Create FallbackFragment for alternative apk sharing method

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

@@ -36,7 +36,7 @@ import org.briarproject.briar.android.attachment.AttachmentModule;
 import org.briarproject.briar.android.attachment.media.MediaModule;
 import org.briarproject.briar.android.conversation.glide.BriarModelLoader;
 import org.briarproject.briar.android.hotspot.AbstractTabsFragment;
-import org.briarproject.briar.android.hotspot.HotspotHelpFragment;
+import org.briarproject.briar.android.hotspot.FallbackFragment;
 import org.briarproject.briar.android.hotspot.HotspotIntroFragment;
 import org.briarproject.briar.android.hotspot.ManualHotspotFragment;
 import org.briarproject.briar.android.hotspot.QrHotspotFragment;
@@ -224,5 +224,5 @@ public interface AndroidComponent
 
 	void inject(ManualHotspotFragment manualHotspotFragment);
 
-	void inject(HotspotHelpFragment hotspotHelpFragment);
+	void inject(FallbackFragment fallbackFragment);
 }

briar-android/src/main/java/org/briarproject/briar/android/fragment/ErrorFragment.java

@@ -40,8 +40,7 @@ public class ErrorFragment extends BaseFragment {
 	public void onCreate(@Nullable Bundle savedInstanceState) {
 		super.onCreate(savedInstanceState);
 
-		Bundle args = getArguments();
-		if (args == null) throw new AssertionError();
+		Bundle args = requireArguments();
 		errorMessage = args.getString(ERROR_MSG);
 	}
 

briar-android/src/main/java/org/briarproject/briar/android/hotspot/FallbackFragment.java

