action_sheet: Add "Mark as unread from here" button

assets/l10n/app_en.arb

@@ -51,6 +51,10 @@
   "@actionSheetOptionCopyMessageLink": {
     "description": "Label for copy message link button on action sheet."
   },
+  "actionSheetOptionMarkAsUnread": "Mark as unread from here",
+  "@actionSheetOptionMarkAsUnread":  {
+    "description": "Label for mark as unread button on action sheet."
+  },
   "actionSheetOptionShare": "Share",
   "@actionSheetOptionShare":  {
     "description": "Label for share button on action sheet."
@@ -436,6 +440,21 @@
   "@errorMarkAsReadFailedTitle": {
     "description": "Error title when mark as read action failed."
   },
+  "markAsUnreadComplete": "Marked {num, plural, =1{1 message} other{{num} messages}} as unread.",
+  "@markAsUnreadComplete": {
+    "description": "Message when marking messages as unread has completed.",
+    "placeholders": {
+      "num": {"type": "int", "example": "4"}
+    }
+  },
+  "markAsUnreadInProgress": "Marking messages as unread...",
+  "@markAsUnreadInProgress": {
+    "description": "Progress message when marking messages as unread."
+  },
+  "errorMarkAsUnreadFailedTitle": "Mark as unread failed",
+  "@errorMarkAsUnreadFailedTitle": {
+    "description": "Error title when mark as unread action failed."
+  },
   "today": "Today",
   "@today": {
     "description": "Term to use to reference the current day."

lib/widgets/action_sheet.dart

@@ -8,6 +8,7 @@ import '../api/model/model.dart';
 import '../api/route/messages.dart';
 import '../model/internal_link.dart';
 import '../model/narrow.dart';
+import 'actions.dart';
 import 'clipboard.dart';
 import 'compose_box.dart';
 import 'dialog.dart';
@@ -28,6 +29,10 @@ void showMessageActionSheet({required BuildContext context, required Message mes
   // any message list, so that's fine.
   final messageListPage = MessageListPage.ancestorOf(context);
   final isComposeBoxOffered = messageListPage.composeBoxController != null;
+  final narrow = messageListPage.narrow;
+  final isMessageRead = message.flags.contains(MessageFlag.read);
+  final markAsUnreadSupported = store.connection.zulipFeatureLevel! >= 155; // TODO(server-6)
+  final showMarkAsUnreadButton = markAsUnreadSupported && isMessageRead;
 
   final hasThumbsUpReactionVote = message.reactions
     ?.aggregated.any((reactionWithVotes) =>
@@ -46,6 +51,11 @@ void showMessageActionSheet({required BuildContext context, required Message mes
           message: message,
           messageListContext: context,
         ),
+        if (showMarkAsUnreadButton) MarkAsUnreadButton(
+          message: message,
+          messageListContext: context,
+          narrow: narrow,
+        ),
         CopyMessageTextButton(message: message, messageListContext: context),
         CopyMessageLinkButton(message: message, messageListContext: context),
         ShareButton(message: message, messageListContext: context),
@@ -278,6 +288,29 @@ class QuoteAndReplyButton extends MessageActionSheetMenuItemButton {
   }
 }
 
+class MarkAsUnreadButton extends MessageActionSheetMenuItemButton {
+  MarkAsUnreadButton({
+    super.key,
+    required super.message,
+    required super.messageListContext,
+    required this.narrow,
+  });
+
+  final Narrow narrow;
+
+  @override IconData get icon => Icons.mark_chat_unread_outlined;
+
+  @override
+  String label(ZulipLocalizations zulipLocalizations) {
+    return zulipLocalizations.actionSheetOptionMarkAsUnread;
+  }
+
+  @override void onPressed(BuildContext context) async {
+    Navigator.of(context).pop();
+    markNarrowAsUnreadFromMessage(messageListContext, message, narrow);
+  }
+}
+
 class CopyMessageTextButton extends MessageActionSheetMenuItemButton {
   CopyMessageTextButton({
     super.key,

lib/widgets/actions.dart

@@ -16,101 +16,174 @@ import '../model/narrow.dart';
 import 'dialog.dart';
 import 'store.dart';
 
