Application: gvSIG desktop » gvSIG tools: ToolBox

package es.unex.sextante.vectorTools.simplifyPolygons;

import com.vividsolutions.jts.geom.Geometry;

import com.vividsolutions.jts.simplify.DouglasPeuckerSimplifier;

import com.vividsolutions.jts.simplify.TopologyPreservingSimplifier;

import es.unex.sextante.additionalInfo.AdditionalInfoNumericalValue;

import es.unex.sextante.additionalInfo.AdditionalInfoVectorLayer;

import es.unex.sextante.core.GeoAlgorithm;

import es.unex.sextante.core.Sextante;

import es.unex.sextante.dataObjects.IFeature;

import es.unex.sextante.dataObjects.IFeatureIterator;

import es.unex.sextante.dataObjects.IVectorLayer;

import es.unex.sextante.dataObjects.vectorFilters.BoundingBoxFilter;

import es.unex.sextante.exceptions.GeoAlgorithmExecutionException;

import es.unex.sextante.exceptions.RepeatedParameterNameException;

import es.unex.sextante.outputs.OutputVectorLayer;

public class SimplifyPolygonsAlgorithm

         extends

            GeoAlgorithm {

   public static final String RESULT    = "RESULT";

   public static final String PRESERVE  = "PRESERVE";

   public static final String TOLERANCE = "TOLERANCE";

   public static final String LAYER     = "LAYER";

   private boolean            m_bPreserve;

   @Override

   public boolean processAlgorithm() throws GeoAlgorithmExecutionException {

      final IVectorLayer layerIn = m_Parameters.getParameterValueAsVectorLayer(LAYER);

      final double dTolerance = m_Parameters.getParameterValueAsDouble(TOLERANCE);

      m_bPreserve = m_Parameters.getParameterValueAsBoolean(PRESERVE);

      if (!m_bIsAutoExtent) {

         layerIn.addFilter(new BoundingBoxFilter(m_AnalysisExtent));

      }

      final IVectorLayer output = getNewVectorLayer(RESULT, Sextante.getText("Simplified_polygons"),

               IVectorLayer.SHAPE_TYPE_POLYGON, layerIn.getFieldTypes(), layerIn.getFieldNames());

      final IFeatureIterator iter = layerIn.iterator();

      int i = 0;

      final int iCount = layerIn.getShapesCount();

      while (iter.hasNext() && setProgress(i, iCount)) {

         final IFeature feature = iter.next();

         final Geometry simpleGeom = getSimpleLine(feature.getGeometry(), dTolerance);

         output.addFeature(simpleGeom, feature.getRecord().getValues());

         i++;

      }

      return !m_Task.isCanceled();

   }

   @Override

   public void defineCharacteristics() {

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

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

      setUserCanDefineAnalysisExtent(true);

      try {

         m_Parameters.addInputVectorLayer(LAYER, Sextante.getText("Polygons"), AdditionalInfoVectorLayer.SHAPE_TYPE_POLYGON, true);

         m_Parameters.addNumericalValue(TOLERANCE, Sextante.getText("Tolerance"),

                  AdditionalInfoNumericalValue.NUMERICAL_VALUE_DOUBLE, 10, 0, Double.MAX_VALUE);

         m_Parameters.addBoolean(PRESERVE, Sextante.getText("Preserve_topology"), false);

         addOutputVectorLayer(RESULT, Sextante.getText("Simplified_polygons"), OutputVectorLayer.SHAPE_TYPE_POLYGON);

      }

      catch (final RepeatedParameterNameException e) {

         Sextante.addErrorToLog(e);

      }

   }

   private Geometry getSimpleLine(final Geometry geometry,

                                  final double dTolerance) {

      Geometry simple;

      if (m_bPreserve) {

         simple = TopologyPreservingSimplifier.simplify(geometry, dTolerance);

      }

      else {

         simple = DouglasPeuckerSimplifier.simplify(geometry, dTolerance);

      }

      return simple;

   }

}