Fix crash(es) caused by failing to dispose Rx observables (#2669)

app/src/main/java/fr/free/nrw/commons/CommonsApplication.java

@@ -44,6 +44,8 @@ import fr.free.nrw.commons.modifications.ModifierSequenceDao;
 import fr.free.nrw.commons.upload.FileUtils;
 import fr.free.nrw.commons.utils.ConfigUtils;
 import io.reactivex.android.schedulers.AndroidSchedulers;
+import io.reactivex.internal.functions.Functions;
+import io.reactivex.plugins.RxJavaPlugins;
 import io.reactivex.schedulers.Schedulers;
 import timber.log.Timber;
 
@@ -128,6 +130,9 @@ public class CommonsApplication extends Application {
 
         createNotificationChannel(this);
 
+        // This handler will catch exceptions thrown from Observables after they are disposed,
+        // or from Observables that are (deliberately or not) missing an onError handler.
+        RxJavaPlugins.setErrorHandler(Functions.emptyConsumer());
 
         if (setupLeakCanary() == RefWatcher.DISABLED) {
             return;

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

@@ -142,6 +142,12 @@ public class AchievementsActivity extends NavigationBaseActivity {
         initDrawer();
     }
 
+    @Override
+    public void onDestroy() {
+        super.onDestroy();
+        compositeDisposable.clear();
+    }
+
     /**
      * To invoke the AlertDialog on clicking info button
      */
@@ -238,12 +244,12 @@ public class AchievementsActivity extends NavigationBaseActivity {
         if (StringUtils.isNullOrWhiteSpace(userName)) {
             return;
         }
-        okHttpJsonApiClient.getWikidataEdits(userName)
+        compositeDisposable.add(okHttpJsonApiClient.getWikidataEdits(userName)
                 .subscribeOn(Schedulers.io())
                 .observeOn(AndroidSchedulers.mainThread())
                 .subscribe(edits -> wikidataEditsText.setText(String.valueOf(edits)), e -> {
                     Timber.e("Error:" + e);
-                });
+                }));
     }
 
     private void showSnackBarWithRetry() {

app/src/main/java/fr/free/nrw/commons/auth/AuthenticatedActivity.java

@@ -58,13 +58,12 @@ public abstract class AuthenticatedActivity extends NavigationBaseActivity {
      * Makes API call to check if user is blocked from Commons. If the user is blocked, a snackbar
      * is created to notify the user
      */
-    protected void showBlockStatus()
+    protected void showBlockStatus() {
-    {
+        compositeDisposable.add(Observable.fromCallable(() -> mediaWikiApi.isUserBlockedFromCommons())
-        Observable.fromCallable(() -> mediaWikiApi.isUserBlockedFromCommons())
                 .subscribeOn(Schedulers.io())
                 .observeOn(AndroidSchedulers.mainThread())
                 .filter(result -> result)
                 .subscribe(result -> ViewUtil.showShortSnackbar(findViewById(android.R.id.content), R.string.block_notification)
-                );
+                ));
     }
 }

app/src/main/java/fr/free/nrw/commons/auth/LoginActivity.java

@@ -52,6 +52,7 @@ import fr.free.nrw.commons.utils.ConfigUtils;
 import fr.free.nrw.commons.utils.ViewUtil;
 import io.reactivex.Observable;
 import io.reactivex.android.schedulers.AndroidSchedulers;
+import io.reactivex.disposables.CompositeDisposable;
 import io.reactivex.schedulers.Schedulers;
 import timber.log.Timber;
 
@@ -83,6 +84,7 @@ public class LoginActivity extends AccountAuthenticatorActivity {
     ProgressDialog progressDialog;
     private AppCompatDelegate delegate;
     private LoginTextWatcher textWatcher = new LoginTextWatcher();
+    private CompositeDisposable compositeDisposable = new CompositeDisposable();
 
     private Boolean loginCurrentlyInProgress = false;
     private Boolean errorMessageShown = false;
@@ -195,6 +197,7 @@ public class LoginActivity extends AccountAuthenticatorActivity {
 
     @Override
     protected void onDestroy() {
+        compositeDisposable.clear();
         try {
             // To prevent leaked window when finish() is called, see http://stackoverflow.com/questions/32065854/activity-has-leaked-window-at-alertdialog-show-method
             if (progressDialog != null && progressDialog.isShowing()) {
@@ -219,10 +222,10 @@ public class LoginActivity extends AccountAuthenticatorActivity {
         String twoFactorCode = twoFactorEdit.getText().toString();
 
         showLoggingProgressBar();
-        Observable.fromCallable(() -> login(username, password, twoFactorCode))
+        compositeDisposable.add(Observable.fromCallable(() -> login(username, password, twoFactorCode))
                 .subscribeOn(Schedulers.io())
                 .observeOn(AndroidSchedulers.mainThread())
-                .subscribe(result -> handleLogin(username, rawUsername, password, result));
+                .subscribe(result -> handleLogin(username, rawUsername, password, result)));
     }
 
     private String login(String username, String password, String twoFactorCode) {

app/src/main/java/fr/free/nrw/commons/bookmarks/pictures/BookmarkPicturesFragment.java

