[android] add real Tor icon

Add method for enabling/disabling plugins to PluginManager

See merge request briar/briar!1214

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

@@ -146,6 +146,12 @@ class AndroidBluetoothPlugin extends BluetoothPlugin<BluetoothServerSocket> {
 		wasEnabledByUs = true;
 	}
 
+	@Override
+	void onAdapterDisabled() {
+		super.onAdapterDisabled();
+		wasEnabledByUs = false;
+	}
+
 	@Override
 	@Nullable
 	String getBluetoothAddress() {

bramble-android/src/main/java/org/briarproject/bramble/plugin/tcp/AndroidLanTcpPlugin.java

@@ -9,11 +9,11 @@ import android.net.wifi.WifiManager;
 
 import org.briarproject.bramble.PoliteExecutor;
 import org.briarproject.bramble.api.event.Event;
-import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.network.event.NetworkStatusEvent;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.PluginCallback;
+import org.briarproject.bramble.api.settings.Settings;
 
 import java.io.IOException;
 import java.net.InetAddress;
@@ -32,10 +32,14 @@ import static android.net.ConnectivityManager.TYPE_WIFI;
 import static android.os.Build.VERSION.SDK_INT;
 import static java.util.Collections.emptyList;
 import static java.util.Collections.singletonList;
+import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.api.plugin.Plugin.State.ACTIVE;
+import static org.briarproject.bramble.api.plugin.Plugin.State.INACTIVE;
+import static org.briarproject.bramble.util.IoUtils.tryToClose;
 
 @NotNullByDefault
-class AndroidLanTcpPlugin extends LanTcpPlugin implements EventListener {
+class AndroidLanTcpPlugin extends LanTcpPlugin {
 
 	private static final Logger LOG =
 			getLogger(AndroidLanTcpPlugin.class.getName());
@@ -79,16 +83,11 @@ class AndroidLanTcpPlugin extends LanTcpPlugin implements EventListener {
 	@Override
 	public void start() {
 		if (used.getAndSet(true)) throw new IllegalStateException();
-		running = true;
+		Settings settings = callback.getSettings();
+		state.setStarted(settings.getBoolean(PREF_PLUGIN_ENABLE, false));
 		updateConnectionStatus();
 	}
 
-	@Override
-	public void stop() {
-		running = false;
-		tryToClose(socket);
-	}
-
 	@Override
 	protected Socket createSocket() throws IOException {
 		return socketFactory.createSocket();
@@ -138,12 +137,14 @@ class AndroidLanTcpPlugin extends LanTcpPlugin implements EventListener {
 
 	@Override
 	public void eventOccurred(Event e) {
+		super.eventOccurred(e);
 		if (e instanceof NetworkStatusEvent) updateConnectionStatus();
 	}
 
 	private void updateConnectionStatus() {
 		connectionStatusExecutor.execute(() -> {
-			if (!running) return;
+			State s = getState();
+			if (s != ACTIVE && s != INACTIVE) return;
 			Collection<InetAddress> addrs = getLocalIpAddresses();
 			if (addrs.contains(WIFI_AP_ADDRESS)) {
 				LOG.info("Providing wifi hotspot");
@@ -152,15 +153,21 @@ class AndroidLanTcpPlugin extends LanTcpPlugin implements EventListener {
 				// make outgoing connections on API 21+ if another network
 				// has internet access
 				socketFactory = SocketFactory.getDefault();
-				if (socket == null || socket.isClosed()) bind();
+				if (s == INACTIVE) bind();
 			} else if (addrs.isEmpty()) {
 				LOG.info("Not connected to wifi");
 				socketFactory = SocketFactory.getDefault();
-				tryToClose(socket);
+				// Server socket may not have been closed automatically when
+				// interface was taken down. Socket will be cleared and state
+				// updated in acceptContactConnections()
+				if (s == ACTIVE) {
+					LOG.info("Closing server socket");
+					tryToClose(state.getServerSocket(), LOG, WARNING);
+				}
 			} else {
 				LOG.info("Connected to wifi");
 				socketFactory = getSocketFactory();
-				if (socket == null || socket.isClosed()) bind();
+				if (s == INACTIVE) bind();
 			}
 		});
 	}

bramble-android/src/main/java/org/briarproject/bramble/plugin/tor/AndroidTorPlugin.java

@@ -74,7 +74,6 @@ class AndroidTorPlugin extends TorPlugin {
 
 	@Override
 	protected void enableNetwork(boolean enable) throws IOException {
-		if (!running) return;
 		if (enable) wakeLock.acquire();
 		super.enableNetwork(enable);
 		if (!enable) wakeLock.release();

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

@@ -61,12 +61,12 @@ class AndroidLocationUtils implements LocationUtils {
 	private String getCountryFromPhoneNetwork() {
 		Object o = appContext.getSystemService(TELEPHONY_SERVICE);
 		TelephonyManager tm = (TelephonyManager) o;
-		return tm.getNetworkCountryIso();
+		return tm == null ? "" : tm.getNetworkCountryIso();
 	}
 
 	private String getCountryFromSimCard() {
 		Object o = appContext.getSystemService(TELEPHONY_SERVICE);
 		TelephonyManager tm = (TelephonyManager) o;
-		return tm.getSimCountryIso();
+		return tm == null ? "" : tm.getSimCountryIso();
 	}
 }

bramble-api/src/main/java/org/briarproject/bramble/api/event/EventBus.java

@@ -18,6 +18,8 @@ public interface EventBus {
 	/**
 	 * Asynchronously notifies all listeners of an event. Listeners are
 	 * notified on the {@link EventExecutor}.
+	 * <p>
+	 * This method can safely be called while holding a lock.
 	 */
 	void broadcast(Event e);
 }

bramble-api/src/main/java/org/briarproject/bramble/api/plugin/BluetoothConstants.java

@@ -9,5 +9,6 @@ public interface BluetoothConstants {
 	String PROP_ADDRESS = "address";
 	String PROP_UUID = "uuid";
 
-	String PREF_BT_ENABLE = "enable";
+	// Reason code returned by Plugin#getReasonDisabled()
+	int REASON_NO_BT_ADAPTER = 2;
 }

bramble-api/src/main/java/org/briarproject/bramble/api/plugin/Plugin.java

@@ -3,12 +3,57 @@ package org.briarproject.bramble.api.plugin;
 import org.briarproject.bramble.api.Pair;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.properties.TransportProperties;
+import org.briarproject.bramble.api.settings.SettingsManager;
 
 import java.util.Collection;
 
 @NotNullByDefault
 public interface Plugin {
 
+	enum State {
+
+		/**
+		 * The plugin has not been started, has been stopped, or is disabled by
+		 * settings.
+		 */
+		DISABLED,
+
+		/**
+		 * The plugin is being enabled and can't yet make or receive
+		 * connections.
+		 */
+		ENABLING,
+
+		/**
+		 * The plugin is enabled and can make or receive connections.
+		 */
+		ACTIVE,
+
+		/**
+		 * The plugin is enabled but can't make or receive connections
+		 */
+		INACTIVE
+	}
+
+	/**
+	 * The string for the boolean preference
+	 * to use with the {@link SettingsManager} to enable or disable the plugin.
+	 */
+	String PREF_PLUGIN_ENABLE = "enable";
+
+	/**
+	 * Reason code returned by {@link #getReasonDisabled()} to indicate that
+	 * the plugin is disabled because it has not been started or has been
+	 * stopped.
+	 */
+	int REASON_STARTING_STOPPING = 0;
+
+	/**
+	 * Reason code returned by {@link #getReasonDisabled()} to indicate that
+	 * the plugin has been disabled by the user.
+	 */
+	int REASON_USER = 1;
+
 	/**
 	 * Returns the plugin's transport identifier.
 	 */
@@ -35,9 +80,19 @@ public interface Plugin {
 	void stop() throws PluginException;
 
 	/**
-	 * Returns true if the plugin is running.
+	 * Returns the current state of the plugin.
 	 */
-	boolean isRunning();
+	State getState();
+
+	/**
+	 * Returns an integer code indicating why the plugin is
+	 * {@link State#DISABLED disabled}, or -1 if the plugin is not disabled.
+	 * <p>
+	 * The codes used are plugin-specific, except the generic codes
+	 * {@link #REASON_STARTING_STOPPING} and {@link #REASON_USER}, which may
+	 * be used by any plugin.
+	 */
+	int getReasonDisabled();
 
 	/**
 	 * Returns true if the plugin should be polled periodically to attempt to

bramble-api/src/main/java/org/briarproject/bramble/api/plugin/PluginCallback.java

@@ -1,6 +1,10 @@
 package org.briarproject.bramble.api.plugin;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.Plugin.State;
+import org.briarproject.bramble.api.plugin.event.TransportActiveEvent;
+import org.briarproject.bramble.api.plugin.event.TransportInactiveEvent;
+import org.briarproject.bramble.api.plugin.event.TransportStateEvent;
 import org.briarproject.bramble.api.properties.TransportProperties;
 import org.briarproject.bramble.api.settings.Settings;
 
@@ -32,12 +36,17 @@ public interface PluginCallback extends ConnectionHandler {
 	void mergeLocalProperties(TransportProperties p);
 
 	/**
-	 * Signals that the transport is enabled.
+	 * Informs the callback of the plugin's current state.
+	 * <p>
+	 * If the current state is different from the previous state, the callback
+	 * will broadcast a {@link TransportStateEvent}. If the current state is
+	 * {@link State#ACTIVE} and the previous state was not
+	 * {@link State#ACTIVE}, the callback will broadcast a
+	 * {@link TransportActiveEvent}. If the current state is not
+	 * {@link State#ACTIVE} and the previous state was {@link State#ACTIVE},
+	 * the callback will broadcast a {@link TransportInactiveEvent}.
+	 * <p>
+	 * This method can safely be called while holding a lock.
 	 */
-	void transportEnabled();
-
-	/**
-	 * Signals that the transport is disabled.
-	 */
-	void transportDisabled();
+	void pluginStateChanged(State state);
 }

bramble-api/src/main/java/org/briarproject/bramble/api/plugin/PluginManager.java

@@ -41,4 +41,17 @@ public interface PluginManager {
 	 * Returns any duplex plugins that support rendezvous.
 	 */
 	Collection<DuplexPlugin> getRendezvousPlugins();
+
+	/**
+	 * Enables or disables the plugin
+	 * identified by the given {@link TransportId}.
+	 * <p>
+	 * Note that this applies the change asynchronously
+	 * and there are no order guarantees.
+	 * <p>
+	 * If no plugin with the given {@link TransportId} is registered,
+	 * this is a no-op.
+	 */
+	void setPluginEnabled(TransportId t, boolean enabled);
+
 }

bramble-api/src/main/java/org/briarproject/bramble/api/plugin/TorConstants.java

@@ -23,4 +23,8 @@ public interface TorConstants {
 	int PREF_TOR_NETWORK_WITH_BRIDGES = 2;
 	int PREF_TOR_NETWORK_NEVER = 3;
 
+	// Reason codes returned by Plugin#getReasonDisabled()
+	int REASON_BATTERY = 2;
+	int REASON_MOBILE_DATA = 3;
+	int REASON_COUNTRY_BLOCKED = 4;
 }

bramble-api/src/main/java/org/briarproject/bramble/api/plugin/event/TransportActiveEvent.java

@@ -2,20 +2,22 @@ package org.briarproject.bramble.api.plugin.event;
 
 import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.Plugin.State;
 import org.briarproject.bramble.api.plugin.TransportId;
 
 import javax.annotation.concurrent.Immutable;
 
 /**
- * An event that is broadcast when a transport is disabled.
+ * An event that is broadcast when a plugin enters the {@link State#ACTIVE}
+ * state.
  */
 @Immutable
 @NotNullByDefault
-public class TransportDisabledEvent extends Event {
+public class TransportActiveEvent extends Event {
 
 	private final TransportId transportId;
 
-	public TransportDisabledEvent(TransportId transportId) {
+	public TransportActiveEvent(TransportId transportId) {
 		this.transportId = transportId;
 	}
 

bramble-api/src/main/java/org/briarproject/bramble/api/plugin/event/TransportInactiveEvent.java

@@ -2,20 +2,22 @@ package org.briarproject.bramble.api.plugin.event;
 
 import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.Plugin.State;
 import org.briarproject.bramble.api.plugin.TransportId;
 
 import javax.annotation.concurrent.Immutable;
 
 /**
- * An event that is broadcast when a transport is enabled.
+ * An event that is broadcast when a plugin leaves the {@link State#ACTIVE}
+ * state.
  */
 @Immutable
 @NotNullByDefault
-public class TransportEnabledEvent extends Event {
+public class TransportInactiveEvent extends Event {
 
 	private final TransportId transportId;
 
-	public TransportEnabledEvent(TransportId transportId) {
+	public TransportInactiveEvent(TransportId transportId) {
 		this.transportId = transportId;
 	}
 

bramble-api/src/main/java/org/briarproject/bramble/api/plugin/event/TransportStateEvent.java

@@ -0,0 +1,32 @@
+package org.briarproject.bramble.api.plugin.event;
+
+import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.Plugin.State;
+import org.briarproject.bramble.api.plugin.TransportId;
+
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * An event that is broadcast when the {@link State state} of a plugin changes.
+ */
+@Immutable
+@NotNullByDefault
+public class TransportStateEvent extends Event {
+
+	private final TransportId transportId;
+	private final State state;
+
+	public TransportStateEvent(TransportId transportId, State state) {
+		this.transportId = transportId;
+		this.state = state;
+	}
+
+	public TransportId getTransportId() {
+		return transportId;
+	}
+
+	public State getState() {
+		return state;
+	}
+}

bramble-core/src/main/java/org/briarproject/bramble/plugin/PluginManagerImpl.java

@@ -8,6 +8,7 @@ import org.briarproject.bramble.api.lifecycle.ServiceException;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.ConnectionManager;
 import org.briarproject.bramble.api.plugin.Plugin;
+import org.briarproject.bramble.api.plugin.Plugin.State;
 import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.plugin.PluginConfig;
 import org.briarproject.bramble.api.plugin.PluginException;
@@ -18,8 +19,9 @@ import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPluginFactory;
 import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
-import org.briarproject.bramble.api.plugin.event.TransportDisabledEvent;
-import org.briarproject.bramble.api.plugin.event.TransportEnabledEvent;
+import org.briarproject.bramble.api.plugin.event.TransportActiveEvent;
+import org.briarproject.bramble.api.plugin.event.TransportInactiveEvent;
+import org.briarproject.bramble.api.plugin.event.TransportStateEvent;
 import org.briarproject.bramble.api.plugin.simplex.SimplexPlugin;
 import org.briarproject.bramble.api.plugin.simplex.SimplexPluginFactory;
 import org.briarproject.bramble.api.properties.TransportProperties;
@@ -36,6 +38,7 @@ import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.Executor;
 import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicReference;
 import java.util.logging.Logger;
 
 import javax.annotation.concurrent.ThreadSafe;
@@ -45,6 +48,9 @@ import static java.util.logging.Level.FINE;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.api.plugin.Plugin.PREF_PLUGIN_ENABLE;
+import static org.briarproject.bramble.api.plugin.Plugin.State.ACTIVE;
+import static org.briarproject.bramble.api.plugin.Plugin.State.DISABLED;
 import static org.briarproject.bramble.util.LogUtils.logDuration;
 import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.bramble.util.LogUtils.now;
@@ -177,6 +183,26 @@ class PluginManagerImpl implements PluginManager, Service {
 		return supported;
 	}
 
+	@Override
+	public void setPluginEnabled(TransportId t, boolean enabled) {
+		Plugin plugin = plugins.get(t);
+		if (plugin == null) return;
+
+		Settings s = new Settings();
+		s.putBoolean(PREF_PLUGIN_ENABLE, enabled);
+		ioExecutor.execute(() -> mergeSettings(s, t.getString()));
+	}
+
+	private void mergeSettings(Settings s, String namespace) {
+		try {
+			long start = now();
+			settingsManager.mergeSettings(s, namespace);
+			logDuration(LOG, "Merging settings", start);
+		} catch (DbException e) {
+			logException(LOG, WARNING, e);
+		}
+	}
+
 	private class PluginStarter implements Runnable {
 
 		private final Plugin plugin;
@@ -250,7 +276,8 @@ class PluginManagerImpl implements PluginManager, Service {
 	private class Callback implements PluginCallback {
 
 		private final TransportId id;
-		private final AtomicBoolean enabled = new AtomicBoolean(false);
+		private final AtomicReference<State> state =
+				new AtomicReference<>(DISABLED);
 
 		private Callback(TransportId id) {
 			this.id = id;
@@ -278,11 +305,7 @@ class PluginManagerImpl implements PluginManager, Service {
 
 		@Override
 		public void mergeSettings(Settings s) {
-			try {
-				settingsManager.mergeSettings(s, id.getString());
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
+			PluginManagerImpl.this.mergeSettings(s, id.getString());
 		}
 
 		@Override
@@ -295,15 +318,20 @@ class PluginManagerImpl implements PluginManager, Service {
 		}
 
 		@Override
-		public void transportEnabled() {
-			if (!enabled.getAndSet(true))
-				eventBus.broadcast(new TransportEnabledEvent(id));
-		}
-
-		@Override
-		public void transportDisabled() {
-			if (enabled.getAndSet(false))
-				eventBus.broadcast(new TransportDisabledEvent(id));
+		public void pluginStateChanged(State newState) {
+			State oldState = state.getAndSet(newState);
+			if (newState != oldState) {
+				if (LOG.isLoggable(INFO)) {
+					LOG.info(id + " changed from state " + oldState
+							+ " to " + newState);
+				}
+				eventBus.broadcast(new TransportStateEvent(id, newState));
+				if (newState == ACTIVE) {
+					eventBus.broadcast(new TransportActiveEvent(id));
+				} else if (oldState == ACTIVE) {
+					eventBus.broadcast(new TransportInactiveEvent(id));
+				}
+			}
 		}
 
 		@Override

bramble-core/src/main/java/org/briarproject/bramble/plugin/PollerImpl.java

@@ -20,8 +20,8 @@ import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
 import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
 import org.briarproject.bramble.api.plugin.event.ConnectionClosedEvent;
 import org.briarproject.bramble.api.plugin.event.ConnectionOpenedEvent;
-import org.briarproject.bramble.api.plugin.event.TransportDisabledEvent;
-import org.briarproject.bramble.api.plugin.event.TransportEnabledEvent;
+import org.briarproject.bramble.api.plugin.event.TransportActiveEvent;
+import org.briarproject.bramble.api.plugin.event.TransportInactiveEvent;
 import org.briarproject.bramble.api.plugin.simplex.SimplexPlugin;
 import org.briarproject.bramble.api.properties.TransportProperties;
 import org.briarproject.bramble.api.properties.TransportPropertyManager;
@@ -106,13 +106,13 @@ class PollerImpl implements Poller, EventListener {
 			ConnectionOpenedEvent c = (ConnectionOpenedEvent) e;
 			// Reschedule polling, the polling interval may have decreased
 			reschedule(c.getTransportId());
-		} else if (e instanceof TransportEnabledEvent) {
-			TransportEnabledEvent t = (TransportEnabledEvent) e;
-			// Poll the newly enabled transport
+		} else if (e instanceof TransportActiveEvent) {
+			TransportActiveEvent t = (TransportActiveEvent) e;
+			// Poll the newly activated transport
 			pollNow(t.getTransportId());
-		} else if (e instanceof TransportDisabledEvent) {
-			TransportDisabledEvent t = (TransportDisabledEvent) e;
-			// Cancel polling for the disabled transport
+		} else if (e instanceof TransportInactiveEvent) {
+			TransportInactiveEvent t = (TransportInactiveEvent) e;
+			// Cancel polling for the deactivated transport
 			cancel(t.getTransportId());
 		}
 	}

bramble-core/src/main/java/org/briarproject/bramble/plugin/bluetooth/BluetoothPlugin.java

@@ -9,7 +9,9 @@ import org.briarproject.bramble.api.keyagreement.KeyAgreementConnection;
 import org.briarproject.bramble.api.keyagreement.KeyAgreementListener;
 import org.briarproject.bramble.api.keyagreement.event.KeyAgreementListeningEvent;
 import org.briarproject.bramble.api.keyagreement.event.KeyAgreementStoppedListeningEvent;
+import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.ConnectionHandler;
@@ -36,16 +38,21 @@ import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.logging.Logger;
 
 import javax.annotation.Nullable;
+import javax.annotation.concurrent.GuardedBy;
+import javax.annotation.concurrent.ThreadSafe;
 
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.TRANSPORT_ID_BLUETOOTH;
 import static org.briarproject.bramble.api.plugin.BluetoothConstants.ID;
-import static org.briarproject.bramble.api.plugin.BluetoothConstants.PREF_BT_ENABLE;
 import static org.briarproject.bramble.api.plugin.BluetoothConstants.PROP_ADDRESS;
 import static org.briarproject.bramble.api.plugin.BluetoothConstants.PROP_UUID;
+import static org.briarproject.bramble.api.plugin.BluetoothConstants.REASON_NO_BT_ADAPTER;
 import static org.briarproject.bramble.api.plugin.BluetoothConstants.UUID_BYTES;
+import static org.briarproject.bramble.api.plugin.Plugin.State.ACTIVE;
+import static org.briarproject.bramble.api.plugin.Plugin.State.DISABLED;
+import static org.briarproject.bramble.api.plugin.Plugin.State.INACTIVE;
 import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.bramble.util.PrivacyUtils.scrubMacAddress;
 import static org.briarproject.bramble.util.StringUtils.isNullOrEmpty;
@@ -68,9 +75,9 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 	private final int maxLatency;
 	private final AtomicBoolean used = new AtomicBoolean(false);
 
-	private volatile boolean running = false, contactConnections = false;
+	protected final PluginState state = new PluginState();
+
 	private volatile String contactConnectionsUuid = null;
-	private volatile SS socket = null;
 
 	abstract void initialiseAdapter() throws IOException;
 
@@ -119,14 +126,18 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 		LOG.info("Bluetooth enabled");
 		// We may not have been able to get the local address before
 		ioExecutor.execute(this::updateProperties);
-		if (shouldAllowContactConnections()) bind();
+		if (getState() == INACTIVE) bind();
 	}
 
 	void onAdapterDisabled() {
 		LOG.info("Bluetooth disabled");
-		tryToClose(socket);
 		connectionLimiter.allConnectionsClosed();
-		callback.transportDisabled();
+		// The server socket may not have been closed automatically
+		SS ss = state.clearServerSocket();
+		if (ss != null) {
+			LOG.info("Closing server socket");
+			tryToClose(ss);
+		}
 	}
 
