| gvSIG desktop 1

package org.gvsig.operators;

import java.awt.geom.Point2D;

import java.util.ArrayList;

import org.apache.bsf.BSFException;

import org.apache.bsf.BSFManager;

import org.cresques.cts.IProjection;

import org.gvsig.baseclasses.GraphicOperator;

import org.gvsig.baseclasses.IOperator;

import org.gvsig.baseclasses.Index;

import org.gvsig.expresions.EvalOperatorsTask;

import com.hardcode.gdbms.driver.exceptions.ReadDriverException;

import com.iver.andami.PluginServices;

import com.iver.andami.messages.NotificationManager;

import com.iver.cit.gvsig.exceptions.expansionfile.ExpansionFileReadException;

import com.iver.cit.gvsig.fmap.MapContext;

import com.iver.cit.gvsig.fmap.ViewPort;

import com.iver.cit.gvsig.fmap.core.FShape;

import com.iver.cit.gvsig.fmap.core.IGeometry;

import com.iver.cit.gvsig.fmap.drivers.DriverIOException;

import com.iver.cit.gvsig.fmap.layers.ReadableVectorial;

import com.iver.cit.gvsig.fmap.tools.geo.Geo;

/**

 * @author Vicente Caballero Navarro

 */

public class Area extends GraphicOperator{

        public String addText(String s) {

                return s.concat(toString()+"()");

        }

        public double process(Index index) throws DriverIOException {

                ReadableVectorial adapter = getLayer().getSource();

                   IGeometry geom=null;

                try {

                        geom = adapter.getShape(index.get());

                } catch (ExpansionFileReadException e) {

                        throw new DriverIOException(e);

                } catch (ReadDriverException e) {

                        throw new DriverIOException(e);

                }

                   int distanceUnits=getLayer().getMapContext().getViewPort().getDistanceUnits();

                return returnArea(geom)/Math.pow(MapContext.CHANGEM[distanceUnits],2);

        }

        public void eval(BSFManager interpreter) throws BSFException {

                interpreter.declareBean("jarea",this,Area.class);

//                interpreter.eval(ExpressionFieldExtension.BEANSHELL,null,-1,-1,"double area(){return area.process(indexRow);};");

                interpreter.exec(EvalOperatorsTask.JYTHON,null,-1,-1,"def area():\n" +

                                "  return jarea.process(indexRow)");

        }

        public String toString() {

                return "area";

        }

        public boolean isEnable() {

                if (getLayer()==null)

                        return false;

                ReadableVectorial adapter = getLayer().getSource();

                int type=FShape.POINT;

                try {

                        type=adapter.getShapeType();

                } catch (ReadDriverException e) {

                        NotificationManager.addError(e);

                }

                return (getType()==IOperator.NUMBER && type==FShape.POLYGON);

        }

        private double returnArea(IGeometry geom) {

                ArrayList parts=getXY(geom);

                double area=0;

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

                Double[][] xsys=(Double[][])parts.get(i);//getXY(geom);

                Double[] xs=xsys[0];

                Double[] ys=xsys[1];

                IProjection proj=getLayer().getMapContext().getProjection();

                if (proj.isProjected()) {

                        area+= returnCoordsArea(xs,ys,new Point2D.Double(xs[xs.length-1].doubleValue(),ys[ys.length-1].doubleValue()));

                }else{

                        area+= returnGeoCArea(xs,ys);

                }

                }

                return area;

        }

        private double returnGeoCArea(Double[] xs,Double[] ys) {

                double[] lat=new double[xs.length];

                double[] lon=new double[xs.length];

                for (int K= 0; K < xs.length; K++){

                        lon[K]= xs[K].doubleValue()/Geo.Degree;

                        lat[K]= ys[K].doubleValue()/Geo.Degree;

                }

                return (Geo.sphericalPolyArea(lat,lon,xs.length-1)*Geo.SqM);

        }

        /**

         * Calcula el ?rea.

         *

         * @param aux ?ltimo punto.

         *

         * @return ?rea.

         */

        public double returnCoordsArea(Double[] xs,Double[] ys, Point2D point) {

                Point2D aux=point;

                double elArea = 0.0;

                Point2D pPixel;

                Point2D p = new Point2D.Double();

                Point2D.Double pAnt = new Point2D.Double();

                ViewPort vp = getLayer().getMapContext().getViewPort();

                for (int pos = 0; pos < xs.length-1; pos++) {

                        pPixel = new Point2D.Double(xs[pos].doubleValue(),

                                        ys[pos].doubleValue());

                        p = pPixel;

                        if (pos == 0) {

                                pAnt.x = aux.getX();

                                pAnt.y = aux.getY();

                        }

                        elArea = elArea + ((pAnt.x - p.getX()) * (pAnt.y + p.getY()));

                        pAnt.setLocation(p);

                }

                elArea = elArea + ((pAnt.x - aux.getX()) * (pAnt.y + aux.getY()));

                elArea = Math.abs(elArea / 2.0);

                return (elArea*(Math.pow(MapContext.CHANGEM[vp.getMapUnits()],2)));

        }

        public String getTooltip(){

                return PluginServices.getText(this,"operator")+":  "+addText("")+"\n"+getDescription();

        }

        public String getDescription() {

        return PluginServices.getText(this, "returns") + ": " +

        PluginServices.getText(this, "numeric_value") + "\n" +

        PluginServices.getText(this, "description") + ": " +

        "Returns the area of polygon geometry of this row.";

    }

}