home: Show starred-message count in main menu, subject to user setting

lib/api/model/events.dart

@@ -185,6 +185,7 @@ class UserSettingsUpdateEvent extends Event {
     switch (UserSettingName.fromRawString(json['property'] as String)) {
       case UserSettingName.twentyFourHourTime:
         return TwentyFourHourTimeMode.fromApiValue(value as bool?);
+      case UserSettingName.starredMessageCounts:
       case UserSettingName.displayEmojiReactionUsers:
         return value as bool;
       case UserSettingName.emojiset:

lib/api/model/initial_snapshot.dart

@@ -60,6 +60,8 @@ class InitialSnapshot {
 
   final UnreadMessagesSnapshot unreadMsgs;
 
+  final List<int> starredMessages;
+
   final List<ZulipStream> streams;
 
   // In register-queue, the name of this field is the singular "user_status",
@@ -178,6 +180,7 @@ class InitialSnapshot {
     required this.subscriptions,
     required this.channelFolders,
     required this.unreadMsgs,
+    required this.starredMessages,
     required this.streams,
     required this.userStatuses,
     required this.userSettings,
@@ -297,6 +300,7 @@ class UserSettings {
   )
   TwentyFourHourTimeMode twentyFourHourTime;
 
+  bool starredMessageCounts;
   bool displayEmojiReactionUsers;
   @JsonKey(unknownEnumValue: Emojiset.unknown)
   Emojiset emojiset;
@@ -310,6 +314,7 @@ class UserSettings {
 
   UserSettings({
     required this.twentyFourHourTime,
+    required this.starredMessageCounts,
     required this.displayEmojiReactionUsers,
     required this.emojiset,
     required this.presenceEnabled,

lib/api/model/model.dart

@@ -337,6 +337,7 @@ class UserStatusChange {
 @JsonEnum(fieldRename: FieldRename.snake, alwaysCreate: true)
 enum UserSettingName {
   twentyFourHourTime,
+  starredMessageCounts,
   displayEmojiReactionUsers,
   emojiset,
   presenceEnabled,

lib/api/route/settings.dart

@@ -16,6 +16,7 @@ Future<void> updateSettings(ApiConnection connection, {
         // TODO(server-future) allow localeDefault for servers that support it
         assert(mode != TwentyFourHourTimeMode.localeDefault);
         value = mode.toJson();
+      case UserSettingName.starredMessageCounts:
       case UserSettingName.displayEmojiReactionUsers:
         value = valueRaw as bool;
       case UserSettingName.emojiset:

lib/model/message.dart

@@ -24,6 +24,9 @@ mixin MessageStore on ChannelStore {
   /// All known messages, indexed by [Message.id].
   Map<int, Message> get messages;
 
+  /// All starred messages, as message IDs.
+  Set<int> get starredMessages;
+
   /// [OutboxMessage]s sent by the user, indexed by [OutboxMessage.localMessageId].
   Map<int, OutboxMessage> get outboxMessages;
 
@@ -208,6 +211,8 @@ mixin ProxyMessageStore on MessageStore {
   @override
   Map<int, Message> get messages => messageStore.messages;
   @override
+  Set<int> get starredMessages => messageStore.starredMessages;
+  @override
   Map<int, OutboxMessage> get outboxMessages => messageStore.outboxMessages;
   @override
   void registerMessageList(MessageListView view) =>
@@ -261,14 +266,19 @@ class _EditMessageRequestStatus {
 }
 
 class MessageStoreImpl extends HasChannelStore with MessageStore, _OutboxMessageStore {
-  MessageStoreImpl({required super.channels})
-    : // There are no messages in InitialSnapshot, so we don't have
-      // a use case for initializing MessageStore with nonempty [messages].
-      messages = {};
+  MessageStoreImpl({
+    required super.channels,
+    required List<int> initialStarredMessages,
+  }) :
+     messages = {},
+     starredMessages = Set.of(initialStarredMessages);
 
   @override
   final Map<int, Message> messages;
 
