Bumped expiry date to 1 May 2017.

Store invitation outcome in metadata and make it available to the UI

This MR is based on !479 and should only be merged after that one has been merged as well.

It stores the invitation outcome in the message metadata  and includes it in the `canBeOpened()` calculation for private groups and sharables.

Closes #877

See merge request !480

bramble-api/src/main/java/org/briarproject/bramble/api/sync/Ack.java

@@ -3,7 +3,7 @@ package org.briarproject.bramble.api.sync;
 import java.util.Collection;
 
 /**
- * A packet acknowledging receipt of one or more {@link Message Messages}.
+ * A record acknowledging receipt of one or more {@link Message Messages}.
  */
 public class Ack {
 

bramble-api/src/main/java/org/briarproject/bramble/api/sync/Group.java

@@ -1,5 +1,7 @@
 package org.briarproject.bramble.api.sync;
 
+import static org.briarproject.bramble.api.sync.SyncConstants.MAX_GROUP_DESCRIPTOR_LENGTH;
+
 public class Group {
 
 	public enum Visibility {
@@ -13,6 +15,8 @@ public class Group {
 	private final byte[] descriptor;
 
 	public Group(GroupId id, ClientId clientId, byte[] descriptor) {
+		if (descriptor.length > MAX_GROUP_DESCRIPTOR_LENGTH)
+			throw new IllegalArgumentException();
 		this.id = id;
 		this.clientId = clientId;
 		this.descriptor = descriptor;

bramble-api/src/main/java/org/briarproject/bramble/api/sync/Offer.java

@@ -3,7 +3,7 @@ package org.briarproject.bramble.api.sync;
 import java.util.Collection;
 
 /**
- * A packet offering the recipient one or more {@link Message Messages}.
+ * A record offering the recipient one or more {@link Message Messages}.
  */
 public class Offer {
 

bramble-api/src/main/java/org/briarproject/bramble/api/sync/RecordReader.java

@@ -5,7 +5,7 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import java.io.IOException;
 
 @NotNullByDefault
-public interface PacketReader {
+public interface RecordReader {
 
 	boolean eof() throws IOException;
 
@@ -24,4 +24,5 @@ public interface PacketReader {
 	boolean hasRequest() throws IOException;
 
 	Request readRequest() throws IOException;
+
 }

bramble-api/src/main/java/org/briarproject/bramble/api/sync/RecordReaderFactory.java

@@ -5,7 +5,7 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import java.io.InputStream;
 
 @NotNullByDefault
-public interface PacketReaderFactory {
+public interface RecordReaderFactory {
 
-	PacketReader createPacketReader(InputStream in);
+	RecordReader createRecordReader(InputStream in);
 }

bramble-api/src/main/java/org/briarproject/bramble/api/sync/RecordTypes.java

@@ -1,12 +1,13 @@
 package org.briarproject.bramble.api.sync;
 
 /**
- * Packet types for the sync protocol.
+ * Record types for the sync protocol.
  */
-public interface PacketTypes {
+public interface RecordTypes {
 
 	byte ACK = 0;
 	byte MESSAGE = 1;
 	byte OFFER = 2;
 	byte REQUEST = 3;
+
 }

bramble-api/src/main/java/org/briarproject/bramble/api/sync/RecordWriter.java

@@ -5,7 +5,7 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import java.io.IOException;
 
 @NotNullByDefault
-public interface PacketWriter {
+public interface RecordWriter {
 
 	void writeAck(Ack a) throws IOException;
 

bramble-api/src/main/java/org/briarproject/bramble/api/sync/RecordWriterFactory.java

@@ -5,7 +5,7 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import java.io.OutputStream;
 
 @NotNullByDefault
-public interface PacketWriterFactory {
+public interface RecordWriterFactory {
 
-	PacketWriter createPacketWriter(OutputStream out);
+	RecordWriter createRecordWriter(OutputStream out);
 }

bramble-api/src/main/java/org/briarproject/bramble/api/sync/Request.java

@@ -3,7 +3,7 @@ package org.briarproject.bramble.api.sync;
 import java.util.Collection;
 
 /**
- * A packet requesting one or more {@link Message Messages} from the recipient.
+ * A record requesting one or more {@link Message Messages} from the recipient.
  */
 public class Request {
 

bramble-api/src/main/java/org/briarproject/bramble/api/sync/SyncConstants.java

@@ -10,19 +10,17 @@ public interface SyncConstants {
 	byte PROTOCOL_VERSION = 0;
 
 	/**
-	 * The length of the packet header in bytes.
+	 * The length of the record header in bytes.
 	 */
-	int PACKET_HEADER_LENGTH = 4;
+	int RECORD_HEADER_LENGTH = 4;
 
 	/**
-	 * The maximum length of the packet payload in bytes.
+	 * The maximum length of the record payload in bytes.
 	 */
-	int MAX_PACKET_PAYLOAD_LENGTH = 32 * 1024; // 32 KiB
+	int MAX_RECORD_PAYLOAD_LENGTH = 48 * 1024; // 48 KiB
 
-	/**
-	 * The maximum length of a message in bytes.
-	 */
-	int MAX_MESSAGE_LENGTH = MAX_PACKET_PAYLOAD_LENGTH - PACKET_HEADER_LENGTH;
+	/** The maximum length of a group descriptor in bytes. */
+	int MAX_GROUP_DESCRIPTOR_LENGTH = 16 * 1024; // 16 KiB
 
 	/**
 	 * The length of the message header in bytes.
@@ -32,10 +30,15 @@ public interface SyncConstants {
 	/**
 	 * The maximum length of a message body in bytes.
 	 */
-	int MAX_MESSAGE_BODY_LENGTH = MAX_MESSAGE_LENGTH - MESSAGE_HEADER_LENGTH;
+	int MAX_MESSAGE_BODY_LENGTH = 32 * 1024; // 32 KiB
 
 	/**
-	 * The maximum number of message IDs in an ack, offer or request packet.
+	 * The maximum length of a message in bytes.
 	 */
-	int MAX_MESSAGE_IDS = MAX_PACKET_PAYLOAD_LENGTH / UniqueId.LENGTH;
+	int MAX_MESSAGE_LENGTH = MESSAGE_HEADER_LENGTH + MAX_MESSAGE_BODY_LENGTH;
+
+	/**
+	 * The maximum number of message IDs in an ack, offer or request record.
+	 */
+	int MAX_MESSAGE_IDS = MAX_RECORD_PAYLOAD_LENGTH / UniqueId.LENGTH;
 }

bramble-api/src/main/java/org/briarproject/bramble/api/sync/SyncSession.java

@@ -5,7 +5,7 @@ import java.io.IOException;
 public interface SyncSession {
 
 	/**
-	 * Runs the session. This method returns when there are no more packets to
+	 * Runs the session. This method returns when there are no more records to
 	 * send or receive, or when the {@link #interrupt()} method has been called.
 	 */
 	void run() throws IOException;

bramble-core/src/main/java/org/briarproject/bramble/keyagreement/KeyAgreementProtocol.java

@@ -52,7 +52,7 @@ class KeyAgreementProtocol {
 
 		void connectionWaiting();
 
-		void initialPacketReceived();
+		void initialRecordReceived();
 	}
 
 	private final Callbacks callbacks;
@@ -117,7 +117,7 @@ class KeyAgreementProtocol {
 
 	private byte[] receiveKey() throws AbortException {
 		byte[] publicKey = transport.receiveKey();
-		callbacks.initialPacketReceived();
+		callbacks.initialRecordReceived();
 		byte[] expected = crypto.deriveKeyCommitment(publicKey);
 		if (!Arrays.equals(expected, theirPayload.getCommitment()))
 			throw new AbortException();

bramble-core/src/main/java/org/briarproject/bramble/keyagreement/KeyAgreementTaskImpl.java

@@ -129,7 +129,7 @@ class KeyAgreementTaskImpl extends Thread implements
 	}
 
 	@Override
-	public void initialPacketReceived() {
+	public void initialRecordReceived() {
 		// We send this here instead of when we create the protocol, so that
 		// if device A makes a connection after getting device B's payload and
 		// starts its protocol, device A's UI doesn't change to prevent device B

bramble-core/src/main/java/org/briarproject/bramble/keyagreement/KeyAgreementTransport.java

@@ -95,20 +95,30 @@ class KeyAgreementTransport {
 		out.flush();
 	}
 
-	private byte[] readRecord(byte type) throws AbortException {
-		byte[] header = readHeader();
-		if (header[0] != PROTOCOL_VERSION)
-			throw new AbortException(); // TODO handle?
-		if (header[1] != type) {
-			// Unexpected packet
-			throw new AbortException(header[1] == ABORT);
-		}
-		int len = ByteUtils.readUint16(header,
-				RECORD_HEADER_PAYLOAD_LENGTH_OFFSET);
-		try {
-			return readData(len);
-		} catch (IOException e) {
-			throw new AbortException(e);
+	private byte[] readRecord(byte expectedType) throws AbortException {
+		while (true) {
+			byte[] header = readHeader();
+			byte version = header[0], type = header[1];
+			int len = ByteUtils.readUint16(header,
+					RECORD_HEADER_PAYLOAD_LENGTH_OFFSET);
+			// Reject unrecognised protocol version
+			if (version != PROTOCOL_VERSION) throw new AbortException(false);
+			if (type == ABORT) throw new AbortException(true);
+			if (type == expectedType) {
+				try {
+					return readData(len);
+				} catch (IOException e) {
+					throw new AbortException(e);
+				}
+			}
+			// Reject recognised but unexpected record type
+			if (type == KEY || type == CONFIRM) throw new AbortException(false);
+			// Skip unrecognised record type
+			try {
+				readData(len);
+			} catch (IOException e) {
+				throw new AbortException(e);
+			}
 		}
 	}
 

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

@@ -14,7 +14,7 @@ import org.briarproject.bramble.api.lifecycle.event.ShutdownEvent;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.Ack;
 import org.briarproject.bramble.api.sync.Offer;
-import org.briarproject.bramble.api.sync.PacketWriter;
+import org.briarproject.bramble.api.sync.RecordWriter;
 import org.briarproject.bramble.api.sync.Request;
 import org.briarproject.bramble.api.sync.SyncSession;
 import org.briarproject.bramble.api.sync.event.GroupVisibilityUpdatedEvent;
@@ -37,19 +37,19 @@ import static java.util.concurrent.TimeUnit.MILLISECONDS;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.api.sync.SyncConstants.MAX_MESSAGE_IDS;
-import static org.briarproject.bramble.api.sync.SyncConstants.MAX_PACKET_PAYLOAD_LENGTH;
+import static org.briarproject.bramble.api.sync.SyncConstants.MAX_RECORD_PAYLOAD_LENGTH;
 
 /**
  * An outgoing {@link SyncSession} suitable for duplex transports. The session
  * offers messages before sending them, keeps its output stream open when there
- * are no packets to send, and reacts to events that make packets available to
+ * are no records to send, and reacts to events that make records available to
  * send.
  */
 @ThreadSafe
 @NotNullByDefault
 class DuplexOutgoingSession implements SyncSession, EventListener {
 
-	// Check for retransmittable packets once every 60 seconds
+	// Check for retransmittable records once every 60 seconds
 	private static final int RETX_QUERY_INTERVAL = 60 * 1000;
 	private static final Logger LOG =
 			Logger.getLogger(DuplexOutgoingSession.class.getName());
@@ -67,14 +67,14 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 	private final Clock clock;
 	private final ContactId contactId;
 	private final int maxLatency, maxIdleTime;
-	private final PacketWriter packetWriter;
+	private final RecordWriter recordWriter;
 	private final BlockingQueue<ThrowingRunnable<IOException>> writerTasks;
 
 	private volatile boolean interrupted = false;
 
 	DuplexOutgoingSession(DatabaseComponent db, Executor dbExecutor,
 			EventBus eventBus, Clock clock, ContactId contactId, int maxLatency,
-			int maxIdleTime, PacketWriter packetWriter) {
+			int maxIdleTime, RecordWriter recordWriter) {
 		this.db = db;
 		this.dbExecutor = dbExecutor;
 		this.eventBus = eventBus;
@@ -82,7 +82,7 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 		this.contactId = contactId;
 		this.maxLatency = maxLatency;
 		this.maxIdleTime = maxIdleTime;
-		this.packetWriter = packetWriter;
+		this.recordWriter = recordWriter;
 		writerTasks = new LinkedBlockingQueue<ThrowingRunnable<IOException>>();
 	}
 
@@ -91,7 +91,7 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 	public void run() throws IOException {
 		eventBus.addListener(this);
 		try {
-			// Start a query for each type of packet
+			// Start a query for each type of record
 			dbExecutor.execute(new GenerateAck());
 			dbExecutor.execute(new GenerateBatch());
 			dbExecutor.execute(new GenerateOffer());
@@ -100,33 +100,33 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 			long nextKeepalive = now + maxIdleTime;
 			long nextRetxQuery = now + RETX_QUERY_INTERVAL;
 			boolean dataToFlush = true;
-			// Write packets until interrupted
+			// Write records until interrupted
 			try {
 				while (!interrupted) {
-					// Work out how long we should wait for a packet
+					// Work out how long we should wait for a record
 					now = clock.currentTimeMillis();
 					long wait = Math.min(nextKeepalive, nextRetxQuery) - now;
 					if (wait < 0) wait = 0;
 					// Flush any unflushed data if we're going to wait
 					if (wait > 0 && dataToFlush && writerTasks.isEmpty()) {
-						packetWriter.flush();
+						recordWriter.flush();
 						dataToFlush = false;
 						nextKeepalive = now + maxIdleTime;
 					}
-					// Wait for a packet
+					// Wait for a record
 					ThrowingRunnable<IOException> task = writerTasks.poll(wait,
 							MILLISECONDS);
 					if (task == null) {
 						now = clock.currentTimeMillis();
 						if (now >= nextRetxQuery) {
-							// Check for retransmittable packets
+							// Check for retransmittable records
 							dbExecutor.execute(new GenerateBatch());
 							dbExecutor.execute(new GenerateOffer());
 							nextRetxQuery = now + RETX_QUERY_INTERVAL;
 						}
 						if (now >= nextKeepalive) {
 							// Flush the stream to keep it alive
-							packetWriter.flush();
+							recordWriter.flush();
 							dataToFlush = false;
 							nextKeepalive = now + maxIdleTime;
 						}
@@ -137,9 +137,9 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 						dataToFlush = true;
 					}
 				}
-				if (dataToFlush) packetWriter.flush();
+				if (dataToFlush) recordWriter.flush();
 			} catch (InterruptedException e) {
-				LOG.info("Interrupted while waiting for a packet to write");
+				LOG.info("Interrupted while waiting for a record to write");
 				Thread.currentThread().interrupt();
 			}
 		} finally {
@@ -215,7 +215,7 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 		@Override
 		public void run() throws IOException {
 			if (interrupted) return;
-			packetWriter.writeAck(ack);
+			recordWriter.writeAck(ack);
 			LOG.info("Sent ack");
 			dbExecutor.execute(new GenerateAck());
 		}
@@ -232,7 +232,7 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 				Transaction txn = db.startTransaction(false);
 				try {
 					b = db.generateRequestedBatch(txn, contactId,
-							MAX_PACKET_PAYLOAD_LENGTH, maxLatency);
+							MAX_RECORD_PAYLOAD_LENGTH, maxLatency);
 					db.commitTransaction(txn);
 				} finally {
 					db.endTransaction(txn);
@@ -259,7 +259,7 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 		@Override
 		public void run() throws IOException {
 			if (interrupted) return;
-			for (byte[] raw : batch) packetWriter.writeMessage(raw);
+			for (byte[] raw : batch) recordWriter.writeMessage(raw);
 			LOG.info("Sent batch");
 			dbExecutor.execute(new GenerateBatch());
 		}
@@ -303,7 +303,7 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 		@Override
 		public void run() throws IOException {
 			if (interrupted) return;
-			packetWriter.writeOffer(offer);
+			recordWriter.writeOffer(offer);
 			LOG.info("Sent offer");
 			dbExecutor.execute(new GenerateOffer());
 		}
@@ -346,7 +346,7 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 		@Override
 		public void run() throws IOException {
 			if (interrupted) return;
-			packetWriter.writeRequest(request);
+			recordWriter.writeRequest(request);
 			LOG.info("Sent request");
 			dbExecutor.execute(new GenerateRequest());
 		}

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

@@ -16,7 +16,7 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.Ack;
 import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.Offer;
-import org.briarproject.bramble.api.sync.PacketReader;
+import org.briarproject.bramble.api.sync.RecordReader;
 import org.briarproject.bramble.api.sync.Request;
 import org.briarproject.bramble.api.sync.SyncSession;
 
@@ -42,18 +42,18 @@ class IncomingSession implements SyncSession, EventListener {
 	private final Executor dbExecutor;
 	private final EventBus eventBus;
 	private final ContactId contactId;
-	private final PacketReader packetReader;
+	private final RecordReader recordReader;
 
 	private volatile boolean interrupted = false;
 
 	IncomingSession(DatabaseComponent db, Executor dbExecutor,
 			EventBus eventBus, ContactId contactId,
-			PacketReader packetReader) {
+			RecordReader recordReader) {
 		this.db = db;
 		this.dbExecutor = dbExecutor;
 		this.eventBus = eventBus;
 		this.contactId = contactId;
-		this.packetReader = packetReader;
+		this.recordReader = recordReader;
 	}
 
 	@IoExecutor
@@ -61,21 +61,22 @@ class IncomingSession implements SyncSession, EventListener {
 	public void run() throws IOException {
 		eventBus.addListener(this);
 		try {
-			// Read packets until interrupted or EOF
-			while (!interrupted && !packetReader.eof()) {
-				if (packetReader.hasAck()) {
-					Ack a = packetReader.readAck();
+			// Read records until interrupted or EOF
+			while (!interrupted && !recordReader.eof()) {
+				if (recordReader.hasAck()) {
+					Ack a = recordReader.readAck();
 					dbExecutor.execute(new ReceiveAck(a));
-				} else if (packetReader.hasMessage()) {
-					Message m = packetReader.readMessage();
+				} else if (recordReader.hasMessage()) {
+					Message m = recordReader.readMessage();
 					dbExecutor.execute(new ReceiveMessage(m));
-				} else if (packetReader.hasOffer()) {
-					Offer o = packetReader.readOffer();
+				} else if (recordReader.hasOffer()) {
+					Offer o = recordReader.readOffer();
 					dbExecutor.execute(new ReceiveOffer(o));
-				} else if (packetReader.hasRequest()) {
-					Request r = packetReader.readRequest();
+				} else if (recordReader.hasRequest()) {
+					Request r = recordReader.readRequest();
 					dbExecutor.execute(new ReceiveRequest(r));
 				} else {
+					// unknown records are ignored in RecordReader#eof()
 					throw new FormatException();
 				}
 			}

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

@@ -30,11 +30,15 @@ class MessageFactoryImpl implements MessageFactory {
 	public Message createMessage(GroupId g, long timestamp, byte[] body) {
 		if (body.length > MAX_MESSAGE_BODY_LENGTH)
 			throw new IllegalArgumentException();
+		byte[] timeBytes = new byte[ByteUtils.INT_64_BYTES];
+		ByteUtils.writeUint64(timestamp, timeBytes, 0);
+		byte[] idHash =
+				crypto.hash(MessageId.LABEL, g.getBytes(), timeBytes, body);
+		MessageId id = new MessageId(idHash);
 		byte[] raw = new byte[MESSAGE_HEADER_LENGTH + body.length];
 		System.arraycopy(g.getBytes(), 0, raw, 0, UniqueId.LENGTH);
 		ByteUtils.writeUint64(timestamp, raw, UniqueId.LENGTH);
 		System.arraycopy(body, 0, raw, MESSAGE_HEADER_LENGTH, body.length);
-		MessageId id = new MessageId(crypto.hash(MessageId.LABEL, raw));
 		return new Message(id, g, timestamp, raw);
 	}
 

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

@@ -1,28 +0,0 @@
-package org.briarproject.bramble.sync;
-
-import org.briarproject.bramble.api.crypto.CryptoComponent;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.sync.PacketReader;
-import org.briarproject.bramble.api.sync.PacketReaderFactory;
-
-import java.io.InputStream;
-
-import javax.annotation.concurrent.Immutable;
-import javax.inject.Inject;
-
-@Immutable
-@NotNullByDefault
-class PacketReaderFactoryImpl implements PacketReaderFactory {
-
-	private final CryptoComponent crypto;
-
-	@Inject
-	PacketReaderFactoryImpl(CryptoComponent crypto) {
-		this.crypto = crypto;
-	}
-
-	@Override
-	public PacketReader createPacketReader(InputStream in) {
-		return new PacketReaderImpl(crypto, in);
-	}
-}

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

@@ -1,16 +0,0 @@
-package org.briarproject.bramble.sync;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.sync.PacketWriter;
-import org.briarproject.bramble.api.sync.PacketWriterFactory;
-
-import java.io.OutputStream;
-
-@NotNullByDefault
-class PacketWriterFactoryImpl implements PacketWriterFactory {
-
-	@Override
-	public PacketWriter createPacketWriter(OutputStream out) {
-		return new PacketWriterImpl(out);
-	}
-}

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

@@ -0,0 +1,28 @@
+package org.briarproject.bramble.sync;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.sync.MessageFactory;
+import org.briarproject.bramble.api.sync.RecordReader;
+import org.briarproject.bramble.api.sync.RecordReaderFactory;
+
+import java.io.InputStream;
+
+import javax.annotation.concurrent.Immutable;
+import javax.inject.Inject;
+
+@Immutable
+@NotNullByDefault
+class RecordReaderFactoryImpl implements RecordReaderFactory {
+
+	private final MessageFactory messageFactory;
+
+	@Inject
+	RecordReaderFactoryImpl(MessageFactory messageFactory) {
+		this.messageFactory = messageFactory;
+	}
+
+	@Override
+	public RecordReader createRecordReader(InputStream in) {
+		return new RecordReaderImpl(messageFactory, in);
+	}
+}

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

@@ -2,14 +2,14 @@ package org.briarproject.bramble.sync;
 
 import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.UniqueId;
-import org.briarproject.bramble.api.crypto.CryptoComponent;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.Ack;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.Message;
+import org.briarproject.bramble.api.sync.MessageFactory;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.sync.Offer;
-import org.briarproject.bramble.api.sync.PacketReader;
+import org.briarproject.bramble.api.sync.RecordReader;
 import org.briarproject.bramble.api.sync.Request;
 import org.briarproject.bramble.util.ByteUtils;
 
@@ -20,66 +20,84 @@ import java.util.List;
 
 import javax.annotation.concurrent.NotThreadSafe;
 
-import static org.briarproject.bramble.api.sync.PacketTypes.ACK;
-import static org.briarproject.bramble.api.sync.PacketTypes.MESSAGE;
-import static org.briarproject.bramble.api.sync.PacketTypes.OFFER;
-import static org.briarproject.bramble.api.sync.PacketTypes.REQUEST;
-import static org.briarproject.bramble.api.sync.SyncConstants.MAX_PACKET_PAYLOAD_LENGTH;
+import static org.briarproject.bramble.api.sync.RecordTypes.ACK;
+import static org.briarproject.bramble.api.sync.RecordTypes.MESSAGE;
+import static org.briarproject.bramble.api.sync.RecordTypes.OFFER;
+import static org.briarproject.bramble.api.sync.RecordTypes.REQUEST;
+import static org.briarproject.bramble.api.sync.SyncConstants.MAX_RECORD_PAYLOAD_LENGTH;
 import static org.briarproject.bramble.api.sync.SyncConstants.MESSAGE_HEADER_LENGTH;
-import static org.briarproject.bramble.api.sync.SyncConstants.PACKET_HEADER_LENGTH;
 import static org.briarproject.bramble.api.sync.SyncConstants.PROTOCOL_VERSION;
+import static org.briarproject.bramble.api.sync.SyncConstants.RECORD_HEADER_LENGTH;
 
 @NotThreadSafe
 @NotNullByDefault
-class PacketReaderImpl implements PacketReader {
+class RecordReaderImpl implements RecordReader {
 
-	private enum State { BUFFER_EMPTY, BUFFER_FULL, EOF }
+	private enum State {BUFFER_EMPTY, BUFFER_FULL, EOF}
 
-	private final CryptoComponent crypto;
+	private final MessageFactory messageFactory;
 	private final InputStream in;
 	private final byte[] header, payload;
 
 	private State state = State.BUFFER_EMPTY;
 	private int payloadLength = 0;
 
-	PacketReaderImpl(CryptoComponent crypto, InputStream in) {
-		this.crypto = crypto;
+	RecordReaderImpl(MessageFactory messageFactory, InputStream in) {
+		this.messageFactory = messageFactory;
 		this.in = in;
-		header = new byte[PACKET_HEADER_LENGTH];
-		payload = new byte[MAX_PACKET_PAYLOAD_LENGTH];
+		header = new byte[RECORD_HEADER_LENGTH];
+		payload = new byte[MAX_RECORD_PAYLOAD_LENGTH];
 	}
 
-	private void readPacket() throws IOException {
+	private void readRecord() throws IOException {
 		if (state != State.BUFFER_EMPTY) throw new IllegalStateException();
-		// Read the header
-		int offset = 0;
-		while (offset < PACKET_HEADER_LENGTH) {
-			int read = in.read(header, offset, PACKET_HEADER_LENGTH - offset);
-			if (read == -1) {
-				if (offset > 0) throw new FormatException();
-				state = State.EOF;
+		while (true) {
+			// Read the header
+			int offset = 0;
+			while (offset < RECORD_HEADER_LENGTH) {
+				int read =
+						in.read(header, offset, RECORD_HEADER_LENGTH - offset);
+				if (read == -1) {
+					if (offset > 0) throw new FormatException();
+					state = State.EOF;
+					return;
+				}
+				offset += read;
+			}
+			byte version = header[0], type = header[1];
+			payloadLength = ByteUtils.readUint16(header, 2);
+			// Check the protocol version
+			if (version != PROTOCOL_VERSION) throw new FormatException();
+			// Check the payload length
+			if (payloadLength > MAX_RECORD_PAYLOAD_LENGTH)
+				throw new FormatException();
+			// Read the payload
+			offset = 0;
+			while (offset < payloadLength) {
+				int read = in.read(payload, offset, payloadLength - offset);
+				if (read == -1) throw new FormatException();
+				offset += read;
+			}
+			state = State.BUFFER_FULL;
+			// Return if this is a known record type, otherwise continue
+			if (type == ACK || type == MESSAGE || type == OFFER ||
+					type == REQUEST) {
 				return;
 			}
-			offset += read;
 		}
-		// Check the protocol version
-		if (header[0] != PROTOCOL_VERSION) throw new FormatException();
-		// Read the payload length
-		payloadLength = ByteUtils.readUint16(header, 2);
-		if (payloadLength > MAX_PACKET_PAYLOAD_LENGTH) throw new FormatException();
-		// Read the payload
-		offset = 0;
-		while (offset < payloadLength) {
-			int read = in.read(payload, offset, payloadLength - offset);
-			if (read == -1) throw new FormatException();
-			offset += read;
-		}
-		state = State.BUFFER_FULL;
 	}
 