@@ -0,0 +1,130 @@
+package org.briarproject.briar.android.hotspot;
+
+import android.content.Context;
+import android.content.Intent;
+import android.content.pm.ResolveInfo;
+import android.net.Uri;
+import android.os.Bundle;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.Button;
+import android.widget.ProgressBar;
+
+import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
+import org.briarproject.briar.R;
+import org.briarproject.briar.android.fragment.BaseFragment;
+
+import java.util.List;
+
+import javax.inject.Inject;
+
+import androidx.activity.result.ActivityResultLauncher;
+import androidx.annotation.Nullable;
+import androidx.fragment.app.Fragment;
+import androidx.fragment.app.FragmentActivity;
+import androidx.lifecycle.ViewModelProvider;
+
+import static android.content.Intent.ACTION_SEND;
+import static android.content.Intent.EXTRA_STREAM;
+import static android.content.Intent.FLAG_GRANT_READ_URI_PERMISSION;
+import static android.content.pm.PackageManager.MATCH_DEFAULT_ONLY;
+import static android.os.Build.VERSION.SDK_INT;
+import static android.view.View.INVISIBLE;
+import static android.view.View.VISIBLE;
+import static androidx.activity.result.contract.ActivityResultContracts.CreateDocument;
+import static androidx.transition.TransitionManager.beginDelayedTransition;
+import static org.briarproject.briar.android.AppModule.getAndroidComponent;
+import static org.briarproject.briar.android.hotspot.HotspotViewModel.getApkFileName;
+
+
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
+public class FallbackFragment extends BaseFragment {
+
+	public static final String TAG = FallbackFragment.class.getName();
+
+	@Inject
+	ViewModelProvider.Factory viewModelFactory;
+
+	private HotspotViewModel viewModel;
+	private final ActivityResultLauncher<String> launcher =
+			registerForActivityResult(new CreateDocument(),
+					this::onDocumentCreated);
+	private Button fallbackButton;
+	private ProgressBar progressBar;
+
+	@Override
+	public String getUniqueTag() {
+		return TAG;
+	}
+
+	@Override
+	public void onAttach(Context context) {
+		super.onAttach(context);
+		FragmentActivity activity = requireActivity();
+		getAndroidComponent(activity).inject(this);
+		viewModel = new ViewModelProvider(activity, viewModelFactory)
+				.get(HotspotViewModel.class);
+	}
+
+	@Nullable
+	@Override
+	public View onCreateView(LayoutInflater inflater,
+			@Nullable ViewGroup container,
+			@Nullable Bundle savedInstanceState) {
+		return inflater
+				.inflate(R.layout.fragment_hotspot_save_apk, container, false);
+	}
+
+	@Override
+	public void onViewCreated(View v, @Nullable Bundle savedInstanceState) {
+		super.onViewCreated(v, savedInstanceState);
+
+		fallbackButton = v.findViewById(R.id.fallbackButton);
+		progressBar = v.findViewById(R.id.progressBar);
+		fallbackButton.setOnClickListener(view -> {
+			beginDelayedTransition((ViewGroup) v);
+			fallbackButton.setVisibility(INVISIBLE);
+			progressBar.setVisibility(VISIBLE);
+
+			if (SDK_INT >= 19) launcher.launch(getApkFileName());
+			else viewModel.exportApk();
+		});
+		viewModel.getSavedApkToUri()
+				.observeEvent(this, uri -> shareUri(this, uri));
+	}
+
+	private void onDocumentCreated(@Nullable Uri uri) {
+		showButton();
+		if (uri != null) viewModel.exportApk(uri);
+	}
+
+	private void showButton() {
+		beginDelayedTransition((ViewGroup) requireView());
+		fallbackButton.setVisibility(VISIBLE);
+		progressBar.setVisibility(INVISIBLE);
+	}
+
+	static void shareUri(Fragment fragment, Uri uri) {
+		Intent i = new Intent(ACTION_SEND);
+		i.putExtra(EXTRA_STREAM, uri);
+		i.setType("*/*"); // gives us all sharing options
+		i.addFlags(FLAG_GRANT_READ_URI_PERMISSION);
+		Context ctx = fragment.requireContext();
+		if (SDK_INT <= 19) {
+			// Workaround for Android bug:
+			// ctx.grantUriPermission also needed for Android 4
+			List<ResolveInfo> resInfoList = ctx.getPackageManager()
+					.queryIntentActivities(i, MATCH_DEFAULT_ONLY);
+			for (ResolveInfo resolveInfo : resInfoList) {
+				String packageName = resolveInfo.activityInfo.packageName;
+				ctx.grantUriPermission(packageName, uri,
+						FLAG_GRANT_READ_URI_PERMISSION);
+			}
+		}
+		fragment.startActivity(Intent.createChooser(i, null));
+	}
+
+}

briar-android/src/main/java/org/briarproject/briar/android/hotspot/HotspotActivity.java

@@ -61,14 +61,8 @@ public class HotspotActivity extends BriarActivity
 					showFragment(fm, new HotspotFragment(), tag);
 				}
 			} else if (hotspotState instanceof HotspotError) {
-				// TODO: handle rotation gracefully. If we just use
-				//  fm.findFragmentByTag(HotspotErrorFragment.TAG) == null)
-				//  we might hide multiple errors. Maybe we could update the
-				//  error message of the existing fragment in that case
-				String error = ((HotspotError) hotspotState).getError();
-				Fragment f = HotspotErrorFragment.newInstance(error);
-				showFragment(getSupportFragmentManager(), f,
-						HotspotErrorFragment.TAG);
+				HotspotError error = ((HotspotError) hotspotState);
+				showErrorFragment(error.getError());
 			}
 		});
 
@@ -80,6 +74,15 @@ public class HotspotActivity extends BriarActivity
 		}
 	}
 
+	private void showErrorFragment(String error) {
+		FragmentManager fm = getSupportFragmentManager();
+		String tag = HotspotErrorFragment.TAG;
+		if (fm.findFragmentByTag(tag) == null) {
+			Fragment f = HotspotErrorFragment.newInstance(error);
+			showFragment(fm, f, tag, false);
+		}
+	}
+
 	@Override
 	public boolean onOptionsItemSelected(MenuItem item) {
 		if (item.getItemId() == android.R.id.home) {

briar-android/src/main/java/org/briarproject/briar/android/hotspot/HotspotErrorFragment.java

