Use ExecutorServices for running threaded tasks

Signed-off-by: Stefan Niedermann <info@niedermann.it>

13 files changed, 87 insertions, 53 deletions

diff --git a/app/src/main/java/it/niedermann/owncloud/notes/edit/BaseNoteFragment.java b/app/src/main/java/it/niedermann/owncloud/notes/edit/BaseNoteFragment.java
index 0a2713eb..fb46af6c 100644
--- a/app/src/main/java/it/niedermann/owncloud/notes/edit/BaseNoteFragment.java
+++ b/app/src/main/java/it/niedermann/owncloud/notes/edit/BaseNoteFragment.java
@@ -33,6 +33,8 @@ import com.nextcloud.android.sso.model.SingleSignOnAccount;
 
 import java.util.ArrayList;
 import java.util.Calendar;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
 
 import it.niedermann.android.util.ColorUtil;
 import it.niedermann.owncloud.notes.R;
@@ -62,6 +64,7 @@ import static java.lang.Boolean.TRUE;
 public abstract class BaseNoteFragment extends BrandedFragment implements CategoryDialogListener, EditTitleListener {
 
     private static final String TAG = BaseNoteFragment.class.getSimpleName();
+    protected final ExecutorService executor = Executors.newCachedThreadPool();
 
     protected static final int MENU_ID_PIN = -1;
     public static final String PARAM_NOTE_ID = "noteId";
@@ -98,7 +101,7 @@ public abstract class BaseNoteFragment extends BrandedFragment implements Catego
     @Override
     public void onCreate(@Nullable Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
-        new Thread(() -> {
+        executor.submit(() -> {
             try {
                 SingleSignOnAccount ssoAccount = SingleAccountHelper.getCurrentSingleSignOnAccount(requireContext().getApplicationContext());
                 this.localAccount = repo.getAccountByName(ssoAccount.name);
@@ -143,7 +146,7 @@ public abstract class BaseNoteFragment extends BrandedFragment implements Catego
             } catch (NextcloudFilesAppAccountNotFoundException | NoCurrentAccountSelectedException e) {
                 e.printStackTrace();
             }
-        }).start();
+        });
         setHasOptionsMenu(true);
     }
 
@@ -214,13 +217,13 @@ public abstract class BaseNoteFragment extends BrandedFragment implements Catego
     public boolean onOptionsItemSelected(MenuItem item) {
         int itemId = item.getItemId();
         if (itemId == R.id.menu_cancel) {
-            new Thread(() -> {
+            executor.submit(() -> {
                 if (originalNote == null) {
                     repo.deleteNoteAndSync(localAccount, note.getId());
                 } else {
                     repo.updateNoteAndSync(localAccount, originalNote, null, null, null);
                 }
-            }).start();
+            });
             listener.close();
             return true;
         } else if (itemId == R.id.menu_delete) {
@@ -239,11 +242,9 @@ public abstract class BaseNoteFragment extends BrandedFragment implements Catego
             showEditTitleDialog();
             return true;
         } else if (itemId == R.id.menu_move) {
-            new Thread(() -> {
-                AccountPickerDialogFragment
-                        .newInstance(new ArrayList<>(repo.getAccounts()), note.getAccountId())
-                        .show(requireActivity().getSupportFragmentManager(), BaseNoteFragment.class.getSimpleName());
-            }).start();
+            executor.submit(() -> AccountPickerDialogFragment
+                    .newInstance(new ArrayList<>(repo.getAccounts()), note.getAccountId())
+                    .show(requireActivity().getSupportFragmentManager(), BaseNoteFragment.class.getSimpleName()));
             return true;
         } else if (itemId == R.id.menu_share) {
             ShareUtil.openShareDialog(requireContext(), note.getTitle(), note.getContent());
@@ -366,10 +367,10 @@ public abstract class BaseNoteFragment extends BrandedFragment implements Catego
     public void onTitleEdited(String newTitle) {
         titleModified = true;
         note.setTitle(newTitle);
-        new Thread(() -> {
+        executor.submit(() -> {
             note = repo.updateNoteAndSync(localAccount, note, note.getContent(), newTitle, null);
             requireActivity().runOnUiThread(() -> listener.onNoteUpdated(note));
-        }).start();
+        });
     }
 