-Future<void> markNarrowAsRead(
-  BuildContext context,
-  Narrow narrow,
-  bool useLegacy, // TODO(server-6)
-) async {
+Future<void> markNarrowAsRead(BuildContext context, Narrow narrow) async {
   final store = PerAccountStoreWidget.of(context);
   final connection = store.connection;
+  final zulipLocalizations = ZulipLocalizations.of(context);
+  final useLegacy = connection.zulipFeatureLevel! < 155; // TODO(server-6)
   if (useLegacy) {
-    return await _legacyMarkNarrowAsRead(context, narrow);
+    try {
+      await _legacyMarkNarrowAsRead(context, narrow);
+      return;
+    } catch (e) {
+      if (!context.mounted) return;
+      await showErrorDialog(context: context,
+        title: zulipLocalizations.errorMarkAsReadFailedTitle,
+        message: e.toString()); // TODO(#741): extract user-facing message better
+      return;
+    }
+  }
+
+  final didPass = await updateMessageFlagsStartingFromAnchor(
+    context: context,
+    // Include `is:unread` in the narrow.  That has a database index, so
+    // this can be an important optimization in narrows with a lot of history.
+    // The server applies the same optimization within the (deprecated)
+    // specialized endpoints for marking messages as read; see
+    // `do_mark_stream_messages_as_read` in `zulip:zerver/actions/message_flags.py`.
+    apiNarrow: narrow.apiEncode()..add(ApiNarrowIsUnread()),
+    // Use [AnchorCode.oldest], because [AnchorCode.firstUnread]
+    // will be the oldest non-muted unread message, which would
+    // result in muted unreads older than the first unread not
+    // being processed.
+    anchor: AnchorCode.oldest,
+    // [AnchorCode.oldest] is an anchor ID lower than any valid
+    // message ID.
+    includeAnchor: false,
+    op: UpdateMessageFlagsOp.add,
+    flag: MessageFlag.read,
+    onCompletedMessage: zulipLocalizations.markAsReadComplete,
+    progressMessage: zulipLocalizations.markAsReadInProgress,
+    onFailedTitle: zulipLocalizations.errorMarkAsReadFailedTitle);
+
+  if (!didPass || !context.mounted) return;
+  if (narrow is CombinedFeedNarrow) {
+    PerAccountStoreWidget.of(context).unreads.handleAllMessagesReadSuccess();
   }
+}
 
-  // Compare web's `mark_all_as_read` in web/src/unread_ops.js
-  // and zulip-mobile's `markAsUnreadFromMessage` in src/action-sheets/index.js .
+Future<void> markNarrowAsUnreadFromMessage(
+  BuildContext context,
+  Message message,
+  Narrow narrow,
+) async {
+  final connection = PerAccountStoreWidget.of(context).connection;
+  assert(connection.zulipFeatureLevel! >= 155); // TODO(server-6)
   final zulipLocalizations = ZulipLocalizations.of(context);
-  final scaffoldMessenger = ScaffoldMessenger.of(context);
-  // Use [AnchorCode.oldest], because [AnchorCode.firstUnread]
-  // will be the oldest non-muted unread message, which would
-  // result in muted unreads older than the first unread not
-  // being processed.
-  Anchor anchor = AnchorCode.oldest;
-  int responseCount = 0;
-  int updatedCount = 0;
+  await updateMessageFlagsStartingFromAnchor(
+    context: context,
+    apiNarrow: narrow.apiEncode(),
+    anchor: NumericAnchor(message.id),
+    includeAnchor: true,
+    op: UpdateMessageFlagsOp.remove,
+    flag: MessageFlag.read,
+    onCompletedMessage: zulipLocalizations.markAsUnreadComplete,
+    progressMessage: zulipLocalizations.markAsUnreadInProgress,
+    onFailedTitle: zulipLocalizations.errorMarkAsUnreadFailedTitle);
+}
 