@@ -30,6 +30,7 @@ import fr.free.nrw.commons.utils.NetworkUtils;
 import fr.free.nrw.commons.utils.ViewUtil;
 import io.reactivex.Observable;
 import io.reactivex.android.schedulers.AndroidSchedulers;
+import io.reactivex.disposables.CompositeDisposable;
 import io.reactivex.schedulers.Schedulers;
 import timber.log.Timber;
 
@@ -41,6 +42,7 @@ public class BookmarkPicturesFragment extends DaggerFragment {
     private static final int TIMEOUT_SECONDS = 15;
 
     private GridViewAdapter gridAdapter;
+    private CompositeDisposable compositeDisposable = new CompositeDisposable();
 
     @BindView(R.id.statusMessage) TextView statusTextView;
     @BindView(R.id.loadingImagesProgressBar) ProgressBar progressBar;
@@ -82,6 +84,12 @@ public class BookmarkPicturesFragment extends DaggerFragment {
         controller.stop();
     }
 
+    @Override
+    public void onDestroy() {
+        super.onDestroy();
+        compositeDisposable.clear();
+    }
+
     @Override
     public void onResume() {
         super.onResume();
@@ -113,11 +121,11 @@ public class BookmarkPicturesFragment extends DaggerFragment {
         progressBar.setVisibility(VISIBLE);
         statusTextView.setVisibility(GONE);
 
-        Observable.fromCallable(() -> controller.loadBookmarkedPictures())
+        compositeDisposable.add(Observable.fromCallable(() -> controller.loadBookmarkedPictures())
                 .subscribeOn(Schedulers.io())
                 .observeOn(AndroidSchedulers.mainThread())
                 .timeout(TIMEOUT_SECONDS, TimeUnit.SECONDS)
-                .subscribe(this::handleSuccess, this::handleError);
+                .subscribe(this::handleSuccess, this::handleError));
     }
 
     /**

app/src/main/java/fr/free/nrw/commons/category/CategoryImagesListFragment.java

@@ -31,6 +31,7 @@ import fr.free.nrw.commons.utils.NetworkUtils;
 import fr.free.nrw.commons.utils.ViewUtil;
 import io.reactivex.Observable;
 import io.reactivex.android.schedulers.AndroidSchedulers;
+import io.reactivex.disposables.CompositeDisposable;
 import io.reactivex.schedulers.Schedulers;
 import timber.log.Timber;
 
@@ -51,6 +52,7 @@ public class CategoryImagesListFragment extends DaggerFragment {
     @BindView(R.id.loadingImagesProgressBar) ProgressBar progressBar;
     @BindView(R.id.categoryImagesList) GridView gridView;
     @BindView(R.id.parentLayout) RelativeLayout parentLayout;
+    private CompositeDisposable compositeDisposable = new CompositeDisposable();
     private boolean hasMoreImages = true;
     private boolean isLoading = true;
     private String categoryName = null;
@@ -74,6 +76,12 @@ public class CategoryImagesListFragment extends DaggerFragment {
         initViews();
     }
 
+    @Override
+    public void onDestroy() {
+        super.onDestroy();
+        compositeDisposable.clear();
+    }
+
     /**
      * Initializes the UI elements for the fragment
      * Setup the grid view to and scroll listener for it
@@ -109,11 +117,11 @@ public class CategoryImagesListFragment extends DaggerFragment {
 
         isLoading = true;
         progressBar.setVisibility(VISIBLE);
-        Observable.fromCallable(() -> controller.getCategoryImages(categoryName))
+        compositeDisposable.add(Observable.fromCallable(() -> controller.getCategoryImages(categoryName))
                 .subscribeOn(Schedulers.io())
                 .observeOn(AndroidSchedulers.mainThread())
                 .timeout(TIMEOUT_SECONDS, TimeUnit.SECONDS)
-                .subscribe(this::handleSuccess, this::handleError);
+                .subscribe(this::handleSuccess, this::handleError));
     }
 
     /**
@@ -215,11 +223,11 @@ public class CategoryImagesListFragment extends DaggerFragment {
         }
 
         progressBar.setVisibility(VISIBLE);
-        Observable.fromCallable(() -> controller.getCategoryImages(categoryName))
+        compositeDisposable.add(Observable.fromCallable(() -> controller.getCategoryImages(categoryName))
                 .subscribeOn(Schedulers.io())
                 .observeOn(AndroidSchedulers.mainThread())
                 .timeout(TIMEOUT_SECONDS, TimeUnit.SECONDS)
-                .subscribe(this::handleSuccess, this::handleError);
+                .subscribe(this::handleSuccess, this::handleError));
     }
 
