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- package de.tudarmstadt.informatik.hostage.logging;
- import java.util.Timer;
- import java.util.TimerTask;
- import android.content.Context;
- import android.location.Location;
- import android.location.LocationListener;
- import android.location.LocationManager;
- import android.os.Bundle;
- import android.util.Log;
- public class MyLocationManager {
-
- private LocationManager locationManager;
- /**
- * Static variable that always holds the newest location update.
- */
- private static Location newestLocation = null;
- private static final int TWO_MINUTES = 1000 * 60 * 2;
-
- public MyLocationManager(Context context){
- // Acquire a reference to the system Location Manager
- locationManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
- newestLocation = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
- }
- // Define a listener that responds to location updates
- LocationListener locationListener = new LocationListener() {
- public void onLocationChanged(Location location) {
- Log.i("MyLocationManager", location.getLatitude() + " " + location.getLongitude() + " " + location.getAccuracy());
- // Called when a new location is found by the network location provider.
- if(isBetterLocation(location, newestLocation)){
- newestLocation = location;
- }
- }
- public void onStatusChanged(String provider, int status, Bundle extras) {}
- public void onProviderEnabled(String provider) {}
- public void onProviderDisabled(String provider) {}
- };
-
- /** Determines whether one Location reading is better than the current Location fix
- * @param location The new Location that you want to evaluate
- * @param currentBestLocation The current Location fix, to which you want to compare the new one
- */
- private boolean isBetterLocation(Location location, Location currentBestLocation) {
- if (currentBestLocation == null) {
- // A new location is always better than no location
- return true;
- }
-
- // Check whether the new location fix is newer or older
- long timeDelta = location.getTime() - currentBestLocation.getTime();
- boolean isSignificantlyNewer = timeDelta > TWO_MINUTES;
- boolean isSignificantlyOlder = timeDelta < -TWO_MINUTES;
- // If it's been more than two minutes since the current location, use the new location
- // because the user has likely moved
- if (isSignificantlyNewer) {
- return true;
- // If the new location is more than two minutes older, it must be worse
- } else if (isSignificantlyOlder) {
- return false;
- }
- // Check whether the new location fix is more or less accurate
- int accuracyDelta = (int) (location.getAccuracy() - currentBestLocation.getAccuracy());
- boolean isMoreAccurate = accuracyDelta < 0;
- // Determine location quality using a combination of timeliness and accuracy
- if (isMoreAccurate) {
- return true;
- }
- return false;
- }
-
- /**
- * Start updating {@link de.tudarmstadt.informatik.hostage.logging.MyLocationManager#newestLocatio newestLocation}
- * if a location provider is enabled and available.
- */
- public void startUpdates(){
- boolean gpsEnabled = false;
- boolean networkEnabled = false;
- //exceptions will be thrown if provider is not permitted.
- try{
- gpsEnabled = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
- }catch(Exception ex){}
- try{
- networkEnabled = locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
- }catch(Exception ex){}
-
- //don't start listeners if no provider is enabled
- if(!gpsEnabled && !networkEnabled)
- return;
- // Register the listener with the Location Manager to receive location updates
- if(gpsEnabled)
- locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);
- if(networkEnabled)
- locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListener);
- }
-
- /**
- * Starts updating the location data for the given amount of time.
- * Calls itself recursive if no location data has been found yet and there are still attempts left.
- * @param time Time to update location data
- * @param attempts Remaining attempts for recieving location data
- */
- public void getUpdates(long time, int attempts){
- startUpdates();
- attempts--;
- Timer timer1=new Timer();
- timer1.schedule(new StopTask() , time);
- if(newestLocation == null && attempts > 0)
- getUpdates(time, attempts);
- }
-
- class StopTask extends TimerTask {
- public void run() {
- stopUpdates();
- }
- }
-
- public void stopUpdates(){
- locationManager.removeUpdates(locationListener);
- }
- public static Location getNewestLocation(){
- return newestLocation;
- }
- }
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