+	/**
+	 * Returns true if there's another record available or false if we've
+	 * reached the end of the input stream.
+	 * <p>
+	 * If a record is available, it's been read into the buffer by the time
+	 * eof() returns, so the method that called eof() can access the record
+	 * from the buffer, for example to check its type or extract its payload.
+	 */
 	@Override
 	public boolean eof() throws IOException {
-		if (state == State.BUFFER_EMPTY) readPacket();
+		if (state == State.BUFFER_EMPTY) readRecord();
 		if (state == State.BUFFER_EMPTY) throw new IllegalStateException();
 		return state == State.EOF;
 	}
@@ -124,13 +142,12 @@ class PacketReaderImpl implements PacketReader {
 		// Timestamp
 		long timestamp = ByteUtils.readUint64(payload, UniqueId.LENGTH);
 		if (timestamp < 0) throw new FormatException();
-		// Raw message
-		byte[] raw = new byte[payloadLength];
-		System.arraycopy(payload, 0, raw, 0, payloadLength);
+		// Body
+		byte[] body = new byte[payloadLength - MESSAGE_HEADER_LENGTH];
+		System.arraycopy(payload, MESSAGE_HEADER_LENGTH, body, 0,
+				payloadLength - MESSAGE_HEADER_LENGTH);
 		state = State.BUFFER_EMPTY;
-		// Message ID
-		MessageId messageId = new MessageId(crypto.hash(MessageId.LABEL, raw));
-		return new Message(messageId, groupId, timestamp, raw);
+		return messageFactory.createMessage(groupId, timestamp, body);
 	}
 
 	@Override
@@ -154,4 +171,5 @@ class PacketReaderImpl implements PacketReader {
 		if (!hasRequest()) throw new FormatException();
 		return new Request(readMessageIds());
 	}
+
 }

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

@@ -0,0 +1,16 @@
+package org.briarproject.bramble.sync;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.sync.RecordWriter;
+import org.briarproject.bramble.api.sync.RecordWriterFactory;
+
+import java.io.OutputStream;
+
+@NotNullByDefault
+class RecordWriterFactoryImpl implements RecordWriterFactory {
+
+	@Override
+	public RecordWriter createRecordWriter(OutputStream out) {
+		return new RecordWriterImpl(out);
+	}
+}

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

@@ -4,8 +4,8 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.Ack;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.sync.Offer;
-import org.briarproject.bramble.api.sync.PacketTypes;
-import org.briarproject.bramble.api.sync.PacketWriter;
+import org.briarproject.bramble.api.sync.RecordTypes;
+import org.briarproject.bramble.api.sync.RecordWriter;
 import org.briarproject.bramble.api.sync.Request;
 import org.briarproject.bramble.util.ByteUtils;
 
@@ -15,30 +15,30 @@ import java.io.OutputStream;
 
 import javax.annotation.concurrent.NotThreadSafe;
 
-import static org.briarproject.bramble.api.sync.PacketTypes.ACK;
-import static org.briarproject.bramble.api.sync.PacketTypes.OFFER;
-import static org.briarproject.bramble.api.sync.PacketTypes.REQUEST;
-import static org.briarproject.bramble.api.sync.SyncConstants.MAX_PACKET_PAYLOAD_LENGTH;
-import static org.briarproject.bramble.api.sync.SyncConstants.PACKET_HEADER_LENGTH;
+import static org.briarproject.bramble.api.sync.RecordTypes.ACK;
+import static org.briarproject.bramble.api.sync.RecordTypes.OFFER;
+import static org.briarproject.bramble.api.sync.RecordTypes.REQUEST;
+import static org.briarproject.bramble.api.sync.SyncConstants.MAX_RECORD_PAYLOAD_LENGTH;
+import static org.briarproject.bramble.api.sync.SyncConstants.RECORD_HEADER_LENGTH;
 import static org.briarproject.bramble.api.sync.SyncConstants.PROTOCOL_VERSION;
 
 @NotThreadSafe
 @NotNullByDefault
-class PacketWriterImpl implements PacketWriter {
+class RecordWriterImpl implements RecordWriter {
 
 	private final OutputStream out;
 	private final byte[] header;
 	private final ByteArrayOutputStream payload;
 
-	PacketWriterImpl(OutputStream out) {
+	RecordWriterImpl(OutputStream out) {
 		this.out = out;
-		header = new byte[PACKET_HEADER_LENGTH];
+		header = new byte[RECORD_HEADER_LENGTH];
 		header[0] = PROTOCOL_VERSION;
-		payload = new ByteArrayOutputStream(MAX_PACKET_PAYLOAD_LENGTH);
+		payload = new ByteArrayOutputStream(MAX_RECORD_PAYLOAD_LENGTH);
 	}
 
-	private void writePacket(byte packetType) throws IOException {
-		header[1] = packetType;
+	private void writeRecord(byte recordType) throws IOException {
+		header[1] = recordType;
 		ByteUtils.writeUint16(payload.size(), header, 2);
 		out.write(header);
 		payload.writeTo(out);
@@ -49,12 +49,12 @@ class PacketWriterImpl implements PacketWriter {
 	public void writeAck(Ack a) throws IOException {
 		if (payload.size() != 0) throw new IllegalStateException();
 		for (MessageId m : a.getMessageIds()) payload.write(m.getBytes());
-		writePacket(ACK);
+		writeRecord(ACK);
 	}
 
 	@Override
 	public void writeMessage(byte[] raw) throws IOException {
-		header[1] = PacketTypes.MESSAGE;
+		header[1] = RecordTypes.MESSAGE;
 		ByteUtils.writeUint16(raw.length, header, 2);
 		out.write(header);
 		out.write(raw);
@@ -64,14 +64,14 @@ class PacketWriterImpl implements PacketWriter {
 	public void writeOffer(Offer o) throws IOException {
 		if (payload.size() != 0) throw new IllegalStateException();
 		for (MessageId m : o.getMessageIds()) payload.write(m.getBytes());
-		writePacket(OFFER);
+		writeRecord(OFFER);
 	}
 
 	@Override
 	public void writeRequest(Request r) throws IOException {
 		if (payload.size() != 0) throw new IllegalStateException();
 		for (MessageId m : r.getMessageIds()) payload.write(m.getBytes());
-		writePacket(REQUEST);
+		writeRecord(REQUEST);
 	}
 
 	@Override

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

@@ -13,7 +13,7 @@ import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.lifecycle.event.ShutdownEvent;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.Ack;
-import org.briarproject.bramble.api.sync.PacketWriter;
+import org.briarproject.bramble.api.sync.RecordWriter;
 import org.briarproject.bramble.api.sync.SyncSession;
 
 import java.io.IOException;
@@ -29,12 +29,12 @@ import javax.annotation.concurrent.ThreadSafe;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.api.sync.SyncConstants.MAX_MESSAGE_IDS;
-import static org.briarproject.bramble.api.sync.SyncConstants.MAX_PACKET_PAYLOAD_LENGTH;
+import static org.briarproject.bramble.api.sync.SyncConstants.MAX_RECORD_PAYLOAD_LENGTH;
 
 /**
  * An outgoing {@link SyncSession} suitable for simplex transports. The session
  * sends messages without offering them first, and closes its output stream
- * when there are no more packets to send.
+ * when there are no more records to send.
  */
 @ThreadSafe
 @NotNullByDefault
@@ -55,7 +55,7 @@ class SimplexOutgoingSession implements SyncSession, EventListener {
 	private final EventBus eventBus;
 	private final ContactId contactId;
 	private final int maxLatency;
-	private final PacketWriter packetWriter;
+	private final RecordWriter recordWriter;
 	private final AtomicInteger outstandingQueries;
 	private final BlockingQueue<ThrowingRunnable<IOException>> writerTasks;
 
@@ -63,14 +63,14 @@ class SimplexOutgoingSession implements SyncSession, EventListener {
 
 	SimplexOutgoingSession(DatabaseComponent db, Executor dbExecutor,
 			EventBus eventBus, ContactId contactId,
-			int maxLatency, PacketWriter packetWriter) {
+			int maxLatency, RecordWriter recordWriter) {
 		this.db = db;
 		this.dbExecutor = dbExecutor;
 		this.eventBus = eventBus;
 		this.contactId = contactId;
 		this.maxLatency = maxLatency;
-		this.packetWriter = packetWriter;
-		outstandingQueries = new AtomicInteger(2); // One per type of packet
+		this.recordWriter = recordWriter;
+		outstandingQueries = new AtomicInteger(2); // One per type of record
 		writerTasks = new LinkedBlockingQueue<ThrowingRunnable<IOException>>();
 	}
 
@@ -79,19 +79,19 @@ class SimplexOutgoingSession implements SyncSession, EventListener {
 	public void run() throws IOException {
 		eventBus.addListener(this);
 		try {
-			// Start a query for each type of packet
+			// Start a query for each type of record
 			dbExecutor.execute(new GenerateAck());
 			dbExecutor.execute(new GenerateBatch());
-			// Write packets until interrupted or no more packets to write
+			// Write records until interrupted or no more records to write
 			try {
 				while (!interrupted) {
 					ThrowingRunnable<IOException> task = writerTasks.take();
 					if (task == CLOSE) break;
 					task.run();
 				}
-				packetWriter.flush();
+				recordWriter.flush();
 			} catch (InterruptedException e) {
-				LOG.info("Interrupted while waiting for a packet to write");
+				LOG.info("Interrupted while waiting for a record to write");
 				Thread.currentThread().interrupt();
 			}
 		} finally {
@@ -157,7 +157,7 @@ class SimplexOutgoingSession implements SyncSession, EventListener {
 		@Override
 		public void run() throws IOException {
 			if (interrupted) return;
-			packetWriter.writeAck(ack);
+			recordWriter.writeAck(ack);
 			LOG.info("Sent ack");
 			dbExecutor.execute(new GenerateAck());
 		}
@@ -174,7 +174,7 @@ class SimplexOutgoingSession implements SyncSession, EventListener {
 				Transaction txn = db.startTransaction(false);
 				try {
 					b = db.generateBatch(txn, contactId,
-							MAX_PACKET_PAYLOAD_LENGTH, maxLatency);
+							MAX_RECORD_PAYLOAD_LENGTH, maxLatency);
 					db.commitTransaction(txn);
 				} finally {
 					db.endTransaction(txn);
@@ -202,7 +202,7 @@ class SimplexOutgoingSession implements SyncSession, EventListener {
 		@Override
 		public void run() throws IOException {
 			if (interrupted) return;
-			for (byte[] raw : batch) packetWriter.writeMessage(raw);
+			for (byte[] raw : batch) recordWriter.writeMessage(raw);
 			LOG.info("Sent batch");
 			dbExecutor.execute(new GenerateBatch());
 		}

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

@@ -7,8 +7,8 @@ import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.sync.GroupFactory;
 import org.briarproject.bramble.api.sync.MessageFactory;
-import org.briarproject.bramble.api.sync.PacketReaderFactory;
-import org.briarproject.bramble.api.sync.PacketWriterFactory;
+import org.briarproject.bramble.api.sync.RecordReaderFactory;
+import org.briarproject.bramble.api.sync.RecordWriterFactory;
 import org.briarproject.bramble.api.sync.SyncSessionFactory;
 import org.briarproject.bramble.api.sync.ValidationManager;
 import org.briarproject.bramble.api.system.Clock;
@@ -40,23 +40,24 @@ public class SyncModule {
 	}
 
 	@Provides
-	PacketReaderFactory providePacketReaderFactory(CryptoComponent crypto) {
-		return new PacketReaderFactoryImpl(crypto);
+	RecordReaderFactory provideRecordReaderFactory(
+			RecordReaderFactoryImpl recordReaderFactory) {
+		return recordReaderFactory;
 	}
 
 	@Provides
-	PacketWriterFactory providePacketWriterFactory() {
-		return new PacketWriterFactoryImpl();
+	RecordWriterFactory provideRecordWriterFactory() {
+		return new RecordWriterFactoryImpl();
 	}
 
 	@Provides
 	@Singleton
 	SyncSessionFactory provideSyncSessionFactory(DatabaseComponent db,
 			@DatabaseExecutor Executor dbExecutor, EventBus eventBus,
-			Clock clock, PacketReaderFactory packetReaderFactory,
-			PacketWriterFactory packetWriterFactory) {
+			Clock clock, RecordReaderFactory recordReaderFactory,
+			RecordWriterFactory recordWriterFactory) {
 		return new SyncSessionFactoryImpl(db, dbExecutor, eventBus, clock,
-				packetReaderFactory, packetWriterFactory);
+				recordReaderFactory, recordWriterFactory);
 	}
 
 	@Provides

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

@@ -5,10 +5,10 @@ import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.sync.PacketReader;
-import org.briarproject.bramble.api.sync.PacketReaderFactory;
-import org.briarproject.bramble.api.sync.PacketWriter;
-import org.briarproject.bramble.api.sync.PacketWriterFactory;
+import org.briarproject.bramble.api.sync.RecordReader;
+import org.briarproject.bramble.api.sync.RecordReaderFactory;
+import org.briarproject.bramble.api.sync.RecordWriter;
+import org.briarproject.bramble.api.sync.RecordWriterFactory;
 import org.briarproject.bramble.api.sync.SyncSession;
 import org.briarproject.bramble.api.sync.SyncSessionFactory;
 import org.briarproject.bramble.api.system.Clock;
@@ -28,41 +28,41 @@ class SyncSessionFactoryImpl implements SyncSessionFactory {
 	private final Executor dbExecutor;
 	private final EventBus eventBus;
 	private final Clock clock;
-	private final PacketReaderFactory packetReaderFactory;
-	private final PacketWriterFactory packetWriterFactory;
+	private final RecordReaderFactory recordReaderFactory;
+	private final RecordWriterFactory recordWriterFactory;
 
 	@Inject
 	SyncSessionFactoryImpl(DatabaseComponent db,
 			@DatabaseExecutor Executor dbExecutor, EventBus eventBus,
-			Clock clock, PacketReaderFactory packetReaderFactory,
-			PacketWriterFactory packetWriterFactory) {
+			Clock clock, RecordReaderFactory recordReaderFactory,
+			RecordWriterFactory recordWriterFactory) {
 		this.db = db;
 		this.dbExecutor = dbExecutor;
 		this.eventBus = eventBus;
 		this.clock = clock;
-		this.packetReaderFactory = packetReaderFactory;
-		this.packetWriterFactory = packetWriterFactory;
+		this.recordReaderFactory = recordReaderFactory;
+		this.recordWriterFactory = recordWriterFactory;
 	}
 
 	@Override
 	public SyncSession createIncomingSession(ContactId c, InputStream in) {
-		PacketReader packetReader = packetReaderFactory.createPacketReader(in);
-		return new IncomingSession(db, dbExecutor, eventBus, c, packetReader);
+		RecordReader recordReader = recordReaderFactory.createRecordReader(in);
+		return new IncomingSession(db, dbExecutor, eventBus, c, recordReader);
 	}
 
 	@Override
 	public SyncSession createSimplexOutgoingSession(ContactId c,
 			int maxLatency, OutputStream out) {
-		PacketWriter packetWriter = packetWriterFactory.createPacketWriter(out);
+		RecordWriter recordWriter = recordWriterFactory.createRecordWriter(out);
 		return new SimplexOutgoingSession(db, dbExecutor, eventBus, c,
-				maxLatency, packetWriter);
+				maxLatency, recordWriter);
 	}
 
 	@Override
 	public SyncSession createDuplexOutgoingSession(ContactId c, int maxLatency,
 			int maxIdleTime, OutputStream out) {
-		PacketWriter packetWriter = packetWriterFactory.createPacketWriter(out);
+		RecordWriter recordWriter = recordWriterFactory.createRecordWriter(out);
 		return new DuplexOutgoingSession(db, dbExecutor, eventBus, clock, c,
-				maxLatency, maxIdleTime, packetWriter);
+				maxLatency, maxIdleTime, recordWriter);
 	}
 }

bramble-core/src/test/java/org/briarproject/bramble/db/DatabaseComponentImplTest.java

@@ -63,6 +63,7 @@ import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_PUBLIC_K
 import static org.briarproject.bramble.api.sync.Group.Visibility.INVISIBLE;
 import static org.briarproject.bramble.api.sync.Group.Visibility.SHARED;
 import static org.briarproject.bramble.api.sync.Group.Visibility.VISIBLE;
+import static org.briarproject.bramble.api.sync.SyncConstants.MAX_GROUP_DESCRIPTOR_LENGTH;
 import static org.briarproject.bramble.api.sync.ValidationManager.State.DELIVERED;
 import static org.briarproject.bramble.api.sync.ValidationManager.State.UNKNOWN;
 import static org.briarproject.bramble.api.transport.TransportConstants.REORDERING_WINDOW_SIZE;
@@ -95,7 +96,7 @@ public class DatabaseComponentImplTest extends BrambleTestCase {
 	public DatabaseComponentImplTest() {
 		clientId = new ClientId(TestUtils.getRandomString(5));
 		groupId = new GroupId(TestUtils.getRandomId());
-		byte[] descriptor = new byte[0];
+		byte[] descriptor = new byte[MAX_GROUP_DESCRIPTOR_LENGTH];
 		group = new Group(groupId, clientId, descriptor);
 		authorId = new AuthorId(TestUtils.getRandomId());
 		author = new Author(authorId, "Alice", new byte[MAX_PUBLIC_KEY_LENGTH]);

bramble-core/src/test/java/org/briarproject/bramble/db/H2DatabaseTest.java

@@ -47,6 +47,7 @@ import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_PUBLIC_K
 import static org.briarproject.bramble.api.sync.Group.Visibility.INVISIBLE;
 import static org.briarproject.bramble.api.sync.Group.Visibility.SHARED;
 import static org.briarproject.bramble.api.sync.Group.Visibility.VISIBLE;
+import static org.briarproject.bramble.api.sync.SyncConstants.MAX_GROUP_DESCRIPTOR_LENGTH;
 import static org.briarproject.bramble.api.sync.SyncConstants.MAX_MESSAGE_LENGTH;
 import static org.briarproject.bramble.api.sync.ValidationManager.State.DELIVERED;
 import static org.briarproject.bramble.api.sync.ValidationManager.State.INVALID;
@@ -84,7 +85,7 @@ public class H2DatabaseTest extends BrambleTestCase {
 	public H2DatabaseTest() throws Exception {
 		groupId = new GroupId(TestUtils.getRandomId());
 		clientId = new ClientId(TestUtils.getRandomString(5));
-		byte[] descriptor = new byte[0];
+		byte[] descriptor = new byte[MAX_GROUP_DESCRIPTOR_LENGTH];
 		group = new Group(groupId, clientId, descriptor);
 		AuthorId authorId = new AuthorId(TestUtils.getRandomId());
 		author = new Author(authorId, "Alice", new byte[MAX_PUBLIC_KEY_LENGTH]);
@@ -1316,7 +1317,7 @@ public class H2DatabaseTest extends BrambleTestCase {
 		// Add a second group
 		GroupId groupId1 = new GroupId(TestUtils.getRandomId());
 		Group group1 = new Group(groupId1, clientId,
-				TestUtils.getRandomBytes(42));
+				TestUtils.getRandomBytes(MAX_GROUP_DESCRIPTOR_LENGTH));
 		db.addGroup(txn, group1);
 
 		// Add a message to the second group

bramble-core/src/test/java/org/briarproject/bramble/keyagreement/KeyAgreementProtocolTest.java

@@ -92,7 +92,7 @@ public class KeyAgreementProtocolTest extends BrambleTestCase {
 			oneOf(callbacks).connectionWaiting();
 			oneOf(transport).receiveKey();
 			will(returnValue(BOB_PUBKEY));
-			oneOf(callbacks).initialPacketReceived();
+			oneOf(callbacks).initialRecordReceived();
 
 			// Alice verifies Bob's public key
 			oneOf(crypto).deriveKeyCommitment(BOB_PUBKEY);
@@ -152,7 +152,7 @@ public class KeyAgreementProtocolTest extends BrambleTestCase {
 			// Bob receives Alice's public key
 			oneOf(transport).receiveKey();
 			will(returnValue(ALICE_PUBKEY));
-			oneOf(callbacks).initialPacketReceived();
+			oneOf(callbacks).initialRecordReceived();
 
 			// Bob verifies Alice's public key
 			oneOf(crypto).deriveKeyCommitment(ALICE_PUBKEY);
@@ -213,7 +213,7 @@ public class KeyAgreementProtocolTest extends BrambleTestCase {
 			oneOf(callbacks).connectionWaiting();
 			oneOf(transport).receiveKey();
 			will(returnValue(BAD_PUBKEY));
-			oneOf(callbacks).initialPacketReceived();
+			oneOf(callbacks).initialRecordReceived();
 
 			// Alice verifies Bob's public key
 			oneOf(crypto).deriveKeyCommitment(BAD_PUBKEY);
@@ -250,7 +250,7 @@ public class KeyAgreementProtocolTest extends BrambleTestCase {
 			// Bob receives a bad public key
 			oneOf(transport).receiveKey();
 			will(returnValue(BAD_PUBKEY));
-			oneOf(callbacks).initialPacketReceived();
+			oneOf(callbacks).initialRecordReceived();
 
 			// Bob verifies Alice's public key
 			oneOf(crypto).deriveKeyCommitment(BAD_PUBKEY);
@@ -296,7 +296,7 @@ public class KeyAgreementProtocolTest extends BrambleTestCase {
 			oneOf(callbacks).connectionWaiting();
 			oneOf(transport).receiveKey();
 			will(returnValue(BOB_PUBKEY));
-			oneOf(callbacks).initialPacketReceived();
+			oneOf(callbacks).initialRecordReceived();
 
 			// Alice verifies Bob's public key
 			oneOf(crypto).deriveKeyCommitment(BOB_PUBKEY);
@@ -357,7 +357,7 @@ public class KeyAgreementProtocolTest extends BrambleTestCase {
 			// Bob receives Alice's public key
 			oneOf(transport).receiveKey();
 			will(returnValue(ALICE_PUBKEY));
-			oneOf(callbacks).initialPacketReceived();
+			oneOf(callbacks).initialRecordReceived();
 
 			// Bob verifies Alice's public key
 			oneOf(crypto).deriveKeyCommitment(ALICE_PUBKEY);

bramble-core/src/test/java/org/briarproject/bramble/keyagreement/KeyAgreementTransportTest.java

