Add transactional helper methods to DbViewModel.

and get rid of ThreadList controllers

.idea/runConfigurations/All_tests.xml

@@ -13,6 +13,7 @@
       <option name="RunConfigurationTask" enabled="true" run_configuration_name="All tests in bramble-core" run_configuration_type="AndroidJUnit" />
       <option name="RunConfigurationTask" enabled="true" run_configuration_name="All tests in bramble-android" run_configuration_type="AndroidJUnit" />
       <option name="RunConfigurationTask" enabled="true" run_configuration_name="All tests in bramble-java" run_configuration_type="AndroidJUnit" />
+      <option name="RunConfigurationTask" enabled="true" run_configuration_name="All tests in briar-api" run_configuration_type="AndroidJUnit" />
       <option name="RunConfigurationTask" enabled="true" run_configuration_name="All tests in briar-core" run_configuration_type="AndroidJUnit" />
       <option name="RunConfigurationTask" enabled="true" run_configuration_name="All tests in briar-headless" run_configuration_type="AndroidJUnit" />
     </method>

.idea/runConfigurations/All_tests_in_briar_api.xml

@@ -0,0 +1,14 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="All tests in briar-api" type="AndroidJUnit" factoryName="Android JUnit">
+    <module name="briar.briar-api" />
+    <option name="PACKAGE_NAME" value="" />
+    <option name="MAIN_CLASS_NAME" value="" />
+    <option name="METHOD_NAME" value="" />
+    <option name="TEST_OBJECT" value="package" />
+    <option name="PARAMETERS" value="" />
+    <option name="WORKING_DIRECTORY" value="file://$PROJECT_DIR$/briar-api" />
+    <method v="2">
+      <option name="Android.Gradle.BeforeRunTask" enabled="true" />
+    </method>
+  </configuration>
+</component>

bramble-android/build.gradle

@@ -5,14 +5,14 @@ apply plugin: 'witness'
 apply from: 'witness.gradle'
 
 android {
-	compileSdkVersion rootProject.ext.compileSdkVersion
-	buildToolsVersion rootProject.ext.buildToolsVersion
+	compileSdkVersion 30
+	buildToolsVersion '30.0.2'
 
 	defaultConfig {
-		minSdkVersion rootProject.ext.minSdkVersion
-		targetSdkVersion rootProject.ext.targetSdkVersion
-		versionCode rootProject.ext.versionCode
-		versionName rootProject.ext.versionName
+		minSdkVersion 16
+		targetSdkVersion 29
+		versionCode 10213
+		versionName "1.2.13"
 		consumerProguardFiles 'proguard-rules.txt'
 
 		testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"

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

@@ -2,7 +2,6 @@ package org.briarproject.bramble.system;
 
 import android.app.Application;
 import android.content.Context;
-import android.content.pm.PackageInfo;
 import android.content.pm.PackageManager;
 import android.os.PowerManager;
 
@@ -106,14 +105,21 @@ class AndroidWakeLockManagerImpl implements AndroidWakeLockManager {
 
 	private String getWakeLockTag(Context ctx) {
 		PackageManager pm = ctx.getPackageManager();
-		for (PackageInfo info : pm.getInstalledPackages(0)) {
-			String name = info.packageName.toLowerCase();
-			if (name.startsWith("com.huawei.powergenie")) {
-				return "LocationManagerService";
-			} else if (name.startsWith("com.evenwell.powermonitor")) {
-				return "AudioIn";
-			}
+		if (isInstalled(pm, "com.huawei.powergenie")) {
+			return "LocationManagerService";
+		} else if (isInstalled(pm, "com.evenwell.PowerMonitor")) {
+			return "AudioIn";
 		}
 		return ctx.getPackageName();
 	}
+
+	private boolean isInstalled(PackageManager pm, String packageName) {
+		try {
+			pm.getPackageInfo(packageName, 0);
+			return true;
+		} catch (PackageManager.NameNotFoundException e) {
+			return false;
+		}
+	}
+
 }

bramble-api/src/main/java/org/briarproject/bramble/api/FeatureFlags.java

@@ -6,4 +6,7 @@ package org.briarproject.bramble.api;
 public interface FeatureFlags {
 
 	boolean shouldEnableImageAttachments();
+
+	boolean shouldEnableProfilePictures();
+
 }

bramble-api/src/main/java/org/briarproject/bramble/api/ThrowingRunnable.java

@@ -0,0 +1,6 @@
+package org.briarproject.bramble.api;
+
+public interface ThrowingRunnable<T extends Throwable> {
+
+	void run() throws T;
+}

bramble-api/src/main/java/org/briarproject/bramble/api/contact/ContactManager.java

@@ -11,7 +11,6 @@ import org.briarproject.bramble.api.db.PendingContactExistsException;
 import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.identity.AuthorId;
-import org.briarproject.bramble.api.identity.AuthorInfo;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
@@ -179,6 +178,11 @@ public interface ContactManager {
 	 */
 	Collection<Contact> getContacts() throws DbException;
 
+	/**
+	 * Returns all contacts.
+	 */
+	Collection<Contact> getContacts(Transaction txn) throws DbException;
+
 	/**
 	 * Removes a contact and all associated state.
 	 */
@@ -215,16 +219,6 @@ public interface ContactManager {
 	boolean contactExists(AuthorId remoteAuthorId, AuthorId localAuthorId)
 			throws DbException;
 
-	/**
-	 * Returns the {@link AuthorInfo} for the given author.
-	 */
-	AuthorInfo getAuthorInfo(AuthorId a) throws DbException;
-
-	/**
-	 * Returns the {@link AuthorInfo} for the given author.
-	 */
-	AuthorInfo getAuthorInfo(Transaction txn, AuthorId a) throws DbException;
-
 	interface ContactHook {
 
 		/**

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/nullsafety/NullSafety.java

@@ -29,4 +29,12 @@ public class NullSafety {
 	public static void requireNull(@Nullable Object o) {
 		if (o != null) throw new AssertionError();
 	}
+
+	/**
+	 * Stand-in for {@code Objects.equals()}.
+	 */
+	public static boolean equals(@Nullable Object a, @Nullable Object b) {
+		return (a == b) || (a != null && a.equals(b));
+	}
+
 }

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/test/java/org/briarproject/bramble/api/identity/AuthorInfoTest.java

@@ -1,42 +0,0 @@
-package org.briarproject.bramble.api.identity;
-
-import org.briarproject.bramble.test.BrambleTestCase;
-import org.junit.Test;
-
-import static org.briarproject.bramble.api.identity.AuthorInfo.Status.NONE;
-import static org.briarproject.bramble.api.identity.AuthorInfo.Status.VERIFIED;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNotEquals;
-
-public class AuthorInfoTest extends BrambleTestCase {
-
-	@Test
-	public void testEquals() {
-		assertEquals(
-				new AuthorInfo(NONE),
-				new AuthorInfo(NONE, null)
-		);
-		assertEquals(
-				new AuthorInfo(NONE, "test"),
-				new AuthorInfo(NONE, "test")
-		);
-
-		assertNotEquals(
-				new AuthorInfo(NONE),
-				new AuthorInfo(VERIFIED)
-		);
-		assertNotEquals(
-				new AuthorInfo(NONE, "test"),
-				new AuthorInfo(NONE)
-		);
-		assertNotEquals(
-				new AuthorInfo(NONE),
-				new AuthorInfo(NONE, "test")
-		);
-		assertNotEquals(
-				new AuthorInfo(NONE, "a"),
-				new AuthorInfo(NONE, "b")
-		);
-	}
-
-}

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

@@ -20,9 +20,7 @@ import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.identity.AuthorId;
-import org.briarproject.bramble.api.identity.AuthorInfo;
 import org.briarproject.bramble.api.identity.IdentityManager;
-import org.briarproject.bramble.api.identity.LocalAuthor;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.transport.KeyManager;
 
@@ -40,10 +38,6 @@ import javax.inject.Inject;
 
 import static org.briarproject.bramble.api.contact.PendingContactState.WAITING_FOR_CONNECTION;
 import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_AUTHOR_NAME_LENGTH;
-import static org.briarproject.bramble.api.identity.AuthorInfo.Status.OURSELVES;
-import static org.briarproject.bramble.api.identity.AuthorInfo.Status.UNKNOWN;
-import static org.briarproject.bramble.api.identity.AuthorInfo.Status.UNVERIFIED;
-import static org.briarproject.bramble.api.identity.AuthorInfo.Status.VERIFIED;
 import static org.briarproject.bramble.util.StringUtils.toUtf8;
 
 @ThreadSafe
@@ -213,6 +207,11 @@ class ContactManagerImpl implements ContactManager, EventListener {
 		return db.transactionWithResult(true, db::getContacts);
 	}
 
+	@Override
+	public Collection<Contact> getContacts(Transaction txn) throws DbException {
+		return db.getContacts(txn);
+	}
+
 	@Override
 	public void removeContact(ContactId c) throws DbException {
 		db.transaction(false, txn -> removeContact(txn, c));
@@ -256,25 +255,6 @@ class ContactManagerImpl implements ContactManager, EventListener {
 		db.removeContact(txn, c);
 	}
 
-	@Override
-	public AuthorInfo getAuthorInfo(AuthorId a) throws DbException {
-		return db.transactionWithResult(true, txn -> getAuthorInfo(txn, a));
-	}
-
-	@Override
-	public AuthorInfo getAuthorInfo(Transaction txn, AuthorId authorId)
-			throws DbException {
-		LocalAuthor localAuthor = identityManager.getLocalAuthor(txn);
-		if (localAuthor.getId().equals(authorId))
-			return new AuthorInfo(OURSELVES);
-		Collection<Contact> contacts = db.getContactsByAuthorId(txn, authorId);
-		if (contacts.isEmpty()) return new AuthorInfo(UNKNOWN);
-		if (contacts.size() > 1) throw new AssertionError();
-		Contact c = contacts.iterator().next();
-		if (c.isVerified()) return new AuthorInfo(VERIFIED, c.getAlias());
-		else return new AuthorInfo(UNVERIFIED, c.getAlias());
-	}
-
 	@Override
 	public void eventOccurred(Event e) {
 		if (e instanceof PendingContactStateChangedEvent) {

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/properties/TransportPropertyValidator.java

@@ -15,6 +15,9 @@ import org.briarproject.bramble.api.system.Clock;
 import javax.annotation.concurrent.Immutable;
 
 import static org.briarproject.bramble.api.plugin.TransportId.MAX_TRANSPORT_ID_LENGTH;
+import static org.briarproject.bramble.api.properties.TransportPropertyConstants.MSG_KEY_LOCAL;
+import static org.briarproject.bramble.api.properties.TransportPropertyConstants.MSG_KEY_TRANSPORT_ID;
+import static org.briarproject.bramble.api.properties.TransportPropertyConstants.MSG_KEY_VERSION;
 import static org.briarproject.bramble.util.ValidationUtils.checkLength;
 import static org.briarproject.bramble.util.ValidationUtils.checkSize;
 
@@ -43,9 +46,9 @@ class TransportPropertyValidator extends BdfMessageValidator {
 		clientHelper.parseAndValidateTransportProperties(dictionary);
 		// Return the metadata
 		BdfDictionary meta = new BdfDictionary();
-		meta.put("transportId", transportId);
-		meta.put("version", version);
-		meta.put("local", false);
+		meta.put(MSG_KEY_TRANSPORT_ID, transportId);
+		meta.put(MSG_KEY_VERSION, version);
+		meta.put(MSG_KEY_LOCAL, false);
 		return new BdfMessageContext(meta);
 	}
 }

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/sync/DuplexOutgoingSession.java

@@ -1,5 +1,6 @@
 package org.briarproject.bramble.sync;
 
+import org.briarproject.bramble.api.ThrowingRunnable;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.event.ContactRemovedEvent;
 import org.briarproject.bramble.api.db.DatabaseComponent;

bramble-core/src/main/java/org/briarproject/bramble/sync/SimplexOutgoingSession.java

@@ -1,5 +1,6 @@
 package org.briarproject.bramble.sync;
 
+import org.briarproject.bramble.api.ThrowingRunnable;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.event.ContactRemovedEvent;
 import org.briarproject.bramble.api.db.DatabaseComponent;

bramble-core/src/main/java/org/briarproject/bramble/sync/ThrowingRunnable.java

@@ -1,6 +0,0 @@
-package org.briarproject.bramble.sync;
-
-interface ThrowingRunnable<T extends Throwable> {
-
-	void run() throws T;
-}

bramble-core/src/test/java/org/briarproject/bramble/contact/ContactManagerImplTest.java

@@ -8,18 +8,15 @@ import org.briarproject.bramble.api.contact.PendingContactState;
 import org.briarproject.bramble.api.crypto.KeyPair;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.db.DatabaseComponent;
-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.identity.Author;
 import org.briarproject.bramble.api.identity.AuthorId;
-import org.briarproject.bramble.api.identity.AuthorInfo;
 import org.briarproject.bramble.api.identity.IdentityManager;
 import org.briarproject.bramble.api.identity.LocalAuthor;
 import org.briarproject.bramble.api.transport.KeyManager;
 import org.briarproject.bramble.test.BrambleMockTestCase;
 import org.briarproject.bramble.test.DbExpectations;
-import org.jmock.Expectations;
 import org.junit.Before;
 import org.junit.Test;
 
@@ -31,10 +28,6 @@ import static java.util.Collections.singletonList;
 import static org.briarproject.bramble.api.contact.HandshakeLinkConstants.BASE32_LINK_BYTES;
 import static org.briarproject.bramble.api.contact.PendingContactState.WAITING_FOR_CONNECTION;
 import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_AUTHOR_NAME_LENGTH;
-import static org.briarproject.bramble.api.identity.AuthorInfo.Status.OURSELVES;
-import static org.briarproject.bramble.api.identity.AuthorInfo.Status.UNKNOWN;
-import static org.briarproject.bramble.api.identity.AuthorInfo.Status.UNVERIFIED;
-import static org.briarproject.bramble.api.identity.AuthorInfo.Status.VERIFIED;
 import static org.briarproject.bramble.test.TestUtils.getAgreementPrivateKey;
 import static org.briarproject.bramble.test.TestUtils.getAgreementPublicKey;
 import static org.briarproject.bramble.test.TestUtils.getAuthor;
@@ -46,7 +39,6 @@ import static org.briarproject.bramble.test.TestUtils.getSecretKey;
 import static org.briarproject.bramble.util.StringUtils.getRandomBase32String;
 import static org.briarproject.bramble.util.StringUtils.getRandomString;
 import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 
 public class ContactManagerImplTest extends BrambleMockTestCase {
@@ -212,75 +204,6 @@ public class ContactManagerImplTest extends BrambleMockTestCase {
 		assertTrue(contactManager.contactExists(remote.getId(), local));
 	}
 
-	@Test
-	public void testGetAuthorInfo() throws Exception {
-		Transaction txn = new Transaction(null, true);
-
-		context.checking(new DbExpectations() {{
-			oneOf(identityManager).getLocalAuthor(txn);
-			will(returnValue(localAuthor));
-			oneOf(db).getContactsByAuthorId(txn, remote.getId());
-			will(returnValue(singletonList(contact)));
-		}});
-
-		AuthorInfo authorInfo =
-				contactManager.getAuthorInfo(txn, remote.getId());
-		assertEquals(UNVERIFIED, authorInfo.getStatus());
-		assertEquals(contact.getAlias(), authorInfo.getAlias());
-	}
-
-	@Test
-	public void testGetAuthorInfoTransaction() throws DbException {
-		Transaction txn = new Transaction(null, true);
-
-		// check unknown author
-		context.checking(new Expectations() {{
-			oneOf(identityManager).getLocalAuthor(txn);
-			will(returnValue(localAuthor));
-			oneOf(db).getContactsByAuthorId(txn, remote.getId());
-			will(returnValue(emptyList()));
-		}});
-
-		AuthorInfo authorInfo =
-				contactManager.getAuthorInfo(txn, remote.getId());
-		assertEquals(UNKNOWN, authorInfo.getStatus());
-		assertNull(authorInfo.getAlias());
-
-		// check unverified contact
-		checkAuthorInfoContext(txn, remote.getId(), singletonList(contact));
-		authorInfo = contactManager.getAuthorInfo(txn, remote.getId());
-		assertEquals(UNVERIFIED, authorInfo.getStatus());
-		assertEquals(contact.getAlias(), authorInfo.getAlias());
-
-		// check verified contact
-		Contact verified = getContact(remote, local, true);
-		checkAuthorInfoContext(txn, remote.getId(), singletonList(verified));
-		authorInfo = contactManager.getAuthorInfo(txn, remote.getId());
-		assertEquals(VERIFIED, authorInfo.getStatus());
-		assertEquals(verified.getAlias(), authorInfo.getAlias());
-
-		// check ourselves
-		context.checking(new Expectations() {{
-			oneOf(identityManager).getLocalAuthor(txn);
-			will(returnValue(localAuthor));
-			never(db).getContactsByAuthorId(txn, remote.getId());
-		}});
-
-		authorInfo = contactManager.getAuthorInfo(txn, localAuthor.getId());
-		assertEquals(OURSELVES, authorInfo.getStatus());
-		assertNull(authorInfo.getAlias());
-	}
-
-	private void checkAuthorInfoContext(Transaction txn, AuthorId authorId,
-			Collection<Contact> contacts) throws DbException {
-		context.checking(new Expectations() {{
-			oneOf(identityManager).getLocalAuthor(txn);
-			will(returnValue(localAuthor));
-			oneOf(db).getContactsByAuthorId(txn, authorId);
-			will(returnValue(contacts));
-		}});
-	}
-
 	@Test
 	public void testGetHandshakeLink() throws Exception {
 		Transaction txn = new Transaction(null, true);

bramble-core/src/test/java/org/briarproject/bramble/test/BrambleCoreIntegrationTestModule.java

@@ -22,6 +22,17 @@ public class BrambleCoreIntegrationTestModule {
 
 	@Provides
 	FeatureFlags provideFeatureFlags() {
-		return () -> true;
+		return new FeatureFlags() {
+
+			@Override
+			public boolean shouldEnableImageAttachments() {
+				return true;
+			}
+
+			@Override
+			public boolean shouldEnableProfilePictures() {
+				return true;
+			}
+		};
 	}
 }

