Implement intro screen for offline app sharing

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

@@ -36,6 +36,7 @@ import org.briarproject.briar.BriarCoreModule;
 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.HotspotIntroFragment;
 import org.briarproject.briar.android.logging.CachingLogHandler;
 import org.briarproject.briar.android.login.SignInReminderReceiver;
 import org.briarproject.briar.android.removabledrive.ChooserFragment;
@@ -216,6 +217,8 @@ public interface AndroidComponent
 
 	void inject(NotificationsFragment notificationsFragment);
 
+	void inject(HotspotIntroFragment hotspotIntroFragment);
+
 	void inject(ChooserFragment chooserFragment);
 
 	void inject(SendFragment sendFragment);

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

@@ -36,6 +36,7 @@ import org.briarproject.briar.android.blog.BlogModule;
 import org.briarproject.briar.android.contact.ContactListModule;
 import org.briarproject.briar.android.contact.add.nearby.AddNearbyContactModule;
 import org.briarproject.briar.android.forum.ForumModule;
+import org.briarproject.briar.android.hotspot.HotspotModule;
 import org.briarproject.briar.android.introduction.IntroductionModule;
 import org.briarproject.briar.android.logging.LoggingModule;
 import org.briarproject.briar.android.login.LoginModule;
@@ -94,6 +95,7 @@ import static org.briarproject.briar.android.TestingConstants.IS_DEBUG_BUILD;
 		GroupListModule.class,
 		GroupConversationModule.class,
 		SharingModule.class,
+		HotspotModule.class,
 		TransferDataModule.class,
 })
 public class AppModule {

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

@@ -38,6 +38,7 @@ import org.briarproject.briar.android.forum.CreateForumActivity;
 import org.briarproject.briar.android.forum.ForumActivity;
 import org.briarproject.briar.android.forum.ForumListFragment;
 import org.briarproject.briar.android.fragment.ScreenFilterDialogFragment;
+import org.briarproject.briar.android.hotspot.HotspotActivity;
 import org.briarproject.briar.android.introduction.ContactChooserFragment;
 import org.briarproject.briar.android.introduction.IntroductionActivity;
 import org.briarproject.briar.android.introduction.IntroductionMessageFragment;
@@ -177,6 +178,8 @@ public interface ActivityComponent {
 
 	void inject(CrashReportActivity crashReportActivity);
 
+	void inject(HotspotActivity hotspotActivity);
+
 	void inject(RemovableDriveActivity activity);
 
 	// Fragments

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

@@ -0,0 +1,62 @@
+package org.briarproject.briar.android.hotspot;
+
+import android.os.Bundle;
+import android.view.MenuItem;
+
+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.activity.BriarActivity;
+
+import javax.annotation.Nullable;
+import javax.inject.Inject;
+
+import androidx.annotation.NonNull;
+import androidx.appcompat.app.ActionBar;
+import androidx.lifecycle.ViewModelProvider;
+
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
+public class HotspotActivity extends BriarActivity {
+
+	@Inject
+	ViewModelProvider.Factory viewModelFactory;
+
+	private HotspotViewModel viewModel;
+
+	@Override
+	public void injectActivity(ActivityComponent component) {
+		component.inject(this);
+		viewModel = new ViewModelProvider(this, viewModelFactory)
+				.get(HotspotViewModel.class);
+	}
+
+	@Override
+	public void onCreate(@Nullable Bundle state) {
+		super.onCreate(state);
+		setContentView(R.layout.activity_fragment_container);
+
+		ActionBar ab = getSupportActionBar();
+		if (ab != null) {
+			ab.setDisplayHomeAsUpEnabled(true);
+		}
+
+		if (state == null) {
+			getSupportFragmentManager().beginTransaction()
+					.replace(R.id.fragmentContainer, new HotspotIntroFragment(),
+							HotspotIntroFragment.TAG)
+					.commit();
+		}
+	}
+
+	@Override
+	public boolean onOptionsItemSelected(@NonNull MenuItem item) {
+		if (item.getItemId() == android.R.id.home) {
+			onBackPressed();
+			return true;
+		}
+		return super.onOptionsItemSelected(item);
+	}
+
+}

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

@@ -0,0 +1,67 @@
+package org.briarproject.briar.android.hotspot;
+
+import android.content.Context;
+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 android.widget.TextView;
+
+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.annotation.Nullable;
+import androidx.fragment.app.Fragment;
+import androidx.lifecycle.ViewModelProvider;
+
+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;
+
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
+public class HotspotIntroFragment extends Fragment {
+
+	public final static String TAG = HotspotIntroFragment.class.getName();
+
+	@Inject
+	ViewModelProvider.Factory viewModelFactory;
+
+	private HotspotViewModel viewModel;
+
+	@Override
+	public void onAttach(Context context) {
+		super.onAttach(context);
+		getAndroidComponent(requireContext()).inject(this);
+		viewModel = new ViewModelProvider(requireActivity(), viewModelFactory)
+				.get(HotspotViewModel.class);
+	}
+
+	@Override
+	public View onCreateView(LayoutInflater inflater,
+			@Nullable ViewGroup container,
+			@Nullable Bundle savedInstanceState) {
+		View v = inflater
+				.inflate(R.layout.fragment_hotspot_intro, container, false);
+
+		Button startButton = v.findViewById(R.id.startButton);
+		ProgressBar progressBar = v.findViewById(R.id.progressBar);
+		TextView progressTextView = v.findViewById(R.id.progressTextView);
+
+		startButton.setOnClickListener(button -> {
+			beginDelayedTransition((ViewGroup) v);
+			startButton.setVisibility(INVISIBLE);
+			progressBar.setVisibility(VISIBLE);
+			progressTextView.setVisibility(VISIBLE);
+		});
+
+		return v;
+	}
+
+}

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

@@ -0,0 +1,18 @@
+package org.briarproject.briar.android.hotspot;
+
+import org.briarproject.briar.android.viewmodel.ViewModelKey;
+
+import androidx.lifecycle.ViewModel;
+import dagger.Binds;
+import dagger.Module;
+import dagger.multibindings.IntoMap;
+
+@Module
+public interface HotspotModule {
+
+	@Binds
+	@IntoMap
+	@ViewModelKey(HotspotViewModel.class)
+	ViewModel bindHotspotViewModel(HotspotViewModel hotspotViewModel);
+
+}

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

@@ -0,0 +1,28 @@
+package org.briarproject.briar.android.hotspot;
+
+import android.app.Application;
+
+import org.briarproject.bramble.api.db.DatabaseExecutor;
+import org.briarproject.bramble.api.db.TransactionManager;
+import org.briarproject.bramble.api.lifecycle.LifecycleManager;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.system.AndroidExecutor;
+import org.briarproject.briar.android.viewmodel.DbViewModel;
+
+import java.util.concurrent.Executor;
+
+import javax.inject.Inject;
+
+@NotNullByDefault
+class HotspotViewModel extends DbViewModel {
+
+	@Inject
+	HotspotViewModel(Application application,
+			@DatabaseExecutor Executor dbExecutor,
+			LifecycleManager lifecycleManager,
+			TransactionManager db,
+			AndroidExecutor androidExecutor) {
+		super(application, dbExecutor, lifecycleManager, db, androidExecutor);
+	}
+
+}