Log row counts for database at startup.

Implement status UI for mailbox connection

Closes #2172

See merge request briar/briar!1617

.gitlab-ci.yml

@@ -123,5 +123,6 @@ pre_release_tests:
   extends: .optional_tests
   script:
     - OPTIONAL_TESTS=org.briarproject.bramble.plugin.tor.BridgeTest ./gradlew --info bramble-java:test --tests BridgeTest
+  timeout: 3h
   only:
     - tags

bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/MailboxManager.java

@@ -32,4 +32,13 @@ public interface MailboxManager {
 	 */
 	MailboxPairingTask startPairingTask(String qrCodePayload);
 
+	/**
+	 * Can be used by the UI to test the mailbox connection.
+	 *
+	 * @return true (success) or false (error).
+	 * A {@link OwnMailboxConnectionStatusEvent} might be broadcast with a new
+	 * {@link MailboxStatus}.
+	 */
+	boolean checkConnection();
+
 }

bramble-core/src/main/java/org/briarproject/bramble/db/JdbcDatabase.java

@@ -1,5 +1,32 @@
 package org.briarproject.bramble.db;
 
+import static org.briarproject.bramble.api.db.DatabaseComponent.NO_CLEANUP_DEADLINE;
+import static org.briarproject.bramble.api.db.DatabaseComponent.TIMER_NOT_STARTED;
+import static org.briarproject.bramble.api.db.Metadata.REMOVE;
+import static org.briarproject.bramble.api.sync.Group.Visibility.INVISIBLE;
+import static org.briarproject.bramble.api.sync.Group.Visibility.SHARED;
+import static org.briarproject.bramble.api.sync.Group.Visibility.VISIBLE;
+import static org.briarproject.bramble.api.sync.SyncConstants.MESSAGE_HEADER_LENGTH;
+import static org.briarproject.bramble.api.sync.validation.MessageState.DELIVERED;
+import static org.briarproject.bramble.api.sync.validation.MessageState.PENDING;
+import static org.briarproject.bramble.api.sync.validation.MessageState.UNKNOWN;
+import static org.briarproject.bramble.db.DatabaseConstants.DB_SETTINGS_NAMESPACE;
+import static org.briarproject.bramble.db.DatabaseConstants.DIRTY_KEY;
+import static org.briarproject.bramble.db.DatabaseConstants.SCHEMA_VERSION_KEY;
+import static org.briarproject.bramble.db.ExponentialBackoff.calculateExpiry;
+import static org.briarproject.bramble.db.JdbcUtils.tryToClose;
+import static org.briarproject.bramble.util.LogUtils.logDuration;
+import static org.briarproject.bramble.util.LogUtils.logException;
+import static org.briarproject.bramble.util.LogUtils.now;
+import static java.sql.Types.BINARY;
+import static java.sql.Types.BOOLEAN;
+import static java.sql.Types.INTEGER;
+import static java.sql.Types.VARCHAR;
+import static java.util.Arrays.asList;
+import static java.util.logging.Level.INFO;
+import static java.util.logging.Level.WARNING;
+import static java.util.logging.Logger.getLogger;
+
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.PendingContact;
@@ -65,33 +92,6 @@ import java.util.logging.Logger;
 import javax.annotation.Nullable;
 import javax.annotation.concurrent.GuardedBy;
 
-import static java.sql.Types.BINARY;
-import static java.sql.Types.BOOLEAN;
-import static java.sql.Types.INTEGER;
-import static java.sql.Types.VARCHAR;
-import static java.util.Arrays.asList;
-import static java.util.logging.Level.INFO;
-import static java.util.logging.Level.WARNING;
-import static java.util.logging.Logger.getLogger;
-import static org.briarproject.bramble.api.db.DatabaseComponent.NO_CLEANUP_DEADLINE;
-import static org.briarproject.bramble.api.db.DatabaseComponent.TIMER_NOT_STARTED;
-import static org.briarproject.bramble.api.db.Metadata.REMOVE;
-import static org.briarproject.bramble.api.sync.Group.Visibility.INVISIBLE;
-import static org.briarproject.bramble.api.sync.Group.Visibility.SHARED;
-import static org.briarproject.bramble.api.sync.Group.Visibility.VISIBLE;
-import static org.briarproject.bramble.api.sync.SyncConstants.MESSAGE_HEADER_LENGTH;
-import static org.briarproject.bramble.api.sync.validation.MessageState.DELIVERED;
-import static org.briarproject.bramble.api.sync.validation.MessageState.PENDING;
-import static org.briarproject.bramble.api.sync.validation.MessageState.UNKNOWN;
-import static org.briarproject.bramble.db.DatabaseConstants.DB_SETTINGS_NAMESPACE;
-import static org.briarproject.bramble.db.DatabaseConstants.DIRTY_KEY;
-import static org.briarproject.bramble.db.DatabaseConstants.SCHEMA_VERSION_KEY;
-import static org.briarproject.bramble.db.ExponentialBackoff.calculateExpiry;
-import static org.briarproject.bramble.db.JdbcUtils.tryToClose;
-import static org.briarproject.bramble.util.LogUtils.logDuration;
-import static org.briarproject.bramble.util.LogUtils.logException;
-import static org.briarproject.bramble.util.LogUtils.now;
-
 /**
  * A generic database implementation that can be used with any JDBC-compatible
  * database library.
@@ -415,6 +415,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			}
 			createIndexes(txn);
 			setDirty(txn, true);
+			if (LOG.isLoggable(INFO)) countAndLogRows(txn);
 			commitTransaction(txn);
 		} catch (DbException e) {
 			abortTransaction(txn);
@@ -565,6 +566,40 @@ abstract class JdbcDatabase implements Database<Connection> {
 		}
 	}
 
