Introduce ViewModel for ContactListFragment

bramble-api/src/main/java/org/briarproject/bramble/api/contact/ContactManager.java

@@ -179,6 +179,11 @@ public interface ContactManager {
 	 */
 	Collection<Contact> getContacts() throws DbException;
 
+	/**
+	 * Returns all contacts.
+	 */
+	Collection<Contact> getContacts(Transaction txn) throws DbException;
+
 	/**
 	 * Removes a contact and all associated state.
 	 */

bramble-core/src/main/java/org/briarproject/bramble/contact/ContactManagerImpl.java

@@ -213,6 +213,11 @@ class ContactManagerImpl implements ContactManager, EventListener {
 		return db.transactionWithResult(true, db::getContacts);
 	}
 
+	@Override
+	public Collection<Contact> getContacts(Transaction txn) throws DbException {
+		return db.getContacts(txn);
+	}
+
 	@Override
 	public void removeContact(ContactId c) throws DbException {
 		db.transaction(false, txn -> removeContact(txn, c));

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

@@ -28,6 +28,7 @@ import org.briarproject.bramble.plugin.tor.AndroidTorPluginFactory;
 import org.briarproject.bramble.util.AndroidUtils;
 import org.briarproject.bramble.util.StringUtils;
 import org.briarproject.briar.android.account.LockManagerImpl;
+import org.briarproject.briar.android.contact.ContactListModule;
 import org.briarproject.briar.android.forum.ForumModule;
 import org.briarproject.briar.android.keyagreement.ContactExchangeModule;
 import org.briarproject.briar.android.login.LoginModule;
@@ -68,6 +69,7 @@ import static org.briarproject.briar.android.TestingConstants.IS_DEBUG_BUILD;
 		NavDrawerModule.class,
 		ViewModelModule.class,
 		DevReportModule.class,
+		ContactListModule.class,
 		// below need to be within same scope as ViewModelProvider.Factory
 		ForumModule.BindsModule.class,
 		GroupListModule.class,

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

@@ -21,7 +21,6 @@ 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.ContactModule;
 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;
@@ -88,7 +87,6 @@ import dagger.Component;
 @Component(modules = {
 		ActivityModule.class,
 		BlogModule.class,
-		ContactModule.class,
 		CreateGroupModule.class,
 		ForumModule.class,
 		GroupInvitationModule.class,

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

@@ -3,14 +3,14 @@ package org.briarproject.briar.android.contact;
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
-import javax.annotation.concurrent.NotThreadSafe;
+import javax.annotation.concurrent.Immutable;
 
-@NotThreadSafe
+@Immutable
 @NotNullByDefault
 public class ContactItem {
 
 	private final Contact contact;
-	private boolean connected;
+	private final boolean connected;
 
 	public ContactItem(Contact contact) {
 		this(contact, false);
@@ -29,8 +29,4 @@ public class ContactItem {
 		return connected;
 	}
 
-	void setConnected(boolean connected) {
-		this.connected = connected;
-	}
-
 }

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

@@ -1,50 +1,68 @@
 package org.briarproject.briar.android.contact;
 
-import android.content.Context;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.briar.R;
+import org.briarproject.briar.android.contact.BaseContactListAdapter.OnContactClickListener;
+
+import androidx.recyclerview.widget.DiffUtil.ItemCallback;
+import androidx.recyclerview.widget.ListAdapter;
 
 @NotNullByDefault
 public class ContactListAdapter extends
-		BaseContactListAdapter<ContactListItem, ContactListItemViewHolder> {
+		ListAdapter<ContactListItem, ContactListItemViewHolder> {
 
-	public ContactListAdapter(Context context,
+	// TODO: using the click listener interface from BaseContactListAdapter on
+	// purpose here because it is entangled with ContactListItemViewHolder. At
+	// some point we probably want to change that.
+	protected final OnContactClickListener<ContactListItem> listener;
+
+	public ContactListAdapter(
 			OnContactClickListener<ContactListItem> listener) {
-		super(context, ContactListItem.class, listener);
+		super(new ContactListCallback());
+		this.listener = listener;
+	}
+
+	@NotNullByDefault
+	private static class ContactListCallback
+			extends ItemCallback<ContactListItem> {
+		@Override
+		public boolean areItemsTheSame(ContactListItem c1, ContactListItem c2) {
+			return c1.getContact().equals(c2.getContact());
+		}
+
+		@Override
+		public boolean areContentsTheSame(ContactListItem c1,
+				ContactListItem c2) {
+			// check for all properties that influence visual
+			// representation of contact
+			if (c1.isEmpty() != c2.isEmpty()) {
+				return false;
+			}
+			if (c1.getUnreadCount() != c2.getUnreadCount()) {
+				return false;
+			}
+			if (c1.getTimestamp() != c2.getTimestamp()) {
+				return false;
+			}
+			return c1.isConnected() == c2.isConnected();
+		}
 	}
 
