {

                                throw new ParseException(NAME, e);

                        }

                        lastTextGeometry = text;

                        lastSRS = srs;

                }

                return lastGeometry;

        }

}