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

@@ -16,14 +16,14 @@ def getStdout = { command, defaultValue ->
 }
 
 android {
-	compileSdkVersion rootProject.ext.compileSdkVersion
-	buildToolsVersion rootProject.ext.buildToolsVersion
+	compileSdkVersion 30
+	buildToolsVersion '30.0.2'
 
 	defaultConfig {
-		minSdkVersion rootProject.ext.minSdkVersion
-		targetSdkVersion rootProject.ext.targetSdkVersion
-		versionCode rootProject.ext.versionCode
-		versionName rootProject.ext.versionName
+		minSdkVersion 16
+		targetSdkVersion 29
+		versionCode 10213
+		versionName "1.2.13"
 		applicationId "org.briarproject.briar.android"
 		buildConfigField "String", "GitHash",
 				"\"${getStdout(['git', 'rev-parse', '--short=7', 'HEAD'], 'No commit hash')}\""
@@ -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'
@@ -109,7 +108,7 @@ dependencies {
 	implementation 'com.vanniktech:emoji-google:0.6.0' // newer versions need minSdk 21
 	implementation 'com.github.kobakei:MaterialFabSpeedDial:1.2.1'
 	implementation 'com.github.chrisbanes:PhotoView:2.3.0'
-	def glideVersion = '4.10.0'
+	def glideVersion = '4.11.0'
 	implementation("com.github.bumptech.glide:glide:$glideVersion") {
 		exclude group: 'com.android.support'
 		exclude module: 'disklrucache' // when there's no disk cache, we can't accidentally use it
@@ -127,10 +126,11 @@ dependencies {
 	testImplementation 'androidx.test:runner:1.3.0'
 	testImplementation 'androidx.test.ext:junit:1.1.2'
 	testImplementation 'androidx.fragment:fragment-testing:1.2.5'
+	testImplementation "androidx.arch.core:core-testing:2.1.0"
 	testImplementation "androidx.test.espresso:espresso-core:$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:$jmockVersion"
@@ -142,11 +142,9 @@ dependencies {
 	androidTestImplementation "androidx.test.espresso:espresso-intents:$espressoVersion"
 	androidTestAnnotationProcessor "com.google.dagger:dagger-compiler:2.24"
 	androidTestCompileOnly 'javax.annotation:jsr250-api:1.0'
-	androidTestImplementation 'junit:junit:4.12'
-	androidTestScreenshotImplementation('tools.fastlane:screengrab:1.2.0') {
-		// workaround for jetifier issue https://issuetracker.google.com/issues/123060356
-		exclude group: 'com.android.support.test.uiautomator'
-	}
+	androidTestImplementation 'junit:junit:4.13.1'
+	androidTestScreenshotImplementation 'tools.fastlane:screengrab:2.0.0'
+	androidTestScreenshotImplementation 'com.jraska:falcon:2.1.1'
 	androidTestScreenshotImplementation 'androidx.test.uiautomator:uiautomator:2.2.0'
 }
 

briar-android/src/androidTestOfficial/java/org/briarproject/briar/android/BriarUiTestComponent.java

@@ -5,6 +5,7 @@ import org.briarproject.bramble.BrambleCoreModule;
 import org.briarproject.bramble.account.BriarAccountModule;
 import org.briarproject.briar.BriarCoreModule;
 import org.briarproject.briar.android.attachment.AttachmentModule;
+import org.briarproject.briar.android.attachment.media.MediaModule;
 import org.briarproject.briar.android.navdrawer.NavDrawerActivityTest;
 
 import javax.inject.Singleton;
@@ -15,6 +16,7 @@ import dagger.Component;
 @Component(modules = {
 		AppModule.class,
 		AttachmentModule.class,
+		MediaModule.class,
 		BriarCoreModule.class,
 		BrambleAndroidModule.class,
 		BriarAccountModule.class,

briar-android/src/androidTestOfficial/java/org/briarproject/briar/android/attachment/AbstractAttachmentCreationTaskTest.java

@@ -1,41 +0,0 @@
-package org.briarproject.briar.android.attachment;
-
-import android.content.res.AssetManager;
-
-import org.junit.Before;
-
-import java.io.IOException;
-import java.io.InputStream;
-
-import static androidx.test.InstrumentationRegistry.getContext;
-import static androidx.test.core.app.ApplicationProvider.getApplicationContext;
-
-abstract class AbstractAttachmentCreationTaskTest {
-
-	private final ImageHelper imageHelper = new ImageHelperImpl();
-	private final ImageSizeCalculator imageSizeCalculator =
-			new ImageSizeCalculator(imageHelper);
-
-	private AttachmentCreationTask task;
-
-	@Before
-	@SuppressWarnings("ConstantConditions")  // add real objects when needed
-	public void setUp() {
-		task = new AttachmentCreationTask(null,
-				getApplicationContext().getContentResolver(), null,
-				imageSizeCalculator, null, null, true);
-	}
-
-	void testCompress(String filename, String contentType)
-			throws IOException {
-		InputStream is = getAssetManager().open(filename);
-		task.compressImage(is, contentType);
-	}
-
-	static AssetManager getAssetManager() {
-		// pm.getResourcesForApplication(packageName).getAssets() did not work
-		//noinspection deprecation
-		return getContext().getAssets();
-	}
-
-}

briar-android/src/androidTestOfficial/java/org/briarproject/briar/android/attachment/AbstractAttachmentRetrieverComponent.java

@@ -0,0 +1,17 @@
+package org.briarproject.briar.android.attachment;
+
+import org.briarproject.briar.android.attachment.media.MediaModule;
+
+import javax.inject.Singleton;
+
+import dagger.Component;
+
+@Singleton
+@Component(modules = {
+		MediaModule.class
+})
+interface AbstractAttachmentRetrieverComponent {
+
+	void inject(AttachmentRetrieverIntegrationTest test);
+
+}

briar-android/src/androidTestOfficial/java/org/briarproject/briar/android/attachment/AttachmentRetrieverIntegrationTest.java

@@ -1,15 +1,20 @@
 package org.briarproject.briar.android.attachment;
 
 import org.briarproject.bramble.api.UniqueId;
+import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.MessageId;
-import org.briarproject.briar.api.messaging.Attachment;
-import org.briarproject.briar.api.messaging.AttachmentHeader;
+import org.briarproject.briar.android.attachment.media.ImageHelper;
+import org.briarproject.briar.android.attachment.media.ImageSizeCalculator;
+import org.briarproject.briar.api.attachment.Attachment;
+import org.briarproject.briar.api.attachment.AttachmentHeader;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
 import java.io.InputStream;
 import java.util.Random;
 
+import javax.inject.Inject;
+
 import androidx.test.ext.junit.runners.AndroidJUnit4;
 
 import static androidx.test.InstrumentationRegistry.getContext;
@@ -24,16 +29,28 @@ public class AttachmentRetrieverIntegrationTest {
 	private final AttachmentDimensions dimensions = new AttachmentDimensions(
 			100, 50, 200, 75, 300
 	);
+	private final GroupId groupId = new GroupId(getRandomId());
 	private final MessageId msgId = new MessageId(getRandomId());
 
-	private final ImageHelper imageHelper = new ImageHelperImpl();
-	private final AttachmentRetriever retriever =
-			new AttachmentRetrieverImpl(null, null, dimensions, imageHelper,
-					new ImageSizeCalculator(imageHelper));
+	@Inject
+	ImageHelper imageHelper;
+	@Inject
+	ImageSizeCalculator imageSizeCalculator;
+
+	private final AttachmentRetriever retriever;
+
+	public AttachmentRetrieverIntegrationTest() {
+		AbstractAttachmentRetrieverComponent component =
+				DaggerAbstractAttachmentRetrieverComponent.builder().build();
+		component.inject(this);
+
+		retriever = new AttachmentRetrieverImpl(null, null, dimensions,
+				imageHelper, imageSizeCalculator);
+	}
 
 	@Test
 	public void testSmallJpegImage() throws Exception {
-		AttachmentHeader h = new AttachmentHeader(msgId, "image/jpeg");
+		AttachmentHeader h = new AttachmentHeader(groupId, msgId, "image/jpeg");
 		InputStream is = getAssetInputStream("kitten_small.jpg");
 		Attachment a = new Attachment(h, is);
 		AttachmentItem item = retriever.createAttachmentItem(a, true);
@@ -49,7 +66,7 @@ public class AttachmentRetrieverIntegrationTest {
 
 	@Test
 	public void testBigJpegImage() throws Exception {
-		AttachmentHeader h = new AttachmentHeader(msgId, "image/jpeg");
+		AttachmentHeader h = new AttachmentHeader(groupId, msgId, "image/jpeg");
 		InputStream is = getAssetInputStream("kitten_original.jpg");
 		Attachment a = new Attachment(h, is);
 		AttachmentItem item = retriever.createAttachmentItem(a, true);
@@ -65,7 +82,7 @@ public class AttachmentRetrieverIntegrationTest {
 
 	@Test
 	public void testSmallPngImage() throws Exception {
-		AttachmentHeader h = new AttachmentHeader(msgId, "image/png");
+		AttachmentHeader h = new AttachmentHeader(groupId, msgId, "image/png");
 		InputStream is = getAssetInputStream("kitten.png");
 		Attachment a = new Attachment(h, is);
 		AttachmentItem item = retriever.createAttachmentItem(a, true);
@@ -81,7 +98,7 @@ public class AttachmentRetrieverIntegrationTest {
 
 	@Test
 	public void testUberGif() throws Exception {
-		AttachmentHeader h = new AttachmentHeader(msgId, "image/gif");
+		AttachmentHeader h = new AttachmentHeader(groupId, msgId, "image/gif");
 		InputStream is = getAssetInputStream("uber.gif");
 		Attachment a = new Attachment(h, is);
 		AttachmentItem item = retriever.createAttachmentItem(a, true);
@@ -96,7 +113,7 @@ public class AttachmentRetrieverIntegrationTest {
 
 	@Test
 	public void testLottaPixels() throws Exception {
-		AttachmentHeader h = new AttachmentHeader(msgId, "image/jpeg");
+		AttachmentHeader h = new AttachmentHeader(groupId, msgId, "image/jpeg");
 		InputStream is = getAssetInputStream("lottapixel.jpg");
 		Attachment a = new Attachment(h, is);
 		AttachmentItem item = retriever.createAttachmentItem(a, true);
@@ -111,7 +128,7 @@ public class AttachmentRetrieverIntegrationTest {
 
 	@Test
 	public void testImageIoCrash() throws Exception {
-		AttachmentHeader h = new AttachmentHeader(msgId, "image/png");
+		AttachmentHeader h = new AttachmentHeader(groupId, msgId, "image/png");
 		InputStream is = getAssetInputStream("image_io_crash.png");
 		Attachment a = new Attachment(h, is);
 		AttachmentItem item = retriever.createAttachmentItem(a, true);
@@ -126,7 +143,7 @@ public class AttachmentRetrieverIntegrationTest {
 
 	@Test
 	public void testGimpCrash() throws Exception {
-		AttachmentHeader h = new AttachmentHeader(msgId, "image/gif");
+		AttachmentHeader h = new AttachmentHeader(groupId, msgId, "image/gif");
 		InputStream is = getAssetInputStream("gimp_crash.gif");
 		Attachment a = new Attachment(h, is);
 		AttachmentItem item = retriever.createAttachmentItem(a, true);
@@ -141,7 +158,7 @@ public class AttachmentRetrieverIntegrationTest {
 
 	@Test
 	public void testOptiPngAfl() throws Exception {
-		AttachmentHeader h = new AttachmentHeader(msgId, "image/gif");
+		AttachmentHeader h = new AttachmentHeader(groupId, msgId, "image/gif");
 		InputStream is = getAssetInputStream("opti_png_afl.gif");
 		Attachment a = new Attachment(h, is);
 		AttachmentItem item = retriever.createAttachmentItem(a, true);
@@ -156,7 +173,7 @@ public class AttachmentRetrieverIntegrationTest {
 
 	@Test
 	public void testLibrawError() throws Exception {
-		AttachmentHeader h = new AttachmentHeader(msgId, "image/jpeg");
+		AttachmentHeader h = new AttachmentHeader(groupId, msgId, "image/jpeg");
 		InputStream is = getAssetInputStream("libraw_error.jpg");
 		Attachment a = new Attachment(h, is);
 		AttachmentItem item = retriever.createAttachmentItem(a, true);
@@ -165,7 +182,7 @@ public class AttachmentRetrieverIntegrationTest {
 
 	@Test
 	public void testSmallAnimatedGifMaxDimensions() throws Exception {
-		AttachmentHeader h = new AttachmentHeader(msgId, "image/gif");
+		AttachmentHeader h = new AttachmentHeader(groupId, msgId, "image/gif");
 		InputStream is = getAssetInputStream("animated.gif");
 		Attachment a = new Attachment(h, is);
 		AttachmentItem item = retriever.createAttachmentItem(a, true);
@@ -180,7 +197,7 @@ public class AttachmentRetrieverIntegrationTest {
 
 	@Test
 	public void testSmallAnimatedGifHugeDimensions() throws Exception {
-		AttachmentHeader h = new AttachmentHeader(msgId, "image/gif");
+		AttachmentHeader h = new AttachmentHeader(groupId, msgId, "image/gif");
 		InputStream is = getAssetInputStream("animated2.gif");
 		Attachment a = new Attachment(h, is);
 		AttachmentItem item = retriever.createAttachmentItem(a, true);
@@ -195,7 +212,7 @@ public class AttachmentRetrieverIntegrationTest {
 
 	@Test
 	public void testSmallGifLargeDimensions() throws Exception {
-		AttachmentHeader h = new AttachmentHeader(msgId, "image/gif");
+		AttachmentHeader h = new AttachmentHeader(groupId, msgId, "image/gif");
 		InputStream is = getAssetInputStream("error_large.gif");
 		Attachment a = new Attachment(h, is);
 		AttachmentItem item = retriever.createAttachmentItem(a, true);
@@ -210,7 +227,7 @@ public class AttachmentRetrieverIntegrationTest {
 
 	@Test
 	public void testHighError() throws Exception {
-		AttachmentHeader h = new AttachmentHeader(msgId, "image/jpeg");
+		AttachmentHeader h = new AttachmentHeader(groupId, msgId, "image/jpeg");
 		InputStream is = getAssetInputStream("error_high.jpg");
 		Attachment a = new Attachment(h, is);
 		AttachmentItem item = retriever.createAttachmentItem(a, true);
@@ -225,7 +242,7 @@ public class AttachmentRetrieverIntegrationTest {
 
 	@Test
 	public void testWideError() throws Exception {
-		AttachmentHeader h = new AttachmentHeader(msgId, "image/jpeg");
+		AttachmentHeader h = new AttachmentHeader(groupId, msgId, "image/jpeg");
 		InputStream is = getAssetInputStream("error_wide.jpg");
 		Attachment a = new Attachment(h, is);
 		AttachmentItem item = retriever.createAttachmentItem(a, true);

briar-android/src/androidTestOfficial/java/org/briarproject/briar/android/attachment/media/AbstractImageCompressorComponent.java

@@ -0,0 +1,15 @@
+package org.briarproject.briar.android.attachment.media;
+
+import javax.inject.Singleton;
+
+import dagger.Component;
+
+@Singleton
+@Component(modules = {
+		MediaModule.class
+})
+interface AbstractImageCompressorComponent {
+
+	void inject(AbstractImageCompressorTest test);
+
+}

briar-android/src/androidTestOfficial/java/org/briarproject/briar/android/attachment/media/AbstractImageCompressorTest.java

@@ -0,0 +1,38 @@
+package org.briarproject.briar.android.attachment.media;
+
+import android.content.res.AssetManager;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+import javax.inject.Inject;
+
+import static androidx.test.InstrumentationRegistry.getContext;
+
+public abstract class AbstractImageCompressorTest {
+
+	@Inject
+	ImageCompressor imageCompressor;
+
+	public AbstractImageCompressorTest() {
+		AbstractImageCompressorComponent component =
+				DaggerAbstractImageCompressorComponent.builder().build();
+		component.inject(this);
+	}
+
+	protected abstract void inject(
+			AbstractImageCompressorComponent component);
+
+	void testCompress(String filename, String contentType)
+			throws IOException {
+		InputStream is = getAssetManager().open(filename);
+		imageCompressor.compressImage(is, contentType);
+	}
+
+	static AssetManager getAssetManager() {
+		// pm.getResourcesForApplication(packageName).getAssets() did not work
+		//noinspection deprecation
+		return getContext().getAssets();
+	}
+
+}

briar-android/src/androidTestOfficial/java/org/briarproject/briar/android/attachment/media/AbstractImageSizeCalculatorComponent.java

@@ -0,0 +1,15 @@
+package org.briarproject.briar.android.attachment.media;
+
+import javax.inject.Singleton;
+
+import dagger.Component;
+
+@Singleton
+@Component(modules = {
+		MediaModule.class
+})
+interface AbstractImageSizeCalculatorComponent {
+
+	void inject(AbstractImageSizeCalculatorTest test);
+
+}

briar-android/src/androidTestOfficial/java/org/briarproject/briar/android/attachment/media/AbstractImageSizeCalculatorTest.java

@@ -0,0 +1,51 @@
+package org.briarproject.briar.android.attachment.media;
+
+import android.content.res.AssetManager;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+import javax.inject.Inject;
+
+import static androidx.test.InstrumentationRegistry.getContext;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+public abstract class AbstractImageSizeCalculatorTest {
+
+	@Inject
+	ImageSizeCalculator imageSizeCalculator;
+
+	public AbstractImageSizeCalculatorTest() {
+		AbstractImageSizeCalculatorComponent component =
+				DaggerAbstractImageSizeCalculatorComponent.builder().build();
+		component.inject(this);
+	}
+
+	protected abstract void inject(
+			AbstractImageSizeCalculatorComponent component);
+
+	void testCanCalculateSize(String filename, String contentType, int width,
+			int height) throws IOException {
+		InputStream is = getAssetManager().open(filename);
+		Size size = imageSizeCalculator.getSize(is, contentType);
+		assertFalse(size.hasError());
+		assertEquals(width, size.getWidth());
+		assertEquals(height, size.getHeight());
+	}
+
+	void testCannotCalculateSize(String filename, String contentType)
+			throws IOException {
+		InputStream is = getAssetManager().open(filename);
+		Size size = imageSizeCalculator.getSize(is, contentType);
+		assertTrue(size.hasError());
+	}
+
+	static AssetManager getAssetManager() {
+		// pm.getResourcesForApplication(packageName).getAssets() did not work
+		//noinspection deprecation
+		return getContext().getAssets();
+	}
+
+}

briar-android/src/androidTestOfficial/java/org/briarproject/briar/android/attachment/media/ImageCompressorTest.java

