Application: gvSIG desktop

/* gvSIG. Sistema de Informaci�n Geogr�fica de la Generalitat Valenciana

 *

 * Copyright (C) 2004 IVER T.I. and Generalitat Valenciana.

 *

 * 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307,USA.

 *

 * For more information, contact:

 *

 *  Generalitat Valenciana

 *   Conselleria d'Infraestructures i Transport

 *   Av. Blasco Ib��ez, 50

 *   46010 VALENCIA

 *   SPAIN

 *

 *      +34 963862235

 *   gvsig@gva.es

 *      www.gvsig.gva.es

 *

 *    or

 *

 *   IVER T.I. S.A

 *   Salamanca 50

 *   46005 Valencia

 *   Spain

 *

 *   +34 963163400

 *   dac@iver.es

 */

package org.gvsig.sldsupport.filterencoding.operations;

import java.util.ArrayList;

import java.util.Hashtable;

import org.gvsig.i18n.Messages;

/**

 * Implements the funcionality of the minus operator

 *

 * @author Pepe Vidal Salvador - jose.vidal.salvador@iver.es

 *

 */

public class MinusOperator extends Operator {

        private ArrayList<Expression> arguments = new ArrayList<Expression>();

        public String getName() {

                return OperationTags.MINUS_OP;

        }

        public MinusOperator(Hashtable<String, Object> symbol_table) {

                super(symbol_table);

        }

        public Object evaluate()throws ExpressionException {

                Double doubleResult = null;

                Integer intResult = null;

                try {

                        intResult = (Integer)((Expression)arguments.get(0)).evaluate();

                        if (intResult == null){

                                intResult=new Integer(0);

                        }

                        if (arguments.size() == 1)

                                return -1*intResult;

                        for (int i = 1; i < arguments.size(); i++){

                                Expression function = (Expression)arguments.get(i);

                                Integer eval=((Integer)function.evaluate());

                                if (eval==null)

                                        eval=new Integer(0);

                                intResult -= eval;

                        }

                        return intResult;

                } catch (ClassCastException e) {

                        doubleResult = new Double(((Expression)arguments.get(0)).evaluate().toString());

                        if (doubleResult == null){

                                doubleResult=new Double(0);

                        }

                        if(arguments.size() == 1)

                                return -1*doubleResult;

                        for (int i = 1; i < arguments.size(); i++){

                                Expression function = (Expression)arguments.get(i);

                                Double eval=(Double)((Expression)function).evaluate();

                                if (eval==null)

                                        eval=new Double(0);

                                doubleResult -= new Double(eval.toString());

                        }

                        return doubleResult;

                }

        }

        public void addArgument(int i, Expression arg) {

                arguments.add(i, arg);

        }

        public String getPattern() {

                return "("+Messages.getText(OperationTags.OPERAND)

                + OperationTags.MINUS_OP +Messages.getText(OperationTags.OPERAND)+ ")\n"+

                Messages.getText(OperationTags.OPERAND) +" = "+

                Messages.getText(OperationTags.NUMERIC_VALUE );

        }

        public ArrayList<Expression> getArguments() {

                return arguments;

        }

        public void setArguments(ArrayList<Expression> arguments) {

                this.arguments = arguments;

        }

        public void check() throws ExpressionException {

                for (int i = 0; i < arguments.size(); i++) {

                        if(!(arguments.get(i)instanceof NumericalConstant))

                                throw new ExpressionException(ExpressionException.CLASS_CASTING_EXCEPTION);

                }

        }

}