Fix: Location update in nearby activity

app/src/main/java/fr/free/nrw/commons/di/ActivityBuilder.java

@@ -3,10 +3,14 @@ package fr.free.nrw.commons.di;
 import dagger.Module;
 import dagger.android.ContributesAndroidInjector;
 import fr.free.nrw.commons.contributions.ContributionsActivity;
+import fr.free.nrw.commons.nearby.NearbyActivity;
 
 @Module
 public abstract class ActivityBuilder {
 
     @ContributesAndroidInjector()
     abstract ContributionsActivity bindSplashScreenActivity();
+
+    @ContributesAndroidInjector()
+    abstract NearbyActivity bindNearbyActivity();
 }

app/src/main/java/fr/free/nrw/commons/di/AppModule.java

@@ -8,6 +8,7 @@ import javax.inject.Singleton;
 import dagger.Module;
 import dagger.Provides;
 import fr.free.nrw.commons.BuildConfig;
+import fr.free.nrw.commons.location.LocationServiceManager;
 import fr.free.nrw.commons.mwapi.ApacheHttpClientMediaWikiApi;
 import fr.free.nrw.commons.mwapi.MediaWikiApi;
 

app/src/main/java/fr/free/nrw/commons/location/LocationServiceManager.java

@@ -7,37 +7,35 @@ import android.location.LocationListener;
 import android.location.LocationManager;
 import android.os.Bundle;
 
-import fr.free.nrw.commons.CommonsApplication;
+import java.util.List;
+import java.util.concurrent.CopyOnWriteArrayList;
+
+import javax.inject.Inject;
+import javax.inject.Singleton;
+
 import timber.log.Timber;
 
+@Singleton
 public class LocationServiceManager implements LocationListener {
 
     private String provider;
     private LocationManager locationManager;
-    private LatLng latestLocation;
+    private LatLng lastLocation;
     private Float latestLocationAccuracy;
+    private final List<LocationUpdateListener> locationListeners = new CopyOnWriteArrayList<>();
 
-    private static LocationServiceManager locationServiceManager;
-
-    private LocationServiceManager() {
-        Context applicationContext = CommonsApplication.getInstance().getApplicationContext();
-        this.locationManager = (LocationManager) applicationContext.getSystemService(Context.LOCATION_SERVICE);
+    @Inject
+    public LocationServiceManager(Context context) {
+        this.locationManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
         provider = locationManager.getBestProvider(new Criteria(), true);
     }
 
-    public static LocationServiceManager getInstance() {
-        if (locationServiceManager == null) {
-            locationServiceManager = new LocationServiceManager();
-        }
-        return locationServiceManager;
-    }
-
     public boolean isProviderEnabled() {
         return locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
     }
 
-    public LatLng getLatestLocation() {
-        return latestLocation;
+    public LatLng getLastLocation() {
+        return lastLocation;
     }
 
     /**
@@ -79,6 +77,16 @@ public class LocationServiceManager implements LocationListener {
         }
     }
 
+    public void addLocationListener(LocationUpdateListener listener) {
+        if (!locationListeners.contains(listener)) {
+            locationListeners.add(listener);
+        }
+    }
+
+    public void removeLocationListener(LocationUpdateListener listener) {
+        locationListeners.remove(listener);
+    }
+
     @Override
     public void onLocationChanged(Location location) {
         double currentLatitude = location.getLatitude();
@@ -86,8 +94,11 @@ public class LocationServiceManager implements LocationListener {
         latestLocationAccuracy = location.getAccuracy();
         Timber.d("Latitude: %f Longitude: %f Accuracy %f",
                 currentLatitude, currentLongitude, latestLocationAccuracy);
+        lastLocation = new LatLng(currentLatitude, currentLongitude, latestLocationAccuracy);
 
-        latestLocation = new LatLng(currentLatitude, currentLongitude, latestLocationAccuracy);
+        for (LocationUpdateListener listener : locationListeners) {
+            listener.onLocationChanged(lastLocation);
+        }
     }
 
     @Override

app/src/main/java/fr/free/nrw/commons/location/LocationUpdateListener.java

@@ -0,0 +1,5 @@
+package fr.free.nrw.commons.location;
+
+public interface LocationUpdateListener {
+    void onLocationChanged(LatLng latLng);
+}

app/src/main/java/fr/free/nrw/commons/nearby/NearbyActivity.java

@@ -27,14 +27,19 @@ import com.google.gson.GsonBuilder;
 
 import java.util.List;
 
+import javax.inject.Inject;
+
 import butterknife.BindView;
 import butterknife.ButterKnife;
+import dagger.android.AndroidInjection;
 import fr.free.nrw.commons.CommonsApplication;
 import fr.free.nrw.commons.R;
 import fr.free.nrw.commons.location.LatLng;
 import fr.free.nrw.commons.location.LocationServiceManager;
+import fr.free.nrw.commons.location.LocationUpdateListener;
 import fr.free.nrw.commons.theme.NavigationBaseActivity;
 import fr.free.nrw.commons.utils.UriSerializer;
+import fr.free.nrw.commons.utils.ViewUtil;
 import io.reactivex.Observable;
 import io.reactivex.android.schedulers.AndroidSchedulers;
 import io.reactivex.disposables.Disposable;
@@ -42,14 +47,15 @@ import io.reactivex.schedulers.Schedulers;
 import timber.log.Timber;
 
 
-public class NearbyActivity extends NavigationBaseActivity {
+public class NearbyActivity extends NavigationBaseActivity implements LocationUpdateListener {
 
