Merge activities for adding contact nearby

and rename related classes to consolidate names

briar-android/src/main/AndroidManifest.xml

@@ -342,7 +342,7 @@
 		</activity>
 
 		<activity
-			android:name="org.briarproject.briar.android.contact.add.nearby.ContactExchangeActivity"
+			android:name="org.briarproject.briar.android.contact.add.nearby.AddNearbyContactActivity"
 			android:label="@string/add_contact_title"
 			android:parentActivityName="org.briarproject.briar.android.navdrawer.NavDrawerActivity"
 			android:theme="@style/BriarTheme.NoActionBar">

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

@@ -31,7 +31,7 @@ import org.briarproject.briar.android.account.DozeHelperModule;
 import org.briarproject.briar.android.account.LockManagerImpl;
 import org.briarproject.briar.android.account.SetupModule;
 import org.briarproject.briar.android.contact.ContactListModule;
-import org.briarproject.briar.android.contact.add.nearby.ContactExchangeModule;
+import org.briarproject.briar.android.contact.add.nearby.AddNearbyContactModule;
 import org.briarproject.briar.android.forum.ForumModule;
 import org.briarproject.briar.android.introduction.IntroductionModule;
 import org.briarproject.briar.android.logging.LoggingModule;
@@ -75,7 +75,7 @@ import static org.briarproject.briar.android.TestingConstants.IS_DEBUG_BUILD;
 @Module(includes = {
 		SetupModule.class,
 		DozeHelperModule.class,
-		ContactExchangeModule.class,
+		AddNearbyContactModule.class,
 		LoggingModule.class,
 		LoginModule.class,
 		NavDrawerModule.class,

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

@@ -21,11 +21,10 @@ import org.briarproject.briar.android.blog.RssFeedImportActivity;
 import org.briarproject.briar.android.blog.RssFeedManageActivity;
 import org.briarproject.briar.android.blog.WriteBlogPostActivity;
 import org.briarproject.briar.android.contact.ContactListFragment;
-import org.briarproject.briar.android.contact.add.nearby.ContactExchangeActivity;
+import org.briarproject.briar.android.contact.add.nearby.AddNearbyContactActivity;
-import org.briarproject.briar.android.contact.add.nearby.ContactExchangeErrorFragment;
+import org.briarproject.briar.android.contact.add.nearby.AddNearbyContactErrorFragment;
-import org.briarproject.briar.android.contact.add.nearby.IntroFragment;
+import org.briarproject.briar.android.contact.add.nearby.AddNearbyContactFragment;
-import org.briarproject.briar.android.contact.add.nearby.KeyAgreementActivity;
+import org.briarproject.briar.android.contact.add.nearby.AddNearbyContactIntroFragment;
-import org.briarproject.briar.android.contact.add.nearby.KeyAgreementFragment;
 import org.briarproject.briar.android.contact.add.remote.AddContactActivity;
 import org.briarproject.briar.android.contact.add.remote.LinkExchangeFragment;
 import org.briarproject.briar.android.contact.add.remote.NicknameFragment;
@@ -109,9 +108,7 @@ public interface ActivityComponent {
 
 	void inject(PanicPreferencesActivity activity);
 
-	void inject(ContactExchangeActivity activity);
+	void inject(AddNearbyContactActivity activity);
-
-	void inject(KeyAgreementActivity activity);
 
 	void inject(ConversationActivity activity);
 
@@ -209,9 +206,9 @@ public interface ActivityComponent {
 
 	void inject(FeedFragment fragment);
 
-	void inject(IntroFragment fragment);
+	void inject(AddNearbyContactIntroFragment fragment);
 
-	void inject(KeyAgreementFragment fragment);
+	void inject(AddNearbyContactFragment fragment);
 
 	void inject(LinkExchangeFragment fragment);
 
@@ -229,7 +226,7 @@ public interface ActivityComponent {
 
 	void inject(ScreenFilterDialogFragment fragment);
 
-	void inject(ContactExchangeErrorFragment fragment);
+	void inject(AddNearbyContactErrorFragment fragment);
 
 	void inject(AliasDialogFragment aliasDialogFragment);
 

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

@@ -15,11 +15,11 @@ 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.contact.add.nearby.AddNearbyContactActivity;
 import org.briarproject.briar.android.contact.add.remote.AddContactActivity;
 import org.briarproject.briar.android.contact.add.remote.PendingContactListActivity;
 import org.briarproject.briar.android.conversation.ConversationActivity;
 import org.briarproject.briar.android.fragment.BaseFragment;
-import org.briarproject.briar.android.contact.add.nearby.ContactExchangeActivity;
 import org.briarproject.briar.android.util.BriarSnackbarBuilder;
 import org.briarproject.briar.android.view.BriarRecyclerView;
 