 	@Override
@@ -151,28 +162,22 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 		try {
 			initialiseAdapter();
 		} catch (IOException e) {
+			state.setNoAdapter();
 			throw new PluginException(e);
 		}
 		updateProperties();
-		running = true;
-		loadSettings(callback.getSettings());
-		if (shouldAllowContactConnections()) {
+		Settings settings = callback.getSettings();
+		boolean enabledByUser = settings.getBoolean(PREF_PLUGIN_ENABLE, false);
+		state.setStarted(enabledByUser);
+		if (enabledByUser) {
 			if (isAdapterEnabled()) bind();
 			else enableAdapter();
 		}
 	}
 
-	private void loadSettings(Settings settings) {
-		contactConnections = settings.getBoolean(PREF_BT_ENABLE, false);
-	}
-
-	private boolean shouldAllowContactConnections() {
-		return contactConnections;
-	}
-
 	private void bind() {
 		ioExecutor.execute(() -> {
-			if (!isRunning() || !shouldAllowContactConnections()) return;
+			if (getState() != INACTIVE) return;
 			// Bind a server socket to accept connections from contacts
 			SS ss;
 			try {
@@ -181,14 +186,13 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 				logException(LOG, WARNING, e);
 				return;
 			}
-			if (!isRunning() || !shouldAllowContactConnections()) {
+			if (!state.setServerSocket(ss)) {
+				LOG.info("Closing redundant server socket");
 				tryToClose(ss);
 				return;
 			}
-			socket = ss;
 			backoff.reset();
-			callback.transportEnabled();
-			acceptContactConnections();
+			acceptContactConnections(ss);
 		});
 	}
 
@@ -217,34 +221,39 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 		if (changed) callback.mergeLocalProperties(p);
 	}
 
-	private void acceptContactConnections() {
+	private void acceptContactConnections(SS ss) {
 		while (true) {
 			DuplexTransportConnection conn;
 			try {
-				conn = acceptConnection(socket);
+				conn = acceptConnection(ss);
 			} catch (IOException e) {
-				// This is expected when the socket is closed
-				if (LOG.isLoggable(INFO)) LOG.info(e.toString());
+				// This is expected when the server socket is closed
+				LOG.info("Server socket closed");
+				state.clearServerSocket();
 				return;
 			}
+			LOG.info("Connection received");
 			backoff.reset();
 			if (connectionLimiter.contactConnectionOpened(conn))
 				callback.handleConnection(conn);
-			if (!running) return;
 		}
 	}
 
 	@Override
 	public void stop() {
-		running = false;
-		tryToClose(socket);
-		callback.transportDisabled();
+		SS ss = state.setStopped();
+		tryToClose(ss);
 		disableAdapterIfEnabledByUs();
 	}
 
 	@Override
-	public boolean isRunning() {
-		return running && isAdapterEnabled();
+	public State getState() {
+		return state.getState();
+	}
+
+	@Override
+	public int getReasonDisabled() {
+		return state.getReasonDisabled();
 	}
 
 	@Override
@@ -260,7 +269,7 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 	@Override
 	public void poll(Collection<Pair<TransportProperties, ConnectionHandler>>
 			properties) {
-		if (!isRunning() || !shouldAllowContactConnections()) return;
+		if (getState() != ACTIVE) return;
 		backoff.increment();
 		for (Pair<TransportProperties, ConnectionHandler> p : properties) {
 			connect(p.getFirst(), p.getSecond());
@@ -273,7 +282,7 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 		String uuid = p.get(PROP_UUID);
 		if (isNullOrEmpty(uuid)) return;
 		ioExecutor.execute(() -> {
-			if (!isRunning() || !shouldAllowContactConnections()) return;
+			if (getState() != ACTIVE) return;
 			if (!connectionLimiter.canOpenContactConnection()) return;
 			DuplexTransportConnection d = createConnection(p);
 			if (d != null) {
@@ -317,7 +326,7 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 
 	@Override
 	public DuplexTransportConnection createConnection(TransportProperties p) {
-		if (!isRunning() || !shouldAllowContactConnections()) return null;
+		if (getState() != ACTIVE) return null;
 		if (!connectionLimiter.canOpenContactConnection()) return null;
 		String address = p.get(PROP_ADDRESS);
 		if (isNullOrEmpty(address)) return null;
@@ -336,7 +345,7 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 
 	@Override
 	public KeyAgreementListener createKeyAgreementListener(byte[] commitment) {
-		if (!isRunning()) return null;
+		if (getState() != ACTIVE) return null;
 		// No truncation necessary because COMMIT_LENGTH = 16
 		String uuid = UUID.nameUUIDFromBytes(commitment).toString();
 		if (LOG.isLoggable(INFO)) LOG.info("Key agreement UUID " + uuid);
@@ -348,7 +357,7 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 			logException(LOG, WARNING, e);
 			return null;
 		}
-		if (!isRunning()) {
+		if (getState() != ACTIVE) {
 			tryToClose(ss);
 			return null;
 		}
@@ -362,7 +371,7 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 	@Override
 	public DuplexTransportConnection createKeyAgreementConnection(
 			byte[] commitment, BdfList descriptor) {
-		if (!isRunning()) return null;
+		if (getState() != ACTIVE) return null;
 		// No truncation necessary because COMMIT_LENGTH = 16
 		String uuid = UUID.nameUUIDFromBytes(commitment).toString();
 		DuplexTransportConnection conn;
@@ -422,17 +431,17 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 		}
 	}
 
+	@IoExecutor
 	private void onSettingsUpdated(Settings settings) {
-		boolean wasAllowed = shouldAllowContactConnections();
-		loadSettings(settings);
-		boolean isAllowed = shouldAllowContactConnections();
-		if (wasAllowed && !isAllowed) {
-			LOG.info("Contact connections disabled");
-			tryToClose(socket);
-			callback.transportDisabled();
+		boolean enabledByUser = settings.getBoolean(PREF_PLUGIN_ENABLE, false);
+		SS ss = state.setEnabledByUser(enabledByUser);
+		State s = getState();
+		if (ss != null) {
+			LOG.info("Disabled by user, closing server socket");
+			tryToClose(ss);
 			disableAdapterIfEnabledByUs();
-		} else if (!wasAllowed && isAllowed) {
-			LOG.info("Contact connections enabled");
+		} else if (s == INACTIVE) {
+			LOG.info("Enabled by user, opening server socket");
 			if (isAdapterEnabled()) bind();
 			else enableAdapter();
 		}
@@ -460,4 +469,77 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 			tryToClose(ss);
 		}
 	}
+
+	@ThreadSafe
+	@NotNullByDefault
+	protected class PluginState {
+
+		@GuardedBy("this")
+		private boolean started = false,
+				stopped = false,
+				noAdapter = false,
+				enabledByUser = false;
+
+		@GuardedBy("this")
+		@Nullable
+		private SS serverSocket = null;
+
+		synchronized void setStarted(boolean enabledByUser) {
+			started = true;
+			this.enabledByUser = enabledByUser;
+			callback.pluginStateChanged(getState());
+		}
+
+		@Nullable
+		synchronized SS setStopped() {
+			stopped = true;
+			SS ss = serverSocket;
+			serverSocket = null;
+			callback.pluginStateChanged(getState());
+			return ss;
+		}
+
+		synchronized void setNoAdapter() {
+			noAdapter = true;
+			callback.pluginStateChanged(getState());
+		}
+
+		@Nullable
+		synchronized SS setEnabledByUser(boolean enabledByUser) {
+			this.enabledByUser = enabledByUser;
+			SS ss = null;
+			if (!enabledByUser) {
+				ss = serverSocket;
+				serverSocket = null;
+			}
+			callback.pluginStateChanged(getState());
+			return ss;
+		}
+
+		synchronized boolean setServerSocket(SS ss) {
+			if (stopped || serverSocket != null) return false;
+			serverSocket = ss;
+			callback.pluginStateChanged(getState());
+			return true;
+		}
+
+		@Nullable
+		synchronized SS clearServerSocket() {
+			SS ss = serverSocket;
+			serverSocket = null;
+			callback.pluginStateChanged(getState());
+			return ss;
+		}
+
+		synchronized State getState() {
+			if (!started || stopped || !enabledByUser) return DISABLED;
+			return serverSocket == null ? INACTIVE : ACTIVE;
+		}
+
+		synchronized int getReasonDisabled() {
+			if (noAdapter && !stopped) return REASON_NO_BT_ADAPTER;
+			if (!started || stopped) return REASON_STARTING_STOPPING;
+			return enabledByUser ? -1 : REASON_USER;
+		}
+	}
 }

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

@@ -16,6 +16,7 @@ import java.util.logging.Logger;
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.api.plugin.FileConstants.PROP_PATH;
+import static org.briarproject.bramble.api.plugin.Plugin.State.ACTIVE;
 import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.bramble.util.StringUtils.isNullOrEmpty;
 
@@ -45,7 +46,7 @@ abstract class FilePlugin implements SimplexPlugin {
 
 	@Override
 	public TransportConnectionReader createReader(TransportProperties p) {
-		if (!isRunning()) return null;
+		if (getState() != ACTIVE) return null;
 		String path = p.get(PROP_PATH);
 		if (isNullOrEmpty(path)) return null;
 		try {
@@ -60,7 +61,7 @@ abstract class FilePlugin implements SimplexPlugin {
 
 	@Override
 	public TransportConnectionWriter createWriter(TransportProperties p) {
-		if (!isRunning()) return null;
+		if (getState() != ACTIVE) return null;
 		String path = p.get(PROP_PATH);
 		if (isNullOrEmpty(path)) return null;
 		try {

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

@@ -11,7 +11,6 @@ import org.briarproject.bramble.api.plugin.TransportId;
 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 java.io.IOException;
 import java.net.Inet4Address;
@@ -19,7 +18,6 @@ import java.net.InetAddress;
 import java.net.InetSocketAddress;
 import java.net.ServerSocket;
 import java.net.Socket;
-import java.net.SocketAddress;
 import java.net.UnknownHostException;
 import java.util.ArrayList;
 import java.util.Comparator;
@@ -38,6 +36,7 @@ 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.IoUtils.tryToClose;
 import static org.briarproject.bramble.util.PrivacyUtils.scrubSocketAddress;
 import static org.briarproject.bramble.util.StringUtils.isNullOrEmpty;
 import static org.briarproject.bramble.util.StringUtils.join;
@@ -149,8 +148,9 @@ class LanTcpPlugin extends TcpPlugin {
 		if (remote.getPort() == 0) return false;
 		if (!isAcceptableAddress(remote.getAddress())) return false;
 		// Try to determine whether the address is on the same LAN as us
-		if (socket == null) return false;
-		byte[] localIp = socket.getInetAddress().getAddress();
+		ServerSocket ss = state.getServerSocket();
+		if (ss == null) return false;
+		byte[] localIp = ss.getInetAddress().getAddress();
 		byte[] remoteIp = remote.getAddress().getAddress();
 		return addressesAreOnSameLan(localIp, remoteIp);
 	}
@@ -209,10 +209,10 @@ class LanTcpPlugin extends TcpPlugin {
 			} catch (IOException e) {
 				if (LOG.isLoggable(INFO))
 					LOG.info("Failed to bind " + scrubSocketAddress(addr));
-				tryToClose(ss);
+				tryToClose(ss, LOG, WARNING);
 			}
 		}
-		if (ss == null || !ss.isBound()) {
+		if (ss == null) {
 			LOG.info("Could not bind server socket for key agreement");
 			return null;
 		}
@@ -228,7 +228,8 @@ class LanTcpPlugin extends TcpPlugin {
 	@Override
 	public DuplexTransportConnection createKeyAgreementConnection(
 			byte[] commitment, BdfList descriptor) {
-		if (!isRunning()) return null;
+		ServerSocket ss = state.getServerSocket();
+		if (ss == null) return null;
 		InetSocketAddress remote;
 		try {
 			remote = parseSocketAddress(descriptor);
@@ -238,10 +239,9 @@ class LanTcpPlugin extends TcpPlugin {
 		}
 		if (!isConnectable(remote)) {
 			if (LOG.isLoggable(INFO)) {
-				SocketAddress local = socket.getLocalSocketAddress();
 				LOG.info(scrubSocketAddress(remote) +
 						" is not connectable from " +
-						scrubSocketAddress(local));
+						scrubSocketAddress(ss.getLocalSocketAddress()));
 			}
 			return null;
 		}
@@ -249,7 +249,7 @@ class LanTcpPlugin extends TcpPlugin {
 			if (LOG.isLoggable(INFO))
 				LOG.info("Connecting to " + scrubSocketAddress(remote));
 			Socket s = createSocket();
-			s.bind(new InetSocketAddress(socket.getInetAddress(), 0));
+			s.bind(new InetSocketAddress(ss.getInetAddress(), 0));
 			s.connect(remote);
 			s.setSoTimeout(socketTimeout);
 			if (LOG.isLoggable(INFO))
@@ -296,7 +296,7 @@ class LanTcpPlugin extends TcpPlugin {
 
 		@Override
 		public void close() {
-			IoUtils.tryToClose(ss, LOG, WARNING);
+			tryToClose(ss, LOG, WARNING);
 		}
 	}
 

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

@@ -1,5 +1,6 @@
 package org.briarproject.bramble.plugin.tcp;
 
+import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.BackoffFactory;
@@ -25,11 +26,13 @@ public class LanTcpPluginFactory implements DuplexPluginFactory {
 	private static final double BACKOFF_BASE = 1.2;
 
 	private final Executor ioExecutor;
+	private final EventBus eventBus;
 	private final BackoffFactory backoffFactory;
 
-	public LanTcpPluginFactory(Executor ioExecutor,
+	public LanTcpPluginFactory(Executor ioExecutor, EventBus eventBus,
 			BackoffFactory backoffFactory) {
 		this.ioExecutor = ioExecutor;
+		this.eventBus = eventBus;
 		this.backoffFactory = backoffFactory;
 	}
 
@@ -47,7 +50,9 @@ public class LanTcpPluginFactory implements DuplexPluginFactory {
 	public DuplexPlugin createPlugin(PluginCallback callback) {
 		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
 				MAX_POLLING_INTERVAL, BACKOFF_BASE);
-		return new LanTcpPlugin(ioExecutor, backoff, callback, MAX_LATENCY,
-				MAX_IDLE_TIME);
+		LanTcpPlugin plugin = new LanTcpPlugin(ioExecutor, backoff, callback,
+				MAX_LATENCY, MAX_IDLE_TIME);
+		eventBus.addListener(plugin);
+		return plugin;
 	}
 }

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

@@ -3,8 +3,12 @@ package org.briarproject.bramble.plugin.tcp;
 import org.briarproject.bramble.PoliteExecutor;
 import org.briarproject.bramble.api.Pair;
 import org.briarproject.bramble.api.data.BdfList;
+import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.keyagreement.KeyAgreementListener;
+import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.ConnectionHandler;
@@ -14,7 +18,8 @@ import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
 import org.briarproject.bramble.api.properties.TransportProperties;
 import org.briarproject.bramble.api.rendezvous.KeyMaterialSource;
 import org.briarproject.bramble.api.rendezvous.RendezvousEndpoint;
-import org.briarproject.bramble.util.IoUtils;
+import org.briarproject.bramble.api.settings.Settings;
+import org.briarproject.bramble.api.settings.event.SettingsUpdatedEvent;
 
 import java.io.IOException;
 import java.net.InetAddress;
@@ -22,7 +27,6 @@ import java.net.InetSocketAddress;
 import java.net.NetworkInterface;
 import java.net.ServerSocket;
 import java.net.Socket;
-import java.net.SocketAddress;
 import java.net.SocketException;
 import java.net.UnknownHostException;
 import java.util.ArrayList;
@@ -35,6 +39,8 @@ import java.util.logging.Logger;
 import java.util.regex.Pattern;
 
 import javax.annotation.Nullable;
+import javax.annotation.concurrent.GuardedBy;
+import javax.annotation.concurrent.ThreadSafe;
 
 import static java.net.NetworkInterface.getNetworkInterfaces;
 import static java.util.Collections.emptyList;
@@ -42,13 +48,17 @@ import static java.util.Collections.list;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.api.plugin.Plugin.State.ACTIVE;
+import static org.briarproject.bramble.api.plugin.Plugin.State.DISABLED;
+import static org.briarproject.bramble.api.plugin.Plugin.State.INACTIVE;
+import static org.briarproject.bramble.util.IoUtils.tryToClose;
 import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.bramble.util.PrivacyUtils.scrubSocketAddress;
 import static org.briarproject.bramble.util.StringUtils.isNullOrEmpty;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
-abstract class TcpPlugin implements DuplexPlugin {
+abstract class TcpPlugin implements DuplexPlugin, EventListener {
 
 	private static final Logger LOG = getLogger(TcpPlugin.class.getName());
 
@@ -60,9 +70,7 @@ abstract class TcpPlugin implements DuplexPlugin {
 	protected final PluginCallback callback;
 	protected final int maxLatency, maxIdleTime, socketTimeout;
 	protected final AtomicBoolean used = new AtomicBoolean(false);
-
-	protected volatile boolean running = false;
-	protected volatile ServerSocket socket = null;
+	protected final PluginState state = new PluginState();
 
 	/**
 	 * Returns zero or more socket addresses on which the plugin should listen,
@@ -86,6 +94,7 @@ abstract class TcpPlugin implements DuplexPlugin {
 	/**
 	 * Returns true if connections to the given address can be attempted.
 	 */
+	@SuppressWarnings("BooleanMethodIsAlwaysInverted")
 	protected abstract boolean isConnectable(InetSocketAddress remote);
 
 	TcpPlugin(Executor ioExecutor, Backoff backoff, PluginCallback callback,
@@ -115,14 +124,14 @@ abstract class TcpPlugin implements DuplexPlugin {
 	@Override
 	public void start() {
 		if (used.getAndSet(true)) throw new IllegalStateException();
-		running = true;
+		Settings settings = callback.getSettings();
+		state.setStarted(settings.getBoolean(PREF_PLUGIN_ENABLE, false));
 		bind();
 	}
 
 	protected void bind() {
 		bindExecutor.execute(() -> {
-			if (!running) return;
-			if (socket != null && !socket.isClosed()) return;
+			if (getState() != INACTIVE) return;
 			ServerSocket ss = null;
 			for (InetSocketAddress addr : getLocalSocketAddresses()) {
 				try {
@@ -132,34 +141,28 @@ abstract class TcpPlugin implements DuplexPlugin {
 				} catch (IOException e) {
 					if (LOG.isLoggable(INFO))
 						LOG.info("Failed to bind " + scrubSocketAddress(addr));
-					tryToClose(ss);
+					tryToClose(ss, LOG, WARNING);
 				}
 			}
-			if (ss == null || !ss.isBound()) {
+			if (ss == null) {
 				LOG.info("Could not bind server socket");
 				return;
 			}
-			if (!running) {
-				tryToClose(ss);
+			if (!state.setServerSocket(ss)) {
+				LOG.info("Closing redundant server socket");
+				tryToClose(ss, LOG, WARNING);
 				return;
 			}
-			socket = ss;
 			backoff.reset();
 			InetSocketAddress local =
 					(InetSocketAddress) ss.getLocalSocketAddress();
 			setLocalSocketAddress(local);
 			if (LOG.isLoggable(INFO))
 				LOG.info("Listening on " + scrubSocketAddress(local));
-			callback.transportEnabled();
-			acceptContactConnections();
+			acceptContactConnections(ss);
 		});
 	}
 
-	protected void tryToClose(@Nullable ServerSocket ss) {
-		IoUtils.tryToClose(ss, LOG, WARNING);
-		callback.transportDisabled();
-	}
-
 	String getIpPortString(InetSocketAddress a) {
 		String addr = a.getAddress().getHostAddress();
 		int percent = addr.indexOf('%');
@@ -167,15 +170,16 @@ abstract class TcpPlugin implements DuplexPlugin {
 		return addr + ":" + a.getPort();
 	}
 
-	private void acceptContactConnections() {
-		while (isRunning()) {
+	private void acceptContactConnections(ServerSocket ss) {
+		while (true) {
 			Socket s;
 			try {
-				s = socket.accept();
+				s = ss.accept();
 				s.setSoTimeout(socketTimeout);
 			} catch (IOException e) {
-				// This is expected when the socket is closed
-				if (LOG.isLoggable(INFO)) LOG.info(e.toString());
+				// This is expected when the server socket is closed
+				LOG.info("Server socket closed");
+				state.clearServerSocket(ss);
 				return;
 			}
 			if (LOG.isLoggable(INFO))
@@ -188,13 +192,18 @@ abstract class TcpPlugin implements DuplexPlugin {
 
 	@Override
 	public void stop() {
-		running = false;
-		tryToClose(socket);
+		ServerSocket ss = state.setStopped();
+		tryToClose(ss, LOG, WARNING);
 	}
 
 	@Override
-	public boolean isRunning() {
-		return running && socket != null && !socket.isClosed();
+	public State getState() {
+		return state.getState();
+	}
+
+	@Override
+	public int getReasonDisabled() {
+		return state.getReasonDisabled();
 	}
 
 	@Override
@@ -210,7 +219,7 @@ abstract class TcpPlugin implements DuplexPlugin {
 	@Override
 	public void poll(Collection<Pair<TransportProperties, ConnectionHandler>>
 			properties) {
-		if (!isRunning()) return;
+		if (getState() != ACTIVE) return;
 		backoff.increment();
 		for (Pair<TransportProperties, ConnectionHandler> p : properties) {
 			connect(p.getFirst(), p.getSecond());
@@ -229,14 +238,14 @@ abstract class TcpPlugin implements DuplexPlugin {
 
