Bump version numbers for 1.2.13 release.

Do not produce malformed links for adding contacts when on other locales such as Turkish

Closes #1885

See merge request briar/briar!1335

bramble-android/src/main/java/org/briarproject/bramble/network/AndroidNetworkManager.java

@@ -1,11 +1,15 @@
 package org.briarproject.bramble.network;
 
+import android.annotation.TargetApi;
 import android.app.Application;
 import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
 import android.net.ConnectivityManager;
+import android.net.LinkAddress;
+import android.net.LinkProperties;
+import android.net.Network;
 import android.net.NetworkInfo;
 
 import org.briarproject.bramble.api.event.EventBus;
@@ -19,6 +23,11 @@ import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.bramble.api.system.TaskScheduler;
 import org.briarproject.bramble.api.system.TaskScheduler.Cancellable;
 
+import java.net.Inet4Address;
+import java.net.InetAddress;
+import java.net.NetworkInterface;
+import java.net.SocketException;
+import java.util.Enumeration;
 import java.util.concurrent.Executor;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
@@ -36,16 +45,22 @@ import static android.net.ConnectivityManager.TYPE_WIFI;
 import static android.net.wifi.p2p.WifiP2pManager.WIFI_P2P_THIS_DEVICE_CHANGED_ACTION;
 import static android.os.Build.VERSION.SDK_INT;
 import static android.os.PowerManager.ACTION_DEVICE_IDLE_MODE_CHANGED;
+import static java.net.NetworkInterface.getNetworkInterfaces;
+import static java.util.Collections.list;
 import static java.util.concurrent.TimeUnit.MINUTES;
 import static java.util.concurrent.TimeUnit.SECONDS;
 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.nullsafety.NullSafety.requireNonNull;
+import static org.briarproject.bramble.util.LogUtils.logException;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
 class AndroidNetworkManager implements NetworkManager, Service {
 
 	private static final Logger LOG =
-			Logger.getLogger(AndroidNetworkManager.class.getName());
+			getLogger(AndroidNetworkManager.class.getName());
 
 	// See android.net.wifi.WifiManager
 	private static final String WIFI_AP_STATE_CHANGED_ACTION =
@@ -54,7 +69,8 @@ class AndroidNetworkManager implements NetworkManager, Service {
 	private final TaskScheduler scheduler;
 	private final EventBus eventBus;
 	private final Executor eventExecutor;
-	private final Context appContext;
+	private final Application app;
+	private final ConnectivityManager connectivityManager;
 	private final AtomicReference<Cancellable> connectivityCheck =
 			new AtomicReference<>();
 	private final AtomicBoolean used = new AtomicBoolean(false);
@@ -67,7 +83,9 @@ class AndroidNetworkManager implements NetworkManager, Service {
 		this.scheduler = scheduler;
 		this.eventBus = eventBus;
 		this.eventExecutor = eventExecutor;
-		this.appContext = app.getApplicationContext();
+		this.app = app;
+		connectivityManager = (ConnectivityManager)
+				requireNonNull(app.getSystemService(CONNECTIVITY_SERVICE));
 	}
 
 	@Override
@@ -82,24 +100,82 @@ class AndroidNetworkManager implements NetworkManager, Service {
 		filter.addAction(WIFI_AP_STATE_CHANGED_ACTION);
 		filter.addAction(WIFI_P2P_THIS_DEVICE_CHANGED_ACTION);
 		if (SDK_INT >= 23) filter.addAction(ACTION_DEVICE_IDLE_MODE_CHANGED);
-		appContext.registerReceiver(networkStateReceiver, filter);
+		app.registerReceiver(networkStateReceiver, filter);
 	}
 
 	@Override
 	public void stopService() {
 		if (networkStateReceiver != null)
-			appContext.unregisterReceiver(networkStateReceiver);
+			app.unregisterReceiver(networkStateReceiver);
 	}
 
 	@Override
 	public NetworkStatus getNetworkStatus() {
-		ConnectivityManager cm = (ConnectivityManager)
-				appContext.getSystemService(CONNECTIVITY_SERVICE);
-		if (cm == null) throw new AssertionError();
-		NetworkInfo net = cm.getActiveNetworkInfo();
+		NetworkInfo net = connectivityManager.getActiveNetworkInfo();
 		boolean connected = net != null && net.isConnected();
-		boolean wifi = connected && net.getType() == TYPE_WIFI;
-		return new NetworkStatus(connected, wifi);
+		boolean wifi = false, ipv6Only = false;
+		if (connected) {
+			wifi = net.getType() == TYPE_WIFI;
+			if (SDK_INT >= 23) ipv6Only = isActiveNetworkIpv6Only();
+			else ipv6Only = areAllAvailableNetworksIpv6Only();
+		}
+		return new NetworkStatus(connected, wifi, ipv6Only);
+	}
+
+	/**
+	 * Returns true if the
+	 * {@link ConnectivityManager#getActiveNetwork() active network} has an
+	 * IPv6 unicast address and no IPv4 addresses. The active network is
+	 * assumed not to be a loopback interface.
+	 */
+	@TargetApi(23)
+	private boolean isActiveNetworkIpv6Only() {
+		Network net = connectivityManager.getActiveNetwork();
+		if (net == null) {
+			LOG.info("No active network");
+			return false;
+		}
+		LinkProperties props = connectivityManager.getLinkProperties(net);
+		if (props == null) {
+			LOG.info("No link properties for active network");
+			return false;
+		}
+		boolean hasIpv6Unicast = false;
+		for (LinkAddress linkAddress : props.getLinkAddresses()) {
+			InetAddress addr = linkAddress.getAddress();
+			if (addr instanceof Inet4Address) return false;
+			if (!addr.isMulticastAddress()) hasIpv6Unicast = true;
+		}
+		return hasIpv6Unicast;
+	}
+
+	/**
+	 * Returns true if the device has at least one network interface with an
+	 * IPv6 unicast address and no interfaces with IPv4 addresses, excluding
+	 * loopback interfaces and interfaces that are
+	 * {@link NetworkInterface#isUp() down}. If this method returns true and
+	 * the device has internet access then it's via IPv6 only.
+	 */
+	private boolean areAllAvailableNetworksIpv6Only() {
+		try {
+			Enumeration<NetworkInterface> interfaces = getNetworkInterfaces();
+			if (interfaces == null) {
+				LOG.info("No network interfaces");
+				return false;
+			}
+			boolean hasIpv6Unicast = false;
+			for (NetworkInterface i : list(interfaces)) {
+				if (i.isLoopback() || !i.isUp()) continue;
+				for (InetAddress addr : list(i.getInetAddresses())) {
+					if (addr instanceof Inet4Address) return false;
+					if (!addr.isMulticastAddress()) hasIpv6Unicast = true;
+				}
+			}
+			return hasIpv6Unicast;
+		} catch (SocketException e) {
+			logException(LOG, WARNING, e);
+			return false;
+		}
 	}
 
 	private void updateConnectionStatus() {

bramble-android/src/main/java/org/briarproject/bramble/system/AndroidSecureRandomProvider.java

@@ -6,8 +6,6 @@ import android.bluetooth.BluetoothAdapter;
 import android.bluetooth.BluetoothDevice;
 import android.content.ContentResolver;
 import android.content.Context;
-import android.net.wifi.WifiConfiguration;
-import android.net.wifi.WifiManager;
 import android.os.Build;
 import android.os.Parcel;
 import android.os.StrictMode;
@@ -17,12 +15,10 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
 import java.io.DataOutputStream;
 import java.io.IOException;
-import java.util.List;
 
 import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 
-import static android.content.Context.WIFI_SERVICE;
 import static android.os.Build.VERSION.SDK_INT;
 import static android.provider.Settings.Secure.ANDROID_ID;
 
@@ -52,15 +48,6 @@ class AndroidSecureRandomProvider extends UnixSecureRandomProvider {
 		String id = Settings.Secure.getString(contentResolver, ANDROID_ID);
 		if (id != null) out.writeUTF(id);
 		Parcel parcel = Parcel.obtain();
-		WifiManager wm = (WifiManager) appContext.getApplicationContext()
-				.getSystemService(WIFI_SERVICE);
-		if (wm != null) {
-			List<WifiConfiguration> configs = wm.getConfiguredNetworks();
-			if (configs != null) {
-				for (WifiConfiguration config : configs)
-					parcel.writeParcelable(config, 0);
-			}
-		}
 		BluetoothAdapter bt = BluetoothAdapter.getDefaultAdapter();
 		if (bt != null) {
 			for (BluetoothDevice device : bt.getBondedDevices())

bramble-api/src/main/java/org/briarproject/bramble/api/client/ClientHelper.java

@@ -1,7 +1,6 @@
 package org.briarproject.bramble.api.client;
 
 import org.briarproject.bramble.api.FormatException;
-import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.crypto.PrivateKey;
 import org.briarproject.bramble.api.crypto.PublicKey;
 import org.briarproject.bramble.api.data.BdfDictionary;
@@ -120,17 +119,4 @@ public interface ClientHelper {
 	Map<TransportId, TransportProperties> parseAndValidateTransportPropertiesMap(
 			BdfDictionary properties) throws FormatException;
 
-	/**
-	 * Retrieves the contact ID from the group metadata of the given contact
-	 * group.
-	 */
-	ContactId getContactId(Transaction txn, GroupId contactGroupId)
-		throws DbException, FormatException;
-
-	/**
-	 * Stores the given contact ID in the group metadata of the given contact
-	 * group.
-	 */
-	void setContactId(Transaction txn, GroupId contactGroupId, ContactId c)
-		throws DbException;
 }

bramble-api/src/main/java/org/briarproject/bramble/api/client/ContactGroupConstants.java

@@ -1,9 +0,0 @@
-package org.briarproject.bramble.api.client;
-
-public interface ContactGroupConstants {
-
-	/**
-	 * Group metadata key for associating a contact ID with a contact group.
-	 */
-	String GROUP_KEY_CONTACT_ID = "contactId";
-}

bramble-api/src/main/java/org/briarproject/bramble/api/network/NetworkStatus.java

@@ -8,11 +8,12 @@ import javax.annotation.concurrent.Immutable;
 @NotNullByDefault
 public class NetworkStatus {
 
-	private final boolean connected, wifi;
+	private final boolean connected, wifi, ipv6Only;
 
-	public NetworkStatus(boolean connected, boolean wifi) {
+	public NetworkStatus(boolean connected, boolean wifi, boolean ipv6Only) {
 		this.connected = connected;
 		this.wifi = wifi;
+		this.ipv6Only = ipv6Only;
 	}
 
 	public boolean isConnected() {
@@ -22,4 +23,8 @@ public class NetworkStatus {
 	public boolean isWifi() {
 		return wifi;
 	}
+
+	public boolean isIpv6Only() {
+		return ipv6Only;
+	}
 }

bramble-api/src/main/java/org/briarproject/bramble/api/reporting/DevReporter.java

@@ -23,6 +23,8 @@ public interface DevReporter {
 
 	/**
 	 * Sends any reports previously stored on disk.
+	 *
+	 * @return The number of reports that were sent.
 	 */
-	void sendReports();
+	int sendReports();
 }

bramble-api/src/main/java/org/briarproject/bramble/util/ValidationUtils.java

@@ -6,9 +6,7 @@ import org.briarproject.bramble.api.data.BdfList;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
 import javax.annotation.Nullable;
-import javax.annotation.concurrent.Immutable;
 
-@Immutable
 @NotNullByDefault
 public class ValidationUtils {
 
@@ -66,9 +64,4 @@ public class ValidationUtils {
 		if (dictionary != null && dictionary.size() != size)
 			throw new FormatException();
 	}
-
-	public static void checkRange(@Nullable Long l, long min, long max)
-			throws FormatException {
-		if (l != null && (l < min || l > max)) throw new FormatException();
-	}
 }

bramble-core/src/main/java/org/briarproject/bramble/client/ClientHelperImpl.java

@@ -2,13 +2,11 @@ package org.briarproject.bramble.client;
 
 import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.client.ClientHelper;
-import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.crypto.CryptoComponent;
 import org.briarproject.bramble.api.crypto.KeyParser;
 import org.briarproject.bramble.api.crypto.PrivateKey;
 import org.briarproject.bramble.api.crypto.PublicKey;
 import org.briarproject.bramble.api.data.BdfDictionary;
-import org.briarproject.bramble.api.data.BdfEntry;
 import org.briarproject.bramble.api.data.BdfList;
 import org.briarproject.bramble.api.data.BdfReader;
 import org.briarproject.bramble.api.data.BdfReaderFactory;
@@ -41,7 +39,6 @@ import java.util.Map.Entry;
 import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 
-import static org.briarproject.bramble.api.client.ContactGroupConstants.GROUP_KEY_CONTACT_ID;
 import static org.briarproject.bramble.api.identity.Author.FORMAT_VERSION;
 import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_AUTHOR_NAME_LENGTH;
 import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_PUBLIC_KEY_LENGTH;
@@ -392,27 +389,4 @@ class ClientHelperImpl implements ClientHelper {
 		return tpMap;
 	}
 
-	@Override
-	public ContactId getContactId(Transaction txn, GroupId contactGroupId)
-			throws DbException {
-		try {
-			BdfDictionary meta =
-					getGroupMetadataAsDictionary(txn, contactGroupId);
-			return new ContactId(meta.getLong(GROUP_KEY_CONTACT_ID).intValue());
-		} catch (FormatException e) {
-			throw new DbException(e); // Invalid group metadata
-		}
-	}
-
-	@Override
-	public void setContactId(Transaction txn, GroupId contactGroupId,
-			ContactId c) throws DbException {
-		BdfDictionary meta = BdfDictionary.of(
-				new BdfEntry(GROUP_KEY_CONTACT_ID, c.getInt()));
-		try {
-			mergeGroupMetadata(txn, contactGroupId, meta);
-		} catch (FormatException e) {
-			throw new AssertionError(e);
-		}
-	}
 }

bramble-core/src/main/java/org/briarproject/bramble/contact/PendingContactFactoryImpl.java

@@ -11,6 +11,7 @@ import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.util.Base32;
 
 import java.security.GeneralSecurityException;
+import java.util.Locale;
 import java.util.regex.Matcher;
 
 import javax.inject.Inject;
@@ -52,7 +53,7 @@ class PendingContactFactoryImpl implements PendingContactFactory {
 		byte[] raw = new byte[RAW_LINK_BYTES];
 		raw[0] = FORMAT_VERSION;
 		arraycopy(encoded, 0, raw, 1, encoded.length);
-		return "briar://" + Base32.encode(raw).toLowerCase();
+		return "briar://" + Base32.encode(raw).toLowerCase(Locale.US);
 	}
 
 	private PublicKey parseHandshakeLink(String link) throws FormatException {

bramble-core/src/main/java/org/briarproject/bramble/plugin/tor/TorPlugin.java

@@ -863,6 +863,7 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 			if (!state.isTorRunning()) return;
 			boolean online = status.isConnected();
 			boolean wifi = status.isWifi();
+			boolean ipv6Only = status.isIpv6Only();
 			String country = locationUtils.getCurrentCountry();
 			boolean blocked =
 					circumventionProvider.isTorProbablyBlocked(country);
@@ -879,7 +880,8 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 			boolean automatic = network == PREF_TOR_NETWORK_AUTOMATIC;
 
 			if (LOG.isLoggable(INFO)) {
-				LOG.info("Online: " + online + ", wifi: " + wifi);
+				LOG.info("Online: " + online + ", wifi: " + wifi
+						+ ", IPv6 only: " + ipv6Only);
 				if (country.isEmpty()) LOG.info("Country code unknown");
 				else LOG.info("Country code: " + country);
 				LOG.info("Charging: " + charging);
@@ -916,7 +918,8 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 					enableNetwork = true;
 					if (network == PREF_TOR_NETWORK_WITH_BRIDGES ||
 							(automatic && bridgesWork)) {
-						if (circumventionProvider.needsMeek(country)) {
+						if (ipv6Only ||
+								circumventionProvider.needsMeek(country)) {
 							LOG.info("Using meek bridges");
 							enableBridges = true;
 							useMeek = true;
@@ -942,6 +945,7 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 				if (enableNetwork) {
 					enableBridges(enableBridges, useMeek);
 					enableConnectionPadding(enableConnectionPadding);
+					useIpv6(ipv6Only);
 				}
 				enableNetwork(enableNetwork);
 			} catch (IOException e) {
@@ -954,6 +958,11 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		controlConnection.setConf("ConnectionPadding", enable ? "1" : "0");
 	}
 
+	private void useIpv6(boolean ipv6Only) throws IOException {
+		controlConnection.setConf("ClientUseIPv4", ipv6Only ? "0" : "1");
+		controlConnection.setConf("ClientUseIPv6", ipv6Only ? "1" : "0");
+	}
+
 	@ThreadSafe
 	@NotNullByDefault
 	protected class PluginState {

bramble-core/src/main/java/org/briarproject/bramble/reporting/DevReporterImpl.java

@@ -29,6 +29,7 @@ import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 import javax.net.SocketFactory;
 
+import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.util.IoUtils.tryToClose;
 
@@ -100,11 +101,12 @@ class DevReporterImpl implements DevReporter, EventListener {
 	}
 
 	@Override
-	public void sendReports() {
+	public int sendReports() {
 		File reportDir = devConfig.getReportDir();
 		File[] reports = reportDir.listFiles();
+		int reportsSent = 0;
 		if (reports == null || reports.length == 0)
-			return; // No reports to send
+			return reportsSent; // No reports to send
 
 		LOG.info("Sending reports to developers");
 		for (File f : reports) {
@@ -116,13 +118,15 @@ class DevReporterImpl implements DevReporter, EventListener {
 				in = new FileInputStream(f);
 				IoUtils.copyAndClose(in, out);
 				f.delete();
+				reportsSent++;
 			} catch (IOException e) {
 				LOG.log(WARNING, "Failed to send reports", e);
 				tryToClose(out, LOG, WARNING);
 				tryToClose(in, LOG, WARNING);
-				return;
+				return reportsSent;
 			}
 		}
-		LOG.info("Reports sent");
+		if (LOG.isLoggable(INFO)) LOG.info(reportsSent + " report(s) sent");
+		return reportsSent;
 	}
 }

bramble-core/src/main/java/org/briarproject/bramble/versioning/ClientVersioningConstants.java

@@ -5,5 +5,6 @@ interface ClientVersioningConstants {
 	// Metadata keys
 	String MSG_KEY_UPDATE_VERSION = "version";
 	String MSG_KEY_LOCAL = "local";
+	String GROUP_KEY_CONTACT_ID = "contactId";
 }
 

bramble-core/src/main/java/org/briarproject/bramble/versioning/ClientVersioningManagerImpl.java

@@ -50,6 +50,7 @@ import static java.util.Collections.emptyList;
 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.versioning.ClientVersioningConstants.GROUP_KEY_CONTACT_ID;
 import static org.briarproject.bramble.versioning.ClientVersioningConstants.MSG_KEY_LOCAL;
 import static org.briarproject.bramble.versioning.ClientVersioningConstants.MSG_KEY_UPDATE_VERSION;
 
@@ -160,7 +161,13 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 		db.addGroup(txn, g);
 		db.setGroupVisibility(txn, c.getId(), g.getId(), SHARED);
 		// Attach the contact ID to the group
-		clientHelper.setContactId(txn, g.getId(), c.getId());
+		BdfDictionary meta = new BdfDictionary();
+		meta.put(GROUP_KEY_CONTACT_ID, c.getId().getInt());
+		try {
+			clientHelper.mergeGroupMetadata(txn, g.getId(), meta);
+		} catch (FormatException e) {
+			throw new AssertionError(e);
+		}
 		// Create and store the first local update
 		List<ClientVersion> versions = new ArrayList<>(clients);
 		Collections.sort(versions);
@@ -222,7 +229,7 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 			Map<ClientMajorVersion, Visibility> after =
 					getVisibilities(newLocalStates, newRemoteStates);
 			// Call hooks for any visibilities that have changed
-			ContactId c = clientHelper.getContactId(txn, m.getGroupId());
+			ContactId c = getContactId(txn, m.getGroupId());
 			if (!before.equals(after)) {
 				Contact contact = db.getContact(txn, c);
 				callVisibilityHooks(txn, contact, before, after);
@@ -514,6 +521,17 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 		storeUpdate(txn, g, states, 1);
 	}
 
+	private ContactId getContactId(Transaction txn, GroupId g)
+			throws DbException {
+		try {
+			BdfDictionary meta =
+					clientHelper.getGroupMetadataAsDictionary(txn, g);
+			return new ContactId(meta.getLong(GROUP_KEY_CONTACT_ID).intValue());
+		} catch (FormatException e) {
+			throw new DbException(e);
+		}
+	}
+
 	private List<ClientState> updateStatesFromRemoteStates(
 			List<ClientState> oldLocalStates, List<ClientState> remoteStates) {
 		Set<ClientMajorVersion> remoteSet = new HashSet<>();

bramble-core/src/test/java/org/briarproject/bramble/versioning/ClientVersioningManagerImplTest.java

@@ -38,6 +38,7 @@ import static org.briarproject.bramble.test.TestUtils.getContact;
 import static org.briarproject.bramble.test.TestUtils.getGroup;
 import static org.briarproject.bramble.test.TestUtils.getMessage;
 import static org.briarproject.bramble.test.TestUtils.getRandomId;
+import static org.briarproject.bramble.versioning.ClientVersioningConstants.GROUP_KEY_CONTACT_ID;
 import static org.briarproject.bramble.versioning.ClientVersioningConstants.MSG_KEY_LOCAL;
 import static org.briarproject.bramble.versioning.ClientVersioningConstants.MSG_KEY_UPDATE_VERSION;
 import static org.junit.Assert.assertEquals;
@@ -59,6 +60,8 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 	private final ClientId clientId = getClientId();
 	private final long now = System.currentTimeMillis();
 	private final Transaction txn = new Transaction(null, false);
+	private final BdfDictionary groupMeta = BdfDictionary.of(
+			new BdfEntry(GROUP_KEY_CONTACT_ID, contact.getId().getInt()));
 
 	private ClientVersioningManagerImpl createInstance() {
 		context.checking(new Expectations() {{
@@ -120,8 +123,8 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 			oneOf(db).addGroup(txn, contactGroup);
 			oneOf(db).setGroupVisibility(txn, contact.getId(),
 					contactGroup.getId(), SHARED);
-			oneOf(clientHelper).setContactId(txn, contactGroup.getId(),
-					contact.getId());
+			oneOf(clientHelper).mergeGroupMetadata(txn, contactGroup.getId(),
+					groupMeta);
 			oneOf(clock).currentTimeMillis();
 			will(returnValue(now));
 			oneOf(clientHelper).createMessage(contactGroup.getId(), now,
@@ -457,8 +460,9 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 			oneOf(db).deleteMessage(txn, oldRemoteUpdateId);
 			oneOf(db).deleteMessageMetadata(txn, oldRemoteUpdateId);
 			// Get contact ID
-			oneOf(clientHelper).getContactId(txn, contactGroup.getId());
-			will(returnValue(contact.getId()));
+			oneOf(clientHelper).getGroupMetadataAsDictionary(txn,
+					contactGroup.getId());
+			will(returnValue(groupMeta));
 			// No states or visibilities have changed
 		}});
 
@@ -488,9 +492,10 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 			// Load the latest local update
 			oneOf(clientHelper).getMessageAsList(txn, oldLocalUpdateId);
 			will(returnValue(oldLocalUpdateBody));
-			// Get contact ID
-			oneOf(clientHelper).getContactId(txn, contactGroup.getId());
-			will(returnValue(contact.getId()));
+			// Get client ID
+			oneOf(clientHelper).getGroupMetadataAsDictionary(txn,
+					contactGroup.getId());
+			will(returnValue(groupMeta));
 			// No states or visibilities have changed
 		}});
 
@@ -541,6 +546,8 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 		BdfDictionary newLocalUpdateMeta = BdfDictionary.of(
 				new BdfEntry(MSG_KEY_UPDATE_VERSION, 2L),
 				new BdfEntry(MSG_KEY_LOCAL, true));
+		BdfDictionary groupMeta = BdfDictionary.of(
+				new BdfEntry(GROUP_KEY_CONTACT_ID, contact.getId().getInt()));
 
 		context.checking(new Expectations() {{
 			oneOf(clientHelper).toList(newRemoteUpdate);
@@ -570,8 +577,9 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 			oneOf(clientHelper).addLocalMessage(txn, newLocalUpdate,
 					newLocalUpdateMeta, true, false);
 			// The client's visibility has changed
-			oneOf(clientHelper).getContactId(txn, contactGroup.getId());
-			will(returnValue(contact.getId()));
+			oneOf(clientHelper).getGroupMetadataAsDictionary(txn,
+					contactGroup.getId());
+			will(returnValue(groupMeta));
 			oneOf(db).getContact(txn, contact.getId());
 			will(returnValue(contact));
 			oneOf(hook).onClientVisibilityChanging(txn, contact, visibility);
@@ -611,6 +619,8 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 		BdfDictionary newLocalUpdateMeta = BdfDictionary.of(
 				new BdfEntry(MSG_KEY_UPDATE_VERSION, 2L),
 				new BdfEntry(MSG_KEY_LOCAL, true));
+		BdfDictionary groupMeta = BdfDictionary.of(
+				new BdfEntry(GROUP_KEY_CONTACT_ID, contact.getId().getInt()));
 
 		context.checking(new Expectations() {{
 			oneOf(clientHelper).toList(newRemoteUpdate);
@@ -640,8 +650,9 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 			oneOf(clientHelper).addLocalMessage(txn, newLocalUpdate,
 					newLocalUpdateMeta, true, false);
 			// The client's visibility has changed
-			oneOf(clientHelper).getContactId(txn, contactGroup.getId());
-			will(returnValue(contact.getId()));
+			oneOf(clientHelper).getGroupMetadataAsDictionary(txn,
+					contactGroup.getId());
+			will(returnValue(groupMeta));
 			oneOf(db).getContact(txn, contact.getId());
 			will(returnValue(contact));
 			oneOf(hook).onClientVisibilityChanging(txn, contact, INVISIBLE);

bramble-java/src/main/java/org/briarproject/bramble/network/JavaNetworkManager.java

@@ -5,6 +5,8 @@ import org.briarproject.bramble.api.network.NetworkStatus;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 
+import java.net.Inet4Address;
+import java.net.InetAddress;
 import java.net.NetworkInterface;
 import java.net.SocketException;
 import java.util.Enumeration;
@@ -14,8 +16,8 @@ import javax.inject.Inject;
 
 import static java.net.NetworkInterface.getNetworkInterfaces;
 import static java.util.Collections.list;
-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.util.LogUtils.logException;
 
 @MethodsNotNullByDefault
@@ -23,7 +25,7 @@ import static org.briarproject.bramble.util.LogUtils.logException;
 class JavaNetworkManager implements NetworkManager {
 
 	private static final Logger LOG =
-			Logger.getLogger(JavaNetworkManager.class.getName());
+			getLogger(JavaNetworkManager.class.getName());
 
 	@Inject
 	JavaNetworkManager() {
@@ -31,26 +33,28 @@ class JavaNetworkManager implements NetworkManager {
 
 	@Override
 	public NetworkStatus getNetworkStatus() {
-		boolean connected = false;
+		boolean connected = false, hasIpv4 = false, hasIpv6Unicast = false;
 		try {
 			Enumeration<NetworkInterface> interfaces = getNetworkInterfaces();
-			if (interfaces != null) {
+			if (interfaces == null) {
+				LOG.info("No network interfaces");
+			} else {
 				for (NetworkInterface i : list(interfaces)) {
-					if (i.isLoopback()) continue;
-					if (i.isUp() && i.getInetAddresses().hasMoreElements()) {
-						if (LOG.isLoggable(INFO)) {
-							LOG.info("Interface " + i.getDisplayName() +
-									" is up with at least one address.");
-						}
+					if (i.isLoopback() || !i.isUp()) continue;
+					for (InetAddress addr : list(i.getInetAddresses())) {
 						connected = true;
-						break;
+						if (addr instanceof Inet4Address) {
+							hasIpv4 = true;
+						} else if (!addr.isMulticastAddress()) {
+							hasIpv6Unicast = true;
+						}
 					}
 				}
 			}
 		} catch (SocketException e) {
 			logException(LOG, WARNING, e);
 		}
-		return new NetworkStatus(connected, false);
+		return new NetworkStatus(connected, false, !hasIpv4 && hasIpv6Unicast);
 	}
 
 }

briar-android/build.gradle

@@ -100,7 +100,6 @@ dependencies {
 	implementation 'com.google.android.material:material:1.2.1'
 	implementation 'androidx.recyclerview:recyclerview-selection:1.1.0-rc03'
 
-	implementation 'ch.acra:acra:4.11'
 	implementation 'info.guardianproject.panic:panic:1.0'
 	implementation 'info.guardianproject.trustedintents:trustedintents:0.2'
 	implementation 'de.hdodenhof:circleimageview:3.0.1'
@@ -127,10 +126,11 @@ dependencies {
 	testImplementation 'androidx.test:runner:1.3.0'
 	testImplementation 'androidx.test.ext:junit:1.1.2'
 	testImplementation 'androidx.fragment:fragment-testing:1.2.5'
+	testImplementation "androidx.arch.core:core-testing:2.1.0"
 	testImplementation "androidx.test.espresso:espresso-core:$espressoVersion"
 	testImplementation 'org.robolectric:robolectric:4.3.1'
 	testImplementation 'org.mockito:mockito-core:3.1.0'
-	testImplementation 'junit:junit:4.12'
+	testImplementation 'junit:junit:4.13.1'
 	testImplementation "org.jmock:jmock:$jmockVersion"
 	testImplementation "org.jmock:jmock-junit4:$jmockVersion"
 	testImplementation "org.jmock:jmock-legacy:$jmockVersion"

briar-android/src/main/AndroidManifest.xml

@@ -65,30 +65,43 @@
 
 		<service
 			android:name="org.briarproject.briar.android.NotificationCleanupService"
-			android:exported="false"></service>
+			android:exported="false" />
 
 		<activity
-			android:name="org.briarproject.briar.android.reporting.DevReportActivity"
+			android:name="org.briarproject.briar.android.reporting.CrashReportActivity"
 			android:excludeFromRecents="true"
 			android:exported="false"
 			android:finishOnTaskLaunch="true"
 			android:label="@string/crash_report_title"
 			android:launchMode="singleInstance"
+			android:process=":briar_error_handler"
 			android:theme="@style/BriarTheme.NoActionBar"
-			android:windowSoftInputMode="adjustResize|stateHidden"></activity>
+			android:windowSoftInputMode="adjustResize|stateHidden" />
+
+		<activity
+			android:name="org.briarproject.briar.android.reporting.FeedbackActivity"
+			android:exported="false"
+			android:label="@string/feedback_title"
+			android:parentActivityName="org.briarproject.briar.android.settings.SettingsActivity"
+			android:theme="@style/BriarTheme.NoActionBar"
+			android:windowSoftInputMode="adjustResize|stateHidden">
+			<meta-data
+				android:name="android.support.PARENT_ACTIVITY"
+				android:value="org.briarproject.briar.android.settings.SettingsActivity" />
+		</activity>
 
 		<activity
 			android:name="org.briarproject.briar.android.splash.ExpiredActivity"
-			android:label="@string/app_name"></activity>
+			android:label="@string/app_name" />
 
 		<activity
 			android:name="org.briarproject.briar.android.login.StartupActivity"
-			android:label="@string/app_name"></activity>
+			android:label="@string/app_name" />
 
 		<activity
 			android:name="org.briarproject.briar.android.account.SetupActivity"
 			android:label="@string/setup_title"
-			android:windowSoftInputMode="adjustResize|stateAlwaysVisible"></activity>
+			android:windowSoftInputMode="adjustResize|stateAlwaysVisible" />
 
 		<activity
 			android:name="org.briarproject.briar.android.splash.SplashScreenActivity"
@@ -141,16 +154,6 @@
 				android:value="org.briarproject.briar.android.conversation.ConversationActivity" />
 		</activity>
 
-		<activity
-			android:name=".android.conversation.ConversationSettingsActivity"
-			android:parentActivityName="org.briarproject.briar.android.conversation.ConversationActivity"
-			android:label="@string/disappearing_messages_title"
-			android:theme="@style/BriarTheme">
-			<meta-data
-				android:name="android.support.PARENT_ACTIVITY"
-				android:value="org.briarproject.briar.android.conversation.ConversationActivity" />
-		</activity>
-
 		<activity
 			android:name="org.briarproject.briar.android.privategroup.creation.CreateGroupActivity"
 			android:label="@string/groups_create_group_title"
@@ -356,7 +359,7 @@
 
 		<activity
 			android:name="org.briarproject.briar.android.StartupFailureActivity"
-			android:label="@string/startup_failed_activity_title"></activity>
+			android:label="@string/startup_failed_activity_title" />
 
 		<activity
 			android:name="org.briarproject.briar.android.settings.SettingsActivity"
@@ -422,11 +425,11 @@
 
 		<activity
 			android:name="org.briarproject.briar.android.logout.ExitActivity"
-			android:theme="@android:style/Theme.NoDisplay"></activity>
+			android:theme="@android:style/Theme.NoDisplay" />
 
 		<activity
 			android:name=".android.logout.HideUiActivity"
-			android:theme="@android:style/Theme.NoDisplay"></activity>
+			android:theme="@android:style/Theme.NoDisplay" />
 
 		<activity
 			android:name=".android.account.UnlockActivity"
@@ -446,4 +449,27 @@
 			android:theme="@style/BriarTheme" />
 
