Merge branch 'use-contact-id-as-conversation-id' into 'master'

Use contact ID rather than messaging group ID to identify conversation

We originally used the private messaging group ID to identify the private conversation, but now that the conversation includes messages from multiple clients it's more appropriate to use the contact ID.

This refactoring isn't urgent - I've had the branch lying around for a while, but I'm putting it up for review because #734 will touch some of the same code.

See merge request !386

briar-android/src/org/briarproject/android/AndroidNotificationManagerImpl.java

@@ -34,7 +34,6 @@ import org.briarproject.api.event.PrivateMessageReceivedEvent;
 import org.briarproject.api.event.SettingsUpdatedEvent;
 import org.briarproject.api.lifecycle.Service;
 import org.briarproject.api.lifecycle.ServiceException;
-import org.briarproject.api.messaging.MessagingManager;
 import org.briarproject.api.settings.Settings;
 import org.briarproject.api.settings.SettingsManager;
 import org.briarproject.api.sync.GroupId;
@@ -65,6 +64,7 @@ import static org.briarproject.android.BriarActivity.GROUP_ID;
 import static org.briarproject.android.NavDrawerActivity.INTENT_BLOGS;
 import static org.briarproject.android.NavDrawerActivity.INTENT_CONTACTS;
 import static org.briarproject.android.NavDrawerActivity.INTENT_FORUMS;
+import static org.briarproject.android.contact.ConversationActivity.CONTACT_ID;
 import static org.briarproject.android.fragment.SettingsFragment.PREF_NOTIFY_BLOG;
 import static org.briarproject.android.fragment.SettingsFragment.SETTINGS_NAMESPACE;
 
@@ -100,19 +100,19 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 
 	private final Executor dbExecutor;
 	private final SettingsManager settingsManager;
-	private final MessagingManager messagingManager;
 	private final AndroidExecutor androidExecutor;
 	private final Context appContext;
 	private final BroadcastReceiver receiver = new DeleteIntentReceiver();
 	private final AtomicBoolean used = new AtomicBoolean(false);
 
 	// The following must only be accessed on the main UI thread
-	private final Map<GroupId, Integer> contactCounts = new HashMap<>();
+	private final Map<ContactId, Integer> contactCounts = new HashMap<>();
 	private final Map<GroupId, Integer> forumCounts = new HashMap<>();
 	private final Map<GroupId, Integer> blogCounts = new HashMap<>();
 	private int contactTotal = 0, forumTotal = 0, blogTotal = 0;
 	private int introductionTotal = 0;
 	private int nextRequestId = 0;
+	private ContactId blockedContact = null;
 	private GroupId blockedGroup = null;
 	private boolean blockContacts = false, blockForums = false;
 	private boolean blockBlogs = false, blockIntroductions = false;
@@ -121,11 +121,10 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 
 	@Inject
 	AndroidNotificationManagerImpl(@DatabaseExecutor Executor dbExecutor,
-			SettingsManager settingsManager, MessagingManager messagingManager,
-			AndroidExecutor androidExecutor, Application app) {
+			SettingsManager settingsManager, AndroidExecutor androidExecutor,
+			Application app) {
 		this.dbExecutor = dbExecutor;
 		this.settingsManager = settingsManager;
-		this.messagingManager = messagingManager;
 		this.androidExecutor = androidExecutor;
 		appContext = app.getApplicationContext();
 	}
@@ -165,7 +164,7 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 		Future<Void> f = androidExecutor.runOnUiThread(new Callable<Void>() {
 			@Override
 			public Void call() {
-				clearPrivateMessageNotification();
+				clearContactNotification();
 				clearForumPostNotification();
 				clearBlogPostNotification();
 				clearIntroductionSuccessNotification();
@@ -181,7 +180,7 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 	}
 
