bug fix, added error message

app/src/main/java/org/nuclearfog/twidda/backend/async/AccountLoader.java

@@ -2,6 +2,8 @@ package org.nuclearfog.twidda.backend.async;
 
 import android.os.AsyncTask;
 
+import androidx.annotation.Nullable;
+
 import org.nuclearfog.twidda.database.AppDatabase;
 import org.nuclearfog.twidda.model.Account;
 import org.nuclearfog.twidda.ui.fragments.AccountFragment;
@@ -45,27 +47,39 @@ public class AccountLoader extends AsyncTask<Long, Void, List<Account>> {
 
 	@Override
 	protected List<Account> doInBackground(Long... param) {
-		// get all logins
+		try {
-		if (mode == MODE_LOAD) {
+			// get all logins
-			return db.getLogins();
+			if (mode == MODE_LOAD) {
-		}
+				return db.getLogins();
-		// delete login
+			}
-		else if (mode == MODE_DELETE) {
+			// delete login
-			db.removeLogin(param[0]);
+			else if (mode == MODE_DELETE) {
-			deleteId = param[0];
+				db.removeLogin(param[0]);
+				deleteId = param[0];
+			}
+		} catch (Exception e) {
+			e.printStackTrace();
 		}
 		return null;
 	}
 
 
 	@Override
-	protected void onPostExecute(List<Account> accounts) {
+	protected void onPostExecute(@Nullable List<Account> accounts) {
 		AccountFragment fragment = weakRef.get();
 		if (fragment != null) {
 			if (mode == MODE_LOAD) {
-				fragment.onSuccess(accounts);
+				if (accounts != null) {
+					fragment.onSuccess(accounts);
+				} else {
+					fragment.onError();
+				}
 			} else if (mode == MODE_DELETE) {
-				fragment.onDelete(deleteId);
+				if (deleteId > 0) {
+					fragment.onDelete(deleteId);
+				} else {
+					fragment.onError();
+				}
 			}
 		}
 	}

app/src/main/java/org/nuclearfog/twidda/backend/async/FilterLoader.java

@@ -20,7 +20,7 @@ import java.util.List;
  *
  * @author nuclearfog
  */
-public class FilterLoader extends AsyncTask<String, Void, Void> {
+public class FilterLoader extends AsyncTask<String, Void, Boolean> {
 
 	/**
 	 * refresh exclude list
@@ -55,34 +55,36 @@ public class FilterLoader extends AsyncTask<String, Void, Void> {
 
 
 	@Override
-	protected Void doInBackground(String... names) {
+	protected Boolean doInBackground(String... names) {
 		try {
 			switch (mode) {
 				case REFRESH:
 					List<Long> ids = connection.getIdBlocklist();
 					db.setFilterlistUserIds(ids);
-					break;
+					return true;
 
 				case MUTE_USER:
 					connection.muteUser(names[0]);
-					break;
+					return true;
 
 				case BLOCK_USER:
 					connection.blockUser(names[0]);
-					break;
+					return true;
 			}
 		} catch (ConnectionException exception) {
 			this.exception = exception;
+		} catch (Exception e) {
+			e.printStackTrace();
 		}
-		return null;
+		return false;
 	}
 
 
 	@Override
-	protected void onPostExecute(Void v) {
+	protected void onPostExecute(Boolean success) {
 		UsersActivity activity = weakRef.get();
 		if (activity != null) {
-			if (exception == null) {
+			if (success) {
 				activity.onSuccess(mode);
 			} else {
 				activity.onError(exception);

app/src/main/java/org/nuclearfog/twidda/backend/async/ImageLoader.java

@@ -14,7 +14,6 @@ import org.nuclearfog.twidda.ui.activities.ImageViewer;
 
 import java.io.File;
 import java.io.FileOutputStream;
-import java.io.IOException;
 import java.io.InputStream;
 import java.lang.ref.WeakReference;
 
@@ -72,15 +71,15 @@ public class ImageLoader extends AsyncTask<Uri, Void, Uri> {
 			return Uri.fromFile(imageFile);
 		} catch (ConnectionException exception) {
 			this.exception = exception;
-		} catch (IOException exception) {
+		} catch (Exception e) {
-			exception.printStackTrace();
+			e.printStackTrace();
 		}
 		return null;
 	}
 
 
 	@Override
-	protected void onPostExecute(Uri localUri) {
+	protected void onPostExecute(@Nullable Uri localUri) {
 		ImageViewer activity = weakRef.get();
 		if (activity != null) {
 			if (localUri != null) {

app/src/main/java/org/nuclearfog/twidda/backend/async/ImageSaver.java

@@ -4,7 +4,6 @@ import android.os.AsyncTask;
 
 import org.nuclearfog.twidda.ui.activities.MediaActivity;
 