     /**

app/src/main/java/fr/free/nrw/commons/category/SubCategoryListFragment.java

@@ -97,17 +97,17 @@ public class SubCategoryListFragment extends CommonsDaggerSupportFragment {
         }
         progressBar.setVisibility(View.VISIBLE);
         if (!isParentCategory){
-            Observable.fromCallable(() -> mwApi.getSubCategoryList(categoryName))
+            compositeDisposable.add(Observable.fromCallable(() -> mwApi.getSubCategoryList(categoryName))
                     .subscribeOn(Schedulers.io())
                     .observeOn(AndroidSchedulers.mainThread())
                     .timeout(TIMEOUT_SECONDS, TimeUnit.SECONDS)
-                    .subscribe(this::handleSuccess, this::handleError);
+                    .subscribe(this::handleSuccess, this::handleError));
         }else {
-            Observable.fromCallable(() -> mwApi.getParentCategoryList(categoryName))
+            compositeDisposable.add(Observable.fromCallable(() -> mwApi.getParentCategoryList(categoryName))
                     .subscribeOn(Schedulers.io())
                     .observeOn(AndroidSchedulers.mainThread())
                     .timeout(TIMEOUT_SECONDS, TimeUnit.SECONDS)
-                    .subscribe(this::handleSuccess, this::handleError);
+                    .subscribe(this::handleSuccess, this::handleError));
         }
     }
 

app/src/main/java/fr/free/nrw/commons/contributions/ContributionsFragment.java

@@ -61,7 +61,6 @@ import fr.free.nrw.commons.utils.ViewUtil;
 import io.reactivex.Observable;
 import io.reactivex.android.schedulers.AndroidSchedulers;
 import io.reactivex.disposables.CompositeDisposable;
-import io.reactivex.disposables.Disposable;
 import io.reactivex.schedulers.Schedulers;
 import timber.log.Timber;
 
@@ -101,7 +100,6 @@ public class ContributionsFragment
     @BindView(R.id.card_view_nearby) public NearbyNotificationCardView nearbyNotificationCardView;
     @BindView(R.id.campaigns_view) CampaignView campaignView;
 
-    private Disposable placesDisposable;
     private LatLng curLatLng;
 
     private boolean firstLocationUpdate = true;
@@ -592,7 +590,7 @@ public class ContributionsFragment
     private void updateClosestNearbyCardViewInfo() {
         curLatLng = locationManager.getLastLocation();
 
-        placesDisposable = Observable.fromCallable(() -> nearbyController
+        compositeDisposable.add(Observable.fromCallable(() -> nearbyController
                 .loadAttractionsFromLocation(curLatLng, curLatLng, true, false)) // thanks to boolean, it will only return closest result
                 .subscribeOn(Schedulers.io())
                 .observeOn(AndroidSchedulers.mainThread())
@@ -600,7 +598,7 @@ public class ContributionsFragment
                         throwable -> {
                             Timber.d(throwable);
                             updateNearbyNotification(null);
-                        });
+                        }));
     }
 
     private void updateNearbyNotification(@Nullable NearbyController.NearbyPlacesInfo nearbyPlacesInfo) {
@@ -635,10 +633,6 @@ public class ContributionsFragment
                 isUploadServiceConnected = false;
             }
         }
-
-        if (placesDisposable != null) {
-            placesDisposable.dispose();
-        }
     }
 
     @Override

app/src/main/java/fr/free/nrw/commons/contributions/MainActivity.java

@@ -307,11 +307,11 @@ public class MainActivity extends AuthenticatedActivity implements FragmentManag
 
     @SuppressLint("CheckResult")
     private void setNotificationCount() {
-        Observable.fromCallable(() -> notificationController.getNotifications(false))
+        compositeDisposable.add(Observable.fromCallable(() -> notificationController.getNotifications(false))
                 .subscribeOn(Schedulers.io())
                 .observeOn(AndroidSchedulers.mainThread())
                 .subscribe(this::initNotificationViews,
-                        throwable -> Timber.e(throwable, "Error occurred while loading notifications"));
+                        throwable -> Timber.e(throwable, "Error occurred while loading notifications")));
     }
 
     private void initNotificationViews(List<Notification> notificationList) {

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

@@ -9,18 +9,27 @@ import androidx.fragment.app.Fragment;
 import dagger.android.AndroidInjector;
 import dagger.android.DispatchingAndroidInjector;
 import dagger.android.support.HasSupportFragmentInjector;
+import io.reactivex.disposables.CompositeDisposable;
 
 public abstract class CommonsDaggerSupportFragment extends Fragment implements HasSupportFragmentInjector {
 
