Add network connectivity listener and inform user acordingly

Author: neslihanturan

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

@@ -1,6 +1,9 @@
 package fr.free.nrw.commons.nearby;
 
+import android.content.BroadcastReceiver;
+import android.content.Context;
 import android.content.Intent;
+import android.content.IntentFilter;
 import android.content.pm.PackageManager;
 import android.net.Uri;
 import android.os.Build;
@@ -10,6 +13,7 @@
 
 import android.support.v4.app.FragmentTransaction;
 import android.support.v7.app.AlertDialog;
+import android.util.Log;
 import android.view.Menu;
 import android.view.MenuInflater;
 import android.view.MenuItem;
@@ -33,6 +37,7 @@
 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.NetworkUtils;
 import fr.free.nrw.commons.utils.UriSerializer;
 
 import fr.free.nrw.commons.utils.ViewUtil;
@@ -69,11 +74,14 @@ public class NearbyActivity extends NavigationBaseActivity implements LocationUp
     private boolean lockNearbyView; //Determines if the nearby places needs to be refreshed
     private BottomSheetBehavior bottomSheetBehavior; // Behavior for list bottom sheet
     private BottomSheetBehavior bottomSheetBehaviorForDetails; // Behavior for details bottom sheet
-    private NearbyMapFragment nearbyMapFragment;
+    public NearbyMapFragment nearbyMapFragment;
     private NearbyListFragment nearbyListFragment;
     private static final String TAG_RETAINED_MAP_FRAGMENT = NearbyMapFragment.class.getSimpleName();
     private static final String TAG_RETAINED_LIST_FRAGMENT = NearbyListFragment.class.getSimpleName();
 
+    private final String NETWORK_INTENT_ACTION = "android.net.conn.CONNECTIVITY_CHANGE";
+    private BroadcastReceiver broadcastReceiver;
+
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
@@ -271,6 +279,7 @@ protected void onResume() {
         super.onResume();
         lockNearbyView = false;
         checkGps();
+        addNetworkBroadcastReceiver();
     }
 
     @Override
@@ -283,9 +292,28 @@ public void onPause() {
             // to the retained fragment object to perform its own cleanup.
             removeMapFragment();
             removeListFragment();
+            unregisterReceiver(broadcastReceiver);
         }
     }
 
+    private void addNetworkBroadcastReceiver() {
+        IntentFilter intentFilter = new IntentFilter(NETWORK_INTENT_ACTION);
+
+        broadcastReceiver = new BroadcastReceiver() {
+
+            @Override
+            public void onReceive(Context context, Intent intent) {
+                if (NetworkUtils.isInternetConnectionEstablished(NearbyActivity.this)) {
+                    refreshView(LocationServiceManager
+                            .LocationChangeType.LOCATION_SIGNIFICANTLY_CHANGED);
+                } else {
+                    ViewUtil.showLongToast(NearbyActivity.this, getString(R.string.no_internet));
+                }
+            }
+        };
+
+        this.registerReceiver(broadcastReceiver, intentFilter);
+    }
 
 
     /**
@@ -297,6 +325,12 @@ private void refreshView(LocationServiceManager.LocationChangeType locationChang
         if (lockNearbyView) {
             return;
         }
+
+        if (!NetworkUtils.isInternetConnectionEstablished(this)) {
+            hideProgressBar();
+            return;
+        }
+
         locationManager.registerLocationManager();
         LatLng lastLocation = locationManager.getLastLocation();
 

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

@@ -0,0 +1,18 @@
+package fr.free.nrw.commons.utils;
+
+
+import android.content.Context;
+import android.net.ConnectivityManager;
+import android.net.NetworkInfo;
+
+public class NetworkUtils {
+
+    public static boolean isInternetConnectionEstablished(Context context) {
+        ConnectivityManager cm =
+                (ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);
+
+        NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
+        return activeNetwork != null &&
+                activeNetwork.isConnectedOrConnecting();
+    }
+}

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

@@ -1,12 +1,19 @@
 package fr.free.nrw.commons.utils;
 
+import android.content.Context;
 import android.support.design.widget.Snackbar;
 import android.view.View;
+import android.widget.Toast;
 
 public class ViewUtil {
 
     public static void showSnackbar(View view, int messageResourceId) {
         Snackbar.make(view, messageResourceId, Snackbar.LENGTH_SHORT).show();
     }
 
+    public static void showLongToast(Context context, String text) {
+        Toast.makeText(context, text,
+                Toast.LENGTH_LONG).show();
+    }
+
 }

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

@@ -253,4 +253,7 @@
   <string name="about_rate_us"><u>Rate Us</u></string>
   <string name="about_faq">Frequently Asked Questions</string>
   <string name="welcome_skip_button">Skip Tutorial</string>
+
+  <string name="no_internet">Internet unavailable</string>
+  <string name="internet_established">Internet available</string>
 </resources>