 	@Override
 	public DuplexTransportConnection createConnection(TransportProperties p) {
-		if (!isRunning()) return null;
+		ServerSocket ss = state.getServerSocket();
+		if (ss == null) return null;
 		for (InetSocketAddress remote : getRemoteSocketAddresses(p)) {
 			if (!isConnectable(remote)) {
 				if (LOG.isLoggable(INFO)) {
-					SocketAddress local = socket.getLocalSocketAddress();
 					LOG.info(scrubSocketAddress(remote) +
 							" is not connectable from " +
-							scrubSocketAddress(local));
+							scrubSocketAddress(ss.getLocalSocketAddress()));
 				}
 				continue;
 			}
@@ -244,7 +253,7 @@ abstract class TcpPlugin implements DuplexPlugin {
 				if (LOG.isLoggable(INFO))
 					LOG.info("Connecting to " + scrubSocketAddress(remote));
 				Socket s = createSocket();
-				s.bind(new InetSocketAddress(socket.getInetAddress(), 0));
+				s.bind(new InetSocketAddress(ss.getInetAddress(), 0));
 				s.connect(remote);
 				s.setSoTimeout(socketTimeout);
 				if (LOG.isLoggable(INFO))
@@ -327,4 +336,93 @@ abstract class TcpPlugin implements DuplexPlugin {
 			return emptyList();
 		}
 	}
+
+	@Override
+	public void eventOccurred(Event e) {
+		if (e instanceof SettingsUpdatedEvent) {
+			SettingsUpdatedEvent s = (SettingsUpdatedEvent) e;
+			if (s.getNamespace().equals(getId().getString()))
+				ioExecutor.execute(() -> onSettingsUpdated(s.getSettings()));
+		}
+	}
+
+	@IoExecutor
+	private void onSettingsUpdated(Settings settings) {
+		boolean enabledByUser = settings.getBoolean(PREF_PLUGIN_ENABLE, false);
+		ServerSocket ss = state.setEnabledByUser(enabledByUser);
+		State s = getState();
+		if (ss != null) {
+			LOG.info("Disabled by user, closing server socket");
+			tryToClose(ss, LOG, WARNING);
+		} else if (s == INACTIVE) {
+			LOG.info("Enabled by user, opening server socket");
+			bind();
+		}
+	}
+
+	@ThreadSafe
+	@NotNullByDefault
+	protected class PluginState {
+
+		@GuardedBy("this")
+		private boolean started = false, stopped = false, enabledByUser = false;
+
+		@GuardedBy("this")
+		@Nullable
+		private ServerSocket serverSocket = null;
+
+		synchronized void setStarted(boolean enabledByUser) {
+			started = true;
+			this.enabledByUser = enabledByUser;
+			callback.pluginStateChanged(getState());
+		}
+
+		@Nullable
+		synchronized ServerSocket setStopped() {
+			stopped = true;
+			ServerSocket ss = serverSocket;
+			serverSocket = null;
+			callback.pluginStateChanged(getState());
+			return ss;
+		}
+
+		@Nullable
+		synchronized ServerSocket setEnabledByUser(boolean enabledByUser) {
+			this.enabledByUser = enabledByUser;
+			ServerSocket ss = null;
+			if (!enabledByUser) {
+				ss = serverSocket;
+				serverSocket = null;
+			}
+			callback.pluginStateChanged(getState());
+			return ss;
+		}
+
+		@Nullable
+		synchronized ServerSocket getServerSocket() {
+			return serverSocket;
+		}
+
+		synchronized boolean setServerSocket(ServerSocket ss) {
+			if (stopped || serverSocket != null) return false;
+			serverSocket = ss;
+			callback.pluginStateChanged(getState());
+			return true;
+		}
+
+		synchronized void clearServerSocket(ServerSocket ss) {
+			if (serverSocket == ss) serverSocket = null;
+			callback.pluginStateChanged(getState());
+		}
+
+		synchronized State getState() {
+			if (!started || stopped || !enabledByUser) return DISABLED;
+			return serverSocket == null ? INACTIVE : ACTIVE;
+		}
+
+		synchronized int getReasonDisabled() {
+			if (!started || stopped) return REASON_STARTING_STOPPING;
+			return enabledByUser ? -1 : REASON_USER;
+		}
+	}
 }

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

@@ -1,5 +1,6 @@
 package org.briarproject.bramble.plugin.tcp;
 
+import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.lifecycle.ShutdownManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.Backoff;
@@ -26,12 +27,14 @@ public class WanTcpPluginFactory implements DuplexPluginFactory {
 	private static final double BACKOFF_BASE = 1.2;
 
 	private final Executor ioExecutor;
+	private final EventBus eventBus;
 	private final BackoffFactory backoffFactory;
 	private final ShutdownManager shutdownManager;
 
-	public WanTcpPluginFactory(Executor ioExecutor,
+	public WanTcpPluginFactory(Executor ioExecutor, EventBus eventBus,
 			BackoffFactory backoffFactory, ShutdownManager shutdownManager) {
 		this.ioExecutor = ioExecutor;
+		this.eventBus = eventBus;
 		this.backoffFactory = backoffFactory;
 		this.shutdownManager = shutdownManager;
 	}
@@ -50,8 +53,10 @@ public class WanTcpPluginFactory implements DuplexPluginFactory {
 	public DuplexPlugin createPlugin(PluginCallback callback) {
 		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
 				MAX_POLLING_INTERVAL, BACKOFF_BASE);
-		return new WanTcpPlugin(ioExecutor, backoff,
+		WanTcpPlugin plugin = new WanTcpPlugin(ioExecutor, backoff,
 				new PortMapperImpl(shutdownManager), callback, MAX_LATENCY,
 				MAX_IDLE_TIME);
+		eventBus.addListener(plugin);
+		return plugin;
 	}
 }

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

@@ -15,6 +15,7 @@ import org.briarproject.bramble.api.network.NetworkManager;
 import org.briarproject.bramble.api.network.NetworkStatus;
 import org.briarproject.bramble.api.network.event.NetworkStatusEvent;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.ConnectionHandler;
@@ -54,6 +55,9 @@ import java.util.logging.Logger;
 import java.util.regex.Pattern;
 import java.util.zip.ZipInputStream;
 
+import javax.annotation.Nullable;
+import javax.annotation.concurrent.GuardedBy;
+import javax.annotation.concurrent.ThreadSafe;
 import javax.net.SocketFactory;
 
 import static java.util.Arrays.asList;
@@ -65,6 +69,10 @@ import static java.util.logging.Logger.getLogger;
 import static net.freehaven.tor.control.TorControlCommands.HS_ADDRESS;
 import static net.freehaven.tor.control.TorControlCommands.HS_PRIVKEY;
 import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
+import static org.briarproject.bramble.api.plugin.Plugin.State.ACTIVE;
+import static org.briarproject.bramble.api.plugin.Plugin.State.DISABLED;
+import static org.briarproject.bramble.api.plugin.Plugin.State.ENABLING;
+import static org.briarproject.bramble.api.plugin.Plugin.State.INACTIVE;
 import static org.briarproject.bramble.api.plugin.TorConstants.CONTROL_PORT;
 import static org.briarproject.bramble.api.plugin.TorConstants.ID;
 import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_MOBILE;
@@ -76,6 +84,9 @@ import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_ONLY_WHE
 import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_PORT;
 import static org.briarproject.bramble.api.plugin.TorConstants.PROP_ONION_V2;
 import static org.briarproject.bramble.api.plugin.TorConstants.PROP_ONION_V3;
+import static org.briarproject.bramble.api.plugin.TorConstants.REASON_BATTERY;
+import static org.briarproject.bramble.api.plugin.TorConstants.REASON_COUNTRY_BLOCKED;
+import static org.briarproject.bramble.api.plugin.TorConstants.REASON_MOBILE_DATA;
 import static org.briarproject.bramble.plugin.tor.TorRendezvousCrypto.SEED_BYTES;
 import static org.briarproject.bramble.util.IoUtils.copyAndClose;
 import static org.briarproject.bramble.util.IoUtils.tryToClose;
@@ -113,16 +124,14 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	private final int maxLatency, maxIdleTime, socketTimeout;
 	private final File torDirectory, torFile, geoIpFile, obfs4File, configFile;
 	private final File doneFile, cookieFile;
-	private final ConnectionStatus connectionStatus;
 	private final AtomicBoolean used = new AtomicBoolean(false);
 
-	private volatile ServerSocket socket = null;
+	protected final PluginState state = new PluginState();
+
 	private volatile Socket controlSocket = null;
 	private volatile TorControlConnection controlConnection = null;
 	private volatile Settings settings = null;
 
-	protected volatile boolean running = false;
-
 	protected abstract int getProcessId();
 
 	protected abstract long getLastUpdateTime();
@@ -159,7 +168,6 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		configFile = new File(torDirectory, "torrc");
 		doneFile = new File(torDirectory, "done");
 		cookieFile = new File(torDirectory, ".tor/control_auth_cookie");
-		connectionStatus = new ConnectionStatus();
 		// Don't execute more than one connection status check at a time
 		connectionStatusExecutor =
 				new PoliteExecutor("TorPlugin", ioExecutor, 1);
@@ -183,6 +191,7 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	@Override
 	public void start() throws PluginException {
 		if (used.getAndSet(true)) throw new IllegalStateException();
+		state.setStarted();
 		if (!torDirectory.exists()) {
 			if (!torDirectory.mkdirs()) {
 				LOG.warning("Could not create Tor directory.");
@@ -190,7 +199,7 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 			}
 		}
 		// Load the settings
-		settings = callback.getSettings();
+		settings = migrateSettings(callback.getSettings());
 		// Install or update the assets if necessary
 		if (!assetsAreUpToDate()) installAssets();
 		if (cookieFile.exists() && !cookieFile.delete())
@@ -258,7 +267,6 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 			// Tell Tor to exit when the control connection is closed
 			controlConnection.takeOwnership();
 			controlConnection.resetConf(singletonList(OWNER));
-			running = true;
 			// Register to receive events from the Tor process
 			controlConnection.setEventHandler(this);
 			controlConnection.setEvents(asList(EVENTS));
@@ -266,11 +274,12 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 			String phase = controlConnection.getInfo("status/bootstrap-phase");
 			if (phase != null && phase.contains("PROGRESS=100")) {
 				LOG.info("Tor has already bootstrapped");
-				connectionStatus.setBootstrapped();
+				state.setBootstrapped();
 			}
 		} catch (IOException e) {
 			throw new PluginException(e);
 		}
+		state.setTorStarted();
 		// Check whether we're online
 		updateConnectionStatus(networkManager.getNetworkStatus(),
 				batteryManager.isCharging());
@@ -278,6 +287,18 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		bind();
 	}
 
+	// TODO: Remove after a reasonable migration period (added 2020-01-16)
+	private Settings migrateSettings(Settings settings) {
+		int network = settings.getInt(PREF_TOR_NETWORK,
+				PREF_TOR_NETWORK_AUTOMATIC);
+		if (network == PREF_TOR_NETWORK_NEVER) {
+			settings.putInt(PREF_TOR_NETWORK, PREF_TOR_NETWORK_AUTOMATIC);
+			settings.putBoolean(PREF_PLUGIN_ENABLE, false);
+			callback.mergeSettings(settings);
+		}
+		return settings;
+	}
+
 	private boolean assetsAreUpToDate() {
 		return doneFile.lastModified() > getLastUpdateTime();
 	}
@@ -393,11 +414,11 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 				tryToClose(ss, LOG, WARNING);
 				return;
 			}
-			if (!running) {
+			if (!state.setServerSocket(ss)) {
+				LOG.info("Closing redundant server socket");
 				tryToClose(ss, LOG, WARNING);
 				return;
 			}
-			socket = ss;
 			// Store the port number
 			String localPort = String.valueOf(ss.getLocalPort());
 			Settings s = new Settings();
@@ -412,7 +433,7 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	}
 
 	private void publishHiddenService(String port) {
-		if (!running) return;
+		if (!state.isTorRunning()) return;
 		LOG.info("Creating hidden service");
 		String privKey = settings.get(HS_PRIVKEY);
 		Map<Integer, String> portLines = singletonMap(80, "127.0.0.1:" + port);
@@ -450,14 +471,15 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	}
 
 	private void acceptContactConnections(ServerSocket ss) {
-		while (running) {
+		while (true) {
 			Socket s;
 			try {
 				s = ss.accept();
 				s.setSoTimeout(socketTimeout);
 			} catch (IOException e) {
-				// This is expected when the socket is closed
-				if (LOG.isLoggable(INFO)) LOG.info(e.toString());
+				// This is expected when the server socket is closed
+				LOG.info("Server socket closed");
+				state.clearServerSocket(ss);
 				return;
 			}
 			LOG.info("Connection received");
@@ -467,10 +489,8 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	}
 
 	protected void enableNetwork(boolean enable) throws IOException {
-		if (!running) return;
-		connectionStatus.enableNetwork(enable);
+		state.enableNetwork(enable);
 		controlConnection.setConf("DisableNetwork", enable ? "0" : "1");
-		if (!enable) callback.transportDisabled();
 	}
 
 	private void enableBridges(boolean enable, boolean needsMeek)
@@ -494,9 +514,8 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 
 	@Override
 	public void stop() {
-		running = false;
-		tryToClose(socket, LOG, WARNING);
-		callback.transportDisabled();
+		ServerSocket ss = state.setStopped();
+		tryToClose(ss, LOG, WARNING);
 		if (controlSocket != null && controlConnection != null) {
 			try {
 				LOG.info("Stopping Tor");
@@ -510,8 +529,13 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	}
 
 	@Override
-	public boolean isRunning() {
-		return running && connectionStatus.isConnected();
+	public State getState() {
+		return state.getState();
+	}
+
+	@Override
+	public int getReasonDisabled() {
+		return state.getReasonDisabled();
 	}
 
 	@Override
@@ -527,7 +551,7 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	@Override
 	public void poll(Collection<Pair<TransportProperties, ConnectionHandler>>
 			properties) {
-		if (!isRunning()) return;
+		if (getState() != ACTIVE) return;
 		backoff.increment();
 		for (Pair<TransportProperties, ConnectionHandler> p : properties) {
 			connect(p.getFirst(), p.getSecond());
@@ -546,7 +570,7 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 
 	@Override
 	public DuplexTransportConnection createConnection(TransportProperties p) {
-		if (!isRunning()) return null;
+		if (getState() != ACTIVE) return null;
 		String bestOnion = null;
 		String onion2 = p.get(PROP_ONION_V2);
 		String onion3 = p.get(PROP_ONION_V3);
@@ -634,8 +658,8 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 								new TorTransportConnection(this, s));
 					}
 				} catch (IOException e) {
-					// This is expected when the socket is closed
-					if (LOG.isLoggable(INFO)) LOG.info(e.toString());
+					// This is expected when the server socket is closed
+					LOG.info("Rendezvous server socket closed");
 				}
 			});
 			Map<Integer, String> portLines =
@@ -663,10 +687,9 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	@Override
 	public void circuitStatus(String status, String id, String path) {
 		if (status.equals("BUILT") &&
-				connectionStatus.getAndSetCircuitBuilt()) {
+				state.getAndSetCircuitBuilt()) {
 			LOG.info("First circuit built");
 			backoff.reset();
-			if (isRunning()) callback.transportEnabled();
 		}
 	}
 
@@ -697,9 +720,8 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	public void message(String severity, String msg) {
 		if (LOG.isLoggable(INFO)) LOG.info(severity + " " + msg);
 		if (severity.equals("NOTICE") && msg.startsWith("Bootstrapped 100%")) {
-			connectionStatus.setBootstrapped();
+			state.setBootstrapped();
 			backoff.reset();
-			if (isRunning()) callback.transportEnabled();
 		}
 	}
 
@@ -736,7 +758,7 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	private void disableNetwork() {
 		connectionStatusExecutor.execute(() -> {
 			try {
-				enableNetwork(false);
+				if (state.isTorRunning()) enableNetwork(false);
 			} catch (IOException ex) {
 				logException(LOG, WARNING, ex);
 			}
@@ -746,12 +768,13 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	private void updateConnectionStatus(NetworkStatus status,
 			boolean charging) {
 		connectionStatusExecutor.execute(() -> {
-			if (!running) return;
+			if (!state.isTorRunning()) return;
 			boolean online = status.isConnected();
 			boolean wifi = status.isWifi();
 			String country = locationUtils.getCurrentCountry();
 			boolean blocked =
 					circumventionProvider.isTorProbablyBlocked(country);
+			boolean enabledByUser = settings.getBoolean(PREF_PLUGIN_ENABLE, true);
 			int network = settings.getInt(PREF_TOR_NETWORK,
 					PREF_TOR_NETWORK_AUTOMATIC);
 			boolean useMobile = settings.getBoolean(PREF_TOR_MOBILE, true);
@@ -762,47 +785,67 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 
 			if (LOG.isLoggable(INFO)) {
 				LOG.info("Online: " + online + ", wifi: " + wifi);
-				if ("".equals(country)) LOG.info("Country code unknown");
+				if (country.isEmpty()) LOG.info("Country code unknown");
 				else LOG.info("Country code: " + country);
 				LOG.info("Charging: " + charging);
 			}
 
-			try {
-				if (!online) {
-					LOG.info("Disabling network, device is offline");
-					enableNetwork(false);
-				} else if (!charging && onlyWhenCharging) {
-					LOG.info("Disabling network, device is on battery");
-					enableNetwork(false);
-				} else if (network == PREF_TOR_NETWORK_NEVER ||
-						(!useMobile && !wifi)) {
-					LOG.info("Disabling network, device is using mobile data");
-					enableNetwork(false);
-				} else if (automatic && blocked && !bridgesWork) {
-					LOG.info("Disabling network, country is blocked");
-					enableNetwork(false);
-				} else if (network == PREF_TOR_NETWORK_WITH_BRIDGES ||
+			boolean enableNetwork = false, enableBridges = false;
+			boolean useMeek = false, enableConnectionPadding = false;
+			boolean disabledBySettings = false;
+			int reasonDisabled = REASON_STARTING_STOPPING;
+
+			if (!online) {
+				LOG.info("Disabling network, device is offline");
+			} else if (!enabledByUser) {
+				LOG.info("Disabling network, user has disabled Tor");
+				disabledBySettings = true;
+				reasonDisabled = REASON_USER;
+			} else if (!charging && onlyWhenCharging) {
+				LOG.info("Disabling network, device is on battery");
+				disabledBySettings = true;
+				reasonDisabled = REASON_BATTERY;
+			} else if (!useMobile && !wifi) {
+				LOG.info("Disabling network, device is using mobile data");
+				disabledBySettings = true;
+				reasonDisabled = REASON_MOBILE_DATA;
+			} else if (automatic && blocked && !bridgesWork) {
+				LOG.info("Disabling network, country is blocked");
+				disabledBySettings = true;
+				reasonDisabled = REASON_COUNTRY_BLOCKED;
+			} else {
+				LOG.info("Enabling network");
+				enableNetwork = true;
+				if (network == PREF_TOR_NETWORK_WITH_BRIDGES ||
 						(automatic && bridgesWork)) {
 					if (circumventionProvider.needsMeek(country)) {
-						LOG.info("Enabling network, using meek bridges");
-						enableBridges(true, true);
+						LOG.info("Using meek bridges");
+						enableBridges = true;
+						useMeek = true;
 					} else {
-						LOG.info("Enabling network, using obfs4 bridges");
-						enableBridges(true, false);
+						LOG.info("Using obfs4 bridges");
+						enableBridges = true;
 					}
-					enableNetwork(true);
 				} else {
-					LOG.info("Enabling network, not using bridges");
-					enableBridges(false, false);
-					enableNetwork(true);
+					LOG.info("Not using bridges");
 				}
-				if (online && wifi && charging) {
+				if (wifi && charging) {
 					LOG.info("Enabling connection padding");
-					enableConnectionPadding(true);
+					enableConnectionPadding = true;
 				} else {
 					LOG.info("Disabling connection padding");
-					enableConnectionPadding(false);
 				}
+			}
+
+
+			state.setDisabledBySettings(disabledBySettings, reasonDisabled);
+
+			try {
+				if (enableNetwork) {
+					enableBridges(enableBridges, useMeek);
+					enableConnectionPadding(enableConnectionPadding);
+				}
+				enableNetwork(enableNetwork);
 			} catch (IOException e) {
 				logException(LOG, WARNING, e);
 			}
@@ -810,33 +853,100 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	}
 
 	private void enableConnectionPadding(boolean enable) throws IOException {
-		if (!running) return;
 		controlConnection.setConf("ConnectionPadding", enable ? "1" : "0");
 	}
 
-	private static class ConnectionStatus {
+	@ThreadSafe
+	@NotNullByDefault
+	protected class PluginState {
 
-		// All of the following are locking: this
-		private boolean networkEnabled = false;
-		private boolean bootstrapped = false, circuitBuilt = false;
+		@GuardedBy("this")
+		private boolean started = false,
+				stopped = false,
+				torStarted = false,
+				networkInitialised = false,
+				networkEnabled = false,
+				bootstrapped = false,
+				circuitBuilt = false,
+				disabledBySettings = false;
 
-		private synchronized void setBootstrapped() {
-			bootstrapped = true;
+		@GuardedBy("this")
+		private int reasonDisabled = REASON_STARTING_STOPPING;
+
+		@GuardedBy("this")
+		@Nullable
+		private ServerSocket serverSocket = null;
+
+		synchronized void setStarted() {
+			started = true;
+			callback.pluginStateChanged(getState());
 		}
 
-		private synchronized boolean getAndSetCircuitBuilt() {
+		// Doesn't affect getState()
+		synchronized void setTorStarted() {
+			torStarted = true;
+		}
+
+		synchronized boolean isTorRunning() {
+			return torStarted && !stopped;
+		}
+
+		@Nullable
+		synchronized ServerSocket setStopped() {
+			stopped = true;
+			ServerSocket ss = serverSocket;
+			serverSocket = null;
+			callback.pluginStateChanged(getState());
+			return ss;
+		}
+
+		synchronized void setBootstrapped() {
+			bootstrapped = true;
+			callback.pluginStateChanged(getState());
+		}
+
+		synchronized boolean getAndSetCircuitBuilt() {
 			boolean firstCircuit = !circuitBuilt;
 			circuitBuilt = true;
+			callback.pluginStateChanged(getState());
 			return firstCircuit;
 		}
 
-		private synchronized void enableNetwork(boolean enable) {
+		synchronized void enableNetwork(boolean enable) {
+			networkInitialised = true;
 			networkEnabled = enable;
 			if (!enable) circuitBuilt = false;
+			callback.pluginStateChanged(getState());
 		}
 
