[android] enable image shared element transition for API 21+22

There's an Android framework bug (#224270) on these APIs that causes a NPE
when the shared element is not visible anymore when returning.
Since we know restore the list position, the shared element should be
visible and thus not produce NPEs anymore.

bramble-android/src/main/java/org/briarproject/bramble/plugin/bluetooth/AndroidBluetoothPlugin.java

@@ -18,8 +18,8 @@ import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
 import org.briarproject.bramble.api.system.AndroidExecutor;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.util.AndroidUtils;
+import org.briarproject.bramble.util.IoUtils;
 
-import java.io.Closeable;
 import java.io.IOException;
 import java.security.SecureRandom;
 import java.util.ArrayList;
@@ -51,7 +51,6 @@ import static android.bluetooth.BluetoothDevice.EXTRA_DEVICE;
 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.util.LogUtils.logException;
 import static org.briarproject.bramble.util.PrivacyUtils.scrubMacAddress;
 
 @MethodsNotNullByDefault
@@ -161,11 +160,7 @@ class AndroidBluetoothPlugin extends BluetoothPlugin<BluetoothServerSocket> {
 
 	@Override
 	void tryToClose(@Nullable BluetoothServerSocket ss) {
-		try {
-			if (ss != null) ss.close();
-		} catch (IOException e) {
-			logException(LOG, WARNING, e);
-		}
+		IoUtils.tryToClose(ss, LOG, WARNING);
 	}
 
 	@Override
@@ -195,7 +190,7 @@ class AndroidBluetoothPlugin extends BluetoothPlugin<BluetoothServerSocket> {
 			s.connect();
 			return wrapSocket(s);
 		} catch (IOException e) {
-			tryToClose(s);
+			IoUtils.tryToClose(s, LOG, WARNING);
 			throw e;
 		}
 	}
@@ -268,14 +263,6 @@ class AndroidBluetoothPlugin extends BluetoothPlugin<BluetoothServerSocket> {
 		return addresses;
 	}
 
-	private void tryToClose(@Nullable Closeable c) {
-		try {
-			if (c != null) c.close();
-		} catch (IOException e) {
-			logException(LOG, WARNING, e);
-		}
-	}
-
 	private class BluetoothStateReceiver extends BroadcastReceiver {
 
 		@Override

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

@@ -1,5 +1,6 @@
 package org.briarproject.bramble.system;
 
+import android.annotation.SuppressLint;
 import android.app.Application;
 import android.bluetooth.BluetoothAdapter;
 import android.bluetooth.BluetoothDevice;
@@ -26,7 +27,7 @@ import static android.provider.Settings.Secure.ANDROID_ID;
 
 @Immutable
 @NotNullByDefault
-class AndroidSecureRandomProvider extends LinuxSecureRandomProvider {
+class AndroidSecureRandomProvider extends UnixSecureRandomProvider {
 
 	private static final int SEED_LENGTH = 32;
 
@@ -37,6 +38,7 @@ class AndroidSecureRandomProvider extends LinuxSecureRandomProvider {
 		appContext = app.getApplicationContext();
 	}
 
+	@SuppressLint("HardwareIds")
 	@Override
 	protected void writeToEntropyPool(DataOutputStream out) throws IOException {
 		super.writeToEntropyPool(out);
@@ -49,12 +51,14 @@ class AndroidSecureRandomProvider extends LinuxSecureRandomProvider {
 		String id = Settings.Secure.getString(contentResolver, ANDROID_ID);
 		if (id != null) out.writeUTF(id);
 		Parcel parcel = Parcel.obtain();
-		WifiManager wm =
-				(WifiManager) appContext.getSystemService(WIFI_SERVICE);
-		List<WifiConfiguration> configs = wm.getConfiguredNetworks();
-		if (configs != null) {
-			for (WifiConfiguration config : configs)
-				parcel.writeParcelable(config, 0);
+		WifiManager wm = (WifiManager) appContext.getApplicationContext()
+				.getSystemService(WIFI_SERVICE);
+		if (wm != null) {
+			List<WifiConfiguration> configs = wm.getConfiguredNetworks();
+			if (configs != null) {
+				for (WifiConfiguration config : configs)
+					parcel.writeParcelable(config, 0);
+			}
 		}
 		BluetoothAdapter bt = BluetoothAdapter.getDefaultAdapter();
 		if (bt != null) {
@@ -77,13 +81,13 @@ class AndroidSecureRandomProvider extends LinuxSecureRandomProvider {
 
 	// Based on https://android-developers.googleblog.com/2013/08/some-securerandom-thoughts.html
 	private void applyOpenSslFix() {
-		byte[] seed = new LinuxSecureRandomSpi().engineGenerateSeed(
+		byte[] seed = new UnixSecureRandomSpi().engineGenerateSeed(
 				SEED_LENGTH);
 		try {
 			// Seed the OpenSSL PRNG
 			Class.forName("org.apache.harmony.xnet.provider.jsse.NativeCrypto")
 					.getMethod("RAND_seed", byte[].class)
-					.invoke(null, seed);
+					.invoke(null, (Object) seed);
 			// Mix the output of the Linux PRNG into the OpenSSL PRNG
 			int bytesRead = (Integer) Class.forName(
 					"org.apache.harmony.xnet.provider.jsse.NativeCrypto")

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

@@ -13,6 +13,8 @@ import java.util.Collection;
 
 import javax.annotation.Nullable;
 
+import static org.briarproject.bramble.api.contact.PendingContact.PendingContactState.FAILED;
+
 @NotNullByDefault
 public interface ContactManager {
 
@@ -52,6 +54,35 @@ public interface ContactManager {
 			long timestamp, boolean alice, boolean verified, boolean active)
 			throws DbException;
 
+	/**
+	 * Returns the static link that needs to be sent to the contact to be added.
+	 */
+	String getRemoteContactLink();
+
+	/**
+	 * Returns true if the given link is syntactically valid.
+	 */
+	boolean isValidRemoteContactLink(String link);
+
+	/**
+	 * Requests a new contact to be added via the given {@code link}.
+	 *
+	 * @param link The link received from the contact we want to add.
+	 * @param alias The alias the user has given this contact.
+	 * @return A PendingContact representing the contact to be added.
+	 */
+	PendingContact addRemoteContactRequest(String link, String alias);
+
+	/**
+	 * Returns a list of {@link PendingContact}s.
+	 */
+	Collection<PendingContact> getPendingContacts();
+
+	/**
+	 * Removes a {@link PendingContact} that is in state {@link FAILED}.
+	 */
+	void removePendingContact(PendingContact pendingContact);
+
 	/**
 	 * Returns the contact with the given ID.
 	 */

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

@@ -0,0 +1,54 @@
+package org.briarproject.bramble.api.contact;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.concurrent.Immutable;
+
+@Immutable
+@NotNullByDefault
+public class PendingContact {
+
+	public enum PendingContactState {
+		WAITING_FOR_CONNECTION,
+		CONNECTED,
+		ADDING_CONTACT,
+		FAILED
+	}
+
+	private final PendingContactId id;
+	private final String alias;
+	private final PendingContactState state;
+	private final long timestamp;
+
+	public PendingContact(PendingContactId id, String alias,
+			PendingContactState state, long timestamp) {
+		this.id = id;
+		this.alias = alias;
+		this.state = state;
+		this.timestamp = timestamp;
+	}
+
+	public String getAlias() {
+		return alias;
+	}
+
+	public PendingContactState getState() {
+		return state;
+	}
+
+	public long getTimestamp() {
+		return timestamp;
+	}
+
+	@Override
+	public int hashCode() {
+		return id.hashCode();
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		return o instanceof PendingContact &&
+				id.equals(((PendingContact) o).id);
+	}
+
+}

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

@@ -0,0 +1,11 @@
+package org.briarproject.bramble.api.contact;
+
+import org.briarproject.bramble.api.UniqueId;
+
+public class PendingContactId extends UniqueId {
+
+	public PendingContactId(byte[] id) {
+		super(id);
+	}
+
+}

bramble-api/src/main/java/org/briarproject/bramble/api/contact/event/PendingContactStateChangedEvent.java

@@ -0,0 +1,34 @@
+package org.briarproject.bramble.api.contact.event;
+
+import org.briarproject.bramble.api.contact.PendingContact.PendingContactState;
+import org.briarproject.bramble.api.contact.PendingContactId;
+import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * An event that is broadcast when a pending contact's state is changed.
+ */
+@Immutable
+@NotNullByDefault
+public class PendingContactStateChangedEvent extends Event {
+
+	private final PendingContactId id;
+	private final PendingContactState state;
+
+	public PendingContactStateChangedEvent(PendingContactId id,
+			PendingContactState state) {
+		this.id = id;
+		this.state = state;
+	}
+
+	public PendingContactId getId() {
+		return id;
+	}
+
+	public PendingContactState getPendingContactState() {
+		return state;
+	}
+
+}

bramble-api/src/main/java/org/briarproject/bramble/api/versioning/ClientVersioningManager.java

@@ -38,6 +38,13 @@ public interface ClientVersioningManager {
 	Visibility getClientVisibility(Transaction txn, ContactId contactId,
 			ClientId clientId, int majorVersion) throws DbException;
 
+	/**
+	 * Returns the minor version of the given client that is supported by the
+	 * given contact, or -1 if the contact does not support the client.
+	 */
+	int getClientMinorVersion(Transaction txn, ContactId contactId,
+			ClientId clientId, int majorVersion) throws DbException;
+
 	interface ClientVersioningHook {
 
 		void onClientVisibilityChanging(Transaction txn, Contact c,

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

@@ -8,12 +8,15 @@ import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.net.ServerSocket;
 import java.net.Socket;
+import java.util.logging.Level;
 import java.util.logging.Logger;
 
 import javax.annotation.Nullable;
 
 import static java.util.logging.Level.WARNING;
+import static org.briarproject.bramble.util.LogUtils.logException;
 
 @NotNullByDefault
 public class IoUtils {
@@ -54,16 +57,35 @@ public class IoUtils {
 			out.flush();
 			out.close();
 		} catch (IOException e) {
-			tryToClose(in);
-			tryToClose(out);
+			tryToClose(in, LOG, WARNING);
+			tryToClose(out, LOG, WARNING);
 		}
 	}
 
-	private static void tryToClose(@Nullable Closeable c) {
+	public static void tryToClose(@Nullable Closeable c, Logger logger,
+			Level level) {
 		try {
 			if (c != null) c.close();
 		} catch (IOException e) {
-			// We did our best
+			logException(logger, level, e);
+		}
+	}
+
+	public static void tryToClose(@Nullable Socket s, Logger logger,
+			Level level) {
+		try {
+			if (s != null) s.close();
+		} catch (IOException e) {
+			logException(logger, level, e);
+		}
+	}
+
+	public static void tryToClose(@Nullable ServerSocket ss, Logger logger,
+			Level level) {
+		try {
+			if (ss != null) ss.close();
+		} catch (IOException e) {
+			logException(logger, level, e);
 		}
 	}
 

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

@@ -10,8 +10,6 @@ public class OsUtils {
 	@Nullable
 	private static final String os = System.getProperty("os.name");
 	@Nullable
-	private static final String version = System.getProperty("os.version");
-	@Nullable
 	private static final String vendor = System.getProperty("java.vendor");
 
 	public static boolean isWindows() {

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

@@ -3,6 +3,8 @@ package org.briarproject.bramble.contact;
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.ContactManager;
+import org.briarproject.bramble.api.contact.PendingContact;
+import org.briarproject.bramble.api.contact.PendingContactId;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.DbException;
@@ -19,12 +21,16 @@ import org.briarproject.bramble.api.transport.KeyManager;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
+import java.util.Random;
 import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.regex.Pattern;
 
 import javax.annotation.Nullable;
 import javax.annotation.concurrent.ThreadSafe;
 import javax.inject.Inject;
 
+import static java.util.Collections.emptyList;
+import static org.briarproject.bramble.api.contact.PendingContact.PendingContactState.WAITING_FOR_CONNECTION;
 import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_AUTHOR_NAME_LENGTH;
 import static org.briarproject.bramble.api.identity.AuthorInfo.Status.OURSELVES;
 import static org.briarproject.bramble.api.identity.AuthorInfo.Status.UNKNOWN;
@@ -36,6 +42,12 @@ import static org.briarproject.bramble.util.StringUtils.toUtf8;
 @NotNullByDefault
 class ContactManagerImpl implements ContactManager {
 
+	private static final int LINK_LENGTH = 64;
+	private static final String REMOTE_CONTACT_LINK =
+			"briar://" + getRandomBase32String(LINK_LENGTH);
+	private static final Pattern LINK_REGEX =
+			Pattern.compile("(briar://)?([a-z2-7]{" + LINK_LENGTH + "})");
+
 	private final DatabaseComponent db;
 	private final KeyManager keyManager;
 	private final IdentityManager identityManager;
@@ -84,6 +96,48 @@ class ContactManagerImpl implements ContactManager {
 						verified, active));
 	}
 
+	@Override
+	public String getRemoteContactLink() {
+		// TODO replace with real implementation
+		return REMOTE_CONTACT_LINK;
+	}
+
+	@SuppressWarnings("SameParameterValue")
+	private static String getRandomBase32String(int length) {
+		Random random = new Random();
+		char[] c = new char[length];
+		for (int i = 0; i < length; i++) {
+			int character = random.nextInt(32);
+			if (character < 26) c[i] = (char) ('a' + character);
+			else c[i] = (char) ('2' + (character - 26));
+		}
+		return new String(c);
+	}
+
+	@Override
+	public boolean isValidRemoteContactLink(String link) {
+		return LINK_REGEX.matcher(link).matches();
+	}
+
+	@Override
+	public PendingContact addRemoteContactRequest(String link, String alias) {
+		// TODO replace with real implementation
+		PendingContactId id = new PendingContactId(link.getBytes());
+		return new PendingContact(id, alias, WAITING_FOR_CONNECTION,
+				System.currentTimeMillis());
+	}
+
+	@Override
+	public Collection<PendingContact> getPendingContacts() {
+		// TODO replace with real implementation
+		return emptyList();
+	}
+
+	@Override
+	public void removePendingContact(PendingContact pendingContact) {
+		// TODO replace with real implementation
+	}
+
 	@Override
 	public Contact getContact(ContactId c) throws DbException {
 		return db.transactionWithResult(true, txn -> db.getContact(txn, c));

bramble-core/src/main/java/org/briarproject/bramble/db/H2Database.java

@@ -15,16 +15,23 @@ import java.sql.DriverManager;
 import java.sql.SQLException;
 import java.sql.Statement;
 import java.util.Properties;
+import java.util.logging.Logger;
 
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
+import static java.util.logging.Level.WARNING;
+import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.db.JdbcUtils.tryToClose;
+
 /**
  * Contains all the H2-specific code for the database.
  */
 @NotNullByDefault
 class H2Database extends JdbcDatabase {
 
+	private static final Logger LOG = getLogger(H2Database.class.getName());
+
 	private static final String HASH_TYPE = "BINARY(32)";
 	private static final String SECRET_TYPE = "BINARY(32)";
 	private static final String BINARY_TYPE = "BINARY";
@@ -121,8 +128,8 @@ class H2Database extends JdbcDatabase {
 			s.close();
 			c.close();
 		} catch (SQLException e) {
-			tryToClose(s);
-			tryToClose(c);
+			tryToClose(s, LOG, WARNING);
+			tryToClose(c, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}

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

@@ -14,16 +14,24 @@ import java.sql.Connection;
 import java.sql.DriverManager;
 import java.sql.SQLException;
 import java.sql.Statement;
+import java.util.logging.Logger;
 
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
+import static java.util.logging.Level.WARNING;
+import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.db.JdbcUtils.tryToClose;
+
 /**
  * Contains all the HSQLDB-specific code for the database.
  */
 @NotNullByDefault
 class HyperSqlDatabase extends JdbcDatabase {
 
+	private static final Logger LOG =
+			getLogger(HyperSqlDatabase.class.getName());
+
 	private static final String HASH_TYPE = "BINARY(32)";
 	private static final String SECRET_TYPE = "BINARY(32)";
 	private static final String BINARY_TYPE = "BINARY";
@@ -72,8 +80,8 @@ class HyperSqlDatabase extends JdbcDatabase {
 			s.close();
 			c.close();
 		} catch (SQLException e) {
-			tryToClose(s);
-			tryToClose(c);
+			tryToClose(s, LOG, WARNING);
+			tryToClose(c, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -122,8 +130,8 @@ class HyperSqlDatabase extends JdbcDatabase {
 			s.close();
 			c.close();
 		} catch (SQLException e) {
-			tryToClose(s);
-			tryToClose(c);
+			tryToClose(s, LOG, WARNING);
+			tryToClose(c, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}

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

@@ -72,6 +72,7 @@ import static org.briarproject.bramble.db.DatabaseConstants.LAST_COMPACTED_KEY;
 import static org.briarproject.bramble.db.DatabaseConstants.MAX_COMPACTION_INTERVAL_MS;
 import static org.briarproject.bramble.db.DatabaseConstants.SCHEMA_VERSION_KEY;
 import static org.briarproject.bramble.db.ExponentialBackoff.calculateExpiry;
+import static org.briarproject.bramble.db.JdbcUtils.tryToClose;
 import static org.briarproject.bramble.util.LogUtils.logDuration;
 import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.bramble.util.LogUtils.now;
@@ -458,30 +459,6 @@ abstract class JdbcDatabase implements Database<Connection> {
 		mergeSettings(txn, s, DB_SETTINGS_NAMESPACE);
 	}
 
-	private void tryToClose(@Nullable ResultSet rs) {
-		try {
-			if (rs != null) rs.close();
-		} catch (SQLException e) {
-			logException(LOG, WARNING, e);
-		}
-	}
-
-	protected void tryToClose(@Nullable Statement s) {
-		try {
-			if (s != null) s.close();
-		} catch (SQLException e) {
-			logException(LOG, WARNING, e);
-		}
-	}
-
-	protected void tryToClose(@Nullable Connection c) {
-		try {
-			if (c != null) c.close();
-		} catch (SQLException e) {
-			logException(LOG, WARNING, e);
-		}
-	}
-
 	private void createTables(Connection txn) throws DbException {
 		Statement s = null;
 		try {
@@ -502,7 +479,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			s.executeUpdate(dbTypes.replaceTypes(CREATE_INCOMING_KEYS));
 			s.close();
 		} catch (SQLException e) {
-			tryToClose(s);
+			tryToClose(s, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -519,7 +496,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			s.executeUpdate(INDEX_STATUSES_BY_CONTACT_ID_TIMESTAMP);
 			s.close();
 		} catch (SQLException e) {
-			tryToClose(s);
+			tryToClose(s, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -566,11 +543,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 		} catch (SQLException e) {
 			// Try to close the connection
 			logException(LOG, WARNING, e);
-			try {
-				txn.close();
-			} catch (SQLException e1) {
-				logException(LOG, WARNING, e1);
-			}
+			tryToClose(txn, LOG, WARNING);
 			// Whatever happens, allow the database to close
 			connectionsLock.lock();
 			try {
@@ -659,8 +632,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return c;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -681,7 +654,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (affected != 1) throw new DbStateException();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -704,7 +677,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			// Create a status row for each message in the group
 			addStatus(txn, c, g, groupShared);
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -735,8 +708,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			rs.close();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -761,7 +734,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (affected != 1) throw new DbStateException();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -810,7 +783,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (affected < 0) throw new DbStateException();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -840,8 +813,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (affected != 1) throw new DbStateException();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -873,7 +846,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (affected != 1) throw new DbStateException();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -915,8 +888,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (affected != 1) throw new DbStateException();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -935,7 +908,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (affected != 1) throw new DbStateException();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1015,8 +988,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return keySetId;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1039,8 +1012,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return found;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1061,8 +1034,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return found;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1083,8 +1056,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return found;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1105,8 +1078,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return found;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1127,8 +1100,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return found;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1149,8 +1122,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return found;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1174,8 +1147,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return found;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1198,8 +1171,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return count;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1223,7 +1196,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (affected < 0) throw new DbStateException();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1240,7 +1213,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (affected < 0) throw new DbStateException();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1273,8 +1246,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			return new Contact(c, author, localAuthorId, alias, verified,
 					active);
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1310,8 +1283,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return contacts;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1333,8 +1306,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return ids;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1371,8 +1344,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return contacts;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1395,8 +1368,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return new Group(g, clientId, majorVersion, descriptor);
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1423,8 +1396,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return groups;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1449,8 +1422,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return v;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1473,8 +1446,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return visible;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1505,8 +1478,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return localAuthor;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1537,8 +1510,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return authors;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1566,8 +1539,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			System.arraycopy(raw, MESSAGE_HEADER_LENGTH, body, 0, body.length);
 			return new Message(m, g, timestamp, body);
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1590,8 +1563,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return ids;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1628,8 +1601,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (intersection == null) throw new AssertionError();
 			return intersection;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1661,8 +1634,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return all;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1696,8 +1669,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return metadata;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1720,8 +1693,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return metadata;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1746,8 +1719,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return metadata;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1776,8 +1749,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return statuses;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1807,8 +1780,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return status;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1837,8 +1810,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return dependencies;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1868,8 +1841,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return dependents;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1891,8 +1864,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return state;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1916,8 +1889,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return ids;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1950,8 +1923,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return ids;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1975,8 +1948,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return ids;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2014,8 +1987,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return ids;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2048,8 +2021,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return ids;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2076,8 +2049,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return ids;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2106,8 +2079,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return nextSendTime;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2145,8 +2118,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return ids;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2168,8 +2141,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return s;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2234,8 +2207,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return keys;
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2254,7 +2227,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (affected != 1) throw new DbStateException();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2281,7 +2254,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			}
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2308,7 +2281,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			}
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2338,7 +2311,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 				if (rows != 1) throw new DbStateException();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2383,8 +2356,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 				if (rows != 1) throw new DbStateException();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2450,7 +2423,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			}
 			return added;
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2497,7 +2470,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 				if (rows != 1) throw new DbStateException();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2516,7 +2489,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (affected < 0 || affected > 1) throw new DbStateException();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2535,7 +2508,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (affected < 0 || affected > 1) throw new DbStateException();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2554,7 +2527,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (affected < 0 || affected > 1) throw new DbStateException();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2571,7 +2544,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (affected != 1) throw new DbStateException();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2587,7 +2560,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (affected != 1) throw new DbStateException();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2615,7 +2588,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (affected < 0) throw new DbStateException();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2632,7 +2605,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (affected != 1) throw new DbStateException();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2648,7 +2621,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (affected != 1) throw new DbStateException();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2667,7 +2640,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			return affected == 1;
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2692,7 +2665,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 				if (rows != 1) throw new DbStateException();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2709,7 +2682,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (affected != 1) throw new DbStateException();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2730,7 +2703,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (affected < 0) throw new DbStateException();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2749,7 +2722,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (affected < 0 || affected > 1) throw new DbStateException();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2767,7 +2740,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (affected < 0 || affected > 1) throw new DbStateException();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2785,7 +2758,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (affected < 0 || affected > 1) throw new DbStateException();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2804,7 +2777,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (affected < 0 || affected > 1) throw new DbStateException();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2834,7 +2807,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (affected < 0) throw new DbStateException();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2860,7 +2833,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (affected < 0) throw new DbStateException();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2913,7 +2886,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (affected < 0) throw new DbStateException();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2936,7 +2909,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (affected < 0 || affected > 1) throw new DbStateException();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2955,7 +2928,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (affected < 0 || affected > 1) throw new DbStateException();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -2991,8 +2964,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (affected != 1) throw new DbStateException();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(rs);
-			tryToClose(ps);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -3059,7 +3032,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 				if (rows < 0 || rows > 1) throw new DbStateException();
 			ps.close();
 		} catch (SQLException e) {
-			tryToClose(ps);
+			tryToClose(ps, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}

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

@@ -0,0 +1,42 @@
+package org.briarproject.bramble.db;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import java.sql.Connection;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.sql.Statement;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import javax.annotation.Nullable;
+
+import static org.briarproject.bramble.util.LogUtils.logException;
+
+@NotNullByDefault
+class JdbcUtils {
+
+	static void tryToClose(@Nullable ResultSet rs, Logger logger, Level level) {
+		try {
+			if (rs != null) rs.close();
+		} catch (SQLException e) {
+			logException(logger, level, e);
+		}
+	}
+
+	static void tryToClose(@Nullable Statement s, Logger logger, Level level) {
+		try {
+			if (s != null) s.close();
+		} catch (SQLException e) {
+			logException(logger, level, e);
+		}
+	}
+
+	static void tryToClose(@Nullable Connection c, Logger logger, Level level) {
+		try {
+			if (c != null) c.close();
+		} catch (SQLException e) {
+			logException(logger, level, e);
+		}
+	}
+}

bramble-core/src/main/java/org/briarproject/bramble/db/Migration38_39.java

@@ -7,10 +7,8 @@ import java.sql.SQLException;
 import java.sql.Statement;
 import java.util.logging.Logger;
 
-import javax.annotation.Nullable;
-
 import static java.util.logging.Level.WARNING;
-import static org.briarproject.bramble.util.LogUtils.logException;
+import static org.briarproject.bramble.db.JdbcUtils.tryToClose;
 
 class Migration38_39 implements Migration<Connection> {
 
@@ -40,16 +38,8 @@ class Migration38_39 implements Migration<Connection> {
 					+ " ALTER COLUMN contactId"
 					+ " SET NOT NULL");
 		} catch (SQLException e) {
-			tryToClose(s);
+			tryToClose(s, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
-
-	private void tryToClose(@Nullable Statement s) {
-		try {
-			if (s != null) s.close();
-		} catch (SQLException e) {
-			logException(LOG, WARNING, e);
-		}
-	}
 }

bramble-core/src/main/java/org/briarproject/bramble/db/Migration39_40.java

@@ -7,10 +7,8 @@ import java.sql.SQLException;
 import java.sql.Statement;
 import java.util.logging.Logger;
 
-import javax.annotation.Nullable;
-
 import static java.util.logging.Level.WARNING;
-import static org.briarproject.bramble.util.LogUtils.logException;
+import static org.briarproject.bramble.db.JdbcUtils.tryToClose;
 
 class Migration39_40 implements Migration<Connection> {
 
@@ -39,16 +37,8 @@ class Migration39_40 implements Migration<Connection> {
 					+ " ALTER COLUMN eta"
 					+ " SET NOT NULL");
 		} catch (SQLException e) {
-			tryToClose(s);
+			tryToClose(s, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
-
-	private void tryToClose(@Nullable Statement s) {
-		try {
-			if (s != null) s.close();
-		} catch (SQLException e) {
-			logException(LOG, WARNING, e);
-		}
-	}
 }

bramble-core/src/main/java/org/briarproject/bramble/db/Migration40_41.java

@@ -7,11 +7,9 @@ import java.sql.SQLException;
 import java.sql.Statement;
 import java.util.logging.Logger;
 
-import javax.annotation.Nullable;
-
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
-import static org.briarproject.bramble.util.LogUtils.logException;
+import static org.briarproject.bramble.db.JdbcUtils.tryToClose;
 
 class Migration40_41 implements Migration<Connection> {
 
@@ -41,16 +39,8 @@ class Migration40_41 implements Migration<Connection> {
 			s.execute("ALTER TABLE contacts"
 					+ dbTypes.replaceTypes(" ADD alias _STRING"));
 		} catch (SQLException e) {
-			tryToClose(s);
+			tryToClose(s, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
-
-	private void tryToClose(@Nullable Statement s) {
-		try {
-			if (s != null) s.close();
-		} catch (SQLException e) {
-			logException(LOG, WARNING, e);
-		}
-	}
 }

bramble-core/src/main/java/org/briarproject/bramble/plugin/file/FileTransportReader.java

@@ -4,12 +4,11 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.TransportConnectionReader;
 
 import java.io.File;
-import java.io.IOException;
 import java.io.InputStream;
 import java.util.logging.Logger;
 
 import static java.util.logging.Level.WARNING;
-import static org.briarproject.bramble.util.LogUtils.logException;
+import static org.briarproject.bramble.util.IoUtils.tryToClose;
 
 @NotNullByDefault
 class FileTransportReader implements TransportConnectionReader {
@@ -34,11 +33,7 @@ class FileTransportReader implements TransportConnectionReader {
 
 	@Override
 	public void dispose(boolean exception, boolean recognised) {
-		try {
-			in.close();
-		} catch (IOException e) {
-			logException(LOG, WARNING, e);
-		}
+		tryToClose(in, LOG, WARNING);
 		plugin.readerFinished(file, exception, recognised);
 	}
 }

bramble-core/src/main/java/org/briarproject/bramble/plugin/file/FileTransportWriter.java

@@ -4,12 +4,11 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
 
 import java.io.File;
-import java.io.IOException;
 import java.io.OutputStream;
 import java.util.logging.Logger;
 
 import static java.util.logging.Level.WARNING;
-import static org.briarproject.bramble.util.LogUtils.logException;
+import static org.briarproject.bramble.util.IoUtils.tryToClose;
 
 @NotNullByDefault
 class FileTransportWriter implements TransportConnectionWriter {
@@ -44,11 +43,7 @@ class FileTransportWriter implements TransportConnectionWriter {
 
 	@Override
 	public void dispose(boolean exception) {
-		try {
-			out.close();
-		} catch (IOException e) {
-			logException(LOG, WARNING, e);
-		}
+		tryToClose(out, LOG, WARNING);
 		plugin.writerFinished(file, exception);
 	}
 }

bramble-core/src/main/java/org/briarproject/bramble/plugin/tcp/LanTcpPlugin.java

@@ -11,6 +11,7 @@ import org.briarproject.bramble.api.plugin.duplex.DuplexPluginCallback;
 import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
 import org.briarproject.bramble.api.properties.TransportProperties;
 import org.briarproject.bramble.api.settings.Settings;
+import org.briarproject.bramble.util.IoUtils;
 import org.briarproject.bramble.util.StringUtils;
 
 import java.io.IOException;
@@ -35,7 +36,6 @@ import static org.briarproject.bramble.api.plugin.LanTcpConstants.ID;
 import static org.briarproject.bramble.api.plugin.LanTcpConstants.PREF_LAN_IP_PORTS;
 import static org.briarproject.bramble.api.plugin.LanTcpConstants.PROP_IP_PORTS;
 import static org.briarproject.bramble.util.ByteUtils.MAX_16_BIT_UNSIGNED;
-import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.bramble.util.PrivacyUtils.scrubSocketAddress;
 
 @NotNullByDefault
@@ -293,11 +293,7 @@ class LanTcpPlugin extends TcpPlugin {
 
 		@Override
 		public void close() {
-			try {
-				ss.close();
-			} catch (IOException e) {
-				logException(LOG, WARNING, e);
-			}
+			IoUtils.tryToClose(ss, LOG, WARNING);
 		}
 	}
 

bramble-core/src/main/java/org/briarproject/bramble/plugin/tcp/TcpPlugin.java

@@ -11,6 +11,7 @@ import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPluginCallback;
 import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
 import org.briarproject.bramble.api.properties.TransportProperties;
+import org.briarproject.bramble.util.IoUtils;
 import org.briarproject.bramble.util.StringUtils;
 
 import java.io.IOException;
@@ -153,13 +154,8 @@ abstract class TcpPlugin implements DuplexPlugin {
 	}
 
 	protected void tryToClose(@Nullable ServerSocket ss) {
-		try {
-			if (ss != null) ss.close();
-		} catch (IOException e) {
-			logException(LOG, WARNING, e);
-		} finally {
-			callback.transportDisabled();
-		}
+		IoUtils.tryToClose(ss, LOG, WARNING);
+		callback.transportDisabled();
 	}
 
 	String getIpPortString(InetSocketAddress a) {

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

@@ -31,7 +31,6 @@ import org.briarproject.bramble.api.system.LocationUtils;
 import org.briarproject.bramble.api.system.ResourceProvider;
 import org.briarproject.bramble.util.IoUtils;
 
-import java.io.Closeable;
 import java.io.EOFException;
 import java.io.File;
 import java.io.FileInputStream;
@@ -303,8 +302,8 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 			IoUtils.copyAndClose(in, out);
 			doneFile.createNewFile();
 		} catch (IOException e) {
-			tryToClose(in);
-			tryToClose(out);
+			IoUtils.tryToClose(in, LOG, WARNING);
+			IoUtils.tryToClose(out, LOG, WARNING);
 			throw new PluginException(e);
 		}
 	}
@@ -341,22 +340,6 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		return getClass().getClassLoader().getResourceAsStream("torrc");
 	}
 
-	private void tryToClose(@Nullable Closeable c) {
-		try {
-			if (c != null) c.close();
-		} catch (IOException e) {
-			logException(LOG, WARNING, e);
-		}
-	}
-
-	private void tryToClose(@Nullable Socket s) {
-		try {
-			if (s != null) s.close();
-		} catch (IOException e) {
-			logException(LOG, WARNING, e);
-		}
-	}
-
 	private void listFiles(File f) {
 		if (f.isDirectory()) {
 			File[] children = f.listFiles();
@@ -378,7 +361,7 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 			}
 			return b;
 		} finally {
-			tryToClose(in);
+			IoUtils.tryToClose(in, LOG, WARNING);
 		}
 	}
 
@@ -418,13 +401,8 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	}
 
 	private void tryToClose(@Nullable ServerSocket ss) {
-		try {
-			if (ss != null) ss.close();
-		} catch (IOException e) {
-			logException(LOG, WARNING, e);
-		} finally {
-			callback.transportDisabled();
-		}
+		IoUtils.tryToClose(ss, LOG, WARNING);
+		callback.transportDisabled();
 	}
 
 	private void publishHiddenService(String port) {
@@ -593,7 +571,7 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 				LOG.info("Could not connect to " + scrubOnion(bestOnion)
 						+ ": " + e.toString());
 			}
-			tryToClose(s);
+			IoUtils.tryToClose(s, LOG, WARNING);
 			return null;
 		}
 	}

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

@@ -12,7 +12,6 @@ import org.briarproject.bramble.api.reporting.DevReporter;
 import org.briarproject.bramble.util.IoUtils;
 import org.briarproject.bramble.util.StringUtils;
 
-import java.io.Closeable;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
@@ -26,13 +25,12 @@ import java.net.Socket;
 import java.util.concurrent.Executor;
 import java.util.logging.Logger;
 
-import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 import javax.net.SocketFactory;
 
 import static java.util.logging.Level.WARNING;
-import static org.briarproject.bramble.util.LogUtils.logException;
+import static org.briarproject.bramble.util.IoUtils.tryToClose;
 
 @Immutable
 @NotNullByDefault
@@ -66,7 +64,7 @@ class DevReporterImpl implements DevReporter, EventListener {
 			s.setSoTimeout(SOCKET_TIMEOUT);
 			return s;
 		} catch (IOException e) {
-			tryToClose(s);
+			tryToClose(s, LOG, WARNING);
 			throw e;
 		}
 	}
@@ -88,8 +86,7 @@ class DevReporterImpl implements DevReporter, EventListener {
 			writer.append(armoured);
 			writer.flush();
 		} finally {
-			if (writer != null)
-				writer.close();
+			tryToClose(writer, LOG, WARNING);
 		}
 	}
 
@@ -121,27 +118,11 @@ class DevReporterImpl implements DevReporter, EventListener {
 				f.delete();
 			} catch (IOException e) {
 				LOG.log(WARNING, "Failed to send reports", e);
-				tryToClose(out);
-				tryToClose(in);
+				tryToClose(out, LOG, WARNING);
+				tryToClose(in, LOG, WARNING);
 				return;
 			}
 		}
 		LOG.info("Reports sent");
 	}
-
-	private void tryToClose(@Nullable Closeable c) {
-		try {
-			if (c != null) c.close();
-		} catch (IOException e) {
-			logException(LOG, WARNING, e);
-		}
-	}
-
-	private void tryToClose(@Nullable Socket s) {
-		try {
-			if (s != null) s.close();
-		} catch (IOException e) {
-			logException(LOG, WARNING, e);
-		}
-	}
 }

bramble-core/src/main/java/org/briarproject/bramble/system/UnixSecureRandomProvider.java