@@ -0,0 +1,251 @@
+package org.briarproject.bramble.keyagreement;
+
+import org.briarproject.bramble.api.keyagreement.KeyAgreementConnection;
+import org.briarproject.bramble.api.plugin.TransportConnectionReader;
+import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
+import org.briarproject.bramble.api.plugin.TransportId;
+import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
+import org.briarproject.bramble.test.BrambleMockTestCase;
+import org.briarproject.bramble.test.TestUtils;
+import org.briarproject.bramble.util.ByteUtils;
+import org.jmock.Expectations;
+import org.junit.Test;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+
+import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.PROTOCOL_VERSION;
+import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.RECORD_HEADER_LENGTH;
+import static org.briarproject.bramble.api.keyagreement.RecordTypes.ABORT;
+import static org.briarproject.bramble.api.keyagreement.RecordTypes.CONFIRM;
+import static org.briarproject.bramble.api.keyagreement.RecordTypes.KEY;
+import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertEquals;
+
+public class KeyAgreementTransportTest extends BrambleMockTestCase {
+
+	private final DuplexTransportConnection duplexTransportConnection =
+			context.mock(DuplexTransportConnection.class);
+	private final TransportConnectionReader transportConnectionReader =
+			context.mock(TransportConnectionReader.class);
+	private final TransportConnectionWriter transportConnectionWriter =
+			context.mock(TransportConnectionWriter.class);
+
+	private final TransportId transportId = new TransportId("test");
+	private final KeyAgreementConnection keyAgreementConnection =
+			new KeyAgreementConnection(duplexTransportConnection, transportId);
+
+	private ByteArrayInputStream inputStream;
+	private ByteArrayOutputStream outputStream;
+	private KeyAgreementTransport kat;
+
+	@Test
+	public void testSendKey() throws Exception {
+		setup(new byte[0]);
+		byte[] key = TestUtils.getRandomBytes(123);
+		kat.sendKey(key);
+		assertRecordSent(KEY, key);
+	}
+
+	@Test
+	public void testSendConfirm() throws Exception {
+		setup(new byte[0]);
+		byte[] confirm = TestUtils.getRandomBytes(123);
+		kat.sendConfirm(confirm);
+		assertRecordSent(CONFIRM, confirm);
+	}
+
+	@Test
+	public void testSendAbortWithException() throws Exception {
+		setup(new byte[0]);
+		context.checking(new Expectations() {{
+			oneOf(transportConnectionReader).dispose(true, true);
+			oneOf(transportConnectionWriter).dispose(true);
+		}});
+		kat.sendAbort(true);
+		assertRecordSent(ABORT, new byte[0]);
+	}
+
+	@Test
+	public void testSendAbortWithoutException() throws Exception {
+		setup(new byte[0]);
+		context.checking(new Expectations() {{
+			oneOf(transportConnectionReader).dispose(false, true);
+			oneOf(transportConnectionWriter).dispose(false);
+		}});
+		kat.sendAbort(false);
+		assertRecordSent(ABORT, new byte[0]);
+	}
+
+	@Test(expected = AbortException.class)
+	public void testReceiveKeyThrowsExceptionIfAtEndOfStream()
+			throws Exception {
+		setup(new byte[0]);
+		kat.receiveKey();
+	}
+
+	@Test(expected = AbortException.class)
+	public void testReceiveKeyThrowsExceptionIfHeaderIsTooShort()
+			throws Exception {
+		byte[] input = new byte[RECORD_HEADER_LENGTH - 1];
+		input[0] = PROTOCOL_VERSION;
+		input[1] = KEY;
+		setup(input);
+		kat.receiveKey();
+	}
+
+	@Test(expected = AbortException.class)
+	public void testReceiveKeyThrowsExceptionIfPayloadIsTooShort()
+			throws Exception {
+		int payloadLength = 123;
+		byte[] input = new byte[RECORD_HEADER_LENGTH + payloadLength - 1];
+		input[0] = PROTOCOL_VERSION;
+		input[1] = KEY;
+		ByteUtils.writeUint16(payloadLength, input, 2);
+		setup(input);
+		kat.receiveKey();
+	}
+
+	@Test(expected = AbortException.class)
+	public void testReceiveKeyThrowsExceptionIfProtocolVersionIsUnrecognised()
+			throws Exception {
+		setup(createRecord((byte) (PROTOCOL_VERSION + 1), KEY, new byte[123]));
+		kat.receiveKey();
+	}
+
+	@Test(expected = AbortException.class)
+	public void testReceiveKeyThrowsExceptionIfAbortIsReceived()
+			throws Exception {
+		setup(createRecord(PROTOCOL_VERSION, ABORT, new byte[0]));
+		kat.receiveKey();
+	}
+
+	@Test(expected = AbortException.class)
+	public void testReceiveKeyThrowsExceptionIfConfirmIsReceived()
+			throws Exception {
+		setup(createRecord(PROTOCOL_VERSION, CONFIRM, new byte[123]));
+		kat.receiveKey();
+	}
+
+	@Test
+	public void testReceiveKeySkipsUnrecognisedRecordTypes() throws Exception {
+		byte[] skip1 = createRecord(PROTOCOL_VERSION, (byte) (ABORT + 1),
+				new byte[123]);
+		byte[] skip2 = createRecord(PROTOCOL_VERSION, (byte) (ABORT + 2),
+				new byte[0]);
+		byte[] payload = TestUtils.getRandomBytes(123);
+		byte[] key = createRecord(PROTOCOL_VERSION, KEY, payload);
+		ByteArrayOutputStream input = new ByteArrayOutputStream();
+		input.write(skip1);
+		input.write(skip2);
+		input.write(key);
+		setup(input.toByteArray());
+		assertArrayEquals(payload, kat.receiveKey());
+	}
+
+	@Test(expected = AbortException.class)
+	public void testReceiveConfirmThrowsExceptionIfAtEndOfStream()
+			throws Exception {
+		setup(new byte[0]);
+		kat.receiveConfirm();
+	}
+
+	@Test(expected = AbortException.class)
+	public void testReceiveConfirmThrowsExceptionIfHeaderIsTooShort()
+			throws Exception {
+		byte[] input = new byte[RECORD_HEADER_LENGTH - 1];
+		input[0] = PROTOCOL_VERSION;
+		input[1] = CONFIRM;
+		setup(input);
+		kat.receiveConfirm();
+	}
+
+	@Test(expected = AbortException.class)
+	public void testReceiveConfirmThrowsExceptionIfPayloadIsTooShort()
+			throws Exception {
+		int payloadLength = 123;
+		byte[] input = new byte[RECORD_HEADER_LENGTH + payloadLength - 1];
+		input[0] = PROTOCOL_VERSION;
+		input[1] = CONFIRM;
+		ByteUtils.writeUint16(payloadLength, input, 2);
+		setup(input);
+		kat.receiveConfirm();
+	}
+
+	@Test(expected = AbortException.class)
+	public void testReceiveConfirmThrowsExceptionIfProtocolVersionIsUnrecognised()
+			throws Exception {
+		setup(createRecord((byte) (PROTOCOL_VERSION + 1), CONFIRM,
+				new byte[123]));
+		kat.receiveConfirm();
+	}
+
+	@Test(expected = AbortException.class)
+	public void testReceiveConfirmThrowsExceptionIfAbortIsReceived()
+			throws Exception {
+		setup(createRecord(PROTOCOL_VERSION, ABORT, new byte[0]));
+		kat.receiveConfirm();
+	}
+
+	@Test(expected = AbortException.class)
+	public void testReceiveKeyThrowsExceptionIfKeyIsReceived()
+			throws Exception {
+		setup(createRecord(PROTOCOL_VERSION, KEY, new byte[123]));
+		kat.receiveConfirm();
+	}
+
+	@Test
+	public void testReceiveConfirmSkipsUnrecognisedRecordTypes()
+			throws Exception {
+		byte[] skip1 = createRecord(PROTOCOL_VERSION, (byte) (ABORT + 1),
+				new byte[123]);
+		byte[] skip2 = createRecord(PROTOCOL_VERSION, (byte) (ABORT + 2),
+				new byte[0]);
+		byte[] payload = TestUtils.getRandomBytes(123);
+		byte[] confirm = createRecord(PROTOCOL_VERSION, CONFIRM, payload);
+		ByteArrayOutputStream input = new ByteArrayOutputStream();
+		input.write(skip1);
+		input.write(skip2);
+		input.write(confirm);
+		setup(input.toByteArray());
+		assertArrayEquals(payload, kat.receiveConfirm());
+	}
+
+	private void setup(byte[] input) throws Exception {
+		inputStream = new ByteArrayInputStream(input);
+		outputStream = new ByteArrayOutputStream();
+		context.checking(new Expectations() {{
+			allowing(duplexTransportConnection).getReader();
+			will(returnValue(transportConnectionReader));
+			allowing(transportConnectionReader).getInputStream();
+			will(returnValue(inputStream));
+			allowing(duplexTransportConnection).getWriter();
+			will(returnValue(transportConnectionWriter));
+			allowing(transportConnectionWriter).getOutputStream();
+			will(returnValue(outputStream));
+		}});
+		kat = new KeyAgreementTransport(keyAgreementConnection);
+	}
+
+	private void assertRecordSent(byte expectedType, byte[] expectedPayload) {
+		byte[] output = outputStream.toByteArray();
+		assertEquals(RECORD_HEADER_LENGTH + expectedPayload.length,
+				output.length);
+		assertEquals(PROTOCOL_VERSION, output[0]);
+		assertEquals(expectedType, output[1]);
+		assertEquals(expectedPayload.length, ByteUtils.readUint16(output, 2));
+		byte[] payload = new byte[output.length - RECORD_HEADER_LENGTH];
+		System.arraycopy(output, RECORD_HEADER_LENGTH, payload, 0,
+				payload.length);
+		assertArrayEquals(expectedPayload, payload);
+	}
+
+	private byte[] createRecord(byte version, byte type, byte[] payload) {
+		byte[] b = new byte[RECORD_HEADER_LENGTH + payload.length];
+		b[0] = version;
+		b[1] = type;
+		ByteUtils.writeUint16(payload.length, b, 2);
+		System.arraycopy(payload, 0, b, RECORD_HEADER_LENGTH, payload.length);
+		return b;
+	}
+}

bramble-core/src/test/java/org/briarproject/bramble/sync/PacketReaderImplTest.java

@@ -1,162 +0,0 @@
-package org.briarproject.bramble.sync;
-
-import org.briarproject.bramble.api.FormatException;
-import org.briarproject.bramble.api.UniqueId;
-import org.briarproject.bramble.test.BrambleTestCase;
-import org.briarproject.bramble.test.TestUtils;
-import org.briarproject.bramble.util.ByteUtils;
-import org.junit.Test;
-
-import java.io.ByteArrayInputStream;
-import java.io.ByteArrayOutputStream;
-
-import static org.briarproject.bramble.api.sync.PacketTypes.ACK;
-import static org.briarproject.bramble.api.sync.PacketTypes.OFFER;
-import static org.briarproject.bramble.api.sync.PacketTypes.REQUEST;
-import static org.briarproject.bramble.api.sync.SyncConstants.MAX_PACKET_PAYLOAD_LENGTH;
-import static org.briarproject.bramble.api.sync.SyncConstants.PACKET_HEADER_LENGTH;
-import static org.junit.Assert.assertEquals;
-
-public class PacketReaderImplTest extends BrambleTestCase {
-
-	@Test(expected = FormatException.class)
-	public void testFormatExceptionIfAckIsTooLarge() throws Exception {
-		byte[] b = createAck(true);
-		ByteArrayInputStream in = new ByteArrayInputStream(b);
-		PacketReaderImpl reader = new PacketReaderImpl(null, in);
-		reader.readAck();
-	}
-
-	@Test
-	public void testNoFormatExceptionIfAckIsMaximumSize() throws Exception {
-		byte[] b = createAck(false);
-		ByteArrayInputStream in = new ByteArrayInputStream(b);
-		PacketReaderImpl reader = new PacketReaderImpl(null, in);
-		reader.readAck();
-	}
-
-	@Test(expected = FormatException.class)
-	public void testEmptyAck() throws Exception {
-		byte[] b = createEmptyAck();
-		ByteArrayInputStream in = new ByteArrayInputStream(b);
-		PacketReaderImpl reader = new PacketReaderImpl(null, in);
-		reader.readAck();
-	}
-
-	@Test(expected = FormatException.class)
-	public void testFormatExceptionIfOfferIsTooLarge() throws Exception {
-		byte[] b = createOffer(true);
-		ByteArrayInputStream in = new ByteArrayInputStream(b);
-		PacketReaderImpl reader = new PacketReaderImpl(null, in);
-		reader.readOffer();
-	}
-
-	@Test
-	public void testNoFormatExceptionIfOfferIsMaximumSize() throws Exception {
-		byte[] b = createOffer(false);
-		ByteArrayInputStream in = new ByteArrayInputStream(b);
-		PacketReaderImpl reader = new PacketReaderImpl(null, in);
-		reader.readOffer();
-	}
-
-	@Test(expected = FormatException.class)
-	public void testEmptyOffer() throws Exception {
-		byte[] b = createEmptyOffer();
-		ByteArrayInputStream in = new ByteArrayInputStream(b);
-		PacketReaderImpl reader = new PacketReaderImpl(null, in);
-		reader.readOffer();
-	}
-
-	@Test(expected = FormatException.class)
-	public void testFormatExceptionIfRequestIsTooLarge() throws Exception {
-		byte[] b = createRequest(true);
-		ByteArrayInputStream in = new ByteArrayInputStream(b);
-		PacketReaderImpl reader = new PacketReaderImpl(null, in);
-		reader.readRequest();
-	}
-
-	@Test
-	public void testNoFormatExceptionIfRequestIsMaximumSize() throws Exception {
-		byte[] b = createRequest(false);
-		ByteArrayInputStream in = new ByteArrayInputStream(b);
-		PacketReaderImpl reader = new PacketReaderImpl(null, in);
-		reader.readRequest();
-	}
-
-	@Test(expected = FormatException.class)
-	public void testEmptyRequest() throws Exception {
-		byte[] b = createEmptyRequest();
-		ByteArrayInputStream in = new ByteArrayInputStream(b);
-		PacketReaderImpl reader = new PacketReaderImpl(null, in);
-		reader.readRequest();
-	}
-
-	private byte[] createAck(boolean tooBig) throws Exception {
-		ByteArrayOutputStream out = new ByteArrayOutputStream();
-		out.write(new byte[PACKET_HEADER_LENGTH]);
-		while (out.size() + UniqueId.LENGTH <= PACKET_HEADER_LENGTH
-				+ MAX_PACKET_PAYLOAD_LENGTH) {
-			out.write(TestUtils.getRandomId());
-		}
-		if (tooBig) out.write(TestUtils.getRandomId());
-		assertEquals(tooBig, out.size() > PACKET_HEADER_LENGTH +
-				MAX_PACKET_PAYLOAD_LENGTH);
-		byte[] packet = out.toByteArray();
-		packet[1] = ACK;
-		ByteUtils.writeUint16(packet.length - PACKET_HEADER_LENGTH, packet, 2);
-		return packet;
-	}
-
-	private byte[] createEmptyAck() throws Exception {
-		byte[] packet = new byte[PACKET_HEADER_LENGTH];
-		packet[1] = ACK;
-		ByteUtils.writeUint16(packet.length - PACKET_HEADER_LENGTH, packet, 2);
-		return packet;
-	}
-
-	private byte[] createOffer(boolean tooBig) throws Exception {
-		ByteArrayOutputStream out = new ByteArrayOutputStream();
-		out.write(new byte[PACKET_HEADER_LENGTH]);
-		while (out.size() + UniqueId.LENGTH <= PACKET_HEADER_LENGTH
-				+ MAX_PACKET_PAYLOAD_LENGTH) {
-			out.write(TestUtils.getRandomId());
-		}
-		if (tooBig) out.write(TestUtils.getRandomId());
-		assertEquals(tooBig, out.size() > PACKET_HEADER_LENGTH +
-				MAX_PACKET_PAYLOAD_LENGTH);
-		byte[] packet = out.toByteArray();
-		packet[1] = OFFER;
-		ByteUtils.writeUint16(packet.length - PACKET_HEADER_LENGTH, packet, 2);
-		return packet;
-	}
-
-	private byte[] createEmptyOffer() throws Exception {
-		byte[] packet = new byte[PACKET_HEADER_LENGTH];
-		packet[1] = OFFER;
-		ByteUtils.writeUint16(packet.length - PACKET_HEADER_LENGTH, packet, 2);
-		return packet;
-	}
-
-	private byte[] createRequest(boolean tooBig) throws Exception {
-		ByteArrayOutputStream out = new ByteArrayOutputStream();
-		out.write(new byte[PACKET_HEADER_LENGTH]);
-		while (out.size() + UniqueId.LENGTH <= PACKET_HEADER_LENGTH
-				+ MAX_PACKET_PAYLOAD_LENGTH) {
-			out.write(TestUtils.getRandomId());
-		}
-		if (tooBig) out.write(TestUtils.getRandomId());
-		assertEquals(tooBig, out.size() > PACKET_HEADER_LENGTH +
-				MAX_PACKET_PAYLOAD_LENGTH);
-		byte[] packet = out.toByteArray();
-		packet[1] = REQUEST;
-		ByteUtils.writeUint16(packet.length - PACKET_HEADER_LENGTH, packet, 2);
-		return packet;
-	}
-
-	private byte[] createEmptyRequest() throws Exception {
-		byte[] packet = new byte[PACKET_HEADER_LENGTH];
-		packet[1] = REQUEST;
-		ByteUtils.writeUint16(packet.length - PACKET_HEADER_LENGTH, packet, 2);
-		return packet;
-	}
-}

bramble-core/src/test/java/org/briarproject/bramble/sync/RecordReaderImplTest.java

@@ -0,0 +1,219 @@
+package org.briarproject.bramble.sync;
+
+import org.briarproject.bramble.api.FormatException;
+import org.briarproject.bramble.api.UniqueId;
+import org.briarproject.bramble.api.sync.Ack;
+import org.briarproject.bramble.api.sync.MessageFactory;
+import org.briarproject.bramble.test.BrambleMockTestCase;
+import org.briarproject.bramble.test.TestUtils;
+import org.briarproject.bramble.util.ByteUtils;
+import org.junit.Test;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+
+import static org.briarproject.bramble.api.sync.RecordTypes.ACK;
+import static org.briarproject.bramble.api.sync.RecordTypes.OFFER;
+import static org.briarproject.bramble.api.sync.RecordTypes.REQUEST;
+import static org.briarproject.bramble.api.sync.SyncConstants.MAX_MESSAGE_IDS;
+import static org.briarproject.bramble.api.sync.SyncConstants.MAX_RECORD_PAYLOAD_LENGTH;
+import static org.briarproject.bramble.api.sync.SyncConstants.PROTOCOL_VERSION;
+import static org.briarproject.bramble.api.sync.SyncConstants.RECORD_HEADER_LENGTH;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+public class RecordReaderImplTest extends BrambleMockTestCase {
+
+	private final MessageFactory messageFactory =
+			context.mock(MessageFactory.class);
+
+	@Test(expected = FormatException.class)
+	public void testFormatExceptionIfAckIsTooLarge() throws Exception {
+		byte[] b = createAck(true);
+		ByteArrayInputStream in = new ByteArrayInputStream(b);
+		RecordReaderImpl reader = new RecordReaderImpl(messageFactory, in);
+		reader.readAck();
+	}
+
+	@Test
+	public void testNoFormatExceptionIfAckIsMaximumSize() throws Exception {
+		byte[] b = createAck(false);
+		ByteArrayInputStream in = new ByteArrayInputStream(b);
+		RecordReaderImpl reader = new RecordReaderImpl(messageFactory, in);
+		reader.readAck();
+	}
+
+	@Test(expected = FormatException.class)
+	public void testFormatExceptionIfAckIsEmpty() throws Exception {
+		byte[] b = createEmptyAck();
+		ByteArrayInputStream in = new ByteArrayInputStream(b);
+		RecordReaderImpl reader = new RecordReaderImpl(messageFactory, in);
+		reader.readAck();
+	}
+
+	@Test(expected = FormatException.class)
+	public void testFormatExceptionIfOfferIsTooLarge() throws Exception {
+		byte[] b = createOffer(true);
+		ByteArrayInputStream in = new ByteArrayInputStream(b);
+		RecordReaderImpl reader = new RecordReaderImpl(messageFactory, in);
+		reader.readOffer();
+	}
+
+	@Test
+	public void testNoFormatExceptionIfOfferIsMaximumSize() throws Exception {
+		byte[] b = createOffer(false);
+		ByteArrayInputStream in = new ByteArrayInputStream(b);
+		RecordReaderImpl reader = new RecordReaderImpl(messageFactory, in);
+		reader.readOffer();
+	}
+
+	@Test(expected = FormatException.class)
+	public void testFormatExceptionIfOfferIsEmpty() throws Exception {
+		byte[] b = createEmptyOffer();
+		ByteArrayInputStream in = new ByteArrayInputStream(b);
+		RecordReaderImpl reader = new RecordReaderImpl(messageFactory, in);
+		reader.readOffer();
+	}
+
+	@Test(expected = FormatException.class)
+	public void testFormatExceptionIfRequestIsTooLarge() throws Exception {
+		byte[] b = createRequest(true);
+		ByteArrayInputStream in = new ByteArrayInputStream(b);
+		RecordReaderImpl reader = new RecordReaderImpl(messageFactory, in);
+		reader.readRequest();
+	}
+
+	@Test
+	public void testNoFormatExceptionIfRequestIsMaximumSize() throws Exception {
+		byte[] b = createRequest(false);
+		ByteArrayInputStream in = new ByteArrayInputStream(b);
+		RecordReaderImpl reader = new RecordReaderImpl(messageFactory, in);
+		reader.readRequest();
+	}
+
+	@Test(expected = FormatException.class)
+	public void testFormatExceptionIfRequestIsEmpty() throws Exception {
+		byte[] b = createEmptyRequest();
+		ByteArrayInputStream in = new ByteArrayInputStream(b);
+		RecordReaderImpl reader = new RecordReaderImpl(messageFactory, in);
+		reader.readRequest();
+	}
+
+	@Test
+	public void testEofReturnsTrueWhenAtEndOfStream() throws Exception {
+		ByteArrayInputStream in = new ByteArrayInputStream(new byte[0]);
+		RecordReaderImpl reader = new RecordReaderImpl(messageFactory, in);
+		assertTrue(reader.eof());
+	}
+
+	@Test
+	public void testEofReturnsFalseWhenNotAtEndOfStream() throws Exception {
+		byte[] b = createAck(false);
+		ByteArrayInputStream in = new ByteArrayInputStream(b);
+		RecordReaderImpl reader = new RecordReaderImpl(messageFactory, in);
+		assertFalse(reader.eof());
+	}
+
+	@Test(expected = FormatException.class)
+	public void testThrowsExceptionIfHeaderIsTooShort() throws Exception {
+		byte[] b = new byte[RECORD_HEADER_LENGTH - 1];
+		b[0] = PROTOCOL_VERSION;
+		b[1] = ACK;
+		ByteArrayInputStream in = new ByteArrayInputStream(b);
+		RecordReaderImpl reader = new RecordReaderImpl(messageFactory, in);
+		reader.eof();
+	}
+
+	@Test(expected = FormatException.class)
+	public void testThrowsExceptionIfPayloadIsTooShort() throws Exception {
+		int payloadLength = 123;
+		byte[] b = new byte[RECORD_HEADER_LENGTH + payloadLength - 1];
+		b[0] = PROTOCOL_VERSION;
+		b[1] = ACK;
+		ByteUtils.writeUint16(payloadLength, b, 2);
+		ByteArrayInputStream in = new ByteArrayInputStream(b);
+		RecordReaderImpl reader = new RecordReaderImpl(messageFactory, in);
+		reader.eof();
+	}
+
+	@Test(expected = FormatException.class)
+	public void testThrowsExceptionIfProtocolVersionIsUnrecognised()
+			throws Exception {
+		byte version = (byte) (PROTOCOL_VERSION + 1);
+		byte[] b = createRecord(version, ACK, new byte[0]);
+		ByteArrayInputStream in = new ByteArrayInputStream(b);
+		RecordReaderImpl reader = new RecordReaderImpl(messageFactory, in);
+		reader.eof();
+	}
+
+	@Test(expected = FormatException.class)
+	public void testThrowsExceptionIfPayloadIsTooLong() throws Exception {
+		byte[] payload = new byte[MAX_RECORD_PAYLOAD_LENGTH + 1];
+		byte[] b = createRecord(PROTOCOL_VERSION, ACK, payload);
+		ByteArrayInputStream in = new ByteArrayInputStream(b);
+		RecordReaderImpl reader = new RecordReaderImpl(messageFactory, in);
+		reader.eof();
+	}
+
+	@Test
+	public void testSkipsUnrecognisedRecordTypes() throws Exception {
+		byte[] skip1 = createRecord(PROTOCOL_VERSION, (byte) (REQUEST + 1),
+				new byte[123]);
+		byte[] skip2 = createRecord(PROTOCOL_VERSION, (byte) (REQUEST + 2),
+				new byte[0]);
+		byte[] ack = createAck(false);
+		ByteArrayOutputStream input = new ByteArrayOutputStream();
+		input.write(skip1);
+		input.write(skip2);
+		input.write(ack);
+		ByteArrayInputStream in = new ByteArrayInputStream(input.toByteArray());
+		RecordReaderImpl reader = new RecordReaderImpl(messageFactory, in);
+		assertTrue(reader.hasAck());
+		Ack a = reader.readAck();
+		assertEquals(MAX_MESSAGE_IDS, a.getMessageIds().size());
+	}
+
+	private byte[] createAck(boolean tooBig) throws Exception {
+		return createRecord(PROTOCOL_VERSION, ACK, createPayload(tooBig));
+	}
+
+	private byte[] createEmptyAck() throws Exception {
+		return createRecord(PROTOCOL_VERSION, ACK, new byte[0]);
+	}
+
+	private byte[] createOffer(boolean tooBig) throws Exception {
+		return createRecord(PROTOCOL_VERSION, OFFER, createPayload(tooBig));
+	}
+
+	private byte[] createEmptyOffer() throws Exception {
+		return createRecord(PROTOCOL_VERSION, OFFER, new byte[0]);
+	}
+
+	private byte[] createRequest(boolean tooBig) throws Exception {
+		return createRecord(PROTOCOL_VERSION, REQUEST, createPayload(tooBig));
+	}
+
+	private byte[] createEmptyRequest() throws Exception {
+		return createRecord(PROTOCOL_VERSION, REQUEST, new byte[0]);
+	}
+
+	private byte[] createRecord(byte version, byte type, byte[] payload) {
+		byte[] b = new byte[RECORD_HEADER_LENGTH + payload.length];
+		b[0] = version;
+		b[1] = type;
+		ByteUtils.writeUint16(payload.length, b, 2);
+		System.arraycopy(payload, 0, b, RECORD_HEADER_LENGTH, payload.length);
+		return b;
+	}
+
+	private byte[] createPayload(boolean tooBig) throws Exception {
+		ByteArrayOutputStream payload = new ByteArrayOutputStream();
+		while (payload.size() + UniqueId.LENGTH <= MAX_RECORD_PAYLOAD_LENGTH) {
+			payload.write(TestUtils.getRandomId());
+		}
+		if (tooBig) payload.write(TestUtils.getRandomId());
+		assertEquals(tooBig, payload.size() > MAX_RECORD_PAYLOAD_LENGTH);
+		return payload.toByteArray();
+	}
+}

bramble-core/src/test/java/org/briarproject/bramble/sync/SimplexOutgoingSessionTest.java

@@ -6,10 +6,10 @@ import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.sync.Ack;
 import org.briarproject.bramble.api.sync.MessageId;
-import org.briarproject.bramble.api.sync.PacketWriter;
 import org.briarproject.bramble.test.BrambleTestCase;
 import org.briarproject.bramble.test.ImmediateExecutor;
 import org.briarproject.bramble.test.TestUtils;
+import org.briarproject.bramble.api.sync.RecordWriter;
 import org.jmock.Expectations;
 import org.jmock.Mockery;
 import org.junit.Test;
@@ -29,14 +29,14 @@ public class SimplexOutgoingSessionTest extends BrambleTestCase {
 	private final ContactId contactId;
 	private final MessageId messageId;
 	private final int maxLatency;
-	private final PacketWriter packetWriter;
+	private final RecordWriter recordWriter;
 
 	public SimplexOutgoingSessionTest() {
 		context = new Mockery();
 		db = context.mock(DatabaseComponent.class);
 		dbExecutor = new ImmediateExecutor();
 		eventBus = context.mock(EventBus.class);
-		packetWriter = context.mock(PacketWriter.class);
+		recordWriter = context.mock(RecordWriter.class);
 		contactId = new ContactId(234);
 		messageId = new MessageId(TestUtils.getRandomId());
 		maxLatency = Integer.MAX_VALUE;
@@ -45,7 +45,7 @@ public class SimplexOutgoingSessionTest extends BrambleTestCase {
 	@Test
 	public void testNothingToSend() throws Exception {
 		final SimplexOutgoingSession session = new SimplexOutgoingSession(db,
-				dbExecutor, eventBus, contactId, maxLatency, packetWriter);
+				dbExecutor, eventBus, contactId, maxLatency, recordWriter);
 		final Transaction noAckTxn = new Transaction(null, false);
 		final Transaction noMsgTxn = new Transaction(null, false);
 