@@ -125,7 +125,8 @@ public class ContactListFragment extends BaseFragment
 		switch (itemId) {
 			case R.id.action_add_contact_nearby:
 				Intent intent =
-						new Intent(getContext(), ContactExchangeActivity.class);
+						new Intent(getContext(),
+								AddNearbyContactActivity.class);
 				startActivity(intent);
 				return;
 			case R.id.action_add_contact_remotely:

briar-android/src/main/java/org/briarproject/briar/android/contact/add/nearby/AddContactState.java

@@ -0,0 +1,76 @@
+package org.briarproject.briar.android.contact.add.nearby;
+
+import android.graphics.Bitmap;
+
+import org.briarproject.bramble.api.identity.Author;
+
+import androidx.annotation.Nullable;
+
+abstract class AddContactState {
+
+	static class KeyAgreementListening extends AddContactState {
+		final Bitmap qrCode;
+
+		KeyAgreementListening(Bitmap qrCode) {
+			this.qrCode = qrCode;
+		}
+	}
+
+	static class QrCodeScanned extends AddContactState {
+	}
+
+	static class KeyAgreementWaiting extends AddContactState {
+	}
+
+	static class KeyAgreementStarted extends AddContactState {
+	}
+
+	static class ContactExchangeStarted extends AddContactState {
+	}
+
+	static class ContactExchangeFinished extends AddContactState {
+		final ContactExchangeResult result;
+
+		ContactExchangeFinished(ContactExchangeResult result) {
+			this.result = result;
+		}
+	}
+
+	static class Failed extends AddContactState {
+		/**
+		 * Non-null if failed due to the scanned QR code version.
+		 * True if the app producing the code is too old.
+		 * False if the scanning app is too old.
+		 */
+		@Nullable
+		final Boolean qrCodeTooOld;
+
+		Failed(@Nullable Boolean qrCodeTooOld) {
+			this.qrCodeTooOld = qrCodeTooOld;
+		}
+
+		Failed() {
+			this(null);
+		}
+	}
+
+	abstract static class ContactExchangeResult {
+		static class Success extends ContactExchangeResult {
+			final Author remoteAuthor;
+
+			Success(Author remoteAuthor) {
+				this.remoteAuthor = remoteAuthor;
+			}
+		}
+
+		static class Error extends ContactExchangeResult {
+			@Nullable
+			final Author duplicateAuthor;
+
+			Error(@Nullable Author duplicateAuthor) {
+				this.duplicateAuthor = duplicateAuthor;
+			}
+		}
+	} // end ContactExchangeResult
+
+}

briar-android/src/main/java/org/briarproject/briar/android/contact/add/nearby/AddNearbyContactActivity.java

@@ -6,13 +6,19 @@ import android.content.Intent;
 import android.content.IntentFilter;
 import android.os.Bundle;
 import android.view.MenuItem;
+import android.widget.Toast;
 
+import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.NullSafety;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.ActivityComponent;
 import org.briarproject.briar.android.activity.BriarActivity;
-import org.briarproject.briar.android.contact.add.nearby.ContactExchangeViewModel.BluetoothDecision;
+import org.briarproject.briar.android.contact.add.nearby.AddContactState.ContactExchangeFinished;
+import org.briarproject.briar.android.contact.add.nearby.AddContactState.ContactExchangeResult;
+import org.briarproject.briar.android.contact.add.nearby.AddContactState.Failed;
+import org.briarproject.briar.android.contact.add.nearby.AddNearbyContactViewModel.BluetoothDecision;
 import org.briarproject.briar.android.fragment.BaseFragment;
 import org.briarproject.briar.android.fragment.BaseFragment.BaseFragmentListener;
 
@@ -21,32 +27,32 @@ import java.util.logging.Logger;
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
-import androidx.annotation.UiThread;
 import androidx.appcompat.widget.Toolbar;
 import androidx.fragment.app.FragmentManager;
 import androidx.lifecycle.ViewModelProvider;
 
 import static android.bluetooth.BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE;
 import static android.bluetooth.BluetoothAdapter.ACTION_SCAN_MODE_CHANGED;
+import static android.widget.Toast.LENGTH_LONG;
+import static java.util.Objects.requireNonNull;
 import static java.util.logging.Logger.getLogger;
-import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
 import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_BLUETOOTH_DISCOVERABLE;
-import static org.briarproject.briar.android.contact.add.nearby.ContactExchangeViewModel.BluetoothDecision.ACCEPTED;
+import static org.briarproject.briar.android.contact.add.nearby.AddNearbyContactViewModel.BluetoothDecision.ACCEPTED;
-import static org.briarproject.briar.android.contact.add.nearby.ContactExchangeViewModel.BluetoothDecision.REFUSED;
+import static org.briarproject.briar.android.contact.add.nearby.AddNearbyContactViewModel.BluetoothDecision.REFUSED;
-import static org.briarproject.briar.android.contact.add.nearby.ContactExchangeViewModel.BluetoothDecision.UNKNOWN;
+import static org.briarproject.briar.android.contact.add.nearby.AddNearbyContactViewModel.BluetoothDecision.UNKNOWN;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
-public abstract class KeyAgreementActivity extends BriarActivity
+public class AddNearbyContactActivity extends BriarActivity
 		implements BaseFragmentListener {
 
