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.labeling.placements;

import java.awt.geom.Point2D;

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

import org.gvsig.fmap.geom.Geometry.TYPES;

import org.gvsig.fmap.geom.GeometryLocator;

import org.gvsig.fmap.geom.GeometryManager;

import org.gvsig.fmap.mapcontext.rendering.legend.styling.ILabelClass;

import org.gvsig.fmap.mapcontext.rendering.legend.styling.IPlacementConstraints;

import org.gvsig.symbology.fmap.mapcontext.rendering.legend.styling.LabelLocationMetrics;

import org.gvsig.tools.task.Cancellable;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

public class LinePlacementInTheMiddle extends AbstractLinePlacement {

        private static Logger logger =

                        LoggerFactory.getLogger(LinePlacementInTheMiddle.class);

    @Override

        public boolean isSuitableFor(

                        IPlacementConstraints placementConstraints,

                        int shapeType) {

        GeometryManager geomManager = GeometryLocator.getGeometryManager();

        if( geomManager.isSubtype(TYPES.CURVE, shapeType) ||

            geomManager.isSubtype(TYPES.MULTICURVE, shapeType) ) {

                        return placementConstraints != null &&

                           placementConstraints.isInTheMiddleOfLine()

                          /* && !placementConstraints.isFollowingLine()*/;

                } else {

                        return false;

                }

        }

    @Override

        public LabelLocationMetrics initialLocation(ILabelClass 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);

        }

}