@@ -68,7 +68,7 @@ public class SimplexOutgoingSessionTest extends BrambleTestCase {
 			oneOf(db).commitTransaction(noMsgTxn);
 			oneOf(db).endTransaction(noMsgTxn);
 			// Flush the output stream
-			oneOf(packetWriter).flush();
+			oneOf(recordWriter).flush();
 			// Remove listener
 			oneOf(eventBus).removeListener(session);
 		}});
@@ -83,7 +83,7 @@ public class SimplexOutgoingSessionTest extends BrambleTestCase {
 		final Ack ack = new Ack(Collections.singletonList(messageId));
 		final byte[] raw = new byte[1234];
 		final SimplexOutgoingSession session = new SimplexOutgoingSession(db,
-				dbExecutor, eventBus, contactId, maxLatency, packetWriter);
+				dbExecutor, eventBus, contactId, maxLatency, recordWriter);
 		final Transaction ackTxn = new Transaction(null, false);
 		final Transaction noAckTxn = new Transaction(null, false);
 		final Transaction msgTxn = new Transaction(null, false);
@@ -99,7 +99,7 @@ public class SimplexOutgoingSessionTest extends BrambleTestCase {
 			will(returnValue(ack));
 			oneOf(db).commitTransaction(ackTxn);
 			oneOf(db).endTransaction(ackTxn);
-			oneOf(packetWriter).writeAck(ack);
+			oneOf(recordWriter).writeAck(ack);
 			// One message to send
 			oneOf(db).startTransaction(false);
 			will(returnValue(msgTxn));
@@ -108,7 +108,7 @@ public class SimplexOutgoingSessionTest extends BrambleTestCase {
 			will(returnValue(Arrays.asList(raw)));
 			oneOf(db).commitTransaction(msgTxn);
 			oneOf(db).endTransaction(msgTxn);
-			oneOf(packetWriter).writeMessage(raw);
+			oneOf(recordWriter).writeMessage(raw);
 			// No more acks
 			oneOf(db).startTransaction(false);
 			will(returnValue(noAckTxn));
@@ -125,7 +125,7 @@ public class SimplexOutgoingSessionTest extends BrambleTestCase {
 			oneOf(db).commitTransaction(noMsgTxn);
 			oneOf(db).endTransaction(noMsgTxn);
 			// Flush the output stream
-			oneOf(packetWriter).flush();
+			oneOf(recordWriter).flush();
 			// Remove listener
 			oneOf(eventBus).removeListener(session);
 		}});

bramble-core/src/test/java/org/briarproject/bramble/sync/SyncIntegrationTest.java

@@ -12,10 +12,10 @@ import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageFactory;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.sync.Offer;
-import org.briarproject.bramble.api.sync.PacketReader;
-import org.briarproject.bramble.api.sync.PacketReaderFactory;
-import org.briarproject.bramble.api.sync.PacketWriter;
-import org.briarproject.bramble.api.sync.PacketWriterFactory;
+import org.briarproject.bramble.api.sync.RecordReader;
+import org.briarproject.bramble.api.sync.RecordReaderFactory;
+import org.briarproject.bramble.api.sync.RecordWriter;
+import org.briarproject.bramble.api.sync.RecordWriterFactory;
 import org.briarproject.bramble.api.sync.Request;
 import org.briarproject.bramble.api.transport.StreamContext;
 import org.briarproject.bramble.api.transport.StreamReaderFactory;
@@ -33,6 +33,7 @@ import java.util.Collection;
 
 import javax.inject.Inject;
 
+import static org.briarproject.bramble.api.sync.SyncConstants.MAX_GROUP_DESCRIPTOR_LENGTH;
 import static org.briarproject.bramble.api.transport.TransportConstants.TAG_LENGTH;
 import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;
@@ -50,9 +51,9 @@ public class SyncIntegrationTest extends BrambleTestCase {
 	@Inject
 	StreamWriterFactory streamWriterFactory;
 	@Inject
-	PacketReaderFactory packetReaderFactory;
+	RecordReaderFactory recordReaderFactory;
 	@Inject
-	PacketWriterFactory packetWriterFactory;
+	RecordWriterFactory recordWriterFactory;
 	@Inject
 	CryptoComponent crypto;
 
@@ -77,7 +78,7 @@ public class SyncIntegrationTest extends BrambleTestCase {
 		streamNumber = 123;
 		// Create a group
 		ClientId clientId = new ClientId(TestUtils.getRandomString(5));
-		byte[] descriptor = new byte[0];
+		byte[] descriptor = new byte[MAX_GROUP_DESCRIPTOR_LENGTH];
 		Group group = groupFactory.createGroup(clientId, descriptor);
 		// Add two messages to the group
 		long timestamp = System.currentTimeMillis();
@@ -98,14 +99,14 @@ public class SyncIntegrationTest extends BrambleTestCase {
 				headerKey, streamNumber);
 		OutputStream streamWriter = streamWriterFactory.createStreamWriter(out,
 				ctx);
-		PacketWriter packetWriter = packetWriterFactory.createPacketWriter(
+		RecordWriter recordWriter = recordWriterFactory.createRecordWriter(
 				streamWriter);
 
-		packetWriter.writeAck(new Ack(messageIds));
-		packetWriter.writeMessage(message.getRaw());
-		packetWriter.writeMessage(message1.getRaw());
-		packetWriter.writeOffer(new Offer(messageIds));
-		packetWriter.writeRequest(new Request(messageIds));
+		recordWriter.writeAck(new Ack(messageIds));
+		recordWriter.writeMessage(message.getRaw());
+		recordWriter.writeMessage(message1.getRaw());
+		recordWriter.writeOffer(new Offer(messageIds));
+		recordWriter.writeRequest(new Request(messageIds));
 
 		streamWriter.flush();
 		return out.toByteArray();
@@ -127,31 +128,31 @@ public class SyncIntegrationTest extends BrambleTestCase {
 				headerKey, streamNumber);
 		InputStream streamReader = streamReaderFactory.createStreamReader(in,
 				ctx);
-		PacketReader packetReader = packetReaderFactory.createPacketReader(
+		RecordReader recordReader = recordReaderFactory.createRecordReader(
 				streamReader);
 
 		// Read the ack
-		assertTrue(packetReader.hasAck());
-		Ack a = packetReader.readAck();
+		assertTrue(recordReader.hasAck());
+		Ack a = recordReader.readAck();
 		assertEquals(messageIds, a.getMessageIds());
 
 		// Read the messages
-		assertTrue(packetReader.hasMessage());
-		Message m = packetReader.readMessage();
+		assertTrue(recordReader.hasMessage());
+		Message m = recordReader.readMessage();
 		checkMessageEquality(message, m);
-		assertTrue(packetReader.hasMessage());
-		m = packetReader.readMessage();
+		assertTrue(recordReader.hasMessage());
+		m = recordReader.readMessage();
 		checkMessageEquality(message1, m);
-		assertFalse(packetReader.hasMessage());
+		assertFalse(recordReader.hasMessage());
 
 		// Read the offer
-		assertTrue(packetReader.hasOffer());
-		Offer o = packetReader.readOffer();
+		assertTrue(recordReader.hasOffer());
+		Offer o = recordReader.readOffer();
 		assertEquals(messageIds, o.getMessageIds());
 
 		// Read the request
-		assertTrue(packetReader.hasRequest());
-		Request req = packetReader.readRequest();
+		assertTrue(recordReader.hasRequest());
+		Request req = recordReader.readRequest();
 		assertEquals(messageIds, req.getMessageIds());
 
 		in.close();

briar-android/src/main/AndroidManifest.xml

@@ -2,12 +2,9 @@
 <manifest
 	package="org.briarproject.briar"
 	xmlns:android="http://schemas.android.com/apk/res/android"
-	xmlns:tools="http://schemas.android.com/tools"
 	android:versionCode="13"
 	android:versionName="0.13">
 
-	<uses-sdk tools:overrideLibrary="android.support.v14.preference"/>
-
 	<uses-feature android:name="android.hardware.bluetooth"/>
 	<uses-feature android:name="android.hardware.camera" />
 
@@ -47,7 +44,7 @@
 			android:label="@string/crash_report_title"
 			android:launchMode="singleInstance"
 			android:process=":briar_error_handler"
-			android:theme="@style/BriarThemeNoActionBar.Default"
+			android:theme="@style/BriarTheme.NoActionBar"
 			android:windowSoftInputMode="stateHidden">
 		</activity>
 
@@ -70,7 +67,7 @@
 
 		<activity
 			android:name=".android.splash.SplashScreenActivity"
-			android:theme="@style/BriarThemeNoActionBar.Default"
+			android:theme="@style/BriarTheme.NoActionBar"
 			android:label="@string/app_name">
 			<intent-filter>
 				<action android:name="android.intent.action.MAIN"/>
@@ -80,14 +77,14 @@
 
 		<activity
 			android:name=".android.navdrawer.NavDrawerActivity"
-			android:theme="@style/BriarThemeNoActionBar.Default"
+			android:theme="@style/BriarTheme.NoActionBar"
 		    android:launchMode="singleTop">
 		</activity>
 
 		<activity
 			android:name=".android.contact.ConversationActivity"
 			android:label="@string/app_name"
-			android:theme="@style/BriarThemeNoActionBar.Default"
+			android:theme="@style/BriarTheme.NoActionBar"
 			android:parentActivityName=".android.navdrawer.NavDrawerActivity"
 			android:windowSoftInputMode="stateHidden|adjustResize">
 			<meta-data
@@ -111,6 +108,7 @@
 			android:name=".android.privategroup.conversation.GroupActivity"
 			android:label="@string/app_name"
 			android:parentActivityName=".android.navdrawer.NavDrawerActivity"
+			android:theme="@style/BriarTheme.NoActionBar"
 			android:windowSoftInputMode="adjustResize|stateHidden">
 			<meta-data
 				android:name="android.support.PARENT_ACTIVITY"
@@ -194,6 +192,7 @@
 			android:name=".android.forum.ForumActivity"
 			android:label="@string/app_name"
 			android:parentActivityName=".android.navdrawer.NavDrawerActivity"
+			android:theme="@style/BriarTheme.NoActionBar"
 			android:windowSoftInputMode="adjustResize|stateHidden">
 			<meta-data
 				android:name="android.support.PARENT_ACTIVITY"
@@ -245,11 +244,11 @@
 
 		<activity
 			android:name=".android.blog.BlogActivity"
-			android:parentActivityName=".android.navdrawer.NavDrawerActivity">
+			android:parentActivityName=".android.navdrawer.NavDrawerActivity"
+			android:theme="@style/BriarTheme.NoActionBar">
 			<meta-data
 				android:name="android.support.PARENT_ACTIVITY"
-				android:value=".android.navdrawer.NavDrawerActivity"
-				/>
+				android:value=".android.navdrawer.NavDrawerActivity"/>
 		</activity>
 
 		<activity
@@ -308,7 +307,7 @@
 		<activity
 			android:name=".android.keyagreement.KeyAgreementActivity"
 			android:label="@string/add_contact_title"
-			android:theme="@style/BriarThemeNoActionBar.Default"
+			android:theme="@style/BriarTheme.NoActionBar"
 			android:parentActivityName=".android.navdrawer.NavDrawerActivity">
 			<meta-data
 				android:name="android.support.PARENT_ACTIVITY"

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

@@ -2,10 +2,12 @@ package org.briarproject.briar.android.activity;
 
 import android.os.Bundle;
 import android.os.IBinder;
+import android.support.annotation.UiThread;
 import android.support.v7.app.AppCompatActivity;
 import android.view.View;
 import android.view.inputmethod.InputMethodManager;
 
+import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.briar.android.AndroidComponent;
 import org.briarproject.briar.android.BriarApplication;
 import org.briarproject.briar.android.DestroyableContext;
@@ -116,4 +118,10 @@ public abstract class BaseActivity extends AppCompatActivity
 		Object o = getSystemService(INPUT_METHOD_SERVICE);
 		((InputMethodManager) o).hideSoftInputFromWindow(token, 0);
 	}
+
+	@UiThread
+	public void handleDbException(DbException e) {
+		supportFinishAfterTransition();
+	}
+
 }

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

@@ -3,6 +3,9 @@ package org.briarproject.briar.android.activity;
 import android.annotation.SuppressLint;
 import android.content.Intent;
 import android.os.Build;
+import android.support.annotation.Nullable;
+import android.support.v7.app.ActionBar;
+import android.support.v7.widget.Toolbar;
 import android.transition.Slide;
 import android.transition.Transition;
 import android.view.Gravity;
@@ -25,6 +28,7 @@ import static android.content.Intent.FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS;
 import static android.content.Intent.FLAG_ACTIVITY_NEW_TASK;
 import static android.content.Intent.FLAG_ACTIVITY_NO_ANIMATION;
 import static android.content.Intent.FLAG_ACTIVITY_SINGLE_TOP;
+import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_PASSWORD;
 
 @SuppressLint("Registered")
 public abstract class BriarActivity extends BaseActivity {
@@ -33,8 +37,6 @@ public abstract class BriarActivity extends BaseActivity {
 	public static final String GROUP_ID = "briar.GROUP_ID";
 	public static final String GROUP_NAME = "briar.GROUP_NAME";
 
-	public static final int REQUEST_PASSWORD = 1;
-
 	private static final Logger LOG =
 			Logger.getLogger(BriarActivity.class.getName());
 
@@ -94,6 +96,27 @@ public abstract class BriarActivity extends BaseActivity {
 		window.setBackgroundDrawableResource(android.R.color.transparent);
 	}
 
+	/**
+	 * This should be called after the content view has been added in onCreate()
+	 *
+	 * @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 = (Toolbar) findViewById(R.id.toolbar);
+		setSupportActionBar(toolbar);
+		ActionBar ab = getSupportActionBar();
+		if (ab != null) {
+			ab.setDisplayShowHomeEnabled(true);
+			ab.setDisplayHomeAsUpEnabled(true);
+			ab.setDisplayShowCustomEnabled(ownLayout);
+			ab.setDisplayShowTitleEnabled(!ownLayout);
+		}
+		return toolbar;
+	}
+
 	protected void signOut(final boolean removeFromRecentApps) {
 		briarController.signOut(new UiResultHandler<Void>(this) {
 			@Override

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

@@ -0,0 +1,14 @@
+package org.briarproject.briar.android.activity;
+
+public interface RequestCodes {
+
+	int REQUEST_PASSWORD = 1;
+	int REQUEST_BLUETOOTH = 2;
+	int REQUEST_INTRODUCTION = 3;
+	int REQUEST_GROUP_INVITE = 4;
+	int REQUEST_SHARE_FORUM = 5;
+	int REQUEST_WRITE_BLOG_POST = 6;
+	int REQUEST_SHARE_BLOG = 7;
+	int REQUEST_RINGTONE = 8;
+
+}

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

@@ -1,6 +1,8 @@
 package org.briarproject.briar.android.blog;
 
 import android.os.Bundle;
+import android.os.Handler;
+import android.os.Looper;
 import android.support.annotation.CallSuper;
 import android.support.annotation.UiThread;
 import android.view.LayoutInflater;
@@ -20,7 +22,7 @@ import javax.annotation.Nullable;
 
 import static android.view.View.INVISIBLE;
 import static android.view.View.VISIBLE;
-import static org.briarproject.briar.android.util.UiUtils.MIN_RESOLUTION;
+import static org.briarproject.briar.android.util.UiUtils.MIN_DATE_RESOLUTION;
 
 @UiThread
 @MethodsNotNullByDefault
@@ -32,8 +34,9 @@ abstract class BasePostFragment extends BaseFragment {
 	private static final Logger LOG =
 			Logger.getLogger(BasePostFragment.class.getName());
 
+	private final Handler handler = new Handler(Looper.getMainLooper());
+
 	protected MessageId postId;
-	private View view;
 	private ProgressBar progressBar;
 	private BlogPostViewHolder ui;
 	private BlogPostItem post;
@@ -50,7 +53,7 @@ abstract class BasePostFragment extends BaseFragment {
 		if (p == null) throw new IllegalStateException("No post ID in args");
 		postId = new MessageId(p);
 
-		view = inflater.inflate(R.layout.fragment_blog_post, container,
+		View view = inflater.inflate(R.layout.fragment_blog_post, container,
 				false);
 		progressBar = (ProgressBar) view.findViewById(R.id.progressBar);
 		progressBar.setVisibility(VISIBLE);
@@ -83,21 +86,19 @@ abstract class BasePostFragment extends BaseFragment {
 		refresher = new Runnable() {
 			@Override
 			public void run() {
-				if (ui == null) return;
 				LOG.info("Updating Content...");
-
 				ui.updateDate(post.getTimestamp());
-				view.postDelayed(refresher, MIN_RESOLUTION);
+				handler.postDelayed(refresher, MIN_DATE_RESOLUTION);
 			}
 		};
 		LOG.info("Adding Handler Callback");
-		view.postDelayed(refresher, MIN_RESOLUTION);
+		handler.postDelayed(refresher, MIN_DATE_RESOLUTION);
 	}
 
 	private void stopPeriodicUpdate() {
-		if (refresher != null && ui != null) {
+		if (refresher != null) {
 			LOG.info("Removing Handler Callback");
-			view.removeCallbacks(refresher);
+			handler.removeCallbacks(refresher);
 		}
 	}
 

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

@@ -3,6 +3,7 @@ package org.briarproject.briar.android.blog;
 import android.content.Intent;
 import android.os.Bundle;
 import android.support.annotation.Nullable;
+import android.support.v7.widget.Toolbar;
 import android.view.View;
 
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
@@ -21,9 +22,6 @@ import javax.inject.Inject;
 public class BlogActivity extends BriarActivity
 		implements BaseFragmentListener {
 
-	static final int REQUEST_WRITE_POST = 2;
-	static final int REQUEST_SHARE = 3;
-
 	@Inject
 	BlogController blogController;
 
@@ -38,12 +36,12 @@ public class BlogActivity extends BriarActivity
 		final GroupId groupId = new GroupId(b);
 		blogController.setGroupId(groupId);
 
-		setContentView(R.layout.activity_fragment_container);
+		setContentView(R.layout.activity_fragment_container_toolbar);
+		Toolbar toolbar = setUpCustomToolbar(false);
 
-		// Open Sharing Status on ActionBar click
-		View actionBar = findViewById(R.id.action_bar);
-		if (actionBar != null) {
-			actionBar.setOnClickListener(
+		// Open Sharing Status on Toolbar click
+		if (toolbar != null) {
+			toolbar.setOnClickListener(
 					new View.OnClickListener() {
 						@Override
 						public void onClick(View v) {

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

@@ -46,8 +46,8 @@ import static android.content.Intent.FLAG_ACTIVITY_CLEAR_TOP;
 import static android.content.Intent.FLAG_ACTIVITY_SINGLE_TOP;
 import static android.widget.Toast.LENGTH_SHORT;
 import static org.briarproject.briar.android.activity.BriarActivity.GROUP_ID;
-import static org.briarproject.briar.android.blog.BlogActivity.REQUEST_SHARE;
-import static org.briarproject.briar.android.blog.BlogActivity.REQUEST_WRITE_POST;
+import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_SHARE_BLOG;
+import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_WRITE_BLOG_POST;
 import static org.briarproject.briar.android.controller.SharingController.SharingListener;
 
 @UiThread
@@ -145,13 +145,13 @@ public class BlogFragment extends BaseFragment
 				Intent i = new Intent(getActivity(),
 						WriteBlogPostActivity.class);
 				i.putExtra(GROUP_ID, groupId.getBytes());
-				startActivityForResult(i, REQUEST_WRITE_POST);
+				startActivityForResult(i, REQUEST_WRITE_BLOG_POST);
 				return true;
 			case R.id.action_blog_share:
 				Intent i2 = new Intent(getActivity(), ShareBlogActivity.class);
 				i2.setFlags(FLAG_ACTIVITY_CLEAR_TOP | FLAG_ACTIVITY_SINGLE_TOP);
 				i2.putExtra(GROUP_ID, groupId.getBytes());
-				startActivityForResult(i2, REQUEST_SHARE);
+				startActivityForResult(i2, REQUEST_SHARE_BLOG);
 				return true;
 			case R.id.action_blog_sharing_status:
 				Intent i3 = new Intent(getActivity(),
@@ -172,10 +172,10 @@ public class BlogFragment extends BaseFragment
 	public void onActivityResult(int request, int result, Intent data) {
 		super.onActivityResult(request, result, data);
 
-		if (request == REQUEST_WRITE_POST && result == RESULT_OK) {
+		if (request == REQUEST_WRITE_BLOG_POST && result == RESULT_OK) {
 			displaySnackbar(R.string.blogs_blog_post_created, true);
 			loadBlogPosts(true);
-		} else if (request == REQUEST_SHARE && result == RESULT_OK) {
+		} else if (request == REQUEST_SHARE_BLOG && result == RESULT_OK) {
 			displaySnackbar(R.string.blogs_sharing_snackbar, false);
 		}
 	}
@@ -205,8 +205,7 @@ public class BlogFragment extends BaseFragment
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						// TODO: Decide how to handle errors in the UI
-						finish();
+						handleDbException(exception);
 					}
 				}
 		);
@@ -234,8 +233,7 @@ public class BlogFragment extends BaseFragment
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						// TODO: Decide how to handle errors in the UI
-						finish();
+						handleDbException(exception);
 					}
 				});
 	}
@@ -254,8 +252,7 @@ public class BlogFragment extends BaseFragment
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						// TODO: Decide how to handle errors in the UI
-						finish();
+						handleDbException(exception);
 					}
 				});
 	}
@@ -277,8 +274,7 @@ public class BlogFragment extends BaseFragment
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						// TODO: Decide how to handle errors in the UI
-						finish();
+						handleDbException(exception);
 					}
 				});
 	}
@@ -373,8 +369,7 @@ public class BlogFragment extends BaseFragment
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						// TODO: Decide how to handle errors in the UI
-						finish();
+						handleDbException(exception);
 					}
 				});
 	}

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

@@ -55,8 +55,7 @@ public class BlogPostFragment extends BasePostFragment {
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						// TODO: Decide how to handle errors in the UI
-						finish();
+						handleDbException(exception);
 					}
 				});
 	}

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

@@ -36,7 +36,7 @@ import javax.inject.Inject;
 import static android.app.Activity.RESULT_OK;
 import static android.support.design.widget.Snackbar.LENGTH_LONG;
 import static org.briarproject.briar.android.activity.BriarActivity.GROUP_ID;
-import static org.briarproject.briar.android.blog.BlogActivity.REQUEST_WRITE_POST;
+import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_WRITE_BLOG_POST;
 
 @UiThread
 @MethodsNotNullByDefault
@@ -96,7 +96,7 @@ public class FeedFragment extends BaseFragment implements
 		super.onActivityResult(requestCode, resultCode, data);
 
 		// The BlogPostAddedEvent arrives when the controller is not listening
-		if (requestCode == REQUEST_WRITE_POST && resultCode == RESULT_OK) {
+		if (requestCode == REQUEST_WRITE_BLOG_POST && resultCode == RESULT_OK) {
 			showSnackBar(R.string.blogs_blog_post_created);
 		}
 	}
@@ -105,6 +105,7 @@ public class FeedFragment extends BaseFragment implements
 	public void onStart() {
 		super.onStart();
 		feedController.onStart();
+		list.startPeriodicUpdate();
 		loadPersonalBlog();
 		loadBlogPosts(false);
 	}
@@ -129,7 +130,7 @@ public class FeedFragment extends BaseFragment implements
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						// TODO: Decide how to handle errors in the UI
+						handleDbException(exception);
 					}
 				});
 	}
@@ -153,11 +154,10 @@ public class FeedFragment extends BaseFragment implements
 					}
 
 					@Override
-					public void onExceptionUi(DbException e) {
-						// TODO: Decide how to handle errors in the UI
+					public void onExceptionUi(DbException exception) {
+						handleDbException(exception);
 					}
 				});
-		list.startPeriodicUpdate();
 	}
 
 	@Override
@@ -174,7 +174,7 @@ public class FeedFragment extends BaseFragment implements
 				Intent i1 =
 						new Intent(getActivity(), WriteBlogPostActivity.class);
 				i1.putExtra(GROUP_ID, personalBlog.getId().getBytes());
-				startActivityForResult(i1, REQUEST_WRITE_POST);
+				startActivityForResult(i1, REQUEST_WRITE_BLOG_POST);
 				return true;
 			case R.id.action_rss_feeds_import:
 				Intent i2 =
@@ -211,7 +211,7 @@ public class FeedFragment extends BaseFragment implements
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						// TODO: Decide how to handle errors in the UI
+						handleDbException(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) {
-						// TODO: Decide how to handle errors in the UI
+						handleDbException(exception);
 					}
 				});
 	}

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

@@ -99,8 +99,7 @@ public class ReblogFragment extends BaseFragment implements TextInputListener {
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						// TODO
-						finish();
+						handleDbException(exception);
 					}
 				});
 	}
@@ -130,8 +129,7 @@ public class ReblogFragment extends BaseFragment implements TextInputListener {
 				new UiExceptionHandler<DbException>(this) {
 					@Override
 					public void onExceptionUi(DbException exception) {
-						// TODO proper error handling
-						// do nothing, this fragment is gone already
+						handleDbException(exception);
 					}
 				});
 		finish();

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

@@ -6,7 +6,6 @@ import android.os.Bundle;
 import android.support.annotation.UiThread;
 import android.support.design.widget.Snackbar;
 import android.support.v4.content.ContextCompat;
-import android.support.v7.app.ActionBar;
 import android.support.v7.app.AlertDialog;
 import android.support.v7.widget.ActionMenuView;
 import android.support.v7.widget.LinearLayoutManager;
@@ -50,8 +49,11 @@ import org.briarproject.bramble.util.StringUtils;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.ActivityComponent;
 import org.briarproject.briar.android.activity.BriarActivity;
+import org.briarproject.briar.android.blog.BlogActivity;
 import org.briarproject.briar.android.contact.ConversationAdapter.ConversationListener;
+import org.briarproject.briar.android.forum.ForumActivity;
 import org.briarproject.briar.android.introduction.IntroductionActivity;
+import org.briarproject.briar.android.privategroup.conversation.GroupActivity;
 import org.briarproject.briar.android.view.BriarRecyclerView;
 import org.briarproject.briar.android.view.TextInputView;
 import org.briarproject.briar.android.view.TextInputView.TextInputListener;
@@ -77,6 +79,8 @@ import org.briarproject.briar.api.sharing.InvitationRequest;
 import org.briarproject.briar.api.sharing.InvitationResponse;
 import org.briarproject.briar.api.sharing.event.InvitationRequestReceivedEvent;
 import org.briarproject.briar.api.sharing.event.InvitationResponseReceivedEvent;
+import org.thoughtcrime.securesms.components.util.FutureTaskListener;
+import org.thoughtcrime.securesms.components.util.ListenableFutureTask;
 
 import java.util.ArrayList;
 import java.util.Collection;
@@ -84,8 +88,10 @@ import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.concurrent.Callable;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.Executor;
+import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.logging.Logger;
 
 import javax.annotation.Nullable;
@@ -101,6 +107,7 @@ import static android.support.v7.util.SortedList.INVALID_POSITION;
 import static android.widget.Toast.LENGTH_SHORT;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
+import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_INTRODUCTION;
 import static org.briarproject.briar.android.settings.SettingsFragment.SETTINGS_NAMESPACE;
 import static org.briarproject.briar.android.util.UiUtils.getAvatarTransitionName;
 import static org.briarproject.briar.android.util.UiUtils.getBulbTransitionName;
@@ -115,7 +122,6 @@ public class ConversationActivity extends BriarActivity
 
 	private static final Logger LOG =
 			Logger.getLogger(ConversationActivity.class.getName());
-	private static final int REQUEST_CODE_INTRODUCTION = 2;
 	private static final String SHOW_ONBOARDING_INTRODUCTION =
 			"showOnboardingIntroduction";
 
