This commit is contained in:
Philipp Schaefer 2013-12-27 17:09:33 +01:00
parent 7ff4c79910
commit 3fe9b91a92

View File

@ -136,6 +136,65 @@ public class IITC_UserLocation implements LocationListener, SensorEventListener
mIitc.invalidateOptionsMenu();
}
private static final int TWO_MINUTES = 1000 * 60 * 2;
/**
* 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
*
* code copied from http://developer.android.com/guide/topics/location/strategies.html#BestEstimate
*/
protected 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;
boolean isNewer = timeDelta > 0;
// 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 isLessAccurate = accuracyDelta > 0;
boolean isMoreAccurate = accuracyDelta < 0;
boolean isSignificantlyLessAccurate = accuracyDelta > 100;
// Check if the old and new location are from the same provider
boolean isFromSameProvider = isSameProvider(location.getProvider(),
currentBestLocation.getProvider());
// Determine location quality using a combination of timeliness and accuracy
if (isMoreAccurate) {
return true;
} else if (isNewer && !isLessAccurate) {
return true;
} else if (isNewer && !isSignificantlyLessAccurate && isFromSameProvider) {
return true;
}
return false;
}
// Checks whether two providers are the same
private boolean isSameProvider(String provider1, String provider2) {
if (provider1 == null) {
return provider2 == null;
}
return provider1.equals(provider2);
}
/**
* set the location mode to use. Available modes:
* 0: don't show user's position
@ -157,10 +216,9 @@ public class IITC_UserLocation implements LocationListener, SensorEventListener
@Override
public void onLocationChanged(Location location) {
mLastLocation = location;
if (!isBetterLocation(location, mLastLocation)) return;
// throw away all positions with accuracy > 100 meters should avoid gps glitches
if (location.getAccuracy() > 100) return;
mLastLocation = location;
// do not touch the javascript while iitc boots
if (mIitc.isLoading()) return;