 	</application>
+
+	<queries>
+		<package android:name="info.guardianproject.ripple" />
+		<package android:name="com.huawei.systemmanager" />
+
+		<intent>
+			<action android:name="android.intent.action.VIEW" />
+			<data android:scheme="https" />
+		</intent>
+		<intent>
+			<action android:name="android.intent.action.VIEW" />
+			<data android:scheme="http" />
+		</intent>
+		<!-- white-listing the intents below does not seem necessary,
+		but they are still included in case modified Android versions require it -->
+		<intent>
+			<action android:name="android.bluetooth.adapter.action.REQUEST_DISCOVERABLE" />
+		</intent>
+		<intent>
+			<action android:name="android.settings.CHANNEL_NOTIFICATION_SETTINGS" />
+		</intent>
+	</queries>
+
 </manifest>

briar-android/src/main/java/org/briarproject/briar/android/AndroidComponent.java

@@ -34,13 +34,11 @@ import org.briarproject.briar.BriarCoreModule;
 import org.briarproject.briar.android.attachment.AttachmentModule;
 import org.briarproject.briar.android.conversation.glide.BriarModelLoader;
 import org.briarproject.briar.android.login.SignInReminderReceiver;
-import org.briarproject.briar.android.reporting.BriarReportSender;
 import org.briarproject.briar.android.view.EmojiTextInputView;
 import org.briarproject.briar.api.android.AndroidNotificationManager;
 import org.briarproject.briar.api.android.DozeWatchdog;
 import org.briarproject.briar.api.android.LockManager;
 import org.briarproject.briar.api.android.ScreenFilterMonitor;
-import org.briarproject.briar.api.autodelete.AutoDeleteManager;
 import org.briarproject.briar.api.blog.BlogManager;
 import org.briarproject.briar.api.blog.BlogPostFactory;
 import org.briarproject.briar.api.blog.BlogSharingManager;
@@ -88,6 +86,8 @@ public interface AndroidComponent
 	@DatabaseExecutor
 	Executor databaseExecutor();
 
+	TransactionManager transactionManager();
+
 	MessageTracker messageTracker();
 
 	LifecycleManager lifecycleManager();
@@ -171,16 +171,10 @@ public interface AndroidComponent
 
 	AndroidWakeLockManager wakeLockManager();
 
-	TransactionManager transactionManager();
-
-	AutoDeleteManager autoDeleteManager();
-
 	void inject(SignInReminderReceiver briarService);
 
 	void inject(BriarService briarService);
 
-	void inject(BriarReportSender briarReportSender);
-
 	void inject(NotificationCleanupService notificationCleanupService);
 
 	void inject(EmojiTextInputView textInputView);

briar-android/src/main/java/org/briarproject/briar/android/AndroidNotificationManagerImpl.java

@@ -109,7 +109,8 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 	@Nullable
 	private GroupId blockedGroup = null;
 	private boolean blockSignInReminder = false;
-	private boolean blockBlogs = false;
+	private boolean blockForums = false, blockGroups = false,
+			blockBlogs = false;
 	private long lastSound = 0;
 
 	private volatile Settings settings = new Settings();
@@ -223,8 +224,8 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 			if (s.getNamespace().equals(SETTINGS_NAMESPACE))
 				settings = s.getSettings();
 		} else if (e instanceof ConversationMessageReceivedEvent) {
-			ConversationMessageReceivedEvent p =
-					(ConversationMessageReceivedEvent) e;
+			ConversationMessageReceivedEvent<?> p =
+					(ConversationMessageReceivedEvent<?>) e;
 			showContactNotification(p.getContactId());
 		} else if (e instanceof GroupMessageAddedEvent) {
 			GroupMessageAddedEvent g = (GroupMessageAddedEvent) e;
@@ -385,6 +386,7 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 
 	@UiThread
 	private void showGroupMessageNotification(GroupId g) {
+		if (blockGroups) return;
 		if (g.equals(blockedGroup)) return;
 		groupCounts.add(g);
 		updateGroupMessageNotification(true);
@@ -452,6 +454,7 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 
 	@UiThread
 	private void showForumPostNotification(GroupId g) {
+		if (blockForums) return;
 		if (g.equals(blockedGroup)) return;
 		forumCounts.add(g);
 		updateForumPostNotification(true);
@@ -681,6 +684,26 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 		});
 	}
 
+	@Override
+	public void blockAllForumPostNotifications() {
+		androidExecutor.runOnUiThread((Runnable) () -> blockForums = true);
+	}
+
+	@Override
+	public void unblockAllForumPostNotifications() {
+		androidExecutor.runOnUiThread((Runnable) () -> blockForums = false);
+	}
+
+	@Override
+	public void blockAllGroupMessageNotifications() {
+		androidExecutor.runOnUiThread((Runnable) () -> blockGroups = true);
+	}
+
+	@Override
+	public void unblockAllGroupMessageNotifications() {
+		androidExecutor.runOnUiThread((Runnable) () -> blockGroups = false);
+	}
+
 	@Override
 	public void blockAllBlogPostNotifications() {
 		androidExecutor.runOnUiThread((Runnable) () -> blockBlogs = true);

briar-android/src/main/java/org/briarproject/briar/android/AppModule.java

@@ -28,9 +28,12 @@ import org.briarproject.bramble.plugin.tor.AndroidTorPluginFactory;
 import org.briarproject.bramble.util.AndroidUtils;
 import org.briarproject.bramble.util.StringUtils;
 import org.briarproject.briar.android.account.LockManagerImpl;
+import org.briarproject.briar.android.forum.ForumModule;
 import org.briarproject.briar.android.keyagreement.ContactExchangeModule;
 import org.briarproject.briar.android.login.LoginModule;
 import org.briarproject.briar.android.navdrawer.NavDrawerModule;
+import org.briarproject.briar.android.privategroup.list.GroupListModule;
+import org.briarproject.briar.android.reporting.DevReportModule;
 import org.briarproject.briar.android.viewmodel.ViewModelModule;
 import org.briarproject.briar.api.android.AndroidNotificationManager;
 import org.briarproject.briar.api.android.DozeWatchdog;
@@ -63,7 +66,11 @@ import static org.briarproject.briar.android.TestingConstants.IS_DEBUG_BUILD;
 		ContactExchangeModule.class,
 		LoginModule.class,
 		NavDrawerModule.class,
-		ViewModelModule.class
+		ViewModelModule.class,
+		DevReportModule.class,
+		// below need to be within same scope as ViewModelProvider.Factory
+		ForumModule.BindsModule.class,
+		GroupListModule.class,
 })
 public class AppModule {
 
@@ -196,7 +203,10 @@ public class AppModule {
 	ScreenFilterMonitor provideScreenFilterMonitor(
 			LifecycleManager lifecycleManager,
 			ScreenFilterMonitorImpl screenFilterMonitor) {
-		lifecycleManager.registerService(screenFilterMonitor);
+		if (SDK_INT <= 29) {
+			// this keeps track of installed apps and does not work on API 30+
+			lifecycleManager.registerService(screenFilterMonitor);
+		}
 		return screenFilterMonitor;
 	}
 

briar-android/src/main/java/org/briarproject/briar/android/BriarApplicationImpl.java

@@ -14,19 +14,13 @@ import android.preference.PreferenceManager;
 import com.vanniktech.emoji.EmojiManager;
 import com.vanniktech.emoji.google.GoogleEmojiProvider;
 
-import org.acra.ACRA;
-import org.acra.ReportingInteractionMode;
-import org.acra.annotation.ReportsCrashes;
 import org.briarproject.bramble.BrambleAndroidEagerSingletons;
 import org.briarproject.bramble.BrambleAppComponent;
 import org.briarproject.bramble.BrambleCoreEagerSingletons;
 import org.briarproject.briar.BriarCoreEagerSingletons;
-import org.briarproject.briar.BuildConfig;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.logging.CachingLogHandler;
-import org.briarproject.briar.android.reporting.BriarReportPrimer;
-import org.briarproject.briar.android.reporting.BriarReportSenderFactory;
-import org.briarproject.briar.android.reporting.DevReportActivity;
+import org.briarproject.briar.android.reporting.BriarExceptionHandler;
 import org.briarproject.briar.android.util.UiUtils;
 
 import java.util.Collection;
@@ -34,50 +28,14 @@ import java.util.logging.Handler;
 import java.util.logging.LogRecord;
 import java.util.logging.Logger;
 
+import androidx.annotation.NonNull;
+
 import static android.app.ActivityManager.RunningAppProcessInfo.IMPORTANCE_FOREGROUND;
 import static java.util.logging.Level.FINE;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Logger.getLogger;
-import static org.acra.ReportField.ANDROID_VERSION;
-import static org.acra.ReportField.APP_VERSION_CODE;
-import static org.acra.ReportField.APP_VERSION_NAME;
-import static org.acra.ReportField.BRAND;
-import static org.acra.ReportField.BUILD_CONFIG;
-import static org.acra.ReportField.CRASH_CONFIGURATION;
-import static org.acra.ReportField.CUSTOM_DATA;
-import static org.acra.ReportField.DEVICE_FEATURES;
-import static org.acra.ReportField.DISPLAY;
-import static org.acra.ReportField.INITIAL_CONFIGURATION;
-import static org.acra.ReportField.PACKAGE_NAME;
-import static org.acra.ReportField.PHONE_MODEL;
-import static org.acra.ReportField.PRODUCT;
-import static org.acra.ReportField.REPORT_ID;
-import static org.acra.ReportField.STACK_TRACE;
-import static org.acra.ReportField.USER_APP_START_DATE;
-import static org.acra.ReportField.USER_CRASH_DATE;
 import static org.briarproject.briar.android.TestingConstants.IS_DEBUG_BUILD;
 
-@ReportsCrashes(
-		reportPrimerClass = BriarReportPrimer.class,
-		logcatArguments = {"-d", "-v", "time", "*:I"},
-		reportSenderFactoryClasses = {BriarReportSenderFactory.class},
-		mode = ReportingInteractionMode.DIALOG,
-		reportDialogClass = DevReportActivity.class,
-		resDialogOkToast = R.string.dev_report_saved,
-		deleteOldUnsentReportsOnApplicationStart = false,
-		buildConfigClass = BuildConfig.class,
-		customReportContent = {
-				REPORT_ID,
-				APP_VERSION_CODE, APP_VERSION_NAME, PACKAGE_NAME,
-				PHONE_MODEL, ANDROID_VERSION, BRAND, PRODUCT,
-				BUILD_CONFIG,
-				CUSTOM_DATA,
-				STACK_TRACE,
-				INITIAL_CONFIGURATION, CRASH_CONFIGURATION,
-				DISPLAY, DEVICE_FEATURES,
-				USER_APP_START_DATE, USER_CRASH_DATE
-		}
-)
 public class BriarApplicationImpl extends Application
 		implements BriarApplication {
 
@@ -85,12 +43,15 @@ public class BriarApplicationImpl extends Application
 			getLogger(BriarApplicationImpl.class.getName());
 
 	private final CachingLogHandler logHandler = new CachingLogHandler();
+	private final BriarExceptionHandler exceptionHandler =
+			new BriarExceptionHandler(this);
 
 	private AndroidComponent applicationComponent;
 	private volatile SharedPreferences prefs;
 
 	@Override
 	protected void attachBaseContext(Context base) {
+		Thread.setDefaultUncaughtExceptionHandler(exceptionHandler);
 		if (prefs == null)
 			prefs = PreferenceManager.getDefaultSharedPreferences(base);
 		// Loading the language needs to be done here.
@@ -98,7 +59,6 @@ public class BriarApplicationImpl extends Application
 		super.attachBaseContext(
 				Localizer.getInstance().setLocale(base));
 		setTheme(base, prefs);
-		ACRA.init(this);
 	}
 
 	@Override
@@ -144,7 +104,7 @@ public class BriarApplicationImpl extends Application
 	}
 
 	@Override
-	public void onConfigurationChanged(Configuration newConfig) {
+	public void onConfigurationChanged(@NonNull Configuration newConfig) {
 		super.onConfigurationChanged(newConfig);
 		Localizer.getInstance().setLocale(this);
 	}

briar-android/src/main/java/org/briarproject/briar/android/ScreenFilterMonitorImpl.java

@@ -58,7 +58,7 @@ class ScreenFilterMonitorImpl implements ScreenFilterMonitor, Service {
 			Logger.getLogger(ScreenFilterMonitorImpl.class.getName());
 
 	/*
- 	 * Ignore Play Services if it uses this package name and public key - it's
+	 * Ignore Play Services if it uses this package name and public key - it's
 	 * effectively a system app, but not flagged as such on older systems
 	 */
 	private static final String PLAY_SERVICES_PACKAGE =
@@ -108,7 +108,7 @@ class ScreenFilterMonitorImpl implements ScreenFilterMonitor, Service {
 		Set<String> allowed = prefs.getStringSet(PREF_KEY_ALLOWED,
 				Collections.emptySet());
 		List<AppDetails> apps = new ArrayList<>();
-		List<PackageInfo> packageInfos =
+		@SuppressLint("QueryPermissionsNeeded") List<PackageInfo> packageInfos =
 				pm.getInstalledPackages(GET_PERMISSIONS);
 		for (PackageInfo packageInfo : packageInfos) {
 			if (!allowed.contains(packageInfo.packageName)

briar-android/src/main/java/org/briarproject/briar/android/activity/ActivityComponent.java

@@ -28,8 +28,6 @@ import org.briarproject.briar.android.contact.add.remote.NicknameFragment;
 import org.briarproject.briar.android.contact.add.remote.PendingContactListActivity;
 import org.briarproject.briar.android.conversation.AliasDialogFragment;
 import org.briarproject.briar.android.conversation.ConversationActivity;
-import org.briarproject.briar.android.conversation.ConversationSettingsActivity;
-import org.briarproject.briar.android.conversation.ConversationSettingsFragment;
 import org.briarproject.briar.android.conversation.ImageActivity;
 import org.briarproject.briar.android.conversation.ImageFragment;
 import org.briarproject.briar.android.forum.CreateForumActivity;
@@ -62,12 +60,14 @@ import org.briarproject.briar.android.privategroup.creation.GroupInviteFragment;
 import org.briarproject.briar.android.privategroup.invitation.GroupInvitationActivity;
 import org.briarproject.briar.android.privategroup.invitation.GroupInvitationModule;
 import org.briarproject.briar.android.privategroup.list.GroupListFragment;
-import org.briarproject.briar.android.privategroup.list.GroupListModule;
 import org.briarproject.briar.android.privategroup.memberlist.GroupMemberListActivity;
 import org.briarproject.briar.android.privategroup.memberlist.GroupMemberModule;
 import org.briarproject.briar.android.privategroup.reveal.GroupRevealModule;
 import org.briarproject.briar.android.privategroup.reveal.RevealContactsActivity;
 import org.briarproject.briar.android.privategroup.reveal.RevealContactsFragment;
+import org.briarproject.briar.android.reporting.CrashFragment;
+import org.briarproject.briar.android.reporting.CrashReportActivity;
+import org.briarproject.briar.android.reporting.ReportFormFragment;
 import org.briarproject.briar.android.settings.SettingsActivity;
 import org.briarproject.briar.android.settings.SettingsFragment;
 import org.briarproject.briar.android.sharing.BlogInvitationActivity;
@@ -93,7 +93,6 @@ import dagger.Component;
 		ForumModule.class,
 		GroupInvitationModule.class,
 		GroupConversationModule.class,
-		GroupListModule.class,
 		GroupMemberModule.class,
 		GroupRevealModule.class,
 		SharingModule.class
@@ -186,7 +185,7 @@ public interface ActivityComponent {
 
 	void inject(PendingContactListActivity activity);
 
-	void inject(ConversationSettingsActivity activity);
+	void inject(CrashReportActivity crashReportActivity);
 
 	// Fragments
 
@@ -238,6 +237,8 @@ public interface ActivityComponent {
 
 	void inject(ImageFragment imageFragment);
 
-	void inject(ConversationSettingsFragment conversationSettingsFragment);
+	void inject(ReportFormFragment reportFormFragment);
+
+	void inject(CrashFragment crashFragment);
 
 }

briar-android/src/main/java/org/briarproject/briar/android/activity/BaseActivity.java

@@ -6,7 +6,6 @@ import android.view.View;
 import android.view.ViewGroup;
 import android.view.ViewGroup.LayoutParams;
 
-import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.briar.R;
@@ -18,7 +17,6 @@ import org.briarproject.briar.android.controller.ActivityLifecycleController;
 import org.briarproject.briar.android.forum.ForumModule;
 import org.briarproject.briar.android.fragment.BaseFragment;
 import org.briarproject.briar.android.fragment.ScreenFilterDialogFragment;
-import org.briarproject.briar.android.reporting.DevReportActivity;
 import org.briarproject.briar.android.util.UiUtils;
 import org.briarproject.briar.android.widget.TapSafeFrameLayout;
 import org.briarproject.briar.android.widget.TapSafeFrameLayout.OnTapFilteredListener;
@@ -40,9 +38,11 @@ import androidx.appcompat.widget.Toolbar;
 import androidx.fragment.app.Fragment;
 import androidx.fragment.app.FragmentManager;
 
+import static android.os.Build.VERSION.SDK_INT;
 import static android.view.ViewGroup.LayoutParams.MATCH_PARENT;
 import static android.view.WindowManager.LayoutParams.FLAG_SECURE;
 import static androidx.lifecycle.Lifecycle.State.STARTED;
+import static java.util.Collections.emptyList;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.briar.android.TestingConstants.PREVENT_SCREENSHOTS;
@@ -50,7 +50,6 @@ import static org.briarproject.briar.android.util.UiUtils.hideSoftKeyboard;
 
 /**
  * Warning: Some activities don't extend {@link BaseActivity}.
- *          E.g. {@link DevReportActivity}
  */
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
@@ -123,6 +122,7 @@ public abstract class BaseActivity extends AppCompatActivity
 		return new ActivityModule(this);
 	}
 
+	// TODO use a test module where this is used in tests
 	protected ForumModule getForumModule() {
 		return new ForumModule();
 	}
@@ -202,9 +202,15 @@ public abstract class BaseActivity extends AppCompatActivity
 		// If the dialog is already visible, filter the tap
 		ScreenFilterDialogFragment f = findDialogFragment();
 		if (f != null && f.isVisible()) return false;
-		Collection<AppDetails> apps = screenFilterMonitor.getApps();
-		// If all overlay apps have been allowed, allow the tap
-		if (apps.isEmpty()) return true;
+		Collection<AppDetails> apps;
+		// querying all apps is only possible at API 29 and below
+		if (SDK_INT <= 29) {
+			apps = screenFilterMonitor.getApps();
+			// If all overlay apps have been allowed, allow the tap
+			if (apps.isEmpty()) return true;
+		} else {
+			apps = emptyList();
+		}
 		// Show dialog unless onSaveInstanceState() has been called, see #1112
 		FragmentManager fm = getSupportFragmentManager();
 		if (!fm.isStateSaved()) {
@@ -241,7 +247,7 @@ public abstract class BaseActivity extends AppCompatActivity
 	}
 
 	@UiThread
-	public void handleDbException(DbException e) {
+	public void handleException(Exception e) {
 		supportFinishAfterTransition();
 	}
 
@@ -266,7 +272,12 @@ public abstract class BaseActivity extends AppCompatActivity
 	private void protectToolbar() {
 		findToolbar();
 		if (toolbar != null) {
-			boolean filter = !screenFilterMonitor.getApps().isEmpty();
+			boolean filter;
+			if (SDK_INT <= 29) {
+				filter = !screenFilterMonitor.getApps().isEmpty();
+			} else {
+				filter = true;
+			}
 			UiUtils.setFilterTouchesWhenObscured(toolbar, filter);
 		}
 	}

briar-android/src/main/java/org/briarproject/briar/android/activity/BriarActivity.java

@@ -129,10 +129,6 @@ public abstract class BriarActivity extends BaseActivity {
 		lockManager.onActivityStop();
 	}
 
-	protected boolean signedIn() {
-		return briarController.accountSignedIn();
-	}
-
 	/**
 	 * Sets the transition animations.
 	 *

briar-android/src/main/java/org/briarproject/briar/android/blog/BlogFragment.java

@@ -232,7 +232,7 @@ public class BlogFragment extends BaseFragment
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						handleDbException(exception);
+						handleException(exception);
 					}
 				}
 		);
@@ -277,7 +277,7 @@ public class BlogFragment extends BaseFragment
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						handleDbException(exception);
+						handleException(exception);
 					}
 				});
 	}
@@ -296,7 +296,7 @@ public class BlogFragment extends BaseFragment
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						handleDbException(exception);
+						handleException(exception);
 					}
 				});
 	}
@@ -318,7 +318,7 @@ public class BlogFragment extends BaseFragment
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						handleDbException(exception);
+						handleException(exception);
 					}
 				});
 	}
@@ -398,7 +398,7 @@ public class BlogFragment extends BaseFragment
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						handleDbException(exception);
+						handleException(exception);
 					}
 				});
 	}

briar-android/src/main/java/org/briarproject/briar/android/blog/BlogPostFragment.java

@@ -58,7 +58,7 @@ public class BlogPostFragment extends BasePostFragment implements BlogListener {
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						handleDbException(exception);
+						handleException(exception);
 					}
 				});
 	}

briar-android/src/main/java/org/briarproject/briar/android/blog/FeedFragment.java

@@ -156,7 +156,7 @@ public class FeedFragment extends BaseFragment implements
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						handleDbException(exception);
+						handleException(exception);
 					}
 				});
 	}
@@ -187,7 +187,7 @@ public class FeedFragment extends BaseFragment implements
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						handleDbException(exception);
+						handleException(exception);
 					}
 				});
 	}
@@ -242,7 +242,7 @@ public class FeedFragment extends BaseFragment implements
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						handleDbException(exception);
+						handleException(exception);
 					}
 				}
 		);

briar-android/src/main/java/org/briarproject/briar/android/blog/FeedPostFragment.java

@@ -79,7 +79,7 @@ public class FeedPostFragment extends BasePostFragment {
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						handleDbException(exception);
+						handleException(exception);
 					}
 				});
 	}

briar-android/src/main/java/org/briarproject/briar/android/blog/ReblogFragment.java

@@ -101,7 +101,7 @@ public class ReblogFragment extends BaseFragment implements SendListener {
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						handleDbException(exception);
+						handleException(exception);
 					}
 				});
 
@@ -128,7 +128,7 @@ public class ReblogFragment extends BaseFragment implements SendListener {
 				new UiExceptionHandler<DbException>(this) {
 					@Override
 					public void onExceptionUi(DbException exception) {
-						handleDbException(exception);
+						handleException(exception);
 					}
 				});
 		finish();

briar-android/src/main/java/org/briarproject/briar/android/contact/add/remote/AddContactViewModel.java

@@ -9,7 +9,11 @@ import org.briarproject.bramble.api.contact.PendingContact;
 import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.NoSuchPendingContactException;
+import org.briarproject.bramble.api.db.TransactionManager;
+import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.system.AndroidExecutor;
+import org.briarproject.briar.android.viewmodel.DbViewModel;
 import org.briarproject.briar.android.viewmodel.LiveEvent;
 import org.briarproject.briar.android.viewmodel.LiveResult;
 import org.briarproject.briar.android.viewmodel.MutableLiveEvent;
@@ -21,7 +25,6 @@ import java.util.logging.Logger;
 import javax.inject.Inject;
 
 import androidx.annotation.Nullable;
-import androidx.lifecycle.AndroidViewModel;
 import androidx.lifecycle.LiveData;
 import androidx.lifecycle.MutableLiveData;
 
@@ -31,14 +34,12 @@ import static org.briarproject.bramble.api.contact.HandshakeLinkConstants.LINK_R
 import static org.briarproject.bramble.util.LogUtils.logException;
 
 @NotNullByDefault
-public class AddContactViewModel extends AndroidViewModel {
+public class AddContactViewModel extends DbViewModel {
 
 	private final static Logger LOG =
 			getLogger(AddContactViewModel.class.getName());
 
 	private final ContactManager contactManager;
-	@DatabaseExecutor
-	private final Executor dbExecutor;
 
 	private final MutableLiveData<String> handshakeLink =
 			new MutableLiveData<>();
@@ -52,10 +53,12 @@ public class AddContactViewModel extends AndroidViewModel {
 	@Inject
 	AddContactViewModel(Application application,
 			ContactManager contactManager,
-			@DatabaseExecutor Executor dbExecutor) {
-		super(application);
+			@DatabaseExecutor Executor dbExecutor,
+			LifecycleManager lifecycleManager,
+			TransactionManager db,
+			AndroidExecutor androidExecutor) {
+		super(application, dbExecutor, lifecycleManager, db, androidExecutor);
 		this.contactManager = contactManager;
-		this.dbExecutor = dbExecutor;
 	}
 
 	void onCreate() {
@@ -63,7 +66,7 @@ public class AddContactViewModel extends AndroidViewModel {
 	}
 
 	private void loadHandshakeLink() {
-		dbExecutor.execute(() -> {
+		runOnDbThread(() -> {
 			try {
 				handshakeLink.postValue(contactManager.getHandshakeLink());
 			} catch (DbException e) {
@@ -102,7 +105,7 @@ public class AddContactViewModel extends AndroidViewModel {
 
 	void addContact(String nickname) {
 		if (remoteHandshakeLink == null) throw new IllegalStateException();
-		dbExecutor.execute(() -> {
+		runOnDbThread(() -> {
 			try {
 				contactManager.addPendingContact(remoteHandshakeLink, nickname);
 				addContactResult.postValue(new LiveResult<>(true));
@@ -122,11 +125,11 @@ public class AddContactViewModel extends AndroidViewModel {
 	}
 
 	public void updatePendingContact(String name, PendingContact p) {
-		dbExecutor.execute(() -> {
+		runOnDbThread(() -> {
 			try {
 				contactManager.removePendingContact(p.getId());
 				addContact(name);
-			} catch(NoSuchPendingContactException e) {
+			} catch (NoSuchPendingContactException e) {
 				logException(LOG, WARNING, e);
 				// no error in UI as pending contact was converted into contact
 			} catch (DbException e) {

briar-android/src/main/java/org/briarproject/briar/android/contact/add/remote/PendingContactListViewModel.java

@@ -11,12 +11,16 @@ import org.briarproject.bramble.api.contact.event.PendingContactRemovedEvent;
 import org.briarproject.bramble.api.contact.event.PendingContactStateChangedEvent;
 import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.db.DbException;
+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.LifecycleManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.rendezvous.RendezvousPoller;
 import org.briarproject.bramble.api.rendezvous.event.RendezvousPollEvent;
+import org.briarproject.bramble.api.system.AndroidExecutor;
+import org.briarproject.briar.android.viewmodel.DbViewModel;
 
 import java.util.ArrayList;
 import java.util.Collection;
@@ -26,7 +30,6 @@ import java.util.logging.Logger;
 
 import javax.inject.Inject;
 
-import androidx.lifecycle.AndroidViewModel;
 import androidx.lifecycle.LiveData;
 import androidx.lifecycle.MutableLiveData;
 
@@ -36,14 +39,12 @@ import static org.briarproject.bramble.api.contact.PendingContactState.OFFLINE;
 import static org.briarproject.bramble.util.LogUtils.logException;
 
 @NotNullByDefault
-public class PendingContactListViewModel extends AndroidViewModel
+public class PendingContactListViewModel extends DbViewModel
 		implements EventListener {
 
 	private final Logger LOG =
 			getLogger(PendingContactListViewModel.class.getName());
 
-	@DatabaseExecutor
-	private final Executor dbExecutor;
 	private final ContactManager contactManager;
 	private final RendezvousPoller rendezvousPoller;
 	private final EventBus eventBus;
@@ -56,11 +57,13 @@ public class PendingContactListViewModel extends AndroidViewModel
 	@Inject
 	PendingContactListViewModel(Application application,
 			@DatabaseExecutor Executor dbExecutor,
+			LifecycleManager lifecycleManager,
+			TransactionManager db,
+			AndroidExecutor androidExecutor,
 			ContactManager contactManager,
 			RendezvousPoller rendezvousPoller,
 			EventBus eventBus) {
-		super(application);
-		this.dbExecutor = dbExecutor;
+		super(application, dbExecutor, lifecycleManager, db, androidExecutor);
 		this.contactManager = contactManager;
 		this.rendezvousPoller = rendezvousPoller;
 		this.eventBus = eventBus;
@@ -87,7 +90,7 @@ public class PendingContactListViewModel extends AndroidViewModel
 	}
 
 	private void loadPendingContacts() {
-		dbExecutor.execute(() -> {
+		runOnDbThread(() -> {
 			try {
 				Collection<Pair<PendingContact, PendingContactState>> pairs =
 						contactManager.getPendingContacts();
@@ -113,7 +116,7 @@ public class PendingContactListViewModel extends AndroidViewModel
 	}
 
 	void removePendingContact(PendingContactId id) {
-		dbExecutor.execute(() -> {
+		runOnDbThread(() -> {
 			try {
 				contactManager.removePendingContact(id);
 			} catch (DbException e) {

briar-android/src/main/java/org/briarproject/briar/android/contactselection/BaseContactSelectorFragment.java

@@ -133,7 +133,7 @@ public abstract class BaseContactSelectorFragment<I extends SelectableContactIte
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						handleDbException(exception);
+						handleException(exception);
 					}
 				});
 	}

briar-android/src/main/java/org/briarproject/briar/android/controller/DbController.java

@@ -2,6 +2,7 @@ package org.briarproject.briar.android.controller;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
+@Deprecated
 @NotNullByDefault
 public interface DbController {
 

briar-android/src/main/java/org/briarproject/briar/android/controller/DbControllerImpl.java

@@ -11,6 +11,7 @@ import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 
 @Immutable
+@Deprecated
 @NotNullByDefault
 public class DbControllerImpl implements DbController {
 

briar-android/src/main/java/org/briarproject/briar/android/conversation/ConversationActivity.java

@@ -98,7 +98,6 @@ import androidx.core.content.ContextCompat;
 import androidx.lifecycle.LiveData;
 import androidx.lifecycle.Observer;
 import androidx.lifecycle.ViewModelProvider;
-import androidx.lifecycle.ViewModelProviders;
 import androidx.recyclerview.selection.Selection;
 import androidx.recyclerview.selection.SelectionPredicates;
 import androidx.recyclerview.selection.SelectionTracker;
@@ -140,8 +139,6 @@ import static org.briarproject.briar.android.util.UiUtils.getBulbTransitionName;
 import static org.briarproject.briar.android.util.UiUtils.observeOnce;
 import static org.briarproject.briar.api.messaging.MessagingConstants.MAX_ATTACHMENTS_PER_MESSAGE;
 import static org.briarproject.briar.api.messaging.MessagingConstants.MAX_PRIVATE_MESSAGE_TEXT_LENGTH;
-import static org.briarproject.briar.api.messaging.PrivateMessageFormat.TEXT_IMAGES_AUTO_DELETE;
-import static org.briarproject.briar.api.messaging.PrivateMessageFormat.TEXT_ONLY;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
@@ -226,8 +223,9 @@ public class ConversationActivity extends BriarActivity
 		if (id == -1) throw new IllegalStateException();
 		contactId = new ContactId(id);
 
-		viewModel = ViewModelProviders.of(this, viewModelFactory)
+		viewModel = new ViewModelProvider(this, viewModelFactory)
 				.get(ConversationViewModel.class);
+		viewModel.setContactId(contactId);
 		attachmentRetriever = viewModel.getAttachmentRetriever();
 
 		setContentView(R.layout.activity_conversation);
@@ -275,11 +273,15 @@ public class ConversationActivity extends BriarActivity
 			ImagePreview imagePreview = findViewById(R.id.imagePreview);
 			sendController = new TextAttachmentController(textInputView,
 					imagePreview, this, viewModel);
-			observeOnce(viewModel.getPrivateMessageFormat(), this, format -> {
-				if (format != TEXT_ONLY) {
-					// TODO: remove cast when removing feature flag
-					((TextAttachmentController) sendController)
-							.setImagesSupported();
+			viewModel.hasImageSupport().observe(this, new Observer<Boolean>() {
+				@Override
+				public void onChanged(@Nullable Boolean hasSupport) {
+					if (hasSupport != null && hasSupport) {
+						// TODO: remove cast when removing feature flag
+						((TextAttachmentController) sendController)
+								.setImagesSupported();
+						viewModel.hasImageSupport().removeObserver(this);
+					}
 				}
 			});
 		} else {
@@ -328,16 +330,6 @@ public class ConversationActivity extends BriarActivity
 		list.startPeriodicUpdate();
 	}
 
-	@Override
-	public void onResume() {
-		super.onResume();
-		// Trigger loading of contact data, noop if data was loaded already.
-		//
-		// We can only start loading data *after* we are sure
-		// the user has signed in. After sign-in, onCreate() isn't run again.
-		if (signedIn()) viewModel.setContactId(contactId);
-	}
-
 	@Override
 	public void onStop() {
 		super.onStop();
@@ -382,12 +374,6 @@ public class ConversationActivity extends BriarActivity
 		// enable alias action if available
 		observeOnce(viewModel.getContact(), this, contact ->
 				menu.findItem(R.id.action_set_alias).setEnabled(true));
-		// show auto-delete timer setting only, if contacts supports it
-		observeOnce(viewModel.getPrivateMessageFormat(), this, format -> {
-			boolean visible = format == TEXT_IMAGES_AUTO_DELETE;
-			menu.findItem(R.id.action_conversation_settings)
-					.setVisible(visible);
-		});
 
 		return super.onCreateOptionsMenu(menu);
 	}
@@ -409,12 +395,6 @@ public class ConversationActivity extends BriarActivity
 				AliasDialogFragment.newInstance().show(
 						getSupportFragmentManager(), AliasDialogFragment.TAG);
 				return true;
-			case R.id.action_conversation_settings:
-				if (contactId == null) return false;
-				intent = new Intent(this, ConversationSettingsActivity.class);
-				intent.putExtra(CONTACT_ID, contactId.getInt());
-				startActivity(intent);
-				return true;
 			case R.id.action_delete_all_messages:
 				askToDeleteAllMessages();
 				return true;
@@ -667,8 +647,8 @@ public class ConversationActivity extends BriarActivity
 				supportFinishAfterTransition();
 			}
 		} else if (e instanceof ConversationMessageReceivedEvent) {
-			ConversationMessageReceivedEvent<?> p =
-					(ConversationMessageReceivedEvent<?>) e;
+			ConversationMessageReceivedEvent p =
+					(ConversationMessageReceivedEvent) e;
 			if (p.getContactId().equals(contactId)) {
 				LOG.info("Message received, adding");
 				onNewConversationMessage(p.getMessageHeader());
@@ -766,10 +746,18 @@ public class ConversationActivity extends BriarActivity
 			List<AttachmentHeader> attachmentHeaders) {
 		if (isNullOrEmpty(text) && attachmentHeaders.isEmpty())
 			throw new AssertionError();
-		viewModel.sendMessage(text, attachmentHeaders);
+		long timestamp = System.currentTimeMillis();
+		timestamp = Math.max(timestamp, getMinTimestampForNewMessage());
+		viewModel.sendMessage(text, attachmentHeaders, timestamp);
 		textInputView.clearText();
 	}
 
