| gvSIG desktop 1

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

import java.awt.geom.PathIterator;

import java.awt.geom.Point2D;

import org.gvsig.fmap.geom.Geometry;

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

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

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

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

import org.gvsig.fmap.mapcontrol.PrimitivesDrawer;

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

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

import org.gvsig.i18n.Messages;

import com.vividsolutions.jts.geom.Coordinate;

import com.vividsolutions.jts.geom.LineSegment;

/**

 * Tangent point snapper.

 *

 * @author Vicente Caballero Navarro

 */

public class TangentPointSnapper extends AbstractSnapper

    implements ISnapperVectorial {

        /* (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 Circle ||

                geom instanceof Arc ||

                geom instanceof Ellipse ||

                geom instanceof Spline)) {

            return null;

        }

        Point2D resul = null;

        Coordinate c = new Coordinate(point.getX(), point.getY());

        PathIterator theIterator = geom.getPathIterator(null,

                geomManager.getFlatness());

        double[] theData = new double[6];

        double minDist = tolerance;

        Coordinate from = null;

        Coordinate first = null;

        while (!theIterator.isDone()) {

            //while not done

            int theType = theIterator.currentSegment(theData);

            switch (theType) {

            case PathIterator.SEG_MOVETO:

                from = new Coordinate(theData[0], theData[1]);

                first = from;

                break;

            case PathIterator.SEG_LINETO:

                // System.out.println("SEG_LINETO");

                Coordinate to = new Coordinate(theData[0], theData[1]);

                LineSegment line = new LineSegment(from, to);

                Coordinate closestPoint = line.closestPoint(c);

                double dist = c.distance(closestPoint);

                if ((dist < minDist)) {

                    resul = new Point2D.Double(closestPoint.x, closestPoint.y);

                    minDist = dist;

                }

                from = to;

                break;

            case PathIterator.SEG_CLOSE:

                line = new LineSegment(from, first);

                closestPoint = line.closestPoint(c);

                dist = c.distance(closestPoint);

                if ((dist < minDist)) {

                    resul = new Point2D.Double(closestPoint.x, closestPoint.y);

                    minDist = dist;

                }

                from = first;

                break;

            } //end switch

            theIterator.next();

        }

        return resul;

    }

    /* (non-Javadoc)

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

     */

    public String getToolTipText() {

        return Messages.getText("Tangent_point");

    }

    /*

     * (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;

        primitivesDrawer.drawLine((int) (pPixels.getX() - half),

            (int) (pPixels.getY() - half), (int) (pPixels.getX() + half),

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

        primitivesDrawer.drawOval((int) (pPixels.getX() - half),

            (int) (pPixels.getY() - half), getSizePixels(), getSizePixels());

    }

}