Show offline fragment before scanning mailbox QR code

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

@@ -46,6 +46,7 @@ import org.briarproject.briar.android.logging.CachingLogHandler;
 import org.briarproject.briar.android.login.SignInReminderReceiver;
 import org.briarproject.briar.android.mailbox.MailboxScanFragment;
 import org.briarproject.briar.android.mailbox.OfflineFragment;
+import org.briarproject.briar.android.mailbox.SetupDownloadFragment;
 import org.briarproject.briar.android.removabledrive.ChooserFragment;
 import org.briarproject.briar.android.removabledrive.ReceiveFragment;
 import org.briarproject.briar.android.removabledrive.SendFragment;
@@ -242,6 +243,8 @@ public interface AndroidComponent
 
 	void inject(BluetoothIntroFragment bluetoothIntroFragment);
 
+	void inject(SetupDownloadFragment setupDownloadFragment);
+
 	void inject(MailboxScanFragment mailboxScanFragment);
 
 	void inject(OfflineFragment offlineFragment);

briar-android/src/main/java/org/briarproject/briar/android/mailbox/MailboxActivity.java

@@ -50,9 +50,11 @@ public class MailboxActivity extends BriarActivity {
 			progressBar.setVisibility(VISIBLE);
 		}
 
-		viewModel.getState().observe(this, state -> {
+		viewModel.getState().observeEvent(this, state -> {
 			if (state instanceof MailboxState.NotSetup) {
 				onNotSetup();
+			} else if (state instanceof MailboxState.ScanningQrCode) {
+				onScanningQrCode();
 			} else if (state instanceof MailboxState.SettingUp) {
 				onCodeScanned();
 			} else if (state instanceof MailboxState.QrCodeWrong) {
@@ -79,7 +81,7 @@ public class MailboxActivity extends BriarActivity {
 	@Override
 	public void onBackPressed() {
 		if (viewModel.getState()
-				.getValue() instanceof MailboxState.SettingUp) {
+				.getLastValue() instanceof MailboxState.SettingUp) {
 			// don't go back in flow if we are already setting up mailbox
 			supportFinishAfterTransition();
 		} else {
@@ -95,6 +97,11 @@ public class MailboxActivity extends BriarActivity {
 				.commit();
 	}
 
+	private void onScanningQrCode() {
+		showFragment(getSupportFragmentManager(), new MailboxScanFragment(),
+				MailboxScanFragment.TAG);
+	}
+
 	private void onCodeScanned() {
 		showFragment(getSupportFragmentManager(),
 				new MailboxConnectingFragment(),

briar-android/src/main/java/org/briarproject/briar/android/mailbox/MailboxState.java

@@ -3,11 +3,16 @@ package org.briarproject.briar.android.mailbox;
 import org.briarproject.bramble.api.mailbox.MailboxProperties;
 import org.briarproject.bramble.api.mailbox.MailboxStatus;
 
+import androidx.annotation.Nullable;
+
 class MailboxState {
 
 	static class NotSetup extends MailboxState {
 	}
 
+	static class ScanningQrCode extends MailboxState {
+	}
+
 	static class SettingUp extends MailboxState {
 	}
 
@@ -15,11 +20,16 @@ class MailboxState {
 	}
 
 	static class OfflineInSetup extends MailboxState {
+		@Nullable
 		final MailboxProperties mailboxProperties;
 
-		OfflineInSetup(MailboxProperties mailboxProperties) {
+		OfflineInSetup(@Nullable MailboxProperties mailboxProperties) {
 			this.mailboxProperties = mailboxProperties;
 		}
+
+		OfflineInSetup() {
+			this(null);
+		}
 	}
 
 	static class IsSetup extends MailboxState {

briar-android/src/main/java/org/briarproject/briar/android/mailbox/MailboxViewModel.java

@@ -22,6 +22,8 @@ import org.briarproject.bramble.api.system.AndroidExecutor;
 import org.briarproject.briar.android.mailbox.MailboxState.NotSetup;
 import org.briarproject.briar.android.qrcode.QrCodeDecoder;
 import org.briarproject.briar.android.viewmodel.DbViewModel;
+import org.briarproject.briar.android.viewmodel.LiveEvent;
+import org.briarproject.briar.android.viewmodel.MutableLiveEvent;
 
 import java.nio.charset.Charset;
 import java.util.Arrays;
@@ -31,8 +33,6 @@ import java.util.logging.Logger;
 import javax.inject.Inject;
 
 import androidx.annotation.UiThread;
-import androidx.lifecycle.LiveData;
-import androidx.lifecycle.MutableLiveData;
 
 import static java.util.Objects.requireNonNull;
 import static java.util.logging.Level.WARNING;
@@ -55,7 +55,8 @@ class MailboxViewModel extends DbViewModel
 	private final PluginManager pluginManager;
 	private final MailboxSettingsManager mailboxSettingsManager;
 
-	private final MutableLiveData<MailboxState> state = new MutableLiveData<>();
+	private final MutableLiveEvent<MailboxState> state =
+			new MutableLiveEvent<>();
 
 	@Inject
 	MailboxViewModel(
@@ -81,15 +82,24 @@ class MailboxViewModel extends DbViewModel
 		runOnDbThread(true, txn -> {
 			MailboxProperties props =
 					mailboxSettingsManager.getOwnMailboxProperties(txn);
-			if (props == null) state.postValue(new NotSetup());
+			if (props == null) state.postEvent(new NotSetup());
 			else {
 				MailboxStatus mailboxStatus =
 						mailboxSettingsManager.getOwnMailboxStatus(txn);
-				state.postValue(new MailboxState.IsSetup(mailboxStatus));
+				state.postEvent(new MailboxState.IsSetup(mailboxStatus));
 			}
 		}, this::handleException);
 	}
 