@@ -13,32 +13,33 @@ import java.util.logging.Logger;
 import javax.annotation.concurrent.Immutable;
 
 import static java.util.logging.Level.WARNING;
+import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.util.LogUtils.logException;
 
 @Immutable
 @NotNullByDefault
-class LinuxSecureRandomProvider extends AbstractSecureRandomProvider {
+class UnixSecureRandomProvider extends AbstractSecureRandomProvider {
 
 	private static final Logger LOG =
-			Logger.getLogger(LinuxSecureRandomProvider.class.getName());
+			getLogger(UnixSecureRandomProvider.class.getName());
 
 	private static final File RANDOM_DEVICE = new File("/dev/urandom");
 
 	private final AtomicBoolean seeded = new AtomicBoolean(false);
 	private final File outputDevice;
 
-	LinuxSecureRandomProvider() {
+	UnixSecureRandomProvider() {
 		this(RANDOM_DEVICE);
 	}
 
-	LinuxSecureRandomProvider(File outputDevice) {
+	UnixSecureRandomProvider(File outputDevice) {
 		this.outputDevice = outputDevice;
 	}
 
 	@Override
 	public Provider getProvider() {
 		if (!seeded.getAndSet(true)) writeSeed();
-		return new LinuxProvider();
+		return new UnixProvider();
 	}
 
 	protected void writeSeed() {
@@ -55,15 +56,15 @@ class LinuxSecureRandomProvider extends AbstractSecureRandomProvider {
 	}
 
 	// Based on https://android-developers.googleblog.com/2013/08/some-securerandom-thoughts.html
-	private static class LinuxProvider extends Provider {
+	private static class UnixProvider extends Provider {
 
-		private LinuxProvider() {
-			super("LinuxPRNG", 1.1, "A Linux-specific PRNG using /dev/urandom");
+		private UnixProvider() {
+			super("UnixPRNG", 1.0, "A Unix-specific PRNG using /dev/urandom");
 			// Although /dev/urandom is not a SHA-1 PRNG, some callers
 			// explicitly request a SHA1PRNG SecureRandom and we need to
 			// prevent them from getting the default implementation whose
 			// output may have low entropy.
-			put("SecureRandom.SHA1PRNG", LinuxSecureRandomSpi.class.getName());
+			put("SecureRandom.SHA1PRNG", UnixSecureRandomSpi.class.getName());
 			put("SecureRandom.SHA1PRNG ImplementedIn", "Software");
 		}
 	}

bramble-core/src/main/java/org/briarproject/bramble/system/UnixSecureRandomSpi.java

@@ -10,22 +10,24 @@ import java.security.SecureRandomSpi;
 import java.util.logging.Logger;
 
 import static java.util.logging.Level.WARNING;
+import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.util.LogUtils.logException;
 
-public class LinuxSecureRandomSpi extends SecureRandomSpi {
+public class UnixSecureRandomSpi extends SecureRandomSpi {
 
 	private static final Logger LOG =
-			Logger.getLogger(LinuxSecureRandomSpi.class.getName());
+			getLogger(UnixSecureRandomSpi.class.getName());
 
 	private static final File RANDOM_DEVICE = new File("/dev/urandom");
 
 	private final File inputDevice, outputDevice;
 
-	public LinuxSecureRandomSpi() {
+	@SuppressWarnings("WeakerAccess")
+	public UnixSecureRandomSpi() {
 		this(RANDOM_DEVICE, RANDOM_DEVICE);
 	}
 
-	LinuxSecureRandomSpi(File inputDevice, File outputDevice) {
+	UnixSecureRandomSpi(File inputDevice, File outputDevice) {
 		this.inputDevice = inputDevice;
 		this.outputDevice = outputDevice;
 	}

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

@@ -89,14 +89,9 @@ class ClientVersioningManagerImpl implements ClientVersioningManager, Client,
 	public Visibility getClientVisibility(Transaction txn, ContactId contactId,
 			ClientId clientId, int majorVersion) throws DbException {
 		try {
-			Contact contact = db.getContact(txn, contactId);
-			Group g = getContactGroup(contact);
-			// Contact may be in the process of being added or removed, so
-			// contact group may not exist
-			if (!db.containsGroup(txn, g.getId())) return INVISIBLE;
-			LatestUpdates latest = findLatestUpdates(txn, g.getId());
+			LatestUpdates latest = findLatestUpdates(txn, contactId);
+			if (latest == null || latest.remote == null) return INVISIBLE;
 			if (latest.local == null) throw new DbException();
-			if (latest.remote == null) return INVISIBLE;
 			Update localUpdate = loadUpdate(txn, latest.local.messageId);
 			Update remoteUpdate = loadUpdate(txn, latest.remote.messageId);
 			Map<ClientMajorVersion, Visibility> visibilities =
@@ -110,6 +105,24 @@ class ClientVersioningManagerImpl implements ClientVersioningManager, Client,
 		}
 	}
 
+	@Override
+	public int getClientMinorVersion(Transaction txn, ContactId contactId,
+			ClientId clientId, int majorVersion) throws DbException {
+		try {
+			LatestUpdates latest = findLatestUpdates(txn, contactId);
+			if (latest == null || latest.remote == null) return -1;
+			Update remoteUpdate = loadUpdate(txn, latest.remote.messageId);
+			ClientMajorVersion cv =
+					new ClientMajorVersion(clientId, majorVersion);
+			for (ClientState remote : remoteUpdate.states) {
+				if (remote.majorVersion.equals(cv)) return remote.minorVersion;
+			}
+			return -1;
+		} catch (FormatException e) {
+			throw new DbException(e);
+		}
+	}
+
 	@Override
 	public void createLocalState(Transaction txn) throws DbException {
 		if (db.containsGroup(txn, localGroup.getId())) return;
@@ -336,6 +349,17 @@ class ClientVersioningManagerImpl implements ClientVersioningManager, Client,
 				MAJOR_VERSION, c);
 	}
 
+	@Nullable
+	private LatestUpdates findLatestUpdates(Transaction txn, ContactId c)
+			throws DbException, FormatException {
+		Contact contact = db.getContact(txn, c);
+		Group g = getContactGroup(contact);
+		// Contact may be in the process of being added or removed, so
+		// contact group may not exist
+		if (!db.containsGroup(txn, g.getId())) return null;
+		return findLatestUpdates(txn, g.getId());
+	}
+
 	private LatestUpdates findLatestUpdates(Transaction txn, GroupId g)
 			throws DbException, FormatException {
 		Map<MessageId, BdfDictionary> metadata =

bramble-core/src/test/java/org/briarproject/bramble/system/UnixSecureRandomProviderTest.java

@@ -1,8 +1,6 @@
 package org.briarproject.bramble.system;
 
 import org.briarproject.bramble.test.BrambleTestCase;
-import org.briarproject.bramble.test.TestUtils;
-import org.briarproject.bramble.util.OsUtils;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
@@ -10,48 +8,50 @@ import org.junit.Test;
 import java.io.File;
 import java.security.Provider;
 
+import static org.briarproject.bramble.test.TestUtils.deleteTestDirectory;
+import static org.briarproject.bramble.test.TestUtils.getTestDirectory;
+import static org.briarproject.bramble.util.OsUtils.isLinux;
+import static org.briarproject.bramble.util.OsUtils.isMac;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
+import static org.junit.Assume.assumeTrue;
 
-public class LinuxSecureRandomProviderTest extends BrambleTestCase {
+public class UnixSecureRandomProviderTest extends BrambleTestCase {
 
-	private final File testDir = TestUtils.getTestDirectory();
+	private final File testDir = getTestDirectory();
 
 	@Before
 	public void setUp() {
-		testDir.mkdirs();
+		assumeTrue(isLinux() || isMac());
+		assertTrue(testDir.mkdirs());
 	}
 
 	@Test
 	public void testGetProviderWritesToRandomDeviceOnFirstCall()
 			throws Exception {
-		if (!(OsUtils.isLinux())) {
-			System.err.println("WARNING: Skipping test, can't run on this OS");
-			return;
-		}
 		// Redirect the provider's output to a file
 		File urandom = new File(testDir, "urandom");
-		urandom.delete();
+		if (urandom.exists()) assertTrue(urandom.delete());
 		assertTrue(urandom.createNewFile());
 		assertEquals(0, urandom.length());
-		LinuxSecureRandomProvider p = new LinuxSecureRandomProvider(urandom);
+		UnixSecureRandomProvider p = new UnixSecureRandomProvider(urandom);
 		// Getting a provider should write entropy to the file
 		Provider provider = p.getProvider();
 		assertNotNull(provider);
-		assertEquals("LinuxPRNG", provider.getName());
+		assertEquals("UnixPRNG", provider.getName());
 		// There should be at least 16 bytes from the clock, 8 from the runtime
 		long length = urandom.length();
 		assertTrue(length >= 24);
 		// Getting another provider should not write to the file again
 		provider = p.getProvider();
 		assertNotNull(provider);
-		assertEquals("LinuxPRNG", provider.getName());
+		assertEquals("UnixPRNG", provider.getName());
 		assertEquals(length, urandom.length());
 	}
 
 	@After
 	public void tearDown() {
-		TestUtils.deleteTestDirectory(testDir);
+		deleteTestDirectory(testDir);
 	}
 }

bramble-core/src/test/java/org/briarproject/bramble/system/UnixSecureRandomSpiTest.java

@@ -4,7 +4,6 @@ import org.briarproject.bramble.api.Bytes;
 import org.briarproject.bramble.test.BrambleTestCase;
 import org.briarproject.bramble.test.TestUtils;
 import org.briarproject.bramble.util.IoUtils;
-import org.briarproject.bramble.util.OsUtils;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
@@ -15,31 +14,33 @@ import java.io.FileOutputStream;
 import java.util.HashSet;
 import java.util.Set;
 
+import static org.briarproject.bramble.test.TestUtils.deleteTestDirectory;
+import static org.briarproject.bramble.test.TestUtils.getTestDirectory;
+import static org.briarproject.bramble.util.OsUtils.isLinux;
+import static org.briarproject.bramble.util.OsUtils.isMac;
 import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
+import static org.junit.Assume.assumeTrue;
 
 
-public class LinuxSecureRandomSpiTest extends BrambleTestCase {
+public class UnixSecureRandomSpiTest extends BrambleTestCase {
 
 	private static final File RANDOM_DEVICE = new File("/dev/urandom");
 	private static final int SEED_BYTES = 32;
 
-	private final File testDir = TestUtils.getTestDirectory();
+	private final File testDir = getTestDirectory();
 
 	@Before
 	public void setUp() {
-		testDir.mkdirs();
+		assumeTrue(isLinux() || isMac());
+		assertTrue(testDir.mkdirs());
 	}
 
 	@Test
 	public void testSeedsAreDistinct() {
-		if (!(OsUtils.isLinux())) {
-			System.err.println("WARNING: Skipping test, can't run on this OS");
-			return;
-		}
 		Set<Bytes> seeds = new HashSet<>();
-		LinuxSecureRandomSpi engine = new LinuxSecureRandomSpi();
+		UnixSecureRandomSpi engine = new UnixSecureRandomSpi();
 		for (int i = 0; i < 1000; i++) {
 			byte[] seed = engine.engineGenerateSeed(SEED_BYTES);
 			assertEquals(SEED_BYTES, seed.length);
@@ -49,19 +50,15 @@ public class LinuxSecureRandomSpiTest extends BrambleTestCase {
 
 	@Test
 	public void testEngineSetSeedWritesToRandomDevice() throws Exception {
-		if (!(OsUtils.isLinux())) {
-			System.err.println("WARNING: Skipping test, can't run on this OS");
-			return;
-		}
 		// Redirect the engine's output to a file
 		File urandom = new File(testDir, "urandom");
-		urandom.delete();
+		if (urandom.exists()) assertTrue(urandom.delete());
 		assertTrue(urandom.createNewFile());
 		assertEquals(0, urandom.length());
 		// Generate a seed
 		byte[] seed = TestUtils.getRandomBytes(SEED_BYTES);
 		// Check that the engine writes the seed to the file
-		LinuxSecureRandomSpi engine = new LinuxSecureRandomSpi(RANDOM_DEVICE,
+		UnixSecureRandomSpi engine = new UnixSecureRandomSpi(RANDOM_DEVICE,
 				urandom);
 		engine.engineSetSeed(seed);
 		assertEquals(SEED_BYTES, urandom.length());
@@ -74,15 +71,11 @@ public class LinuxSecureRandomSpiTest extends BrambleTestCase {
 
 	@Test
 	public void testEngineNextBytesReadsFromRandomDevice() throws Exception {
-		if (!(OsUtils.isLinux())) {
-			System.err.println("WARNING: Skipping test, can't run on this OS");
-			return;
-		}
 		// Generate some entropy
 		byte[] entropy = TestUtils.getRandomBytes(SEED_BYTES);
 		// Write the entropy to a file
 		File urandom = new File(testDir, "urandom");
-		urandom.delete();
+		if (urandom.exists()) assertTrue(urandom.delete());
 		FileOutputStream out = new FileOutputStream(urandom);
 		out.write(entropy);
 		out.flush();
@@ -90,7 +83,7 @@ public class LinuxSecureRandomSpiTest extends BrambleTestCase {
 		assertTrue(urandom.exists());
 		assertEquals(SEED_BYTES, urandom.length());
 		// Check that the engine reads from the file
-		LinuxSecureRandomSpi engine = new LinuxSecureRandomSpi(urandom,
+		UnixSecureRandomSpi engine = new UnixSecureRandomSpi(urandom,
 				RANDOM_DEVICE);
 		byte[] b = new byte[SEED_BYTES];
 		engine.engineNextBytes(b);
@@ -99,15 +92,11 @@ public class LinuxSecureRandomSpiTest extends BrambleTestCase {
 
 	@Test
 	public void testEngineGenerateSeedReadsFromRandomDevice() throws Exception {
-		if (!(OsUtils.isLinux())) {
-			System.err.println("WARNING: Skipping test, can't run on this OS");
-			return;
-		}
 		// Generate some entropy
 		byte[] entropy = TestUtils.getRandomBytes(SEED_BYTES);
 		// Write the entropy to a file
 		File urandom = new File(testDir, "urandom");
-		urandom.delete();
+		if (urandom.exists()) assertTrue(urandom.delete());
 		FileOutputStream out = new FileOutputStream(urandom);
 		out.write(entropy);
 		out.flush();
@@ -115,7 +104,7 @@ public class LinuxSecureRandomSpiTest extends BrambleTestCase {
 		assertTrue(urandom.exists());
 		assertEquals(SEED_BYTES, urandom.length());
 		// Check that the engine reads from the file
-		LinuxSecureRandomSpi engine = new LinuxSecureRandomSpi(urandom,
+		UnixSecureRandomSpi engine = new UnixSecureRandomSpi(urandom,
 				RANDOM_DEVICE);
 		byte[] b = engine.engineGenerateSeed(SEED_BYTES);
 		assertArrayEquals(entropy, b);
@@ -123,6 +112,6 @@ public class LinuxSecureRandomSpiTest extends BrambleTestCase {
 
 	@After
 	public void tearDown() {
-		TestUtils.deleteTestDirectory(testDir);
+		deleteTestDirectory(testDir);
 	}
 }

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

@@ -8,6 +8,7 @@ import org.briarproject.bramble.api.data.BdfDictionary;
 import org.briarproject.bramble.api.data.BdfEntry;
 import org.briarproject.bramble.api.data.BdfList;
 import org.briarproject.bramble.api.db.DatabaseComponent;
+import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.Metadata;
 import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.sync.ClientId;
@@ -43,6 +44,7 @@ import static org.briarproject.bramble.util.StringUtils.getRandomString;
 import static org.briarproject.bramble.versioning.ClientVersioningConstants.GROUP_KEY_CONTACT_ID;
 import static org.briarproject.bramble.versioning.ClientVersioningConstants.MSG_KEY_LOCAL;
 import static org.briarproject.bramble.versioning.ClientVersioningConstants.MSG_KEY_UPDATE_VERSION;
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 
 public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
@@ -657,4 +659,327 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 		c.registerClient(clientId, 123, 234, hook);
 		assertFalse(c.incomingMessage(txn, newRemoteUpdate, new Metadata()));
 	}
+
+	@Test
+	public void testReturnsInvisibleIfContactGroupDoesNotExist()
+			throws Exception {
+		expectGetContactGroup(false);
+
+		ClientVersioningManagerImpl c = createInstance();
+		assertEquals(INVISIBLE, c.getClientVisibility(txn, contact.getId(),
+				clientId, 123));
+	}
+
+	@Test
+	public void testReturnsInvisibleIfNoRemoteUpdateExists() throws Exception {
+		MessageId localUpdateId = new MessageId(getRandomId());
+		BdfDictionary localUpdateMeta = BdfDictionary.of(
+				new BdfEntry(MSG_KEY_UPDATE_VERSION, 1L),
+				new BdfEntry(MSG_KEY_LOCAL, true));
+
+		expectGetContactGroup(true);
+		context.checking(new Expectations() {{
+			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
+					contactGroup.getId());
+			will(returnValue(singletonMap(localUpdateId, localUpdateMeta)));
+		}});
+
+		ClientVersioningManagerImpl c = createInstance();
+		assertEquals(INVISIBLE, c.getClientVisibility(txn, contact.getId(),
+				clientId, 123));
+	}
+
+	@Test(expected = DbException.class)
+	public void testThrowsExceptionIfNoLocalUpdateExists() throws Exception {
+		MessageId remoteUpdateId = new MessageId(getRandomId());
+		BdfDictionary remoteUpdateMeta = BdfDictionary.of(
+				new BdfEntry(MSG_KEY_UPDATE_VERSION, 1L),
+				new BdfEntry(MSG_KEY_LOCAL, false));
+
+		expectGetContactGroup(true);
+		context.checking(new Expectations() {{
+			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
+					contactGroup.getId());
+			will(returnValue(singletonMap(remoteUpdateId, remoteUpdateMeta)));
+		}});
+
+		ClientVersioningManagerImpl c = createInstance();
+		c.getClientVisibility(txn, contact.getId(), clientId, 123);
+	}
+
+	@Test
+	public void testReturnsInvisibleIfClientNotSupportedLocally()
+			throws Exception {
+		MessageId localUpdateId = new MessageId(getRandomId());
+		BdfDictionary localUpdateMeta = BdfDictionary.of(
+				new BdfEntry(MSG_KEY_UPDATE_VERSION, 1L),
+				new BdfEntry(MSG_KEY_LOCAL, true));
+		MessageId remoteUpdateId = new MessageId(getRandomId());
+		BdfDictionary remoteUpdateMeta = BdfDictionary.of(
+				new BdfEntry(MSG_KEY_UPDATE_VERSION, 1L),
+				new BdfEntry(MSG_KEY_LOCAL, false));
+		Map<MessageId, BdfDictionary> messageMetadata = new HashMap<>();
+		messageMetadata.put(localUpdateId, localUpdateMeta);
+		messageMetadata.put(remoteUpdateId, remoteUpdateMeta);
+		// The client is supported remotely but not locally
+		BdfList localUpdateBody = BdfList.of(new BdfList(), 1L);
+		BdfList remoteUpdateBody = BdfList.of(BdfList.of(
+				BdfList.of(clientId.getString(), 123, 234, false)), 1L);
+
+		expectGetContactGroup(true);
+		context.checking(new Expectations() {{
+			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
+					contactGroup.getId());
+			will(returnValue(messageMetadata));
+			oneOf(clientHelper).getMessageAsList(txn, localUpdateId);
+			will(returnValue(localUpdateBody));
+			oneOf(clientHelper).getMessageAsList(txn, remoteUpdateId);
+			will(returnValue(remoteUpdateBody));
+		}});
+
+		ClientVersioningManagerImpl c = createInstance();
+		assertEquals(INVISIBLE, c.getClientVisibility(txn, contact.getId(),
+				clientId, 123));
+	}
+
+	@Test
+	public void testReturnsInvisibleIfClientNotSupportedRemotely()
+			throws Exception {
+		MessageId localUpdateId = new MessageId(getRandomId());
+		BdfDictionary localUpdateMeta = BdfDictionary.of(
+				new BdfEntry(MSG_KEY_UPDATE_VERSION, 1L),
+				new BdfEntry(MSG_KEY_LOCAL, true));
+		MessageId remoteUpdateId = new MessageId(getRandomId());
+		BdfDictionary remoteUpdateMeta = BdfDictionary.of(
+				new BdfEntry(MSG_KEY_UPDATE_VERSION, 1L),
+				new BdfEntry(MSG_KEY_LOCAL, false));
+		Map<MessageId, BdfDictionary> messageMetadata = new HashMap<>();
+		messageMetadata.put(localUpdateId, localUpdateMeta);
+		messageMetadata.put(remoteUpdateId, remoteUpdateMeta);
+		// The client is supported locally but not remotely
+		BdfList localUpdateBody = BdfList.of(BdfList.of(
+				BdfList.of(clientId.getString(), 123, 234, false)), 1L);
+		BdfList remoteUpdateBody = BdfList.of(new BdfList(), 1L);
+
+		expectGetContactGroup(true);
+		context.checking(new Expectations() {{
+			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
+					contactGroup.getId());
+			will(returnValue(messageMetadata));
+			oneOf(clientHelper).getMessageAsList(txn, localUpdateId);
+			will(returnValue(localUpdateBody));
+			oneOf(clientHelper).getMessageAsList(txn, remoteUpdateId);
+			will(returnValue(remoteUpdateBody));
+		}});
+
+		ClientVersioningManagerImpl c = createInstance();
+		assertEquals(INVISIBLE, c.getClientVisibility(txn, contact.getId(),
+				clientId, 123));
+	}
+
+	@Test
+	public void testReturnsVisibleIfClientNotActiveRemotely() throws Exception {
+		MessageId localUpdateId = new MessageId(getRandomId());
+		BdfDictionary localUpdateMeta = BdfDictionary.of(
+				new BdfEntry(MSG_KEY_UPDATE_VERSION, 1L),
+				new BdfEntry(MSG_KEY_LOCAL, true));
+		MessageId remoteUpdateId = new MessageId(getRandomId());
+		BdfDictionary remoteUpdateMeta = BdfDictionary.of(
+				new BdfEntry(MSG_KEY_UPDATE_VERSION, 1L),
+				new BdfEntry(MSG_KEY_LOCAL, false));
+		Map<MessageId, BdfDictionary> messageMetadata = new HashMap<>();
+		messageMetadata.put(localUpdateId, localUpdateMeta);
+		messageMetadata.put(remoteUpdateId, remoteUpdateMeta);
+		// The client is supported locally and remotely but not active
+		BdfList localUpdateBody = BdfList.of(BdfList.of(
+				BdfList.of(clientId.getString(), 123, 234, false)), 1L);
+		BdfList remoteUpdateBody = BdfList.of(BdfList.of(
+				BdfList.of(clientId.getString(), 123, 234, false)), 1L);
+
+		expectGetContactGroup(true);
+		context.checking(new Expectations() {{
+			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
+					contactGroup.getId());
+			will(returnValue(messageMetadata));
+			oneOf(clientHelper).getMessageAsList(txn, localUpdateId);
+			will(returnValue(localUpdateBody));
+			oneOf(clientHelper).getMessageAsList(txn, remoteUpdateId);
+			will(returnValue(remoteUpdateBody));
+		}});
+
+		ClientVersioningManagerImpl c = createInstance();
+		assertEquals(VISIBLE, c.getClientVisibility(txn, contact.getId(),
+				clientId, 123));
+	}
+
+	@Test
+	public void testReturnsSharedIfClientActiveRemotely() throws Exception {
+		MessageId localUpdateId = new MessageId(getRandomId());
+		BdfDictionary localUpdateMeta = BdfDictionary.of(
+				new BdfEntry(MSG_KEY_UPDATE_VERSION, 1L),
+				new BdfEntry(MSG_KEY_LOCAL, true));
+		MessageId remoteUpdateId = new MessageId(getRandomId());
+		BdfDictionary remoteUpdateMeta = BdfDictionary.of(
+				new BdfEntry(MSG_KEY_UPDATE_VERSION, 1L),
+				new BdfEntry(MSG_KEY_LOCAL, false));
+		Map<MessageId, BdfDictionary> messageMetadata = new HashMap<>();
+		messageMetadata.put(localUpdateId, localUpdateMeta);
+		messageMetadata.put(remoteUpdateId, remoteUpdateMeta);
+		// The client is supported locally and remotely and active
+		BdfList localUpdateBody = BdfList.of(BdfList.of(
+				BdfList.of(clientId.getString(), 123, 234, true)), 1L);
+		BdfList remoteUpdateBody = BdfList.of(BdfList.of(
+				BdfList.of(clientId.getString(), 123, 234, true)), 1L);
+
+		expectGetContactGroup(true);
+		context.checking(new Expectations() {{
+			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
+					contactGroup.getId());
+			will(returnValue(messageMetadata));
+			oneOf(clientHelper).getMessageAsList(txn, localUpdateId);
+			will(returnValue(localUpdateBody));
+			oneOf(clientHelper).getMessageAsList(txn, remoteUpdateId);
+			will(returnValue(remoteUpdateBody));
+		}});
+
+		ClientVersioningManagerImpl c = createInstance();
+		assertEquals(SHARED, c.getClientVisibility(txn, contact.getId(),
+				clientId, 123));
+	}
+
+	@Test
+	public void testReturnsNegativeIfContactGroupDoesNotExist()
+			throws Exception {
+		expectGetContactGroup(false);
+
+		ClientVersioningManagerImpl c = createInstance();
+		assertEquals(-1, c.getClientMinorVersion(txn, contact.getId(),
+				clientId, 123));
+	}
+
+	@Test
+	public void testReturnsNegativeIfNoRemoteUpdateExists() throws Exception {
+		MessageId localUpdateId = new MessageId(getRandomId());
+		BdfDictionary localUpdateMeta = BdfDictionary.of(
+				new BdfEntry(MSG_KEY_UPDATE_VERSION, 1L),
+				new BdfEntry(MSG_KEY_LOCAL, true));
+
+		expectGetContactGroup(true);
+		context.checking(new Expectations() {{
+			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
+					contactGroup.getId());
+			will(returnValue(singletonMap(localUpdateId, localUpdateMeta)));
+		}});
+
+		ClientVersioningManagerImpl c = createInstance();
+		assertEquals(-1, c.getClientMinorVersion(txn, contact.getId(),
+				clientId, 123));
+	}
+
+	@Test
+	public void testReturnsNegativeIfClientNotSupportedRemotely()
+			throws Exception {
+		MessageId localUpdateId = new MessageId(getRandomId());
+		BdfDictionary localUpdateMeta = BdfDictionary.of(
+				new BdfEntry(MSG_KEY_UPDATE_VERSION, 1L),
+				new BdfEntry(MSG_KEY_LOCAL, true));
+		MessageId remoteUpdateId = new MessageId(getRandomId());
+		BdfDictionary remoteUpdateMeta = BdfDictionary.of(
+				new BdfEntry(MSG_KEY_UPDATE_VERSION, 1L),
+				new BdfEntry(MSG_KEY_LOCAL, false));
+		Map<MessageId, BdfDictionary> messageMetadata = new HashMap<>();
+		messageMetadata.put(localUpdateId, localUpdateMeta);
+		messageMetadata.put(remoteUpdateId, remoteUpdateMeta);
+		// The client is not supported remotely
+		BdfList remoteUpdateBody = BdfList.of(new BdfList(), 1L);
+
+		expectGetContactGroup(true);
+		context.checking(new Expectations() {{
+			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
+					contactGroup.getId());
+			will(returnValue(messageMetadata));
+			oneOf(clientHelper).getMessageAsList(txn, remoteUpdateId);
+			will(returnValue(remoteUpdateBody));
+		}});
+
+		ClientVersioningManagerImpl c = createInstance();
+		assertEquals(-1, c.getClientMinorVersion(txn, contact.getId(),
+				clientId, 123));
+	}
+
+	@Test
+	public void testReturnsMinorVersionIfClientNotActiveRemotely()
+			throws Exception {
+		MessageId localUpdateId = new MessageId(getRandomId());
+		BdfDictionary localUpdateMeta = BdfDictionary.of(
+				new BdfEntry(MSG_KEY_UPDATE_VERSION, 1L),
+				new BdfEntry(MSG_KEY_LOCAL, true));
+		MessageId remoteUpdateId = new MessageId(getRandomId());
+		BdfDictionary remoteUpdateMeta = BdfDictionary.of(
+				new BdfEntry(MSG_KEY_UPDATE_VERSION, 1L),
+				new BdfEntry(MSG_KEY_LOCAL, false));
+		Map<MessageId, BdfDictionary> messageMetadata = new HashMap<>();
+		messageMetadata.put(localUpdateId, localUpdateMeta);
+		messageMetadata.put(remoteUpdateId, remoteUpdateMeta);
+		// The client is supported remotely but not active
+		BdfList remoteUpdateBody = BdfList.of(BdfList.of(
+				BdfList.of(clientId.getString(), 123, 234, false)), 1L);
+
+		expectGetContactGroup(true);
+		context.checking(new Expectations() {{
+			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
+					contactGroup.getId());
+			will(returnValue(messageMetadata));
+			oneOf(clientHelper).getMessageAsList(txn, remoteUpdateId);
+			will(returnValue(remoteUpdateBody));
+		}});
+
+		ClientVersioningManagerImpl c = createInstance();
+		assertEquals(234, c.getClientMinorVersion(txn, contact.getId(),
+				clientId, 123));
+	}
+
+	@Test
+	public void testReturnsMinorVersionIfClientActiveRemotely()
+			throws Exception {
+		MessageId localUpdateId = new MessageId(getRandomId());
+		BdfDictionary localUpdateMeta = BdfDictionary.of(
+				new BdfEntry(MSG_KEY_UPDATE_VERSION, 1L),
+				new BdfEntry(MSG_KEY_LOCAL, true));
+		MessageId remoteUpdateId = new MessageId(getRandomId());
+		BdfDictionary remoteUpdateMeta = BdfDictionary.of(
+				new BdfEntry(MSG_KEY_UPDATE_VERSION, 1L),
+				new BdfEntry(MSG_KEY_LOCAL, false));
+		Map<MessageId, BdfDictionary> messageMetadata = new HashMap<>();
+		messageMetadata.put(localUpdateId, localUpdateMeta);
+		messageMetadata.put(remoteUpdateId, remoteUpdateMeta);
+		// The client is supported remotely and active
+		BdfList remoteUpdateBody = BdfList.of(BdfList.of(
+				BdfList.of(clientId.getString(), 123, 234, true)), 1L);
+
+		expectGetContactGroup(true);
+		context.checking(new Expectations() {{
+			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
+					contactGroup.getId());
+			will(returnValue(messageMetadata));
+			oneOf(clientHelper).getMessageAsList(txn, remoteUpdateId);
+			will(returnValue(remoteUpdateBody));
+		}});
+
+		ClientVersioningManagerImpl c = createInstance();
+		assertEquals(234, c.getClientMinorVersion(txn, contact.getId(),
+				clientId, 123));
+	}
+
+	private void expectGetContactGroup(boolean exists) throws Exception {
+		context.checking(new Expectations() {{
+			oneOf(db).getContact(txn, contact.getId());
+			will(returnValue(contact));
+			oneOf(contactGroupFactory).createContactGroup(CLIENT_ID,
+					MAJOR_VERSION, contact);
+			will(returnValue(contactGroup));
+			oneOf(db).containsGroup(txn, contactGroup.getId());
+			will(returnValue(exists));
+		}});
+	}
 }

bramble-java/src/main/java/org/briarproject/bramble/lifecycle/DesktopLifecycleModule.java

@@ -1,20 +1,21 @@
 package org.briarproject.bramble.lifecycle;
 
 import org.briarproject.bramble.api.lifecycle.ShutdownManager;
-import org.briarproject.bramble.util.OsUtils;
 
 import javax.inject.Singleton;
 
 import dagger.Module;
 import dagger.Provides;
 
+import static org.briarproject.bramble.util.OsUtils.isWindows;
+
 @Module
 public class DesktopLifecycleModule extends LifecycleModule {
 
 	@Provides
 	@Singleton
 	ShutdownManager provideDesktopShutdownManager() {
-		if (OsUtils.isWindows()) return new WindowsShutdownManagerImpl();
+		if (isWindows()) return new WindowsShutdownManagerImpl();
 		else return new ShutdownManagerImpl();
 	}
 }

bramble-java/src/main/java/org/briarproject/bramble/lifecycle/WindowsShutdownManagerImpl.java

@@ -15,7 +15,6 @@ import com.sun.jna.win32.W32APIFunctionMapper;
 import com.sun.jna.win32.W32APITypeMapper;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.util.OsUtils;
 
 import java.util.Collections;
 import java.util.HashMap;
@@ -29,6 +28,7 @@ import static com.sun.jna.Library.OPTION_FUNCTION_MAPPER;
 import static com.sun.jna.Library.OPTION_TYPE_MAPPER;
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.util.LogUtils.logException;
+import static org.briarproject.bramble.util.OsUtils.isWindows;
 
 @ThreadSafe
 @NotNullByDefault
@@ -71,7 +71,7 @@ class WindowsShutdownManagerImpl extends ShutdownManagerImpl {
 
 	// Locking: lock
 	private void initialise() {
-		if (OsUtils.isWindows()) {
+		if (isWindows()) {
 			new EventLoop().start();
 		} else {
 			LOG.warning("Windows shutdown manager used on non-Windows OS");
@@ -111,7 +111,7 @@ class WindowsShutdownManagerImpl extends ShutdownManagerImpl {
 		public void run() {
 			try {
 				// Load user32.dll
-				User32 user32 = (User32) Native.loadLibrary("user32",
+				User32 user32 = Native.loadLibrary("user32",
 						User32.class, options);
 				// Create a callback to handle the WM_QUERYENDSESSION message
 				WindowProc proc = (hwnd, msg, wp, lp) -> {

bramble-java/src/main/java/org/briarproject/bramble/plugin/tor/JavaTorPlugin.java

@@ -10,7 +10,6 @@ import org.briarproject.bramble.api.system.LocationUtils;
 import org.briarproject.bramble.api.system.ResourceProvider;
 
 import java.io.File;
-import java.io.IOException;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.security.CodeSource;
@@ -19,9 +18,9 @@ import java.util.concurrent.Executor;
 import javax.net.SocketFactory;
 
 @NotNullByDefault
-class LinuxTorPlugin extends TorPlugin {
+abstract class JavaTorPlugin extends TorPlugin {
 
-	LinuxTorPlugin(Executor ioExecutor, NetworkManager networkManager,
+	JavaTorPlugin(Executor ioExecutor, NetworkManager networkManager,
 			LocationUtils locationUtils, SocketFactory torSocketFactory,
 			Clock clock, ResourceProvider resourceProvider,
 			CircumventionProvider circumventionProvider,
@@ -34,17 +33,6 @@ class LinuxTorPlugin extends TorPlugin {
 				torDirectory);
 	}
 
-	@Override
-	protected int getProcessId() {
-		try {
-			// Java 9: ProcessHandle.current().pid()
-			return Integer.parseInt(
-					new File("/proc/self").getCanonicalFile().getName());
-		} catch (IOException e) {
-			throw new AssertionError(e);
-		}
-	}
-
 	@Override
 	protected long getLastUpdateTime() {
 		CodeSource codeSource =
@@ -58,5 +46,4 @@ class LinuxTorPlugin extends TorPlugin {
 			throw new AssertionError(e);
 		}
 	}
-
 }

bramble-java/src/main/java/org/briarproject/bramble/plugin/tor/UnixTorPlugin.java