@@ -1,4 +1,4 @@
-package org.briarproject.briar.android.attachment;
+package org.briarproject.briar.android.attachment.media;
 
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -9,8 +9,13 @@ import static android.os.Build.VERSION.SDK_INT;
 import static org.junit.Assume.assumeTrue;
 
 @RunWith(AndroidJUnit4.class)
-public class AttachmentCreationTaskTest
-		extends AbstractAttachmentCreationTaskTest {
+public class ImageCompressorTest
+		extends AbstractImageCompressorTest {
+
+	@Override
+	protected void inject(AbstractImageCompressorComponent component) {
+		component.inject(this);
+	}
 
 	@Test
 	public void testCompressSmallPng() throws Exception {

briar-android/src/androidTestOfficial/java/org/briarproject/briar/android/attachment/media/ImageSizeCalculatorTest.java

@@ -0,0 +1,80 @@
+package org.briarproject.briar.android.attachment.media;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+
+import static android.os.Build.VERSION.SDK_INT;
+import static org.junit.Assume.assumeTrue;
+
+@RunWith(AndroidJUnit4.class)
+public class ImageSizeCalculatorTest
+		extends AbstractImageSizeCalculatorTest {
+
+	@Override
+	protected void inject(AbstractImageSizeCalculatorComponent component) {
+		component.inject(this);
+	}
+
+	@Test
+	public void testCalculateSizeKittenSmall() throws Exception {
+		testCanCalculateSize("kitten_small.jpg", "image/jpeg", 160, 240);
+	}
+
+	@Test
+	public void testCalculateSizeKittenSmallNoExif() throws Exception {
+		testCanCalculateSize("kitten_small_noexif.jpg", "image/jpeg", 160, 240);
+	}
+
+	@Test
+	public void testCalculateSizeSmallPng() throws Exception {
+		testCanCalculateSize("red-100x100.png", "image/png", 100, 100);
+	}
+
+	@Test
+	public void testCalculateSizeMediumPng() throws Exception {
+		testCanCalculateSize("blue-500x500.png", "image/png", 500, 500);
+	}
+
+	@Test
+	public void testCalculateSizeLargePng() throws Exception {
+		testCanCalculateSize("green-1000x2000.png", "image/png", 1000, 2000);
+	}
+
+	@Test
+	public void testCalculateSizeTransparentPng() throws Exception {
+		testCanCalculateSize("transparent-100x100.png", "image/png", 100, 100);
+	}
+
+	@Test
+	public void testCalculateSizeVeryHighJpg() throws Exception {
+		testCanCalculateSize("error_high.jpg", "image/jpeg", 1, 10000);
+	}
+
+	@Test
+	public void testCalculateSizeVeryWideJpg() throws Exception {
+		testCanCalculateSize("error_wide.jpg", "image/jpeg", 1920, 1);
+	}
+
+	@Test
+	public void testCalculateSizeAnimatedGif1() throws Exception {
+		// TODO: Remove this assumption when we support large messages
+		assumeTrue(SDK_INT >= 24);
+		testCanCalculateSize("animated.gif", "image/gif", 65535, 65535);
+	}
+
+	@Test
+	public void testCalculateSizeAnimatedGif2() throws Exception {
+		// TODO: Remove this assumption when we support large messages
+		assumeTrue(SDK_INT >= 24);
+		testCanCalculateSize("animated2.gif", "image/gif", 10000, 10000);
+	}
+
+	@Test
+	public void testCalculateSizeVeryLargeGif() throws Exception {
+		// TODO: Remove this assumption when we support large messages
+		assumeTrue(SDK_INT >= 24);
+		testCanCalculateSize("error_large.gif", "image/gif", 16384, 16384);
+	}
+}

briar-android/src/androidTestOfficial/java/org/briarproject/briar/android/attachment/media/PngSuiteImageCompressorTest.java

@@ -1,4 +1,4 @@
-package org.briarproject.briar.android.attachment;
+package org.briarproject.briar.android.attachment.media;
 
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -17,11 +17,16 @@ import static org.junit.Assert.fail;
 import static org.junit.Assume.assumeTrue;
 
 @RunWith(Parameterized.class)
-public class PngSuiteAttachmentCreationTaskTest
-		extends AbstractAttachmentCreationTaskTest {
+public class PngSuiteImageCompressorTest
+		extends AbstractImageCompressorTest {
 
 	private static final Logger LOG =
-			getLogger(PngSuiteAttachmentCreationTaskTest.class.getName());
+			getLogger(PngSuiteImageCompressorTest.class.getName());
+
+	@Override
+	protected void inject(AbstractImageCompressorComponent component) {
+		component.inject(this);
+	}
 
 	@Parameters
 	public static Iterable<String> data() throws IOException {
@@ -34,14 +39,14 @@ public class PngSuiteAttachmentCreationTaskTest
 
 	private final String filename;
 
-	public PngSuiteAttachmentCreationTaskTest(String filename) {
+	public PngSuiteImageCompressorTest(String filename) {
 		this.filename = filename;
 	}
 
 	@Test
 	public void testPngSuiteCompress() throws Exception {
 		assumeTrue(isOptionalTestEnabled(
-				PngSuiteAttachmentCreationTaskTest.class));
+				PngSuiteImageCompressorTest.class));
 		LOG.info("Testing " + filename);
 		if (filename.startsWith("x")) {
 			try {

briar-android/src/androidTestOfficial/java/org/briarproject/briar/android/attachment/media/PngSuiteImageSizeCalculatorTest.java

@@ -0,0 +1,80 @@
+package org.briarproject.briar.android.attachment.media;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameters;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.logging.Logger;
+
+import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
+import static org.briarproject.bramble.test.TestUtils.isOptionalTestEnabled;
+import static org.junit.Assume.assumeTrue;
+
+@RunWith(Parameterized.class)
+public class PngSuiteImageSizeCalculatorTest
+		extends AbstractImageSizeCalculatorTest {
+
+	private static final Logger LOG =
+			getLogger(PngSuiteImageSizeCalculatorTest.class.getName());
+
+	@Override
+	protected void inject(AbstractImageSizeCalculatorComponent component) {
+		component.inject(this);
+	}
+
+	@Parameters
+	public static Iterable<String> data() throws IOException {
+		List<String> data = new ArrayList<>();
+		String[] files = requireNonNull(getAssetManager().list("PngSuite"));
+		for (String filename : files)
+			if (filename.endsWith(".png")) data.add(filename);
+		return data;
+	}
+
+	private final String filename;
+
+	public PngSuiteImageSizeCalculatorTest(String filename) {
+		this.filename = filename;
+	}
+
+	//  some files have sizes other than 32x32
+	private Map<String, Size> customSizes = new HashMap<>();
+
+	{
+		customSizes.put("cdfn2c08.png", new Size(8, 32, "image/png"));
+		customSizes.put("cdhn2c08.png", new Size(32, 8, "image/png"));
+		customSizes.put("cdsn2c08.png", new Size(8, 8, "image/png"));
+		customSizes.put("PngSuite.png", new Size(256, 256, "image/png"));
+	}
+
+	@Test
+	public void testPngSuiteCalculateSizes() throws Exception {
+		assumeTrue(isOptionalTestEnabled(
+				PngSuiteImageSizeCalculatorTest.class));
+		LOG.info("Testing " + filename);
+		if (filename.startsWith("x") && !filename.equals("xcsn0g01.png")) {
+			testCannotCalculateSize("PngSuite/" + filename, "image/png");
+		} else if (filename.startsWith("s")) {
+			int size = Integer.parseInt(filename.substring(1, 3));
+			testCanCalculateSize("PngSuite/" + filename, "image/png", size,
+					size);
+		} else {
+			int width = 32;
+			int height = 32;
+			if (customSizes.containsKey(filename)) {
+				Size size = customSizes.get(filename);
+				width = size.getWidth();
+				height = size.getHeight();
+			}
+			testCanCalculateSize("PngSuite/" + filename, "image/png", width,
+					height);
+		}
+	}
+}

briar-android/src/androidTestScreenshot/java/org/briarproject/briar/android/BriarUiTestComponent.java

@@ -5,6 +5,7 @@ import org.briarproject.bramble.BrambleCoreModule;
 import org.briarproject.bramble.account.BriarAccountModule;
 import org.briarproject.briar.BriarCoreModule;
 import org.briarproject.briar.android.attachment.AttachmentModule;
+import org.briarproject.briar.android.attachment.media.MediaModule;
 import org.briarproject.briar.android.conversation.ConversationActivityScreenshotTest;
 import org.briarproject.briar.android.settings.SettingsActivityScreenshotTest;
 
@@ -16,6 +17,7 @@ import dagger.Component;
 @Component(modules = {
 		AppModule.class,
 		AttachmentModule.class,
+		MediaModule.class,
 		BriarCoreModule.class,
 		BrambleAndroidModule.class,
 		BriarAccountModule.class,
@@ -26,6 +28,7 @@ public interface BriarUiTestComponent extends AndroidComponent {
 	void inject(SetupDataTest test);
 
 	void inject(ConversationActivityScreenshotTest test);
+
 	void inject(SettingsActivityScreenshotTest test);
 
 }

briar-android/src/androidTestScreenshot/java/org/briarproject/briar/android/SetupDataTest.java

@@ -116,7 +116,7 @@ public class SetupDataTest extends ScreenshotTest {
 			throws DbException {
 		Context ctx = getApplicationContext();
 		String bobName = ctx.getString(R.string.screenshot_bob);
-		Contact bob = testDataCreator.addContact(bobName);
+		Contact bob = testDataCreator.addContact(bobName, true);
 
 		// TODO add messages
 

briar-android/src/debug/java/org/briarproject/briar/android/test/TestAvatarCreatorImpl.java

@@ -0,0 +1,105 @@
+/*
+ * Some code was taken from:
+ *
+ * RIG – Random Image Generator
+ * https://github.com/stedi-akk/RandomImageGenerator
+ * licenced under Apache2 license.
+ */
+
+package org.briarproject.briar.android.test;
+
+import android.graphics.Bitmap;
+import android.graphics.Canvas;
+import android.graphics.Color;
+import android.graphics.Paint;
+import android.graphics.Rect;
+
+import org.briarproject.briar.android.attachment.media.ImageCompressor;
+import org.briarproject.briar.api.test.TestAvatarCreator;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Random;
+
+import javax.annotation.Nullable;
+import javax.inject.Inject;
+
+public class TestAvatarCreatorImpl implements TestAvatarCreator {
+	private final int WIDTH = 800;
+	private final int HEIGHT = 640;
+
+	private final Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
+	private final float[] hsv = new float[3];
+	private final Random random = new Random();
+
+	private final ImageCompressor imageCompressor;
+
+	@Inject
+	TestAvatarCreatorImpl(ImageCompressor imageCompressor) {
+		this.imageCompressor = imageCompressor;
+	}
+
+	@Nullable
+	@Override
+	public InputStream getAvatarInputStream() throws IOException {
+		Bitmap bitmap = generateBitmap();
+		return imageCompressor.compressImage(bitmap);
+	}
+
+	private Bitmap generateBitmap() {
+		// one pattern is boring, let's at least use two
+		if (random.nextBoolean()) {
+			return generateColoredPixels();
+		} else {
+			return generateColoredCircles();
+		}
+	}
+
+	private Bitmap generateColoredPixels() {
+		Bitmap bitmap = getBitmapWithRandomBackground();
+		Canvas canvas = new Canvas(bitmap);
+		Rect pixel = new Rect();
+		int pixelMultiplier = random.nextInt(500) + 1;
+		for (int x = 0; x < WIDTH; x += pixelMultiplier) {
+			for (int y = 0; y < HEIGHT; y += pixelMultiplier) {
+				pixel.set(x, y, x + pixelMultiplier, y + pixelMultiplier);
+				paint.setColor(getRandomColor());
+				canvas.drawRect(pixel, paint);
+			}
+		}
+		return bitmap;
+	}
+
+	private Bitmap generateColoredCircles() {
+		Bitmap bitmap = getBitmapWithRandomBackground();
+		int biggestSide = Math.max(WIDTH, HEIGHT);
+		int selectedCount = random.nextInt(10) + 2;
+		Canvas canvas = new Canvas(bitmap);
+		float radiusFrom = biggestSide / 12f;
+		float radiusTo = biggestSide / 4f;
+		for (int i = 0; i < selectedCount; i++) {
+			float cx = random.nextInt(WIDTH);
+			float cy = random.nextInt(HEIGHT);
+			float radius =
+					random.nextInt((int) (radiusTo - radiusFrom)) + radiusFrom;
+			paint.setColor(getRandomColor());
+			canvas.drawCircle(cx, cy, radius, paint);
+		}
+		return bitmap;
+	}
+
+	private Bitmap getBitmapWithRandomBackground() {
+		Bitmap bitmap =
+				Bitmap.createBitmap(WIDTH, HEIGHT, Bitmap.Config.ARGB_8888);
+		bitmap.eraseColor(getRandomColor());
+		return bitmap;
+	}
+
+	private int getRandomColor() {
+		hsv[0] = random.nextInt(360);
+		hsv[1] = random.nextFloat();
+		hsv[2] = 1f;
+		return Color.HSVToColor(hsv);
+	}
+
+}

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"
@@ -346,7 +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"
@@ -412,11 +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"
@@ -436,4 +449,29 @@
 			android:theme="@style/BriarTheme" />
 
 	</application>
+
+	<queries>
+		<package android:name="info.guardianproject.ripple" />
+		<package android:name="com.huawei.systemmanager" />
+		<package android:name="com.huawei.powergenie" />
+		<package android:name="com.evenwell.PowerMonitor" />
+
+		<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

@@ -14,6 +14,7 @@ import org.briarproject.bramble.api.contact.ContactManager;
 import org.briarproject.bramble.api.crypto.CryptoExecutor;
 import org.briarproject.bramble.api.crypto.PasswordStrengthEstimator;
 import org.briarproject.bramble.api.db.DatabaseExecutor;
+import org.briarproject.bramble.api.db.TransactionManager;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.identity.IdentityManager;
 import org.briarproject.bramble.api.keyagreement.KeyAgreementTask;
@@ -31,14 +32,15 @@ import org.briarproject.bramble.plugin.tor.CircumventionProvider;
 import org.briarproject.briar.BriarCoreEagerSingletons;
 import org.briarproject.briar.BriarCoreModule;
 import org.briarproject.briar.android.attachment.AttachmentModule;
+import org.briarproject.briar.android.attachment.media.MediaModule;
 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.attachment.AttachmentReader;
 import org.briarproject.briar.api.blog.BlogManager;
 import org.briarproject.briar.api.blog.BlogPostFactory;
 import org.briarproject.briar.api.blog.BlogSharingManager;
@@ -47,6 +49,7 @@ import org.briarproject.briar.api.conversation.ConversationManager;
 import org.briarproject.briar.api.feed.FeedManager;
 import org.briarproject.briar.api.forum.ForumManager;
 import org.briarproject.briar.api.forum.ForumSharingManager;
+import org.briarproject.briar.api.identity.AuthorManager;
 import org.briarproject.briar.api.introduction.IntroductionManager;
 import org.briarproject.briar.api.messaging.MessagingManager;
 import org.briarproject.briar.api.messaging.PrivateMessageFactory;
@@ -71,7 +74,8 @@ import dagger.Component;
 		BrambleAndroidModule.class,
 		BriarAccountModule.class,
 		AppModule.class,
-		AttachmentModule.class
+		AttachmentModule.class,
+		MediaModule.class
 })
 public interface AndroidComponent
 		extends BrambleCoreEagerSingletons, BrambleAndroidEagerSingletons,
@@ -86,12 +90,18 @@ public interface AndroidComponent
 	@DatabaseExecutor
 	Executor databaseExecutor();
 
+	TransactionManager transactionManager();
+
 	MessageTracker messageTracker();
 
 	LifecycleManager lifecycleManager();
 
 	IdentityManager identityManager();
 
+	AttachmentReader attachmentReader();
+
+	AuthorManager authorManager();
+
 	PluginManager pluginManager();
 
 	EventBus eventBus();
@@ -173,8 +183,6 @@ public interface AndroidComponent
 
 	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

@@ -27,15 +27,26 @@ import org.briarproject.bramble.plugin.tcp.AndroidLanTcpPluginFactory;
 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.DozeHelperModule;
 import org.briarproject.briar.android.account.LockManagerImpl;
+import org.briarproject.briar.android.account.SetupModule;
+import org.briarproject.briar.android.contact.ContactListModule;
+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.conversation.GroupConversationModule;
+import org.briarproject.briar.android.settings.SettingsModule;
+import org.briarproject.briar.android.privategroup.list.GroupListModule;
+import org.briarproject.briar.android.reporting.DevReportModule;
+import org.briarproject.briar.android.sharing.SharingModule;
+import org.briarproject.briar.android.test.TestAvatarCreatorImpl;
 import org.briarproject.briar.android.viewmodel.ViewModelModule;
 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.test.TestAvatarCreator;
 
 import java.io.File;
 import java.security.GeneralSecurityException;
@@ -60,10 +71,20 @@ import static org.briarproject.bramble.api.reporting.ReportingConstants.DEV_PUBL
 import static org.briarproject.briar.android.TestingConstants.IS_DEBUG_BUILD;
 
 @Module(includes = {
+		SetupModule.class,
+		DozeHelperModule.class,
 		ContactExchangeModule.class,
 		LoginModule.class,
 		NavDrawerModule.class,
-		ViewModelModule.class
+		ViewModelModule.class,
+		SettingsModule.class,
+		DevReportModule.class,
+		ContactListModule.class,
+		// below need to be within same scope as ViewModelProvider.Factory
+		ForumModule.class,
+		GroupListModule.class,
+		GroupConversationModule.class,
+		SharingModule.class,
 })
 public class AppModule {
 