+	private long getMinTimestampForNewMessage() {
+		// Don't use an earlier timestamp than the newest message
+		ConversationItem item = adapter.getLastItem();
+		return item == null ? 0 : item.getTime() + 1;
+	}
+
 	private void onAddedPrivateMessage(@Nullable PrivateMessageHeader h) {
 		if (h == null) return;
 		addConversationItem(h.accept(visitor));
@@ -974,11 +962,13 @@ public class ConversationActivity extends BriarActivity
 			adapter.notifyItemChanged(position, item);
 		}
 		runOnDbThread(() -> {
+			long timestamp = System.currentTimeMillis();
+			timestamp = Math.max(timestamp, getMinTimestampForNewMessage());
 			try {
 				switch (item.getRequestType()) {
 					case INTRODUCTION:
 						respondToIntroductionRequest(item.getSessionId(),
-								accept);
+								accept, timestamp);
 						break;
 					case FORUM:
 						respondToForumRequest(item.getSessionId(), accept);
@@ -1054,8 +1044,9 @@ public class ConversationActivity extends BriarActivity
 
 	@DatabaseExecutor
 	private void respondToIntroductionRequest(SessionId sessionId,
-			boolean accept) throws DbException {
-		introductionManager.respondToIntroduction(contactId, sessionId, accept);
+			boolean accept, long time) throws DbException {
+		introductionManager.respondToIntroduction(contactId, sessionId, time,
+				accept);
 	}
 
 	@DatabaseExecutor

briar-android/src/main/java/org/briarproject/briar/android/conversation/ConversationItem.java

@@ -22,7 +22,7 @@ abstract class ConversationItem {
 	protected String text;
 	private final MessageId id;
 	private final GroupId groupId;
-	private final long time, autoDeleteTimer;
+	private final long time;
 	private final boolean isIncoming;
 	private boolean read, sent, seen;
 
@@ -32,7 +32,6 @@ abstract class ConversationItem {
 		this.id = h.getId();
 		this.groupId = h.getGroupId();
 		this.time = h.getTimestamp();
-		this.autoDeleteTimer = h.getAutoDeleteTimer();
 		this.read = h.isRead();
 		this.sent = h.isSent();
 		this.seen = h.isSeen();
@@ -69,10 +68,6 @@ abstract class ConversationItem {
 		return time;
 	}
 
-	public long getAutoDeleteTimer() {
-		return autoDeleteTimer;
-	}
-
 	/**
 	 * Only useful for incoming messages.
 	 */

briar-android/src/main/java/org/briarproject/briar/android/conversation/ConversationItemViewHolder.java

@@ -12,11 +12,8 @@ import androidx.annotation.UiThread;
 import androidx.constraintlayout.widget.ConstraintLayout;
 import androidx.recyclerview.widget.RecyclerView.ViewHolder;
 
-import static android.view.View.GONE;
-import static android.view.View.VISIBLE;
 import static org.briarproject.bramble.util.StringUtils.trim;
 import static org.briarproject.briar.android.util.UiUtils.formatDate;
-import static org.briarproject.briar.api.autodelete.AutoDeleteConstants.NO_AUTO_DELETE_TIMER;
 
 @UiThread
 @NotNullByDefault
@@ -29,7 +26,6 @@ abstract class ConversationItemViewHolder extends ViewHolder {
 	private final OutItemViewHolder outViewHolder;
 	private final TextView text;
 	protected final TextView time;
-	private final View bomb;
 	@Nullable
 	private String itemKey = null;
 
@@ -42,7 +38,6 @@ abstract class ConversationItemViewHolder extends ViewHolder {
 		layout = v.findViewById(R.id.layout);
 		text = v.findViewById(R.id.text);
 		time = v.findViewById(R.id.time);
-		bomb = v.findViewById(R.id.bomb);
 	}
 
 	@CallSuper
@@ -57,9 +52,6 @@ abstract class ConversationItemViewHolder extends ViewHolder {
 		long timestamp = item.getTime();
 		time.setText(formatDate(time.getContext(), timestamp));
 
-		boolean showBomb = item.getAutoDeleteTimer() != NO_AUTO_DELETE_TIMER;
-		bomb.setVisibility(showBomb ? VISIBLE : GONE);
-
 		if (outViewHolder != null) outViewHolder.bind(item);
 	}
 

briar-android/src/main/java/org/briarproject/briar/android/conversation/ConversationSettingsActivity.java

@@ -1,80 +0,0 @@
-package org.briarproject.briar.android.conversation;
-
-import android.content.Intent;
-import android.os.Bundle;
-import android.view.MenuItem;
-
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
-import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
-import org.briarproject.briar.R;
-import org.briarproject.briar.android.activity.ActivityComponent;
-import org.briarproject.briar.android.activity.BriarActivity;
-import org.briarproject.briar.android.fragment.BaseFragment.BaseFragmentListener;
-
-import javax.annotation.Nullable;
-import javax.inject.Inject;
-
-import androidx.appcompat.app.ActionBar;
-import androidx.lifecycle.ViewModelProvider;
-import androidx.lifecycle.ViewModelProviders;
-
-import static org.briarproject.briar.android.conversation.ConversationActivity.CONTACT_ID;
-
-@MethodsNotNullByDefault
-@ParametersNotNullByDefault
-public class ConversationSettingsActivity extends BriarActivity implements
-		BaseFragmentListener {
-
-	@Inject
-	ViewModelProvider.Factory viewModelFactory;
-
-	private ConversationViewModel viewModel;
-	private ContactId contactId;
-
-	@Override
-	public void onCreate(@Nullable Bundle bundle) {
-		super.onCreate(bundle);
-
-		Intent i = getIntent();
-		int id = i.getIntExtra(CONTACT_ID, -1);
-		if (id == -1) throw new IllegalStateException();
-		contactId = new ContactId(id);
-
-		ActionBar actionBar = getSupportActionBar();
-		if (actionBar != null) {
-			actionBar.setHomeButtonEnabled(true);
-			actionBar.setDisplayHomeAsUpEnabled(true);
-		}
-
-		setContentView(R.layout.activity_conversation_settings);
-
-		viewModel = ViewModelProviders.of(this, viewModelFactory)
-				.get(ConversationViewModel.class);
-	}
-
-	@Override
-	public void onResume() {
-		super.onResume();
-		// Trigger loading of contact data, noop if data was loaded already.
-		//
-		// We can only start loading data *after* we are sure
-		// the user has signed in. After sign-in, onCreate() isn't run again.
-		if (signedIn()) viewModel.setContactId(contactId);
-	}
-
-	@Override
-	public void injectActivity(ActivityComponent component) {
-		component.inject(this);
-	}
-
-	@Override
-	public boolean onOptionsItemSelected(MenuItem item) {
-		if (item.getItemId() == android.R.id.home) {
-			onBackPressed();
-			return true;
-		}
-		return false;
-	}
-
-}

briar-android/src/main/java/org/briarproject/briar/android/conversation/ConversationSettingsFragment.java

@@ -1,158 +0,0 @@
-package org.briarproject.briar.android.conversation;
-
-import android.content.Context;
-import android.os.Bundle;
-import android.view.LayoutInflater;
-import android.view.Menu;
-import android.view.MenuInflater;
-import android.view.MenuItem;
-import android.view.View;
-import android.view.ViewGroup;
-import android.widget.TextView;
-
-import org.briarproject.bramble.api.db.DatabaseExecutor;
-import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.db.TransactionManager;
-import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
-import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
-import org.briarproject.briar.R;
-import org.briarproject.briar.android.fragment.BaseFragment;
-import org.briarproject.briar.api.autodelete.AutoDeleteManager;
-
-import java.util.concurrent.Executor;
-import java.util.logging.Logger;
-
-import javax.annotation.Nullable;
-import javax.inject.Inject;
-
-import androidx.appcompat.widget.SwitchCompat;
-import androidx.lifecycle.ViewModelProvider;
-import androidx.lifecycle.ViewModelProviders;
-
-import static java.util.logging.Level.WARNING;
-import static org.briarproject.bramble.util.LogUtils.logException;
-import static org.briarproject.briar.android.util.UiUtils.observeOnce;
-import static org.briarproject.briar.api.autodelete.AutoDeleteConstants.NO_AUTO_DELETE_TIMER;
-
-@MethodsNotNullByDefault
-@ParametersNotNullByDefault
-public class ConversationSettingsFragment extends BaseFragment {
-
-	public static final String TAG =
-			ConversationSettingsFragment.class.getName();
-
-	private static final Logger LOG =
-			Logger.getLogger(ConversationSettingsFragment.class.getName());
-
-	@Inject
-	ViewModelProvider.Factory viewModelFactory;
-	@Inject
-	@DatabaseExecutor
-	Executor dbExecutor;
-	@Inject
-	TransactionManager db;
-	@Inject
-	AutoDeleteManager autoDeleteManager;
-
-	private ConversationSettingsActivity listener;
-	private ConversationViewModel viewModel;
-	private SwitchCompat switchDisappearingMessages;
-	private volatile boolean disappearingMessages = false;
-
-	@Override
-	public String getUniqueTag() {
-		return TAG;
-	}
-
-	@Override
-	public void onAttach(Context context) {
-		super.onAttach(context);
-		listener = (ConversationSettingsActivity) context;
-		listener.getActivityComponent().inject(this);
-	}
-
-	@Override
-	public void onCreate(@Nullable Bundle savedInstanceState) {
-		super.onCreate(savedInstanceState);
-		setHasOptionsMenu(true);
-	}
-
-	@Override
-	public View onCreateView(LayoutInflater inflater,
-			@Nullable ViewGroup container,
-			@Nullable Bundle savedInstanceState) {
-		View contentView =
-				inflater.inflate(R.layout.fragment_conversation_settings,
-						container, false);
-
-		switchDisappearingMessages =
-				contentView.findViewById(R.id.switchDisappearingMessages);
-
-		switchDisappearingMessages
-				.setOnCheckedChangeListener((button, value) -> viewModel
-						.setAutoDeleteTimerEnabled(value));
-
-		TextView buttonLearnMore =
-				contentView.findViewById(R.id.buttonLearnMore);
-		buttonLearnMore.setOnClickListener(e -> showLearnMoreDialog());
-
-		viewModel = ViewModelProviders.of(requireActivity(), viewModelFactory)
-				.get(ConversationViewModel.class);
-
-		return contentView;
-	}
-
-	@Override
-	public void onStart() {
-		super.onStart();
-		switchDisappearingMessages.setEnabled(false);
-		loadSettings();
-	}
-
-	private void loadSettings() {
-		observeOnce(viewModel.getContact(), this, c -> {
-			dbExecutor.execute(() -> {
-				try {
-					db.transaction(false, txn -> {
-						long timer = autoDeleteManager
-								.getAutoDeleteTimer(txn, c.getId());
-						disappearingMessages = timer != NO_AUTO_DELETE_TIMER;
-					});
-					listener.runOnUiThreadUnlessDestroyed(
-							this::displaySettings);
-				} catch (DbException e) {
-					logException(LOG, WARNING, e);
-				}
-			});
-		});
-	}
-
-	private void displaySettings() {
-		switchDisappearingMessages.setChecked(disappearingMessages);
-		switchDisappearingMessages.setEnabled(true);
-	}
-
-	@Override
-	public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
-		inflater.inflate(R.menu.help_action, menu);
-		super.onCreateOptionsMenu(menu, inflater);
-	}
-
-
-	@Override
-	public boolean onOptionsItemSelected(MenuItem item) {
-		if (item.getItemId() == R.id.action_help) {
-			showLearnMoreDialog();
-			return true;
-		}
-		return super.onOptionsItemSelected(item);
-	}
-
-	private void showLearnMoreDialog() {
-		ConversationSettingsLearnMoreDialog
-				dialog = new ConversationSettingsLearnMoreDialog();
-		dialog.show(requireActivity().getSupportFragmentManager(),
-				ConversationSettingsLearnMoreDialog.TAG);
-	}
-
-}

briar-android/src/main/java/org/briarproject/briar/android/conversation/ConversationSettingsLearnMoreDialog.java

@@ -1,44 +0,0 @@
-package org.briarproject.briar.android.conversation;
-
-import android.app.Dialog;
-import android.os.Bundle;
-import android.view.LayoutInflater;
-import android.view.View;
-
-import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
-import org.briarproject.briar.R;
-
-import androidx.appcompat.app.AlertDialog;
-import androidx.fragment.app.DialogFragment;
-import androidx.fragment.app.FragmentActivity;
-
-@MethodsNotNullByDefault
-public class ConversationSettingsLearnMoreDialog extends DialogFragment {
-
-	final static String TAG =
-			ConversationSettingsLearnMoreDialog.class.getName();
-
-	static ConversationSettingsLearnMoreDialog newInstance() {
-		return new ConversationSettingsLearnMoreDialog();
-	}
-
-	@Override
-	public Dialog onCreateDialog(Bundle savedInstanceState) {
-		FragmentActivity activity = requireActivity();
-
-		AlertDialog.Builder builder =
-				new AlertDialog.Builder(activity, R.style.BriarDialogTheme);
-
-		LayoutInflater inflater = LayoutInflater.from(getContext());
-		View view = inflater.inflate(
-				R.layout.fragment_conversation_settings_learn_more, null);
-		builder.setView(view);
-
-		builder.setTitle(R.string.disappearing_messages_title);
-		builder.setNeutralButton(R.string.ok, null);
-
-		return builder.create();
-	}
-
-
-}

briar-android/src/main/java/org/briarproject/briar/android/conversation/ConversationViewModel.java

@@ -10,32 +10,31 @@ import org.briarproject.bramble.api.contact.ContactManager;
 import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.NoSuchContactException;
-import org.briarproject.bramble.api.db.Transaction;
 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.identity.AuthorId;
+import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.settings.Settings;
 import org.briarproject.bramble.api.settings.SettingsManager;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageId;
+import org.briarproject.bramble.api.system.AndroidExecutor;
 import org.briarproject.briar.android.attachment.AttachmentCreator;
 import org.briarproject.briar.android.attachment.AttachmentManager;
 import org.briarproject.briar.android.attachment.AttachmentResult;
 import org.briarproject.briar.android.attachment.AttachmentRetriever;
 import org.briarproject.briar.android.util.UiUtils;
+import org.briarproject.briar.android.viewmodel.DbViewModel;
 import org.briarproject.briar.android.viewmodel.LiveEvent;
 import org.briarproject.briar.android.viewmodel.MutableLiveEvent;
-import org.briarproject.briar.api.autodelete.AutoDeleteManager;
-import org.briarproject.briar.api.conversation.ConversationManager;
 import org.briarproject.briar.api.messaging.AttachmentHeader;
 import org.briarproject.briar.api.messaging.MessagingManager;
 import org.briarproject.briar.api.messaging.PrivateMessage;
 import org.briarproject.briar.api.messaging.PrivateMessageFactory;
-import org.briarproject.briar.api.messaging.PrivateMessageFormat;
 import org.briarproject.briar.api.messaging.PrivateMessageHeader;
 import org.briarproject.briar.api.messaging.event.AttachmentReceivedEvent;
 
@@ -48,13 +47,11 @@ import javax.inject.Inject;
 
 import androidx.annotation.Nullable;
 import androidx.annotation.UiThread;
-import androidx.lifecycle.AndroidViewModel;
 import androidx.lifecycle.LiveData;
 import androidx.lifecycle.MutableLiveData;
 import androidx.lifecycle.Transformations;
 
 import static java.util.Objects.requireNonNull;
-import static java.util.concurrent.TimeUnit.DAYS;
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.util.LogUtils.logDuration;
@@ -62,12 +59,9 @@ import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.bramble.util.LogUtils.now;
 import static org.briarproject.briar.android.settings.SettingsFragment.SETTINGS_NAMESPACE;
 import static org.briarproject.briar.android.util.UiUtils.observeForeverOnce;
-import static org.briarproject.briar.api.autodelete.AutoDeleteConstants.NO_AUTO_DELETE_TIMER;
-import static org.briarproject.briar.api.messaging.PrivateMessageFormat.TEXT_IMAGES;
-import static org.briarproject.briar.api.messaging.PrivateMessageFormat.TEXT_ONLY;
 
 @NotNullByDefault
-public class ConversationViewModel extends AndroidViewModel
+public class ConversationViewModel extends DbViewModel
 		implements EventListener, AttachmentManager {
 
 	private static final Logger LOG =
@@ -78,8 +72,6 @@ public class ConversationViewModel extends AndroidViewModel
 	private static final String SHOW_ONBOARDING_INTRODUCTION =
 			"showOnboardingIntroduction";
 
-	@DatabaseExecutor
-	private final Executor dbExecutor;
 	private final TransactionManager db;
 	private final EventBus eventBus;
 	private final MessagingManager messagingManager;
@@ -88,8 +80,6 @@ public class ConversationViewModel extends AndroidViewModel
 	private final PrivateMessageFactory privateMessageFactory;
 	private final AttachmentRetriever attachmentRetriever;
 	private final AttachmentCreator attachmentCreator;
-	private final AutoDeleteManager autoDeleteManager;
-	private final ConversationManager conversationManager;
 
 	@Nullable
 	private ContactId contactId = null;
@@ -99,7 +89,7 @@ public class ConversationViewModel extends AndroidViewModel
 	private final LiveData<String> contactName =
 			Transformations.map(contact, UiUtils::getContactDisplayName);
 	private final LiveData<GroupId> messagingGroupId;
-	private final MutableLiveData<PrivateMessageFormat> privateMessageFormat =
+	private final MutableLiveData<Boolean> imageSupport =
 			new MutableLiveData<>();
 	private final MutableLiveEvent<Boolean> showImageOnboarding =
 			new MutableLiveEvent<>();
@@ -115,18 +105,17 @@ public class ConversationViewModel extends AndroidViewModel
 	@Inject
 	ConversationViewModel(Application application,
 			@DatabaseExecutor Executor dbExecutor,
+			LifecycleManager lifecycleManager,
 			TransactionManager db,
+			AndroidExecutor androidExecutor,
 			EventBus eventBus,
 			MessagingManager messagingManager,
 			ContactManager contactManager,
 			SettingsManager settingsManager,
 			PrivateMessageFactory privateMessageFactory,
 			AttachmentRetriever attachmentRetriever,
-			AttachmentCreator attachmentCreator,
-			AutoDeleteManager autoDeleteManager,
-			ConversationManager conversationManager) {
-		super(application);
-		this.dbExecutor = dbExecutor;
+			AttachmentCreator attachmentCreator) {
+		super(application, dbExecutor, lifecycleManager, db, androidExecutor);
 		this.db = db;
 		this.eventBus = eventBus;
 		this.messagingManager = messagingManager;
@@ -135,8 +124,6 @@ public class ConversationViewModel extends AndroidViewModel
 		this.privateMessageFactory = privateMessageFactory;
 		this.attachmentRetriever = attachmentRetriever;
 		this.attachmentCreator = attachmentCreator;
-		this.autoDeleteManager = autoDeleteManager;
-		this.conversationManager = conversationManager;
 		messagingGroupId = Transformations
 				.map(contact, c -> messagingManager.getContactGroup(c).getId());
 		contactDeleted.setValue(false);
@@ -157,7 +144,7 @@ public class ConversationViewModel extends AndroidViewModel
 			AttachmentReceivedEvent a = (AttachmentReceivedEvent) e;
 			if (a.getContactId().equals(contactId)) {
 				LOG.info("Attachment received");
-				dbExecutor.execute(() -> attachmentRetriever
+				runOnDbThread(() -> attachmentRetriever
 						.loadAttachmentItem(a.getMessageId()));
 			}
 		}
@@ -177,7 +164,7 @@ public class ConversationViewModel extends AndroidViewModel
 	}
 
 	private void loadContact(ContactId contactId) {
-		dbExecutor.execute(() -> {
+		runOnDbThread(() -> {
 			try {
 				long start = now();
 				Contact c = contactManager.getContact(contactId);
@@ -195,7 +182,7 @@ public class ConversationViewModel extends AndroidViewModel
 	}
 
 	void markMessageRead(GroupId g, MessageId m) {
-		dbExecutor.execute(() -> {
+		runOnDbThread(() -> {
 			try {
 				long start = now();
 				messagingManager.setReadFlag(g, m, true);
@@ -207,7 +194,7 @@ public class ConversationViewModel extends AndroidViewModel
 	}
 
 	void setContactAlias(String alias) {
-		dbExecutor.execute(() -> {
+		runOnDbThread(() -> {
 			try {
 				contactManager.setContactAlias(requireNonNull(contactId),
 						alias.isEmpty() ? null : alias);
@@ -219,13 +206,16 @@ public class ConversationViewModel extends AndroidViewModel
 	}
 
 	@UiThread
-	void sendMessage(@Nullable String text, List<AttachmentHeader> headers) {
+	void sendMessage(@Nullable String text,
+			List<AttachmentHeader> headers, long timestamp) {
 		// messagingGroupId is loaded with the contact
 		observeForeverOnce(messagingGroupId, groupId -> {
 			requireNonNull(groupId);
-			observeForeverOnce(privateMessageFormat, format ->
-					storeMessage(requireNonNull(contactId), groupId, text,
-							headers, format));
+			observeForeverOnce(imageSupport, hasImageSupport -> {
+				requireNonNull(hasImageSupport);
+				createMessage(groupId, text, headers, timestamp,
+						hasImageSupport);
+			});
 		});
 	}
 
@@ -255,10 +245,10 @@ public class ConversationViewModel extends AndroidViewModel
 
 	@DatabaseExecutor
 	private void checkFeaturesAndOnboarding(ContactId c) throws DbException {
-		// check if images and auto-deletion are supported
-		PrivateMessageFormat format = db.transactionWithResult(true, txn ->
-				messagingManager.getContactMessageFormat(txn, c));
-		privateMessageFormat.postValue(format);
+		// check if images are supported
+		boolean imagesSupported = db.transactionWithResult(true, txn ->
+				messagingManager.contactSupportsImages(txn, c));
+		imageSupport.postValue(imagesSupported);
 
 		// check if introductions are supported
 		Collection<Contact> contacts = contactManager.getContacts();
@@ -267,7 +257,7 @@ public class ConversationViewModel extends AndroidViewModel
 
 		// we only show one onboarding dialog at a time
 		Settings settings = settingsManager.getSettings(SETTINGS_NAMESPACE);
-		if (format != TEXT_ONLY &&
+		if (imagesSupported &&
 				settings.getBoolean(SHOW_ONBOARDING_IMAGE, true)) {
 			onOnboardingShown(SHOW_ONBOARDING_IMAGE);
 			showImageOnboarding.postEvent(true);
@@ -285,67 +275,40 @@ public class ConversationViewModel extends AndroidViewModel
 		settingsManager.mergeSettings(settings, SETTINGS_NAMESPACE);
 	}
 
-	private PrivateMessage createMessage(Transaction txn, ContactId c,
-			GroupId groupId, @Nullable String text,
-			List<AttachmentHeader> headers, PrivateMessageFormat format)
-			throws DbException {
-		long timestamp =
-				conversationManager.getTimestampForOutgoingMessage(txn, c);
+	@UiThread
+	private void createMessage(GroupId groupId, @Nullable String text,
+			List<AttachmentHeader> headers, long timestamp,
+			boolean hasImageSupport) {
 		try {
-			if (format == TEXT_ONLY) {
-				return privateMessageFactory.createLegacyPrivateMessage(
-						groupId, timestamp, requireNonNull(text));
-			} else if (format == TEXT_IMAGES) {
-				return privateMessageFactory.createPrivateMessage(groupId,
+			PrivateMessage pm;
+			if (hasImageSupport) {
+				pm = privateMessageFactory.createPrivateMessage(groupId,
 						timestamp, text, headers);
 			} else {
-				long timer = autoDeleteManager.getAutoDeleteTimer(txn, c,
-						timestamp);
-				return privateMessageFactory.createPrivateMessage(groupId,
-						timestamp, text, headers, timer);
+				pm = privateMessageFactory.createLegacyPrivateMessage(
+						groupId, timestamp, requireNonNull(text));
 			}
+			storeMessage(pm);
 		} catch (FormatException e) {
 			throw new AssertionError(e);
 		}
 	}
 
 	@UiThread
-	private void storeMessage(ContactId c, GroupId groupId,
-			@Nullable String text, List<AttachmentHeader> headers,
-			PrivateMessageFormat format) {
-		dbExecutor.execute(() -> {
+	private void storeMessage(PrivateMessage m) {
+		attachmentCreator.onAttachmentsSent(m.getMessage().getId());
+		runOnDbThread(() -> {
 			try {
-				db.transaction(false, txn -> {
-					long start = now();
-					PrivateMessage m = createMessage(txn, c, groupId, text,
-							headers, format);
-					messagingManager.addLocalMessage(txn, m);
-					logDuration(LOG, "Storing message", start);
-					Message message = m.getMessage();
-					PrivateMessageHeader h = new PrivateMessageHeader(
-							message.getId(), message.getGroupId(),
-							message.getTimestamp(), true, true, false, false,
-							m.hasText(), m.getAttachmentHeaders(),
-							m.getAutoDeleteTimer());
-					// TODO add text to cache when available here
-					MessageId id = message.getId();
-					txn.attach(() -> attachmentCreator.onAttachmentsSent(id));
-					addedHeader.postEvent(h);
-				});
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
-		});
-	}
-
-	void setAutoDeleteTimerEnabled(boolean enabled) {
-		final long timer = enabled ? DAYS.toMillis(7) : NO_AUTO_DELETE_TIMER;
-		// ContactId is set before menu gets inflated and UI interaction
-		final ContactId c = requireNonNull(contactId);
-		dbExecutor.execute(() -> {
-			try {
-				db.transaction(false, txn ->
-						autoDeleteManager.setAutoDeleteTimer(txn, c, timer));
+				long start = now();
+				messagingManager.addLocalMessage(m);
+				logDuration(LOG, "Storing message", start);
+				Message message = m.getMessage();
+				PrivateMessageHeader h = new PrivateMessageHeader(
+						message.getId(), message.getGroupId(),
+						message.getTimestamp(), true, true, false, false,
+						m.hasText(), m.getAttachmentHeaders());
+				// TODO add text to cache when available here
+				addedHeader.postEvent(h);
 			} catch (DbException e) {
 				logException(LOG, WARNING, e);
 			}
@@ -368,8 +331,8 @@ public class ConversationViewModel extends AndroidViewModel
 		return contactName;
 	}
 
-	LiveData<PrivateMessageFormat> getPrivateMessageFormat() {
-		return privateMessageFormat;
+	LiveData<Boolean> hasImageSupport() {
+		return imageSupport;
 	}
 
 	LiveEvent<Boolean> showImageOnboarding() {
@@ -394,7 +357,7 @@ public class ConversationViewModel extends AndroidViewModel
 
 	@UiThread
 	void recheckFeaturesAndOnboarding(ContactId contactId) {
-		dbExecutor.execute(() -> {
+		runOnDbThread(() -> {
 			try {
 				checkFeaturesAndOnboarding(contactId);
 			} catch (DbException e) {

briar-android/src/main/java/org/briarproject/briar/android/conversation/ImageViewModel.java

@@ -7,13 +7,17 @@ import android.view.View;
 
 import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.db.DbException;
+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.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.MessageId;
+import org.briarproject.bramble.api.system.AndroidExecutor;
 import org.briarproject.briar.android.attachment.AttachmentItem;
+import org.briarproject.briar.android.viewmodel.DbViewModel;
 import org.briarproject.briar.android.viewmodel.LiveEvent;
 import org.briarproject.briar.android.viewmodel.MutableLiveEvent;
 import org.briarproject.briar.api.messaging.Attachment;
@@ -37,7 +41,6 @@ import javax.inject.Inject;
 
 import androidx.annotation.Nullable;
 import androidx.annotation.UiThread;
-import androidx.lifecycle.AndroidViewModel;
 
 import static android.media.MediaScannerConnection.scanFile;
 import static android.os.Environment.DIRECTORY_PICTURES;
@@ -49,20 +52,18 @@ import static org.briarproject.bramble.util.IoUtils.copyAndClose;
 import static org.briarproject.bramble.util.LogUtils.logException;
 
 @NotNullByDefault
-public class ImageViewModel extends AndroidViewModel implements EventListener {
+public class ImageViewModel extends DbViewModel implements EventListener {
 
-	private static Logger LOG = getLogger(ImageViewModel.class.getName());
+	private static final Logger LOG = getLogger(ImageViewModel.class.getName());
 
 	private final MessagingManager messagingManager;
 	private final EventBus eventBus;
-	@DatabaseExecutor
-	private final Executor dbExecutor;
 	@IoExecutor
 	private final Executor ioExecutor;
 
 	private boolean receivedAttachmentsInitialized = false;
-	private HashMap<MessageId, MutableLiveEvent<Boolean>> receivedAttachments =
-			new HashMap<>();
+	private final HashMap<MessageId, MutableLiveEvent<Boolean>>
+			receivedAttachments = new HashMap<>();
 
 	/**
 	 * true means there was an error saving the image, false if image was saved.
@@ -75,13 +76,16 @@ public class ImageViewModel extends AndroidViewModel implements EventListener {
 
 	@Inject
 	ImageViewModel(Application application,
-			MessagingManager messagingManager, EventBus eventBus,
+			MessagingManager messagingManager,
+			EventBus eventBus,
 			@DatabaseExecutor Executor dbExecutor,
+			LifecycleManager lifecycleManager,
+			TransactionManager db,
+			AndroidExecutor androidExecutor,
 			@IoExecutor Executor ioExecutor) {
-		super(application);
+		super(application, dbExecutor, lifecycleManager, db, androidExecutor);
 		this.messagingManager = messagingManager;
 		this.eventBus = eventBus;
-		this.dbExecutor = dbExecutor;
 		this.ioExecutor = ioExecutor;
 
 		eventBus.addListener(this);
@@ -195,7 +199,7 @@ public class ImageViewModel extends AndroidViewModel implements EventListener {
 
 	private void saveImage(AttachmentItem attachment, OutputStreamProvider osp,
 			@Nullable Runnable afterCopy) {
-		dbExecutor.execute(() -> {
+		runOnDbThread(() -> {
 			try {
 				Attachment a =
 						messagingManager.getAttachment(attachment.getHeader());

briar-android/src/main/java/org/briarproject/briar/android/forum/ForumActivity.java

@@ -38,7 +38,7 @@ import static org.briarproject.briar.api.forum.ForumConstants.MAX_FORUM_POST_TEX
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
 public class ForumActivity extends
-		ThreadListActivity<Forum, ForumItem, ThreadItemAdapter<ForumItem>>
+		ThreadListActivity<Forum, ForumPostItem, ThreadItemAdapter<ForumPostItem>>
 		implements ForumListener {
 
 	@Inject
@@ -50,7 +50,7 @@ public class ForumActivity extends
 	}
 
 	@Override
-	protected ThreadListController<Forum, ForumItem> getController() {
+	protected ThreadListController<Forum, ForumPostItem> getController() {
 		return forumController;
 	}
 
@@ -82,7 +82,7 @@ public class ForumActivity extends
 	}
 
 	@Override
-	protected ThreadItemAdapter<ForumItem> createAdapter(
+	protected ThreadItemAdapter<ForumPostItem> createAdapter(
 			LinearLayoutManager layoutManager) {
 		return new ThreadItemAdapter<>(this, layoutManager);
 	}
@@ -156,7 +156,7 @@ public class ForumActivity extends
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						handleDbException(exception);
+						handleException(exception);
 					}
 				});
 	}

briar-android/src/main/java/org/briarproject/briar/android/forum/ForumController.java

@@ -8,9 +8,9 @@ import org.briarproject.briar.api.forum.Forum;
 import androidx.annotation.UiThread;
 
 @NotNullByDefault
-interface ForumController extends ThreadListController<Forum, ForumItem> {
+interface ForumController extends ThreadListController<Forum, ForumPostItem> {
 
-	interface ForumListener extends ThreadListListener<ForumItem> {
+	interface ForumListener extends ThreadListListener<ForumPostItem> {
 		@UiThread
 		void onForumLeft(ContactId c);
 	}

briar-android/src/main/java/org/briarproject/briar/android/forum/ForumControllerImpl.java

@@ -43,7 +43,7 @@ import static org.briarproject.bramble.util.LogUtils.logException;
 
 @NotNullByDefault
 class ForumControllerImpl extends
-		ThreadListControllerImpl<Forum, ForumItem, ForumPostHeader, ForumPost, ForumListener>
+		ThreadListControllerImpl<Forum, ForumPostItem, ForumPostHeader, ForumPost, ForumListener>
 		implements ForumController {
 
 	private static final Logger LOG =
@@ -138,8 +138,8 @@ class ForumControllerImpl extends
 
 	@Override
 	public void createAndStoreMessage(String text,
-			@Nullable ForumItem parentItem,
-			ResultExceptionHandler<ForumItem, DbException> handler) {
+			@Nullable ForumPostItem parentItem,
+			ResultExceptionHandler<ForumPostItem, DbException> handler) {
 		runOnDbThread(() -> {
 			try {
 				LocalAuthor author = identityManager.getLocalAuthor();
@@ -158,7 +158,7 @@ class ForumControllerImpl extends
 
 	private void createMessage(String text, long timestamp,
 			@Nullable MessageId parentId, LocalAuthor author,
-			ResultExceptionHandler<ForumItem, DbException> handler) {
+			ResultExceptionHandler<ForumPostItem, DbException> handler) {
 		cryptoExecutor.execute(() -> {
 			LOG.info("Creating forum post...");
 			ForumPost msg = forumManager.createLocalPost(getGroupId(), text,
@@ -178,8 +178,8 @@ class ForumControllerImpl extends
 	}
 