@@ -12,7 +12,11 @@ import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.fragment.BaseFragment;
 
+import javax.inject.Inject;
+
 import androidx.annotation.Nullable;
+import androidx.fragment.app.FragmentTransaction;
+import androidx.lifecycle.ViewModelProvider;
 
 import static org.briarproject.briar.android.util.UiUtils.triggerFeedback;
 
@@ -23,6 +27,9 @@ public class HotspotErrorFragment extends BaseFragment {
 
 	public static final String TAG = HotspotErrorFragment.class.getName();
 
+	@Inject
+	ViewModelProvider.Factory viewModelFactory;
+
 	private static final String ERROR_MSG = "errorMessage";
 
 	public static HotspotErrorFragment newInstance(String message) {
@@ -44,8 +51,7 @@ public class HotspotErrorFragment extends BaseFragment {
 	public void onCreate(@Nullable Bundle savedInstanceState) {
 		super.onCreate(savedInstanceState);
 
-		Bundle args = getArguments();
-		if (args == null) throw new AssertionError();
+		Bundle args = requireArguments();
 		errorMessage = args.getString(ERROR_MSG);
 	}
 
@@ -54,8 +60,13 @@ public class HotspotErrorFragment extends BaseFragment {
 	public View onCreateView(LayoutInflater inflater,
 			@Nullable ViewGroup container,
 			@Nullable Bundle savedInstanceState) {
-		View v = inflater
+		return inflater
 				.inflate(R.layout.fragment_hotspot_error, container, false);
+	}
+
+	@Override
+	public void onViewCreated(View v, @Nullable Bundle savedInstanceState) {
+		super.onViewCreated(v, savedInstanceState);
 		TextView msg = v.findViewById(R.id.errorMessageDetail);
 		msg.setText(errorMessage);
 
@@ -63,10 +74,9 @@ public class HotspotErrorFragment extends BaseFragment {
 		feedbackButton.setOnClickListener(
 				button -> triggerFeedback(requireContext()));
 
-		Button fallbackButton = v.findViewById(R.id.fallbackButton);
-		// TODO: export apk
-
-		return v;
+		FallbackFragment fallbackFragment = new FallbackFragment();
+		FragmentTransaction ta = getChildFragmentManager().beginTransaction();
+		ta.replace(R.id.fallbackPlaceholder, fallbackFragment).commit();
 	}
 
 }

briar-android/src/main/java/org/briarproject/briar/android/hotspot/HotspotHelpFragment.java

@@ -1,42 +1,21 @@
 package org.briarproject.briar.android.hotspot;
 
-import android.content.Context;
-import android.content.Intent;
-import android.content.pm.ResolveInfo;
-import android.net.Uri;
 import android.os.Bundle;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
-import android.widget.Button;
-import android.widget.ProgressBar;
 
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.briar.R;
 
-import java.util.List;
-
 import javax.inject.Inject;
 
-import androidx.activity.result.ActivityResultLauncher;
-import androidx.activity.result.contract.ActivityResultContracts.CreateDocument;
 import androidx.annotation.Nullable;
 import androidx.fragment.app.Fragment;
-import androidx.fragment.app.FragmentActivity;
+import androidx.fragment.app.FragmentTransaction;
 import androidx.lifecycle.ViewModelProvider;
 
-import static android.content.Intent.ACTION_SEND;
-import static android.content.Intent.EXTRA_STREAM;
-import static android.content.Intent.FLAG_GRANT_READ_URI_PERMISSION;
-import static android.content.pm.PackageManager.MATCH_DEFAULT_ONLY;
-import static android.os.Build.VERSION.SDK_INT;
-import static android.view.View.INVISIBLE;
-import static android.view.View.VISIBLE;
-import static androidx.transition.TransitionManager.beginDelayedTransition;
-import static org.briarproject.briar.android.AppModule.getAndroidComponent;
-import static org.briarproject.briar.android.hotspot.HotspotViewModel.getApkFileName;
-
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
 public class HotspotHelpFragment extends Fragment {
@@ -46,22 +25,6 @@ public class HotspotHelpFragment extends Fragment {
 	@Inject
 	ViewModelProvider.Factory viewModelFactory;
 