+	private void countAndLogRows(Connection txn) throws DbException {
+		Statement s = null;
+		try {
+			s = txn.createStatement();
+			countAndLogRows(s, "settings");
+			countAndLogRows(s, "localAuthors");
+			countAndLogRows(s, "contacts");
+			countAndLogRows(s, "groups");
+			countAndLogRows(s, "groupMetadata");
+			countAndLogRows(s, "groupVisibilities");
+			countAndLogRows(s, "messages");
+			countAndLogRows(s, "messageMetadata");
+			countAndLogRows(s, "messageDependencies");
+			countAndLogRows(s, "offers");
+			countAndLogRows(s, "statuses");
+			countAndLogRows(s, "transports");
+			countAndLogRows(s, "incomingKeys");
+			countAndLogRows(s, "outgoingKeys");
+			s.close();
+		} catch (SQLException e) {
+			tryToClose(s, LOG, WARNING);
+			throw new DbException(e);
+		}
+	}
+
+	private void countAndLogRows(Statement s, String tableName)
+			throws SQLException {
+		ResultSet rs = s.executeQuery("SELECT COUNT (*) FROM " + tableName);
+		if (rs.next())
+			LOG.info("Table " + tableName + ": " + rs.getInt(1) + " rows");
+		else LOG.warning("Table " + tableName + " could not be counted");
+		rs.close();
+	}
+
 	@Override
 	public Connection startTransaction() throws DbException {
 		Connection txn;

bramble-core/src/main/java/org/briarproject/bramble/mailbox/MailboxManagerImpl.java

@@ -2,27 +2,42 @@ package org.briarproject.bramble.mailbox;
 
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.Transaction;
+import org.briarproject.bramble.api.db.TransactionManager;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.mailbox.MailboxManager;
 import org.briarproject.bramble.api.mailbox.MailboxPairingTask;
+import org.briarproject.bramble.api.mailbox.MailboxProperties;
 import org.briarproject.bramble.api.mailbox.MailboxSettingsManager;
 import org.briarproject.bramble.api.mailbox.MailboxStatus;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.system.Clock;
 
+import java.io.IOException;
 import java.util.concurrent.Executor;
+import java.util.logging.Logger;
 
 import javax.annotation.Nullable;
 import javax.annotation.concurrent.GuardedBy;
 import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 
+import static java.util.logging.Level.WARNING;
+import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.util.LogUtils.logException;
+
 @Immutable
 @NotNullByDefault
 class MailboxManagerImpl implements MailboxManager {
 
+	private static final String TAG = MailboxManagerImpl.class.getName();
+	private final static Logger LOG = getLogger(TAG);
+
 	private final Executor ioExecutor;
+	private final MailboxApi api;
+	private final TransactionManager db;
 	private final MailboxSettingsManager mailboxSettingsManager;
 	private final MailboxPairingTaskFactory pairingTaskFactory;
+	private final Clock clock;
 	private final Object lock = new Object();
 
 	@Nullable
@@ -32,11 +47,17 @@ class MailboxManagerImpl implements MailboxManager {
 	@Inject
 	MailboxManagerImpl(
 			@IoExecutor Executor ioExecutor,
+			MailboxApi api,
+			TransactionManager db,
 			MailboxSettingsManager mailboxSettingsManager,
-			MailboxPairingTaskFactory pairingTaskFactory) {
+			MailboxPairingTaskFactory pairingTaskFactory,
+			Clock clock) {
 		this.ioExecutor = ioExecutor;
+		this.api = api;
+		this.db = db;
 		this.mailboxSettingsManager = mailboxSettingsManager;
 		this.pairingTaskFactory = pairingTaskFactory;
+		this.clock = clock;
 	}
 
 	@Override
@@ -75,4 +96,29 @@ class MailboxManagerImpl implements MailboxManager {
 		return created;
 	}
 