@@ -175,6 +196,12 @@ public class AppModule {
 		return devConfig;
 	}
 
+	@Provides
+	TestAvatarCreator provideTestAvatarCreator(
+			TestAvatarCreatorImpl testAvatarCreator) {
+		return testAvatarCreator;
+	}
+
 	@Provides
 	SharedPreferences provideSharedPreferences(Application app) {
 		// FIXME unify this with getDefaultSharedPreferences()
@@ -196,7 +223,10 @@ 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;
 	}
 
@@ -235,6 +265,17 @@ public class AppModule {
 
 	@Provides
 	FeatureFlags provideFeatureFlags() {
-		return () -> IS_DEBUG_BUILD;
+		return new FeatureFlags() {
+
+			@Override
+			public boolean shouldEnableImageAttachments() {
+				return IS_DEBUG_BUILD;
+			}
+
+			@Override
+			public boolean shouldEnableProfilePictures() {
+				return IS_DEBUG_BUILD;
+			}
+		};
 	}
 }

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/BriarService.java

@@ -14,6 +14,8 @@ import android.content.ServiceConnection;
 import android.os.Binder;
 import android.os.IBinder;
 
+import com.bumptech.glide.Glide;
+
 import org.briarproject.bramble.api.account.AccountManager;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
@@ -246,10 +248,13 @@ public class BriarService extends Service {
 			LOG.info("Trim memory: near end of LRU list");
 		} else if (level == TRIM_MEMORY_RUNNING_MODERATE) {
 			LOG.info("Trim memory: running moderately low");
+			Glide.get(getApplicationContext()).clearMemory();
 		} else if (level == TRIM_MEMORY_RUNNING_LOW) {
 			LOG.info("Trim memory: running low");
+			// TODO investigate if we can clear Glide cache here as well
 		} else if (level == TRIM_MEMORY_RUNNING_CRITICAL) {
 			LOG.warning("Trim memory: running critically low");
+			// TODO investigate if we can clear Glide cache here as well
 			// If we're not in the foreground, clear the UI to save memory
 			if (app.isRunningInBackground()) hideUi();
 		} else if (LOG.isLoggable(INFO)) {

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/account/AuthorNameFragment.java

@@ -81,8 +81,7 @@ public class AuthorNameFragment extends SetupFragment {
 	public void onClick(View view) {
 		Editable text = authorNameInput.getText();
 		if (text != null) {
-			setupController.setAuthorName(text.toString().trim());
-			setupController.showPasswordFragment();
+			viewModel.setAuthorName(text.toString().trim());
 		}
 	}
 

briar-android/src/main/java/org/briarproject/briar/android/account/DozeFragment.java

@@ -104,9 +104,15 @@ public class DozeFragment extends SetupFragment
 
 	@Override
 	public void onClick(View view) {
-		next.setVisibility(INVISIBLE);
-		progressBar.setVisibility(VISIBLE);
-		setupController.createAccount();
+		setNextClicked();
+		viewModel.dozeExceptionConfirmed();
 	}
 
+	@Override
+	void setNextClicked() {
+		super.setNextClicked();
+
+		next.setVisibility(INVISIBLE);
+		progressBar.setVisibility(VISIBLE);
+	}
 }

briar-android/src/main/java/org/briarproject/briar/android/account/DozeHelper.java

@@ -0,0 +1,8 @@
+package org.briarproject.briar.android.account;
+
+import android.content.Context;
+
+interface DozeHelper {
+
+	boolean needToShowDozeFragment(Context context);
+}

briar-android/src/main/java/org/briarproject/briar/android/account/DozeHelperImpl.java

@@ -0,0 +1,14 @@
+package org.briarproject.briar.android.account;
+
+import android.content.Context;
+
+import static org.briarproject.briar.android.account.HuaweiView.needsToBeShown;
+import static org.briarproject.briar.android.util.UiUtils.needsDozeWhitelisting;
+
+class DozeHelperImpl implements DozeHelper {
+	@Override
+	public boolean needToShowDozeFragment(Context context) {
+		return needsDozeWhitelisting(context.getApplicationContext()) ||
+				needsToBeShown(context.getApplicationContext());
+	}
+}

briar-android/src/main/java/org/briarproject/briar/android/account/DozeHelperModule.java

@@ -0,0 +1,13 @@
+package org.briarproject.briar.android.account;
+
+import dagger.Module;
+import dagger.Provides;
+
+@Module
+public class DozeHelperModule {
+
+	@Provides
+	DozeHelper provideDozeHelper() {
+		return new DozeHelperImpl();
+	}
+}

briar-android/src/main/java/org/briarproject/briar/android/account/SetPasswordFragment.java

@@ -30,7 +30,6 @@ import static org.briarproject.briar.android.util.UiUtils.setError;
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
 public class SetPasswordFragment extends SetupFragment {
-
 	private final static String TAG = SetPasswordFragment.class.getName();
 
 	private TextInputLayout passwordEntryWrapper;
@@ -56,7 +55,7 @@ public class SetPasswordFragment extends SetupFragment {
 			@Nullable Bundle savedInstanceState) {
 		requireActivity().setTitle(getString(R.string.setup_password_intro));
 		View v = inflater.inflate(R.layout.fragment_setup_password, container,
-						false);
+				false);
 
 		strengthMeter = v.findViewById(R.id.strength_meter);
 		passwordEntryWrapper = v.findViewById(R.id.password_entry_wrapper);
@@ -71,7 +70,7 @@ public class SetPasswordFragment extends SetupFragment {
 		passwordConfirmation.addTextChangedListener(this);
 		nextButton.setOnClickListener(this);
 
-		if (!setupController.needToShowDozeFragment()) {
+		if (!viewModel.needToShowDozeFragment()) {
 			nextButton.setText(R.string.create_account_button);
 			passwordConfirmation.setImeOptions(IME_ACTION_DONE);
 		}
@@ -97,7 +96,7 @@ public class SetPasswordFragment extends SetupFragment {
 
 		strengthMeter
 				.setVisibility(password1.length() > 0 ? VISIBLE : INVISIBLE);
-		float strength = setupController.estimatePasswordStrength(password1);
+		float strength = viewModel.estimatePasswordStrength(password1);
 		strengthMeter.setStrength(strength);
 		boolean strongEnough = strength >= QUITE_WEAK;
 
@@ -117,14 +116,20 @@ public class SetPasswordFragment extends SetupFragment {
 		IBinder token = passwordEntry.getWindowToken();
 		Object o = getContext().getSystemService(INPUT_METHOD_SERVICE);
 		((InputMethodManager) o).hideSoftInputFromWindow(token, 0);
-		setupController.setPassword(passwordEntry.getText().toString());
-		if (setupController.needToShowDozeFragment()) {
-			setupController.showDozeFragment();
-		} else {
-			nextButton.setVisibility(INVISIBLE);
-			progressBar.setVisibility(VISIBLE);
-			setupController.createAccount();
-		}
+
+		setNextClicked();
+		viewModel.setPassword(passwordEntry.getText().toString());
 	}
 
+	@Override
+	void setNextClicked() {
+		super.setNextClicked();
+
+		passwordEntry.setFocusable(false);
+		passwordConfirmation.setFocusable(false);
+		if (!viewModel.needToShowDozeFragment()) {
+			nextButton.setVisibility(INVISIBLE);
+			progressBar.setVisibility(VISIBLE);
+		}
+	}
 }

briar-android/src/main/java/org/briarproject/briar/android/account/SetupActivity.java

@@ -4,7 +4,6 @@ import android.annotation.TargetApi;
 import android.content.Intent;
 import android.os.Bundle;
 
-import org.briarproject.bramble.api.account.AccountManager;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.briar.R;
@@ -15,28 +14,36 @@ import org.briarproject.briar.android.fragment.BaseFragment.BaseFragmentListener
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
+import androidx.lifecycle.ViewModelProvider;
+
 import static android.content.Intent.FLAG_ACTIVITY_CLEAR_TASK;
 import static android.content.Intent.FLAG_ACTIVITY_CLEAR_TOP;
 import static android.content.Intent.FLAG_ACTIVITY_NEW_TASK;
 import static android.content.Intent.FLAG_ACTIVITY_TASK_ON_HOME;
 import static org.briarproject.briar.android.BriarApplication.ENTRY_ACTIVITY;
+import static org.briarproject.briar.android.account.SetupViewModel.State.AUTHOR_NAME;
+import static org.briarproject.briar.android.account.SetupViewModel.State.CREATED;
+import static org.briarproject.briar.android.account.SetupViewModel.State.DOZE;
+import static org.briarproject.briar.android.account.SetupViewModel.State.FAILED;
+import static org.briarproject.briar.android.account.SetupViewModel.State.SET_PASSWORD;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
 public class SetupActivity extends BaseActivity
 		implements BaseFragmentListener {
 
-	private static final String STATE_KEY_AUTHOR_NAME = "authorName";
-	private static final String STATE_KEY_PASSWORD = "password";
-
 	@Inject
-	AccountManager accountManager;
+	ViewModelProvider.Factory viewModelFactory;
+	SetupViewModel viewModel;
 
-	@Inject
-	SetupController setupController;
+	@Override
+	public void injectActivity(ActivityComponent component) {
+		component.inject(this);
 
-	@Nullable
-	private String authorName, password;
+		viewModel = new ViewModelProvider(this, viewModelFactory)
+				.get(SetupViewModel.class);
+		viewModel.getState().observeEvent(this, this::onStateChanged);
+	}
 
 	@Override
 	public void onCreate(@Nullable Bundle state) {
@@ -44,58 +51,27 @@ public class SetupActivity extends BaseActivity
 		// fade-in after splash screen instead of default animation
 		overridePendingTransition(R.anim.fade_in, R.anim.fade_out);
 		setContentView(R.layout.activity_fragment_container);
+	}
 
-		if (state == null) {
-			if (accountManager.accountExists()) throw new AssertionError();
+	private void onStateChanged(SetupViewModel.State state) {
+		if (state == AUTHOR_NAME) {
 			showInitialFragment(AuthorNameFragment.newInstance());
-		} else {
-			authorName = state.getString(STATE_KEY_AUTHOR_NAME);
-			password = state.getString(STATE_KEY_PASSWORD);
+		} else if (state == SET_PASSWORD) {
+			showPasswordFragment();
+		} else if (state == DOZE) {
+			showDozeFragment();
+		} else if (state == CREATED || state == FAILED) {
+			// TODO: Show an error if failed
+			showApp();
 		}
 	}
 
-	@Override
-	public void injectActivity(ActivityComponent component) {
-		component.inject(this);
-		setupController.setSetupActivity(this);
-	}
-
-	@Override
-	protected void onSaveInstanceState(Bundle state) {
-		super.onSaveInstanceState(state);
-		if (authorName != null)
-			state.putString(STATE_KEY_AUTHOR_NAME, authorName);
-		if (password != null)
-			state.putString(STATE_KEY_PASSWORD, password);
-	}
-
-	@Nullable
-	String getAuthorName() {
-		return authorName;
-	}
-
-	void setAuthorName(String authorName) {
-		this.authorName = authorName;
-	}
-
-	@Nullable
-	String getPassword() {
-		return password;
-	}
-
-	void setPassword(String password) {
-		this.password = password;
-	}
-
 	void showPasswordFragment() {
-		if (authorName == null) throw new IllegalStateException();
 		showNextFragment(SetPasswordFragment.newInstance());
 	}
 
 	@TargetApi(23)
 	void showDozeFragment() {
-		if (authorName == null) throw new IllegalStateException();
-		if (password == null) throw new IllegalStateException();
 		showNextFragment(DozeFragment.newInstance());
 	}
 

briar-android/src/main/java/org/briarproject/briar/android/account/SetupController.java

@@ -1,34 +0,0 @@
-package org.briarproject.briar.android.account;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-@NotNullByDefault
-public interface SetupController {
-
-	void setSetupActivity(SetupActivity setupActivity);
-
-	boolean needToShowDozeFragment();
-
-	void setAuthorName(String authorName);
-
-	float estimatePasswordStrength(String password);
-
-	void setPassword(String password);
-
-	/**
-	 * This should be called after the author name has been set.
-	 */
-	void showPasswordFragment();
-
-	/**
-	 * This should be called after the author name and the password have been
-	 * set.
-	 */
-	void showDozeFragment();
-
-	/**
-	 * This should be called after the author name and the password have been
-	 * set.
-	 */
-	void createAccount();
-}

briar-android/src/main/java/org/briarproject/briar/android/account/SetupControllerImpl.java

@@ -1,115 +0,0 @@
-package org.briarproject.briar.android.account;
-
-import org.briarproject.bramble.api.account.AccountManager;
-import org.briarproject.bramble.api.crypto.PasswordStrengthEstimator;
-import org.briarproject.bramble.api.lifecycle.IoExecutor;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.briar.android.controller.handler.ResultHandler;
-import org.briarproject.briar.android.controller.handler.UiResultHandler;
-
-import java.util.concurrent.Executor;
-import java.util.logging.Logger;
-
-import javax.inject.Inject;
-
-import androidx.annotation.Nullable;
-
-@NotNullByDefault
-public class SetupControllerImpl implements SetupController {
-
-	private static final Logger LOG =
-			Logger.getLogger(SetupControllerImpl.class.getName());
-
-	private final AccountManager accountManager;
-	private final PasswordStrengthEstimator strengthEstimator;
-	@IoExecutor
-	private final Executor ioExecutor;
-	@Nullable
-	private volatile SetupActivity setupActivity;
-
-	@Inject
-	SetupControllerImpl(AccountManager accountManager,
-			@IoExecutor Executor ioExecutor,
-			PasswordStrengthEstimator strengthEstimator) {
-		this.accountManager = accountManager;
-		this.strengthEstimator = strengthEstimator;
-		this.ioExecutor = ioExecutor;
-	}
-
-	@Override
-	public void setSetupActivity(SetupActivity setupActivity) {
-		this.setupActivity = setupActivity;
-	}
-
-	@Override
-	public boolean needToShowDozeFragment() {
-		SetupActivity setupActivity = this.setupActivity;
-		if (setupActivity == null) throw new IllegalStateException();
-		return DozeView.needsToBeShown(setupActivity) ||
-				HuaweiView.needsToBeShown(setupActivity);
-	}
-
-	@Override
-	public void setAuthorName(String authorName) {
-		SetupActivity setupActivity = this.setupActivity;
-		if (setupActivity == null) throw new IllegalStateException();
-		setupActivity.setAuthorName(authorName);
-	}
-
-	@Override
-	public float estimatePasswordStrength(String password) {
-		return strengthEstimator.estimateStrength(password);
-	}
-
-	@Override
-	public void setPassword(String password) {
-		SetupActivity setupActivity = this.setupActivity;
-		if (setupActivity == null) throw new IllegalStateException();
-		setupActivity.setPassword(password);
-	}
-
-	@Override
-	public void showPasswordFragment() {
-		SetupActivity setupActivity = this.setupActivity;
-		if (setupActivity == null) throw new IllegalStateException();
-		setupActivity.showPasswordFragment();
-	}
-
-	@Override
-	public void showDozeFragment() {
-		SetupActivity setupActivity = this.setupActivity;
-		if (setupActivity == null) throw new IllegalStateException();
-		setupActivity.showDozeFragment();
-	}
-
-	@Override
-	public void createAccount() {
-		SetupActivity setupActivity = this.setupActivity;
-		UiResultHandler<Boolean> resultHandler =
-				new UiResultHandler<Boolean>(setupActivity) {
-					@Override
-					public void onResultUi(Boolean result) {
-						// TODO: Show an error if result is false
-						if (setupActivity == null)
-							throw new IllegalStateException();
-						setupActivity.showApp();
-					}
-				};
-		createAccount(resultHandler);
-	}
-
-	// Package access for testing
-	void createAccount(ResultHandler<Boolean> resultHandler) {
-		SetupActivity setupActivity = this.setupActivity;
-		if (setupActivity == null) throw new IllegalStateException();
-		String authorName = setupActivity.getAuthorName();
-		if (authorName == null) throw new IllegalStateException();
-		String password = setupActivity.getPassword();
-		if (password == null) throw new IllegalStateException();
-		ioExecutor.execute(() -> {
-			LOG.info("Creating account");
-			resultHandler.onResult(accountManager.createAccount(authorName,
-					password));
-		});
-	}
-}

briar-android/src/main/java/org/briarproject/briar/android/account/SetupFragment.java

@@ -1,11 +1,13 @@
 package org.briarproject.briar.android.account;
 
+import android.os.Bundle;
 import android.text.Editable;
 import android.text.TextWatcher;
 import android.view.KeyEvent;
 import android.view.Menu;
 import android.view.MenuInflater;
 import android.view.MenuItem;
+import android.view.View;
 import android.view.View.OnClickListener;
 import android.widget.TextView;
 import android.widget.TextView.OnEditorActionListener;
@@ -17,7 +19,10 @@ import org.briarproject.briar.android.fragment.BaseFragment;
 
 import javax.inject.Inject;
 
+import androidx.annotation.CallSuper;
+import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
+import androidx.lifecycle.ViewModelProvider;
 
 import static android.view.inputmethod.EditorInfo.IME_ACTION_DONE;
 import static android.view.inputmethod.EditorInfo.IME_ACTION_NEXT;
@@ -29,8 +34,40 @@ import static org.briarproject.briar.android.util.UiUtils.showOnboardingDialog;
 abstract class SetupFragment extends BaseFragment implements TextWatcher,
 		OnEditorActionListener, OnClickListener {
 
+	private final static String STATE_KEY_CLICKED = "setupFragmentClicked";
+	private boolean clicked = false;
+
 	@Inject
-	SetupController setupController;
+	ViewModelProvider.Factory viewModelFactory;
+	SetupViewModel viewModel;
+
+	@Override
+	public void onCreate(@Nullable Bundle savedInstanceState) {
+		super.onCreate(savedInstanceState);
+		viewModel = new ViewModelProvider(requireActivity())
+				.get(SetupViewModel.class);
+	}
+
+	@Override
+	public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
+		if (savedInstanceState != null) {
+			clicked = savedInstanceState.getBoolean(STATE_KEY_CLICKED);
+		}
+		if (clicked) {
+			setNextClicked();
+		}
+	}
+
+	@Override
+	public void onSaveInstanceState(@NonNull Bundle outState) {
+		super.onSaveInstanceState(outState);
+		outState.putBoolean(STATE_KEY_CLICKED, clicked);
+	}
+
+	@CallSuper
+	void setNextClicked() {
+		this.clicked = true;
+	}
 