 	private static final Logger LOG =
-			getLogger(KeyAgreementActivity.class.getName());
+			getLogger(AddNearbyContactActivity.class.getName());
 
 	@Inject
 	ViewModelProvider.Factory viewModelFactory;
 
-	protected ContactExchangeViewModel viewModel;
+	private AddNearbyContactViewModel viewModel;
 	private AddNearbyContactPermissionManager permissionManager;
 
 	/**
@@ -62,7 +68,7 @@ public abstract class KeyAgreementActivity extends BriarActivity
 	public void injectActivity(ActivityComponent component) {
 		component.inject(this);
 		viewModel = new ViewModelProvider(this, viewModelFactory)
-				.get(ContactExchangeViewModel.class);
+				.get(AddNearbyContactViewModel.class);
 		permissionManager = new AddNearbyContactPermissionManager(this,
 				viewModel.isBluetoothSupported());
 	}
@@ -73,9 +79,10 @@ public abstract class KeyAgreementActivity extends BriarActivity
 		setContentView(R.layout.activity_fragment_container_toolbar);
 		Toolbar toolbar = findViewById(R.id.toolbar);
 		setSupportActionBar(toolbar);
-		requireNonNull(getSupportActionBar()).setDisplayHomeAsUpEnabled(true);
+		NullSafety.requireNonNull(getSupportActionBar())
+				.setDisplayHomeAsUpEnabled(true);
 		if (state == null) {
-			showInitialFragment(IntroFragment.newInstance());
+			showInitialFragment(AddNearbyContactIntroFragment.newInstance());
 		}
 		IntentFilter filter = new IntentFilter(ACTION_SCAN_MODE_CHANGED);
 		bluetoothReceiver = new BluetoothStateReceiver();
@@ -90,6 +97,10 @@ public abstract class KeyAgreementActivity extends BriarActivity
 		viewModel.getShowQrCodeFragment().observeEvent(this, show -> {
 			if (show) showQrCodeFragment();
 		});
+		requireNonNull(getSupportActionBar())
+				.setTitle(R.string.add_contact_title);
+		viewModel.getState()
+				.observe(this, this::onAddContactStateChanged);
 	}
 
 	@Override
@@ -120,15 +131,6 @@ public abstract class KeyAgreementActivity extends BriarActivity
 		if (bluetoothReceiver != null) unregisterReceiver(bluetoothReceiver);
 	}
 
-	@Override
-	public boolean onOptionsItemSelected(MenuItem item) {
-		if (item.getItemId() == android.R.id.home) {
-			onBackPressed();
-			return true;
-		}
-		return super.onOptionsItemSelected(item);
-	}
-
 	@Override
 	public void onActivityResult(int request, int result,
 			@Nullable Intent data) {
@@ -145,7 +147,15 @@ public abstract class KeyAgreementActivity extends BriarActivity
 	}
 
 	@Override
-	@UiThread
+	public boolean onOptionsItemSelected(MenuItem item) {
+		if (item.getItemId() == android.R.id.home) {
+			onBackPressed();
+			return true;
+		}
+		return super.onOptionsItemSelected(item);
+	}
+
+	@Override
 	public void onRequestPermissionsResult(int requestCode,
 			String[] permissions, int[] grantResults) {
 		super.onRequestPermissionsResult(requestCode, permissions,
@@ -154,6 +164,16 @@ public abstract class KeyAgreementActivity extends BriarActivity
 				grantResults, this::showQrCodeFragmentIfAllowed);
 	}
 