     public void moveNote(Account account) {
diff --git a/app/src/main/java/it/niedermann/owncloud/notes/edit/NotePreviewFragment.java b/app/src/main/java/it/niedermann/owncloud/notes/edit/NotePreviewFragment.java
index f1626149..f15d0e59 100644
--- a/app/src/main/java/it/niedermann/owncloud/notes/edit/NotePreviewFragment.java
+++ b/app/src/main/java/it/niedermann/owncloud/notes/edit/NotePreviewFragment.java
@@ -155,22 +155,22 @@ public class NotePreviewFragment extends SearchableBaseNoteFragment implements O
     public void onRefresh() {
         if (noteLoaded && repo.isSyncPossible() && SSOUtil.isConfigured(getContext())) {
             binding.swiperefreshlayout.setRefreshing(true);
-            new Thread(() -> {
+            executor.submit(() -> {
                 try {
                     final Account account = repo.getAccountByName(SingleAccountHelper.getCurrentSingleSignOnAccount(requireContext()).name);
-                    repo.addCallbackPull(account, () -> new Thread(() -> {
+                    repo.addCallbackPull(account, () -> executor.submit(() -> {
                         note = repo.getNoteById(note.getId());
                         changedText = note.getContent();
                         requireActivity().runOnUiThread(() -> {
                             binding.singleNoteContent.setMarkdownString(note.getContent());
                             binding.swiperefreshlayout.setRefreshing(false);
                         });
-                    }).start());
+                    }));
                     repo.scheduleSync(account, false);
                 } catch (NextcloudFilesAppAccountNotFoundException | NoCurrentAccountSelectedException e) {
                     e.printStackTrace();
                 }
-            }).start();
+            });
         } else {
             binding.swiperefreshlayout.setRefreshing(false);
             Toast.makeText(requireContext(), getString(R.string.error_sync, getString(R.string.error_no_network)), Toast.LENGTH_LONG).show();
diff --git a/app/src/main/java/it/niedermann/owncloud/notes/importaccount/ImportAccountActivity.java b/app/src/main/java/it/niedermann/owncloud/notes/importaccount/ImportAccountActivity.java
index 2abbd82d..2e78af2c 100644
--- a/app/src/main/java/it/niedermann/owncloud/notes/importaccount/ImportAccountActivity.java
+++ b/app/src/main/java/it/niedermann/owncloud/notes/importaccount/ImportAccountActivity.java
@@ -21,6 +21,8 @@ import com.nextcloud.android.sso.helper.SingleAccountHelper;
 import com.nextcloud.android.sso.ui.UiExceptionManager;
 
 import java.net.HttpURLConnection;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
 
 import it.niedermann.owncloud.notes.R;
 import it.niedermann.owncloud.notes.branding.BrandingUtil;
@@ -39,6 +41,8 @@ public class ImportAccountActivity extends AppCompatActivity {
     private static final String TAG = ImportAccountActivity.class.getSimpleName();
     public static final int REQUEST_CODE_IMPORT_ACCOUNT = 1;
 
+    private final ExecutorService executor = Executors.newSingleThreadExecutor();
+
     private ImportAccountViewModel importAccountViewModel;
     private ActivityImportAccountBinding binding;
 
@@ -86,7 +90,7 @@ public class ImportAccountActivity extends AppCompatActivity {
                 runOnUiThread(() -> binding.progressCircular.setVisibility(View.VISIBLE));
 