 	@Override
 	public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {

briar-android/src/main/java/org/briarproject/briar/android/account/SetupModule.java

@@ -0,0 +1,18 @@
+package org.briarproject.briar.android.account;
+
+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 SetupModule {
+
+	@Binds
+	@IntoMap
+	@ViewModelKey(SetupViewModel.class)
+	abstract ViewModel bindSetupViewModel(
+			SetupViewModel setupViewModel);
+}

briar-android/src/main/java/org/briarproject/briar/android/account/SetupViewModel.java

@@ -0,0 +1,110 @@
+package org.briarproject.briar.android.account;
+
+import android.app.Application;
+
+import org.briarproject.bramble.api.account.AccountManager;
+import org.briarproject.bramble.api.crypto.PasswordStrengthEstimator;
+import org.briarproject.bramble.api.lifecycle.IoExecutor;
+import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
+import org.briarproject.briar.android.viewmodel.LiveEvent;
+import org.briarproject.briar.android.viewmodel.MutableLiveEvent;
+
+import java.util.concurrent.Executor;
+import java.util.logging.Logger;
+
+import javax.inject.Inject;
+
+import androidx.annotation.Nullable;
+import androidx.lifecycle.AndroidViewModel;
+
+import static java.util.logging.Logger.getLogger;
+import static org.briarproject.briar.android.account.SetupViewModel.State.AUTHOR_NAME;
+import static org.briarproject.briar.android.account.SetupViewModel.State.CREATED;
+import static org.briarproject.briar.android.account.SetupViewModel.State.DOZE;
+import static org.briarproject.briar.android.account.SetupViewModel.State.FAILED;
+import static org.briarproject.briar.android.account.SetupViewModel.State.SET_PASSWORD;
+
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
+class SetupViewModel extends AndroidViewModel {
+	enum State {AUTHOR_NAME, SET_PASSWORD, DOZE, CREATED, FAILED}
+
+	private static final Logger LOG =
+			getLogger(SetupActivity.class.getName());
+
+	@Nullable
+	private String authorName, password;
+	private final MutableLiveEvent<State> state = new MutableLiveEvent<>();
+
+	private final AccountManager accountManager;
+	private final Executor ioExecutor;
+	private final PasswordStrengthEstimator strengthEstimator;
+	private final DozeHelper dozeHelper;
+
+	@Inject
+	SetupViewModel(Application app,
+			AccountManager accountManager,
+			@IoExecutor Executor ioExecutor,
+			PasswordStrengthEstimator strengthEstimator,
+			DozeHelper dozeHelper) {
+		super(app);
+		this.accountManager = accountManager;
+		this.ioExecutor = ioExecutor;
+		this.strengthEstimator = strengthEstimator;
+		this.dozeHelper = dozeHelper;
+
+		ioExecutor.execute(() -> {
+			if (accountManager.accountExists()) {
+				throw new AssertionError();
+			} else {
+				state.postEvent(AUTHOR_NAME);
+			}
+		});
+	}
+
+	LiveEvent<State> getState() {
+		return state;
+	}
+
+	void setAuthorName(String authorName) {
+		this.authorName = authorName;
+		state.setEvent(SET_PASSWORD);
+	}
+
+	void setPassword(String password) {
+		if (authorName == null) throw new IllegalStateException();
+		this.password = password;
+		if (needToShowDozeFragment()) {
+			state.setEvent(DOZE);
+		} else {
+			createAccount();
+		}
+	}
+
+	float estimatePasswordStrength(String password) {
+		return strengthEstimator.estimateStrength(password);
+	}
+
+	boolean needToShowDozeFragment() {
+		return dozeHelper.needToShowDozeFragment(getApplication());
+	}
+
+	void dozeExceptionConfirmed() {
+		createAccount();
+	}
+
+	private void createAccount() {
+		if (authorName == null) throw new IllegalStateException();
+		if (password == null) throw new IllegalStateException();
+		ioExecutor.execute(() -> {
+			if (accountManager.createAccount(authorName, password)) {
+				LOG.info("Created account");
+				state.postEvent(CREATED);
+			} else {
+				LOG.warning("Failed to create account");
+				state.postEvent(FAILED);
+			}
+		});
+	}
+}

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

@@ -21,7 +21,6 @@ import org.briarproject.briar.android.blog.RssFeedImportActivity;
 import org.briarproject.briar.android.blog.RssFeedManageActivity;
 import org.briarproject.briar.android.blog.WriteBlogPostActivity;
 import org.briarproject.briar.android.contact.ContactListFragment;
-import org.briarproject.briar.android.contact.ContactModule;
 import org.briarproject.briar.android.contact.add.remote.AddContactActivity;
 import org.briarproject.briar.android.contact.add.remote.LinkExchangeFragment;
 import org.briarproject.briar.android.contact.add.remote.NicknameFragment;
@@ -33,7 +32,6 @@ import org.briarproject.briar.android.conversation.ImageFragment;
 import org.briarproject.briar.android.forum.CreateForumActivity;
 import org.briarproject.briar.android.forum.ForumActivity;
 import org.briarproject.briar.android.forum.ForumListFragment;
-import org.briarproject.briar.android.forum.ForumModule;
 import org.briarproject.briar.android.fragment.ScreenFilterDialogFragment;
 import org.briarproject.briar.android.introduction.ContactChooserFragment;
 import org.briarproject.briar.android.introduction.IntroductionActivity;
@@ -51,7 +49,6 @@ import org.briarproject.briar.android.navdrawer.TransportsActivity;
 import org.briarproject.briar.android.panic.PanicPreferencesActivity;
 import org.briarproject.briar.android.panic.PanicResponderActivity;
 import org.briarproject.briar.android.privategroup.conversation.GroupActivity;
-import org.briarproject.briar.android.privategroup.conversation.GroupConversationModule;
 import org.briarproject.briar.android.privategroup.creation.CreateGroupActivity;
 import org.briarproject.briar.android.privategroup.creation.CreateGroupFragment;
 import org.briarproject.briar.android.privategroup.creation.CreateGroupModule;
@@ -60,12 +57,15 @@ 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.ConfirmAvatarDialogFragment;
 import org.briarproject.briar.android.settings.SettingsActivity;
 import org.briarproject.briar.android.settings.SettingsFragment;
 import org.briarproject.briar.android.sharing.BlogInvitationActivity;
@@ -86,15 +86,11 @@ import dagger.Component;
 @Component(modules = {
 		ActivityModule.class,
 		BlogModule.class,
-		ContactModule.class,
 		CreateGroupModule.class,
-		ForumModule.class,
 		GroupInvitationModule.class,
-		GroupConversationModule.class,
-		GroupListModule.class,
 		GroupMemberModule.class,
 		GroupRevealModule.class,
-		SharingModule.class
+		SharingModule.SharingLegacyModule.class
 }, dependencies = AndroidComponent.class)
 public interface ActivityComponent {
 
@@ -184,6 +180,8 @@ public interface ActivityComponent {
 
 	void inject(PendingContactListActivity activity);
 
+	void inject(CrashReportActivity crashReportActivity);
+
 	// Fragments
 
 	void inject(AuthorNameFragment fragment);
@@ -234,4 +232,10 @@ public interface ActivityComponent {
 
 	void inject(ImageFragment imageFragment);
 
+	void inject(ReportFormFragment reportFormFragment);
+
+	void inject(CrashFragment crashFragment);
+
+	void inject(ConfirmAvatarDialogFragment fragment);
+
 }

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

@@ -2,8 +2,6 @@ package org.briarproject.briar.android.activity;
 
 import android.app.Activity;
 
-import org.briarproject.briar.android.account.SetupController;
-import org.briarproject.briar.android.account.SetupControllerImpl;
 import org.briarproject.briar.android.controller.BriarController;
 import org.briarproject.briar.android.controller.BriarControllerImpl;
 import org.briarproject.briar.android.controller.DbController;
@@ -35,13 +33,6 @@ public class ActivityModule {
 		return activity;
 	}
 
-	@ActivityScope
-	@Provides
-	SetupController provideSetupController(
-			SetupControllerImpl setupController) {
-		return setupController;
-	}
-
 	@ActivityScope
 	@Provides
 	protected BriarController provideBriarController(

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;
@@ -15,10 +14,8 @@ import org.briarproject.briar.android.BriarApplication;
 import org.briarproject.briar.android.DestroyableContext;
 import org.briarproject.briar.android.Localizer;
 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 +37,11 @@ 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 +49,6 @@ import static org.briarproject.briar.android.util.UiUtils.hideSoftKeyboard;
 
 /**
  * Warning: Some activities don't extend {@link BaseActivity}.
- *          E.g. {@link DevReportActivity}
  */
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
@@ -88,7 +86,6 @@ public abstract class BaseActivity extends AppCompatActivity
 		activityComponent = DaggerActivityComponent.builder()
 				.androidComponent(applicationComponent)
 				.activityModule(getActivityModule())
-				.forumModule(getForumModule())
 				.build();
 		injectActivity(activityComponent);
 		super.onCreate(state);
@@ -123,10 +120,6 @@ public abstract class BaseActivity extends AppCompatActivity
 		return new ActivityModule(this);
 	}
 
-	protected ForumModule getForumModule() {
-		return new ForumModule();
-	}
-
 	@Override
 	protected void onStart() {
 		super.onStart();
@@ -202,9 +195,15 @@ 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 +240,7 @@ public abstract class BaseActivity extends AppCompatActivity
 	}
 
 	@UiThread
-	public void handleDbException(DbException e) {
+	public void handleException(Exception e) {
 		supportFinishAfterTransition();
 	}
 
@@ -266,7 +265,12 @@ 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.
 	 *
@@ -164,7 +160,6 @@ public abstract class BriarActivity extends BaseActivity {
 	 * @param ownLayout true if the custom toolbar brings its own layout
 	 * @return the Toolbar object or null if content view did not contain one
 	 */
-	@Nullable
 	protected Toolbar setUpCustomToolbar(boolean ownLayout) {
 		// Custom Toolbar
 		Toolbar toolbar = findViewById(R.id.toolbar);

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

@@ -16,5 +16,6 @@ public interface RequestCodes {
 	int REQUEST_KEYGUARD_UNLOCK = 12;
 	int REQUEST_ATTACH_IMAGE = 13;
 	int REQUEST_SAVE_ATTACHMENT = 14;
+	int REQUEST_AVATAR_IMAGE = 15;
 
 }

briar-android/src/main/java/org/briarproject/briar/android/attachment/AttachmentCreationTask.java

@@ -1,33 +1,24 @@
 package org.briarproject.briar.android.attachment;
 
 import android.content.ContentResolver;
-import android.graphics.Bitmap;
-import android.graphics.BitmapFactory.Options;
 import android.net.Uri;
 
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.GroupId;
-import org.briarproject.briar.api.messaging.AttachmentHeader;
+import org.briarproject.briar.android.attachment.media.ImageCompressor;
+import org.briarproject.briar.api.attachment.AttachmentHeader;
 import org.briarproject.briar.api.messaging.MessagingManager;
-import org.jsoup.UnsupportedMimeTypeException;
 
-import java.io.BufferedInputStream;
-import java.io.ByteArrayInputStream;
-import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.Collection;
 import java.util.logging.Logger;
 
 import androidx.annotation.Nullable;
-import androidx.annotation.VisibleForTesting;
 
-import static android.graphics.Bitmap.CompressFormat.JPEG;
-import static android.graphics.BitmapFactory.decodeStream;
 import static java.util.Arrays.asList;
-import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.util.AndroidUtils.getSupportedImageContentTypes;
@@ -35,19 +26,16 @@ import static org.briarproject.bramble.util.IoUtils.tryToClose;
 import static org.briarproject.bramble.util.LogUtils.logDuration;
 import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.bramble.util.LogUtils.now;
-import static org.briarproject.briar.api.messaging.MessagingConstants.MAX_IMAGE_SIZE;
 
 @NotNullByDefault
 class AttachmentCreationTask {
 
-	private static Logger LOG =
+	private static final Logger LOG =
 			getLogger(AttachmentCreationTask.class.getName());
 
-	private static final int MAX_ATTACHMENT_DIMENSION = 1000;
-
 	private final MessagingManager messagingManager;
 	private final ContentResolver contentResolver;
-	private final ImageSizeCalculator imageSizeCalculator;
+	private final ImageCompressor imageCompressor;
 	private final GroupId groupId;
 	private final Collection<Uri> uris;
 	private final boolean needsSize;
@@ -59,11 +47,11 @@ class AttachmentCreationTask {
 	AttachmentCreationTask(MessagingManager messagingManager,
 			ContentResolver contentResolver,
 			AttachmentCreator attachmentCreator,
-			ImageSizeCalculator imageSizeCalculator,
+			ImageCompressor imageCompressor,
 			GroupId groupId, Collection<Uri> uris, boolean needsSize) {
 		this.messagingManager = messagingManager;
 		this.contentResolver = contentResolver;
-		this.imageSizeCalculator = imageSizeCalculator;
+		this.imageCompressor = imageCompressor;
 		this.groupId = groupId;
 		this.uris = uris;
 		this.needsSize = needsSize;
@@ -110,66 +98,19 @@ class AttachmentCreationTask {
 		String contentType = contentResolver.getType(uri);
 		if (contentType == null) throw new IOException("null content type");
 		if (!asList(getSupportedImageContentTypes()).contains(contentType)) {
-			String uriString = uri.toString();
-			throw new UnsupportedMimeTypeException("", contentType, uriString);
+			throw new UnsupportedMimeTypeException(contentType, uri);
 		}
 		InputStream is = contentResolver.openInputStream(uri);
 		if (is == null) throw new IOException();
-		is = compressImage(is, contentType);
-		contentType = "image/jpeg";
+		is = imageCompressor
+				.compressImage(is, contentType);
 		long timestamp = System.currentTimeMillis();
 		AttachmentHeader h = messagingManager
-				.addLocalAttachment(groupId, timestamp, contentType, is);
+				.addLocalAttachment(groupId, timestamp,
+						ImageCompressor.MIME_TYPE, is);
 		tryToClose(is, LOG, WARNING);
 		logDuration(LOG, "Storing attachment", start);
 		return h;
 	}
 
-	@VisibleForTesting
-	InputStream compressImage(InputStream is, String contentType)
-			throws IOException {
-		ByteArrayOutputStream out = new ByteArrayOutputStream();
-		try {
-			Bitmap bitmap = createBitmap(is, contentType);
-			for (int quality = 100; quality >= 0; quality -= 10) {
-				if (!bitmap.compress(JPEG, quality, out))
-					throw new IOException();
-				if (out.size() <= MAX_IMAGE_SIZE) {
-					if (LOG.isLoggable(INFO)) {
-						LOG.info("Compressed image to "
-								+ out.size() + " bytes, quality " + quality);
-					}
-					return new ByteArrayInputStream(out.toByteArray());
-				}
-				out.reset();
-			}
-			throw new IOException();
-		} finally {
-			tryToClose(is, LOG, WARNING);
-		}
-	}
-
-	private Bitmap createBitmap(InputStream is, String contentType)
-			throws IOException {
-		is = new BufferedInputStream(is);
-		Size size = imageSizeCalculator.getSize(is, contentType);
-		if (size.error) throw new IOException();
-		if (LOG.isLoggable(INFO))
-			LOG.info("Original image size: " + size.width + "x" + size.height);
-		int dimension = Math.max(size.width, size.height);
-		int inSampleSize = 1;
-		while (dimension > MAX_ATTACHMENT_DIMENSION) {
-			inSampleSize *= 2;
-			dimension /= 2;
-		}
-		if (LOG.isLoggable(INFO))
-			LOG.info("Scaling attachment by factor of " + inSampleSize);
-		Options options = new Options();
-		options.inSampleSize = inSampleSize;
-		if (contentType.equals("image/png"))
-			options.inPreferredConfig = Bitmap.Config.RGB_565;
-		Bitmap bitmap = decodeStream(is, null, options);
-		if (bitmap == null) throw new IOException();
-		return bitmap;
-	}
 }

briar-android/src/main/java/org/briarproject/briar/android/attachment/AttachmentCreator.java

@@ -6,7 +6,7 @@ import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.MessageId;
-import org.briarproject.briar.api.messaging.AttachmentHeader;
+import org.briarproject.briar.api.attachment.AttachmentHeader;
 
 import java.util.Collection;
 import java.util.List;

briar-android/src/main/java/org/briarproject/briar/android/attachment/AttachmentCreatorImpl.java

@@ -10,11 +10,11 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.briar.R;
-import org.briarproject.briar.api.messaging.Attachment;
-import org.briarproject.briar.api.messaging.AttachmentHeader;
-import org.briarproject.briar.api.messaging.FileTooBigException;
+import org.briarproject.briar.android.attachment.media.ImageCompressor;
+import org.briarproject.briar.api.attachment.Attachment;
+import org.briarproject.briar.api.attachment.AttachmentHeader;
+import org.briarproject.briar.api.attachment.FileTooBigException;
 import org.briarproject.briar.api.messaging.MessagingManager;
-import org.jsoup.UnsupportedMimeTypeException;
 
 import java.io.IOException;
 import java.util.ArrayList;
@@ -36,12 +36,12 @@ import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.briar.android.attachment.AttachmentItem.State.ERROR;
 import static org.briarproject.briar.android.util.UiUtils.observeForeverOnce;
-import static org.briarproject.briar.api.messaging.MessagingConstants.MAX_IMAGE_SIZE;
+import static org.briarproject.briar.api.attachment.MediaConstants.MAX_IMAGE_SIZE;
 