+	@Override
+	public boolean checkConnection() {
+		boolean success;
+		try {
+			MailboxProperties props = db.transactionWithNullableResult(true,
+					mailboxSettingsManager::getOwnMailboxProperties);
+			success = api.checkStatus(props);
+		} catch (DbException | IOException | MailboxApi.ApiException e) {
+			success = false;
+			logException(LOG, WARNING, e);
+		}
+		if (success) {
+			try {
+				// we are only recording successful connections here
+				// as those update the UI and failures might be false negatives
+				db.transaction(false, txn ->
+						mailboxSettingsManager.recordSuccessfulConnection(txn,
+								clock.currentTimeMillis()));
+			} catch (DbException e) {
+				logException(LOG, WARNING, e);
+			}
+		}
+		return success;
+	}
+
 }

bramble-core/src/main/java/org/briarproject/bramble/mailbox/MailboxPropertyManagerImpl.java

@@ -158,6 +158,12 @@ class MailboxPropertyManagerImpl implements MailboxPropertyManager,
 			BdfList body = clientHelper.getMessageAsList(txn, m.getId());
 			MailboxPropertiesUpdate p = parseProperties(body);
 			txn.attach(new RemoteMailboxPropertiesUpdateEvent(c, p));
+			// Reset message retransmission timers for the contact. Avoiding
+			// messages getting stranded:
+			// - on our mailbox, if they now have a mailbox but didn't before
+			// - on the contact's old mailbox, if they removed their mailbox
+			// - on the contact's old mailbox, if they replaced their mailbox
+			db.resetUnackedMessagesToSend(txn, c);
 		} catch (FormatException e) {
 			throw new InvalidMessageException(e);
 		}

bramble-core/src/test/java/org/briarproject/bramble/mailbox/MailboxPropertyManagerImplTest.java

@@ -281,6 +281,7 @@ public class MailboxPropertyManagerImplTest extends BrambleMockTestCase {
 	public void testDoesNotDeleteAnythingWhenFirstUpdateIsDelivered()
 			throws Exception {
 		Transaction txn = new Transaction(null, false);
+		Contact contact = getContact();
 		GroupId contactGroupId = new GroupId(getRandomId());
 		Message message = getMessage(contactGroupId);
 		BdfList body = BdfList.of(1, propsDict);
@@ -304,11 +305,13 @@ public class MailboxPropertyManagerImplTest extends BrambleMockTestCase {
 					contactGroupId);
 			will(returnValue(messageMetadata));
 			oneOf(clientHelper).getContactId(txn, contactGroupId);
+			will(returnValue(contact.getId()));
 			oneOf(clientHelper).getMessageAsList(txn, message.getId());
 			will(returnValue(body));
 			oneOf(clientHelper).parseAndValidateMailboxPropertiesUpdate(
 					propsDict);
 			will(returnValue(props));
+			oneOf(db).resetUnackedMessagesToSend(txn, contact.getId());
 		}});
 
 		MailboxPropertyManagerImpl t = createInstance();
@@ -321,6 +324,7 @@ public class MailboxPropertyManagerImplTest extends BrambleMockTestCase {
 	public void testDeletesOlderUpdateWhenUpdateIsDelivered()
 			throws Exception {
 		Transaction txn = new Transaction(null, false);
+		Contact contact = getContact();
 		GroupId contactGroupId = new GroupId(getRandomId());
 		Message message = getMessage(contactGroupId);
 		BdfList body = BdfList.of(1, propsDict);
@@ -352,11 +356,13 @@ public class MailboxPropertyManagerImplTest extends BrambleMockTestCase {
 			oneOf(db).deleteMessage(txn, updateId);
 			oneOf(db).deleteMessageMetadata(txn, updateId);
 			oneOf(clientHelper).getContactId(txn, contactGroupId);
+			will(returnValue(contact.getId()));
 			oneOf(clientHelper).getMessageAsList(txn, message.getId());
 			will(returnValue(body));
 			oneOf(clientHelper).parseAndValidateMailboxPropertiesUpdate(
 					propsDict);
 			will(returnValue(props));
+			oneOf(db).resetUnackedMessagesToSend(txn, contact.getId());
 		}});
 
 		MailboxPropertyManagerImpl t = createInstance();

briar-android/src/main/java/org/briarproject/briar/android/mailbox/MailboxActivity.java

@@ -47,11 +47,11 @@ public class MailboxActivity extends BriarActivity {
 		setContentView(R.layout.activity_mailbox);
 
 		progressBar = findViewById(R.id.progressBar);
-		if (viewModel.getState().getValue() == null) {
+		if (viewModel.getPairingState().getValue() == null) {
 			progressBar.setVisibility(VISIBLE);
 		}
 
-		viewModel.getState().observeEvent(this, state -> {
+		viewModel.getPairingState().observeEvent(this, state -> {
 			if (state instanceof MailboxState.NotSetup) {
 				onNotSetup();
 			} else if (state instanceof MailboxState.ShowDownload) {
@@ -67,7 +67,7 @@ public class MailboxActivity extends BriarActivity {
 			} else if (state instanceof MailboxState.CameraError) {
 				onCameraError();
 			} else if (state instanceof MailboxState.IsPaired) {
-				onIsPaired();
+				onIsPaired(((MailboxState.IsPaired) state).isOnline);
 			} else {
 				throw new AssertionError("Unknown state: " + state);
 			}
@@ -85,7 +85,7 @@ public class MailboxActivity extends BriarActivity {
 