-		private synchronized boolean isConnected() {
-			return networkEnabled && bootstrapped && circuitBuilt;
+		synchronized void setDisabledBySettings(boolean disabledBySettings,
+				int reasonDisabled) {
+			this.disabledBySettings = disabledBySettings;
+			this.reasonDisabled = reasonDisabled;
+			callback.pluginStateChanged(getState());
+		}
+
+		// Doesn't affect getState()
+		synchronized boolean setServerSocket(ServerSocket ss) {
+			if (stopped || serverSocket != null) return false;
+			serverSocket = ss;
+			return true;
+		}
+
+		// Doesn't affect getState()
+		synchronized void clearServerSocket(ServerSocket ss) {
+			if (serverSocket == ss) serverSocket = null;
+		}
+
+		synchronized State getState() {
+			if (!started || stopped || disabledBySettings) return DISABLED;
+			if (!networkInitialised) return ENABLING;
+			if (!networkEnabled) return INACTIVE;
+			return bootstrapped && circuitBuilt ? ACTIVE : ENABLING;
+		}
+
+		synchronized int getReasonDisabled() {
+			return getState() == DISABLED ? reasonDisabled : -1;
 		}
 	}
 }

bramble-core/src/main/java/org/briarproject/bramble/rendezvous/RendezvousPollerImpl.java

@@ -31,8 +31,8 @@ import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
 import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
-import org.briarproject.bramble.api.plugin.event.TransportDisabledEvent;
-import org.briarproject.bramble.api.plugin.event.TransportEnabledEvent;
+import org.briarproject.bramble.api.plugin.event.TransportActiveEvent;
+import org.briarproject.bramble.api.plugin.event.TransportInactiveEvent;
 import org.briarproject.bramble.api.properties.TransportProperties;
 import org.briarproject.bramble.api.rendezvous.KeyMaterialSource;
 import org.briarproject.bramble.api.rendezvous.RendezvousEndpoint;
@@ -269,11 +269,11 @@ class RendezvousPollerImpl implements RendezvousPoller, Service, EventListener {
 		} else if (e instanceof PendingContactRemovedEvent) {
 			PendingContactRemovedEvent p = (PendingContactRemovedEvent) e;
 			removePendingContactAsync(p.getId());
-		} else if (e instanceof TransportEnabledEvent) {
-			TransportEnabledEvent t = (TransportEnabledEvent) e;
+		} else if (e instanceof TransportActiveEvent) {
+			TransportActiveEvent t = (TransportActiveEvent) e;
 			addTransportAsync(t.getTransportId());
-		} else if (e instanceof TransportDisabledEvent) {
-			TransportDisabledEvent t = (TransportDisabledEvent) e;
+		} else if (e instanceof TransportInactiveEvent) {
+			TransportInactiveEvent t = (TransportInactiveEvent) e;
 			removeTransportAsync(t.getTransportId());
 		} else if (e instanceof RendezvousConnectionOpenedEvent) {
 			RendezvousConnectionOpenedEvent r =

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

@@ -6,7 +6,7 @@ import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.TorConstants;
-import org.briarproject.bramble.api.plugin.event.TransportEnabledEvent;
+import org.briarproject.bramble.api.plugin.event.TransportActiveEvent;
 import org.briarproject.bramble.api.reporting.DevConfig;
 import org.briarproject.bramble.api.reporting.DevReporter;
 import org.briarproject.bramble.util.IoUtils;
@@ -92,8 +92,8 @@ class DevReporterImpl implements DevReporter, EventListener {
 
 	@Override
 	public void eventOccurred(Event e) {
-		if (e instanceof TransportEnabledEvent) {
-			TransportEnabledEvent t = (TransportEnabledEvent) e;
+		if (e instanceof TransportActiveEvent) {
+			TransportActiveEvent t = (TransportActiveEvent) e;
 			if (t.getTransportId().equals(TorConstants.ID))
 				ioExecutor.execute(this::sendReports);
 		}

bramble-core/src/test/java/org/briarproject/bramble/plugin/PollerImplTest.java

@@ -13,8 +13,8 @@ import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
 import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
 import org.briarproject.bramble.api.plugin.event.ConnectionClosedEvent;
 import org.briarproject.bramble.api.plugin.event.ConnectionOpenedEvent;
-import org.briarproject.bramble.api.plugin.event.TransportDisabledEvent;
-import org.briarproject.bramble.api.plugin.event.TransportEnabledEvent;
+import org.briarproject.bramble.api.plugin.event.TransportActiveEvent;
+import org.briarproject.bramble.api.plugin.event.TransportInactiveEvent;
 import org.briarproject.bramble.api.plugin.simplex.SimplexPlugin;
 import org.briarproject.bramble.api.properties.TransportProperties;
 import org.briarproject.bramble.api.properties.TransportPropertyManager;
@@ -322,7 +322,7 @@ public class PollerImplTest extends BrambleMockTestCase {
 	}
 
 	@Test
-	public void testPollsOnTransportEnabled() throws Exception {
+	public void testPollsOnTransportActivated() throws Exception {
 		DuplexPlugin plugin = context.mock(DuplexPlugin.class);
 
 		context.checking(new Expectations() {{
@@ -361,7 +361,7 @@ public class PollerImplTest extends BrambleMockTestCase {
 					pairOf(equal(properties), any(ConnectionHandler.class)))));
 		}});
 
-		poller.eventOccurred(new TransportEnabledEvent(transportId));
+		poller.eventOccurred(new TransportActiveEvent(transportId));
 	}
 
 	@Test
@@ -402,11 +402,11 @@ public class PollerImplTest extends BrambleMockTestCase {
 			// All contacts are connected, so don't poll the plugin
 		}});
 
-		poller.eventOccurred(new TransportEnabledEvent(transportId));
+		poller.eventOccurred(new TransportActiveEvent(transportId));
 	}
 
 	@Test
-	public void testCancelsPollingOnTransportDisabled() {
+	public void testCancelsPollingOnTransportDeactivated() {
 		Plugin plugin = context.mock(Plugin.class);
 
 		context.checking(new Expectations() {{
@@ -424,11 +424,11 @@ public class PollerImplTest extends BrambleMockTestCase {
 			oneOf(scheduler).schedule(with(any(Runnable.class)), with(0L),
 					with(MILLISECONDS));
 			will(returnValue(future));
-			// The plugin is disabled before the task runs - cancel the task
+			// The plugin is deactivated before the task runs - cancel the task
 			oneOf(future).cancel(false);
 		}});
 
-		poller.eventOccurred(new TransportEnabledEvent(transportId));
-		poller.eventOccurred(new TransportDisabledEvent(transportId));
+		poller.eventOccurred(new TransportActiveEvent(transportId));
+		poller.eventOccurred(new TransportInactiveEvent(transportId));
 	}
 }

bramble-core/src/test/java/org/briarproject/bramble/plugin/tcp/LanTcpPluginTest.java

@@ -4,6 +4,7 @@ import org.briarproject.bramble.api.data.BdfList;
 import org.briarproject.bramble.api.keyagreement.KeyAgreementListener;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.Backoff;
+import org.briarproject.bramble.api.plugin.Plugin.State;
 import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.plugin.TransportConnectionReader;
 import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
@@ -33,6 +34,7 @@ import static java.util.concurrent.Executors.newCachedThreadPool;
 import static java.util.concurrent.TimeUnit.SECONDS;
 import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.COMMIT_LENGTH;
 import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.TRANSPORT_ID_LAN;
+import static org.briarproject.bramble.api.plugin.Plugin.PREF_PLUGIN_ENABLE;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
@@ -327,6 +329,7 @@ public class LanTcpPluginTest extends BrambleTestCase {
 		assertEquals(0, comparator.compare(linkLocal, linkLocal));
 	}
 
+	@SuppressWarnings("BooleanMethodIsAlwaysInverted")
 	private boolean systemHasLocalIpv4Address() throws Exception {
 		for (NetworkInterface i : list(getNetworkInterfaces())) {
 			for (InetAddress a : list(i.getInetAddresses())) {
@@ -343,10 +346,15 @@ public class LanTcpPluginTest extends BrambleTestCase {
 		private final CountDownLatch propertiesLatch = new CountDownLatch(1);
 		private final CountDownLatch connectionsLatch = new CountDownLatch(1);
 		private final TransportProperties local = new TransportProperties();
+		private final Settings settings = new Settings();
+
+		private Callback() {
+			settings.putBoolean(PREF_PLUGIN_ENABLE, true);
+		}
 
 		@Override
 		public Settings getSettings() {
-			return new Settings();
+			return settings;
 		}
 
 		@Override
@@ -365,11 +373,7 @@ public class LanTcpPluginTest extends BrambleTestCase {
 		}
 
 		@Override
-		public void transportEnabled() {
-		}
-
-		@Override
-		public void transportDisabled() {
+		public void pluginStateChanged(State newState) {
 		}
 
 		@Override

bramble-core/src/test/java/org/briarproject/bramble/rendezvous/RendezvousPollerImplTest.java

@@ -17,8 +17,8 @@ import org.briarproject.bramble.api.plugin.ConnectionManager;
 import org.briarproject.bramble.api.plugin.PluginManager;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
-import org.briarproject.bramble.api.plugin.event.TransportDisabledEvent;
-import org.briarproject.bramble.api.plugin.event.TransportEnabledEvent;
+import org.briarproject.bramble.api.plugin.event.TransportActiveEvent;
+import org.briarproject.bramble.api.plugin.event.TransportInactiveEvent;
 import org.briarproject.bramble.api.properties.TransportProperties;
 import org.briarproject.bramble.api.rendezvous.KeyMaterialSource;
 import org.briarproject.bramble.api.rendezvous.RendezvousEndpoint;
@@ -178,10 +178,10 @@ public class RendezvousPollerImplTest extends BrambleMockTestCase {
 		rendezvousPoller.startService();
 		context.assertIsSatisfied();
 
-		// Enable the transport - no endpoints should be created yet
+		// Activate the transport - no endpoints should be created yet
 		expectGetPlugin();
 
-		rendezvousPoller.eventOccurred(new TransportEnabledEvent(transportId));
+		rendezvousPoller.eventOccurred(new TransportActiveEvent(transportId));
 		context.assertIsSatisfied();
 
 		// Add the pending contact - endpoint should be created and polled
@@ -212,8 +212,8 @@ public class RendezvousPollerImplTest extends BrambleMockTestCase {
 				new PendingContactRemovedEvent(pendingContact.getId()));
 		context.assertIsSatisfied();
 
-		// Disable the transport - endpoint is already closed
-		rendezvousPoller.eventOccurred(new TransportDisabledEvent(transportId));
+		// Deactivate the transport - endpoint is already closed
+		rendezvousPoller.eventOccurred(new TransportInactiveEvent(transportId));
 	}
 
 	@Test
@@ -230,10 +230,10 @@ public class RendezvousPollerImplTest extends BrambleMockTestCase {
 		rendezvousPoller.startService();
 		context.assertIsSatisfied();
 
-		// Enable the transport - no endpoints should be created yet
+		// Activate the transport - no endpoints should be created yet
 		expectGetPlugin();
 
-		rendezvousPoller.eventOccurred(new TransportEnabledEvent(transportId));
+		rendezvousPoller.eventOccurred(new TransportActiveEvent(transportId));
 		context.assertIsSatisfied();
 
 		// Add the pending contact - endpoint should be created and polled
@@ -269,12 +269,12 @@ public class RendezvousPollerImplTest extends BrambleMockTestCase {
 				new PendingContactRemovedEvent(pendingContact.getId()));
 		context.assertIsSatisfied();
 
-		// Disable the transport - endpoint is already closed
-		rendezvousPoller.eventOccurred(new TransportDisabledEvent(transportId));
+		// Deactivate the transport - endpoint is already closed
+		rendezvousPoller.eventOccurred(new TransportInactiveEvent(transportId));
 	}
 
 	@Test
-	public void testCreatesAndClosesEndpointsWhenTransportIsEnabledAndDisabled()
+	public void testCreatesAndClosesEndpointsWhenTransportIsActivatedAndDeactivated()
 			throws Exception {
 		long beforeExpiry = pendingContact.getTimestamp();
 
@@ -292,19 +292,19 @@ public class RendezvousPollerImplTest extends BrambleMockTestCase {
 				new PendingContactAddedEvent(pendingContact));
 		context.assertIsSatisfied();
 
-		// Enable the transport - endpoint should be created
+		// Activate the transport - endpoint should be created
 		expectGetPlugin();
 		expectCreateEndpoint();
 		expectStateChangedEvent(WAITING_FOR_CONNECTION);
 
-		rendezvousPoller.eventOccurred(new TransportEnabledEvent(transportId));
+		rendezvousPoller.eventOccurred(new TransportActiveEvent(transportId));
 		context.assertIsSatisfied();
 
-		// Disable the transport - endpoint should be closed
+		// Deactivate the transport - endpoint should be closed
 		expectCloseEndpoint();
 		expectStateChangedEvent(OFFLINE);
 
-		rendezvousPoller.eventOccurred(new TransportDisabledEvent(transportId));
+		rendezvousPoller.eventOccurred(new TransportInactiveEvent(transportId));
 		context.assertIsSatisfied();
 
 		// Remove the pending contact - endpoint is already closed

bramble-java/src/main/java/org/briarproject/bramble/plugin/DesktopPluginModule.java

@@ -37,9 +37,9 @@ public class DesktopPluginModule extends PluginModule {
 						backoffFactory);
 		DuplexPluginFactory modem = new ModemPluginFactory(ioExecutor,
 				reliabilityFactory);
-		DuplexPluginFactory lan = new LanTcpPluginFactory(ioExecutor,
+		DuplexPluginFactory lan = new LanTcpPluginFactory(ioExecutor, eventBus,
 				backoffFactory);
-		DuplexPluginFactory wan = new WanTcpPluginFactory(ioExecutor,
+		DuplexPluginFactory wan = new WanTcpPluginFactory(ioExecutor, eventBus,
 				backoffFactory, shutdownManager);
 		Collection<DuplexPluginFactory> duplex =
 				asList(bluetooth, modem, lan, wan);

bramble-java/src/main/java/org/briarproject/bramble/plugin/modem/ModemPlugin.java

@@ -4,6 +4,7 @@ import org.briarproject.bramble.api.Pair;
 import org.briarproject.bramble.api.data.BdfList;
 import org.briarproject.bramble.api.keyagreement.KeyAgreementListener;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.bramble.api.plugin.ConnectionHandler;
 import org.briarproject.bramble.api.plugin.PluginCallback;
@@ -23,9 +24,16 @@ import java.util.Collection;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.logging.Logger;
 
+import javax.annotation.concurrent.GuardedBy;
+import javax.annotation.concurrent.ThreadSafe;
+
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.api.plugin.Plugin.State.ACTIVE;
+import static org.briarproject.bramble.api.plugin.Plugin.State.DISABLED;
+import static org.briarproject.bramble.api.plugin.Plugin.State.ENABLING;
+import static org.briarproject.bramble.api.plugin.Plugin.State.INACTIVE;
 import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.bramble.util.StringUtils.isNullOrEmpty;
 
@@ -44,8 +52,8 @@ class ModemPlugin implements DuplexPlugin, Modem.Callback {
 	private final PluginCallback callback;
 	private final int maxLatency;
 	private final AtomicBoolean used = new AtomicBoolean(false);
+	private final PluginState state = new PluginState();
 
-	private volatile boolean running = false;
 	private volatile Modem modem = null;
 
 	ModemPlugin(ModemFactory modemFactory, SerialPortList serialPortList,
@@ -75,6 +83,7 @@ class ModemPlugin implements DuplexPlugin, Modem.Callback {
 	@Override
 	public void start() throws PluginException {
 		if (used.getAndSet(true)) throw new IllegalStateException();
+		state.setStarted();
 		for (String portName : serialPortList.getPortNames()) {
 			if (LOG.isLoggable(INFO))
 				LOG.info("Trying to initialise modem on " + portName);
@@ -83,18 +92,20 @@ class ModemPlugin implements DuplexPlugin, Modem.Callback {
 				if (!modem.start()) continue;
 				if (LOG.isLoggable(INFO))
 					LOG.info("Initialised modem on " + portName);
-				running = true;
+				state.setInitialised();
 				return;
 			} catch (IOException e) {
 				logException(LOG, WARNING, e);
 			}
 		}
+		LOG.warning("Failed to initialised modem");
+		state.setFailed();
 		throw new PluginException();
 	}
 
 	@Override
 	public void stop() {
-		running = false;
+		state.setStopped();
 		if (modem != null) {
 			try {
 				modem.stop();
@@ -105,8 +116,13 @@ class ModemPlugin implements DuplexPlugin, Modem.Callback {
 	}
 
 	@Override
-	public boolean isRunning() {
-		return running;
+	public State getState() {
+		return state.getState();
+	}
+
+	@Override
+	public int getReasonDisabled() {
+		return getState() == DISABLED ? REASON_STARTING_STOPPING : -1;
 	}
 
 	@Override
@@ -125,8 +141,8 @@ class ModemPlugin implements DuplexPlugin, Modem.Callback {
 		throw new UnsupportedOperationException();
 	}
 
-	private boolean resetModem() {
-		if (!running) return false;
+	private void resetModem() {
+		if (getState() != ACTIVE) return;
 		for (String portName : serialPortList.getPortNames()) {
 			if (LOG.isLoggable(INFO))
 				LOG.info("Trying to initialise modem on " + portName);
@@ -135,18 +151,18 @@ class ModemPlugin implements DuplexPlugin, Modem.Callback {
 				if (!modem.start()) continue;
 				if (LOG.isLoggable(INFO))
 					LOG.info("Initialised modem on " + portName);
-				return true;
+				return;
 			} catch (IOException e) {
 				logException(LOG, WARNING, e);
 			}
 		}
-		running = false;
-		return false;
+		LOG.warning("Failed to initialise modem");
+		state.setFailed();
 	}
 
 	@Override
 	public DuplexTransportConnection createConnection(TransportProperties p) {
-		if (!running) return null;
+		if (getState() != ACTIVE) return null;
 		// Get the ISO 3166 code for the caller's country
 		String fromIso = callback.getLocalProperties().get("iso3166");
 		if (isNullOrEmpty(fromIso)) return null;
@@ -232,4 +248,41 @@ class ModemPlugin implements DuplexPlugin, Modem.Callback {
 			if (exception) resetModem();
 		}
 	}
+
+	@ThreadSafe
+	@NotNullByDefault
+	private class PluginState {
+
+		@GuardedBy("this")
+		private boolean started = false,
+				stopped = false,
+				initialised = false,
+				failed = false;
+
+		private synchronized void setStarted() {
+			started = true;
+			callback.pluginStateChanged(getState());
+		}
+
+		private synchronized void setStopped() {
+			stopped = true;
+			callback.pluginStateChanged(getState());
+		}
+
+		private synchronized void setInitialised() {
+			initialised = true;
+			callback.pluginStateChanged(getState());
+		}
+
+		private synchronized void setFailed() {
+			failed = true;
+			callback.pluginStateChanged(getState());
+		}
+
+		private State getState() {
+			if (!started || stopped) return DISABLED;
+			if (failed) return INACTIVE;
+			return initialised ? ACTIVE : ENABLING;
+		}
+	}
 }

bramble-java/src/test/java/org/briarproject/bramble/plugin/modem/ModemPluginTest.java

@@ -9,6 +9,8 @@ import org.junit.Test;
 
 import java.io.IOException;
 
+import static org.briarproject.bramble.api.plugin.Plugin.State.ACTIVE;
+import static org.briarproject.bramble.api.plugin.Plugin.State.ENABLING;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
 
@@ -33,6 +35,7 @@ public class ModemPluginTest extends BrambleMockTestCase {
 	@Test
 	public void testModemCreation() throws Exception {
 		context.checking(new Expectations() {{
+			oneOf(callback).pluginStateChanged(ENABLING);
 			oneOf(serialPortList).getPortNames();
 			will(returnValue(new String[] {"foo", "bar", "baz"}));
 			// First call to createModem() returns false
@@ -50,6 +53,7 @@ public class ModemPluginTest extends BrambleMockTestCase {
 			will(returnValue(modem));
 			oneOf(modem).start();
 			will(returnValue(true));
+			oneOf(callback).pluginStateChanged(ACTIVE);
 		}});
 
 		plugin.start();
@@ -65,12 +69,14 @@ public class ModemPluginTest extends BrambleMockTestCase {
 
 		context.checking(new Expectations() {{
 			// start()
+			oneOf(callback).pluginStateChanged(ENABLING);
 			oneOf(serialPortList).getPortNames();
 			will(returnValue(new String[] {"foo"}));
 			oneOf(modemFactory).createModem(plugin, "foo");
 			will(returnValue(modem));
 			oneOf(modem).start();
 			will(returnValue(true));
+			oneOf(callback).pluginStateChanged(ACTIVE);
 			// createConnection()
 			oneOf(callback).getLocalProperties();
 			will(returnValue(local));
@@ -93,12 +99,14 @@ public class ModemPluginTest extends BrambleMockTestCase {
 
 		context.checking(new Expectations() {{
 			// start()
+			oneOf(callback).pluginStateChanged(ENABLING);
 			oneOf(serialPortList).getPortNames();
 			will(returnValue(new String[] {"foo"}));
 			oneOf(modemFactory).createModem(plugin, "foo");
 			will(returnValue(modem));
 			oneOf(modem).start();
 			will(returnValue(true));
+			oneOf(callback).pluginStateChanged(ACTIVE);
 			// createConnection()
 			oneOf(callback).getLocalProperties();
 			will(returnValue(local));
@@ -121,12 +129,14 @@ public class ModemPluginTest extends BrambleMockTestCase {
 
 		context.checking(new Expectations() {{
 			// start()
+			oneOf(callback).pluginStateChanged(ENABLING);
 			oneOf(serialPortList).getPortNames();
 			will(returnValue(new String[] {"foo"}));
 			oneOf(modemFactory).createModem(plugin, "foo");
 			will(returnValue(modem));
 			oneOf(modem).start();
 			will(returnValue(true));
+			oneOf(callback).pluginStateChanged(ACTIVE);
 			// createConnection()
 			oneOf(callback).getLocalProperties();
 			will(returnValue(local));

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

@@ -32,6 +32,7 @@ import javax.net.SocketFactory;
 import static java.util.Collections.singletonList;
 import static java.util.concurrent.TimeUnit.SECONDS;
 import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.api.plugin.Plugin.State.ACTIVE;
 import static org.briarproject.bramble.test.TestUtils.deleteTestDirectory;
 import static org.briarproject.bramble.test.TestUtils.getTestDirectory;
 import static org.briarproject.bramble.test.TestUtils.isOptionalTestEnabled;
@@ -141,10 +142,10 @@ public class BridgeTest extends BrambleTestCase {
 			plugin.start();
 			long start = clock.currentTimeMillis();
 			while (clock.currentTimeMillis() - start < TIMEOUT) {
-				if (plugin.isRunning()) return;
+				if (plugin.getState() == ACTIVE) return;
 				clock.sleep(500);
 			}
-			if (!plugin.isRunning()) {
+			if (plugin.getState() != ACTIVE) {
 				fail("Could not connect to Tor within timeout.");
 			}
 		} finally {