 @NotNullByDefault
 class AttachmentCreatorImpl implements AttachmentCreator {
 
-	private static Logger LOG =
+	private static final Logger LOG =
 			getLogger(AttachmentCreatorImpl.class.getName());
 
 	private final Application app;
@@ -49,7 +49,7 @@ class AttachmentCreatorImpl implements AttachmentCreator {
 	private final Executor ioExecutor;
 	private final MessagingManager messagingManager;
 	private final AttachmentRetriever retriever;
-	private final ImageSizeCalculator imageSizeCalculator;
+	private final ImageCompressor imageCompressor;
 
 	private final CopyOnWriteArrayList<Uri> uris = new CopyOnWriteArrayList<>();
 	private final CopyOnWriteArrayList<AttachmentItemResult> itemResults =
@@ -64,12 +64,12 @@ class AttachmentCreatorImpl implements AttachmentCreator {
 	@Inject
 	AttachmentCreatorImpl(Application app, @IoExecutor Executor ioExecutor,
 			MessagingManager messagingManager, AttachmentRetriever retriever,
-			ImageSizeCalculator imageSizeCalculator) {
+			ImageCompressor imageCompressor) {
 		this.app = app;
 		this.ioExecutor = ioExecutor;
 		this.messagingManager = messagingManager;
 		this.retriever = retriever;
-		this.imageSizeCalculator = imageSizeCalculator;
+		this.imageCompressor = imageCompressor;
 	}
 
 	@Override
@@ -89,7 +89,7 @@ class AttachmentCreatorImpl implements AttachmentCreator {
 			if (id == null) throw new IllegalStateException();
 			boolean needsSize = uris.size() == 1;
 			task = new AttachmentCreationTask(messagingManager,
-					app.getContentResolver(), this, imageSizeCalculator, id,
+					app.getContentResolver(), this, imageCompressor, id,
 					uris, needsSize);
 			ioExecutor.execute(() -> task.storeAttachments());
 		});

briar-android/src/main/java/org/briarproject/briar/android/attachment/AttachmentItem.java

@@ -4,8 +4,9 @@ import android.os.Parcel;
 import android.os.Parcelable;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.MessageId;
-import org.briarproject.briar.api.messaging.AttachmentHeader;
+import org.briarproject.briar.api.attachment.AttachmentHeader;
 
 import javax.annotation.concurrent.Immutable;
 
@@ -78,6 +79,9 @@ public class AttachmentItem implements Parcelable {
 	}
 
 	protected AttachmentItem(Parcel in) {
+		byte[] groupIdByte = new byte[GroupId.LENGTH];
+		in.readByteArray(groupIdByte);
+		GroupId groupId = new GroupId(groupIdByte);
 		byte[] messageIdByte = new byte[MessageId.LENGTH];
 		in.readByteArray(messageIdByte);
 		MessageId messageId = new MessageId(messageIdByte);
@@ -88,7 +92,7 @@ public class AttachmentItem implements Parcelable {
 		thumbnailWidth = in.readInt();
 		thumbnailHeight = in.readInt();
 		state = State.valueOf(requireNonNull(in.readString()));
-		header = new AttachmentHeader(messageId, mimeType);
+		header = new AttachmentHeader(groupId, messageId, mimeType);
 	}
 
 	public AttachmentHeader getHeader() {
@@ -142,6 +146,7 @@ public class AttachmentItem implements Parcelable {
 
 	@Override
 	public void writeToParcel(Parcel dest, int flags) {
+		dest.writeByteArray(header.getGroupId().getBytes());
 		dest.writeByteArray(header.getMessageId().getBytes());
 		dest.writeInt(width);
 		dest.writeInt(height);

briar-android/src/main/java/org/briarproject/briar/android/attachment/AttachmentManager.java

@@ -3,7 +3,7 @@ package org.briarproject.briar.android.attachment;
 import android.net.Uri;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.briar.api.messaging.AttachmentHeader;
+import org.briarproject.briar.api.attachment.AttachmentHeader;
 
 import java.util.Collection;
 import java.util.List;

briar-android/src/main/java/org/briarproject/briar/android/attachment/AttachmentModule.java

@@ -12,16 +12,6 @@ import static org.briarproject.briar.android.attachment.AttachmentDimensions.get
 @Module
 public class AttachmentModule {
 
-	@Provides
-	ImageHelper provideImageHelper(ImageHelperImpl imageHelper) {
-		return imageHelper;
-	}
-
-	@Provides
-	ImageSizeCalculator provideImageSizeCalculator(ImageHelper imageHelper) {
-		return new ImageSizeCalculator(imageHelper);
-	}
-
 	@Provides
 	AttachmentDimensions provideAttachmentDimensions(Application app) {
 		return getAttachmentDimensions(app.getResources());

briar-android/src/main/java/org/briarproject/briar/android/attachment/AttachmentRetriever.java

@@ -4,8 +4,8 @@ import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.MessageId;
-import org.briarproject.briar.api.messaging.Attachment;
-import org.briarproject.briar.api.messaging.AttachmentHeader;
+import org.briarproject.briar.api.attachment.Attachment;
+import org.briarproject.briar.api.attachment.AttachmentHeader;
 import org.briarproject.briar.api.messaging.PrivateMessageHeader;
 import org.briarproject.briar.api.messaging.event.AttachmentReceivedEvent;
 
@@ -49,10 +49,10 @@ public interface AttachmentRetriever {
 	 * Loads an {@link AttachmentItem}
 	 * that arrived via an {@link AttachmentReceivedEvent}
 	 * and notifies the associated {@link LiveData}.
-	 *
+	 * <p>
 	 * Note that you need to call {@link #getAttachmentItems(PrivateMessageHeader)}
 	 * first to get the LiveData.
-	 *
+	 * <p>
 	 * It is possible that no LiveData is available,
 	 * because the message of the AttachmentItem did not arrive, yet.
 	 * In this case, the load wil be deferred until the message arrives.

briar-android/src/main/java/org/briarproject/briar/android/attachment/AttachmentRetrieverImpl.java

@@ -6,9 +6,12 @@ import org.briarproject.bramble.api.db.NoSuchMessageException;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.briar.android.attachment.AttachmentItem.State;
-import org.briarproject.briar.api.messaging.Attachment;
-import org.briarproject.briar.api.messaging.AttachmentHeader;
-import org.briarproject.briar.api.messaging.MessagingManager;
+import org.briarproject.briar.android.attachment.media.ImageHelper;
+import org.briarproject.briar.android.attachment.media.ImageSizeCalculator;
+import org.briarproject.briar.android.attachment.media.Size;
+import org.briarproject.briar.api.attachment.Attachment;
+import org.briarproject.briar.api.attachment.AttachmentHeader;
+import org.briarproject.briar.api.attachment.AttachmentReader;
 import org.briarproject.briar.api.messaging.PrivateMessageHeader;
 
 import java.io.BufferedInputStream;
@@ -43,7 +46,7 @@ class AttachmentRetrieverImpl implements AttachmentRetriever {
 
 	@DatabaseExecutor
 	private final Executor dbExecutor;
-	private final MessagingManager messagingManager;
+	private final AttachmentReader attachmentReader;
 	private final ImageHelper imageHelper;
 	private final ImageSizeCalculator imageSizeCalculator;
 	private final int defaultSize;
@@ -57,11 +60,10 @@ class AttachmentRetrieverImpl implements AttachmentRetriever {
 
 	@Inject
 	AttachmentRetrieverImpl(@DatabaseExecutor Executor dbExecutor,
-			MessagingManager messagingManager,
-			AttachmentDimensions dimensions, ImageHelper imageHelper,
-			ImageSizeCalculator imageSizeCalculator) {
+			AttachmentReader attachmentReader, AttachmentDimensions dimensions,
+			ImageHelper imageHelper, ImageSizeCalculator imageSizeCalculator) {
 		this.dbExecutor = dbExecutor;
-		this.messagingManager = messagingManager;
+		this.attachmentReader = attachmentReader;
 		this.imageHelper = imageHelper;
 		this.imageSizeCalculator = imageSizeCalculator;
 		defaultSize = dimensions.defaultSize;
@@ -75,7 +77,7 @@ class AttachmentRetrieverImpl implements AttachmentRetriever {
 	@DatabaseExecutor
 	public Attachment getMessageAttachment(AttachmentHeader h)
 			throws DbException {
-		return messagingManager.getAttachment(h);
+		return attachmentReader.getAttachment(h);
 	}
 
 	@Override
@@ -86,13 +88,11 @@ class AttachmentRetrieverImpl implements AttachmentRetriever {
 		boolean needsSize = headers.size() == 1;
 		for (AttachmentHeader h : headers) {
 			// try cache for existing item live data
-			MutableLiveData<AttachmentItem> liveData;
-			if (needsSize) liveData = itemsWithSize.get(h.getMessageId());
-			else {
-				// try items with size first, as they work as well
-				liveData = itemsWithSize.get(h.getMessageId());
-				if (liveData == null)
-					liveData = itemsWithoutSize.get(h.getMessageId());
+			MutableLiveData<AttachmentItem> liveData =
+					itemsWithSize.get(h.getMessageId());
+			if (!needsSize && liveData == null) {
+				// check cache for items that don't need the size
+				liveData = itemsWithoutSize.get(h.getMessageId());
 			}
 
 			// create new live data with LOADING item if cache miss
@@ -131,7 +131,7 @@ class AttachmentRetrieverImpl implements AttachmentRetriever {
 		// If a live data is already cached we don't need to do anything
 		if (itemsWithSize.containsKey(h.getMessageId())) return;
 		try {
-			Attachment a = messagingManager.getAttachment(h);
+			Attachment a = attachmentReader.getAttachment(h);
 			AttachmentItem item = createAttachmentItem(a, true);
 			MutableLiveData<AttachmentItem> liveData =
 					new MutableLiveData<>(item);
@@ -173,7 +173,7 @@ class AttachmentRetrieverImpl implements AttachmentRetriever {
 		Attachment a;
 		AttachmentItem item;
 		try {
-			a = messagingManager.getAttachment(h);
+			a = attachmentReader.getAttachment(h);
 			item = createAttachmentItem(a, needsSize);
 		} catch (NoSuchMessageException e) {
 			LOG.info("Attachment not received yet");
@@ -210,26 +210,30 @@ class AttachmentRetrieverImpl implements AttachmentRetriever {
 
 	private AttachmentItem createAttachmentItem(AttachmentHeader h, Size size) {
 		// calculate thumbnail size
-		Size thumbnailSize = new Size(defaultSize, defaultSize, size.mimeType);
-		if (!size.error) {
+		Size thumbnailSize =
+				new Size(defaultSize, defaultSize, size.getMimeType());
+		if (!size.hasError()) {
 			thumbnailSize =
-					getThumbnailSize(size.width, size.height, size.mimeType);
+					getThumbnailSize(size.getWidth(), size.getHeight(),
+							size.getMimeType());
 		}
 		// get file extension
-		String extension = imageHelper.getExtensionFromMimeType(size.mimeType);
-		boolean hasError = extension == null || size.error;
-		if (!h.getContentType().equals(size.mimeType)) {
+		String extension =
+				imageHelper.getExtensionFromMimeType(size.getMimeType());
+		boolean hasError = extension == null || size.hasError();
+		if (!h.getContentType().equals(size.getMimeType())) {
 			if (LOG.isLoggable(WARNING)) {
 				LOG.warning("Header has different mime type (" +
-						h.getContentType() + ") than image (" + size.mimeType +
-						").");
+						h.getContentType() + ") than image (" +
+						size.getMimeType() + ").");
 			}
 			hasError = true;
 		}
 		if (extension == null) extension = "";
 		State state = hasError ? ERROR : AVAILABLE;
-		return new AttachmentItem(h, size.width, size.height,
-				extension, thumbnailSize.width, thumbnailSize.height, state);
+		return new AttachmentItem(h, size.getWidth(), size.getHeight(),
+				extension, thumbnailSize.getWidth(), thumbnailSize.getHeight(),
+				state);
 	}
 
 	private Size getThumbnailSize(int width, int height, String mimeType) {

briar-android/src/main/java/org/briarproject/briar/android/attachment/Size.java

@@ -1,23 +0,0 @@
-package org.briarproject.briar.android.attachment;
-
-class Size {
-
-	final int width;
-	final int height;
-	final String mimeType;
-	final boolean error;
-
-	Size(int width, int height, String mimeType) {
-		this.width = width;
-		this.height = height;
-		this.mimeType = mimeType;
-		this.error = false;
-	}
-
-	Size() {
-		this.width = 0;
-		this.height = 0;
-		this.mimeType = "";
-		this.error = true;
-	}
-}

briar-android/src/main/java/org/briarproject/briar/android/attachment/UnsupportedMimeTypeException.java

@@ -0,0 +1,24 @@
+package org.briarproject.briar.android.attachment;
+
+import android.net.Uri;
+
+import java.io.IOException;
+
+public class UnsupportedMimeTypeException extends IOException {
+
+	private final String mimeType;
+	private final Uri uri;
+
+	public UnsupportedMimeTypeException(String mimeType, Uri uri) {
+		this.mimeType = mimeType;
+		this.uri = uri;
+	}
+
+	public String getMimeType() {
+		return mimeType;
+	}
+
+	public Uri getUri() {
+		return uri;
+	}
+}

briar-android/src/main/java/org/briarproject/briar/android/attachment/media/ImageCompressor.java

@@ -0,0 +1,39 @@
+package org.briarproject.briar.android.attachment.media;
+
+import android.graphics.Bitmap;
+import android.net.Uri;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+public interface ImageCompressor {
+
+	/**
+	 * The MIME type of compressed images
+	 */
+	String MIME_TYPE = "image/jpeg";
+
+	/**
+	 * Load an image from {@code is}, compress it and return an InputStream
+	 * from which the resulting image can be read. The image will be compressed
+	 * as a JPEG image such that it fits into a message.
+	 *
+	 * @param is the stream to read the source image from
+	 * @param contentType the mimetype of the source image such as "image/jpeg"
+	 * as obtained by {@link android.content.ContentResolver#getType(Uri)}
+	 * @return a stream from which the resulting image can be read
+	 */
+	InputStream compressImage(InputStream is, String contentType)
+			throws IOException;
+
+	/**
+	 * Compress an image and return an InputStream from which the resulting
+	 * image can be read. The image will be compressed as a JPEG image such that
+	 * it fits into a message.
+	 *
+	 * @param bitmap the source image
+	 * @return a stream from which the resulting image can be read
+	 */
+	InputStream compressImage(Bitmap bitmap) throws IOException;
+
+}

briar-android/src/main/java/org/briarproject/briar/android/attachment/media/ImageCompressorImpl.java

@@ -0,0 +1,92 @@
+package org.briarproject.briar.android.attachment.media;
+
+import android.graphics.Bitmap;
+import android.graphics.BitmapFactory;
+
+import java.io.BufferedInputStream;
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.logging.Logger;
+
+import javax.inject.Inject;
+
+import static android.graphics.Bitmap.CompressFormat.JPEG;
+import static android.graphics.BitmapFactory.decodeStream;
+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.IoUtils.tryToClose;
+import static org.briarproject.briar.api.attachment.MediaConstants.MAX_IMAGE_SIZE;
+
+class ImageCompressorImpl implements ImageCompressor {
+
+	private static final Logger LOG =
+			getLogger(ImageCompressorImpl.class.getName());
+
+	private static final int MAX_ATTACHMENT_DIMENSION = 1000;
+
+	private final ImageSizeCalculator imageSizeCalculator;
+
+	@Inject
+	ImageCompressorImpl(ImageSizeCalculator imageSizeCalculator) {
+		this.imageSizeCalculator = imageSizeCalculator;
+	}
+
+	@Override
+	public InputStream compressImage(InputStream is, String contentType)
+			throws IOException {
+		try {
+			Bitmap bitmap =
+					createBitmap(is, contentType, MAX_ATTACHMENT_DIMENSION);
+			return compressImage(bitmap);
+		} finally {
+			tryToClose(is, LOG, WARNING);
+		}
+	}
+
+	@Override
+	public InputStream compressImage(Bitmap bitmap) throws IOException {
+		ByteArrayOutputStream out = new ByteArrayOutputStream();
+		for (int quality = 100; quality >= 0; quality -= 10) {
+			if (!bitmap.compress(JPEG, quality, out))
+				throw new IOException();
+			if (out.size() <= MAX_IMAGE_SIZE) {
+				if (LOG.isLoggable(INFO)) {
+					LOG.info("Compressed image to "
+							+ out.size() + " bytes, quality " + quality);
+				}
+				return new ByteArrayInputStream(out.toByteArray());
+			}
+			out.reset();
+		}
+		throw new IOException();
+	}
+
+	private Bitmap createBitmap(InputStream is, String contentType, int maxSize)
+			throws IOException {
+		is = new BufferedInputStream(is);
+		Size size = imageSizeCalculator.getSize(is, contentType);
+		if (size.hasError()) throw new IOException();
+		if (LOG.isLoggable(INFO))
+			LOG.info("Original image size: " + size.getWidth() + "x" +
+					size.getHeight());
+		int dimension = Math.max(size.getWidth(), size.getHeight());
+		int inSampleSize = 1;
+		while (dimension > maxSize) {
+			inSampleSize *= 2;
+			dimension /= 2;
+		}
+		if (LOG.isLoggable(INFO))
+			LOG.info("Scaling attachment by factor of " + inSampleSize);
+		BitmapFactory.Options options = new BitmapFactory.Options();
+		options.inSampleSize = inSampleSize;
+		if (contentType.equals("image/png"))
+			options.inPreferredConfig = Bitmap.Config.RGB_565;
+		Bitmap bitmap = decodeStream(is, null, options);
+		if (bitmap == null) throw new IOException();
+		return bitmap;
+	}
+
+}

briar-android/src/main/java/org/briarproject/briar/android/attachment/media/ImageHelper.java

@@ -1,4 +1,4 @@
-package org.briarproject.briar.android.attachment;
+package org.briarproject.briar.android.attachment.media;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 

briar-android/src/main/java/org/briarproject/briar/android/attachment/media/ImageHelperImpl.java

@@ -1,4 +1,4 @@
-package org.briarproject.briar.android.attachment;
+package org.briarproject.briar.android.attachment.media;
 
 import android.graphics.BitmapFactory;
 import android.webkit.MimeTypeMap;

briar-android/src/main/java/org/briarproject/briar/android/attachment/media/ImageSizeCalculator.java

@@ -0,0 +1,18 @@
+package org.briarproject.briar.android.attachment.media;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import java.io.InputStream;
+
+@NotNullByDefault
+public interface ImageSizeCalculator {
+
+	/**
+	 * Determine the size of the image that can be read from {@code is}.
+	 *
+	 * @param contentType the mime type of the image. If "image/jpeg" is passed,
+	 * the implementation will try to determine the size from the Exif header
+	 */
+	Size getSize(InputStream is, String contentType);
+
+}

briar-android/src/main/java/org/briarproject/briar/android/attachment/media/ImageSizeCalculatorImpl.java