     @Inject
     DispatchingAndroidInjector<Fragment> childFragmentInjector;
 
+    protected CompositeDisposable compositeDisposable = new CompositeDisposable();
+
     @Override
     public void onAttach(Context context) {
         inject();
         super.onAttach(context);
     }
 
+    @Override
+    public void onDestroy() {
+        super.onDestroy();
+        compositeDisposable.clear();
+    }
+
     @Override
     public AndroidInjector<Fragment> supportFragmentInjector() {
         return childFragmentInjector;

app/src/main/java/fr/free/nrw/commons/explore/SearchActivity.java

@@ -98,7 +98,7 @@ public class SearchActivity extends NavigationBaseActivity implements MediaDetai
 
         viewPagerAdapter.setTabData(fragmentList, titleList);
         viewPagerAdapter.notifyDataSetChanged();
-        RxSearchView.queryTextChanges(searchView)
+        compositeDisposable.add(RxSearchView.queryTextChanges(searchView)
                 .takeUntil(RxView.detaches(searchView))
                 .debounce(500, TimeUnit.MILLISECONDS)
                 .observeOn(AndroidSchedulers.mainThread())
@@ -120,7 +120,7 @@ public class SearchActivity extends NavigationBaseActivity implements MediaDetai
                                 searchHistoryContainer.setVisibility(View.VISIBLE);
                             }
                         }
-                );
+                ));
     }
 
     /**

app/src/main/java/fr/free/nrw/commons/explore/categories/SearchCategoryFragment.java

@@ -3,7 +3,6 @@ package fr.free.nrw.commons.explore.categories;
 
 import android.content.res.Configuration;
 import android.os.Bundle;
-import android.os.Handler;
 import androidx.recyclerview.widget.GridLayoutManager;
 import androidx.recyclerview.widget.LinearLayoutManager;
 import androidx.recyclerview.widget.RecyclerView;
@@ -136,12 +135,12 @@ public class SearchCategoryFragment extends CommonsDaggerSupportFragment {
         progressBar.setVisibility(GONE);
         queryList.clear();
         categoriesAdapter.clear();
-        Observable.fromCallable(() -> mwApi.searchCategory(query,queryList.size()))
+        compositeDisposable.add(Observable.fromCallable(() -> mwApi.searchCategory(query,queryList.size()))
                 .subscribeOn(Schedulers.io())
                 .observeOn(AndroidSchedulers.mainThread())
                 .timeout(TIMEOUT_SECONDS, TimeUnit.SECONDS)
                 .doOnSubscribe(disposable -> saveQuery(query))
-                .subscribe(this::handleSuccess, this::handleError);
+                .subscribe(this::handleSuccess, this::handleError));
     }
 
 
@@ -152,11 +151,11 @@ public class SearchCategoryFragment extends CommonsDaggerSupportFragment {
         this.query = query;
         bottomProgressBar.setVisibility(View.VISIBLE);
         progressBar.setVisibility(GONE);
-        Observable.fromCallable(() -> mwApi.searchCategory(query,queryList.size()))
+        compositeDisposable.add(Observable.fromCallable(() -> mwApi.searchCategory(query,queryList.size()))
                 .subscribeOn(Schedulers.io())
                 .observeOn(AndroidSchedulers.mainThread())
                 .timeout(TIMEOUT_SECONDS, TimeUnit.SECONDS)
-                .subscribe(this::handlePaginationSuccess, this::handleError);
+                .subscribe(this::handlePaginationSuccess, this::handleError));
     }
 
     /**

app/src/main/java/fr/free/nrw/commons/explore/images/SearchImageFragment.java

@@ -4,7 +4,6 @@ package fr.free.nrw.commons.explore.images;
 import android.annotation.SuppressLint;
 import android.content.res.Configuration;
 import android.os.Bundle;
-import android.os.Handler;
 import androidx.recyclerview.widget.GridLayoutManager;
 import androidx.recyclerview.widget.LinearLayoutManager;
 import androidx.recyclerview.widget.RecyclerView;
@@ -142,12 +141,12 @@ public class SearchImageFragment extends CommonsDaggerSupportFragment {
         bottomProgressBar.setVisibility(GONE);
         queryList.clear();
         imagesAdapter.clear();
-        okHttpJsonApiClient.searchImages(query, queryList.size())
+        compositeDisposable.add(okHttpJsonApiClient.searchImages(query, queryList.size())
                 .subscribeOn(Schedulers.io())
                 .observeOn(AndroidSchedulers.mainThread())
                 .timeout(TIMEOUT_SECONDS, TimeUnit.SECONDS)
                 .doOnSubscribe(disposable -> saveQuery(query))
-                .subscribe(this::handleSuccess, this::handleError);
+                .subscribe(this::handleSuccess, this::handleError));
     }
 
