Load private group text lazily too, what the heck.

briar-android/src/main/java/org/briarproject/briar/android/forum/ForumPostItem.java

@@ -9,7 +9,7 @@ import javax.annotation.concurrent.NotThreadSafe;
 public class ForumPostItem extends ThreadItem {
 
 	ForumPostItem(ForumPostHeader h) {
-		super(h.getId(), h.getParentId(), null, h.getTimestamp(), h.getAuthor(),
+		super(h.getId(), h.getParentId(), h.getTimestamp(), h.getAuthor(),
 				h.getAuthorInfo(), h.isRead());
 	}
 

briar-android/src/main/java/org/briarproject/briar/android/privategroup/conversation/GroupMessageItem.java

@@ -1,14 +1,10 @@
 package org.briarproject.briar.android.privategroup.conversation;
 
-import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.sync.GroupId;
-import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.threaded.ThreadItem;
-import org.briarproject.briar.api.identity.AuthorInfo;
 import org.briarproject.briar.api.privategroup.GroupMessageHeader;
 
-import javax.annotation.Nullable;
 import javax.annotation.concurrent.NotThreadSafe;
 
 import androidx.annotation.LayoutRes;
@@ -20,16 +16,10 @@ public class GroupMessageItem extends ThreadItem {
 
 	private final GroupId groupId;
 
-	private GroupMessageItem(MessageId messageId, GroupId groupId,
+	GroupMessageItem(GroupMessageHeader h) {
-			@Nullable MessageId parentId, String text, long timestamp,
+		super(h.getId(), h.getParentId(), h.getTimestamp(), h.getAuthor(),
-			Author author, AuthorInfo authorInfo, boolean isRead) {
+				h.getAuthorInfo(), h.isRead());
-		super(messageId, parentId, text, timestamp, author, authorInfo, isRead);
+		this.groupId = h.getGroupId();
-		this.groupId = groupId;
-	}
-
-	GroupMessageItem(GroupMessageHeader h, String text) {
-		this(h.getId(), h.getGroupId(), h.getParentId(), text, h.getTimestamp(),
-				h.getAuthor(), h.getAuthorInfo(), h.isRead());
 	}
 
 	public GroupId getGroupId() {

briar-android/src/main/java/org/briarproject/briar/android/privategroup/conversation/GroupViewModel.java

@@ -99,7 +99,7 @@ class GroupViewModel extends ThreadListViewModel<GroupMessageItem> {
 			// only act on non-local messages in this group
 			if (!g.isLocal() && g.getGroupId().equals(groupId)) {
 				LOG.info("Group message received, adding...");
-				GroupMessageItem item = buildItem(g.getHeader(), g.getText());
+				GroupMessageItem item = buildItem(g.getHeader());
 				addItem(item, false);
 				// In case the join message comes from the creator,
 				// we need to reload the sharing contacts
@@ -167,33 +167,19 @@ class GroupViewModel extends ThreadListViewModel<GroupMessageItem> {
 			List<GroupMessageHeader> headers =
 					privateGroupManager.getHeaders(txn, groupId);
 			logDuration(LOG, "Loading headers", start);
-			start = now();
 			List<GroupMessageItem> items = new ArrayList<>();
 			for (GroupMessageHeader header : headers) {
-				items.add(loadItem(txn, header));
+				items.add(buildItem(header));
 			}
-			logDuration(LOG, "Loading bodies and creating items", start);
 			return items;
 		}, this::setItems);
 	}
 
-	private GroupMessageItem loadItem(Transaction txn,
+	private GroupMessageItem buildItem(GroupMessageHeader header) {
-			GroupMessageHeader header) throws DbException {
-		String text;
 		if (header instanceof JoinMessageHeader) {
-			// will be looked up later
+			return new JoinMessageItem((JoinMessageHeader) header);
-			text = "";
-		} else {
-			text = privateGroupManager.getMessageText(txn, header.getId());
 		}
-		return buildItem(header, text);
+		return new GroupMessageItem(header);
-	}
-
-	private GroupMessageItem buildItem(GroupMessageHeader header, String text) {
-		if (header instanceof JoinMessageHeader) {
-			return new JoinMessageItem((JoinMessageHeader) header, text);
-		}
-		return new GroupMessageItem(header, text);
 	}
 