 	@Override
 	public ContactListItemViewHolder onCreateViewHolder(ViewGroup viewGroup,
-			int i) {
+			int viewType) {
 		View v = LayoutInflater.from(viewGroup.getContext()).inflate(
 				R.layout.list_item_contact, viewGroup, false);
-
 		return new ContactListItemViewHolder(v);
 	}
 
 	@Override
-	public boolean areContentsTheSame(ContactListItem c1, ContactListItem c2) {
+	public void onBindViewHolder(ContactListItemViewHolder viewHolder,
-		// check for all properties that influence visual
+			int position) {
-		// representation of contact
+		viewHolder.bind(getItem(position), listener);
-		if (c1.isEmpty() != c2.isEmpty()) {
-			return false;
-		}
-		if (c1.getUnreadCount() != c2.getUnreadCount()) {
-			return false;
-		}
-		if (c1.getTimestamp() != c2.getTimestamp()) {
-			return false;
-		}
-		return c1.isConnected() == c2.isConnected();
 	}
-
-	@Override
-	public int compare(ContactListItem c1, ContactListItem c2) {
-		return Long.compare(c2.getTimestamp(), c1.getTimestamp());
-	}
-
 }

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

@@ -10,23 +10,9 @@ import android.widget.TextView;
 import com.google.android.material.floatingactionbutton.FloatingActionButton;
 import com.google.android.material.snackbar.Snackbar;
 
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
-import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.contact.ContactManager;
-import org.briarproject.bramble.api.contact.event.ContactAddedEvent;
-import org.briarproject.bramble.api.contact.event.ContactRemovedEvent;
-import org.briarproject.bramble.api.contact.event.PendingContactAddedEvent;
-import org.briarproject.bramble.api.contact.event.PendingContactRemovedEvent;
-import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.db.NoSuchContactException;
-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.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
-import org.briarproject.bramble.api.plugin.event.ContactConnectedEvent;
-import org.briarproject.bramble.api.plugin.event.ContactDisconnectedEvent;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.ActivityComponent;
 import org.briarproject.briar.android.contact.BaseContactListAdapter.OnContactClickListener;
@@ -37,55 +23,35 @@ import org.briarproject.briar.android.fragment.BaseFragment;
 import org.briarproject.briar.android.keyagreement.ContactExchangeActivity;
 import org.briarproject.briar.android.util.BriarSnackbarBuilder;
 import org.briarproject.briar.android.view.BriarRecyclerView;
-import org.briarproject.briar.api.android.AndroidNotificationManager;
-import org.briarproject.briar.api.client.MessageTracker.GroupCount;
-import org.briarproject.briar.api.conversation.ConversationManager;
-import org.briarproject.briar.api.conversation.ConversationMessageHeader;
-import org.briarproject.briar.api.conversation.event.ConversationMessageReceivedEvent;
-
-import java.util.ArrayList;
-import java.util.List;
-import java.util.logging.Logger;
 
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
 import androidx.annotation.UiThread;
-import androidx.core.app.ActivityCompat;
+import androidx.lifecycle.ViewModelProvider;
-import androidx.core.app.ActivityOptionsCompat;
-import androidx.core.util.Pair;
 import androidx.recyclerview.widget.LinearLayoutManager;
 import io.github.kobakei.materialfabspeeddial.FabSpeedDial;
 import io.github.kobakei.materialfabspeeddial.FabSpeedDial.OnMenuItemClickListener;
 
-import static android.os.Build.VERSION.SDK_INT;
-import static androidx.core.app.ActivityOptionsCompat.makeSceneTransitionAnimation;
-import static androidx.core.view.ViewCompat.getTransitionName;
 import static com.google.android.material.snackbar.BaseTransientBottomBar.LENGTH_INDEFINITE;
-import static java.util.logging.Level.WARNING;
+import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
-import static org.briarproject.bramble.util.LogUtils.logDuration;
-import static org.briarproject.bramble.util.LogUtils.logException;
-import static org.briarproject.bramble.util.LogUtils.now;
 import static org.briarproject.briar.android.conversation.ConversationActivity.CONTACT_ID;
-import static org.briarproject.briar.android.util.UiUtils.isSamsung7;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
-public class ContactListFragment extends BaseFragment implements EventListener,
+public class ContactListFragment extends BaseFragment
-		OnMenuItemClickListener {
+		implements OnMenuItemClickListener,
+		OnContactClickListener<ContactListItem> {
 
 	public static final String TAG = ContactListFragment.class.getName();
-	private static final Logger LOG = Logger.getLogger(TAG);
 
 	@Inject
-	ConnectionRegistry connectionRegistry;
+	ViewModelProvider.Factory viewModelFactory;
-	@Inject
-	EventBus eventBus;
-	@Inject
-	AndroidNotificationManager notificationManager;
 
