Application: gvSIG desktop

package com.iver.cit.gvsig.project.documents.table.operators;

import java.awt.geom.Point2D;

import org.apache.bsf.BSFException;

import org.apache.bsf.BSFManager;

import org.cresques.cts.IProjection;

import com.iver.cit.gvsig.ExpresionFieldExtension;

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;

import com.iver.cit.gvsig.project.documents.table.GraphicOperator;

import com.iver.cit.gvsig.project.documents.table.IOperator;

import com.iver.cit.gvsig.project.documents.table.Index;

/**

 * @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=adapter.getShape(index.get());

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

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

        }

        public void eval(BSFManager interpreter) throws BSFException {

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

                interpreter.eval(ExpresionFieldExtension.BEANSHELL,null,-1,-1,"double area(){return area.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 (DriverIOException e) {

                        e.printStackTrace();

                }

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

        }

        private double returnArea(IGeometry geom) {

                Double[][] xsys=getXY(geom);

                Double[] xs=xsys[0];

                Double[] ys=xsys[1];

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

                if (proj.isProjected()) {

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

                }

                return returnGeoCArea(xs,ys);

        }

        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)));

        }

}