+	@Override
+	public void onBackPressed() {
+		if (viewModel.getState().getValue() instanceof Failed) {
+			// finish this activity when going back in failed state
+			supportFinishAfterTransition();
+		} else {
+			super.onBackPressed();
+		}
+	}
+
 	private void requestBluetoothDiscoverable() {
 		if (!viewModel.isBluetoothSupported()) {
 			viewModel.bluetoothDecision = BluetoothDecision.NO_ADAPTER;
@@ -174,7 +194,8 @@ public abstract class KeyAgreementActivity extends BriarActivity
 	@SuppressWarnings("StatementWithEmptyBody")
 	private void showQrCodeFragmentIfAllowed() {
 		boolean continueClicked = // never set to null
-				requireNonNull(viewModel.getWasContinueClicked().getValue());
+				NullSafety.requireNonNull(
+						viewModel.getWasContinueClicked().getValue());
 		boolean permissionsGranted =
 				permissionManager.areEssentialPermissionsGranted();
 		if (isResumed && continueClicked && permissionsGranted) {
@@ -197,8 +218,8 @@ public abstract class KeyAgreementActivity extends BriarActivity
 	private void showQrCodeFragment() {
 		// FIXME #824
 		FragmentManager fm = getSupportFragmentManager();
-		if (fm.findFragmentByTag(KeyAgreementFragment.TAG) == null) {
+		if (fm.findFragmentByTag(AddNearbyContactFragment.TAG) == null) {
-			BaseFragment f = KeyAgreementFragment.newInstance();
+			BaseFragment f = AddNearbyContactFragment.newInstance();
 			fm.beginTransaction()
 					.replace(R.id.fragmentContainer, f, f.getUniqueTag())
 					.addToBackStack(f.getUniqueTag())
@@ -206,6 +227,65 @@ public abstract class KeyAgreementActivity extends BriarActivity
 		}
 	}
 
+	private void onAddContactStateChanged(AddContactState state) {
+		if (state instanceof ContactExchangeFinished) {
+			ContactExchangeResult result =
+					((ContactExchangeFinished) state).result;
+			onContactExchangeResult(result);
+		} else if (state instanceof Failed) {
+			// Remove navigation icon, so user can't go back when failed
+			// ErrorFragment will finish or relaunch this activity
+			Toolbar toolbar = findViewById(R.id.toolbar);
+			toolbar.setNavigationIcon(null);
+
+			Boolean qrCodeTooOld = ((Failed) state).qrCodeTooOld;
+			onAddingContactFailed(qrCodeTooOld);
+		}
+	}
+
+	private void onContactExchangeResult(ContactExchangeResult result) {
+		if (result instanceof ContactExchangeResult.Success) {
+			Author remoteAuthor =
+					((ContactExchangeResult.Success) result).remoteAuthor;
+			String contactName = remoteAuthor.getName();
+			String text = getString(R.string.contact_added_toast, contactName);
+			Toast.makeText(this, text, LENGTH_LONG).show();
+			supportFinishAfterTransition();
+		} else if (result instanceof ContactExchangeResult.Error) {
+			Author duplicateAuthor =
+					((ContactExchangeResult.Error) result).duplicateAuthor;
+			if (duplicateAuthor == null) {
+				showErrorFragment();
+			} else {
+				String contactName = duplicateAuthor.getName();
+				String text =
+						getString(R.string.contact_already_exists, contactName);
+				Toast.makeText(this, text, LENGTH_LONG).show();
+				supportFinishAfterTransition();
+			}
+		} else throw new AssertionError();
+	}
+
+	private void onAddingContactFailed(@Nullable Boolean qrCodeTooOld) {
+		if (qrCodeTooOld == null) {
+			showErrorFragment();
+		} else {
+			String msg;
+			if (qrCodeTooOld) {
+				msg = getString(R.string.qr_code_too_old,
+						getString(R.string.app_name));
+			} else {
+				msg = getString(R.string.qr_code_too_new,
+						getString(R.string.app_name));
+			}
+			showNextFragment(AddNearbyContactErrorFragment.newInstance(msg));
+		}
+	}
+
+	private void showErrorFragment() {
+		showNextFragment(new AddNearbyContactErrorFragment());
+	}
+
 	private class BluetoothStateReceiver extends BroadcastReceiver {
 		@Override
 		public void onReceive(Context context, Intent intent) {

briar-android/src/main/java/org/briarproject/briar/android/contact/add/nearby/AddNearbyContactErrorFragment.java

@@ -24,14 +24,14 @@ import static org.briarproject.briar.android.util.UiUtils.onSingleLinkClick;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
-public class ContactExchangeErrorFragment extends BaseFragment {
+public class AddNearbyContactErrorFragment extends BaseFragment {
 
 	public static final String TAG =
-			ContactExchangeErrorFragment.class.getName();
+			AddNearbyContactErrorFragment.class.getName();
 	private static final String ERROR_MSG = "errorMessage";
 