-	private HotspotViewModel viewModel;
-	private final ActivityResultLauncher<String> launcher =
-			registerForActivityResult(new CreateDocument(),
-					this::onDocumentCreated);
-	private Button button;
-	private ProgressBar progressBar;
-
-	@Override
-	public void onAttach(Context context) {
-		super.onAttach(context);
-		FragmentActivity activity = requireActivity();
-		getAndroidComponent(activity).inject(this);
-		viewModel = new ViewModelProvider(activity, viewModelFactory)
-				.get(HotspotViewModel.class);
-	}
-
 	@Override
 	public View onCreateView(LayoutInflater inflater,
 			@Nullable ViewGroup container,
@@ -73,48 +36,10 @@ public class HotspotHelpFragment extends Fragment {
 	@Override
 	public void onViewCreated(View v, @Nullable Bundle savedInstanceState) {
 		super.onViewCreated(v, savedInstanceState);
-		button = v.findViewById(R.id.fallbackButton);
-		progressBar = v.findViewById(R.id.progressBar);
-		button.setOnClickListener(view -> {
-			beginDelayedTransition((ViewGroup) v);
-			button.setVisibility(INVISIBLE);
-			progressBar.setVisibility(VISIBLE);
 
-			if (SDK_INT >= 19) launcher.launch(getApkFileName());
-			else viewModel.exportApk();
-		});
-		viewModel.getSavedApkToUri().observeEvent(this, this::shareUri);
-	}
-
-	private void onDocumentCreated(@Nullable Uri uri) {
-		showButton();
-		if (uri != null) viewModel.exportApk(uri);
-	}
-
-	private void shareUri(Uri uri) {
-		Intent i = new Intent(ACTION_SEND);
-		i.putExtra(EXTRA_STREAM, uri);
-		i.setType("*/*"); // gives us all sharing options
-		i.addFlags(FLAG_GRANT_READ_URI_PERMISSION);
-		Context ctx = requireContext();
-		if (SDK_INT <= 19) {
-			// Workaround for Android bug:
-			// ctx.grantUriPermission also needed for Android 4
-			List<ResolveInfo> resInfoList = ctx.getPackageManager()
-					.queryIntentActivities(i, MATCH_DEFAULT_ONLY);
-			for (ResolveInfo resolveInfo : resInfoList) {
-				String packageName = resolveInfo.activityInfo.packageName;
-				ctx.grantUriPermission(packageName, uri,
-						FLAG_GRANT_READ_URI_PERMISSION);
-			}
-		}
-		startActivity(Intent.createChooser(i, null));
-	}
-
-	private void showButton() {
-		beginDelayedTransition((ViewGroup) requireView());
-		button.setVisibility(VISIBLE);
-		progressBar.setVisibility(INVISIBLE);
+		FallbackFragment fallbackFragment = new FallbackFragment();
+		FragmentTransaction ta = getChildFragmentManager().beginTransaction();
+		ta.replace(R.id.fallbackPlaceholder, fallbackFragment).commit();
 	}
 
 }

briar-android/src/main/java/org/briarproject/briar/android/hotspot/HotspotViewModel.java

@@ -145,7 +145,7 @@ class HotspotViewModel extends DbViewModel
 	@Override
 	public void onHotspotError(String error) {
 		LOG.warning("Hotspot error: " + error);
-		state.setValue(new HotspotError(error));
+		state.postValue(new HotspotError(error));
 		ioExecutor.execute(webServerManager::stopWebServer);
 		notificationManager.clearHotspotNotification();
 	}