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

@@ -1,6 +1,7 @@
 package org.briarproject.bramble.plugin.tor;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.Plugin.State;
 import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.plugin.TransportConnectionReader;
 import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
@@ -30,11 +31,7 @@ public class TestPluginCallback implements PluginCallback {
 	}
 
 	@Override
-	public void transportEnabled() {
-	}
-
-	@Override
-	public void transportDisabled() {
+	public void pluginStateChanged(State state) {
 	}
 
 	@Override

briar-android/artwork/transports_list_scene.xml

@@ -0,0 +1,117 @@
+<?xml version="1.0" encoding="utf-8"?>
+<MotionScene xmlns:android="http://schemas.android.com/apk/res/android"
+	xmlns:app="http://schemas.android.com/apk/res-auto">
+
+	<Transition
+		app:constraintSetEnd="@+id/end"
+		app:constraintSetStart="@id/start"
+		app:duration="1000">
+		<OnClick app:targetId="@+id/chevronView" />
+	</Transition>
+
+	<ConstraintSet android:id="@+id/start">
+		<Constraint
+			android:id="@+id/chevronView"
+			android:layout_width="0dp"
+			android:layout_height="24dp"
+			android:layout_marginBottom="8dp"
+			app:layout_constraintBottom_toTopOf="@+id/longRangeLabel"
+			app:layout_constraintEnd_toEndOf="parent"
+			app:layout_constraintStart_toStartOf="parent"
+			app:layout_constraintTop_toBottomOf="@+id/navigation"
+			app:layout_constraintVertical_bias="1.0">
+			<CustomAttribute
+				app:attributeName="crossfade"
+				app:customFloatValue="0" />
+		</Constraint>
+	</ConstraintSet>
+
+	<ConstraintSet android:id="@+id/end">
+		<Constraint
+			android:id="@+id/chevronView"
+			android:layout_width="0dp"
+			android:layout_height="24dp"
+			android:layout_marginBottom="8dp"
+			app:layout_constraintBottom_toTopOf="@+id/connectionsLabel"
+			app:layout_constraintEnd_toEndOf="parent"
+			app:layout_constraintStart_toStartOf="parent"
+			app:layout_constraintVertical_bias="1.0">
+			<CustomAttribute
+				app:attributeName="crossfade"
+				app:customFloatValue="1" />
+		</Constraint>
+		<Constraint
+			android:id="@+id/backgroundView"
+			android:layout_width="0dp"
+			android:layout_height="0dp"
+			app:layout_constraintBottom_toBottomOf="parent"
+			app:layout_constraintEnd_toEndOf="parent"
+			app:layout_constraintStart_toStartOf="parent"
+			app:layout_constraintTop_toBottomOf="@+id/chevronView" />
+		<Constraint
+			android:id="@+id/torSwitch"
+			android:visibility="gone"
+			app:layout_constraintBottom_toTopOf="@id/nearbyLabel"
+			app:layout_constraintStart_toEndOf="parent" />
+		<Constraint
+			android:id="@+id/wifiSwitch"
+			android:visibility="gone"
+			app:layout_constraintBottom_toTopOf="@+id/btSwitch"
+			app:layout_constraintStart_toEndOf="parent" />
+		<Constraint
+			android:id="@+id/btSwitch"
+			android:visibility="gone"
+			app:layout_constraintBottom_toBottomOf="parent"
+			app:layout_constraintStart_toEndOf="parent" />
+		<Constraint
+			android:id="@+id/longRangeLabel"
+			android:visibility="gone"
+			app:layout_constraintBottom_toTopOf="@+id/torSwitch"
+			app:layout_constraintStart_toEndOf="parent" />
+		<Constraint
+			android:id="@+id/nearbyLabel"
+			android:visibility="gone"
+			app:layout_constraintBottom_toTopOf="@+id/wifiSwitch"
+			app:layout_constraintStart_toEndOf="parent" />
+		<Constraint
+			android:id="@+id/torIcon"
+			android:layout_width="20dp"
+			android:layout_height="20dp"
+			android:layout_marginEnd="8dp"
+			android:layout_marginRight="8dp"
+			app:layout_constraintBottom_toBottomOf="parent"
+			app:layout_constraintEnd_toStartOf="@+id/wifiIcon"
+			app:layout_constraintTop_toBottomOf="@+id/chevronView" />
+		<Constraint
+			android:id="@+id/wifiIcon"
+			android:layout_width="20dp"
+			android:layout_height="20dp"
+			android:layout_marginEnd="8dp"
+			android:layout_marginRight="8dp"
+			app:layout_constraintBottom_toBottomOf="parent"
+			app:layout_constraintEnd_toStartOf="@+id/btIcon"
+			app:layout_constraintTop_toBottomOf="@+id/chevronView" />
+		<Constraint
+			android:id="@+id/btIcon"
+			android:layout_width="20dp"
+			android:layout_height="20dp"
+			android:layout_marginTop="8dp"
+			android:layout_marginEnd="8dp"
+			android:layout_marginRight="8dp"
+			android:layout_marginBottom="8dp"
+			app:layout_constraintBottom_toBottomOf="parent"
+			app:layout_constraintEnd_toEndOf="parent"
+			app:layout_constraintTop_toBottomOf="@+id/chevronView" />
+		<Constraint
+			android:id="@+id/connectionsLabel"
+			android:layout_marginStart="8dp"
+			android:layout_marginLeft="8dp"
+			android:layout_marginEnd="8dp"
+			android:layout_marginRight="8dp"
+			android:visibility="visible"
+			app:layout_constraintBottom_toBottomOf="@+id/torIcon"
+			app:layout_constraintEnd_toStartOf="@+id/torIcon"
+			app:layout_constraintStart_toStartOf="parent"
+			app:layout_constraintTop_toTopOf="@+id/torIcon" />
+	</ConstraintSet>
+</MotionScene>

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

@@ -36,6 +36,7 @@ import org.briarproject.bramble.util.AndroidUtils;
 import org.briarproject.bramble.util.StringUtils;
 import org.briarproject.briar.android.account.LockManagerImpl;
 import org.briarproject.briar.android.keyagreement.ContactExchangeModule;
+import org.briarproject.briar.android.navdrawer.NavDrawerModule;
 import org.briarproject.briar.android.viewmodel.ViewModelModule;
 import org.briarproject.briar.api.android.AndroidNotificationManager;
 import org.briarproject.briar.api.android.DozeWatchdog;
@@ -64,7 +65,11 @@ import static org.briarproject.bramble.api.reporting.ReportingConstants.DEV_ONIO
 import static org.briarproject.bramble.api.reporting.ReportingConstants.DEV_PUBLIC_KEY_HEX;
 import static org.briarproject.briar.android.TestingConstants.IS_DEBUG_BUILD;
 
-@Module(includes = {ContactExchangeModule.class, ViewModelModule.class})
+@Module(includes = {
+		NavDrawerModule.class,
+		ContactExchangeModule.class,
+		ViewModelModule.class
+})
 public class AppModule {
 
 	static class EagerSingletons {

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

@@ -10,8 +10,6 @@ import org.briarproject.briar.android.controller.DbController;
 import org.briarproject.briar.android.controller.DbControllerImpl;
 import org.briarproject.briar.android.login.ChangePasswordController;
 import org.briarproject.briar.android.login.ChangePasswordControllerImpl;
-import org.briarproject.briar.android.navdrawer.NavDrawerController;
-import org.briarproject.briar.android.navdrawer.NavDrawerControllerImpl;
 
 import dagger.Module;
 import dagger.Provides;
@@ -67,14 +65,6 @@ public class ActivityModule {
 		return dbController;
 	}
 
-	@ActivityScope
-	@Provides
-	NavDrawerController provideNavDrawerController(
-			NavDrawerControllerImpl navDrawerController) {
-		activity.addLifecycleController(navDrawerController);
-		return navDrawerController;
-	}
-
 	@ActivityScope
 	@Provides
 	BriarServiceConnection provideBriarServiceConnection() {

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

@@ -9,6 +9,7 @@ import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.ActivityComponent;
+import org.briarproject.briar.android.fragment.BaseFragment;
 
 import javax.annotation.Nullable;
 import javax.inject.Inject;
@@ -79,13 +80,13 @@ public class ContactExchangeActivity extends KeyAgreementActivity {
 
 	@UiThread
 	private void contactExchangeFailed() {
-		showErrorFragment(R.string.connection_error_explanation);
+		showErrorFragment();
 	}
 
 	@UiThread
 	@Override
 	public void keyAgreementFailed() {
-		showErrorFragment(R.string.connection_error_explanation);
+		showErrorFragment();
 	}
 
 	@UiThread
@@ -103,7 +104,7 @@ public class ContactExchangeActivity extends KeyAgreementActivity {
 	@UiThread
 	@Override
 	public void keyAgreementAborted(boolean remoteAborted) {
-		showErrorFragment(R.string.connection_error_explanation);
+		showErrorFragment();
 	}
 
 	@UiThread
@@ -112,4 +113,10 @@ public class ContactExchangeActivity extends KeyAgreementActivity {
 		startContactExchange(result);
 		return getString(R.string.exchanging_contact_details);
 	}
+
+	protected void showErrorFragment() {
+		String errorMsg = getString(R.string.connection_error_explanation);
+		BaseFragment f = ContactExchangeErrorFragment.newInstance(errorMsg);
+		showNextFragment(f);
+	}
 }

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

@@ -8,10 +8,18 @@ import android.content.IntentFilter;
 import android.os.Bundle;
 import android.view.MenuItem;
 
+import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.event.EventBus;
+import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
+import org.briarproject.bramble.api.plugin.BluetoothConstants;
+import org.briarproject.bramble.api.plugin.LanTcpConstants;
+import org.briarproject.bramble.api.plugin.Plugin;
+import org.briarproject.bramble.api.plugin.Plugin.State;
+import org.briarproject.bramble.api.plugin.PluginManager;
 import org.briarproject.bramble.api.plugin.event.BluetoothEnabledEvent;
+import org.briarproject.bramble.api.plugin.event.TransportStateEvent;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.ActivityComponent;
 import org.briarproject.briar.android.activity.BriarActivity;
@@ -37,13 +45,14 @@ import static android.Manifest.permission.ACCESS_COARSE_LOCATION;
 import static android.Manifest.permission.CAMERA;
 import static android.bluetooth.BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE;
 import static android.bluetooth.BluetoothAdapter.ACTION_SCAN_MODE_CHANGED;
-import static android.bluetooth.BluetoothAdapter.ACTION_STATE_CHANGED;
-import static android.bluetooth.BluetoothAdapter.EXTRA_SCAN_MODE;
-import static android.bluetooth.BluetoothAdapter.EXTRA_STATE;
-import static android.bluetooth.BluetoothAdapter.SCAN_MODE_CONNECTABLE;
 import static android.bluetooth.BluetoothAdapter.SCAN_MODE_CONNECTABLE_DISCOVERABLE;
-import static android.bluetooth.BluetoothAdapter.STATE_ON;
 import static android.content.pm.PackageManager.PERMISSION_GRANTED;
+import static java.util.logging.Level.INFO;
+import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
+import static org.briarproject.bramble.api.plugin.Plugin.State.ACTIVE;
+import static org.briarproject.bramble.api.plugin.Plugin.State.DISABLED;
+import static org.briarproject.bramble.api.plugin.Plugin.State.INACTIVE;
 import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_BLUETOOTH_DISCOVERABLE;
 import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_PERMISSION_CAMERA_LOCATION;
 
@@ -51,10 +60,33 @@ import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_PERMI
 @ParametersNotNullByDefault
 public abstract class KeyAgreementActivity extends BriarActivity implements
 		BaseFragmentListener, IntroScreenSeenListener,
-		KeyAgreementEventListener {
+		KeyAgreementEventListener, EventListener {
 
-	private enum BluetoothState {
-		UNKNOWN, NO_ADAPTER, WAITING, REFUSED, ENABLED, DISCOVERABLE
+	private enum BluetoothDecision {
+		/**
+		 * We haven't asked the user about Bluetooth discoverability.
+		 */
+		UNKNOWN,
+
+		/**
+		 * The device doesn't have a Bluetooth adapter.
+		 */
+		NO_ADAPTER,
+
+		/**
+		 * We're waiting for the user to accept or refuse discoverability.
+		 */
+		WAITING,
+
+		/**
+		 * The user has accepted discoverability.
+		 */
+		ACCEPTED,
+
+		/**
+		 * The user has refused discoverability.
+		 */
+		REFUSED
 	}
 
 	private enum Permission {
@@ -62,11 +94,14 @@ public abstract class KeyAgreementActivity extends BriarActivity implements
 	}
 
 	private static final Logger LOG =
-			Logger.getLogger(KeyAgreementActivity.class.getName());
+			getLogger(KeyAgreementActivity.class.getName());
 
 	@Inject
 	EventBus eventBus;
 
+	@Inject
+	PluginManager pluginManager;
+
 	/**
 	 * Set to true in onPostResume() and false in onPause(). This prevents the
 	 * QR code fragment from being shown if onRequestPermissionsResult() is
@@ -74,21 +109,36 @@ public abstract class KeyAgreementActivity extends BriarActivity implements
 	 * https://issuetracker.google.com/issues/37067655.
 	 */
 	private boolean isResumed = false;
+
 	/**
 	 * Set to true when the continue button is clicked, and false when the QR
 	 * code fragment is shown. This prevents the QR code fragment from being
 	 * shown automatically before the continue button has been clicked.
 	 */
 	private boolean continueClicked = false;
+
 	/**
 	 * Records whether the Bluetooth adapter was already enabled before we
 	 * asked for Bluetooth discoverability, so we know whether to broadcast a
 	 * {@link BluetoothEnabledEvent}.
 	 */
 	private boolean wasAdapterEnabled = false;
+
+	/**
+	 * Records whether we've enabled the wifi plugin so we don't enable it more
+	 * than once.
+	 */
+	private boolean hasEnabledWifi = false;
+
+	/**
+	 * Records whether we've enabled the Bluetooth plugin so we don't enable it
+	 * more than once.
+	 */
+	private boolean hasEnabledBluetooth = false;
+
 	private Permission cameraPermission = Permission.UNKNOWN;
 	private Permission locationPermission = Permission.UNKNOWN;
-	private BluetoothState bluetoothState = BluetoothState.UNKNOWN;
+	private BluetoothDecision bluetoothDecision = BluetoothDecision.UNKNOWN;
 	private BroadcastReceiver bluetoothReceiver = null;
 
 	@Override
@@ -96,20 +146,17 @@ public abstract class KeyAgreementActivity extends BriarActivity implements
 		component.inject(this);
 	}
 
-	@SuppressWarnings("ConstantConditions")
 	@Override
 	public void onCreate(@Nullable Bundle state) {
 		super.onCreate(state);
 		setContentView(R.layout.activity_fragment_container_toolbar);
 		Toolbar toolbar = findViewById(R.id.toolbar);
 		setSupportActionBar(toolbar);
-		getSupportActionBar().setDisplayHomeAsUpEnabled(true);
+		requireNonNull(getSupportActionBar()).setDisplayHomeAsUpEnabled(true);
 		if (state == null) {
 			showInitialFragment(IntroFragment.newInstance());
 		}
-		IntentFilter filter = new IntentFilter();
-		filter.addAction(ACTION_STATE_CHANGED);
-		filter.addAction(ACTION_SCAN_MODE_CHANGED);
+		IntentFilter filter = new IntentFilter(ACTION_SCAN_MODE_CHANGED);
 		bluetoothReceiver = new BluetoothStateReceiver();
 		registerReceiver(bluetoothReceiver, filter);
 	}
@@ -122,18 +169,17 @@ public abstract class KeyAgreementActivity extends BriarActivity implements
 
 	@Override
 	public boolean onOptionsItemSelected(MenuItem item) {
-		switch (item.getItemId()) {
-			case android.R.id.home:
-				onBackPressed();
-				return true;
-			default:
-				return super.onOptionsItemSelected(item);
+		if (item.getItemId() == android.R.id.home) {
+			onBackPressed();
+			return true;
 		}
+		return super.onOptionsItemSelected(item);
 	}
 
 	@Override
 	public void onStart() {
 		super.onStart();
+		eventBus.addListener(this);
 		// Permissions may have been granted manually while we were stopped
 		cameraPermission = Permission.UNKNOWN;
 		locationPermission = Permission.UNKNOWN;
@@ -150,11 +196,22 @@ public abstract class KeyAgreementActivity extends BriarActivity implements
 
 	private void showQrCodeFragmentIfAllowed() {
 		if (isResumed && continueClicked && areEssentialPermissionsGranted()) {
-			if (bluetoothState == BluetoothState.UNKNOWN ||
-					bluetoothState == BluetoothState.ENABLED) {
-				requestBluetoothDiscoverable();
-			} else if (bluetoothState != BluetoothState.WAITING) {
+			if (isWifiReady() && isBluetoothReady()) {
+				LOG.info("Wifi and Bluetooth are ready");
 				showQrCodeFragment();
+			} else {
+				if (shouldEnableWifi()) {
+					LOG.info("Enabling wifi plugin");
+					hasEnabledWifi = true;
+					pluginManager.setPluginEnabled(LanTcpConstants.ID, true);
+				}
+				if (bluetoothDecision == BluetoothDecision.UNKNOWN) {
+					requestBluetoothDiscoverable();
+				} else if (shouldEnableBluetooth()) {
+					LOG.info("Enabling Bluetooth plugin");
+					hasEnabledBluetooth = true;
+					pluginManager.setPluginEnabled(BluetoothConstants.ID, true);
+				}
 			}
 		}
 	}
@@ -167,57 +224,104 @@ public abstract class KeyAgreementActivity extends BriarActivity implements
 						locationPermission == Permission.PERMANENTLY_DENIED);
 	}
 
+	private boolean isWifiReady() {
+		Plugin p = pluginManager.getPlugin(LanTcpConstants.ID);
+		if (p == null) return true; // Continue without wifi
+		State state = p.getState();
+		// Wait for plugin to become enabled
+		return state == ACTIVE || state == INACTIVE;
+	}
+
+	private boolean isBluetoothReady() {
+		if (bluetoothDecision == BluetoothDecision.UNKNOWN ||
+				bluetoothDecision == BluetoothDecision.WAITING) {
+			// Wait for decision
+			return false;
+		}
+		if (bluetoothDecision == BluetoothDecision.NO_ADAPTER
+				|| bluetoothDecision == BluetoothDecision.REFUSED) {
+			// Continue without Bluetooth
+			return true;
+		}
+		BluetoothAdapter bt = BluetoothAdapter.getDefaultAdapter();
+		if (bt == null) return true; // Continue without Bluetooth
+		if (bt.getScanMode() != SCAN_MODE_CONNECTABLE_DISCOVERABLE) {
+			// Wait for adapter to become discoverable
+			return false;
+		}
+		Plugin p = pluginManager.getPlugin(BluetoothConstants.ID);
+		if (p == null) return true; // Continue without Bluetooth
+		// Wait for plugin to become active
+		return p.getState() == ACTIVE;
+	}
+
+	private boolean shouldEnableWifi() {
+		if (hasEnabledWifi) return false;
+		Plugin p = pluginManager.getPlugin(LanTcpConstants.ID);
+		return p != null && p.getState() == DISABLED;
+	}
+
+	private void requestBluetoothDiscoverable() {
+		BluetoothAdapter bt = BluetoothAdapter.getDefaultAdapter();
+		if (bt == null) {
+			bluetoothDecision = BluetoothDecision.NO_ADAPTER;
+			showQrCodeFragmentIfAllowed();
+		} else {
+			Intent i = new Intent(ACTION_REQUEST_DISCOVERABLE);
+			if (i.resolveActivity(getPackageManager()) != null) {
+				LOG.info("Asking for Bluetooth discoverability");
+				bluetoothDecision = BluetoothDecision.WAITING;
+				wasAdapterEnabled = bt.isEnabled();
+				startActivityForResult(i, REQUEST_BLUETOOTH_DISCOVERABLE);
+			} else {
+				bluetoothDecision = BluetoothDecision.NO_ADAPTER;
+				showQrCodeFragmentIfAllowed();
+			}
+		}
+	}
+
+	private boolean shouldEnableBluetooth() {
+		if (bluetoothDecision != BluetoothDecision.ACCEPTED) return false;
+		if (hasEnabledBluetooth) return false;
+		Plugin p = pluginManager.getPlugin(BluetoothConstants.ID);
+		return p != null && p.getState() == DISABLED;
+	}
+
 	@Override
 	protected void onPause() {
 		super.onPause();
 		isResumed = false;
 	}
 
+	@Override
+	protected void onStop() {
+		super.onStop();
+		eventBus.removeListener(this);
+	}
+
 	@Override
 	public void showNextScreen() {
 		continueClicked = true;
 		if (checkPermissions()) showQrCodeFragmentIfAllowed();
 	}
 
-	private void requestBluetoothDiscoverable() {
-		BluetoothAdapter bt = BluetoothAdapter.getDefaultAdapter();
-		if (bt == null) {
-			setBluetoothState(BluetoothState.NO_ADAPTER);
-		} else {
-			Intent i = new Intent(ACTION_REQUEST_DISCOVERABLE);
-			if (i.resolveActivity(getPackageManager()) != null) {
-				setBluetoothState(BluetoothState.WAITING);
-				wasAdapterEnabled = bt.isEnabled();
-				startActivityForResult(i, REQUEST_BLUETOOTH_DISCOVERABLE);
-			} else {
-				setBluetoothState(BluetoothState.NO_ADAPTER);
-			}
-		}
-	}
-
-	private void setBluetoothState(BluetoothState bluetoothState) {
-		LOG.info("Setting Bluetooth state to " + bluetoothState);
-		this.bluetoothState = bluetoothState;
-		if (!wasAdapterEnabled && bluetoothState == BluetoothState.ENABLED) {
-			eventBus.broadcast(new BluetoothEnabledEvent());
-			wasAdapterEnabled = true;
-		}
-		showQrCodeFragmentIfAllowed();
-	}
-
 	@Override
-	public void onActivityResult(int request, int result, Intent data) {
+	public void onActivityResult(int request, int result,
+			@Nullable Intent data) {
 		if (request == REQUEST_BLUETOOTH_DISCOVERABLE) {
 			if (result == RESULT_CANCELED) {
-				setBluetoothState(BluetoothState.REFUSED);
+				LOG.info("Bluetooth discoverability was refused");
+				bluetoothDecision = BluetoothDecision.REFUSED;
 			} else {
-				// If Bluetooth is already discoverable, show the QR code -
-				// otherwise wait for the state or scan mode to change
-				BluetoothAdapter bt = BluetoothAdapter.getDefaultAdapter();
-				if (bt == null) throw new AssertionError();
-				if (bt.getScanMode() == SCAN_MODE_CONNECTABLE_DISCOVERABLE)
-					setBluetoothState(BluetoothState.DISCOVERABLE);
+				LOG.info("Bluetooth discoverability was accepted");
+				bluetoothDecision = BluetoothDecision.ACCEPTED;
+				if (!wasAdapterEnabled) {
+					LOG.info("Bluetooth adapter was enabled by us");
+					eventBus.broadcast(new BluetoothEnabledEvent());
+					wasAdapterEnabled = true;
+				}
 			}
+			showQrCodeFragmentIfAllowed();
 		} else super.onActivityResult(request, result, data);
 	}
 
