Application: gvSIG desktop

/**

 * 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.

 */

package org.gvsig.app.project.documents.view.toolListeners.snapping.snappers;

import java.awt.geom.Point2D;

import java.util.ArrayList;

import java.util.Iterator;

import java.util.List;

import com.vividsolutions.jts.geom.GeometryFactory;

import com.vividsolutions.jts.geom.MultiPoint;

import com.vividsolutions.jts.geom.Point;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

import org.gvsig.fmap.geom.Geometry;

import org.gvsig.fmap.geom.aggregate.MultiCurve;

import org.gvsig.fmap.geom.aggregate.MultiSurface;

import org.gvsig.fmap.geom.primitive.Curve;

import org.gvsig.fmap.geom.primitive.Envelope;

import org.gvsig.fmap.geom.primitive.Surface;

import org.gvsig.fmap.mapcontrol.PrimitivesDrawer;

import org.gvsig.fmap.mapcontrol.tools.snapping.snappers.ISnapperGeometriesVectorial;

import org.gvsig.fmap.mapcontrol.tools.snapping.snappers.impl.AbstractSnapper;

import org.gvsig.i18n.Messages;

/**

 * Intersection point snapper.

 *

 * @author Vicente Caballero Navarro

 */

public class IntersectionPointSnapper extends AbstractSnapper

    implements ISnapperGeometriesVectorial {

    private static final Logger LOG = LoggerFactory.getLogger(IntersectionPointSnapper.class);

    public static final int MAX_GEOMETRIES_IN_RELAXED_LIST = 30;

    public static final int MAX_GEOMETRIES_WITHIN_TOLERANCE = 5;

        private List relaxedList = null;

        private GeometryFactory jtsGeoFact = null;

        private long errorMsgCount = 0;

    public Point2D getSnapPoint(

        Point2D point,

        Geometry geom,

        double tolerance,

        Point2D lastPointEntered) {

        if (geom == null) {

            return null;

        }

        if (relaxedList == null

            || relaxedList.size() < 2 /* We need 2 to intersect */

            || relaxedList.size() > MAX_GEOMETRIES_IN_RELAXED_LIST) {

            /*

             * If there are a lot of geometries, we assume the user

             * is not interested in snapping now. The relaxed list

             * might be long because the spatial index used perhaps

             * is "lazy" so the value of MAX_GEOMETRIES_IN_RELAXED_LIST

             * has to be not very small

             */

            return null;

        }

        List<Geometry> refinedList = null;

        try {

            refinedList = refineList(relaxedList, point, tolerance);

        } catch (Exception e1) {

            errorMsgCount++;

            if (errorMsgCount % 100 == 0) {

                /*

                 * Prevents too many lines in logger. If this happens,

                 * it will happen many times, so we'll see it in the log file.

                 */

                LOG.info("Error while refining list: " + e1.getMessage());

                errorMsgCount = 0;

            }

            return null;

        }

        if (refinedList.size() > MAX_GEOMETRIES_WITHIN_TOLERANCE) {

            /*

             * This refined list contains the geometries that are

             * close to the current mouse. Again we use an upper limit

             * to prevent the case where the user is in a zoom where

             * he is not interested in snapping.

             */

            return null;

        }

        List<Point> interPoints = getInterPoints(refinedList);

        if (interPoints.size() == 0) {

            return null;

        }

        com.vividsolutions.jts.geom.Geometry jtsg = null;

        try {

            jtsg = (com.vividsolutions.jts.geom.Geometry) geom.invokeOperation("toJTS", null);

        } catch (Exception e) {

            errorMsgCount++;

            if (errorMsgCount % 100 == 0) {

                /*

                 * Prevents too many lines in logger. If this happens,

                 * it will happen many times, so we'll see it in the log file.

                 */

                LOG.info("Error while refining list: " + e.getMessage());

                errorMsgCount = 0;

            }

            return null;

        }

        double zerodist = 0.001 * tolerance;

        int n = interPoints.size();

        Point po = null;

        for (int i=0; i<n; i++) {

            po = interPoints.get(i);

            if (point.distance(po.getX(), po.getY()) < tolerance) {

                // This is a candidate, now we check that it belongs to the

                // current geometry

                if (jtsg.distance(po) < zerodist) {

                    return new Point2D.Double(po.getX(), po.getY());

                }

            }

        }

        return null;

    }

    private List<Geometry> refineList(

        List geomlist,

        Point2D point,

        double tolerance) throws Exception {

        List<Geometry> resp = new ArrayList<Geometry>();

        if (geomlist == null || geomlist.size() == 0) {

            return resp;

        }

        double point_tol_north = point.getY() + tolerance; 

        double point_tol_south = point.getY() - tolerance;

        double point_tol_east = point.getX() + tolerance;

        double point_tol_west = point.getX() - tolerance;

        Geometry item = null;

        Envelope env = null;