@@ -0,0 +1,47 @@
+package org.briarproject.bramble.plugin.tor;
+
+import com.sun.jna.Library;
+import com.sun.jna.Native;
+
+import org.briarproject.bramble.api.battery.BatteryManager;
+import org.briarproject.bramble.api.network.NetworkManager;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.Backoff;
+import org.briarproject.bramble.api.plugin.duplex.DuplexPluginCallback;
+import org.briarproject.bramble.api.system.Clock;
+import org.briarproject.bramble.api.system.LocationUtils;
+import org.briarproject.bramble.api.system.ResourceProvider;
+
+import java.io.File;
+import java.util.concurrent.Executor;
+
+import javax.net.SocketFactory;
+
+@NotNullByDefault
+class UnixTorPlugin extends JavaTorPlugin {
+
+	UnixTorPlugin(Executor ioExecutor, NetworkManager networkManager,
+			LocationUtils locationUtils, SocketFactory torSocketFactory,
+			Clock clock, ResourceProvider resourceProvider,
+			CircumventionProvider circumventionProvider,
+			BatteryManager batteryManager, Backoff backoff,
+			DuplexPluginCallback callback, String architecture, int maxLatency,
+			int maxIdleTime, File torDirectory) {
+		super(ioExecutor, networkManager, locationUtils, torSocketFactory,
+				clock, resourceProvider, circumventionProvider, batteryManager,
+				backoff, callback, architecture, maxLatency, maxIdleTime,
+				torDirectory);
+	}
+
+	@Override
+	protected int getProcessId() {
+		return CLibrary.INSTANCE.getpid();
+	}
+
+	private interface CLibrary extends Library {
+
+		CLibrary INSTANCE = (CLibrary) Native.loadLibrary("c", CLibrary.class);
+
+		int getpid();
+	}
+}

bramble-java/src/main/java/org/briarproject/bramble/plugin/tor/UnixTorPluginFactory.java

@@ -22,14 +22,15 @@ import java.util.logging.Logger;
 import javax.annotation.concurrent.Immutable;
 import javax.net.SocketFactory;
 
+import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.util.OsUtils.isLinux;
 
 @Immutable
 @NotNullByDefault
-public class LinuxTorPluginFactory implements DuplexPluginFactory {
+public class UnixTorPluginFactory implements DuplexPluginFactory {
 
 	private static final Logger LOG =
-			Logger.getLogger(LinuxTorPluginFactory.class.getName());
+			getLogger(UnixTorPluginFactory.class.getName());
 
 	private static final int MAX_LATENCY = 30 * 1000; // 30 seconds
 	private static final int MAX_IDLE_TIME = 30 * 1000; // 30 seconds
@@ -49,7 +50,7 @@ public class LinuxTorPluginFactory implements DuplexPluginFactory {
 	private final Clock clock;
 	private final File torDirectory;
 
-	public LinuxTorPluginFactory(Executor ioExecutor,
+	public UnixTorPluginFactory(Executor ioExecutor,
 			NetworkManager networkManager, LocationUtils locationUtils,
 			EventBus eventBus, SocketFactory torSocketFactory,
 			BackoffFactory backoffFactory, ResourceProvider resourceProvider,
@@ -95,7 +96,7 @@ public class LinuxTorPluginFactory implements DuplexPluginFactory {
 
 		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
 				MAX_POLLING_INTERVAL, BACKOFF_BASE);
-		LinuxTorPlugin plugin = new LinuxTorPlugin(ioExecutor, networkManager,
+		UnixTorPlugin plugin = new UnixTorPlugin(ioExecutor, networkManager,
 				locationUtils, torSocketFactory, clock, resourceProvider,
 				circumventionProvider, batteryManager, backoff, callback,
 				architecture, MAX_LATENCY, MAX_IDLE_TIME, torDirectory);

bramble-java/src/main/java/org/briarproject/bramble/system/DesktopSecureRandomModule.java

@@ -1,19 +1,24 @@
 package org.briarproject.bramble.system;
 
 import org.briarproject.bramble.api.system.SecureRandomProvider;
-import org.briarproject.bramble.util.OsUtils;
 
 import javax.inject.Singleton;
 
 import dagger.Module;
 import dagger.Provides;
 
+import static org.briarproject.bramble.util.OsUtils.isLinux;
+import static org.briarproject.bramble.util.OsUtils.isMac;
+
 @Module
 public class DesktopSecureRandomModule {
 
 	@Provides
 	@Singleton
 	SecureRandomProvider provideSecureRandomProvider() {
-		return OsUtils.isLinux() ? new LinuxSecureRandomProvider() : null;
+		if (isLinux() || isMac())
+			return new UnixSecureRandomProvider();
+		// TODO: Create a secure random provider for Windows
+		throw new UnsupportedOperationException();
 	}
 }

bramble-java/src/test/java/org/briarproject/bramble/plugin/tor/BridgeTest.java

@@ -70,7 +70,7 @@ public class BridgeTest extends BrambleTestCase {
 	private final File torDir = getTestDirectory();
 	private final String bridge;
 
-	private LinuxTorPluginFactory factory;
+	private UnixTorPluginFactory factory;
 
 	public BridgeTest(String bridge) {
 		this.bridge = bridge;
@@ -108,7 +108,7 @@ public class BridgeTest extends BrambleTestCase {
 				return singletonList(bridge);
 			}
 		};
-		factory = new LinuxTorPluginFactory(ioExecutor, networkManager,
+		factory = new UnixTorPluginFactory(ioExecutor, networkManager,
 				locationUtils, eventBus, torSocketFactory, backoffFactory,
 				resourceProvider, bridgeProvider, batteryManager, clock,
 				torDir);
@@ -124,7 +124,7 @@ public class BridgeTest extends BrambleTestCase {
 		DuplexPlugin duplexPlugin =
 				factory.createPlugin(new TorPluginCallBack());
 		assertNotNull(duplexPlugin);
-		LinuxTorPlugin plugin = (LinuxTorPlugin) duplexPlugin;
+		UnixTorPlugin plugin = (UnixTorPlugin) duplexPlugin;
 
 		LOG.warning("Testing " + bridge);
 		try {

briar-android/build.gradle

@@ -104,6 +104,8 @@ dependencies {
 	}
 	implementation "com.android.support:cardview-v7:$supportVersion"
 	implementation "com.android.support:support-annotations:$supportVersion"
+	implementation "com.android.support:exifinterface:$supportVersion"
+	implementation "com.android.support:palette-v7:$supportVersion"
 	implementation 'com.android.support.constraint:constraint-layout:1.1.3'
 	implementation "android.arch.lifecycle:extensions:1.1.1"
 
@@ -117,8 +119,15 @@ dependencies {
 	implementation 'com.google.zxing:core:3.3.3'
 	implementation 'uk.co.samuelwall:material-tap-target-prompt:2.12.4'
 	implementation 'com.vanniktech:emoji-google:0.5.1'
+	def glideVersion = '4.8.0'
+	implementation("com.github.bumptech.glide:glide:$glideVersion") {
+		exclude group: 'com.android.support'
+		exclude module: 'disklrucache' // when there's no disk cache, we can't accidentally use it
+	}
+	implementation 'com.github.chrisbanes:PhotoView:2.1.4' // later versions already use androidx
 
 	annotationProcessor 'com.google.dagger:dagger-compiler:2.19'
+	annotationProcessor "com.github.bumptech.glide:compiler:$glideVersion"
 
 	compileOnly 'javax.annotation:jsr250-api:1.0'
 

briar-android/proguard-rules.txt

@@ -30,3 +30,6 @@
 
 # Emoji
 -keep class com.vanniktech.emoji.**
+
+# Glide
+-dontwarn com.bumptech.glide.load.engine.cache.DiskLruCacheWrapper

briar-android/src/main/AndroidManifest.xml

@@ -17,6 +17,7 @@
 	<uses-permission android:name="android.permission.USE_FINGERPRINT"/>
 	<uses-permission android:name="android.permission.VIBRATE" />
 	<uses-permission android:name="android.permission.WAKE_LOCK" />
+	<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
 	<uses-permission-sdk-23 android:name="android.permission.ACCESS_COARSE_LOCATION" />
 	<uses-permission-sdk-23 android:name="android.permission.REQUEST_IGNORE_BATTERY_OPTIMIZATIONS"/>
 	<uses-permission-sdk-23 android:name="android.permission.USE_BIOMETRIC" />
@@ -113,6 +114,15 @@
 				/>
 		</activity>
 
+		<activity
+			android:name=".android.conversation.ImageActivity"
+			android:parentActivityName="org.briarproject.briar.android.conversation.ConversationActivity"
+			android:theme="@style/BriarTheme.Transparent.NoActionBar">
+			<meta-data
+				android:name="android.support.PARENT_ACTIVITY"
+				android:value="org.briarproject.briar.android.conversation.ConversationActivity"/>
+		</activity>
+
 		<activity
 			android:name="org.briarproject.briar.android.privategroup.creation.CreateGroupActivity"
 			android:label="@string/groups_create_group_title"

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

@@ -29,9 +29,10 @@ import org.briarproject.bramble.api.system.LocationUtils;
 import org.briarproject.bramble.plugin.tor.CircumventionProvider;
 import org.briarproject.briar.BriarCoreEagerSingletons;
 import org.briarproject.briar.BriarCoreModule;
+import org.briarproject.briar.android.conversation.glide.BriarModelLoader;
 import org.briarproject.briar.android.login.SignInReminderReceiver;
 import org.briarproject.briar.android.reporting.BriarReportSender;
-import org.briarproject.briar.android.view.TextInputView;
+import org.briarproject.briar.android.view.EmojiTextInputView;
 import org.briarproject.briar.api.android.AndroidNotificationManager;
 import org.briarproject.briar.api.android.DozeWatchdog;
 import org.briarproject.briar.api.android.LockManager;
@@ -168,7 +169,9 @@ public interface AndroidComponent
 
 	void inject(NotificationCleanupService notificationCleanupService);
 
-	void inject(TextInputView textInputView);
+	void inject(EmojiTextInputView textInputView);
+
+	void inject(BriarModelLoader briarModelLoader);
 
 	// Eager singleton load
 	void inject(AppModule.EagerSingletons init);

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

@@ -30,4 +30,10 @@ public interface TestingConstants {
 	long EXPIRY_DATE = IS_DEBUG_BUILD || IS_BETA_BUILD ?
 			BuildConfig.BuildTimestamp + 90 * 24 * 60 * 60 * 1000L :
 			Long.MAX_VALUE;
+
+	/**
+	 * Feature flag for enabling image attachments.
+	 */
+	boolean FEATURE_FLAG_IMAGE_ATTACHMENTS = IS_DEBUG_BUILD;
+
 }

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

@@ -15,10 +15,12 @@ import org.briarproject.briar.android.blog.ReblogFragment;
 import org.briarproject.briar.android.blog.RssFeedImportActivity;
 import org.briarproject.briar.android.blog.RssFeedManageActivity;
 import org.briarproject.briar.android.blog.WriteBlogPostActivity;
-import org.briarproject.briar.android.conversation.AliasDialogFragment;
 import org.briarproject.briar.android.contact.ContactListFragment;
 import org.briarproject.briar.android.contact.ContactModule;
+import org.briarproject.briar.android.conversation.AliasDialogFragment;
 import org.briarproject.briar.android.conversation.ConversationActivity;
+import org.briarproject.briar.android.conversation.ImageActivity;
+import org.briarproject.briar.android.conversation.ImageFragment;
 import org.briarproject.briar.android.forum.CreateForumActivity;
 import org.briarproject.briar.android.forum.ForumActivity;
 import org.briarproject.briar.android.forum.ForumListFragment;
@@ -110,6 +112,8 @@ public interface ActivityComponent {
 
 	void inject(ConversationActivity activity);
 
+	void inject(ImageActivity activity);
+
 	void inject(ForumInvitationActivity activity);
 
 	void inject(BlogInvitationActivity activity);
@@ -215,4 +219,6 @@ public interface ActivityComponent {
 
 	void inject(AliasDialogFragment aliasDialogFragment);
 
+	void inject(ImageFragment imageFragment);
+
 }

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

@@ -2,12 +2,11 @@ package org.briarproject.briar.android.activity;
 
 import android.annotation.SuppressLint;
 import android.content.Intent;
+import android.support.annotation.RequiresApi;
 import android.support.v7.app.ActionBar;
 import android.support.v7.app.AlertDialog;
 import android.support.v7.widget.Toolbar;
-import android.transition.Slide;
 import android.transition.Transition;
-import android.view.Gravity;
 import android.view.Window;
 import android.widget.CheckBox;
 
@@ -33,6 +32,7 @@ import static android.os.Build.VERSION.SDK_INT;
 import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_DOZE_WHITELISTING;
 import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_PASSWORD;
 import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_UNLOCK;
+import static org.briarproject.briar.android.util.UiUtils.excludeSystemUi;
 import static org.briarproject.briar.android.util.UiUtils.getDozeWhitelistingIntent;
 import static org.briarproject.briar.android.util.UiUtils.isSamsung7;
 
@@ -111,21 +111,28 @@ public abstract class BriarActivity extends BaseActivity {
 		lockManager.onActivityStop();
 	}
 
-	public void setSceneTransitionAnimation() {
-		if (SDK_INT < 21) return;
+	/**
+	 * Sets the transition animations.
+	 * @param enterTransition used to move views into initial positions
+	 * @param exitTransition used to move views out when starting a <b>new</b> activity.
+	 * @param returnTransition used when window is closing, because the activity is finishing.
+	 */
+	@RequiresApi(api = 21)
+	public void setSceneTransitionAnimation(
+			@Nullable Transition enterTransition,
+			@Nullable Transition exitTransition,
+			@Nullable Transition returnTransition) {
 		// workaround for #1007
 		if (isSamsung7()) {
 			return;
 		}
-		Transition slide = new Slide(Gravity.RIGHT);
-		slide.excludeTarget(android.R.id.statusBarBackground, true);
-		slide.excludeTarget(android.R.id.navigationBarBackground, true);
+		if (enterTransition != null) excludeSystemUi(enterTransition);
+		if (exitTransition != null) excludeSystemUi(exitTransition);
+		if (returnTransition != null) excludeSystemUi(returnTransition);
 		Window window = getWindow();
-		window.requestFeature(Window.FEATURE_CONTENT_TRANSITIONS);
-		window.setExitTransition(slide);
-		window.setEnterTransition(slide);
-		window.setTransitionBackgroundFadeDuration(getResources()
-				.getInteger(android.R.integer.config_longAnimTime));
+		window.setEnterTransition(enterTransition);
+		window.setExitTransition(exitTransition);
+		window.setReturnTransition(returnTransition);
 	}
 
 	/**

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

@@ -14,5 +14,7 @@ public interface RequestCodes {
 	int REQUEST_BLUETOOTH_DISCOVERABLE = 10;
 	int REQUEST_UNLOCK = 11;
 	int REQUEST_KEYGUARD_UNLOCK = 12;
+	int REQUEST_ATTACH_IMAGE = 13;
+	int REQUEST_SAVE_ATTACHMENT = 14;
 
 }

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

@@ -18,7 +18,6 @@ public class ReblogActivity extends BriarActivity implements
 
 	@Override
 	public void onCreate(Bundle savedInstanceState) {
-		setSceneTransitionAnimation();
 		super.onCreate(savedInstanceState);
 
 		Intent intent = getIntent();

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

@@ -1,5 +1,6 @@
 package org.briarproject.briar.android.blog;
 
+import android.net.Uri;
 import android.os.Bundle;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -18,7 +19,10 @@ import org.briarproject.briar.android.controller.handler.UiExceptionHandler;
 import org.briarproject.briar.android.controller.handler.UiResultExceptionHandler;
 import org.briarproject.briar.android.fragment.BaseFragment;
 import org.briarproject.briar.android.view.TextInputView;
-import org.briarproject.briar.android.view.TextInputView.TextInputListener;
+import org.briarproject.briar.android.view.TextSendController;
+import org.briarproject.briar.android.view.TextSendController.SendListener;
+
+import java.util.List;
 
 import javax.annotation.Nullable;
 import javax.inject.Inject;
@@ -29,10 +33,11 @@ import static android.view.View.INVISIBLE;
 import static android.view.View.VISIBLE;
 import static org.briarproject.briar.android.activity.BriarActivity.GROUP_ID;
 import static org.briarproject.briar.android.blog.BasePostFragment.POST_ID;
+import static org.briarproject.briar.api.blog.BlogConstants.MAX_BLOG_POST_TEXT_LENGTH;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
-public class ReblogFragment extends BaseFragment implements TextInputListener {
+public class ReblogFragment extends BaseFragment implements SendListener {
 
 	public static final String TAG = ReblogFragment.class.getName();
 
@@ -77,7 +82,11 @@ public class ReblogFragment extends BaseFragment implements TextInputListener {
 		View v = inflater.inflate(R.layout.fragment_reblog, container, false);
 		ui = new ViewHolder(v);
 		ui.post.setTransitionName(postId);
-		ui.input.setSendButtonEnabled(false);
+		TextSendController sendController =
+				new TextSendController(ui.input, this, true);
+		ui.input.setSendController(sendController);
+		ui.input.setEnabled(false);
+		ui.input.setMaxTextLength(MAX_BLOG_POST_TEXT_LENGTH);
 		showProgressBar();
 
 		return v;
@@ -112,16 +121,14 @@ public class ReblogFragment extends BaseFragment implements TextInputListener {
 		ui.post.bindItem(item);
 		ui.post.hideReblogButton();
 
-		ui.input.setListener(this);
-		ui.input.setSendButtonEnabled(true);
+		ui.input.setEnabled(true);
 		ui.scrollView.post(() -> ui.scrollView.fullScroll(FOCUS_DOWN));
 	}
 
 	@Override
-	public void onSendClick(String text) {
+	public void onSendClick(@Nullable String text, List<Uri> imageUris) {
 		ui.input.hideSoftKeyboard();
-		String comment = getComment();
-		feedController.repeatPost(item, comment,
+		feedController.repeatPost(item, text,
 				new UiExceptionHandler<DbException>(this) {
 					@Override
 					public void onExceptionUi(DbException exception) {
@@ -131,12 +138,6 @@ public class ReblogFragment extends BaseFragment implements TextInputListener {
 		finish();
 	}
 
-	@Nullable
-	private String getComment() {
-		if (ui.input.getText().length() == 0) return null;
-		return ui.input.getText().toString();
-	}
-
 	private void showProgressBar() {
 		ui.progressBar.setVisibility(VISIBLE);
 		ui.input.setVisibility(GONE);

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

@@ -1,9 +1,9 @@
 package org.briarproject.briar.android.blog;
 
 import android.content.Intent;
+import android.net.Uri;
 import android.os.Bundle;
-import android.text.Editable;
-import android.text.TextWatcher;
+import android.support.annotation.Nullable;
 import android.view.KeyEvent;
 import android.view.MenuItem;
 import android.widget.ProgressBar;
@@ -14,19 +14,22 @@ import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.identity.IdentityManager;
 import org.briarproject.bramble.api.identity.LocalAuthor;
+import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.bramble.api.sync.GroupId;
-import org.briarproject.bramble.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.view.TextInputView;
-import org.briarproject.briar.android.view.TextInputView.TextInputListener;
+import org.briarproject.briar.android.view.TextSendController;
+import org.briarproject.briar.android.view.TextSendController.SendListener;
 import org.briarproject.briar.api.android.AndroidNotificationManager;
 import org.briarproject.briar.api.blog.BlogManager;
 import org.briarproject.briar.api.blog.BlogPost;
 import org.briarproject.briar.api.blog.BlogPostFactory;
 
 import java.security.GeneralSecurityException;
+import java.util.List;
 import java.util.logging.Logger;
 
 import javax.inject.Inject;
@@ -35,10 +38,13 @@ import static android.view.View.GONE;
 import static android.view.View.VISIBLE;
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.util.LogUtils.logException;
+import static org.briarproject.bramble.util.StringUtils.isNullOrEmpty;
 import static org.briarproject.briar.api.blog.BlogConstants.MAX_BLOG_POST_TEXT_LENGTH;
 
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
 public class WriteBlogPostActivity extends BriarActivity
-		implements OnEditorActionListener, TextInputListener {
+		implements OnEditorActionListener, SendListener {
 
 	private static final Logger LOG =
 			Logger.getLogger(WriteBlogPostActivity.class.getName());
@@ -58,9 +64,8 @@ public class WriteBlogPostActivity extends BriarActivity
 	@Inject
 	volatile BlogManager blogManager;
 
-	@SuppressWarnings("ConstantConditions")
 	@Override
-	public void onCreate(Bundle state) {
+	public void onCreate(@Nullable Bundle state) {
 		super.onCreate(state);
 
 		Intent i = getIntent();
@@ -71,24 +76,10 @@ public class WriteBlogPostActivity extends BriarActivity
 		setContentView(R.layout.activity_write_blog_post);
 
 		input = findViewById(R.id.textInput);
-		input.setSendButtonEnabled(false);
-		input.addTextChangedListener(new TextWatcher() {
-			@Override
-			public void beforeTextChanged(CharSequence s, int start, int count,
-					int after) {
-			}
-
-			@Override
-			public void onTextChanged(CharSequence s, int start, int before,
-					int count) {
-			}
-
-			@Override
-			public void afterTextChanged(Editable s) {
-				enableOrDisablePublishButton();
-			}
-		});
-		input.setListener(this);
+		TextSendController sendController =
+				new TextSendController(input, this, false);
+		input.setSendController(sendController);
+		input.setMaxTextLength(MAX_BLOG_POST_TEXT_LENGTH);
 
 		progressBar = findViewById(R.id.progressBar);
 	}
@@ -127,18 +118,15 @@ public class WriteBlogPostActivity extends BriarActivity
 		return true;
 	}
 
-	private void enableOrDisablePublishButton() {
-		input.setSendButtonEnabled(input.getText().length() > 0);
-	}
-
 	@Override
-	public void onSendClick(String text) {
+	public void onSendClick(@Nullable String text, List<Uri> imageUris) {
+		if (isNullOrEmpty(text)) throw new AssertionError();
+
 		// hide publish button, show progress bar
 		input.hideSoftKeyboard();
 		input.setVisibility(GONE);
 		progressBar.setVisibility(VISIBLE);
 
-		text = StringUtils.truncateUtf8(text, MAX_BLOG_POST_TEXT_LENGTH);
 		storePost(text);
 	}
 

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

@@ -0,0 +1,250 @@
+package org.briarproject.briar.android.conversation;
+
+import android.content.res.Resources;
+import android.graphics.BitmapFactory;
+import android.support.annotation.Nullable;
+import android.support.media.ExifInterface;
+import android.webkit.MimeTypeMap;
+
+import org.briarproject.bramble.api.Pair;
+import org.briarproject.bramble.api.db.DatabaseExecutor;
+import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.sync.MessageId;
+import org.briarproject.briar.R;
+import org.briarproject.briar.api.messaging.Attachment;
+import org.briarproject.briar.api.messaging.AttachmentHeader;
+import org.briarproject.briar.api.messaging.MessagingManager;
+
+import java.io.BufferedInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.logging.Logger;
+
+import static android.support.media.ExifInterface.ORIENTATION_ROTATE_270;
+import static android.support.media.ExifInterface.ORIENTATION_ROTATE_90;
+import static android.support.media.ExifInterface.ORIENTATION_TRANSPOSE;
+import static android.support.media.ExifInterface.ORIENTATION_TRANSVERSE;
+import static android.support.media.ExifInterface.TAG_IMAGE_LENGTH;
+import static android.support.media.ExifInterface.TAG_IMAGE_WIDTH;
+import static android.support.media.ExifInterface.TAG_ORIENTATION;
+import static java.util.logging.Level.WARNING;
+import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.util.IoUtils.tryToClose;
+import static org.briarproject.bramble.util.LogUtils.logDuration;
+import static org.briarproject.bramble.util.LogUtils.logException;
+import static org.briarproject.bramble.util.LogUtils.now;
+
+@NotNullByDefault
+class AttachmentController {
+
+	private static final Logger LOG =
+			getLogger(AttachmentController.class.getName());
+
+	private final MessagingManager messagingManager;
+	private final int defaultSize;
+	private final int minWidth, maxWidth;
+	private final int minHeight, maxHeight;
+
+	private final Map<MessageId, List<AttachmentItem>> attachmentCache =
+			new ConcurrentHashMap<>();
+
+	AttachmentController(MessagingManager messagingManager, Resources res) {
+		this.messagingManager = messagingManager;
+		defaultSize =
+				res.getDimensionPixelSize(R.dimen.message_bubble_image_default);
+		minWidth = res.getDimensionPixelSize(
+				R.dimen.message_bubble_image_min_width);
+		maxWidth = res.getDimensionPixelSize(
+				R.dimen.message_bubble_image_max_width);
+		minHeight = res.getDimensionPixelSize(
+				R.dimen.message_bubble_image_min_height);
+		maxHeight = res.getDimensionPixelSize(
+				R.dimen.message_bubble_image_max_height);
+	}
+
+	void put(MessageId messageId, List<AttachmentItem> attachments) {
+		attachmentCache.put(messageId, attachments);
+	}
+
+	@Nullable
+	List<AttachmentItem> get(MessageId messageId) {
+		return attachmentCache.get(messageId);
+	}
+
+	@DatabaseExecutor
+	List<Pair<AttachmentHeader, Attachment>> getMessageAttachments(
+			List<AttachmentHeader> headers) throws DbException {
+		long start = now();
+		List<Pair<AttachmentHeader, Attachment>> attachments =
+				new ArrayList<>(headers.size());
+		for (AttachmentHeader h : headers) {
+			Attachment a =
+					messagingManager.getAttachment(h.getMessageId());
+			attachments.add(new Pair<>(h, a));
+		}
+		logDuration(LOG, "Loading attachment", start);
+		return attachments;
+	}
+
+	/**
+	 * Creates {@link AttachmentItem}s from the passed headers and Attachments.
+	 *
+	 * Note: This closes the {@link Attachment}'s {@link InputStream}.
+	 */
+	List<AttachmentItem> getAttachmentItems(
+			List<Pair<AttachmentHeader, Attachment>> attachments) {
+		boolean needsSize = attachments.size() == 1;
+		List<AttachmentItem> items = new ArrayList<>(attachments.size());
+		for (Pair<AttachmentHeader, Attachment> a : attachments) {
+			AttachmentItem item =
+					getAttachmentItem(a.getFirst(), a.getSecond(), needsSize);
+			items.add(item);
+		}
+		return items;
+	}
+
+	/**
+	 * Creates an {@link AttachmentItem} from the {@link Attachment}'s
+	 * {@link InputStream} which will be closed when this method returns.
+	 */
+	AttachmentItem getAttachmentItem(AttachmentHeader h, Attachment a,
+			boolean needsSize) {
+		MessageId messageId = h.getMessageId();
+		if (!needsSize) {
+			String mimeType = h.getContentType();
+			String extension = getExtensionFromMimeType(mimeType);
+			boolean hasError = false;
+			if (extension == null) {
+				extension = "";
+				hasError = true;
+			}
+			return new AttachmentItem(messageId, 0, 0, mimeType, extension, 0,
+					0, hasError);
+		}
+
+		Size size = new Size();
+		InputStream is = new BufferedInputStream(a.getStream());
+		is.mark(Integer.MAX_VALUE);
+		try {
+			// use exif to get size
+			if (h.getContentType().equals("image/jpeg")) {
+				size = getSizeFromExif(is);
+			}
+		} catch (IOException e) {
+			logException(LOG, WARNING, e);
+		}
+		try {
+			// use BitmapFactory to get size
+			if (size.error) {
+				is.reset();
+				size = getSizeFromBitmap(is);
+			}
+		} catch (IOException e) {
+			logException(LOG, WARNING, e);
+		} finally {
+			tryToClose(is, LOG, WARNING);
+		}
+
+		// calculate thumbnail size
+		Size thumbnailSize = new Size(defaultSize, defaultSize, size.mimeType);
+		if (!size.error) {
+			thumbnailSize =
+					getThumbnailSize(size.width, size.height, size.mimeType);
+		}
+		// get file extension
+		String extension = getExtensionFromMimeType(size.mimeType);
+		if (extension == null) {
+			return new AttachmentItem(messageId, 0, 0, "", "", 0, 0, true);
+		}
+		return new AttachmentItem(messageId, size.width, size.height,
+				size.mimeType, extension, thumbnailSize.width,
+				thumbnailSize.height, size.error);
+	}
+
+	@Nullable
+	private String getExtensionFromMimeType(String mimeType) {
+		MimeTypeMap mimeTypeMap = MimeTypeMap.getSingleton();
+		return mimeTypeMap.getExtensionFromMimeType(mimeType);
+	}
+
+	/**
+	 * Gets the size of a JPEG {@link InputStream} if EXIF info is available.
+	 */
+	private static Size getSizeFromExif(InputStream is)
+			throws IOException {
+		ExifInterface exif = new ExifInterface(is);
+		// these can return 0 independent of default value
+		int width = exif.getAttributeInt(TAG_IMAGE_WIDTH, 0);
+		int height = exif.getAttributeInt(TAG_IMAGE_LENGTH, 0);
+		if (width == 0 || height == 0) return new Size();
+		int orientation = exif.getAttributeInt(TAG_ORIENTATION, 0);
+		if (orientation == ORIENTATION_ROTATE_90 ||
+				orientation == ORIENTATION_ROTATE_270 ||
+				orientation == ORIENTATION_TRANSVERSE ||
+				orientation == ORIENTATION_TRANSPOSE) {
+			//noinspection SuspiciousNameCombination
+			return new Size(height, width, "image/jpeg");
+		}
+		return new Size(width, height, "image/jpeg");
+	}
+
+	/**
+	 * Gets the size of any image {@link InputStream}.
+	 */
+	private static Size getSizeFromBitmap(InputStream is) {
+		BitmapFactory.Options options = new BitmapFactory.Options();
+		options.inJustDecodeBounds = true;
+		BitmapFactory.decodeStream(is, null, options);
+		if (options.outWidth < 1 || options.outHeight < 1)
+			return new Size();
+		return new Size(options.outWidth, options.outHeight,
+				options.outMimeType);
+	}
+
+	private Size getThumbnailSize(int width, int height, String mimeType) {
+		float widthPercentage = maxWidth / (float) width;
+		float heightPercentage = maxHeight / (float) height;
+		float scaleFactor = Math.min(widthPercentage, heightPercentage);
+		if (scaleFactor > 1) scaleFactor = 1f;
+		int thumbnailWidth = (int) (width * scaleFactor);
+		int thumbnailHeight = (int) (height * scaleFactor);
+		if (thumbnailWidth < minWidth || thumbnailHeight < minHeight) {
+			widthPercentage = minWidth / (float) width;
+			heightPercentage = minHeight / (float) height;
+			scaleFactor = Math.max(widthPercentage, heightPercentage);
+			thumbnailWidth = (int) (width * scaleFactor);
+			thumbnailHeight = (int) (height * scaleFactor);
+			if (thumbnailWidth > maxWidth) thumbnailWidth = maxWidth;
+			if (thumbnailHeight > maxHeight) thumbnailHeight = maxHeight;
+		}
+		return new Size(thumbnailWidth, thumbnailHeight, mimeType);
+	}
+
+	private static class Size {
+
+		private final int width;
+		private final int height;
+		private final String mimeType;
+		private final boolean error;
+
+		private Size(int width, int height, String mimeType) {
+			this.width = width;
+			this.height = height;
+			this.mimeType = mimeType;
+			this.error = false;
+		}
+
+		private Size() {
+			this.width = 0;
+			this.height = 0;
+			this.mimeType = "";
+			this.error = true;
+		}
+	}
+
+}

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

@@ -0,0 +1,121 @@
+package org.briarproject.briar.android.conversation;
+
+import android.os.Parcel;
+import android.os.Parcelable;
+import android.support.annotation.Nullable;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.sync.MessageId;
+
+import javax.annotation.concurrent.Immutable;
+
+@Immutable
+@NotNullByDefault
+public class AttachmentItem implements Parcelable {
+
+	private final MessageId messageId;
+	private final int width, height;
+	private final String mimeType, extension;
+	private final int thumbnailWidth, thumbnailHeight;
+	private final boolean hasError;
+
+	public static final Creator<AttachmentItem> CREATOR =
+			new Creator<AttachmentItem>() {
+				@Override
+				public AttachmentItem createFromParcel(Parcel in) {
+					return new AttachmentItem(in);
+				}
+
+				@Override
+				public AttachmentItem[] newArray(int size) {
+					return new AttachmentItem[size];
+				}
+			};
+
+	AttachmentItem(MessageId messageId, int width, int height, String mimeType,
+			String extension, int thumbnailWidth, int thumbnailHeight,
+			boolean hasError) {
+		this.messageId = messageId;
+		this.width = width;
+		this.height = height;
+		this.mimeType = mimeType;
+		this.extension = extension;
+		this.thumbnailWidth = thumbnailWidth;
+		this.thumbnailHeight = thumbnailHeight;
+		this.hasError = hasError;
+	}
+
+	protected AttachmentItem(Parcel in) {
+		byte[] messageIdByte = new byte[MessageId.LENGTH];
+		in.readByteArray(messageIdByte);
+		messageId = new MessageId(messageIdByte);
+		width = in.readInt();
+		height = in.readInt();
+		mimeType = in.readString();
+		extension = in.readString();
+		thumbnailWidth = in.readInt();
+		thumbnailHeight = in.readInt();
+		hasError = in.readByte() != 0;
+	}
+
+	public MessageId getMessageId() {
+		return messageId;
+	}
+
+	int getWidth() {
+		return width;
+	}
+
+	int getHeight() {
+		return height;
+	}
+
+	String getMimeType() {
+		return mimeType;
+	}
+
+	String getExtension() {
+		return extension;
+	}
+
+	int getThumbnailWidth() {
+		return thumbnailWidth;
+	}
+
+	int getThumbnailHeight() {
+		return thumbnailHeight;
+	}
+
+	boolean hasError() {
+		return hasError;
+	}
+
+	// TODO use counter instead, because in theory one attachment can appear in more than one messages
+	String getTransitionName() {
+		return String.valueOf(messageId.hashCode());
+	}
+
+	@Override
+	public int describeContents() {
+		return 0;
+	}
+
+	@Override
+	public void writeToParcel(Parcel dest, int flags) {
+		dest.writeByteArray(messageId.getBytes());
+		dest.writeInt(width);
+		dest.writeInt(height);
+		dest.writeString(mimeType);
+		dest.writeString(extension);
+		dest.writeInt(thumbnailWidth);
+		dest.writeInt(thumbnailHeight);
+		dest.writeByte((byte) (hasError ? 1 : 0));
+	}
+
+	@Override
+	public boolean equals(@Nullable Object o) {
+		return o instanceof AttachmentItem &&
+				messageId.equals(((AttachmentItem) o).messageId);
+	}
+
+}

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

@@ -1,19 +1,26 @@
 package org.briarproject.briar.android.conversation;
 
+import android.annotation.SuppressLint;
 import android.arch.lifecycle.Observer;
 import android.arch.lifecycle.ViewModelProvider;
 import android.arch.lifecycle.ViewModelProviders;
 import android.content.DialogInterface;
 import android.content.Intent;
+import android.net.Uri;
 import android.os.Bundle;
+import android.os.Parcelable;
 import android.support.annotation.Nullable;
 import android.support.annotation.UiThread;
 import android.support.design.widget.Snackbar;
+import android.support.v4.app.ActivityCompat;
+import android.support.v4.app.ActivityOptionsCompat;
 import android.support.v4.content.ContextCompat;
 import android.support.v7.app.AlertDialog;
 import android.support.v7.widget.ActionMenuView;
 import android.support.v7.widget.LinearLayoutManager;
 import android.support.v7.widget.Toolbar;
+import android.transition.Slide;
+import android.transition.Transition;
 import android.util.SparseArray;
 import android.view.Menu;
 import android.view.MenuInflater;
@@ -23,7 +30,7 @@ import android.widget.ImageView;
 import android.widget.TextView;
 import android.widget.Toast;
 
