[android] Add average speed calculation and change speed view to display it

Signed-off-by: David Gekeler <git@davidgekeler.eu>

android/app/src/main/java/app/organicmaps/routing/NavigationController.java

@@ -18,6 +18,7 @@ import app.organicmaps.R;
 import app.organicmaps.maplayer.MapButtonsViewModel;
 import app.organicmaps.sdk.Framework;
 import app.organicmaps.sdk.Router;
+import app.organicmaps.sdk.location.LocationHelper;
 import app.organicmaps.sdk.maplayer.traffic.TrafficManager;
 import app.organicmaps.sdk.routing.CarDirection;
 import app.organicmaps.sdk.routing.RoutingController;
@@ -267,16 +268,18 @@ public class NavigationController implements TrafficManager.TrafficCallback, Nav
 
   private void updateSpeedWidgets(@NonNull final RoutingInfo info)
   {
-    final Location location = MwmApplication.from(mFrame.getContext()).getLocationHelper().getSavedLocation();
+    final LocationHelper locationHelper = MwmApplication.from(mFrame.getContext()).getLocationHelper();
+    final Location location = locationHelper.getSavedLocation();
     if (location == null)
     {
       mSpeedLimit.setSpeedLimit(-1, false);
       mCurrentSpeed.setCurrentSpeed(-1);
       return;
     }
+    final double currentAvgSpeed = locationHelper.getAverageSpeed();
     final int fSpeedLimit = StringUtils.nativeFormatSpeed(info.speedLimitMps);
-    final boolean speedLimitExceeded = fSpeedLimit < StringUtils.nativeFormatSpeed(location.getSpeed());
+    final boolean speedLimitExceeded = fSpeedLimit < StringUtils.nativeFormatSpeed(currentAvgSpeed);
     mSpeedLimit.setSpeedLimit(fSpeedLimit, speedLimitExceeded);
-    mCurrentSpeed.setCurrentSpeed(location.getSpeed());
+    mCurrentSpeed.setCurrentSpeed(currentAvgSpeed);
   }
 }

android/sdk/src/main/java/app/organicmaps/sdk/location/LocationHelper.java

@@ -26,6 +26,7 @@ import app.organicmaps.sdk.util.LocationUtils;
 import app.organicmaps.sdk.util.NetworkPolicy;
 import app.organicmaps.sdk.util.log.Logger;
 import org.chromium.base.ObserverList;
+import java.util.ArrayList;
 
 public class LocationHelper implements BaseLocationProvider.Listener
 {
@@ -35,6 +36,8 @@ public class LocationHelper implements BaseLocationProvider.Listener
   private static final long AGPS_EXPIRATION_TIME_MS = 16 * 60 * 60 * 1000; // 16 hours
   private static final long LOCATION_UPDATE_TIMEOUT_MS = 30 * 1000; // 30 seconds
 
+  private static final double SPEED_AVERAGING_TIME = 0.5; // 0.5 seconds
+
   @NonNull
   private final Context mContext;
   @NonNull
@@ -56,6 +59,10 @@ public class LocationHelper implements BaseLocationProvider.Listener
   private Handler mHandler;
   private Runnable mLocationTimeoutRunnable = this::notifyLocationUpdateTimeout;
 
+  private double mTimeElapsedAtLastAverage = Double.NaN;
+  private float mLastAverageSpeed = Float.NaN;
+  private ArrayList<Float> mSpeedHistory = new ArrayList<>();
+
   @NonNull
   private final GnssStatusCompat.Callback mGnssStatusCallback = new GnssStatusCompat.Callback() {
     @Override
@@ -167,6 +174,8 @@ public class LocationHelper implements BaseLocationProvider.Listener
                                         mSavedLocation.getLongitude(), mSavedLocation.getAccuracy(),
                                         mSavedLocation.getAltitude(), mSavedLocation.getSpeed(),
                                         mSavedLocation.getBearing());
+
+    updateSpeedHistory();
   }
 
   private void notifyLocationUpdateTimeout()
@@ -479,4 +488,49 @@ public class LocationHelper implements BaseLocationProvider.Listener
       Framework.nativeRunFirstLaunchAnimation();
     }
   }
+
+  private void updateSpeedHistory()
+  {
+    if (mSavedLocation == null)
+    {
+      return;
+    }
+
+    if (Double.isNaN(mTimeElapsedAtLastAverage))
+    {
+      mTimeElapsedAtLastAverage = mSavedLocation.getElapsedRealtimeNanos() * 1.0E-9;
+    }
+    mSpeedHistory.add(mSavedLocation.getSpeed());
+  }
+
+  public float getAverageSpeed()
+  {
+    if (mSavedLocation == null)
+    {
+      return Float.NaN;
+    }
+    if (Double.isNaN(mTimeElapsedAtLastAverage))
+    {
+      updateSpeedHistory();
+    }
+    if (mSavedLocation.getElapsedRealtimeNanos() * 1.0E-9 - mTimeElapsedAtLastAverage < SPEED_AVERAGING_TIME)
+    {
+      if (!Float.isNaN(mLastAverageSpeed))
+      {
+        return mLastAverageSpeed;
+      }
+      else
+      {
+        return mSavedLocation.getSpeed();
+      }
+    }
+    else
+    {
+      mLastAverageSpeed = mSpeedHistory.stream().reduce(0.0F, Float::sum);
+      mLastAverageSpeed /= mSpeedHistory.size();
+      mSpeedHistory.clear();
+      mTimeElapsedAtLastAverage = mSavedLocation.getElapsedRealtimeNanos() * 1.0E-9;
+      return mLastAverageSpeed;
+    }
+  }
 }