        Iterator iter = geomlist.iterator();

        while (iter.hasNext()) {

            item = (Geometry) iter.next();

            if (item.intersects(

                point_tol_west, point_tol_south,

                point_tol_east - point_tol_west,

                point_tol_north - point_tol_south)) {

                resp.add(item);

            }

        }

        return resp;

    }

    public void draw(PrimitivesDrawer primitivesDrawer, Point2D pPixels) {

            primitivesDrawer.setColor(getColor());

        int half = getSizePixels() / 2;

        int x1 = (int) (pPixels.getX() - half);

        int x2 = (int) (pPixels.getX() + half);

        int y1 = (int) (pPixels.getY() - half);

        int y2 = (int) (pPixels.getY() + half);

        primitivesDrawer.drawLine(x1, y1, x2, y2);

        primitivesDrawer.drawLine(x1, y2, x2, y1);

    }

    public String getToolTipText() {

        return Messages.getText("Intersection_point");

    }

        public void setGeometries(List geoms) {

            relaxedList = leaveUsefulGeometries(geoms);

        }

        private List<Point> getInterPoints(List geomes) {

            List<Point> resp = new ArrayList<Point>();

            List borders = getJTSBorders(geomes);

            com.vividsolutions.jts.geom.Geometry jtsg1 = null;

            com.vividsolutions.jts.geom.Geometry jtsg2 = null;

            com.vividsolutions.jts.geom.Geometry jtsinter = null;

            int n = borders.size();

            Point jtsp = null;

            MultiPoint jtsmp = null;

            for (int i=0; i<n; i++) {

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

                    if (i != j) {

                        jtsg1 = (com.vividsolutions.jts.geom.Geometry) borders.get(i);

                        jtsg2 = (com.vividsolutions.jts.geom.Geometry) borders.get(j);

                        jtsinter = jtsg1.intersection(jtsg2);

                        if (jtsinter instanceof Point) {

                            jtsp = (Point) jtsinter;

                            resp.add(jtsp);

                        } else {

                            if (jtsinter instanceof MultiPoint) {

                                jtsmp = (MultiPoint) jtsinter;

                                int m = jtsmp.getNumGeometries();

                                for (int k=0; k<m; k++) {

                                    jtsp = (Point) jtsmp.getGeometryN(k);

                                    resp.add(jtsp);

                                }

                            }

                        }

                    }

                }

            }

            return resp;

        }

    private List getJTSBorders(List gvsigGeoms) {

        List resp = new ArrayList();

        com.vividsolutions.jts.geom.Geometry jtsborder = null;

        if (gvsigGeoms != null && gvsigGeoms.size() > 0) {

            Iterator iter = gvsigGeoms.iterator();

            Object itemobj = null;

            while (iter.hasNext()) {

                itemobj = iter.next();

                if (itemobj instanceof Geometry) {

                    jtsborder = getJTSBorder((Geometry) itemobj);

                    if (jtsborder != null) {

                        resp.add(jtsborder);

                    }

                }

            }

        }

        return resp;

    }

    private com.vividsolutions.jts.geom.Geometry getJTSBorder(Geometry geom) {

        com.vividsolutions.jts.geom.Geometry resp = null;

        if (geom instanceof Curve || geom instanceof MultiCurve) {

            try {

                resp = (com.vividsolutions.jts.geom.Geometry)

                    geom.invokeOperation("toJTS", null);

            } catch (Exception e) {

                errorMsgCount++;

                if (errorMsgCount % 100 == 0) {

                    /*

                     * Prevents too many lines in logger. If this happens,

                     * it will happen many times, so we'll see it in the log file.

                     */

                    LOG.info("Error while refining list: " + e.getMessage());

                    errorMsgCount = 0;

                }

                return null;

            }

            return resp;

        } else {

            if (geom instanceof Surface || geom instanceof MultiSurface) {

                try {

                    resp = (com.vividsolutions.jts.geom.Geometry)

                        geom.invokeOperation("toJTS", null);

                    return resp.getBoundary();

                } catch (Exception e) {

                    errorMsgCount++;

                    if (errorMsgCount % 100 == 0) {

                        /*

                         * Prevents too many lines in logger. If this happens,

                         * it will happen many times, so we'll see it in the log file.

                         */

                        LOG.info("Error while refining list: " + e.getMessage());

                        errorMsgCount = 0;

                    }

                    return null;

                }

            } else {

                return null;

            }

        }

    }

    private List<Geometry> leaveUsefulGeometries(List geoms) {

        List resp = new ArrayList();

        if (geoms == null || geoms.size() == 0) {

            return resp;

        }

        Object item = null;

        Iterator iter = geoms.iterator();

        while (iter.hasNext()) {

            item = iter.next();

            if (item instanceof Curve || item instanceof Surface

                || item instanceof MultiCurve || item instanceof MultiSurface) {

                resp.add(item);

            }

        }

        return resp;

    }        

}