org.geomajas.gwt.client.util.DistanceFormat.java Source code

Introduction

Here is the source code for org.geomajas.gwt.client.util.DistanceFormat.java

Source

/*
 * This is part of Geomajas, a GIS framework, http://www.geomajas.org/.
 *
 * Copyright 2008-2013 Geosparc nv, http://www.geosparc.com/, Belgium.
 *
 * The program is available in open source according to the GNU Affero
 * General Public License. All contributions in this program are covered
 * by the Geomajas Contributors License Agreement. For full licensing
 * details, see LICENSE.txt in the project root.
 */

package org.geomajas.gwt.client.util;

import org.geomajas.configuration.client.UnitType;
import org.geomajas.gwt.client.widget.MapWidget;

import com.google.gwt.i18n.client.NumberFormat;

/**
 * General formatter for distances and areas.
 * 
 * @author Pieter De Graef
 */
public final class DistanceFormat {

    private static final double METERS_IN_MILE = 1609.344d;

    private static final double METERS_IN_YARD = 0.9144d;

    private static final double FEET_IN_METER = 3.2808399d;

    private static final double FEET_IN_MILE = 5280d;

    private static final double METERS_IN_KM = 1000;

    private DistanceFormat() {
        // Private default constructor. This is a utility class after all!
    }

    /**
     * Distance formatting method. Requires a length as parameter, expressed in the CRS units of the given map.
     * 
     * @param map
     *            The map for which a distance should be formatted. This map may be configured to use the metric system
     *            or the English system.
     * @param length
     *            The original length, expressed in the coordinate reference system of the given map.
     * @return Returns a string that is the formatted distance of the given length. Preference goes to meters or yards
     *         (depending on the configured unit type), but when the number is larger than 10000, it will switch
     *         automatically to kilometer/mile.
     */
    public static String asMapLength(MapWidget map, double length) {
        double unitLength = map.getUnitLength();
        double distance = length * unitLength;

        String unit = "m";
        if (map.getMapModel().getMapInfo().getDisplayUnitType() == UnitType.METRIC) {
            // Right now, the distance is expressed in meter. Switch to km?
            if (distance > 10000) {
                distance /= METERS_IN_KM;
                unit = "km";
            }
        } else if (map.getMapModel().getMapInfo().getDisplayUnitType() == UnitType.ENGLISH) {
            if (distance / METERS_IN_YARD > 10000) {
                // More than 10000 yard; switch to mile:
                distance = distance / METERS_IN_MILE;
                unit = "mi";
            } else {
                distance /= METERS_IN_YARD; // use yards.
                unit = "yd";
            }
        } else if (map.getMapModel().getMapInfo().getDisplayUnitType() == UnitType.ENGLISH_FOOT) {
            if (distance * FEET_IN_METER > FEET_IN_MILE) {
                // More than 1 mile (5280 feet); switch to mile:
                distance = distance / METERS_IN_MILE;
                unit = "mi";
            } else {
                distance *= FEET_IN_METER; // use feet.
                unit = "ft";
            }
        } else if (map.getMapModel().getMapInfo().getDisplayUnitType() == UnitType.CRS) {
            unit = "u";
        }

        String formatted = NumberFormat.getDecimalFormat().format(distance);
        return formatted + unit;
    }

    /**
     * Area formatting method. Requires an area as parameter, expressed in the CRS units of the given map.
     * 
     * @param map
     *            The map for which an area should be formatted. This map may be configured to use the metric system or
     *            the English system.
     * @param area
     *            The original area, expressed in the coordinate reference system of the given map.
     * @return Returns a string that is the formatted area of the given area. Preference goes to meters or yards
     *            (depending on the configured unit type), but when the number is larger than meters (or yards), it will
     *            switch automatically to kilometers/miles.
     */
    public static String asMapArea(MapWidget map, double area) {
        double unitLength = map.getUnitLength();
        double distance = area * unitLength * unitLength;

        String unit = "m";
        if (map.getMapModel().getMapInfo().getDisplayUnitType() == UnitType.METRIC) {
            // Right now, the distance is expressed in meter. Switch to km?
            if (distance > (METERS_IN_KM * METERS_IN_KM)) {
                distance /= (METERS_IN_KM * METERS_IN_KM);
                unit = "km";
            }
        } else if (map.getMapModel().getMapInfo().getDisplayUnitType() == UnitType.ENGLISH) {
            if (distance > (METERS_IN_MILE * METERS_IN_MILE)) {
                // Switch to mile:
                distance = distance / (METERS_IN_MILE * METERS_IN_MILE);
                unit = "mi";
            } else {
                distance /= (METERS_IN_YARD * METERS_IN_YARD); // use yards.
                unit = "yd";
            }
        } else if (map.getMapModel().getMapInfo().getDisplayUnitType() == UnitType.CRS) {
            unit = "u";
        }

        String formatted = NumberFormat.getDecimalFormat().format(distance);
        return formatted + unit + "²";
    }
}