@@ -1,9 +1,9 @@
-package org.briarproject.briar.android.attachment;
+package org.briarproject.briar.android.attachment.media;
 
 import com.bumptech.glide.util.MarkEnforcingInputStream;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.briar.android.attachment.ImageHelper.DecodeResult;
+import org.briarproject.briar.android.attachment.media.ImageHelper.DecodeResult;
 
 import java.io.IOException;
 import java.io.InputStream;
@@ -23,20 +23,21 @@ import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.util.LogUtils.logException;
 
 @NotNullByDefault
-class ImageSizeCalculator {
+class ImageSizeCalculatorImpl implements ImageSizeCalculator {
 
 	private static final Logger LOG =
-			getLogger(ImageSizeCalculator.class.getName());
+			getLogger(ImageSizeCalculatorImpl.class.getName());
 
 	private static final int READ_LIMIT = 1024 * 8192;
 
 	private final ImageHelper imageHelper;
 
-	ImageSizeCalculator(ImageHelper imageHelper) {
+	ImageSizeCalculatorImpl(ImageHelper imageHelper) {
 		this.imageHelper = imageHelper;
 	}
 
-	Size getSize(InputStream is, String contentType) {
+	@Override
+	public Size getSize(InputStream is, String contentType) {
 		Size size = new Size();
 		is = new MarkEnforcingInputStream(is);
 		is.mark(READ_LIMIT);
@@ -49,7 +50,7 @@ class ImageSizeCalculator {
 				logException(LOG, WARNING, e);
 			}
 		}
-		if (size.error) {
+		if (size.hasError()) {
 			// need to mark again to re-add read limit
 			is.mark(READ_LIMIT);
 			try {

briar-android/src/main/java/org/briarproject/briar/android/attachment/media/MediaModule.java

@@ -0,0 +1,24 @@
+package org.briarproject.briar.android.attachment.media;
+
+import dagger.Module;
+import dagger.Provides;
+
+@Module
+public class MediaModule {
+
+	@Provides
+	ImageHelper provideImageHelper(ImageHelperImpl imageHelper) {
+		return imageHelper;
+	}
+
+	@Provides
+	ImageSizeCalculator provideImageSizeCalculator(ImageHelper imageHelper) {
+		return new ImageSizeCalculatorImpl(imageHelper);
+	}
+
+	@Provides
+	ImageCompressor provideImageCompressor(
+			ImageCompressorImpl imageCompressor) {
+		return imageCompressor;
+	}
+}

briar-android/src/main/java/org/briarproject/briar/android/attachment/media/Size.java

@@ -0,0 +1,46 @@
+package org.briarproject.briar.android.attachment.media;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.concurrent.Immutable;
+
+@Immutable
+@NotNullByDefault
+public class Size {
+
+	private final int width;
+	private final int height;
+	private final String mimeType;
+	private final boolean error;
+
+	public Size(int width, int height, String mimeType) {
+		this.width = width;
+		this.height = height;
+		this.mimeType = mimeType;
+		this.error = false;
+	}
+
+	public Size() {
+		this.width = 0;
+		this.height = 0;
+		this.mimeType = "";
+		this.error = true;
+	}
+
+	public int getWidth() {
+		return width;
+	}
+
+	public int getHeight() {
+		return height;
+	}
+
+	public String getMimeType() {
+		return mimeType;
+	}
+
+	public boolean hasError() {
+		return error;
+	}
+
+}

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/BlogPostItem.java

@@ -1,7 +1,7 @@
 package org.briarproject.briar.android.blog;
 
 import org.briarproject.bramble.api.identity.Author;
-import org.briarproject.bramble.api.identity.AuthorInfo;
+import org.briarproject.briar.api.identity.AuthorInfo;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.briar.api.blog.BlogPostHeader;

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

@@ -20,7 +20,7 @@ import org.briarproject.briar.android.fragment.BaseFragment;
 import org.briarproject.briar.android.view.TextInputView;
 import org.briarproject.briar.android.view.TextSendController;
 import org.briarproject.briar.android.view.TextSendController.SendListener;
-import org.briarproject.briar.api.messaging.AttachmentHeader;
+import org.briarproject.briar.api.attachment.AttachmentHeader;
 
 import java.util.List;
 
@@ -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();
@@ -156,16 +156,16 @@ public class ReblogFragment extends BaseFragment implements SendListener {
 			progressBar = v.findViewById(R.id.progressBar);
 			post = new BlogPostViewHolder(v.findViewById(R.id.postLayout),
 					true, new OnBlogPostClickListener() {
-						@Override
-						public void onBlogPostClick(BlogPostItem post) {
-							// do nothing
-						}
+				@Override
+				public void onBlogPostClick(BlogPostItem post) {
+					// do nothing
+				}
 
-						@Override
-						public void onAuthorClick(BlogPostItem post) {
-							// probably don't want to allow author clicks here
-						}
-					}, getFragmentManager());
+				@Override
+				public void onAuthorClick(BlogPostItem post) {
+					// probably don't want to allow author clicks here
+				}
+			}, getFragmentManager());
 			input = v.findViewById(R.id.inputText);
 		}
 	}

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

@@ -19,10 +19,10 @@ import org.briarproject.briar.android.view.TextInputView;
 import org.briarproject.briar.android.view.TextSendController;
 import org.briarproject.briar.android.view.TextSendController.SendListener;
 import org.briarproject.briar.api.android.AndroidNotificationManager;
+import org.briarproject.briar.api.attachment.AttachmentHeader;
 import org.briarproject.briar.api.blog.BlogManager;
 import org.briarproject.briar.api.blog.BlogPost;
 import org.briarproject.briar.api.blog.BlogPostFactory;
-import org.briarproject.briar.api.messaging.AttachmentHeader;
 
 import java.security.GeneralSecurityException;
 import java.util.List;

briar-android/src/main/java/org/briarproject/briar/android/contact/BaseContactListAdapter.java

@@ -3,14 +3,12 @@ package org.briarproject.briar.android.contact;
 import android.content.Context;
 import android.view.View;
 
-import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.briar.android.util.BriarAdapter;
 
 import javax.annotation.Nullable;
 
 import androidx.annotation.NonNull;
 
-import static androidx.recyclerview.widget.SortedList.INVALID_POSITION;
 import static org.briarproject.briar.android.util.UiUtils.getContactDisplayName;
 
 public abstract class BaseContactListAdapter<I extends ContactItem, VH extends ContactItemViewHolder<I>>
@@ -47,15 +45,6 @@ public abstract class BaseContactListAdapter<I extends ContactItem, VH extends C
 		return true;
 	}
 
-	int findItemPosition(ContactId c) {
-		for (int i = 0; i < getItemCount(); i++) {
-			I item = getItemAt(i);
-			if (item != null && item.getContact().getId().equals(c))
-				return i;
-		}
-		return INVALID_POSITION; // Not found
-	}
-
 	public interface OnContactClickListener<I> {
 		void onItemClick(View view, I item);
 	}

briar-android/src/main/java/org/briarproject/briar/android/contact/ContactItem.java

@@ -2,22 +2,26 @@ package org.briarproject.briar.android.contact;
 
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.briar.api.identity.AuthorInfo;
 
-import javax.annotation.concurrent.NotThreadSafe;
+import javax.annotation.concurrent.Immutable;
 
-@NotThreadSafe
+@Immutable
 @NotNullByDefault
 public class ContactItem {
 
 	private final Contact contact;
-	private boolean connected;
+	private final AuthorInfo authorInfo;
+	private final boolean connected;
 
-	public ContactItem(Contact contact) {
-		this(contact, false);
+	public ContactItem(Contact contact, AuthorInfo authorInfo) {
+		this(contact, authorInfo, false);
 	}
 
-	public ContactItem(Contact contact, boolean connected) {
+	public ContactItem(Contact contact, AuthorInfo authorInfo,
+			boolean connected) {
 		this.contact = contact;
+		this.authorInfo = authorInfo;
 		this.connected = connected;
 	}
 
@@ -25,12 +29,12 @@ public class ContactItem {
 		return contact;
 	}
 
+	public AuthorInfo getAuthorInfo() {
+		return authorInfo;
+	}
+
 	boolean isConnected() {
 		return connected;
 	}
 
-	void setConnected(boolean connected) {
-		this.connected = connected;
-	}
-
 }

briar-android/src/main/java/org/briarproject/briar/android/contact/ContactItemViewHolder.java

@@ -5,7 +5,6 @@ import android.view.ViewGroup;
 import android.widget.ImageView;
 import android.widget.TextView;
 
-import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.contact.BaseContactListAdapter.OnContactClickListener;
@@ -14,9 +13,9 @@ import javax.annotation.Nullable;
 
 import androidx.annotation.UiThread;
 import androidx.recyclerview.widget.RecyclerView;
-import im.delight.android.identicons.IdenticonDrawable;
 
 import static org.briarproject.briar.android.util.UiUtils.getContactDisplayName;
+import static org.briarproject.briar.android.view.AuthorView.setAvatar;
 
 @UiThread
 @NotNullByDefault
@@ -40,9 +39,7 @@ public class ContactItemViewHolder<I extends ContactItem>
 	}
 
 	protected void bind(I item, @Nullable OnContactClickListener<I> listener) {
-		Author author = item.getContact().getAuthor();
-		avatar.setImageDrawable(
-				new IdenticonDrawable(author.getId().getBytes()));
+		setAvatar(avatar, item);
 		name.setText(getContactDisplayName(item.getContact()));
 
 		if (bulb != null) {

briar-android/src/main/java/org/briarproject/briar/android/contact/ContactListAdapter.java

@@ -1,50 +1,73 @@
 package org.briarproject.briar.android.contact;
 
-import android.content.Context;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.NullSafety;
 import org.briarproject.briar.R;
+import org.briarproject.briar.android.contact.BaseContactListAdapter.OnContactClickListener;
+
+import androidx.recyclerview.widget.DiffUtil.ItemCallback;
+import androidx.recyclerview.widget.ListAdapter;
 
 @NotNullByDefault
 public class ContactListAdapter extends
-		BaseContactListAdapter<ContactListItem, ContactListItemViewHolder> {
+		ListAdapter<ContactListItem, ContactListItemViewHolder> {
 
-	public ContactListAdapter(Context context,
+	// TODO: using the click listener interface from BaseContactListAdapter on
+	// purpose here because it is entangled with ContactListItemViewHolder. At
+	// some point we probably want to change that.
+	protected final OnContactClickListener<ContactListItem> listener;
+
+	public ContactListAdapter(
 			OnContactClickListener<ContactListItem> listener) {
-		super(context, ContactListItem.class, listener);
+		super(new ContactListCallback());
+		this.listener = listener;
+	}
+
+	@NotNullByDefault
+	private static class ContactListCallback
+			extends ItemCallback<ContactListItem> {
+		@Override
+		public boolean areItemsTheSame(ContactListItem c1, ContactListItem c2) {
+			return c1.getContact().equals(c2.getContact());
+		}
+
+		@Override
+		public boolean areContentsTheSame(ContactListItem c1,
+				ContactListItem c2) {
+			// check for all properties that influence visual
+			// representation of contact
+			if (c1.isEmpty() != c2.isEmpty()) {
+				return false;
+			}
+			if (c1.getUnreadCount() != c2.getUnreadCount()) {
+				return false;
+			}
+			if (c1.getTimestamp() != c2.getTimestamp()) {
+				return false;
+			}
+			if (c1.isConnected() != c2.isConnected()) {
+				return false;
+			}
+			return NullSafety.equals(c1.getAuthorInfo().getAvatarHeader(),
+					c2.getAuthorInfo().getAvatarHeader());
+		}
 	}
 
 	@Override
 	public ContactListItemViewHolder onCreateViewHolder(ViewGroup viewGroup,
-			int i) {
+			int viewType) {
 		View v = LayoutInflater.from(viewGroup.getContext()).inflate(
 				R.layout.list_item_contact, viewGroup, false);
-
 		return new ContactListItemViewHolder(v);
 	}
 
 	@Override
-	public boolean areContentsTheSame(ContactListItem c1, ContactListItem c2) {
-		// check for all properties that influence visual
-		// representation of contact
-		if (c1.isEmpty() != c2.isEmpty()) {
-			return false;
-		}
-		if (c1.getUnreadCount() != c2.getUnreadCount()) {
-			return false;
-		}
-		if (c1.getTimestamp() != c2.getTimestamp()) {
-			return false;
-		}
-		return c1.isConnected() == c2.isConnected();
+	public void onBindViewHolder(ContactListItemViewHolder viewHolder,
+			int position) {
+		viewHolder.bind(getItem(position), listener);
 	}
-
-	@Override
-	public int compare(ContactListItem c1, ContactListItem c2) {
-		return Long.compare(c2.getTimestamp(), c1.getTimestamp());
-	}
-
 }

briar-android/src/main/java/org/briarproject/briar/android/contact/ContactListFragment.java

@@ -10,23 +10,9 @@ import android.widget.TextView;
 import com.google.android.material.floatingactionbutton.FloatingActionButton;
 import com.google.android.material.snackbar.Snackbar;
 
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
-import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.contact.ContactManager;
-import org.briarproject.bramble.api.contact.event.ContactAddedEvent;
-import org.briarproject.bramble.api.contact.event.ContactRemovedEvent;
-import org.briarproject.bramble.api.contact.event.PendingContactAddedEvent;
-import org.briarproject.bramble.api.contact.event.PendingContactRemovedEvent;
-import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.db.NoSuchContactException;
-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.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
-import org.briarproject.bramble.api.plugin.event.ContactConnectedEvent;
-import org.briarproject.bramble.api.plugin.event.ContactDisconnectedEvent;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.ActivityComponent;
 import org.briarproject.briar.android.contact.BaseContactListAdapter.OnContactClickListener;
@@ -37,55 +23,35 @@ import org.briarproject.briar.android.fragment.BaseFragment;
 import org.briarproject.briar.android.keyagreement.ContactExchangeActivity;
 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.conversation.ConversationManager;
-import org.briarproject.briar.api.conversation.ConversationMessageHeader;
-import org.briarproject.briar.api.conversation.event.ConversationMessageReceivedEvent;
-
-import java.util.ArrayList;
-import java.util.List;
-import java.util.logging.Logger;
 
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
 import androidx.annotation.UiThread;
-import androidx.core.app.ActivityCompat;
-import androidx.core.app.ActivityOptionsCompat;
-import androidx.core.util.Pair;
+import androidx.lifecycle.ViewModelProvider;
 import androidx.recyclerview.widget.LinearLayoutManager;
 import io.github.kobakei.materialfabspeeddial.FabSpeedDial;
 import io.github.kobakei.materialfabspeeddial.FabSpeedDial.OnMenuItemClickListener;
 
-import static android.os.Build.VERSION.SDK_INT;
-import static androidx.core.app.ActivityOptionsCompat.makeSceneTransitionAnimation;
-import static androidx.core.view.ViewCompat.getTransitionName;
 import static com.google.android.material.snackbar.BaseTransientBottomBar.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.bramble.api.nullsafety.NullSafety.requireNonNull;
 import static org.briarproject.briar.android.conversation.ConversationActivity.CONTACT_ID;
-import static org.briarproject.briar.android.util.UiUtils.isSamsung7;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
-public class ContactListFragment extends BaseFragment implements EventListener,
-		OnMenuItemClickListener {
+public class ContactListFragment extends BaseFragment
+		implements OnMenuItemClickListener,
+		OnContactClickListener<ContactListItem> {
 
 	public static final String TAG = ContactListFragment.class.getName();
-	private static final Logger LOG = Logger.getLogger(TAG);
 
 	@Inject
-	ConnectionRegistry connectionRegistry;
-	@Inject
-	EventBus eventBus;
-	@Inject
-	AndroidNotificationManager notificationManager;
+	ViewModelProvider.Factory viewModelFactory;
 
-	private ContactListAdapter adapter;
+	private ContactListViewModel viewModel;
+	private final ContactListAdapter adapter = new ContactListAdapter(this);
 	private BriarRecyclerView list;
+
 	/**
 	 * The Snackbar is non-null when shown and null otherwise.
 	 * Use {@link #showSnackBar()} and {@link #dismissSnackBar()} to interact.
@@ -93,12 +59,6 @@ public class ContactListFragment extends BaseFragment implements EventListener,
 	@Nullable
 	private Snackbar snackbar = null;
 
-	// Fields that are accessed from background threads must be volatile
-	@Inject
-	volatile ContactManager contactManager;
-	@Inject
-	volatile ConversationManager conversationManager;
-
 	public static ContactListFragment newInstance() {
 		Bundle args = new Bundle();
 		ContactListFragment fragment = new ContactListFragment();
@@ -114,6 +74,8 @@ public class ContactListFragment extends BaseFragment implements EventListener,
 	@Override
 	public void injectFragment(ActivityComponent component) {
 		component.inject(this);
+		viewModel = new ViewModelProvider(this, viewModelFactory)
+				.get(ContactListViewModel.class);
 	}
 
 	@Nullable
@@ -129,37 +91,6 @@ public class ContactListFragment extends BaseFragment implements EventListener,
 		FabSpeedDial speedDial = contentView.findViewById(R.id.speedDial);
 		speedDial.addOnMenuItemClickListener(this);
 
-		OnContactClickListener<ContactListItem> onContactClickListener =
-				(view, item) -> {
-					Intent i = new Intent(getActivity(),
-							ConversationActivity.class);
-					ContactId contactId = item.getContact().getId();
-					i.putExtra(CONTACT_ID, contactId.getInt());
-
-					if (SDK_INT >= 23 && !isSamsung7()) {
-						ContactListItemViewHolder holder =
-								(ContactListItemViewHolder) list
-										.getRecyclerView()
-										.findViewHolderForAdapterPosition(
-												adapter.findItemPosition(item));
-						Pair<View, String> avatar =
-								Pair.create(holder.avatar,
-										getTransitionName(holder.avatar));
-						Pair<View, String> bulb =
-								Pair.create(holder.bulb,
-										getTransitionName(holder.bulb));
-						ActivityOptionsCompat options =
-								makeSceneTransitionAnimation(getActivity(),
-										avatar, bulb);
-						ActivityCompat.startActivity(getActivity(), i,
-								options.toBundle());
-					} else {
-						// work-around for android bug #224270
-						startActivity(i);
-					}
-				};
-		adapter = new ContactListAdapter(requireContext(),
-				onContactClickListener);
 		list = contentView.findViewById(R.id.list);
 		list.setLayoutManager(new LinearLayoutManager(requireContext()));
 		list.setAdapter(adapter);
@@ -167,9 +98,30 @@ public class ContactListFragment extends BaseFragment implements EventListener,
 		list.setEmptyText(getString(R.string.no_contacts));
 		list.setEmptyAction(getString(R.string.no_contacts_action));
 