-import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.lang.ref.WeakReference;
@@ -43,11 +42,11 @@ public class ImageSaver extends AsyncTask<Void, Void, Boolean> {
 			}
 			mediaStream.close();
 			fileStream.close();
-		} catch (IOException err) {
+			return true;
-			err.printStackTrace();
+		} catch (Exception e) {
-			return false;
+			e.printStackTrace();
 		}
-		return true;
+		return false;
 	}
 
 

app/src/main/java/org/nuclearfog/twidda/backend/async/LinkLoader.java

@@ -156,19 +156,21 @@ public class LinkLoader extends AsyncTask<Uri, Void, LinkLoader.DataHolder> {
 			}
 		} catch (ConnectionException exception) {
 			this.exception = exception;
+		} catch (Exception e) {
+			e.printStackTrace();
 		}
 		return null;
 	}
 
 
 	@Override
-	protected void onPostExecute(DataHolder result) {
+	protected void onPostExecute(@Nullable DataHolder result) {
 		MainActivity activity = weakRef.get();
 		if (activity != null) {
-			if (exception != null) {
+			if (result != null) {
-				activity.onError(exception);
-			} else {
 				activity.onSuccess(result);
+			} else {
+				activity.onError(exception);
 			}
 		}
 	}

app/src/main/java/org/nuclearfog/twidda/backend/async/ListAction.java

@@ -2,6 +2,8 @@ package org.nuclearfog.twidda.backend.async;
 
 import android.os.AsyncTask;
 
+import androidx.annotation.Nullable;
+
 import org.nuclearfog.twidda.backend.api.Connection;
 import org.nuclearfog.twidda.backend.api.ConnectionException;
 import org.nuclearfog.twidda.backend.api.ConnectionManager;
@@ -77,13 +79,15 @@ public class ListAction extends AsyncTask<Void, Void, UserList> {
 			}
 		} catch (ConnectionException exception) {
 			this.exception = exception;
+		} catch (Exception e) {
+			e.printStackTrace();
 		}
 		return null;
 	}
 
 
 	@Override
-	protected void onPostExecute(UserList userList) {
+	protected void onPostExecute(@Nullable UserList userList) {
 		UserlistActivity callback = this.weakRef.get();
 		if (callback != null) {
 			if (userList != null) {

app/src/main/java/org/nuclearfog/twidda/backend/async/ListLoader.java

@@ -71,13 +71,15 @@ public class ListLoader extends AsyncTask<Long, Void, UserLists> {
 			}
 		} catch (ConnectionException exception) {
 			this.exception = exception;
+		} catch (Exception e) {
+			e.printStackTrace();
 		}
 		return null;
 	}
 
 
 	@Override
-	protected void onPostExecute(UserLists result) {
+	protected void onPostExecute(@Nullable UserLists result) {
 		UserListFragment fragment = weakRef.get();
 		if (fragment != null) {
 			if (result != null) {

app/src/main/java/org/nuclearfog/twidda/backend/async/ListManager.java

@@ -18,7 +18,7 @@ import java.lang.ref.WeakReference;
  *
  * @author nuclearfog
  */
-public class ListManager extends AsyncTask<Void, Void, Void> {
+public class ListManager extends AsyncTask<Void, Void, Boolean> {
 
 	/**
 	 * add user to list
@@ -57,29 +57,31 @@ public class ListManager extends AsyncTask<Void, Void, Void> {
 
 
 	@Override
-	protected Void doInBackground(Void... v) {
+	protected Boolean doInBackground(Void... v) {
 		try {
 			switch (action) {
 				case ADD_USER:
 					connection.addUserToList(listId, username);
-					break;
+					return true;
 
 				case DEL_USER:
 					connection.removeUserFromList(listId, username);
-					break;
+					return true;
 			}
 		} catch (ConnectionException exception) {
 			this.exception = exception;
+		} catch (Exception e) {
+			e.printStackTrace();
 		}
-		return null;
+		return false;
 	}
 
 
 	@Override
-	protected void onPostExecute(Void v) {
+	protected void onPostExecute(Boolean success) {
 		UserlistActivity callback = weakRef.get();
 		if (callback != null) {
-			if (exception == null) {
+			if (success) {
 				callback.onSuccess(action, username);
 			} else {
 				callback.onFailure(exception);

app/src/main/java/org/nuclearfog/twidda/backend/async/ListUpdater.java

@@ -48,13 +48,15 @@ public class ListUpdater extends AsyncTask<Void, Void, UserList> {
 			return connection.createUserlist(update);
 		} catch (ConnectionException exception) {
 			this.exception = exception;
+		} catch (Exception e) {
+			e.printStackTrace();
 		}
 		return null;
 	}
 