-	private ContactListAdapter adapter;
+	private ContactListViewModel viewModel;
+	private final ContactListAdapter adapter = new ContactListAdapter(this);
 	private BriarRecyclerView list;
+
 	/**
 	 * The Snackbar is non-null when shown and null otherwise.
 	 * Use {@link #showSnackBar()} and {@link #dismissSnackBar()} to interact.
@@ -93,12 +59,6 @@ public class ContactListFragment extends BaseFragment implements EventListener,
 	@Nullable
 	private Snackbar snackbar = null;
 
-	// Fields that are accessed from background threads must be volatile
-	@Inject
-	volatile ContactManager contactManager;
-	@Inject
-	volatile ConversationManager conversationManager;
-
 	public static ContactListFragment newInstance() {
 		Bundle args = new Bundle();
 		ContactListFragment fragment = new ContactListFragment();
@@ -114,6 +74,8 @@ public class ContactListFragment extends BaseFragment implements EventListener,
 	@Override
 	public void injectFragment(ActivityComponent component) {
 		component.inject(this);
+		viewModel = new ViewModelProvider(this, viewModelFactory)
+				.get(ContactListViewModel.class);
 	}
 
 	@Nullable
@@ -129,37 +91,6 @@ public class ContactListFragment extends BaseFragment implements EventListener,
 		FabSpeedDial speedDial = contentView.findViewById(R.id.speedDial);
 		speedDial.addOnMenuItemClickListener(this);
 
-		OnContactClickListener<ContactListItem> onContactClickListener =
-				(view, item) -> {
-					Intent i = new Intent(getActivity(),
-							ConversationActivity.class);
-					ContactId contactId = item.getContact().getId();
-					i.putExtra(CONTACT_ID, contactId.getInt());
-
-					if (SDK_INT >= 23 && !isSamsung7()) {
-						ContactListItemViewHolder holder =
-								(ContactListItemViewHolder) list
-										.getRecyclerView()
-										.findViewHolderForAdapterPosition(
-												adapter.findItemPosition(item));
-						Pair<View, String> avatar =
-								Pair.create(holder.avatar,
-										getTransitionName(holder.avatar));
-						Pair<View, String> bulb =
-								Pair.create(holder.bulb,
-										getTransitionName(holder.bulb));
-						ActivityOptionsCompat options =
-								makeSceneTransitionAnimation(getActivity(),
-										avatar, bulb);
-						ActivityCompat.startActivity(getActivity(), i,
-								options.toBundle());
-					} else {
-						// work-around for android bug #224270
-						startActivity(i);
-					}
-				};
-		adapter = new ContactListAdapter(requireContext(),
-				onContactClickListener);
 		list = contentView.findViewById(R.id.list);
 		list.setLayoutManager(new LinearLayoutManager(requireContext()));
 		list.setAdapter(adapter);
@@ -167,9 +98,30 @@ public class ContactListFragment extends BaseFragment implements EventListener,
 		list.setEmptyText(getString(R.string.no_contacts));
 		list.setEmptyAction(getString(R.string.no_contacts_action));
 
+		viewModel.getContactListItems()
+				.observe(getViewLifecycleOwner(), result -> {
+					result.onError(this::handleException).onSuccess(items -> {
+						adapter.submitList(items);
+						if (requireNonNull(items).size() == 0) list.showData();
+					});
+				});
+		viewModel.getHasPendingContacts()
+				.observe(getViewLifecycleOwner(), hasPending -> {
+					if (hasPending) showSnackBar();
+					else dismissSnackBar();
+				});
+
 		return contentView;
 	}
 
+	@Override
+	public void onItemClick(View view, ContactListItem item) {
+		Intent i = new Intent(getActivity(), ConversationActivity.class);
+		ContactId contactId = item.getContact().getId();
+		i.putExtra(CONTACT_ID, contactId.getInt());
+		startActivity(i);
+	}
+
 	@Override
 	public void onMenuItemClick(FloatingActionButton fab, @Nullable TextView v,
 			int itemId) {
@@ -188,131 +140,20 @@ public class ContactListFragment extends BaseFragment implements EventListener,
 	@Override
 	public void onStart() {
 		super.onStart();
-		eventBus.addListener(this);
+		viewModel.clearAllContactNotifications();
-		notificationManager.clearAllContactNotifications();
+		viewModel.clearAllContactAddedNotifications();
-		notificationManager.clearAllContactAddedNotifications();
+		viewModel.loadContacts();
-		loadContacts();
+		viewModel.checkForPendingContacts();
-		checkForPendingContacts();
 		list.startPeriodicUpdate();
 	}
 
