Application: gvSIG desktop

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.utiles.swing.threads.Cancellable;

/**

 * LinePlacementAtExtremities.java

 *

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

 *

 */

public class LinePlacementAtExtremities extends AbstractLinePlacement {

	public LabelLocationMetrics initialLocation(LabelClass lc, IPlacementConstraints pc, PathLength pathLen, Cancellable cancel) {

		if (cancel.isCanceled()) return null;

		float distance = 0;

		if (pc.isAtTheEndOfLine()) {

			distance = (float) (pathLen.lengthOfPath()) ;

		}

		Point2D p = pathLen.pointAtLength(distance);

		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;

		}

		 * 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 sinTheta = Math.sin(theta);

		double cosTheta = Math.cos(theta);

		double xOffset = halfHeight * sinTheta;

		double yOffset = halfHeight * cosTheta;

		if (pc.isAtTheEndOfLine()) {

			double width = lc.getBounds().getWidth();

			xOffset -= width * cosTheta;

			yOffset += width * sinTheta;

		}

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

		return new LabelLocationMetrics(

				p,

				theta,

	public boolean isSuitableFor(IPlacementConstraints placementConstraints,

			int shapeType) {

		if (shapeType == FShape.LINE) {

					&& (placementConstraints.isAtTheBeginingOfLine() || placementConstraints

							.isAtTheEndOfLine());

		}