Android: calculate location age with elapsed real time if supported

Author: Agontuk

android/src/main/java/com/agontuk/RNFusedLocation/FusedLocationProvider.java

@@ -90,7 +90,7 @@ public void getCurrentLocation(final LocationOptions locationOptions, final Loca
         @Override
         public void onSuccess(Location location) {
           if (location != null &&
-            (System.currentTimeMillis() - location.getTime()) < locationOptions.getMaximumAge()
+            LocationUtils.getLocationAge(location) < locationOptions.getMaximumAge()
           ) {
             Log.i(RNFusedLocationModule.TAG, "returning cached location.");
             locationChangeListener.onLocationChange(location);

android/src/main/java/com/agontuk/RNFusedLocation/LocationManagerProvider.java

@@ -81,7 +81,7 @@ public void getCurrentLocation(LocationOptions locationOptions, LocationChangeLi
     Location location = locationManager.getLastKnownLocation(provider);
 
     if (location != null &&
-      (System.currentTimeMillis() - location.getTime()) < locationOptions.getMaximumAge()
+      LocationUtils.getLocationAge(location) < locationOptions.getMaximumAge()
     ) {
       Log.i(RNFusedLocationModule.TAG, "returning cached location.");
       locationChangeListener.onLocationChange(location);

android/src/main/java/com/agontuk/RNFusedLocation/LocationUtils.java

@@ -6,6 +6,7 @@
 import android.location.LocationManager;
 import android.Manifest;
 import android.os.Build;
+import android.os.SystemClock;
 import android.text.TextUtils;
 import android.provider.Settings;
 
@@ -19,6 +20,17 @@
 import com.google.android.gms.common.GoogleApiAvailability;
 
 public class LocationUtils {
+  /**
+   * Calculates the age of a location fix in milliseconds
+   */
+  public static long getLocationAge(Location location) {
+    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
+      return (SystemClock.elapsedRealtimeNanos() - location.getElapsedRealtimeNanos()) / 1000000;
+    }
+
+    return System.currentTimeMillis() - location.getTime();
+  }
+
   /**
    * Check if location permissions are granted.
    */