-import org.briarproject.bramble.api.FormatException;
+import org.briarproject.bramble.api.Pair;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.ContactManager;
 import org.briarproject.bramble.api.contact.event.ContactRemovedEvent;
@@ -42,22 +49,25 @@ import org.briarproject.bramble.api.plugin.event.ContactDisconnectedEvent;
 import org.briarproject.bramble.api.settings.Settings;
 import org.briarproject.bramble.api.settings.SettingsManager;
 import org.briarproject.bramble.api.sync.GroupId;
-import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.sync.event.MessagesAckedEvent;
 import org.briarproject.bramble.api.sync.event.MessagesSentEvent;
-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.conversation.ConversationVisitor.AttachmentCache;
 import org.briarproject.briar.android.conversation.ConversationVisitor.TextCache;
 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.ImagePreview;
+import org.briarproject.briar.android.view.TextAttachmentController;
+import org.briarproject.briar.android.view.TextAttachmentController.AttachImageListener;
 import org.briarproject.briar.android.view.TextInputView;
-import org.briarproject.briar.android.view.TextInputView.TextInputListener;
+import org.briarproject.briar.android.view.TextSendController;
+import org.briarproject.briar.android.view.TextSendController.SendListener;
 import org.briarproject.briar.api.android.AndroidNotificationManager;
 import org.briarproject.briar.api.blog.BlogSharingManager;
 import org.briarproject.briar.api.client.ProtocolStateException;
@@ -69,8 +79,9 @@ import org.briarproject.briar.api.conversation.ConversationResponse;
 import org.briarproject.briar.api.conversation.event.ConversationMessageReceivedEvent;
 import org.briarproject.briar.api.forum.ForumSharingManager;
 import org.briarproject.briar.api.introduction.IntroductionManager;
+import org.briarproject.briar.api.messaging.Attachment;
+import org.briarproject.briar.api.messaging.AttachmentHeader;
 import org.briarproject.briar.api.messaging.MessagingManager;
-import org.briarproject.briar.api.messaging.PrivateMessage;
 import org.briarproject.briar.api.messaging.PrivateMessageFactory;
 import org.briarproject.briar.api.messaging.PrivateMessageHeader;
 import org.briarproject.briar.api.privategroup.invitation.GroupInvitationManager;
@@ -92,8 +103,11 @@ import im.delight.android.identicons.IdenticonDrawable;
 import uk.co.samuelwall.materialtaptargetprompt.MaterialTapTargetPrompt;
 import uk.co.samuelwall.materialtaptargetprompt.MaterialTapTargetPrompt.PromptStateChangeListener;
 
+import static android.os.Build.VERSION.SDK_INT;
+import static android.support.v4.app.ActivityOptionsCompat.makeSceneTransitionAnimation;
 import static android.support.v4.view.ViewCompat.setTransitionName;
 import static android.support.v7.util.SortedList.INVALID_POSITION;
+import static android.view.Gravity.RIGHT;
 import static android.widget.Toast.LENGTH_SHORT;
 import static java.util.Collections.emptyList;
 import static java.util.Collections.sort;
@@ -103,7 +117,14 @@ import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.util.LogUtils.logDuration;
 import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.bramble.util.LogUtils.now;
+import static org.briarproject.bramble.util.StringUtils.isNullOrEmpty;
+import static org.briarproject.briar.android.TestingConstants.FEATURE_FLAG_IMAGE_ATTACHMENTS;
+import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_ATTACH_IMAGE;
 import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_INTRODUCTION;
+import static org.briarproject.briar.android.conversation.ImageActivity.ATTACHMENTS;
+import static org.briarproject.briar.android.conversation.ImageActivity.ATTACHMENT_POSITION;
+import static org.briarproject.briar.android.conversation.ImageActivity.DATE;
+import static org.briarproject.briar.android.conversation.ImageActivity.NAME;
 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;
@@ -115,8 +136,8 @@ import static uk.co.samuelwall.materialtaptargetprompt.MaterialTapTargetPrompt.S
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
 public class ConversationActivity extends BriarActivity
-		implements EventListener, ConversationListener, TextInputListener,
-		TextCache {
+		implements EventListener, ConversationListener, SendListener,
+		TextCache, AttachmentCache, AttachImageListener {
 
 	public static final String CONTACT_ID = "briar.CONTACT_ID";
 
@@ -134,6 +155,7 @@ public class ConversationActivity extends BriarActivity
 	Executor cryptoExecutor;
 
 	private final Map<MessageId, String> textCache = new ConcurrentHashMap<>();
+	private AttachmentController attachmentController;
 
 	private ConversationViewModel viewModel;
 	private ConversationVisitor visitor;
@@ -143,7 +165,9 @@ public class ConversationActivity extends BriarActivity
 	private ImageView toolbarStatus;
 	private TextView toolbarTitle;
 	private BriarRecyclerView list;
+	private LinearLayoutManager layoutManager;
 	private TextInputView textInputView;
+	private TextSendController sendController;
 
 	// Fields that are accessed from background threads must be volatile
 	@Inject
@@ -171,7 +195,7 @@ public class ConversationActivity extends BriarActivity
 
 	private volatile ContactId contactId;
 	@Nullable
-	private volatile GroupId messagingGroupId;
+	private Parcelable layoutManagerState;
 
 	private final Observer<String> contactNameObserver = name -> {
 		requireNonNull(name);
@@ -180,7 +204,12 @@ public class ConversationActivity extends BriarActivity
 
 	@Override
 	public void onCreate(@Nullable Bundle state) {
-		setSceneTransitionAnimation();
+		if (SDK_INT >= 21) {
+			// Spurious lint warning - using END causes a crash
+			@SuppressLint("RtlHardcoded")
+			Transition slide = new Slide(RIGHT);
+			setSceneTransitionAnimation(slide, null, slide);
+		}
 		super.onCreate(state);
 
 		Intent i = getIntent();
@@ -191,6 +220,7 @@ public class ConversationActivity extends BriarActivity
 		viewModel = ViewModelProviders.of(this, viewModelFactory)
 				.get(ConversationViewModel.class);
 		viewModel.setContactId(contactId);
+		attachmentController = viewModel.getAttachmentController();
 
 		setContentView(R.layout.activity_conversation);
 
@@ -213,20 +243,32 @@ public class ConversationActivity extends BriarActivity
 			requireNonNull(deleted);
 			if (deleted) finish();
 		});
+		viewModel.getAddedPrivateMessage()
+				.observe(this, this::onAddedPrivateMessage);
 
 		setTransitionName(toolbarAvatar, getAvatarTransitionName(contactId));
 		setTransitionName(toolbarStatus, getBulbTransitionName(contactId));
 
-		visitor = new ConversationVisitor(this, this,
+		visitor = new ConversationVisitor(this, this, this,
 				viewModel.getContactDisplayName());
 		adapter = new ConversationAdapter(this, this);
 		list = findViewById(R.id.conversationView);
-		list.setLayoutManager(new LinearLayoutManager(this));
+		layoutManager = new LinearLayoutManager(this);
+		list.setLayoutManager(layoutManager);
 		list.setAdapter(adapter);
 		list.setEmptyText(getString(R.string.no_private_messages));
 
 		textInputView = findViewById(R.id.text_input_container);
-		textInputView.setListener(this);
+		if (FEATURE_FLAG_IMAGE_ATTACHMENTS) {
+			ImagePreview imagePreview = findViewById(R.id.imagePreview);
+			sendController = new TextAttachmentController(textInputView,
+					imagePreview, this, this);
+		} else {
+			sendController = new TextSendController(textInputView, this, false);
+		}
+		textInputView.setSendController(sendController);
+		textInputView.setMaxTextLength(MAX_PRIVATE_MESSAGE_TEXT_LENGTH);
+		textInputView.setEnabled(false);
 	}
 
 	@Override
@@ -243,6 +285,9 @@ public class ConversationActivity extends BriarActivity
 					Snackbar.LENGTH_SHORT);
 			snackbar.getView().setBackgroundResource(R.color.briar_primary);
 			snackbar.show();
+		} else if (request == REQUEST_ATTACH_IMAGE && result == RESULT_OK) {
+			// remove cast when removing FEATURE_FLAG_IMAGE_ATTACHMENTS
+			((TextAttachmentController) sendController).onImageReceived(data);
 		}
 	}
 
@@ -266,6 +311,21 @@ public class ConversationActivity extends BriarActivity
 		list.stopPeriodicUpdate();
 	}
 
+	@Override
+	protected void onSaveInstanceState(Bundle outState) {
+		super.onSaveInstanceState(outState);
+		if (layoutManager != null) {
+			layoutManagerState = layoutManager.onSaveInstanceState();
+			outState.putParcelable("layoutManager", layoutManagerState);
+		}
+	}
+
+	@Override
+	protected void onRestoreInstanceState(Bundle savedInstanceState) {
+		super.onRestoreInstanceState(savedInstanceState);
+		layoutManagerState = savedInstanceState.getParcelable("layoutManager");
+	}
+
 	@Override
 	public boolean onCreateOptionsMenu(Menu menu) {
 		// Inflate the menu items for use in the action bar
@@ -340,14 +400,30 @@ public class ConversationActivity extends BriarActivity
 					// If the latest header is a private message, eagerly load
 					// its text so we can set the scroll position correctly
 					ConversationMessageHeader latest = sorted.get(0);
-					if (latest instanceof PrivateMessageHeader &&
-							((PrivateMessageHeader) latest).hasText()) {
+					if (latest instanceof PrivateMessageHeader) {
 						MessageId id = latest.getId();
-						String text = textCache.get(id);
-						if (text == null) {
-							LOG.info("Eagerly loading text of latest message");
-							text = messagingManager.getMessageText(id);
-							textCache.put(id, text);
+						PrivateMessageHeader h = (PrivateMessageHeader) latest;
+						if (h.hasText()) {
+							String text = textCache.get(id);
+							if (text == null) {
+								LOG.info(
+										"Eagerly loading text of latest message");
+								text = messagingManager.getMessageText(id);
+								textCache.put(id, text);
+							}
+						}
+						if (h.getAttachmentHeaders().size() == 1) {
+							List<AttachmentItem> items =
+									attachmentController.get(id);
+							if (items == null) {
+								LOG.info(
+										"Eagerly loading image size for latest message");
+								items = attachmentController.getAttachmentItems(
+										attachmentController
+												.getMessageAttachments(
+														h.getAttachmentHeaders()));
+								attachmentController.put(id, items);
+							}
 						}
 					}
 				}
@@ -365,12 +441,16 @@ public class ConversationActivity extends BriarActivity
 		runOnUiThreadUnlessDestroyed(() -> {
 			if (revision == adapter.getRevision()) {
 				adapter.incrementRevision();
-				textInputView.setSendButtonEnabled(true);
+				textInputView.setEnabled(true);
 				List<ConversationItem> items = createItems(headers);
 				adapter.addAll(items);
 				list.showData();
-				// Scroll to the bottom
-				list.scrollToPosition(adapter.getItemCount() - 1);
+				if (layoutManagerState == null) {
+					// Scroll to the bottom
+					list.scrollToPosition(adapter.getItemCount() - 1);
+				} else {
+					layoutManager.onRestoreInstanceState(layoutManagerState);
+				}
 			} else {
 				LOG.info("Concurrent update, reloading");
 				loadMessages();
@@ -408,16 +488,46 @@ public class ConversationActivity extends BriarActivity
 	private void displayMessageText(MessageId m, String text) {
 		runOnUiThreadUnlessDestroyed(() -> {
 			textCache.put(m, text);
-			SparseArray<ConversationMessageItem> messages =
-					adapter.getMessageItems();
-			for (int i = 0; i < messages.size(); i++) {
-				ConversationItem item = messages.valueAt(i);
-				if (item.getId().equals(m)) {
-					item.setText(text);
-					adapter.notifyItemChanged(messages.keyAt(i));
-					list.scrollToPosition(adapter.getItemCount() - 1);
-					return;
-				}
+			Pair<Integer, ConversationMessageItem> pair =
+					adapter.getMessageItem(m);
+			if (pair != null) {
+				pair.getSecond().setText(text);
+				boolean bottom = layoutManagerState == null &&
+						adapter.isScrolledToBottom(layoutManager);
+				adapter.notifyItemChanged(pair.getFirst());
+				if (bottom) list.scrollToPosition(adapter.getItemCount() - 1);
+			}
+		});
+	}
+
+	private void loadMessageAttachments(MessageId messageId,
+			List<AttachmentHeader> headers) {
+		runOnDbThread(() -> {
+			try {
+				List<Pair<AttachmentHeader, Attachment>> attachments =
+						attachmentController.getMessageAttachments(headers);
+				// TODO move getting the items off to IoExecutor, if size == 1
+				List<AttachmentItem> items =
+						attachmentController.getAttachmentItems(attachments);
+				displayMessageAttachments(messageId, items);
+			} catch (DbException e) {
+				logException(LOG, WARNING, e);
+			}
+		});
+	}
+
+	private void displayMessageAttachments(MessageId m,
+			List<AttachmentItem> items) {
+		runOnUiThreadUnlessDestroyed(() -> {
+			attachmentController.put(m, items);
+			Pair<Integer, ConversationMessageItem> pair =
+					adapter.getMessageItem(m);
+			if (pair != null) {
+				pair.getSecond().setAttachments(items);
+				boolean bottom = layoutManagerState == null &&
+						adapter.isScrolledToBottom(layoutManager);
+				adapter.notifyItemChanged(pair.getFirst());
+				if (bottom) list.scrollToPosition(adapter.getItemCount() - 1);
 			}
 		});
 	}
@@ -466,10 +576,11 @@ public class ConversationActivity extends BriarActivity
 
 	private void addConversationItem(ConversationItem item) {
 		runOnUiThreadUnlessDestroyed(() -> {
+			boolean bottom = layoutManagerState == null &&
+					adapter.isScrolledToBottom(layoutManager);
 			adapter.incrementRevision();
 			adapter.add(item);
-			// Scroll to the bottom
-			list.scrollToPosition(adapter.getItemCount() - 1);
+			if (bottom) list.scrollToPosition(adapter.getItemCount() - 1);
 		});
 	}
 
@@ -505,14 +616,18 @@ public class ConversationActivity extends BriarActivity
 	}
 
 	@Override
-	public void onSendClick(String text) {
-		if (text.isEmpty()) return;
-		text = StringUtils.truncateUtf8(text, MAX_PRIVATE_MESSAGE_TEXT_LENGTH);
+	public void onAttachImage(Intent intent) {
+		startActivityForResult(intent, REQUEST_ATTACH_IMAGE);
+	}
+
+	@Override
+	public void onSendClick(@Nullable String text, List<Uri> imageUris) {
+		if (isNullOrEmpty(text) && imageUris.isEmpty())
+			throw new AssertionError();
 		long timestamp = System.currentTimeMillis();
 		timestamp = Math.max(timestamp, getMinTimestampForNewMessage());
-		if (messagingGroupId == null) loadGroupId(text, timestamp);
-		else createMessage(text, timestamp);
-		textInputView.setText("");
+		viewModel.sendMessage(text, imageUris, timestamp);
+		textInputView.clearText();
 	}
 
 	private long getMinTimestampForNewMessage() {
@@ -521,48 +636,10 @@ public class ConversationActivity extends BriarActivity
 		return item == null ? 0 : item.getTime() + 1;
 	}
 
-	private void loadGroupId(String text, long timestamp) {
-		runOnDbThread(() -> {
-			try {
-				messagingGroupId =
-						messagingManager.getConversationId(contactId);
-				createMessage(text, timestamp);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
-
-		});
-	}
-
-	private void createMessage(String text, long timestamp) {
-		cryptoExecutor.execute(() -> {
-			try {
-				//noinspection ConstantConditions init in loadGroupId()
-				storeMessage(privateMessageFactory.createPrivateMessage(
-						messagingGroupId, timestamp, text, emptyList()), text);
-			} catch (FormatException e) {
-				throw new RuntimeException(e);
-			}
-		});
-	}
-
-	private void storeMessage(PrivateMessage m, String text) {
-		runOnDbThread(() -> {
-			try {
-				long start = now();
-				messagingManager.addLocalMessage(m);
-				logDuration(LOG, "Storing message", start);
-				Message message = m.getMessage();
-				PrivateMessageHeader h = new PrivateMessageHeader(
-						message.getId(), message.getGroupId(),
-						message.getTimestamp(), true, false, false, false,
-						true, emptyList());
-				textCache.put(message.getId(), text);
-				addConversationItem(h.accept(visitor));
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
-		});
+	private void onAddedPrivateMessage(@Nullable PrivateMessageHeader h) {
+		if (h == null) return;
+		addConversationItem(h.accept(visitor));
+		viewModel.onAddedPrivateMessageSeen();
 	}
 
 	private void askToRemoveContact() {
@@ -750,6 +827,30 @@ public class ConversationActivity extends BriarActivity
 		startActivity(i);
 	}
 
+	@Override
+	public void onAttachmentClicked(View view,
+			ConversationMessageItem messageItem, AttachmentItem item) {
+		String name;
+		if (messageItem.isIncoming()) {
+			// must be available when items are being displayed
+			name = viewModel.getContactDisplayName().getValue();
+		} else {
+			name = getString(R.string.you);
+		}
+		ArrayList<AttachmentItem> attachments =
+				new ArrayList<>(messageItem.getAttachments());
+		Intent i = new Intent(this, ImageActivity.class);
+		i.putParcelableArrayListExtra(ATTACHMENTS, attachments);
+		i.putExtra(ATTACHMENT_POSITION, attachments.indexOf(item));
+		i.putExtra(NAME, name);
+		i.putExtra(DATE, messageItem.getTime());
+		// restoring list position should not trigger android bug #224270
+		String transitionName = item.getTransitionName();
+		ActivityOptionsCompat options =
+				makeSceneTransitionAnimation(this, view, transitionName);
+		ActivityCompat.startActivity(this, i, options.toBundle());
+	}
+
 	@DatabaseExecutor
 	private void respondToIntroductionRequest(SessionId sessionId,
 			boolean accept, long time) throws DbException {
@@ -782,4 +883,16 @@ public class ConversationActivity extends BriarActivity
 		if (text == null) loadMessageText(m);
 		return text;
 	}
+
+	@Override
+	public List<AttachmentItem> getAttachmentItems(MessageId m,
+			List<AttachmentHeader> headers) {
+		List<AttachmentItem> attachments = attachmentController.get(m);
+		if (attachments == null) {
+			loadMessageAttachments(m, headers);
+			return emptyList();
+		}
+		return attachments;
+	}
+
 }

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

@@ -2,12 +2,16 @@ package org.briarproject.briar.android.conversation;
 
 import android.content.Context;
 import android.support.annotation.LayoutRes;
+import android.support.v7.widget.LinearLayoutManager;
+import android.support.v7.widget.RecyclerView.RecycledViewPool;
 import android.util.SparseArray;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 
+import org.briarproject.bramble.api.Pair;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.util.BriarAdapter;
 
@@ -18,11 +22,17 @@ class ConversationAdapter
 		extends BriarAdapter<ConversationItem, ConversationItemViewHolder> {
 
 	private ConversationListener listener;
+	private final RecycledViewPool imageViewPool;
+	private final ImageItemDecoration imageItemDecoration;
 
 	ConversationAdapter(Context ctx,
 			ConversationListener conversationListener) {
 		super(ctx, ConversationItem.class);
 		listener = conversationListener;
+		// This shares the same pool for view recycling between all image lists
+		imageViewPool = new RecycledViewPool();
+		// Share the item decoration as well
+		imageItemDecoration = new ImageItemDecoration(ctx);
 	}
 
 	@LayoutRes
@@ -39,15 +49,17 @@ class ConversationAdapter
 				type, viewGroup, false);
 		switch (type) {
 			case R.layout.list_item_conversation_msg_in:
-				return new ConversationMessageViewHolder(v, true);
+				return new ConversationMessageViewHolder(v, listener, true,
+						imageViewPool, imageItemDecoration);
 			case R.layout.list_item_conversation_msg_out:
-				return new ConversationMessageViewHolder(v, false);
+				return new ConversationMessageViewHolder(v, listener, false,
+						imageViewPool, imageItemDecoration);
 			case R.layout.list_item_conversation_notice_in:
-				return new ConversationNoticeViewHolder(v, true);
+				return new ConversationNoticeViewHolder(v, listener, true);
 			case R.layout.list_item_conversation_notice_out:
-				return new ConversationNoticeViewHolder(v, false);
+				return new ConversationNoticeViewHolder(v, listener, false);
 			case R.layout.list_item_conversation_request:
-				return new ConversationRequestViewHolder(v, true);
+				return new ConversationRequestViewHolder(v, listener, true);
 			default:
 				throw new IllegalArgumentException("Unknown ConversationItem");
 		}
@@ -56,7 +68,7 @@ class ConversationAdapter
 	@Override
 	public void onBindViewHolder(ConversationItemViewHolder ui, int position) {
 		ConversationItem item = items.get(position);
-		ui.bind(item, listener);
+		ui.bind(item);
 		listener.onItemVisible(item);
 	}
 
@@ -98,16 +110,20 @@ class ConversationAdapter
 		return messages;
 	}
 
-	SparseArray<ConversationMessageItem> getMessageItems() {
-		SparseArray<ConversationMessageItem> messages = new SparseArray<>();
-
+	@Nullable
+	Pair<Integer, ConversationMessageItem> getMessageItem(MessageId messageId) {
 		for (int i = 0; i < items.size(); i++) {
 			ConversationItem item = items.get(i);
-			if (item instanceof ConversationMessageItem) {
-				messages.put(i, (ConversationMessageItem) item);
+			if (item instanceof ConversationMessageItem &&
+					item.getId().equals(messageId)) {
+				return new Pair<>(i, (ConversationMessageItem) item);
 			}
 		}
-		return messages;
+		return null;
+	}
+
+	boolean isScrolledToBottom(LinearLayoutManager layoutManager) {
+		return layoutManager.findLastVisibleItemPosition() == items.size() - 1;
 	}
 
 }

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

@@ -3,9 +3,9 @@ package org.briarproject.briar.android.conversation;
 import android.support.annotation.CallSuper;
 import android.support.annotation.Nullable;
 import android.support.annotation.UiThread;
+import android.support.constraint.ConstraintLayout;
 import android.support.v7.widget.RecyclerView.ViewHolder;
 import android.view.View;
-import android.view.ViewGroup;
 import android.widget.TextView;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
@@ -18,14 +18,17 @@ import static org.briarproject.briar.android.util.UiUtils.formatDate;
 @NotNullByDefault
 abstract class ConversationItemViewHolder extends ViewHolder {
 
-	protected final ViewGroup layout;
+	protected final ConversationListener listener;
+	protected final ConstraintLayout layout;
 	@Nullable
 	private final OutItemViewHolder outViewHolder;
 	private final TextView text;
-	private final TextView time;
+	protected final TextView time;
 
-	ConversationItemViewHolder(View v, boolean isIncoming) {
+	ConversationItemViewHolder(View v, ConversationListener listener,
+			boolean isIncoming) {
 		super(v);
+		this.listener = listener;
 		this.outViewHolder = isIncoming ? null : new OutItemViewHolder(v);
 		layout = v.findViewById(R.id.layout);
 		text = v.findViewById(R.id.text);
@@ -33,7 +36,7 @@ abstract class ConversationItemViewHolder extends ViewHolder {
 	}
 
 	@CallSuper
-	void bind(ConversationItem item, ConversationListener listener) {
+	void bind(ConversationItem item) {
 		if (item.getText() != null) {
 			text.setText(trim(item.getText()));
 		}

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

@@ -1,6 +1,7 @@
 package org.briarproject.briar.android.conversation;
 
 import android.support.annotation.UiThread;
+import android.view.View;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
@@ -14,4 +15,7 @@ interface ConversationListener {
 
 	void openRequestedShareable(ConversationRequestItem item);
 
+	void onAttachmentClicked(View view, ConversationMessageItem messageItem,
+			AttachmentItem attachmentItem);
+
 }

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

@@ -3,7 +3,6 @@ package org.briarproject.briar.android.conversation;
 import android.support.annotation.LayoutRes;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.briar.api.messaging.AttachmentHeader;
 import org.briarproject.briar.api.messaging.PrivateMessageHeader;
 
 import java.util.List;
@@ -14,15 +13,20 @@ import javax.annotation.concurrent.NotThreadSafe;
 @NotNullByDefault
 class ConversationMessageItem extends ConversationItem {
 
-	private final List<AttachmentHeader> attachments;
+	private List<AttachmentItem> attachments;
 
-	ConversationMessageItem(@LayoutRes int layoutRes, PrivateMessageHeader h) {
+	ConversationMessageItem(@LayoutRes int layoutRes, PrivateMessageHeader h,
+			List<AttachmentItem> attachments) {
 		super(layoutRes, h);
-		this.attachments = h.getAttachmentHeaders();
+		this.attachments = attachments;
 	}
 
-	List<AttachmentHeader> getAttachments() {
+	List<AttachmentItem> getAttachments() {
 		return attachments;
 	}
 
+	void setAttachments(List<AttachmentItem> attachments) {
+		this.attachments = attachments;
+	}
+
 }

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

@@ -1,18 +1,113 @@
 package org.briarproject.briar.android.conversation;
 
 import android.support.annotation.UiThread;
+import android.support.constraint.ConstraintSet;
+import android.support.v7.widget.RecyclerView;
+import android.support.v7.widget.RecyclerView.RecycledViewPool;
 import android.view.View;
+import android.view.ViewGroup;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.briar.R;
+
+import static android.support.constraint.ConstraintSet.WRAP_CONTENT;
+import static android.support.v4.content.ContextCompat.getColor;
 
 @UiThread
 @NotNullByDefault
 class ConversationMessageViewHolder extends ConversationItemViewHolder {
 
-	// image support will be added here (#1242)
+	private final ImageAdapter adapter;
+	private final ViewGroup statusLayout;
+	private final int timeColor, timeColorBubble;
+	private final ConstraintSet textConstraints = new ConstraintSet();
+	private final ConstraintSet imageConstraints = new ConstraintSet();
+	private final ConstraintSet imageTextConstraints = new ConstraintSet();
 
-	ConversationMessageViewHolder(View v, boolean isIncoming) {
-		super(v, isIncoming);
+	ConversationMessageViewHolder(View v, ConversationListener listener,
+			boolean isIncoming, RecycledViewPool imageViewPool,
+			ImageItemDecoration imageItemDecoration) {
+		super(v, listener, isIncoming);
+		statusLayout = v.findViewById(R.id.statusLayout);
+
+		// image list
+		RecyclerView list = v.findViewById(R.id.imageList);
+		list.setRecycledViewPool(imageViewPool);
+		adapter = new ImageAdapter(v.getContext(), listener);
+		list.setAdapter(adapter);
+		list.addItemDecoration(imageItemDecoration);
+
+		// remember original status text color
+		timeColor = time.getCurrentTextColor();
+		timeColorBubble = getColor(v.getContext(), R.color.briar_white);
+
+		// clone constraint sets from layout files
+		textConstraints
+				.clone(v.getContext(), R.layout.list_item_conversation_msg_in);
+		imageConstraints.clone(v.getContext(),
+				R.layout.list_item_conversation_msg_image);
+		imageTextConstraints.clone(v.getContext(),
+				R.layout.list_item_conversation_msg_image_text);
+
+		// in/out are different layouts, so we need to do this only once
+		textConstraints
+				.setHorizontalBias(R.id.statusLayout, isIncoming() ? 1 : 0);
+		imageConstraints
+				.setHorizontalBias(R.id.statusLayout, isIncoming() ? 1 : 0);
+		imageTextConstraints
+				.setHorizontalBias(R.id.statusLayout, isIncoming() ? 1 : 0);
+	}
+
+	@Override
+	void bind(ConversationItem conversationItem) {
+		super.bind(conversationItem);
+		ConversationMessageItem item =
+				(ConversationMessageItem) conversationItem;
+		if (item.getAttachments().isEmpty()) {
+			bindTextItem();
+		} else {
+			bindImageItem(item);
+		}
+	}
+
+	private void bindTextItem() {
+		resetStatusLayoutForText();
+		textConstraints.applyTo(layout);
+		adapter.clear();
+	}
+
+	private void bindImageItem(ConversationMessageItem item) {
+		ConstraintSet constraintSet;
+		if (item.getText() == null) {
+			statusLayout.setBackgroundResource(R.drawable.msg_status_bubble);
+			time.setTextColor(timeColorBubble);
+			constraintSet = imageConstraints;
+		} else {
+			resetStatusLayoutForText();
+			constraintSet = imageTextConstraints;
+		}
+
+		if (item.getAttachments().size() == 1) {
+			// apply image size constraints for a single image
+			AttachmentItem attachment = item.getAttachments().get(0);
+			int width = attachment.getThumbnailWidth();
+			int height = attachment.getThumbnailHeight();
+			constraintSet.constrainWidth(R.id.imageList, width);
+			constraintSet.constrainHeight(R.id.imageList, height);
+		} else {
+			// bubble adapts to size of image list
+			constraintSet.constrainWidth(R.id.imageList, WRAP_CONTENT);
+			constraintSet.constrainHeight(R.id.imageList, WRAP_CONTENT);
+		}
+		constraintSet.applyTo(layout);
+		adapter.setConversationItem(item);
+	}
+
+	private void resetStatusLayoutForText() {
+		statusLayout.setBackgroundResource(0);
+		// also reset padding (the background drawable defines some)
+		statusLayout.setPadding(0, 0, 0, 0);
+		time.setTextColor(timeColor);
 	}
 
 }

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

@@ -0,0 +1,19 @@
+package org.briarproject.briar.android.conversation;
+
+import org.briarproject.briar.android.activity.ActivityScope;
+import org.briarproject.briar.android.conversation.glide.BriarDataFetcherFactory;
+
+import dagger.Module;
+import dagger.Provides;
+
+@Module
+public class ConversationModule {
+
+	@ActivityScope
+	@Provides
+	BriarDataFetcherFactory provideBriarDataFetcherFactory(
+			BriarDataFetcherFactory dataFetcherFactory) {
+		return dataFetcherFactory;
+	}
+
+}

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

@@ -19,16 +19,17 @@ class ConversationNoticeViewHolder extends ConversationItemViewHolder {
 
 	private final TextView msgText;
 
-	ConversationNoticeViewHolder(View v, boolean isIncoming) {
-		super(v, isIncoming);
+	ConversationNoticeViewHolder(View v, ConversationListener listener,
+			boolean isIncoming) {
+		super(v, listener, isIncoming);
 		msgText = v.findViewById(R.id.msgText);
 	}
 
 	@Override
 	@CallSuper
-	void bind(ConversationItem item, ConversationListener listener) {
+	void bind(ConversationItem item) {
 		ConversationNoticeItem notice = (ConversationNoticeItem) item;
-		super.bind(notice, listener);
+		super.bind(notice);
 
 		String text = notice.getMsgText();
 		if (isNullOrEmpty(text)) {

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

@@ -17,16 +17,17 @@ class ConversationRequestViewHolder extends ConversationNoticeViewHolder {
 	private final Button acceptButton;
 	private final Button declineButton;
 
-	ConversationRequestViewHolder(View v, boolean isIncoming) {
-		super(v, isIncoming);
+	ConversationRequestViewHolder(View v, ConversationListener listener,
+			boolean isIncoming) {
+		super(v, listener, isIncoming);
 		acceptButton = v.findViewById(R.id.acceptButton);
 		declineButton = v.findViewById(R.id.declineButton);
 	}
 
 	@Override
-	void bind(ConversationItem item, ConversationListener listener) {
+	void bind(ConversationItem item) {
 		ConversationRequestItem request = (ConversationRequestItem) item;
-		super.bind(request, listener);
+		super.bind(request);
 
 		if (request.wasAnswered() && request.canBeOpened()) {
 			acceptButton.setVisibility(VISIBLE);

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

@@ -5,18 +5,36 @@ import android.arch.lifecycle.AndroidViewModel;
 import android.arch.lifecycle.LiveData;
 import android.arch.lifecycle.MutableLiveData;
 import android.arch.lifecycle.Transformations;
+import android.content.ContentResolver;
+import android.net.Uri;
 import android.support.annotation.Nullable;
+import android.support.annotation.UiThread;
 
+import org.briarproject.bramble.api.FormatException;
+import org.briarproject.bramble.api.Pair;
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.ContactManager;
+import org.briarproject.bramble.api.crypto.CryptoExecutor;
 import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.NoSuchContactException;
 import org.briarproject.bramble.api.identity.AuthorId;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.sync.GroupId;
+import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.briar.android.util.UiUtils;
+import org.briarproject.briar.api.messaging.Attachment;
+import org.briarproject.briar.api.messaging.AttachmentHeader;
+import org.briarproject.briar.api.messaging.MessagingManager;
+import org.briarproject.briar.api.messaging.PrivateMessage;
+import org.briarproject.briar.api.messaging.PrivateMessageFactory;
+import org.briarproject.briar.api.messaging.PrivateMessageHeader;
 
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.ArrayList;
+import java.util.List;
 import java.util.concurrent.Executor;
 import java.util.logging.Logger;
 
@@ -25,9 +43,11 @@ import javax.inject.Inject;
 import static java.util.Objects.requireNonNull;
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.util.IoUtils.tryToClose;
 import static org.briarproject.bramble.util.LogUtils.logDuration;
 import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.bramble.util.LogUtils.now;
+import static org.briarproject.briar.android.util.UiUtils.observeForeverOnce;
 
 @NotNullByDefault
 public class ConversationViewModel extends AndroidViewModel {
@@ -37,7 +57,12 @@ public class ConversationViewModel extends AndroidViewModel {
 
 	@DatabaseExecutor
 	private final Executor dbExecutor;
+	@CryptoExecutor
+	private final Executor cryptoExecutor;
+	private final MessagingManager messagingManager;
 	private final ContactManager contactManager;
+	private final PrivateMessageFactory privateMessageFactory;
+	private final AttachmentController attachmentController;
 
 	@Nullable
 	private ContactId contactId = null;
@@ -48,14 +73,26 @@ public class ConversationViewModel extends AndroidViewModel {
 			Transformations.map(contact, UiUtils::getContactDisplayName);
 	private final MutableLiveData<Boolean> contactDeleted =
 			new MutableLiveData<>();
+	private final MutableLiveData<GroupId> messagingGroupId =
+			new MutableLiveData<>();
+	private final MutableLiveData<PrivateMessageHeader> addedHeader =
+			new MutableLiveData<>();
 
 	@Inject
 	ConversationViewModel(Application application,
 			@DatabaseExecutor Executor dbExecutor,
-			ContactManager contactManager) {
+			@CryptoExecutor Executor cryptoExecutor,
+			MessagingManager messagingManager,
+			ContactManager contactManager,
+			PrivateMessageFactory privateMessageFactory) {
 		super(application);
 		this.dbExecutor = dbExecutor;
+		this.cryptoExecutor = cryptoExecutor;
+		this.messagingManager = messagingManager;
 		this.contactManager = contactManager;
+		this.privateMessageFactory = privateMessageFactory;
+		this.attachmentController = new AttachmentController(messagingManager,
+				application.getResources());
 		contactDeleted.setValue(false);
 	}
 
@@ -96,6 +133,123 @@ public class ConversationViewModel extends AndroidViewModel {
 		});
 	}
 