 
 	@Override
-	protected void onPostExecute(UserList result) {
+	protected void onPostExecute(@Nullable UserList result) {
 		UserlistEditor activity = weakRef.get();
 		if (activity != null) {
 			if (result != null) {

app/src/main/java/org/nuclearfog/twidda/backend/async/LocationLoader.java

@@ -41,13 +41,15 @@ public class LocationLoader extends AsyncTask<Void, Void, List<Location>> {
 			return connection.getLocations();
 		} catch (ConnectionException exception) {
 			this.exception = exception;
+		} catch (Exception e) {
+			e.printStackTrace();
 		}
 		return null;
 	}
 
 
 	@Override
-	protected void onPostExecute(List<Location> locations) {
+	protected void onPostExecute(@Nullable List<Location> locations) {
 		SettingsActivity activity = weakRef.get();
 		if (activity != null) {
 			if (locations != null) {

app/src/main/java/org/nuclearfog/twidda/backend/async/LoginAction.java

@@ -94,13 +94,15 @@ public class LoginAction extends AsyncTask<String, Void, String> {
 			}
 		} catch (ConnectionException exception) {
 			this.exception = exception;
+		} catch (Exception e) {
+			e.printStackTrace();
 		}
 		return null;
 	}
 
 
 	@Override
-	protected void onPostExecute(String result) {
+	protected void onPostExecute(@Nullable String result) {
 		LoginActivity activity = weakRef.get();
 		if (activity != null) {
 			if (result != null) {

app/src/main/java/org/nuclearfog/twidda/backend/async/MessageLoader.java

@@ -93,6 +93,8 @@ public class MessageLoader extends AsyncTask<Void, Void, Messages> {
 			if (exception.getErrorCode() == ConnectionException.RESOURCE_NOT_FOUND) {
 				db.removeMessage(messageId);
 			}
+		} catch (Exception e) {
+			e.printStackTrace();
 		}
 		return null;
 	}
@@ -102,16 +104,23 @@ public class MessageLoader extends AsyncTask<Void, Void, Messages> {
 	protected void onPostExecute(@Nullable Messages messages) {
 		MessageFragment fragment = weakRef.get();
 		if (fragment != null) {
-			if (exception != null) {
+			switch (action) {
-				fragment.onError(exception, messageId);
+				case DB:
-			} else {
+				case LOAD:
-				if (action == DB || action == LOAD) {
 					if (messages != null) {
 						fragment.setData(messages);
+					} else {
+						fragment.onError(exception, messageId);
 					}
-				} else if (action == DEL) {
+					break;
-					fragment.removeItem(messageId);
+
-				}
+				case DEL:
+					if (exception == null) {
+						fragment.removeItem(messageId);
+					} else {
+						fragment.onError(exception, messageId);
+					}
+					break;
 			}
 		}
 	}

app/src/main/java/org/nuclearfog/twidda/backend/async/MessageUpdater.java

@@ -58,6 +58,8 @@ public class MessageUpdater extends AsyncTask<Void, Void, Boolean> {
 			return true;
 		} catch (ConnectionException exception) {
 			this.exception = exception;
+		} catch (Exception e) {
+			e.printStackTrace();
 		} finally {
 			// close all streams
 			message.close();

app/src/main/java/org/nuclearfog/twidda/backend/async/NotificationLoader.java

@@ -62,18 +62,21 @@ public class NotificationLoader extends AsyncTask<Long, Void, List<Notification>
 			}
 		} catch (ConnectionException exception) {
 			this.exception = exception;
+		} catch (Exception e) {
+			e.printStackTrace();
 		}
 		return result;
 	}
 
 
 	@Override
-	protected void onPostExecute(List<Notification> notifications) {
+	protected void onPostExecute(@Nullable List<Notification> notifications) {
 		NotificationFragment fragment = callback.get();
 		if (fragment != null) {
 			if (notifications != null) {
 				fragment.onSuccess(notifications, pos);
-			} else {
+			}
+			if (exception != null) {
 				fragment.onError(exception);
 			}
 		}

app/src/main/java/org/nuclearfog/twidda/backend/async/StatusAction.java

@@ -19,7 +19,7 @@ import java.lang.ref.WeakReference;
  * @author nuclearfog
  * @see StatusActivity
  */
-public class StatusAction extends AsyncTask<Long, Status, Void> {
+public class StatusAction extends AsyncTask<Long, Status, Boolean> {
 