 
@@ -159,11 +158,11 @@ public class SearchImageFragment extends CommonsDaggerSupportFragment {
         this.query = query;
         bottomProgressBar.setVisibility(View.VISIBLE);
         progressBar.setVisibility(GONE);
-        okHttpJsonApiClient.searchImages(query, queryList.size())
+        compositeDisposable.add(okHttpJsonApiClient.searchImages(query, queryList.size())
                 .subscribeOn(Schedulers.io())
                 .observeOn(AndroidSchedulers.mainThread())
                 .timeout(TIMEOUT_SECONDS, TimeUnit.SECONDS)
-                .subscribe(this::handlePaginationSuccess, this::handleError);
+                .subscribe(this::handlePaginationSuccess, this::handleError));
     }
 
     /**

app/src/main/java/fr/free/nrw/commons/media/MediaDetailFragment.java

@@ -420,7 +420,7 @@ public class MediaDetailFragment extends CommonsDaggerSupportFragment {
     private void onDeleteClicked(Spinner spinner) {
         String reason = spinner.getSelectedItem().toString();
         Single<String> deletionReason = reasonBuilder.getReason(media, reason);
-        deletionReason
+        compositeDisposable.add(deletionReason
                 .subscribeOn(Schedulers.io())
                 .observeOn(AndroidSchedulers.mainThread())
                 .subscribe(s -> {
@@ -428,7 +428,7 @@ public class MediaDetailFragment extends CommonsDaggerSupportFragment {
                     deleteTask.execute();
                     isDeleted = true;
                     enableDeleteButton(false);
-                });
+                }));
     }
 
     @OnClick(R.id.seeMore)

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

@@ -42,7 +42,6 @@ import fr.free.nrw.commons.utils.ViewUtil;
 import fr.free.nrw.commons.wikidata.WikidataEditListener;
 import io.reactivex.Observable;
 import io.reactivex.android.schedulers.AndroidSchedulers;
-import io.reactivex.disposables.Disposable;
 import io.reactivex.schedulers.Schedulers;
 import timber.log.Timber;
 
@@ -85,8 +84,6 @@ public class NearbyFragment extends CommonsDaggerSupportFragment
     private BottomSheetBehavior bottomSheetBehaviorForDetails; // Behavior for details bottom sheet
 
     private LatLng curLatLng;
-    private Disposable placesDisposable;
-    private Disposable placesDisposableCustom;
     private boolean lockNearbyView; //Determines if the nearby places needs to be refreshed
     public View view;
     private Snackbar snackbar;
@@ -298,7 +295,7 @@ public class NearbyFragment extends CommonsDaggerSupportFragment
             bundle.clear();
             bundle.putString("CurLatLng", gsonCurLatLng);
 
-            placesDisposable = Observable.fromCallable(() -> nearbyController
+            compositeDisposable.add(Observable.fromCallable(() -> nearbyController
                     .loadAttractionsFromLocation(curLatLng, curLatLng, false, true))
                     .subscribeOn(Schedulers.io())
                     .observeOn(AndroidSchedulers.mainThread())
@@ -307,7 +304,7 @@ public class NearbyFragment extends CommonsDaggerSupportFragment
                                 Timber.d(throwable);
                                 showErrorMessage(getString(R.string.error_fetching_nearby_places));
                                 progressBar.setVisibility(View.GONE);
-                            });
+                            }));
 
         } else if (locationChangeType
                 .equals(LOCATION_SLIGHTLY_CHANGED) && nearbyMapFragment != null) {
@@ -335,7 +332,7 @@ public class NearbyFragment extends CommonsDaggerSupportFragment
 
         populateForCurrentLocation = refreshForCurrentLocation;
         this.customLatLng = customLatLng;
-        placesDisposableCustom = Observable.fromCallable(() -> nearbyController
+        compositeDisposable.add(Observable.fromCallable(() -> nearbyController
                 .loadAttractionsFromLocation(curLatLng, customLatLng, false, populateForCurrentLocation))
                 .subscribeOn(Schedulers.io())
                 .observeOn(AndroidSchedulers.mainThread())
@@ -343,7 +340,7 @@ public class NearbyFragment extends CommonsDaggerSupportFragment
                         throwable -> {
                             Timber.d(throwable);
                             showErrorMessage(getString(R.string.error_fetching_nearby_places));
-                        });
+                        }));
 