 	@Override
-	protected ForumItem buildItem(ForumPostHeader header, String text) {
-		return new ForumItem(header, text);
+	protected ForumPostItem buildItem(ForumPostHeader header, String text) {
+		return new ForumPostItem(header, text);
 	}
 
 }

briar-android/src/main/java/org/briarproject/briar/android/forum/ForumListAdapter.java

@@ -1,134 +1,47 @@
 package org.briarproject.briar.android.forum;
 
-import android.content.Context;
-import android.content.Intent;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
-import android.widget.TextView;
 
-import org.briarproject.bramble.api.sync.GroupId;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.briar.R;
-import org.briarproject.briar.android.util.BriarAdapter;
-import org.briarproject.briar.android.util.UiUtils;
-import org.briarproject.briar.android.view.TextAvatarView;
-import org.briarproject.briar.api.forum.Forum;
 
-import androidx.recyclerview.widget.RecyclerView;
+import androidx.recyclerview.widget.DiffUtil.ItemCallback;
+import androidx.recyclerview.widget.ListAdapter;
 
-import static android.view.View.GONE;
-import static android.view.View.VISIBLE;
-import static androidx.recyclerview.widget.SortedList.INVALID_POSITION;
-import static org.briarproject.briar.android.activity.BriarActivity.GROUP_ID;
-import static org.briarproject.briar.android.activity.BriarActivity.GROUP_NAME;
+@NotNullByDefault
+class ForumListAdapter extends ListAdapter<ForumListItem, ForumViewHolder> {
 
-class ForumListAdapter
-		extends BriarAdapter<ForumListItem, ForumListAdapter.ForumViewHolder> {
-
-	ForumListAdapter(Context ctx) {
-		super(ctx, ForumListItem.class);
+	ForumListAdapter() {
+		super(new ForumListCallback());
 	}
 
 	@Override
 	public ForumViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
-		View v = LayoutInflater.from(ctx).inflate(
+		View v = LayoutInflater.from(parent.getContext()).inflate(
 				R.layout.list_item_forum, parent, false);
 		return new ForumViewHolder(v);
 	}
 
 	@Override
-	public void onBindViewHolder(ForumViewHolder ui, int position) {
-		ForumListItem item = getItemAt(position);
-		if (item == null) return;
+	public void onBindViewHolder(ForumViewHolder viewHolder, int position) {
+		viewHolder.bind(getItem(position));
+	}
 
-		// Avatar
-		ui.avatar.setText(item.getForum().getName().substring(0, 1));
-		ui.avatar.setBackgroundBytes(item.getForum().getId().getBytes());
-		ui.avatar.setUnreadCount(item.getUnreadCount());
-
-		// Forum Name
-		ui.name.setText(item.getForum().getName());
-
-		// Post Count
-		int postCount = item.getPostCount();
-		if (postCount > 0) {
-			ui.postCount.setText(ctx.getResources()
-					.getQuantityString(R.plurals.posts, postCount,
-							postCount));
-		} else {
-			ui.postCount.setText(ctx.getString(R.string.no_posts));
+	@NotNullByDefault
+	private static class ForumListCallback extends ItemCallback<ForumListItem> {
+		@Override
+		public boolean areItemsTheSame(ForumListItem a, ForumListItem b) {
+			return a.equals(b);
 		}
 
-		// Date
-		if (item.isEmpty()) {
-			ui.date.setVisibility(GONE);
-		} else {
-			long timestamp = item.getTimestamp();
-			ui.date.setText(UiUtils.formatDate(ctx, timestamp));
-			ui.date.setVisibility(VISIBLE);
-		}
-
-		// Open Forum on Click
-		ui.layout.setOnClickListener(v -> {
-			Intent i = new Intent(ctx, ForumActivity.class);
-			Forum f = item.getForum();
-			i.putExtra(GROUP_ID, f.getId().getBytes());
-			i.putExtra(GROUP_NAME, f.getName());
-			ctx.startActivity(i);
-		});
-	}
-
-	@Override
-	public int compare(ForumListItem a, ForumListItem b) {
-		if (a == b) return 0;
-		// The forum with the newest message comes first
-		long aTime = a.getTimestamp(), bTime = b.getTimestamp();
-		if (aTime > bTime) return -1;
-		if (aTime < bTime) return 1;
-		// Break ties by forum name
-		String aName = a.getForum().getName();
-		String bName = b.getForum().getName();
-		return String.CASE_INSENSITIVE_ORDER.compare(aName, bName);
-	}
-
-	@Override
-	public boolean areContentsTheSame(ForumListItem a, ForumListItem b) {
-		return a.isEmpty() == b.isEmpty() &&
-				a.getTimestamp() == b.getTimestamp() &&
-				a.getUnreadCount() == b.getUnreadCount();
-	}
-
-	@Override
-	public boolean areItemsTheSame(ForumListItem a, ForumListItem b) {
-		return a.getForum().equals(b.getForum());
-	}
-
-	int findItemPosition(GroupId g) {
-		int count = getItemCount();
-		for (int i = 0; i < count; i++) {
-			ForumListItem item = getItemAt(i);
-			if (item != null && item.getForum().getGroup().getId().equals(g))
-				return i;
-		}
-		return INVALID_POSITION; // Not found
-	}
-
-	static class ForumViewHolder extends RecyclerView.ViewHolder {
-
-		private final ViewGroup layout;
-		private final TextAvatarView avatar;
-		private final TextView name;
-		private final TextView postCount;
-		private final TextView date;
-
-		private ForumViewHolder(View v) {
-			super(v);
-
-			layout = (ViewGroup) v;
-			avatar = v.findViewById(R.id.avatarView);
-			name = v.findViewById(R.id.forumNameView);
-			postCount = v.findViewById(R.id.postCountView);
-			date = v.findViewById(R.id.dateView);
+		@Override
+		public boolean areContentsTheSame(ForumListItem a, ForumListItem b) {
+			return a.isEmpty() == b.isEmpty() &&
+					a.getTimestamp() == b.getTimestamp() &&
+					a.getUnreadCount() == b.getUnreadCount();
 		}
 	}
+
 }

briar-android/src/main/java/org/briarproject/briar/android/forum/ForumListFragment.java

@@ -12,80 +12,48 @@ import android.view.ViewGroup;
 
 import com.google.android.material.snackbar.Snackbar;
 
-import org.briarproject.bramble.api.contact.event.ContactRemovedEvent;
-import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.db.NoSuchGroupException;
-import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
-import org.briarproject.bramble.api.sync.GroupId;
-import org.briarproject.bramble.api.sync.event.GroupAddedEvent;
-import org.briarproject.bramble.api.sync.event.GroupRemovedEvent;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.ActivityComponent;
-import org.briarproject.briar.android.fragment.BaseEventFragment;
+import org.briarproject.briar.android.fragment.BaseFragment;
 import org.briarproject.briar.android.sharing.ForumInvitationActivity;
 import org.briarproject.briar.android.util.BriarSnackbarBuilder;
 import org.briarproject.briar.android.view.BriarRecyclerView;
-import org.briarproject.briar.api.android.AndroidNotificationManager;
-import org.briarproject.briar.api.client.MessageTracker.GroupCount;
-import org.briarproject.briar.api.forum.Forum;
-import org.briarproject.briar.api.forum.ForumManager;
-import org.briarproject.briar.api.forum.ForumPostHeader;
-import org.briarproject.briar.api.forum.ForumSharingManager;
-import org.briarproject.briar.api.forum.event.ForumInvitationRequestReceivedEvent;
-import org.briarproject.briar.api.forum.event.ForumPostReceivedEvent;
-
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.logging.Logger;
 
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
-import androidx.annotation.UiThread;
+import androidx.lifecycle.ViewModelProvider;
 import androidx.recyclerview.widget.LinearLayoutManager;
 
 import static com.google.android.material.snackbar.Snackbar.LENGTH_INDEFINITE;
-import static java.util.logging.Level.WARNING;
-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 org.briarproject.briar.api.forum.ForumManager.CLIENT_ID;
+import static java.util.Objects.requireNonNull;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
-public class ForumListFragment extends BaseEventFragment implements
+public class ForumListFragment extends BaseFragment implements
 		OnClickListener {
 
 	public final static String TAG = ForumListFragment.class.getName();
-	private final static Logger LOG = Logger.getLogger(TAG);
 
+	private ForumListViewModel viewModel;
 	private BriarRecyclerView list;
-	private ForumListAdapter adapter;
 	private Snackbar snackbar;
+	private final ForumListAdapter adapter = new ForumListAdapter();
 
 	@Inject
-	AndroidNotificationManager notificationManager;
-
-	// Fields that are accessed from background threads must be volatile
-	@Inject
-	volatile ForumManager forumManager;
-	@Inject
-	volatile ForumSharingManager forumSharingManager;
+	ViewModelProvider.Factory viewModelFactory;
 
 	public static ForumListFragment newInstance() {
-
-		Bundle args = new Bundle();
-
-		ForumListFragment fragment = new ForumListFragment();
-		fragment.setArguments(args);
-		return fragment;
+		return new ForumListFragment();
 	}
 
 	@Override
 	public void injectFragment(ActivityComponent component) {
 		component.inject(this);
+		viewModel = new ViewModelProvider(this, viewModelFactory)
+				.get(ForumListViewModel.class);
 	}
 
 	@Nullable
@@ -93,24 +61,35 @@ public class ForumListFragment extends BaseEventFragment implements
 	public View onCreateView(LayoutInflater inflater,
 			@Nullable ViewGroup container,
 			@Nullable Bundle savedInstanceState) {
-
 		requireActivity().setTitle(R.string.forums_button);
 
-		View contentView =
-				inflater.inflate(R.layout.fragment_forum_list, container,
-						false);
+		View v = inflater.inflate(R.layout.fragment_forum_list, container,
+				false);
 
-		adapter = new ForumListAdapter(getActivity());
-
-		list = contentView.findViewById(R.id.forumList);
+		list = v.findViewById(R.id.forumList);
 		list.setLayoutManager(new LinearLayoutManager(getActivity()));
 		list.setAdapter(adapter);
+		viewModel.getForumListItems().observe(getViewLifecycleOwner(), result ->
+				result.onError(this::handleException).onSuccess(items -> {
+					adapter.submitList(items);
+					if (requireNonNull(items).size() == 0) list.showData();
+				})
+		);
 
 		snackbar = new BriarSnackbarBuilder()
 				.setAction(R.string.show, this)
 				.make(list, "", LENGTH_INDEFINITE);
+		viewModel.getNumInvitations().observe(getViewLifecycleOwner(), num -> {
+			if (num == 0) {
+				snackbar.dismiss();
+			} else {
+				snackbar.setText(getResources().getQuantityString(
+						R.plurals.forums_shared, num, num));
+				if (!snackbar.isShownOrQueued()) snackbar.show();
+			}
+		});
 
-		return contentView;
+		return v;
 	}
 
 	@Override
@@ -121,18 +100,23 @@ public class ForumListFragment extends BaseEventFragment implements
 	@Override
 	public void onStart() {
 		super.onStart();
-		notificationManager.clearAllForumPostNotifications();
-		loadForums();
-		loadAvailableForums();
+		viewModel.blockAllForumPostNotifications();
+		viewModel.clearAllForumPostNotifications();
+		// The attributes and sorting of the forums may have changed while we
+		// were stopped and we have no way finding out about them, so re-load
+		// e.g. less unread posts in a forum after viewing it.
+		viewModel.loadForums();
+		// The number of invitations might have changed while we were stopped
+		// e.g. because of accepting an invitation which does not trigger event
+		viewModel.loadForumInvitations();
 		list.startPeriodicUpdate();
 	}
 
 	@Override
 	public void onStop() {
 		super.onStop();
-		adapter.clear();
-		list.showProgressBar();
 		list.stopPeriodicUpdate();
+		viewModel.unblockAllForumPostNotifications();
 	}
 
 	@Override
@@ -144,123 +128,12 @@ public class ForumListFragment extends BaseEventFragment implements
 	@Override
 	public boolean onOptionsItemSelected(MenuItem item) {
 		// Handle presses on the action bar items
-		switch (item.getItemId()) {
-			case R.id.action_create_forum:
-				Intent intent =
-						new Intent(getContext(), CreateForumActivity.class);
-				startActivity(intent);
-				return true;
-			default:
-				return super.onOptionsItemSelected(item);
+		if (item.getItemId() == R.id.action_create_forum) {
+			Intent intent = new Intent(getContext(), CreateForumActivity.class);
+			startActivity(intent);
+			return true;
 		}
-	}
-
-	private void loadForums() {
-		int revision = adapter.getRevision();
-		listener.runOnDbThread(() -> {
-			try {
-				long start = now();
-				Collection<ForumListItem> forums = new ArrayList<>();
-				for (Forum f : forumManager.getForums()) {
-					try {
-						GroupCount count =
-								forumManager.getGroupCount(f.getId());
-						forums.add(new ForumListItem(f, count));
-					} catch (NoSuchGroupException e) {
-						// Continue
-					}
-				}
-				logDuration(LOG, "Full load", start);
-				displayForums(revision, forums);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
-		});
-	}
-
-	private void displayForums(int revision, Collection<ForumListItem> forums) {
-		runOnUiThreadUnlessDestroyed(() -> {
-			if (revision == adapter.getRevision()) {
-				adapter.incrementRevision();
-				if (forums.isEmpty()) list.showData();
-				else adapter.replaceAll(forums);
-			} else {
-				LOG.info("Concurrent update, reloading");
-				loadForums();
-			}
-		});
-	}
-
-	private void loadAvailableForums() {
-		listener.runOnDbThread(() -> {
-			try {
-				long start = now();
-				int available = forumSharingManager.getInvitations().size();
-				logDuration(LOG, "Loading available", start);
-				displayAvailableForums(available);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
-		});
-	}
-
-	private void displayAvailableForums(int availableCount) {
-		runOnUiThreadUnlessDestroyed(() -> {
-			if (availableCount == 0) {
-				snackbar.dismiss();
-			} else {
-				snackbar.setText(getResources().getQuantityString(
-						R.plurals.forums_shared, availableCount,
-						availableCount));
-				if (!snackbar.isShownOrQueued()) snackbar.show();
-			}
-		});
-	}
-
-	@Override
-	public void eventOccurred(Event e) {
-		if (e instanceof ContactRemovedEvent) {
-			LOG.info("Contact removed, reloading available forums");
-			loadAvailableForums();
-		} else if (e instanceof GroupAddedEvent) {
-			GroupAddedEvent g = (GroupAddedEvent) e;
-			if (g.getGroup().getClientId().equals(CLIENT_ID)) {
-				LOG.info("Forum added, reloading forums");
-				loadForums();
-			}
-		} else if (e instanceof GroupRemovedEvent) {
-			GroupRemovedEvent g = (GroupRemovedEvent) e;
-			if (g.getGroup().getClientId().equals(CLIENT_ID)) {
-				LOG.info("Forum removed, removing from list");
-				removeForum(g.getGroup().getId());
-			}
-		} else if (e instanceof ForumPostReceivedEvent) {
-			ForumPostReceivedEvent f = (ForumPostReceivedEvent) e;
-			LOG.info("Forum post added, updating item");
-			updateItem(f.getGroupId(), f.getHeader());
-		} else if (e instanceof ForumInvitationRequestReceivedEvent) {
-			LOG.info("Forum invitation received, reloading available forums");
-			loadAvailableForums();
-		}
-	}
-
-	@UiThread
-	private void updateItem(GroupId g, ForumPostHeader m) {
-		adapter.incrementRevision();
-		int position = adapter.findItemPosition(g);
-		ForumListItem item = adapter.getItemAt(position);
-		if (item != null) {
-			item.addHeader(m);
-			adapter.updateItemAt(position, item);
-		}
-	}
-
-	@UiThread
-	private void removeForum(GroupId g) {
-		adapter.incrementRevision();
-		int position = adapter.findItemPosition(g);
-		ForumListItem item = adapter.getItemAt(position);
-		if (item != null) adapter.remove(item);
+		return super.onOptionsItemSelected(item);
 	}
 
 	@Override

briar-android/src/main/java/org/briarproject/briar/android/forum/ForumListItem.java

@@ -4,12 +4,16 @@ import org.briarproject.briar.api.client.MessageTracker.GroupCount;
 import org.briarproject.briar.api.forum.Forum;
 import org.briarproject.briar.api.forum.ForumPostHeader;
 
-// This class is NOT thread-safe
-class ForumListItem {
+import javax.annotation.concurrent.Immutable;
+
+import androidx.annotation.Nullable;
+
+@Immutable
+class ForumListItem implements Comparable<ForumListItem> {
 
 	private final Forum forum;
-	private int postCount, unread;
-	private long timestamp;
+	private final int postCount, unread;
+	private final long timestamp;
 
 	ForumListItem(Forum forum, GroupCount count) {
 		this.forum = forum;
@@ -18,10 +22,11 @@ class ForumListItem {
 		this.timestamp = count.getLatestMsgTime();
 	}
 
-	void addHeader(ForumPostHeader h) {
-		postCount++;
-		if (!h.isRead()) unread++;
-		if (h.getTimestamp() > timestamp) timestamp = h.getTimestamp();
+	ForumListItem(ForumListItem item, ForumPostHeader h) {
+		this.forum = item.forum;
+		this.postCount = item.postCount + 1;
+		this.unread = item.unread + (h.isRead() ? 0 : 1);
+		this.timestamp = Math.max(item.timestamp, h.getTimestamp());
 	}
 
 	Forum getForum() {
@@ -43,4 +48,29 @@ class ForumListItem {
 	int getUnreadCount() {
 		return unread;
 	}
+
+	@Override
+	public int hashCode() {
+		return forum.getId().hashCode();
+	}
+
+	@Override
+	public boolean equals(@Nullable Object o) {
+		return o instanceof ForumListItem && getForum().equals(
+				((ForumListItem) o).getForum());
+	}
+
+	@Override
+	public int compareTo(ForumListItem o) {
+		if (this == o) return 0;
+		// The forum with the newest message comes first
+		long aTime = getTimestamp(), bTime = o.getTimestamp();
+		if (aTime > bTime) return -1;
+		if (aTime < bTime) return 1;
+		// Break ties by forum name
+		String aName = getForum().getName();
+		String bName = o.getForum().getName();
+		return String.CASE_INSENSITIVE_ORDER.compare(aName, bName);
+	}
+
 }

briar-android/src/main/java/org/briarproject/briar/android/forum/ForumListViewModel.java

@@ -0,0 +1,187 @@
+package org.briarproject.briar.android.forum;
+
+import android.app.Application;
+
+import org.briarproject.bramble.api.contact.event.ContactRemovedEvent;
+import org.briarproject.bramble.api.db.DatabaseExecutor;
+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.event.Event;
+import org.briarproject.bramble.api.event.EventBus;
+import org.briarproject.bramble.api.event.EventListener;
+import org.briarproject.bramble.api.lifecycle.LifecycleManager;
+import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
+import org.briarproject.bramble.api.sync.GroupId;
+import org.briarproject.bramble.api.sync.event.GroupAddedEvent;
+import org.briarproject.bramble.api.sync.event.GroupRemovedEvent;
+import org.briarproject.bramble.api.system.AndroidExecutor;
+import org.briarproject.briar.android.viewmodel.DbViewModel;
+import org.briarproject.briar.android.viewmodel.LiveResult;
+import org.briarproject.briar.api.android.AndroidNotificationManager;
+import org.briarproject.briar.api.client.MessageTracker.GroupCount;
+import org.briarproject.briar.api.forum.Forum;
+import org.briarproject.briar.api.forum.ForumManager;
+import org.briarproject.briar.api.forum.ForumPostHeader;
+import org.briarproject.briar.api.forum.ForumSharingManager;
+import org.briarproject.briar.api.forum.event.ForumInvitationRequestReceivedEvent;
+import org.briarproject.briar.api.forum.event.ForumPostReceivedEvent;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.concurrent.Executor;
+import java.util.logging.Logger;
+
+import javax.inject.Inject;
+
+import androidx.annotation.UiThread;
+import androidx.lifecycle.LiveData;
+import androidx.lifecycle.MutableLiveData;
+
+import static java.util.logging.Level.WARNING;
+import static java.util.logging.Logger.getLogger;
+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 org.briarproject.briar.api.forum.ForumManager.CLIENT_ID;
+
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
+class ForumListViewModel extends DbViewModel implements EventListener {
+
+	private static final Logger LOG =
+			getLogger(ForumListViewModel.class.getName());
+
+	private final ForumManager forumManager;
+	private final ForumSharingManager forumSharingManager;
+	private final AndroidNotificationManager notificationManager;
+	private final EventBus eventBus;
+
+	private final MutableLiveData<LiveResult<List<ForumListItem>>> forumItems =
+			new MutableLiveData<>();
+	private final MutableLiveData<Integer> numInvitations =
+			new MutableLiveData<>();
+
+	@Inject
+	ForumListViewModel(Application application,
+			@DatabaseExecutor Executor dbExecutor,
+			LifecycleManager lifecycleManager,
+			TransactionManager db,
+			AndroidExecutor androidExecutor,
+			ForumManager forumManager,
+			ForumSharingManager forumSharingManager,
+			AndroidNotificationManager notificationManager, EventBus eventBus) {
+		super(application, dbExecutor, lifecycleManager, db, androidExecutor);
+		this.forumManager = forumManager;
+		this.forumSharingManager = forumSharingManager;
+		this.notificationManager = notificationManager;
+		this.eventBus = eventBus;
+		this.eventBus.addListener(this);
+	}
+
+	@Override
+	protected void onCleared() {
+		super.onCleared();
+		eventBus.removeListener(this);
+	}
+
+	void clearAllForumPostNotifications() {
+		notificationManager.clearAllForumPostNotifications();
+	}
+
+	void blockAllForumPostNotifications() {
+		notificationManager.blockAllForumPostNotifications();
+	}
+
+	void unblockAllForumPostNotifications() {
+		notificationManager.unblockAllForumPostNotifications();
+	}
+
+	@Override
+	public void eventOccurred(Event e) {
+		if (e instanceof ContactRemovedEvent) {
+			LOG.info("Contact removed, reloading available forums");
+			loadForumInvitations();
+		} else if (e instanceof ForumInvitationRequestReceivedEvent) {
+			LOG.info("Forum invitation received, reloading available forums");
+			loadForumInvitations();
+		} else if (e instanceof GroupAddedEvent) {
+			GroupAddedEvent g = (GroupAddedEvent) e;
+			if (g.getGroup().getClientId().equals(CLIENT_ID)) {
+				LOG.info("Forum added, reloading forums");
+				loadForums();
+			}
+		} else if (e instanceof GroupRemovedEvent) {
+			GroupRemovedEvent g = (GroupRemovedEvent) e;
+			if (g.getGroup().getClientId().equals(CLIENT_ID)) {
+				LOG.info("Forum removed, removing from list");
+				onGroupRemoved(g.getGroup().getId());
+			}
+		} else if (e instanceof ForumPostReceivedEvent) {
+			ForumPostReceivedEvent f = (ForumPostReceivedEvent) e;
+			LOG.info("Forum post added, updating item");
+			onForumPostReceived(f.getGroupId(), f.getHeader());
+		}
+	}
+
+	public void loadForums() {
+		loadList(this::loadForums, forumItems::setValue);
+	}
+
+	@DatabaseExecutor
+	private List<ForumListItem> loadForums(Transaction txn) throws DbException {
+		long start = now();
+		List<ForumListItem> forums = new ArrayList<>();
+		for (Forum f : forumManager.getForums(txn)) {
+			GroupCount count = forumManager.getGroupCount(txn, f.getId());
+			forums.add(new ForumListItem(f, count));
+		}
+		Collections.sort(forums);
+		logDuration(LOG, "Loading forums", start);
+		return forums;
+	}
+
+	@UiThread
+	private void onForumPostReceived(GroupId g, ForumPostHeader header) {
+		List<ForumListItem> list = updateListItems(forumItems,
+				itemToTest -> itemToTest.getForum().getId().equals(g),
+				itemToUpdate -> new ForumListItem(itemToUpdate, header));
+		if (list == null) return;
+		// re-sort as the order of items may have changed
+		Collections.sort(list);
+		forumItems.setValue(new LiveResult<>(list));
+	}
+
+	@UiThread
+	private void onGroupRemoved(GroupId groupId) {
+		List<ForumListItem> list = removeListItems(forumItems, i ->
+				i.getForum().getId().equals(groupId)
+		);
+		if (list == null) return;
+		forumItems.setValue(new LiveResult<>(list));
+	}
+
+	void loadForumInvitations() {
+		runOnDbThread(() -> {
+			try {
+				long start = now();
+				int available = forumSharingManager.getInvitations().size();
+				logDuration(LOG, "Loading available", start);
+				numInvitations.postValue(available);
+			} catch (DbException e) {
+				logException(LOG, WARNING, e);
+			}
+		});
+	}
+
+	LiveData<LiveResult<List<ForumListItem>>> getForumListItems() {
+		return forumItems;
+	}
+
+	LiveData<Integer> getNumInvitations() {
+		return numInvitations;
+	}
+
+}

briar-android/src/main/java/org/briarproject/briar/android/forum/ForumModule.java

@@ -2,13 +2,25 @@ package org.briarproject.briar.android.forum;
 
 import org.briarproject.briar.android.activity.ActivityScope;
 import org.briarproject.briar.android.activity.BaseActivity;
+import org.briarproject.briar.android.viewmodel.ViewModelKey;
 
+import androidx.lifecycle.ViewModel;
+import dagger.Binds;
 import dagger.Module;
 import dagger.Provides;
+import dagger.multibindings.IntoMap;
 
 @Module
 public class ForumModule {
 
+	@Module
+	public interface BindsModule {
+		@Binds
+		@IntoMap
+		@ViewModelKey(ForumListViewModel.class)
+		ViewModel bindForumListViewModel(ForumListViewModel forumListViewModel);
+	}
+
 	@ActivityScope
 	@Provides
 	ForumController provideForumController(BaseActivity activity,

briar-android/src/main/java/org/briarproject/briar/android/forum/ForumPostItem.java

@@ -10,15 +10,15 @@ import javax.annotation.Nullable;
 import javax.annotation.concurrent.NotThreadSafe;
 
 @NotThreadSafe
-class ForumItem extends ThreadItem {
+class ForumPostItem extends ThreadItem {
 
-	ForumItem(ForumPostHeader h, String text) {
+	ForumPostItem(ForumPostHeader h, String text) {
 		super(h.getId(), h.getParentId(), text, h.getTimestamp(), h.getAuthor(),
 				h.getAuthorInfo(), h.isRead());
 	}
 
-	ForumItem(MessageId messageId, @Nullable MessageId parentId, String text,
-			long timestamp, Author author, AuthorInfo authorInfo) {
+	ForumPostItem(MessageId messageId, @Nullable MessageId parentId,
+			String text, long timestamp, Author author, AuthorInfo authorInfo) {
 		super(messageId, parentId, text, timestamp, author, authorInfo, true);
 	}
 

briar-android/src/main/java/org/briarproject/briar/android/forum/ForumViewHolder.java

@@ -0,0 +1,77 @@
+package org.briarproject.briar.android.forum;
+
+import android.content.Context;
+import android.content.Intent;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.TextView;
+
+import org.briarproject.briar.R;
+import org.briarproject.briar.android.util.UiUtils;
+import org.briarproject.briar.android.view.TextAvatarView;
+import org.briarproject.briar.api.forum.Forum;
+
+import androidx.recyclerview.widget.RecyclerView;
+
+import static android.view.View.GONE;
+import static android.view.View.VISIBLE;
+import static org.briarproject.briar.android.activity.BriarActivity.GROUP_ID;
+import static org.briarproject.briar.android.activity.BriarActivity.GROUP_NAME;
+
+class ForumViewHolder extends RecyclerView.ViewHolder {
+
+	private final Context ctx;
+	private final ViewGroup layout;
+	private final TextAvatarView avatar;
+	private final TextView name;
+	private final TextView postCount;
+	private final TextView date;
+
+	ForumViewHolder(View v) {
+		super(v);
+		ctx = v.getContext();
+		layout = (ViewGroup) v;
+		avatar = v.findViewById(R.id.avatarView);
+		name = v.findViewById(R.id.forumNameView);
+		postCount = v.findViewById(R.id.postCountView);
+		date = v.findViewById(R.id.dateView);
+	}
+
+	void bind(ForumListItem item) {
+		// Avatar
+		avatar.setText(item.getForum().getName().substring(0, 1));
+		avatar.setBackgroundBytes(item.getForum().getId().getBytes());
+		avatar.setUnreadCount(item.getUnreadCount());
+
+		// Forum Name
+		name.setText(item.getForum().getName());
+
+		// Post Count
+		int count = item.getPostCount();
+		if (count > 0) {
+			postCount.setText(ctx.getResources()
+					.getQuantityString(R.plurals.posts, count, count));
+		} else {
+			postCount.setText(ctx.getString(R.string.no_posts));
+		}
+
+		// Date
+		if (item.isEmpty()) {
+			date.setVisibility(GONE);
+		} else {
+			long timestamp = item.getTimestamp();
+			date.setText(UiUtils.formatDate(ctx, timestamp));
+			date.setVisibility(VISIBLE);
+		}
+
+		// Open Forum on Click
+		layout.setOnClickListener(v -> {
+			Intent i = new Intent(ctx, ForumActivity.class);
+			Forum f = item.getForum();
+			i.putExtra(GROUP_ID, f.getId().getBytes());
+			i.putExtra(GROUP_NAME, f.getName());
+			ctx.startActivity(i);
+		});
+	}
+
+}

briar-android/src/main/java/org/briarproject/briar/android/fragment/BaseFragment.java

@@ -5,7 +5,6 @@ import android.content.Context;
 import android.os.Bundle;
 import android.view.MenuItem;
 
-import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.briar.android.DestroyableContext;
@@ -77,7 +76,7 @@ public abstract class BaseFragment extends Fragment
 		void showNextFragment(BaseFragment f);
 
 		@UiThread
-		void handleDbException(DbException e);
+		void handleException(Exception e);
 	}
 
 	@CallSuper
@@ -100,8 +99,8 @@ public abstract class BaseFragment extends Fragment
 	}
 
 	@UiThread
-	protected void handleDbException(DbException e) {
-		listener.handleDbException(e);
+	protected void handleException(Exception e) {
+		listener.handleException(e);
 	}
 
 }

briar-android/src/main/java/org/briarproject/briar/android/fragment/ScreenFilterDialogFragment.java

@@ -5,6 +5,7 @@ import android.app.Activity;
 import android.app.Dialog;
 import android.content.Context;
 import android.content.DialogInterface;
+import android.content.Intent;
 import android.os.Bundle;
 import android.text.TextUtils;
 import android.view.LayoutInflater;
@@ -28,6 +29,10 @@ import javax.inject.Inject;
 import androidx.appcompat.app.AlertDialog;
 import androidx.fragment.app.DialogFragment;
 
+import static android.os.Build.VERSION.SDK_INT;
+import static android.provider.Settings.ACTION_MANAGE_OVERLAY_PERMISSION;
+import static android.view.View.GONE;
+
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
 public class ScreenFilterDialogFragment extends DialogFragment {
@@ -37,7 +42,7 @@ public class ScreenFilterDialogFragment extends DialogFragment {
 	@Inject
 	ScreenFilterMonitor screenFilterMonitor;
 
-	DismissListener dismissListener = null;
+	private DismissListener dismissListener = null;
 
 	public static ScreenFilterDialogFragment newInstance(
 			Collection<AppDetails> apps) {
@@ -83,10 +88,20 @@ public class ScreenFilterDialogFragment extends DialogFragment {
 		View dialogView = inflater.inflate(R.layout.dialog_screen_filter, null);
 		builder.setView(dialogView);
 		TextView message = dialogView.findViewById(R.id.screen_filter_message);
-		message.setText(getString(R.string.screen_filter_body,
-				TextUtils.join("\n", appNames)));
 		CheckBox allow = dialogView.findViewById(R.id.screen_filter_checkbox);
-		builder.setNeutralButton(R.string.continue_button, (dialog, which) -> {
+		if (SDK_INT <= 29) {
+			message.setText(getString(R.string.screen_filter_body,
+					TextUtils.join("\n", appNames)));
+		} else {
+			message.setText(R.string.screen_filter_body_api_30);
+			allow.setVisibility(GONE);
+			builder.setNeutralButton(R.string.screen_filter_review_apps,
+					(dialog, which) -> {
+						Intent i = new Intent(ACTION_MANAGE_OVERLAY_PERMISSION);
+						startActivity(i);
+					});
+		}
+		builder.setPositiveButton(R.string.continue_button, (dialog, which) -> {
 			if (allow.isChecked()) screenFilterMonitor.allowApps(packageNames);
 			dialog.dismiss();
 		});

briar-android/src/main/java/org/briarproject/briar/android/introduction/IntroductionMessageFragment.java

@@ -211,7 +211,8 @@ public class IntroductionMessageFragment extends BaseFragment
 		introductionActivity.runOnDbThread(() -> {
 			// actually make the introduction
 			try {
-				introductionManager.makeIntroduction(c1, c2, text);
+				long timestamp = System.currentTimeMillis();
+				introductionManager.makeIntroduction(c1, c2, text, timestamp);
 			} catch (DbException e) {
 				logException(LOG, WARNING, e);
 				introductionError();

briar-android/src/main/java/org/briarproject/briar/android/keyagreement/ContactExchangeErrorFragment.java

@@ -10,14 +10,11 @@ import android.widget.TextView;
 
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
-import org.briarproject.bramble.api.system.AndroidExecutor;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.ActivityComponent;
 import org.briarproject.briar.android.fragment.BaseFragment;
 import org.briarproject.briar.android.util.UiUtils;
 
-import javax.inject.Inject;
-
 import androidx.annotation.Nullable;
 import androidx.fragment.app.FragmentActivity;
 
@@ -41,9 +38,6 @@ public class ContactExchangeErrorFragment extends BaseFragment {
 		return f;
 	}
 