 	/**
 	 * Load status
@@ -92,7 +92,7 @@ public class StatusAction extends AsyncTask<Long, Status, Void> {
 	 * @param ids first value is the status ID. The second value is the repost status ID. Required for delete operations
 	 */
 	@Override
-	protected Void doInBackground(Long... ids) {
+	protected Boolean doInBackground(Long... ids) {
 		org.nuclearfog.twidda.model.Status status;
 		try {
 			switch (action) {
@@ -110,21 +110,21 @@ public class StatusAction extends AsyncTask<Long, Status, Void> {
 						// update status if there is a database entry
 						db.updateStatus(status);
 					}
-					break;
+					return true;
 
 				case DELETE:
 					connection.deleteStatus(ids[0]);
 					db.removeStatus(ids[0]);
 					// removing repost reference to this status
 					db.removeStatus(ids[1]);
-					break;
+					return true;
 
 				case REPOST:
 					status = connection.repostStatus(ids[0]);
 					if (status.getEmbeddedStatus() != null)
 						publishProgress(status.getEmbeddedStatus());
 					db.updateStatus(status);
-					break;
+					return true;
 
 				case REMOVE_REPOST:
 					status = connection.removeRepost(ids[0]);
@@ -133,29 +133,29 @@ public class StatusAction extends AsyncTask<Long, Status, Void> {
 					// removing repost reference to this status
 					if (ids.length == 2)
 						db.removeStatus(ids[1]);
-					break;
+					return true;
 
 				case FAVORITE:
 					status = connection.favoriteStatus(ids[0]);
 					publishProgress(status);
 					db.saveToFavorites(status);
-					break;
+					return true;
 
 				case UNFAVORITE:
 					status = connection.unfavoriteStatus(ids[0]);
 					publishProgress(status);
 					db.removeFavorite(status);
-					break;
+					return true;
 
 				case HIDE:
 					connection.muteConversation(ids[0]);
 					db.hideStatus(ids[0], true);
-					break;
+					return true;
 
 				case UNHIDE:
 					connection.unmuteConversation(ids[0]);
 					db.hideStatus(ids[0], false);
-					break;
+					return true;
 			}
 		} catch (ConnectionException exception) {
 			this.exception = exception;
@@ -167,8 +167,10 @@ public class StatusAction extends AsyncTask<Long, Status, Void> {
 					db.removeStatus(ids[1]);
 				}
 			}
+		} catch (Exception e) {
+			e.printStackTrace();
 		}
-		return null;
+		return false;
 	}
 
 
@@ -182,10 +184,10 @@ public class StatusAction extends AsyncTask<Long, Status, Void> {
 
 
 	@Override
-	protected void onPostExecute(Void v) {
+	protected void onPostExecute(Boolean success) {
 		StatusActivity activity = weakRef.get();
 		if (activity != null) {
-			if (exception == null) {
+			if (success) {
 				activity.OnSuccess(action);
 			} else {
 				activity.onError(exception);

app/src/main/java/org/nuclearfog/twidda/backend/async/StatusLoader.java

@@ -202,12 +202,13 @@ public class StatusLoader extends AsyncTask<Long, Void, List<Status>> {
 
 
 	@Override
-	protected void onPostExecute(List<org.nuclearfog.twidda.model.Status> statuses) {
+	protected void onPostExecute(@Nullable List<org.nuclearfog.twidda.model.Status> statuses) {
 		StatusFragment fragment = weakRef.get();
 		if (fragment != null) {
 			if (statuses != null) {
 				fragment.setData(statuses, pos);
-			} else {
+			}
+			if (exception != null) {
 				fragment.onError(exception);
 			}
 		}

app/src/main/java/org/nuclearfog/twidda/backend/async/StatusUpdater.java

@@ -17,7 +17,7 @@ import java.lang.ref.WeakReference;
  * @author nuclearfog
  * @see StatusEditor
  */
-public class StatusUpdater extends AsyncTask<StatusUpdate, Void, Void> {
+public class StatusUpdater extends AsyncTask<StatusUpdate, Void, Boolean> {
 
 	private Connection connection;
 	private ConnectionException exception;
@@ -36,7 +36,7 @@ public class StatusUpdater extends AsyncTask<StatusUpdate, Void, Void> {
 
 
 	@Override
-	protected Void doInBackground(StatusUpdate... statusUpdates) {
+	protected Boolean doInBackground(StatusUpdate... statusUpdates) {
 		StatusUpdate statusUpdate = statusUpdates[0];
 		try {
 			// upload media first
@@ -50,21 +50,24 @@ public class StatusUpdater extends AsyncTask<StatusUpdate, Void, Void> {
 			if (!isCancelled()) {
 				connection.uploadStatus(statusUpdate, mediaIds);
 			}
+			return true;
 		} catch (ConnectionException exception) {
 			this.exception = exception;
+		} catch (Exception e) {
+			e.printStackTrace();
 		} finally {
 			// close inputstreams
 			statusUpdate.close();
 		}
-		return null;
+		return false;
 	}
 