+	void sendMessage(@Nullable String text, List<Uri> uris, long timestamp) {
+		if (messagingGroupId.getValue() == null) loadGroupId();
+		observeForeverOnce(messagingGroupId, groupId -> {
+			if (groupId == null) return;
+			// calls through to creating and storing the message
+			storeAttachments(groupId, text, uris, timestamp);
+		});
+	}
+
+	private void loadGroupId() {
+		if (contactId == null) throw new IllegalStateException();
+		dbExecutor.execute(() -> {
+			try {
+				messagingGroupId.postValue(
+						messagingManager.getConversationId(contactId));
+			} catch (DbException e) {
+				logException(LOG, WARNING, e);
+			}
+		});
+	}
+
+	private void storeAttachments(GroupId groupId, @Nullable String text,
+			List<Uri> uris, long timestamp) {
+		dbExecutor.execute(() -> {
+			long start = now();
+			List<AttachmentHeader> attachments = new ArrayList<>();
+			List<AttachmentItem> items = new ArrayList<>();
+			boolean needsSize = uris.size() == 1;
+			for (Uri uri : uris) {
+				Pair<AttachmentHeader, AttachmentItem> pair =
+						createAttachmentHeader(groupId, uri, timestamp,
+								needsSize);
+				if (pair == null) continue;
+				attachments.add(pair.getFirst());
+				items.add(pair.getSecond());
+			}
+			logDuration(LOG, "Storing attachments", start);
+			createMessage(groupId, text, attachments, items, timestamp);
+		});
+	}
+
+	@Nullable
+	@DatabaseExecutor
+	private Pair<AttachmentHeader, AttachmentItem> createAttachmentHeader(
+			GroupId groupId, Uri uri, long timestamp, boolean needsSize) {
+		InputStream is = null;
+		try {
+			ContentResolver contentResolver =
+					getApplication().getContentResolver();
+			is = contentResolver.openInputStream(uri);
+			if (is == null) throw new IOException();
+			String contentType = contentResolver.getType(uri);
+			if (contentType == null) throw new IOException("null content type");
+			AttachmentHeader h = messagingManager
+					.addLocalAttachment(groupId, timestamp, contentType, is);
+			is.close();
+			// re-open stream to get AttachmentItem
+			is = contentResolver.openInputStream(uri);
+			if (is == null) throw new IOException();
+			AttachmentItem item = attachmentController
+					.getAttachmentItem(h, new Attachment(is), needsSize);
+			return new Pair<>(h, item);
+		} catch (DbException | IOException e) {
+			logException(LOG, WARNING, e);
+			return null;
+		} finally {
+			if (is != null) tryToClose(is, LOG, WARNING);
+		}
+	}
+
+	private void createMessage(GroupId groupId, @Nullable String text,
+			List<AttachmentHeader> attachments, List<AttachmentItem> aItems,
+			long timestamp) {
+		cryptoExecutor.execute(() -> {
+			try {
+				// TODO remove when text can be null in the backend
+				String msgText = text == null ? "null" : text;
+				PrivateMessage pm = privateMessageFactory
+						.createPrivateMessage(groupId, timestamp, msgText,
+								attachments);
+				attachmentController.put(pm.getMessage().getId(), aItems);
+				storeMessage(pm, msgText, attachments);
+			} catch (FormatException e) {
+				throw new RuntimeException(e);
+			}
+		});
+	}
+
+	private void storeMessage(PrivateMessage m, @Nullable String text,
+			List<AttachmentHeader> attachments) {
+		dbExecutor.execute(() -> {
+			try {
+				long start = now();
+				messagingManager.addLocalMessage(m);
+				logDuration(LOG, "Storing message", start);
+				Message message = m.getMessage();
+				PrivateMessageHeader h = new PrivateMessageHeader(
+						message.getId(), message.getGroupId(),
+						message.getTimestamp(), true, true, false, false,
+						text != null, attachments);
+				// TODO add text to cache when available here
+				addedHeader.postValue(h);
+			} catch (DbException e) {
+				logException(LOG, WARNING, e);
+			}
+		});
+	}
+
+	@UiThread
+	void onAddedPrivateMessageSeen() {
+		addedHeader.setValue(null);
+	}
+
+	AttachmentController getAttachmentController() {
+		return attachmentController;
+	}
+
 	LiveData<Contact> getContact() {
 		return contact;
 	}
@@ -112,4 +266,8 @@ public class ConversationViewModel extends AndroidViewModel {
 		return contactDeleted;
 	}
 
+	LiveData<PrivateMessageHeader> getAddedPrivateMessage() {
+		return addedHeader;
+	}
+
 }

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

@@ -14,12 +14,16 @@ import org.briarproject.briar.api.forum.ForumInvitationRequest;
 import org.briarproject.briar.api.forum.ForumInvitationResponse;
 import org.briarproject.briar.api.introduction.IntroductionRequest;
 import org.briarproject.briar.api.introduction.IntroductionResponse;
+import org.briarproject.briar.api.messaging.AttachmentHeader;
 import org.briarproject.briar.api.messaging.PrivateMessageHeader;
 import org.briarproject.briar.api.privategroup.invitation.GroupInvitationRequest;
 import org.briarproject.briar.api.privategroup.invitation.GroupInvitationResponse;
 
+import java.util.List;
+
 import javax.annotation.Nullable;
 
+import static java.util.Collections.emptyList;
 import static org.briarproject.briar.android.conversation.ConversationRequestItem.RequestType.BLOG;
 import static org.briarproject.briar.android.conversation.ConversationRequestItem.RequestType.FORUM;
 import static org.briarproject.briar.android.conversation.ConversationRequestItem.RequestType.GROUP;
@@ -33,24 +37,33 @@ class ConversationVisitor implements
 
 	private final Context ctx;
 	private final TextCache textCache;
+	private final AttachmentCache attachmentCache;
 	private final LiveData<String> contactName;
 
 	ConversationVisitor(Context ctx, TextCache textCache,
-			LiveData<String> contactName) {
+			AttachmentCache attachmentCache, LiveData<String> contactName) {
 		this.ctx = ctx;
 		this.textCache = textCache;
+		this.attachmentCache = attachmentCache;
 		this.contactName = contactName;
 	}
 
 	@Override
 	public ConversationItem visitPrivateMessageHeader(PrivateMessageHeader h) {
 		ConversationItem item;
+		List<AttachmentItem> attachments;
+		if (h.getAttachmentHeaders().isEmpty()) {
+			attachments = emptyList();
+		} else {
+			attachments = attachmentCache
+					.getAttachmentItems(h.getId(), h.getAttachmentHeaders());
+		}
 		if (h.isLocal()) {
 			item = new ConversationMessageItem(
-					R.layout.list_item_conversation_msg_out, h);
+					R.layout.list_item_conversation_msg_out, h, attachments);
 		} else {
 			item = new ConversationMessageItem(
-					R.layout.list_item_conversation_msg_in, h);
+					R.layout.list_item_conversation_msg_in, h, attachments);
 		}
 		if (h.hasText()) {
 			String text = textCache.getText(h.getId());
@@ -279,4 +292,9 @@ class ConversationVisitor implements
 		@Nullable
 		String getText(MessageId m);
 	}
+
+	interface AttachmentCache {
+		List<AttachmentItem> getAttachmentItems(MessageId m,
+				List<AttachmentHeader> headers);
+	}
 }

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

@@ -0,0 +1,322 @@
+package org.briarproject.briar.android.conversation;
+
+import android.arch.lifecycle.ViewModelProvider;
+import android.arch.lifecycle.ViewModelProviders;
+import android.content.DialogInterface.OnClickListener;
+import android.content.Intent;
+import android.graphics.drawable.Drawable;
+import android.os.Bundle;
+import android.support.annotation.Nullable;
+import android.support.annotation.RequiresApi;
+import android.support.design.widget.AppBarLayout;
+import android.support.design.widget.Snackbar;
+import android.support.v4.app.Fragment;
+import android.support.v4.app.FragmentManager;
+import android.support.v4.app.FragmentStatePagerAdapter;
+import android.support.v4.content.ContextCompat;
+import android.support.v4.graphics.drawable.DrawableCompat;
+import android.support.v4.view.ViewPager;
+import android.support.v7.app.AlertDialog.Builder;
+import android.support.v7.widget.Toolbar;
+import android.transition.Fade;
+import android.transition.Transition;
+import android.view.Menu;
+import android.view.MenuItem;
+import android.view.View;
+import android.view.ViewTreeObserver.OnGlobalLayoutListener;
+import android.view.Window;
+import android.widget.TextView;
+
+import org.briarproject.briar.R;
+import org.briarproject.briar.android.activity.ActivityComponent;
+import org.briarproject.briar.android.activity.BriarActivity;
+import org.briarproject.briar.android.view.PullDownLayout;
+
+import java.text.SimpleDateFormat;
+import java.util.Date;
+import java.util.List;
+import java.util.Locale;
+
+import javax.inject.Inject;
+
+import static android.content.Intent.ACTION_CREATE_DOCUMENT;
+import static android.content.Intent.CATEGORY_OPENABLE;
+import static android.content.Intent.EXTRA_TITLE;
+import static android.graphics.Color.TRANSPARENT;
+import static android.os.Build.VERSION.SDK_INT;
+import static android.support.design.widget.Snackbar.LENGTH_LONG;
+import static android.view.View.GONE;
+import static android.view.View.SYSTEM_UI_FLAG_FULLSCREEN;
+import static android.view.View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN;
+import static android.view.View.SYSTEM_UI_FLAG_LAYOUT_STABLE;
+import static android.view.View.VISIBLE;
+import static android.view.WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS;
+import static java.util.Objects.requireNonNull;
+import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_SAVE_ATTACHMENT;
+import static org.briarproject.briar.android.util.UiUtils.formatDateAbsolute;
+
+public class ImageActivity extends BriarActivity
+		implements PullDownLayout.Callback, OnGlobalLayoutListener {
+
+	final static String ATTACHMENTS = "attachments";
+	final static String ATTACHMENT_POSITION = "position";
+	final static String NAME = "name";
+	final static String DATE = "date";
+
+	@Inject
+	ViewModelProvider.Factory viewModelFactory;
+
+	private ImageViewModel viewModel;
+	private PullDownLayout layout;
+	private AppBarLayout appBarLayout;
+	private ViewPager viewPager;
+	private List<AttachmentItem> attachments;
+
+	@Override
+	public void injectActivity(ActivityComponent component) {
+		component.inject(this);
+	}
+
+	@Override
+	public void onCreate(@Nullable Bundle state) {
+		super.onCreate(state);
+
+		// Transitions
+		if (state == null) supportPostponeEnterTransition();
+		Window window = getWindow();
+		if (SDK_INT >= 21) {
+			Transition transition = new Fade();
+			setSceneTransitionAnimation(transition, null, transition);
+		}
+
+		// get View Model
+		viewModel = ViewModelProviders.of(this, viewModelFactory)
+				.get(ImageViewModel.class);
+		viewModel.getSaveState().observe(this, this::onImageSaveStateChanged);
+
+		// inflate layout
+		setContentView(R.layout.activity_image);
+		layout = findViewById(R.id.layout);
+		layout.getBackground().setAlpha(255);
+		layout.setCallback(this);
+		layout.getViewTreeObserver().addOnGlobalLayoutListener(this);
+
+		// Status Bar
+		if (SDK_INT >= 21) {
+			window.setStatusBarColor(TRANSPARENT);
+		} else if (SDK_INT >= 19) {
+			// we can't make the status bar transparent, but translucent
+			window.addFlags(FLAG_TRANSLUCENT_STATUS);
+		}
+
+		// Toolbar
+		appBarLayout = findViewById(R.id.appBarLayout);
+		Toolbar toolbar = requireNonNull(setUpCustomToolbar(true));
+		TextView contactName = toolbar.findViewById(R.id.contactName);
+		TextView dateView = toolbar.findViewById(R.id.dateView);
+
+		// Intent Extras
+		Intent i = getIntent();
+		attachments = i.getParcelableArrayListExtra(ATTACHMENTS);
+		int position = i.getIntExtra(ATTACHMENT_POSITION, -1);
+		if (position == -1) throw new IllegalStateException();
+		String name = i.getStringExtra(NAME);
+		long time = i.getLongExtra(DATE, 0);
+		String date = formatDateAbsolute(this, time);
+		contactName.setText(name);
+		dateView.setText(date);
+
+		// Set up image ViewPager
+		viewPager = findViewById(R.id.viewPager);
+		ImagePagerAdapter pagerAdapter =
+				new ImagePagerAdapter(getSupportFragmentManager());
+		viewPager.setAdapter(pagerAdapter);
+		viewPager.setCurrentItem(position);
+
+		if (SDK_INT >= 16) {
+			viewModel.getOnImageClicked().observe(this, this::onImageClicked);
+			window.getDecorView().setSystemUiVisibility(
+					SYSTEM_UI_FLAG_LAYOUT_STABLE |
+							SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN);
+		}
+	}
+
+	@Override
+	public boolean onCreateOptionsMenu(Menu menu) {
+		getMenuInflater().inflate(R.menu.image_actions, menu);
+		return super.onCreateOptionsMenu(menu);
+	}
+
+	@Override
+	public boolean onOptionsItemSelected(MenuItem item) {
+		switch (item.getItemId()) {
+			case android.R.id.home:
+				onBackPressed();
+				return true;
+			case R.id.action_save_image:
+				showSaveImageDialog();
+				return true;
+			default:
+				return super.onOptionsItemSelected(item);
+		}
+	}
+
+	@Override
+	public void onGlobalLayout() {
+		viewModel.setToolbarPosition(
+				appBarLayout.getTop(), appBarLayout.getBottom()
+		);
+		if (SDK_INT >= 16) {
+			layout.getViewTreeObserver().removeOnGlobalLayoutListener(this);
+		} else {
+			layout.getViewTreeObserver().removeGlobalOnLayoutListener(this);
+		}
+	}
+
+	@Override
+	protected void onActivityResult(int request, int result, Intent data) {
+		super.onActivityResult(request, result, data);
+		if (request == REQUEST_SAVE_ATTACHMENT && result == RESULT_OK) {
+			viewModel.saveImage(getVisibleAttachment(), data.getData());
+		}
+	}
+
+	@Override
+	public void onPullStart() {
+		appBarLayout.animate()
+				.alpha(0f)
+				.start();
+	}
+
+	@Override
+	public void onPull(float progress) {
+		layout.getBackground().setAlpha(Math.round((1 - progress) * 255));
+	}
+
+	@Override
+	public void onPullCancel() {
+		appBarLayout.animate()
+				.alpha(1f)
+				.start();
+	}
+
+	@Override
+	public void onPullComplete() {
+		supportFinishAfterTransition();
+	}
+
+	@RequiresApi(api = 16)
+	private void onImageClicked(@Nullable Boolean clicked) {
+		if (clicked != null && clicked) {
+			toggleSystemUi();
+			viewModel.onOnImageClickSeen();
+		}
+	}
+
+	@RequiresApi(api = 16)
+	private void toggleSystemUi() {
+		View decorView = getWindow().getDecorView();
+		if (appBarLayout.getVisibility() == VISIBLE) {
+			hideSystemUi(decorView);
+		} else {
+			showSystemUi(decorView);
+		}
+	}
+
+	@RequiresApi(api = 16)
+	private void hideSystemUi(View decorView) {
+		decorView.setSystemUiVisibility(SYSTEM_UI_FLAG_FULLSCREEN |
+				SYSTEM_UI_FLAG_LAYOUT_STABLE | SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
+		);
+		appBarLayout.animate()
+				.translationYBy(-1 * appBarLayout.getHeight())
+				.alpha(0f)
+				.withEndAction(() -> appBarLayout.setVisibility(GONE))
+				.start();
+	}
+
+	@RequiresApi(api = 16)
+	private void showSystemUi(View decorView) {
+		decorView.setSystemUiVisibility(
+				SYSTEM_UI_FLAG_LAYOUT_STABLE | SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
+		);
+		appBarLayout.animate()
+				.translationYBy(appBarLayout.getHeight())
+				.alpha(1f)
+				.withStartAction(() -> appBarLayout.setVisibility(VISIBLE))
+				.start();
+	}
+
+	private void showSaveImageDialog() {
+		OnClickListener okListener = (dialog, which) -> {
+			if (SDK_INT >= 19) {
+				Intent intent = getCreationIntent();
+				startActivityForResult(intent, REQUEST_SAVE_ATTACHMENT);
+			} else {
+				viewModel.saveImage(getVisibleAttachment());
+			}
+		};
+		Builder builder = new Builder(this, R.style.BriarDialogTheme);
+		builder.setTitle(getString(R.string.dialog_title_save_image));
+		builder.setMessage(getString(R.string.dialog_message_save_image));
+		Drawable icon = ContextCompat.getDrawable(this, R.drawable.ic_security);
+		DrawableCompat.setTint(requireNonNull(icon),
+				ContextCompat.getColor(this, R.color.color_primary));
+		builder.setIcon(icon);
+		builder.setPositiveButton(R.string.save_image, okListener);
+		builder.setNegativeButton(R.string.cancel, null);
+		builder.show();
+	}
+
+	@RequiresApi(api = 19)
+	private Intent getCreationIntent() {
+		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss",
+				Locale.getDefault());
+		String fileName = sdf.format(new Date());
+		Intent intent = new Intent(ACTION_CREATE_DOCUMENT);
+		intent.addCategory(CATEGORY_OPENABLE);
+		intent.setType(getVisibleAttachment().getMimeType());
+		intent.putExtra(EXTRA_TITLE, fileName);
+		return intent;
+	}
+
+	private void onImageSaveStateChanged(@Nullable Boolean error) {
+		if (error == null) return;
+		int stringRes = error ?
+				R.string.save_image_error : R.string.save_image_success;
+		int colorRes = error ?
+				R.color.briar_red : R.color.briar_primary;
+		Snackbar s = Snackbar.make(layout, stringRes, LENGTH_LONG);
+		s.getView().setBackgroundResource(colorRes);
+		s.show();
+		viewModel.onSaveStateSeen();
+	}
+
+	AttachmentItem getVisibleAttachment() {
+		return attachments.get(viewPager.getCurrentItem());
+	}
+
+	private class ImagePagerAdapter extends FragmentStatePagerAdapter {
+
+		private boolean isFirst = true;
+
+		private ImagePagerAdapter(FragmentManager fm) {
+			super(fm);
+		}
+
+		@Override
+		public Fragment getItem(int position) {
+			Fragment f = ImageFragment
+					.newInstance(attachments.get(position), isFirst);
+			isFirst = false;
+			return f;
+		}
+
+		@Override
+		public int getCount() {
+			return attachments.size();
+		}
+
+	}
+
+}

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

@@ -0,0 +1,155 @@
+package org.briarproject.briar.android.conversation;
+
+import android.content.Context;
+import android.content.res.Resources;
+import android.support.annotation.Nullable;
+import android.support.v7.widget.RecyclerView.Adapter;
+import android.util.DisplayMetrics;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.view.WindowManager;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.briar.R;
+import org.briarproject.briar.android.conversation.glide.Radii;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import static android.content.Context.WINDOW_SERVICE;
+import static java.util.Objects.requireNonNull;
+import static org.briarproject.briar.android.util.UiUtils.isRtl;
+
+@NotNullByDefault
+class ImageAdapter extends Adapter<ImageViewHolder> {
+
+	private final List<AttachmentItem> items = new ArrayList<>();
+	private final ConversationListener listener;
+	private final int imageSize;
+	private final int radiusBig, radiusSmall;
+	private final boolean isRtl;
+	@Nullable
+	private ConversationMessageItem conversationItem;
+
+	ImageAdapter(Context ctx, ConversationListener listener) {
+		this.listener = listener;
+		imageSize = getImageSize(ctx);
+		Resources res = ctx.getResources();
+		radiusBig =
+				res.getDimensionPixelSize(R.dimen.message_bubble_radius_big);
+		radiusSmall =
+				res.getDimensionPixelSize(R.dimen.message_bubble_radius_small);
+		isRtl = isRtl(ctx);
+	}
+
+	@Override
+	public ImageViewHolder onCreateViewHolder(ViewGroup viewGroup, int type) {
+		View v = LayoutInflater.from(viewGroup.getContext()).inflate(
+				R.layout.list_item_image, viewGroup, false);
+		return new ImageViewHolder(v, imageSize);
+	}
+
+	@Override
+	public void onBindViewHolder(ImageViewHolder imageViewHolder,
+			int position) {
+		// get item
+		requireNonNull(conversationItem);
+		AttachmentItem item = items.get(position);
+		// set onClick listener
+		imageViewHolder.itemView.setOnClickListener(v ->
+				listener.onAttachmentClicked(v, conversationItem, item)
+		);
+		// bind view holder
+		int size = items.size();
+		boolean isIncoming = conversationItem.isIncoming();
+		boolean hasText = conversationItem.getText() != null;
+		Radii r = getRadii(position, size, isIncoming, hasText);
+		imageViewHolder.bind(item, r, size == 1, singleInRow(position, size));
+	}
+
+	@Override
+	public int getItemCount() {
+		return items.size();
+	}
+
+	void setConversationItem(ConversationMessageItem item) {
+		this.conversationItem = item;
+		this.items.clear();
+		this.items.addAll(item.getAttachments());
+		notifyDataSetChanged();
+	}
+
+	private int getImageSize(Context ctx) {
+		Resources res = ctx.getResources();
+		WindowManager windowManager =
+				(WindowManager) ctx.getSystemService(WINDOW_SERVICE);
+		DisplayMetrics displayMetrics = new DisplayMetrics();
+		if (windowManager == null) {
+			return res.getDimensionPixelSize(
+					R.dimen.message_bubble_image_default);
+		}
+		windowManager.getDefaultDisplay().getMetrics(displayMetrics);
+		int imageSize = displayMetrics.widthPixels / 3;
+		int maxSize = res.getDimensionPixelSize(
+				R.dimen.message_bubble_image_max_width);
+		return Math.min(imageSize, maxSize);
+	}
+
+	private Radii getRadii(int pos, int num, boolean isIncoming,
+			boolean hasText) {
+		boolean left = isLeft(pos);
+		boolean single = num == 1;
+		// Top Row
+		int topLeft;
+		int topRight;
+		if (single) {
+			topLeft = isIncoming ? radiusSmall : radiusBig;
+			topRight = !isIncoming ? radiusSmall : radiusBig;
+		} else if (isTopRow(pos)) {
+			topLeft = left ? (isIncoming ? radiusSmall : radiusBig) : 0;
+			topRight = !left ? (!isIncoming ? radiusSmall : radiusBig) : 0;
+		} else {
+			topLeft = 0;
+			topRight = 0;
+		}
+		// Bottom Row
+		boolean singleInRow = singleInRow(pos, num);
+		int bottomLeft;
+		int bottomRight;
+		if (!hasText && isBottomRow(pos, num)) {
+			bottomLeft = singleInRow || left ? radiusBig : 0;
+			bottomRight = singleInRow || !left ? radiusBig : 0;
+		} else {
+			bottomLeft = 0;
+			bottomRight = 0;
+		}
+		if (isRtl) return new Radii(topRight, topLeft, bottomRight, bottomLeft);
+		return new Radii(topLeft, topRight, bottomLeft, bottomRight);
+	}
+
+	void clear() {
+		items.clear();
+		notifyDataSetChanged();
+	}
+
+	static boolean isTopRow(int pos) {
+		return pos < 2;
+	}
+
+	static boolean isLeft(int pos) {
+		return pos % 2 == 0;
+	}
+
+	static boolean isBottomRow(int pos, int num) {
+		return num % 2 == 0 ?
+				pos >= num - 2 : // last two, if even
+				pos > num - 2;   // last one, if odd
+	}
+
+	static boolean singleInRow(int pos, int num) {
+		// last item of an odd number
+		return num % 2 != 0 && pos == num -1;
+	}
+
+}

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

@@ -0,0 +1,131 @@
+package org.briarproject.briar.android.conversation;
+
+import android.arch.lifecycle.ViewModelProvider;
+import android.arch.lifecycle.ViewModelProviders;
+import android.graphics.drawable.Animatable;
+import android.graphics.drawable.Drawable;
+import android.os.Bundle;
+import android.support.annotation.Nullable;
+import android.support.v4.app.Fragment;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+
+import com.bumptech.glide.load.DataSource;
+import com.bumptech.glide.load.engine.GlideException;
+import com.bumptech.glide.request.RequestListener;
+import com.bumptech.glide.request.target.Target;
+import com.github.chrisbanes.photoview.PhotoView;
+
+import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.briar.R;
+import org.briarproject.briar.android.activity.BaseActivity;
+import org.briarproject.briar.android.conversation.glide.GlideApp;
+
+import javax.annotation.ParametersAreNonnullByDefault;
+import javax.inject.Inject;
+
+import static android.os.Build.VERSION.SDK_INT;
+import static android.widget.ImageView.ScaleType.FIT_START;
+import static com.bumptech.glide.load.engine.DiskCacheStrategy.NONE;
+import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
+import static org.briarproject.briar.android.conversation.ImageActivity.ATTACHMENT_POSITION;
+
+@MethodsNotNullByDefault
+@ParametersAreNonnullByDefault
+public class ImageFragment extends Fragment {
+
+	private final static String IS_FIRST = "isFirst";
+
+	@Inject
+	ViewModelProvider.Factory viewModelFactory;
+
+	private AttachmentItem attachment;
+	private boolean isFirst;
+	private ImageViewModel viewModel;
+	private PhotoView photoView;
+
+	static ImageFragment newInstance(AttachmentItem a, boolean isFirst) {
+		ImageFragment f = new ImageFragment();
+		Bundle args = new Bundle();
+		args.putParcelable(ATTACHMENT_POSITION, a);
+		args.putBoolean(IS_FIRST, isFirst);
+		f.setArguments(args);
+		return f;
+	}
+
+	@Override
+	public void onActivityCreated(@Nullable Bundle savedInstanceState) {
+		super.onActivityCreated(savedInstanceState);
+		BaseActivity a = (BaseActivity) requireNonNull(getActivity());
+		a.getActivityComponent().inject(this);
+	}
+
+	@Override
+	public void onCreate(@Nullable Bundle savedInstanceState) {
+		super.onCreate(savedInstanceState);
+
+		Bundle args = requireNonNull(getArguments());
+		attachment = requireNonNull(args.getParcelable(ATTACHMENT_POSITION));
+		isFirst = args.getBoolean(IS_FIRST);
+	}
+
+	@Nullable
+	@Override
+	public View onCreateView(LayoutInflater inflater,
+			@Nullable ViewGroup container,
+			@Nullable Bundle savedInstanceState) {
+		View v = inflater.inflate(R.layout.fragment_image, container,
+				false);
+
+		viewModel = ViewModelProviders.of(requireNonNull(getActivity()),
+				viewModelFactory).get(ImageViewModel.class);
+
+		photoView = v.findViewById(R.id.photoView);
+		photoView.setOnClickListener(view -> viewModel.clickImage());
+
+		// Request Listener
+		RequestListener<Drawable> listener = new RequestListener<Drawable>() {
+			@Override
+			public boolean onLoadFailed(@Nullable GlideException e,
+					Object model, Target<Drawable> target,
+					boolean isFirstResource) {
+				if (getActivity() != null && isFirst)
+					getActivity().supportStartPostponedEnterTransition();
+				return false;
+			}
+
+			@Override
+			public boolean onResourceReady(Drawable resource, Object model,
+					Target<Drawable> target, DataSource dataSource,
+					boolean isFirstResource) {
+				if (SDK_INT >= 21 && !(resource instanceof Animatable)) {
+					// set transition name only when not animatable,
+					// because the animation won't start otherwise
+					photoView.setTransitionName(
+							attachment.getTransitionName());
+				}
+				// Move image to the top if overlapping toolbar
+				if (viewModel.isOverlappingToolbar(photoView, resource)) {
+					photoView.setScaleType(FIT_START);
+				}
+				if (getActivity() != null && isFirst) {
+					getActivity().supportStartPostponedEnterTransition();
+				}
+				return false;
+			}
+		};
+
+		// Load Image
+		GlideApp.with(this)
+				.load(attachment)
+				.diskCacheStrategy(NONE)
+				.error(R.drawable.ic_image_broken)
+				.dontTransform()
+				.addListener(listener)
+				.into(photoView);
+
+		return v;
+	}
+
+}

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

@@ -0,0 +1,54 @@
+package org.briarproject.briar.android.conversation;
+
+import android.content.Context;
+import android.content.res.Resources;
+import android.graphics.Rect;
+import android.support.v7.widget.RecyclerView;
+import android.support.v7.widget.RecyclerView.ItemDecoration;
+import android.support.v7.widget.RecyclerView.State;
+import android.view.View;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.briar.R;
+import org.briarproject.briar.android.util.UiUtils;
+
+import static org.briarproject.briar.android.conversation.ImageAdapter.isBottomRow;
+import static org.briarproject.briar.android.conversation.ImageAdapter.isLeft;
+import static org.briarproject.briar.android.conversation.ImageAdapter.isTopRow;
+import static org.briarproject.briar.android.conversation.ImageAdapter.singleInRow;
+
+@NotNullByDefault
+class ImageItemDecoration extends ItemDecoration {
+
+	private final int border;
+	private final boolean isRtl;
+
+	ImageItemDecoration(Context ctx) {
+		Resources res = ctx.getResources();
+
+		// for pixel perfection, add a pixel to the border if it has an odd size
+		int b = res.getDimensionPixelSize(R.dimen.message_bubble_border);
+		int realBorderSize = b % 2 == 0 ? b : b + 1;
+
+		// we are applying half the border around the insides of each image
+		// to prevent differently sized images looking slightly broken
+		border = realBorderSize / 2;
+
+		// find out if we are showing a RTL language
+		isRtl = UiUtils.isRtl(ctx);
+	}
+
+	@Override
+	public void getItemOffsets(Rect outRect, View view, RecyclerView parent,
+			State state) {
+		if (state.getItemCount() == 1) return;
+		int pos = parent.getChildAdapterPosition(view);
+		int num = state.getItemCount();
+		boolean start = isLeft(pos) ^ isRtl;
+		outRect.top = isTopRow(pos) ? 0 : border;
+		outRect.left = start ? 0 : border;
+		outRect.right = start && !singleInRow(pos, num) ? border : 0;
+		outRect.bottom = isBottomRow(pos, num) ? 0 : border;
+	}
+
+}

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

@@ -0,0 +1,74 @@
+package org.briarproject.briar.android.conversation;
+
+import android.graphics.Bitmap;
+import android.support.annotation.DrawableRes;
+import android.support.v7.widget.RecyclerView.ViewHolder;
+import android.support.v7.widget.StaggeredGridLayoutManager.LayoutParams;
+import android.view.View;
+import android.widget.ImageView;
+
+import com.bumptech.glide.load.Transformation;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.briar.R;
+import org.briarproject.briar.android.conversation.glide.BriarImageTransformation;
+import org.briarproject.briar.android.conversation.glide.GlideApp;
+import org.briarproject.briar.android.conversation.glide.Radii;
+
+import static android.os.Build.VERSION.SDK_INT;
+import static com.bumptech.glide.load.engine.DiskCacheStrategy.NONE;
+import static com.bumptech.glide.load.resource.drawable.DrawableTransitionOptions.withCrossFade;
+
+@NotNullByDefault
+class ImageViewHolder extends ViewHolder {
+
+	@DrawableRes
+	private static final int ERROR_RES = R.drawable.ic_image_broken;
+
+	protected final ImageView imageView;
+	private final int imageSize;
+
+	ImageViewHolder(View v, int imageSize) {
+		super(v);
+		imageView = v.findViewById(R.id.imageView);
+		this.imageSize = imageSize;
+	}
+
+	void bind(AttachmentItem attachment, Radii r, boolean single,
+			boolean needsStretch) {
+		if (attachment.hasError()) {
+			GlideApp.with(imageView)
+					.clear(imageView);
+			imageView.setImageResource(ERROR_RES);
+		} else {
+			setImageViewDimensions(attachment, single, needsStretch);
+			loadImage(attachment, r);
+			if (SDK_INT >= 21) {
+				imageView.setTransitionName(attachment.getTransitionName());
+			}
+		}
+	}
+
+	private void setImageViewDimensions(AttachmentItem a, boolean single,
+			boolean needsStretch) {
+		LayoutParams params = (LayoutParams) imageView.getLayoutParams();
+		int width = needsStretch ? imageSize * 2 : imageSize;
+		params.width = single ? a.getThumbnailWidth() : width;
+		params.height = single ? a.getThumbnailHeight() : imageSize;
+		params.setFullSpan(!single && needsStretch);
+		imageView.setLayoutParams(params);
+	}
+
+	private void loadImage(AttachmentItem a, Radii r) {
+		Transformation<Bitmap> transformation = new BriarImageTransformation(r);
+		GlideApp.with(imageView)
+				.load(a)
+				.diskCacheStrategy(NONE)
+				.error(ERROR_RES)
+				.transform(transformation)
+				.transition(withCrossFade())
+				.into(imageView)
+				.waitForLayout();
+	}
+
+}

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

@@ -0,0 +1,210 @@
+package org.briarproject.briar.android.conversation;
+
+import android.app.Application;
+import android.arch.lifecycle.AndroidViewModel;
+import android.arch.lifecycle.LiveData;
+import android.arch.lifecycle.MutableLiveData;
+import android.graphics.drawable.Drawable;
+import android.net.Uri;
+import android.support.annotation.Nullable;
+import android.support.annotation.UiThread;
+import android.view.View;
+
+import org.briarproject.bramble.api.db.DatabaseExecutor;
+import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.lifecycle.IoExecutor;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.sync.MessageId;
+import org.briarproject.briar.api.messaging.Attachment;
+import org.briarproject.briar.api.messaging.MessagingManager;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+import java.util.Locale;
+import java.util.concurrent.Executor;
+import java.util.logging.Logger;
+
+import javax.inject.Inject;
+
+import static android.media.MediaScannerConnection.scanFile;
+import static android.os.Environment.DIRECTORY_PICTURES;
+import static android.os.Environment.getExternalStoragePublicDirectory;
+import static java.util.logging.Level.WARNING;
+import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.util.IoUtils.copyAndClose;
+import static org.briarproject.bramble.util.LogUtils.logException;
+
+@NotNullByDefault
+public class ImageViewModel extends AndroidViewModel {
+
+	private static Logger LOG = getLogger(ImageViewModel.class.getName());
+
+	private final MessagingManager messagingManager;
+	@DatabaseExecutor
+	private final Executor dbExecutor;
+	@IoExecutor
+	private final Executor ioExecutor;
+
+	private final MutableLiveData<Boolean> imageClicked =
+			new MutableLiveData<>();
+	private final MutableLiveData<Boolean> saveState = new MutableLiveData<>();
+	private int toolbarTop, toolbarBottom;
+
+	@Inject
+	ImageViewModel(Application application,
+			MessagingManager messagingManager,
+			@DatabaseExecutor Executor dbExecutor,
+			@IoExecutor Executor ioExecutor) {
+		super(application);
+		this.messagingManager = messagingManager;
+		this.dbExecutor = dbExecutor;
+		this.ioExecutor = ioExecutor;
+	}
+
+	void clickImage() {
+		imageClicked.setValue(true);
+	}
+
+	/**
+	 * A LiveData that is true if the image was clicked,
+	 * false if it wasn't.
+	 *
+	 * Call {@link #onOnImageClickSeen()} after consuming an update.
+	 */
+	LiveData<Boolean> getOnImageClicked() {
+		return imageClicked;
+	}
+
+	@UiThread
+	void onOnImageClickSeen() {
+		imageClicked.setValue(false);
+	}
+
+	void setToolbarPosition(int top, int bottom) {
+		toolbarTop = top;
+		toolbarBottom = bottom;
+	}
+
+	boolean isOverlappingToolbar(View screenView, Drawable drawable) {
+		int width = drawable.getIntrinsicWidth();
+		int height = drawable.getIntrinsicHeight();
+		float widthPercentage = screenView.getWidth() / (float) width;
+		float heightPercentage = screenView.getHeight() / (float) height;
+		float scaleFactor = Math.min(widthPercentage, heightPercentage);
+		int realWidth = (int) (width * scaleFactor);
+		int realHeight = (int) (height * scaleFactor);
+		// return if image doesn't use the full width,
+		// because it will be moved to the right otherwise
+		if (realWidth < screenView.getWidth()) return false;
+		int drawableTop = (screenView.getHeight() - realHeight) / 2;
+		return drawableTop < toolbarBottom && drawableTop != toolbarTop;
+	}
+
+	/**
+	 * A LiveData that is true if the image was saved,
+	 * false if there was an error and null otherwise.
+	 *
+	 * Call {@link #onSaveStateSeen()} after consuming an update.
+	 */
+	LiveData<Boolean> getSaveState() {
+		return saveState;
+	}
+
+	@UiThread
+	void onSaveStateSeen() {
+		saveState.setValue(null);
+	}
+
+	/**
+	 * Saves the attachment to a writeable {@link Uri}.
+	 */
+	@UiThread
+	void saveImage(AttachmentItem attachment, @Nullable Uri uri) {
+		if (uri == null) {
+			saveState.setValue(false);
+		} else {
+			saveImage(attachment, () -> getOutputStream(uri), null);
+		}
+	}
+
+	/**
+	 * Saves the attachment on external storage,
+	 * assuming the permission was granted during install time.
+	 */
+	void saveImage(AttachmentItem attachment) {
+		File file = getImageFile(attachment);
+		saveImage(attachment, () -> getOutputStream(file), () -> scanFile(
+				getApplication(), new String[] {file.toString()}, null, null));
+	}
+
+	private void saveImage(AttachmentItem attachment, OutputStreamProvider osp,
+			@Nullable Runnable afterCopy) {
+		MessageId messageId = attachment.getMessageId();
+		dbExecutor.execute(() -> {
+			try {
+				Attachment a = messagingManager.getAttachment(messageId);
+				copyImageFromDb(a, osp, afterCopy);
+			} catch (DbException e) {
+				logException(LOG, WARNING, e);
+				saveState.postValue(true);
+			}
+		});
+	}
+
+	private void copyImageFromDb(Attachment a, OutputStreamProvider osp,
+			@Nullable Runnable afterCopy) {
+		ioExecutor.execute(() -> {
+			try {
+				InputStream is = a.getStream();
+				OutputStream os = osp.getOutputStream();
+				copyAndClose(is, os);
+				if (afterCopy != null) afterCopy.run();
+				saveState.postValue(false);
+			} catch (IOException e) {
+				logException(LOG, WARNING, e);
+				saveState.postValue(true);
+			}
+		});
+	}
+
+	private String getFileName() {
+		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss",
+				Locale.getDefault());
+		return sdf.format(new Date());
+	}
+
+	private File getImageFile(AttachmentItem attachment) {
+		File path = getExternalStoragePublicDirectory(DIRECTORY_PICTURES);
+		//noinspection ResultOfMethodCallIgnored
+		path.mkdirs();
+		String fileName = getFileName();
+		String ext = "." + attachment.getExtension();
+		File file = new File(path, fileName + ext);
+		int i = 1;
+		while (file.exists()) {
+			file = new File(path, fileName + " (" + i + ")" + ext);
+		}
+		return file;
+	}
+
+	private OutputStream getOutputStream(File file) throws IOException {
+		return new FileOutputStream(file);
+	}
+
+	private OutputStream getOutputStream(Uri uri) throws IOException {
+		OutputStream os =
+				getApplication().getContentResolver().openOutputStream(uri);
+		if (os == null) throw new IOException();
+		return os;
+	}
+
+	private interface OutputStreamProvider {
+		OutputStream getOutputStream() throws IOException;
+	}
+
+}

briar-android/src/main/java/org/briarproject/briar/android/conversation/glide/BriarDataFetcher.java