     @BindView(R.id.progressBar)
     ProgressBar progressBar;
     private static final int LOCATION_REQUEST = 1;
     private static final String MAP_LAST_USED_PREFERENCE = "mapLastUsed";
 
-    private LocationServiceManager locationManager;
+    @Inject
+    LocationServiceManager locationManager;
     private LatLng curLatLang;
     private Bundle bundle;
     private SharedPreferences sharedPreferences;
@@ -59,10 +65,10 @@ public class NearbyActivity extends NavigationBaseActivity {
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
+        AndroidInjection.inject(this);
         sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
         setContentView(R.layout.activity_nearby);
         ButterKnife.bind(this);
-        locationManager = LocationServiceManager.getInstance();
         checkLocationPermission();
         bundle = new Bundle();
         initDrawer();
@@ -95,7 +101,7 @@ public class NearbyActivity extends NavigationBaseActivity {
         // Handle item selection
         switch (item.getItemId()) {
             case R.id.action_refresh:
-                refreshView();
+                refreshView(true);
                 return true;
             case R.id.action_toggle_view:
                 viewMode = viewMode.toggle();
@@ -107,16 +113,11 @@ public class NearbyActivity extends NavigationBaseActivity {
         }
     }
 
-    private void startLookingForNearby() {
-        curLatLang = locationManager.getLatestLocation();
-        setupPlaceList(getBaseContext());
-    }
-
     private void checkLocationPermission() {
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
             if (ContextCompat.checkSelfPermission(this,
                     Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
-                startLookingForNearby();
+                refreshView(false);
             } else {
                 if (ContextCompat.checkSelfPermission(this,
                         Manifest.permission.ACCESS_FINE_LOCATION)
@@ -157,7 +158,7 @@ public class NearbyActivity extends NavigationBaseActivity {
                 }
             }
         } else {
-            startLookingForNearby();
+            refreshView(false);
         }
     }
 
@@ -166,7 +167,7 @@ public class NearbyActivity extends NavigationBaseActivity {
         switch (requestCode) {
             case LOCATION_REQUEST: {
                 if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
-                    startLookingForNearby();
+                    refreshView(false);
                 } else {
                     //If permission not granted, go to page that says Nearby Places cannot be displayed
                     if (progressBar != null) {
@@ -222,7 +223,7 @@ public class NearbyActivity extends NavigationBaseActivity {
         super.onActivityResult(requestCode, resultCode, data);
         if (requestCode == 1) {
             Timber.d("User is back from Settings page");
-            refreshView();
+            refreshView(false);
         }
     }
 
@@ -239,11 +240,13 @@ public class NearbyActivity extends NavigationBaseActivity {
     protected void onStart() {
         super.onStart();
         locationManager.registerLocationManager();
+        locationManager.addLocationListener(this);
     }
 
     @Override
     protected void onStop() {
         super.onStop();
+        locationManager.removeLocationListener(this);
         locationManager.unregisterLocationManager();
     }
 
@@ -259,13 +262,24 @@ public class NearbyActivity extends NavigationBaseActivity {
         checkGps();
     }
 
-    private void refreshView() {
-        curLatLang = locationManager.getLatestLocation();
+    private void refreshView(boolean isToastRequired) {
+        LatLng lastLocation = locationManager.getLastLocation();
+        if (curLatLang != null && curLatLang.equals(lastLocation)) { //refresh view only if location has changed
+            if (isToastRequired) {
+                ViewUtil.showLongToast(this, R.string.nearby_location_has_not_changed);
+            }
+            return;
+        }
+        curLatLang = lastLocation;
         progressBar.setVisibility(View.VISIBLE);
-        setupPlaceList(getBaseContext());
+        setupPlaceList(this);
     }
 
     private void setupPlaceList(Context context) {
+        if (curLatLang == null) {
+            Timber.d("Skipping update of nearby places as location is unavailable");
+            return;
+        }
         placesDisposable = Observable.fromCallable(() -> NearbyController
                 .loadAttractionsFromLocation(curLatLang, CommonsApplication.getInstance()))
                 .subscribeOn(Schedulers.io())
@@ -330,4 +344,9 @@ public class NearbyActivity extends NavigationBaseActivity {
         Intent settingsIntent = new Intent(context, NearbyActivity.class);
         context.startActivity(settingsIntent);
     }
+
+    @Override
+    public void onLocationChanged(LatLng latLng) {
+        refreshView(false);
+    }
 }

app/src/main/java/fr/free/nrw/commons/utils/ViewUtil.java

@@ -0,0 +1,17 @@
+package fr.free.nrw.commons.utils;
+
+import android.content.Context;
+import android.support.annotation.StringRes;
+import android.widget.Toast;
+
+public class ViewUtil {
+
+    public static void showLongToast(final Context context, @StringRes final int stringResId) {
+        ExecutorUtils.uiExecutor().execute(new Runnable() {
+            @Override
+            public void run() {
+                Toast.makeText(context, context.getString(stringResId), Toast.LENGTH_LONG).show();
+            }
+        });
+    }
+}

app/src/main/res/values/strings.xml

@@ -210,4 +210,6 @@ Tap this message (or hit back) to skip this step.</string>
   <string name="send_log_file">Send log file</string>
   <string name="send_log_file_description">Send log file to developers via email</string>
   <string name="login_to_your_account">Login to your account</string>
+
+  <string name="nearby_location_has_not_changed">Location has not changed.</string>
 </resources>