org.jxmapviewer.viewer.GeoBounds Maven / Gradle / Ivy

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package org.jxmapviewer.viewer;

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

/**
 * The GeoBounds 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 GeoBounds objects.
     */
    public GeoBounds(Set 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].getMaxY(), rects[0].getX());
    }

    /**
     * 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.getY(), r.getMaxX());
    }

}