                 SingleAccountHelper.setCurrentAccount(getApplicationContext(), ssoAccount.name);
-                new Thread(() -> {
+                executor.submit(() -> {
                     Log.i(TAG, "Added account: " + "name:" + ssoAccount.name + ", " + ssoAccount.url + ", userId" + ssoAccount.userId);
                     try {
                         Log.i(TAG, "Loading capabilities for " + ssoAccount.name);
@@ -140,7 +144,7 @@ public class ImportAccountActivity extends AppCompatActivity {
                             }
                         });
                     }
-                }).start();
+                });
             });
         } catch (AccountImportCancelledException e) {
             restoreCleanState();
diff --git a/app/src/main/java/it/niedermann/owncloud/notes/main/MainActivity.java b/app/src/main/java/it/niedermann/owncloud/notes/main/MainActivity.java
index 9ab3c81f..517904b2 100644
--- a/app/src/main/java/it/niedermann/owncloud/notes/main/MainActivity.java
+++ b/app/src/main/java/it/niedermann/owncloud/notes/main/MainActivity.java
@@ -49,6 +49,8 @@ import com.nextcloud.android.sso.helper.SingleAccountHelper;
 import java.net.HttpURLConnection;
 import java.util.Collection;
 import java.util.LinkedList;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
 
 import it.niedermann.owncloud.notes.LockedActivity;
 import it.niedermann.owncloud.notes.R;
@@ -104,6 +106,8 @@ public class MainActivity extends LockedActivity implements NoteClickListener, A
 
     private static final String TAG = MainActivity.class.getSimpleName();
 
+    protected final ExecutorService executor = Executors.newCachedThreadPool();
+
     protected MainViewModel mainViewModel;
     private CategoryViewModel categoryViewModel;
 
@@ -164,14 +168,14 @@ public class MainActivity extends LockedActivity implements NoteClickListener, A
             if (count == 0) {
                 startActivityForResult(new Intent(this, ImportAccountActivity.class), ImportAccountActivity.REQUEST_CODE_IMPORT_ACCOUNT);
             } else {
-                new Thread(() -> {
+                executor.submit(() -> {
                     try {
                         final Account account = mainViewModel.getLocalAccountByAccountName(SingleAccountHelper.getCurrentSingleSignOnAccount(getApplicationContext()).name);
                         runOnUiThread(() -> mainViewModel.postCurrentAccount(account));
                     } catch (NextcloudFilesAppAccountNotFoundException | NoCurrentAccountSelectedException e) {
                         runOnUiThread(() -> ExceptionDialogFragment.newInstance(e).show(getSupportFragmentManager(), ExceptionDialogFragment.class.getSimpleName()));
                     }
-                }).start();
+                });
             }
         });
 
@@ -649,7 +653,7 @@ public class MainActivity extends LockedActivity implements NoteClickListener, A
                 try {
                     AccountImporter.onActivityResult(requestCode, resultCode, data, this, (ssoAccount) -> {
                         CapabilitiesWorker.update(this);
-                        new Thread(() -> {
+                        executor.submit(() -> {
                             Log.i(TAG, "Added account: " + "name:" + ssoAccount.name + ", " + ssoAccount.url + ", userId" + ssoAccount.userId);
                             try {
                                 Log.i(TAG, "Refreshing capabilities for " + ssoAccount.name);
@@ -658,11 +662,11 @@ public class MainActivity extends LockedActivity implements NoteClickListener, A
                                 mainViewModel.addAccount(ssoAccount.url, ssoAccount.userId, ssoAccount.name, capabilities, displayName, new IResponseCallback<Account>() {
                                     @Override
                                     public void onSuccess(Account result) {
-                                        new Thread(() -> {
+                                        executor.submit(() -> {
                                             Log.i(TAG, capabilities.toString());
                                             final Account a = mainViewModel.getLocalAccountByAccountName(ssoAccount.name);
                                             runOnUiThread(() -> mainViewModel.postCurrentAccount(a));
-                                        }).start();
+                                        });
                                     }
 
