org.mapsforge.core.GeoPoint.java Source code

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Here is the source code for org.mapsforge.core.GeoPoint.java

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/*
 * Copyright 2010, 2011, 2012 mapsforge.org
 *
 * This program is free software: you can redistribute it and/or modify it under the
 * terms of the GNU Lesser 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along with
 * this program. If not, see <http://www.gnu.org/licenses/>.
 */
package org.mapsforge.core;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.Serializable;

import org.json.JSONArray;
import org.json.JSONException;

/**
 * A GeoPoint represents an immutable pair of latitude and longitude coordinates.
 */
public class GeoPoint implements Comparable<GeoPoint>, Serializable {
    /**
     * Conversion factor from degrees to microdegrees.
     */
    private static final double CONVERSION_FACTOR = 1000000d;

    private static final long serialVersionUID = 1L;

    /**
     * The latitude value of this GeoPoint in microdegrees (degrees * 10^6).
     */
    public final int latitudeE6;

    /**
     * The longitude value of this GeoPoint in microdegrees (degrees * 10^6).
     */
    public final int longitudeE6;

    /**
     * The hash code of this object.
     */
    private transient int hashCodeValue;

    /**
     * @param latitude
     *            the latitude in degrees, will be limited to the possible latitude range.
     * @param longitude
     *            the longitude in degrees, will be limited to the possible longitude range.
     */
    public GeoPoint(double latitude, double longitude) {
        double limitLatitude = MercatorProjection.limitLatitude(latitude);
        this.latitudeE6 = (int) (limitLatitude * CONVERSION_FACTOR);

        double limitLongitude = MercatorProjection.limitLongitude(longitude);
        this.longitudeE6 = (int) (limitLongitude * CONVERSION_FACTOR);

        this.hashCodeValue = calculateHashCode();
    }

    /**
     * @param latitudeE6
     *            the latitude in microdegrees (degrees * 10^6), will be limited to the possible latitude range.
     * @param longitudeE6
     *            the longitude in microdegrees (degrees * 10^6), will be limited to the possible longitude range.
     */
    public GeoPoint(int latitudeE6, int longitudeE6) {
        this(latitudeE6 / CONVERSION_FACTOR, longitudeE6 / CONVERSION_FACTOR);
    }

    @Override
    public int compareTo(GeoPoint geoPoint) {
        if (this.longitudeE6 > geoPoint.longitudeE6) {
            return 1;
        } else if (this.longitudeE6 < geoPoint.longitudeE6) {
            return -1;
        } else if (this.latitudeE6 > geoPoint.latitudeE6) {
            return 1;
        } else if (this.latitudeE6 < geoPoint.latitudeE6) {
            return -1;
        }
        return 0;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        } else if (!(obj instanceof GeoPoint)) {
            return false;
        }
        GeoPoint other = (GeoPoint) obj;
        if (this.latitudeE6 != other.latitudeE6) {
            return false;
        } else if (this.longitudeE6 != other.longitudeE6) {
            return false;
        }
        return true;
    }

    /**
     * @return the latitude value of this GeoPoint in degrees.
     */
    public double getLatitude() {
        return this.latitudeE6 / CONVERSION_FACTOR;
    }

    /**
     * @return the longitude value of this GeoPoint in degrees.
     */
    public double getLongitude() {
        return this.longitudeE6 / CONVERSION_FACTOR;
    }

    @Override
    public int hashCode() {
        return this.hashCodeValue;
    }

    @Override
    public String toString() {
        StringBuilder stringBuilder = new StringBuilder();
        stringBuilder.append("GeoPoint [latitudeE6=");
        stringBuilder.append(this.latitudeE6);
        stringBuilder.append(", longitudeE6=");
        stringBuilder.append(this.longitudeE6);
        stringBuilder.append("]");
        return stringBuilder.toString();
    }

    public JSONArray toJSONArray() {
        JSONArray array = new JSONArray();
        try {
            array.put(getLatitude());
            array.put(getLongitude());
        } catch (JSONException e) {
            e.printStackTrace();
        }
        return array;
    }

    /**
     * @return the hash code of this object.
     */
    private int calculateHashCode() {
        int result = 7;
        result = 31 * result + this.latitudeE6;
        result = 31 * result + this.longitudeE6;
        return result;
    }

    private void readObject(ObjectInputStream objectInputStream) throws IOException, ClassNotFoundException {
        objectInputStream.defaultReadObject();
        this.hashCodeValue = calculateHashCode();
    }
}