@@ -227,7 +331,12 @@ public abstract class KeyAgreementActivity extends BriarActivity implements
 		continueClicked = false;
 		// If we return to the intro fragment, ask for Bluetooth
 		// discoverability again before showing the QR code fragment
-		bluetoothState = BluetoothState.UNKNOWN;
+		bluetoothDecision = BluetoothDecision.UNKNOWN;
+		// If we return to the intro fragment, we may need to enable wifi and
+		// Bluetooth again
+		hasEnabledWifi = false;
+		hasEnabledBluetooth = false;
+
 		// FIXME #824
 		FragmentManager fm = getSupportFragmentManager();
 		if (fm.findFragmentByTag(KeyAgreementFragment.TAG) == null) {
@@ -239,12 +348,6 @@ public abstract class KeyAgreementActivity extends BriarActivity implements
 		}
 	}
 
-	protected void showErrorFragment(@StringRes int errorResId) {
-		String errorMsg = getString(errorResId);
-		BaseFragment f = ContactExchangeErrorFragment.newInstance(errorMsg);
-		showNextFragment(f);
-	}
-
 	private boolean checkPermissions() {
 		if (areEssentialPermissionsGranted()) return true;
 		// If the camera permission has been permanently denied, ask the
@@ -335,24 +438,30 @@ public abstract class KeyAgreementActivity extends BriarActivity implements
 				permission);
 	}
 
+	@Override
+	public void eventOccurred(Event e) {
+		if (e instanceof TransportStateEvent) {
+			TransportStateEvent t = (TransportStateEvent) e;
+			if (t.getTransportId().equals(BluetoothConstants.ID)) {
+				if (LOG.isLoggable(INFO)) {
+					LOG.info("Bluetooth state changed to " + t.getState());
+				}
+				showQrCodeFragmentIfAllowed();
+			} else if (t.getTransportId().equals(LanTcpConstants.ID)) {
+				if (LOG.isLoggable(INFO)) {
+					LOG.info("Wifi state changed to " + t.getState());
+				}
+				showQrCodeFragmentIfAllowed();
+			}
+		}
+	}
+
 	private class BluetoothStateReceiver extends BroadcastReceiver {
 
 		@Override
 		public void onReceive(Context context, Intent intent) {
-			String action = intent.getAction();
-			if (ACTION_STATE_CHANGED.equals(action)) {
-				int state = intent.getIntExtra(EXTRA_STATE, 0);
-				if (state == STATE_ON)
-					setBluetoothState(BluetoothState.ENABLED);
-				else setBluetoothState(BluetoothState.UNKNOWN);
-			} else if (ACTION_SCAN_MODE_CHANGED.equals(action)) {
-				int scanMode = intent.getIntExtra(EXTRA_SCAN_MODE, 0);
-				if (scanMode == SCAN_MODE_CONNECTABLE_DISCOVERABLE)
-					setBluetoothState(BluetoothState.DISCOVERABLE);
-				else if (scanMode == SCAN_MODE_CONNECTABLE)
-					setBluetoothState(BluetoothState.ENABLED);
-				else setBluetoothState(BluetoothState.UNKNOWN);
-			}
+			LOG.info("Bluetooth scan mode changed");
+			showQrCodeFragmentIfAllowed();
 		}
 	}
 }

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

@@ -1,17 +1,15 @@
 package org.briarproject.briar.android.navdrawer;
 
-import android.annotation.SuppressLint;
 import android.content.Intent;
 import android.content.res.Configuration;
 import android.net.Uri;
 import android.os.Bundle;
-import android.view.LayoutInflater;
 import android.view.MenuItem;
 import android.view.View;
 import android.view.ViewGroup;
-import android.widget.BaseAdapter;
-import android.widget.GridView;
+import android.view.ViewTreeObserver.OnGlobalLayoutListener;
 import android.widget.ImageView;
+import android.widget.ScrollView;
 import android.widget.TextView;
 
 import com.google.android.material.navigation.NavigationView;
@@ -21,16 +19,11 @@ import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
-import org.briarproject.bramble.api.plugin.BluetoothConstants;
-import org.briarproject.bramble.api.plugin.LanTcpConstants;
-import org.briarproject.bramble.api.plugin.TorConstants;
-import org.briarproject.bramble.api.plugin.TransportId;
 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.FeedFragment;
 import org.briarproject.briar.android.contact.ContactListFragment;
-import org.briarproject.briar.android.controller.handler.UiResultHandler;
 import org.briarproject.briar.android.forum.ForumListFragment;
 import org.briarproject.briar.android.fragment.BaseFragment;
 import org.briarproject.briar.android.fragment.BaseFragment.BaseFragmentListener;
@@ -38,25 +31,25 @@ import org.briarproject.briar.android.logout.SignOutFragment;
 import org.briarproject.briar.android.privategroup.list.GroupListFragment;
 import org.briarproject.briar.android.settings.SettingsActivity;
 
-import java.util.ArrayList;
-import java.util.List;
 import java.util.logging.Logger;
 
 import javax.inject.Inject;
 
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
-import androidx.annotation.UiThread;
 import androidx.appcompat.app.ActionBar;
 import androidx.appcompat.app.ActionBarDrawerToggle;
 import androidx.appcompat.widget.Toolbar;
 import androidx.core.app.ActivityCompat;
-import androidx.core.content.ContextCompat;
 import androidx.drawerlayout.widget.DrawerLayout;
 import androidx.fragment.app.FragmentManager;
 import androidx.fragment.app.FragmentTransaction;
+import androidx.lifecycle.ViewModelProvider;
+import androidx.lifecycle.ViewModelProviders;
 
+import static android.view.View.FOCUS_DOWN;
 import static android.view.View.GONE;
+import static android.view.View.INVISIBLE;
 import static android.view.View.VISIBLE;
 import static androidx.core.view.GravityCompat.START;
 import static androidx.drawerlayout.widget.DrawerLayout.LOCK_MODE_LOCKED_CLOSED;
@@ -72,8 +65,7 @@ import static org.briarproject.briar.android.util.UiUtils.getDaysUntilExpiry;
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
 public class NavDrawerActivity extends BriarActivity implements
-		BaseFragmentListener, TransportStateListener,
-		OnNavigationItemSelectedListener {
+		BaseFragmentListener, OnNavigationItemSelectedListener {
 
 	private static final Logger LOG =
 			getLogger(NavDrawerActivity.class.getName());
@@ -91,19 +83,18 @@ public class NavDrawerActivity extends BriarActivity implements
 	public static Uri SIGN_OUT_URI =
 			Uri.parse("briar-content://org.briarproject.briar/sign-out");
 
+	private NavDrawerViewModel viewModel;
 	private ActionBarDrawerToggle drawerToggle;
 
 	@Inject
-	NavDrawerController controller;
+	ViewModelProvider.Factory viewModelFactory;
 	@Inject
 	LifecycleManager lifecycleManager;
 
 	private DrawerLayout drawerLayout;
+	private ScrollView drawerScrollView;
 	private NavigationView navigation;
 
-	private List<Transport> transports;
-	private BaseAdapter transportsAdapter;
-
 	@Override
 	public void injectActivity(ActivityComponent component) {
 		component.inject(this);
@@ -115,10 +106,38 @@ public class NavDrawerActivity extends BriarActivity implements
 		exitIfStartupFailed(getIntent());
 		setContentView(R.layout.activity_nav_drawer);
 
+		viewModel = ViewModelProviders.of(this, viewModelFactory)
+				.get(NavDrawerViewModel.class);
+
+		viewModel.showExpiryWarning().observe(this, this::showExpiryWarning);
+		viewModel.shouldAskForDozeWhitelisting().observe(this, ask -> {
+			if (ask) showDozeDialog(getString(R.string.setup_doze_intro));
+		});
+
+		drawerScrollView = findViewById(R.id.drawerScrollView);
+		View chevronView = drawerScrollView.findViewById(R.id.chevronView);
+		drawerScrollView.getViewTreeObserver().addOnGlobalLayoutListener(
+				new OnGlobalLayoutListener() {
+					@Override
+					public void onGlobalLayout() {
+						// hide/show chevron depending on whether we can scroll
+						if (drawerScrollView.canScrollVertically(1)) {
+							chevronView.setVisibility(VISIBLE);
+						} else {
+							chevronView.setVisibility(INVISIBLE);
+						}
+						drawerScrollView.getViewTreeObserver()
+								.removeOnGlobalLayoutListener(this);
+					}
+				});
+		new PluginViewController(drawerScrollView, this, viewModel);
+		chevronView.setOnClickListener(v ->
+				drawerScrollView.fullScroll(FOCUS_DOWN)
+		);
+
 		Toolbar toolbar = findViewById(R.id.toolbar);
 		drawerLayout = findViewById(R.id.drawer_layout);
 		navigation = findViewById(R.id.navigation);
-		GridView transportsView = findViewById(R.id.transportsView);
 
 		setSupportActionBar(toolbar);
 		ActionBar actionBar = requireNonNull(getSupportActionBar());
@@ -131,9 +150,6 @@ public class NavDrawerActivity extends BriarActivity implements
 		drawerLayout.addDrawerListener(drawerToggle);
 		navigation.setNavigationItemSelectedListener(this);
 
-		initializeTransports(getLayoutInflater());
-		transportsView.setAdapter(transportsAdapter);
-
 		lockManager.isLockable().observe(this, this::setLockVisible);
 
 		if (lifecycleManager.getLifecycleState().isAfter(RUNNING)) {
@@ -149,17 +165,10 @@ public class NavDrawerActivity extends BriarActivity implements
 	}
 
 	@Override
-	@SuppressLint("NewApi")
 	public void onStart() {
 		super.onStart();
-		updateTransports();
 		lockManager.checkIfLockable();
-		controller.showExpiryWarning(new UiResultHandler<Boolean>(this) {
-			@Override
-			public void onResultUi(Boolean expiry) {
-				if (expiry) showExpiryWarning();
-			}
-		});
+		viewModel.checkExpiryWarning();
 	}
 
 	@Override
@@ -167,16 +176,7 @@ public class NavDrawerActivity extends BriarActivity implements
 			@Nullable Intent data) {
 		super.onActivityResult(request, result, data);
 		if (request == REQUEST_PASSWORD && result == RESULT_OK) {
-			controller.shouldAskForDozeWhitelisting(this,
-					new UiResultHandler<Boolean>(this) {
-						@Override
-						public void onResultUi(Boolean ask) {
-							if (ask) {
-								showDozeDialog(
-										getString(R.string.setup_doze_intro));
-							}
-						}
-					});
+			viewModel.checkDozeWhitelisting();
 		}
 	}
 
@@ -346,134 +346,31 @@ public class NavDrawerActivity extends BriarActivity implements
 		if (item != null) item.setVisible(visible);
 	}
 
-	private void showExpiryWarning() {
+	private void showExpiryWarning(boolean show) {
 		int daysUntilExpiry = getDaysUntilExpiry();
-		if (daysUntilExpiry < 0) signOut();
+		if (daysUntilExpiry < 0) {
+			signOut();
+			return;
+		}
 
-		// show expiry warning text
 		ViewGroup expiryWarning = findViewById(R.id.expiryWarning);
-		TextView expiryWarningText =
-				expiryWarning.findViewById(R.id.expiryWarningText);
-		// make close button functional
-		ImageView expiryWarningClose =
-				expiryWarning.findViewById(R.id.expiryWarningClose);
-
-		expiryWarningText.setText(getResources()
-				.getQuantityString(R.plurals.expiry_warning,
-						daysUntilExpiry, daysUntilExpiry));
-
-		expiryWarningClose.setOnClickListener(v -> {
-			controller.expiryWarningDismissed();
+		if (show) {
+			// show expiry warning text
+			TextView expiryWarningText =
+					expiryWarning.findViewById(R.id.expiryWarningText);
+			String text = getResources().getQuantityString(
+					R.plurals.expiry_warning, daysUntilExpiry, daysUntilExpiry);
+			expiryWarningText.setText(text);
+			// make close button functional
+			ImageView expiryWarningClose =
+					expiryWarning.findViewById(R.id.expiryWarningClose);
+			expiryWarningClose.setOnClickListener(v ->
+					viewModel.expiryWarningDismissed()
+			);
+			expiryWarning.setVisibility(VISIBLE);
+		} else {
 			expiryWarning.setVisibility(GONE);
-		});
-
-		expiryWarning.setVisibility(VISIBLE);
-	}
-
-	private void initializeTransports(LayoutInflater inflater) {
-		transports = new ArrayList<>(3);
-
-		Transport tor = new Transport();
-		tor.id = TorConstants.ID;
-		tor.enabled = controller.isTransportRunning(tor.id);
-		tor.iconId = R.drawable.transport_tor;
-		tor.textId = R.string.transport_tor;
-		transports.add(tor);
-
-		Transport bt = new Transport();
-		bt.id = BluetoothConstants.ID;
-		bt.enabled = controller.isTransportRunning(bt.id);
-		bt.iconId = R.drawable.transport_bt;
-		bt.textId = R.string.transport_bt;
-		transports.add(bt);
-
-		Transport lan = new Transport();
-		lan.id = LanTcpConstants.ID;
-		lan.enabled = controller.isTransportRunning(lan.id);
-		lan.iconId = R.drawable.transport_lan;
-		lan.textId = R.string.transport_lan;
-		transports.add(lan);
-
-		transportsAdapter = new BaseAdapter() {
-			@Override
-			public int getCount() {
-				return transports.size();
-			}
-
-			@Override
-			public Transport getItem(int position) {
-				return transports.get(position);
-			}
-
-			@Override
-			public long getItemId(int position) {
-				return 0;
-			}
-
-			@Override
-			public View getView(int position, View convertView,
-					ViewGroup parent) {
-				View view;
-				if (convertView != null) {
-					view = convertView;
-				} else {
-					view = inflater.inflate(R.layout.list_item_transport,
-							parent, false);
-				}
-
-				Transport t = getItem(position);
-				int c;
-				if (t.enabled) {
-					c = ContextCompat.getColor(NavDrawerActivity.this,
-							R.color.briar_green_light);
-				} else {
-					c = ContextCompat.getColor(NavDrawerActivity.this,
-							android.R.color.tertiary_text_light);
-				}
-
-				ImageView icon = view.findViewById(R.id.imageView);
-				icon.setImageDrawable(ContextCompat
-						.getDrawable(NavDrawerActivity.this, t.iconId));
-				icon.setColorFilter(c);
-
-				TextView text = view.findViewById(R.id.textView);
-				text.setText(getString(t.textId));
-
-				return view;
-			}
-		};
-	}
-
-	@UiThread
-	private void setTransport(TransportId id, boolean enabled) {
-		if (transports == null || transportsAdapter == null) return;
-		for (Transport t : transports) {
-			if (t.id.equals(id)) {
-				t.enabled = enabled;
-				transportsAdapter.notifyDataSetChanged();
-				break;
-			}
 		}
 	}
 
-	private void updateTransports() {
-		if (transports == null || transportsAdapter == null) return;
-		for (Transport t : transports) {
-			t.enabled = controller.isTransportRunning(t.id);
-		}
-		transportsAdapter.notifyDataSetChanged();
-	}
-
-	@Override
-	public void stateUpdate(TransportId id, boolean enabled) {
-		setTransport(id, enabled);
-	}
-
-	private static class Transport {
-
-		private TransportId id;
-		private boolean enabled;
-		private int iconId;
-		private int textId;
-	}
 }

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

@@ -1,22 +0,0 @@
-package org.briarproject.briar.android.navdrawer;
-
-import android.content.Context;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.briar.android.controller.ActivityLifecycleController;
-import org.briarproject.briar.android.controller.handler.ResultHandler;
-
-@NotNullByDefault
-public interface NavDrawerController extends ActivityLifecycleController {
-
-	boolean isTransportRunning(TransportId transportId);
-
-	void showExpiryWarning(ResultHandler<Boolean> handler);
-
-	void expiryWarningDismissed();
-
-	void shouldAskForDozeWhitelisting(Context ctx,
-			ResultHandler<Boolean> handler);
-
-}

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

@@ -1,182 +0,0 @@
-package org.briarproject.briar.android.navdrawer;
-
-import android.app.Activity;
-import android.content.Context;
-
-import org.briarproject.bramble.api.db.DatabaseExecutor;
-import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.event.Event;
-import org.briarproject.bramble.api.event.EventBus;
-import org.briarproject.bramble.api.event.EventListener;
-import org.briarproject.bramble.api.lifecycle.LifecycleManager;
-import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
-import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
-import org.briarproject.bramble.api.plugin.Plugin;
-import org.briarproject.bramble.api.plugin.PluginManager;
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.plugin.event.TransportDisabledEvent;
-import org.briarproject.bramble.api.plugin.event.TransportEnabledEvent;
-import org.briarproject.bramble.api.settings.Settings;
-import org.briarproject.bramble.api.settings.SettingsManager;
-import org.briarproject.briar.android.controller.DbControllerImpl;
-import org.briarproject.briar.android.controller.handler.ResultHandler;
-
-import java.util.concurrent.Executor;
-import java.util.logging.Logger;
-
-import javax.inject.Inject;
-
-import static java.util.concurrent.TimeUnit.DAYS;
-import static java.util.logging.Level.INFO;
-import static java.util.logging.Level.WARNING;
-import static java.util.logging.Logger.getLogger;
-import static org.briarproject.bramble.util.LogUtils.logException;
-import static org.briarproject.briar.android.TestingConstants.EXPIRY_DATE;
-import static org.briarproject.briar.android.TestingConstants.IS_DEBUG_BUILD;
-import static org.briarproject.briar.android.controller.BriarControllerImpl.DOZE_ASK_AGAIN;
-import static org.briarproject.briar.android.settings.SettingsFragment.SETTINGS_NAMESPACE;
-import static org.briarproject.briar.android.util.UiUtils.needsDozeWhitelisting;
-
-@MethodsNotNullByDefault
-@ParametersNotNullByDefault
-public class NavDrawerControllerImpl extends DbControllerImpl
-		implements NavDrawerController, EventListener {
-
-	private static final Logger LOG =
-			getLogger(NavDrawerControllerImpl.class.getName());
-
-	private static final String EXPIRY_DATE_WARNING = "expiryDateWarning";
-
-	private final PluginManager pluginManager;
-	private final SettingsManager settingsManager;
-	private final EventBus eventBus;
-
-	// UI thread
-	private TransportStateListener listener;
-
-	@Inject
-	NavDrawerControllerImpl(@DatabaseExecutor Executor dbExecutor,
-			LifecycleManager lifecycleManager, PluginManager pluginManager,
-			SettingsManager settingsManager, EventBus eventBus) {
-		super(dbExecutor, lifecycleManager);
-		this.pluginManager = pluginManager;
-		this.settingsManager = settingsManager;
-		this.eventBus = eventBus;
-	}
-
-	@Override
-	public void onActivityCreate(Activity activity) {
-		listener = (TransportStateListener) activity;
-	}
-
-	@Override
-	public void onActivityStart() {
-		eventBus.addListener(this);
-	}
-
-	@Override
-	public void onActivityStop() {
-		eventBus.removeListener(this);
-	}
-
-	@Override
-	public void onActivityDestroy() {
-	}
-
-	@Override
-	public void eventOccurred(Event e) {
-		if (e instanceof TransportEnabledEvent) {
-			TransportId id = ((TransportEnabledEvent) e).getTransportId();
-			if (LOG.isLoggable(INFO)) {
-				LOG.info("TransportEnabledEvent: " + id.getString());
-			}
-			listener.stateUpdate(id, true);
-		} else if (e instanceof TransportDisabledEvent) {
-			TransportId id = ((TransportDisabledEvent) e).getTransportId();
-			if (LOG.isLoggable(INFO)) {
-				LOG.info("TransportDisabledEvent: " + id.getString());
-			}
-			listener.stateUpdate(id, false);
-		}
-	}
-
-	@Override
-	public void showExpiryWarning(ResultHandler<Boolean> handler) {
-		if (!IS_DEBUG_BUILD) {
-			handler.onResult(false);
-			return;
-		}
-		runOnDbThread(() -> {
-			try {
-				Settings settings =
-						settingsManager.getSettings(SETTINGS_NAMESPACE);
-				int warningInt = settings.getInt(EXPIRY_DATE_WARNING, 0);
-
-				if (warningInt == 0) {
-					// we have not warned before
-					handler.onResult(true);
-				} else {
-					long warningLong = warningInt * 1000L;
-					long now = System.currentTimeMillis();
-					long daysSinceLastWarning =
-							(now - warningLong) / DAYS.toMillis(1);
-					long daysBeforeExpiry =
-							(EXPIRY_DATE - now) / DAYS.toMillis(1);
-
-					if (daysSinceLastWarning >= 30) {
-						handler.onResult(true);
-					} else if (daysBeforeExpiry <= 3 &&
-							daysSinceLastWarning > 0) {
-						handler.onResult(true);
-					} else {
-						handler.onResult(false);
-					}
-				}
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
-		});
-	}
-
-	@Override
-	public void expiryWarningDismissed() {
-		runOnDbThread(() -> {
-			try {
-				Settings settings = new Settings();
-				int date = (int) (System.currentTimeMillis() / 1000L);
-				settings.putInt(EXPIRY_DATE_WARNING, date);
-				settingsManager.mergeSettings(settings, SETTINGS_NAMESPACE);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
-		});
-	}
-
-	@Override
-	public void shouldAskForDozeWhitelisting(Context ctx,
-			ResultHandler<Boolean> handler) {
-		// check this first, to hit the DbThread only when really necessary
-		if (!needsDozeWhitelisting(ctx)) {
-			handler.onResult(false);
-			return;
-		}
-		runOnDbThread(() -> {
-			try {
-				Settings settings =
-						settingsManager.getSettings(SETTINGS_NAMESPACE);
-				boolean ask = settings.getBoolean(DOZE_ASK_AGAIN, true);
-				handler.onResult(ask);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-				handler.onResult(true);
-			}
-		});
-	}
-
-	@Override
-	public boolean isTransportRunning(TransportId transportId) {
-		Plugin plugin = pluginManager.getPlugin(transportId);
-		return plugin != null && plugin.isRunning();
-	}
-
-}