                                     @Override
@@ -691,7 +695,7 @@ public class MainActivity extends LockedActivity implements NoteClickListener, A
                                     });
                                 }
                             }
-                        }).start();
+                        });
                     });
                 } catch (AccountImportCancelledException e) {
                     Log.i(TAG, "AccountImport has been cancelled.");
diff --git a/app/src/main/java/it/niedermann/owncloud/notes/main/MainViewModel.java b/app/src/main/java/it/niedermann/owncloud/notes/main/MainViewModel.java
index 9497d69f..716bbd79 100644
--- a/app/src/main/java/it/niedermann/owncloud/notes/main/MainViewModel.java
+++ b/app/src/main/java/it/niedermann/owncloud/notes/main/MainViewModel.java
@@ -26,6 +26,8 @@ import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
 import java.util.stream.Collectors;
 
 import it.niedermann.owncloud.notes.BuildConfig;
@@ -67,6 +69,8 @@ public class MainViewModel extends AndroidViewModel {
 
     private static final String TAG = MainViewModel.class.getSimpleName();
 
+    private final ExecutorService executor = Executors.newCachedThreadPool();
+
     private final SavedStateHandle state;
 
     private static final String KEY_CURRENT_ACCOUNT = "currentAccount";
@@ -391,7 +395,7 @@ public class MainViewModel extends AndroidViewModel {
      * Updates the network status if necessary and pulls the latest {@link Capabilities} of the given {@param localAccount}
      */
     public void synchronizeCapabilities(@NonNull Account localAccount, @NonNull IResponseCallback<Void> callback) {
-        new Thread(() -> {
+        executor.submit(() -> {
             if (!repo.isSyncPossible()) {
                 repo.updateNetworkStatus();
             }
@@ -428,14 +432,14 @@ public class MainViewModel extends AndroidViewModel {
                     callback.onError(new NetworkErrorException("Sync is not possible, because network is not connected."));
                 }
             }
-        }, "SYNC_CAPABILITIES").start();
+        }, "SYNC_CAPABILITIES");
     }
 
     /**
      * Updates the network status if necessary and pulls the latest notes of the given {@param localAccount}
      */
     public void synchronizeNotes(@NonNull Account currentAccount, @NonNull IResponseCallback<Void> callback) {
-        new Thread(() -> {
+        executor.submit(() -> {
             Log.v(TAG, "[synchronize] - currentAccount: " + currentAccount.getAccountName());
             if (!repo.isSyncPossible()) {
                 repo.updateNetworkStatus();
@@ -450,7 +454,7 @@ public class MainViewModel extends AndroidViewModel {
                     callback.onError(new NetworkErrorException("Sync is not possible, because network is not connected."));
                 }
             }
-        }, "SYNC_NOTES").start();
+        }, "SYNC_NOTES");
     }
 
     public LiveData<Boolean> getSyncStatus() {
@@ -554,12 +558,12 @@ public class MainViewModel extends AndroidViewModel {
             } else {
                 Log.v(TAG, "[getNote] - currentAccount: " + currentAccount.getAccountName());
                 final MutableLiveData<List<Note>> notes = new MutableLiveData<>();
-                new Thread(() -> notes.postValue(
+                executor.submit(() -> notes.postValue(
                         ids
                                 .stream()
                                 .map(repo::getNoteById)
                                 .collect(Collectors.toList())
-                )).start();
+                ));
                 return notes;
             }
         });
diff --git a/app/src/main/java/it/niedermann/owncloud/notes/main/MultiSelectedActionModeCallback.java b/app/src/main/java/it/niedermann/owncloud/notes/main/MultiSelectedActionModeCallback.java
index fa9bb879..cb51cdfc 100644
--- a/app/src/main/java/it/niedermann/owncloud/notes/main/MultiSelectedActionModeCallback.java
+++ b/app/src/main/java/it/niedermann/owncloud/notes/main/MultiSelectedActionModeCallback.java
@@ -21,6 +21,8 @@ import com.google.android.material.snackbar.Snackbar;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
 
 import it.niedermann.owncloud.notes.R;
 import it.niedermann.owncloud.notes.accountpicker.AccountPickerDialogFragment;
@@ -32,6 +34,7 @@ import it.niedermann.owncloud.notes.shared.util.ShareUtil;
 
