Application: gvSIG desktop

/* gvSIG. Sistema de Informaci?n Geogr?fica de la Generalitat Valenciana

 *

 * Copyright (C) 2004 IVER T.I. and Generalitat Valenciana.

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version 2

 * of the License, or (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,USA.

 *

 * For more information, contact:

 *

 *  Generalitat Valenciana

 *   Conselleria d'Infraestructures i Transport

 *   Av. Blasco Ib??ez, 50

 *   46010 VALENCIA

 *   SPAIN

 *

 *      +34 963862235

 *   gvsig@gva.es

 *      www.gvsig.gva.es

 *

 *    or

 *

 *   IVER T.I. S.A

 *   Salamanca 50

 *   46005 Valencia

 *   Spain

 *

 *   +34 963163400

 *   dac@iver.es

 */

package com.iver.cit.gvsig.fmap.tools;

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

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

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

import com.iver.cit.gvsig.fmap.tools.Events.MeasureEvent;

import com.iver.cit.gvsig.fmap.tools.Listeners.PolylineListener;

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

import java.awt.Cursor;

import java.awt.Image;

import java.awt.Point;

import java.awt.Toolkit;

import java.awt.geom.Point2D;

import javax.swing.ImageIcon;

/**

 * <p>Listener for calculating the area of a polygon, defined in the associated {@link MapControl MapControl}

 *  object.</p>

 * 

 * <p>If the view port of the associated <code>MapControl</code> isn't projected gets the area according the

 *  geographical coordinates.</p>

 *

 * @author Vicente Caballero Navarro

 */

public class AreaListenerImpl implements PolylineListener {

        /**

         * The image to display when the cursor is active.

         */

        private final Image iarea = new ImageIcon(MapControl.class.getResource(

                                "images/AreaCursor.gif")).getImage();

        /**

         * The cursor used to work with this tool listener.

         * 

         * @see #getCursor()

         */

        private Cursor cur = Toolkit.getDefaultToolkit().createCustomCursor(iarea,

                        new Point(16, 16), "");

        /**

         * Reference to the <code>MapControl</code> object that uses.

         */

        protected MapControl mapCtrl;

        /**

         * Information about all vertexes and {@link GeneralPathX GeneralPathX}s of the polyline. 

         */

        protected MeasureEvent event;

        /**

          * <p>Creates a new listener for calculating the area of a polygon.</p>

         *

         * @param mc the <code>MapControl</code> where is calculated the area

         */

        public AreaListenerImpl(MapControl mc) {

                this.mapCtrl = mc;

        }

        /*

         * (non-Javadoc)

         * @see com.iver.cit.gvsig.fmap.tools.Listeners.PolylineListener#points(com.iver.cit.gvsig.fmap.tools.Events.MeasureEvent)

         */

        public void points(MeasureEvent event) {

                this.event = event;

                double dist = 0;

                double distAll = 0;

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

                for (int i = 0; i < (event.getXs().length - 1); i++) {

                        dist = 0;

                        Point p = new Point(event.getXs()[i].intValue(),

                                        event.getXs()[i].intValue());

                        Point p2 = new Point(event.getXs()[i + 1].intValue(),

                                        event.getXs()[i + 1].intValue());

                        ///dist = vp.toMapDistance((int) p.distance(p2));

                        dist = vp.distanceWorld(p, p2);

                        distAll += dist;

                }

                System.out.println("Per?metro = " + distAll + " ?rea = " +

                        (returnArea(vp.toMapPoint(

                                        new Point2D.Double(

                                                event.getXs()[event.getXs().length - 2].doubleValue(),

                                                event.getYs()[event.getYs().length - 2].doubleValue())))));

        }

        /**

         * <p>Returns the area of the polygon, using {@link #returnCoordsArea(Double[], Double[], Point2D) returnCoordsArea}

         *  if the <code>ViewPort</code> of the associated <code>MapControl</code> is projected, or using

         *  {@link #returnGeoCArea(Double[], Double[], Point2D) returnGeoCArea} if isn't.</p>

         *

         * @param point unused parameter

         *

         * @return area from the vertexes stored at the measure event in real coordinates, or, if the <code>MapControl</code>

         *  isn't projected, in geographical coordinates

         * 

         * @see #returnCoordsArea(Double[], Double[], Point2D)

         * @see #returnGeoCArea(Double[], Double[], Point2D)

         */

        protected double returnArea(Point2D point) {

                Double[] xs=event.getXs();

                Double[] ys=event.getYs();

                if (mapCtrl.getProjection().isProjected()) {

                        return returnCoordsArea(xs,ys,point);

                }

                return returnGeoCArea(xs,ys,point);

        }

        /**

         * <p>Returns the area in geographical coordinates of the polygon, according the

         *  <a href="http://en.wikipedia.org/wiki/Haversine_formula">Haversine function</a>.</p> 

         * 

         * @see Geo#sphericalPolyArea(double[], double[], int)

         */

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

                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);

        }

        /**

         * <p>Returns the area of the polygon using <i>point</i> as initial, in

         *  real values with the current measure unit, according the projection in the <code>ViewPort</code>

         *  of the <code>MapControl</code>.</p>

         *

         * @param xs abscissa coordinate of all vertexes of the polygon

         * @param ys ordinate coordinate of all vertexes of the polygon

         * @param point point 2D used as first vertex in the calculation of the area

         *

         * @return the area of the polygon

         */

        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 = mapCtrl.getMapContext().getViewPort();

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

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

                                        ys[pos].doubleValue());

                        p = pPixel;//vp.toMapPoint(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)));

        }

        /*

         * (non-Javadoc)

         * @see com.iver.cit.gvsig.fmap.tools.Listeners.ToolListener#getCursor()

         */

        public Cursor getCursor() {

                return cur;

        }

        /*

         * (non-Javadoc)

         * @see com.iver.cit.gvsig.fmap.tools.Listeners.PolylineListener#pointFixed(com.iver.cit.gvsig.fmap.tools.Events.MeasureEvent)

         */

        public void pointFixed(MeasureEvent event) {

        }

        /*

         * (non-Javadoc)

         * @see com.iver.cit.gvsig.fmap.tools.Listeners.PolylineListener#polylineFinished(com.iver.cit.gvsig.fmap.tools.Events.MeasureEvent)

         */

        public void polylineFinished(MeasureEvent event) {

        }

        /*

         * (non-Javadoc)

         * @see com.iver.cit.gvsig.fmap.tools.Listeners.ToolListener#cancelDrawing()

         */

        public boolean cancelDrawing() {

                return false;

        }

}