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

@@ -61,6 +61,7 @@ import androidx.core.util.Consumer;
 import androidx.fragment.app.Fragment;
 import androidx.fragment.app.FragmentActivity;
 import androidx.fragment.app.FragmentManager;
+import androidx.fragment.app.FragmentTransaction;
 import androidx.lifecycle.LifecycleOwner;
 import androidx.lifecycle.LiveData;
 import androidx.lifecycle.Observer;
@@ -143,13 +144,18 @@ public class UiUtils {
 
 	public static void showFragment(FragmentManager fm, Fragment f,
 			@Nullable String tag) {
-		fm.beginTransaction()
+		showFragment(fm, f, tag, true);
+	}
+
+	public static void showFragment(FragmentManager fm, Fragment f,
+			@Nullable String tag, boolean addToBackStack) {
+		FragmentTransaction ta = fm.beginTransaction()
 				.setCustomAnimations(R.anim.step_next_in,
 						R.anim.step_previous_out, R.anim.step_previous_in,
 						R.anim.step_next_out)
-				.replace(R.id.fragmentContainer, f, tag)
-				.addToBackStack(tag)
-				.commit();
+				.replace(R.id.fragmentContainer, f, tag);
+		if (addToBackStack) ta.addToBackStack(tag);
+		ta.commit();
 	}
 
 	public static String getContactDisplayName(Author author,

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

@@ -9,11 +9,7 @@
 		android:id="@+id/errorIcon"
 		android:layout_width="128dp"
 		android:layout_height="128dp"
-		android:layout_marginStart="8dp"
-		android:layout_marginLeft="8dp"
-		android:layout_marginTop="8dp"
-		android:layout_marginEnd="8dp"
-		android:layout_marginRight="8dp"
+		android:layout_margin="8dp"
 		app:layout_constraintEnd_toEndOf="parent"
 		app:layout_constraintStart_toStartOf="parent"
 		app:layout_constraintTop_toTopOf="parent"
@@ -25,11 +21,7 @@
 		android:id="@+id/errorTitle"
 		android:layout_width="wrap_content"
 		android:layout_height="wrap_content"
-		android:layout_marginStart="8dp"
-		android:layout_marginLeft="8dp"
-		android:layout_marginTop="8dp"
-		android:layout_marginEnd="8dp"
-		android:layout_marginRight="8dp"
+		android:layout_margin="8dp"
 		android:text="@string/sorry"
 		android:textSize="@dimen/text_size_xlarge"
 		app:layout_constraintEnd_toEndOf="parent"

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

@@ -7,63 +7,44 @@
 
 	<androidx.constraintlayout.widget.ConstraintLayout
 		android:layout_width="match_parent"
-		android:layout_height="wrap_content">
+		android:layout_height="wrap_content"
+		android:padding="16dp">
 
 		<androidx.appcompat.widget.AppCompatImageView
 			android:id="@+id/errorIcon"
-			android:layout_width="128dp"
-			android:layout_height="128dp"
-			android:layout_marginStart="8dp"
-			android:layout_marginLeft="8dp"
-			android:layout_marginTop="8dp"
-			android:layout_marginEnd="8dp"
-			android:layout_marginRight="8dp"
-			app:layout_constraintEnd_toEndOf="parent"
+			android:layout_width="32dp"
+			android:layout_height="32dp"
+			android:layout_marginVertical="8dp"
+			app:layout_constraintBottom_toBottomOf="@id/errorMessageIntro"
+			app:layout_constraintEnd_toStartOf="@id/errorMessageIntro"
 			app:layout_constraintStart_toStartOf="parent"
 			app:layout_constraintTop_toTopOf="parent"
 			app:srcCompat="@drawable/alerts_and_states_error"
 			app:tint="?attr/colorControlNormal"
 			tools:ignore="ContentDescription" />
 