 public class MultiSelectedActionModeCallback implements Callback {
 
+    private final ExecutorService executor = Executors.newSingleThreadExecutor();
     @ColorInt
     private final int colorAccent;
     @NonNull
@@ -125,11 +128,9 @@ public class MultiSelectedActionModeCallback implements Callback {
             final LiveData<Account> currentAccount$ = mainViewModel.getCurrentAccount();
             currentAccount$.observe(lifecycleOwner, account -> {
                 currentAccount$.removeObservers(lifecycleOwner);
-                new Thread(() -> {
-                    AccountPickerDialogFragment
-                            .newInstance(new ArrayList<>(mainViewModel.getAccounts()), account.getId())
-                            .show(fragmentManager, AccountPickerDialogFragment.class.getSimpleName());
-                }).start();
+                executor.submit(() -> AccountPickerDialogFragment
+                        .newInstance(new ArrayList<>(mainViewModel.getAccounts()), account.getId())
+                        .show(fragmentManager, AccountPickerDialogFragment.class.getSimpleName()));
             });
             return true;
         } else if (itemId == R.id.menu_share) {
@@ -139,7 +140,7 @@ public class MultiSelectedActionModeCallback implements Callback {
             }
             tracker.clearSelection();
 
-            new Thread(() -> {
+            executor.submit(() -> {
                 if (selection.size() == 1) {
                     final Note note = mainViewModel.getFullNote(selection.get(0));
                     ShareUtil.openShareDialog(context, note.getTitle(), note.getContent());
@@ -148,7 +149,7 @@ public class MultiSelectedActionModeCallback implements Callback {
                             context.getResources().getQuantityString(R.plurals.share_multiple, selection.size(), selection.size()),
                             mainViewModel.collectNoteContents(selection));
                 }
-            }).start();
+            });
             return true;
         } else if (itemId == R.id.menu_category) {// TODO detect whether all selected notes do have the same category - in this case preselect it
             final LiveData<Account> accountLiveData = mainViewModel.getCurrentAccount();
diff --git a/app/src/main/java/it/niedermann/owncloud/notes/manageaccounts/ManageAccountsViewModel.java b/app/src/main/java/it/niedermann/owncloud/notes/manageaccounts/ManageAccountsViewModel.java
index 2ee45cf8..ce88f2c2 100644
--- a/app/src/main/java/it/niedermann/owncloud/notes/manageaccounts/ManageAccountsViewModel.java
+++ b/app/src/main/java/it/niedermann/owncloud/notes/manageaccounts/ManageAccountsViewModel.java
@@ -13,8 +13,9 @@ import com.nextcloud.android.sso.exceptions.NoCurrentAccountSelectedException;
 import com.nextcloud.android.sso.helper.SingleAccountHelper;
 
 import java.util.List;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
 
-import it.niedermann.owncloud.notes.persistence.NotesDatabase;
 import it.niedermann.owncloud.notes.persistence.NotesRepository;
 import it.niedermann.owncloud.notes.persistence.entity.Account;
 import it.niedermann.owncloud.notes.shared.model.IResponseCallback;
@@ -23,7 +24,7 @@ import static androidx.lifecycle.Transformations.distinctUntilChanged;
 
 public class ManageAccountsViewModel extends AndroidViewModel {
 
-    private static final String TAG = ManageAccountsViewModel.class.getSimpleName();
+    private final ExecutorService executor = Executors.newCachedThreadPool();
 
