Application: gvSIG desktop » gvSIG tools: Expression Field

/**

 * *****************************************************************************

 * gvSIG. Desktop Geographic Information System.

 *

 * Copyright (C) 2007-2013 gvSIG Association.

 *

 * 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 3 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., 51

 * Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

 *

 * For any additional information, do not hesitate to contact us at info AT

 * gvsig.com, or visit our website www.gvsig.com.

 *

 ******************************************************************************

 */

public class Perimeter extends GraphicOperator {

    public String addText(String s) {

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

    }

    public double process(Feature feature) {

        org.gvsig.fmap.geom.Geometry geom = null;

        geom = feature.getDefaultGeometry();//adapter.getShape(index.get());

        ArrayList parts = getXY(geom);

        double perimeter = 0;

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

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

            double dist = 0;

            double distAll = 0;

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

            for (int i = 0; i < (xsys[0].length - 1); i++) {

                dist = 0;

                Point2D p = new Point2D.Double(xsys[0][i].doubleValue(), xsys[1][i].doubleValue());//vp.toMapPoint(new Point(event.getXs()[i].intValue(), event.getYs()[i].intValue()));

                Point2D p2 = new Point2D.Double(xsys[0][i + 1].doubleValue(), xsys[1][i + 1].doubleValue());//vp.toMapPoint(new Point(event.getXs()[i + 1].intValue(), event.getYs()[i + 1].intValue()));

                dist = vp.distanceWorld(p, p2);

                //System.out.println("distancia parcial = "+dist);

                distAll += dist;

            }

            int distanceUnits = vp.getDistanceUnits();

            perimeter += distAll / MapContext.getDistanceTrans2Meter()[distanceUnits];

        return perimeter;

    }

    public void eval(BSFManager interpreter) throws BSFException {

        interpreter.declareBean("jperimeter", this, Perimeter.class);

        interpreter.exec(ExpressionFieldExtension.JYTHON, null, -1, -1, "def perimeter():\n"

                + "  return jperimeter.process(featureContainer.getFeature())");

    public String toString() {

        return "perimeter";

    }

    public boolean isEnable() {

        if (getLayer() == null) {

            return false;

        }

        int geomType = org.gvsig.fmap.geom.Geometry.TYPES.POINT;

        try {

            FeatureStore store = getLayer().getFeatureStore();

            geomType = store.getDefaultFeatureType().getAttributeDescriptor(store.getDefaultFeatureType().getDefaultGeometryAttributeIndex()).getGeometryType();

        } catch (DataException e) {

            NotificationManager.addError(e);

        }

        return (getType() == IOperator.NUMBER

                && (geomType == org.gvsig.fmap.geom.Geometry.TYPES.SURFACE

                || geomType == org.gvsig.fmap.geom.Geometry.TYPES.MULTISURFACE

                || geomType == org.gvsig.fmap.geom.Geometry.TYPES.CURVE

                || geomType == org.gvsig.fmap.geom.Geometry.TYPES.MULTICURVE));

    }

    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 perimeter of polygon or line geometry  of this row in the units of the view.";

    }