Application: gvSIG desktop » gvSIG tools: ToolBox

package it.falciano.sextante.polygonize;

import java.util.ArrayList;

import java.util.Collection;

import com.vividsolutions.jts.geom.Geometry;

import com.vividsolutions.jts.geom.GeometryCollection;

import com.vividsolutions.jts.geom.GeometryFactory;

import com.vividsolutions.jts.geom.LineString;

import com.vividsolutions.jts.geom.MultiLineString;

import com.vividsolutions.jts.geom.Polygon;

import com.vividsolutions.jts.geom.TopologyException;

import com.vividsolutions.jts.operation.polygonize.Polygonizer;

import com.vividsolutions.jts.precision.EnhancedPrecisionOp;

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 PolygonizeAlgorithm

         extends

            GeoAlgorithm {

   public static final String LAYER  = "LAYER";

   public static final String RESULT = "RESULT";

   private IVectorLayer       m_Layer;

   private IVectorLayer       m_Output;

   @Override

   public void defineCharacteristics() {

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

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

      setUserCanDefineAnalysisExtent(true);

      try {

         m_Parameters.addInputVectorLayer(LAYER, Sextante.getText("Polylines"), AdditionalInfoVectorLayer.SHAPE_TYPE_LINE, true);

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

      }

      catch (final RepeatedParameterNameException e) {

         Sextante.addErrorToLog(e);

      }

   }

   @Override

   @SuppressWarnings("unchecked")

   public boolean processAlgorithm() throws GeoAlgorithmExecutionException {

      m_Layer = m_Parameters.getParameterValueAsVectorLayer(LAYER);

      if (!m_bIsAutoExtent) {

         m_Layer.addFilter(new BoundingBoxFilter(m_AnalysisExtent));

      }

      final IFeatureIterator iter = m_Layer.iterator();

      int i = 0;

      int k = 0;

      final Collection<LineString> cLineStrings = new ArrayList<LineString>();

      // Converting MultiLineString to Linestring

      while (iter.hasNext()) {

         final IFeature feature = iter.next();

         final Geometry geom = feature.getGeometry();

         if (MultiLineString.class.isAssignableFrom(geom.getClass())) {

            final MultiLineString mls = (MultiLineString) geom;

            final int N = mls.getNumGeometries();

            for (int j = 0; j < N; j++) {

               cLineStrings.add((LineString) mls.getGeometryN(j));

               k++;

            }

         }

         i++;

      }

      try {

         // Noding a set of linestrings

         final GeometryFactory factory = new GeometryFactory();

         final GeometryCollection geometryCollection = (GeometryCollection) factory.buildGeometry(cLineStrings);

         Geometry nodedLineStrings = (geometryCollection).getGeometryN(0);

         // Union of noded linestrings

         for (int j = 1; j < cLineStrings.size(); j++) {

            // here there could be a TopologyException, so I enhance the precision!!!

            final LineString newLineString = ((ArrayList<LineString>) cLineStrings).get(j);

            nodedLineStrings = EnhancedPrecisionOp.union(nodedLineStrings, newLineString);

            setProgress(j, cLineStrings.size());

         }

         // Polygonization

         final Polygonizer polygonizer = new Polygonizer();

         polygonizer.add(nodedLineStrings);

         final Collection<Polygon> cPolygons = polygonizer.getPolygons();

         // Preparing the output(s)

         final Class[] outputFieldTypes = new Class[1];

         final String[] outputFieldNames = new String[1];

         outputFieldTypes[0] = Integer.class;

         outputFieldNames[0] = "ID";

         m_Output = getNewVectorLayer(RESULT, m_Layer.getName(), IVectorLayer.SHAPE_TYPE_POLYGON, outputFieldTypes,

                  outputFieldNames);

         final Polygon[] aPolygons = cPolygons.toArray(new Polygon[cPolygons.size()]);

         final Integer[] outputValues = new Integer[1];

         for (int k1 = 0; k1 < aPolygons.length; k1++) {

            outputValues[0] = k1;

            m_Output.addFeature(aPolygons[k1].getGeometryN(0), outputValues);

         }

      }

      catch (final TopologyException e) {

         Sextante.addErrorToLog(e);

      }

      return !m_Task.isCanceled();

   }

}