Don't pass UI classes to the core, use events instead

This removed the ContactExchangeListener in favor of new events

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

@@ -1,20 +0,0 @@
-package org.briarproject.bramble.api.contact;
-
-import org.briarproject.bramble.api.identity.Author;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-@NotNullByDefault
-public interface ContactExchangeListener {
-
-	void contactExchangeSucceeded(Author remoteAuthor);
-
-	/**
-	 * The exchange failed because the contact already exists.
-	 */
-	void duplicateContact(Author remoteAuthor);
-
-	/**
-	 * A general failure.
-	 */
-	void contactExchangeFailed();
-}

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

@@ -41,8 +41,7 @@ public interface ContactExchangeTask {
 	/**
 	 * Exchanges contact information with a remote peer.
 	 */
-	void startExchange(ContactExchangeListener listener,
+	void startExchange(LocalAuthor localAuthor, SecretKey masterSecret,
-			LocalAuthor localAuthor, SecretKey masterSecret,
 			DuplexTransportConnection conn, TransportId transportId,
 			boolean alice);
 }

bramble-api/src/main/java/org/briarproject/bramble/api/contact/event/ContactExchangeFailedEvent.java

@@ -0,0 +1,32 @@
+package org.briarproject.bramble.api.contact.event;
+
+import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.identity.Author;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.Nullable;
+
+@NotNullByDefault
+public class ContactExchangeFailedEvent extends Event {
+
+	@Nullable
+	private final Author duplicateRemoteAuthor;
+
+	public ContactExchangeFailedEvent(@Nullable Author duplicateRemoteAuthor) {
+		this.duplicateRemoteAuthor = duplicateRemoteAuthor;
+	}
+
+	public ContactExchangeFailedEvent() {
+		this(null);
+	}
+
+	@Nullable
+	public Author getDuplicateRemoteAuthor() {
+		return duplicateRemoteAuthor;
+	}
+
+	public boolean wasDuplicateContact() {
+		return duplicateRemoteAuthor != null;
+	}
+
+}

bramble-api/src/main/java/org/briarproject/bramble/api/contact/event/ContactExchangeSucceededEvent.java

@@ -0,0 +1,20 @@
+package org.briarproject.bramble.api.contact.event;
+
+import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.identity.Author;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+@NotNullByDefault
+public class ContactExchangeSucceededEvent extends Event {
+
+	private final Author remoteAuthor;
+
+	public ContactExchangeSucceededEvent(Author remoteAuthor) {
+		this.remoteAuthor = remoteAuthor;
+	}
+
+	public Author getRemoteAuthor() {
+		return remoteAuthor;
+	}
+
+}

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

@@ -2,10 +2,11 @@ package org.briarproject.bramble.contact;
 
 import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.client.ClientHelper;
-import org.briarproject.bramble.api.contact.ContactExchangeListener;
 import org.briarproject.bramble.api.contact.ContactExchangeTask;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.ContactManager;
+import org.briarproject.bramble.api.contact.event.ContactExchangeFailedEvent;
+import org.briarproject.bramble.api.contact.event.ContactExchangeSucceededEvent;
 import org.briarproject.bramble.api.crypto.CryptoComponent;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.data.BdfDictionary;
@@ -13,6 +14,7 @@ import org.briarproject.bramble.api.data.BdfList;
 import org.briarproject.bramble.api.db.ContactExistsException;
 import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.identity.LocalAuthor;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
@@ -63,6 +65,7 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 	private final ClientHelper clientHelper;
 	private final RecordReaderFactory recordReaderFactory;
 	private final RecordWriterFactory recordWriterFactory;
+	private final EventBus eventBus;
 	private final Clock clock;
 	private final ConnectionManager connectionManager;
 	private final ContactManager contactManager;
@@ -71,7 +74,6 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 	private final StreamReaderFactory streamReaderFactory;
 	private final StreamWriterFactory streamWriterFactory;
 