 	@Override
 	public void onBackPressed() {
-		MailboxState s = viewModel.getState().getLastValue();
+		MailboxState s = viewModel.getPairingState().getLastValue();
 		if (s instanceof MailboxState.Pairing) {
 			// don't go back in the flow if we are already pairing
 			// with the mailbox. We provide a try-again button instead.
@@ -181,10 +181,13 @@ public class MailboxActivity extends BriarActivity {
 		showFragment(getSupportFragmentManager(), f, ErrorFragment.TAG);
 	}
 
-	private void onIsPaired() {
+	private void onIsPaired(boolean isOnline) {
 		progressBar.setVisibility(INVISIBLE);
-		showFragment(getSupportFragmentManager(), new MailboxStatusFragment(),
+		Fragment f = isOnline ?
-				MailboxStatusFragment.TAG, false);
+				new MailboxStatusFragment() : new OfflineStatusFragment();
+		String tag = isOnline ?
+				MailboxStatusFragment.TAG : OfflineStatusFragment.TAG;
+		showFragment(getSupportFragmentManager(), f, tag, false);
 	}
 
 }

briar-android/src/main/java/org/briarproject/briar/android/mailbox/MailboxState.java

@@ -1,7 +1,6 @@
 package org.briarproject.briar.android.mailbox;
 
 import org.briarproject.bramble.api.mailbox.MailboxPairingState;
-import org.briarproject.bramble.api.mailbox.MailboxStatus;
 
 class MailboxState {
 
@@ -29,10 +28,10 @@ class MailboxState {
 	}
 
 	static class IsPaired extends MailboxState {
-		final MailboxStatus mailboxStatus;
+		final boolean isOnline;
 
-		IsPaired(MailboxStatus mailboxStatus) {
+		IsPaired(boolean isOnline) {
-			this.mailboxStatus = mailboxStatus;
+			this.isOnline = isOnline;
 		}
 	}
 

briar-android/src/main/java/org/briarproject/briar/android/mailbox/MailboxStatusFragment.java

@@ -1,37 +1,62 @@
 package org.briarproject.briar.android.mailbox;
 
 import android.content.Context;
+import android.content.res.ColorStateList;
 import android.os.Bundle;
+import android.os.Handler;
+import android.os.Looper;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
+import android.widget.Button;
+import android.widget.ImageView;
+import android.widget.ProgressBar;
 import android.widget.TextView;
+import android.widget.Toast;
 
+import org.briarproject.bramble.api.mailbox.MailboxStatus;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.briar.R;
 
 import javax.inject.Inject;
 
+import androidx.annotation.ColorRes;
+import androidx.annotation.DrawableRes;
 import androidx.annotation.Nullable;
+import androidx.annotation.UiThread;
 import androidx.fragment.app.Fragment;
 import androidx.fragment.app.FragmentActivity;
 import androidx.lifecycle.ViewModelProvider;
 
-import static java.util.Objects.requireNonNull;
+import static android.view.View.INVISIBLE;
+import static android.view.View.VISIBLE;
+import static androidx.core.content.ContextCompat.getColor;
+import static androidx.core.widget.ImageViewCompat.setImageTintList;
+import static androidx.transition.TransitionManager.beginDelayedTransition;
 import static org.briarproject.briar.android.AppModule.getAndroidComponent;
+import static org.briarproject.briar.android.util.UiUtils.MIN_DATE_RESOLUTION;
 import static org.briarproject.briar.android.util.UiUtils.formatDate;
+import static org.briarproject.briar.android.util.UiUtils.observeOnce;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
 public class MailboxStatusFragment extends Fragment {
 
 	static final String TAG = MailboxStatusFragment.class.getName();
+	private static final int NUM_FAILURES = 4;
 
 	@Inject
 	ViewModelProvider.Factory viewModelFactory;
 
 	private MailboxViewModel viewModel;
+	private final Handler handler = new Handler(Looper.getMainLooper());
+	@Nullable // UiThread
+	private Runnable refresher = null;
+
+	private ImageView imageView;
+	private TextView statusTitleView;
+	private TextView statusInfoView;
 