 	@UiThread
-	private void clearPrivateMessageNotification() {
+	private void clearContactNotification() {
 		contactCounts.clear();
 		contactTotal = 0;
 		Object o = appContext.getSystemService(NOTIFICATION_SERVICE);
@@ -222,7 +221,7 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 			if (s.getNamespace().equals(SETTINGS_NAMESPACE)) loadSettings();
 		} else if (e instanceof PrivateMessageReceivedEvent) {
 			PrivateMessageReceivedEvent p = (PrivateMessageReceivedEvent) e;
-			showPrivateMessageNotification(p.getGroupId());
+			showContactNotification(p.getContactId());
 		} else if (e instanceof ForumPostReceivedEvent) {
 			ForumPostReceivedEvent f = (ForumPostReceivedEvent) e;
 			showForumPostNotification(f.getGroupId());
@@ -231,16 +230,17 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 			showBlogPostNotification(b.getGroupId());
 		} else if (e instanceof IntroductionRequestReceivedEvent) {
 			ContactId c = ((IntroductionRequestReceivedEvent) e).getContactId();
-			showNotificationForPrivateConversation(c);
+			showContactNotification(c);
 		} else if (e instanceof IntroductionResponseReceivedEvent) {
-			ContactId c = ((IntroductionResponseReceivedEvent) e).getContactId();
-			showNotificationForPrivateConversation(c);
+			ContactId c =
+					((IntroductionResponseReceivedEvent) e).getContactId();
+			showContactNotification(c);
 		} else if (e instanceof InvitationRequestReceivedEvent) {
 			ContactId c = ((InvitationRequestReceivedEvent) e).getContactId();
-			showNotificationForPrivateConversation(c);
+			showContactNotification(c);
 		} else if (e instanceof InvitationResponseReceivedEvent) {
 			ContactId c = ((InvitationResponseReceivedEvent) e).getContactId();
-			showNotificationForPrivateConversation(c);
+			showContactNotification(c);
 		} else if (e instanceof IntroductionSucceededEvent) {
 			showIntroductionNotification();
 		}
@@ -260,38 +260,38 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 		});
 	}
 
-	private void showPrivateMessageNotification(final GroupId g) {
+	private void showContactNotification(final ContactId c) {
 		androidExecutor.runOnUiThread(new Runnable() {
 			@Override
 			public void run() {
 				if (blockContacts) return;
-				if (g.equals(blockedGroup)) return;
-				Integer count = contactCounts.get(g);
-				if (count == null) contactCounts.put(g, 1);
-				else contactCounts.put(g, count + 1);
+				if (c.equals(blockedContact)) return;
+				Integer count = contactCounts.get(c);
+				if (count == null) contactCounts.put(c, 1);
+				else contactCounts.put(c, count + 1);
 				contactTotal++;
-				updatePrivateMessageNotification();
+				updateContactNotification();
 			}
 		});
 	}
 
 	@Override
-	public void clearPrivateMessageNotification(final GroupId g) {
+	public void clearContactNotification(final ContactId c) {
 		androidExecutor.runOnUiThread(new Runnable() {
 			@Override
 			public void run() {
-				Integer count = contactCounts.remove(g);
+				Integer count = contactCounts.remove(c);
 				if (count == null) return; // Already cleared
 				contactTotal -= count;
-				updatePrivateMessageNotification();
+				updateContactNotification();
 			}
 		});
 	}
 
 	@UiThread
-	private void updatePrivateMessageNotification() {
+	private void updateContactNotification() {
 		if (contactTotal == 0) {
-			clearPrivateMessageNotification();
+			clearContactNotification();
 		} else if (settings.getBoolean("notifyPrivateMessages", true)) {
 			NotificationCompat.Builder b =
 					new NotificationCompat.Builder(appContext);
@@ -315,10 +315,9 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 			if (contactCounts.size() == 1) {
 				// Touching the notification shows the relevant conversation
 				Intent i = new Intent(appContext, ConversationActivity.class);
-				GroupId g = contactCounts.keySet().iterator().next();
-				i.putExtra(GROUP_ID, g.getBytes());
-				String idHex = StringUtils.toHexString(g.getBytes());
-				i.setData(Uri.parse(CONTACT_URI + "/" + idHex));
+				ContactId c = contactCounts.keySet().iterator().next();
+				i.putExtra(CONTACT_ID, c.getInt());
+				i.setData(Uri.parse(CONTACT_URI + "/" + c.getInt()));
 				i.setFlags(FLAG_ACTIVITY_CLEAR_TOP | FLAG_ACTIVITY_SINGLE_TOP);
 				TaskStackBuilder t = TaskStackBuilder.create(appContext);
 				t.addParentStack(ConversationActivity.class);
@@ -362,7 +361,7 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 		androidExecutor.runOnUiThread(new Runnable() {
 			@Override
 			public void run() {
-				clearPrivateMessageNotification();
+				clearContactNotification();
 				clearIntroductionSuccessNotification();
 			}
 		});
@@ -613,6 +612,26 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 		});
 	}
 