+	@UiThread
+	void onScanButtonClicked() {
+		if (isTorActive()) {
+			state.setEvent(new MailboxState.ScanningQrCode());
+		} else {
+			state.setEvent(new MailboxState.OfflineInSetup());
+		}
+	}
+
 	@Override
 	@IoExecutor
 	public void onQrCodeDecoded(Result result) {
@@ -98,12 +108,13 @@ class MailboxViewModel extends DbViewModel
 		try {
 			properties = decodeQrCode(result.getText());
 		} catch (FormatException e) {
-			state.postValue(new MailboxState.QrCodeWrong());
+			state.postEvent(new MailboxState.QrCodeWrong());
 			return;
 		}
 		onMailboxPropertiesReceived(properties);
 	}
 
+	@IoExecutor
 	// TODO move this into core #2168
 	private MailboxProperties decodeQrCode(String payload)
 			throws FormatException {
@@ -133,9 +144,9 @@ class MailboxViewModel extends DbViewModel
 	private void onMailboxPropertiesReceived(MailboxProperties properties) {
 		if (isTorActive()) {
 			// TODO pass props to core #2168
-			state.postValue(new MailboxState.SettingUp());
+			state.postEvent(new MailboxState.SettingUp());
 		} else {
-			state.postValue(new MailboxState.OfflineInSetup(properties));
+			state.postEvent(new MailboxState.OfflineInSetup(properties));
 		}
 	}
 
@@ -148,8 +159,13 @@ class MailboxViewModel extends DbViewModel
 	@UiThread
 	void tryAgainWhenOffline() {
 		MailboxState.OfflineInSetup offline =
-				(MailboxState.OfflineInSetup) requireNonNull(state.getValue());
-		onMailboxPropertiesReceived(offline.mailboxProperties);
+				(MailboxState.OfflineInSetup) requireNonNull(
+						state.getLastValue());
+		if (offline.mailboxProperties == null) {
+			onScanButtonClicked();
+		} else {
+			onMailboxPropertiesReceived(offline.mailboxProperties);
+		}
 	}
 
 	@UiThread
@@ -158,8 +174,7 @@ class MailboxViewModel extends DbViewModel
 	}
 
 	@UiThread
-	LiveData<MailboxState> getState() {
+	LiveEvent<MailboxState> getState() {
 		return state;
 	}
-
 }

briar-android/src/main/java/org/briarproject/briar/android/mailbox/OfflineFragment.java

@@ -26,6 +26,7 @@ import androidx.fragment.app.FragmentActivity;
 import androidx.lifecycle.ViewModelProvider;
 
 import static android.view.View.FOCUS_DOWN;
+import static java.util.Objects.requireNonNull;
 import static org.briarproject.briar.android.AppModule.getAndroidComponent;
 
 @MethodsNotNullByDefault
@@ -94,7 +95,16 @@ public class OfflineFragment extends Fragment {
 	}
 
 	private void onBackButtonPressed() {
-		requireActivity().supportFinishAfterTransition();
+		MailboxState state = viewModel.getState().getLastValue();
+		MailboxState.OfflineInSetup offline =
+				(MailboxState.OfflineInSetup) requireNonNull(state);
+		if (offline.mailboxProperties == null) {
+			// not yet scanned, go back to previous fragment
+			requireActivity().getSupportFragmentManager().popBackStack();
+		} else {
+			// we had scanned already, so go back to beginning
+			requireActivity().supportFinishAfterTransition();
+		}
 	}
 
 }

briar-android/src/main/java/org/briarproject/briar/android/mailbox/SetupDownloadFragment.java

@@ -14,16 +14,19 @@ import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.briar.R;
 
+import javax.inject.Inject;
+
 import androidx.activity.result.ActivityResultLauncher;
 import androidx.activity.result.contract.ActivityResultContracts.RequestMultiplePermissions;
 import androidx.annotation.Nullable;
 import androidx.fragment.app.Fragment;
-import androidx.fragment.app.FragmentManager;
+import androidx.fragment.app.FragmentActivity;
+import androidx.lifecycle.ViewModelProvider;
 
 import static android.content.Intent.ACTION_SEND;
 import static android.content.Intent.EXTRA_TEXT;
 import static android.widget.Toast.LENGTH_LONG;
-import static org.briarproject.briar.android.util.UiUtils.showFragment;
+import static org.briarproject.briar.android.AppModule.getAndroidComponent;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
@@ -31,6 +34,11 @@ public class SetupDownloadFragment extends Fragment {
 
 	static final String TAG = SetupDownloadFragment.class.getName();
 
+	@Inject
+	ViewModelProvider.Factory viewModelFactory;
+
+	private MailboxViewModel viewModel;
+
 	private CameraPermissionManager permissionManager;
 
 	private final ActivityResultLauncher<String[]> permissionLauncher =
@@ -41,6 +49,15 @@ public class SetupDownloadFragment extends Fragment {
 				}
 			});
 
+	@Override
+	public void onAttach(Context context) {
+		super.onAttach(context);
+		FragmentActivity activity = requireActivity();
+		getAndroidComponent(activity).inject(this);
+		viewModel = new ViewModelProvider(activity, viewModelFactory)
+				.get(MailboxViewModel.class);
+	}
+
 	@Nullable
 	@Override
 	public View onCreateView(LayoutInflater inflater,
@@ -95,9 +112,7 @@ public class SetupDownloadFragment extends Fragment {
 	}
 
 	private void scanCode() {
-		FragmentManager fm = getParentFragmentManager();
-		Fragment f = new MailboxScanFragment();
-		showFragment(fm, f, MailboxScanFragment.TAG);
+		viewModel.onScanButtonClicked();
 	}
 
 }