 	@Override
 	public void onAttach(Context context) {
@@ -54,11 +79,72 @@ public class MailboxStatusFragment extends Fragment {
 	@Override
 	public void onViewCreated(View v, @Nullable Bundle savedInstanceState) {
 		super.onViewCreated(v, savedInstanceState);
-		MailboxState.IsPaired state =
+
-				(MailboxState.IsPaired) viewModel.getState().getLastValue();
+		Button checkButton = v.findViewById(R.id.checkButton);
-		requireNonNull(state); // TODO check assumption
+		ProgressBar checkProgress = v.findViewById(R.id.checkProgress);
-		TextView statusInfoView = v.findViewById(R.id.statusInfoView);
+		checkButton.setOnClickListener(view -> {
-		long lastSuccess = state.mailboxStatus.getTimeOfLastSuccess();
+			beginDelayedTransition((ViewGroup) v);
+			checkButton.setVisibility(INVISIBLE);
+			checkProgress.setVisibility(VISIBLE);
+			observeOnce(viewModel.checkConnection(), this, result -> {
+				beginDelayedTransition((ViewGroup) v);
+				checkButton.setVisibility(VISIBLE);
+				checkProgress.setVisibility(INVISIBLE);
+			});
+		});
+
+		imageView = v.findViewById(R.id.imageView);
+		statusTitleView = v.findViewById(R.id.statusTitleView);
+		statusInfoView = v.findViewById(R.id.statusInfoView);
+		viewModel.getStatus()
+				.observe(getViewLifecycleOwner(), this::onMailboxStateChanged);
+
+		// TODO
+		//  * detect problems and show them #2175
+		//  * add "Unlink" button confirmation dialog and functionality #2173
+		Button unlinkButton = v.findViewById(R.id.unlinkButton);
+		unlinkButton.setOnClickListener(view -> Toast.makeText(requireContext(),
+				"NOT IMPLEMENTED", Toast.LENGTH_SHORT).show());
+	}
+
+	@Override
+	public void onStart() {
+		super.onStart();
+		requireActivity().setTitle(R.string.mailbox_status_title);
+		refresher = this::refreshLastConnection;
+		handler.postDelayed(refresher, MIN_DATE_RESOLUTION);
+	}
+
+	@Override
+	public void onStop() {
+		super.onStop();
+		handler.removeCallbacks(refresher);
+		refresher = null;
+	}
+
+	private void onMailboxStateChanged(MailboxStatus status) {
+		@ColorRes int tintRes;
+		@DrawableRes int iconRes;
+		String title;
+		if (status.getAttemptsSinceSuccess() == 0) {
+			iconRes = R.drawable.ic_check_circle_outline;
+			title = getString(R.string.mailbox_status_connected_title);
+			tintRes = R.color.briar_brand_green;
+		} else if (status.getAttemptsSinceSuccess() < NUM_FAILURES) {
+			iconRes = R.drawable.ic_help_outline_white;
+			title = getString(R.string.mailbox_status_problem_title);
+			tintRes = R.color.briar_orange_500;
+		} else {
+			tintRes = R.color.briar_red_500;
+			title = getString(R.string.mailbox_status_failure_title);
+			iconRes = R.drawable.alerts_and_states_error;
+		}
+		imageView.setImageResource(iconRes);
+		int color = getColor(requireContext(), tintRes);
+		setImageTintList(imageView, ColorStateList.valueOf(color));
+		statusTitleView.setText(title);
+
+		long lastSuccess = status.getTimeOfLastSuccess();
 		String lastConnectionText;
 		if (lastSuccess < 0) {
 			lastConnectionText =
@@ -66,21 +152,19 @@ public class MailboxStatusFragment extends Fragment {
 		} else {
 			lastConnectionText = formatDate(requireContext(), lastSuccess);
 		}
-		String statusInfoText = getString(
+		String statusInfoText =
-				R.string.mailbox_status_connected_info, lastConnectionText);
+				getString(R.string.mailbox_status_connected_info,
+						lastConnectionText);
 		statusInfoView.setText(statusInfoText);
-		// TODO
-		//  * react to status changes
-		//  * detect problems and show them
-		//  * update connection time periodically like conversation timestamps
-		//  * add "Check connection" button
-		//  * add "Unlink" button with confirmation dialog
 	}
 
-	@Override
+	@UiThread
-	public void onStart() {
+	private void refreshLastConnection() {
-		super.onStart();
+		MailboxStatus status = viewModel.getStatus().getValue();
-		requireActivity().setTitle(R.string.mailbox_status_title);
+		if (status != null) onMailboxStateChanged(status);
+		if (refresher != null) {
+			handler.postDelayed(refresher, MIN_DATE_RESOLUTION);
+		}
 	}
 
 }

briar-android/src/main/java/org/briarproject/briar/android/mailbox/MailboxViewModel.java