@@ -137,6 +143,18 @@ public class ConversationActivity extends BriarActivity
 	private BriarRecyclerView list;
 	private TextInputView textInputView;
 
+	private final ListenableFutureTask<String> contactNameTask =
+			new ListenableFutureTask<>(new Callable<String>() {
+				@Override
+				public String call() throws Exception {
+					Contact c = contactManager.getContact(contactId);
+					contactName = c.getAuthor().getName();
+					return c.getAuthor().getName();
+				}
+			});
+	private final AtomicBoolean contactNameTaskStarted =
+			new AtomicBoolean(false);
+
 	// Fields that are accessed from background threads must be volatile
 	@Inject
 	volatile ContactManager contactManager;
@@ -158,8 +176,11 @@ public class ConversationActivity extends BriarActivity
 	volatile GroupInvitationManager groupInvitationManager;
 
 	private volatile ContactId contactId;
+	@Nullable
 	private volatile String contactName;
+	@Nullable
 	private volatile AuthorId contactAuthorId;
+	@Nullable
 	private volatile GroupId messagingGroupId;
 
 	@SuppressWarnings("ConstantConditions")
@@ -176,21 +197,13 @@ public class ConversationActivity extends BriarActivity
 		setContentView(R.layout.activity_conversation);
 
 		// Custom Toolbar
-		toolbar = (Toolbar) findViewById(R.id.toolbar);
+		toolbar = setUpCustomToolbar(true);
 		if (toolbar != null) {
 			toolbarAvatar =
 					(CircleImageView) toolbar.findViewById(R.id.contactAvatar);
 			toolbarStatus =
 					(ImageView) toolbar.findViewById(R.id.contactStatus);
 			toolbarTitle = (TextView) toolbar.findViewById(R.id.contactName);
-			setSupportActionBar(toolbar);
-		}
-		ActionBar ab = getSupportActionBar();
-		if (ab != null) {
-			ab.setDisplayShowHomeEnabled(true);
-			ab.setDisplayHomeAsUpEnabled(true);
-			ab.setDisplayShowCustomEnabled(true);
-			ab.setDisplayShowTitleEnabled(false);
 		}
 
 		setTransitionName(toolbarAvatar, getAvatarTransitionName(contactId));
@@ -215,7 +228,7 @@ public class ConversationActivity extends BriarActivity
 	protected void onActivityResult(int request, int result, Intent data) {
 		super.onActivityResult(request, result, data);
 
-		if (request == REQUEST_CODE_INTRODUCTION && result == RESULT_OK) {
+		if (request == REQUEST_INTRODUCTION && result == RESULT_OK) {
 			Snackbar snackbar = Snackbar.make(list, R.string.introduction_sent,
 					Snackbar.LENGTH_SHORT);
 			snackbar.getView().setBackgroundResource(R.color.briar_primary);
@@ -229,8 +242,8 @@ public class ConversationActivity extends BriarActivity
 		eventBus.addListener(this);
 		notificationManager.blockContactNotification(contactId);
 		notificationManager.clearContactNotification(contactId);
-		loadContactDetails();
-		loadMessages();
+		displayContactOnlineStatus();
+		loadContactDetailsAndMessages();
 		list.startPeriodicUpdate();
 	}
 
@@ -265,7 +278,7 @@ public class ConversationActivity extends BriarActivity
 				if (contactId == null) return false;
 				Intent intent = new Intent(this, IntroductionActivity.class);
 				intent.putExtra(CONTACT_ID, contactId.getInt());
-				startActivityForResult(intent, REQUEST_CODE_INTRODUCTION);
+				startActivityForResult(intent, REQUEST_INTRODUCTION);
 				return true;
 			case R.id.action_social_remove_person:
 				askToRemoveContact();
@@ -275,7 +288,7 @@ public class ConversationActivity extends BriarActivity
 		}
 	}
 
-	private void loadContactDetails() {
+	private void loadContactDetailsAndMessages() {
 		runOnDbThread(new Runnable() {
 			@Override
 			public void run() {
@@ -289,6 +302,7 @@ public class ConversationActivity extends BriarActivity
 					long duration = System.currentTimeMillis() - now;
 					if (LOG.isLoggable(INFO))
 						LOG.info("Loading contact took " + duration + " ms");
+					loadMessages();
 					displayContactDetails();
 				} catch (NoSuchContactException e) {
 					finishOnUiThread();
@@ -304,10 +318,18 @@ public class ConversationActivity extends BriarActivity
 		runOnUiThreadUnlessDestroyed(new Runnable() {
 			@Override
 			public void run() {
+				//noinspection ConstantConditions
 				toolbarAvatar.setImageDrawable(
 						new IdenticonDrawable(contactAuthorId.getBytes()));
 				toolbarTitle.setText(contactName);
+			}
+		});
+	}
 
+	private void displayContactOnlineStatus() {
+		runOnUiThreadUnlessDestroyed(new Runnable() {
+			@Override
+			public void run() {
 				if (connectionRegistry.isConnected(contactId)) {
 					toolbarStatus.setImageDrawable(ContextCompat
 							.getDrawable(ConversationActivity.this,
@@ -347,7 +369,8 @@ public class ConversationActivity extends BriarActivity
 							groupInvitationManager
 									.getInvitationMessages(contactId);
 					List<InvitationMessage> invitations = new ArrayList<>(
-							forumInvitations.size() + blogInvitations.size());
+							forumInvitations.size() + blogInvitations.size() +
+									groupInvitations.size());
 					invitations.addAll(forumInvitations);
 					invitations.addAll(blogInvitations);
 					invitations.addAll(groupInvitations);
@@ -390,6 +413,12 @@ public class ConversationActivity extends BriarActivity
 		});
 	}
 
+	/**
+	 * Creates ConversationItems from headers loaded from the database.
+	 *
+	 * Attention: Call this only after contactName has been initialized.
+	 */
+	@SuppressWarnings("ConstantConditions")
 	private List<ConversationItem> createItems(
 			Collection<PrivateMessageHeader> headers,
 			Collection<IntroductionMessage> introductions,
@@ -468,18 +497,6 @@ public class ConversationActivity extends BriarActivity
 		});
 	}
 
-	private void addConversationItem(final ConversationItem item) {
-		runOnUiThreadUnlessDestroyed(new Runnable() {
-			@Override
-			public void run() {
-				adapter.incrementRevision();
-				adapter.add(item);
-				// Scroll to the bottom
-				list.scrollToPosition(adapter.getItemCount() - 1);
-			}
-		});
-	}
-
 	@Override
 	public void eventOccurred(Event e) {
 		if (e instanceof ContactRemovedEvent) {
@@ -512,13 +529,13 @@ public class ConversationActivity extends BriarActivity
 			ContactConnectedEvent c = (ContactConnectedEvent) e;
 			if (c.getContactId().equals(contactId)) {
 				LOG.info("Contact connected");
-				displayContactDetails();
+				displayContactOnlineStatus();
 			}
 		} else if (e instanceof ContactDisconnectedEvent) {
 			ContactDisconnectedEvent c = (ContactDisconnectedEvent) e;
 			if (c.getContactId().equals(contactId)) {
 				LOG.info("Contact disconnected");
-				displayContactDetails();
+				displayContactOnlineStatus();
 			}
 		} else if (e instanceof IntroductionRequestReceivedEvent) {
 			IntroductionRequestReceivedEvent event =
@@ -526,9 +543,7 @@ public class ConversationActivity extends BriarActivity
 			if (event.getContactId().equals(contactId)) {
 				LOG.info("Introduction request received, adding...");
 				IntroductionRequest ir = event.getIntroductionRequest();
-				ConversationItem item =
-						ConversationItem.from(this, contactName, ir);
-				addConversationItem(item);
+				handleIntroductionRequest(ir);
 			}
 		} else if (e instanceof IntroductionResponseReceivedEvent) {
 			IntroductionResponseReceivedEvent event =
@@ -536,9 +551,7 @@ public class ConversationActivity extends BriarActivity
 			if (event.getContactId().equals(contactId)) {
 				LOG.info("Introduction response received, adding...");
 				IntroductionResponse ir = event.getIntroductionResponse();
-				ConversationItem item =
-						ConversationItem.from(this, contactName, ir);
-				addConversationItem(item);
+				handleIntroductionResponse(ir);
 			}
 		} else if (e instanceof InvitationRequestReceivedEvent) {
 			InvitationRequestReceivedEvent event =
@@ -546,9 +559,7 @@ public class ConversationActivity extends BriarActivity
 			if (event.getContactId().equals(contactId)) {
 				LOG.info("Invitation received, adding...");
 				InvitationRequest ir = event.getRequest();
-				ConversationItem item =
-						ConversationItem.from(this, contactName, ir);
-				addConversationItem(item);
+				handleInvitationRequest(ir);
 			}
 		} else if (e instanceof InvitationResponseReceivedEvent) {
 			InvitationResponseReceivedEvent event =
@@ -556,13 +567,127 @@ public class ConversationActivity extends BriarActivity
 			if (event.getContactId().equals(contactId)) {
 				LOG.info("Invitation response received, adding...");
 				InvitationResponse ir = event.getResponse();
-				ConversationItem item =
-						ConversationItem.from(this, contactName, ir);
-				addConversationItem(item);
+				handleInvitationResponse(ir);
 			}
 		}
 	}
 
+	private void addConversationItem(final ConversationItem item) {
+		runOnUiThreadUnlessDestroyed(new Runnable() {
+			@Override
+			public void run() {
+				adapter.incrementRevision();
+				adapter.add(item);
+				// Scroll to the bottom
+				list.scrollToPosition(adapter.getItemCount() - 1);
+			}
+		});
+	}
+
+	private void handleIntroductionRequest(final IntroductionRequest m) {
+		getContactNameTask().addListener(new FutureTaskListener<String>() {
+			@Override
+			public void onSuccess(final String contactName) {
+				runOnUiThreadUnlessDestroyed(new Runnable() {
+					@Override
+					public void run() {
+						ConversationItem item = ConversationItem
+								.from(ConversationActivity.this, contactName,
+										m);
+						addConversationItem(item);
+					}
+				});
+			}
+			@Override
+			public void onFailure(final Throwable exception) {
+				runOnUiThreadUnlessDestroyed(new Runnable() {
+					@Override
+					public void run() {
+						handleDbException((DbException) exception);
+					}
+				});
+			}
+		});
+	}
+
+	private void handleIntroductionResponse(final IntroductionResponse m) {
+		getContactNameTask().addListener(new FutureTaskListener<String>() {
+			@Override
+			public void onSuccess(final String contactName) {
+				runOnUiThreadUnlessDestroyed(new Runnable() {
+					@Override
+					public void run() {
+						ConversationItem item = ConversationItem
+								.from(ConversationActivity.this, contactName,
+										m);
+						addConversationItem(item);
+					}
+				});
+			}
+			@Override
+			public void onFailure(final Throwable exception) {
+				runOnUiThreadUnlessDestroyed(new Runnable() {
+					@Override
+					public void run() {
+						handleDbException((DbException) exception);
+					}
+				});
+			}
+		});
+	}
+
+	private void handleInvitationRequest(final InvitationRequest m) {
+		getContactNameTask().addListener(new FutureTaskListener<String>() {
+			@Override
+			public void onSuccess(final String contactName) {
+				runOnUiThreadUnlessDestroyed(new Runnable() {
+					@Override
+					public void run() {
+						ConversationItem item = ConversationItem
+								.from(ConversationActivity.this, contactName,
+										m);
+						addConversationItem(item);
+					}
+				});
+			}
+			@Override
+			public void onFailure(final Throwable exception) {
+				runOnUiThreadUnlessDestroyed(new Runnable() {
+					@Override
+					public void run() {
+						handleDbException((DbException) exception);
+					}
+				});
+			}
+		});
+	}
+
+	private void handleInvitationResponse(final InvitationResponse m) {
+		getContactNameTask().addListener(new FutureTaskListener<String>() {
+			@Override
+			public void onSuccess(final String contactName) {
+				runOnUiThreadUnlessDestroyed(new Runnable() {
+					@Override
+					public void run() {
+						ConversationItem item = ConversationItem
+								.from(ConversationActivity.this, contactName,
+										m);
+						addConversationItem(item);
+					}
+				});
+			}
+			@Override
+			public void onFailure(final Throwable exception) {
+				runOnUiThreadUnlessDestroyed(new Runnable() {
+					@Override
+					public void run() {
+						handleDbException((DbException) exception);
+					}
+				});
+			}
+		});
+	}
+
 	private void markMessages(final Collection<MessageId> messageIds,
 			final boolean sent, final boolean seen) {
 		runOnUiThreadUnlessDestroyed(new Runnable() {
@@ -623,6 +748,7 @@ public class ConversationActivity extends BriarActivity
 			@Override
 			public void run() {
 				try {
+					//noinspection ConstantConditions init in loadGroupId()
 					storeMessage(privateMessageFactory.createPrivateMessage(
 							messagingGroupId, timestamp, body), body);
 				} catch (FormatException e) {
@@ -854,11 +980,33 @@ public class ConversationActivity extends BriarActivity
 					if (LOG.isLoggable(WARNING))
 						LOG.log(WARNING, e.toString(), e);
 				}
-
 			}
 		});
 	}
 
+	@UiThread
+	@Override
+	public void openRequestedShareable(ConversationRequestItem item) {
+		if (item.getRequestedGroupId() == null)
+			throw new IllegalArgumentException();
+		Intent i;
+		switch (item.getRequestType()) {
+			case FORUM:
+				i = new Intent(this, ForumActivity.class);
+				break;
+			case BLOG:
+				i = new Intent(this, BlogActivity.class);
+				break;
+			case GROUP:
+				i = new Intent(this, GroupActivity.class);
+				break;
+			default:
+				throw new IllegalArgumentException("Unknown Request Type");
+		}
+		i.putExtra(GROUP_ID, item.getRequestedGroupId().getBytes());
+		startActivity(i);
+	}
+
 	@DatabaseExecutor
 	private void respondToIntroductionRequest(SessionId sessionId,
 			boolean accept, long time) throws DbException, FormatException {
@@ -872,13 +1020,13 @@ public class ConversationActivity extends BriarActivity
 	@DatabaseExecutor
 	private void respondToForumRequest(SessionId id, boolean accept)
 			throws DbException {
-		forumSharingManager.respondToInvitation(id, accept);
+		forumSharingManager.respondToInvitation(contactId, id, accept);
 	}
 
 	@DatabaseExecutor
 	private void respondToBlogRequest(SessionId id, boolean accept)
 			throws DbException {
-		blogSharingManager.respondToInvitation(id, accept);
+		blogSharingManager.respondToInvitation(contactId, id, accept);
 	}
 
 	@DatabaseExecutor
@@ -902,4 +1050,10 @@ public class ConversationActivity extends BriarActivity
 		});
 	}
 
+	private ListenableFutureTask<String> getContactNameTask() {
+		if (!contactNameTaskStarted.getAndSet(true))
+			runOnDbThread(contactNameTask);
+		return contactNameTask;
+	}
+
 }

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

@@ -139,6 +139,9 @@ class ConversationAdapter
 		void onItemVisible(ConversationItem item);
 
 		void respondToRequest(ConversationRequestItem item, boolean accept);
+
+		void openRequestedShareable(ConversationRequestItem item);
+
 	}
 
 }

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

@@ -101,9 +101,6 @@ abstract class ConversationItem {
 				text = ctx.getString(
 						R.string.introduction_request_answered_received,
 						contactName, ir.getName());
-				return new ConversationNoticeInItem(ir.getMessageId(),
-						ir.getGroupId(), text, ir.getMessage(), ir.getTimestamp(),
-						ir.isRead());
 			} else if (ir.contactExists()){
 				text = ctx.getString(
 						R.string.introduction_request_exists_received,
@@ -114,8 +111,8 @@ abstract class ConversationItem {
 			}
 			return new ConversationRequestItem(ir.getMessageId(),
 					ir.getGroupId(), INTRODUCTION, ir.getSessionId(), text,
-					ir.getMessage(), ir.getTimestamp(), ir.isRead(),
-					ir.wasAnswered());
+					ir.getMessage(), ir.getTimestamp(), ir.isRead(), null,
+					ir.wasAnswered(), false);
 		}
 	}
 
@@ -173,8 +170,7 @@ abstract class ConversationItem {
 			} else if (ir instanceof GroupInvitationRequest) {
 				text = ctx.getString(
 						R.string.groups_invitations_invitation_sent,
-						contactName,
-						((GroupInvitationRequest) ir).getGroupName());
+						contactName, ir.getShareable().getName());
 			} else {
 				throw new IllegalArgumentException("Unknown InvitationRequest");
 			}
@@ -197,20 +193,16 @@ abstract class ConversationItem {
 			} else if (ir instanceof GroupInvitationRequest) {
 				text = ctx.getString(
 						R.string.groups_invitations_invitation_received,
-						contactName,
-						((GroupInvitationRequest) ir).getGroupName());
+						contactName, ir.getShareable().getName());
 				type = GROUP;
 			} else {
 				throw new IllegalArgumentException("Unknown InvitationRequest");
 			}
-			if (!ir.isAvailable()) {
-				return new ConversationNoticeInItem(ir.getId(), ir.getGroupId(),
-						text, ir.getMessage(), ir.getTimestamp(), ir.isRead());
-			}
 			return new ConversationRequestItem(ir.getId(),
 					ir.getGroupId(), type, ir.getSessionId(), text,
 					ir.getMessage(), ir.getTimestamp(), ir.isRead(),
-					!ir.isAvailable());
+					ir.getShareable().getId(), !ir.isAvailable(),
+					ir.canBeOpened());
 		}
 	}
 

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

@@ -17,18 +17,23 @@ class ConversationRequestItem extends ConversationNoticeInItem {
 
 	enum RequestType { INTRODUCTION, FORUM, BLOG, GROUP }
 
+	@Nullable
+	private final GroupId requestedGroupId;
 	private final RequestType requestType;
 	private final SessionId sessionId;
-	private boolean answered;
+	private final boolean answered, canBeOpened;
 
 	ConversationRequestItem(MessageId id, GroupId groupId,
 			RequestType requestType, SessionId sessionId, String text,
 			@Nullable String msgText, long time, boolean read,
-			boolean answered) {
+			@Nullable GroupId requestedGroupId, boolean answered,
+			boolean canBeOpened) {
 		super(id, groupId, text, msgText, time, read);
 		this.requestType = requestType;
 		this.sessionId = sessionId;
+		this.requestedGroupId = requestedGroupId;
 		this.answered = answered;
+		this.canBeOpened = canBeOpened;
 	}
 
 	RequestType getRequestType() {
@@ -39,12 +44,17 @@ class ConversationRequestItem extends ConversationNoticeInItem {
 		return sessionId;
 	}
 
+	@Nullable
+	public GroupId getRequestedGroupId() {
+		return requestedGroupId;
+	}
+
 	boolean wasAnswered() {
 		return answered;
 	}
 
-	void setAnswered(boolean answered) {
-		this.answered = answered;
+	public boolean canBeOpened() {
+		return canBeOpened;
 	}
 
 	@LayoutRes

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

@@ -32,15 +32,25 @@ class ConversationRequestViewHolder extends ConversationNoticeInViewHolder {
 		final ConversationRequestItem item =
 				(ConversationRequestItem) conversationItem;
 
-		if (item.wasAnswered()) {
+		if (item.wasAnswered() && item.canBeOpened()) {
+			acceptButton.setVisibility(VISIBLE);
+			acceptButton.setText(R.string.open);
+			acceptButton.setOnClickListener(new OnClickListener() {
+				@Override
+				public void onClick(View v) {
+					listener.openRequestedShareable(item);
+				}
+			});
+			declineButton.setVisibility(GONE);
+		} else if (item.wasAnswered()) {
 			acceptButton.setVisibility(GONE);
 			declineButton.setVisibility(GONE);
 		} else {
 			acceptButton.setVisibility(VISIBLE);
+			acceptButton.setText(R.string.accept);
 			acceptButton.setOnClickListener(new OnClickListener() {
 				@Override
 				public void onClick(View v) {
-					item.setAnswered(true);
 					listener.respondToRequest(item, true);
 				}
 			});
@@ -48,7 +58,6 @@ class ConversationRequestViewHolder extends ConversationNoticeInViewHolder {
 			declineButton.setOnClickListener(new OnClickListener() {
 				@Override
 				public void onClick(View v) {
-					item.setAnswered(true);
 					listener.respondToRequest(item, false);
 				}
 			});

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

@@ -130,8 +130,7 @@ public abstract class BaseContactSelectorFragment<I extends SelectableContactIte
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						// TODO error handling
-						finish();
+						handleDbException(exception);
 					}
 				});
 	}

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

@@ -4,10 +4,10 @@ import android.content.DialogInterface;
 import android.content.DialogInterface.OnClickListener;
 import android.content.Intent;
 import android.os.Bundle;
-import android.support.annotation.LayoutRes;
 import android.support.annotation.StringRes;
 import android.support.v7.app.AlertDialog;
 import android.support.v7.widget.LinearLayoutManager;
+import android.support.v7.widget.Toolbar;
 import android.view.Menu;
 import android.view.MenuInflater;
 import android.view.MenuItem;
@@ -36,6 +36,7 @@ import javax.inject.Inject;
 import static android.content.Intent.FLAG_ACTIVITY_CLEAR_TOP;
 import static android.content.Intent.FLAG_ACTIVITY_SINGLE_TOP;
 import static android.widget.Toast.LENGTH_SHORT;
+import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_SHARE_FORUM;
 import static org.briarproject.briar.api.forum.ForumConstants.MAX_FORUM_POST_BODY_LENGTH;
 
 @MethodsNotNullByDefault
@@ -44,8 +45,6 @@ public class ForumActivity extends
 		ThreadListActivity<Forum, ThreadItemAdapter<ForumItem>, ForumItem, ForumPostHeader>
 		implements ForumListener {
 
-	private static final int REQUEST_FORUM_SHARED = 3;
-
 	@Inject
 	ForumController forumController;
 
@@ -63,15 +62,16 @@ public class ForumActivity extends
 	public void onCreate(@Nullable Bundle state) {
 		super.onCreate(state);
 
+		Toolbar toolbar = setUpCustomToolbar(false);
+
 		Intent i = getIntent();
 		String groupName = i.getStringExtra(GROUP_NAME);
 		if (groupName != null) setTitle(groupName);
 		else loadNamedGroup();
 
-		// Open Sharing Status on ActionBar click
-		View actionBar = findViewById(R.id.action_bar);
-		if (actionBar != null) {
-			actionBar.setOnClickListener(
+		// Open member list on Toolbar click
+		if (toolbar != null) {
+			toolbar.setOnClickListener(
 					new View.OnClickListener() {
 						@Override
 						public void onClick(View v) {
@@ -89,12 +89,6 @@ public class ForumActivity extends
 		setTitle(forum.getName());
 	}
 
-	@Override
-	@LayoutRes
-	protected int getLayout() {
-		return R.layout.activity_forum;
-	}
-
 	@Override
 	protected ThreadItemAdapter<ForumItem> createAdapter(
 			LinearLayoutManager layoutManager) {
@@ -105,8 +99,8 @@ public class ForumActivity extends
 	protected void onActivityResult(int request, int result, Intent data) {
 		super.onActivityResult(request, result, data);
 
-		if (request == REQUEST_FORUM_SHARED && result == RESULT_OK) {
-			displaySnackbarShort(R.string.forum_shared_snackbar);
+		if (request == REQUEST_SHARE_FORUM && result == RESULT_OK) {
+			displaySnackbar(R.string.forum_shared_snackbar);
 		}
 	}
 
@@ -130,7 +124,7 @@ public class ForumActivity extends
 				Intent i2 = new Intent(this, ShareForumActivity.class);
 				i2.setFlags(FLAG_ACTIVITY_CLEAR_TOP | FLAG_ACTIVITY_SINGLE_TOP);
 				i2.putExtra(GROUP_ID, groupId.getBytes());
-				startActivityForResult(i2, REQUEST_FORUM_SHARED);
+				startActivityForResult(i2, REQUEST_SHARE_FORUM);
 				return true;
 			case R.id.action_forum_sharing_status:
 				Intent i3 = new Intent(this, ForumSharingStatusActivity.class);
@@ -157,12 +151,6 @@ public class ForumActivity extends
 		return R.string.forum_new_entry_posted;
 	}
 
-	@Override
-	@StringRes
-	protected int getItemReceivedString() {
-		return R.string.forum_new_entry_received;
-	}
-
 	private void showUnsubscribeDialog() {
 		OnClickListener okListener = new OnClickListener() {
 			@Override
@@ -190,8 +178,7 @@ public class ForumActivity extends
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						// TODO proper error handling
-						finish();
+						handleDbException(exception);
 					}
 				});
 	}

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

@@ -8,6 +8,7 @@ import android.support.annotation.UiThread;
 import android.support.v4.app.Fragment;
 import android.view.MenuItem;
 
+import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.briar.android.DestroyableContext;
 import org.briarproject.briar.android.activity.ActivityComponent;
 
@@ -71,6 +72,9 @@ public abstract class BaseFragment extends Fragment
 
 		@UiThread
 		void showNextFragment(BaseFragment f);
+
+		@UiThread
+		void handleDbException(DbException e);
 	}
 
 	@CallSuper
@@ -95,4 +99,9 @@ public abstract class BaseFragment extends Fragment
 		listener.showNextFragment(f);
 	}
 
+	@UiThread
+	protected void handleDbException(DbException e) {
+		listener.handleDbException(e);
+	}
+
 }

briar-android/src/main/java/org/briarproject/briar/android/invitation/AddContactActivity.java

@@ -25,6 +25,7 @@ import javax.inject.Inject;
 import static android.widget.Toast.LENGTH_LONG;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
+import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_BLUETOOTH;
 import static org.briarproject.briar.android.invitation.ConfirmationCodeView.ConfirmationState.CONNECTED;
 import static org.briarproject.briar.android.invitation.ConfirmationCodeView.ConfirmationState.DETAILS;
 import static org.briarproject.briar.android.invitation.ConfirmationCodeView.ConfirmationState.WAIT_FOR_CONTACT;
@@ -32,8 +33,6 @@ import static org.briarproject.briar.android.invitation.ConfirmationCodeView.Con
 public class AddContactActivity extends BriarActivity
 		implements InvitationListener {
 
-	static final int REQUEST_BLUETOOTH = 1;
-
 	private static final Logger LOG =
 			Logger.getLogger(AddContactActivity.class.getName());
 

briar-android/src/main/java/org/briarproject/briar/android/invitation/ChooseIdentityView.java