+	@Override
+	public void blockContactNotification(final ContactId c) {
+		androidExecutor.runOnUiThread(new Runnable() {
+			@Override
+			public void run() {
+				blockedContact = c;
+			}
+		});
+	}
+
+	@Override
+	public void unblockContactNotification(final ContactId c) {
+		androidExecutor.runOnUiThread(new Runnable() {
+			@Override
+			public void run() {
+				if (c.equals(blockedContact)) blockedContact = null;
+			}
+		});
+	}
+
 	@Override
 	public void blockAllContactNotifications() {
 		androidExecutor.runOnUiThread(new Runnable() {
@@ -675,21 +694,6 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 		});
 	}
 
-	private void showNotificationForPrivateConversation(final ContactId c) {
-		dbExecutor.execute(new Runnable() {
-			@Override
-			public void run() {
-				try {
-					GroupId g = messagingManager.getConversationId(c);
-					showPrivateMessageNotification(g);
-				} catch (DbException e) {
-					if (LOG.isLoggable(WARNING))
-						LOG.log(WARNING, e.toString(), e);
-				}
-			}
-		});
-	}
-
 	private class DeleteIntentReceiver extends BroadcastReceiver {
 
 		@Override
@@ -699,7 +703,7 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 				@Override
 				public void run() {
 					if (CLEAR_PRIVATE_MESSAGE_ACTION.equals(action)) {
-						clearPrivateMessageNotification();
+						clearContactNotification();
 					} else if (CLEAR_FORUM_ACTION.equals(action)) {
 						clearForumPostNotification();
 					} else if (CLEAR_BLOG_ACTION.equals(action)) {

briar-android/src/org/briarproject/android/api/AndroidNotificationManager.java

@@ -1,5 +1,6 @@
 package org.briarproject.android.api;
 
+import org.briarproject.api.contact.ContactId;
 import org.briarproject.api.sync.GroupId;
 
 /**
@@ -8,7 +9,7 @@ import org.briarproject.api.sync.GroupId;
  */
 public interface AndroidNotificationManager {
 
-	void clearPrivateMessageNotification(GroupId g);
+	void clearContactNotification(ContactId c);
 
 	void clearAllContactNotifications();
 
@@ -20,6 +21,10 @@ public interface AndroidNotificationManager {
 
 	void clearAllBlogPostNotifications();
 
+	void blockContactNotification(ContactId c);
+
+	void unblockContactNotification(ContactId c);
+
 	void blockNotification(GroupId g);
 
 	void unblockNotification(GroupId g);

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

@@ -10,6 +10,7 @@ import javax.annotation.concurrent.NotThreadSafe;
 public class ContactItem {
 
 	private final Contact contact;
+
 	private boolean connected;
 
 	public ContactItem(Contact contact, boolean connected) {

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

@@ -48,7 +48,6 @@ import org.briarproject.api.messaging.PrivateMessageHeader;
 import org.briarproject.api.plugins.ConnectionRegistry;
 import org.briarproject.api.sharing.InvitationRequest;
 import org.briarproject.api.sharing.InvitationResponse;
-import org.briarproject.api.sync.GroupId;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -60,7 +59,7 @@ import static android.support.v4.app.ActivityOptionsCompat.makeSceneTransitionAn
 import static android.support.v4.view.ViewCompat.getTransitionName;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
-import static org.briarproject.android.BriarActivity.GROUP_ID;
+import static org.briarproject.android.contact.ConversationActivity.CONTACT_ID;
 
 public class ContactListFragment extends BaseFragment implements EventListener {
 
@@ -111,10 +110,10 @@ public class ContactListFragment extends BaseFragment implements EventListener {
 				new OnContactClickListener<ContactListItem>() {
 					@Override
 					public void onItemClick(View view, ContactListItem item) {
-						GroupId groupId = item.getGroupId();
 						Intent i = new Intent(getActivity(),
 								ConversationActivity.class);
-						i.putExtra(GROUP_ID, groupId.getBytes());
+						ContactId contactId = item.getContact().getId();
+						i.putExtra(CONTACT_ID, contactId.getInt());
 
 						// work-around for android bug #224270
 						if (Build.VERSION.SDK_INT >= 23) {
@@ -200,14 +199,12 @@ public class ContactListFragment extends BaseFragment implements EventListener {
 					for (Contact c : contactManager.getActiveContacts()) {
 						try {
 							ContactId id = c.getId();
-							GroupId groupId =
-									conversationManager.getConversationId(id);
 							GroupCount count =
 									conversationManager.getGroupCount(id);
 							boolean connected =
 									connectionRegistry.isConnected(c.getId());
 							contacts.add(new ContactListItem(c, connected,
-									groupId, count));
+									count));
 						} catch (NoSuchContactException e) {
 							// Continue
 						}