-	private void checkForPendingContacts() {
-		listener.runOnDbThread(() -> {
-			try {
-				if (contactManager.getPendingContacts().isEmpty()) {
-					runOnUiThreadUnlessDestroyed(this::dismissSnackBar);
-				} else {
-					runOnUiThreadUnlessDestroyed(this::showSnackBar);
-				}
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
-		});
-	}
-
 	@Override
 	public void onStop() {
 		super.onStop();
-		eventBus.removeListener(this);
-		adapter.clear();
-		list.showProgressBar();
 		list.stopPeriodicUpdate();
 		dismissSnackBar();
 	}
 
-	private void loadContacts() {
-		int revision = adapter.getRevision();
-		listener.runOnDbThread(() -> {
-			try {
-				long start = now();
-				List<ContactListItem> contacts = new ArrayList<>();
-				for (Contact c : contactManager.getContacts()) {
-					try {
-						ContactId id = c.getId();
-						GroupCount count =
-								conversationManager.getGroupCount(id);
-						boolean connected =
-								connectionRegistry.isConnected(c.getId());
-						contacts.add(new ContactListItem(c, connected, count));
-					} catch (NoSuchContactException e) {
-						// Continue
-					}
-				}
-				logDuration(LOG, "Full load", start);
-				displayContacts(revision, contacts);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
-		});
-	}
-
-	private void displayContacts(int revision, List<ContactListItem> contacts) {
-		runOnUiThreadUnlessDestroyed(() -> {
-			if (revision == adapter.getRevision()) {
-				adapter.incrementRevision();
-				if (contacts.isEmpty()) list.showData();
-				else adapter.replaceAll(contacts);
-			} else {
-				LOG.info("Concurrent update, reloading");
-				loadContacts();
-			}
-		});
-	}
-
-	@Override
-	public void eventOccurred(Event e) {
-		if (e instanceof ContactAddedEvent) {
-			LOG.info("Contact added, reloading");
-			loadContacts();
-		} else if (e instanceof ContactConnectedEvent) {
-			setConnected(((ContactConnectedEvent) e).getContactId(), true);
-		} else if (e instanceof ContactDisconnectedEvent) {
-			setConnected(((ContactDisconnectedEvent) e).getContactId(), false);
-		} else if (e instanceof ContactRemovedEvent) {
-			LOG.info("Contact removed, removing item");
-			removeItem(((ContactRemovedEvent) e).getContactId());
-		} else if (e instanceof ConversationMessageReceivedEvent) {
-			LOG.info("Conversation message received, updating item");
-			ConversationMessageReceivedEvent<?> p =
-					(ConversationMessageReceivedEvent<?>) e;
-			ConversationMessageHeader h = p.getMessageHeader();
-			updateItem(p.getContactId(), h);
-		} else if (e instanceof PendingContactAddedEvent ||
-				e instanceof PendingContactRemovedEvent) {
-			checkForPendingContacts();
-		}
-	}
-
-	@UiThread
-	private void updateItem(ContactId c, ConversationMessageHeader h) {
-		adapter.incrementRevision();
-		int position = adapter.findItemPosition(c);
-		ContactListItem item = adapter.getItemAt(position);
-		if (item != null) {
-			item.addMessage(h);
-			adapter.updateItemAt(position, item);
-		}
-	}
-
-	@UiThread
-	private void removeItem(ContactId c) {
-		adapter.incrementRevision();
-		int position = adapter.findItemPosition(c);
-		ContactListItem item = adapter.getItemAt(position);
-		if (item != null) adapter.remove(item);
-	}
-
-	@UiThread
-	private void setConnected(ContactId c, boolean connected) {
-		adapter.incrementRevision();
-		int position = adapter.findItemPosition(c);
-		ContactListItem item = adapter.getItemAt(position);
-		if (item != null) {
-			item.setConnected(connected);
-			adapter.updateItemAt(position, item);
-		}
-	}
-
 	@UiThread
 	private void showSnackBar() {
 		if (snackbar != null) return;
@@ -335,5 +176,4 @@ public class ContactListFragment extends BaseFragment implements EventListener,
 		Intent i = new Intent(getContext(), PendingContactListActivity.class);
 		startActivity(i);
 	}
-
 }

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

@@ -5,15 +5,16 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.briar.api.client.MessageTracker.GroupCount;
 import org.briarproject.briar.api.conversation.ConversationMessageHeader;
 
-import javax.annotation.concurrent.NotThreadSafe;
+import javax.annotation.concurrent.Immutable;
 
-@NotThreadSafe
+@Immutable
 @NotNullByDefault
-public class ContactListItem extends ContactItem {
+public class ContactListItem extends ContactItem
+		implements Comparable<ContactListItem> {
 