 
 	@Override
-	protected void onPostExecute(Void v) {
+	protected void onPostExecute(Boolean success) {
 		StatusEditor activity = weakRef.get();
 		if (activity != null) {
-			if (exception == null) {
+			if (success) {
 				activity.onSuccess();
 			} else {
 				activity.onError(exception);

app/src/main/java/org/nuclearfog/twidda/backend/async/TrendLoader.java

@@ -59,18 +59,21 @@ public class TrendLoader extends AsyncTask<Void, Void, List<Trend>> {
 			return trends;
 		} catch (ConnectionException exception) {
 			this.exception = exception;
+		} catch (Exception e) {
+			e.printStackTrace();
 		}
 		return null;
 	}
 
 
 	@Override
-	protected void onPostExecute(List<Trend> trends) {
+	protected void onPostExecute(@Nullable List<Trend> trends) {
 		TrendFragment fragment = weakRef.get();
 		if (fragment != null) {
 			if (trends != null) {
 				fragment.setData(trends);
-			} else {
+			}
+			if (exception != null) {
 				fragment.onError(exception);
 			}
 		}

app/src/main/java/org/nuclearfog/twidda/backend/async/UserAction.java

@@ -2,6 +2,8 @@ package org.nuclearfog.twidda.backend.async;
 
 import android.os.AsyncTask;
 
+import androidx.annotation.Nullable;
+
 import org.nuclearfog.twidda.backend.api.Connection;
 import org.nuclearfog.twidda.backend.api.ConnectionException;
 import org.nuclearfog.twidda.backend.api.ConnectionManager;
@@ -91,9 +93,7 @@ public class UserAction extends AsyncTask<Void, User, Relation> {
 					User user;
 					if (userId > 0) {
 						user = db.getUser(userId);
-						if (user != null) {
+						publishProgress(user);
-							publishProgress(user);
-						}
 					}
 
 				case PROFILE_lOAD:
@@ -151,6 +151,8 @@ public class UserAction extends AsyncTask<Void, User, Relation> {
 			return connection.getUserRelationship(userId);
 		} catch (ConnectionException exception) {
 			this.error = exception;
+		} catch (Exception e) {
+			e.printStackTrace();
 		}
 		return null;
 	}
@@ -159,14 +161,14 @@ public class UserAction extends AsyncTask<Void, User, Relation> {
 	@Override
 	protected void onProgressUpdate(User[] users) {
 		ProfileActivity activity = weakRef.get();
-		if (activity != null) {
+		if (activity != null && users[0] != null) {
 			activity.setUser(users[0]);
 		}
 	}
 
 
 	@Override
-	protected void onPostExecute(Relation relation) {
+	protected void onPostExecute(@Nullable Relation relation) {
 		ProfileActivity activity = weakRef.get();
 		if (activity != null) {
 			if (relation != null) {

app/src/main/java/org/nuclearfog/twidda/backend/async/UserLoader.java

@@ -143,13 +143,15 @@ public class UserLoader extends AsyncTask<Long, Void, Users> {
 			}
 		} catch (ConnectionException exception) {
 			this.exception = exception;
+		} catch (Exception e) {
+			e.printStackTrace();
 		}
 		return null;
 	}
 
 
 	@Override
-	protected void onPostExecute(Users users) {
+	protected void onPostExecute(@Nullable Users users) {
 		UserFragment fragment = weakRef.get();
 		if (fragment != null) {
 			if (users != null) {

app/src/main/java/org/nuclearfog/twidda/backend/async/UserUpdater.java

@@ -30,6 +30,7 @@ public class UserUpdater extends AsyncTask<Void, Void, User> {
 	private ConnectionException exception;
 	private ProfileUpdate profile;
 
+
 	public UserUpdater(ProfileEditor activity, ProfileUpdate profile) {
 		super();
 		db = new AppDatabase(activity);
@@ -48,6 +49,8 @@ public class UserUpdater extends AsyncTask<Void, Void, User> {
 			return user;
 		} catch (ConnectionException exception) {
 			this.exception = exception;
+		} catch (Exception e) {
+			e.printStackTrace();
 		} finally {
 			// close image streams
 			profile.close();

app/src/main/java/org/nuclearfog/twidda/ui/activities/ImageViewer.java

@@ -134,7 +134,7 @@ public class ImageViewer extends MediaActivity {
 	 *
 	 * @param uri Uri of the cached image file
 	 */
-	public void onSuccess(Uri uri) {
+	public void onSuccess(@NonNull Uri uri) {
 		cacheUri = uri;
 		zoomImage.reset();
 		zoomImage.setImageURI(uri);
@@ -144,7 +144,7 @@ public class ImageViewer extends MediaActivity {
 	/**
 	 * Called from {@link ImageLoader} when an error occurs
 	 */
-	public void onError(ConnectionException err) {
+	public void onError(@Nullable ConnectionException err) {
 		ErrorHandler.handleFailure(getApplicationContext(), err);
 		finish();
 	}