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

@@ -3,7 +3,6 @@ package org.briarproject.android.contact;
 import org.briarproject.api.clients.MessageTracker.GroupCount;
 import org.briarproject.api.contact.Contact;
 import org.briarproject.api.nullsafety.NotNullByDefault;
-import org.briarproject.api.sync.GroupId;
 
 import javax.annotation.concurrent.NotThreadSafe;
 
@@ -11,15 +10,13 @@ import javax.annotation.concurrent.NotThreadSafe;
 @NotNullByDefault
 public class ContactListItem extends ContactItem {
 
-	private final GroupId groupId;
 	private boolean empty;
 	private long timestamp;
 	private int unread;
 
-	public ContactListItem(Contact contact,	boolean connected, GroupId groupId,
+	public ContactListItem(Contact contact, boolean connected,
 			GroupCount count) {
 		super(contact, connected);
-		this.groupId = groupId;
 		this.empty = count.getMsgCount() == 0;
 		this.unread = count.getUnreadCount();
 		this.timestamp = count.getLatestMsgTime();
@@ -32,10 +29,6 @@ public class ContactListItem extends ContactItem {
 			unread++;
 	}
 
-	GroupId getGroupId() {
-		return groupId;
-	}
-
 	boolean isEmpty() {
 		return empty;
 	}

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

@@ -7,13 +7,13 @@ import android.widget.TextView;
 
 import org.briarproject.R;
 import org.briarproject.android.contact.BaseContactListAdapter.OnContactClickListener;
+import org.briarproject.android.util.AndroidUtils;
+import org.briarproject.api.contact.ContactId;
 import org.briarproject.api.nullsafety.NotNullByDefault;
-import org.briarproject.api.sync.GroupId;
 import org.jetbrains.annotations.Nullable;
 
 import static android.support.v4.view.ViewCompat.setTransitionName;
 import static org.briarproject.android.util.AndroidUtils.formatDate;
-import static org.briarproject.util.StringUtils.toHexString;
 
 @UiThread
 @NotNullByDefault
@@ -23,7 +23,7 @@ class ContactListItemViewHolder extends ContactItemViewHolder<ContactListItem> {
 	private final TextView unread;
 	private final TextView date;
 
-	public ContactListItemViewHolder(View v) {
+	ContactListItemViewHolder(View v) {
 		super(v);
 		bulb = (ImageView) v.findViewById(R.id.bulbView);
 		unread = (TextView) v.findViewById(R.id.unreadCountView);
@@ -59,16 +59,9 @@ class ContactListItemViewHolder extends ContactItemViewHolder<ContactListItem> {
 			bulb.setImageResource(R.drawable.contact_disconnected);
 		}
 
-		setTransitionName(avatar, getAvatarTransitionName(item.getGroupId()));
-		setTransitionName(bulb, getBulbTransitionName(item.getGroupId()));
-	}
-
-	private String getAvatarTransitionName(GroupId g) {
-		return "avatar" + toHexString(g.getBytes());
-	}
-
-	private String getBulbTransitionName(GroupId g) {
-		return "bulb" + toHexString(g.getBytes());
+		ContactId c = item.getContact().getId();
+		setTransitionName(avatar, AndroidUtils.getAvatarTransitionName(c));
+		setTransitionName(bulb, AndroidUtils.getBulbTransitionName(c));
 	}
 
 }

briar-android/src/org/briarproject/android/contact/ConversationActivity.java

@@ -30,6 +30,7 @@ import org.briarproject.android.BriarActivity;
 import org.briarproject.android.api.AndroidNotificationManager;
 import org.briarproject.android.contact.ConversationAdapter.RequestListener;
 import org.briarproject.android.introduction.IntroductionActivity;
+import org.briarproject.android.util.AndroidUtils;
 import org.briarproject.android.view.BriarRecyclerView;
 import org.briarproject.android.view.TextInputView;
 import org.briarproject.android.view.TextInputView.TextInputListener;
@@ -57,6 +58,7 @@ import org.briarproject.api.event.MessagesAckedEvent;
 import org.briarproject.api.event.MessagesSentEvent;
 import org.briarproject.api.event.PrivateMessageReceivedEvent;
 import org.briarproject.api.forum.ForumSharingManager;
+import org.briarproject.api.identity.AuthorId;
 import org.briarproject.api.introduction.IntroductionManager;
 import org.briarproject.api.introduction.IntroductionMessage;
 import org.briarproject.api.introduction.IntroductionRequest;
@@ -73,6 +75,7 @@ import org.briarproject.api.sharing.InvitationMessage;
 import org.briarproject.api.sharing.InvitationRequest;
 import org.briarproject.api.sharing.InvitationResponse;
 import org.briarproject.api.sync.GroupId;
+import org.briarproject.api.sync.Message;
 import org.briarproject.api.sync.MessageId;
 import org.briarproject.util.StringUtils;
 import org.jetbrains.annotations.NotNull;
@@ -106,6 +109,8 @@ import static org.briarproject.api.messaging.MessagingConstants.MAX_PRIVATE_MESS
 public class ConversationActivity extends BriarActivity
 		implements EventListener, RequestListener, TextInputListener {
 
