Application: gvSIG desktop

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

 *

 * Copyright (C) 2005 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 org.gvsig.symbology.fmap.labeling.placements;

import java.awt.geom.Point2D;

import org.apache.batik.ext.awt.geom.PathLength;

import com.iver.cit.gvsig.fmap.core.FShape;

import com.iver.cit.gvsig.fmap.rendering.styling.labeling.IPlacementConstraints;

import com.iver.cit.gvsig.fmap.rendering.styling.labeling.LabelClass;

import com.iver.cit.gvsig.fmap.rendering.styling.labeling.LabelLocationMetrics;

import com.iver.utiles.swing.threads.Cancellable;

/**

 * 

 * LinePlacementInTheMiddle.java

 *

 * 

 * @author jaume dominguez faus - jaume.dominguez@iver.es Dec 17, 2007

 *

 */

public class LinePlacementInTheMiddle extends AbstractLinePlacement {

        public boolean isSuitableFor(IPlacementConstraints placementConstraints,

                        int shapeType) {

                if (shapeType == FShape.LINE) {

                        return placementConstraints.isInTheMiddleOfLine() && !placementConstraints.isFollowingLine();

                }

                return false;

        }

        @Override

        LabelLocationMetrics initialLocation(LabelClass lc,

                        IPlacementConstraints pc, PathLength pathLen, Cancellable cancel) {

                if (cancel.isCanceled()) return null;

                float length = pathLen.lengthOfPath();

                float distance = (float) (length * 0.5);

                double theta = 0;

                if (pc.isParallel()) {

                        // get the line theta and apply it

                        theta = pathLen.angleAtLength(distance);

                } else if (pc.isPerpendicular()) {

                        // get the line theta with 90 degrees

                        theta = pathLen.angleAtLength(distance) + AbstractLinePlacement.HALF_PI;

                }

                Point2D p = pathLen.pointAtLength(distance);

                /* 

                 * Offset the point to a distance of the height of the

                 * label class's height to make the label appear to

                 * be on the line.

                 * 

                 */ 

                double x = p.getX();

                double y = p.getY();

                double halfHeight = lc.getBounds().getHeight()*.5;

                double halfWidth = lc.getBounds().getWidth()*.5;

                double sinTheta = Math.sin(theta);

                double cosTheta = Math.cos(theta);

                double xOffset = halfHeight * sinTheta;

                double yOffset = halfHeight * cosTheta;

                /*

                 * now, offset the anchor point as much as need to

                 * make the center of the label be the middle of the

                 * line 

                 */

                xOffset -= halfWidth * cosTheta;

                yOffset += halfWidth * sinTheta;

                p.setLocation(x + xOffset, y - yOffset);

                return new LabelLocationMetrics(

                                p,

                                theta,

                                true);

        }

}