     @NonNull
     private final NotesRepository repo;
@@ -46,7 +47,7 @@ public class ManageAccountsViewModel extends AndroidViewModel {
     }
 
     public void deleteAccount(@NonNull Account account, @NonNull Context context) {
-        new Thread(() -> {
+        executor.submit(() -> {
             final List<Account> accounts = repo.getAccounts();
             for (int i = 0; i < accounts.size(); i++) {
                 if (accounts.get(i).getId() == account.getId()) {
@@ -61,7 +62,7 @@ public class ManageAccountsViewModel extends AndroidViewModel {
                     break;
                 }
             }
-        }).start();
+        });
     }
 
     public void selectAccount(@Nullable Account account, @NonNull Context context) {
@@ -69,6 +70,6 @@ public class ManageAccountsViewModel extends AndroidViewModel {
     }
 
     public void countUnsynchronizedNotes(long accountId, @NonNull IResponseCallback<Long> callback) {
-        new Thread(() -> callback.onSuccess(repo.countUnsynchronizedNotes(accountId))).start();
+        executor.submit(() -> callback.onSuccess(repo.countUnsynchronizedNotes(accountId)));
     }
 }
\ No newline at end of file
diff --git a/app/src/main/java/it/niedermann/owncloud/notes/persistence/migration/Migration_18_19.java b/app/src/main/java/it/niedermann/owncloud/notes/persistence/migration/Migration_18_19.java
index 343f9e81..576e2204 100644
--- a/app/src/main/java/it/niedermann/owncloud/notes/persistence/migration/Migration_18_19.java
+++ b/app/src/main/java/it/niedermann/owncloud/notes/persistence/migration/Migration_18_19.java
@@ -9,9 +9,13 @@ import androidx.sqlite.db.SupportSQLiteDatabase;
 
 import com.bumptech.glide.Glide;
 
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
 public class Migration_18_19 extends Migration {
 
     private static final String TAG = Migration_18_19.class.getSimpleName();
+    private final ExecutorService executor = Executors.newSingleThreadExecutor();
     @NonNull
     private final Context context;
 
@@ -27,9 +31,9 @@ public class Migration_18_19 extends Migration {
      */
     @Override
     public void migrate(@NonNull SupportSQLiteDatabase db) {
-        new Thread(() -> {
+        executor.submit(() -> {
             Log.i(TAG, "Clearing Glide disk cache");
             Glide.get(context.getApplicationContext()).clearDiskCache();
-        }).start();
+        });
     }
 }
diff --git a/app/src/main/java/it/niedermann/owncloud/notes/widget/notelist/NoteListWidget.java b/app/src/main/java/it/niedermann/owncloud/notes/widget/notelist/NoteListWidget.java
index 7cc84de3..8825ad98 100644
--- a/app/src/main/java/it/niedermann/owncloud/notes/widget/notelist/NoteListWidget.java
+++ b/app/src/main/java/it/niedermann/owncloud/notes/widget/notelist/NoteListWidget.java
@@ -11,6 +11,8 @@ import android.util.Log;
 import android.widget.RemoteViews;
 
 import java.util.NoSuchElementException;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
 
 import it.niedermann.owncloud.notes.R;
 import it.niedermann.owncloud.notes.persistence.NotesRepository;
@@ -18,6 +20,7 @@ import it.niedermann.owncloud.notes.persistence.entity.NotesListWidgetData;
 
 public class NoteListWidget extends AppWidgetProvider {
     private static final String TAG = NoteListWidget.class.getSimpleName();
+    private final ExecutorService executor = Executors.newCachedThreadPool();
 
     static void updateAppWidget(Context context, AppWidgetManager awm, int[] appWidgetIds) {
         final NotesRepository repo = NotesRepository.getInstance(context);
@@ -83,7 +86,7 @@ public class NoteListWidget extends AppWidgetProvider {
         final NotesRepository repo = NotesRepository.getInstance(context);
 
         for (int appWidgetId : appWidgetIds) {
-            new Thread(() -> repo.removeNoteListWidget(appWidgetId)).start();
+            executor.submit(() -> repo.removeNoteListWidget(appWidgetId));
         }
     }
 
diff --git a/app/src/main/java/it/niedermann/owncloud/notes/widget/notelist/NoteListWidgetConfigurationActivity.java b/app/src/main/java/it/niedermann/owncloud/notes/widget/notelist/NoteListWidgetConfigurationActivity.java
index a750ee1e..3d7122da 100644
--- a/app/src/main/java/it/niedermann/owncloud/notes/widget/notelist/NoteListWidgetConfigurationActivity.java
+++ b/app/src/main/java/it/niedermann/owncloud/notes/widget/notelist/NoteListWidgetConfigurationActivity.java
@@ -14,6 +14,9 @@ import com.nextcloud.android.sso.exceptions.NextcloudFilesAppAccountNotFoundExce
 import com.nextcloud.android.sso.exceptions.NoCurrentAccountSelectedException;
 import com.nextcloud.android.sso.helper.SingleAccountHelper;
 
