GeoUtils.java

/**
 * Copyright (c) 2011 Ontology Engineering Group, 
 * Departamento de Inteligencia Artificial,
 * Facultad de Informetica, Universidad 
 * Politecnica de Madrid, Spain
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package es.upm.fi.dia.oeg.map4rdf.client.util;

import java.util.Collection;
import java.util.HashSet;

import org.gwtopenmaps.openlayers.client.util.JSObject;

import es.upm.fi.dia.oeg.map4rdf.share.BoundingBox;
import es.upm.fi.dia.oeg.map4rdf.share.BoundingBoxBean;
import es.upm.fi.dia.oeg.map4rdf.share.Circle;
import es.upm.fi.dia.oeg.map4rdf.share.Geometry;
import es.upm.fi.dia.oeg.map4rdf.share.MultiPolygon;
import es.upm.fi.dia.oeg.map4rdf.share.Point;
import es.upm.fi.dia.oeg.map4rdf.share.PointBean;
import es.upm.fi.dia.oeg.map4rdf.share.Polygon;
import es.upm.fi.dia.oeg.map4rdf.share.TwoDimentionalCoordinateBean;
import es.upm.fi.dia.oeg.map4rdf.share.WKTGeometry;

/**
 * @author Alexander De Leon
 */
public class GeoUtils {
	// Can only be accessed in client mode
	public static BoundingBox computeBoundingBoxFromGeometries(
			Collection<Geometry> geometries, String projection) {
		HashSet<Point> points = new HashSet<Point>();
		for (Geometry geometry : geometries) {
			points.addAll(geometry.getPoints());
		}
		return computeBoundingBox(points, projection);
	}

	// Can only be accessed in client mode
	public static BoundingBox computeBoundingBox(Collection<Point> points,
			String projection) {
		double maxX = Double.NEGATIVE_INFINITY;
		double minX = Double.POSITIVE_INFINITY;
		double maxY = Double.NEGATIVE_INFINITY;
		double minY = Double.POSITIVE_INFINITY;

		for (Point p : points) {
			p.transform(p.getProjection(), projection);
			double x = p.getX();
			double y = p.getY();
			if (x > maxX) {
				maxX = x;
			}
			if (x < minX) {
				minX = x;
			}
			if (y > maxY) {
				maxY = y;
			}
			if (y < minY) {
				minY = y;
			}
		}
		return new BoundingBoxBean(new TwoDimentionalCoordinateBean(minX, minY,
				projection), new TwoDimentionalCoordinateBean(maxX, maxY,
				projection), projection);
	}

	public static Point getCentroid(Geometry geometry) {
		try {
			switch (geometry.getType()) {
			case CIRCLE:
				Circle circle = (Circle) geometry;
				return new PointBean(geometry.getUri(), circle.getCenter()
						.getX(), circle.getCenter().getY(),
						geometry.getProjection());
			case MULTIPOLYGON:
				MultiPolygon multiPolygon = (MultiPolygon) geometry;
				org.gwtopenmaps.openlayers.client.geometry.Polygon polygons[] = new org.gwtopenmaps.openlayers.client.geometry.Polygon[multiPolygon
						.getPolygons().size()];
				int i = 0;
				for (Polygon polygon : multiPolygon.getPolygons()) {
					org.gwtopenmaps.openlayers.client.geometry.LinearRing rings[] = { new org.gwtopenmaps.openlayers.client.geometry.LinearRing(
							getPoints(polygon.getPoints())) };
					polygons[i++] = new org.gwtopenmaps.openlayers.client.geometry.Polygon(
							rings);
				}
				org.gwtopenmaps.openlayers.client.geometry.MultiPolygon openMultiPolygon = new org.gwtopenmaps.openlayers.client.geometry.MultiPolygon(
						polygons);
				return new PointBean(geometry.getUri(),
						getGeometryCentroidX(openMultiPolygon.getJSObject()),
						getGeometryCentroidY(openMultiPolygon.getJSObject()),
						geometry.getProjection());
			case POINT:
				return (Point) geometry;
			case POLYGON:
				org.gwtopenmaps.openlayers.client.geometry.LinearRing rings[] = { new org.gwtopenmaps.openlayers.client.geometry.LinearRing(
						getPoints(geometry.getPoints())) };
				org.gwtopenmaps.openlayers.client.geometry.Polygon polygon = new org.gwtopenmaps.openlayers.client.geometry.Polygon(
						rings);
				return new PointBean(geometry.getUri(),
						getGeometryCentroidX(polygon.getJSObject()),
						getGeometryCentroidY(polygon.getJSObject()),
						geometry.getProjection());
			case POLYLINE:
				org.gwtopenmaps.openlayers.client.geometry.LineString lineString = new org.gwtopenmaps.openlayers.client.geometry.LineString(
						getPoints(geometry.getPoints()));
				return new PointBean(geometry.getUri(),
						getGeometryCentroidX(lineString.getJSObject()),
						getGeometryCentroidY(lineString.getJSObject()),
						geometry.getProjection());
			case WKTGEOMETRY:
				WKTGeometry wktGeometry = (WKTGeometry) geometry;
				org.gwtopenmaps.openlayers.client.geometry.Geometry openLayersGeometry = org.gwtopenmaps.openlayers.client.geometry.Geometry
						.fromWKT(wktGeometry.getWKT());
				return new PointBean(geometry.getUri(),
						getGeometryCentroidX(openLayersGeometry.getJSObject()),
						getGeometryCentroidY(openLayersGeometry.getJSObject()),
						geometry.getProjection());
			default:
				// Make compiler happy.
				break;

			}
		} catch (Exception e) {
			// TODO create log client class for logging.
		}
		return null;
	}

	/**
	 * JSObject geometry need to be a
	 * org.gwtopenmaps.openlayers.client.geometry.Geometry convert to JSObject
	 * Use geometry.getJSObject();
	 * */
	private native static double getGeometryCentroidX(JSObject geometry) /*-{
		return geometry.getCentroid().x;
	}-*/;

	/**
	 * JSObject geometry need to be a
	 * org.gwtopenmaps.openlayers.client.geometry.Geometry convert to JSObject
	 * Use geometry.getJSObject();
	 * */
	private native static double getGeometryCentroidY(JSObject geometry) /*-{
		return geometry.getCentroid().y;
	}-*/;

	private static org.gwtopenmaps.openlayers.client.geometry.Point[] getPoints(
			Collection<Point> points) {
		org.gwtopenmaps.openlayers.client.geometry.Point[] pointsArray = new org.gwtopenmaps.openlayers.client.geometry.Point[points
				.size()];
		int index = 0;
		for (Point p : points) {
			pointsArray[index++] = new org.gwtopenmaps.openlayers.client.geometry.Point(
					p.getX(), p.getY());
		}
		return pointsArray;
	}

}