-	public static ContactExchangeErrorFragment newInstance(String errorMsg) {
+	public static AddNearbyContactErrorFragment newInstance(String errorMsg) {
-		ContactExchangeErrorFragment f = new ContactExchangeErrorFragment();
+		AddNearbyContactErrorFragment f = new AddNearbyContactErrorFragment();
 		Bundle args = new Bundle();
 		args.putString(ERROR_MSG, errorMsg);
 		f.setArguments(args);
@@ -72,7 +72,7 @@ public class ContactExchangeErrorFragment extends BaseFragment {
 		tryAgain.setOnClickListener(view -> {
 			// Recreate the activity so we return to the intro fragment
 			FragmentActivity activity = requireActivity();
-			Intent i = new Intent(activity, ContactExchangeActivity.class);
+			Intent i = new Intent(activity, AddNearbyContactActivity.class);
 			i.setFlags(FLAG_ACTIVITY_CLEAR_TOP);
 			activity.startActivity(i);
 		});

briar-android/src/main/java/org/briarproject/briar/android/contact/add/nearby/AddNearbyContactFragment.java

@@ -14,11 +14,11 @@ 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.contact.add.nearby.ContactAddingState.ContactExchangeStarted;
+import org.briarproject.briar.android.contact.add.nearby.AddContactState.ContactExchangeStarted;
-import org.briarproject.briar.android.contact.add.nearby.ContactAddingState.Failed;
+import org.briarproject.briar.android.contact.add.nearby.AddContactState.Failed;
-import org.briarproject.briar.android.contact.add.nearby.ContactAddingState.KeyAgreementStarted;
+import org.briarproject.briar.android.contact.add.nearby.AddContactState.KeyAgreementStarted;
-import org.briarproject.briar.android.contact.add.nearby.ContactAddingState.KeyAgreementWaiting;
+import org.briarproject.briar.android.contact.add.nearby.AddContactState.KeyAgreementWaiting;
-import org.briarproject.briar.android.contact.add.nearby.ContactAddingState.QrCodeScanned;
+import org.briarproject.briar.android.contact.add.nearby.AddContactState.QrCodeScanned;
 import org.briarproject.briar.android.fragment.BaseFragment;
 import org.briarproject.briar.android.view.QrCodeView;
 
@@ -42,26 +42,26 @@ import static org.briarproject.bramble.util.LogUtils.logException;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
-public class KeyAgreementFragment extends BaseFragment
+public class AddNearbyContactFragment extends BaseFragment
 		implements QrCodeView.FullscreenListener {
 
-	static final String TAG = KeyAgreementFragment.class.getName();
+	static final String TAG = AddNearbyContactFragment.class.getName();
 
 	private static final Logger LOG = Logger.getLogger(TAG);
 
 	@Inject
 	ViewModelProvider.Factory viewModelFactory;
 
-	private ContactExchangeViewModel viewModel;
+	private AddNearbyContactViewModel viewModel;
 	private CameraView cameraView;
 	private LinearLayout cameraOverlay;
 	private View statusView;
 	private QrCodeView qrCodeView;
 	private TextView status;
 
-	public static KeyAgreementFragment newInstance() {
+	public static AddNearbyContactFragment newInstance() {
 		Bundle args = new Bundle();
-		KeyAgreementFragment fragment = new KeyAgreementFragment();
+		AddNearbyContactFragment fragment = new AddNearbyContactFragment();
 		fragment.setArguments(args);
 		return fragment;
 	}
@@ -70,7 +70,7 @@ public class KeyAgreementFragment extends BaseFragment
 	public void injectFragment(ActivityComponent component) {
 		component.inject(this);
 		viewModel = new ViewModelProvider(requireActivity(), viewModelFactory)
-				.get(ContactExchangeViewModel.class);
+				.get(AddNearbyContactViewModel.class);
 	}
 
 	@Nullable
@@ -93,7 +93,7 @@ public class KeyAgreementFragment extends BaseFragment
 		qrCodeView.setFullscreenListener(this);
 
 		viewModel.getState().observe(getViewLifecycleOwner(),
-				this::onContactAddingStateChanged);
+				this::onAddContactStateChanged);
 	}
 
 	@Override
@@ -153,10 +153,10 @@ public class KeyAgreementFragment extends BaseFragment
 	}
 
 	@UiThread
-	private void onContactAddingStateChanged(ContactAddingState state) {
+	private void onAddContactStateChanged(AddContactState state) {
-		if (state instanceof ContactAddingState.KeyAgreementListening) {
+		if (state instanceof AddContactState.KeyAgreementListening) {
 			Bitmap qrCode =
-					((ContactAddingState.KeyAgreementListening) state).qrCode;
+					((AddContactState.KeyAgreementListening) state).qrCode;
 			qrCodeView.setQrCode(qrCode);
 		} else if (state instanceof QrCodeScanned) {
 			try {

briar-android/src/main/java/org/briarproject/briar/android/contact/add/nearby/AddNearbyContactIntroFragment.java

@@ -21,20 +21,21 @@ import static android.view.View.FOCUS_DOWN;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
-public class IntroFragment extends BaseFragment {
+public class AddNearbyContactIntroFragment extends BaseFragment {
 