+	public static final String CONTACT_ID = "briar.CONTACT_ID";
+
 	private static final Logger LOG =
 			Logger.getLogger(ConversationActivity.class.getName());
 	private static final int REQUEST_CODE_INTRODUCTION = 1;
@@ -150,10 +155,10 @@ public class ConversationActivity extends BriarActivity
 	@Inject
 	volatile GroupInvitationManager groupInvitationManager;
 
-	private volatile GroupId groupId = null;
-	private volatile ContactId contactId = null;
-	private volatile String contactName = null;
-	private volatile byte[] contactIdenticonKey = null;
+	private volatile ContactId contactId;
+	private volatile String contactName;
+	private volatile AuthorId contactAuthorId;
+	private volatile GroupId messagingGroupId;
 
 	@SuppressWarnings("ConstantConditions")
 	@Override
@@ -161,9 +166,9 @@ public class ConversationActivity extends BriarActivity
 		super.onCreate(state);
 
 		Intent i = getIntent();
-		byte[] b = i.getByteArrayExtra("briar.GROUP_ID");
-		if (b == null) throw new IllegalStateException();
-		groupId = new GroupId(b);
+		int id = i.getIntExtra(CONTACT_ID, -1);
+		if (id == -1) throw new IllegalStateException();
+		contactId = new ContactId(id);
 
 		setContentView(R.layout.activity_conversation);
 
@@ -185,9 +190,10 @@ public class ConversationActivity extends BriarActivity
 			ab.setDisplayShowTitleEnabled(false);
 		}
 
-		String hexGroupId = StringUtils.toHexString(b);
-		ViewCompat.setTransitionName(toolbarAvatar, "avatar" + hexGroupId);
-		ViewCompat.setTransitionName(toolbarStatus, "bulb" + hexGroupId);
+		ViewCompat.setTransitionName(toolbarAvatar,
+				AndroidUtils.getAvatarTransitionName(contactId));
+		ViewCompat.setTransitionName(toolbarStatus,
+				AndroidUtils.getBulbTransitionName(contactId));
 
 		adapter = new ConversationAdapter(this, this);
 		list = (BriarRecyclerView) findViewById(R.id.conversationView);
@@ -220,8 +226,8 @@ public class ConversationActivity extends BriarActivity
 	public void onStart() {
 		super.onStart();
 		eventBus.addListener(this);
-		notificationManager.blockNotification(groupId);
-		notificationManager.clearPrivateMessageNotification(groupId);
+		notificationManager.blockContactNotification(contactId);
+		notificationManager.clearContactNotification(contactId);
 		loadContactDetails();
 		loadMessages();
 		list.startPeriodicUpdate();
@@ -231,7 +237,7 @@ public class ConversationActivity extends BriarActivity
 	public void onStop() {
 		super.onStop();
 		eventBus.removeListener(this);
-		notificationManager.unblockNotification(groupId);
+		notificationManager.unblockContactNotification(contactId);
 		list.stopPeriodicUpdate();
 		if (isFinishing()) markMessagesRead();
 	}
@@ -287,13 +293,10 @@ public class ConversationActivity extends BriarActivity
 			public void run() {
 				try {
 					long now = System.currentTimeMillis();
-					if (contactId == null)
-						contactId = messagingManager.getContactId(groupId);
-					if (contactName == null || contactIdenticonKey == null) {
+					if (contactName == null || contactAuthorId == null) {
 						Contact contact = contactManager.getContact(contactId);
 						contactName = contact.getAuthor().getName();
-						contactIdenticonKey =
-								contact.getAuthor().getId().getBytes();
+						contactAuthorId = contact.getAuthor().getId();
 					}
 					long duration = System.currentTimeMillis() - now;
 					if (LOG.isLoggable(INFO))
@@ -314,7 +317,7 @@ public class ConversationActivity extends BriarActivity
 			@Override
 			public void run() {
 				toolbarAvatar.setImageDrawable(
-						new IdenticonDrawable(contactIdenticonKey));
+						new IdenticonDrawable(contactAuthorId.getBytes()));
 				toolbarTitle.setText(contactName);
 