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
 import it.niedermann.owncloud.notes.LockedActivity;
 import it.niedermann.owncloud.notes.NotesApplication;
 import it.niedermann.owncloud.notes.R;
@@ -34,6 +37,8 @@ import static it.niedermann.owncloud.notes.shared.model.ENavigationCategoryType.
 public class NoteListWidgetConfigurationActivity extends LockedActivity {
     private static final String TAG = Activity.class.getSimpleName();
 
+    private final ExecutorService executor = Executors.newCachedThreadPool();
+
     private int appWidgetId = AppWidgetManager.INVALID_APPWIDGET_ID;
 
     private Account localAccount = null;
@@ -104,7 +109,7 @@ public class NoteListWidgetConfigurationActivity extends LockedActivity {
                 data.setAccountId(localAccount.getId());
                 data.setThemeMode(NotesApplication.getAppTheme(getApplicationContext()).getModeId());
 
-                new Thread(() -> {
+                executor.submit(() -> {
                     repo.createOrUpdateNoteListWidgetData(data);
 
                     final Intent updateIntent = new Intent(AppWidgetManager.ACTION_APPWIDGET_UPDATE, null, getApplicationContext(), NoteListWidget.class)
@@ -112,7 +117,7 @@ public class NoteListWidgetConfigurationActivity extends LockedActivity {
                     setResult(RESULT_OK, updateIntent);
                     getApplicationContext().sendBroadcast(updateIntent);
                     finish();
-                }).start();
+                });
             }
 
             public void onIconClick(NavigationItem item) {
@@ -122,7 +127,7 @@ public class NoteListWidgetConfigurationActivity extends LockedActivity {
 
         binding.recyclerView.setAdapter(adapterCategories);
 
-        new Thread(() -> {
+        executor.submit(() -> {
             try {
                 this.localAccount = repo.getAccountByName(SingleAccountHelper.getCurrentSingleSignOnAccount(this).name);
             } catch (NextcloudFilesAppAccountNotFoundException | NoCurrentAccountSelectedException e) {
@@ -133,7 +138,7 @@ public class NoteListWidgetConfigurationActivity extends LockedActivity {
                 finish();
             }
             runOnUiThread(() -> viewModel.getAdapterCategories(localAccount.getId()).observe(this, (navigationItems) -> adapterCategories.setItems(navigationItems)));
-        }).start();
+        });
     }
 
     @Override
diff --git a/app/src/main/java/it/niedermann/owncloud/notes/widget/singlenote/SingleNoteWidget.java b/app/src/main/java/it/niedermann/owncloud/notes/widget/singlenote/SingleNoteWidget.java
index e208603a..106b9f93 100644
--- a/app/src/main/java/it/niedermann/owncloud/notes/widget/singlenote/SingleNoteWidget.java
+++ b/app/src/main/java/it/niedermann/owncloud/notes/widget/singlenote/SingleNoteWidget.java
@@ -10,6 +10,9 @@ import android.net.Uri;
 import android.util.Log;
 import android.widget.RemoteViews;
 