-	private boolean empty;
+	private final boolean empty;
-	private long timestamp;
+	private final long timestamp;
-	private int unread;
+	private final int unread;
 
 	public ContactListItem(Contact contact, boolean connected,
 			GroupCount count) {
@@ -23,10 +24,23 @@ public class ContactListItem extends ContactItem {
 		this.timestamp = count.getLatestMsgTime();
 	}
 
-	void addMessage(ConversationMessageHeader h) {
+	private ContactListItem(Contact contact, boolean connected, boolean empty,
-		empty = false;
+			int unread, long timestamp) {
-		if (h.getTimestamp() > timestamp) timestamp = h.getTimestamp();
+		super(contact, connected);
-		if (!h.isRead()) unread++;
+		this.empty = empty;
+		this.timestamp = timestamp;
+		this.unread = unread;
+	}
+
+	ContactListItem(ContactListItem item, boolean connected) {
+		this(item.getContact(), connected, item.empty, item.unread,
+				item.timestamp);
+	}
+
+	ContactListItem(ContactListItem item, ConversationMessageHeader h) {
+		this(item.getContact(), item.isConnected(), false,
+				h.isRead() ? item.unread : item.unread + 1,
+				Math.max(h.getTimestamp(), item.timestamp));
 	}
 
 	boolean isEmpty() {
@@ -41,4 +55,8 @@ public class ContactListItem extends ContactItem {
 		return unread;
 	}
 
+	@Override
+	public int compareTo(ContactListItem o) {
+		return Long.compare(o.getTimestamp(), timestamp);
+	}
 }

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

@@ -3,11 +3,9 @@ package org.briarproject.briar.android.contact;
 import android.view.View;
 import android.widget.TextView;
 
-import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.contact.BaseContactListAdapter.OnContactClickListener;
-import org.briarproject.briar.android.util.UiUtils;
 
 import java.util.Locale;
 
@@ -15,7 +13,6 @@ import javax.annotation.Nullable;
 
 import androidx.annotation.UiThread;
 
-import static androidx.core.view.ViewCompat.setTransitionName;
 import static org.briarproject.briar.android.util.UiUtils.formatDate;
 
 @UiThread
@@ -39,7 +36,8 @@ class ContactListItemViewHolder extends ContactItemViewHolder<ContactListItem> {
 		// unread count
 		int unreadCount = item.getUnreadCount();
 		if (unreadCount > 0) {
-			unread.setText(String.format(Locale.getDefault(), "%d", unreadCount));
+			unread.setText(
+					String.format(Locale.getDefault(), "%d", unreadCount));
 			unread.setVisibility(View.VISIBLE);
 		} else {
 			unread.setVisibility(View.INVISIBLE);
@@ -52,10 +50,6 @@ class ContactListItemViewHolder extends ContactItemViewHolder<ContactListItem> {
 			long timestamp = item.getTimestamp();
 			date.setText(formatDate(date.getContext(), timestamp));
 		}
-
-		ContactId c = item.getContact().getId();
-		setTransitionName(avatar, UiUtils.getAvatarTransitionName(c));
-		setTransitionName(bulb, UiUtils.getBulbTransitionName(c));
 	}
 
 }

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

@@ -0,0 +1,19 @@
+package org.briarproject.briar.android.contact;
+
+import org.briarproject.briar.android.viewmodel.ViewModelKey;
+
+import androidx.lifecycle.ViewModel;
+import dagger.Binds;
+import dagger.Module;
+import dagger.multibindings.IntoMap;
+
+@Module
+public abstract class ContactListModule {
+
+	@Binds
+	@IntoMap
+	@ViewModelKey(ContactListViewModel.class)
+	abstract ViewModel bindContactListViewModel(
+			ContactListViewModel contactListViewModel);
+
+}