 				if (connectionRegistry.isConnected(contactId)) {
@@ -341,8 +344,6 @@ public class ConversationActivity extends BriarActivity
 			public void run() {
 				try {
 					long now = System.currentTimeMillis();
-					if (contactId == null)
-						contactId = messagingManager.getContactId(groupId);
 					Collection<PrivateMessageHeader> headers =
 							messagingManager.getMessageHeaders(contactId);
 					Collection<IntroductionMessage> introductions =
@@ -419,12 +420,10 @@ public class ConversationActivity extends BriarActivity
 			ConversationItem item;
 			if (m instanceof IntroductionRequest) {
 				IntroductionRequest i = (IntroductionRequest) m;
-				item = ConversationItem
-						.from(ConversationActivity.this, contactName, i);
+				item = ConversationItem.from(this, contactName, i);
 			} else {
 				IntroductionResponse i = (IntroductionResponse) m;
-				item = ConversationItem
-						.from(ConversationActivity.this, contactName, i);
+				item = ConversationItem.from(this, contactName, i);
 			}
 			items.add(item);
 		}
@@ -432,12 +431,10 @@ public class ConversationActivity extends BriarActivity
 			ConversationItem item;
 			if (i instanceof InvitationRequest) {
 				InvitationRequest r = (InvitationRequest) i;
-				item = ConversationItem
-						.from(ConversationActivity.this, contactName, r);
+				item = ConversationItem.from(this, contactName, r);
 			} else {
 				InvitationResponse r = (InvitationResponse) i;
-				item = ConversationItem
-						.from(ConversationActivity.this, contactName, r);
+				item = ConversationItem.from(this, contactName, r);
 			}
 			items.add(item);
 		}
@@ -540,7 +537,7 @@ public class ConversationActivity extends BriarActivity
 			}
 		} else if (e instanceof PrivateMessageReceivedEvent) {
 			PrivateMessageReceivedEvent p = (PrivateMessageReceivedEvent) e;
-			if (p.getGroupId().equals(groupId)) {
+			if (p.getContactId().equals(contactId)) {
 				LOG.info("Message received, adding");
 				PrivateMessageHeader h = p.getMessageHeader();
 				addConversationItem(ConversationItem.from(h));
@@ -640,7 +637,8 @@ public class ConversationActivity extends BriarActivity
 		text = StringUtils.truncateUtf8(text, MAX_PRIVATE_MESSAGE_BODY_LENGTH);
 		long timestamp = System.currentTimeMillis();
 		timestamp = Math.max(timestamp, getMinTimestampForNewMessage());
-		createMessage(text, timestamp);
+		if (messagingGroupId == null) loadGroupId(text, timestamp);
+		else createMessage(text, timestamp);
 		textInputView.setText("");
 	}
 
@@ -650,13 +648,30 @@ public class ConversationActivity extends BriarActivity
 		return item == null ? 0 : item.getTime() + 1;
 	}
 
+	private void loadGroupId(final String body, final long timestamp) {
+		runOnDbThread(new Runnable() {
+			@Override
+			public void run() {
+				try {
+					messagingGroupId =
+							messagingManager.getConversationId(contactId);
+					createMessage(body, timestamp);
+				} catch (DbException e) {
+					if (LOG.isLoggable(WARNING))
+						LOG.log(WARNING, e.toString(), e);
+				}
+
+			}
+		});
+	}
+
 	private void createMessage(final String body, final long timestamp) {
 		cryptoExecutor.execute(new Runnable() {
 			@Override
 			public void run() {
 				try {
 					storeMessage(privateMessageFactory.createPrivateMessage(
-							groupId, timestamp, body), body);
+							messagingGroupId, timestamp, body), body);
 				} catch (FormatException e) {
 					throw new RuntimeException(e);
 				}
@@ -674,14 +689,13 @@ public class ConversationActivity extends BriarActivity
 					long duration = System.currentTimeMillis() - now;
 					if (LOG.isLoggable(INFO))
 						LOG.info("Storing message took " + duration + " ms");
-					MessageId id = m.getMessage().getId();
-					PrivateMessageHeader h =
-							new PrivateMessageHeader(id, groupId,
-									m.getMessage().getTimestamp(), true, false,
-									false, false);
+					Message message = m.getMessage();
+					PrivateMessageHeader h = new PrivateMessageHeader(
+							message.getId(), message.getGroupId(),
+							message.getTimestamp(), true, false, false, false);
 					ConversationItem item = ConversationItem.from(h);
 					item.setBody(body);
-					bodyCache.put(id, body);
+					bodyCache.put(message.getId(), body);
 					addConversationItem(item);
 				} catch (DbException e) {
 					if (LOG.isLoggable(WARNING))
@@ -714,10 +728,6 @@ public class ConversationActivity extends BriarActivity
 			@Override
 			public void run() {
 				try {
-					// make sure contactId is initialised
-					if (contactId == null)
-						contactId = messagingManager.getContactId(groupId);
-					// remove contact with that ID
 					contactManager.removeContact(contactId);
 				} catch (DbException e) {
 					if (LOG.isLoggable(WARNING))
@@ -847,7 +857,7 @@ public class ConversationActivity extends BriarActivity
 					switch (item.getRequestType()) {
 						case INTRODUCTION:
 							respondToIntroductionRequest(item.getSessionId(),
-								accept, timestamp);
+									accept, timestamp);
 							break;
 						case FORUM:
 							respondToForumRequest(item.getSessionId(), accept);

