Bug fix issue commons-app#2042

* Added a sticky snack bar in achievements activity which shows up when fetch api fails
* Snackbar comes with an action button which on click retries fetch. This way user is never shown a blank screen and always has an option to retry fetches

Author: ashishkumar468

app/src/main/java/fr/free/nrw/commons/achievements/AchievementsActivity.java

@@ -9,6 +9,7 @@
 import android.graphics.drawable.Drawable;
 import android.net.Uri;
 import android.os.Bundle;
+import android.support.design.widget.Snackbar;
 import android.support.v4.content.res.ResourcesCompat;
 import android.support.v7.app.AlertDialog;
 import android.support.v7.widget.Toolbar;
@@ -23,19 +24,10 @@
 import android.widget.ProgressBar;
 import android.widget.RelativeLayout;
 import android.widget.TextView;
-
-import com.dinuscxj.progressbar.CircleProgressBar;
-
-import java.io.File;
-import java.io.FileOutputStream;
-import java.io.IOException;
-import java.util.Objects;
-
-import javax.inject.Inject;
-
 import butterknife.BindView;
 import butterknife.ButterKnife;
 import butterknife.OnClick;
+import com.dinuscxj.progressbar.CircleProgressBar;
 import fr.free.nrw.commons.R;
 import fr.free.nrw.commons.Utils;
 import fr.free.nrw.commons.auth.SessionManager;
@@ -45,6 +37,11 @@
 import io.reactivex.android.schedulers.AndroidSchedulers;
 import io.reactivex.disposables.CompositeDisposable;
 import io.reactivex.schedulers.Schedulers;
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.util.Objects;
+import javax.inject.Inject;
 import timber.log.Timber;
 
 /**
@@ -185,6 +182,7 @@ void shareScreen(Bitmap bitmap) {
      * which then calls parseJson when results are fetched
      */
     private void setAchievements() {
+        progressBar.setVisibility(View.VISIBLE);
         if (checkAccount()) {
             compositeDisposable.add(mediaWikiApi
                     .getAchievements(Objects.requireNonNull(sessionManager.getCurrentAccount()).name)
@@ -195,17 +193,32 @@ private void setAchievements() {
                                 if (response != null) {
                                     setUploadCount(Achievements.from(response));
                                 } else {
-                                    onError();
+                                    showSnackBarWithRetry();
                                 }
                             },
                             t -> {
                                 Timber.e(t, "Fetching achievements statistics failed");
-                                onError();
+                                showSnackBarWithRetry();
                             }
                     ));
         }
     }
 
+    /**
+     * As there would be no other way to refresh data when api call fails, lets give him an option
+     * to retry using the snackbar
+     */
+    private void showSnackBarWithRetry() {
+        progressBar.setVisibility(View.GONE);
+        Snackbar snackbar = Snackbar.make(findViewById(android.R.id.content),
+            getString(R.string.achievements_fetch_failed), Snackbar.LENGTH_INDEFINITE);
+        snackbar.setAction(getString(R.string.retry), view -> {
+            snackbar.dismiss();
+            setAchievements();
+        });
+        snackbar.show();
+    }
+
     /**
      * Shows a generic error toast when error occurs while loading achievements or uploads
      */

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

@@ -431,5 +431,6 @@ Upload your first media by touching the camera or gallery icon above.</string>
   <string name="never_ask_again">Never ask this again</string>
   <string name="display_location_permission_title">Display location permission</string>
   <string name="display_location_permission_explanation">Ask for location permission when needed for nearby notification card view feature.</string>
+  <string name="achievements_fetch_failed">Something went wrong, we could not fetch your achievements</string>
 
 </resources>