         if (nearbyMapFragment != null) {
             nearbyMapFragment.searchThisAreaButton.setVisibility(View.GONE);
@@ -467,7 +464,7 @@ public class NearbyFragment extends CommonsDaggerSupportFragment
                     || curLatLng.getLongitude() < nearbyMapFragment.boundaryCoordinates[2].getLongitude()
                     || curLatLng.getLongitude() > nearbyMapFragment.boundaryCoordinates[3].getLongitude())) {
                 // populate places
-                placesDisposable = Observable.fromCallable(() -> nearbyController
+                compositeDisposable.add(Observable.fromCallable(() -> nearbyController
                         .loadAttractionsFromLocation(curLatLng, curLatLng, false, updateViaButton))
                         .subscribeOn(Schedulers.io())
                         .observeOn(AndroidSchedulers.mainThread())
@@ -476,7 +473,7 @@ public class NearbyFragment extends CommonsDaggerSupportFragment
                                     Timber.d(throwable);
                                     showErrorMessage(getString(R.string.error_fetching_nearby_places));
                                     progressBar.setVisibility(View.GONE);
-                                });
+                                }));
                 nearbyMapFragment.setBundleForUpdates(bundle);
                 nearbyMapFragment.updateMapSignificantlyForCurrentLocation();
                 updateListFragment();
@@ -782,13 +779,7 @@ public class NearbyFragment extends CommonsDaggerSupportFragment
     @Override
     public void onDestroy() {
         super.onDestroy();
-        if (placesDisposable != null) {
-            placesDisposable.dispose();
-        }
         wikidataEditListener.setAuthenticationStateListener(null);
-        if (placesDisposableCustom != null) {
-            placesDisposableCustom.dispose();
-        }
     }
 
     @Override

app/src/main/java/fr/free/nrw/commons/theme/BaseActivity.java

@@ -8,13 +8,14 @@ import javax.inject.Named;
 import fr.free.nrw.commons.R;
 import fr.free.nrw.commons.di.CommonsDaggerAppCompatActivity;
 import fr.free.nrw.commons.kvstore.JsonKvStore;
-import fr.free.nrw.commons.kvstore.JsonKvStore;
+import io.reactivex.disposables.CompositeDisposable;
 
 public abstract class BaseActivity extends CommonsDaggerAppCompatActivity {
     @Inject
     @Named("default_preferences")
     public JsonKvStore defaultKvStore;
 
+    protected CompositeDisposable compositeDisposable = new CompositeDisposable();
     protected boolean wasPreviouslyDarkTheme;
 
     @Override
@@ -33,4 +34,10 @@ public abstract class BaseActivity extends CommonsDaggerAppCompatActivity {
 
         super.onResume();
     }
+
+    @Override
+    protected void onDestroy() {
+        super.onDestroy();
+        compositeDisposable.clear();
+    }
 }

app/src/main/java/fr/free/nrw/commons/upload/FileProcessor.java

@@ -17,6 +17,7 @@ import androidx.exifinterface.media.ExifInterface;
 import fr.free.nrw.commons.caching.CacheController;
 import fr.free.nrw.commons.kvstore.JsonKvStore;
 import fr.free.nrw.commons.mwapi.CategoryApi;
+import io.reactivex.disposables.CompositeDisposable;
 import io.reactivex.schedulers.Schedulers;
 import timber.log.Timber;
 
@@ -42,11 +43,16 @@ public class FileProcessor implements SimilarImageDialogFragment.onResponse {
     private ExifInterface exifInterface;
     private boolean haveCheckedForOtherImages = false;
     private GPSExtractor tempImageObj;
+    private CompositeDisposable compositeDisposable = new CompositeDisposable();
 
     @Inject
     FileProcessor() {
     }
 
+    public void cleanup() {
+        compositeDisposable.clear();
+    }
+
     void initFileDetails(@NonNull String filePath, ContentResolver contentResolver) {
         this.filePath = filePath;
         this.contentResolver = contentResolver;
@@ -138,7 +144,7 @@ public class FileProcessor implements SimilarImageDialogFragment.onResponse {
 
             // If no categories found in cache, call MediaWiki API to match image coords with nearby Commons categories
             if (catListEmpty) {
-                apiCall.request(decimalCoords)
+                compositeDisposable.add(apiCall.request(decimalCoords)
                         .subscribeOn(Schedulers.io())
                         .observeOn(Schedulers.io())
                         .subscribe(
@@ -147,7 +153,7 @@ public class FileProcessor implements SimilarImageDialogFragment.onResponse {
                                     Timber.e(throwable);
                                     gpsCategoryModel.clear();
                                 }
-                        );
+                        ));
                 Timber.d("displayCatList size 0, calling MWAPI %s", displayCatList);
             } else {
                 Timber.d("Cache found, setting categoryList in model to %s", displayCatList);

app/src/main/java/fr/free/nrw/commons/upload/ImageProcessingService.java

@@ -33,16 +33,19 @@ public class ImageProcessingService {
     private final MediaWikiApi mwApi;
     private final ReadFBMD readFBMD;
     private final EXIFReader EXIFReader;
+    private final Context context;
 