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

@@ -23,7 +23,6 @@ import org.briarproject.api.contact.ContactManager;
 import org.briarproject.api.db.DbException;
 import org.briarproject.api.messaging.ConversationManager;
 import org.briarproject.api.plugins.ConnectionRegistry;
-import org.briarproject.api.sync.GroupId;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -53,9 +52,9 @@ public class ContactChooserFragment extends BaseFragment {
 	volatile ConnectionRegistry connectionRegistry;
 
 	public static ContactChooserFragment newInstance() {
-		
+
 		Bundle args = new Bundle();
-		
+
 		ContactChooserFragment fragment = new ContactChooserFragment();
 		fragment.setArguments(args);
 		return fragment;
@@ -132,14 +131,12 @@ public class ContactChooserFragment extends BaseFragment {
 							c1 = c;
 						} else {
 							ContactId id = c.getId();
-							GroupId groupId =
-									conversationManager.getConversationId(id);
 							GroupCount count =
 									conversationManager.getGroupCount(id);
 							boolean connected =
 									connectionRegistry.isConnected(c.getId());
 							contacts.add(new ContactListItem(c, connected,
-									groupId, count));
+									count));
 						}
 					}
 					displayContacts(contacts);

briar-android/src/org/briarproject/android/privategroup/creation/BaseGroupInviteActivity.java

@@ -7,9 +7,7 @@ import org.briarproject.R;
 import org.briarproject.android.controller.handler.UiResultExceptionHandler;
 import org.briarproject.android.sharing.BaseMessageFragment.MessageFragmentListener;
 import org.briarproject.android.sharing.ContactSelectorActivity;
-import org.briarproject.api.contact.Contact;
 import org.briarproject.api.contact.ContactId;
-import org.briarproject.api.db.DatabaseExecutor;
 import org.briarproject.api.db.DbException;
 import org.briarproject.api.sync.GroupId;
 import org.jetbrains.annotations.NotNull;

briar-android/src/org/briarproject/android/sharing/ContactSelectorActivity.java

@@ -7,10 +7,7 @@ import android.support.annotation.UiThread;
 import org.briarproject.R;
 import org.briarproject.android.BriarActivity;
 import org.briarproject.android.fragment.BaseFragment.BaseFragmentListener;
-import org.briarproject.api.contact.Contact;
 import org.briarproject.api.contact.ContactId;
-import org.briarproject.api.db.DatabaseExecutor;
-import org.briarproject.api.db.DbException;
 import org.briarproject.api.sync.GroupId;
 
 import java.util.ArrayList;
@@ -58,10 +55,6 @@ public abstract class ContactSelectorActivity extends BriarActivity implements
 		this.contacts = contacts;
 	}
 
-	@DatabaseExecutor
-	public abstract boolean isDisabled(GroupId groupId, Contact c)
-			throws DbException;
-
 	static ArrayList<Integer> getContactsFromIds(
 			Collection<ContactId> contacts) {
 		// transform ContactIds to Integers so they can be added to a bundle

briar-android/src/org/briarproject/android/sharing/ContactSelectorListener.java

@@ -11,7 +11,7 @@ import org.briarproject.api.sync.GroupId;
 
 import java.util.Collection;
 
-public interface ContactSelectorListener extends DestroyableContext {
+interface ContactSelectorListener extends DestroyableContext {
 
 	@Deprecated
 	void runOnDbThread(Runnable runnable);

briar-android/src/org/briarproject/android/sharing/SelectableContactItem.java

@@ -8,26 +8,26 @@ import javax.annotation.concurrent.NotThreadSafe;
 
