Enable BT plugin before showing QR code.

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

@@ -8,10 +8,20 @@ import android.content.IntentFilter;
 import android.os.Bundle;
 import android.view.MenuItem;
 
+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.IoExecutor;
 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.Plugin;
+import org.briarproject.bramble.api.plugin.PluginManager;
 import org.briarproject.bramble.api.plugin.event.BluetoothEnabledEvent;
+import org.briarproject.bramble.api.plugin.event.TransportActiveEvent;
+import org.briarproject.bramble.api.settings.Settings;
+import org.briarproject.bramble.api.settings.SettingsManager;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.ActivityComponent;
 import org.briarproject.briar.android.activity.BriarActivity;
@@ -21,6 +31,7 @@ import org.briarproject.briar.android.keyagreement.IntroFragment.IntroScreenSeen
 import org.briarproject.briar.android.keyagreement.KeyAgreementFragment.KeyAgreementEventListener;
 import org.briarproject.briar.android.util.UiUtils;
 
+import java.util.concurrent.Executor;
 import java.util.logging.Logger;
 
 import javax.annotation.Nullable;
@@ -37,15 +48,15 @@ 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.WARNING;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
+import static org.briarproject.bramble.api.plugin.BluetoothConstants.PREF_BT_ENABLE;
+import static org.briarproject.bramble.api.plugin.Plugin.State.ACTIVE;
+import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_BLUETOOTH_DISCOVERABLE;
 import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_PERMISSION_CAMERA_LOCATION;
 
@@ -53,10 +64,41 @@ 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
+		/**
+		 * We don't yet know the state of the Bluetooth adapter or plugin.
+		 */
+		UNKNOWN,
+
+		/**
+		 * The device doesn't have a Bluetooth adapter.
+		 */
+		NO_ADAPTER,
+
+		/**
+		 * We're waiting for the user to decide whether to allow
+		 * discoverability, or the user has allowed discoverability and we're
+		 * waiting for the adapter to become discoverable.
+		 */
+		WAITING,
+
+		/**
+		 * The user has refused discoverability.
+		 */
+		REFUSED,
+
+		/**
+		 * The Bluetooth adapter is discoverable.
+		 */
+		DISCOVERABLE,
+
+		/**
+		 * The Bluetooth adapter is discoverable and we're waiting for the
+		 * Bluetooth plugin to become active.
+		 */
+		ACTIVATING_PLUGIN
 	}
 
 	private enum Permission {
@@ -69,6 +111,16 @@ public abstract class KeyAgreementActivity extends BriarActivity implements
 	@Inject
 	EventBus eventBus;
 
+	@Inject
+	PluginManager pluginManager;
+
+	@Inject
+	@IoExecutor
+	Executor ioExecutor;
+
+	@Inject
+	SettingsManager settingsManager;
+
 	/**
 	 * Set to true in onPostResume() and false in onPause(). This prevents the
 	 * QR code fragment from being shown if onRequestPermissionsResult() is
@@ -91,6 +143,13 @@ public abstract class KeyAgreementActivity extends BriarActivity implements
 	 */
 	private boolean wasAdapterEnabled = false;
 
+	/**
+	 * Records whether the user accepted the most recent request (if any) to
+	 * make the Bluetooth adapter discoverable, so we know whether to broadcast
+	 * a {@link BluetoothEnabledEvent}.
+	 */
+	private boolean wasRequestAccepted = false;
+
 	private Permission cameraPermission = Permission.UNKNOWN;
 	private Permission locationPermission = Permission.UNKNOWN;
 	private BluetoothState bluetoothState = BluetoothState.UNKNOWN;
@@ -111,9 +170,7 @@ public abstract class KeyAgreementActivity extends BriarActivity implements
 		if (state == null) {
 			showInitialFragment(IntroFragment.newInstance());
 		}
-		IntentFilter filter = new IntentFilter();
+		IntentFilter filter = new IntentFilter(ACTION_SCAN_MODE_CHANGED);
-		filter.addAction(ACTION_STATE_CHANGED);
-		filter.addAction(ACTION_SCAN_MODE_CHANGED);
 		bluetoothReceiver = new BluetoothStateReceiver();
 		registerReceiver(bluetoothReceiver, filter);
 	}
@@ -136,6 +193,7 @@ public abstract class KeyAgreementActivity extends BriarActivity implements
 	@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;
@@ -152,11 +210,22 @@ public abstract class KeyAgreementActivity extends BriarActivity implements
 