     @Inject
     public ImageProcessingService(FileUtilsWrapper fileUtilsWrapper,
                                   ImageUtilsWrapper imageUtilsWrapper,
-                                  MediaWikiApi mwApi, ReadFBMD readFBMD, EXIFReader EXIFReader) {
+                                  MediaWikiApi mwApi, ReadFBMD readFBMD, EXIFReader EXIFReader,
+                                  Context context) {
         this.fileUtilsWrapper = fileUtilsWrapper;
         this.imageUtilsWrapper = imageUtilsWrapper;
         this.mwApi = mwApi;
         this.readFBMD = readFBMD;
         this.EXIFReader = EXIFReader;
+        this.context = context;
     }
 
     /**
@@ -61,13 +64,13 @@ public class ImageProcessingService {
         Timber.d("Checking the validity of image");
         String filePath = uploadItem.getMediaUri().getPath();
         Uri contentUri=uploadItem.getContentUri();
-        Context context=uploadItem.getContext();
         Single<Integer> duplicateImage = checkDuplicateImage(filePath);
         Single<Integer> wrongGeoLocation = checkImageGeoLocation(uploadItem.getPlace(), filePath);
         Single<Integer> darkImage = checkDarkImage(filePath);
         Single<Integer> itemTitle = checkTitle ? validateItemTitle(uploadItem) : Single.just(ImageUtils.IMAGE_OK);
         Single<Integer> checkFBMD = checkFBMD(context,contentUri);
         Single<Integer> checkEXIF = checkEXIF(filePath);
+
         Single<Integer> zipResult = Single.zip(duplicateImage, wrongGeoLocation, darkImage, itemTitle,
                 (duplicate, wrongGeo, dark, title) -> {
                     Timber.d("Result for duplicate: %d, geo: %d, dark: %d, title: %d", duplicate, wrongGeo, dark, title);

app/src/main/java/fr/free/nrw/commons/upload/UploadActivity.java

@@ -5,7 +5,6 @@ import android.annotation.SuppressLint;
 import android.app.ProgressDialog;
 import android.content.Intent;
 import android.net.Uri;
-import android.os.Build;
 import android.os.Bundle;
 import com.google.android.material.textfield.TextInputLayout;
 import androidx.appcompat.app.AlertDialog;
@@ -67,7 +66,6 @@ import fr.free.nrw.commons.utils.PermissionUtils;
 import fr.free.nrw.commons.utils.ViewUtil;
 import io.reactivex.Observable;
 import io.reactivex.android.schedulers.AndroidSchedulers;
-import io.reactivex.disposables.CompositeDisposable;
 import io.reactivex.schedulers.Schedulers;
 import timber.log.Timber;
 
@@ -134,7 +132,6 @@ public class UploadActivity extends BaseActivity implements UploadView, SimilarI
 
     private DescriptionsAdapter descriptionsAdapter;
     private RVRendererAdapter<CategoryItem> categoriesAdapter;
-    private CompositeDisposable compositeDisposable;
     private ProgressDialog progressDialog;
 
 
@@ -145,7 +142,6 @@ public class UploadActivity extends BaseActivity implements UploadView, SimilarI
 
         setContentView(R.layout.activity_upload);
         ButterKnife.bind(this);
-        compositeDisposable = new CompositeDisposable();
 
         configureLayout();
         configureTopCard();
@@ -211,8 +207,6 @@ public class UploadActivity extends BaseActivity implements UploadView, SimilarI
     @Override
     protected void onPause() {
         presenter.removeView();
-        compositeDisposable.dispose();
-        compositeDisposable = new CompositeDisposable();
         super.onPause();
     }
 
@@ -571,7 +565,7 @@ public class UploadActivity extends BaseActivity implements UploadView, SimilarI
     @SuppressLint("CheckResult")
     private void updateCategoryList(String filter) {
         List<String> imageTitleList = presenter.getImageTitleList();
-        Observable.fromIterable(categoriesModel.getSelectedCategories())
+        compositeDisposable.add(Observable.fromIterable(categoriesModel.getSelectedCategories())
                 .subscribeOn(Schedulers.io())
                 .observeOn(AndroidSchedulers.mainThread())
                 .doOnSubscribe(disposable -> {
@@ -602,7 +596,7 @@ public class UploadActivity extends BaseActivity implements UploadView, SimilarI
                                 categoriesSearchContainer.setError("No categories found");
                             }
                         }
-                );
+                ));
     }
 