 	@Override
@@ -221,19 +207,17 @@ class GroupViewModel extends ThreadListViewModel<GroupMessageItem> {
 			LOG.info("Creating group message...");
 			GroupMessage msg = groupMessageFactory.createGroupMessage(groupId,
 					timestamp, parentId, author, text, previousMsgId);
-			storePost(msg, text);
+			storePost(msg);
 		});
 	}
 
-	private void storePost(GroupMessage msg, String text) {
+	private void storePost(GroupMessage msg) {
 		runOnDbThread(false, txn -> {
 			long start = now();
 			GroupMessageHeader header =
 					privateGroupManager.addLocalMessage(txn, msg);
 			logDuration(LOG, "Storing group message", start);
-			txn.attach(() ->
+			txn.attach(() -> addItem(buildItem(header), true));
-					addItem(buildItem(header, text), true)
-			);
 		}, this::handleException);
 	}
 

briar-android/src/main/java/org/briarproject/briar/android/privategroup/conversation/JoinMessageItem.java

@@ -14,8 +14,8 @@ class JoinMessageItem extends GroupMessageItem {
 
 	private final boolean isInitial;
 
-	JoinMessageItem(JoinMessageHeader h, String text) {
+	JoinMessageItem(JoinMessageHeader h) {
-		super(h, text);
+		super(h);
 		isInitial = h.isInitial();
 	}
 

briar-android/src/main/java/org/briarproject/briar/android/privategroup/conversation/JoinMessageItemViewHolder.java

@@ -26,10 +26,8 @@ class JoinMessageItemViewHolder
 	}
 
 	@Override
-	public void bind(GroupMessageItem item, LifecycleOwner lifecycleOwner,
+	protected void setText(GroupMessageItem item, LifecycleOwner lifecycleOwner,
 			ThreadItemListener<GroupMessageItem> listener) {
-		super.bind(item, lifecycleOwner, listener);
-
 		if (isCreator) bindForCreator((JoinMessageItem) item);
 		else bind((JoinMessageItem) item);
 	}

briar-android/src/main/java/org/briarproject/briar/android/threaded/BaseThreadItemViewHolder.java

@@ -53,19 +53,7 @@ public abstract class BaseThreadItemViewHolder<I extends ThreadItem>
 	public void bind(I item, LifecycleOwner lifecycleOwner,
 			ThreadItemListener<I> listener) {
 		boundMessageId = item.getId();
-		String text = item.getText();
+		setText(item, lifecycleOwner, listener);
-		if (text == null) {
-			textView.setText(null);
-			LiveData<String> textLiveData = listener.loadItemText(item.getId());
-			textLiveData.observe(lifecycleOwner, t -> {
-				// Check that the ViewHolder hasn't been re-bound while loading
-				if (item.getId().equals(boundMessageId)) {
-					textView.setText(t);
-				}
-			});
-		} else {
-			textView.setText(trim(text));
-		}
 		Linkify.addLinks(textView, Linkify.WEB_URLS);
 		makeLinksClickable(textView, listener::onLinkClick);
 
@@ -82,6 +70,18 @@ public abstract class BaseThreadItemViewHolder<I extends ThreadItem>
 		}
 	}
 
+	protected void setText(I item, LifecycleOwner lifecycleOwner,
+			ThreadItemListener<I> listener) {
+		textView.setText(null);
+		LiveData<String> textLiveData = listener.loadItemText(item.getId());
+		textLiveData.observe(lifecycleOwner, t -> {
+			// Check that the ViewHolder hasn't been re-bound while loading
+			if (item.getId().equals(boundMessageId)) {
+				textView.setText(trim(t));
+			}
+		});
+	}
+
 	private void animateFadeOut() {
 		setIsRecyclable(false);
 		ValueAnimator anim = new ValueAnimator();
@@ -94,6 +94,7 @@ public abstract class BaseThreadItemViewHolder<I extends ThreadItem>
 			@Override
 			public void onAnimationStart(Animator animation) {
 			}
+
 			@Override
 			public void onAnimationEnd(Animator animation) {
 				layout.setBackgroundResource(
@@ -101,9 +102,11 @@ public abstract class BaseThreadItemViewHolder<I extends ThreadItem>
 				layout.setActivated(false);
 				setIsRecyclable(true);
 			}
+
 			@Override
 			public void onAnimationCancel(Animator animation) {
 			}
+
 			@Override
 			public void onAnimationRepeat(Animator animation) {
 			}

briar-android/src/main/java/org/briarproject/briar/android/threaded/ThreadItem.java