 	private void showQrCodeFragmentIfAllowed() {
 		if (isResumed && continueClicked && areEssentialPermissionsGranted()) {
-			if (bluetoothState == BluetoothState.UNKNOWN ||
+			if (bluetoothState == BluetoothState.UNKNOWN) {
-					bluetoothState == BluetoothState.ENABLED) {
 				requestBluetoothDiscoverable();
-			} else if (bluetoothState != BluetoothState.WAITING) {
+			} else if (bluetoothState == BluetoothState.NO_ADAPTER ||
+					bluetoothState == BluetoothState.REFUSED) {
+				LOG.info("Continuing without Bluetooth");
 				showQrCodeFragment();
+			} else if (bluetoothState == BluetoothState.DISCOVERABLE ||
+					bluetoothState == BluetoothState.ACTIVATING_PLUGIN) {
+				if (isBluetoothPluginActive()) {
+					LOG.info("Bluetooth plugin is active");
+					showQrCodeFragment();
+				} else {
+					LOG.info("Enabling Bluetooth plugin");
+					bluetoothState = BluetoothState.ACTIVATING_PLUGIN;
+					enableBluetoothPlugin();
+				}
 			}
 		}
 	}
@@ -169,12 +238,36 @@ public abstract class KeyAgreementActivity extends BriarActivity implements
 						locationPermission == Permission.PERMANENTLY_DENIED);
 	}
 
+	private boolean isBluetoothPluginActive() {
+		Plugin p = pluginManager.getPlugin(BluetoothConstants.ID);
+		return p != null && p.getState() == ACTIVE;
+	}
+
+	private void enableBluetoothPlugin() {
+		ioExecutor.execute(() -> {
+			try {
+				Settings s = new Settings();
+				s.putBoolean(PREF_BT_ENABLE, true);
+				String namespace = BluetoothConstants.ID.getString();
+				settingsManager.mergeSettings(s, namespace);
+			} catch (DbException e) {
+				logException(LOG, WARNING, e);
+			}
+		});
+	}
+
 	@Override
 	protected void onPause() {
 		super.onPause();
 		isResumed = false;
 	}
 
+	@Override
+	protected void onStop() {
+		super.onStop();
+		eventBus.removeListener(this);
+	}
+
 	@Override
 	public void showNextScreen() {
 		continueClicked = true;
@@ -200,8 +293,11 @@ public abstract class KeyAgreementActivity extends BriarActivity implements
 	private void setBluetoothState(BluetoothState bluetoothState) {
 		LOG.info("Setting Bluetooth state to " + bluetoothState);
 		this.bluetoothState = bluetoothState;
-		if (!wasAdapterEnabled && bluetoothState == BluetoothState.ENABLED) {
+		if (!wasAdapterEnabled && wasRequestAccepted &&
+				bluetoothState == BluetoothState.DISCOVERABLE) {
+			LOG.info("Bluetooth adapter was enabled by us");
 			eventBus.broadcast(new BluetoothEnabledEvent());
+			wasRequestAccepted = false;
 			wasAdapterEnabled = true;
 		}
 		showQrCodeFragmentIfAllowed();
@@ -214,12 +310,14 @@ public abstract class KeyAgreementActivity extends BriarActivity implements
 			if (result == RESULT_CANCELED) {
 				setBluetoothState(BluetoothState.REFUSED);
 			} else {
+				wasRequestAccepted = true;
 				// 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)
+				if (bt.getScanMode() == SCAN_MODE_CONNECTABLE_DISCOVERABLE) {
 					setBluetoothState(BluetoothState.DISCOVERABLE);
+				}
 			}
 		} else super.onActivityResult(request, result, data);
 	}
@@ -332,23 +430,30 @@ public abstract class KeyAgreementActivity extends BriarActivity implements
 				permission);
 	}
 
+	@Override
+	public void eventOccurred(Event e) {
+		if (e instanceof TransportActiveEvent) {
+			TransportActiveEvent t = (TransportActiveEvent) e;
+			if (t.getTransportId().equals(BluetoothConstants.ID)) {
+				showQrCodeFragmentIfAllowed();
+			}
+		}
+	}
+
 	private class BluetoothStateReceiver extends BroadcastReceiver {
 
 		@Override
 		public void onReceive(Context context, Intent intent) {
 			String action = intent.getAction();
-			if (ACTION_STATE_CHANGED.equals(action)) {
+			if (ACTION_SCAN_MODE_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)
+				if (scanMode == SCAN_MODE_CONNECTABLE_DISCOVERABLE) {
+					LOG.info("Bluetooth adapter is discoverable");
 					setBluetoothState(BluetoothState.DISCOVERABLE);
-				else if (scanMode == SCAN_MODE_CONNECTABLE)
+				} else if (bluetoothState == BluetoothState.DISCOVERABLE) {
-					setBluetoothState(BluetoothState.ENABLED);
+					LOG.info("Bluetooth adapter is not discoverable");
-				else setBluetoothState(BluetoothState.UNKNOWN);
+					setBluetoothState(BluetoothState.UNKNOWN);
+				}
 			}
 		}
 	}