+		viewModel.getContactListItems()
+				.observe(getViewLifecycleOwner(), result -> {
+					result.onError(this::handleException).onSuccess(items -> {
+						adapter.submitList(items);
+						if (requireNonNull(items).size() == 0) list.showData();
+					});
+				});
+		viewModel.getHasPendingContacts()
+				.observe(getViewLifecycleOwner(), hasPending -> {
+					if (hasPending) showSnackBar();
+					else dismissSnackBar();
+				});
+
 		return contentView;
 	}
 
+	@Override
+	public void onItemClick(View view, ContactListItem item) {
+		Intent i = new Intent(getActivity(), ConversationActivity.class);
+		ContactId contactId = item.getContact().getId();
+		i.putExtra(CONTACT_ID, contactId.getInt());
+		startActivity(i);
+	}
+
 	@Override
 	public void onMenuItemClick(FloatingActionButton fab, @Nullable TextView v,
 			int itemId) {
@@ -188,131 +140,20 @@ public class ContactListFragment extends BaseFragment implements EventListener,
 	@Override
 	public void onStart() {
 		super.onStart();
-		eventBus.addListener(this);
-		notificationManager.clearAllContactNotifications();
-		notificationManager.clearAllContactAddedNotifications();
-		loadContacts();
-		checkForPendingContacts();
+		viewModel.clearAllContactNotifications();
+		viewModel.clearAllContactAddedNotifications();
+		viewModel.loadContacts();
+		viewModel.checkForPendingContacts();
 		list.startPeriodicUpdate();
 	}
 
-	private void checkForPendingContacts() {
-		listener.runOnDbThread(() -> {
-			try {
-				if (contactManager.getPendingContacts().isEmpty()) {
-					runOnUiThreadUnlessDestroyed(this::dismissSnackBar);
-				} else {
-					runOnUiThreadUnlessDestroyed(this::showSnackBar);
-				}
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
-		});
-	}
-
 	@Override
 	public void onStop() {
 		super.onStop();
-		eventBus.removeListener(this);
-		adapter.clear();
-		list.showProgressBar();
 		list.stopPeriodicUpdate();
 		dismissSnackBar();
 	}
 
-	private void loadContacts() {
-		int revision = adapter.getRevision();
-		listener.runOnDbThread(() -> {
-			try {
-				long start = now();
-				List<ContactListItem> contacts = new ArrayList<>();
-				for (Contact c : contactManager.getContacts()) {
-					try {
-						ContactId id = c.getId();
-						GroupCount count =
-								conversationManager.getGroupCount(id);
-						boolean connected =
-								connectionRegistry.isConnected(c.getId());
-						contacts.add(new ContactListItem(c, connected, count));
-					} catch (NoSuchContactException e) {
-						// Continue
-					}
-				}
-				logDuration(LOG, "Full load", start);
-				displayContacts(revision, contacts);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
-		});
-	}
-
-	private void displayContacts(int revision, List<ContactListItem> contacts) {
-		runOnUiThreadUnlessDestroyed(() -> {
-			if (revision == adapter.getRevision()) {
-				adapter.incrementRevision();
-				if (contacts.isEmpty()) list.showData();
-				else adapter.replaceAll(contacts);
-			} else {
-				LOG.info("Concurrent update, reloading");
-				loadContacts();
-			}
-		});
-	}
-
-	@Override
-	public void eventOccurred(Event e) {
-		if (e instanceof ContactAddedEvent) {
-			LOG.info("Contact added, reloading");
-			loadContacts();
-		} else if (e instanceof ContactConnectedEvent) {
-			setConnected(((ContactConnectedEvent) e).getContactId(), true);
-		} else if (e instanceof ContactDisconnectedEvent) {
-			setConnected(((ContactDisconnectedEvent) e).getContactId(), false);
-		} else if (e instanceof ContactRemovedEvent) {
-			LOG.info("Contact removed, removing item");
-			removeItem(((ContactRemovedEvent) e).getContactId());
-		} else if (e instanceof ConversationMessageReceivedEvent) {
-			LOG.info("Conversation message received, updating item");
-			ConversationMessageReceivedEvent<?> p =
-					(ConversationMessageReceivedEvent<?>) e;
-			ConversationMessageHeader h = p.getMessageHeader();
-			updateItem(p.getContactId(), h);
-		} else if (e instanceof PendingContactAddedEvent ||
-				e instanceof PendingContactRemovedEvent) {
-			checkForPendingContacts();
-		}
-	}
-
-	@UiThread
-	private void updateItem(ContactId c, ConversationMessageHeader h) {
-		adapter.incrementRevision();
-		int position = adapter.findItemPosition(c);
-		ContactListItem item = adapter.getItemAt(position);
-		if (item != null) {
-			item.addMessage(h);
-			adapter.updateItemAt(position, item);
-		}
-	}
-
-	@UiThread
-	private void removeItem(ContactId c) {
-		adapter.incrementRevision();
-		int position = adapter.findItemPosition(c);
-		ContactListItem item = adapter.getItemAt(position);
-		if (item != null) adapter.remove(item);
-	}
-
-	@UiThread
-	private void setConnected(ContactId c, boolean connected) {
-		adapter.incrementRevision();
-		int position = adapter.findItemPosition(c);
-		ContactListItem item = adapter.getItemAt(position);
-		if (item != null) {
-			item.setConnected(connected);
-			adapter.updateItemAt(position, item);
-		}
-	}
-
 	@UiThread
 	private void showSnackBar() {
 		if (snackbar != null) return;
@@ -335,5 +176,4 @@ public class ContactListFragment extends BaseFragment implements EventListener,
 		Intent i = new Intent(getContext(), PendingContactListActivity.class);
 		startActivity(i);
 	}
-
 }

briar-android/src/main/java/org/briarproject/briar/android/contact/ContactListItem.java

@@ -2,31 +2,58 @@ package org.briarproject.briar.android.contact;
 
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.briar.api.attachment.AttachmentHeader;
 import org.briarproject.briar.api.client.MessageTracker.GroupCount;
 import org.briarproject.briar.api.conversation.ConversationMessageHeader;
+import org.briarproject.briar.api.identity.AuthorInfo;
 
-import javax.annotation.concurrent.NotThreadSafe;
+import javax.annotation.concurrent.Immutable;
 
-@NotThreadSafe
+@Immutable
 @NotNullByDefault
-public class ContactListItem extends ContactItem {
+public class ContactListItem extends ContactItem
+		implements Comparable<ContactListItem> {
 
-	private boolean empty;
-	private long timestamp;
-	private int unread;
+	private final boolean empty;
+	private final long timestamp;
+	private final int unread;
 
-	public ContactListItem(Contact contact, boolean connected,
-			GroupCount count) {
-		super(contact, connected);
+	public ContactListItem(Contact contact, AuthorInfo authorInfo,
+			boolean connected, GroupCount count) {
+		super(contact, authorInfo, connected);
 		this.empty = count.getMsgCount() == 0;
 		this.unread = count.getUnreadCount();
 		this.timestamp = count.getLatestMsgTime();
 	}
 
-	void addMessage(ConversationMessageHeader h) {
-		empty = false;
-		if (h.getTimestamp() > timestamp) timestamp = h.getTimestamp();
-		if (!h.isRead()) unread++;
+	private ContactListItem(Contact contact, AuthorInfo authorInfo,
+			boolean connected, boolean empty, int unread, long timestamp) {
+		super(contact, authorInfo, connected);
+		this.empty = empty;
+		this.timestamp = timestamp;
+		this.unread = unread;
+	}
+
+	ContactListItem(ContactListItem item, boolean connected) {
+		this(item.getContact(), item.getAuthorInfo(), connected, item.empty,
+				item.unread, item.timestamp);
+	}
+
+	ContactListItem(ContactListItem item, ConversationMessageHeader h) {
+		this(item.getContact(), item.getAuthorInfo(), item.isConnected(), false,
+				h.isRead() ? item.unread : item.unread + 1,
+				Math.max(h.getTimestamp(), item.timestamp));
+	}
+
+	/**
+	 * Creates a new copy of the given item with a new avatar
+	 * referenced by the given attachment header.
+	 */
+	ContactListItem(ContactListItem item,
+			AttachmentHeader attachmentHeader) {
+		this(item.getContact(), new AuthorInfo(item.getAuthorInfo().getStatus(),
+						item.getAuthorInfo().getAlias(), attachmentHeader),
+				item.isConnected(), item.empty, item.unread, item.timestamp);
 	}
 
 	boolean isEmpty() {
@@ -41,4 +68,8 @@ public class ContactListItem extends ContactItem {
 		return unread;
 	}
 
+	@Override
+	public int compareTo(ContactListItem o) {
+		return Long.compare(o.getTimestamp(), timestamp);
+	}
 }

briar-android/src/main/java/org/briarproject/briar/android/contact/ContactListItemViewHolder.java

@@ -3,11 +3,9 @@ package org.briarproject.briar.android.contact;
 import android.view.View;
 import android.widget.TextView;
 
-import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.contact.BaseContactListAdapter.OnContactClickListener;
-import org.briarproject.briar.android.util.UiUtils;
 
 import java.util.Locale;
 
@@ -15,7 +13,6 @@ import javax.annotation.Nullable;
 
 import androidx.annotation.UiThread;
 
-import static androidx.core.view.ViewCompat.setTransitionName;
 import static org.briarproject.briar.android.util.UiUtils.formatDate;
 
 @UiThread
@@ -39,7 +36,8 @@ class ContactListItemViewHolder extends ContactItemViewHolder<ContactListItem> {
 		// unread count
 		int unreadCount = item.getUnreadCount();
 		if (unreadCount > 0) {
-			unread.setText(String.format(Locale.getDefault(), "%d", unreadCount));
+			unread.setText(
+					String.format(Locale.getDefault(), "%d", unreadCount));
 			unread.setVisibility(View.VISIBLE);
 		} else {
 			unread.setVisibility(View.INVISIBLE);
@@ -52,10 +50,6 @@ class ContactListItemViewHolder extends ContactItemViewHolder<ContactListItem> {
 			long timestamp = item.getTimestamp();
 			date.setText(formatDate(date.getContext(), timestamp));
 		}
-
-		ContactId c = item.getContact().getId();
-		setTransitionName(avatar, UiUtils.getAvatarTransitionName(c));
-		setTransitionName(bulb, UiUtils.getBulbTransitionName(c));
 	}
 
 }

briar-android/src/main/java/org/briarproject/briar/android/contact/ContactListModule.java

@@ -0,0 +1,19 @@
+package org.briarproject.briar.android.contact;
+
+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 ContactListModule {
+
+	@Binds
+	@IntoMap
+	@ViewModelKey(ContactListViewModel.class)
+	abstract ViewModel bindContactListViewModel(
+			ContactListViewModel contactListViewModel);
+
+}

briar-android/src/main/java/org/briarproject/briar/android/contact/ContactListViewModel.java

@@ -0,0 +1,188 @@
+package org.briarproject.briar.android.contact;
+
+import android.app.Application;
+
+import org.briarproject.bramble.api.connection.ConnectionRegistry;
+import org.briarproject.bramble.api.contact.Contact;
+import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.contact.ContactManager;
+import org.briarproject.bramble.api.contact.event.ContactAddedEvent;
+import org.briarproject.bramble.api.contact.event.ContactRemovedEvent;
+import org.briarproject.bramble.api.contact.event.PendingContactAddedEvent;
+import org.briarproject.bramble.api.contact.event.PendingContactRemovedEvent;
+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.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.event.ContactConnectedEvent;
+import org.briarproject.bramble.api.plugin.event.ContactDisconnectedEvent;
+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.avatar.event.AvatarUpdatedEvent;
+import org.briarproject.briar.api.client.MessageTracker;
+import org.briarproject.briar.api.conversation.ConversationManager;
+import org.briarproject.briar.api.conversation.ConversationMessageHeader;
+import org.briarproject.briar.api.conversation.event.ConversationMessageReceivedEvent;
+import org.briarproject.briar.api.identity.AuthorInfo;
+import org.briarproject.briar.api.identity.AuthorManager;
+
+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.arch.core.util.Function;
+import androidx.lifecycle.LiveData;
+import androidx.lifecycle.MutableLiveData;
+
+import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.util.LogUtils.logDuration;
+import static org.briarproject.bramble.util.LogUtils.now;
+
+@NotNullByDefault
+class ContactListViewModel extends DbViewModel implements EventListener {
+
+	private static final Logger LOG =
+			getLogger(ContactListViewModel.class.getName());
+
+	private final ContactManager contactManager;
+	private final AuthorManager authorManager;
+	private final ConversationManager conversationManager;
+	private final ConnectionRegistry connectionRegistry;
+	private final EventBus eventBus;
+	private final AndroidNotificationManager notificationManager;
+
+	private final MutableLiveData<LiveResult<List<ContactListItem>>>
+			contactListItems = new MutableLiveData<>();
+
+	private final MutableLiveData<Boolean> hasPendingContacts =
+			new MutableLiveData<>();
+
+	@Inject
+	ContactListViewModel(Application application,
+			@DatabaseExecutor Executor dbExecutor,
+			LifecycleManager lifecycleManager, TransactionManager db,
+			AndroidExecutor androidExecutor, ContactManager contactManager,
+			AuthorManager authorManager,
+			ConversationManager conversationManager,
+			ConnectionRegistry connectionRegistry, EventBus eventBus,
+			AndroidNotificationManager notificationManager) {
+		super(application, dbExecutor, lifecycleManager, db, androidExecutor);
+		this.contactManager = contactManager;
+		this.authorManager = authorManager;
+		this.conversationManager = conversationManager;
+		this.connectionRegistry = connectionRegistry;
+		this.eventBus = eventBus;
+		this.notificationManager = notificationManager;
+		this.eventBus.addListener(this);
+	}
+
+	@Override
+	protected void onCleared() {
+		super.onCleared();
+		eventBus.removeListener(this);
+	}
+
+	void loadContacts() {
+		loadList(this::loadContacts, contactListItems::setValue);
+	}
+
+	private List<ContactListItem> loadContacts(Transaction txn)
+			throws DbException {
+		long start = now();
+		List<ContactListItem> contacts = new ArrayList<>();
+		for (Contact c : contactManager.getContacts(txn)) {
+			ContactId id = c.getId();
+			AuthorInfo authorInfo = authorManager.getAuthorInfo(txn, c);
+			MessageTracker.GroupCount count =
+					conversationManager.getGroupCount(txn, id);
+			boolean connected = connectionRegistry.isConnected(c.getId());
+			contacts.add(new ContactListItem(c, authorInfo, connected, count));
+		}
+		Collections.sort(contacts);
+		logDuration(LOG, "Full load", start);
+		return contacts;
+	}
+
+	@Override
+	public void eventOccurred(Event e) {
+		if (e instanceof ContactAddedEvent) {
+			LOG.info("Contact added, reloading");
+			loadContacts();
+		} else if (e instanceof ContactConnectedEvent) {
+			updateItem(((ContactConnectedEvent) e).getContactId(),
+					item -> new ContactListItem(item, true), false);
+		} else if (e instanceof ContactDisconnectedEvent) {
+			updateItem(((ContactDisconnectedEvent) e).getContactId(),
+					item -> new ContactListItem(item, false), false);
+		} else if (e instanceof ContactRemovedEvent) {
+			LOG.info("Contact removed, removing item");
+			removeItem(((ContactRemovedEvent) e).getContactId());
+		} else if (e instanceof ConversationMessageReceivedEvent) {
+			LOG.info("Conversation message received, updating item");
+			ConversationMessageReceivedEvent<?> p =
+					(ConversationMessageReceivedEvent<?>) e;
+			ConversationMessageHeader h = p.getMessageHeader();
+			updateItem(p.getContactId(), item -> new ContactListItem(item, h),
+					true);
+		} else if (e instanceof PendingContactAddedEvent ||
+				e instanceof PendingContactRemovedEvent) {
+			checkForPendingContacts();
+		} else if (e instanceof AvatarUpdatedEvent) {
+			AvatarUpdatedEvent a = (AvatarUpdatedEvent) e;
+			updateItem(a.getContactId(), item -> new ContactListItem(item,
+					a.getAttachmentHeader()), false);
+		}
+	}
+
+	LiveData<LiveResult<List<ContactListItem>>> getContactListItems() {
+		return contactListItems;
+	}
+
+	LiveData<Boolean> getHasPendingContacts() {
+		return hasPendingContacts;
+	}
+
+	private void updateItem(ContactId c,
+			Function<ContactListItem, ContactListItem> replacer, boolean sort) {
+		List<ContactListItem> list = updateListItems(contactListItems,
+				itemToTest -> itemToTest.getContact().getId().equals(c),
+				replacer);
+		if (list == null) return;
+		if (sort) Collections.sort(list);
+		contactListItems.setValue(new LiveResult<>(list));
+	}
+
+	private void removeItem(ContactId c) {
+		List<ContactListItem> list = removeListItems(contactListItems,
+				itemToTest -> itemToTest.getContact().getId().equals(c));
+		if (list == null) return;
+		contactListItems.setValue(new LiveResult<>(list));
+	}
+
+	void checkForPendingContacts() {
+		runOnDbThreadOrLogException(() -> {
+			boolean hasPending = !contactManager.getPendingContacts().isEmpty();
+			hasPendingContacts.postValue(hasPending);
+		});
+	}
+
+	void clearAllContactNotifications() {
+		notificationManager.clearAllContactNotifications();
+	}
+
+	void clearAllContactAddedNotifications() {
+		notificationManager.clearAllContactAddedNotifications();
+	}
+
+}

briar-android/src/main/java/org/briarproject/briar/android/contact/ContactModule.java

@@ -1,7 +0,0 @@
-package org.briarproject.briar.android.contact;
-
-import dagger.Module;
-
-@Module
-public class ContactModule {
-}