-	private volatile ContactExchangeListener listener;
 	private volatile LocalAuthor localAuthor;
 	private volatile DuplexTransportConnection conn;
 	private volatile TransportId transportId;
@@ -81,8 +83,9 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 	@Inject
 	ContactExchangeTaskImpl(DatabaseComponent db, ClientHelper clientHelper,
 			RecordReaderFactory recordReaderFactory,
-			RecordWriterFactory recordWriterFactory, Clock clock,
+			RecordWriterFactory recordWriterFactory, EventBus eventBus,
-			ConnectionManager connectionManager, ContactManager contactManager,
+			Clock clock, ConnectionManager connectionManager,
+			ContactManager contactManager,
 			TransportPropertyManager transportPropertyManager,
 			CryptoComponent crypto, StreamReaderFactory streamReaderFactory,
 			StreamWriterFactory streamWriterFactory) {
@@ -90,6 +93,7 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 		this.clientHelper = clientHelper;
 		this.recordReaderFactory = recordReaderFactory;
 		this.recordWriterFactory = recordWriterFactory;
+		this.eventBus = eventBus;
 		this.clock = clock;
 		this.connectionManager = connectionManager;
 		this.contactManager = contactManager;
@@ -100,11 +104,9 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 	}
 
 	@Override
-	public void startExchange(ContactExchangeListener listener,
+	public void startExchange(LocalAuthor localAuthor, SecretKey masterSecret,
-			LocalAuthor localAuthor, SecretKey masterSecret,
 			DuplexTransportConnection conn, TransportId transportId,
 			boolean alice) {
-		this.listener = listener;
 		this.localAuthor = localAuthor;
 		this.conn = conn;
 		this.transportId = transportId;
@@ -123,8 +125,8 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 			out = conn.getWriter().getOutputStream();
 		} catch (IOException e) {
 			logException(LOG, WARNING, e);
-			listener.contactExchangeFailed();
 			tryToClose(conn);
+			eventBus.broadcast(new ContactExchangeFailedEvent());
 			return;
 		}
 
@@ -134,7 +136,7 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 			localProperties = transportPropertyManager.getLocalProperties();
 		} catch (DbException e) {
 			logException(LOG, WARNING, e);
-			listener.contactExchangeFailed();
+			eventBus.broadcast(new ContactExchangeFailedEvent());
 			tryToClose(conn);
 			return;
 		}
@@ -196,7 +198,7 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 			}
 		} catch (IOException e) {
 			logException(LOG, WARNING, e);
-			listener.contactExchangeFailed();
+			eventBus.broadcast(new ContactExchangeFailedEvent());
 			tryToClose(conn);
 			return;
 		}
@@ -204,7 +206,7 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 		// Verify the contact's signature
 		if (!verify(remoteInfo.author, remoteNonce, remoteInfo.signature)) {
 			LOG.warning("Invalid signature");
-			listener.contactExchangeFailed();
+			eventBus.broadcast(new ContactExchangeFailedEvent());
 			tryToClose(conn);
 			return;
 		}
@@ -221,15 +223,17 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 					conn);
 			// Pseudonym exchange succeeded
 			LOG.info("Pseudonym exchange succeeded");
-			listener.contactExchangeSucceeded(remoteInfo.author);
+			eventBus.broadcast(
+					new ContactExchangeSucceededEvent(remoteInfo.author));
 		} catch (ContactExistsException e) {
 			logException(LOG, WARNING, e);
 			tryToClose(conn);
-			listener.duplicateContact(remoteInfo.author);
+			eventBus.broadcast(
+					new ContactExchangeFailedEvent(remoteInfo.author));
 		} catch (DbException e) {
 			logException(LOG, WARNING, e);
 			tryToClose(conn);
-			listener.contactExchangeFailed();
+			eventBus.broadcast(new ContactExchangeFailedEvent());
 		}
 	}
 

briar-android/src/main/java/org/briarproject/briar/android/keyagreement/ContactExchangeActivity.java

