GeoBounds.java

/*******************************************************************************
 *     SDR Trunk 
 *     Copyright (C) 2014 Dennis Sheirer
 * 
 *     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, see <http://www.gnu.org/licenses/>
 ******************************************************************************/
package org.jdesktop.swingx.mapviewer;

import java.awt.geom.Rectangle2D;
import java.util.Set;

/**
 * The <code>GeoBounds</code> class provides access the the North East and South West corners of the bounds and provides
 * an intersects method.
 * @author Dan Andrews
 */
public class GeoBounds
{

	/** Internal representation of the bounds */
	private Rectangle2D[] rects;

	/**
	 * Constructor.
	 * @param minLat The minimum latitude.
	 * @param minLng The minimum longitude.
	 * @param maxLat The maximum latitude.
	 * @param maxLng The maximum longitude.
	 */
	public GeoBounds(double minLat, double minLng, double maxLat, double maxLng)
	{
		setRect(minLat, minLng, maxLat, maxLng);
	}

	/**
	 * Constructor.
	 * @param geoPositions A non null list of 2 or more different <code>GeoBounds</code> objects.
	 */
	public GeoBounds(Set<GeoPosition> geoPositions)
	{
		if (geoPositions == null || geoPositions.size() < 2)
		{
			throw new IllegalArgumentException("The attribute 'geoPositions' cannot be null and must "
					+ "have 2 or more elements.");
		}
		double minLat = Integer.MAX_VALUE;
		double minLng = Integer.MAX_VALUE;
		double maxLat = Integer.MIN_VALUE;
		double maxLng = Integer.MIN_VALUE;
		for (GeoPosition position : geoPositions)
		{
			minLat = Math.min(minLat, position.getLatitude());
			minLng = Math.min(minLng, position.getLongitude());
			maxLat = Math.max(maxLat, position.getLatitude());
			maxLng = Math.max(maxLng, position.getLongitude());
		}
		setRect(minLat, minLng, maxLat, maxLng);
	}

	/**
	 * Sets the internal rectangle representation.
	 * @param minLat The minimum latitude.
	 * @param minLng The minimum longitude.
	 * @param maxLat The maximum latitude.
	 * @param maxLng The maximum longitude.
	 */
	private void setRect(double minLat, double minLng, double maxLat, double maxLng)
	{
		if (!(minLat < maxLat))
		{
			throw new IllegalArgumentException("GeoBounds is not valid - minLat must be less that maxLat.");
		}
		if (!(minLng < maxLng))
		{
			if (minLng > 0 && minLng < 180 && maxLng < 0)
			{
				rects = new Rectangle2D[] {
						// split into two rects e.g. 176.8793 to 180 and -180 to
						// -175.0104
						new Rectangle2D.Double(minLng, minLat, 180 - minLng, maxLat - minLat),
						new Rectangle2D.Double(-180, minLat, maxLng + 180, maxLat - minLat) };
			}
			else
			{
				rects = new Rectangle2D[] { new Rectangle2D.Double(minLng, minLat, maxLng - minLng, maxLat - minLat) };

				throw new IllegalArgumentException("GeoBounds is not valid - minLng must be less that maxLng or "
						+ "minLng must be greater than 0 and maxLng must be less than 0.");
			}
		}
		else
		{
			rects = new Rectangle2D[] { new Rectangle2D.Double(minLng, minLat, maxLng - minLng, maxLat - minLat) };
		}
	}

	/**
	 * Determines if this bounds intersects the other bounds.
	 * @param other The other bounds to test for intersection with.
	 * @return Returns true if bounds intersect.
	 */
	public boolean intersects(GeoBounds other)
	{
		boolean rv = false;
		for (Rectangle2D r1 : rects)
		{
			for (Rectangle2D r2 : other.rects)
			{
				rv = r1.intersects(r2);
				if (rv)
				{
					break;
				}
			}
			if (rv)
			{
				break;
			}

		}
		return rv;
	}

	/**
	 * Gets the north west position.
	 * @return Returns the north west position.
	 */
	public GeoPosition getNorthWest()
	{
		return new GeoPosition(rects[0].getX(), rects[0].getMaxY());
	}

	/**
	 * Gets the south east position.
	 * @return Returns the south east position.
	 */
	public GeoPosition getSouthEast()
	{
		Rectangle2D r = rects[0];
		if (rects.length > 1)
		{
			r = rects[1];
		}
		return new GeoPosition(r.getMaxX(), r.getY());
	}

}