-	@Inject
-	AndroidExecutor androidExecutor;
-
 	@Override
 	public String getUniqueTag() {
 		return TAG;
@@ -88,8 +82,8 @@ public class ContactExchangeErrorFragment extends BaseFragment {
 	}
 
 	private void triggerFeedback() {
+		UiUtils.triggerFeedback(requireContext());
 		finish();
-		UiUtils.triggerFeedback(androidExecutor);
 	}
 
 }

briar-android/src/main/java/org/briarproject/briar/android/navdrawer/NavDrawerActivity.java

@@ -17,7 +17,6 @@ import android.widget.TextView;
 import com.google.android.material.navigation.NavigationView;
 import com.google.android.material.navigation.NavigationView.OnNavigationItemSelectedListener;
 
-import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
@@ -365,7 +364,7 @@ public class NavDrawerActivity extends BriarActivity implements
 	}
 
 	@Override
-	public void handleDbException(DbException e) {
+	public void handleException(Exception e) {
 		// Do nothing for now
 	}
 

briar-android/src/main/java/org/briarproject/briar/android/navdrawer/NavDrawerViewModel.java

@@ -4,9 +4,13 @@ import android.app.Application;
 
 import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.db.TransactionManager;
+import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.settings.Settings;
 import org.briarproject.bramble.api.settings.SettingsManager;
+import org.briarproject.bramble.api.system.AndroidExecutor;
+import org.briarproject.briar.android.viewmodel.DbViewModel;
 
 import java.util.concurrent.Executor;
 import java.util.logging.Logger;
@@ -14,7 +18,6 @@ import java.util.logging.Logger;
 import javax.inject.Inject;
 
 import androidx.annotation.UiThread;
-import androidx.lifecycle.AndroidViewModel;
 import androidx.lifecycle.LiveData;
 import androidx.lifecycle.MutableLiveData;
 
@@ -28,7 +31,7 @@ import static org.briarproject.briar.android.settings.SettingsFragment.SETTINGS_
 import static org.briarproject.briar.android.util.UiUtils.needsDozeWhitelisting;
 
 @NotNullByDefault
-public class NavDrawerViewModel extends AndroidViewModel {
+public class NavDrawerViewModel extends DbViewModel {
 
 	private static final Logger LOG =
 			getLogger(NavDrawerViewModel.class.getName());
@@ -37,8 +40,6 @@ public class NavDrawerViewModel extends AndroidViewModel {
 	private static final String SHOW_TRANSPORTS_ONBOARDING =
 			"showTransportsOnboarding";
 
-	@DatabaseExecutor
-	private final Executor dbExecutor;
 	private final SettingsManager settingsManager;
 
 	private final MutableLiveData<Boolean> showExpiryWarning =
@@ -49,10 +50,13 @@ public class NavDrawerViewModel extends AndroidViewModel {
 			new MutableLiveData<>();
 
 	@Inject
-	NavDrawerViewModel(Application app, @DatabaseExecutor Executor dbExecutor,
+	NavDrawerViewModel(Application app,
+			@DatabaseExecutor Executor dbExecutor,
+			LifecycleManager lifecycleManager,
+			TransactionManager db,
+			AndroidExecutor androidExecutor,
 			SettingsManager settingsManager) {
-		super(app);
-		this.dbExecutor = dbExecutor;
+		super(app, dbExecutor, lifecycleManager, db, androidExecutor);
 		this.settingsManager = settingsManager;
 	}
 
@@ -62,7 +66,7 @@ public class NavDrawerViewModel extends AndroidViewModel {
 
 	@UiThread
 	void checkExpiryWarning() {
-		dbExecutor.execute(() -> {
+		runOnDbThread(() -> {
 			try {
 				Settings settings =
 						settingsManager.getSettings(SETTINGS_NAMESPACE);
@@ -97,7 +101,7 @@ public class NavDrawerViewModel extends AndroidViewModel {
 	@UiThread
 	void expiryWarningDismissed() {
 		showExpiryWarning.setValue(false);
-		dbExecutor.execute(() -> {
+		runOnDbThread(() -> {
 			try {
 				Settings settings = new Settings();
 				int date = (int) (System.currentTimeMillis() / 1000L);
@@ -120,7 +124,7 @@ public class NavDrawerViewModel extends AndroidViewModel {
 			shouldAskForDozeWhitelisting.setValue(false);
 			return;
 		}
-		dbExecutor.execute(() -> {
+		runOnDbThread(() -> {
 			try {
 				Settings settings =
 						settingsManager.getSettings(SETTINGS_NAMESPACE);
@@ -141,7 +145,7 @@ public class NavDrawerViewModel extends AndroidViewModel {
 	@UiThread
 	void checkTransportsOnboarding() {
 		if (showTransportsOnboarding.getValue() != null) return;
-		dbExecutor.execute(() -> {
+		runOnDbThread(() -> {
 			try {
 				Settings settings =
 						settingsManager.getSettings(SETTINGS_NAMESPACE);
@@ -157,7 +161,7 @@ public class NavDrawerViewModel extends AndroidViewModel {
 	@UiThread
 	void transportsOnboardingShown() {
 		showTransportsOnboarding.setValue(false);
-		dbExecutor.execute(() -> {
+		runOnDbThread(() -> {
 			try {
 				Settings settings = new Settings();
 				settings.putBoolean(SHOW_TRANSPORTS_ONBOARDING, false);

briar-android/src/main/java/org/briarproject/briar/android/navdrawer/PluginViewModel.java

@@ -9,9 +9,11 @@ import android.content.IntentFilter;
 
 import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.db.DbException;
+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.LifecycleManager;
 import org.briarproject.bramble.api.network.NetworkManager;
 import org.briarproject.bramble.api.network.NetworkStatus;
 import org.briarproject.bramble.api.network.event.NetworkStatusEvent;
@@ -27,6 +29,8 @@ import org.briarproject.bramble.api.plugin.event.TransportStateEvent;
 import org.briarproject.bramble.api.settings.Settings;
 import org.briarproject.bramble.api.settings.SettingsManager;
 import org.briarproject.bramble.api.settings.event.SettingsUpdatedEvent;
+import org.briarproject.bramble.api.system.AndroidExecutor;
+import org.briarproject.briar.android.viewmodel.DbViewModel;
 
 import java.util.concurrent.Executor;
 import java.util.logging.Logger;
@@ -34,7 +38,6 @@ import java.util.logging.Logger;
 import javax.inject.Inject;
 
 import androidx.annotation.Nullable;
-import androidx.lifecycle.AndroidViewModel;
 import androidx.lifecycle.LiveData;
 import androidx.lifecycle.MutableLiveData;
 
@@ -51,13 +54,12 @@ import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.bramble.util.LogUtils.now;
 
 @NotNullByDefault
-public class PluginViewModel extends AndroidViewModel implements EventListener {
+public class PluginViewModel extends DbViewModel implements EventListener {
 
 	private static final Logger LOG =
 			getLogger(PluginViewModel.class.getName());
 
 	private final Application app;
-	private final Executor dbExecutor;
 	private final SettingsManager settingsManager;
 	private final PluginManager pluginManager;
 	private final EventBus eventBus;
@@ -85,11 +87,12 @@ public class PluginViewModel extends AndroidViewModel implements EventListener {
 
 	@Inject
 	PluginViewModel(Application app, @DatabaseExecutor Executor dbExecutor,
-			SettingsManager settingsManager, PluginManager pluginManager,
-			EventBus eventBus, NetworkManager networkManager) {
-		super(app);
+			LifecycleManager lifecycleManager, TransactionManager db,
+			AndroidExecutor androidExecutor, SettingsManager settingsManager,
+			PluginManager pluginManager, EventBus eventBus,
+			NetworkManager networkManager) {
+		super(app, dbExecutor, lifecycleManager, db, androidExecutor);
 		this.app = app;
-		this.dbExecutor = dbExecutor;
 		this.settingsManager = settingsManager;
 		this.pluginManager = pluginManager;
 		this.eventBus = eventBus;
@@ -182,7 +185,7 @@ public class PluginViewModel extends AndroidViewModel implements EventListener {
 	}
 
 	private void loadSettings() {
-		dbExecutor.execute(() -> {
+		runOnDbThread(() -> {
 			try {
 				boolean tor = isPluginEnabled(TorConstants.ID,
 						TorConstants.DEFAULT_PREF_PLUGIN_ENABLE);
@@ -219,7 +222,7 @@ public class PluginViewModel extends AndroidViewModel implements EventListener {
 	}
 
 	private void mergeSettings(Settings s, String namespace) {
-		dbExecutor.execute(() -> {
+		runOnDbThread(() -> {
 			try {
 				long start = now();
 				settingsManager.mergeSettings(s, namespace);
@@ -235,8 +238,7 @@ public class PluginViewModel extends AndroidViewModel implements EventListener {
 		@Override
 		public void onReceive(Context context, Intent intent) {
 			int state = intent.getIntExtra(EXTRA_STATE, 0);
-			if (state == STATE_ON) bluetoothTurnedOn.postValue(true);
-			else bluetoothTurnedOn.postValue(false);
+			bluetoothTurnedOn.postValue(state == STATE_ON);
 		}
 	}
 }

briar-android/src/main/java/org/briarproject/briar/android/panic/PanicPreferencesFragment.java

@@ -82,6 +82,7 @@ public class PanicPreferencesFragment extends PreferenceFragmentCompat
 		entries.add(0, getString(R.string.panic_app_setting_none));
 		entryValues.add(0, PACKAGE_NAME_NONE);
 
+		// only info.guardianproject.ripple is whitelisted in manifest
 		for (ResolveInfo resolveInfo : PanicResponder.resolveTriggerApps(pm)) {
 			if (resolveInfo.activityInfo == null)
 				continue;

briar-android/src/main/java/org/briarproject/briar/android/privategroup/conversation/GroupActivity.java

@@ -106,7 +106,7 @@ public class GroupActivity extends
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						handleDbException(exception);
+						handleException(exception);
 					}
 				});
 	}
@@ -125,7 +125,7 @@ public class GroupActivity extends
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						handleDbException(exception);
+						handleException(exception);
 					}
 				});
 	}
@@ -264,7 +264,7 @@ public class GroupActivity extends
 					// GroupRemovedEvent being fired
 					@Override
 					public void onExceptionUi(DbException exception) {
-						handleDbException(exception);
+						handleException(exception);
 					}
 				});
 	}

briar-android/src/main/java/org/briarproject/briar/android/privategroup/creation/CreateGroupActivity.java

@@ -51,7 +51,7 @@ public class CreateGroupActivity extends BriarActivity
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						handleDbException(exception);
+						handleException(exception);
 					}
 				});
 	}

briar-android/src/main/java/org/briarproject/briar/android/privategroup/creation/CreateGroupControllerImpl.java

@@ -7,8 +7,6 @@ import org.briarproject.bramble.api.crypto.CryptoExecutor;
 import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.NoSuchContactException;
-import org.briarproject.bramble.api.db.Transaction;
-import org.briarproject.bramble.api.db.TransactionManager;
 import org.briarproject.bramble.api.identity.IdentityManager;
 import org.briarproject.bramble.api.identity.LocalAuthor;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
@@ -17,8 +15,6 @@ import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.briar.android.contactselection.ContactSelectorControllerImpl;
 import org.briarproject.briar.android.controller.handler.ResultExceptionHandler;
-import org.briarproject.briar.api.autodelete.AutoDeleteManager;
-import org.briarproject.briar.api.conversation.ConversationManager;
 import org.briarproject.briar.api.privategroup.GroupMessage;
 import org.briarproject.briar.api.privategroup.GroupMessageFactory;
 import org.briarproject.briar.api.privategroup.PrivateGroup;
@@ -39,8 +35,6 @@ import javax.inject.Inject;
 import androidx.annotation.Nullable;
 
 import static java.util.logging.Level.WARNING;
-import static java.util.logging.Logger.getLogger;
-import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
 import static org.briarproject.bramble.util.LogUtils.logException;
 
 @Immutable
@@ -49,12 +43,9 @@ class CreateGroupControllerImpl extends ContactSelectorControllerImpl
 		implements CreateGroupController {
 
 	private static final Logger LOG =
-			getLogger(CreateGroupControllerImpl.class.getName());
+			Logger.getLogger(CreateGroupControllerImpl.class.getName());
 
 	private final Executor cryptoExecutor;
-	private final TransactionManager db;
-	private final AutoDeleteManager autoDeleteManager;
-	private final ConversationManager conversationManager;
 	private final ContactManager contactManager;
 	private final IdentityManager identityManager;
 	private final PrivateGroupFactory groupFactory;
@@ -65,26 +56,16 @@ class CreateGroupControllerImpl extends ContactSelectorControllerImpl
 	private final Clock clock;
 
 	@Inject
-	CreateGroupControllerImpl(
-			@DatabaseExecutor Executor dbExecutor,
+	CreateGroupControllerImpl(@DatabaseExecutor Executor dbExecutor,
 			@CryptoExecutor Executor cryptoExecutor,
-			TransactionManager db,
-			AutoDeleteManager autoDeleteManager,
-			ConversationManager conversationManager,
-			LifecycleManager lifecycleManager,
-			ContactManager contactManager,
-			IdentityManager identityManager,
-			PrivateGroupFactory groupFactory,
+			LifecycleManager lifecycleManager, ContactManager contactManager,
+			IdentityManager identityManager, PrivateGroupFactory groupFactory,
 			GroupMessageFactory groupMessageFactory,
 			PrivateGroupManager groupManager,
 			GroupInvitationFactory groupInvitationFactory,
-			GroupInvitationManager groupInvitationManager,
-			Clock clock) {
+			GroupInvitationManager groupInvitationManager, Clock clock) {
 		super(dbExecutor, lifecycleManager, contactManager);
 		this.cryptoExecutor = cryptoExecutor;
-		this.db = db;
-		this.autoDeleteManager = autoDeleteManager;
-		this.conversationManager = conversationManager;
 		this.contactManager = contactManager;
 		this.identityManager = identityManager;
 		this.groupFactory = groupFactory;
@@ -148,14 +129,16 @@ class CreateGroupControllerImpl extends ContactSelectorControllerImpl
 			ResultExceptionHandler<Void, DbException> handler) {
 		runOnDbThread(() -> {
 			try {
-				db.transaction(true, txn -> {
-					LocalAuthor localAuthor =
-							identityManager.getLocalAuthor(txn);
-					List<InvitationContext> contexts =
-							createInvitationContexts(txn, contactIds);
-					txn.attach(() -> signInvitations(g, localAuthor, contexts,
-							text, handler));
-				});
+				LocalAuthor localAuthor = identityManager.getLocalAuthor();
+				List<Contact> contacts = new ArrayList<>();
+				for (ContactId c : contactIds) {
+					try {
+						contacts.add(contactManager.getContact(c));
+					} catch (NoSuchContactException e) {
+						// Continue
+					}
+				}
+				signInvitations(g, localAuthor, contacts, text, handler);
 			} catch (DbException e) {
 				logException(LOG, WARNING, e);
 				handler.onException(e);
@@ -163,32 +146,17 @@ class CreateGroupControllerImpl extends ContactSelectorControllerImpl
 		});
 	}
 
-	private List<InvitationContext> createInvitationContexts(Transaction txn,
-			Collection<ContactId> contactIds) throws DbException {
-		List<InvitationContext> contexts = new ArrayList<>();
-		for (ContactId c : contactIds) {
-			try {
-				Contact contact = contactManager.getContact(txn, c);
-				long timestamp = conversationManager
-						.getTimestampForOutgoingMessage(txn, c);
-				long timer = autoDeleteManager.getAutoDeleteTimer(txn, c,
-						timestamp);
-				contexts.add(new InvitationContext(contact, timestamp, timer));
-			} catch (NoSuchContactException e) {
-				// Continue
-			}
-		}
-		return contexts;
-	}
-
 	private void signInvitations(GroupId g, LocalAuthor localAuthor,
-			List<InvitationContext> contexts, @Nullable String text,
+			Collection<Contact> contacts, @Nullable String text,
 			ResultExceptionHandler<Void, DbException> handler) {
 		cryptoExecutor.execute(() -> {
-			for (InvitationContext ctx : contexts) {
-				ctx.signature = groupInvitationFactory.signInvitation(
-						ctx.contact, g, ctx.timestamp,
-						localAuthor.getPrivateKey());
+			long timestamp = clock.currentTimeMillis();
+			List<InvitationContext> contexts = new ArrayList<>();
+			for (Contact c : contacts) {
+				byte[] signature = groupInvitationFactory.signInvitation(c, g,
+						timestamp, localAuthor.getPrivateKey());
+				contexts.add(new InvitationContext(c.getId(), timestamp,
+						signature));
 			}
 			sendInvitations(g, contexts, text, handler);
 		});
@@ -199,16 +167,16 @@ class CreateGroupControllerImpl extends ContactSelectorControllerImpl
 			ResultExceptionHandler<Void, DbException> handler) {
 		runOnDbThread(() -> {
 			try {
-				for (InvitationContext ctx : contexts) {
+				for (InvitationContext context : contexts) {
 					try {
 						groupInvitationManager.sendInvitation(g,
-								ctx.contact.getId(), text, ctx.timestamp,
-								requireNonNull(ctx.signature),
-								ctx.autoDeleteTimer);
+								context.contactId, text, context.timestamp,
+								context.signature);
 					} catch (NoSuchContactException e) {
 						// Continue
 					}
 				}
+				//noinspection ConstantConditions
 				handler.onResult(null);
 			} catch (DbException e) {
 				logException(LOG, WARNING, e);
@@ -219,16 +187,15 @@ class CreateGroupControllerImpl extends ContactSelectorControllerImpl
 
 	private static class InvitationContext {
 
-		private final Contact contact;
-		private final long timestamp, autoDeleteTimer;
-		@Nullable
-		private byte[] signature = null;
+		private final ContactId contactId;
+		private final long timestamp;
+		private final byte[] signature;
 
-		private InvitationContext(Contact contact, long timestamp,
-				long autoDeleteTimer) {
-			this.contact = contact;
+		private InvitationContext(ContactId contactId, long timestamp,
+				byte[] signature) {
+			this.contactId = contactId;
 			this.timestamp = timestamp;
-			this.autoDeleteTimer = autoDeleteTimer;
+			this.signature = signature;
 		}
 	}
 }

briar-android/src/main/java/org/briarproject/briar/android/privategroup/creation/GroupInviteActivity.java

@@ -69,7 +69,7 @@ public class GroupInviteActivity extends ContactSelectorActivity
 					@Override
 					public void onExceptionUi(DbException exception) {
 						setResult(RESULT_CANCELED);
-						handleDbException(exception);
+						handleException(exception);
 					}
 				});
 	}

briar-android/src/main/java/org/briarproject/briar/android/privategroup/list/GroupItem.java

@@ -8,15 +8,19 @@ import org.briarproject.briar.api.client.MessageTracker.GroupCount;
 import org.briarproject.briar.api.privategroup.GroupMessageHeader;
 import org.briarproject.briar.api.privategroup.PrivateGroup;
 
-// This class is not thread-safe
+import javax.annotation.concurrent.Immutable;
+
+import androidx.annotation.Nullable;
+
+@Immutable
 @NotNullByDefault
-class GroupItem {
+class GroupItem implements Comparable<GroupItem> {
 
 	private final PrivateGroup privateGroup;
 	private final AuthorInfo authorInfo;
-	private int messageCount, unreadCount;
-	private long timestamp;
-	private boolean dissolved;
+	private final int messageCount, unreadCount;
+	private final long timestamp;
+	private final boolean dissolved;
 
 	GroupItem(PrivateGroup privateGroup, AuthorInfo authorInfo,
 			GroupCount count, boolean dissolved) {
@@ -28,18 +32,22 @@ class GroupItem {
 		this.dissolved = dissolved;
 	}
 
-	void addMessageHeader(GroupMessageHeader header) {
-		messageCount++;
-		if (header.getTimestamp() > timestamp) {
-			timestamp = header.getTimestamp();
-		}
-		if (!header.isRead()) {
-			unreadCount++;
-		}
+	GroupItem(GroupItem item, GroupMessageHeader header) {
+		this.privateGroup = item.privateGroup;
+		this.authorInfo = item.authorInfo;
+		this.messageCount = item.messageCount + 1;
+		this.unreadCount = item.unreadCount + (header.isRead() ? 0 : 1);
+		this.timestamp = Math.max(header.getTimestamp(), item.timestamp);
+		this.dissolved = item.dissolved;
 	}
 
-	PrivateGroup getPrivateGroup() {
-		return privateGroup;
+	GroupItem(GroupItem item, boolean isDissolved) {
+		this.privateGroup = item.privateGroup;
+		this.authorInfo = item.authorInfo;
+		this.messageCount = item.messageCount;
+		this.unreadCount = item.unreadCount;
+		this.timestamp = item.timestamp;
+		this.dissolved = isDissolved;
 	}
 
 	GroupId getId() {
@@ -78,8 +86,27 @@ class GroupItem {
 		return dissolved;
 	}
 
-	void setDissolved() {
-		dissolved = true;
+	@Override
+	public int hashCode() {
+		return getId().hashCode();
 	}
 
+	@Override
+	public boolean equals(@Nullable Object o) {
+		return o instanceof GroupItem &&
+				getId().equals(((GroupItem) o).getId());
+	}
+
+	@Override
+	public int compareTo(GroupItem o) {
+		if (this == o) return 0;
+		// The group with the latest message comes first
+		long aTime = getTimestamp(), bTime = o.getTimestamp();
+		if (aTime > bTime) return -1;
+		if (aTime < bTime) return 1;
+		// Break ties by group name
+		String aName = getName();
+		String bName = o.getName();
+		return String.CASE_INSENSITIVE_ORDER.compare(aName, bName);
+	}
 }

briar-android/src/main/java/org/briarproject/briar/android/privategroup/list/GroupListAdapter.java

@@ -1,81 +1,52 @@
 package org.briarproject.briar.android.privategroup.list;
 
-import android.content.Context;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
-import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.privategroup.list.GroupViewHolder.OnGroupRemoveClickListener;
-import org.briarproject.briar.android.util.BriarAdapter;
 
-import static androidx.recyclerview.widget.SortedList.INVALID_POSITION;
+import androidx.recyclerview.widget.DiffUtil.ItemCallback;
+import androidx.recyclerview.widget.ListAdapter;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
-class GroupListAdapter extends BriarAdapter<GroupItem, GroupViewHolder> {
+class GroupListAdapter extends ListAdapter<GroupItem, GroupViewHolder> {
 
 	private final OnGroupRemoveClickListener listener;
 
-	GroupListAdapter(Context ctx, OnGroupRemoveClickListener listener) {
-		super(ctx, GroupItem.class);
+	GroupListAdapter(OnGroupRemoveClickListener listener) {
+		super(new GroupItemCallback());
 		this.listener = listener;
 	}
 
 	@Override
 	public GroupViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
-		View v = LayoutInflater.from(ctx).inflate(
-				R.layout.list_item_group, parent, false);
+		View v = LayoutInflater.from(parent.getContext())
+				.inflate(R.layout.list_item_group, parent, false);
 		return new GroupViewHolder(v);
 	}
 
 	@Override
 	public void onBindViewHolder(GroupViewHolder ui, int position) {
-		ui.bindView(ctx, items.get(position), listener);
+		ui.bindView(getItem(position), listener);
 	}
 
-	@Override
-	public int compare(GroupItem a, GroupItem b) {
-		if (a == b) return 0;
-		// The group with the latest message comes first
-		long aTime = a.getTimestamp(), bTime = b.getTimestamp();
-		if (aTime > bTime) return -1;
-		if (aTime < bTime) return 1;
-		// Break ties by group name
-		String aName = a.getName();
-		String bName = b.getName();
-		return String.CASE_INSENSITIVE_ORDER.compare(aName, bName);
-	}
-
-	@Override
-	public boolean areContentsTheSame(GroupItem a, GroupItem b) {
-		return a.getMessageCount() == b.getMessageCount() &&
-				a.getTimestamp() == b.getTimestamp() &&
-				a.getUnreadCount() == b.getUnreadCount() &&
-				a.isDissolved() == b.isDissolved();
-	}
-
-	@Override
-	public boolean areItemsTheSame(GroupItem a, GroupItem b) {
-		return a.getId().equals(b.getId());
-	}
-
-	int findItemPosition(GroupId g) {
-		for (int i = 0; i < items.size(); i++) {
-			GroupItem item = items.get(i);
-			if (item.getId().equals(g)) {
-				return i;
-			}
+	private static class GroupItemCallback extends ItemCallback<GroupItem> {
+		@Override
+		public boolean areItemsTheSame(GroupItem a, GroupItem b) {
+			return a.equals(b);
 		}
-		return INVALID_POSITION;
-	}
 
-	void removeItem(GroupId groupId) {
-		int pos = findItemPosition(groupId);
-		if (pos != INVALID_POSITION) items.removeItemAt(pos);
+		@Override
+		public boolean areContentsTheSame(GroupItem a, GroupItem b) {
+			return a.getMessageCount() == b.getMessageCount() &&
+					a.getTimestamp() == b.getTimestamp() &&
+					a.getUnreadCount() == b.getUnreadCount() &&
+					a.isDissolved() == b.isDissolved();
+		}
 	}
-
 }

briar-android/src/main/java/org/briarproject/briar/android/privategroup/list/GroupListController.java

@@ -1,60 +0,0 @@
-package org.briarproject.briar.android.privategroup.list;
-
-import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.sync.GroupId;
-import org.briarproject.briar.android.controller.DbController;
-import org.briarproject.briar.android.controller.handler.ExceptionHandler;
-import org.briarproject.briar.android.controller.handler.ResultExceptionHandler;
-import org.briarproject.briar.api.privategroup.GroupMessageHeader;
-
-import java.util.Collection;
-
-import androidx.annotation.UiThread;
-
-@NotNullByDefault
-interface GroupListController extends DbController {
-
-	/**
-	 * The listener must be set right after the controller was injected
-	 */
-	@UiThread
-	void setGroupListListener(GroupListListener listener);
-
-	@UiThread
-	void unsetGroupListListener(GroupListListener listener);
-
-	@UiThread
-	void onStart();
-
-	@UiThread
-	void onStop();
-
-	void loadGroups(
-			ResultExceptionHandler<Collection<GroupItem>, DbException> result);
-
-	void removeGroup(GroupId g, ExceptionHandler<DbException> result);
-
-	void loadAvailableGroups(
-			ResultExceptionHandler<Integer, DbException> result);
-
-	interface GroupListListener {
-
-		@UiThread
-		void onGroupMessageAdded(GroupMessageHeader header);
-
-		@UiThread
-		void onGroupInvitationReceived();
-
-		@UiThread
-		void onGroupAdded(GroupId groupId);
-
-		@UiThread
-		void onGroupRemoved(GroupId groupId);
-
-		@UiThread
-		void onGroupDissolved(GroupId groupId);
-
-	}
-
-}

briar-android/src/main/java/org/briarproject/briar/android/privategroup/list/GroupListFragment.java

@@ -12,57 +12,50 @@ import android.view.ViewGroup;
 
 import com.google.android.material.snackbar.Snackbar;
 
-import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
-import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.ActivityComponent;
-import org.briarproject.briar.android.controller.handler.UiExceptionHandler;
-import org.briarproject.briar.android.controller.handler.UiResultExceptionHandler;
 import org.briarproject.briar.android.fragment.BaseFragment;
 import org.briarproject.briar.android.privategroup.creation.CreateGroupActivity;
 import org.briarproject.briar.android.privategroup.invitation.GroupInvitationActivity;
-import org.briarproject.briar.android.privategroup.list.GroupListController.GroupListListener;
 import org.briarproject.briar.android.privategroup.list.GroupViewHolder.OnGroupRemoveClickListener;
 import org.briarproject.briar.android.util.BriarSnackbarBuilder;
 import org.briarproject.briar.android.view.BriarRecyclerView;
-import org.briarproject.briar.api.privategroup.GroupMessageHeader;
-
-import java.util.Collection;
-import java.util.logging.Logger;
 
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
 import androidx.annotation.UiThread;
+import androidx.lifecycle.ViewModelProvider;
 import androidx.recyclerview.widget.LinearLayoutManager;
 
 import static com.google.android.material.snackbar.Snackbar.LENGTH_INDEFINITE;
+import static java.util.Objects.requireNonNull;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
 public class GroupListFragment extends BaseFragment implements
-		GroupListListener, OnGroupRemoveClickListener, OnClickListener {
+		OnGroupRemoveClickListener, OnClickListener {
 
 	public final static String TAG = GroupListFragment.class.getName();
-	private static final Logger LOG = Logger.getLogger(TAG);
 
 	public static GroupListFragment newInstance() {
 		return new GroupListFragment();
 	}
 
 	@Inject
-	GroupListController controller;
+	ViewModelProvider.Factory viewModelFactory;
 
+	private GroupListViewModel viewModel;
 	private BriarRecyclerView list;
 	private GroupListAdapter adapter;
-	private Snackbar snackbar;
 
 	@Override
 	public void injectFragment(ActivityComponent component) {
 		component.inject(this);
-		controller.setGroupListListener(this);
+		viewModel = new ViewModelProvider(this, viewModelFactory)
+				.get(GroupListViewModel.class);
 	}
 
 	@Nullable
@@ -75,17 +68,32 @@ public class GroupListFragment extends BaseFragment implements
 
 		View v = inflater.inflate(R.layout.list, container, false);
 
-		adapter = new GroupListAdapter(getActivity(), this);
+		adapter = new GroupListAdapter(this);
 		list = v.findViewById(R.id.list);
 		list.setEmptyImage(R.drawable.ic_empty_state_group_list);
 		list.setEmptyText(R.string.groups_list_empty);
 		list.setEmptyAction(R.string.groups_list_empty_action);
 		list.setLayoutManager(new LinearLayoutManager(getContext()));
 		list.setAdapter(adapter);
+		viewModel.getGroupItems().observe(getViewLifecycleOwner(), result ->
+				result.onError(this::handleException).onSuccess(items -> {
+					adapter.submitList(items);
+					if (requireNonNull(items).size() == 0) list.showData();
+				})
+		);
 
-		snackbar = new BriarSnackbarBuilder()
+		Snackbar snackbar = new BriarSnackbarBuilder()
 				.setAction(R.string.show, this)
 				.make(list, "", LENGTH_INDEFINITE);
+		viewModel.getNumInvitations().observe(getViewLifecycleOwner(), num -> {
+			if (num == 0) {
+				snackbar.dismiss();
+			} else {
+				snackbar.setText(getResources().getQuantityString(
+						R.plurals.groups_invitations_open, num, num));
+				if (!snackbar.isShownOrQueued()) snackbar.show();
+			}
+		});
 
 		return v;
 	}
@@ -93,25 +101,23 @@ public class GroupListFragment extends BaseFragment implements
 	@Override
 	public void onStart() {
 		super.onStart();
-		controller.onStart();
+		viewModel.blockAllGroupMessageNotifications();
+		viewModel.clearAllGroupMessageNotifications();
+		// The attributes and sorting of the groups may have changed while we
+		// were stopped and we have no way finding out about them, so re-load
+		// e.g. less unread messages in a group after viewing it.
+		viewModel.loadGroups();
+		// The number of invitations might have changed while we were stopped
+		// e.g. because of accepting an invitation which does not trigger event
+		viewModel.loadNumInvitations();
 		list.startPeriodicUpdate();
-		loadGroups();
-		loadAvailableGroups();
 	}
 
 	@Override
 	public void onStop() {
 		super.onStop();
-		controller.onStop();
 		list.stopPeriodicUpdate();
-		adapter.clear();
-		list.showProgressBar();
-	}
-
-	@Override
-	public void onDestroy() {
-		super.onDestroy();
-		controller.unsetGroupListListener(this);
+		viewModel.unblockAllGroupMessageNotifications();
 	}
 
 	@Override
@@ -122,68 +128,18 @@ public class GroupListFragment extends BaseFragment implements
 
 	@Override
 	public boolean onOptionsItemSelected(MenuItem item) {
-		switch (item.getItemId()) {
-			case R.id.action_add_group:
-				Intent i = new Intent(getContext(), CreateGroupActivity.class);
-				startActivity(i);
-				return true;
-			default:
-				return super.onOptionsItemSelected(item);
+		if (item.getItemId() == R.id.action_add_group) {
+			Intent i = new Intent(getContext(), CreateGroupActivity.class);
+			startActivity(i);
+			return true;
 		}
+		return super.onOptionsItemSelected(item);
 	}
 
 	@UiThread
 	@Override
 	public void onGroupRemoveClick(GroupItem item) {
-		controller.removeGroup(item.getId(),
-				new UiExceptionHandler<DbException>(this) {
-					// result handled by GroupRemovedEvent and onGroupRemoved()
-					@Override
-					public void onExceptionUi(DbException exception) {
-						handleDbException(exception);
-					}
-				});
-	}
-
-	@UiThread
-	@Override
-	public void onGroupMessageAdded(GroupMessageHeader header) {
-		adapter.incrementRevision();
-		int position = adapter.findItemPosition(header.getGroupId());
-		GroupItem item = adapter.getItemAt(position);
-		if (item != null) {
-			item.addMessageHeader(header);
-			adapter.updateItemAt(position, item);
-		}
-	}
-
-	@Override
-	public void onGroupInvitationReceived() {
-		loadAvailableGroups();
-	}
-
-	@UiThread
-	@Override
-	public void onGroupAdded(GroupId groupId) {
-		loadGroups();
-	}
-
-	@UiThread
-	@Override
-	public void onGroupRemoved(GroupId groupId) {
-		adapter.incrementRevision();
-		adapter.removeItem(groupId);
-	}
-
-	@Override
-	public void onGroupDissolved(GroupId groupId) {
-		adapter.incrementRevision();
-		int position = adapter.findItemPosition(groupId);
-		GroupItem item = adapter.getItemAt(position);
-		if (item != null) {
-			item.setDissolved();
-			adapter.updateItemAt(position, item);
-		}
+		viewModel.removeGroup(item.getId());
 	}
 
 	@Override
@@ -191,52 +147,6 @@ public class GroupListFragment extends BaseFragment implements
 		return TAG;
 	}
 