app/src/main/java/org/nuclearfog/twidda/ui/activities/LoginActivity.java

@@ -329,7 +329,7 @@ public class LoginActivity extends AppCompatActivity implements OnClickListener,
 	/**
 	 * Called when the app is registered successfully
 	 */
-	public void onSuccess(int mode, String result) {
+	public void onSuccess(int mode, @NonNull String result) {
 		switch (mode) {
 			case LoginAction.MODE_LOGIN:
 				setResult(RETURN_LOGIN_SUCCESSFUL);

app/src/main/java/org/nuclearfog/twidda/ui/activities/MainActivity.java

@@ -283,27 +283,27 @@ public class MainActivity extends AppCompatActivity implements OnTabSelectedList
 	 *
 	 * @param holder holder with activity information and extras
 	 */
-	public void onSuccess(@Nullable LinkLoader.DataHolder holder) {
+	public void onSuccess(@NonNull LinkLoader.DataHolder holder) {
 		loadingCircle.dismiss();
-		if (holder != null) {
+		if (holder.activity == MainActivity.class) {
-			if (holder.activity == MainActivity.class) {
+			int page = holder.data.getInt(KEY_TAB_PAGE, 0);
-				int page = holder.data.getInt(KEY_TAB_PAGE, 0);
+			pager.setCurrentItem(page);
-				pager.setCurrentItem(page);
-			} else {
-				Intent intent = new Intent(this, holder.activity);
-				intent.putExtras(holder.data);
-				startActivity(intent);
-			}
 		} else {
-			Toast.makeText(this, R.string.error_open_link, Toast.LENGTH_SHORT).show();
+			Intent intent = new Intent(this, holder.activity);
+			intent.putExtras(holder.data);
+			startActivity(intent);
 		}
 	}
 
 	/**
 	 * called from {@link LinkLoader} when an error occurs
 	 */
-	public void onError(ConnectionException error) {
+	public void onError(@Nullable ConnectionException error) {
-		ErrorHandler.handleFailure(this, error);
+		if (error != null) {
+			ErrorHandler.handleFailure(this, error);
+		} else {
+			Toast.makeText(this, R.string.error_open_link, Toast.LENGTH_SHORT).show();
+		}
 		loadingCircle.dismiss();
 	}
 }

app/src/main/java/org/nuclearfog/twidda/ui/activities/ProfileActivity.java

@@ -689,7 +689,7 @@ public class ProfileActivity extends AppCompatActivity implements OnClickListene
 	 *
 	 * @param relation relation to an user
 	 */
-	public void onAction(Relation relation) {
+	public void onAction(@NonNull Relation relation) {
 		if (this.relation != null) {
 			// check if block status changed
 			if (relation.isBlocked() != this.relation.isBlocked()) {

app/src/main/java/org/nuclearfog/twidda/ui/activities/ProfileEditor.java

@@ -273,7 +273,7 @@ public class ProfileEditor extends MediaActivity implements OnClickListener, OnP
 	/**
 	 * called after user profile was updated successfully
 	 */
-	public void onSuccess(User user) {
+	public void onSuccess(@NonNull User user) {
 		Intent data = new Intent();
 		data.putExtra(KEY_UPDATED_PROFILE, user);
 		Toast.makeText(this, R.string.info_profile_updated, Toast.LENGTH_SHORT).show();
@@ -286,7 +286,7 @@ public class ProfileEditor extends MediaActivity implements OnClickListener, OnP
 	 *
 	 * @param err Engine Exception
 	 */
-	public void onError(ConnectionException err) {
+	public void onError(@Nullable ConnectionException err) {
 		String message = ErrorHandler.getErrorMessage(this, err);
 		confirmDialog.show(ConfirmDialog.PROFILE_EDITOR_ERROR, message);
 		loadingCircle.dismiss();

app/src/main/java/org/nuclearfog/twidda/ui/activities/SettingsActivity.java

@@ -572,7 +572,7 @@ public class SettingsActivity extends AppCompatActivity implements OnClickListen
 	 *
 	 * @param data location data
 	 */
-	public void setLocationData(List<Location> data) {
+	public void setLocationData(@NonNull List<Location> data) {
 		locationAdapter.replaceItems(data);
 		int position = locationAdapter.indexOf(settings.getTrendLocation());
 		if (position > 0)
@@ -585,7 +585,7 @@ public class SettingsActivity extends AppCompatActivity implements OnClickListen
 	 *
 	 * @param err exception from twitter
 	 */
-	public void onError(ConnectionException err) {
+	public void onError(@Nullable ConnectionException err) {
 		ErrorHandler.handleFailure(this, err);
 	}
 

app/src/main/java/org/nuclearfog/twidda/ui/activities/StatusActivity.java

@@ -651,7 +651,7 @@ public class StatusActivity extends AppCompatActivity implements OnClickListener
 	 *
 	 * @param status Tweet information
 	 */
-	public void setStatus(Status status) {
+	public void setStatus(@NonNull Status status) {
 		this.status = status;
 		if (status.getEmbeddedStatus() != null) {
 			repostName.setVisibility(VISIBLE);