-		<TextView
-			android:id="@+id/errorTitle"
-			android:layout_width="wrap_content"
-			android:layout_height="wrap_content"
-			android:layout_marginStart="8dp"
-			android:layout_marginLeft="8dp"
-			android:layout_marginTop="8dp"
-			android:layout_marginEnd="8dp"
-			android:layout_marginRight="8dp"
-			android:text="@string/sorry"
-			android:textSize="@dimen/text_size_xlarge"
-			app:layout_constraintEnd_toEndOf="parent"
-			app:layout_constraintStart_toStartOf="parent"
-			app:layout_constraintTop_toBottomOf="@+id/errorIcon" />
-
 		<TextView
 			android:id="@+id/errorMessageIntro"
 			android:layout_width="0dp"
 			android:layout_height="wrap_content"
 			android:layout_marginStart="16dp"
 			android:layout_marginLeft="16dp"
-			android:layout_marginTop="8dp"
 			android:layout_marginEnd="16dp"
 			android:layout_marginRight="16dp"
 			android:text="@string/hotspot_error_intro"
 			android:textSize="@dimen/text_size_medium"
 			app:layout_constraintEnd_toEndOf="parent"
-			app:layout_constraintStart_toStartOf="parent"
-			app:layout_constraintTop_toBottomOf="@+id/errorTitle" />
+			app:layout_constraintStart_toEndOf="@+id/errorIcon"
+			app:layout_constraintTop_toTopOf="parent" />
 
 		<TextView
 			android:id="@+id/errorMessageDetail"
 			android:layout_width="0dp"
 			android:layout_height="wrap_content"
-			android:layout_marginStart="16dp"
-			android:layout_marginLeft="16dp"
-			android:layout_marginTop="16dp"
-			android:layout_marginEnd="16dp"
-			android:layout_marginRight="16dp"
+			android:layout_marginVertical="16dp"
+			android:background="@color/briar_warning_background"
+			android:padding="8dp"
+			android:textColor="@color/briar_text_primary_inverse"
 			android:textSize="@dimen/text_size_medium"
 			app:layout_constraintEnd_toEndOf="parent"
 			app:layout_constraintHorizontal_bias="0.0"
@@ -82,32 +63,14 @@
 			app:layout_constraintStart_toStartOf="parent"
 			app:layout_constraintTop_toBottomOf="@+id/errorMessageDetail" />
 
-		<TextView
-			android:id="@+id/fallbackIntro"
-			android:layout_width="0dp"
+		<FrameLayout
+			android:id="@+id/fallbackPlaceholder"
+			android:layout_width="match_parent"
 			android:layout_height="wrap_content"
-			android:layout_marginStart="16dp"
-			android:layout_marginLeft="16dp"
-			android:layout_marginTop="16dp"
-			android:layout_marginEnd="16dp"
-			android:layout_marginRight="16dp"
-			android:text="@string/hotspot_help_fallback_intro"
-			android:textSize="@dimen/text_size_medium"
 			app:layout_constraintEnd_toEndOf="parent"
 			app:layout_constraintStart_toStartOf="parent"
 			app:layout_constraintTop_toBottomOf="@+id/feedbackButton" />
 
-		<Button
-			android:id="@+id/fallbackButton"
-			style="@style/BriarButtonFlat.Positive"
-			android:layout_width="wrap_content"
-			android:layout_height="wrap_content"
-			android:layout_marginTop="16dp"
-			android:text="@string/hotspot_help_fallback_button"
-			app:layout_constraintEnd_toEndOf="parent"
-			app:layout_constraintStart_toStartOf="parent"
-			app:layout_constraintTop_toBottomOf="@+id/fallbackIntro" />
-
 	</androidx.constraintlayout.widget.ConstraintLayout>
 
 </ScrollView>

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

@@ -110,50 +110,14 @@
 			app:layout_constraintStart_toStartOf="parent"
 			app:layout_constraintTop_toBottomOf="@+id/site3View" />
 
-		<TextView
-			android:id="@+id/fallbackTitleView"
-			android:layout_width="0dp"
+		<FrameLayout
+			android:id="@+id/fallbackPlaceholder"
+			android:layout_width="match_parent"
 			android:layout_height="wrap_content"
-			android:layout_marginTop="32dp"
-			android:text="@string/hotspot_help_fallback_title"
-			android:textSize="16sp"
-			android:textStyle="bold"
 			app:layout_constraintEnd_toEndOf="parent"
 			app:layout_constraintStart_toStartOf="parent"
 			app:layout_constraintTop_toBottomOf="@+id/site4View" />
 
