Improvements in Notification Activity (commons-app#1374)

* Improvements in Notification Activity

* Update NotificationActivity.java

Author: ujjwalagrawal17

app/src/main/java/fr/free/nrw/commons/notification/NotificationActivity.java

@@ -6,6 +6,7 @@
 import android.content.Intent;
 import android.net.Uri;
 import android.os.Bundle;
+import android.support.design.widget.Snackbar;
 import android.support.v7.widget.DividerItemDecoration;
 import android.support.v7.widget.LinearLayoutManager;
 import android.support.v7.widget.RecyclerView;
@@ -15,6 +16,7 @@
 
 import com.pedrogomez.renderers.RVRendererAdapter;
 
+import java.lang.ref.WeakReference;
 import java.util.Collections;
 import java.util.List;
 
@@ -25,6 +27,7 @@
 import fr.free.nrw.commons.R;
 import fr.free.nrw.commons.Utils;
 import fr.free.nrw.commons.theme.NavigationBaseActivity;
+import fr.free.nrw.commons.utils.NetworkUtils;
 import fr.free.nrw.commons.utils.ViewUtil;
 import io.reactivex.Observable;
 import io.reactivex.android.schedulers.AndroidSchedulers;
@@ -62,9 +65,23 @@ private void initListView() {
         recyclerView.setLayoutManager(new LinearLayoutManager(this));
         DividerItemDecoration itemDecor = new DividerItemDecoration(recyclerView.getContext(), DividerItemDecoration.VERTICAL);
         recyclerView.addItemDecoration(itemDecor);
-        addNotifications();
+        refresh();
     }
 
+    private void refresh() {
+        if (!NetworkUtils.isInternetConnectionEstablished(this)) {
+            progressBar.setVisibility(View.GONE);
+            Snackbar.make(relativeLayout , R.string.no_internet, Snackbar.LENGTH_INDEFINITE)
+                    .setAction(R.string.retry, view -> {
+                        refresh();
+                    }).show();
+        }else {
+            progressBar.setVisibility(View.VISIBLE);
+            addNotifications();
+        }
+    }
+
+
     @SuppressLint("CheckResult")
     private void addNotifications() {
         Timber.d("Add notifications");
@@ -124,4 +141,4 @@ private void initializeAndSetNotificationList(List<Notification> notificationLis
                 .commit();
         mNotificationWorkerFragment.setNotificationList(notificationList);
     }
-}
+}

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

@@ -267,5 +267,6 @@
   <string name="about_translate_message">Select the language that you would like to submit translations for</string>
   <string name="about_translate_proceed">Proceed</string>
   <string name="about_translate_cancel">Cancel</string>
+  <string name="retry">Retry</string>
 
 </resources>