+  @override
+  final Set<int> starredMessages;
+
   @override
   final Set<MessageListView> _messageListViews = {};
 
@@ -410,6 +420,17 @@ class MessageStoreImpl extends HasChannelStore with MessageStore, _OutboxMessage
     assert(!_disposed);
     for (int i = 0; i < messages.length; i++) {
       final message = messages[i];
+
+      // TODO(#649) update Unreads, if [Unreads.oldUnreadsMissing]
+      // TODO(#650) update RecentDmConversationsView
+
+      // It's tempting to update [starredMessages] based on fetched messages,
+      // like Unreads and RecentDmConversationsView.
+      // But we don't need to: per the API doc, InitialSnapshot.starredMessages
+      // is the complete list of starred message IDs. So we can maintain it
+      // using just the event system, avoiding the fetch/event race
+      // as a cause of inaccuracies.
+
       messages[i] = this.messages.update(message.id,
         ifAbsent: () => _reconcileUnrecognizedMessage(message),
         (current) => _reconcileRecognizedMessage(current, message));
@@ -593,6 +614,13 @@ class MessageStoreImpl extends HasChannelStore with MessageStore, _OutboxMessage
   void handleMessageEvent(MessageEvent event) {
     final message = event.message;
 
+    if (message.flags.contains(MessageFlag.starred)) { // TODO(log)
+      // It would be surprising if a newly-sent message could be starred.
+      // (I notice that the send-message endpoint doesn't offer a way to
+      // set the starred flag.)
+      // If it turns out to be possible, we should update [starredMessages].
+    }
+
     // If the message is one we already know about (from a fetch),
     // clobber it with the one from the event system.
     // See [reconcileMessages] for reasoning.
@@ -716,18 +744,25 @@ class MessageStoreImpl extends HasChannelStore with MessageStore, _OutboxMessage
     }
   }
 
-  void handleDeleteMessageEvent(DeleteMessageEvent event) {
+  /// Handle a [DeleteMessageEvent]
+  /// and return true if the [PerAccountStore] should notify listeners.
+  bool handleDeleteMessageEvent(DeleteMessageEvent event) {
+    bool perAccountStoreShouldNotify = false;
     for (final messageId in event.messageIds) {
       messages.remove(messageId);
+      perAccountStoreShouldNotify |= starredMessages.remove(messageId);
       _maybeStaleChannelMessages.remove(messageId);
       _editMessageRequests.remove(messageId);
     }
     for (final view in _messageListViews) {
       view.handleDeleteMessageEvent(event);
     }
+    return perAccountStoreShouldNotify;
   }
 
-  void handleUpdateMessageFlagsEvent(UpdateMessageFlagsEvent event) {
+  /// Handle an [UpdateMessageFlagsEvent]
+  /// and return true if the [PerAccountStore] should notify listeners.
+  bool handleUpdateMessageFlagsEvent(UpdateMessageFlagsEvent event) {
     final isAdd = switch (event) {
       UpdateMessageFlagsAddEvent()    => true,
       UpdateMessageFlagsRemoveEvent() => false,
@@ -765,6 +800,15 @@ class MessageStoreImpl extends HasChannelStore with MessageStore, _OutboxMessage
         _notifyMessageListViews(event.messages);
       }
     }
+
+    if (event.flag == MessageFlag.starred) {
+      isAdd
+        ? starredMessages.addAll(event.messages)
+        : starredMessages.removeAll(event.messages);
+      return true;
+    }
+
+    return false;
   }
 