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

@@ -0,0 +1,184 @@
+package org.briarproject.briar.android.contact;
+
+import android.app.Application;
+
+import org.briarproject.bramble.api.connection.ConnectionRegistry;
+import org.briarproject.bramble.api.contact.Contact;
+import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.contact.ContactManager;
+import org.briarproject.bramble.api.contact.event.ContactAddedEvent;
+import org.briarproject.bramble.api.contact.event.ContactRemovedEvent;
+import org.briarproject.bramble.api.contact.event.PendingContactAddedEvent;
+import org.briarproject.bramble.api.contact.event.PendingContactRemovedEvent;
+import org.briarproject.bramble.api.db.DatabaseExecutor;
+import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.db.Transaction;
+import org.briarproject.bramble.api.db.TransactionManager;
+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.LifecycleManager;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.event.ContactConnectedEvent;
+import org.briarproject.bramble.api.plugin.event.ContactDisconnectedEvent;
+import org.briarproject.bramble.api.system.AndroidExecutor;
+import org.briarproject.briar.android.viewmodel.DbViewModel;
+import org.briarproject.briar.android.viewmodel.LiveResult;
+import org.briarproject.briar.api.android.AndroidNotificationManager;
+import org.briarproject.briar.api.client.MessageTracker;
+import org.briarproject.briar.api.conversation.ConversationManager;
+import org.briarproject.briar.api.conversation.ConversationMessageHeader;
+import org.briarproject.briar.api.conversation.event.ConversationMessageReceivedEvent;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.concurrent.Executor;
+import java.util.logging.Logger;
+
+import javax.inject.Inject;
+
+import androidx.arch.core.util.Function;
+import androidx.lifecycle.LiveData;
+import androidx.lifecycle.MutableLiveData;
+
+import static java.util.logging.Level.WARNING;
+import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.util.LogUtils.logDuration;
+import static org.briarproject.bramble.util.LogUtils.logException;
+import static org.briarproject.bramble.util.LogUtils.now;
+
+@NotNullByDefault
+class ContactListViewModel extends DbViewModel implements EventListener {
+
+	private static final Logger LOG =
+			getLogger(ContactListViewModel.class.getName());
+
+	private final ContactManager contactManager;
+	private final ConversationManager conversationManager;
+	private final ConnectionRegistry connectionRegistry;
+	private final EventBus eventBus;
+	private final AndroidNotificationManager notificationManager;
+
+	private final MutableLiveData<LiveResult<List<ContactListItem>>>
+			contactListItems = new MutableLiveData<>();
+
+	private final MutableLiveData<Boolean> hasPendingContacts =
+			new MutableLiveData<>();
+
+	@Inject
+	ContactListViewModel(Application application,
+			@DatabaseExecutor Executor dbExecutor,
+			LifecycleManager lifecycleManager, TransactionManager db,
+			AndroidExecutor androidExecutor, ContactManager contactManager,
+			ConversationManager conversationManager,
+			ConnectionRegistry connectionRegistry, EventBus eventBus,
+			AndroidNotificationManager notificationManager) {
+		super(application, dbExecutor, lifecycleManager, db, androidExecutor);
+		this.contactManager = contactManager;
+		this.conversationManager = conversationManager;
+		this.connectionRegistry = connectionRegistry;
+		this.eventBus = eventBus;
+		this.notificationManager = notificationManager;
+		this.eventBus.addListener(this);
+	}
+
+	@Override
+	protected void onCleared() {
+		super.onCleared();
+		eventBus.removeListener(this);
+	}
+
+	void loadContacts() {
+		loadList(this::loadContacts, contactListItems::setValue);
+	}
+
+	private List<ContactListItem> loadContacts(Transaction txn)
+			throws DbException {
+		long start = now();
+		List<ContactListItem> contacts = new ArrayList<>();
+		for (Contact c : contactManager.getContacts(txn)) {
+			ContactId id = c.getId();
+			MessageTracker.GroupCount count =
+					conversationManager.getGroupCount(txn, id);
+			boolean connected = connectionRegistry.isConnected(c.getId());
+			contacts.add(new ContactListItem(c, connected, count));
+		}
+		Collections.sort(contacts);
+		logDuration(LOG, "Full load", start);
+		return contacts;
+	}
+
+	@Override
+	public void eventOccurred(Event e) {
+		if (e instanceof ContactAddedEvent) {
+			LOG.info("Contact added, reloading");
+			loadContacts();
+		} else if (e instanceof ContactConnectedEvent) {
+			updateItem(((ContactConnectedEvent) e).getContactId(),
+					item -> new ContactListItem(item, true), false);
+		} else if (e instanceof ContactDisconnectedEvent) {
+			updateItem(((ContactDisconnectedEvent) e).getContactId(),
+					item -> new ContactListItem(item, false), false);
+		} else if (e instanceof ContactRemovedEvent) {
+			LOG.info("Contact removed, removing item");
+			removeItem(((ContactRemovedEvent) e).getContactId());
+		} else if (e instanceof ConversationMessageReceivedEvent) {
+			LOG.info("Conversation message received, updating item");
+			ConversationMessageReceivedEvent<?> p =
+					(ConversationMessageReceivedEvent<?>) e;
+			ConversationMessageHeader h = p.getMessageHeader();
+			updateItem(p.getContactId(), item -> new ContactListItem(item, h),
+					true);
+		} else if (e instanceof PendingContactAddedEvent ||
+				e instanceof PendingContactRemovedEvent) {
+			checkForPendingContacts();
+		}
+	}
+
+	LiveData<LiveResult<List<ContactListItem>>> getContactListItems() {
+		return contactListItems;
+	}
+
+	LiveData<Boolean> getHasPendingContacts() {
+		return hasPendingContacts;
+	}
+
+	private void updateItem(ContactId c,
+			Function<ContactListItem, ContactListItem> replacer, boolean sort) {
+		List<ContactListItem> list = updateListItems(contactListItems,
+				itemToTest -> itemToTest.getContact().getId().equals(c),
+				replacer);
+		if (list == null) return;
+		if (sort) Collections.sort(list);
+		contactListItems.setValue(new LiveResult<>(list));
+	}
+
+	private void removeItem(ContactId c) {
+		List<ContactListItem> list = removeListItems(contactListItems,
+				itemToTest -> itemToTest.getContact().getId().equals(c));
+		if (list == null) return;
+		contactListItems.setValue(new LiveResult<>(list));
+	}
+
+	void checkForPendingContacts() {
+		runOnDbThread(() -> {
+			try {
+				boolean hasPending =
+						!contactManager.getPendingContacts().isEmpty();
+				hasPendingContacts.postValue(hasPending);
+			} catch (DbException e) {
+				logException(LOG, WARNING, e);
+			}
+		});
+	}
+
+	void clearAllContactNotifications() {
+		notificationManager.clearAllContactNotifications();
+	}
+
+	void clearAllContactAddedNotifications() {
+		notificationManager.clearAllContactAddedNotifications();
+	}
+
+}