-	private void loadGroups() {
-		int revision = adapter.getRevision();
-		controller.loadGroups(
-				new UiResultExceptionHandler<Collection<GroupItem>, DbException>(
-						this) {
-					@Override
-					public void onResultUi(Collection<GroupItem> groups) {
-						if (revision == adapter.getRevision()) {
-							adapter.incrementRevision();
-							if (groups.isEmpty()) list.showData();
-							else adapter.replaceAll(groups);
-						} else {
-							LOG.info("Concurrent update, reloading");
-							loadGroups();
-						}
-					}
-
-					@Override
-					public void onExceptionUi(DbException exception) {
-						handleDbException(exception);
-					}
-				});
-	}
-
-	private void loadAvailableGroups() {
-		controller.loadAvailableGroups(
-				new UiResultExceptionHandler<Integer, DbException>(this) {
-					@Override
-					public void onResultUi(Integer num) {
-						if (num == 0) {
-							snackbar.dismiss();
-						} else {
-							snackbar.setText(getResources().getQuantityString(
-									R.plurals.groups_invitations_open, num,
-									num));
-							if (!snackbar.isShownOrQueued()) snackbar.show();
-						}
-					}
-
-					@Override
-					public void onExceptionUi(DbException exception) {
-						handleDbException(exception);
-					}
-				});
-	}
-
 	/**
 	 * This method is handling the available groups snackbar action
 	 */

briar-android/src/main/java/org/briarproject/briar/android/privategroup/list/GroupListModule.java

@@ -1,17 +1,18 @@
 package org.briarproject.briar.android.privategroup.list;
 
-import org.briarproject.briar.android.activity.ActivityScope;
+import org.briarproject.briar.android.viewmodel.ViewModelKey;
 
+import androidx.lifecycle.ViewModel;
+import dagger.Binds;
 import dagger.Module;
-import dagger.Provides;
+import dagger.multibindings.IntoMap;
 
 @Module
-public class GroupListModule {
+public abstract class GroupListModule {
 
-	@ActivityScope
-	@Provides
-	GroupListController provideGroupListController(
-			GroupListControllerImpl groupListController) {
-		return groupListController;
-	}
+	@Binds
+	@IntoMap
+	@ViewModelKey(GroupListViewModel.class)
+	abstract ViewModel bindGroupListViewModel(
+			GroupListViewModel groupListViewModel);
 }

briar-android/src/main/java/org/briarproject/briar/android/privategroup/list/GroupListViewModel.java

@@ -1,9 +1,12 @@
 package org.briarproject.briar.android.privategroup.list;
 
+import android.app.Application;
+
 import org.briarproject.bramble.api.contact.ContactManager;
 import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.db.NoSuchGroupException;
+import org.briarproject.bramble.api.db.Transaction;
+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;
@@ -16,11 +19,12 @@ import org.briarproject.bramble.api.sync.ClientId;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.event.GroupAddedEvent;
 import org.briarproject.bramble.api.sync.event.GroupRemovedEvent;
-import org.briarproject.briar.android.controller.DbControllerImpl;
-import org.briarproject.briar.android.controller.handler.ExceptionHandler;
-import org.briarproject.briar.android.controller.handler.ResultExceptionHandler;
+import org.briarproject.bramble.api.system.AndroidExecutor;
+import org.briarproject.briar.android.viewmodel.DbViewModel;
+import org.briarproject.briar.android.viewmodel.LiveResult;
 import org.briarproject.briar.api.android.AndroidNotificationManager;
 import org.briarproject.briar.api.client.MessageTracker.GroupCount;
+import org.briarproject.briar.api.privategroup.GroupMessageHeader;
 import org.briarproject.briar.api.privategroup.PrivateGroup;
 import org.briarproject.briar.api.privategroup.PrivateGroupManager;
 import org.briarproject.briar.api.privategroup.event.GroupDissolvedEvent;
@@ -30,6 +34,7 @@ import org.briarproject.briar.api.privategroup.invitation.GroupInvitationManager
 
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -38,10 +43,13 @@ import java.util.logging.Logger;
 
 import javax.inject.Inject;
 
-import androidx.annotation.CallSuper;
-import androidx.annotation.Nullable;
+import androidx.annotation.UiThread;
+import androidx.lifecycle.LiveData;
+import androidx.lifecycle.MutableLiveData;
 
+import static java.util.Objects.requireNonNull;
 import static java.util.logging.Level.WARNING;
+import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.util.LogUtils.logDuration;
 import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.bramble.util.LogUtils.now;
@@ -49,11 +57,10 @@ import static org.briarproject.briar.api.privategroup.PrivateGroupManager.CLIENT
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
-class GroupListControllerImpl extends DbControllerImpl
-		implements GroupListController, EventListener {
+class GroupListViewModel extends DbViewModel implements EventListener {
 
 	private static final Logger LOG =
-			Logger.getLogger(GroupListControllerImpl.class.getName());
+			getLogger(GroupListViewModel.class.getName());
 
 	private final PrivateGroupManager groupManager;
 	private final GroupInvitationManager groupInvitationManager;
@@ -61,120 +68,137 @@ class GroupListControllerImpl extends DbControllerImpl
 	private final AndroidNotificationManager notificationManager;
 	private final EventBus eventBus;
 
-	// UI thread
-	@Nullable
-	private GroupListListener listener;
+	private final MutableLiveData<LiveResult<List<GroupItem>>> groupItems =
+			new MutableLiveData<>();
+	private final MutableLiveData<Integer> numInvitations =
+			new MutableLiveData<>();
 
 	@Inject
-	GroupListControllerImpl(@DatabaseExecutor Executor dbExecutor,
-			LifecycleManager lifecycleManager, PrivateGroupManager groupManager,
+	GroupListViewModel(Application application,
+			@DatabaseExecutor Executor dbExecutor,
+			LifecycleManager lifecycleManager,
+			TransactionManager db,
+			AndroidExecutor androidExecutor,
+			PrivateGroupManager groupManager,
 			GroupInvitationManager groupInvitationManager,
 			ContactManager contactManager,
 			AndroidNotificationManager notificationManager, EventBus eventBus) {
-		super(dbExecutor, lifecycleManager);
+		super(application, dbExecutor, lifecycleManager, db, androidExecutor);
 		this.groupManager = groupManager;
 		this.groupInvitationManager = groupInvitationManager;
 		this.contactManager = contactManager;
 		this.notificationManager = notificationManager;
 		this.eventBus = eventBus;
+		this.eventBus.addListener(this);
 	}
 
 	@Override
-	public void setGroupListListener(GroupListListener listener) {
-		this.listener = listener;
-	}
-
-	@Override
-	public void unsetGroupListListener(GroupListListener listener) {
-		if (this.listener == listener) this.listener = null;
-	}
-
-	@Override
-	@CallSuper
-	public void onStart() {
-		if (listener == null) throw new IllegalStateException();
-		eventBus.addListener(this);
-		notificationManager.clearAllGroupMessageNotifications();
-	}
-
-	@Override
-	@CallSuper
-	public void onStop() {
+	protected void onCleared() {
+		super.onCleared();
 		eventBus.removeListener(this);
 	}
 
+	void clearAllGroupMessageNotifications() {
+		notificationManager.clearAllGroupMessageNotifications();
+	}
+
+	void blockAllGroupMessageNotifications() {
+		notificationManager.blockAllGroupMessageNotifications();
+	}
+
+	void unblockAllGroupMessageNotifications() {
+		notificationManager.unblockAllGroupMessageNotifications();
+	}
+
 	@Override
-	@CallSuper
 	public void eventOccurred(Event e) {
-		if (listener == null) throw new IllegalStateException();
 		if (e instanceof GroupMessageAddedEvent) {
 			GroupMessageAddedEvent g = (GroupMessageAddedEvent) e;
 			LOG.info("Private group message added");
-			listener.onGroupMessageAdded(g.getHeader());
+			onGroupMessageAdded(g.getHeader());
 		} else if (e instanceof GroupInvitationRequestReceivedEvent) {
 			LOG.info("Private group invitation received");
-			listener.onGroupInvitationReceived();
+			loadNumInvitations();
 		} else if (e instanceof GroupAddedEvent) {
 			GroupAddedEvent g = (GroupAddedEvent) e;
 			ClientId id = g.getGroup().getClientId();
 			if (id.equals(CLIENT_ID)) {
 				LOG.info("Private group added");
-				listener.onGroupAdded(g.getGroup().getId());
+				loadGroups();
 			}
 		} else if (e instanceof GroupRemovedEvent) {
 			GroupRemovedEvent g = (GroupRemovedEvent) e;
 			ClientId id = g.getGroup().getClientId();
 			if (id.equals(CLIENT_ID)) {
 				LOG.info("Private group removed");
-				listener.onGroupRemoved(g.getGroup().getId());
+				onGroupRemoved(g.getGroup().getId());
 			}
 		} else if (e instanceof GroupDissolvedEvent) {
 			GroupDissolvedEvent g = (GroupDissolvedEvent) e;
 			LOG.info("Private group dissolved");
-			listener.onGroupDissolved(g.getGroupId());
+			onGroupDissolved(g.getGroupId());
 		}
 	}
 
-	@Override
-	public void loadGroups(
-			ResultExceptionHandler<Collection<GroupItem>, DbException> handler) {
-		runOnDbThread(() -> {
-			try {
-				long start = now();
-				Collection<PrivateGroup> groups =
-						groupManager.getPrivateGroups();
-				List<GroupItem> items = new ArrayList<>(groups.size());
-				Map<AuthorId, AuthorInfo> authorInfos = new HashMap<>();
-				for (PrivateGroup g : groups) {
-					try {
-						GroupId id = g.getId();
-						AuthorId authorId = g.getCreator().getId();
-						AuthorInfo authorInfo;
-						if (authorInfos.containsKey(authorId)) {
-							authorInfo = authorInfos.get(authorId);
-						} else {
-							authorInfo = contactManager.getAuthorInfo(authorId);
-							authorInfos.put(authorId, authorInfo);
-						}
-						GroupCount count = groupManager.getGroupCount(id);
-						boolean dissolved = groupManager.isDissolved(id);
-						items.add(
-								new GroupItem(g, authorInfo, count, dissolved));
-					} catch (NoSuchGroupException e) {
-						// Continue
-					}
-				}
-				logDuration(LOG, "Loading groups", start);
-				handler.onResult(items);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-				handler.onException(e);
-			}
-		});
+	void loadGroups() {
+		loadList(this::loadGroups, groupItems::setValue);
 	}
 
-	@Override
-	public void removeGroup(GroupId g, ExceptionHandler<DbException> handler) {
+	@DatabaseExecutor
+	private List<GroupItem> loadGroups(Transaction txn) throws DbException {
+		long start = now();
+		Collection<PrivateGroup> groups = groupManager.getPrivateGroups(txn);
+		List<GroupItem> items = new ArrayList<>(groups.size());
+		Map<AuthorId, AuthorInfo> authorInfos = new HashMap<>();
+		for (PrivateGroup g : groups) {
+			GroupId id = g.getId();
+			AuthorId authorId = g.getCreator().getId();
+			AuthorInfo authorInfo;
+			if (authorInfos.containsKey(authorId)) {
+				authorInfo = requireNonNull(authorInfos.get(authorId));
+			} else {
+				authorInfo = contactManager.getAuthorInfo(txn, authorId);
+				authorInfos.put(authorId, authorInfo);
+			}
+			GroupCount count = groupManager.getGroupCount(txn, id);
+			boolean dissolved = groupManager.isDissolved(txn, id);
+			items.add(new GroupItem(g, authorInfo, count, dissolved));
+		}
+		Collections.sort(items);
+		logDuration(LOG, "Loading groups", start);
+		return items;
+	}
+
+	@UiThread
+	private void onGroupMessageAdded(GroupMessageHeader header) {
+		GroupId g = header.getGroupId();
+		List<GroupItem> list = updateListItems(groupItems,
+				itemToTest -> itemToTest.getId().equals(g),
+				itemToUpdate -> new GroupItem(itemToUpdate, header));
+		if (list == null) return;
+		// re-sort as the order of items may have changed
+		Collections.sort(list);
+		groupItems.setValue(new LiveResult<>(list));
+	}
+
+	@UiThread
+	private void onGroupDissolved(GroupId groupId) {
+		List<GroupItem> list = updateListItems(groupItems,
+				itemToTest -> itemToTest.getId().equals(groupId),
+				itemToUpdate -> new GroupItem(itemToUpdate, true));
+		if (list == null) return;
+		groupItems.setValue(new LiveResult<>(list));
+	}
+
+	@UiThread
+	private void onGroupRemoved(GroupId groupId) {
+		List<GroupItem> list =
+				removeListItems(groupItems, i -> i.getId().equals(groupId));
+		if (list == null) return;
+		groupItems.setValue(new LiveResult<>(list));
+	}
+
+	void removeGroup(GroupId g) {
 		runOnDbThread(() -> {
 			try {
 				long start = now();
@@ -182,23 +206,26 @@ class GroupListControllerImpl extends DbControllerImpl
 				logDuration(LOG, "Removing group", start);
 			} catch (DbException e) {
 				logException(LOG, WARNING, e);
-				handler.onException(e);
 			}
 		});
 	}
 
-	@Override
-	public void loadAvailableGroups(
-			ResultExceptionHandler<Integer, DbException> handler) {
+	void loadNumInvitations() {
 		runOnDbThread(() -> {
 			try {
-				handler.onResult(
-						groupInvitationManager.getInvitations().size());
+				int i = groupInvitationManager.getInvitations().size();
+				numInvitations.postValue(i);
 			} catch (DbException e) {
 				logException(LOG, WARNING, e);
-				handler.onException(e);
 			}
 		});
 	}
 
+	LiveData<LiveResult<List<GroupItem>>> getGroupItems() {
+		return groupItems;
+	}
+
+	LiveData<Integer> getNumInvitations() {
+		return numInvitations;
+	}
 }

briar-android/src/main/java/org/briarproject/briar/android/privategroup/list/GroupViewHolder.java

@@ -29,6 +29,7 @@ class GroupViewHolder extends RecyclerView.ViewHolder {
 
 	private final static float ALPHA = 0.42f;
 
+	private final Context ctx;
 	private final ViewGroup layout;
 	private final TextAvatarView avatar;
 	private final TextView name;
@@ -40,7 +41,7 @@ class GroupViewHolder extends RecyclerView.ViewHolder {
 
 	GroupViewHolder(View v) {
 		super(v);
-
+		ctx = v.getContext();
 		layout = (ViewGroup) v;
 		avatar = v.findViewById(R.id.avatarView);
 		name = v.findViewById(R.id.nameView);
@@ -51,8 +52,7 @@ class GroupViewHolder extends RecyclerView.ViewHolder {
 		remove = v.findViewById(R.id.removeButton);
 	}
 
-	void bindView(Context ctx, GroupItem group,
-			OnGroupRemoveClickListener listener) {
+	void bindView(GroupItem group, OnGroupRemoveClickListener listener) {
 		// Avatar
 		avatar.setText(group.getName().substring(0, 1));
 		avatar.setBackgroundBytes(group.getId().getBytes());

briar-android/src/main/java/org/briarproject/briar/android/privategroup/memberlist/GroupMemberListActivity.java

@@ -124,7 +124,7 @@ public class GroupMemberListActivity extends BriarActivity
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						handleDbException(exception);
+						handleException(exception);
 					}
 				});
 	}

briar-android/src/main/java/org/briarproject/briar/android/privategroup/reveal/RevealContactsActivity.java

@@ -80,7 +80,7 @@ public class RevealContactsActivity extends ContactSelectorActivity
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						handleDbException(exception);
+						handleException(exception);
 					}
 				});
 	}
@@ -120,7 +120,7 @@ public class RevealContactsActivity extends ContactSelectorActivity
 				new UiExceptionHandler<DbException>(this) {
 					@Override
 					public void onExceptionUi(DbException exception) {
-						handleDbException(exception);
+						handleException(exception);
 					}
 				});
 	}
@@ -137,7 +137,7 @@ public class RevealContactsActivity extends ContactSelectorActivity
 				new UiExceptionHandler<DbException>(this) {
 					@Override
 					public void onExceptionUi(DbException exception) {
-						handleDbException(exception);
+						handleException(exception);
 					}
 				});
 		supportFinishAfterTransition();

briar-android/src/main/java/org/briarproject/briar/android/reporting/BriarExceptionHandler.java

@@ -0,0 +1,31 @@
+package org.briarproject.briar.android.reporting;
+
+import android.content.Context;
+import android.os.Process;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import java.lang.Thread.UncaughtExceptionHandler;
+
+import static org.briarproject.briar.android.util.UiUtils.startDevReportActivity;
+
+@NotNullByDefault
+public class BriarExceptionHandler implements UncaughtExceptionHandler {
+
+	private final Context ctx;
+	private final long appStartTime;
+
+	public BriarExceptionHandler(Context ctx) {
+		this.ctx = ctx;
+		this.appStartTime = System.currentTimeMillis();
+	}
+
+	@Override
+	public void uncaughtException(Thread t, Throwable e) {
+		// activity runs in its own process, so we can kill the old one
+		startDevReportActivity(ctx, CrashReportActivity.class, e, appStartTime);
+		Process.killProcess(Process.myPid());
+		System.exit(10);
+	}
+
+}

briar-android/src/main/java/org/briarproject/briar/android/reporting/BriarReportCollector.java

@@ -0,0 +1,343 @@
+/*
+  Some of the code in this file was copied from or inspired by ACRA
+  which is licenced under Apache 2.0 and authored by F43nd1r.
+  https://github.com/ACRA/acra/blob/3b9034/acra-core/src/main/java/org/acra/collector/
+ */
+
+package org.briarproject.briar.android.reporting;
+
+import android.annotation.SuppressLint;
+import android.app.ActivityManager;
+import android.bluetooth.BluetoothAdapter;
+import android.content.Context;
+import android.content.pm.FeatureInfo;
+import android.content.pm.PackageInfo;
+import android.content.pm.PackageManager;
+import android.content.pm.PackageManager.NameNotFoundException;
+import android.net.ConnectivityManager;
+import android.net.NetworkInfo;
+import android.net.wifi.WifiInfo;
+import android.net.wifi.WifiManager;
+import android.os.Build;
+import android.os.Environment;
+
+import org.briarproject.bramble.api.Pair;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.briar.BuildConfig;
+import org.briarproject.briar.R;
+import org.briarproject.briar.android.BriarApplication;
+import org.briarproject.briar.android.logging.BriefLogFormatter;
+import org.briarproject.briar.android.reporting.ReportData.MultiReportInfo;
+import org.briarproject.briar.android.reporting.ReportData.ReportItem;
+import org.briarproject.briar.android.reporting.ReportData.SingleReportInfo;
+
+import java.io.File;
+import java.io.PrintWriter;
+import java.io.StringWriter;
+import java.io.Writer;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.net.InetAddress;
+import java.net.UnknownHostException;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+import java.util.logging.Formatter;
+import java.util.logging.LogRecord;
+
+import javax.annotation.concurrent.Immutable;
+
+import androidx.annotation.Nullable;
+
+import static android.bluetooth.BluetoothAdapter.SCAN_MODE_CONNECTABLE;
+import static android.bluetooth.BluetoothAdapter.SCAN_MODE_CONNECTABLE_DISCOVERABLE;
+import static android.content.Context.WIFI_P2P_SERVICE;
+import static android.net.ConnectivityManager.TYPE_MOBILE;
+import static android.net.ConnectivityManager.TYPE_WIFI;
+import static android.net.wifi.WifiManager.WIFI_STATE_ENABLED;
+import static android.os.Build.VERSION.SDK_INT;
+import static androidx.core.content.ContextCompat.getSystemService;
+import static java.util.Locale.US;
+import static java.util.Objects.requireNonNull;
+import static java.util.TimeZone.getTimeZone;
+import static org.briarproject.bramble.util.AndroidUtils.getBluetoothAddressAndMethod;
+import static org.briarproject.bramble.util.PrivacyUtils.scrubInetAddress;
+import static org.briarproject.bramble.util.PrivacyUtils.scrubMacAddress;
+import static org.briarproject.bramble.util.StringUtils.isNullOrEmpty;
+
+@Immutable
+@NotNullByDefault
+class BriarReportCollector {
+
+	private final Context ctx;
+
+	BriarReportCollector(Context ctx) {
+		this.ctx = ctx;
+	}
+
+	public ReportData collectReportData(@Nullable Throwable t,
+			long appStartTime) {
+		ReportData reportData = new ReportData()
+				.add(getBasicInfo(t))
+				.add(getDeviceInfo());
+		if (t != null) reportData.add(getStacktrace(t));
+		return reportData
+				.add(getTimeInfo(appStartTime))
+				.add(getMemory())
+				.add(getStorage())
+				.add(getConnectivity())
+				.add(getBuildConfig())
+				.add(getLogcat())
+				.add(getDeviceFeatures());
+	}
+
+	private ReportItem getBasicInfo(@Nullable Throwable t) {
+		String packageName = ctx.getPackageName();
+		PackageManager pm = ctx.getPackageManager();
+		String versionName;
+		int versionCode;
+		try {
+			PackageInfo packageInfo = pm.getPackageInfo(packageName, 0);
+			versionName = packageInfo.versionName;
+			versionCode = packageInfo.versionCode;
+		} catch (NameNotFoundException e) {
+			versionName = e.toString();
+			versionCode = 0;
+		}
+		MultiReportInfo basicInfo = new MultiReportInfo()
+				.add("PackageName", packageName)
+				.add("VersionName", versionName)
+				.add("VersionCode", versionCode)
+				.add("IsCrashReport", t != null);
+		return new ReportItem("BasicInfo", R.string.dev_report_basic_info,
+				basicInfo, false);
+	}
+
+	private ReportItem getDeviceInfo() {
+		MultiReportInfo deviceInfo = new MultiReportInfo()
+				.add("AndroidVersion", Build.VERSION.RELEASE)
+				.add("AndroidApi", SDK_INT)
+				.add("Product", Build.PRODUCT)
+				.add("Model", Build.MODEL)
+				.add("Brand", Build.BRAND);
+		return new ReportItem("DeviceInfo", R.string.dev_report_device_info,
+				deviceInfo);
+	}
+
+	private ReportItem getStacktrace(Throwable t) {
+		final Writer sw = new StringWriter();
+		final PrintWriter printWriter = new PrintWriter(sw);
+		if (!isNullOrEmpty(t.getMessage())) {
+			printWriter.println(t.getMessage());
+		}
+		t.printStackTrace(printWriter);
+		SingleReportInfo stacktrace = new SingleReportInfo(sw.toString());
+		return new ReportItem("Stacktrace", R.string.dev_report_stacktrace,
+				stacktrace);
+	}
+
+	private ReportItem getTimeInfo(long startTime) {
+		MultiReportInfo timeInfo = new MultiReportInfo()
+				.add("ReportTime", formatTime(System.currentTimeMillis()));
+		if (startTime > -1) {
+			timeInfo.add("AppStartTime", formatTime(startTime));
+		}
+		return new ReportItem("TimeInfo", R.string.dev_report_time_info,
+				timeInfo);
+	}
+
+	private String formatTime(long time) {
+		SimpleDateFormat format =
+				new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS", US);
+		format.setTimeZone(getTimeZone("UTC"));
+		return format.format(new Date(time));
+	}
+
+	private ReportItem getMemory() {
+		MultiReportInfo memInfo = new MultiReportInfo();
+
+		// System memory
+		ActivityManager am = getSystemService(ctx, ActivityManager.class);
+		ActivityManager.MemoryInfo mem = new ActivityManager.MemoryInfo();
+		requireNonNull(am).getMemoryInfo(mem);
+		memInfo.add("SystemMemoryTotal", mem.totalMem);
+		memInfo.add("SystemMemoryFree", mem.availMem);
+		memInfo.add("SystemMemoryThreshold", mem.threshold);
+
+		// Virtual machine memory
+		Runtime runtime = Runtime.getRuntime();
+		memInfo.add("VirtualMachineMemoryAllocated", runtime.totalMemory());
+		memInfo.add("VirtualMachineMemoryFree", runtime.freeMemory());
+		memInfo.add("VirtualMachineMemoryMaximum", runtime.maxMemory());
+
+		return new ReportItem("Memory", R.string.dev_report_memory, memInfo);
+	}
+
+	private ReportItem getStorage() {
+		MultiReportInfo storageInfo = new MultiReportInfo();
+
+		// Internal storage
+		File root = Environment.getRootDirectory();
+		storageInfo.add("InternalStorageTotal", root.getTotalSpace());
+		storageInfo.add("InternalStorageFree", root.getFreeSpace());
+
+		// External storage (SD card)
+		File sd = Environment.getExternalStorageDirectory();
+		storageInfo.add("ExternalStorageTotal", sd.getTotalSpace());
+		storageInfo.add("ExternalStorageFree", sd.getFreeSpace());
+
+		return new ReportItem("Storage", R.string.dev_report_storage,
+				storageInfo);
+	}
+
+	private ReportItem getConnectivity() {
+		MultiReportInfo connectivityInfo = new MultiReportInfo();
+
+		// Is mobile data available?
+		ConnectivityManager cm = requireNonNull(
+				getSystemService(ctx, ConnectivityManager.class));
+		NetworkInfo mobile = cm.getNetworkInfo(TYPE_MOBILE);
+		boolean mobileAvailable = mobile != null && mobile.isAvailable();
+		connectivityInfo.add("MobileDataAvailable", mobileAvailable);
+
+		// Is mobile data enabled?
+		boolean mobileEnabled = false;
+		try {
+			Class<?> clazz = Class.forName(cm.getClass().getName());
+			Method method = clazz.getDeclaredMethod("getMobileDataEnabled");
+			method.setAccessible(true);
+			mobileEnabled = (Boolean) requireNonNull(method.invoke(cm));
+		} catch (ClassNotFoundException
+				| NoSuchMethodException
+				| IllegalArgumentException
+				| InvocationTargetException
+				| IllegalAccessException e) {
+			connectivityInfo
+					.add("MobileDataReflectionException", e.toString());
+		}
+		connectivityInfo.add("MobileDataEnabled", mobileEnabled);
+
+		// Is mobile data connected ?
+		boolean mobileConnected = mobile != null && mobile.isConnected();
+		connectivityInfo.add("MobileDataConnected", mobileConnected);
+
+		// Is wifi available?
+		NetworkInfo wifi = cm.getNetworkInfo(TYPE_WIFI);
+		boolean wifiAvailable = wifi != null && wifi.isAvailable();
+		connectivityInfo.add("WifiAvailable", wifiAvailable);
+
+		// Is wifi enabled?
+		WifiManager wm = getSystemService(ctx, WifiManager.class);
+		boolean wifiEnabled = wm != null &&
+				wm.getWifiState() == WIFI_STATE_ENABLED;
+		connectivityInfo.add("WifiEnabled", wifiEnabled);
+
+		// Is wifi connected?
+		boolean wifiConnected = wifi != null && wifi.isConnected();
+		connectivityInfo.add("WifiConnected", wifiConnected);
+
+		// Is wifi direct supported?
+		boolean wifiDirect = ctx.getSystemService(WIFI_P2P_SERVICE) != null;
+		connectivityInfo.add("WiFiDirectSupported", wifiDirect);
+
+		if (wm != null) {
+			WifiInfo wifiInfo = wm.getConnectionInfo();
+			if (wifiInfo != null) {
+				int ip = wifiInfo.getIpAddress(); // Nice API, Google
+				byte[] ipBytes = new byte[4];
+				ipBytes[0] = (byte) (ip & 0xFF);
+				ipBytes[1] = (byte) ((ip >> 8) & 0xFF);
+				ipBytes[2] = (byte) ((ip >> 16) & 0xFF);
+				ipBytes[3] = (byte) ((ip >> 24) & 0xFF);
+				try {
+					InetAddress address = InetAddress.getByAddress(ipBytes);
+					connectivityInfo.add("WiFiAddress",
+							scrubInetAddress(address));
+				} catch (UnknownHostException ignored) {
+					// Should only be thrown if address has illegal length
+				}
+			}
+		}
+
+		// Is Bluetooth available?
+		BluetoothAdapter bt = BluetoothAdapter.getDefaultAdapter();
+		if (bt == null) {
+			connectivityInfo.add("BluetoothAvailable", false);
+		} else {
+			connectivityInfo.add("BluetoothAvailable", true);
+
+			// Is Bluetooth enabled?
+			@SuppressLint("HardwareIds")
+			boolean btEnabled = bt.isEnabled()
+					&& !isNullOrEmpty(bt.getAddress());
+			connectivityInfo.add("BluetoothEnabled", btEnabled);
+
+			// Is Bluetooth connectable?
+			int scanMode = bt.getScanMode();
+			boolean btConnectable = scanMode == SCAN_MODE_CONNECTABLE ||
+					scanMode == SCAN_MODE_CONNECTABLE_DISCOVERABLE;
+			connectivityInfo.add("BluetoothConnectable", btConnectable);
+
+			// Is Bluetooth discoverable?
+			boolean btDiscoverable =
+					scanMode == SCAN_MODE_CONNECTABLE_DISCOVERABLE;
+			connectivityInfo.add("BluetoothDiscoverable", btDiscoverable);
+
+			if (SDK_INT >= 21) {
+				// Is Bluetooth LE scanning and advertising supported?
+				boolean btLeScan = bt.getBluetoothLeScanner() != null;
+				connectivityInfo.add("BluetoothLeScanningSupported", btLeScan);
+				boolean btLeAdvertise =
+						bt.getBluetoothLeAdvertiser() != null;
+				connectivityInfo.add("BluetoothLeAdvertisingSupported",
+						btLeAdvertise);
+			}
+
+			Pair<String, String> p = getBluetoothAddressAndMethod(ctx, bt);
+			String address = p.getFirst();
+			String method = p.getSecond();
+			connectivityInfo.add("BluetoothAddress", scrubMacAddress(address));
+			connectivityInfo.add("BluetoothAddressMethod", method);
+		}
+		return new ReportItem("Connectivity", R.string.dev_report_connectivity,
+				connectivityInfo);
+	}
+
+	private ReportItem getBuildConfig() {
+		MultiReportInfo buildConfig = new MultiReportInfo()
+				.add("GitHash", BuildConfig.GitHash)
+				.add("BuildType", BuildConfig.BUILD_TYPE)
+				.add("Flavor", BuildConfig.FLAVOR)
+				.add("Debug", BuildConfig.DEBUG)
+				.add("BuildTimestamp", formatTime(BuildConfig.BuildTimestamp));
+		return new ReportItem("BuildConfig", R.string.dev_report_build_config,
+				buildConfig);
+	}
+
+	private ReportItem getLogcat() {
+		BriarApplication app = (BriarApplication) ctx.getApplicationContext();
+		StringBuilder sb = new StringBuilder();
+		Formatter formatter = new BriefLogFormatter();
+		for (LogRecord record : app.getRecentLogRecords()) {
+			sb.append(formatter.format(record)).append('\n');
+		}
+		return new ReportItem("Logcat", R.string.dev_report_logcat,
+				sb.toString());
+	}
+
+	private ReportItem getDeviceFeatures() {
+		PackageManager pm = ctx.getPackageManager();
+		FeatureInfo[] features = pm.getSystemAvailableFeatures();
+		MultiReportInfo deviceFeatures = new MultiReportInfo();
+		for (FeatureInfo feature : features) {
+			String featureName = feature.name;
+			if (featureName != null) {
+				deviceFeatures.add(featureName, true);
+			} else {
+				deviceFeatures.add("glEsVersion", feature.getGlEsVersion());
+			}
+		}
+		return new ReportItem("DeviceFeatures",
+				R.string.dev_report_device_features, deviceFeatures);
+	}
+
+}

briar-android/src/main/java/org/briarproject/briar/android/reporting/BriarReportPrimer.java