-	public static final String TAG = IntroFragment.class.getName();
+	public static final String TAG = AddNearbyContactIntroFragment.class.getName();
 
 	@Inject
 	ViewModelProvider.Factory viewModelFactory;
 
-	private ContactExchangeViewModel viewModel;
+	private AddNearbyContactViewModel viewModel;
 
 	private ScrollView scrollView;
 
-	public static IntroFragment newInstance() {
+	public static AddNearbyContactIntroFragment newInstance() {
 		Bundle args = new Bundle();
-		IntroFragment fragment = new IntroFragment();
+		AddNearbyContactIntroFragment
+				fragment = new AddNearbyContactIntroFragment();
 		fragment.setArguments(args);
 		return fragment;
 	}
@@ -43,7 +44,7 @@ public class IntroFragment extends BaseFragment {
 	public void injectFragment(ActivityComponent component) {
 		component.inject(this);
 		viewModel = new ViewModelProvider(requireActivity(), viewModelFactory)
-				.get(ContactExchangeViewModel.class);
+				.get(AddNearbyContactViewModel.class);
 	}
 
 	@Nullable

briar-android/src/main/java/org/briarproject/briar/android/contact/add/nearby/AddNearbyContactModule.java

@@ -8,12 +8,12 @@ import dagger.Module;
 import dagger.multibindings.IntoMap;
 
 @Module
-public abstract class ContactExchangeModule {
+public abstract class AddNearbyContactModule {
 
 	@Binds
 	@IntoMap
-	@ViewModelKey(ContactExchangeViewModel.class)
+	@ViewModelKey(AddNearbyContactViewModel.class)
 	abstract ViewModel bindContactExchangeViewModel(
-			ContactExchangeViewModel contactExchangeViewModel);
+			AddNearbyContactViewModel addNearbyContactViewModel);
 
 }

briar-android/src/main/java/org/briarproject/briar/android/contact/add/nearby/AddNearbyContactViewModel.java

@@ -40,13 +40,13 @@ import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
 import org.briarproject.bramble.api.plugin.event.TransportStateEvent;
 import org.briarproject.briar.R;
-import org.briarproject.briar.android.contact.add.nearby.ContactAddingState.ContactExchangeFinished;
+import org.briarproject.briar.android.contact.add.nearby.AddContactState.ContactExchangeFinished;
-import org.briarproject.briar.android.contact.add.nearby.ContactAddingState.ContactExchangeStarted;
+import org.briarproject.briar.android.contact.add.nearby.AddContactState.ContactExchangeResult.Error;
-import org.briarproject.briar.android.contact.add.nearby.ContactAddingState.KeyAgreementListening;
+import org.briarproject.briar.android.contact.add.nearby.AddContactState.ContactExchangeResult.Success;
-import org.briarproject.briar.android.contact.add.nearby.ContactAddingState.KeyAgreementStarted;
+import org.briarproject.briar.android.contact.add.nearby.AddContactState.ContactExchangeStarted;
-import org.briarproject.briar.android.contact.add.nearby.ContactAddingState.KeyAgreementWaiting;
+import org.briarproject.briar.android.contact.add.nearby.AddContactState.KeyAgreementListening;
-import org.briarproject.briar.android.contact.add.nearby.ContactExchangeResult.Error;
+import org.briarproject.briar.android.contact.add.nearby.AddContactState.KeyAgreementStarted;
-import org.briarproject.briar.android.contact.add.nearby.ContactExchangeResult.Success;
+import org.briarproject.briar.android.contact.add.nearby.AddContactState.KeyAgreementWaiting;
 import org.briarproject.briar.android.viewmodel.LiveEvent;
 import org.briarproject.briar.android.viewmodel.MutableLiveEvent;
 
@@ -75,15 +75,15 @@ 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.api.plugin.Plugin.State.STARTING_STOPPING;
 import static org.briarproject.bramble.util.LogUtils.logException;
-import static org.briarproject.briar.android.contact.add.nearby.ContactExchangeViewModel.BluetoothDecision.REFUSED;
+import static org.briarproject.briar.android.contact.add.nearby.AddNearbyContactViewModel.BluetoothDecision.REFUSED;
-import static org.briarproject.briar.android.contact.add.nearby.ContactExchangeViewModel.BluetoothDecision.UNKNOWN;
+import static org.briarproject.briar.android.contact.add.nearby.AddNearbyContactViewModel.BluetoothDecision.UNKNOWN;
 