@@ -0,0 +1,85 @@
+package org.briarproject.briar.android.conversation.glide;
+
+import android.support.annotation.Nullable;
+
+import com.bumptech.glide.Priority;
+import com.bumptech.glide.load.DataSource;
+import com.bumptech.glide.load.data.DataFetcher;
+
+import org.briarproject.bramble.api.db.DatabaseExecutor;
+import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.sync.MessageId;
+import org.briarproject.briar.android.conversation.AttachmentItem;
+import org.briarproject.briar.api.messaging.MessagingManager;
+
+import java.io.InputStream;
+import java.util.concurrent.Executor;
+import java.util.logging.Logger;
+
+import javax.inject.Inject;
+
+import static com.bumptech.glide.load.DataSource.LOCAL;
+import static java.util.logging.Level.WARNING;
+import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.util.IoUtils.tryToClose;
+
+@NotNullByDefault
+class BriarDataFetcher implements DataFetcher<InputStream> {
+
+	private final static Logger LOG =
+			getLogger(BriarDataFetcher.class.getName());
+
+	private final MessagingManager messagingManager;
+	@DatabaseExecutor
+	private final Executor dbExecutor;
+	private final AttachmentItem attachment;
+
+	@Nullable
+	private volatile InputStream inputStream;
+	private volatile boolean cancel = false;
+
+	@Inject
+	public BriarDataFetcher(MessagingManager messagingManager,
+			@DatabaseExecutor Executor dbExecutor, AttachmentItem attachment) {
+		this.messagingManager = messagingManager;
+		this.dbExecutor = dbExecutor;
+		this.attachment = attachment;
+	}
+
+	@Override
+	public void loadData(Priority priority,
+			DataCallback<? super InputStream> callback) {
+		MessageId id = attachment.getMessageId();
+		dbExecutor.execute(() -> {
+			if (cancel) return;
+			try {
+				inputStream = messagingManager.getAttachment(id).getStream();
+				callback.onDataReady(inputStream);
+			} catch (DbException e) {
+				callback.onLoadFailed(e);
+			}
+		});
+	}
+
+	@Override
+	public void cleanup() {
+		tryToClose(inputStream, LOG, WARNING);
+	}
+
+	@Override
+	public void cancel() {
+		cancel = true;
+	}
+
+	@Override
+	public Class<InputStream> getDataClass() {
+		return InputStream.class;
+	}
+
+	@Override
+	public DataSource getDataSource() {
+		return LOCAL;
+	}
+
+}

briar-android/src/main/java/org/briarproject/briar/android/conversation/glide/BriarDataFetcherFactory.java

@@ -0,0 +1,30 @@
+package org.briarproject.briar.android.conversation.glide;
+
+import org.briarproject.bramble.api.db.DatabaseExecutor;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.briar.android.conversation.AttachmentItem;
+import org.briarproject.briar.api.messaging.MessagingManager;
+
+import java.util.concurrent.Executor;
+
+import javax.inject.Inject;
+
+@NotNullByDefault
+public class BriarDataFetcherFactory {
+
+	private final MessagingManager messagingManager;
+	@DatabaseExecutor
+	private final Executor dbExecutor;
+
+	@Inject
+	public BriarDataFetcherFactory(MessagingManager messagingManager,
+			@DatabaseExecutor Executor dbExecutor) {
+		this.messagingManager = messagingManager;
+		this.dbExecutor = dbExecutor;
+	}
+
+	BriarDataFetcher createBriarDataFetcher(AttachmentItem model) {
+		return new BriarDataFetcher(messagingManager, dbExecutor, model);
+	}
+
+}

briar-android/src/main/java/org/briarproject/briar/android/conversation/glide/BriarGlideModule.java

@@ -0,0 +1,44 @@
+package org.briarproject.briar.android.conversation.glide;
+
+import android.content.Context;
+
+import com.bumptech.glide.Glide;
+import com.bumptech.glide.GlideBuilder;
+import com.bumptech.glide.Registry;
+import com.bumptech.glide.annotation.GlideModule;
+import com.bumptech.glide.module.AppGlideModule;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.briar.android.BriarApplication;
+import org.briarproject.briar.android.conversation.AttachmentItem;
+
+import java.io.InputStream;
+
+import static android.util.Log.DEBUG;
+import static android.util.Log.WARN;
+import static org.briarproject.briar.android.TestingConstants.IS_DEBUG_BUILD;
+
+@GlideModule
+@NotNullByDefault
+public final class BriarGlideModule extends AppGlideModule {
+
+	@Override
+	public void registerComponents(Context context, Glide glide,
+			Registry registry) {
+		BriarApplication app =
+				(BriarApplication) context.getApplicationContext();
+		BriarModelLoaderFactory factory = new BriarModelLoaderFactory(app);
+		registry.prepend(AttachmentItem.class, InputStream.class, factory);
+	}
+
+	@Override
+	public void applyOptions(Context context, GlideBuilder builder) {
+		builder.setLogLevel(IS_DEBUG_BUILD ? DEBUG : WARN);
+	}
+
+	@Override
+	public boolean isManifestParsingEnabled() {
+		return false;
+	}
+
+}

briar-android/src/main/java/org/briarproject/briar/android/conversation/glide/BriarImageTransformation.java

@@ -0,0 +1,14 @@
+package org.briarproject.briar.android.conversation.glide;
+
+import android.graphics.Bitmap;
+
+import com.bumptech.glide.load.MultiTransformation;
+import com.bumptech.glide.load.resource.bitmap.CenterCrop;
+
+public class BriarImageTransformation extends MultiTransformation<Bitmap> {
+
+	public BriarImageTransformation(Radii r) {
+		super(new CenterCrop(), new CustomCornersTransformation(r));
+	}
+
+}

briar-android/src/main/java/org/briarproject/briar/android/conversation/glide/BriarModelLoader.java

@@ -0,0 +1,42 @@
+package org.briarproject.briar.android.conversation.glide;
+
+
+import com.bumptech.glide.load.Options;
+import com.bumptech.glide.load.model.ModelLoader;
+import com.bumptech.glide.signature.ObjectKey;
+
+import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
+import org.briarproject.briar.android.BriarApplication;
+import org.briarproject.briar.android.conversation.AttachmentItem;
+
+import java.io.InputStream;
+
+import javax.inject.Inject;
+
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
+public final class BriarModelLoader
+		implements ModelLoader<AttachmentItem, InputStream> {
+
+	@Inject
+	BriarDataFetcherFactory dataFetcherFactory;
+
+	public BriarModelLoader(BriarApplication app) {
+		app.getApplicationComponent().inject(this);
+	}
+
+	@Override
+	public LoadData<InputStream> buildLoadData(AttachmentItem model, int width,
+			int height, Options options) {
+		ObjectKey key = new ObjectKey(model.getMessageId());
+		BriarDataFetcher dataFetcher =
+				dataFetcherFactory.createBriarDataFetcher(model);
+		return new LoadData<>(key, dataFetcher);
+	}
+
+	@Override
+	public boolean handles(AttachmentItem model) {
+		return true;
+	}
+}

briar-android/src/main/java/org/briarproject/briar/android/conversation/glide/BriarModelLoaderFactory.java

@@ -0,0 +1,34 @@
+package org.briarproject.briar.android.conversation.glide;
+
+import com.bumptech.glide.load.model.ModelLoader;
+import com.bumptech.glide.load.model.ModelLoaderFactory;
+import com.bumptech.glide.load.model.MultiModelLoaderFactory;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.briar.android.BriarApplication;
+import org.briarproject.briar.android.conversation.AttachmentItem;
+
+import java.io.InputStream;
+
+@NotNullByDefault
+class BriarModelLoaderFactory
+		implements ModelLoaderFactory<AttachmentItem, InputStream> {
+
+	private final BriarApplication app;
+
+	public BriarModelLoaderFactory(BriarApplication app) {
+		this.app = app;
+	}
+
+	@Override
+	public ModelLoader<AttachmentItem, InputStream> build(
+			MultiModelLoaderFactory multiFactory) {
+		return new BriarModelLoader(app);
+	}
+
+	@Override
+	public void teardown() {
+		// noop
+	}
+
+}

briar-android/src/main/java/org/briarproject/briar/android/conversation/glide/CustomCornersTransformation.java

@@ -0,0 +1,128 @@
+package org.briarproject.briar.android.conversation.glide;
+
+import android.graphics.Bitmap;
+import android.graphics.BitmapShader;
+import android.graphics.Canvas;
+import android.graphics.Paint;
+import android.graphics.RectF;
+import android.support.annotation.NonNull;
+
+import com.bumptech.glide.load.engine.bitmap_recycle.BitmapPool;
+import com.bumptech.glide.load.resource.bitmap.BitmapTransformation;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import java.security.MessageDigest;
+
+import javax.annotation.concurrent.Immutable;
+
+import static android.graphics.Bitmap.Config.ARGB_8888;
+import static android.graphics.Shader.TileMode.CLAMP;
+
+@Immutable
+@NotNullByDefault
+public class CustomCornersTransformation extends BitmapTransformation {
+
+	private static final String ID = CustomCornersTransformation.class.getName();
+
+	private final Radii radii;
+
+	public CustomCornersTransformation(Radii radii) {
+		this.radii = radii;
+	}
+
+	@Override
+	protected Bitmap transform(BitmapPool pool, Bitmap toTransform,
+			int outWidth, int outHeight) {
+		int width = toTransform.getWidth();
+		int height = toTransform.getHeight();
+
+		Bitmap bitmap = pool.get(width, height, ARGB_8888);
+		bitmap.setHasAlpha(true);
+
+		Canvas canvas = new Canvas(bitmap);
+		Paint paint = new Paint();
+		paint.setAntiAlias(true);
+		paint.setShader(new BitmapShader(toTransform, CLAMP, CLAMP));
+		drawRect(canvas, paint, width, height);
+		return bitmap;
+	}
+
+	private void drawRect(Canvas canvas, Paint paint, float width,
+			float height) {
+		drawTopLeft(canvas, paint, radii.topLeft, width, height);
+		drawTopRight(canvas, paint, radii.topRight, width, height);
+		drawBottomLeft(canvas, paint, radii.bottomLeft, width, height);
+		drawBottomRight(canvas, paint, radii.bottomRight, width, height);
+	}
+
+	private void drawTopLeft(Canvas canvas, Paint paint, int radius,
+			float width, float height) {
+		RectF rect = new RectF(
+				0,
+				0,
+				width / 2 + radius + 1,
+				height / 2 + radius + 1
+		);
+		if (radius == 0) canvas.drawRect(rect, paint);
+		else canvas.drawRoundRect(rect, radius, radius, paint);
+	}
+
+	private void drawTopRight(Canvas canvas, Paint paint, int radius,
+			float width, float height) {
+		RectF rect = new RectF(
+				width / 2 - radius,
+				0,
+				width,
+				height / 2 + radius + 1
+		);
+		if (radius == 0) canvas.drawRect(rect, paint);
+		else canvas.drawRoundRect(rect, radius, radius, paint);
+	}
+
+	private void drawBottomLeft(Canvas canvas, Paint paint, int radius,
+			float width, float height) {
+		RectF rect = new RectF(
+				0,
+				height / 2 - radius,
+				width / 2 + radius + 1,
+				height
+		);
+		if (radius == 0) canvas.drawRect(rect, paint);
+		else canvas.drawRoundRect(rect, radius, radius, paint);
+	}
+
+	private void drawBottomRight(Canvas canvas, Paint paint, int radius,
+			float width, float height) {
+		RectF rect = new RectF(
+				width / 2 - radius,
+				height / 2 - radius,
+				width,
+				height
+		);
+		if (radius == 0) canvas.drawRect(rect, paint);
+		else canvas.drawRoundRect(rect, radius, radius, paint);
+	}
+
+	@Override
+	public String toString() {
+		return "ImageCornerTransformation(" + radii + ")";
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		return o instanceof CustomCornersTransformation &&
+				radii.equals(((CustomCornersTransformation) o).radii);
+	}
+
+	@Override
+	public int hashCode() {
+		return ID.hashCode() + radii.hashCode();
+	}
+
+	@Override
+	public void updateDiskCacheKey(@NonNull MessageDigest messageDigest) {
+		messageDigest.update((ID + radii).getBytes(CHARSET));
+	}
+
+}

briar-android/src/main/java/org/briarproject/briar/android/conversation/glide/Radii.java

@@ -0,0 +1,41 @@
+package org.briarproject.briar.android.conversation.glide;
+
+import android.support.annotation.Nullable;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+@NotNullByDefault
+public class Radii {
+
+	public final int topLeft, topRight, bottomLeft, bottomRight;
+
+	public Radii(int topLeft, int topRight, int bottomLeft, int bottomRight) {
+		this.topLeft = topLeft;
+		this.topRight = topRight;
+		this.bottomLeft = bottomLeft;
+		this.bottomRight = bottomRight;
+	}
+
+	@Override
+	public boolean equals(@Nullable Object o) {
+		return o instanceof Radii &&
+				topLeft == ((Radii) o).topLeft &&
+				topRight == ((Radii) o).topRight &&
+				bottomLeft == ((Radii) o).bottomLeft &&
+				bottomRight == ((Radii) o).bottomRight;
+	}
+
+	@Override
+	public int hashCode() {
+		return topLeft << 24 ^ topRight << 16 ^ bottomLeft << 8 ^ bottomRight;
+	}
+
+	@Override
+	public String toString() {
+		return "Radii(topLeft=" + topLeft +
+				",topRight=" + topRight +
+				",bottomLeft=" + bottomLeft +
+				",bottomRight=" + bottomRight;
+	}
+
+}

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

@@ -1,8 +1,8 @@
 package org.briarproject.briar.android.introduction;
 
 import android.content.Context;
+import android.net.Uri;
 import android.os.Bundle;
-import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 import android.support.v7.app.ActionBar;
 import android.view.LayoutInflater;
@@ -17,14 +17,17 @@ import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.ContactManager;
 import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.util.StringUtils;
+import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.ActivityComponent;
 import org.briarproject.briar.android.fragment.BaseFragment;
 import org.briarproject.briar.android.view.TextInputView;
-import org.briarproject.briar.android.view.TextInputView.TextInputListener;
+import org.briarproject.briar.android.view.TextSendController;
+import org.briarproject.briar.android.view.TextSendController.SendListener;
 import org.briarproject.briar.api.introduction.IntroductionManager;
 
+import java.util.List;
 import java.util.logging.Logger;
 
 import javax.inject.Inject;
@@ -41,8 +44,10 @@ import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.briar.android.util.UiUtils.getContactDisplayName;
 import static org.briarproject.briar.api.introduction.IntroductionConstants.MAX_INTRODUCTION_TEXT_LENGTH;
 
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
 public class IntroductionMessageFragment extends BaseFragment
-		implements TextInputListener {
+		implements SendListener {
 
 	public static final String TAG =
 			IntroductionMessageFragment.class.getName();
@@ -84,8 +89,9 @@ public class IntroductionMessageFragment extends BaseFragment
 	}
 
 	@Override
-	public View onCreateView(@NonNull LayoutInflater inflater,
-			ViewGroup container, Bundle savedInstanceState) {
+	public View onCreateView(LayoutInflater inflater,
+			@Nullable ViewGroup container,
+			@Nullable Bundle savedInstanceState) {
 
 		// change toolbar text
 		ActionBar actionBar = introductionActivity.getSupportActionBar();
@@ -97,7 +103,11 @@ public class IntroductionMessageFragment extends BaseFragment
 		View v = inflater.inflate(R.layout.introduction_message, container,
 				false);
 		ui = new ViewHolder(v);
-		ui.message.setSendButtonEnabled(false);
+		TextSendController sendController =
+				new TextSendController(ui.message, this, true);
+		ui.message.setSendController(sendController);
+		ui.message.setMaxTextLength(MAX_INTRODUCTION_TEXT_LENGTH);
+		ui.message.setEnabled(false);
 
 		return v;
 	}
@@ -156,13 +166,10 @@ public class IntroductionMessageFragment extends BaseFragment
 			ui.progressBar.setVisibility(GONE);
 
 			if (possible) {
-				// set button action
-				ui.message.setListener(IntroductionMessageFragment.this);
-
 				// show views
 				ui.notPossible.setVisibility(GONE);
 				ui.message.setVisibility(VISIBLE);
-				ui.message.setSendButtonEnabled(true);
+				ui.message.setEnabled(true);
 				ui.message.showSoftKeyboard();
 			} else {
 				ui.notPossible.setVisibility(VISIBLE);
@@ -184,14 +191,11 @@ public class IntroductionMessageFragment extends BaseFragment
 	}
 
 	@Override
-	public void onSendClick(@NonNull String text) {
+	public void onSendClick(@Nullable String text, List<Uri> imageUris) {
 		// disable button to prevent accidental double invitations
-		ui.message.setSendButtonEnabled(false);
+		ui.message.setEnabled(false);
 
-		String txt = ui.message.getText().toString();
-		if (txt.isEmpty()) txt = null;
-		else txt = StringUtils.truncateUtf8(txt, MAX_INTRODUCTION_TEXT_LENGTH);
-		makeIntroduction(contact1, contact2, txt);
+		makeIntroduction(contact1, contact2, text);
 
 		// don't wait for the introduction to be made before finishing activity
 		introductionActivity.hideSoftKeyboard(ui.message);

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

@@ -196,7 +196,7 @@ public class GroupActivity extends
 
 	private void setGroupEnabled(boolean enabled) {
 		isDissolved = !enabled;
-		textInput.setSendButtonEnabled(enabled);
+		textInput.setEnabled(enabled);
 		list.getRecyclerView().setAlpha(enabled ? 1f : 0.5f);
 
 		if (!enabled) {

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

@@ -1,5 +1,7 @@
 package org.briarproject.briar.android.privategroup.creation;
 
+import android.support.annotation.Nullable;
+
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
@@ -18,6 +20,7 @@ public interface CreateGroupController
 			ResultExceptionHandler<GroupId, DbException> result);
 
 	void sendInvitation(GroupId g, Collection<ContactId> contacts,
-			String text, ResultExceptionHandler<Void, DbException> result);
+			@Nullable String text,
+			ResultExceptionHandler<Void, DbException> result);
 
 }

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

@@ -1,5 +1,7 @@
 package org.briarproject.briar.android.privategroup.creation;
 
+import android.support.annotation.Nullable;
+
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.ContactManager;
@@ -123,7 +125,8 @@ class CreateGroupControllerImpl extends ContactSelectorControllerImpl
 
 	@Override
 	public void sendInvitation(GroupId g, Collection<ContactId> contactIds,
-			String text, ResultExceptionHandler<Void, DbException> handler) {
+			@Nullable String text,
+			ResultExceptionHandler<Void, DbException> handler) {
 		runOnDbThread(() -> {
 			try {
 				LocalAuthor localAuthor = identityManager.getLocalAuthor();
@@ -144,7 +147,7 @@ class CreateGroupControllerImpl extends ContactSelectorControllerImpl
 	}
 
 	private void signInvitations(GroupId g, LocalAuthor localAuthor,
-			Collection<Contact> contacts, String text,
+			Collection<Contact> contacts, @Nullable String text,
 			ResultExceptionHandler<Void, DbException> handler) {
 		cryptoExecutor.execute(() -> {
 			long timestamp = clock.currentTimeMillis();
@@ -160,15 +163,14 @@ class CreateGroupControllerImpl extends ContactSelectorControllerImpl
 	}
 
 	private void sendInvitations(GroupId g,
-			Collection<InvitationContext> contexts, String text,
+			Collection<InvitationContext> contexts, @Nullable String text,
 			ResultExceptionHandler<Void, DbException> handler) {
 		runOnDbThread(() -> {
 			try {
-				String txt = text.isEmpty() ? null : text;
 				for (InvitationContext context : contexts) {
 					try {
 						groupInvitationManager.sendInvitation(g,
-								context.contactId, txt, context.timestamp,
+								context.contactId, text, context.timestamp,
 								context.signature);
 					} catch (NoSuchContactException e) {
 						// Continue

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

@@ -55,7 +55,7 @@ public class GroupInviteActivity extends ContactSelectorActivity
 	}
 
 	@Override
-	public boolean onButtonClick(String text) {
+	public void onButtonClick(@Nullable String text) {
 		if (groupId == null)
 			throw new IllegalStateException("GroupId was not initialized");
 		controller.sendInvitation(groupId, contacts, text,
@@ -72,7 +72,6 @@ public class GroupInviteActivity extends ContactSelectorActivity
 						handleDbException(exception);
 					}
 				});
-		return true;
 	}
 
 	@Override

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

@@ -42,6 +42,7 @@ import static android.content.Context.WIFI_SERVICE;
 import static android.net.ConnectivityManager.TYPE_MOBILE;
 import static android.net.ConnectivityManager.TYPE_WIFI;
 import static android.net.wifi.WifiManager.WIFI_STATE_ENABLED;
+import static org.briarproject.bramble.util.PrivacyUtils.scrubInetAddress;
 import static org.briarproject.bramble.util.PrivacyUtils.scrubMacAddress;
 
 public class BriarReportPrimer implements ReportPrimer {
@@ -192,7 +193,7 @@ public class BriarReportPrimer implements ReportPrimer {
 					int ip3 = (ip >> 16) & 0xFF;
 					int ip4 = (ip >> 24) & 0xFF;
 					String address = ip1 + "." + ip2 + "." + ip3 + "." + ip4;
-					customData.put("Wi-Fi address", address);
+					customData.put("Wi-Fi address", scrubInetAddress(address));
 				}
 			}
 

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

@@ -1,28 +1,31 @@
 package org.briarproject.briar.android.sharing;
 
 import android.content.Context;
+import android.net.Uri;
 import android.os.Bundle;
+import android.support.annotation.Nullable;
 import android.support.annotation.StringRes;
 import android.support.annotation.UiThread;
-import android.support.design.widget.Snackbar;
 import android.view.LayoutInflater;
 import android.view.MenuItem;
 import android.view.View;
 import android.view.ViewGroup;
 
+import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.fragment.BaseFragment;
 import org.briarproject.briar.android.view.LargeTextInputView;
-import org.briarproject.briar.android.view.TextInputView.TextInputListener;
+import org.briarproject.briar.android.view.TextSendController;
+import org.briarproject.briar.android.view.TextSendController.SendListener;
 
-import static android.support.design.widget.Snackbar.LENGTH_SHORT;
-import static org.briarproject.bramble.util.StringUtils.truncateUtf8;
-import static org.briarproject.bramble.util.StringUtils.utf8IsTooLong;
-import static org.briarproject.briar.api.sharing.SharingConstants.MAX_INVITATION_TEXT_LENGTH;
+import java.util.List;
 
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
 public abstract class BaseMessageFragment extends BaseFragment
-		implements TextInputListener {
+		implements SendListener {
 
 	protected LargeTextInputView message;
 	private MessageFragmentListener listener;
@@ -34,16 +37,20 @@ public abstract class BaseMessageFragment extends BaseFragment
 	}
 
 	@Override
-	public View onCreateView(LayoutInflater inflater, ViewGroup container,
-			Bundle savedInstanceState) {
+	public View onCreateView(@Nullable LayoutInflater inflater,
+			@Nullable ViewGroup container,
+			@Nullable Bundle savedInstanceState) {
 
 		// inflate view
 		View v = inflater.inflate(R.layout.fragment_message, container,
 				false);
 		message = v.findViewById(R.id.messageView);
+		TextSendController sendController =
+				new TextSendController(message, this, true);
+		message.setSendController(sendController);
+		message.setMaxTextLength(listener.getMaximumTextLength());
 		message.setButtonText(getString(getButtonText()));
 		message.setHint(getHintText());
-		message.setListener(this);
 
 		return v;
 	}
@@ -76,21 +83,12 @@ public abstract class BaseMessageFragment extends BaseFragment
 	}
 
 	@Override
-	public void onSendClick(String text) {
-		if (utf8IsTooLong(text, listener.getMaximumTextLength())) {
-			Snackbar.make(message, R.string.text_too_long, LENGTH_SHORT).show();
-			return;
-		}
-
+	public void onSendClick(@Nullable String text, List<Uri> imageUris) {
 		// disable button to prevent accidental double actions
-		message.setSendButtonEnabled(false);
+		message.setEnabled(false);
 		message.hideSoftKeyboard();
 
-		text = truncateUtf8(text, MAX_INVITATION_TEXT_LENGTH);
-		if(!listener.onButtonClick(text)) {
-			message.setSendButtonEnabled(true);
-			message.showSoftKeyboard();
-		}
+		listener.onButtonClick(text);
 	}
 
 	@UiThread
@@ -101,8 +99,7 @@ public abstract class BaseMessageFragment extends BaseFragment
 
 		void setTitle(@StringRes int titleRes);
 
-		/** Returns true when the button click has been consumed. */
-		boolean onButtonClick(String text);
+		void onButtonClick(@Nullable String text);
 
 		int getMaximumTextLength();
 

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

@@ -41,13 +41,12 @@ public abstract class ShareActivity extends ContactSelectorActivity
 
 	@UiThread
 	@Override
-	public boolean onButtonClick(String text) {
+	public void onButtonClick(@Nullable String text) {
 		share(contacts, text);
 		setResult(RESULT_OK);
 		supportFinishAfterTransition();
-		return true;
 	}
 
-	abstract void share(Collection<ContactId> contacts, String text);
+	abstract void share(Collection<ContactId> contacts, @Nullable String text);
 
 }

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

@@ -51,7 +51,7 @@ public class ShareBlogActivity extends ShareActivity {
 	}
 
 	@Override
-	void share(Collection<ContactId> contacts, String text) {
+	void share(Collection<ContactId> contacts, @Nullable String text) {
 		controller.share(groupId, contacts, text,
 				new UiExceptionHandler<DbException>(this) {
 					@Override

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

@@ -9,10 +9,12 @@ import org.briarproject.briar.android.controller.handler.ExceptionHandler;
 
 import java.util.Collection;
 
+import javax.annotation.Nullable;
+
 public interface ShareBlogController
 		extends ContactSelectorController<SelectableContactItem> {
 
-	void share(GroupId g, Collection<ContactId> contacts, String text,
+	void share(GroupId g, Collection<ContactId> contacts, @Nullable String text,
 			ExceptionHandler<DbException> handler);
 
 }

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

@@ -20,12 +20,12 @@ import java.util.Collection;
 import java.util.concurrent.Executor;
 import java.util.logging.Logger;
 
+import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.util.LogUtils.logException;
-import static org.briarproject.bramble.util.StringUtils.isNullOrEmpty;
 
 @Immutable
 @NotNullByDefault
@@ -56,17 +56,16 @@ class ShareBlogControllerImpl extends ContactSelectorControllerImpl
 	}
 
 	@Override
-	public void share(GroupId g, Collection<ContactId> contacts, String text,
-			ExceptionHandler<DbException> handler) {
+	public void share(GroupId g, Collection<ContactId> contacts, @Nullable
+			String text, ExceptionHandler<DbException> handler) {
 		runOnDbThread(() -> {
 			try {
-				String txt = isNullOrEmpty(text) ? null : text;
 				for (ContactId c : contacts) {
 					try {
 						long time = Math.max(clock.currentTimeMillis(),
 								conversationManager.getGroupCount(c)
 										.getLatestMsgTime() + 1);
-						blogSharingManager.sendInvitation(g, c, txt, time);
+						blogSharingManager.sendInvitation(g, c, text, time);
 					} catch (NoSuchContactException | NoSuchGroupException e) {
 						logException(LOG, WARNING, e);
 					}

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

@@ -51,7 +51,7 @@ public class ShareForumActivity extends ShareActivity {
 	}
 
 	@Override
-	void share(Collection<ContactId> contacts, String text) {
+	void share(Collection<ContactId> contacts, @Nullable String text) {
 		controller.share(groupId, contacts, text,
 				new UiExceptionHandler<DbException>(this) {
 					@Override

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

@@ -9,10 +9,12 @@ import org.briarproject.briar.android.controller.handler.ExceptionHandler;
 
 import java.util.Collection;
 
+import javax.annotation.Nullable;
+
 public interface ShareForumController
 		extends ContactSelectorController<SelectableContactItem> {
 
-	void share(GroupId g, Collection<ContactId> contacts, String text,
+	void share(GroupId g, Collection<ContactId> contacts, @Nullable String text,
 			ExceptionHandler<DbException> handler);
 
 }

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

@@ -13,19 +13,19 @@ 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.conversation.ConversationManager;
+import org.briarproject.briar.api.forum.ForumSharingManager;
 
 import java.util.Collection;
 import java.util.concurrent.Executor;
 import java.util.logging.Logger;
 
+import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.util.LogUtils.logException;
-import static org.briarproject.bramble.util.StringUtils.isNullOrEmpty;
 
 @Immutable
 @NotNullByDefault
@@ -57,16 +57,15 @@ class ShareForumControllerImpl extends ContactSelectorControllerImpl
 
 	@Override
 	public void share(GroupId g, Collection<ContactId> contacts,
-			String text, ExceptionHandler<DbException> handler) {
+			@Nullable String text, ExceptionHandler<DbException> handler) {
 		runOnDbThread(() -> {
 			try {
-				String txt = isNullOrEmpty(text) ? null : text;
 				for (ContactId c : contacts) {
 					try {
 						long time = Math.max(clock.currentTimeMillis(),
 								conversationManager.getGroupCount(c)
 										.getLatestMsgTime() + 1);
-						forumSharingManager.sendInvitation(g, c, txt, time);
+						forumSharingManager.sendInvitation(g, c, text, time);
 					} catch (NoSuchContactException | NoSuchGroupException e) {
 						logException(LOG, WARNING, e);
 					}

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

@@ -1,6 +1,7 @@
 package org.briarproject.briar.android.threaded;
 
 import android.content.Intent;
+import android.net.Uri;
 import android.os.Bundle;
 import android.support.annotation.CallSuper;
 import android.support.annotation.StringRes;
@@ -26,13 +27,15 @@ import org.briarproject.briar.android.threaded.ThreadItemAdapter.ThreadItemListe
 import org.briarproject.briar.android.threaded.ThreadListController.ThreadListDataSource;
 import org.briarproject.briar.android.threaded.ThreadListController.ThreadListListener;
 import org.briarproject.briar.android.view.BriarRecyclerView;
+import org.briarproject.briar.android.view.KeyboardAwareLinearLayout;
 import org.briarproject.briar.android.view.TextInputView;
-import org.briarproject.briar.android.view.TextInputView.TextInputListener;
+import org.briarproject.briar.android.view.TextSendController;
+import org.briarproject.briar.android.view.TextSendController.SendListener;
 import org.briarproject.briar.android.view.UnreadMessageButton;
 import org.briarproject.briar.api.client.NamedGroup;
-import org.thoughtcrime.securesms.components.KeyboardAwareLinearLayout;
 
 import java.util.Collection;
+import java.util.List;
 import java.util.logging.Logger;
 
 import javax.annotation.Nullable;
@@ -42,14 +45,14 @@ 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 java.util.logging.Level.INFO;
-import static org.briarproject.bramble.util.StringUtils.utf8IsTooLong;
+import static org.briarproject.bramble.util.StringUtils.isNullOrEmpty;
 import static org.briarproject.briar.android.threaded.ThreadItemAdapter.UnreadCount;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
 public abstract class ThreadListActivity<G extends NamedGroup, I extends ThreadItem, A extends ThreadItemAdapter<I>>
 		extends BriarActivity
-		implements ThreadListListener<I>, TextInputListener, SharingListener,
+		implements ThreadListListener<I>, SendListener, SharingListener,
 		ThreadItemListener<I>, ThreadListDataSource {
 
 	protected static final String KEY_REPLY_ID = "replyId";
@@ -86,7 +89,10 @@ public abstract class ThreadListActivity<G extends NamedGroup, I extends ThreadI
 		getController().setGroupId(groupId);
 
 		textInput = findViewById(R.id.text_input_container);
-		textInput.setListener(this);
+		TextSendController sendController =
+				new TextSendController(textInput, this, false);
+		textInput.setSendController(sendController);
+		textInput.setMaxTextLength(getMaxTextLength());
 		list = findViewById(R.id.list);
 		layoutManager = new LinearLayoutManager(this);
 		// FIXME pre-fetching messes with read state, find better solution #1289
@@ -266,7 +272,7 @@ public abstract class ThreadListActivity<G extends NamedGroup, I extends ThreadI
 	@Override
 	public void onBackPressed() {
 		if (adapter.getHighlightedItem() != null) {
-			textInput.setText("");
+			textInput.clearText();
 			replyId = null;
 			updateTextInput();
 		} else {
@@ -348,13 +354,9 @@ public abstract class ThreadListActivity<G extends NamedGroup, I extends ThreadI
 	}
 