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

@@ -0,0 +1,19 @@
+package org.briarproject.briar.android.navdrawer;
+
+import org.briarproject.briar.android.viewmodel.ViewModelKey;
+
+import androidx.lifecycle.ViewModel;
+import dagger.Binds;
+import dagger.Module;
+import dagger.multibindings.IntoMap;
+
+@Module
+public abstract class NavDrawerModule {
+
+	@Binds
+	@IntoMap
+	@ViewModelKey(NavDrawerViewModel.class)
+	abstract ViewModel bindNavDrawerViewModel(
+			NavDrawerViewModel navDrawerViewModel);
+
+}

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

@@ -0,0 +1,223 @@
+package org.briarproject.briar.android.navdrawer;
+
+import android.app.Application;
+
+import org.briarproject.bramble.api.db.DatabaseExecutor;
+import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.event.EventBus;
+import org.briarproject.bramble.api.event.EventListener;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.BluetoothConstants;
+import org.briarproject.bramble.api.plugin.LanTcpConstants;
+import org.briarproject.bramble.api.plugin.Plugin;
+import org.briarproject.bramble.api.plugin.Plugin.State;
+import org.briarproject.bramble.api.plugin.PluginManager;
+import org.briarproject.bramble.api.plugin.TorConstants;
+import org.briarproject.bramble.api.plugin.TransportId;
+import org.briarproject.bramble.api.plugin.event.TransportStateEvent;
+import org.briarproject.bramble.api.settings.Settings;
+import org.briarproject.bramble.api.settings.SettingsManager;
+
+import java.util.concurrent.Executor;
+import java.util.logging.Logger;
+
+import javax.inject.Inject;
+
+import androidx.annotation.Nullable;
+import androidx.annotation.UiThread;
+import androidx.lifecycle.AndroidViewModel;
+import androidx.lifecycle.LiveData;
+import androidx.lifecycle.MutableLiveData;
+
+import static java.util.concurrent.TimeUnit.DAYS;
+import static java.util.logging.Level.INFO;
+import static java.util.logging.Level.WARNING;
+import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.api.plugin.Plugin.State.DISABLED;
+import static org.briarproject.bramble.util.LogUtils.logException;
+import static org.briarproject.briar.android.TestingConstants.EXPIRY_DATE;
+import static org.briarproject.briar.android.TestingConstants.IS_DEBUG_BUILD;
+import static org.briarproject.briar.android.controller.BriarControllerImpl.DOZE_ASK_AGAIN;
+import static org.briarproject.briar.android.settings.SettingsFragment.SETTINGS_NAMESPACE;
+import static org.briarproject.briar.android.util.UiUtils.needsDozeWhitelisting;
+
+@NotNullByDefault
+public class NavDrawerViewModel extends AndroidViewModel
+		implements EventListener {
+
+	private static final Logger LOG =
+			getLogger(NavDrawerViewModel.class.getName());
+
+	private static final String EXPIRY_DATE_WARNING = "expiryDateWarning";
+	static final TransportId[] TRANSPORT_IDS =
+			{TorConstants.ID, LanTcpConstants.ID, BluetoothConstants.ID};
+
+	@DatabaseExecutor
+	private final Executor dbExecutor;
+	private final SettingsManager settingsManager;
+	private final PluginManager pluginManager;
+	private final EventBus eventBus;
+
+	private final MutableLiveData<Boolean> showExpiryWarning =
+			new MutableLiveData<>();
+	private final MutableLiveData<Boolean> shouldAskForDozeWhitelisting =
+			new MutableLiveData<>();
+
+	private final MutableLiveData<Plugin.State> torPluginState =
+			new MutableLiveData<>();
+	private final MutableLiveData<Plugin.State> wifiPluginState =
+			new MutableLiveData<>();
+	private final MutableLiveData<Plugin.State> btPluginState =
+			new MutableLiveData<>();
+
+	@Inject
+	NavDrawerViewModel(Application app, @DatabaseExecutor Executor dbExecutor,
+			SettingsManager settingsManager, PluginManager pluginManager,
+			EventBus eventBus) {
+		super(app);
+		this.dbExecutor = dbExecutor;
+		this.settingsManager = settingsManager;
+		this.pluginManager = pluginManager;
+		this.eventBus = eventBus;
+		eventBus.addListener(this);
+		updatePluginStates();
+	}
+
+	@Override
+	protected void onCleared() {
+		eventBus.removeListener(this);
+	}
+
+	@Override
+	public void eventOccurred(Event e) {
+		if (e instanceof TransportStateEvent) {
+			TransportStateEvent t = (TransportStateEvent) e;
+			TransportId id = t.getTransportId();
+			State state = t.getState();
+			if (LOG.isLoggable(INFO)) {
+				LOG.info("TransportStateEvent: " + id + " is " + state);
+			}
+			MutableLiveData<Plugin.State> liveData = getPluginLiveData(id);
+			if (liveData != null) liveData.postValue(state);
+		}
+	}
+
+	LiveData<Boolean> showExpiryWarning() {
+		return showExpiryWarning;
+	}
+
+	@UiThread
+	void checkExpiryWarning() {
+		if (!IS_DEBUG_BUILD) {
+			showExpiryWarning.setValue(false);
+			return;
+		}
+		dbExecutor.execute(() -> {
+			try {
+				Settings settings =
+						settingsManager.getSettings(SETTINGS_NAMESPACE);
+				int warningInt = settings.getInt(EXPIRY_DATE_WARNING, 0);
+
+				if (warningInt == 0) {
+					// we have not warned before
+					showExpiryWarning.postValue(true);
+				} else {
+					long warningLong = warningInt * 1000L;
+					long now = System.currentTimeMillis();
+					long daysSinceLastWarning =
+							(now - warningLong) / DAYS.toMillis(1);
+					long daysBeforeExpiry =
+							(EXPIRY_DATE - now) / DAYS.toMillis(1);
+
+					if (daysSinceLastWarning >= 30) {
+						showExpiryWarning.postValue(true);
+					} else if (daysBeforeExpiry <= 3 &&
+							daysSinceLastWarning > 0) {
+						showExpiryWarning.postValue(true);
+					} else {
+						showExpiryWarning.postValue(false);
+					}
+				}
+			} catch (DbException e) {
+				logException(LOG, WARNING, e);
+			}
+		});
+	}
+
+	@UiThread
+	void expiryWarningDismissed() {
+		showExpiryWarning.setValue(false);
+		dbExecutor.execute(() -> {
+			try {
+				Settings settings = new Settings();
+				int date = (int) (System.currentTimeMillis() / 1000L);
+				settings.putInt(EXPIRY_DATE_WARNING, date);
+				settingsManager.mergeSettings(settings, SETTINGS_NAMESPACE);
+			} catch (DbException e) {
+				logException(LOG, WARNING, e);
+			}
+		});
+	}
+
+	LiveData<Boolean> shouldAskForDozeWhitelisting() {
+		return shouldAskForDozeWhitelisting;
+	}
+
+	@UiThread
+	void checkDozeWhitelisting() {
+		// check this first, to hit the DbThread only when really necessary
+		if (!needsDozeWhitelisting(getApplication())) {
+			shouldAskForDozeWhitelisting.setValue(false);
+			return;
+		}
+		dbExecutor.execute(() -> {
+			try {
+				Settings settings =
+						settingsManager.getSettings(SETTINGS_NAMESPACE);
+				boolean ask = settings.getBoolean(DOZE_ASK_AGAIN, true);
+				shouldAskForDozeWhitelisting.postValue(ask);
+			} catch (DbException e) {
+				logException(LOG, WARNING, e);
+				shouldAskForDozeWhitelisting.postValue(true);
+			}
+		});
+	}
+
+	private void updatePluginStates() {
+		for (TransportId t : TRANSPORT_IDS) {
+			MutableLiveData<Plugin.State> liveData = getPluginLiveData(t);
+			if (liveData == null) throw new AssertionError();
+			liveData.setValue(getTransportState(t));
+		}
+	}
+
+	private State getTransportState(TransportId id) {
+		Plugin plugin = pluginManager.getPlugin(id);
+		return plugin == null ? DISABLED : plugin.getState();
+	}
+
+	@Nullable
+	private MutableLiveData<State> getPluginLiveData(TransportId t) {
+		if (t.equals(TorConstants.ID)) {
+			return torPluginState;
+		} else if (t.equals(LanTcpConstants.ID)) {
+			return wifiPluginState;
+		} else if (t.equals(BluetoothConstants.ID)) {
+			return btPluginState;
+		} else {
+			return null;
+		}
+	}
+
+	LiveData<State> getPluginState(TransportId t) {
+		LiveData<Plugin.State> liveData = getPluginLiveData(t);
+		if (liveData == null) throw new AssertionError();
+		return liveData;
+	}
+
+	void setPluginEnabled(TransportId t, boolean enabled) {
+		pluginManager.setPluginEnabled(t, enabled);
+	}
+
+}

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

@@ -0,0 +1,86 @@
+package org.briarproject.briar.android.navdrawer;
+
+import android.view.View;
+import android.widget.ImageView;
+
+import org.briarproject.bramble.api.plugin.BluetoothConstants;
+import org.briarproject.bramble.api.plugin.LanTcpConstants;
+import org.briarproject.bramble.api.plugin.Plugin.State;
+import org.briarproject.bramble.api.plugin.TorConstants;
+import org.briarproject.bramble.api.plugin.TransportId;
+import org.briarproject.briar.R;
+
+import androidx.appcompat.widget.SwitchCompat;
+import androidx.lifecycle.LifecycleOwner;
+
+import static androidx.core.content.ContextCompat.getColor;
+import static org.briarproject.bramble.api.plugin.Plugin.State.ACTIVE;
+import static org.briarproject.bramble.api.plugin.Plugin.State.DISABLED;
+import static org.briarproject.bramble.api.plugin.Plugin.State.ENABLING;
+import static org.briarproject.briar.android.navdrawer.NavDrawerViewModel.TRANSPORT_IDS;
+
+class PluginViewController {
+
+	private final ImageView torIcon, wifiIcon, btIcon;
+	private final SwitchCompat torSwitch, wifiSwitch, btSwitch;
+
+	PluginViewController(View v, LifecycleOwner owner,
+			NavDrawerViewModel viewModel) {
+
+		torIcon = v.findViewById(R.id.torIcon);
+		wifiIcon = v.findViewById(R.id.wifiIcon);
+		btIcon = v.findViewById(R.id.btIcon);
+
+		torSwitch = v.findViewById(R.id.torSwitch);
+		wifiSwitch = v.findViewById(R.id.wifiSwitch);
+		btSwitch = v.findViewById(R.id.btSwitch);
+
+		for (TransportId t : TRANSPORT_IDS) {
+			// a OnCheckedChangeListener would get triggered on programmatic updates
+			SwitchCompat switchCompat = getSwitch(t);
+			switchCompat.setOnClickListener(buttonView ->
+					// TODO check reason first and change settings if needed
+					viewModel.setPluginEnabled(t, switchCompat.isChecked())
+			);
+			viewModel.getPluginState(t)
+					.observe(owner, state -> stateUpdate(t, state));
+		}
+	}
+
+	private void stateUpdate(TransportId id, State state) {
+		updateIcon(getIcon(id), state);
+		updateSwitch(getSwitch(id), state);
+	}
+
+	private SwitchCompat getSwitch(TransportId id) {
+		if (id == TorConstants.ID) return torSwitch;
+		if (id == BluetoothConstants.ID) return btSwitch;
+		if (id == LanTcpConstants.ID) return wifiSwitch;
+		throw new AssertionError();
+	}
+
+	private void updateSwitch(SwitchCompat switchCompat, State state) {
+		switchCompat.setChecked(state != DISABLED);
+	}
+
+	private ImageView getIcon(TransportId id) {
+		if (id == TorConstants.ID) return torIcon;
+		if (id == BluetoothConstants.ID) return btIcon;
+		if (id == LanTcpConstants.ID) return wifiIcon;
+		throw new AssertionError();
+	}
+
+	private void updateIcon(ImageView icon, State state) {
+		int colorRes;
+		if (state == ACTIVE) {
+			colorRes = R.color.briar_green_light;
+		} else if (state == ENABLING) {
+			colorRes = R.color.briar_yellow;
+		} else {
+			colorRes = android.R.color.tertiary_text_light;
+		}
+		int color = getColor(icon.getContext(), colorRes);
+		icon.setColorFilter(color);
+	}
+
+}

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

@@ -1,11 +0,0 @@
-package org.briarproject.briar.android.navdrawer;
-
-import org.briarproject.bramble.api.plugin.TransportId;
-
-import androidx.annotation.UiThread;
-
-interface TransportStateListener {
-
-	@UiThread
-	void stateUpdate(TransportId id, boolean enabled);
-}

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

@@ -20,7 +20,6 @@ import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
-import org.briarproject.bramble.api.plugin.BluetoothConstants;
 import org.briarproject.bramble.api.plugin.TorConstants;
 import org.briarproject.bramble.api.settings.Settings;
 import org.briarproject.bramble.api.settings.SettingsManager;
@@ -41,6 +40,7 @@ import java.util.logging.Logger;
 
 import javax.inject.Inject;
 
+import androidx.annotation.Nullable;
 import androidx.annotation.StringRes;
 import androidx.core.content.ContextCompat;
 import androidx.core.text.TextUtilsCompat;
@@ -72,7 +72,6 @@ import static android.widget.Toast.LENGTH_SHORT;
 import static androidx.core.view.ViewCompat.LAYOUT_DIRECTION_LTR;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
-import static org.briarproject.bramble.api.plugin.BluetoothConstants.PREF_BT_ENABLE;
 import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_MOBILE;
 import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_NETWORK;
 import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_NETWORK_AUTOMATIC;
@@ -105,16 +104,16 @@ public class SettingsFragment extends PreferenceFragmentCompat
 		implements EventListener, OnPreferenceChangeListener {
 
 	public static final String SETTINGS_NAMESPACE = "android-ui";
-	public static final String BT_NAMESPACE = BluetoothConstants.ID.getString();
-	public static final String TOR_NAMESPACE = TorConstants.ID.getString();
 	public static final String LANGUAGE = "pref_key_language";
 	public static final String PREF_SCREEN_LOCK = "pref_key_lock";
 	public static final String PREF_SCREEN_LOCK_TIMEOUT =
 			"pref_key_lock_timeout";
 	public static final String NOTIFY_SIGN_IN = "pref_key_notify_sign_in";
-	public static final String TOR_NETWORK = "pref_key_tor_network";
-	public static final String TOR_MOBILE = "pref_key_tor_mobile_data";
-	public static final String TOR_ONLY_WHEN_CHARGING =
+
+	private static final String TOR_NAMESPACE = TorConstants.ID.getString();
+	private static final String TOR_NETWORK = "pref_key_tor_network";
+	private static final String TOR_MOBILE = "pref_key_tor_mobile_data";
+	private static final String TOR_ONLY_WHEN_CHARGING =
 			"pref_key_tor_only_when_charging";
 
 	private static final Logger LOG =
@@ -122,7 +121,6 @@ public class SettingsFragment extends PreferenceFragmentCompat
 
 	private SettingsActivity listener;
 	private ListPreference language;
-	private ListPreference enableBluetooth;
 	private ListPreference torNetwork;
 	private SwitchPreference torMobile;
 	private SwitchPreference torOnlyWhenCharging;
@@ -137,7 +135,7 @@ public class SettingsFragment extends PreferenceFragmentCompat
 	private Preference notifySound;
 
 	// Fields that are accessed from background threads must be volatile
-	private volatile Settings settings, btSettings, torSettings;
+	private volatile Settings settings, torSettings;
 	private volatile boolean settingsLoaded = false;
 
 	@Inject
@@ -163,28 +161,20 @@ public class SettingsFragment extends PreferenceFragmentCompat
 	public void onCreatePreferences(Bundle bundle, String s) {
 		addPreferencesFromResource(R.xml.settings);
 
-		language = (ListPreference) findPreference(LANGUAGE);
+		language = findPreference(LANGUAGE);
 		setLanguageEntries();
-		ListPreference theme =
-				(ListPreference) findPreference("pref_key_theme");
-		enableBluetooth = (ListPreference) findPreference("pref_key_bluetooth");
-		torNetwork = (ListPreference) findPreference(TOR_NETWORK);
-		torMobile = (SwitchPreference) findPreference(TOR_MOBILE);
-		torOnlyWhenCharging =
-				(SwitchPreference) findPreference(TOR_ONLY_WHEN_CHARGING);
-		screenLock = (SwitchPreference) findPreference(PREF_SCREEN_LOCK);
-		screenLockTimeout =
-				(ListPreference) findPreference(PREF_SCREEN_LOCK_TIMEOUT);
-		notifyPrivateMessages = (SwitchPreference) findPreference(
-				"pref_key_notify_private_messages");
-		notifyGroupMessages = (SwitchPreference) findPreference(
-				"pref_key_notify_group_messages");
-		notifyForumPosts = (SwitchPreference) findPreference(
-				"pref_key_notify_forum_posts");
-		notifyBlogPosts = (SwitchPreference) findPreference(
-				"pref_key_notify_blog_posts");
-		notifyVibration = (SwitchPreference) findPreference(
-				"pref_key_notify_vibration");
+		ListPreference theme = findPreference("pref_key_theme");
+		torNetwork = findPreference(TOR_NETWORK);
+		torMobile = findPreference(TOR_MOBILE);
+		torOnlyWhenCharging = findPreference(TOR_ONLY_WHEN_CHARGING);
+		screenLock = findPreference(PREF_SCREEN_LOCK);
+		screenLockTimeout = findPreference(PREF_SCREEN_LOCK_TIMEOUT);
+		notifyPrivateMessages =
+				findPreference("pref_key_notify_private_messages");
+		notifyGroupMessages = findPreference("pref_key_notify_group_messages");
+		notifyForumPosts = findPreference("pref_key_notify_forum_posts");
+		notifyBlogPosts = findPreference("pref_key_notify_blog_posts");
+		notifyVibration = findPreference("pref_key_notify_vibration");
 		notifySound = findPreference("pref_key_notify_sound");
 
 		language.setOnPreferenceChangeListener(this);
@@ -194,8 +184,7 @@ public class SettingsFragment extends PreferenceFragmentCompat
 				UiUtils.setTheme(getActivity(), (String) newValue);
 				// bring up parent activity, so it can change its theme as well
 				// upstream bug: https://issuetracker.google.com/issues/38352704
-				Intent intent =
-						new Intent(getActivity(), ENTRY_ACTIVITY);
+				Intent intent = new Intent(getActivity(), ENTRY_ACTIVITY);
 				intent.setFlags(
 						FLAG_ACTIVITY_CLEAR_TASK | FLAG_ACTIVITY_NEW_TASK);
 				startActivity(intent);
@@ -206,7 +195,6 @@ public class SettingsFragment extends PreferenceFragmentCompat
 			}
 			return true;
 		});
-		enableBluetooth.setOnPreferenceChangeListener(this);
 		torNetwork.setOnPreferenceChangeListener(this);
 		torMobile.setOnPreferenceChangeListener(this);
 		torOnlyWhenCharging.setOnPreferenceChangeListener(this);
@@ -249,8 +237,9 @@ public class SettingsFragment extends PreferenceFragmentCompat
 	}
 
 	@Override
-	public View onCreateView(LayoutInflater inflater, ViewGroup container,
-			Bundle savedInstanceState) {
+	public View onCreateView(LayoutInflater inflater,
+			@Nullable ViewGroup container,
+			@Nullable Bundle savedInstanceState) {
 		View view = super.onCreateView(inflater, container, savedInstanceState);
 		ColorDrawable divider = new ColorDrawable(
 				ContextCompat.getColor(requireContext(), R.color.divider));
@@ -335,7 +324,8 @@ public class SettingsFragment extends PreferenceFragmentCompat
 		boolean blocked =
 				circumventionProvider.isTorProbablyBlocked(country);
 		boolean useBridges = circumventionProvider.doBridgesWork(country);
-		String setting = getString(R.string.tor_network_setting_without_bridges);
+		String setting =
+				getString(R.string.tor_network_setting_without_bridges);
 		if (blocked && useBridges) {
 			setting = getString(R.string.tor_network_setting_with_bridges);
 		} else if (blocked) {
@@ -351,7 +341,6 @@ public class SettingsFragment extends PreferenceFragmentCompat
 			try {
 				long start = now();
 				settings = settingsManager.getSettings(SETTINGS_NAMESPACE);
-				btSettings = settingsManager.getSettings(BT_NAMESPACE);
 				torSettings = settingsManager.getSettings(TOR_NAMESPACE);
 				settingsLoaded = true;
 				logDuration(LOG, "Loading settings", start);
@@ -367,10 +356,6 @@ public class SettingsFragment extends PreferenceFragmentCompat
 			// due to events, we might try to display before a load completed
 			if (!settingsLoaded) return;
 
-			boolean btEnabledSetting =
-					btSettings.getBoolean(PREF_BT_ENABLE, false);
-			enableBluetooth.setValue(Boolean.toString(btEnabledSetting));
-
 			int torNetworkSetting = torSettings.getInt(PREF_TOR_NETWORK,
 					PREF_TOR_NETWORK_AUTOMATIC);
 			torNetwork.setValue(Integer.toString(torNetworkSetting));
@@ -442,7 +427,6 @@ public class SettingsFragment extends PreferenceFragmentCompat
 		// preferences partly needed here, because they have their own logic
 		// - pref_key_lock (screenLock -> displayScreenLockSetting())
 		// - pref_key_lock_timeout (screenLockTimeout)
-		enableBluetooth.setEnabled(enabled);
 		torNetwork.setEnabled(enabled);
 		torMobile.setEnabled(enabled);
 		torOnlyWhenCharging.setEnabled(enabled);
@@ -544,9 +528,6 @@ public class SettingsFragment extends PreferenceFragmentCompat
 			if (!language.getValue().equals(newValue))
 				languageChanged((String) newValue);
 			return false;
-		} else if (preference == enableBluetooth) {
-			boolean btSetting = Boolean.valueOf((String) newValue);
-			storeBluetoothSettings(btSetting);
 		} else if (preference == torNetwork) {
 			int torNetworkSetting = Integer.valueOf((String) newValue);
 			storeTorNetworkSetting(torNetworkSetting);
@@ -628,12 +609,6 @@ public class SettingsFragment extends PreferenceFragmentCompat
 		mergeSettings(s, TOR_NAMESPACE);
 	}
 