-		<TextView
-			android:id="@+id/fallbackIntroView"
-			android:layout_width="0dp"
-			android:layout_height="wrap_content"
-			android:layout_marginTop="6dp"
-			android:text="@string/hotspot_help_fallback_intro"
-			app:layout_constraintEnd_toEndOf="parent"
-			app:layout_constraintStart_toStartOf="parent"
-			app:layout_constraintTop_toBottomOf="@+id/fallbackTitleView" />
-
-		<Button
-			android:id="@+id/fallbackButton"
-			style="@style/BriarButtonFlat.Positive"
-			android:layout_width="0dp"
-			android:layout_height="wrap_content"
-			android:layout_margin="16dp"
-			android:text="@string/hotspot_help_fallback_button"
-			app:layout_constraintEnd_toEndOf="parent"
-			app:layout_constraintStart_toStartOf="parent"
-			app:layout_constraintTop_toBottomOf="@+id/fallbackIntroView" />
-
-		<ProgressBar
-			android:id="@+id/progressBar"
-			style="?android:progressBarStyle"
-			android:layout_width="wrap_content"
-			android:layout_height="wrap_content"
-			android:visibility="invisible"
-			app:layout_constraintBottom_toBottomOf="@+id/fallbackButton"
-			app:layout_constraintEnd_toEndOf="parent"
-			app:layout_constraintStart_toStartOf="parent"
-			app:layout_constraintTop_toTopOf="@+id/fallbackButton" />
-
 	</androidx.constraintlayout.widget.ConstraintLayout>
 
 </ScrollView>

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

@@ -0,0 +1,53 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+	xmlns:app="http://schemas.android.com/apk/res-auto"
+	android:layout_width="match_parent"
+	android:layout_height="wrap_content">
+
+	<TextView
+		android:id="@id/fallbackTitleView"
+		android:layout_width="0dp"
+		android:layout_height="wrap_content"
+		android:layout_marginTop="32dp"
+		android:text="@string/hotspot_help_fallback_title"
+		android:textSize="16sp"
+		android:textStyle="bold"
+		app:layout_constraintEnd_toEndOf="parent"
+		app:layout_constraintStart_toStartOf="parent"
+		app:layout_constraintTop_toBottomOf="parent"
+		app:layout_constraintTop_toTopOf="parent" />
+
+	<TextView
+		android:id="@+id/fallbackIntro"
+		android:layout_width="0dp"
+		android:layout_height="wrap_content"
+		android:layout_marginVertical="16dp"
+		android:text="@string/hotspot_help_fallback_intro"
+		android:textSize="@dimen/text_size_medium"
+		app:layout_constraintEnd_toEndOf="parent"
+		app:layout_constraintStart_toStartOf="parent"
+		app:layout_constraintTop_toBottomOf="@+id/fallbackTitleView" />
+
+	<Button
+		android:id="@+id/fallbackButton"
+		style="@style/BriarButtonFlat.Positive"
+		android:layout_width="wrap_content"
+		android:layout_height="wrap_content"
+		android:layout_marginTop="16dp"
+		android:text="@string/hotspot_help_fallback_button"
+		app:layout_constraintEnd_toEndOf="parent"
+		app:layout_constraintStart_toStartOf="parent"
+		app:layout_constraintTop_toBottomOf="@+id/fallbackIntro" />
+
+	<ProgressBar
+		android:id="@+id/progressBar"
+		style="?android:progressBarStyle"
+		android:layout_width="wrap_content"
+		android:layout_height="wrap_content"
+		android:visibility="invisible"
+		app:layout_constraintBottom_toBottomOf="@+id/fallbackButton"
+		app:layout_constraintEnd_toEndOf="parent"
+		app:layout_constraintStart_toStartOf="parent"
+		app:layout_constraintTop_toTopOf="@+id/fallbackButton" />
+
+</androidx.constraintlayout.widget.ConstraintLayout>