Add support for private messages without text

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

@@ -460,8 +460,8 @@ public class ConversationActivity extends BriarActivity
 				observeOnce(viewModel.getContactDisplayName(), this,
 						name -> addConversationItem(h.accept(visitor)));
 			} else {
+				// visitor also loads message text (if existing)
 				addConversationItem(h.accept(visitor));
-				loadMessageText(h.getId());
 			}
 		});
 	}
@@ -535,7 +535,7 @@ public class ConversationActivity extends BriarActivity
 				PrivateMessageHeader h = new PrivateMessageHeader(
 						message.getId(), message.getGroupId(),
 						message.getTimestamp(), true, false, false, false,
-						emptyList());
+						true, emptyList());
 				textCache.put(message.getId(), text);
 				addConversationItem(h.accept(visitor));
 			} catch (DbException e) {

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

@@ -34,9 +34,7 @@ abstract class ConversationItemViewHolder extends ViewHolder {
 
 	@CallSuper
 	void bind(ConversationItem item, ConversationListener listener) {
-		if (item.getText() == null) {
+		if (item.getText() != null) {
-			text.setText("\u2026");
-		} else {
 			text.setText(trim(item.getText()));
 		}
 

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

@@ -52,8 +52,10 @@ class ConversationVisitor implements
 			item = new ConversationMessageItem(
 					R.layout.list_item_conversation_msg_in, h);
 		}
-		String text = textCache.getText(h.getId());
+		if (h.hasText()) {
-		if (text != null) item.setText(text);
+			String text = textCache.getText(h.getId());
+			if (text != null) item.setText(text);
+		}
 		return item;
 	}
 

briar-api/src/main/java/org/briarproject/briar/api/messaging/PrivateMessageHeader.java

@@ -14,15 +14,21 @@ import javax.annotation.concurrent.Immutable;
 @NotNullByDefault
 public class PrivateMessageHeader extends ConversationMessageHeader {
 
+	private final boolean hasText;
 	private final List<AttachmentHeader> attachmentHeaders;
 
 	public PrivateMessageHeader(MessageId id, GroupId groupId, long timestamp,
 			boolean local, boolean read, boolean sent, boolean seen,
-			List<AttachmentHeader> attachmentHeaders) {
+			boolean hasText, List<AttachmentHeader> attachmentHeaders) {
 		super(id, groupId, timestamp, local, read, sent, seen);
+		this.hasText = hasText;
 		this.attachmentHeaders = attachmentHeaders;
 	}
 
+	public boolean hasText() {
+		return hasText;
+	}
+
 	public List<AttachmentHeader> getAttachmentHeaders() {
 		return attachmentHeaders;
 	}

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

@@ -122,7 +122,7 @@ class MessagingManagerImpl extends ConversationClientImpl
 		boolean read = meta.getBoolean(MSG_KEY_READ);
 		PrivateMessageHeader header =
 				new PrivateMessageHeader(m.getId(), groupId, timestamp, local,
-						read, false, false, emptyList());
+						read, false, false, true, emptyList());
 		ContactId contactId = getContactId(txn, groupId);
 		PrivateMessageReceivedEvent event =
 				new PrivateMessageReceivedEvent(header, contactId);
@@ -217,7 +217,7 @@ class MessagingManagerImpl extends ConversationClientImpl
 				boolean local = meta.getBoolean("local");
 				boolean read = meta.getBoolean("read");
 				headers.add(new PrivateMessageHeader(id, g, timestamp, local,
-						read, s.isSent(), s.isSeen(), emptyList()));
+						read, s.isSent(), s.isSeen(), true, emptyList()));
 			} catch (FormatException e) {
 				throw new DbException(e);
 			}

briar-headless/src/test/java/org/briarproject/briar/headless/event/WebSocketControllerTest.kt

@@ -28,7 +28,17 @@ internal class WebSocketControllerTest : ControllerTest() {
     private val controller = WebSocketControllerImpl(ImmediateExecutor())
 
     private val header =
-        PrivateMessageHeader(message.id, group.id, timestamp, true, true, true, true, emptyList())
+        PrivateMessageHeader(
+            message.id,
+            group.id,
+            timestamp,
+            true,
+            true,
+            true,
+            true,
+            true,
+            emptyList()
+        )
     private val event = PrivateMessageReceivedEvent(header, contact.id)
     private val outputEvent = OutputEvent(EVENT_CONVERSATION_MESSAGE, event.output(text))
 

briar-headless/src/test/java/org/briarproject/briar/headless/messaging/MessagingControllerImplTest.kt

@@ -50,7 +50,17 @@ internal class MessagingControllerImplTest : ControllerTest() {
     )
 
     private val header =
-        PrivateMessageHeader(message.id, group.id, timestamp, true, true, true, true, emptyList())
+        PrivateMessageHeader(
+            message.id,
+            group.id,
+            timestamp,
+            true,
+            true,
+            true,
+            true,
+            true,
+            emptyList()
+        )
     private val sessionId = SessionId(getRandomId())
     private val privateMessage = PrivateMessage(message)