app/src/main/java/org/nuclearfog/twidda/ui/activities/UserlistActivity.java

@@ -395,7 +395,7 @@ public class UserlistActivity extends AppCompatActivity implements OnTabSelected
 	 *
 	 * @param userList userlist update
 	 */
-	public void onSuccess(UserList userList, int action) {
+	public void onSuccess(@NonNull UserList userList, int action) {
 		this.userList = userList;
 		switch (action) {
 			case ListAction.LOAD:

app/src/main/java/org/nuclearfog/twidda/ui/activities/UserlistEditor.java

@@ -15,6 +15,7 @@ import android.widget.ImageView;
 import android.widget.TextView;
 import android.widget.Toast;
 
+import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.appcompat.app.AppCompatActivity;
 
@@ -164,17 +165,11 @@ public class UserlistEditor extends AppCompatActivity implements OnClickListener
 	/**
 	 * called when a list was updated successfully
 	 */
-	public void onSuccess(UserList result) {
+	public void onSuccess(@NonNull UserList result) {
-		if (userList != null) {
+		Toast.makeText(getApplicationContext(), R.string.info_list_updated, Toast.LENGTH_SHORT).show();
-			Toast.makeText(this, R.string.info_list_updated, Toast.LENGTH_SHORT).show();
+		Intent data = new Intent();
-			Intent data = new Intent();
+		data.putExtra(KEY_UPDATED_USERLIST, result);
-			data.putExtra(KEY_UPDATED_USERLIST, result);
+		setResult(RETURN_LIST_CHANGED, data);
-			setResult(RETURN_LIST_CHANGED, data);
-		} else {
-			// it's a new list, if no list is defined
-			Toast.makeText(this, R.string.info_list_created, Toast.LENGTH_SHORT).show();
-			setResult(RETURN_LIST_CREATED);
-		}
 		finish();
 	}
 

app/src/main/java/org/nuclearfog/twidda/ui/activities/UsersActivity.java

@@ -15,6 +15,7 @@ import android.view.ViewGroup;
 import android.widget.Toast;
 
 import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
 import androidx.appcompat.app.AppCompatActivity;
 import androidx.appcompat.widget.SearchView;
 import androidx.appcompat.widget.SearchView.OnQueryTextListener;
@@ -313,7 +314,7 @@ public class UsersActivity extends AppCompatActivity implements OnTabSelectedLis
 	/**
 	 * called from {@link FilterLoader} if an error occurs
 	 */
-	public void onError(ConnectionException err) {
+	public void onError(@Nullable ConnectionException err) {
 		ErrorHandler.handleFailure(this, err);
 	}
 }

app/src/main/java/org/nuclearfog/twidda/ui/fragments/AccountFragment.java

@@ -118,7 +118,7 @@ public class AccountFragment extends ListFragment implements OnAccountClickListe
 	 *
 	 * @param result login information
 	 */
-	public void onSuccess(List<Account> result) {
+	public void onSuccess(@NonNull List<Account> result) {
 		adapter.replaceItems(result);
 		setRefresh(false);
 	}
@@ -131,4 +131,11 @@ public class AccountFragment extends ListFragment implements OnAccountClickListe
 	public void onDelete(long id) {
 		adapter.removeItem(id);
 	}
+
+	/**
+	 * called from {@link AccountLoader} when an error occurs
+	 */
+	public void onError() {
+		Toast.makeText(requireContext(), R.string.error_acc_loading, Toast.LENGTH_SHORT).show();
+	}
 }

app/src/main/java/org/nuclearfog/twidda/ui/fragments/MessageFragment.java

@@ -192,7 +192,7 @@ public class MessageFragment extends ListFragment implements OnMessageClickListe
 	 *
 	 * @param data list of direct messages
 	 */
-	public void setData(Messages data) {
+	public void setData(@NonNull Messages data) {
 		adapter.addItems(data);
 		setRefresh(false);
 	}
@@ -212,9 +212,9 @@ public class MessageFragment extends ListFragment implements OnMessageClickListe
 	 *
 	 * @param messageId ID of the message assosiated with the error
 	 */
-	public void onError(@NonNull ConnectionException error, long messageId) {
+	public void onError(@Nullable ConnectionException error, long messageId) {
 		ErrorHandler.handleFailure(requireContext(), error);
-		if (error.getErrorCode() == ConnectionException.RESOURCE_NOT_FOUND) {
+		if (error != null && error.getErrorCode() == ConnectionException.RESOURCE_NOT_FOUND) {
 			adapter.removeItem(messageId);
 		}
 		setRefresh(false);