@@ -11,7 +11,7 @@ import org.briarproject.briar.R;
 
 import static android.bluetooth.BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE;
 import static android.bluetooth.BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION;
-import static org.briarproject.briar.android.invitation.AddContactActivity.REQUEST_BLUETOOTH;
+import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_BLUETOOTH;
 
 class ChooseIdentityView extends AddContactView implements OnClickListener {
 

briar-android/src/main/java/org/briarproject/briar/android/invitation/ErrorView.java

@@ -12,7 +12,7 @@ import org.briarproject.briar.R;
 
 import static android.bluetooth.BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE;
 import static android.bluetooth.BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION;
-import static org.briarproject.briar.android.invitation.AddContactActivity.REQUEST_BLUETOOTH;
+import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_BLUETOOTH;
 
 class ErrorView extends AddContactView implements OnClickListener {
 

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

@@ -60,7 +60,7 @@ public class KeyAgreementActivity extends BriarActivity implements
 	@Override
 	public void onCreate(@Nullable Bundle state) {
 		super.onCreate(state);
-		setContentView(R.layout.activity_plain);
+		setContentView(R.layout.activity_fragment_container_toolbar);
 
 		Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
 

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

@@ -86,6 +86,7 @@ public class ShowQrCodeFragment extends BaseEventFragment
 
 	private BluetoothStateReceiver receiver;
 	private boolean gotRemotePayload, waitingForBluetooth;
+	private volatile boolean gotLocalPayload;
 	private KeyAgreementTask task;
 
 	public static ShowQrCodeFragment newInstance() {
@@ -202,6 +203,7 @@ public class ShowQrCodeFragment extends BaseEventFragment
 		statusView.setVisibility(INVISIBLE);
 		cameraView.setVisibility(VISIBLE);
 		gotRemotePayload = false;
+		gotLocalPayload = false;
 		startListening();
 	}
 
@@ -227,6 +229,7 @@ public class ShowQrCodeFragment extends BaseEventFragment
 	public void eventOccurred(Event e) {
 		if (e instanceof KeyAgreementListeningEvent) {
 			KeyAgreementListeningEvent event = (KeyAgreementListeningEvent) e;
+			gotLocalPayload = true;
 			setQrCode(event.getLocalPayload());
 		} else if (e instanceof KeyAgreementFailedEvent) {
 			keyAgreementFailed();
@@ -341,6 +344,10 @@ public class ShowQrCodeFragment extends BaseEventFragment
 			@Override
 			public void run() {
 				LOG.info("Got result from decoder");
+				// Ignore results until the KeyAgreementTask is ready
+				if (!gotLocalPayload) {
+					return;
+				}
 				if (!gotRemotePayload) {
 					gotRemotePayload = true;
 					qrCodeScanned(result.getText());

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

@@ -19,6 +19,7 @@ import android.widget.GridView;
 import android.widget.ImageView;
 import android.widget.TextView;
 
+import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.plugin.BluetoothConstants;
 import org.briarproject.bramble.api.plugin.LanTcpConstants;
 import org.briarproject.bramble.api.plugin.TorConstants;
@@ -74,13 +75,13 @@ public class NavDrawerActivity extends BriarActivity implements
 		exitIfStartupFailed(intent);
 		// TODO don't create new instances if they are on the stack (#606)
 		if (intent.getBooleanExtra(INTENT_GROUPS, false)) {
-			startFragment(GroupListFragment.newInstance());
+			startFragment(GroupListFragment.newInstance(), R.id.nav_btn_groups);
 		} else if (intent.getBooleanExtra(INTENT_FORUMS, false)) {
-			startFragment(ForumListFragment.newInstance());
+			startFragment(ForumListFragment.newInstance(), R.id.nav_btn_forums);
 		} else if (intent.getBooleanExtra(INTENT_CONTACTS, false)) {
-			startFragment(ContactListFragment.newInstance());
+			startFragment(ContactListFragment.newInstance(), R.id.nav_btn_contacts);
 		} else if (intent.getBooleanExtra(INTENT_BLOGS, false)) {
-			startFragment(FeedFragment.newInstance());
+			startFragment(FeedFragment.newInstance(), R.id.nav_btn_blogs);
 		}
 		setIntent(null);
 	}
@@ -116,8 +117,7 @@ public class NavDrawerActivity extends BriarActivity implements
 		transportsView.setAdapter(transportsAdapter);
 
 		if (state == null) {
-			navigation.setCheckedItem(R.id.nav_btn_contacts);
-			startFragment(ContactListFragment.newInstance());
+			startFragment(ContactListFragment.newInstance(), R.id.nav_btn_contacts);
 		}
 		if (getIntent() != null) {
 			onNewIntent(getIntent());
@@ -194,8 +194,7 @@ public class NavDrawerActivity extends BriarActivity implements
 			 * exiting. This models the typical Google navigation behaviour such
 			 * as in Gmail/Inbox.
 			 */
-			navigation.setCheckedItem(R.id.nav_btn_contacts);
-			startFragment(ContactListFragment.newInstance());
+			startFragment(ContactListFragment.newInstance(), R.id.nav_btn_contacts);
 		} else {
 			super.onBackPressed();
 		}
@@ -220,6 +219,11 @@ public class NavDrawerActivity extends BriarActivity implements
 		super.signOut();
 	}
 
+	private void startFragment(BaseFragment fragment, int itemId){
+		navigation.setCheckedItem(itemId);
+		startFragment(fragment);
+	}
+
 	private void startFragment(BaseFragment fragment) {
 		if (getSupportFragmentManager().getBackStackEntryCount() == 0)
 			startFragment(fragment, false);
@@ -246,6 +250,11 @@ public class NavDrawerActivity extends BriarActivity implements
 				POP_BACK_STACK_INCLUSIVE);
 	}
 
+	@Override
+	public void handleDbException(DbException e) {
+		// Do nothing for now
+	}
+
 	private void initializeTransports(final LayoutInflater inflater) {
 		transports = new ArrayList<>(3);
 

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

@@ -4,10 +4,10 @@ import android.content.DialogInterface;
 import android.content.DialogInterface.OnClickListener;
 import android.content.Intent;
 import android.os.Bundle;
-import android.support.annotation.LayoutRes;
 import android.support.annotation.StringRes;
 import android.support.v7.app.AlertDialog;
 import android.support.v7.widget.LinearLayoutManager;
+import android.support.v7.widget.Toolbar;
 import android.view.Menu;
 import android.view.MenuInflater;
 import android.view.MenuItem;
@@ -37,6 +37,7 @@ import javax.annotation.Nullable;
 import javax.inject.Inject;
 
 import static android.view.View.GONE;
+import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_GROUP_INVITE;
 import static org.briarproject.briar.api.privategroup.PrivateGroupConstants.MAX_GROUP_POST_BODY_LENGTH;
 
 @MethodsNotNullByDefault
@@ -45,8 +46,6 @@ public class GroupActivity extends
 		ThreadListActivity<PrivateGroup, GroupMessageAdapter, GroupMessageItem, GroupMessageHeader>
 		implements GroupListener, OnClickListener {
 
-	private final static int REQUEST_INVITE = 2;
-
 	@Inject
 	GroupController controller;
 
@@ -68,15 +67,16 @@ public class GroupActivity extends
 	public void onCreate(@Nullable Bundle state) {
 		super.onCreate(state);
 
+		Toolbar toolbar = setUpCustomToolbar(false);
+
 		Intent i = getIntent();
 		String groupName = i.getStringExtra(GROUP_NAME);
 		if (groupName != null) setTitle(groupName);
 		loadNamedGroup();
 
-		// Open member list on ActionBar click
-		View actionBar = findViewById(R.id.action_bar);
-		if (actionBar != null) {
-			actionBar.setOnClickListener(
+		// Open member list on Toolbar click
+		if (toolbar != null) {
+			toolbar.setOnClickListener(
 					new View.OnClickListener() {
 						@Override
 						public void onClick(View v) {
@@ -91,12 +91,6 @@ public class GroupActivity extends
 		setGroupEnabled(false);
 	}
 
-	@Override
-	@LayoutRes
-	protected int getLayout() {
-		return R.layout.activity_forum;
-	}
-
 	@Override
 	protected GroupMessageAdapter createAdapter(
 			LinearLayoutManager layoutManager) {
@@ -115,8 +109,7 @@ public class GroupActivity extends
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						// TODO proper error handling
-						finish();
+						handleDbException(exception);
 					}
 				});
 	}
@@ -135,8 +128,7 @@ public class GroupActivity extends
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						// TODO proper error handling
-						finish();
+						handleDbException(exception);
 					}
 				});
 	}
@@ -176,7 +168,7 @@ public class GroupActivity extends
 			case R.id.action_group_invite:
 				Intent i3 = new Intent(this, GroupInviteActivity.class);
 				i3.putExtra(GROUP_ID, groupId.getBytes());
-				startActivityForResult(i3, REQUEST_INVITE);
+				startActivityForResult(i3, REQUEST_GROUP_INVITE);
 				return true;
 			case R.id.action_group_leave:
 				showLeaveGroupDialog();
@@ -190,8 +182,8 @@ public class GroupActivity extends
 
 	@Override
 	protected void onActivityResult(int request, int result, Intent data) {
-		if (request == REQUEST_INVITE && result == RESULT_OK) {
-			displaySnackbarShort(R.string.groups_invitation_sent);
+		if (request == REQUEST_GROUP_INVITE && result == RESULT_OK) {
+			displaySnackbar(R.string.groups_invitation_sent);
 		} else super.onActivityResult(request, result, data);
 	}
 
@@ -206,12 +198,6 @@ public class GroupActivity extends
 		return R.string.groups_message_sent;
 	}
 
-	@Override
-	@StringRes
-	protected int getItemReceivedString() {
-		return R.string.groups_message_received;
-	}
-
 	@Override
 	public void onReplyClick(GroupMessageItem item) {
 		if (!isDissolved) super.onReplyClick(item);
@@ -274,8 +260,7 @@ public class GroupActivity extends
 					// GroupRemovedEvent being fired
 					@Override
 					public void onExceptionUi(DbException exception) {
-						// TODO proper error handling
-						finish();
+						handleDbException(exception);
 					}
 				});
 	}

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

@@ -31,9 +31,8 @@ class GroupMessageAdapter extends ThreadItemAdapter<GroupMessageItem> {
 	@LayoutRes
 	@Override
 	public int getItemViewType(int position) {
-		GroupMessageItem item = getVisibleItem(position);
-		if (item != null) return item.getLayout();
-		return R.layout.list_item_thread;
+		GroupMessageItem item = items.get(position);
+		return item.getLayout();
 	}
 
 	@Override
@@ -58,7 +57,7 @@ class GroupMessageAdapter extends ThreadItemAdapter<GroupMessageItem> {
 			GroupMessageItem item = items.get(position);
 			if (item instanceof JoinMessageItem) {
 				((JoinMessageItem) item).setVisibility(v);
-				notifyItemChanged(getVisiblePos(item), item);
+				notifyItemChanged(findItemPosition(item), item);
 			}
 		}
 	}

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

@@ -1,6 +1,7 @@
 package org.briarproject.briar.android.privategroup.conversation;
 
 import android.support.annotation.LayoutRes;
+import android.support.annotation.Nullable;
 import android.support.annotation.UiThread;
 
 import org.briarproject.bramble.api.identity.Author;
@@ -20,9 +21,8 @@ class GroupMessageItem extends ThreadItem {
 	private final GroupId groupId;
 
 	private GroupMessageItem(MessageId messageId, GroupId groupId,
-			MessageId parentId,
-			String text, long timestamp, Author author, Status status,
-			boolean isRead) {
+			@Nullable MessageId parentId, String text, long timestamp,
+			Author author, Status status, boolean isRead) {
 		super(messageId, parentId, text, timestamp, author, status, isRead);
 		this.groupId = groupId;
 	}

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

@@ -27,11 +27,6 @@ class JoinMessageItem extends GroupMessageItem {
 		return 0;
 	}
 
-	@Override
-	public boolean hasDescendants() {
-		return false;
-	}
-
 	@Override
 	@LayoutRes
 	public int getLayout() {

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

@@ -12,7 +12,6 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.privategroup.reveal.RevealContactsActivity;
 import org.briarproject.briar.android.threaded.BaseThreadItemViewHolder;
-import org.briarproject.briar.android.threaded.ThreadItemAdapter;
 import org.briarproject.briar.android.threaded.ThreadItemAdapter.ThreadItemListener;
 
 import static org.briarproject.bramble.api.identity.Author.Status.OURSELVES;
@@ -41,10 +40,9 @@ class JoinMessageItemViewHolder
 	}
 
 	@Override
-	public void bind(ThreadItemAdapter<GroupMessageItem> adapter,
-			ThreadItemListener<GroupMessageItem> listener,
-			GroupMessageItem item, int pos) {
-		super.bind(adapter, listener, item, pos);
+	public void bind(GroupMessageItem item,
+			ThreadItemListener<GroupMessageItem> listener) {
+		super.bind(item, listener);
 
 		if (isCreator) bindForCreator((JoinMessageItem) item);
 		else bind((JoinMessageItem) item);

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

@@ -43,9 +43,8 @@ public abstract class BaseGroupInviteActivity
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						// TODO proper error handling
 						setResult(RESULT_CANCELED);
-						finish();
+						handleDbException(exception);
 					}
 				});
 		return true;

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

@@ -58,8 +58,7 @@ public class CreateGroupActivity extends BaseGroupInviteActivity implements
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						// TODO proper error handling
-						finish();
+						handleDbException(exception);
 					}
 				});
 	}

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

@@ -132,7 +132,7 @@ public class GroupListFragment extends BaseFragment implements
 					// result handled by GroupRemovedEvent and onGroupRemoved()
 					@Override
 					public void onExceptionUi(DbException exception) {
-						// TODO handle error
+						handleDbException(exception);
 					}
 				});
 	}
@@ -202,7 +202,7 @@ public class GroupListFragment extends BaseFragment implements
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						// TODO handle this error
+						handleDbException(exception);
 					}
 				});
 	}
@@ -224,8 +224,7 @@ public class GroupListFragment extends BaseFragment implements
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						// TODO handle this error
-						finish();
+						handleDbException(exception);
 					}
 				});
 	}

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

@@ -67,8 +67,7 @@ public class GroupMemberListActivity extends BriarActivity {
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						// TODO proper error handling
-						finish();
+						handleDbException(exception);
 					}
 				});
 		list.startPeriodicUpdate();

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

@@ -80,8 +80,7 @@ public class RevealContactsActivity extends ContactSelectorActivity
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						// TODO proper error handling
-						finish();
+						handleDbException(exception);
 					}
 				});
 	}
@@ -132,7 +131,7 @@ public class RevealContactsActivity extends ContactSelectorActivity
 				new UiExceptionHandler<DbException>(this) {
 					@Override
 					public void onExceptionUi(DbException exception) {
-						// TODO proper error handling
+						handleDbException(exception);
 					}
 				});
 	}
@@ -149,8 +148,7 @@ public class RevealContactsActivity extends ContactSelectorActivity
 				new UiExceptionHandler<DbException>(this) {
 					@Override
 					public void onExceptionUi(DbException exception) {
-						// TODO proper error handling
-						finish();
+						handleDbException(exception);
 					}
 				});
 		supportFinishAfterTransition();

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

@@ -45,13 +45,13 @@ import static android.media.RingtoneManager.TYPE_NOTIFICATION;
 import static android.provider.Settings.System.DEFAULT_NOTIFICATION_URI;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
+import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_RINGTONE;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
 public class SettingsFragment extends PreferenceFragmentCompat
 		implements EventListener, Preference.OnPreferenceChangeListener {
 
-	private static final int REQUEST_RINGTONE = 2;
 	public static final String SETTINGS_NAMESPACE = "android-ui";
 	public static final String PREF_NOTIFY_GROUP = "notifyGroupMessages";
 	public static final String PREF_NOTIFY_BLOG = "notifyBlogPosts";

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

@@ -97,8 +97,7 @@ public abstract class InvitationActivity<I extends InvitationItem>
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						// TODO proper error handling
-						finish();
+						handleDbException(exception);
 					}
 				});
 	}
@@ -111,8 +110,7 @@ public abstract class InvitationActivity<I extends InvitationItem>
 				new UiExceptionHandler<DbException>(this) {
 					@Override
 					public void onExceptionUi(DbException exception) {
-						// TODO proper error handling
-						finish();
+						handleDbException(exception);
 					}
 				});
 	}

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

@@ -56,10 +56,10 @@ public class ShareBlogActivity extends ShareActivity {
 				new UiExceptionHandler<DbException>(this) {
 					@Override
 					public void onExceptionUi(DbException exception) {
-						// TODO proper error handling
 						Toast.makeText(ShareBlogActivity.this,
 								R.string.blogs_sharing_error, LENGTH_SHORT)
 								.show();
+						handleDbException(exception);
 					}
 				});
 

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

@@ -10,9 +10,11 @@ import org.briarproject.bramble.api.db.NoSuchGroupException;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.GroupId;
+import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.briar.android.contactselection.ContactSelectorControllerImpl;
 import org.briarproject.briar.android.controller.handler.ExceptionHandler;
 import org.briarproject.briar.api.blog.BlogSharingManager;
+import org.briarproject.briar.api.messaging.ConversationManager;
 
 import java.util.Collection;
 import java.util.concurrent.Executor;
@@ -22,6 +24,7 @@ import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 
 import static java.util.logging.Level.WARNING;
+import static org.briarproject.bramble.util.StringUtils.isNullOrEmpty;
 
 @Immutable
 @NotNullByDefault
@@ -31,14 +34,19 @@ class ShareBlogControllerImpl extends ContactSelectorControllerImpl
 	private final static Logger LOG =
 			Logger.getLogger(ShareBlogControllerImpl.class.getName());
 
+	private final ConversationManager conversationManager;
 	private final BlogSharingManager blogSharingManager;
+	private final Clock clock;
 
 	@Inject
 	ShareBlogControllerImpl(@DatabaseExecutor Executor dbExecutor,
 			LifecycleManager lifecycleManager, ContactManager contactManager,
-			BlogSharingManager blogSharingManager) {
+			ConversationManager conversationManager,
+			BlogSharingManager blogSharingManager, Clock clock) {
 		super(dbExecutor, lifecycleManager, contactManager);
+		this.conversationManager = conversationManager;
 		this.blogSharingManager = blogSharingManager;
+		this.clock = clock;
 	}
 
 	@Override
@@ -48,15 +56,19 @@ class ShareBlogControllerImpl extends ContactSelectorControllerImpl
 
 	@Override
 	public void share(final GroupId g, final Collection<ContactId> contacts,
-			final String msg,
+			final String message,
 			final ExceptionHandler<DbException> handler) {
 		runOnDbThread(new Runnable() {
 			@Override
 			public void run() {
 				try {
+					String msg = isNullOrEmpty(message) ? null : message;
 					for (ContactId c : contacts) {
 						try {
-							blogSharingManager.sendInvitation(g, c, msg);
+							long time = Math.max(clock.currentTimeMillis(),
+									conversationManager.getGroupCount(c)
+											.getLatestMsgTime() + 1);
+							blogSharingManager.sendInvitation(g, c, msg, time);
 						} catch (NoSuchContactException | NoSuchGroupException e) {
 							if (LOG.isLoggable(WARNING))
 								LOG.log(WARNING, e.toString(), e);

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

@@ -56,10 +56,10 @@ public class ShareForumActivity extends ShareActivity {
 				new UiExceptionHandler<DbException>(this) {
 					@Override
 					public void onExceptionUi(DbException exception) {
-						// TODO proper error handling
 						Toast.makeText(ShareForumActivity.this,
 								R.string.forum_share_error, LENGTH_SHORT)
 								.show();
+						handleDbException(exception);
 					}
 				});
 	}

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

@@ -10,9 +10,11 @@ import org.briarproject.bramble.api.db.NoSuchGroupException;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.GroupId;
+import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.briar.android.contactselection.ContactSelectorControllerImpl;
 import org.briarproject.briar.android.controller.handler.ExceptionHandler;
 import org.briarproject.briar.api.forum.ForumSharingManager;
+import org.briarproject.briar.api.messaging.ConversationManager;
 
 import java.util.Collection;
 import java.util.concurrent.Executor;
@@ -22,6 +24,7 @@ import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 
 import static java.util.logging.Level.WARNING;
+import static org.briarproject.bramble.util.StringUtils.isNullOrEmpty;
 
 @Immutable
 @NotNullByDefault
@@ -31,14 +34,19 @@ class ShareForumControllerImpl extends ContactSelectorControllerImpl
 	private final static Logger LOG =
 			Logger.getLogger(ShareForumControllerImpl.class.getName());
 
+	private final ConversationManager conversationManager;
 	private final ForumSharingManager forumSharingManager;
+	private final Clock clock;
 
 	@Inject
 	ShareForumControllerImpl(@DatabaseExecutor Executor dbExecutor,
 			LifecycleManager lifecycleManager, ContactManager contactManager,
-			ForumSharingManager forumSharingManager) {
+			ConversationManager conversationManager,
+			ForumSharingManager forumSharingManager, Clock clock) {
 		super(dbExecutor, lifecycleManager, contactManager);
+		this.conversationManager = conversationManager;
 		this.forumSharingManager = forumSharingManager;
+		this.clock = clock;
 	}
 
 	@Override
@@ -48,15 +56,19 @@ class ShareForumControllerImpl extends ContactSelectorControllerImpl
 
 	@Override
 	public void share(final GroupId g, final Collection<ContactId> contacts,
-			final String msg,
+			final String message,
 			final ExceptionHandler<DbException> handler) {
 		runOnDbThread(new Runnable() {
 			@Override
 			public void run() {
 				try {
+					String msg = isNullOrEmpty(message) ? null : message;
 					for (ContactId c : contacts) {
 						try {
-							forumSharingManager.sendInvitation(g, c, msg);
+							long time = Math.max(clock.currentTimeMillis(),
+									conversationManager.getGroupCount(c)
+											.getLatestMsgTime() + 1);
+							forumSharingManager.sendInvitation(g, c, msg, time);
 						} catch (NoSuchContactException | NoSuchGroupException e) {
 							if (LOG.isLoggable(WARNING))
 								LOG.log(WARNING, e.toString(), e);

briar-android/src/main/java/org/briarproject/briar/android/splash/SplashScreenActivity.java

@@ -30,8 +30,8 @@ public class SplashScreenActivity extends BaseActivity {
 	private static final Logger LOG =
 			Logger.getLogger(SplashScreenActivity.class.getName());
 
-	// This build expires on 1 January 2017
-	private static final long EXPIRY_DATE = 1483225200 * 1000L;
+	// This build expires on 1 May 2017
+	private static final long EXPIRY_DATE = 1493593200 * 1000L;
 
 	@Inject
 	protected ConfigController configController;

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

@@ -11,6 +11,7 @@ import android.support.v4.content.ContextCompat;
 import android.support.v7.widget.RecyclerView;
 import android.view.View;
 import android.view.ViewGroup;
+import android.view.animation.AccelerateInterpolator;
 import android.widget.TextView;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
@@ -29,7 +30,6 @@ public abstract class BaseThreadItemViewHolder<I extends ThreadItem>
 	protected final TextView textView;
 	private final ViewGroup layout;
 	private final AuthorView author;
-	private final View topDivider;
 
 	public BaseThreadItemViewHolder(View v) {
 		super(v);
@@ -37,71 +37,52 @@ public abstract class BaseThreadItemViewHolder<I extends ThreadItem>
 		layout = (ViewGroup) v.findViewById(R.id.layout);
 		textView = (TextView) v.findViewById(R.id.text);
 		author = (AuthorView) v.findViewById(R.id.author);
-		topDivider = v.findViewById(R.id.top_divider);
 	}
 
-	// TODO improve encapsulation, so we don't need to pass the adapter here
 	@CallSuper
-	public void bind(final ThreadItemAdapter<I> adapter,
-			final ThreadItemListener<I> listener, final I item, int pos) {
-
+	public void bind(final I item, final ThreadItemListener<I> listener) {
 		textView.setText(StringUtils.trim(item.getText()));
 
-		if (pos == 0) {
-			topDivider.setVisibility(View.INVISIBLE);
-		} else {
-			topDivider.setVisibility(View.VISIBLE);
-		}
-
 		author.setAuthor(item.getAuthor());
 		author.setDate(item.getTimestamp());
 		author.setAuthorStatus(item.getStatus());
 
-		if (item.equals(adapter.getReplyItem())) {
-			layout.setBackgroundColor(ContextCompat
-					.getColor(getContext(), R.color.forum_cell_highlight));
-		} else if (item.equals(adapter.getAddedItem())) {
-			layout.setBackgroundColor(ContextCompat
-					.getColor(getContext(), R.color.forum_cell_highlight));
-			animateFadeOut(adapter, adapter.getAddedItem());
-			adapter.clearAddedItem();
+		if (item.isHighlighted()) {
+			layout.setActivated(true);
+		} else if (!item.isRead()) {
+			layout.setActivated(true);
+			animateFadeOut();
+			listener.onUnreadItemVisible(item);
 		} else {
-			layout.setBackgroundColor(ContextCompat
-					.getColor(getContext(), R.color.window_background));
+			layout.setActivated(false);
 		}
 	}
 
-	private void animateFadeOut(final ThreadItemAdapter<I> adapter,
-			final I addedItem) {
-
+	private void animateFadeOut() {
 		setIsRecyclable(false);
 		ValueAnimator anim = new ValueAnimator();
-		adapter.addAnimatingItem(addedItem, anim);
-		ColorDrawable viewColor = (ColorDrawable) layout.getBackground();
+		ColorDrawable viewColor = new ColorDrawable(ContextCompat
+				.getColor(getContext(), R.color.forum_cell_highlight));
 		anim.setIntValues(viewColor.getColor(), ContextCompat
 				.getColor(getContext(), R.color.window_background));
 		anim.setEvaluator(new ArgbEvaluator());
+		anim.setInterpolator(new AccelerateInterpolator());
 		anim.addListener(new Animator.AnimatorListener() {
 			@Override
 			public void onAnimationStart(Animator animation) {
-
 			}
-
 			@Override
 			public void onAnimationEnd(Animator animation) {
+				layout.setBackgroundResource(
+						R.drawable.list_item_thread_background);
+				layout.setActivated(false);
 				setIsRecyclable(true);
-				adapter.removeAnimatingItem(addedItem);
 			}
-
 			@Override
 			public void onAnimationCancel(Animator animation) {
-				setIsRecyclable(true);
-				adapter.removeAnimatingItem(addedItem);
 			}
-
 			@Override
 			public void onAnimationRepeat(Animator animation) {
-
 			}
 		});
 		anim.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {

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

@@ -23,9 +23,7 @@ public abstract class ThreadItem implements MessageNode {
 	private final Author author;
 	private final Status status;
 	private int level = UNDEFINED;
-	private boolean isShowingDescendants = true;
-	private int descendantCount = 0;
-	private boolean isRead;
+	private boolean isRead, highlighted;
 
 	public ThreadItem(MessageId messageId, @Nullable MessageId parentId,
 			String text, long timestamp, Author author, Status status,
@@ -37,6 +35,7 @@ public abstract class ThreadItem implements MessageNode {
 		this.author = author;
 		this.status = status;
 		this.isRead = isRead;
+		this.highlighted = false;
 	}
 
 	public String getText() {
@@ -71,19 +70,11 @@ public abstract class ThreadItem implements MessageNode {
 		return status;
 	}
 
-	public boolean isShowingDescendants() {
-		return isShowingDescendants;
-	}
-
 	@Override
 	public void setLevel(int level) {
 		this.level = level;
 	}
 
-	public void setShowingDescendants(boolean showingDescendants) {
-		this.isShowingDescendants = showingDescendants;
-	}
-
 	public boolean isRead() {
 		return isRead;
 	}
@@ -92,13 +83,12 @@ public abstract class ThreadItem implements MessageNode {
 		isRead = read;
 	}
 
-	public boolean hasDescendants() {
-		return descendantCount > 0;
+	public void setHighlighted(boolean highlighted) {
+		this.highlighted = highlighted;
 	}
 
-	@Override
-	public void setDescendantCount(int descendantCount) {
-		this.descendantCount = descendantCount;
+	public boolean isHighlighted() {
+		return highlighted;
 	}
 
 }

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

@@ -1,6 +1,6 @@
 package org.briarproject.briar.android.threaded;
 
-import android.animation.ValueAnimator;
+import android.support.annotation.Nullable;
 import android.support.annotation.UiThread;
 import android.support.v7.widget.LinearLayoutManager;
 import android.support.v7.widget.RecyclerView;
@@ -12,16 +12,11 @@ import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.util.VersionedAdapter;
 
-import java.util.ArrayList;
 import java.util.Collection;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-
-import javax.annotation.Nullable;
 
 import static android.support.v7.widget.RecyclerView.NO_POSITION;
 
+@UiThread
 public class ThreadItemAdapter<I extends ThreadItem>
 		extends RecyclerView.Adapter<BaseThreadItemViewHolder<I>>
 		implements VersionedAdapter {
@@ -29,15 +24,9 @@ public class ThreadItemAdapter<I extends ThreadItem>
 	static final int UNDEFINED = -1;
 
 	protected final NestedTreeList<I> items = new NestedTreeList<>();
-	private final Map<I, ValueAnimator> animatingItems = new HashMap<>();
 	private final ThreadItemListener<I> listener;
 	private final LinearLayoutManager layoutManager;
 
-	// highlight not dependant on time
-	private I replyItem;
-	// temporary highlight
-	private I addedItem;
-
 	private volatile int revision = 0;
 
 	public ThreadItemAdapter(ThreadItemListener<I> listener,
@@ -56,24 +45,23 @@ public class ThreadItemAdapter<I extends ThreadItem>
 
 	@Override
 	public void onBindViewHolder(BaseThreadItemViewHolder<I> ui, int position) {
-		I item = getVisibleItem(position);
-		if (item == null) return;
-		listener.onItemVisible(item);
-		ui.bind(this, listener, item, position);
+		I item = items.get(position);
+		ui.bind(item, listener);
 	}
 
-	/**
-	 * Contrary to the super class adapter,
-	 * this returns the number of <b>visible</b> items,
-	 * not all items in the dataset.
-	 */
 	@Override
 	public int getItemCount() {
-		return getVisiblePos(null);
+		return items.size();
 	}
 
-	I getReplyItem() {
-		return replyItem;
+	@Override
+	public int getRevision() {
+		return revision;
+	}
+
+	@Override
+	public void incrementRevision() {
+		revision++;
 	}
 
 	public void setItems(Collection<I> items) {
@@ -84,249 +72,116 @@ public class ThreadItemAdapter<I extends ThreadItem>
 
 	public void add(I item) {
 		items.add(item);
-		addedItem = item;
-		if (item.getParentId() == null) {
-			notifyItemInserted(getVisiblePos(item));
-		} else {
-			// Try to find the item's parent and perform the proper ui update if
-			// it's present and visible.
-			for (int i = items.indexOf(item) - 1; i >= 0; i--) {
-				I higherItem = items.get(i);
-				if (higherItem.getLevel() < item.getLevel()) {
-					// parent found
-					if (higherItem.isShowingDescendants()) {
-						int parentVisiblePos = getVisiblePos(higherItem);
-						if (parentVisiblePos != NO_POSITION) {
-							// parent is visible, we need to update its ui
-							notifyItemChanged(parentVisiblePos);
-							// new item insert ui
-							int visiblePos = getVisiblePos(item);
-							notifyItemInserted(visiblePos);
-							break;
-						}
-					} else {
-						// do not show the new item if its parent is not showing
-						// descendants (this can be overridden by the user by
-						// pressing the snack bar)
-						break;
-					}
-				}
-			}
-		}
+		notifyItemInserted(findItemPosition(item));
 	}
 
-	void scrollTo(I item) {
-		int visiblePos = getVisiblePos(item);
-		MessageId parentId = item.getParentId();
-		if (visiblePos == NO_POSITION && parentId != null) {
-			// The item is not visible due to being hidden by its parent item.
-			// Find the parent and make it visible and traverse up the parent
-			// chain if necessary to make the item visible
-			for (int i = items.indexOf(item) - 1; i >= 0; i--) {
-				I higherItem = items.get(i);
-				if (higherItem.getId().equals(parentId)) {
-					// parent found
-					showDescendants(higherItem);
-					int parentPos = getVisiblePos(higherItem);
-					if (parentPos != NO_POSITION) {
-						// parent or ancestor is visible, item's visibility
-						// is ensured
-						notifyItemChanged(parentPos);
-						visiblePos = parentPos;
-						break;
-					}
-					// parent or ancestor is hidden, we need to continue up the
-					// dependency chain
-					parentId = higherItem.getParentId();
-					if (parentId == null) throw new AssertionError();
-				}
-			}
+	@Nullable
+	public I getItemAt(int position) {
+		if (position == NO_POSITION || position >= items.size()) {
+			return null;
 		}
-		if (visiblePos != NO_POSITION)
-			layoutManager.scrollToPositionWithOffset(visiblePos, 0);
+		return items.get(position);
 	}
 
-	int getReplyCount(I item) {
-		int counter = 0;
-		int pos = items.indexOf(item);
-		if (pos >= 0) {
-			int ancestorLvl = item.getLevel();
-			for (int i = pos + 1; i < items.size(); i++) {
-				int descendantLvl = items.get(i).getLevel();
-				if (descendantLvl <= ancestorLvl)
-					break;
-				if (descendantLvl == ancestorLvl + 1)
-					counter++;
-			}
+	protected int findItemPosition(@Nullable I item) {
+		for (int i = 0; i < items.size(); i++) {
+			if (items.get(i).equals(item)) return i;
 		}
-		return counter;
+		return NO_POSITION; // Not found
 	}
 
-	void setReplyItem(@Nullable I item) {
-		if (replyItem != null) {
-			notifyItemChanged(getVisiblePos(replyItem));
-		}
-		replyItem = item;
-		if (replyItem != null) {
-			notifyItemChanged(getVisiblePos(replyItem));
-		}
-	}
-
-	void setReplyItemById(MessageId id) {
-		for (I item : items) {
-			if (item.getId().equals(id)) {
-				setReplyItem(item);
-				break;
-			}
-		}
-	}
-
-	private List<Integer> getSubTreeIndexes(int pos, int levelLimit) {
-		List<Integer> indexList = new ArrayList<>();
-
-		for (int i = pos + 1; i < getItemCount(); i++) {
-			I item = getVisibleItem(i);
-			if (item != null && item.getLevel() > levelLimit) {
-				indexList.add(i);
-			} else {
-				break;
-			}
-		}
-		return indexList;
-	}
-
-	public void showDescendants(I item) {
-		item.setShowingDescendants(true);
-		int visiblePos = getVisiblePos(item);
-		List<Integer> indexList =
-				getSubTreeIndexes(visiblePos, item.getLevel());
-		if (!indexList.isEmpty()) {
-			if (indexList.size() == 1) {
-				notifyItemInserted(indexList.get(0));
-			} else {
-				notifyItemRangeInserted(indexList.get(0),
-						indexList.size());
-			}
-		}
-	}
-
-	public void hideDescendants(I item) {
-		int visiblePos = getVisiblePos(item);
-		List<Integer> indexList =
-				getSubTreeIndexes(visiblePos, item.getLevel());
-		if (!indexList.isEmpty()) {
-			// stop animating children
-			for (int index : indexList) {
-				ValueAnimator anim = animatingItems.get(items.get(index));
-				if (anim != null && anim.isRunning()) {
-					anim.cancel();
-				}
-			}
-			if (indexList.size() == 1) {
-				notifyItemRemoved(indexList.get(0));
-			} else {
-				notifyItemRangeRemoved(indexList.get(0),
-						indexList.size());
-			}
-		}
-		item.setShowingDescendants(false);
-	}
-
-
 	/**
-	 * Returns the visible item at the given position
+	 * Highlights the item with the given {@link MessageId}
+	 * and disables the highlight for a previously highlighted item, if any.
 	 *
-	 * @param position is visible item index
-	 * @return the visible item at index 'position' from an ordered list of
-	 * visible items, or null if 'position' is larger than the number of
-	 * visible items.
+	 * Only one item can be highlighted at a time.
 	 */
+	void setHighlightedItem(@Nullable MessageId id) {
+		for (int i = 0; i < items.size(); i++) {
+			I item = items.get(i);
+			if (id != null && item.getId().equals(id)) {
+				item.setHighlighted(true);
+				notifyItemChanged(i, item);
+			} else if (item.isHighlighted()) {
+				item.setHighlighted(false);
+				notifyItemChanged(i, item);
+			}
+		}
+	}
+
 	@Nullable
-	public I getVisibleItem(int position) {
-		int levelLimit = UNDEFINED;
-		for (I item : items) {
-			if (levelLimit >= 0) {
-				// skip hidden items that their parent is hiding
-				if (item.getLevel() > levelLimit) {
-					continue;
-				}
-				levelLimit = UNDEFINED;
-			}
-			if (!item.isShowingDescendants()) {
-				levelLimit = item.getLevel();
-			}
-			if (position-- == 0) {
-				return item;
-			}
+	I getHighlightedItem() {
+		for (I i : items) {
+			if (i.isHighlighted()) return i;
 		}
 		return null;
 	}
 
-	boolean isVisible(I item) {
-		return getVisiblePos(item) != NO_POSITION;
+	/**
+	 * Gets the number of unread items above and below the current view port.
+	 *
+	 * Attention: Do not call this when the list is still scrolling,
+	 *            because then the view port is unknown.
+	 */
+	public UnreadCount getUnreadCount() {
+		final int positionTop = layoutManager.findFirstVisibleItemPosition();
+		final int positionBottom = layoutManager.findLastVisibleItemPosition();
+		if (positionTop == NO_POSITION && positionBottom == NO_POSITION)
+			return new UnreadCount(0, 0);
+
+		int unreadCounterTop = 0, unreadCounterBottom = 0;
+		for (int i = 0; i < items.size(); i++) {
+			I item = items.get(i);
+			if (i < positionTop && !item.isRead()) {
+				unreadCounterTop++;
+			} else if (i > positionBottom && !item.isRead()) {
+				unreadCounterBottom++;
+			}
+		}
+		return new UnreadCount(unreadCounterTop, unreadCounterBottom);
 	}
 
 	/**
-	 * Returns the visible position of the given item.
-	 *
-	 * @param item the item to find the visible position of, or null to
-	 *             return the total count of visible items.
-	 * @return the visible position of 'item', or the total number of visible
-	 * items if 'item' is null. If 'item' is not visible, NO_POSITION is
-	 * returned.
+	 * Returns the position of the first unread item below the current viewport
 	 */
-	protected int getVisiblePos(@Nullable I item) {
-		int visibleCounter = 0;
-		int levelLimit = UNDEFINED;
-		for (I i : items) {
-			if (levelLimit >= 0) {
-				if (i.getLevel() > levelLimit) {
-					// skip all the items below a non visible branch
-					continue;
-				}
-				levelLimit = UNDEFINED;
-			}
-			if (item != null && item.equals(i)) {
-				return visibleCounter;
-			} else if (!i.isShowingDescendants()) {
-				levelLimit = i.getLevel();
-			}
-			visibleCounter++;
+	public int getVisibleUnreadPosBottom() {
+		final int positionBottom = layoutManager.findLastVisibleItemPosition();
+		if (positionBottom == NO_POSITION) return NO_POSITION;
+		for (int i = positionBottom + 1; i < items.size(); i++) {
+			if (!items.get(i).isRead()) return i;
 		}
-		return item == null ? visibleCounter : NO_POSITION;
+		return NO_POSITION;
 	}
 
-	I getAddedItem() {
-		return addedItem;
+	/**
+	 * Returns the position of the first unread item above the current viewport
+	 */
+	public int getVisibleUnreadPosTop() {
+		final int positionTop = layoutManager.findFirstVisibleItemPosition();
+		int position = NO_POSITION;
+		for (int i = 0; i < items.size(); i++) {
+			if (i < positionTop && !items.get(i).isRead()) {
+				position = i;
+			} else if (i >= positionTop) {
+				return position;
+			}
+		}
+		return NO_POSITION;
 	}
 
-	void clearAddedItem() {
-		addedItem = null;
-	}
+	static class UnreadCount {
+		final int top, bottom;
 
-	void addAnimatingItem(I item, ValueAnimator anim) {
-		animatingItems.put(item, anim);
-	}
-
-	void removeAnimatingItem(I item) {
-		animatingItems.remove(item);
-	}
-
-	@Override
-	public int getRevision() {
-		return revision;
-	}
-
-	@UiThread
-	@Override
-	public void incrementRevision() {
-		revision++;
+		private UnreadCount(int top, int bottom) {
+			this.top = top;
+			this.bottom = bottom;
+		}
 	}
 
 	public interface ThreadItemListener<I> {
-
-		void onItemVisible(I item);
+		void onUnreadItemVisible(I item);
 
 		void onReplyClick(I item);
 	}
+
 }

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

@@ -3,13 +3,13 @@ package org.briarproject.briar.android.threaded;
 import android.content.Intent;
 import android.os.Bundle;
 import android.support.annotation.CallSuper;
-import android.support.annotation.LayoutRes;
+import android.support.annotation.Nullable;
 import android.support.annotation.StringRes;
 import android.support.annotation.UiThread;
 import android.support.design.widget.Snackbar;
-import android.support.v4.content.ContextCompat;
 import android.support.v7.app.ActionBar;
 import android.support.v7.widget.LinearLayoutManager;
+import android.support.v7.widget.RecyclerView;
 import android.view.MenuItem;
 import android.view.View;
 
@@ -30,18 +30,23 @@ import org.briarproject.briar.android.threaded.ThreadListController.ThreadListLi
 import org.briarproject.briar.android.view.BriarRecyclerView;
 import org.briarproject.briar.android.view.TextInputView;
 import org.briarproject.briar.android.view.TextInputView.TextInputListener;
+import org.briarproject.briar.android.view.UnreadMessageButton;
 import org.briarproject.briar.api.client.NamedGroup;
 import org.briarproject.briar.api.client.PostHeader;
+import org.thoughtcrime.securesms.components.KeyboardAwareLinearLayout;
 
 import java.util.Collection;
 import java.util.logging.Logger;
 
-import javax.annotation.Nullable;
 import javax.inject.Inject;
 
 import static android.support.design.widget.Snackbar.make;
+import static android.support.v7.widget.RecyclerView.NO_POSITION;
+import static android.support.v7.widget.RecyclerView.SCROLL_STATE_IDLE;
 import static android.view.View.GONE;
 import static android.view.View.VISIBLE;
+import static java.util.logging.Level.INFO;
+import static org.briarproject.briar.android.threaded.ThreadItemAdapter.UnreadCount;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
@@ -58,8 +63,11 @@ public abstract class ThreadListActivity<G extends NamedGroup, A extends ThreadI
 
 	protected A adapter;
 	protected BriarRecyclerView list;
+	private LinearLayoutManager layoutManager;
 	protected TextInputView textInput;
 	protected GroupId groupId;
+	private UnreadMessageButton upButton, downButton;
+	@Nullable
 	private MessageId replyId;
 
 	protected abstract ThreadListController<G, I, H> getController();
@@ -72,7 +80,7 @@ public abstract class ThreadListActivity<G extends NamedGroup, A extends ThreadI
 	public void onCreate(@Nullable Bundle state) {
 		super.onCreate(state);
 
-		setContentView(getLayout());
+		setContentView(R.layout.activity_threaded_conversation);
 
 		Intent i = getIntent();
 		byte[] b = i.getByteArrayExtra(GROUP_ID);
@@ -84,11 +92,52 @@ public abstract class ThreadListActivity<G extends NamedGroup, A extends ThreadI
 		textInput.setVisibility(GONE);
 		textInput.setListener(this);
 		list = (BriarRecyclerView) findViewById(R.id.list);
-		LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this);
-		list.setLayoutManager(linearLayoutManager);
-		adapter = createAdapter(linearLayoutManager);
+		layoutManager = new LinearLayoutManager(this);
+		list.setLayoutManager(layoutManager);
+		adapter = createAdapter(layoutManager);
 		list.setAdapter(adapter);
 
+		list.getRecyclerView().addOnScrollListener(
+				new RecyclerView.OnScrollListener() {
+					@Override
+					public void onScrolled(RecyclerView recyclerView, int dx,
+							int dy) {
+						super.onScrolled(recyclerView, dx, dy);
+						if (dx == 0 && dy == 0) {
+							// scrollToPosition has been called and finished
+							updateUnreadCount();
+						}
+					}
+					@Override
+					public void onScrollStateChanged(RecyclerView recyclerView,
+							int newState) {
+						super.onScrollStateChanged(recyclerView, newState);
+						if (newState == SCROLL_STATE_IDLE) {
+							updateUnreadCount();
+						}
+					}
+				});
+		upButton = (UnreadMessageButton) findViewById(R.id.upButton);
+		downButton = (UnreadMessageButton) findViewById(R.id.downButton);
+		upButton.setOnClickListener(new View.OnClickListener() {
+			@Override
+			public void onClick(View v) {
+				int position = adapter.getVisibleUnreadPosTop();
+				if (position != NO_POSITION) {
+					list.getRecyclerView().scrollToPosition(position);
+				}
+			}
+		});
+		downButton.setOnClickListener(new View.OnClickListener() {
+			@Override
+			public void onClick(View v) {
+				int position = adapter.getVisibleUnreadPosBottom();
+				if (position != NO_POSITION) {
+					list.getRecyclerView().scrollToPosition(position);
+				}
+			}
+		});
+
 		if (state != null) {
 			byte[] replyIdBytes = state.getByteArray(KEY_REPLY_ID);
 			if (replyIdBytes != null) replyId = new MessageId(replyIdBytes);
@@ -99,9 +148,6 @@ public abstract class ThreadListActivity<G extends NamedGroup, A extends ThreadI
 		loadSharingContacts();
 	}
 
-	@LayoutRes
-	protected abstract int getLayout();
-
 	protected abstract A createAdapter(LinearLayoutManager layoutManager);
 
 	protected void loadNamedGroup() {
@@ -114,8 +160,7 @@ public abstract class ThreadListActivity<G extends NamedGroup, A extends ThreadI
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						// TODO Proper error handling
-						finish();
+						handleDbException(exception);
 					}
 				});
 	}
@@ -137,7 +182,7 @@ public abstract class ThreadListActivity<G extends NamedGroup, A extends ThreadI
 								adapter.setItems(items);
 								list.showData();
 								if (replyId != null)
-									adapter.setReplyItemById(replyId);
+									adapter.setHighlightedItem(replyId);
 							}
 						} else {
 							LOG.info("Concurrent update, reloading");
@@ -147,8 +192,7 @@ public abstract class ThreadListActivity<G extends NamedGroup, A extends ThreadI
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						// TODO Proper error handling
-						finish();
+						handleDbException(exception);
 					}
 				});
 	}
@@ -165,9 +209,8 @@ public abstract class ThreadListActivity<G extends NamedGroup, A extends ThreadI
 					}
 
 					@Override
-					public void onExceptionUi(DbException e) {
-						// TODO Proper error handling
-						finish();
+					public void onExceptionUi(DbException exception) {
+						handleDbException(exception);
 					}
 				});
 	}
@@ -200,7 +243,7 @@ public abstract class ThreadListActivity<G extends NamedGroup, A extends ThreadI
 		super.onSaveInstanceState(outState);
 		boolean visible = textInput.getVisibility() == VISIBLE;
 		outState.putBoolean(KEY_INPUT_VISIBILITY, visible);
-		ThreadItem replyItem = adapter.getReplyItem();
+		ThreadItem replyItem = adapter.getHighlightedItem();
 		if (replyItem != null) {
 			outState.putByteArray(KEY_REPLY_ID, replyItem.getId().getBytes());
 		}
@@ -221,14 +264,14 @@ public abstract class ThreadListActivity<G extends NamedGroup, A extends ThreadI
 	public void onBackPressed() {
 		if (textInput.getVisibility() == VISIBLE) {
 			textInput.setVisibility(GONE);
-			adapter.setReplyItem(null);
+			adapter.setHighlightedItem(null);
 		} else {
 			super.onBackPressed();
 		}
 	}
 
 	@Override
-	public void onItemVisible(I item) {
+	public void onUnreadItemVisible(I item) {
 		if (!item.isRead()) {
 			item.setRead(true);
 			getController().markItemRead(item);
@@ -236,8 +279,21 @@ public abstract class ThreadListActivity<G extends NamedGroup, A extends ThreadI
 	}
 
 	@Override
-	public void onReplyClick(I item) {
+	public void onReplyClick(final I item) {
 		showTextInput(item);
+		if (textInput.isKeyboardOpen()) {
+			scrollToItemAtTop(item);
+		} else {
+			// wait with scrolling until keyboard opened
+			textInput.addOnKeyboardShownListener(
+					new KeyboardAwareLinearLayout.OnKeyboardShownListener() {
+						@Override
+						public void onKeyboardShown() {
+							scrollToItemAtTop(item);
+							textInput.removeOnKeyboardShownListener(this);
+						}
+					});
+		}
 	}
 
 	@Override
@@ -260,7 +316,15 @@ public abstract class ThreadListActivity<G extends NamedGroup, A extends ThreadI
 		}
 	}
 
-	protected void displaySnackbarShort(@StringRes int stringId) {
+	private void scrollToItemAtTop(I item) {
+		int position = adapter.findItemPosition(item);
+		if (position != NO_POSITION) {
+			layoutManager
+					.scrollToPositionWithOffset(position, 0);
+		}
+	}
+
+	protected void displaySnackbar(@StringRes int stringId) {
 		Snackbar snackbar = make(list, stringId, Snackbar.LENGTH_SHORT);
 		snackbar.getView().setBackgroundResource(R.color.briar_primary);
 		snackbar.show();
@@ -278,7 +342,8 @@ public abstract class ThreadListActivity<G extends NamedGroup, A extends ThreadI
 		textInput.showSoftKeyboard();
 		textInput.setHint(replyItem == null ? R.string.forum_new_message_hint :
 				R.string.forum_message_reply_hint);
-		adapter.setReplyItem(replyItem);
+		adapter.setHighlightedItem(
+				replyItem == null ? null : replyItem.getId());
 	}
 
 	@Override
@@ -286,10 +351,10 @@ public abstract class ThreadListActivity<G extends NamedGroup, A extends ThreadI
 		if (text.trim().length() == 0)
 			return;
 		if (StringUtils.utf8IsTooLong(text, getMaxBodyLength())) {
-			displaySnackbarShort(R.string.text_too_long);
+			displaySnackbar(R.string.text_too_long);
 			return;
 		}
-		I replyItem = adapter.getReplyItem();
+		I replyItem = adapter.getHighlightedItem();
 		UiResultExceptionHandler<I, DbException> handler =
 				new UiResultExceptionHandler<I, DbException>(this) {
 					@Override
@@ -299,15 +364,14 @@ public abstract class ThreadListActivity<G extends NamedGroup, A extends ThreadI
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						// TODO add proper exception handling
-						finish();
+						handleDbException(exception);
 					}
 				};
 		getController().createAndStoreMessage(text, replyItem, handler);
 		textInput.hideSoftKeyboard();
 		textInput.setVisibility(GONE);
 		textInput.setText("");
-		adapter.setReplyItem(null);
+		adapter.setHighlightedItem(null);
 	}
 
 	protected abstract int getMaxBodyLength();
@@ -323,8 +387,7 @@ public abstract class ThreadListActivity<G extends NamedGroup, A extends ThreadI
 
 					@Override
 					public void onExceptionUi(DbException exception) {
-						// TODO add proper exception handling
-						finish();
+						handleDbException(exception);
 					}
 				});
 	}
@@ -334,34 +397,29 @@ public abstract class ThreadListActivity<G extends NamedGroup, A extends ThreadI
 		supportFinishAfterTransition();
 	}
 
-	protected void addItem(final I item, boolean isLocal) {
+	protected void addItem(I item, boolean isLocal) {
 		adapter.incrementRevision();
 		adapter.add(item);
-		if (isLocal && adapter.isVisible(item)) {
-			displaySnackbarShort(getItemPostedString());
+
+		if (isLocal) {
+			displaySnackbar(getItemPostedString());
+			scrollToItemAtTop(item);
 		} else {
-			Snackbar snackbar = Snackbar.make(list,
-					isLocal ? getItemPostedString() : getItemReceivedString(),
-					Snackbar.LENGTH_LONG);
-			snackbar.getView().setBackgroundResource(R.color.briar_primary);
-			snackbar.setActionTextColor(ContextCompat
-					.getColor(ThreadListActivity.this,
-							R.color.briar_button_positive));
-			snackbar.setAction(R.string.show, new View.OnClickListener() {
-				@Override
-				public void onClick(View v) {
-					adapter.scrollTo(item);
-				}
-			});
-			snackbar.getView().setBackgroundResource(R.color.briar_primary);
-			snackbar.show();
+			updateUnreadCount();
 		}
 	}
 