     private void receiveSharedItems() {

app/src/main/java/fr/free/nrw/commons/upload/UploadModel.java

@@ -26,7 +26,7 @@ import fr.free.nrw.commons.utils.ImageUtils;
 import io.reactivex.Observable;
 import io.reactivex.Single;
 import io.reactivex.android.schedulers.AndroidSchedulers;
-import io.reactivex.disposables.Disposable;
+import io.reactivex.disposables.CompositeDisposable;
 import io.reactivex.functions.Consumer;
 import io.reactivex.schedulers.Schedulers;
 import io.reactivex.subjects.BehaviorSubject;
@@ -45,6 +45,7 @@ public class UploadModel {
     };
     private final JsonKvStore store;
     private final List<String> licenses;
+    private final Context context;
     private String license;
     private final Map<String, String> licensesByName;
     private List<UploadItem> items = new ArrayList<>();
@@ -52,8 +53,7 @@ public class UploadModel {
     private boolean bottomCardState = true;
     private boolean rightCardState = true;
     private int currentStepIndex = 0;
-    public static Context context;
+    private CompositeDisposable compositeDisposable = new CompositeDisposable();
-    private Disposable badImageSubscription;
 
     private SessionManager sessionManager;
     private FileProcessor fileProcessor;
@@ -77,6 +77,11 @@ public class UploadModel {
         this.imageProcessingService = imageProcessingService;
     }
 
+    void cleanup() {
+        compositeDisposable.clear();
+        fileProcessor.cleanup();
+    }
+
     @SuppressLint("CheckResult")
     Observable<UploadItem> preProcessImages(List<UploadableFile> uploadableFiles,
                                             Place place,
@@ -219,8 +224,7 @@ public class UploadModel {
     }
 
     public void previous() {
-        if (badImageSubscription != null)
+        cleanup();
-            badImageSubscription.dispose();
         markCurrentUploadVisited();
         if (currentStepIndex > 0) {
             currentStepIndex--;
@@ -305,16 +309,16 @@ public class UploadModel {
     }
 
     void deletePicture() {
-        badImageSubscription.dispose();
+        cleanup();
         updateItemState();
     }
 
     void subscribeBadPicture(Consumer<Integer> consumer, boolean checkTitle) {
         if (isShowingItem()) {
-            badImageSubscription = getImageQuality(getCurrentItem(), checkTitle)
+            compositeDisposable.add(getImageQuality(getCurrentItem(), checkTitle)
                     .subscribeOn(Schedulers.io())
                     .observeOn(AndroidSchedulers.mainThread())
-                    .subscribe(consumer, Timber::e);
+                    .subscribe(consumer, Timber::e));
         }
     }
 
@@ -432,10 +436,6 @@ public class UploadModel {
         public Uri getContentUri() {
             return originalContentUri;
         }
-
-        public Context getContext(){
-            return UploadModel.context;
-        }
     }
 
 }

app/src/main/java/fr/free/nrw/commons/upload/UploadPresenter.java

@@ -21,6 +21,7 @@ import fr.free.nrw.commons.settings.Prefs;
 import fr.free.nrw.commons.utils.StringUtils;
 import io.reactivex.Observable;
 import io.reactivex.android.schedulers.AndroidSchedulers;
+import io.reactivex.disposables.CompositeDisposable;
 import io.reactivex.schedulers.Schedulers;
 import timber.log.Timber;
 
@@ -52,6 +53,7 @@ public class UploadPresenter {
     private final UploadController uploadController;
     private final Context context;
     private final JsonKvStore directKvStore;
+    private CompositeDisposable compositeDisposable = new CompositeDisposable();
 
     @Inject
     UploadPresenter(UploadModel uploadModel,
@@ -77,12 +79,12 @@ public class UploadPresenter {
         Observable<UploadItem> uploadItemObservable = uploadModel
                 .preProcessImages(media, place, source, similarImageInterface);
 
-        uploadItemObservable
+        compositeDisposable.add(uploadItemObservable
                 .toList()
                 .subscribeOn(Schedulers.io())
                 .observeOn(AndroidSchedulers.mainThread())
                 .subscribe(uploadItems -> onImagesProcessed(uploadItems, place),
-                        throwable -> Timber.e(throwable, "Error occurred in processing images"));
+                        throwable -> Timber.e(throwable, "Error occurred in processing images")));
     }
 
     private void onImagesProcessed(List<UploadItem> uploadItems, Place place) {
@@ -211,9 +213,9 @@ public class UploadPresenter {
     @SuppressLint("CheckResult")
     void handleSubmit(CategoriesModel categoriesModel) {
         if (view.checkIfLoggedIn())
-            uploadModel.buildContributions(categoriesModel.getCategoryStringList())
+            compositeDisposable.add(uploadModel.buildContributions(categoriesModel.getCategoryStringList())
                     .observeOn(Schedulers.io())
-                    .subscribe(uploadController::startUpload);
+                    .subscribe(uploadController::startUpload));
     }
 
     /**
@@ -286,6 +288,8 @@ public class UploadPresenter {
     }
 
     void cleanup() {
+        compositeDisposable.clear();
+        uploadModel.cleanup();
         uploadController.cleanup();
     }