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

@@ -1,7 +0,0 @@
-package org.briarproject.briar.android.contact;
-
-import dagger.Module;
-
-@Module
-public class ContactModule {
-}

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

@@ -0,0 +1,50 @@
+package org.briarproject.briar.android.contact;
+
+import android.content.Context;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.briar.R;
+
+@NotNullByDefault
+public class LegacyContactListAdapter extends
+		BaseContactListAdapter<ContactListItem, ContactListItemViewHolder> {
+
+	public LegacyContactListAdapter(Context context,
+			OnContactClickListener<ContactListItem> listener) {
+		super(context, ContactListItem.class, listener);
+	}
+
+	@Override
+	public ContactListItemViewHolder onCreateViewHolder(ViewGroup viewGroup,
+			int i) {
+		View v = LayoutInflater.from(viewGroup.getContext()).inflate(
+				R.layout.list_item_contact, viewGroup, false);
+
+		return new ContactListItemViewHolder(v);
+	}
+
+	@Override
+	public boolean areContentsTheSame(ContactListItem c1, ContactListItem c2) {
+		// check for all properties that influence visual
+		// representation of contact
+		if (c1.isEmpty() != c2.isEmpty()) {
+			return false;
+		}
+		if (c1.getUnreadCount() != c2.getUnreadCount()) {
+			return false;
+		}
+		if (c1.getTimestamp() != c2.getTimestamp()) {
+			return false;
+		}
+		return c1.isConnected() == c2.isConnected();
+	}
+
+	@Override
+	public int compare(ContactListItem c1, ContactListItem c2) {
+		return Long.compare(c2.getTimestamp(), c1.getTimestamp());
+	}
+
+}

briar-android/src/main/java/org/briarproject/briar/android/conversation/ConversationActivity.java

@@ -113,7 +113,6 @@ import static android.os.Build.VERSION.SDK_INT;
 import static android.view.Gravity.RIGHT;
 import static android.widget.Toast.LENGTH_SHORT;
 import static androidx.core.app.ActivityOptionsCompat.makeSceneTransitionAnimation;
-import static androidx.core.view.ViewCompat.setTransitionName;
 import static androidx.lifecycle.Lifecycle.State.STARTED;
 import static androidx.recyclerview.widget.SortedList.INVALID_POSITION;
 import static java.util.Collections.sort;
@@ -134,8 +133,6 @@ import static org.briarproject.briar.android.conversation.ImageActivity.ATTACHME
 import static org.briarproject.briar.android.conversation.ImageActivity.DATE;
 import static org.briarproject.briar.android.conversation.ImageActivity.ITEM_ID;
 import static org.briarproject.briar.android.conversation.ImageActivity.NAME;
-import static org.briarproject.briar.android.util.UiUtils.getAvatarTransitionName;
-import static org.briarproject.briar.android.util.UiUtils.getBulbTransitionName;
 import static org.briarproject.briar.android.util.UiUtils.observeOnce;
 import static org.briarproject.briar.api.messaging.MessagingConstants.MAX_ATTACHMENTS_PER_MESSAGE;
 import static org.briarproject.briar.api.messaging.MessagingConstants.MAX_PRIVATE_MESSAGE_TEXT_LENGTH;
@@ -252,9 +249,6 @@ public class ConversationActivity extends BriarActivity
 		viewModel.getAddedPrivateMessage().observeEvent(this,
 				this::onAddedPrivateMessage);
 
-		setTransitionName(toolbarAvatar, getAvatarTransitionName(contactId));
-		setTransitionName(toolbarStatus, getBulbTransitionName(contactId));
-
 		visitor = new ConversationVisitor(this, this, this,
 				viewModel.getContactDisplayName());
 		adapter = new ConversationAdapter(this, this);

briar-android/src/main/java/org/briarproject/briar/android/introduction/ContactChooserFragment.java