 @NotNullByDefault
-class ContactExchangeViewModel extends AndroidViewModel
+class AddNearbyContactViewModel extends AndroidViewModel
 		implements EventListener, QrCodeDecoder.ResultCallback {
 
 	private static final Logger LOG =
-			getLogger(ContactExchangeViewModel.class.getName());
+			getLogger(AddNearbyContactViewModel.class.getName());
 
 	enum BluetoothDecision {
 		/**
@@ -135,7 +135,7 @@ class ContactExchangeViewModel extends AndroidViewModel
 			new MutableLiveEvent<>();
 	private final MutableLiveEvent<TransportId> transportStateChanged =
 			new MutableLiveEvent<>();
-	private final MutableLiveData<ContactAddingState> state =
+	private final MutableLiveData<AddContactState> state =
 			new MutableLiveData<>();
 
 	final QrCodeDecoder qrCodeDecoder;
@@ -164,7 +164,7 @@ class ContactExchangeViewModel extends AndroidViewModel
 	private volatile boolean gotLocalPayload = false, gotRemotePayload = false;
 
 	@Inject
-	ContactExchangeViewModel(Application app,
+	AddNearbyContactViewModel(Application app,
 			EventBus eventBus,
 			@IoExecutor Executor ioExecutor,
 			PluginManager pluginManager,
@@ -336,11 +336,11 @@ class ContactExchangeViewModel extends AndroidViewModel
 		} else if (e instanceof KeyAgreementAbortedEvent) {
 			LOG.info("KeyAgreementAbortedEvent received");
 			resetPayloadFlags();
-			state.setValue(new ContactAddingState.Failed());
+			state.setValue(new AddContactState.Failed());
 		} else if (e instanceof KeyAgreementFailedEvent) {
 			LOG.info("KeyAgreementFailedEvent received");
 			resetPayloadFlags();
-			state.setValue(new ContactAddingState.Failed());
+			state.setValue(new AddContactState.Failed());
 		}
 	}
 
@@ -377,16 +377,16 @@ class ContactExchangeViewModel extends AndroidViewModel
 			Payload remotePayload = payloadParser.parse(payloadBytes);
 			gotRemotePayload = true;
 			requireNonNull(task).connectAndRunProtocol(remotePayload);
-			state.postValue(new ContactAddingState.QrCodeScanned());
+			state.postValue(new AddContactState.QrCodeScanned());
 		} catch (UnsupportedVersionException e) {
 			resetPayloadFlags();
-			state.postValue(new ContactAddingState.Failed(e.isTooOld()));
+			state.postValue(new AddContactState.Failed(e.isTooOld()));
 		} catch (IOException | IllegalArgumentException e) {
 			LOG.log(WARNING, "QR Code Invalid", e);
 			Toast.makeText(getApplication(), R.string.qr_code_invalid,
 					LENGTH_LONG).show();
 			resetPayloadFlags();
-			state.postValue(new ContactAddingState.Failed());
+			state.postValue(new AddContactState.Failed());
 		}
 	}
 
@@ -448,7 +448,7 @@ class ContactExchangeViewModel extends AndroidViewModel
 		return showQrCodeFragment;
 	}
 
-	LiveData<ContactAddingState> getState() {
+	LiveData<AddContactState> getState() {
 		return state;
 	}
 

briar-android/src/main/java/org/briarproject/briar/android/contact/add/nearby/ContactAddingState.java

@@ -1,55 +0,0 @@
-package org.briarproject.briar.android.contact.add.nearby;
-
-import android.graphics.Bitmap;
-
-import androidx.annotation.Nullable;
-
-abstract class ContactAddingState {
-
-	static class KeyAgreementListening extends ContactAddingState {
-		final Bitmap qrCode;
-
-		KeyAgreementListening(Bitmap qrCode) {
-			this.qrCode = qrCode;
-		}
-	}
-
-	static class QrCodeScanned extends ContactAddingState {
-	}
-
-	static class KeyAgreementWaiting extends ContactAddingState {
-	}
-
-	static class KeyAgreementStarted extends ContactAddingState {
-	}
-
-	static class ContactExchangeStarted extends ContactAddingState {
-	}
-
-	static class ContactExchangeFinished extends ContactAddingState {
-		final ContactExchangeResult result;
-
-		ContactExchangeFinished(ContactExchangeResult result) {
-			this.result = result;
-		}
-	}
-
-	static class Failed extends ContactAddingState {
-		/**
-		 * Non-null if failed due to the scanned QR code version.
-		 * True if the app producing the code is too old.
-		 * False if the scanning app is too old.
-		 */
-		@Nullable
-		final Boolean qrCodeTooOld;
-
-		Failed(@Nullable Boolean qrCodeTooOld) {
-			this.qrCodeTooOld = qrCodeTooOld;
-		}
-
-		Failed() {
-			this(null);
-		}
-	}
-
-}

briar-android/src/main/java/org/briarproject/briar/android/contact/add/nearby/ContactExchangeActivity.java