+	private void updateUnreadCount() {
+		UnreadCount unreadCount = adapter.getUnreadCount();
+		if (LOG.isLoggable(INFO)) {
+			LOG.info("Updating unread count: top=" + unreadCount.top +
+					" bottom=" + unreadCount.bottom);
+		}
+		upButton.setUnreadCount(unreadCount.top);
+		downButton.setUnreadCount(unreadCount.bottom);
+	}
+
 	@StringRes
 	protected abstract int getItemPostedString();
 
-	@StringRes
-	protected abstract int getItemReceivedString();
-
 }

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

@@ -9,7 +9,6 @@ import org.briarproject.briar.R;
 import org.briarproject.briar.android.threaded.ThreadItemAdapter.ThreadItemListener;
 
 import static android.view.View.GONE;
-import static android.view.View.INVISIBLE;
 import static android.view.View.VISIBLE;
 
 @UiThread
@@ -17,32 +16,29 @@ import static android.view.View.VISIBLE;
 public class ThreadPostViewHolder<I extends ThreadItem>
 		extends BaseThreadItemViewHolder<I> {
 
-	private final TextView  lvlText, repliesText;
+	private final TextView  lvlText;
 	private final View[] lvls;
-	private final View chevron, replyButton;
+	private final View replyButton;
+
+	private final static int[] nestedLineIds = {
+			R.id.nested_line_1, R.id.nested_line_2, R.id.nested_line_3,
+			R.id.nested_line_4, R.id.nested_line_5
+	};
 
 	public ThreadPostViewHolder(View v) {
 		super(v);
 
 		lvlText = (TextView) v.findViewById(R.id.nested_line_text);
-		repliesText = (TextView) v.findViewById(R.id.replies);
-		int[] nestedLineIds = {
-				R.id.nested_line_1, R.id.nested_line_2, R.id.nested_line_3,
-				R.id.nested_line_4, R.id.nested_line_5
-		};
 		lvls = new View[nestedLineIds.length];
 		for (int i = 0; i < lvls.length; i++) {
 			lvls[i] = v.findViewById(nestedLineIds[i]);
 		}
-		chevron = v.findViewById(R.id.chevron);
 		replyButton = v.findViewById(R.id.btn_reply);
 	}
 
-	// TODO improve encapsulation, so we don't need to pass the adapter here
 	@Override
-	public void bind(final ThreadItemAdapter<I> adapter,
-			final ThreadItemListener<I> listener, final I item, int pos) {
-		super.bind(adapter, listener, item, pos);
+	public void bind(final I item, final ThreadItemListener<I> listener) {
+		super.bind(item, listener);
 
 		for (int i = 0; i < lvls.length; i++) {
 			lvls[i].setVisibility(i < item.getLevel() ? VISIBLE : GONE);
@@ -54,41 +50,10 @@ public class ThreadPostViewHolder<I extends ThreadItem>
 			lvlText.setVisibility(GONE);
 		}
 
-		int replies = adapter.getReplyCount(item);
-		if (replies == 0) {
-			repliesText.setText("");
-		} else {
-			repliesText.setText(getContext().getResources()
-					.getQuantityString(R.plurals.message_replies, replies,
-							replies));
-		}
-
-		if (item.hasDescendants()) {
-			chevron.setVisibility(VISIBLE);
-			if (item.isShowingDescendants()) {
-				chevron.setSelected(false);
-			} else {
-				chevron.setSelected(true);
-			}
-			chevron.setOnClickListener(new View.OnClickListener() {
-				@Override
-				public void onClick(View v) {
-					chevron.setSelected(!chevron.isSelected());
-					if (chevron.isSelected()) {
-						adapter.hideDescendants(item);
-					} else {
-						adapter.showDescendants(item);
-					}
-				}
-			});
-		} else {
-			chevron.setVisibility(INVISIBLE);
-		}
 		replyButton.setOnClickListener(new View.OnClickListener() {
 			@Override
 			public void onClick(View v) {
 				listener.onReplyClick(item);
-				adapter.scrollTo(item);
 			}
 		});
 	}

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

@@ -33,7 +33,7 @@ import static android.text.format.DateUtils.WEEK_IN_MILLIS;
 
 public class UiUtils {
 
-	public static final long MIN_RESOLUTION = MINUTE_IN_MILLIS;
+	public static final long MIN_DATE_RESOLUTION = MINUTE_IN_MILLIS;
 	public static final int TEASER_LENGTH = 320;
 	public static final float GREY_OUT = 0.5f;
 
@@ -51,15 +51,16 @@ public class UiUtils {
 				FORMAT_SHOW_DATE | FORMAT_ABBREV_TIME | FORMAT_ABBREV_MONTH;
 
 		long diff = System.currentTimeMillis() - time;
-		if (diff < MIN_RESOLUTION) return ctx.getString(R.string.now);
+		if (diff < MIN_DATE_RESOLUTION) return ctx.getString(R.string.now);
 		if (diff >= DAY_IN_MILLIS && diff < WEEK_IN_MILLIS) {
 			// also show time when older than a day, but newer than a week
 			return DateUtils.getRelativeDateTimeString(ctx, time,
-					MIN_RESOLUTION, WEEK_IN_MILLIS, flags).toString();
+					MIN_DATE_RESOLUTION, WEEK_IN_MILLIS, flags).toString();
 		}
 		// otherwise just show "...ago" or date string
 		return DateUtils.getRelativeTimeSpanString(time,
-				System.currentTimeMillis(), MIN_RESOLUTION, flags).toString();
+				System.currentTimeMillis(),
+				MIN_DATE_RESOLUTION, flags).toString();
 	}
 
 	public static SpannableStringBuilder getTeaser(Context ctx, Spanned body) {

briar-android/src/main/java/org/briarproject/briar/android/view/BriarRecyclerView.java

@@ -2,6 +2,8 @@ package org.briarproject.briar.android.view;
 
 import android.content.Context;
 import android.content.res.TypedArray;
+import android.os.Handler;
+import android.os.Looper;
 import android.support.v7.widget.RecyclerView;
 import android.support.v7.widget.RecyclerView.Adapter;
 import android.util.AttributeSet;
@@ -17,14 +19,15 @@ import java.util.logging.Logger;
 
 import javax.annotation.Nullable;
 
-import static org.briarproject.briar.android.util.UiUtils.MIN_RESOLUTION;
+import static org.briarproject.briar.android.util.UiUtils.MIN_DATE_RESOLUTION;
 
 public class BriarRecyclerView extends FrameLayout {
 
-	private static final long DEFAULT_REFRESH_INTERVAL = MIN_RESOLUTION;
 	private static final Logger LOG =
 			Logger.getLogger(BriarRecyclerView.class.getName());
 
+	private final Handler handler = new Handler(Looper.getMainLooper());
+
 	private RecyclerView recyclerView;
 	private TextView emptyView;
 	private ProgressBar progressBar;
@@ -192,18 +195,20 @@ public class BriarRecyclerView extends FrameLayout {
 			@Override
 			public void run() {
 				LOG.info("Updating Content...");
-				recyclerView.getAdapter().notifyDataSetChanged();
-				postDelayed(refresher, DEFAULT_REFRESH_INTERVAL);
+				Adapter adapter = recyclerView.getAdapter();
+				adapter.notifyItemRangeChanged(0, adapter.getItemCount());
+				handler.postDelayed(refresher, MIN_DATE_RESOLUTION);
 			}
 		};
 		LOG.info("Adding Handler Callback");
-		postDelayed(refresher, DEFAULT_REFRESH_INTERVAL);
+		handler.postDelayed(refresher, MIN_DATE_RESOLUTION);
 	}
 
 	public void stopPeriodicUpdate() {
 		if (refresher != null) {
 			LOG.info("Removing Handler Callback");
-			removeCallbacks(refresher);
+			handler.removeCallbacks(refresher);
+			refresher = null;
 		}
 	}
 

briar-android/src/main/java/org/briarproject/briar/android/view/UnreadMessageButton.java

@@ -0,0 +1,80 @@
+package org.briarproject.briar.android.view;
+
+import android.content.Context;
+import android.content.res.TypedArray;
+import android.support.annotation.Nullable;
+import android.support.annotation.UiThread;
+import android.support.design.widget.FloatingActionButton;
+import android.util.AttributeSet;
+import android.view.LayoutInflater;
+import android.widget.FrameLayout;
+import android.widget.TextView;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.briar.R;
+
+@UiThread
+@NotNullByDefault
+public class UnreadMessageButton extends FrameLayout {
+
+	private final static int UP = 0, DOWN = 1;
+
+	private final FloatingActionButton fab;
+	private final TextView unread;
+
+	public UnreadMessageButton(Context context) {
+		this(context, null);
+	}
+
+	public UnreadMessageButton(Context context, @Nullable AttributeSet attrs) {
+		this(context, attrs, 0);
+	}
+
+	public UnreadMessageButton(Context context, @Nullable AttributeSet attrs,
+			int defStyleAttr) {
+		super(context, attrs, defStyleAttr);
+
+		LayoutInflater inflater = (LayoutInflater) context
+				.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
+		inflater
+				.inflate(R.layout.unread_message_button, this, true);
+
+		fab = (FloatingActionButton) findViewById(R.id.fab);
+		unread = (TextView) findViewById(R.id.unreadCountView);
+
+		TypedArray attributes = context.obtainStyledAttributes(attrs,
+				R.styleable.UnreadMessageButton);
+		int direction = attributes
+				.getInteger(R.styleable.UnreadMessageButton_direction, DOWN);
+		setDirection(direction);
+		attributes.recycle();
+
+		setUnreadCount(0);
+	}
+
+	private void setDirection(int direction) {
+		if (direction == UP) {
+			fab.setImageResource(R.drawable.chevron_up_white);
+		} else if (direction == DOWN) {
+			fab.setImageResource(R.drawable.chevron_down_white);
+		} else {
+			throw new IllegalArgumentException();
+		}
+	}
+
+	public void setUnreadCount(int count) {
+		if (count == 0) {
+			fab.setVisibility(GONE);
+//			fab.hide();
+			unread.setVisibility(GONE);
+		} else {
+			// FIXME: Use animations when upgrading to support library 24.2.0
+			//        https://code.google.com/p/android/issues/detail?id=216469
+			fab.setVisibility(VISIBLE);
+//			if (!fab.isShown()) fab.show();
+			unread.setVisibility(VISIBLE);
+			unread.setText(String.valueOf(count));
+		}
+	}
+
+}

briar-android/src/main/res/drawable/chevron_down_white.xml

@@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+        android:width="24dp"
+        android:height="24dp"
+        android:viewportHeight="24.0"
+        android:viewportWidth="24.0">
+	<path
+		android:fillColor="#FFFFFFFF"
+		android:pathData="M7.41,7.84L12,12.42l4.59,-4.58L18,9.25l-6,6 -6,-6z"/>
+</vector>

briar-android/src/main/res/drawable/chevron_up_white.xml

@@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+        android:width="24dp"
+        android:height="24dp"
+        android:viewportHeight="24.0"
+        android:viewportWidth="24.0">
+	<path
+		android:fillColor="#FFFFFFFF"
+		android:pathData="M7.41,15.41L12,10.83l4.59,4.58L18,14l-6,-6 -6,6z"/>
+</vector>

briar-android/src/main/res/drawable/list_item_thread_background.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<selector
+	xmlns:android="http://schemas.android.com/apk/res/android">
+
+	<item
+		android:drawable="@color/forum_cell_highlight"
+		android:state_activated="true"/>
+	<item
+		android:drawable="@color/window_background"/>
+
+</selector>

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

@@ -11,17 +11,7 @@
 		android:orientation="vertical"
 		tools:context=".android.reporting.DevReportActivity">
 
-		<android.support.design.widget.AppBarLayout
-			android:layout_width="match_parent"
-			android:layout_height="wrap_content">
-
-			<android.support.v7.widget.Toolbar
-				android:id="@+id/toolbar"
-				style="@style/BriarToolbar"
-				android:layout_width="match_parent"
-				android:layout_height="wrap_content"/>
-
-		</android.support.design.widget.AppBarLayout>
+		<include layout="@layout/toolbar"/>
 
 		<RelativeLayout
 			android:layout_width="match_parent"

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

@@ -1,25 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<LinearLayout
-	xmlns:android="http://schemas.android.com/apk/res/android"
-	xmlns:app="http://schemas.android.com/apk/res-auto"
-	android:layout_width="match_parent"
-	android:layout_height="match_parent"
-	android:orientation="vertical">
-
-	<org.briarproject.briar.android.view.BriarRecyclerView
-		android:id="@+id/list"
-		android:layout_width="match_parent"
-		android:layout_height="0dp"
-		android:layout_weight="1"
-		app:emptyText="@string/no_forum_posts"
-		app:scrollToEnd="false"/>
-
-	<org.briarproject.briar.android.view.TextInputView
-		android:id="@+id/text_input_container"
-		android:layout_width="match_parent"
-		android:layout_height="wrap_content"
-		android:background="@color/button_bar_background"
-		android:elevation="@dimen/margin_tiny"
-		app:hint="@string/forum_new_message_hint"/>
-
-</LinearLayout>

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

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout
+	xmlns:android="http://schemas.android.com/apk/res/android"
+	xmlns:tools="http://schemas.android.com/tools"
+	android:layout_width="match_parent"
+	android:layout_height="match_parent"
+	android:orientation="vertical"
+	tools:context=".android.keyagreement.KeyAgreementActivity">
+
+	<include layout="@layout/toolbar"/>
+
+	<FrameLayout
+		android:id="@+id/fragmentContainer"
+		xmlns:android="http://schemas.android.com/apk/res/android"
+		android:layout_width="match_parent"
+		android:layout_height="match_parent"/>
+
+</LinearLayout>

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

@@ -2,8 +2,10 @@
 <android.support.v4.widget.DrawerLayout
 	android:id="@+id/drawer_layout"
 	xmlns:android="http://schemas.android.com/apk/res/android"
+	xmlns:tools="http://schemas.android.com/tools"
 	android:layout_width="match_parent"
-	android:layout_height="match_parent">
+	android:layout_height="match_parent"
+	tools:context=".android.navdrawer.NavDrawerActivity">
 
 	<!-- The first child(root) is the content view -->
 	<LinearLayout
@@ -11,17 +13,7 @@
 		android:layout_height="match_parent"
 		android:orientation="vertical">
 
-		<android.support.design.widget.AppBarLayout
-			android:layout_width="match_parent"
-			android:layout_height="wrap_content">
-
-			<android.support.v7.widget.Toolbar
-				android:id="@+id/toolbar"
-				style="@style/BriarToolbar"
-				android:layout_width="match_parent"
-				android:layout_height="wrap_content"/>
-
-		</android.support.design.widget.AppBarLayout>
+		<include layout="@layout/toolbar"/>
 
 		<FrameLayout
 			android:id="@+id/fragmentContainer"

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

@@ -1,26 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<LinearLayout
-	xmlns:android="http://schemas.android.com/apk/res/android"
-	android:layout_width="match_parent"
-	android:layout_height="match_parent"
-	android:orientation="vertical">
-
-	<android.support.design.widget.AppBarLayout
-		android:layout_width="match_parent"
-		android:layout_height="wrap_content">
-
-		<android.support.v7.widget.Toolbar
-			android:id="@+id/toolbar"
-			style="@style/BriarToolbar"
-			android:layout_width="match_parent"
-			android:layout_height="wrap_content"/>
-
-	</android.support.design.widget.AppBarLayout>
-
-	<FrameLayout
-		android:id="@+id/fragmentContainer"
-		android:layout_width="match_parent"
-		android:layout_height="match_parent"
-		android:background="@color/window_background"/>
-
-</LinearLayout>

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

@@ -0,0 +1,49 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout
+	xmlns:android="http://schemas.android.com/apk/res/android"
+	xmlns:app="http://schemas.android.com/apk/res-auto"
+	xmlns:tools="http://schemas.android.com/tools"
+	android:layout_width="match_parent"
+	android:layout_height="match_parent"
+	android:orientation="vertical"
+	tools:context=".android.forum.ForumActivity">
+
+	<include layout="@layout/toolbar"/>
+
+	<FrameLayout
+		android:layout_width="match_parent"
+		android:layout_height="0dp"
+		android:layout_weight="1">
+
+		<org.briarproject.briar.android.view.BriarRecyclerView
+			android:id="@+id/list"
+			android:layout_width="match_parent"
+			android:layout_height="match_parent"
+			app:emptyText="@string/no_forum_posts"
+			app:scrollToEnd="false"/>
+
+		<org.briarproject.briar.android.view.UnreadMessageButton
+			android:id="@+id/upButton"
+			android:layout_width="wrap_content"
+			android:layout_height="wrap_content"
+			android:layout_gravity="top|right"
+			app:direction="up"/>
+
+		<org.briarproject.briar.android.view.UnreadMessageButton
+			android:id="@+id/downButton"
+			android:layout_width="wrap_content"
+			android:layout_height="wrap_content"
+			android:layout_gravity="bottom|right"
+			app:direction="down"/>
+
+	</FrameLayout>
+
+	<org.briarproject.briar.android.view.TextInputView
+		android:id="@+id/text_input_container"
+		android:layout_width="match_parent"
+		android:layout_height="wrap_content"
+		android:background="@color/button_bar_background"
+		android:elevation="@dimen/margin_tiny"
+		app:hint="@string/forum_new_message_hint"/>
+
+</LinearLayout>

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

@@ -43,7 +43,7 @@
 			android:layout_height="wrap_content"
 			android:layout_alignEnd="@+id/text"
 			android:layout_alignRight="@+id/text"
-			android:layout_below="@+id/declineButton"
+			android:layout_below="@+id/acceptButton"
 			android:layout_marginTop="@dimen/message_bubble_timestamp_margin"
 			android:textColor="@color/private_message_date"
 			android:textSize="@dimen/text_size_tiny"
@@ -57,6 +57,7 @@
 			android:layout_alignEnd="@+id/text"
 			android:layout_alignRight="@+id/text"
 			android:layout_below="@+id/text"
+			android:layout_marginBottom="-10dp"
 			android:text="@string/accept"/>
 
 		<Button
@@ -64,8 +65,8 @@
 			style="@style/BriarButtonFlat.Negative"
 			android:layout_width="wrap_content"
 			android:layout_height="wrap_content"
-			android:layout_below="@+id/text"
-			android:layout_marginBottom="-15dp"
+			android:layout_alignBottom="@+id/acceptButton"
+			android:layout_alignTop="@+id/acceptButton"
 			android:layout_toLeftOf="@+id/acceptButton"
 			android:layout_toStartOf="@+id/acceptButton"
 			android:text="@string/decline"/>

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

@@ -60,7 +60,7 @@
 		tools:text="Dec 24"/>
 
 	<View
-		style="@style/Divider.ForumList"
+		style="@style/Divider.ThreadItem"
 		android:layout_alignParentLeft="true"
 		android:layout_alignParentStart="true"
 		android:layout_below="@+id/postCountView"/>

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

@@ -97,7 +97,7 @@
 
 	<View
 		android:id="@+id/divider"
-		style="@style/Divider.ForumList"
+		style="@style/Divider.ThreadItem"
 		android:layout_alignParentLeft="true"
 		android:layout_alignParentStart="true"
 		android:layout_below="@+id/statusView"

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

@@ -6,23 +6,14 @@
 	xmlns:tools="http://schemas.android.com/tools"
 	android:layout_width="match_parent"
 	android:layout_height="wrap_content"
-	android:layout_marginLeft="@dimen/margin_medium"
 	android:baselineAligned="false"
 	android:orientation="vertical">
 
-	<View
-		android:id="@+id/top_divider"
-		style="@style/Divider.ForumList"
-		android:layout_alignParentTop="true"/>
-
 	<org.thoughtcrime.securesms.components.emoji.EmojiTextView
 		android:id="@+id/text"
 		android:layout_width="match_parent"
 		android:layout_height="wrap_content"
-		android:layout_below="@+id/top_divider"
-		android:layout_marginBottom="@dimen/margin_small"
-		android:layout_marginRight="@dimen/margin_medium"
-		android:layout_marginTop="@dimen/margin_medium"
+		android:layout_margin="@dimen/margin_medium"
 		android:textColor="@color/briar_text_secondary"
 		android:textSize="@dimen/text_size_medium"
 		android:textStyle="italic"
@@ -32,9 +23,12 @@
 		android:id="@+id/icon"
 		android:layout_width="wrap_content"
 		android:layout_height="wrap_content"
+		android:layout_alignBottom="@+id/info"
 		android:layout_alignLeft="@+id/text"
+		android:layout_alignTop="@+id/info"
 		android:layout_below="@+id/text"
-		android:layout_marginRight="@dimen/margin_small"
+		android:layout_marginRight="@dimen/margin_medium"
+		android:scaleType="center"
 		tools:ignore="ContentDescription"
 		tools:src="@drawable/ic_visibility"/>
 
@@ -45,6 +39,7 @@
 		android:layout_alignEnd="@+id/text"
 		android:layout_alignRight="@+id/text"
 		android:layout_below="@+id/text"
+		android:layout_marginBottom="@dimen/margin_medium"
 		android:layout_toRightOf="@+id/icon"
 		android:gravity="center_vertical"
 		android:minHeight="24dp"
@@ -57,10 +52,10 @@
 	<org.briarproject.briar.android.view.AuthorView
 		android:id="@+id/author"
 		android:layout_width="wrap_content"
-		android:layout_height="@dimen/button_size"
+		android:layout_height="wrap_content"
 		android:layout_alignLeft="@+id/text"
 		android:layout_below="@+id/info"
-		android:gravity="center"
+		android:layout_toLeftOf="@+id/optionsButton"
 		app:persona="commenter"/>
 
 	<Button
@@ -68,11 +63,16 @@
 		style="@style/BriarButtonFlat.Positive.Tiny"
 		android:layout_width="wrap_content"
 		android:layout_height="wrap_content"
+		android:layout_alignBottom="@+id/author"
 		android:layout_alignEnd="@+id/text"
 		android:layout_alignRight="@+id/text"
-		android:layout_alignTop="@+id/author"
-		android:layout_toRightOf="@+id/author"
+		android:layout_below="@+id/info"
 		android:gravity="right|center_vertical"
 		android:text="@string/options"/>
 
+	<View
+		style="@style/Divider.ThreadItem"
+		android:layout_below="@+id/author"
+		android:layout_marginTop="@dimen/margin_medium"/>
+
 </RelativeLayout>

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

@@ -81,7 +81,7 @@
 		android:text="@string/decline"/>
 
 	<View
-		style="@style/Divider.ForumList"
+		style="@style/Divider.ThreadItem"
 		android:layout_alignParentLeft="true"
 		android:layout_alignParentStart="true"
 		android:layout_below="@+id/acceptButton"/>

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

@@ -113,7 +113,7 @@
 		tools:text="This is a description of the RSS feed. It can be several lines long, but it can also not exist at all if it is not present in the feed itself."/>
 
 	<View
-		style="@style/Divider.ForumList"
+		style="@style/Divider.ThreadItem"
 		android:layout_alignParentLeft="true"
 		android:layout_alignParentStart="true"
 		android:layout_below="@+id/descriptionView"

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

@@ -6,6 +6,7 @@
 	xmlns:tools="http://schemas.android.com/tools"
 	android:layout_width="match_parent"
 	android:layout_height="wrap_content"
+	android:background="@drawable/list_item_thread_background"
 	android:baselineAligned="false"
 	android:orientation="horizontal">
 
@@ -61,23 +62,20 @@
 			android:background="@drawable/level_indicator_circle"
 			android:gravity="center"
 			android:textSize="@dimen/text_size_small"
-			android:visibility="gone"
-			/>
+			android:visibility="gone"/>
 
 	</RelativeLayout>
 
 	<RelativeLayout
 		android:layout_width="0dp"
 		android:layout_height="wrap_content"
-		android:layout_marginLeft="@dimen/margin_medium"
 		android:layout_weight="1">
 
 		<org.thoughtcrime.securesms.components.emoji.EmojiTextView
 			android:id="@+id/text"
 			android:layout_width="match_parent"
 			android:layout_height="wrap_content"
-			android:paddingRight="@dimen/margin_medium"
-			android:paddingTop="@dimen/margin_medium"
+			android:padding="@dimen/margin_medium"
 			android:textColor="@color/briar_text_primary"
 			android:textIsSelectable="true"
 			android:textSize="@dimen/text_size_medium"
@@ -86,26 +84,12 @@
 		<org.briarproject.briar.android.view.AuthorView
 			android:id="@+id/author"
 			android:layout_width="wrap_content"
-			android:layout_height="@dimen/button_size"
+			android:layout_height="wrap_content"
 			android:layout_alignLeft="@id/text"
 			android:layout_below="@id/text"
-			android:gravity="center"
-			app:persona="commenter"/>
-
-		<TextView
-			android:id="@+id/replies"
-			android:layout_width="wrap_content"
-			android:layout_height="wrap_content"
-			android:layout_alignBottom="@+id/author"
-			android:layout_alignTop="@+id/author"
+			android:layout_marginLeft="@dimen/margin_medium"
 			android:layout_toLeftOf="@+id/btn_reply"
-			android:layout_toRightOf="@+id/author"
-			android:ellipsize="end"
-			android:gravity="right|end|center_vertical"
-			android:maxLines="1"
-			android:padding="@dimen/margin_medium"
-			android:textSize="@dimen/text_size_tiny"
-			tools:text="2 replies"/>
+			app:persona="commenter"/>
 
 		<TextView
 			android:id="@+id/btn_reply"
@@ -113,31 +97,18 @@
 			android:layout_width="wrap_content"
 			android:layout_height="wrap_content"
 			android:layout_alignBottom="@+id/author"
-			android:layout_toLeftOf="@+id/chevron"
+			android:layout_alignParentRight="true"
+			android:layout_below="@+id/text"
+			android:layout_marginRight="@dimen/margin_medium"
 			android:text="@string/btn_reply"
 			android:textSize="@dimen/text_size_tiny"/>
 
-		<ImageView
-			android:id="@+id/chevron"
-			android:layout_width="@dimen/button_size"
-			android:layout_height="@dimen/button_size"
-			android:layout_alignBottom="@+id/author"
-			android:layout_alignParentRight="true"
-			android:background="?attr/selectableItemBackground"
-			android:clickable="true"
-			android:padding="@dimen/margin_medium"
-			android:scaleType="center"
-			android:src="@drawable/selector_chevron"/>
-
 		<View
-			android:id="@+id/top_divider"
-			style="@style/Divider.ForumList"
-			android:layout_width="match_parent"
-			android:layout_height="@dimen/margin_separator"
+			style="@style/Divider.ThreadItem"
 			android:layout_alignLeft="@id/text"
-			android:layout_alignParentTop="true"/>
+			android:layout_below="@+id/author"
+			android:layout_marginTop="@dimen/margin_medium"/>
 
 	</RelativeLayout>
 
-
-</LinearLayout>
+</LinearLayout>