EncodedPolylineBean.java

/* 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 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.opentripplanner.util.model;

import java.io.Serializable;

/**
 * A list of coordinates encoded as a string.
 * 
 * See <a href="http://code.google.com/apis/maps/documentation/polylinealgorithm.html">Encoded
 * polyline algorithm format</a>
 */

public class EncodedPolylineBean implements Serializable {

    private static final long serialVersionUID = 1L;

    private String points;

    private String levels;

    private int length;

    public EncodedPolylineBean() {

    }

    public EncodedPolylineBean(String points, String levels, int length) {
        this.points = points;
        this.levels = levels;
        this.length = length;
    }

    /**
     * The encoded points of the polyline.
     */
    public String getPoints() {
        return points;
    }

    public void setPoints(String points) {
        this.points = points;
    }

    /**
     * Levels describes which points should be shown at various zoom levels. Presently, we show all
     * points at all zoom levels.
    */
    public String getLevels() {
        return levels;
    }

    public String getLevels(int defaultLevel) {
        if (levels == null) {
            StringBuilder b = new StringBuilder();
            String l = encodeNumber(defaultLevel);
            for (int i = 0; i < length; i++)
                b.append(l);
            return b.toString();
        }
        return levels;
    }

    public void setLevels(String levels) {
        this.levels = levels;
    }

    /**
     * The number of points in the string
     */
    public int getLength() {
        return length;
    }

    public void setLength(int length) {
        this.length = length;
    }

    private static String encodeNumber(int num) {

        StringBuffer encodeString = new StringBuffer();

        while (num >= 0x20) {
            int nextValue = (0x20 | (num & 0x1f)) + 63;
            encodeString.append((char) (nextValue));
            num >>= 5;
        }

        num += 63;
        encodeString.append((char) (num));

        return encodeString.toString();
    }
}