 @NotThreadSafe
 @NotNullByDefault
-public class SelectableContactItem extends ContactItem {
+class SelectableContactItem extends ContactItem {
 
 	private boolean selected, disabled;
 
-	public SelectableContactItem(Contact contact, boolean connected,
+	SelectableContactItem(Contact contact, boolean connected,
 			boolean selected, boolean disabled) {
 		super(contact, connected);
 		this.selected = selected;
 		this.disabled = disabled;
 	}
 
-	public boolean isSelected() {
+	boolean isSelected() {
 		return selected;
 	}
 
-	public void toggleSelected() {
+	void toggleSelected() {
 		selected = !selected;
 	}
 
-	public boolean isDisabled() {
+	boolean isDisabled() {
 		return disabled;
 	}
 

briar-android/src/org/briarproject/android/util/AndroidUtils.java

@@ -23,6 +23,7 @@ import android.widget.TextView;
 import org.briarproject.R;
 import org.briarproject.android.view.ArticleMovementMethod;
 import org.briarproject.android.widget.LinkDialogFragment;
+import org.briarproject.api.contact.ContactId;
 import org.briarproject.util.IoUtils;
 import org.briarproject.util.StringUtils;
 
@@ -173,4 +174,11 @@ public class AndroidUtils {
 		v.setMovementMethod(ArticleMovementMethod.getInstance());
 	}
 
+	public static String getAvatarTransitionName(ContactId c) {
+		return "avatar" + c.getInt();
+	}
+
+	public static String getBulbTransitionName(ContactId c) {
+		return "bulb" + c.getInt();
+	}
 }

briar-api/src/org/briarproject/api/messaging/ConversationManager.java

@@ -4,7 +4,6 @@ import org.briarproject.api.clients.MessageTracker.GroupCount;
 import org.briarproject.api.contact.ContactId;
 import org.briarproject.api.db.DbException;
 import org.briarproject.api.db.Transaction;
-import org.briarproject.api.sync.GroupId;
 
 public interface ConversationManager {
 
@@ -14,9 +13,6 @@ public interface ConversationManager {
 	 */
 	void registerConversationClient(ConversationClient client);
 
-	/** Get the main group ID that represents this conversation */
-	GroupId getConversationId(ContactId contactId) throws DbException;
-
 	/** Get the unified group count for all private conversation messages. */
 	GroupCount getGroupCount(ContactId contactId) throws DbException;
 

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

@@ -1,15 +1,11 @@
 package org.briarproject.messaging;
 
-import org.briarproject.api.clients.ContactGroupFactory;
 import org.briarproject.api.clients.MessageTracker.GroupCount;
-import org.briarproject.api.contact.Contact;
 import org.briarproject.api.contact.ContactId;
 import org.briarproject.api.db.DatabaseComponent;
 import org.briarproject.api.db.DbException;
 import org.briarproject.api.db.Transaction;
 import org.briarproject.api.messaging.ConversationManager;
-import org.briarproject.api.sync.Group;
-import org.briarproject.api.sync.GroupId;
 
 import java.util.Set;
 import java.util.concurrent.CopyOnWriteArraySet;
@@ -19,14 +15,11 @@ import javax.inject.Inject;
 class ConversationManagerImpl implements ConversationManager {
 
 	private final DatabaseComponent db;
-	private final ContactGroupFactory contactGroupFactory;
 	private final Set<ConversationClient> clients;
 
 	@Inject
-	ConversationManagerImpl(DatabaseComponent db,
-			ContactGroupFactory contactGroupFactory) {
+	ConversationManagerImpl(DatabaseComponent db) {
 		this.db = db;
-		this.contactGroupFactory = contactGroupFactory;
 		clients = new CopyOnWriteArraySet<ConversationClient>();
 	}
 
@@ -38,23 +31,6 @@ class ConversationManagerImpl implements ConversationManager {
 		}
 	}
 
-	@Override
-	public GroupId getConversationId(ContactId contactId) throws DbException {
-		// TODO we should probably transition this to its own group
-		//      and/or work with the ContactId in the UI instead
-		Contact contact;
-		Transaction txn = db.startTransaction(true);
-		try {
-			contact = db.getContact(txn, contactId);
-			db.commitTransaction(txn);
-		} finally {
-			db.endTransaction(txn);
-		}
-		Group group = contactGroupFactory
-				.createContactGroup(MessagingManagerImpl.CLIENT_ID, contact);
-		return group.getId();
-	}
-
 	@Override
 	public GroupCount getGroupCount(ContactId contactId)
 			throws DbException {