@@ -15,8 +15,8 @@ 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.BaseContactListAdapter.OnContactClickListener;
-import org.briarproject.briar.android.contact.ContactListAdapter;
 import org.briarproject.briar.android.contact.ContactListItem;
+import org.briarproject.briar.android.contact.LegacyContactListAdapter;
 import org.briarproject.briar.android.fragment.BaseFragment;
 import org.briarproject.briar.android.view.BriarRecyclerView;
 import org.briarproject.briar.api.client.MessageTracker.GroupCount;
@@ -45,7 +45,7 @@ public class ContactChooserFragment extends BaseFragment {
 	private static final Logger LOG = Logger.getLogger(TAG);
 
 	private BriarRecyclerView list;
-	private ContactListAdapter adapter;
+	private LegacyContactListAdapter adapter;
 	private ContactId contactId;
 
 	// Fields that are accessed from background threads must be volatile
@@ -72,7 +72,8 @@ public class ContactChooserFragment extends BaseFragment {
 	}
 
 	@Override
-	public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container,
+	public View onCreateView(LayoutInflater inflater,
+			@Nullable ViewGroup container,
 			@Nullable Bundle savedInstanceState) {
 
 		View contentView = inflater.inflate(R.layout.list, container, false);
@@ -83,7 +84,7 @@ public class ContactChooserFragment extends BaseFragment {
 					Contact c2 = item.getContact();
 					showMessageScreen(c1, c2);
 				};
-		adapter = new ContactListAdapter(requireActivity(),
+		adapter = new LegacyContactListAdapter(requireActivity(),
 				onContactClickListener);
 
 		list = contentView.findViewById(R.id.list);

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

@@ -28,7 +28,6 @@ import android.widget.TextView;
 import com.google.android.material.textfield.TextInputLayout;
 
 import org.briarproject.bramble.api.contact.Contact;
-import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
@@ -240,14 +239,6 @@ public class UiUtils {
 		textView.setMovementMethod(new LinkMovementMethod());
 	}
 
-	public static String getAvatarTransitionName(ContactId c) {
-		return "avatar" + c.getInt();
-	}
-
-	public static String getBulbTransitionName(ContactId c) {
-		return "bulb" + c.getInt();
-	}
-
 	public static OnClickListener getGoToSettingsListener(Context context) {
 		return (dialog, which) -> {
 			Intent i = new Intent();

briar-api/src/main/java/org/briarproject/briar/api/conversation/ConversationManager.java

@@ -43,6 +43,11 @@ public interface ConversationManager {
 	 */
 	GroupCount getGroupCount(ContactId c) throws DbException;
 
+	/**
+	 * Returns the unified group count for all private conversation messages.
+	 */
+	GroupCount getGroupCount(Transaction txn, ContactId c) throws DbException;
+
 	/**
 	 * Deletes all messages exchanged with the given contact.
 	 */

briar-core/src/main/java/org/briarproject/briar/messaging/ConversationManagerImpl.java

@@ -57,20 +57,21 @@ class ConversationManagerImpl implements ConversationManager {
 
 	@Override
 	public GroupCount getGroupCount(ContactId contactId) throws DbException {
+		return db.transactionWithResult(true,
+				txn -> getGroupCount(txn, contactId));
+	}
+
+	@Override
+	public GroupCount getGroupCount(Transaction txn, ContactId contactId)
+			throws DbException {
 		int msgCount = 0, unreadCount = 0;
 		long latestTime = 0;
-		Transaction txn = db.startTransaction(true);
+		for (ConversationClient client : clients) {
-		try {
+			GroupCount count = client.getGroupCount(txn, contactId);
-			for (ConversationClient client : clients) {
+			msgCount += count.getMsgCount();
-				GroupCount count = client.getGroupCount(txn, contactId);
+			unreadCount += count.getUnreadCount();
-				msgCount += count.getMsgCount();
+			if (count.getLatestMsgTime() > latestTime)
-				unreadCount += count.getUnreadCount();
+				latestTime = count.getLatestMsgTime();
-				if (count.getLatestMsgTime() > latestTime)
-					latestTime = count.getLatestMsgTime();
-			}
-			db.commitTransaction(txn);
-		} finally {
-			db.endTransaction(txn);
 		}
 		return new GroupCount(msgCount, unreadCount, latestTime);
 	}
@@ -87,7 +88,8 @@ class ConversationManagerImpl implements ConversationManager {
 	}
 
 	@Override
-	public DeletionResult deleteMessages(ContactId c, Collection<MessageId> toDelete)
+	public DeletionResult deleteMessages(ContactId c,
+			Collection<MessageId> toDelete)
 			throws DbException {
 		return db.transactionWithResult(false, txn -> {
 			DeletionResult result = new DeletionResult();