@@ -1,277 +0,0 @@
-package org.briarproject.briar.android.reporting;
-
-import android.app.ActivityManager;
-import android.bluetooth.BluetoothAdapter;
-import android.content.Context;
-import android.net.ConnectivityManager;
-import android.net.NetworkInfo;
-import android.net.wifi.WifiInfo;
-import android.net.wifi.WifiManager;
-import android.os.Environment;
-import android.os.Handler;
-import android.os.Looper;
-
-import org.acra.builder.ReportBuilder;
-import org.acra.builder.ReportPrimer;
-import org.briarproject.bramble.api.Pair;
-import org.briarproject.briar.BuildConfig;
-import org.briarproject.briar.android.BriarApplication;
-import org.briarproject.briar.android.logging.BriefLogFormatter;
-
-import java.io.File;
-import java.lang.reflect.InvocationTargetException;
-import java.lang.reflect.Method;
-import java.net.InetAddress;
-import java.net.UnknownHostException;
-import java.util.LinkedHashMap;
-import java.util.Map;
-import java.util.concurrent.Callable;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.FutureTask;
-import java.util.logging.Formatter;
-import java.util.logging.LogRecord;
-
-import androidx.annotation.NonNull;
-
-import static android.bluetooth.BluetoothAdapter.SCAN_MODE_CONNECTABLE;
-import static android.bluetooth.BluetoothAdapter.SCAN_MODE_CONNECTABLE_DISCOVERABLE;
-import static android.content.Context.ACTIVITY_SERVICE;
-import static android.content.Context.CONNECTIVITY_SERVICE;
-import static android.content.Context.WIFI_P2P_SERVICE;
-import static android.content.Context.WIFI_SERVICE;
-import static android.net.ConnectivityManager.TYPE_MOBILE;
-import static android.net.ConnectivityManager.TYPE_WIFI;
-import static android.net.wifi.WifiManager.WIFI_STATE_ENABLED;
-import static android.os.Build.VERSION.SDK_INT;
-import static java.util.Collections.unmodifiableMap;
-import static org.briarproject.bramble.util.AndroidUtils.getBluetoothAddressAndMethod;
-import static org.briarproject.bramble.util.PrivacyUtils.scrubInetAddress;
-import static org.briarproject.bramble.util.PrivacyUtils.scrubMacAddress;
-import static org.briarproject.bramble.util.StringUtils.isNullOrEmpty;
-
-public class BriarReportPrimer implements ReportPrimer {
-
-	@Override
-	public void primeReport(@NonNull Context ctx,
-			@NonNull ReportBuilder builder) {
-		CustomDataTask task = new CustomDataTask(ctx);
-		FutureTask<Map<String, String>> futureTask = new FutureTask<>(task);
-		// Use a new thread as the Android executor thread may have died
-		new SingleShotAndroidExecutor(futureTask).start();
-		try {
-			builder.customData(futureTask.get());
-		} catch (InterruptedException | ExecutionException e) {
-			builder.customData("Custom data exception", e.toString());
-		}
-	}
-
-	private static class CustomDataTask
-			implements Callable<Map<String, String>> {
-
-		private final Context ctx;
-
-		private CustomDataTask(Context ctx) {
-			this.ctx = ctx;
-		}
-
-		@Override
-		public Map<String, String> call() {
-			Map<String, String> customData = new LinkedHashMap<>();
-
-			// Log
-			BriarApplication app =
-					(BriarApplication) ctx.getApplicationContext();
-			StringBuilder sb = new StringBuilder();
-			Formatter formatter = new BriefLogFormatter();
-			for (LogRecord record : app.getRecentLogRecords()) {
-				sb.append(formatter.format(record)).append('\n');
-			}
-			customData.put("Log", sb.toString());
-
-			// System memory
-			Object o = ctx.getSystemService(ACTIVITY_SERVICE);
-			ActivityManager am = (ActivityManager) o;
-			ActivityManager.MemoryInfo mem = new ActivityManager.MemoryInfo();
-			am.getMemoryInfo(mem);
-			String systemMemory;
-			systemMemory = (mem.totalMem / 1024 / 1024) + " MiB total, "
-					+ (mem.availMem / 1024 / 1204) + " MiB free, "
-					+ (mem.threshold / 1024 / 1024) + " MiB threshold";
-			customData.put("System memory", systemMemory);
-
-			// Virtual machine memory
-			Runtime runtime = Runtime.getRuntime();
-			long heap = runtime.totalMemory();
-			long heapFree = runtime.freeMemory();
-			long heapMax = runtime.maxMemory();
-			String vmMemory = (heap / 1024 / 1024) + " MiB allocated, "
-					+ (heapFree / 1024 / 1024) + " MiB free, "
-					+ (heapMax / 1024 / 1024) + " MiB maximum";
-			customData.put("Virtual machine memory", vmMemory);
-
-			// Internal storage
-			File root = Environment.getRootDirectory();
-			long rootTotal = root.getTotalSpace();
-			long rootFree = root.getFreeSpace();
-			String internal = (rootTotal / 1024 / 1024) + " MiB total, "
-					+ (rootFree / 1024 / 1024) + " MiB free";
-			customData.put("Internal storage", internal);
-
-			// External storage (SD card)
-			File sd = Environment.getExternalStorageDirectory();
-			long sdTotal = sd.getTotalSpace();
-			long sdFree = sd.getFreeSpace();
-			String external = (sdTotal / 1024 / 1024) + " MiB total, "
-					+ (sdFree / 1024 / 1024) + " MiB free";
-			customData.put("External storage", external);
-
-			// Is mobile data available?
-			o = ctx.getSystemService(CONNECTIVITY_SERVICE);
-			ConnectivityManager cm = (ConnectivityManager) o;
-			NetworkInfo mobile = cm.getNetworkInfo(TYPE_MOBILE);
-			boolean mobileAvailable = mobile != null && mobile.isAvailable();
-			// Is mobile data enabled?
-			boolean mobileEnabled = false;
-			try {
-				Class<?> clazz = Class.forName(cm.getClass().getName());
-				Method method = clazz.getDeclaredMethod("getMobileDataEnabled");
-				method.setAccessible(true);
-				mobileEnabled = (Boolean) method.invoke(cm);
-			} catch (ClassNotFoundException
-					| NoSuchMethodException
-					| IllegalArgumentException
-					| InvocationTargetException
-					| IllegalAccessException e) {
-				customData.put("Mobile data reflection exception",
-						e.toString());
-			}
-			// Is mobile data connected ?
-			boolean mobileConnected = mobile != null && mobile.isConnected();
-
-			String mobileStatus;
-			if (mobileAvailable) mobileStatus = "Available, ";
-			else mobileStatus = "Not available, ";
-			if (mobileEnabled) mobileStatus += "enabled, ";
-			else mobileStatus += "not enabled, ";
-			if (mobileConnected) mobileStatus += "connected";
-			else mobileStatus += "not connected";
-			customData.put("Mobile data status", mobileStatus);
-
-			// Is wifi available?
-			NetworkInfo wifi = cm.getNetworkInfo(TYPE_WIFI);
-			boolean wifiAvailable = wifi != null && wifi.isAvailable();
-			// Is wifi enabled?
-			o = ctx.getApplicationContext().getSystemService(WIFI_SERVICE);
-			WifiManager wm = (WifiManager) o;
-			boolean wifiEnabled = wm != null &&
-					wm.getWifiState() == WIFI_STATE_ENABLED;
-			// Is wifi connected?
-			boolean wifiConnected = wifi != null && wifi.isConnected();
-
-			String wifiStatus;
-			if (wifiAvailable) wifiStatus = "Available, ";
-			else wifiStatus = "Not available, ";
-			if (wifiEnabled) wifiStatus += "enabled, ";
-			else wifiStatus += "not enabled, ";
-			if (wifiConnected) wifiStatus += "connected";
-			else wifiStatus += "not connected";
-			customData.put("Wi-Fi status", wifiStatus);
-
-			// Is wifi direct supported?
-			String wifiDirectStatus = "Supported";
-			if (ctx.getSystemService(WIFI_P2P_SERVICE) == null)
-				wifiDirectStatus = "Not supported";
-			customData.put("Wi-Fi Direct", wifiDirectStatus);
-
-			if (wm != null) {
-				WifiInfo wifiInfo = wm.getConnectionInfo();
-				if (wifiInfo != null) {
-					int ip = wifiInfo.getIpAddress(); // Nice API, Google
-					byte[] ipBytes = new byte[4];
-					ipBytes[0] = (byte) (ip & 0xFF);
-					ipBytes[1] = (byte) ((ip >> 8) & 0xFF);
-					ipBytes[2] = (byte) ((ip >> 16) & 0xFF);
-					ipBytes[3] = (byte) ((ip >> 24) & 0xFF);
-					try {
-						InetAddress address = InetAddress.getByAddress(ipBytes);
-						customData.put("Wi-Fi address",
-								scrubInetAddress(address));
-					} catch (UnknownHostException ignored) {
-						// Should only be thrown if address has illegal length
-					}
-				}
-			}
-
-			// Is Bluetooth available?
-			BluetoothAdapter bt = BluetoothAdapter.getDefaultAdapter();
-			if (bt == null) {
-				customData.put("Bluetooth status", "Not available");
-			} else {
-				// Is Bluetooth enabled?
-				boolean btEnabled = bt.isEnabled()
-						&& !isNullOrEmpty(bt.getAddress());
-				// Is Bluetooth connectable?
-				int scanMode = bt.getScanMode();
-				boolean btConnectable = scanMode == SCAN_MODE_CONNECTABLE ||
-						scanMode == SCAN_MODE_CONNECTABLE_DISCOVERABLE;
-				// Is Bluetooth discoverable?
-				boolean btDiscoverable =
-						scanMode == SCAN_MODE_CONNECTABLE_DISCOVERABLE;
-
-				String btStatus;
-				if (btEnabled) btStatus = "Available, enabled, ";
-				else btStatus = "Available, not enabled, ";
-				if (btConnectable) btStatus += "connectable, ";
-				else btStatus += "not connectable, ";
-				if (btDiscoverable) btStatus += "discoverable";
-				else btStatus += "not discoverable";
-				customData.put("Bluetooth status", btStatus);
-
-				if (SDK_INT >= 21) {
-					// Is Bluetooth LE scanning and advertising supported?
-					boolean btLeScan = bt.getBluetoothLeScanner() != null;
-					boolean btLeAdvertise =
-							bt.getBluetoothLeAdvertiser() != null;
-					String btLeStatus;
-					if (btLeScan) btLeStatus = "Scanning, ";
-					else btLeStatus = "No scanning, ";
-					if (btLeAdvertise) btLeStatus += "advertising";
-					else btLeStatus += "no advertising";
-					customData.put("Bluetooth LE status", btLeStatus);
-				}
-
-				Pair<String, String> p = getBluetoothAddressAndMethod(ctx, bt);
-				String address = p.getFirst();
-				String method = p.getSecond();
-				customData.put("Bluetooth address", scrubMacAddress(address));
-				customData.put("Bluetooth address method", method);
-			}
-
-			// Git commit ID
-			customData.put("Commit ID", BuildConfig.GitHash);
-
-			return unmodifiableMap(customData);
-		}
-	}
-
-	private static class SingleShotAndroidExecutor extends Thread {
-
-		private final Runnable runnable;
-
-		private SingleShotAndroidExecutor(Runnable runnable) {
-			this.runnable = runnable;
-		}
-
-		@Override
-		public void run() {
-			Looper.prepare();
-			Handler handler = new Handler();
-			handler.post(runnable);
-			handler.post(() -> {
-				Looper looper = Looper.myLooper();
-				if (looper != null) looper.quit();
-			});
-			Looper.loop();
-		}
-	}
-}

briar-android/src/main/java/org/briarproject/briar/android/reporting/BriarReportSender.java

@@ -1,46 +0,0 @@
-package org.briarproject.briar.android.reporting;
-
-import android.content.Context;
-
-import org.acra.collector.CrashReportData;
-import org.acra.sender.ReportSender;
-import org.acra.sender.ReportSenderException;
-import org.briarproject.bramble.api.reporting.DevReporter;
-import org.briarproject.bramble.util.AndroidUtils;
-import org.briarproject.briar.android.AndroidComponent;
-
-import java.io.File;
-import java.io.FileNotFoundException;
-
-import javax.inject.Inject;
-
-import androidx.annotation.NonNull;
-
-import static org.acra.ReportField.REPORT_ID;
-
-public class BriarReportSender implements ReportSender {
-
-	private final AndroidComponent component;
-
-	@Inject
-	DevReporter reporter;
-
-	BriarReportSender(AndroidComponent component) {
-		this.component = component;
-	}
-
-	@Override
-	public void send(@NonNull Context ctx,
-			@NonNull CrashReportData errorContent)
-			throws ReportSenderException {
-		component.inject(this);
-		String crashReport = errorContent.toJSON().toString();
-		try {
-			File reportDir = AndroidUtils.getReportDir(ctx);
-			String reportId = errorContent.getProperty(REPORT_ID);
-			reporter.encryptReportToFile(reportDir, reportId, crashReport);
-		} catch (FileNotFoundException e) {
-			throw new ReportSenderException("Failed to encrypt report", e);
-		}
-	}
-}

briar-android/src/main/java/org/briarproject/briar/android/reporting/BriarReportSenderFactory.java

@@ -1,22 +0,0 @@
-package org.briarproject.briar.android.reporting;
-
-import android.content.Context;
-
-import org.acra.config.ACRAConfiguration;
-import org.acra.sender.ReportSender;
-import org.acra.sender.ReportSenderFactory;
-import org.briarproject.briar.android.BriarApplication;
-
-import androidx.annotation.NonNull;
-
-public class BriarReportSenderFactory implements ReportSenderFactory {
-
-	@NonNull
-	@Override
-	public ReportSender create(@NonNull Context ctx,
-			@NonNull ACRAConfiguration config) {
-		// ACRA passes in the Application as context
-		BriarApplication app = (BriarApplication) ctx;
-		return new BriarReportSender(app.getApplicationComponent());
-	}
-}

briar-android/src/main/java/org/briarproject/briar/android/reporting/CrashFragment.java

@@ -8,13 +8,36 @@ import android.view.ViewGroup;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.briar.R;
+import org.briarproject.briar.android.activity.ActivityComponent;
+import org.briarproject.briar.android.fragment.BaseFragment;
+
+import javax.inject.Inject;
 
 import androidx.annotation.Nullable;
-import androidx.fragment.app.Fragment;
+import androidx.lifecycle.ViewModelProvider;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
-public class CrashFragment extends Fragment {
+public class CrashFragment extends BaseFragment {
+
+	public final static String TAG = CrashFragment.class.getName();
+
+	@Inject
+	ViewModelProvider.Factory viewModelFactory;
+
+	@Override
+	public void injectFragment(ActivityComponent component) {
+		component.inject(this);
+	}
+
+	private ReportViewModel viewModel;
+
+	@Override
+	public void onCreate(@Nullable Bundle savedInstanceState) {
+		super.onCreate(savedInstanceState);
+		viewModel = new ViewModelProvider(requireActivity(), viewModelFactory)
+				.get(ReportViewModel.class);
+	}
 
 	@Nullable
 	@Override
@@ -25,15 +48,16 @@ public class CrashFragment extends Fragment {
 				.inflate(R.layout.fragment_crash, container, false);
 
 		v.findViewById(R.id.acceptButton).setOnClickListener(view ->
-				getDevReportActivity().displayFragment(true));
+				viewModel.showReport());
 		v.findViewById(R.id.declineButton).setOnClickListener(view ->
-				getDevReportActivity().closeReport());
+				viewModel.closeReport());
 
 		return v;
 	}
 
-	private DevReportActivity getDevReportActivity() {
-		return (DevReportActivity) requireActivity();
+	@Override
+	public String getUniqueTag() {
+		return TAG;
 	}
 
 }

briar-android/src/main/java/org/briarproject/briar/android/reporting/CrashReportActivity.java

@@ -0,0 +1,117 @@
+package org.briarproject.briar.android.reporting;
+
+import android.content.Intent;
+import android.os.Bundle;
+import android.os.Handler;
+import android.os.Looper;
+import android.os.Process;
+import android.widget.Toast;
+
+import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
+import org.briarproject.briar.R;
+import org.briarproject.briar.android.activity.ActivityComponent;
+import org.briarproject.briar.android.activity.BaseActivity;
+import org.briarproject.briar.android.fragment.BaseFragment;
+import org.briarproject.briar.android.fragment.BaseFragment.BaseFragmentListener;
+import org.briarproject.briar.android.logout.HideUiActivity;
+
+import javax.inject.Inject;
+
+import androidx.annotation.Nullable;
+import androidx.appcompat.widget.Toolbar;
+import androidx.lifecycle.ViewModelProvider;
+
+import static android.content.Intent.FLAG_ACTIVITY_CLEAR_TASK;
+import static android.content.Intent.FLAG_ACTIVITY_NEW_TASK;
+import static android.content.Intent.FLAG_ACTIVITY_NO_ANIMATION;
+import static android.widget.Toast.LENGTH_LONG;
+import static java.util.Objects.requireNonNull;
+
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
+public class CrashReportActivity extends BaseActivity
+		implements BaseFragmentListener {
+
+	public static final String EXTRA_THROWABLE = "throwable";
+	public static final String EXTRA_APP_START_TIME = "appStartTime";
+
+	@Inject
+	ViewModelProvider.Factory viewModelFactory;
+
+	private ReportViewModel viewModel;
+
+	@Override
+	public void injectActivity(ActivityComponent component) {
+		component.inject(this);
+	}
+
+	@Override
+	public void onCreate(@Nullable Bundle savedInstanceState) {
+		super.onCreate(savedInstanceState);
+		setContentView(R.layout.activity_dev_report);
+
+		viewModel = new ViewModelProvider(this, viewModelFactory)
+				.get(ReportViewModel.class);
+		Intent intent = getIntent();
+		Throwable t = (Throwable) intent.getSerializableExtra(EXTRA_THROWABLE);
+		long appStartTime = intent.getLongExtra(EXTRA_APP_START_TIME, -1);
+		viewModel.init(t, appStartTime);
+		viewModel.getShowReport().observeEvent(this, show -> {
+			if (show) displayFragment(true);
+		});
+		viewModel.getCloseReport().observeEvent(this, res -> {
+			if (res != 0) {
+				Toast.makeText(this, res, LENGTH_LONG).show();
+			}
+			exit();
+		});
+
+		Toolbar toolbar = findViewById(R.id.toolbar);
+		setSupportActionBar(toolbar);
+
+		if (savedInstanceState == null) displayFragment(viewModel.isFeedback());
+	}
+
+	@Override
+	public void runOnDbThread(Runnable runnable) {
+		throw new AssertionError("deprecated!!!");
+	}
+
+	@Override
+	public void onBackPressed() {
+		exit();
+	}
+
+	void displayFragment(boolean showReportForm) {
+		BaseFragment f;
+		if (showReportForm) {
+			f = new ReportFormFragment();
+			requireNonNull(getSupportActionBar()).show();
+		} else {
+			f = new CrashFragment();
+			requireNonNull(getSupportActionBar()).hide();
+		}
+		getSupportFragmentManager().beginTransaction()
+				.replace(R.id.fragmentContainer, f, f.getUniqueTag())
+				.commit();
+	}
+
+	void exit() {
+		if (!viewModel.isFeedback()) {
+			Intent i = new Intent(this, HideUiActivity.class);
+			i.addFlags(FLAG_ACTIVITY_NEW_TASK
+					| FLAG_ACTIVITY_NO_ANIMATION
+					| FLAG_ACTIVITY_CLEAR_TASK);
+			startActivity(i);
+			// crash reports run in their own process that we should kill now
+			// otherwise it keeps running and e.g. doesn't pick up theme changes
+			new Handler(Looper.getMainLooper()).postDelayed(() -> {
+				Process.killProcess(Process.myPid());
+				// kill the process with some delay to keep the Toast visible
+			}, 5000);
+		}
+		finish();
+	}
+
+}

briar-android/src/main/java/org/briarproject/briar/android/reporting/DevReportActivity.java

@@ -1,188 +0,0 @@
-package org.briarproject.briar.android.reporting;
-
-import android.content.Context;
-import android.content.Intent;
-import android.content.res.Configuration;
-import android.os.Bundle;
-
-import org.acra.dialog.BaseCrashReportDialog;
-import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
-import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
-import org.briarproject.briar.R;
-import org.briarproject.briar.android.Localizer;
-import org.briarproject.briar.android.logout.HideUiActivity;
-import org.briarproject.briar.android.util.UserFeedback;
-
-import java.io.File;
-
-import androidx.annotation.NonNull;
-import androidx.annotation.Nullable;
-import androidx.appcompat.app.AppCompatDelegate;
-import androidx.appcompat.widget.Toolbar;
-import androidx.fragment.app.Fragment;
-
-import static android.content.Intent.FLAG_ACTIVITY_CLEAR_TASK;
-import static android.content.Intent.FLAG_ACTIVITY_NEW_TASK;
-import static android.content.Intent.FLAG_ACTIVITY_NO_ANIMATION;
-import static android.os.Build.VERSION.SDK_INT;
-import static android.view.WindowManager.LayoutParams.FLAG_SECURE;
-import static java.util.Objects.requireNonNull;
-import static org.acra.ACRAConstants.EXTRA_REPORT_FILE;
-import static org.briarproject.briar.android.TestingConstants.PREVENT_SCREENSHOTS;
-
-@MethodsNotNullByDefault
-@ParametersNotNullByDefault
-public class DevReportActivity extends BaseCrashReportDialog {
-
-	private AppCompatDelegate delegate;
-
-	private AppCompatDelegate getDelegate() {
-		if (delegate == null) {
-			delegate = AppCompatDelegate.create(this, null);
-		}
-		return delegate;
-	}
-
-	@Override
-	protected void preInit(@Nullable Bundle savedInstanceState) {
-		super.preInit(savedInstanceState);
-		getDelegate().installViewFactory();
-		getDelegate().onCreate(savedInstanceState);
-		getDelegate().applyDayNight();
-		// We always need to re-apply the theme
-		// for day/night the changes to take effect.
-		// On API 23+, we should bypass setTheme(), which will no-op
-		// if the theme ID is identical to the current theme ID.
-		int theme = R.style.BriarTheme_NoActionBar;
-		if (SDK_INT >= 23) {
-			onApplyThemeResource(getTheme(), theme, false);
-		} else {
-			setTheme(theme);
-		}
-	}
-
-	@Override
-	public void init(@Nullable Bundle state) {
-		super.init(state);
-
-		if (PREVENT_SCREENSHOTS) getWindow().addFlags(FLAG_SECURE);
-
-		getDelegate().setContentView(R.layout.activity_dev_report);
-
-		Toolbar toolbar = findViewById(R.id.toolbar);
-		getDelegate().setSupportActionBar(toolbar);
-
-		String title = getString(isFeedback() ? R.string.feedback_title :
-				R.string.crash_report_title);
-		requireNonNull(getDelegate().getSupportActionBar()).setTitle(title);
-
-		if (state == null) displayFragment(isFeedback());
-	}
-
-	@Override
-	protected void attachBaseContext(Context base) {
-		super.attachBaseContext(
-				Localizer.getInstance().setLocale(base));
-	}
-
-	@Override
-	public void onPostCreate(@Nullable Bundle state) {
-		super.onPostCreate(state);
-		getDelegate().onPostCreate(state);
-	}
-
-	@Override
-	protected void onStart() {
-		super.onStart();
-		getDelegate().onStart();
-	}
-
-	@Override
-	protected void onPostResume() {
-		super.onPostResume();
-		getDelegate().onPostResume();
-	}
-
-	@Override
-	public void onTitleChanged(CharSequence title, int color) {
-		super.onTitleChanged(title, color);
-		getDelegate().setTitle(title);
-	}
-
-	@Override
-	public void onConfigurationChanged(Configuration newConfig) {
-		super.onConfigurationChanged(newConfig);
-		getDelegate().onConfigurationChanged(newConfig);
-	}
-
-	@Override
-	protected void onSaveInstanceState(@NonNull Bundle outState) {
-		super.onSaveInstanceState(outState);
-		getDelegate().onSaveInstanceState(outState);
-	}
-
-	@Override
-	public void onStop() {
-		super.onStop();
-		getDelegate().onStop();
-	}
-
-	@Override
-	public void onDestroy() {
-		super.onDestroy();
-		getDelegate().onDestroy();
-	}
-
-	@Override
-	public void onBackPressed() {
-		closeReport();
-	}
-
-	void sendCrashReport(String comment, String email) {
-		sendCrash(comment, email);
-	}
-
-	private boolean isFeedback() {
-		return getException() instanceof UserFeedback;
-	}
-
-	void displayFragment(boolean showReportForm) {
-		Fragment f;
-		if (showReportForm) {
-			File file =
-					(File) getIntent().getSerializableExtra(EXTRA_REPORT_FILE);
-			f = ReportFormFragment.newInstance(isFeedback(), file);
-			requireNonNull(getDelegate().getSupportActionBar()).show();
-		} else {
-			f = new CrashFragment();
-			requireNonNull(getDelegate().getSupportActionBar()).hide();
-		}
-		getSupportFragmentManager().beginTransaction()
-				.replace(R.id.fragmentContainer, f, f.getTag())
-				.commit();
-
-	}
-
-	@Override
-	public void invalidateOptionsMenu() {
-		super.invalidateOptionsMenu();
-		getDelegate().invalidateOptionsMenu();
-	}
-
-	void closeReport() {
-		cancelReports();
-		exit();
-	}
-
-	void exit() {
-		if (!isFeedback()) {
-			Intent i = new Intent(this, HideUiActivity.class);
-			i.addFlags(FLAG_ACTIVITY_NEW_TASK
-					| FLAG_ACTIVITY_NO_ANIMATION
-					| FLAG_ACTIVITY_CLEAR_TASK);
-			startActivity(i);
-		}
-		finish();
-	}
-
-}

briar-android/src/main/java/org/briarproject/briar/android/reporting/DevReportModule.java

@@ -0,0 +1,18 @@
+package org.briarproject.briar.android.reporting;
+
+import org.briarproject.briar.android.viewmodel.ViewModelKey;
+
+import androidx.lifecycle.ViewModel;
+import dagger.Binds;
+import dagger.Module;
+import dagger.multibindings.IntoMap;
+
+@Module
+public abstract class DevReportModule {
+
+	@Binds
+	@IntoMap
+	@ViewModelKey(ReportViewModel.class)
+	abstract ViewModel bindReportViewModel(ReportViewModel reportViewModel);
+
+}

briar-android/src/main/java/org/briarproject/briar/android/reporting/FeedbackActivity.java

@@ -0,0 +1,20 @@
+package org.briarproject.briar.android.reporting;
+
+import android.os.Bundle;
+
+import androidx.annotation.Nullable;
+import androidx.appcompat.app.ActionBar;
+
+public class FeedbackActivity extends CrashReportActivity {
+
+	@Override
+	public void onCreate(@Nullable Bundle savedInstanceState) {
+		super.onCreate(savedInstanceState);
+
+		ActionBar actionBar = getSupportActionBar();
+		if (actionBar != null) {
+			actionBar.setHomeButtonEnabled(true);
+			actionBar.setDisplayHomeAsUpEnabled(true);
+		}
+	}
+}

briar-android/src/main/java/org/briarproject/briar/android/reporting/ReportData.java

@@ -0,0 +1,123 @@
+package org.briarproject.briar.android.reporting;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.TreeMap;
+
+import javax.annotation.concurrent.Immutable;
+import javax.annotation.concurrent.NotThreadSafe;
+
+import androidx.annotation.Nullable;
+import androidx.annotation.StringRes;
+
+@NotThreadSafe
+@NotNullByDefault
+class ReportData {
+
+	private final ArrayList<ReportItem> items = new ArrayList<>();
+
+	ReportData add(ReportItem item) {
+		items.add(item);
+		return this;
+	}
+
+	List<ReportItem> getItems() {
+		return items;
+	}
+
+	public JSONObject toJson(boolean includeReport) throws JSONException {
+		JSONObject json = new JSONObject();
+		for (ReportItem item : items) {
+			// only include required items when report not added
+			if (!includeReport && item.isOptional) continue;
+			// only include what should be included
+			if (!item.isIncluded) continue;
+			json.put(item.name, item.info.toJson());
+		}
+		return json;
+	}
+
+	@NotNullByDefault
+	static class ReportItem {
+		final String name;
+		@StringRes
+		final int nameRes;
+		final ReportInfo info;
+		final boolean isOptional;
+		boolean isIncluded = true;
+
+		ReportItem(String name, int nameRes, ReportInfo info) {
+			this(name, nameRes, info, true);
+		}
+
+		ReportItem(String name, int nameRes, String info) {
+			this(name, nameRes, new SingleReportInfo(info), true);
+		}
+
+		ReportItem(String name, int nameRes, ReportInfo info,
+				boolean isOptional) {
+			this.name = name;
+			this.nameRes = nameRes;
+			this.info = info;
+			this.isOptional = isOptional;
+		}
+	}
+
+	interface ReportInfo {
+		Object toJson();
+	}
+
+	@Immutable
+	@NotNullByDefault
+	static class SingleReportInfo implements ReportInfo {
+		private final String string;
+
+		SingleReportInfo(String string) {
+			this.string = string;
+		}
+
+		@Override
+		public String toString() {
+			return string;
+		}
+
+		@Override
+		public Object toJson() {
+			return string;
+		}
+	}
+
+	@NotNullByDefault
+	static class MultiReportInfo implements ReportInfo {
+		private final Map<String, Object> map = new TreeMap<>();
+
+		MultiReportInfo add(String key, @Nullable Object value) {
+			map.put(key, value == null ? "null" : value);
+			return this;
+		}
+
+		@Override
+		public String toString() {
+			StringBuilder sb = new StringBuilder();
+			for (Map.Entry<String, Object> entry : map.entrySet()) {
+				sb
+						.append(entry.getKey())
+						.append(": ")
+						.append(entry.getValue())
+						.append("\n");
+			}
+			return sb.toString();
+		}
+
+		@Override
+		public Object toJson() {
+			return new JSONObject(map);
+		}
+	}
+
+}

briar-android/src/main/java/org/briarproject/briar/android/reporting/ReportDataAdapter.java

@@ -0,0 +1,67 @@
+package org.briarproject.briar.android.reporting;
+
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.CheckBox;
+import android.widget.TextView;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.briar.R;
+import org.briarproject.briar.android.reporting.ReportData.ReportItem;
+
+import java.util.List;
+
+import androidx.recyclerview.widget.RecyclerView;
+import androidx.recyclerview.widget.RecyclerView.Adapter;
+
+@NotNullByDefault
+class ReportDataAdapter
+		extends Adapter<ReportDataAdapter.ReportDataViewHolder> {
+
+	private final List<ReportItem> items;
+
+	ReportDataAdapter(List<ReportItem> items) {
+		this.items = items;
+	}
+
+	@Override
+	public ReportDataViewHolder onCreateViewHolder(ViewGroup parent,
+			int viewType) {
+		View v = LayoutInflater.from(parent.getContext())
+				.inflate(R.layout.list_item_crash, parent, false);
+		return new ReportDataViewHolder(v);
+	}
+
+	@Override
+	public void onBindViewHolder(ReportDataViewHolder holder, int position) {
+		holder.bind(items.get(position));
+	}
+
+	@Override
+	public int getItemCount() {
+		return items.size();
+	}
+
+	static class ReportDataViewHolder extends RecyclerView.ViewHolder {
+		private final CheckBox cb;
+		private final TextView content;
+
+		private ReportDataViewHolder(View v) {
+			super(v);
+			cb = v.findViewById(R.id.include_in_report);
+			content = v.findViewById(R.id.content);
+		}
+
+		public void bind(ReportItem item) {
+			cb.setChecked(!item.isOptional || item.isIncluded);
+			cb.setEnabled(item.isOptional);
+			cb.setOnCheckedChangeListener((buttonView, isChecked) ->
+					item.isIncluded = isChecked
+			);
+			cb.setText(item.nameRes);
+			content.setText(item.info.toString());
+		}
+	}
+
+}

briar-android/src/main/java/org/briarproject/briar/android/reporting/ReportFormFragment.java

@@ -1,6 +1,5 @@
 package org.briarproject.briar.android.reporting;
 
-import android.os.AsyncTask;
 import android.os.Bundle;
 import android.view.LayoutInflater;
 import android.view.Menu;
@@ -10,92 +9,58 @@ import android.view.View;
 import android.view.ViewGroup;
 import android.widget.Button;
 import android.widget.CheckBox;
-import android.widget.CompoundButton;
-import android.widget.CompoundButton.OnCheckedChangeListener;
 import android.widget.EditText;
-import android.widget.LinearLayout;
-import android.widget.TextView;
+import android.widget.Toast;
 
-import org.acra.ReportField;
-import org.acra.collector.CrashReportData;
-import org.acra.file.CrashReportPersister;
-import org.acra.model.Element;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.briar.R;
-import org.json.JSONException;
+import org.briarproject.briar.android.activity.ActivityComponent;
+import org.briarproject.briar.android.fragment.BaseFragment;
 
-import java.io.File;
-import java.io.IOException;
-import java.util.HashSet;
-import java.util.Iterator;
-import java.util.Map;
-import java.util.Set;
-import java.util.logging.Logger;
+import javax.inject.Inject;
 
 import androidx.annotation.Nullable;
-import androidx.fragment.app.Fragment;
+import androidx.lifecycle.ViewModelProvider;
+import androidx.recyclerview.widget.RecyclerView;
 
-import static android.view.MenuItem.SHOW_AS_ACTION_ALWAYS;
 import static android.view.View.GONE;
 import static android.view.View.INVISIBLE;
 import static android.view.View.VISIBLE;
+import static android.widget.Toast.LENGTH_SHORT;
 import static java.util.Objects.requireNonNull;
-import static java.util.logging.Level.WARNING;
-import static java.util.logging.Logger.getLogger;
-import static org.acra.ACRAConstants.EXTRA_REPORT_FILE;
-import static org.acra.ReportField.ANDROID_VERSION;
-import static org.acra.ReportField.APP_VERSION_CODE;
-import static org.acra.ReportField.APP_VERSION_NAME;
-import static org.acra.ReportField.PACKAGE_NAME;
-import static org.acra.ReportField.REPORT_ID;
-import static org.acra.ReportField.STACK_TRACE;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
-public class ReportFormFragment extends Fragment
-		implements OnCheckedChangeListener {
+public class ReportFormFragment extends BaseFragment {
 
-	private static final Logger LOG =
-			getLogger(ReportFormFragment.class.getName());
-	private static final String IS_FEEDBACK = "isFeedback";
-	private static final Set<ReportField> requiredFields = new HashSet<>();
-	private static final Set<ReportField> excludedFields = new HashSet<>();
-	static {
-		requiredFields.add(REPORT_ID);
-		requiredFields.add(APP_VERSION_CODE);
-		requiredFields.add(APP_VERSION_NAME);
-		requiredFields.add(PACKAGE_NAME);
-		requiredFields.add(ANDROID_VERSION);
-		requiredFields.add(STACK_TRACE);
-	}
+	public final static String TAG = ReportFormFragment.class.getName();
 
-	private boolean isFeedback;
-	private File reportFile;
+	@Inject
+	ViewModelProvider.Factory viewModelFactory;
+
+	private ReportViewModel viewModel;
 
 	private EditText userCommentView;
 	private EditText userEmailView;
 	private CheckBox includeDebugReport;
 	private Button chevron;
-	private LinearLayout report;
+	private RecyclerView list;
 	private View progress;
 	@Nullable
 	private MenuItem sendReport;
 
-	static ReportFormFragment newInstance(boolean isFeedback,
-			File reportFile) {
-		ReportFormFragment f = new ReportFormFragment();
-		Bundle args = new Bundle();
-		args.putBoolean(IS_FEEDBACK, isFeedback);
-		args.putSerializable(EXTRA_REPORT_FILE, reportFile);
-		f.setArguments(args);
-		return f;
+	@Override
+	public void injectFragment(ActivityComponent component) {
+		component.inject(this);
 	}
 
 	@Override
 	public void onCreate(@Nullable Bundle savedInstanceState) {
 		super.onCreate(savedInstanceState);
 		setHasOptionsMenu(true);
+		viewModel = new ViewModelProvider(requireActivity(), viewModelFactory)
+				.get(ReportViewModel.class);
 	}
 