app/src/main/java/org/nuclearfog/twidda/ui/fragments/NotificationFragment.java

@@ -131,7 +131,7 @@ public class NotificationFragment extends ListFragment implements OnNotification
 	 * @param notifications new items
 	 * @param position      index where to insert the new items
 	 */
-	public void onSuccess(List<Notification> notifications, int position) {
+	public void onSuccess(@NonNull List<Notification> notifications, int position) {
 		adapter.addItems(notifications, position);
 		setRefresh(false);
 	}
@@ -139,7 +139,7 @@ public class NotificationFragment extends ListFragment implements OnNotification
 	/**
 	 * called from {@link NotificationLoader} if an error occurs
 	 */
-	public void onError(@Nullable ConnectionException exception) {
+	public void onError(ConnectionException exception) {
 		ErrorHandler.handleFailure(requireContext(), exception);
 		adapter.disableLoading();
 		setRefresh(false);

app/src/main/java/org/nuclearfog/twidda/ui/fragments/StatusFragment.java

@@ -207,7 +207,7 @@ public class StatusFragment extends ListFragment implements StatusSelectListener
 	 * @param statuses List of statuses
 	 * @param pos      position where statuses should be added
 	 */
-	public void setData(List<Status> statuses, int pos) {
+	public void setData(@NonNull List<Status> statuses, int pos) {
 		if (pos == CLEAR_LIST) {
 			adapter.replaceItems(statuses);
 		} else {
@@ -219,7 +219,7 @@ public class StatusFragment extends ListFragment implements StatusSelectListener
 	/**
 	 * called from {@link StatusLoader} if an error occurs
 	 */
-	public void onError(@Nullable ConnectionException error) {
+	public void onError(ConnectionException error) {
 		ErrorHandler.handleFailure(requireContext(), error);
 		adapter.disableLoading();
 		setRefresh(false);

app/src/main/java/org/nuclearfog/twidda/ui/fragments/TrendFragment.java

@@ -84,16 +84,6 @@ public class TrendFragment extends ListFragment implements TrendClickListener {
 		}
 	}
 
-	/**
-	 * set trend data to list
-	 *
-	 * @param data Trend data
-	 */
-	public void setData(List<Trend> data) {
-		adapter.replaceItems(data);
-		setRefresh(false);
-	}
-
 	/**
 	 * check if list is empty
 	 *
@@ -103,10 +93,20 @@ public class TrendFragment extends ListFragment implements TrendClickListener {
 		return adapter.isEmpty();
 	}
 
+	/**
+	 * set trend data to list
+	 *
+	 * @param data Trend data
+	 */
+	public void setData(@NonNull List<Trend> data) {
+		adapter.replaceItems(data);
+		setRefresh(false);
+	}
+
 	/**
 	 * called from {@link TrendLoader} if an error occurs
 	 */
-	public void onError(@Nullable ConnectionException error) {
+	public void onError(ConnectionException error) {
 		ErrorHandler.handleFailure(requireContext(), error);
 		setRefresh(false);
 	}

app/src/main/java/org/nuclearfog/twidda/ui/fragments/UserFragment.java

@@ -239,7 +239,7 @@ public class UserFragment extends ListFragment implements UserClickListener {
 	 *
 	 * @param data list of users
 	 */
-	public void setData(Users data) {
+	public void setData(@NonNull Users data) {
 		adapter.addItems(data);
 		setRefresh(false);
 	}
@@ -247,7 +247,7 @@ public class UserFragment extends ListFragment implements UserClickListener {
 	/**
 	 * called when an error occurs
 	 */
-	public void onError(ConnectionException exception) {
+	public void onError(@Nullable ConnectionException exception) {
 		ErrorHandler.handleFailure(requireContext(), exception);
 		adapter.disableLoading();
 		setRefresh(false);

app/src/main/java/org/nuclearfog/twidda/ui/fragments/UserListFragment.java

@@ -170,7 +170,7 @@ public class UserListFragment extends ListFragment implements ListClickListener
 	/**
 	 * set data to list
 	 */
-	public void setData(UserLists data) {
+	public void setData(@NonNull UserLists data) {
 		adapter.addItems(data);
 		setRefresh(false);
 	}

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

@@ -93,6 +93,7 @@
 	<string name="error_cant_reply_to_tweet">You can\'t reply to this status!</string>
 	<string name="error_corrupt_api_key">Error, corrupt API key!</string>
 	<string name="error_acc_update">Account update failed! Please check your input!</string>
+	<string name="error_acc_loading">Error while loading login information!</string>
 	<string name="error_api_access_denied">Error, API access denied! Please check your API Keys.</string>
 	<string name="error_api_access_limited">Error, API access limited by Twitter!</string>
 	<string name="error_api_key_expired">Error, API Keys expired! Please update app!</string>