@@ -1,101 +0,0 @@
-package org.briarproject.briar.android.contact.add.nearby;
-
-import android.os.Bundle;
-import android.widget.Toast;
-
-import org.briarproject.bramble.api.identity.Author;
-import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
-import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
-import org.briarproject.briar.R;
-import org.briarproject.briar.android.contact.add.nearby.ContactAddingState.ContactExchangeFinished;
-import org.briarproject.briar.android.contact.add.nearby.ContactAddingState.Failed;
-
-import javax.annotation.Nullable;
-
-import androidx.appcompat.widget.Toolbar;
-
-import static android.widget.Toast.LENGTH_LONG;
-import static java.util.Objects.requireNonNull;
-
-@MethodsNotNullByDefault
-@ParametersNotNullByDefault
-public class ContactExchangeActivity extends KeyAgreementActivity {
-
-	@Override
-	public void onCreate(@Nullable Bundle state) {
-		super.onCreate(state);
-		requireNonNull(getSupportActionBar())
-				.setTitle(R.string.add_contact_title);
-		viewModel.getState()
-				.observe(this, this::onContactAddingStateChanged);
-	}
-
-	@Override
-	public void onBackPressed() {
-		if (viewModel.getState().getValue() instanceof Failed) {
-			// finish this activity when going back in failed state
-			supportFinishAfterTransition();
-		} else {
-			super.onBackPressed();
-		}
-	}
-
-	private void onContactAddingStateChanged(ContactAddingState state) {
-		if (state instanceof ContactExchangeFinished) {
-			ContactExchangeResult result =
-					((ContactExchangeFinished) state).result;
-			onContactExchangeResult(result);
-		} else if (state instanceof Failed) {
-			// Remove navigation icon, so user can't go back when failed
-			// ErrorFragment will finish or relaunch this activity
-			Toolbar toolbar = findViewById(R.id.toolbar);
-			toolbar.setNavigationIcon(null);
-
-			Boolean qrCodeTooOld = ((Failed) state).qrCodeTooOld;
-			onAddingContactFailed(qrCodeTooOld);
-		}
-	}
-
-	private void onContactExchangeResult(ContactExchangeResult result) {
-		if (result instanceof ContactExchangeResult.Success) {
-			Author remoteAuthor =
-					((ContactExchangeResult.Success) result).remoteAuthor;
-			String contactName = remoteAuthor.getName();
-			String text = getString(R.string.contact_added_toast, contactName);
-			Toast.makeText(this, text, LENGTH_LONG).show();
-			supportFinishAfterTransition();
-		} else if (result instanceof ContactExchangeResult.Error) {
-			Author duplicateAuthor =
-					((ContactExchangeResult.Error) result).duplicateAuthor;
-			if (duplicateAuthor == null) {
-				showErrorFragment();
-			} else {
-				String contactName = duplicateAuthor.getName();
-				String text =
-						getString(R.string.contact_already_exists, contactName);
-				Toast.makeText(this, text, LENGTH_LONG).show();
-				supportFinishAfterTransition();
-			}
-		} else throw new AssertionError();
-	}
-
-	private void onAddingContactFailed(@Nullable Boolean qrCodeTooOld) {
-		if (qrCodeTooOld == null) {
-			showErrorFragment();
-		} else {
-			String msg;
-			if (qrCodeTooOld) {
-				msg = getString(R.string.qr_code_too_old,
-						getString(R.string.app_name));
-			} else {
-				msg = getString(R.string.qr_code_too_new,
-						getString(R.string.app_name));
-			}
-			showNextFragment(ContactExchangeErrorFragment.newInstance(msg));
-		}
-	}
-
-	private void showErrorFragment() {
-		showNextFragment(new ContactExchangeErrorFragment());
-	}
-}

briar-android/src/main/java/org/briarproject/briar/android/contact/add/nearby/ContactExchangeResult.java

@@ -1,30 +0,0 @@
-package org.briarproject.briar.android.contact.add.nearby;
-
-import org.briarproject.bramble.api.identity.Author;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import javax.annotation.Nullable;
-import javax.annotation.concurrent.Immutable;
-
-@Immutable
-@NotNullByDefault
-abstract class ContactExchangeResult {
-
-	static class Success extends ContactExchangeResult {
-		final Author remoteAuthor;
-
-		Success(Author remoteAuthor) {
-			this.remoteAuthor = remoteAuthor;
-		}
-	}
-
-	static class Error extends ContactExchangeResult {
-		@Nullable
-		final Author duplicateAuthor;
-
-		Error(@Nullable Author duplicateAuthor) {
-			this.duplicateAuthor = duplicateAuthor;
-		}
-	}
-
-}