Android Open Source - sigimera-android-app Distance Controller

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License

The source code is released under:

GNU General Public License

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Java Source Code

package org.sigimera.app.android.controller;
//from  w  w  w  .j av a2  s  .co m
import java.math.BigDecimal;

import org.sigimera.app.android.model.Crisis;

import android.location.Location;

public abstract class DistanceController {
  private static int decimalPlaces = 2;

  /**
   * 
   * @param _nearCrisis
   * @param _userLocation
   * @return
   */
  public static double getNearCrisisDistance(Crisis _nearCrisis, Location _userLocation) {
    if ( _nearCrisis != null && _userLocation != null ) {
      return computeDistance(
          _userLocation.getLatitude(), _userLocation.getLongitude(), 
          _nearCrisis.getLatitude(), _nearCrisis.getLongitude());
    }
    return -1;
  }

  /**
   * Compute the distance between two GPS locations based on Vincenty Formula.
   * 
   * @param lat1
   * @param long1
   * @param lat2
   * @param long2
   * @return
   */
  public static double computeDistance(double lat1, double long1,
      double lat2, double long2) {
    double earthRadius = 6371;
    double dLatBot = Math.toRadians(lat2 - lat1);
    double dLonBot = Math.toRadians(long2 - long1);
    double a = Math.sin(dLatBot / 2) * Math.sin(dLatBot / 2)
        + Math.cos(Math.toRadians(lat1))
        * Math.cos(Math.toRadians(lat2)) * Math.sin(dLonBot / 2)
        * Math.sin(dLonBot / 2);
    double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
    double distance = earthRadius * c;

    BigDecimal bigD = new BigDecimal(distance);
    bigD = bigD.setScale(decimalPlaces, BigDecimal.ROUND_HALF_UP);

    return bigD.doubleValue();
  }
}

Java Source Code List