@@ -7,16 +7,22 @@ import com.google.zxing.Result;
 import org.briarproject.bramble.api.Consumer;
 import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.db.TransactionManager;
+import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.event.EventBus;
+import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.mailbox.MailboxManager;
 import org.briarproject.bramble.api.mailbox.MailboxPairingState;
 import org.briarproject.bramble.api.mailbox.MailboxPairingTask;
 import org.briarproject.bramble.api.mailbox.MailboxStatus;
+import org.briarproject.bramble.api.mailbox.OwnMailboxConnectionStatusEvent;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.Plugin;
 import org.briarproject.bramble.api.plugin.PluginManager;
 import org.briarproject.bramble.api.plugin.TorConstants;
+import org.briarproject.bramble.api.plugin.TransportId;
+import org.briarproject.bramble.api.plugin.event.TransportInactiveEvent;
 import org.briarproject.bramble.api.system.AndroidExecutor;
 import org.briarproject.briar.android.mailbox.MailboxState.NotSetup;
 import org.briarproject.briar.android.qrcode.QrCodeDecoder;
@@ -32,6 +38,8 @@ import javax.inject.Inject;
 import androidx.annotation.AnyThread;
 import androidx.annotation.Nullable;
 import androidx.annotation.UiThread;
+import androidx.lifecycle.LiveData;
+import androidx.lifecycle.MutableLiveData;
 
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Logger.getLogger;
@@ -39,17 +47,22 @@ import static org.briarproject.bramble.api.plugin.Plugin.State.ACTIVE;
 
 @NotNullByDefault
 class MailboxViewModel extends DbViewModel
-		implements QrCodeDecoder.ResultCallback, Consumer<MailboxPairingState> {
+		implements QrCodeDecoder.ResultCallback, Consumer<MailboxPairingState>,
+		EventListener {
 
 	private static final Logger LOG =
 			getLogger(MailboxViewModel.class.getName());
 
+	private final EventBus eventBus;
+	private final Executor ioExecutor;
 	private final QrCodeDecoder qrCodeDecoder;
 	private final PluginManager pluginManager;
 	private final MailboxManager mailboxManager;
 
-	private final MutableLiveEvent<MailboxState> state =
+	private final MutableLiveEvent<MailboxState> pairingState =
 			new MutableLiveEvent<>();
+	private final MutableLiveData<MailboxStatus> status =
+			new MutableLiveData<>();
 	@Nullable
 	private MailboxPairingTask pairingTask = null;
 
@@ -60,19 +73,24 @@ class MailboxViewModel extends DbViewModel
 			LifecycleManager lifecycleManager,
 			TransactionManager db,
 			AndroidExecutor androidExecutor,
+			EventBus eventBus,
 			@IoExecutor Executor ioExecutor,
 			PluginManager pluginManager,
 			MailboxManager mailboxManager) {
 		super(app, dbExecutor, lifecycleManager, db, androidExecutor);
+		this.eventBus = eventBus;
+		this.ioExecutor = ioExecutor;
 		this.pluginManager = pluginManager;
 		this.mailboxManager = mailboxManager;
 		qrCodeDecoder = new QrCodeDecoder(androidExecutor, ioExecutor, this);
+		eventBus.addListener(this);
 		checkIfSetup();
 	}
 
 	@Override
 	protected void onCleared() {
 		super.onCleared();
+		eventBus.removeListener(this);
 		MailboxPairingTask task = pairingTask;
 		if (task != null) {
 			task.removeObserver(this);
@@ -89,9 +107,11 @@ class MailboxViewModel extends DbViewModel
 				if (isPaired) {
 					MailboxStatus mailboxStatus =
 							mailboxManager.getMailboxStatus(txn);
-					state.postEvent(new MailboxState.IsPaired(mailboxStatus));
+					boolean isOnline = isTorActive();
+					pairingState.postEvent(new MailboxState.IsPaired(isOnline));
+					status.postValue(mailboxStatus);
 				} else {
-					state.postEvent(new NotSetup());
+					pairingState.postEvent(new NotSetup());
 				}
 			}, this::handleException);
 		} else {
@@ -100,18 +120,37 @@ class MailboxViewModel extends DbViewModel
 		}
 	}
 
+	@UiThread
+	@Override
+	public void eventOccurred(Event e) {
+		if (e instanceof OwnMailboxConnectionStatusEvent) {
+			MailboxStatus status =
+					((OwnMailboxConnectionStatusEvent) e).getStatus();
+			this.status.setValue(status);
+		} else if (e instanceof TransportInactiveEvent) {
+			TransportId id = ((TransportInactiveEvent) e).getTransportId();
+			if (!TorConstants.ID.equals(id)) return;
+			MailboxState lastState = pairingState.getLastValue();
+			if (lastState instanceof MailboxState.IsPaired) {
+				pairingState.setEvent(new MailboxState.IsPaired(false));
+			} else if (lastState != null) {
+				pairingState.setEvent(new MailboxState.OfflineWhenPairing());
+			}
+		}
+	}
+
 	@UiThread
 	void onScanButtonClicked() {
 		if (isTorActive()) {
-			state.setEvent(new MailboxState.ScanningQrCode());
+			pairingState.setEvent(new MailboxState.ScanningQrCode());
 		} else {
-			state.setEvent(new MailboxState.OfflineWhenPairing());
+			pairingState.setEvent(new MailboxState.OfflineWhenPairing());
 		}
 	}
 