 	@Override
-	public void onSendClick(String text) {
-		if (text.trim().length() == 0)
-			return;
-		if (utf8IsTooLong(text, getMaxTextLength())) {
-			displaySnackbar(R.string.text_too_long);
-			return;
-		}
+	public void onSendClick(@Nullable String text, List<Uri> imageUris) {
+		if (isNullOrEmpty(text)) throw new AssertionError();
+
 		I replyItem = adapter.getHighlightedItem();
 		UiResultExceptionHandler<I, DbException> handler =
 				new UiResultExceptionHandler<I, DbException>(this) {
@@ -370,7 +372,7 @@ public abstract class ThreadListActivity<G extends NamedGroup, I extends ThreadI
 				};
 		getController().createAndStoreMessage(text, replyItem, handler);
 		textInput.hideSoftKeyboard();
-		textInput.setText("");
+		textInput.clearText();
 		replyId = null;
 		updateTextInput();
 	}

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

@@ -14,8 +14,9 @@ import android.os.PowerManager;
 import android.support.annotation.AttrRes;
 import android.support.annotation.ColorInt;
 import android.support.annotation.ColorRes;
-import android.support.annotation.MainThread;
 import android.support.annotation.Nullable;
+import android.support.annotation.RequiresApi;
+import android.support.annotation.UiThread;
 import android.support.design.widget.TextInputLayout;
 import android.support.v4.app.FragmentManager;
 import android.support.v4.content.ContextCompat;
@@ -31,6 +32,7 @@ import android.text.method.LinkMovementMethod;
 import android.text.style.ClickableSpan;
 import android.text.style.ForegroundColorSpan;
 import android.text.style.URLSpan;
+import android.transition.Transition;
 import android.util.TypedValue;
 import android.view.KeyEvent;
 import android.view.View;
@@ -54,18 +56,23 @@ import static android.content.Intent.FLAG_ACTIVITY_NEW_TASK;
 import static android.os.Build.MANUFACTURER;
 import static android.os.Build.VERSION.SDK_INT;
 import static android.provider.Settings.ACTION_REQUEST_IGNORE_BATTERY_OPTIMIZATIONS;
+import static android.support.v4.view.ViewCompat.LAYOUT_DIRECTION_RTL;
 import static android.support.v7.app.AppCompatDelegate.MODE_NIGHT_AUTO;
 import static android.support.v7.app.AppCompatDelegate.MODE_NIGHT_FOLLOW_SYSTEM;
 import static android.support.v7.app.AppCompatDelegate.MODE_NIGHT_NO;
 import static android.support.v7.app.AppCompatDelegate.MODE_NIGHT_YES;
 import static android.support.v7.app.AppCompatDelegate.setDefaultNightMode;
 import static android.text.format.DateUtils.DAY_IN_MILLIS;
+import static android.text.format.DateUtils.FORMAT_ABBREV_ALL;
 import static android.text.format.DateUtils.FORMAT_ABBREV_MONTH;
 import static android.text.format.DateUtils.FORMAT_ABBREV_RELATIVE;
 import static android.text.format.DateUtils.FORMAT_ABBREV_TIME;
 import static android.text.format.DateUtils.FORMAT_SHOW_DATE;
+import static android.text.format.DateUtils.FORMAT_SHOW_TIME;
+import static android.text.format.DateUtils.FORMAT_SHOW_YEAR;
 import static android.text.format.DateUtils.MINUTE_IN_MILLIS;
 import static android.text.format.DateUtils.WEEK_IN_MILLIS;
+import static android.text.format.DateUtils.YEAR_IN_MILLIS;
 import static android.view.KeyEvent.ACTION_DOWN;
 import static android.view.KeyEvent.KEYCODE_ENTER;
 import static android.view.inputmethod.EditorInfo.IME_NULL;
@@ -117,6 +124,13 @@ public class UiUtils {
 				MIN_DATE_RESOLUTION, flags).toString();
 	}
 
+	public static String formatDateAbsolute(Context ctx, long time) {
+		int flags = FORMAT_SHOW_TIME | FORMAT_SHOW_DATE | FORMAT_ABBREV_ALL;
+		long diff = System.currentTimeMillis() - time;
+		if (diff >= YEAR_IN_MILLIS) flags |= FORMAT_SHOW_YEAR;
+		return DateUtils.formatDateTime(ctx, time, flags);
+	}
+
 	public static int getDaysUntilExpiry() {
 		long now = System.currentTimeMillis();
 		long daysBeforeExpiry = (EXPIRY_DATE - now) / 1000 / 60 / 60 / 24;
@@ -194,7 +208,7 @@ public class UiUtils {
 				runnable.run();
 			}
 		};
-		ssb.setSpan(cSpan, start + 1, end, 0);
+		ssb.setSpan(cSpan, start, end, 0);
 		textView.setText(ssb);
 		textView.setMovementMethod(new LinkMovementMethod());
 	}
@@ -318,12 +332,18 @@ public class UiUtils {
 				keyEvent.getKeyCode() == KEYCODE_ENTER;
 	}
 
+	@RequiresApi(api = 21)
+	public static void excludeSystemUi(Transition transition) {
+		transition.excludeTarget(android.R.id.statusBarBackground, true);
+		transition.excludeTarget(android.R.id.navigationBarBackground, true);
+	}
+
 	/**
 	 * Observes the given {@link LiveData} until the first change.
 	 * If the LiveData's value is available, the {@link Observer} will be
 	 * called right away.
 	 */
-	@MainThread
+	@UiThread
 	public static <T> void observeOnce(LiveData<T> liveData,
 			LifecycleOwner owner, Observer<T> observer) {
 		liveData.observe(owner, new Observer<T>() {
@@ -335,4 +355,28 @@ public class UiUtils {
 		});
 	}
 
+	/**
+	 * Same as {@link #observeOnce(LiveData, LifecycleOwner, Observer)},
+	 * but without a {@link LifecycleOwner}.
+	 *
+	 * Warning: Do NOT call from objects that have a lifecycle.
+	 */
+	@UiThread
+	public static <T> void observeForeverOnce(LiveData<T> liveData,
+			Observer<T> observer) {
+		liveData.observeForever(new Observer<T>() {
+			@Override
+			public void onChanged(@Nullable T t) {
+				observer.onChanged(t);
+				liveData.removeObserver(this);
+			}
+		});
+	}
+
+	public static boolean isRtl(Context ctx) {
+		if (SDK_INT < 17) return false;
+		return ctx.getResources().getConfiguration().getLayoutDirection() ==
+				LAYOUT_DIRECTION_RTL;
+	}
+
 }

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

@@ -0,0 +1,239 @@
+package org.briarproject.briar.android.view;
+
+import android.content.Context;
+import android.content.res.TypedArray;
+import android.graphics.Rect;
+import android.os.IBinder;
+import android.support.annotation.Nullable;
+import android.support.annotation.StringRes;
+import android.support.v7.widget.AppCompatImageButton;
+import android.text.Editable;
+import android.text.TextWatcher;
+import android.util.AttributeSet;
+import android.view.LayoutInflater;
+import android.view.inputmethod.InputMethodManager;
+import android.widget.EditText;
+
+import com.vanniktech.emoji.EmojiEditText;
+import com.vanniktech.emoji.EmojiPopup;
+import com.vanniktech.emoji.RecentEmoji;
+
+import org.briarproject.briar.R;
+import org.briarproject.briar.android.BriarApplication;
+
+import javax.inject.Inject;
+
+import static android.content.Context.INPUT_METHOD_SERVICE;
+import static android.content.Context.LAYOUT_INFLATER_SERVICE;
+import static android.view.KeyEvent.KEYCODE_ENTER;
+import static android.view.inputmethod.InputMethodManager.SHOW_IMPLICIT;
+import static java.util.Objects.requireNonNull;
+import static org.briarproject.bramble.util.StringUtils.utf8IsTooLong;
+
+public class EmojiTextInputView extends KeyboardAwareLinearLayout implements
+		TextWatcher {
+
+	@Inject
+	RecentEmoji recentEmoji;
+
+	private final AppCompatImageButton emojiToggle;
+	private final EmojiPopup emojiPopup;
+	private final EditText editText;
+
+	@Nullable
+	private TextInputListener listener;
+	private int maxLength = Integer.MAX_VALUE;
+	private boolean emptyTextAllowed = false;
+	private boolean isEmpty = true;
+
+	public EmojiTextInputView(Context context) {
+		this(context, null);
+	}
+
+	public EmojiTextInputView(Context context, @Nullable AttributeSet attrs) {
+		this(context, attrs, 0);
+	}
+
+	public EmojiTextInputView(Context context, @Nullable AttributeSet attrs,
+			int defStyleAttr) {
+		super(context, attrs, defStyleAttr);
+
+		// inflate layout
+		LayoutInflater inflater = (LayoutInflater) requireNonNull(
+				context.getSystemService(LAYOUT_INFLATER_SERVICE));
+		inflater.inflate(R.layout.emoji_text_input_view, this, true);
+
+		// get attributes
+		TypedArray a = context.obtainStyledAttributes(attrs,
+				R.styleable.EmojiTextInputView);
+		int paddingBottom = a.getDimensionPixelSize(
+				R.styleable.EmojiTextInputView_textPaddingBottom, 0);
+		int paddingEnd = a.getDimensionPixelSize(
+				R.styleable.EmojiTextInputView_textPaddingEnd, 0);
+		int maxLines =
+				a.getInteger(R.styleable.EmojiTextInputView_maxTextLines, 0);
+		a.recycle();
+
+		// apply attributes to editText
+		editText = findViewById(R.id.input_text);
+		editText.setPadding(0, 0, paddingEnd, paddingBottom);
+		if (maxLines > 0) editText.setMaxLines(maxLines);
+		editText.setOnClickListener(v -> showSoftKeyboard());
+		editText.addTextChangedListener(this);
+		// support sending with Ctrl+Enter
+		editText.setOnKeyListener((v, keyCode, event) -> {
+			if (listener != null && keyCode == KEYCODE_ENTER &&
+					event.isCtrlPressed()) {
+				listener.onSendEvent();
+				return true;
+			}
+			return false;
+		});
+		emojiToggle = findViewById(R.id.emoji_toggle);
+
+		// stuff we can't do in edit mode goes below
+		if (isInEditMode()) {
+			emojiPopup = null;
+			return;
+		}
+		BriarApplication app =
+				(BriarApplication) context.getApplicationContext();
+		app.getApplicationComponent().inject(this);
+		emojiPopup = EmojiPopup.Builder
+				.fromRootView(this)
+				.setRecentEmoji(recentEmoji)
+				.setOnEmojiPopupShownListener(this::showKeyboardIcon)
+				.setOnEmojiPopupDismissListener(this::showEmojiIcon)
+				.build((EmojiEditText) editText);
+		emojiToggle.setOnClickListener(v -> emojiPopup.toggle());
+	}
+
+	@Override
+	public void beforeTextChanged(CharSequence s, int start, int count,
+			int after) {
+	}
+
+	@Override
+	public void onTextChanged(CharSequence s, int start, int before,
+			int count) {
+		// Need to start at position 0 to change empty
+		if (start != 0 || emptyTextAllowed || listener == null) return;
+		if (s.length() == 0) {
+			if (!isEmpty) {
+				isEmpty = true;
+				listener.onTextIsEmptyChanged(true);
+			}
+		} else if (isEmpty) {
+			isEmpty = false;
+			listener.onTextIsEmptyChanged(false);
+		}
+	}
+
+	@Override
+	public void afterTextChanged(Editable s) {
+	}
+
+	@Override
+	public void setEnabled(boolean enabled) {
+		super.setEnabled(enabled);
+		editText.setEnabled(enabled);
+		emojiToggle.setEnabled(enabled);
+	}
+
+	@Override
+	public void setGravity(int gravity) {
+		editText.setGravity(gravity);
+	}
+
+	@Override
+	public boolean requestFocus(int direction, Rect previouslyFocusedRect) {
+		return editText.requestFocus(direction, previouslyFocusedRect);
+	}
+
+	@Override
+	public void onDetachedFromWindow() {
+		super.onDetachedFromWindow();
+		if (emojiPopup.isShowing()) emojiPopup.dismiss();
+	}
+
+	void setTextInputListener(@Nullable TextInputListener listener) {
+		this.listener = listener;
+	}
+
+	void setAllowEmptyText(boolean emptyTextAllowed) {
+		this.emptyTextAllowed = emptyTextAllowed;
+	}
+
+	void setMaxLength(int maxLength) {
+		this.maxLength = maxLength;
+	}
+
+	void setMaxLines(int maxLines) {
+		editText.setMaxLines(maxLines);
+	}
+
+	/**
+	 * Returns the current text or {@code null},
+	 * if it is empty or only consists of white-spaces.
+	 */
+	@Nullable
+	String getText() {
+		Editable editable = editText.getText();
+		String str = editable == null ? null : editable.toString().trim();
+		if (str == null || str.length() == 0) return null;
+		return str;
+	}
+
+	void clearText() {
+		editText.setText(null);
+	}
+
+	boolean isEmpty() {
+		return getText() == null;
+	}
+
+	boolean isTooLong() {
+		return editText.getText() != null &&
+				utf8IsTooLong(editText.getText().toString().trim(), maxLength);
+	}
+
+	CharSequence getHint() {
+		return editText.getHint();
+	}
+
+	void setHint(@StringRes int res) {
+		setHint(getContext().getString(res));
+	}
+
+	void setHint(CharSequence hint) {
+		editText.setHint(hint);
+	}
+
+	private void showEmojiIcon() {
+		emojiToggle.setImageResource(R.drawable.ic_emoji_toggle);
+	}
+
+	private void showKeyboardIcon() {
+		emojiToggle.setImageResource(R.drawable.ic_keyboard);
+	}
+
+	void showSoftKeyboard() {
+		Object o = getContext().getSystemService(INPUT_METHOD_SERVICE);
+		InputMethodManager imm = (InputMethodManager) requireNonNull(o);
+		imm.showSoftInput(editText, SHOW_IMPLICIT);
+	}
+
+	void hideSoftKeyboard() {
+		if (emojiPopup.isShowing()) emojiPopup.dismiss();
+		IBinder token = editText.getWindowToken();
+		Object o = getContext().getSystemService(INPUT_METHOD_SERVICE);
+		InputMethodManager imm = (InputMethodManager) requireNonNull(o);
+		imm.hideSoftInputFromWindow(token, 0);
+	}
+
+	interface TextInputListener {
+		void onTextIsEmptyChanged(boolean isEmpty);
+		void onSendEvent();
+	}
+
+}

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

@@ -0,0 +1,119 @@
+package org.briarproject.briar.android.view;
+
+import android.content.Context;
+import android.graphics.Bitmap;
+import android.net.Uri;
+import android.support.annotation.Nullable;
+import android.support.constraint.ConstraintLayout;
+import android.support.v7.graphics.Palette;
+import android.util.AttributeSet;
+import android.view.LayoutInflater;
+import android.widget.ImageView;
+import android.widget.Toast;
+
+import com.bumptech.glide.load.DataSource;
+import com.bumptech.glide.load.engine.GlideException;
+import com.bumptech.glide.request.RequestListener;
+import com.bumptech.glide.request.target.Target;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.briar.R;
+import org.briarproject.briar.android.conversation.glide.GlideApp;
+
+import java.util.List;
+
+import static android.content.Context.LAYOUT_INFLATER_SERVICE;
+import static android.graphics.Color.BLACK;
+import static android.graphics.Color.WHITE;
+import static android.support.v7.app.AppCompatDelegate.MODE_NIGHT_YES;
+import static android.support.v7.app.AppCompatDelegate.getDefaultNightMode;
+import static android.widget.Toast.LENGTH_LONG;
+import static com.bumptech.glide.load.engine.DiskCacheStrategy.NONE;
+import static com.bumptech.glide.load.resource.bitmap.DownsampleStrategy.FIT_CENTER;
+import static java.util.Objects.requireNonNull;
+
+@NotNullByDefault
+public class ImagePreview extends ConstraintLayout {
+
+	private final ImageView imageView;
+	private final int backgroundColor =
+			getDefaultNightMode() == MODE_NIGHT_YES ? BLACK : WHITE;
+
+	@Nullable
+	private ImagePreviewListener listener;
+
+	public ImagePreview(Context context) {
+		this(context, null);
+	}
+
+	public ImagePreview(Context context, @Nullable AttributeSet attrs) {
+		this(context, attrs, 0);
+	}
+
+	public ImagePreview(Context context, @Nullable AttributeSet attrs,
+			int defStyleAttr) {
+		super(context, attrs, defStyleAttr);
+
+		// inflate layout
+		LayoutInflater inflater = (LayoutInflater) requireNonNull(
+				context.getSystemService(LAYOUT_INFLATER_SERVICE));
+		inflater.inflate(R.layout.image_preview, this, true);
+
+		// find image view and set background color
+		imageView = findViewById(R.id.imageView);
+		imageView.setBackgroundColor(backgroundColor);
+
+		// set cancel listener
+		findViewById(R.id.imageCancelButton).setOnClickListener(view -> {
+			if (listener != null) listener.onCancel();
+		});
+	}
+
+	void setImagePreviewListener(ImagePreviewListener listener) {
+		this.listener = listener;
+	}
+
+	void showPreview(List<Uri> imageUris) {
+		setVisibility(VISIBLE);
+		GlideApp.with(imageView)
+				.asBitmap()
+				.load(imageUris.get(0))  // TODO show more than the first
+				.diskCacheStrategy(NONE)
+				.downsample(FIT_CENTER)
+				.addListener(new RequestListener<Bitmap>() {
+					@Override
+					public boolean onLoadFailed(@Nullable GlideException e,
+							Object model, Target<Bitmap> target,
+							boolean isFirstResource) {
+						if (listener != null) listener.onCancel();
+						Toast.makeText(imageView.getContext(),
+								R.string.image_attach_error, LENGTH_LONG)
+								.show();
+						return false;
+					}
+
+					@Override
+					public boolean onResourceReady(Bitmap resource,
+							Object model, Target<Bitmap> target,
+							DataSource dataSource, boolean isFirstResource) {
+						Palette.from(resource).generate(
+								ImagePreview.this::onPaletteGenerated);
+						return false;
+					}
+				})
+				.into(imageView);
+	}
+
+	void onPaletteGenerated(@Nullable Palette palette) {
+		if (palette == null) return;
+		int color = getDefaultNightMode() == MODE_NIGHT_YES ?
+				palette.getDarkMutedColor(backgroundColor) :
+				palette.getLightMutedColor(backgroundColor);
+		imageView.setBackgroundColor(color);
+	}
+
+	interface ImagePreviewListener {
+		void onCancel();
+	}
+
+}

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

@@ -1,4 +1,8 @@
-package org.thoughtcrime.securesms.components;
+/*
+  Taken from Signal, licences under GPLv3
+ */
+
+package org.briarproject.briar.android.view;
 
 import android.annotation.TargetApi;
 import android.content.Context;
@@ -24,6 +28,7 @@ import javax.annotation.Nullable;
 import static android.content.Context.WINDOW_SERVICE;
 import static android.view.Surface.ROTATION_270;
 import static android.view.Surface.ROTATION_90;
+import static java.util.Objects.requireNonNull;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 
@@ -38,8 +43,6 @@ public class KeyboardAwareLinearLayout extends LinearLayout {
 			Logger.getLogger(KeyboardAwareLinearLayout.class.getName());
 
 	private final Rect rect = new Rect();
-	private final Set<OnKeyboardHiddenListener> hiddenListeners =
-			new HashSet<>();
 	private final Set<OnKeyboardShownListener> shownListeners = new HashSet<>();
 	private final int minKeyboardSize;
 	private final int minCustomKeyboardSize;
@@ -153,7 +156,6 @@ public class KeyboardAwareLinearLayout extends LinearLayout {
 	protected void onKeyboardClose() {
 		LOG.info("onKeyboardClose()");
 		keyboardOpen = false;
-		notifyHiddenListeners();
 	}
 
 	public boolean isKeyboardOpen() {
@@ -173,7 +175,7 @@ public class KeyboardAwareLinearLayout extends LinearLayout {
 	private int getDeviceRotation() {
 		WindowManager windowManager =
 				(WindowManager) getContext().getSystemService(WINDOW_SERVICE);
-		return windowManager.getDefaultDisplay().getRotation();
+		return requireNonNull(windowManager).getDefaultDisplay().getRotation();
 	}
 
 	private int getKeyboardLandscapeHeight() {
@@ -199,43 +201,6 @@ public class KeyboardAwareLinearLayout extends LinearLayout {
 		prefs.edit().putInt("keyboard_height_portrait", height).apply();
 	}
 
-	public void postOnKeyboardClose(Runnable runnable) {
-		if (keyboardOpen) {
-			addOnKeyboardHiddenListener(new OnKeyboardHiddenListener() {
-				@Override
-				public void onKeyboardHidden() {
-					removeOnKeyboardHiddenListener(this);
-					runnable.run();
-				}
-			});
-		} else {
-			runnable.run();
-		}
-	}
-
-	public void postOnKeyboardOpen(Runnable runnable) {
-		if (!keyboardOpen) {
-			addOnKeyboardShownListener(new OnKeyboardShownListener() {
-				@Override
-				public void onKeyboardShown() {
-					removeOnKeyboardShownListener(this);
-					runnable.run();
-				}
-			});
-		} else {
-			runnable.run();
-		}
-	}
-
-	public void addOnKeyboardHiddenListener(OnKeyboardHiddenListener listener) {
-		hiddenListeners.add(listener);
-	}
-
-	public void removeOnKeyboardHiddenListener(
-			OnKeyboardHiddenListener listener) {
-		hiddenListeners.remove(listener);
-	}
-
 	public void addOnKeyboardShownListener(OnKeyboardShownListener listener) {
 		shownListeners.add(listener);
 	}
@@ -245,15 +210,6 @@ public class KeyboardAwareLinearLayout extends LinearLayout {
 		shownListeners.remove(listener);
 	}
 
-	private void notifyHiddenListeners() {
-		// Make a copy as listeners may remove themselves when called
-		Set<OnKeyboardHiddenListener> listeners =
-				new HashSet<>(hiddenListeners);
-		for (OnKeyboardHiddenListener listener : listeners) {
-			listener.onKeyboardHidden();
-		}
-	}
-
 	private void notifyShownListeners() {
 		// Make a copy as listeners may remove themselves when called
 		Set<OnKeyboardShownListener> listeners = new HashSet<>(shownListeners);
@@ -262,11 +218,8 @@ public class KeyboardAwareLinearLayout extends LinearLayout {
 		}
 	}
 
-	public interface OnKeyboardHiddenListener {
-		void onKeyboardHidden();
-	}
-
 	public interface OnKeyboardShownListener {
 		void onKeyboardShown();
 	}
+
 }

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

@@ -4,7 +4,6 @@ import android.content.Context;
 import android.content.res.TypedArray;
 import android.support.annotation.UiThread;
 import android.util.AttributeSet;
-import android.view.LayoutInflater;
 import android.view.ViewGroup;
 import android.widget.Button;
 
@@ -14,6 +13,7 @@ import org.briarproject.briar.R;
 
 import javax.annotation.Nullable;
 
+import static android.view.Gravity.BOTTOM;
 import static android.view.ViewGroup.LayoutParams.MATCH_PARENT;
 
 @UiThread
@@ -32,18 +32,6 @@ public class LargeTextInputView extends TextInputView {
 	public LargeTextInputView(Context context, @Nullable AttributeSet attrs,
 			int defStyleAttr) {
 		super(context, attrs, defStyleAttr);
-	}
-
-	@Override
-	protected void inflateLayout(Context context) {
-		LayoutInflater inflater = (LayoutInflater) context
-				.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
-		inflater.inflate(R.layout.text_input_view_large, this, true);
-	}
-
-	@Override
-	protected void setUpViews(Context context, @Nullable AttributeSet attrs) {
-		super.setUpViews(context, attrs);
 
 		// get attributes
 		TypedArray attributes = context.obtainStyledAttributes(attrs,
@@ -57,21 +45,27 @@ public class LargeTextInputView extends TextInputView {
 		attributes.recycle();
 
 		if (buttonText != null) setButtonText(buttonText);
-		if (maxLines > 0) editText.setMaxLines(maxLines);
+		if (maxLines > 0) textInput.setMaxLines(maxLines);
 		if (fillHeight) {
 			ViewGroup layout = findViewById(R.id.input_layout);
 			LayoutParams params = (LayoutParams) layout.getLayoutParams();
 			params.height = 0;
 			params.weight = 1;
 			layout.setLayoutParams(params);
-			ViewGroup.LayoutParams editParams = editText.getLayoutParams();
-			editParams.height = MATCH_PARENT;
-			editText.setLayoutParams(editParams);
+			ViewGroup.LayoutParams inputParams = textInput.getLayoutParams();
+			inputParams.height = MATCH_PARENT;
+			textInput.setLayoutParams(inputParams);
 		}
+		textInput.setGravity(BOTTOM);
+	}
+
+	@Override
+	protected int getLayout() {
+		return R.layout.text_input_view_large;
 	}
 
 	public void setButtonText(String text) {
-		((Button) sendButton).setText(text);
+		((Button) findViewById(R.id.btn_send)).setText(text);
 	}
 
 }

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

@@ -0,0 +1,161 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2015 XiNGRZ <xxx@oxo.ooo>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package org.briarproject.briar.android.view;
+
+import android.content.Context;
+import android.support.annotation.Nullable;
+import android.support.v4.view.ViewCompat;
+import android.support.v4.widget.ViewDragHelper;
+import android.util.AttributeSet;
+import android.view.MotionEvent;
+import android.view.View;
+import android.view.ViewConfiguration;
+import android.widget.FrameLayout;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+@NotNullByDefault
+public class PullDownLayout extends FrameLayout {
+
+	private final ViewDragHelper dragger;
+
+	private final int minimumFlingVelocity;
+
+	@Nullable
+	private Callback callback;
+
+	public PullDownLayout(Context context) {
+		this(context, null);
+	}
+
+	public PullDownLayout(Context context, @Nullable AttributeSet attrs) {
+		this(context, attrs, 0);
+	}
+
+	public PullDownLayout(Context context, @Nullable AttributeSet attrs,
+			int defStyleAttr) {
+		super(context, attrs, defStyleAttr);
+		dragger = ViewDragHelper.create(this, 1f / 8f, new ViewDragCallback());
+		minimumFlingVelocity =
+				ViewConfiguration.get(context).getScaledMinimumFlingVelocity();
+	}
+
+	public void setCallback(@Nullable Callback callback) {
+		this.callback = callback;
+	}
+
+	@Override
+	public boolean onInterceptTouchEvent(MotionEvent ev) {
+		return dragger.shouldInterceptTouchEvent(ev);
+	}
+
+	@Override
+	public boolean onTouchEvent(MotionEvent event) {
+		dragger.processTouchEvent(event);
+		return true;
+	}
+
+	@Override
+	public void computeScroll() {
+		if (dragger.continueSettling(true)) {
+			ViewCompat.postInvalidateOnAnimation(this);
+		}
+	}
+
+	public interface Callback {
+
+		void onPullStart();
+
+		void onPull(float progress);
+
+		void onPullCancel();
+
+		void onPullComplete();
+
+	}
+
+	private class ViewDragCallback extends ViewDragHelper.Callback {
+
+		@Override
+		public boolean tryCaptureView(View child, int pointerId) {
+			return true;
+		}
+
+		@Override
+		public int clampViewPositionHorizontal(View child, int left, int dx) {
+			return 0;
+		}
+
+		@Override
+		public int clampViewPositionVertical(View child, int top, int dy) {
+			return Math.max(0, top);
+		}
+
+		@Override
+		public int getViewHorizontalDragRange(View child) {
+			return 0;
+		}
+
+		@Override
+		public int getViewVerticalDragRange(View child) {
+			return getHeight();
+		}
+
+		@Override
+		public void onViewCaptured(View capturedChild, int activePointerId) {
+			if (callback != null) {
+				callback.onPullStart();
+			}
+		}
+
+		@Override
+		public void onViewPositionChanged(View changedView, int left, int top,
+				int dx, int dy) {
+			if (callback != null) {
+				callback.onPull((float) top / (float) getHeight());
+			}
+		}
+
+		@Override
+		public void onViewReleased(View releasedChild, float xvel, float yvel) {
+			int slop = yvel > minimumFlingVelocity ? getHeight() / 6 :
+					getHeight() / 3;
+			if (releasedChild.getTop() > slop) {
+				if (callback != null) {
+					callback.onPullComplete();
+				}
+			} else {
+				if (callback != null) {
+					callback.onPullCancel();
+				}
+
+				dragger.settleCapturedViewAt(0, 0);
+				invalidate();
+			}
+		}
+
+	}
+
+}

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

@@ -0,0 +1,214 @@
+package org.briarproject.briar.android.view;
+
+import android.content.ClipData;
+import android.content.Intent;
+import android.net.Uri;
+import android.os.Parcel;
+import android.os.Parcelable;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.support.annotation.UiThread;
+import android.support.v4.view.AbsSavedState;
+import android.support.v7.widget.AppCompatImageButton;
+
+import org.briarproject.briar.R;
+import org.briarproject.briar.android.view.ImagePreview.ImagePreviewListener;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import static android.content.Intent.ACTION_GET_CONTENT;
+import static android.content.Intent.ACTION_OPEN_DOCUMENT;
+import static android.content.Intent.CATEGORY_OPENABLE;
+import static android.content.Intent.EXTRA_ALLOW_MULTIPLE;
+import static android.os.Build.VERSION.SDK_INT;
+import static android.support.v4.view.AbsSavedState.EMPTY_STATE;
+import static android.view.View.GONE;
+import static android.view.View.INVISIBLE;
+import static android.view.View.VISIBLE;
+import static java.util.Collections.emptyList;
+import static java.util.Collections.singletonList;
+import static java.util.Objects.requireNonNull;
+
+@UiThread
+public class TextAttachmentController extends TextSendController
+		implements ImagePreviewListener {
+
+	private final AppCompatImageButton imageButton;
+	private final ImagePreview imagePreview;
+
+	private final AttachImageListener imageListener;
+
+	private CharSequence textHint;
+	private List<Uri> imageUris = emptyList();
+
+	public TextAttachmentController(TextInputView v, ImagePreview imagePreview,
+			SendListener listener, AttachImageListener imageListener) {
+		super(v, listener, false);
+		this.imageListener = imageListener;
+		this.imagePreview = imagePreview;
+		this.imagePreview.setImagePreviewListener(this);
+
+		imageButton = v.findViewById(R.id.imageButton);
+		imageButton.setOnClickListener(view -> onImageButtonClicked());
+
+		textHint = textInput.getHint();
+
+		// show image button
+		showImageButton(true);
+	}
+
+	@Override
+	public void onTextIsEmptyChanged(boolean isEmpty) {
+		if (imageUris.isEmpty()) showImageButton(isEmpty);
+	}
+
+	@Override
+	public void onSendEvent() {
+		if (canSend()) {
+			listener.onSendClick(textInput.getText(), imageUris);
+			reset();
+		}
+	}
+
+	@Override
+	protected boolean canSendEmptyText() {
+		return !imageUris.isEmpty();
+	}
+
+	private void onImageButtonClicked() {
+		Intent intent = new Intent(SDK_INT >= 19 ?
+				ACTION_OPEN_DOCUMENT : ACTION_GET_CONTENT);
+		intent.addCategory(CATEGORY_OPENABLE);
+		intent.setType("image/*");
+		if (SDK_INT >= 18)  // TODO set true to allow attaching multiple images
+			intent.putExtra(EXTRA_ALLOW_MULTIPLE, false);
+		requireNonNull(imageListener).onAttachImage(intent);
+	}
+
+	public void onImageReceived(@Nullable Intent resultData) {
+		if (resultData == null) return;
+		if (resultData.getData() != null) {
+			imageUris = singletonList(resultData.getData());
+			onNewUris();
+		} else if (SDK_INT >= 18 && resultData.getClipData() != null) {
+			ClipData clipData = resultData.getClipData();
+			imageUris = new ArrayList<>(clipData.getItemCount());
+			for (int i = 0; i < clipData.getItemCount(); i++) {
+				imageUris.add(clipData.getItemAt(i).getUri());
+			}
+			onNewUris();
+		}
+	}
+
+	private void onNewUris() {
+		if (imageUris.isEmpty()) return;
+		showImageButton(false);
+		textInput.setHint(R.string.image_caption_hint);
+		imagePreview.showPreview(imageUris);
+	}
+
+	private void showImageButton(boolean showImageButton) {
+		if (showImageButton) {
+			imageButton.setVisibility(VISIBLE);
+			sendButton.setEnabled(false);
+			if (SDK_INT <= 15) {
+				sendButton.setVisibility(INVISIBLE);
+				imageButton.setEnabled(true);
+			} else {
+				sendButton.clearAnimation();
+				sendButton.animate().alpha(0f).withEndAction(() -> {
+					sendButton.setVisibility(INVISIBLE);
+					imageButton.setEnabled(true);
+				}).start();
+				imageButton.clearAnimation();
+				imageButton.animate().alpha(1f).start();
+			}
+		} else {
+			sendButton.setVisibility(VISIBLE);
+			// enable/disable buttons right away to allow fast sending
+			sendButton.setEnabled(enabled);
+			imageButton.setEnabled(false);
+			if (SDK_INT <= 15) {
+				imageButton.setVisibility(INVISIBLE);
+			} else {
+				sendButton.clearAnimation();
+				sendButton.animate().alpha(1f).start();
+				imageButton.clearAnimation();
+				imageButton.animate().alpha(0f).withEndAction(() ->
+						imageButton.setVisibility(INVISIBLE)
+				).start();
+			}
+		}
+	}
+
+	private void reset() {
+		// restore hint
+		textInput.setHint(textHint);
+		// hide image layout
+		imagePreview.setVisibility(GONE);
+		// reset image URIs
+		imageUris = emptyList();
+		// show the image button again, so images can get attached
+		showImageButton(true);
+	}
+
+	@Override
+	public Parcelable onSaveInstanceState(@Nullable Parcelable superState) {
+		SavedState state =
+				new SavedState(superState == null ? EMPTY_STATE : superState);
+		state.imageUris = imageUris;
+		return state;
+	}
+
+	@Override
+	@Nullable
+	public Parcelable onRestoreInstanceState(@NonNull Parcelable inState) {
+		SavedState state = (SavedState) inState;
+		imageUris = state.imageUris;
+		onNewUris();
+		return state.getSuperState();
+	}
+
+	@Override
+	public void onCancel() {
+		textInput.clearText();
+		reset();
+	}
+
+	private static class SavedState extends AbsSavedState {
+		private List<Uri> imageUris;
+
+		private SavedState(Parcelable superState) {
+			super(superState);
+		}
+
+		private SavedState(Parcel in) {
+			super(in);
+			//noinspection unchecked
+			imageUris = in.readArrayList(Uri.class.getClassLoader());
+		}
+
+		@Override
+		public void writeToParcel(Parcel out, int flags) {
+			super.writeToParcel(out, flags);
+			out.writeList(imageUris);
+		}
+
+		public static final Parcelable.Creator<SavedState> CREATOR
+				= new Parcelable.Creator<SavedState>() {
+			public SavedState createFromParcel(Parcel in) {
+				return new SavedState(in);
+			}
+
+			public SavedState[] newArray(int size) {
+				return new SavedState[size];
+			}
+		};
+	}
+
+	public interface AttachImageListener {
+		void onAttachImage(Intent intent);
+	}
+
+}

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

@@ -4,51 +4,31 @@ import android.animation.LayoutTransition;
 import android.content.Context;
 import android.content.res.TypedArray;
 import android.graphics.Rect;
-import android.os.IBinder;
-import android.support.annotation.CallSuper;
+import android.os.Parcelable;
+import android.support.annotation.LayoutRes;
+import android.support.annotation.Nullable;
 import android.support.annotation.StringRes;
 import android.support.annotation.UiThread;
-import android.support.v7.widget.AppCompatImageButton;
-import android.text.Editable;
-import android.text.TextWatcher;
 import android.util.AttributeSet;
 import android.view.LayoutInflater;
-import android.view.View;
-import android.view.inputmethod.InputMethodManager;
-
-import com.vanniktech.emoji.EmojiEditText;
-import com.vanniktech.emoji.EmojiPopup;
-import com.vanniktech.emoji.RecentEmoji;
+import android.widget.LinearLayout;
 
