Application: gvSIG desktop

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

import java.awt.geom.Point2D;

import java.util.List;

import org.gvsig.fmap.geom.Geometry;

import org.gvsig.fmap.geom.exception.CreateGeometryException;

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

import org.gvsig.fmap.geom.util.Converter;

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;

/**

 * Intersection point snapper.

 *

 * @author Vicente Caballero Navarro

 */

public class IntersectionPointSnapper extends AbstractSnapper

    implements ISnapperGeometriesVectorial {

        private static int maxPointsGeom=200;

        private List<Geometry> geometries;

    /* (non-Javadoc)

     * @see com.iver.cit.gvsig.gui.cad.snapping.ISnapper#getSnapPoint(Point2D point,

     * IGeometry geom,double tolerance, Point2D lastPointEntered)

     */

    public Point2D getSnapPoint(Point2D point, Geometry geom,

        double tolerance, Point2D lastPointEntered) {

            if (!(geom instanceof Curve)){

                    return null;

            }

            Point2D result = null;

        if (geometries == null) {

            return null;

        }

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

                Point2D r = intersects(geom, geometries.get(i), point, tolerance);

            if (r != null) {

                result = r;

            }

        }

        return result;

    }

    private Point2D intersects(Geometry g1, Geometry g2, Point2D point,

            double tolerance) {

            com.vividsolutions.jts.geom.Geometry g1JTS = Converter.geometryToJts(g1);

            com.vividsolutions.jts.geom.Geometry g2JTS = Converter.geometryToJts(g2);

            //If there is a topology error don't intersects

            if ((g1JTS == null) || (g2JTS == null)){

                return null;

            }

            if (g1JTS.getNumPoints()>maxPointsGeom || g2JTS.getNumPoints()>maxPointsGeom){

                    return null;

            }

            com.vividsolutions.jts.geom.Geometry intersection=g1JTS.intersection(g2JTS);

            Geometry g =null;

                try {

                        g = Converter.jtsToGeometry(intersection);

                } catch (CreateGeometryException e) {

                        e.printStackTrace();

                }

            if (g!=null && g.getType()==Geometry.TYPES.POINT){

                    return g.getHandlers(Geometry.SELECTHANDLER)[0].getPoint();

            }

            return null;

    }

    /*

     * (non-Javadoc)

     * @see org.gvsig.fmap.mapcontrol.tools.snapping.snappers.ISnapper#draw(org.gvsig.fmap.mapcontrol.PrimitivesDrawer, java.awt.geom.Point2D)

     */

    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);

    }

   /* (non-Javadoc)

     * @see com.iver.cit.gvsig.gui.cad.snapping.ISnapper#getToolTipText()

     */

    public String getToolTipText() {

        return "intersection_point";

    }

        public void setGeometries(List geoms) {

            this.geometries = geoms;                

        }

}