 	@UiThread
 	void onCameraError() {
-		state.setEvent(new MailboxState.CameraError());
+		pairingState.setEvent(new MailboxState.CameraError());
 	}
 
 	@Override
@@ -127,7 +166,7 @@ class MailboxViewModel extends DbViewModel
 			pairingTask = mailboxManager.startPairingTask(qrCodePayload);
 			pairingTask.addObserver(this);
 		} else {
-			state.postEvent(new MailboxState.OfflineWhenPairing());
+			pairingState.postEvent(new MailboxState.OfflineWhenPairing());
 		}
 	}
 
@@ -138,7 +177,7 @@ class MailboxViewModel extends DbViewModel
 			LOG.info("New pairing state: " +
 					mailboxPairingState.getClass().getSimpleName());
 		}
-		state.setEvent(new MailboxState.Pairing(mailboxPairingState));
+		pairingState.setEvent(new MailboxState.Pairing(mailboxPairingState));
 	}
 
 	private boolean isTorActive() {
@@ -148,7 +187,7 @@ class MailboxViewModel extends DbViewModel
 
 	@UiThread
 	void showDownloadFragment() {
-		state.setEvent(new MailboxState.ShowDownload());
+		pairingState.setEvent(new MailboxState.ShowDownload());
 	}
 
 	@UiThread
@@ -157,7 +196,37 @@ class MailboxViewModel extends DbViewModel
 	}
 
 	@UiThread
-	LiveEvent<MailboxState> getState() {
+	void checkIfOnlineWhenPaired() {
-		return state;
+		boolean isOnline = isTorActive();
+		pairingState.setEvent(new MailboxState.IsPaired(isOnline));
+	}
+
+	LiveData<Boolean> checkConnection() {
+		MutableLiveData<Boolean> liveData = new MutableLiveData<>();
+		ioExecutor.execute(() -> {
+			boolean success = mailboxManager.checkConnection();
+			if (LOG.isLoggable(INFO)) {
+				LOG.info("Got result from connection check: " + success);
+			}
+			liveData.postValue(success);
+			if (!success) { // force failure screen
+				MailboxStatus lastStatus = status.getValue();
+				long lastSuccess = lastStatus == null ?
+						-1 : lastStatus.getTimeOfLastSuccess();
+				long now = System.currentTimeMillis();
+				status.postValue(new MailboxStatus(now, lastSuccess, 999));
+			}
+		});
+		return liveData;
+	}
+
+	@UiThread
+	LiveEvent<MailboxState> getPairingState() {
+		return pairingState;
+	}
+
+	@UiThread
+	LiveData<MailboxStatus> getStatus() {
+		return status;
 	}
 }

briar-android/src/main/java/org/briarproject/briar/android/mailbox/OfflineFragment.java

@@ -33,10 +33,9 @@ public class OfflineFragment extends Fragment {
 	@Inject
 	ViewModelProvider.Factory viewModelFactory;
 
-	private MailboxViewModel viewModel;
+	protected MailboxViewModel viewModel;
 
 	private NestedScrollView scrollView;
-	protected Button buttonView;
 
 	@Override
 	public void onAttach(Context context) {
@@ -61,8 +60,8 @@ public class OfflineFragment extends Fragment {
 			Intent i = new Intent(requireContext(), TransportsActivity.class);
 			startActivity(i);
 		});
-		buttonView = v.findViewById(R.id.button);
+		Button buttonView = v.findViewById(R.id.button);
-		buttonView.setOnClickListener(view -> viewModel.showDownloadFragment());
+		buttonView.setOnClickListener(view -> onTryAgainClicked());
 
 		return v;
 	}
@@ -74,4 +73,8 @@ public class OfflineFragment extends Fragment {
 		scrollView.post(() -> scrollView.fullScroll(FOCUS_DOWN));
 	}
 
+	protected void onTryAgainClicked() {
+		viewModel.showDownloadFragment();
+	}
+
 }

briar-android/src/main/java/org/briarproject/briar/android/mailbox/OfflineStatusFragment.java

@@ -0,0 +1,17 @@
+package org.briarproject.briar.android.mailbox;
+
+import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
+
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
+public class OfflineStatusFragment extends OfflineFragment {
+
+	public static final String TAG = OfflineStatusFragment.class.getName();
+
+	@Override
+	protected void onTryAgainClicked() {
+		viewModel.checkIfOnlineWhenPaired();
+	}
+
+}