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.briar.R;
-import org.briarproject.briar.android.BriarApplication;
-import org.thoughtcrime.securesms.components.KeyboardAwareLinearLayout;
+import org.briarproject.briar.android.view.KeyboardAwareLinearLayout.OnKeyboardShownListener;
 
-import javax.annotation.Nullable;
-import javax.inject.Inject;
-
-import static android.content.Context.INPUT_METHOD_SERVICE;
 import static android.content.Context.LAYOUT_INFLATER_SERVICE;
-import static android.view.KeyEvent.KEYCODE_ENTER;
-import static android.view.inputmethod.InputMethodManager.SHOW_IMPLICIT;
+import static java.util.Objects.requireNonNull;
 
 @UiThread
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
-public class TextInputView extends KeyboardAwareLinearLayout {
-
-	@Inject
-	RecentEmoji recentEmoji;
+public class TextInputView extends LinearLayout {
 
 	@Nullable
-	TextInputListener listener;
-
-	AppCompatImageButton emojiToggle;
-	EmojiEditText editText;
-	EmojiPopup emojiPopup;
-	View sendButton;
+	TextSendController textSendController;
+	final EmojiTextInputView textInput;
 
 	public TextInputView(Context context) {
 		this(context, null);
@@ -61,118 +41,109 @@ public class TextInputView extends KeyboardAwareLinearLayout {
 	public TextInputView(Context context, @Nullable AttributeSet attrs,
 			int defStyleAttr) {
 		super(context, attrs, defStyleAttr);
-		if (!isInEditMode()) {
-			BriarApplication app =
-					(BriarApplication) context.getApplicationContext();
-			app.getApplicationComponent().inject(this);
-		}
+		setSaveEnabled(true);
 		setOrientation(VERTICAL);
 		setLayoutTransition(new LayoutTransition());
-		inflateLayout(context);
-		setUpViews(context, attrs);
-	}
 
-	protected void inflateLayout(Context context) {
-		LayoutInflater inflater = (LayoutInflater) context
-				.getSystemService(LAYOUT_INFLATER_SERVICE);
-		inflater.inflate(R.layout.text_input_view, this, true);
-	}
-
-	@CallSuper
-	protected void setUpViews(Context context, @Nullable AttributeSet attrs) {
-		emojiToggle = findViewById(R.id.emoji_toggle);
-		editText = findViewById(R.id.input_text);
-		emojiPopup = EmojiPopup.Builder
-				.fromRootView(this)
-				.setRecentEmoji(recentEmoji)
-				.setOnEmojiPopupShownListener(this::showKeyboardIcon)
-				.setOnEmojiPopupDismissListener(this::showEmojiIcon)
-				.build(editText);
-		sendButton = findViewById(R.id.btn_send);
+		// inflate layout
+		LayoutInflater inflater = (LayoutInflater) requireNonNull(
+				context.getSystemService(LAYOUT_INFLATER_SERVICE));
+		inflater.inflate(getLayout(), this, true);
 
 		// get attributes
 		TypedArray attributes = context.obtainStyledAttributes(attrs,
 				R.styleable.TextInputView);
 		String hint = attributes.getString(R.styleable.TextInputView_hint);
+		boolean allowEmptyText = attributes
+				.getBoolean(R.styleable.TextInputView_allowEmptyText, false);
 		attributes.recycle();
 
-		if (hint != null) editText.setHint(hint);
-
-		emojiToggle.setOnClickListener(v -> emojiPopup.toggle());
-		editText.setOnClickListener(v -> showSoftKeyboard());
-		editText.setOnKeyListener((v, keyCode, event) -> {
-			if (keyCode == KEYCODE_ENTER && event.isCtrlPressed()) {
-				trySendMessage();
-				return true;
-			}
-			return false;
-		});
-		sendButton.setOnClickListener(v -> trySendMessage());
+		textInput = findViewById(R.id.emojiTextInput);
+		textInput.setAllowEmptyText(allowEmptyText);
+		if (hint != null) textInput.setHint(hint);
 	}
 
-	private void showEmojiIcon() {
-		emojiToggle.setImageResource(R.drawable.ic_emoji_toggle);
+	@LayoutRes
+	protected int getLayout() {
+		return R.layout.text_input_view;
 	}
 
-	private void showKeyboardIcon() {
-		emojiToggle.setImageResource(R.drawable.ic_keyboard);
-	}
-
-	private void trySendMessage() {
-		if (listener != null) {
-			listener.onSendClick(editText.getText().toString());
+	@Nullable
+	@Override
+	protected Parcelable onSaveInstanceState() {
+		Parcelable superState = super.onSaveInstanceState();
+		if (textSendController != null) {
+			superState = textSendController.onSaveInstanceState(superState);
 		}
+		return superState;
+	}
+
+	@Override
+	protected void onRestoreInstanceState(Parcelable state) {
+		if (textSendController != null) {
+			Parcelable outState =
+					textSendController.onRestoreInstanceState(state);
+			super.onRestoreInstanceState(outState);
+		} else {
+			super.onRestoreInstanceState(state);
+		}
+	}
+
+	/**
+	 * Call this in onCreate() before any other methods of this class.
+	 */
+	public <T extends TextSendController> void setSendController(T controller) {
+		textSendController = controller;
+		textInput.setTextInputListener(textSendController);
+	}
+
+	@Override
+	public void setEnabled(boolean enabled) {
+		super.setEnabled(enabled);
+		textInput.setEnabled(enabled);
+		requireNonNull(textSendController).setEnabled(enabled);
 	}
 
 	@Override
 	public boolean requestFocus(int direction, Rect previouslyFocusedRect) {
-		return editText.requestFocus(direction, previouslyFocusedRect);
+		return textInput.requestFocus(direction, previouslyFocusedRect);
 	}
 
-	@Override
-	public void onDetachedFromWindow() {
-		super.onDetachedFromWindow();
-		if (emojiPopup.isShowing()) emojiPopup.dismiss();
+	EmojiTextInputView getEmojiTextInputView() {
+		return textInput;
 	}
 
-	public void setText(String text) {
-		editText.setText(text);
-	}
-
-	public Editable getText() {
-		return editText.getText();
+	public void clearText() {
+		textInput.clearText();
 	}
 
 	public void setHint(@StringRes int res) {
-		editText.setHint(res);
+		textInput.setHint(getContext().getString(res));
 	}
 
-	public void setSendButtonEnabled(boolean enabled) {
-		sendButton.setEnabled(enabled);
+	public void setMaxTextLength(int maxLength) {
+		textInput.setMaxLength(maxLength);
 	}
 
-	public void addTextChangedListener(TextWatcher watcher) {
-		editText.addTextChangedListener(watcher);
-	}
-
-	public void setListener(TextInputListener listener) {
-		this.listener = listener;
+	public boolean isKeyboardOpen() {
+		return textInput.isKeyboardOpen();
 	}
 
 	public void showSoftKeyboard() {
-		Object o = getContext().getSystemService(INPUT_METHOD_SERVICE);
-		((InputMethodManager) o).showSoftInput(editText, SHOW_IMPLICIT);
+		textInput.showSoftKeyboard();
 	}
 
 	public void hideSoftKeyboard() {
-		if (emojiPopup.isShowing()) emojiPopup.dismiss();
-		IBinder token = editText.getWindowToken();
-		Object o = getContext().getSystemService(INPUT_METHOD_SERVICE);
-		((InputMethodManager) o).hideSoftInputFromWindow(token, 0);
+		textInput.hideSoftKeyboard();
 	}
 
-	public interface TextInputListener {
-		void onSendClick(String text);
+	public void addOnKeyboardShownListener(OnKeyboardShownListener listener) {
+		textInput.addOnKeyboardShownListener(listener);
+	}
+
+	public void removeOnKeyboardShownListener(
+			OnKeyboardShownListener listener) {
+		textInput.removeOnKeyboardShownListener(listener);
 	}
 
 }

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

@@ -0,0 +1,88 @@
+package org.briarproject.briar.android.view;
+
+import android.net.Uri;
+import android.os.Parcelable;
+import android.support.annotation.CallSuper;
+import android.support.annotation.Nullable;
+import android.support.annotation.UiThread;
+import android.support.design.widget.Snackbar;
+import android.view.View;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.briar.R;
+import org.briarproject.briar.android.view.EmojiTextInputView.TextInputListener;
+
+import java.util.List;
+
+import static android.support.design.widget.Snackbar.LENGTH_SHORT;
+import static java.util.Collections.emptyList;
+
+@UiThread
+@NotNullByDefault
+public class TextSendController implements TextInputListener {
+
+	protected final EmojiTextInputView textInput;
+	protected final View sendButton;
+	protected final SendListener listener;
+	protected boolean enabled = true;
+	protected final boolean allowEmptyText;
+
+	private boolean wasEmpty = true;
+
+	public TextSendController(TextInputView v, SendListener listener,
+			boolean allowEmptyText) {
+		this.sendButton = v.findViewById(R.id.btn_send);
+		this.sendButton.setOnClickListener(view -> onSendEvent());
+		this.sendButton.setEnabled(allowEmptyText);
+		this.listener = listener;
+		this.textInput = v.getEmojiTextInputView();
+		this.allowEmptyText = allowEmptyText;
+	}
+
+	@Override
+	public void onTextIsEmptyChanged(boolean isEmpty) {
+		sendButton.setEnabled(enabled && (!isEmpty || canSendEmptyText()));
+		wasEmpty = isEmpty;
+	}
+
+	@Override
+	public void onSendEvent() {
+		if (canSend()) {
+			listener.onSendClick(textInput.getText(), emptyList());
+		}
+	}
+
+	protected final boolean canSend() {
+		if (textInput.isTooLong()) {
+			Snackbar.make(sendButton, R.string.text_too_long, LENGTH_SHORT)
+					.show();
+			return false;
+		}
+		return enabled && (canSendEmptyText() || !textInput.isEmpty());
+	}
+
+	protected boolean canSendEmptyText() {
+		return allowEmptyText;
+	}
+
+	@Nullable
+	public Parcelable onSaveInstanceState(@Nullable Parcelable superState) {
+		return superState;
+	}
+
+	@Nullable
+	public Parcelable onRestoreInstanceState(Parcelable state) {
+		return state;
+	}
+
+	@CallSuper
+	public void setEnabled(boolean enabled) {
+		sendButton.setEnabled(enabled && (!wasEmpty || canSendEmptyText()));
+		this.enabled = enabled;
+	}
+
+	public interface SendListener {
+		void onSendClick(@Nullable String text, List<Uri> imageUris);
+	}
+
+}

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

@@ -4,6 +4,7 @@ import android.arch.lifecycle.ViewModel;
 import android.arch.lifecycle.ViewModelProvider;
 
 import org.briarproject.briar.android.conversation.ConversationViewModel;
+import org.briarproject.briar.android.conversation.ImageViewModel;
 
 import javax.inject.Singleton;
 
@@ -20,6 +21,12 @@ public abstract class ViewModelModule {
 	abstract ViewModel bindConversationViewModel(
 			ConversationViewModel conversationViewModel);
 
+	@Binds
+	@IntoMap
+	@ViewModelKey(ImageViewModel.class)
+	abstract ViewModel bindImageViewModel(
+			ImageViewModel imageViewModel);
+
 	@Binds
 	@Singleton
 	abstract ViewModelProvider.Factory bindViewModelFactory(

briar-android/src/main/java/org/thoughtcrime/securesms/LICENSE

@@ -1,621 +0,0 @@
-                    GNU GENERAL PUBLIC LICENSE
-                       Version 3, 29 June 2007
-
- Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
- Everyone is permitted to copy and distribute verbatim copies
- of this license document, but changing it is not allowed.
-
-                            Preamble
-
-  The GNU General Public License is a free, copyleft license for
-software and other kinds of works.
-
-  The licenses for most software and other practical works are designed
-to take away your freedom to share and change the works.  By contrast,
-the GNU General Public License is intended to guarantee your freedom to
-share and change all versions of a program--to make sure it remains free
-software for all its users.  We, the Free Software Foundation, use the
-GNU General Public License for most of our software; it applies also to
-any other work released this way by its authors.  You can apply it to
-your programs, too.
-
-  When we speak of free software, we are referring to freedom, not
-price.  Our General Public Licenses are designed to make sure that you
-have the freedom to distribute copies of free software (and charge for
-them if you wish), that you receive source code or can get it if you
-want it, that you can change the software or use pieces of it in new
-free programs, and that you know you can do these things.
-
-  To protect your rights, we need to prevent others from denying you
-these rights or asking you to surrender the rights.  Therefore, you have
-certain responsibilities if you distribute copies of the software, or if
-you modify it: responsibilities to respect the freedom of others.
-
-  For example, if you distribute copies of such a program, whether
-gratis or for a fee, you must pass on to the recipients the same
-freedoms that you received.  You must make sure that they, too, receive
-or can get the source code.  And you must show them these terms so they
-know their rights.
-
-  Developers that use the GNU GPL protect your rights with two steps:
-(1) assert copyright on the software, and (2) offer you this License
-giving you legal permission to copy, distribute and/or modify it.
-
-  For the developers' and authors' protection, the GPL clearly explains
-that there is no warranty for this free software.  For both users' and
-authors' sake, the GPL requires that modified versions be marked as
-changed, so that their problems will not be attributed erroneously to
-authors of previous versions.
-
-  Some devices are designed to deny users access to install or run
-modified versions of the software inside them, although the manufacturer
-can do so.  This is fundamentally incompatible with the aim of
-protecting users' freedom to change the software.  The systematic
-pattern of such abuse occurs in the area of products for individuals to
-use, which is precisely where it is most unacceptable.  Therefore, we
-have designed this version of the GPL to prohibit the practice for those
-products.  If such problems arise substantially in other domains, we
-stand ready to extend this provision to those domains in future versions
-of the GPL, as needed to protect the freedom of users.
-
-  Finally, every program is threatened constantly by software patents.
-States should not allow patents to restrict development and use of
-software on general-purpose computers, but in those that do, we wish to
-avoid the special danger that patents applied to a free program could
-make it effectively proprietary.  To prevent this, the GPL assures that
-patents cannot be used to render the program non-free.
-
-  The precise terms and conditions for copying, distribution and
-modification follow.
-
-                       TERMS AND CONDITIONS
-
-  0. Definitions.
-
-  "This License" refers to version 3 of the GNU General Public License.
-
-  "Copyright" also means copyright-like laws that apply to other kinds of
-works, such as semiconductor masks.
-
-  "The Program" refers to any copyrightable work licensed under this
-License.  Each licensee is addressed as "you".  "Licensees" and
-"recipients" may be individuals or organizations.
-
-  To "modify" a work means to copy from or adapt all or part of the work
-in a fashion requiring copyright permission, other than the making of an
-exact copy.  The resulting work is called a "modified version" of the
-earlier work or a work "based on" the earlier work.
-
-  A "covered work" means either the unmodified Program or a work based
-on the Program.
-
-  To "propagate" a work means to do anything with it that, without
-permission, would make you directly or secondarily liable for
-infringement under applicable copyright law, except executing it on a
-computer or modifying a private copy.  Propagation includes copying,
-distribution (with or without modification), making available to the
-public, and in some countries other activities as well.
-
-  To "convey" a work means any kind of propagation that enables other
-parties to make or receive copies.  Mere interaction with a user through
-a computer network, with no transfer of a copy, is not conveying.
-
-  An interactive user interface displays "Appropriate Legal Notices"
-to the extent that it includes a convenient and prominently visible
-feature that (1) displays an appropriate copyright notice, and (2)
-tells the user that there is no warranty for the work (except to the
-extent that warranties are provided), that licensees may convey the
-work under this License, and how to view a copy of this License.  If
-the interface presents a list of user commands or options, such as a
-menu, a prominent item in the list meets this criterion.
-
-  1. Source Code.
-
-  The "source code" for a work means the preferred form of the work
-for making modifications to it.  "Object code" means any non-source
-form of a work.
-
-  A "Standard Interface" means an interface that either is an official
-standard defined by a recognized standards body, or, in the case of
-interfaces specified for a particular programming language, one that
-is widely used among developers working in that language.
-
-  The "System Libraries" of an executable work include anything, other
-than the work as a whole, that (a) is included in the normal form of
-packaging a Major Component, but which is not part of that Major
-Component, and (b) serves only to enable use of the work with that
-Major Component, or to implement a Standard Interface for which an
-implementation is available to the public in source code form.  A
-"Major Component", in this context, means a major essential component
-(kernel, window system, and so on) of the specific operating system
-(if any) on which the executable work runs, or a compiler used to
-produce the work, or an object code interpreter used to run it.
-
-  The "Corresponding Source" for a work in object code form means all
-the source code needed to generate, install, and (for an executable
-work) run the object code and to modify the work, including scripts to
-control those activities.  However, it does not include the work's
-System Libraries, or general-purpose tools or generally available free
-programs which are used unmodified in performing those activities but
-which are not part of the work.  For example, Corresponding Source
-includes interface definition files associated with source files for
-the work, and the source code for shared libraries and dynamically
-linked subprograms that the work is specifically designed to require,
-such as by intimate data communication or control flow between those
-subprograms and other parts of the work.
-
-  The Corresponding Source need not include anything that users
-can regenerate automatically from other parts of the Corresponding
-Source.
-
-  The Corresponding Source for a work in source code form is that
-same work.
-
-  2. Basic Permissions.
-
-  All rights granted under this License are granted for the term of
-copyright on the Program, and are irrevocable provided the stated
-conditions are met.  This License explicitly affirms your unlimited
-permission to run the unmodified Program.  The output from running a
-covered work is covered by this License only if the output, given its
-content, constitutes a covered work.  This License acknowledges your
-rights of fair use or other equivalent, as provided by copyright law.
-
-  You may make, run and propagate covered works that you do not
-convey, without conditions so long as your license otherwise remains
-in force.  You may convey covered works to others for the sole purpose
-of having them make modifications exclusively for you, or provide you
-with facilities for running those works, provided that you comply with
-the terms of this License in conveying all material for which you do
-not control copyright.  Those thus making or running the covered works
-for you must do so exclusively on your behalf, under your direction
-and control, on terms that prohibit them from making any copies of
-your copyrighted material outside their relationship with you.
-
-  Conveying under any other circumstances is permitted solely under
-the conditions stated below.  Sublicensing is not allowed; section 10
-makes it unnecessary.
-
-  3. Protecting Users' Legal Rights From Anti-Circumvention Law.
-
-  No covered work shall be deemed part of an effective technological
-measure under any applicable law fulfilling obligations under article
-11 of the WIPO copyright treaty adopted on 20 December 1996, or
-similar laws prohibiting or restricting circumvention of such
-measures.
-
-  When you convey a covered work, you waive any legal power to forbid
-circumvention of technological measures to the extent such circumvention
-is effected by exercising rights under this License with respect to
-the covered work, and you disclaim any intention to limit operation or
-modification of the work as a means of enforcing, against the work's
-users, your or third parties' legal rights to forbid circumvention of
-technological measures.
-
-  4. Conveying Verbatim Copies.
-
-  You may convey verbatim copies of the Program's source code as you
-receive it, in any medium, provided that you conspicuously and
-appropriately publish on each copy an appropriate copyright notice;
-keep intact all notices stating that this License and any
-non-permissive terms added in accord with section 7 apply to the code;
-keep intact all notices of the absence of any warranty; and give all
-recipients a copy of this License along with the Program.
-
-  You may charge any price or no price for each copy that you convey,
-and you may offer support or warranty protection for a fee.
-
-  5. Conveying Modified Source Versions.
-
-  You may convey a work based on the Program, or the modifications to
-produce it from the Program, in the form of source code under the
-terms of section 4, provided that you also meet all of these conditions:
-
-    a) The work must carry prominent notices stating that you modified
-    it, and giving a relevant date.
-
-    b) The work must carry prominent notices stating that it is
-    released under this License and any conditions added under section
-    7.  This requirement modifies the requirement in section 4 to
-    "keep intact all notices".
-
-    c) You must license the entire work, as a whole, under this
-    License to anyone who comes into possession of a copy.  This
-    License will therefore apply, along with any applicable section 7
-    additional terms, to the whole of the work, and all its parts,
-    regardless of how they are packaged.  This License gives no
-    permission to license the work in any other way, but it does not
-    invalidate such permission if you have separately received it.
-
-    d) If the work has interactive user interfaces, each must display
-    Appropriate Legal Notices; however, if the Program has interactive
-    interfaces that do not display Appropriate Legal Notices, your
-    work need not make them do so.
-
-  A compilation of a covered work with other separate and independent
-works, which are not by their nature extensions of the covered work,
-and which are not combined with it such as to form a larger program,
-in or on a volume of a storage or distribution medium, is called an
-"aggregate" if the compilation and its resulting copyright are not
-used to limit the access or legal rights of the compilation's users
-beyond what the individual works permit.  Inclusion of a covered work
-in an aggregate does not cause this License to apply to the other
-parts of the aggregate.
-
-  6. Conveying Non-Source Forms.
-
-  You may convey a covered work in object code form under the terms
-of sections 4 and 5, provided that you also convey the
-machine-readable Corresponding Source under the terms of this License,
-in one of these ways:
-
-    a) Convey the object code in, or embodied in, a physical product
-    (including a physical distribution medium), accompanied by the
-    Corresponding Source fixed on a durable physical medium
-    customarily used for software interchange.
-
-    b) Convey the object code in, or embodied in, a physical product
-    (including a physical distribution medium), accompanied by a
-    written offer, valid for at least three years and valid for as
-    long as you offer spare parts or customer support for that product
-    model, to give anyone who possesses the object code either (1) a
-    copy of the Corresponding Source for all the software in the
-    product that is covered by this License, on a durable physical
-    medium customarily used for software interchange, for a price no
-    more than your reasonable cost of physically performing this
-    conveying of source, or (2) access to copy the
-    Corresponding Source from a network server at no charge.
-
-    c) Convey individual copies of the object code with a copy of the
-    written offer to provide the Corresponding Source.  This
-    alternative is allowed only occasionally and noncommercially, and
-    only if you received the object code with such an offer, in accord
-    with subsection 6b.
-
-    d) Convey the object code by offering access from a designated
-    place (gratis or for a charge), and offer equivalent access to the
-    Corresponding Source in the same way through the same place at no
-    further charge.  You need not require recipients to copy the
-    Corresponding Source along with the object code.  If the place to
-    copy the object code is a network server, the Corresponding Source
-    may be on a different server (operated by you or a third party)
-    that supports equivalent copying facilities, provided you maintain
-    clear directions next to the object code saying where to find the
-    Corresponding Source.  Regardless of what server hosts the
-    Corresponding Source, you remain obligated to ensure that it is
-    available for as long as needed to satisfy these requirements.
-
-    e) Convey the object code using peer-to-peer transmission, provided
-    you inform other peers where the object code and Corresponding
-    Source of the work are being offered to the general public at no
-    charge under subsection 6d.
-
-  A separable portion of the object code, whose source code is excluded
-from the Corresponding Source as a System Library, need not be
-included in conveying the object code work.
-
-  A "User Product" is either (1) a "consumer product", which means any
-tangible personal property which is normally used for personal, family,
-or household purposes, or (2) anything designed or sold for incorporation
-into a dwelling.  In determining whether a product is a consumer product,
-doubtful cases shall be resolved in favor of coverage.  For a particular
-product received by a particular user, "normally used" refers to a
-typical or common use of that class of product, regardless of the status
-of the particular user or of the way in which the particular user
-actually uses, or expects or is expected to use, the product.  A product
-is a consumer product regardless of whether the product has substantial
-commercial, industrial or non-consumer uses, unless such uses represent
-the only significant mode of use of the product.
-
-  "Installation Information" for a User Product means any methods,
-procedures, authorization keys, or other information required to install
-and execute modified versions of a covered work in that User Product from
-a modified version of its Corresponding Source.  The information must
-suffice to ensure that the continued functioning of the modified object
-code is in no case prevented or interfered with solely because
-modification has been made.
-
-  If you convey an object code work under this section in, or with, or
-specifically for use in, a User Product, and the conveying occurs as
-part of a transaction in which the right of possession and use of the
-User Product is transferred to the recipient in perpetuity or for a
-fixed term (regardless of how the transaction is characterized), the
-Corresponding Source conveyed under this section must be accompanied
-by the Installation Information.  But this requirement does not apply
-if neither you nor any third party retains the ability to install
-modified object code on the User Product (for example, the work has
-been installed in ROM).
-
-  The requirement to provide Installation Information does not include a
-requirement to continue to provide support service, warranty, or updates
-for a work that has been modified or installed by the recipient, or for
-the User Product in which it has been modified or installed.  Access to a
-network may be denied when the modification itself materially and
-adversely affects the operation of the network or violates the rules and
-protocols for communication across the network.
-
-  Corresponding Source conveyed, and Installation Information provided,
-in accord with this section must be in a format that is publicly
-documented (and with an implementation available to the public in
-source code form), and must require no special password or key for
-unpacking, reading or copying.
-
-  7. Additional Terms.
-
-  "Additional permissions" are terms that supplement the terms of this
-License by making exceptions from one or more of its conditions.
-Additional permissions that are applicable to the entire Program shall
-be treated as though they were included in this License, to the extent
-that they are valid under applicable law.  If additional permissions
-apply only to part of the Program, that part may be used separately
-under those permissions, but the entire Program remains governed by
-this License without regard to the additional permissions.
-
-  When you convey a copy of a covered work, you may at your option
-remove any additional permissions from that copy, or from any part of
-it.  (Additional permissions may be written to require their own
-removal in certain cases when you modify the work.)  You may place
-additional permissions on material, added by you to a covered work,
-for which you have or can give appropriate copyright permission.
-
-  Notwithstanding any other provision of this License, for material you
-add to a covered work, you may (if authorized by the copyright holders of
-that material) supplement the terms of this License with terms:
-
-    a) Disclaiming warranty or limiting liability differently from the
-    terms of sections 15 and 16 of this License; or
-
-    b) Requiring preservation of specified reasonable legal notices or
-    author attributions in that material or in the Appropriate Legal
-    Notices displayed by works containing it; or
-
-    c) Prohibiting misrepresentation of the origin of that material, or
-    requiring that modified versions of such material be marked in
-    reasonable ways as different from the original version; or
-
-    d) Limiting the use for publicity purposes of names of licensors or
-    authors of the material; or
-
-    e) Declining to grant rights under trademark law for use of some
-    trade names, trademarks, or service marks; or
-
-    f) Requiring indemnification of licensors and authors of that
-    material by anyone who conveys the material (or modified versions of
-    it) with contractual assumptions of liability to the recipient, for
-    any liability that these contractual assumptions directly impose on
-    those licensors and authors.
-
-  All other non-permissive additional terms are considered "further
-restrictions" within the meaning of section 10.  If the Program as you
-received it, or any part of it, contains a notice stating that it is
-governed by this License along with a term that is a further
-restriction, you may remove that term.  If a license document contains
-a further restriction but permits relicensing or conveying under this
-License, you may add to a covered work material governed by the terms
-of that license document, provided that the further restriction does
-not survive such relicensing or conveying.
-
-  If you add terms to a covered work in accord with this section, you
-must place, in the relevant source files, a statement of the
-additional terms that apply to those files, or a notice indicating
-where to find the applicable terms.
-
-  Additional terms, permissive or non-permissive, may be stated in the
-form of a separately written license, or stated as exceptions;
-the above requirements apply either way.
-
-  8. Termination.
-
-  You may not propagate or modify a covered work except as expressly
-provided under this License.  Any attempt otherwise to propagate or
-modify it is void, and will automatically terminate your rights under
-this License (including any patent licenses granted under the third
-paragraph of section 11).
-
-  However, if you cease all violation of this License, then your
-license from a particular copyright holder is reinstated (a)
-provisionally, unless and until the copyright holder explicitly and
-finally terminates your license, and (b) permanently, if the copyright
-holder fails to notify you of the violation by some reasonable means
-prior to 60 days after the cessation.
-
-  Moreover, your license from a particular copyright holder is
-reinstated permanently if the copyright holder notifies you of the
-violation by some reasonable means, this is the first time you have
-received notice of violation of this License (for any work) from that
-copyright holder, and you cure the violation prior to 30 days after
-your receipt of the notice.
-
-  Termination of your rights under this section does not terminate the
-licenses of parties who have received copies or rights from you under
-this License.  If your rights have been terminated and not permanently
-reinstated, you do not qualify to receive new licenses for the same
-material under section 10.
-
-  9. Acceptance Not Required for Having Copies.
-
-  You are not required to accept this License in order to receive or
-run a copy of the Program.  Ancillary propagation of a covered work
-occurring solely as a consequence of using peer-to-peer transmission
-to receive a copy likewise does not require acceptance.  However,
-nothing other than this License grants you permission to propagate or
-modify any covered work.  These actions infringe copyright if you do
-not accept this License.  Therefore, by modifying or propagating a
-covered work, you indicate your acceptance of this License to do so.
-
-  10. Automatic Licensing of Downstream Recipients.
-
-  Each time you convey a covered work, the recipient automatically
-receives a license from the original licensors, to run, modify and
-propagate that work, subject to this License.  You are not responsible
-for enforcing compliance by third parties with this License.
-
-  An "entity transaction" is a transaction transferring control of an
-organization, or substantially all assets of one, or subdividing an
-organization, or merging organizations.  If propagation of a covered
-work results from an entity transaction, each party to that
-transaction who receives a copy of the work also receives whatever
-licenses to the work the party's predecessor in interest had or could
-give under the previous paragraph, plus a right to possession of the
-Corresponding Source of the work from the predecessor in interest, if
-the predecessor has it or can get it with reasonable efforts.
-
-  You may not impose any further restrictions on the exercise of the
-rights granted or affirmed under this License.  For example, you may
-not impose a license fee, royalty, or other charge for exercise of
-rights granted under this License, and you may not initiate litigation
-(including a cross-claim or counterclaim in a lawsuit) alleging that
-any patent claim is infringed by making, using, selling, offering for
-sale, or importing the Program or any portion of it.
-
-  11. Patents.
-
-  A "contributor" is a copyright holder who authorizes use under this
-License of the Program or a work on which the Program is based.  The
-work thus licensed is called the contributor's "contributor version".
-
-  A contributor's "essential patent claims" are all patent claims
-owned or controlled by the contributor, whether already acquired or
-hereafter acquired, that would be infringed by some manner, permitted
-by this License, of making, using, or selling its contributor version,
-but do not include claims that would be infringed only as a
-consequence of further modification of the contributor version.  For
-purposes of this definition, "control" includes the right to grant
-patent sublicenses in a manner consistent with the requirements of
-this License.
-
-  Each contributor grants you a non-exclusive, worldwide, royalty-free
-patent license under the contributor's essential patent claims, to
-make, use, sell, offer for sale, import and otherwise run, modify and
-propagate the contents of its contributor version.
-
-  In the following three paragraphs, a "patent license" is any express
-agreement or commitment, however denominated, not to enforce a patent
-(such as an express permission to practice a patent or covenant not to
-sue for patent infringement).  To "grant" such a patent license to a
-party means to make such an agreement or commitment not to enforce a
-patent against the party.
-
-  If you convey a covered work, knowingly relying on a patent license,
-and the Corresponding Source of the work is not available for anyone
-to copy, free of charge and under the terms of this License, through a
-publicly available network server or other readily accessible means,
-then you must either (1) cause the Corresponding Source to be so
-available, or (2) arrange to deprive yourself of the benefit of the
-patent license for this particular work, or (3) arrange, in a manner
-consistent with the requirements of this License, to extend the patent
-license to downstream recipients.  "Knowingly relying" means you have
-actual knowledge that, but for the patent license, your conveying the
-covered work in a country, or your recipient's use of the covered work
-in a country, would infringe one or more identifiable patents in that
-country that you have reason to believe are valid.
-
-  If, pursuant to or in connection with a single transaction or
-arrangement, you convey, or propagate by procuring conveyance of, a
-covered work, and grant a patent license to some of the parties
-receiving the covered work authorizing them to use, propagate, modify
-or convey a specific copy of the covered work, then the patent license
-you grant is automatically extended to all recipients of the covered
-work and works based on it.
-
-  A patent license is "discriminatory" if it does not include within
-the scope of its coverage, prohibits the exercise of, or is
-conditioned on the non-exercise of one or more of the rights that are
-specifically granted under this License.  You may not convey a covered
-work if you are a party to an arrangement with a third party that is
-in the business of distributing software, under which you make payment
-to the third party based on the extent of your activity of conveying
-the work, and under which the third party grants, to any of the
-parties who would receive the covered work from you, a discriminatory
-patent license (a) in connection with copies of the covered work
-conveyed by you (or copies made from those copies), or (b) primarily
-for and in connection with specific products or compilations that
-contain the covered work, unless you entered into that arrangement,
-or that patent license was granted, prior to 28 March 2007.
-
-  Nothing in this License shall be construed as excluding or limiting
-any implied license or other defenses to infringement that may
-otherwise be available to you under applicable patent law.
-
-  12. No Surrender of Others' Freedom.
-
-  If conditions are imposed on you (whether by court order, agreement or
-otherwise) that contradict the conditions of this License, they do not
-excuse you from the conditions of this License.  If you cannot convey a
-covered work so as to satisfy simultaneously your obligations under this
-License and any other pertinent obligations, then as a consequence you may
-not convey it at all.  For example, if you agree to terms that obligate you
-to collect a royalty for further conveying from those to whom you convey
-the Program, the only way you could satisfy both those terms and this
-License would be to refrain entirely from conveying the Program.
-
-  13. Use with the GNU Affero General Public License.
-
-  Notwithstanding any other provision of this License, you have
-permission to link or combine any covered work with a work licensed
-under version 3 of the GNU Affero General Public License into a single
-combined work, and to convey the resulting work.  The terms of this
-License will continue to apply to the part which is the covered work,
-but the special requirements of the GNU Affero General Public License,
-section 13, concerning interaction through a network will apply to the
-combination as such.
-
-  14. Revised Versions of this License.
-
-  The Free Software Foundation may publish revised and/or new versions of
-the GNU General Public License from time to time.  Such new versions will
-be similar in spirit to the present version, but may differ in detail to
-address new problems or concerns.
-
-  Each version is given a distinguishing version number.  If the
-Program specifies that a certain numbered version of the GNU General
-Public License "or any later version" applies to it, you have the
-option of following the terms and conditions either of that numbered
-version or of any later version published by the Free Software
-Foundation.  If the Program does not specify a version number of the
-GNU General Public License, you may choose any version ever published
-by the Free Software Foundation.
-
-  If the Program specifies that a proxy can decide which future
-versions of the GNU General Public License can be used, that proxy's
-public statement of acceptance of a version permanently authorizes you
-to choose that version for the Program.
-
-  Later license versions may give you additional or different
-permissions.  However, no additional obligations are imposed on any
-author or copyright holder as a result of your choosing to follow a
-later version.
-
-  15. Disclaimer of Warranty.
-
-  THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
-APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
-HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
-OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
-THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
-PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
-IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
-ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
-
-  16. Limitation of Liability.
-
-  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
-WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
-THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
-GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
-USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
-DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
-PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
-EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
-SUCH DAMAGES.
-
-  17. Interpretation of Sections 15 and 16.
-
-  If the disclaimer of warranty and limitation of liability provided
-above cannot be given local legal effect according to their terms,
-reviewing courts shall apply local law that most closely approximates
-an absolute waiver of all civil liability in connection with the
-Program, unless a warranty or assumption of liability accompanies a
-copy of the Program in return for a fee.
-
-                     END OF TERMS AND CONDITIONS