-	private void storeBluetoothSettings(boolean btSetting) {
-		Settings s = new Settings();
-		s.putBoolean(PREF_BT_ENABLE, btSetting);
-		mergeSettings(s, BT_NAMESPACE);
-	}
-
 	private void storeSettings(Settings s) {
 		mergeSettings(s, SETTINGS_NAMESPACE);
 	}
@@ -692,10 +667,6 @@ public class SettingsFragment extends PreferenceFragmentCompat
 				LOG.info("Settings updated");
 				settings = s.getSettings();
 				displaySettings();
-			} else if (namespace.equals(BT_NAMESPACE)) {
-				LOG.info("Bluetooth settings updated");
-				btSettings = s.getSettings();
-				displaySettings();
 			} else if (namespace.equals(TOR_NAMESPACE)) {
 				LOG.info("Tor settings updated");
 				torSettings = s.getSettings();

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

@@ -0,0 +1,12 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+  <group>
+    <path
+        android:fillColor="#000000"
+        android:pathData="M20,9H4v2h16V9zM4,15h16v-2H4v2z" />
+  </group>
+</vector>
+

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

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
 	xmlns:app="http://schemas.android.com/apk/res-auto"
-	xmlns:tools="http://schemas.android.com/tools"
+	android:id="@+id/drawerScrollView"
 	android:layout_width="wrap_content"
 	android:layout_height="match_parent"
 	android:background="@color/window_background"
@@ -22,37 +22,21 @@
 			app:itemBackground="@drawable/navigation_item_background"
 			app:itemIconTint="?attr/colorControlNormal"
 			app:itemTextColor="?android:textColorPrimary"
+			app:layout_constraintBottom_toTopOf="@+id/chevronView"
 			app:layout_constraintStart_toStartOf="parent"
 			app:layout_constraintTop_toTopOf="parent"
+			app:layout_constraintVertical_bias="0.0"
+			app:layout_constraintVertical_chainStyle="spread_inside"
 			app:menu="@menu/navigation_drawer" />
 
-		<View
-			android:id="@+id/divider1"
-			style="@style/Divider.Horizontal"
-			android:layout_width="0dp"
-			app:layout_constraintEnd_toEndOf="@+id/navigation"
-			app:layout_constraintStart_toStartOf="parent"
-			app:layout_constraintTop_toBottomOf="@+id/navigation" />
-
-		<View
-			android:id="@+id/spacer"
-			android:layout_width="0dp"
-			android:layout_height="0dp"
-			app:layout_constraintBottom_toTopOf="@+id/transports"
-			app:layout_constraintStart_toStartOf="parent"
-			app:layout_constraintTop_toBottomOf="@+id/divider1"
-			app:layout_constraintVertical_weight="1" />
-
 		<include
-			android:id="@+id/transports"
 			layout="@layout/transports_list"
 			android:layout_width="0dp"
 			android:layout_height="wrap_content"
 			app:layout_constraintBottom_toBottomOf="parent"
-			app:layout_constraintEnd_toEndOf="@+id/navigation"
+			app:layout_constraintEnd_toEndOf="parent"
 			app:layout_constraintStart_toStartOf="parent"
-			app:layout_constraintTop_toBottomOf="@+id/spacer"
-			tools:layout_height="75dp" />
+			app:layout_constraintTop_toBottomOf="@+id/navigation" />
 
 	</androidx.constraintlayout.widget.ConstraintLayout>
 

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

@@ -1,19 +1,163 @@
 <?xml version="1.0" encoding="utf-8"?>
-<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<merge xmlns:android="http://schemas.android.com/apk/res/android"
+	xmlns:app="http://schemas.android.com/apk/res-auto"
 	xmlns:tools="http://schemas.android.com/tools"
-	android:layout_width="match_parent"
+	android:layout_width="wrap_content"
 	android:layout_height="wrap_content"
-	android:orientation="vertical"
+	tools:parentTag="androidx.constraintlayout.widget.ConstraintLayout"
 	tools:showIn="@layout/navigation_menu">
 
-	<View style="@style/Divider.Horizontal" />
+	<androidx.appcompat.widget.AppCompatImageButton
+		android:id="@+id/chevronView"
+		android:layout_width="0dp"
+		android:layout_height="24dp"
+		android:layout_marginBottom="8dp"
+		android:background="@color/divider"
+		android:foreground="?attr/selectableItemBackground"
+		android:src="@drawable/chevron_down_white"
+		app:layout_constraintBottom_toTopOf="@+id/longRangeLabel"
+		app:layout_constraintEnd_toEndOf="parent"
+		app:layout_constraintStart_toStartOf="parent"
+		app:layout_constraintTop_toBottomOf="@+id/navigation"
+		app:layout_constraintVertical_bias="1.0"
+		app:tint="?attr/colorControlNormal"
+		tools:ignore="ContentDescription"
+		tools:visibility="visible" />
 
-	<GridView
-		android:id="@+id/transportsView"
-		android:layout_width="match_parent"
+	<View
+		android:id="@+id/backgroundView"
+		android:layout_width="0dp"
+		android:layout_height="0dp"
+		android:layout_marginBottom="8dp"
+		android:background="@color/item_background_highlight"
+		app:layout_constraintBottom_toTopOf="@+id/nearbyLabel"
+		app:layout_constraintEnd_toEndOf="parent"
+		app:layout_constraintStart_toStartOf="parent"
+		app:layout_constraintTop_toBottomOf="@+id/chevronView" />
+
+	<TextView
+		android:id="@+id/longRangeLabel"
+		android:layout_width="wrap_content"
 		android:layout_height="wrap_content"
-		android:listSelector="@android:color/transparent"
-		android:numColumns="3"
-		tools:listitem="@layout/list_item_transport" />
+		android:layout_marginBottom="8dp"
+		android:text="@string/transport_internet"
+		android:textSize="12sp"
+		app:layout_constraintBottom_toTopOf="@+id/torSwitch"
+		app:layout_constraintStart_toStartOf="@+id/torIcon" />
 
-</LinearLayout>
+	<ImageView
+		android:id="@+id/torIcon"
+		android:layout_width="wrap_content"
+		android:layout_height="wrap_content"
+		android:layout_marginStart="16dp"
+		android:layout_marginLeft="16dp"
+		android:src="@drawable/transport_tor"
+		app:layout_constraintBottom_toBottomOf="@+id/torSwitch"
+		app:layout_constraintStart_toStartOf="parent"
+		app:layout_constraintTop_toTopOf="@+id/torSwitch"
+		tools:ignore="ContentDescription"
+		tools:tint="@color/briar_green" />
+
+	<androidx.appcompat.widget.SwitchCompat
+		android:id="@+id/torSwitch"
+		android:layout_width="0dp"
+		android:layout_height="wrap_content"
+		android:layout_marginStart="16dp"
+		android:layout_marginLeft="16dp"
+		android:layout_marginEnd="16dp"
+		android:layout_marginRight="16dp"
+		android:layout_marginBottom="16dp"
+		android:text="@string/transport_tor"
+		app:layout_constraintBottom_toTopOf="@id/nearbyLabel"
+		app:layout_constraintEnd_toEndOf="parent"
+		app:layout_constraintStart_toEndOf="@+id/torIcon"
+		tools:checked="true" />
+
+	<TextView
+		android:id="@+id/nearbyLabel"
+		android:layout_width="wrap_content"
+		android:layout_height="wrap_content"
+		android:layout_marginTop="16dp"
+		android:layout_marginBottom="8dp"
+		android:gravity="center_vertical"
+		android:text="@string/transport_nearby"
+		android:textSize="12sp"
+		app:layout_constraintBottom_toTopOf="@+id/wifiSwitch"
+		app:layout_constraintStart_toStartOf="@+id/torIcon" />
+
+	<ImageView
+		android:id="@+id/wifiIcon"
+		android:layout_width="wrap_content"
+		android:layout_height="wrap_content"
+		android:layout_marginStart="16dp"
+		android:layout_marginLeft="16dp"
+		android:src="@drawable/transport_lan"
+		app:layout_constraintBottom_toBottomOf="@+id/wifiSwitch"
+		app:layout_constraintStart_toStartOf="parent"
+		app:layout_constraintTop_toTopOf="@+id/wifiSwitch"
+		tools:checked="true"
+		tools:ignore="ContentDescription"
+		tools:tint="@color/briar_green" />
+
+	<androidx.appcompat.widget.SwitchCompat
+		android:id="@+id/wifiSwitch"
+		android:layout_width="0dp"
+		android:layout_height="wrap_content"
+		android:layout_marginStart="16dp"
+		android:layout_marginLeft="16dp"
+		android:layout_marginEnd="16dp"
+		android:layout_marginRight="16dp"
+		android:layout_marginBottom="8dp"
+		android:text="@string/transport_lan"
+		app:layout_constraintBottom_toTopOf="@+id/btSwitch"
+		app:layout_constraintEnd_toEndOf="parent"
+		app:layout_constraintStart_toEndOf="@+id/wifiIcon"
+		tools:checked="true" />
+
+	<ImageView
+		android:id="@+id/btIcon"
+		android:layout_width="wrap_content"
+		android:layout_height="wrap_content"
+		android:layout_marginStart="16dp"
+		android:layout_marginLeft="16dp"
+		android:src="@drawable/transport_bt"
+		app:layout_constraintBottom_toBottomOf="@+id/btSwitch"
+		app:layout_constraintStart_toStartOf="parent"
+		app:layout_constraintTop_toTopOf="@+id/btSwitch"
+		tools:checked="true"
+		tools:ignore="ContentDescription"
+		tools:tint="@color/briar_green" />
+
+	<androidx.appcompat.widget.SwitchCompat
+		android:id="@+id/btSwitch"
+		android:layout_width="0dp"
+		android:layout_height="wrap_content"
+		android:layout_marginStart="16dp"
+		android:layout_marginLeft="16dp"
+		android:layout_marginEnd="16dp"
+		android:layout_marginRight="16dp"
+		android:layout_marginBottom="8dp"
+		android:text="@string/transport_bt"
+		app:layout_constraintBottom_toBottomOf="parent"
+		app:layout_constraintEnd_toEndOf="parent"
+		app:layout_constraintStart_toEndOf="@+id/btIcon"
+		app:layout_constraintVertical_bias="1.0"
+		tools:checked="true" />
+
+	<TextView
+		android:id="@+id/connectionsLabel"
+		android:layout_width="wrap_content"
+		android:layout_height="wrap_content"
+		android:layout_marginStart="8dp"
+		android:layout_marginLeft="8dp"
+		android:layout_marginEnd="8dp"
+		android:layout_marginRight="8dp"
+		android:text="@string/transport_connection"
+		android:textSize="12sp"
+		android:visibility="gone"
+		app:layout_constraintBottom_toBottomOf="@+id/torIcon"
+		app:layout_constraintEnd_toStartOf="@+id/torIcon"
+		app:layout_constraintStart_toStartOf="parent"
+		app:layout_constraintTop_toTopOf="@+id/torIcon" />
+
+</merge>

briar-android/src/main/res/menu/navigation_drawer.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
-<menu
-	xmlns:android="http://schemas.android.com/apk/res/android">
+<menu xmlns:android="http://schemas.android.com/apk/res/android"
+	xmlns:tools="http://schemas.android.com/tools">
 
 	<group android:checkableBehavior="single">
 		<item
@@ -30,7 +30,8 @@
 			android:id="@+id/nav_btn_lock"
 			android:icon="@drawable/startup_lock"
 			android:title="@string/lock_button"
-			android:visible="false"/>
+			android:visible="false"
+			tools:visible="false" />
 		<item
 			android:id="@+id/nav_btn_signout"
 			android:icon="@drawable/ic_signout"

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

@@ -1,14 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
-	<string-array name="boolean_array">
-		<item>true</item>
-		<item>false</item>
-	</string-array>
-	<string-array name="bt_setting_names">
-		<item>@string/bluetooth_setting_enabled</item>
-		<item>@string/bluetooth_setting_disabled</item>
-	</string-array>
-
 	<string-array name="tor_network_setting_names">
 		<item>@string/tor_network_setting_automatic</item>
 		<item>@string/tor_network_setting_without_bridges</item>
@@ -66,6 +57,7 @@
 		<item>zh-CN</item>
 		<item>zh-TW</item>
 	</string-array>
+
 	<string-array name="pref_theme_entries">
 		<item>@string/pref_theme_light</item>
 		<item>@string/pref_theme_dark</item>

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

@@ -68,7 +68,10 @@
 	<string name="sign_out_button">Sign Out</string>
 
 	<!-- Transports -->
-	<string name="transport_tor">Internet</string>
+	<string name="transport_connection">Connections</string>
+	<string name="transport_internet">Internet</string>
+	<string name="transport_tor">Tor</string>
+	<string name="transport_nearby">Nearby</string>
 	<string name="transport_bt">Bluetooth</string>
 	<string name="transport_lan">Wi-Fi</string>
 
@@ -106,7 +109,6 @@
 	<string name="delete">Delete</string>
 	<string name="accept">Accept</string>
 	<string name="decline">Decline</string>
-	<string name="options">Options</string>
 	<string name="online">Online</string>
 	<string name="offline">Offline</string>
 	<string name="send">Send</string>
@@ -188,7 +190,6 @@
 	<string name="add_contact_remotely_title_case">Add Contact at a Distance</string>
 	<string name="add_contact_nearby_title">Add contact nearby</string>
 	<string name="add_contact_remotely_title">Add contact at a distance</string>
-	<string name="contact_name_hint">Give contact a nickname</string>
 	<string name="contact_link_intro">Enter the link from your contact here</string>
 	<string name="contact_link_hint">Contact\'s link</string>
 	<string name="paste_button">Paste</string>
@@ -206,7 +207,6 @@
 	<string name="pending_contact_requests_snackbar">There are pending contact requests</string>
 	<string name="pending_contact_requests">Pending Contact Requests</string>
 	<string name="no_pending_contacts">No pending contacts</string>
-	<string name="add_contact_remote_connecting">Connecting…</string>
 	<string name="waiting_for_contact_to_come_online">Waiting for contact to come online…</string>
 	<string name="connecting">Connecting…</string>
 	<string name="adding_contact">Adding contact…</string>
@@ -227,9 +227,6 @@
 		<item quantity="one">New contact added.</item>
 		<item quantity="other">%d new contacts added.</item>
 	</plurals>
-	<string name="adding_contact_slow_warning">Adding this contact is taking longer than usual</string>
-	<string name="adding_contact_slow_title">Cannot Connect to Contact</string>
-	<string name="adding_contact_slow_text">Adding this contact is taking longer than usual.\n\nPlease check that your contact has received your link and added you:</string>
 	<string name="offline_state">No Internet connection</string>
 	<string name="duplicate_link_dialog_title">Duplicate Link</string>
 	<string name="duplicate_link_dialog_text_1">You already have a pending contact with this link: %s</string>
@@ -259,11 +256,9 @@
 	<string name="introduction_button">Make Introduction</string>
 	<string name="introduction_sent">Your introduction has been sent.</string>
 	<string name="introduction_error">There was an error making the introduction.</string>
-	<string name="introduction_response_error">Error when responding to introduction</string>
 	<string name="introduction_request_sent">You have asked to introduce %1$s to %2$s.</string>
 	<string name="introduction_request_received">%1$s has asked to introduce you to %2$s. Do you want to add %2$s to your contact list?</string>
 	<string name="introduction_request_exists_received">%1$s has asked to introduce you to %2$s, but %2$s is already in your contact list. Since %1$s might not know that, you can still respond:</string>
-	<string name="introduction_request_answered_received">%1$s has asked to introduce you to %2$s.</string>
 	<string name="introduction_response_accepted_sent">You accepted the introduction to %1$s.</string>
 	<string name="introduction_response_accepted_sent_info">Before %1$s gets added to your contacts, they need to accept the introduction as well. This might take some time.</string>
 	<string name="introduction_response_declined_sent">You declined the introduction to %1$s.</string>
@@ -441,12 +436,9 @@
 	<string name="pref_theme_auto">Automatic (Daytime)</string>
 	<string name="pref_theme_system">System Default</string>
 
-	<!-- Settings Network -->
-	<string name="network_settings_title">Networks</string>
-	<string name="bluetooth_setting">Connect via Bluetooth</string>
-	<string name="bluetooth_setting_enabled">Whenever contacts are nearby</string>
-	<string name="bluetooth_setting_disabled">Only when adding contacts</string>
-	<string name="tor_network_setting">Connect via Internet (Tor)</string>
+	<!-- Settings Connections -->
+	<string name="network_settings_title">Connections</string>
+	<string name="tor_network_setting">Connection method for Internet (Tor)</string>
 	<string name="tor_network_setting_automatic">Automatic based on location</string>
 	<string name="tor_network_setting_without_bridges">Use Tor without bridges</string>
 	<string name="tor_network_setting_with_bridges">Use Tor with bridges</string>
@@ -497,8 +489,6 @@
 	<string name="panic_setting_signout_summary">Sign out of Briar if a panic button is pressed</string>
 	<string name="purge_setting_title">Delete Account</string>
 	<string name="purge_setting_summary">Delete your Briar account if a panic button is pressed. Caution: This will permanently delete your identities, contacts and messages</string>
-	<string name="uninstall_setting_title">Uninstall Briar</string>
-	<string name="uninstall_setting_summary">This requires manual confirmation in a panic event</string>
 
 	<!-- Settings Notifications -->
 	<string name="notification_settings_title">Notifications</string>

briar-android/src/main/res/xml/settings.xml

@@ -29,16 +29,6 @@
 		android:layout="@layout/preferences_category"
 		android:title="@string/network_settings_title">
 
-		<ListPreference
-			android:defaultValue="false"
-			android:entries="@array/bt_setting_names"
-			android:entryValues="@array/boolean_array"
-			android:key="pref_key_bluetooth"
-			android:persistent="false"
-			android:summary="%s"
-			android:title="@string/bluetooth_setting"
-			app:iconSpaceReserved="false"/>
-
 		<ListPreference
 			android:defaultValue="0"
 			android:entries="@array/tor_network_setting_names"

briar-core/src/main/java/org/briarproject/briar/feed/FeedManagerImpl.java

@@ -24,7 +24,8 @@ import org.briarproject.bramble.api.lifecycle.LifecycleManager.OpenDatabaseHook;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.TorConstants;
 import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.plugin.event.TransportEnabledEvent;
+import org.briarproject.bramble.api.plugin.event.TransportActiveEvent;
+import org.briarproject.bramble.api.plugin.event.TransportInactiveEvent;
 import org.briarproject.bramble.api.sync.Group;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.system.Clock;
@@ -97,6 +98,8 @@ class FeedManagerImpl implements FeedManager, EventListener, OpenDatabaseHook,
 	private final Dns noDnsLookups;
 	private final AtomicBoolean fetcherStarted = new AtomicBoolean(false);
 
+	private volatile boolean torActive = false;
+
 	@Inject
 	FeedManagerImpl(@Scheduler ScheduledExecutorService scheduler,
 			@IoExecutor Executor ioExecutor, DatabaseComponent db,
@@ -120,14 +123,23 @@ class FeedManagerImpl implements FeedManager, EventListener, OpenDatabaseHook,
 
 	@Override
 	public void eventOccurred(Event e) {
-		if (e instanceof TransportEnabledEvent) {
-			TransportId t = ((TransportEnabledEvent) e).getTransportId();
+		if (e instanceof TransportActiveEvent) {
+			TransportId t = ((TransportActiveEvent) e).getTransportId();
 			if (t.equals(TorConstants.ID)) {
+				setTorActive(true);
 				startFeedExecutor();
 			}
+		} else if (e instanceof TransportInactiveEvent) {
+			TransportId t = ((TransportInactiveEvent) e).getTransportId();
+			if (t.equals(TorConstants.ID)) setTorActive(false);
 		}
 	}
 
+	// Package access for testing
+	void setTorActive(boolean active) {
+		torActive = active;
+	}
+
 	private void startFeedExecutor() {
 		if (fetcherStarted.getAndSet(true)) return;
 		LOG.info("Tor started, scheduling RSS feed fetcher");
@@ -279,6 +291,7 @@ class FeedManagerImpl implements FeedManager, EventListener, OpenDatabaseHook,
 	 * and we can not block the database that long.
 	 */
 	void fetchFeeds() {
+		if (!torActive) return;
 		LOG.info("Updating RSS feeds...");
 
 		// Get current feeds

briar-core/src/test/java/org/briarproject/briar/feed/FeedManagerImplTest.java

@@ -76,15 +76,22 @@ public class FeedManagerImplTest extends BrambleMockTestCase {
 					SocketFactory.getDefault(), clock, noDnsLookups);
 
 	@Test
-	public void testEmptyFetchFeed() throws Exception {
-		BdfList feedList = new BdfList();
-		expectGetFeeds(feedList);
-		expectStoreFeed(feedList);
+	public void testFetchFeedsReturnsEarlyIfTorIsNotActive() {
+		feedManager.setTorActive(false);
 		feedManager.fetchFeeds();
 	}
 
 	@Test
-	public void testFetchFeedIoException() throws Exception {
+	public void testEmptyFetchFeeds() throws Exception {
+		BdfList feedList = new BdfList();
+		expectGetFeeds(feedList);
+		expectStoreFeed(feedList);
+		feedManager.setTorActive(true);
+		feedManager.fetchFeeds();
+	}
+
+	@Test
+	public void testFetchFeedsIoException() throws Exception {
 		BdfDictionary feedDict= new BdfDictionary();
 		BdfList feedList = BdfList.of(feedDict);
 
@@ -95,6 +102,7 @@ public class FeedManagerImplTest extends BrambleMockTestCase {
 		}});
 		expectStoreFeed(feedList);
 
+		feedManager.setTorActive(true);
 		feedManager.fetchFeeds();
 	}