briar-android/src/main/res/layout/fragment_mailbox_status.xml

@@ -10,13 +10,14 @@
 		android:id="@+id/imageView"
 		android:layout_width="32dp"
 		android:layout_height="32dp"
-		android:layout_marginStart="16dp"
+		android:layout_marginHorizontal="16dp"
-		android:layout_marginLeft="16dp"
+		app:layout_constraintBottom_toTopOf="@+id/statusTitleView"
-		app:layout_constraintBottom_toBottomOf="parent"
+		app:layout_constraintEnd_toEndOf="parent"
-		app:layout_constraintEnd_toStartOf="@+id/statusTitleView"
+		app:layout_constraintHorizontal_bias="0.5"
 		app:layout_constraintHorizontal_chainStyle="packed"
 		app:layout_constraintStart_toStartOf="parent"
 		app:layout_constraintTop_toTopOf="parent"
+		app:layout_constraintVertical_bias="0.25"
 		app:layout_constraintVertical_chainStyle="packed"
 		app:srcCompat="@drawable/ic_check_circle_outline"
 		app:tint="@color/briar_brand_green"
@@ -26,14 +27,37 @@
 		android:id="@+id/statusTitleView"
 		android:layout_width="wrap_content"
 		android:layout_height="wrap_content"
-		android:layout_marginHorizontal="16dp"
+		android:layout_margin="16dp"
 		android:text="@string/mailbox_status_connected_title"
 		android:textAppearance="@style/TextAppearance.MaterialComponents.Headline6"
 		app:layout_constrainedWidth="true"
-		app:layout_constraintBottom_toBottomOf="@+id/imageView"
+		app:layout_constraintBottom_toTopOf="@+id/checkButton"
 		app:layout_constraintEnd_toEndOf="parent"
-		app:layout_constraintStart_toEndOf="@+id/imageView"
+		app:layout_constraintStart_toStartOf="parent"
-		app:layout_constraintTop_toTopOf="@+id/imageView" />
+		app:layout_constraintTop_toBottomOf="@+id/imageView" />
+
+	<Button
+		android:id="@+id/checkButton"
+		style="@style/BriarButtonFlat.Neutral"
+		android:layout_width="wrap_content"
+		android:layout_height="wrap_content"
+		android:layout_marginHorizontal="16dp"
+		android:text="@string/mailbox_status_check_button"
+		app:layout_constraintBottom_toTopOf="@+id/statusInfoView"
+		app:layout_constraintEnd_toEndOf="parent"
+		app:layout_constraintStart_toStartOf="parent"
+		app:layout_constraintTop_toBottomOf="@+id/statusTitleView" />
+
+	<ProgressBar
+		android:id="@+id/checkProgress"
+		android:layout_width="wrap_content"
+		android:layout_height="wrap_content"
+		android:visibility="invisible"
+		app:layout_constraintBottom_toBottomOf="@+id/checkButton"
+		app:layout_constraintEnd_toEndOf="@+id/checkButton"
+		app:layout_constraintStart_toStartOf="@+id/checkButton"
+		app:layout_constraintTop_toTopOf="@+id/checkButton"
+		tools:visibility="visible" />
 
 	<TextView
 		android:id="@+id/statusInfoView"
@@ -41,11 +65,21 @@
 		android:layout_height="wrap_content"
 		android:layout_margin="16dp"
 		android:gravity="center"
-		app:layout_constraintBottom_toBottomOf="parent"
+		app:layout_constraintBottom_toTopOf="@+id/unlinkButton"
 		app:layout_constraintEnd_toEndOf="parent"
 		app:layout_constraintStart_toStartOf="parent"
-		app:layout_constraintTop_toBottomOf="@+id/statusTitleView"
+		app:layout_constraintTop_toBottomOf="@+id/checkButton"
-		app:layout_constraintVertical_bias="0.0"
 		tools:text="@string/mailbox_status_connected_info" />
 
+	<Button
+		android:id="@+id/unlinkButton"
+		style="@style/BriarButtonFlat.Negative"
+		android:layout_width="wrap_content"
+		android:layout_height="wrap_content"
+		android:layout_margin="16dp"
+		android:text="@string/mailbox_status_unlink_button"
+		app:layout_constraintBottom_toBottomOf="parent"
+		app:layout_constraintEnd_toEndOf="parent"
+		app:layout_constraintStart_toStartOf="parent" />
+
 </androidx.constraintlayout.widget.ConstraintLayout>

briar-android/src/main/res/values/strings.xml

@@ -643,10 +643,14 @@
 	<string name="tor_offline_button_check">Check connection settings</string>
 	<string name="mailbox_status_title">Mailbox status</string>
 	<string name="mailbox_status_connected_title">Mailbox is running</string>
+	<string name="mailbox_status_problem_title">We are having trouble connecting to the mailbox</string>
+	<string name="mailbox_status_failure_title">Mailbox is unavailable</string>
+	<string name="mailbox_status_check_button">Check Connection</string>
 	<!-- Example for string substitution: Last connection: 3min ago-->
 	<string name="mailbox_status_connected_info">Last connection: %s</string>
 	<!-- Indicates that there never was a connection to the mailbox. Last connection: Never -->
 	<string name="mailbox_status_connected_never">Never</string>
+	<string name="mailbox_status_unlink_button">Unlink</string>
 
 	<!-- Conversation Settings -->
 	<string name="disappearing_messages_title">Disappearing messages</string>