@@ -4,9 +4,12 @@ import android.os.Bundle;
 import android.support.annotation.UiThread;
 import android.widget.Toast;
 
-import org.briarproject.bramble.api.contact.ContactExchangeListener;
 import org.briarproject.bramble.api.contact.ContactExchangeTask;
+import org.briarproject.bramble.api.contact.event.ContactExchangeFailedEvent;
+import org.briarproject.bramble.api.contact.event.ContactExchangeSucceededEvent;
 import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.identity.IdentityManager;
 import org.briarproject.bramble.api.identity.LocalAuthor;
@@ -28,7 +31,7 @@ import static org.briarproject.bramble.util.LogUtils.logException;
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
 public class ContactExchangeActivity extends KeyAgreementActivity implements
-		ContactExchangeListener {
+		EventListener {
 
 	private static final Logger LOG =
 			Logger.getLogger(ContactExchangeActivity.class.getName());
@@ -50,6 +53,20 @@ public class ContactExchangeActivity extends KeyAgreementActivity implements
 		getSupportActionBar().setTitle(R.string.add_contact_title);
 	}
 
+	@Override
+	public void onStart() {
+		super.onStart();
+		// Listen to updates from contactExchangeTask
+		eventBus.addListener(this);
+	}
+
+	@Override
+	protected void onStop() {
+		super.onStop();
+		// Stop listen to updates from contactExchangeTask
+		eventBus.addListener(this);
+	}
+
 	private void startContactExchange(KeyAgreementResult result) {
 		runOnDbThread(() -> {
 			LocalAuthor localAuthor;
@@ -63,15 +80,28 @@ public class ContactExchangeActivity extends KeyAgreementActivity implements
 			}
 
 			// Exchange contact details
-			contactExchangeTask.startExchange(ContactExchangeActivity.this,
+			contactExchangeTask.startExchange(localAuthor,
-					localAuthor, result.getMasterKey(),
+					result.getMasterKey(), result.getConnection(),
-					result.getConnection(), result.getTransportId(),
+					result.getTransportId(), result.wasAlice());
-					result.wasAlice());
 		});
 	}
 
 	@Override
-	public void contactExchangeSucceeded(Author remoteAuthor) {
+	public void eventOccurred(Event e) {
+		if (e instanceof ContactExchangeSucceededEvent) {
+			contactExchangeSucceeded(
+					((ContactExchangeSucceededEvent) e).getRemoteAuthor());
+		} else if (e instanceof ContactExchangeFailedEvent) {
+			ContactExchangeFailedEvent fe = (ContactExchangeFailedEvent) e;
+			if (fe.wasDuplicateContact()) {
+				duplicateContact(fe.getDuplicateRemoteAuthor());
+			} else {
+				contactExchangeFailed();
+			}
+		}
+	}
+
+	private void contactExchangeSucceeded(Author remoteAuthor) {
 		runOnUiThreadUnlessDestroyed(() -> {
 			String contactName = remoteAuthor.getName();
 			String format = getString(R.string.contact_added_toast);
@@ -82,8 +112,7 @@ public class ContactExchangeActivity extends KeyAgreementActivity implements
 		});
 	}
 
-	@Override
+	private void duplicateContact(Author remoteAuthor) {
-	public void duplicateContact(Author remoteAuthor) {
 		runOnUiThreadUnlessDestroyed(() -> {
 			String contactName = remoteAuthor.getName();
 			String format = getString(R.string.contact_already_exists);
@@ -94,8 +123,7 @@ public class ContactExchangeActivity extends KeyAgreementActivity implements
 		});
 	}
 
-	@Override
+	private void contactExchangeFailed() {
-	public void contactExchangeFailed() {
 		runOnUiThreadUnlessDestroyed(() -> {
 			showErrorFragment(R.string.connection_error_explanation);
 		});