Application: gvSIG desktop » gvSIG tools: ToolBox

package es.unex.sextante.nonSpatial.calculator;

import java.util.HashMap;

import java.util.Iterator;

import java.util.Set;

import org.nfunk.jep.JEP;

import es.unex.sextante.core.GeoAlgorithm;

import es.unex.sextante.core.Sextante;

import es.unex.sextante.exceptions.GeoAlgorithmExecutionException;

import es.unex.sextante.exceptions.RepeatedParameterNameException;

import es.unex.sextante.gui.modeler.ModelAlgorithm;

import es.unex.sextante.modeler.elements.ModelElementNumericalValue;

public class CalculatorAlgorithm

         extends

            GeoAlgorithm {

   public static final String FORMULA = "FORMULA";

   public static final String RESULT  = "RESULT";

   @Override

   public void defineCharacteristics() {

      setName(Sextante.getText("Calculator"));

      setGroup(Sextante.getText("nonSpatial"));

      setUserCanDefineAnalysisExtent(false);

      try {

         m_Parameters.addString(FORMULA, Sextante.getText("Formula"));

         addOutputNumericalValue(RESULT, Sextante.getText("Result"));

      }

      catch (final RepeatedParameterNameException e) {

      }

   }

   @Override

   public boolean processAlgorithm() throws GeoAlgorithmExecutionException {

      final String sFormula = m_Parameters.getParameterValueAsString(FORMULA);

      final JEP jep = new JEP();

      jep.addStandardConstants();

      jep.addStandardFunctions();

      jep.parseExpression(sFormula);

      if (jep.hasError()) {

         Sextante.addErrorToLog(jep.getErrorInfo());

         throw new GeoAlgorithmExecutionException(Sextante.getText("Syntax_error"));

      }

      addOutputNumericalValue(RESULT, jep.getValue());

      return true;

   }

   @Override

   public boolean preprocessForModeller(final Object obj) throws GeoAlgorithmExecutionException {

      final ModelAlgorithm model = (ModelAlgorithm) obj;

      try {

         String sFormula = m_Parameters.getParameterValueAsString(FORMULA);

         final HashMap inputs = model.getInputs();

         final Set set = inputs.keySet();

         final Iterator iter = set.iterator();

         while (iter.hasNext()) {

            final Object key = iter.next();

            final Object input = inputs.get(key);

            if (input instanceof Double) {

               if (sFormula.contains((String) key)) {

                  sFormula = sFormula.replace(key.toString(), input.toString());

               }

            }

            if (input instanceof ModelElementNumericalValue) {

               if (sFormula.contains(((String) key).toLowerCase())) {

                  return false;

               }

            }

         }

         m_Parameters.getParameter(FORMULA).setParameterValue(sFormula);

      }

      catch (final Exception e) {

         throw new GeoAlgorithmExecutionException(Sextante.getText("Syntax_error"));

      }

      return true;

   }

}