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
 import it.niedermann.owncloud.notes.R;
 import it.niedermann.owncloud.notes.edit.BaseNoteFragment;
 import it.niedermann.owncloud.notes.edit.EditNoteActivity;
@@ -19,6 +22,7 @@ import it.niedermann.owncloud.notes.persistence.entity.SingleNoteWidgetData;
 public class SingleNoteWidget extends AppWidgetProvider {
 
     private static final String TAG = SingleNoteWidget.class.getSimpleName();
+    private final ExecutorService executor = Executors.newCachedThreadPool();
 
     static void updateAppWidget(Context context, AppWidgetManager awm, int[] appWidgetIds) {
         final Intent templateIntent = new Intent(context, EditNoteActivity.class);
@@ -69,7 +73,7 @@ public class SingleNoteWidget extends AppWidgetProvider {
         final NotesRepository repo = NotesRepository.getInstance(context);
 
         for (int appWidgetId : appWidgetIds) {
-            new Thread(() -> repo.removeSingleNoteWidget(appWidgetId)).start();
+            executor.submit(() -> repo.removeSingleNoteWidget(appWidgetId));
         }
         super.onDeleted(context, appWidgetIds);
     }
diff --git a/app/src/main/java/it/niedermann/owncloud/notes/widget/singlenote/SingleNoteWidgetConfigurationActivity.java b/app/src/main/java/it/niedermann/owncloud/notes/widget/singlenote/SingleNoteWidgetConfigurationActivity.java
index eb06201a..a487e669 100644
--- a/app/src/main/java/it/niedermann/owncloud/notes/widget/singlenote/SingleNoteWidgetConfigurationActivity.java
+++ b/app/src/main/java/it/niedermann/owncloud/notes/widget/singlenote/SingleNoteWidgetConfigurationActivity.java
@@ -52,7 +52,7 @@ public class SingleNoteWidgetConfigurationActivity extends MainActivity {
 
         int appWidgetId = extras.getInt(AppWidgetManager.EXTRA_APPWIDGET_ID, AppWidgetManager.INVALID_APPWIDGET_ID);
 
-        new Thread(() -> {
+        executor.submit(() -> {
             try {
                 mainViewModel.createOrUpdateSingleNoteWidgetData(
                         new SingleNoteWidgetData(
@@ -71,6 +71,6 @@ public class SingleNoteWidgetConfigurationActivity extends MainActivity {
             } catch (SQLException e) {
                 Toast.makeText(this, e.getLocalizedMessage(), Toast.LENGTH_LONG).show();
             }
-        }).start();
+        });
     }
 }
diff --git a/markdown/src/main/java/it/niedermann/android/markdown/markwon/span/InterceptedURLSpan.java b/markdown/src/main/java/it/niedermann/android/markdown/markwon/span/InterceptedURLSpan.java
index d6c57659..35c456e0 100644
--- a/markdown/src/main/java/it/niedermann/android/markdown/markwon/span/InterceptedURLSpan.java
+++ b/markdown/src/main/java/it/niedermann/android/markdown/markwon/span/InterceptedURLSpan.java
@@ -7,6 +7,8 @@ import android.view.View;
 import androidx.annotation.NonNull;
 
 import java.util.Collection;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
 import java.util.function.Function;
 
 public class InterceptedURLSpan extends URLSpan {
@@ -14,6 +16,7 @@ public class InterceptedURLSpan extends URLSpan {
     private static final String TAG = InterceptedURLSpan.class.getSimpleName();
     @NonNull
     private final Collection<Function<String, Boolean>> onLinkClickCallbacks;
+    private final ExecutorService executor = Executors.newCachedThreadPool();
 
     public InterceptedURLSpan(@NonNull Collection<Function<String, Boolean>> onLinkClickCallbacks, String url) {
         super(url);
@@ -23,7 +26,7 @@ public class InterceptedURLSpan extends URLSpan {
     @Override
     public void onClick(View widget) {
         if (onLinkClickCallbacks.size() > 0) {
-            new Thread(() -> {
+            executor.submit(() -> {
                 for (Function<String, Boolean> callback : onLinkClickCallbacks) {
                     try {
                         if (callback.apply(getURL())) {
@@ -34,7 +37,7 @@ public class InterceptedURLSpan extends URLSpan {
                     }
                 }
                 super.onClick(widget);
-            }).start();
+            });
         } else {
             super.onClick(widget);
         }