 	@Nullable
@@ -110,15 +75,10 @@ public class ReportFormFragment extends Fragment
 		userEmailView = v.findViewById(R.id.user_email);
 		includeDebugReport = v.findViewById(R.id.include_debug_report);
 		chevron = v.findViewById(R.id.chevron);
-		report = v.findViewById(R.id.report_content);
+		list = v.findViewById(R.id.list);
 		progress = v.findViewById(R.id.progress_wheel);
 
-		Bundle args = requireArguments();
-		isFeedback = args.getBoolean(IS_FEEDBACK);
-		reportFile =
-				(File) requireNonNull(args.getSerializable(EXTRA_REPORT_FILE));
-
-		if (isFeedback) {
+		if (viewModel.isFeedback()) {
 			includeDebugReport
 					.setText(getString(R.string.include_debug_report_feedback));
 			userCommentView.setHint(R.string.enter_feedback);
@@ -129,163 +89,73 @@ public class ReportFormFragment extends Fragment
 
 		chevron.setOnClickListener(view -> {
 			boolean show = chevron.getText().equals(getString(R.string.show));
-			if (show) {
-				chevron.setText(R.string.hide);
-				refresh();
-			} else {
-				chevron.setText(R.string.show);
-				report.setVisibility(GONE);
-			}
+			viewModel.showReportData(show);
 		});
 
+		viewModel.getShowReportData().observe(getViewLifecycleOwner(), show -> {
+			if (show) {
+				chevron.setText(R.string.hide);
+				list.setVisibility(VISIBLE);
+				if (list.getAdapter() == null) {
+					progress.setVisibility(VISIBLE);
+				} else {
+					progress.setVisibility(INVISIBLE);
+				}
+			} else {
+				chevron.setText(R.string.show);
+				list.setVisibility(GONE);
+				progress.setVisibility(INVISIBLE);
+			}
+		});
 		return v;
 	}
 
-	@Override
-	public void onStart() {
-		super.onStart();
-		if (chevron.isSelected()) refresh();
-	}
-
 	@Override
 	public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
 		inflater.inflate(R.menu.dev_report_actions, menu);
 		sendReport = menu.findItem(R.id.action_send_report);
-		// calling setShowAsAction() shouldn't be needed, but for some reason is
-		sendReport.setShowAsAction(SHOW_AS_ACTION_ALWAYS);
+		sendReport.setEnabled(false);
+		viewModel.getReportData().observe(getViewLifecycleOwner(), data -> {
+			list.setAdapter(new ReportDataAdapter(data.getItems()));
+			sendReport.setEnabled(true);
+			progress.setVisibility(INVISIBLE);
+		});
 		super.onCreateOptionsMenu(menu, inflater);
 	}
 
 	@Override
 	public boolean onOptionsItemSelected(MenuItem item) {
 		if (item.getItemId() == R.id.action_send_report) {
-			processReport();
+			sendReport();
 			return true;
 		}
 		return super.onOptionsItemSelected(item);
 	}
 
 	@Override
-	public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
-		ReportField field = (ReportField) buttonView.getTag();
-		if (field != null) {
-			if (isChecked) excludedFields.remove(field);
-			else excludedFields.add(field);
-		}
+	public String getUniqueTag() {
+		return TAG;
 	}
 
-	private void refresh() {
-		report.setVisibility(INVISIBLE);
-		progress.setVisibility(VISIBLE);
-		report.removeAllViews();
-		new AsyncTask<Void, Void, CrashReportData>() {
-
-			@Override
-			protected CrashReportData doInBackground(Void... args) {
-				CrashReportPersister persister = new CrashReportPersister();
-				try {
-					return persister.load(reportFile);
-				} catch (IOException | JSONException e) {
-					LOG.log(WARNING, "Could not load report file", e);
-					return null;
-				}
-			}
-
-			@Override
-			protected void onPostExecute(CrashReportData crashData) {
-				LayoutInflater inflater = getLayoutInflater();
-				if (crashData != null) {
-					for (Map.Entry<ReportField, Element> e : crashData
-							.entrySet()) {
-						ReportField field = e.getKey();
-						StringBuilder valueBuilder = new StringBuilder();
-						for (String pair : e.getValue().flatten()) {
-							valueBuilder.append(pair).append("\n");
-						}
-						String value = valueBuilder.toString();
-						boolean required = requiredFields.contains(field);
-						boolean excluded = excludedFields.contains(field);
-						View v = inflater.inflate(R.layout.list_item_crash,
-								report, false);
-						CheckBox cb = v.findViewById(R.id.include_in_report);
-						cb.setTag(field);
-						cb.setChecked(required || !excluded);
-						cb.setEnabled(!required);
-						cb.setOnCheckedChangeListener(ReportFormFragment.this);
-						cb.setText(field.toString());
-						TextView content = v.findViewById(R.id.content);
-						content.setText(value);
-						report.addView(v);
-					}
-				} else {
-					View v = inflater.inflate(
-							android.R.layout.simple_list_item_1, report, false);
-					TextView error = v.findViewById(android.R.id.text1);
-					error.setText(R.string.could_not_load_report_data);
-					report.addView(v);
-				}
-				report.setVisibility(VISIBLE);
-				progress.setVisibility(GONE);
-			}
-		}.execute();
-	}
-
-	private void processReport() {
+	private void sendReport() {
 		userCommentView.setEnabled(false);
 		userEmailView.setEnabled(false);
 		requireNonNull(sendReport).setEnabled(false);
+		list.setVisibility(GONE); // ensures that progress fits on screen
 		progress.setVisibility(VISIBLE);
-		boolean includeReport = !isFeedback || includeDebugReport.isChecked();
-		new AsyncTask<Void, Void, Boolean>() {
 
-			@Override
-			protected Boolean doInBackground(Void... args) {
-				CrashReportPersister persister = new CrashReportPersister();
-				try {
-					CrashReportData data = persister.load(reportFile);
-					if (includeReport) {
-						for (ReportField field : excludedFields) {
-							LOG.info("Removing field " + field.name());
-							data.remove(field);
-						}
-					} else {
-						Iterator<Map.Entry<ReportField, Element>> iter =
-								data.entrySet().iterator();
-						while (iter.hasNext()) {
-							Map.Entry<ReportField, Element> e = iter.next();
-							if (!requiredFields.contains(e.getKey())) {
-								iter.remove();
-							}
-						}
-					}
-					persister.store(data, reportFile);
-					return true;
-				} catch (IOException | JSONException e) {
-					LOG.log(WARNING, "Error processing report file", e);
-					return false;
-				}
-			}
+		// Retrieve user's comment and email address, if any
+		String comment = userCommentView.getText().toString();
+		String email = userEmailView.getText().toString();
 
-			@Override
-			protected void onPostExecute(Boolean success) {
-				if (success) {
-					// Retrieve user's comment and email address, if any
-					String comment = "";
-					if (userCommentView != null)
-						comment = userCommentView.getText().toString();
-					String email = "";
-					if (userEmailView != null) {
-						email = userEmailView.getText().toString();
-					}
-					getDevReportActivity().sendCrashReport(comment, email);
-				}
-				if (getActivity() != null) getDevReportActivity().exit();
-			}
-		}.execute();
-	}
+		boolean includeReport = includeDebugReport.isChecked();
 
-	private DevReportActivity getDevReportActivity() {
-		return (DevReportActivity) requireActivity();
+		// Send report (now or after next sign-in)
+		if (viewModel.sendReport(comment, email, includeReport)) {
+			// trying to send now
+			Toast.makeText(requireContext(), R.string.dev_report_sending,
+					LENGTH_SHORT).show();
+		}
 	}
 
 }

briar-android/src/main/java/org/briarproject/briar/android/reporting/ReportViewModel.java

@@ -0,0 +1,213 @@
+package org.briarproject.briar.android.reporting;
+
+import android.app.Application;
+import android.os.Handler;
+import android.os.Looper;
+
+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.reporting.DevReporter;
+import org.briarproject.bramble.util.AndroidUtils;
+import org.briarproject.briar.R;
+import org.briarproject.briar.android.reporting.ReportData.MultiReportInfo;
+import org.briarproject.briar.android.viewmodel.LiveEvent;
+import org.briarproject.briar.android.viewmodel.MutableLiveEvent;
+import org.json.JSONException;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.util.UUID;
+import java.util.logging.Logger;
+
+import javax.inject.Inject;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.annotation.UiThread;
+import androidx.lifecycle.AndroidViewModel;
+import androidx.lifecycle.LiveData;
+import androidx.lifecycle.MutableLiveData;
+
+import static java.util.Objects.requireNonNull;
+import static java.util.logging.Level.WARNING;
+import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.api.plugin.Plugin.State.ACTIVE;
+import static org.briarproject.bramble.util.LogUtils.logException;
+import static org.briarproject.bramble.util.StringUtils.isNullOrEmpty;
+
+@NotNullByDefault
+public class ReportViewModel extends AndroidViewModel {
+
+	private static final Logger LOG =
+			getLogger(ReportViewModel.class.getName());
+
+	private final BriarReportCollector collector;
+	private final DevReporter reporter;
+	private final PluginManager pluginManager;
+
+	private final MutableLiveEvent<Boolean> showReport =
+			new MutableLiveEvent<>();
+	private final MutableLiveData<Boolean> showReportData =
+			new MutableLiveData<>();
+	private final MutableLiveData<ReportData> reportData =
+			new MutableLiveData<>();
+	private final MutableLiveEvent<Integer> closeReport =
+			new MutableLiveEvent<>();
+	private boolean isFeedback;
+
+	@Inject
+	public ReportViewModel(@NonNull Application application,
+			DevReporter reporter, PluginManager pluginManager) {
+		super(application);
+		this.collector = new BriarReportCollector(application);
+		this.reporter = reporter;
+		this.pluginManager = pluginManager;
+	}
+
+	void init(@Nullable Throwable t, long appStartTime) {
+		isFeedback = t == null;
+		if (reportData.getValue() == null) new SingleShotAndroidExecutor(() -> {
+			ReportData data = collector.collectReportData(t, appStartTime);
+			reportData.postValue(data);
+		}).start();
+	}
+
+	boolean isFeedback() {
+		return isFeedback;
+	}
+
+	/**
+	 * Call this from the crash screen, if the user wants to report a crash.
+	 */
+	@UiThread
+	void showReport() {
+		showReport.setEvent(true);
+	}
+
+	/**
+	 * Will be set to true when the user wants to report a crash.
+	 */
+	LiveEvent<Boolean> getShowReport() {
+		return showReport;
+	}
+
+	/**
+	 * The report data will be made visible in the UI when visible is true,
+	 * otherwise hidden.
+	 */
+	@UiThread
+	void showReportData(boolean visible) {
+		showReportData.setValue(visible);
+	}
+
+	/**
+	 * Will be set to true when the user wants to see report data.
+	 */
+	LiveData<Boolean> getShowReportData() {
+		return showReportData;
+	}
+
+	/**
+	 * The content of the report
+	 * that will be loaded after {@link #init(Throwable, long)} was called.
+	 */
+	LiveData<ReportData> getReportData() {
+		return reportData;
+	}
+
+	/**
+	 * Sends reports and returns now if reports are being sent now
+	 * or false, if reports will be sent next time TorPlugin becomes active.
+	 */
+	@UiThread
+	boolean sendReport(String comment, String email, boolean includeReport) {
+		ReportData data = requireNonNull(reportData.getValue());
+		if (!isNullOrEmpty(comment) || isNullOrEmpty(email)) {
+			MultiReportInfo userInfo = new MultiReportInfo();
+			if (!isNullOrEmpty(comment)) userInfo.add("Comment", comment);
+			if (!isNullOrEmpty(email)) userInfo.add("Email", email);
+			data.add(new ReportData.ReportItem("UserInfo", 0, userInfo, false));
+		}
+
+		// check the state of the TorPlugin, if this is feedback
+		boolean sendFeedbackNow;
+		if (isFeedback) {
+			Plugin plugin = pluginManager.getPlugin(TorConstants.ID);
+			sendFeedbackNow = plugin != null && plugin.getState() == ACTIVE;
+		} else {
+			sendFeedbackNow = false;
+		}
+
+		Runnable reportSender =
+				getReportSender(includeReport, data, sendFeedbackNow);
+		new SingleShotAndroidExecutor(reportSender).start();
+		return sendFeedbackNow;
+	}
+
+	private Runnable getReportSender(boolean includeReport, ReportData data,
+			boolean sendFeedbackNow) {
+		return () -> {
+			boolean error = false;
+			try {
+				File reportDir = AndroidUtils.getReportDir(getApplication());
+				String reportId = UUID.randomUUID().toString();
+				String report = data.toJson(includeReport).toString();
+				reporter.encryptReportToFile(reportDir, reportId, report);
+			} catch (FileNotFoundException | JSONException e) {
+				logException(LOG, WARNING, e);
+				error = true;
+			}
+
+			int stringRes;
+			if (error) {
+				stringRes = R.string.dev_report_error;
+			} else if (sendFeedbackNow) {
+				boolean sent = reporter.sendReports() > 0;
+				stringRes = sent ?
+						R.string.dev_report_sent : R.string.dev_report_saved;
+			} else {
+				stringRes = R.string.dev_report_saved;
+			}
+			closeReport.postEvent(stringRes);
+		};
+	}
+
+	@UiThread
+	void closeReport() {
+		closeReport.setEvent(0);
+	}
+
+	/**
+	 * An integer representing a string resource
+	 * informing about the outcome of the report
+	 * or 0 if no information is required, such as when back button was pressed.
+	 */
+	LiveEvent<Integer> getCloseReport() {
+		return closeReport;
+	}
+
+	// Used for a new thread as the Android executor thread may have died
+	private static class SingleShotAndroidExecutor extends Thread {
+
+		private final Runnable runnable;
+
+		private SingleShotAndroidExecutor(Runnable runnable) {
+			this.runnable = runnable;
+		}
+
+		@Override
+		public void run() {
+			Looper.prepare();
+			Handler handler = new Handler();
+			handler.post(runnable);
+			handler.post(() -> {
+				Looper looper = Looper.myLooper();
+				if (looper != null) looper.quit();
+			});
+			Looper.loop();
+		}
+	}
+
+}

briar-android/src/main/java/org/briarproject/briar/android/settings/SettingsFragment.java

@@ -26,7 +26,6 @@ import org.briarproject.bramble.api.plugin.TorConstants;
 import org.briarproject.bramble.api.settings.Settings;
 import org.briarproject.bramble.api.settings.SettingsManager;
 import org.briarproject.bramble.api.settings.event.SettingsUpdatedEvent;
-import org.briarproject.bramble.api.system.AndroidExecutor;
 import org.briarproject.bramble.api.system.LocationUtils;
 import org.briarproject.bramble.plugin.tor.CircumventionProvider;
 import org.briarproject.bramble.util.StringUtils;
@@ -72,6 +71,7 @@ import static android.provider.Settings.EXTRA_CHANNEL_ID;
 import static android.provider.Settings.System.DEFAULT_NOTIFICATION_URI;
 import static android.widget.Toast.LENGTH_SHORT;
 import static androidx.core.view.ViewCompat.LAYOUT_DIRECTION_LTR;
+import static java.util.Objects.requireNonNull;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.api.plugin.Plugin.PREF_PLUGIN_ENABLE;
@@ -166,9 +166,6 @@ public class SettingsFragment extends PreferenceFragmentCompat
 	@Inject
 	CircumventionProvider circumventionProvider;
 
-	@Inject
-	AndroidExecutor androidExecutor;
-
 	@Override
 	public void onAttach(Context context) {
 		super.onAttach(context);
@@ -226,11 +223,12 @@ public class SettingsFragment extends PreferenceFragmentCompat
 		screenLock.setOnPreferenceChangeListener(this);
 		screenLockTimeout.setOnPreferenceChangeListener(this);
 
-		findPreference("pref_key_send_feedback").setOnPreferenceClickListener(
-				preference -> {
-					triggerFeedback(androidExecutor);
-					return true;
-				});
+		Preference prefFeedback =
+				requireNonNull(findPreference("pref_key_send_feedback"));
+		prefFeedback.setOnPreferenceClickListener(preference -> {
+			triggerFeedback(requireContext());
+			return true;
+		});
 
 		if (SDK_INT < 27) {
 			// remove System Default Theme option from preference entries
@@ -245,17 +243,15 @@ public class SettingsFragment extends PreferenceFragmentCompat
 			values.remove(getString(R.string.pref_theme_system_value));
 			theme.setEntryValues(values.toArray(new CharSequence[0]));
 		}
+		Preference explode = requireNonNull(findPreference("pref_key_explode"));
 		if (IS_DEBUG_BUILD) {
-			findPreference("pref_key_explode").setOnPreferenceClickListener(
-					preference -> {
-						throw new RuntimeException("Boom!");
-					}
-			);
+			explode.setOnPreferenceClickListener(preference -> {
+				throw new RuntimeException("Boom!");
+			});
 		} else {
-			findPreference("pref_key_explode").setVisible(false);
+			explode.setVisible(false);
 			findPreference("pref_key_test_data").setVisible(false);
-			PreferenceGroup testing =
-					findPreference("pref_key_explode").getParent();
+			PreferenceGroup testing = explode.getParent();
 			if (testing == null) throw new AssertionError();
 			testing.setVisible(false);
 		}

briar-android/src/main/java/org/briarproject/briar/android/sharing/InvitationActivity.java

@@ -98,7 +98,7 @@ public abstract class InvitationActivity<I extends InvitationItem>
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						handleDbException(exception);
+						handleException(exception);
 					}
 				});
 	}
@@ -110,7 +110,7 @@ public abstract class InvitationActivity<I extends InvitationItem>
 				new UiExceptionHandler<DbException>(this) {
 					@Override
 					public void onExceptionUi(DbException exception) {
-						handleDbException(exception);
+						handleException(exception);
 					}
 				});
 	}

briar-android/src/main/java/org/briarproject/briar/android/sharing/ShareBlogActivity.java

@@ -59,7 +59,7 @@ public class ShareBlogActivity extends ShareActivity {
 						Toast.makeText(ShareBlogActivity.this,
 								R.string.blogs_sharing_error, LENGTH_SHORT)
 								.show();
-						handleDbException(exception);
+						handleException(exception);
 					}
 				});
 

briar-android/src/main/java/org/briarproject/briar/android/sharing/ShareBlogControllerImpl.java

@@ -10,9 +10,11 @@ import org.briarproject.bramble.api.db.NoSuchGroupException;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.GroupId;
+import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.briar.android.contactselection.ContactSelectorControllerImpl;
 import org.briarproject.briar.android.controller.handler.ExceptionHandler;
 import org.briarproject.briar.api.blog.BlogSharingManager;
+import org.briarproject.briar.api.conversation.ConversationManager;
 
 import java.util.Collection;
 import java.util.concurrent.Executor;
@@ -23,7 +25,6 @@ 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
@@ -32,16 +33,21 @@ class ShareBlogControllerImpl extends ContactSelectorControllerImpl
 		implements ShareBlogController {
 
 	private final static Logger LOG =
-			getLogger(ShareBlogControllerImpl.class.getName());
+			Logger.getLogger(ShareBlogControllerImpl.class.getName());
 
+	private final ConversationManager conversationManager;
 	private final BlogSharingManager blogSharingManager;
+	private final Clock clock;
 
 	@Inject
 	ShareBlogControllerImpl(@DatabaseExecutor Executor dbExecutor,
 			LifecycleManager lifecycleManager, ContactManager contactManager,
-			BlogSharingManager blogSharingManager) {
+			ConversationManager conversationManager,
+			BlogSharingManager blogSharingManager, Clock clock) {
 		super(dbExecutor, lifecycleManager, contactManager);
+		this.conversationManager = conversationManager;
 		this.blogSharingManager = blogSharingManager;
+		this.clock = clock;
 	}
 
 	@Override
@@ -56,7 +62,10 @@ class ShareBlogControllerImpl extends ContactSelectorControllerImpl
 			try {
 				for (ContactId c : contacts) {
 					try {
-						blogSharingManager.sendInvitation(g, c, text);
+						long time = Math.max(clock.currentTimeMillis(),
+								conversationManager.getGroupCount(c)
+										.getLatestMsgTime() + 1);
+						blogSharingManager.sendInvitation(g, c, text, time);
 					} catch (NoSuchContactException | NoSuchGroupException e) {
 						logException(LOG, WARNING, e);
 					}

briar-android/src/main/java/org/briarproject/briar/android/sharing/ShareForumActivity.java

@@ -59,7 +59,7 @@ public class ShareForumActivity extends ShareActivity {
 						Toast.makeText(ShareForumActivity.this,
 								R.string.forum_share_error, LENGTH_SHORT)
 								.show();
-						handleDbException(exception);
+						handleException(exception);
 					}
 				});
 	}

briar-android/src/main/java/org/briarproject/briar/android/sharing/ShareForumControllerImpl.java

@@ -10,8 +10,10 @@ import org.briarproject.bramble.api.db.NoSuchGroupException;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.GroupId;
+import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.briar.android.contactselection.ContactSelectorControllerImpl;
 import org.briarproject.briar.android.controller.handler.ExceptionHandler;
+import org.briarproject.briar.api.conversation.ConversationManager;
 import org.briarproject.briar.api.forum.ForumSharingManager;
 
 import java.util.Collection;
@@ -23,7 +25,6 @@ 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
@@ -32,16 +33,21 @@ class ShareForumControllerImpl extends ContactSelectorControllerImpl
 		implements ShareForumController {
 
 	private final static Logger LOG =
-			getLogger(ShareForumControllerImpl.class.getName());
+			Logger.getLogger(ShareForumControllerImpl.class.getName());
 
+	private final ConversationManager conversationManager;
 	private final ForumSharingManager forumSharingManager;
+	private final Clock clock;
 
 	@Inject
 	ShareForumControllerImpl(@DatabaseExecutor Executor dbExecutor,
 			LifecycleManager lifecycleManager, ContactManager contactManager,
-			ForumSharingManager forumSharingManager) {
+			ConversationManager conversationManager,
+			ForumSharingManager forumSharingManager, Clock clock) {
 		super(dbExecutor, lifecycleManager, contactManager);
+		this.conversationManager = conversationManager;
 		this.forumSharingManager = forumSharingManager;
+		this.clock = clock;
 	}
 
 	@Override
@@ -56,7 +62,10 @@ class ShareForumControllerImpl extends ContactSelectorControllerImpl
 			try {
 				for (ContactId c : contacts) {
 					try {
-						forumSharingManager.sendInvitation(g, c, text);
+						long time = Math.max(clock.currentTimeMillis(),
+								conversationManager.getGroupCount(c)
+										.getLatestMsgTime() + 1);
+						forumSharingManager.sendInvitation(g, c, text, time);
 					} catch (NoSuchContactException | NoSuchGroupException e) {
 						logException(LOG, WARNING, e);
 					}

briar-android/src/main/java/org/briarproject/briar/android/threaded/ThreadListActivity.java

@@ -152,7 +152,7 @@ public abstract class ThreadListActivity<G extends NamedGroup, I extends ThreadI
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						handleDbException(exception);
+						handleException(exception);
 					}
 				});
 	}
@@ -183,7 +183,7 @@ public abstract class ThreadListActivity<G extends NamedGroup, I extends ThreadI
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						handleDbException(exception);
+						handleException(exception);
 					}
 				});
 	}
@@ -214,7 +214,7 @@ public abstract class ThreadListActivity<G extends NamedGroup, I extends ThreadI
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						handleDbException(exception);
+						handleException(exception);
 					}
 				});
 	}
@@ -351,7 +351,7 @@ public abstract class ThreadListActivity<G extends NamedGroup, I extends ThreadI
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						handleDbException(exception);
+						handleException(exception);
 					}
 				};
 		getController().createAndStoreMessage(text, replyItem, handler);

briar-android/src/main/java/org/briarproject/briar/android/util/UiUtils.java

@@ -27,14 +27,13 @@ import android.widget.TextView;
 
 import com.google.android.material.textfield.TextInputLayout;
 
-import org.acra.ACRA;
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
-import org.briarproject.bramble.api.system.AndroidExecutor;
 import org.briarproject.briar.R;
+import org.briarproject.briar.android.reporting.FeedbackActivity;
 import org.briarproject.briar.android.view.ArticleMovementMethod;
 import org.briarproject.briar.android.widget.LinkDialogFragment;
 
@@ -51,6 +50,7 @@ import androidx.appcompat.app.AlertDialog;
 import androidx.core.content.ContextCompat;
 import androidx.core.hardware.fingerprint.FingerprintManagerCompat;
 import androidx.core.text.HtmlCompat;
+import androidx.fragment.app.FragmentActivity;
 import androidx.fragment.app.FragmentManager;
 import androidx.lifecycle.LifecycleOwner;
 import androidx.lifecycle.LiveData;
@@ -92,6 +92,8 @@ import static java.util.Objects.requireNonNull;
 import static java.util.concurrent.TimeUnit.DAYS;
 import static org.briarproject.briar.BuildConfig.APPLICATION_ID;
 import static org.briarproject.briar.android.TestingConstants.EXPIRY_DATE;
+import static org.briarproject.briar.android.reporting.CrashReportActivity.EXTRA_APP_START_TIME;
+import static org.briarproject.briar.android.reporting.CrashReportActivity.EXTRA_THROWABLE;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
@@ -345,10 +347,18 @@ public class UiUtils {
 		return fm.hasEnrolledFingerprints() && fm.isHardwareDetected();
 	}
 
-	public static void triggerFeedback(AndroidExecutor androidExecutor) {
-		androidExecutor.runOnBackgroundThread(
-				() -> ACRA.getErrorReporter()
-						.handleException(new UserFeedback(), false));
+	public static void triggerFeedback(Context ctx) {
+		startDevReportActivity(ctx, FeedbackActivity.class, null, null);
+	}
+
+	public static void startDevReportActivity(Context ctx,
+			Class<? extends FragmentActivity> activity, @Nullable Throwable t,
+			@Nullable Long appStartTime) {
+		final Intent dialogIntent = new Intent(ctx, activity);
+		dialogIntent.setFlags(FLAG_ACTIVITY_NEW_TASK);
+		dialogIntent.putExtra(EXTRA_THROWABLE, t);
+		dialogIntent.putExtra(EXTRA_APP_START_TIME, appStartTime);
+		ctx.startActivity(dialogIntent);
 	}
 
 	public static boolean enterPressed(int actionId,

briar-android/src/main/java/org/briarproject/briar/android/util/UserFeedback.java

@@ -1,5 +0,0 @@
-package org.briarproject.briar.android.util;
-
-public class UserFeedback extends Exception {
-
-}

briar-android/src/main/java/org/briarproject/briar/android/viewmodel/DbViewModel.java

@@ -0,0 +1,195 @@
+package org.briarproject.briar.android.viewmodel;
+
+import android.app.Application;
+
+import org.briarproject.bramble.api.db.DatabaseExecutor;
+import org.briarproject.bramble.api.db.DbCallable;
+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.LifecycleManager;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.system.AndroidExecutor;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.ListIterator;
+import java.util.concurrent.Executor;
+import java.util.logging.Logger;
+
+import javax.annotation.concurrent.Immutable;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.annotation.UiThread;
+import androidx.arch.core.util.Function;
+import androidx.lifecycle.AndroidViewModel;
+import androidx.lifecycle.LiveData;
+import androidx.recyclerview.widget.RecyclerView;
+
+import static java.util.logging.Level.WARNING;
+import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.util.LogUtils.logException;
+
+@Immutable
+@NotNullByDefault
+public abstract class DbViewModel extends AndroidViewModel {
+
+	private static final Logger LOG = getLogger(DbViewModel.class.getName());
+
+	@DatabaseExecutor
+	private final Executor dbExecutor;
+	private final LifecycleManager lifecycleManager;
+	private final TransactionManager db;
+	private final AndroidExecutor androidExecutor;
+
+	public DbViewModel(
+			@NonNull Application application,
+			@DatabaseExecutor Executor dbExecutor,
+			LifecycleManager lifecycleManager,
+			TransactionManager db,
+			AndroidExecutor androidExecutor) {
+		super(application);
+		this.dbExecutor = dbExecutor;
+		this.lifecycleManager = lifecycleManager;
+		this.db = db;
+		this.androidExecutor = androidExecutor;
+	}
+
+	/**
+	 * Runs the given task on the {@link DatabaseExecutor}
+	 * and waits for the DB to open.
+	 * <p>
+	 * If you need a list of items to be displayed in a
+	 * {@link RecyclerView.Adapter},
+	 * use {@link #loadList(DbCallable, UiConsumer)} instead.
+	 */
+	protected void runOnDbThread(Runnable task) {
+		dbExecutor.execute(() -> {
+			try {
+				lifecycleManager.waitForDatabase();
+				task.run();
+			} catch (InterruptedException e) {
+				LOG.warning("Interrupted while waiting for database");
+				Thread.currentThread().interrupt();
+			}
+		});
+	}
+
+	/**
+	 * Loads a list of items on the {@link DatabaseExecutor} within a single
+	 * {@link Transaction} and publishes it as a {@link LiveResult}
+	 * to the {@link UiThread}.
+	 * <p>
+	 * Use this to ensure that modifications to your local list do not get
+	 * overridden by database loads that were in progress while the modification
+	 * was made.
+	 * E.g. An event about the removal of a message causes the message item to
+	 * be removed from the local list while all messages are reloaded.
+	 * This method ensures that those operations can be processed on the
+	 * UiThread in the correct order so that the removed message will not be
+	 * re-added when the re-load completes.
+	 */
+	protected <T extends List<?>> void loadList(
+			DbCallable<T, DbException> task,
+			UiConsumer<LiveResult<T>> uiConsumer) {
+		dbExecutor.execute(() -> {
+			try {
+				lifecycleManager.waitForDatabase();
+				db.transaction(true, txn -> {
+					T t = task.call(txn);
+					txn.attach(() -> uiConsumer.accept(new LiveResult<>(t)));
+				});
+			} catch (InterruptedException e) {
+				LOG.warning("Interrupted while waiting for database");
+				Thread.currentThread().interrupt();
+			} catch (DbException e) {
+				logException(LOG, WARNING, e);
+				androidExecutor.runOnUiThread(
+						() -> uiConsumer.accept(new LiveResult<>(e)));
+			}
+		});
+	}
+
+	@NotNullByDefault
+	public interface UiConsumer<T> {
+		@UiThread
+		void accept(T t);
+	}
+
+	/**
+	 * Creates a copy of the list available in the given LiveData
+	 * and replaces items where the given test function returns true.
+	 *
+	 * @return a copy of the list in the LiveData with item(s) replaced
+	 * or null when the
+	 * <ul>
+	 * <li> LiveData does not have a value
+	 * <li> LiveResult in the LiveData has an error
+	 * <li> test function did return false for all items in the list
+	 * </ul>
+	 */
+	@Nullable
+	protected <T> List<T> updateListItems(
+			LiveData<LiveResult<List<T>>> liveData, Function<T, Boolean> test,
+			Function<T, T> replacer) {
+		List<T> items = getListCopy(liveData);
+		if (items == null) return null;
+
+		ListIterator<T> iterator = items.listIterator();
+		boolean changed = false;
+		while (iterator.hasNext()) {
+			T item = iterator.next();
+			if (test.apply(item)) {
+				changed = true;
+				iterator.set(replacer.apply(item));
+			}
+		}
+		return changed ? items : null;
+	}
+
+	/**
+	 * Creates a copy of the list available in the given LiveData
+	 * and removes the items from it where the given test function returns true.
+	 *
+	 * @return a copy of the list in the LiveData with item(s) removed
+	 * or null when the
+	 * <ul>
+	 * <li> LiveData does not have a value
+	 * <li> LiveResult in the LiveData has an error
+	 * <li> test function did return false for all items in the list
+	 * </ul>
+	 */
+	@Nullable
+	protected <T> List<T> removeListItems(
+			LiveData<LiveResult<List<T>>> liveData, Function<T, Boolean> test) {
+		List<T> items = getListCopy(liveData);
+		if (items == null) return null;
+
+		ListIterator<T> iterator = items.listIterator();
+		boolean changed = false;
+		while (iterator.hasNext()) {
+			T item = iterator.next();
+			if (test.apply(item)) {
+				changed = true;
+				iterator.remove();
+			}
+		}
+		return changed ? items : null;
+	}
+
+	/**
+	 * Retrieves a copy of the list of items from the given LiveData
+	 * or null if it is not available.
+	 * The list copy can be safely mutated.
+	 */
+	@Nullable
+	private <T> List<T> getListCopy(LiveData<LiveResult<List<T>>> liveData) {
+		LiveResult<List<T>> value = liveData.getValue();
+		if (value == null) return null;
+		List<T> list = value.getResultOrNull();
+		if (list == null) return null;
+		return new ArrayList<>(list);
+	}
+
+}

briar-android/src/main/java/org/briarproject/briar/android/viewmodel/LiveResult.java

@@ -3,14 +3,15 @@ package org.briarproject.briar.android.viewmodel;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
 import androidx.annotation.Nullable;
+import androidx.core.util.Consumer;
 
 @NotNullByDefault
 public class LiveResult<T> {
 
 	@Nullable
-	private T result;
+	private final T result;
 	@Nullable
-	private Exception exception;
+	private final Exception exception;
 
 	public LiveResult(T result) {
 		this.result = result;
@@ -36,4 +37,20 @@ public class LiveResult<T> {
 		return exception != null;
 	}
 
+	/**
+	 * Runs the given function, if {@link #hasError()} is true.
+	 */
+	public LiveResult<T> onError(Consumer<Exception> fun) {
+		if (exception != null) fun.accept(exception);
+		return this;
+	}
+
+	/**
+	 * Runs the given function, if {@link #hasError()} is false.
+	 */
+	public LiveResult<T> onSuccess(Consumer<T> fun) {
+		if (result != null) fun.accept(result);
+		return this;
+	}
+
 }

briar-android/src/main/java/org/briarproject/briar/api/android/AndroidNotificationManager.java

@@ -82,6 +82,14 @@ public interface AndroidNotificationManager {
 
 	void unblockNotification(GroupId g);
 
+	void blockAllForumPostNotifications();
+
+	void unblockAllForumPostNotifications();
+
+	void blockAllGroupMessageNotifications();
+
+	void unblockAllGroupMessageNotifications();
+
 	void blockAllBlogPostNotifications();
 
 	void unblockAllBlogPostNotifications();