   void handleReactionEvent(ReactionEvent event) {

lib/model/message_list.dart

@@ -668,7 +668,10 @@ class MessageListView with ChangeNotifier, _MessageSequence {
   /// This depends in particular on whether the message is muted in
   /// one way or another.
   ///
-  /// See also [_allMessagesVisible].
+  /// See also:
+  ///   - [_allMessagesVisible], message-fetch optimization related to this
+  ///   - Message-list UI that mitigates spam/harrassment
+  ///     by obscuring messages from muted senders, with a "reveal" button
   bool _messageVisible(MessageBase message) {
     switch (narrow) {
       case CombinedFeedNarrow():
@@ -694,7 +697,23 @@ class MessageListView with ChangeNotifier, _MessageSequence {
         // If changing this, consider whether [Unreads.countInMentionsNarrow]
         // should be changed correspondingly, so the message-list view matches
         // the unread-count badge.
+        if (message.conversation case DmConversation(:final allRecipientIds)) {
+          return !store.shouldMuteDmConversation(DmNarrow(
+            allRecipientIds: allRecipientIds, selfUserId: store.selfUserId));
+        }
+        return true;
+
       case StarredMessagesNarrow():
+        // Include messages even if muted in some way.
+        // Other users can't spam this view by starring messages;
+        // the starred state is read/write by the self-user only.
+        //
+        // If we want to change this, consider that we need to compute a
+        // starred-message count without relying on fetched message data:
+        //   https://zulip.com/help/star-a-message#view-your-starred-messages
+        // ([MessageStore.starredMessages] is just a list of message IDs.)
+        return true;
+
       case KeywordSearchNarrow():
         if (message.conversation case DmConversation(:final allRecipientIds)) {
           return !store.shouldMuteDmConversation(DmNarrow(
@@ -718,7 +737,11 @@ class MessageListView with ChangeNotifier, _MessageSequence {
         return true;
 
       case MentionsNarrow():
+        return false;
+
       case StarredMessagesNarrow():
+        return true;
+
       case KeywordSearchNarrow():
         return false;
     }

lib/model/store.dart

@@ -571,7 +571,8 @@ class PerAccountStore extends PerAccountStoreBase with
       presence: Presence(realm: realm,
         initial: initialSnapshot.presences),
       channels: channels,
-      messages: MessageStoreImpl(channels: channels),
+      messages: MessageStoreImpl(channels: channels,
+        initialStarredMessages: initialSnapshot.starredMessages),
       unreads: Unreads(core: core, channelStore: channels,
         initial: initialSnapshot.unreadMsgs),
       recentDmConversationsView: RecentDmConversationsView(core: core,
@@ -783,6 +784,8 @@ class PerAccountStore extends PerAccountStoreBase with
         switch (event.property!) {
           case UserSettingName.twentyFourHourTime:
             userSettings.twentyFourHourTime        = event.value as TwentyFourHourTimeMode;
+          case UserSettingName.starredMessageCounts:
+            userSettings.starredMessageCounts      = event.value as bool;
           case UserSettingName.displayEmojiReactionUsers:
             userSettings.displayEmojiReactionUsers = event.value as bool;
           case UserSettingName.emojiset:
@@ -889,18 +892,22 @@ class PerAccountStore extends PerAccountStoreBase with
 
       case DeleteMessageEvent():
         assert(debugLog("server event: delete_message ${event.messageIds}"));
+        bool shouldNotify = false;
         // This should be called before [_messages.handleDeleteMessageEvent(event)],
         // as we need to know about each message for [event.messageIds],
         // specifically, their `senderId`s. By calling this after the
         // aforementioned line, we'll lose reference to those messages.
         recentSenders.handleDeleteMessageEvent(event, messages);
-        _messages.handleDeleteMessageEvent(event);
+        shouldNotify |= _messages.handleDeleteMessageEvent(event);
         unreads.handleDeleteMessageEvent(event);
+        if (shouldNotify) notifyListeners();
 
       case UpdateMessageFlagsEvent():
         assert(debugLog("server event: update_message_flags/${event.op} ${event.flag.toJson()}"));
-        _messages.handleUpdateMessageFlagsEvent(event);
+        bool shouldNotify = false;
+        shouldNotify |= _messages.handleUpdateMessageFlagsEvent(event);
         unreads.handleUpdateMessageFlagsEvent(event);
+        if (shouldNotify) notifyListeners();
 
       case SubmessageEvent():
         assert(debugLog("server event: submessage ${event.content}"));