@@ -19,8 +19,6 @@ public abstract class ThreadItem implements MessageNode {
 	private final MessageId messageId;
 	@Nullable
 	private final MessageId parentId;
-	@Nullable
-	private final String text;
 	private final long timestamp;
 	private final Author author;
 	private final AuthorInfo authorInfo;
@@ -28,11 +26,10 @@ public abstract class ThreadItem implements MessageNode {
 	private boolean isRead, highlighted;
 
 	public ThreadItem(MessageId messageId, @Nullable MessageId parentId,
-			@Nullable String text, long timestamp, Author author,
+			long timestamp, Author author, AuthorInfo authorInfo,
-			AuthorInfo authorInfo, boolean isRead) {
+			boolean isRead) {
 		this.messageId = messageId;
 		this.parentId = parentId;
-		this.text = text;
 		this.timestamp = timestamp;
 		this.author = author;
 		this.authorInfo = authorInfo;
@@ -40,11 +37,6 @@ public abstract class ThreadItem implements MessageNode {
 		this.highlighted = false;
 	}
 
-	@Nullable
-	public String getText() {
-		return text;
-	}
-
 	public int getLevel() {
 		return level;
 	}

briar-android/src/main/java/org/briarproject/briar/android/threaded/ThreadListActivity.java

@@ -85,6 +85,9 @@ public abstract class ThreadListActivity<I extends ThreadItem, A extends ThreadI
 		scrollListener = new ThreadScrollListener<>(adapter, viewModel,
 				upButton, downButton);
 		list.getRecyclerView().addOnScrollListener(scrollListener);
+		// This is a tradeoff between memory consumption for cached views
+		// and the cost of loading message text from the database
+		list.getRecyclerView().setItemViewCacheSize(20);
 
 		upButton.setOnClickListener(v -> {
 			int position = adapter.getVisibleUnreadPosTop(layoutManager);

briar-api/src/main/java/org/briarproject/briar/api/privategroup/event/GroupMessageAddedEvent.java

@@ -17,14 +17,12 @@ public class GroupMessageAddedEvent extends Event {
 
 	private final GroupId groupId;
 	private final GroupMessageHeader header;
-	private final String text;
 	private final boolean local;
 
 	public GroupMessageAddedEvent(GroupId groupId, GroupMessageHeader header,
-			String text, boolean local) {
+			boolean local) {
 		this.groupId = groupId;
 		this.header = header;
-		this.text = text;
 		this.local = local;
 	}
 
@@ -36,10 +34,6 @@ public class GroupMessageAddedEvent extends Event {
 		return header;
 	}
 
-	public String getText() {
-		return text;
-	}
-
 	public boolean isLocal() {
 		return local;
 	}

briar-core/src/main/java/org/briarproject/briar/privategroup/PrivateGroupManagerImpl.java

@@ -170,6 +170,7 @@ class PrivateGroupManagerImpl extends BdfIncomingMessageHook
 				txn -> getPreviousMsgId(txn, g));
 	}
 
+	@Override
 	public MessageId getPreviousMsgId(Transaction txn, GroupId g)
 			throws DbException {
 		try {
@@ -605,9 +606,7 @@ class PrivateGroupManagerImpl extends BdfIncomingMessageHook
 			throws DbException, FormatException {
 		GroupMessageHeader header = getGroupMessageHeader(txn, m.getGroupId(),
 				m.getId(), meta, Collections.emptyMap());
-		String text = getMessageText(clientHelper.toList(m));
+		txn.attach(new GroupMessageAddedEvent(m.getGroupId(), header, local));
-		txn.attach(new GroupMessageAddedEvent(m.getGroupId(), header, text,
-				local));
 	}
 
 	private void attachJoinMessageAddedEvent(Transaction txn, Message m,
@@ -615,8 +614,7 @@ class PrivateGroupManagerImpl extends BdfIncomingMessageHook
 			throws DbException, FormatException {
 		JoinMessageHeader header = getJoinMessageHeader(txn, m.getGroupId(),
 				m.getId(), meta, Collections.emptyMap());
-		txn.attach(new GroupMessageAddedEvent(m.getGroupId(), header, "",
+		txn.attach(new GroupMessageAddedEvent(m.getGroupId(), header, local));
-				local));
 	}
 
 	private void addMember(Transaction txn, GroupId g, Author a, Visibility v)