-  // Include `is:unread` in the narrow.  That has a database index, so
-  // this can be an important optimization in narrows with a lot of history.
-  // The server applies the same optimization within the (deprecated)
-  // specialized endpoints for marking messages as read; see
-  // `do_mark_stream_messages_as_read` in `zulip:zerver/actions/message_flags.py`.
-  final apiNarrow = narrow.apiEncode()..add(ApiNarrowIsUnread());
+/// Add or remove the given flag from the anchor to the end of the narrow,
+/// showing feedback to the user on progress or failure.
+///
+/// This has the semantics of [updateMessageFlagsForNarrow]
+/// (see https://zulip.com/api/update-message-flags-for-narrow)
+/// with `numBefore: 0` and infinite `numAfter`.  It operates by calling that
+/// endpoint with a finite `numAfter` as a batch size, in a loop.
+///
+/// If the operation requires more than one batch, the user is shown progress
+/// feedback through [SnackBar], using [progressMessage] and [onCompletedMessage].
+/// If the operation fails, the user is shown an error dialog box with title
+/// [onFailedTitle].
+///
+/// Returns true just if the operation finished successfully.
+Future<bool> updateMessageFlagsStartingFromAnchor({
+  required BuildContext context,
+  required List<ApiNarrowElement> apiNarrow,
+  required Anchor anchor,
+  required bool includeAnchor,
+  required UpdateMessageFlagsOp op,
+  required MessageFlag flag,
+  required String Function(int) onCompletedMessage,
+  required String progressMessage,
+  required String onFailedTitle,
+}) async {
+  try {
+    final store = PerAccountStoreWidget.of(context);
+    final connection = store.connection;
+    final scaffoldMessenger = ScaffoldMessenger.of(context);
 
-  while (true) {
-    final result = await updateMessageFlagsForNarrow(connection,
-      anchor: anchor,
-      // [AnchorCode.oldest] is an anchor ID lower than any valid
-      // message ID; and follow-up requests will have already
-      // processed the anchor ID, so we just want this to be
-      // unconditionally false.
-      includeAnchor: false,
-      // There is an upper limit of 5000 messages per batch
-      // (numBefore + numAfter <= 5000) enforced on the server.
-      // See `update_message_flags_in_narrow` in zerver/views/message_flags.py .
-      // zulip-mobile uses `numAfter` of 5000, but web uses 1000
-      // for more responsive feedback. See zulip@f0d87fcf6.
-      numBefore: 0,
-      numAfter: 1000,
-      narrow: apiNarrow,
-      op: UpdateMessageFlagsOp.add,
-      flag: MessageFlag.read);
-    if (!context.mounted) {
-      scaffoldMessenger.clearSnackBars();
-      return;
-    }
-    responseCount++;
-    updatedCount += result.updatedCount;
+    // Compare web's `mark_all_as_read` in web/src/unread_ops.js
+    // and zulip-mobile's `markAsUnreadFromMessage` in src/action-sheets/index.js .
+    int responseCount = 0;
+    int updatedCount = 0;
+    while (true) {
+      final result = await updateMessageFlagsForNarrow(connection,
+        anchor: anchor,
+        includeAnchor: includeAnchor,
+        // There is an upper limit of 5000 messages per batch
+        // (numBefore + numAfter <= 5000) enforced on the server.
+        // See `update_message_flags_in_narrow` in zerver/views/message_flags.py .
+        // zulip-mobile uses `numAfter` of 5000, but web uses 1000
+        // for more responsive feedback. See zulip@f0d87fcf6.
+        numBefore: 0,
+        numAfter: 1000,
+        narrow: apiNarrow,
+        op: op,
+        flag: flag);
+      if (!context.mounted) {
+        scaffoldMessenger.clearSnackBars();
+        return false;
+      }
+      responseCount++;
+      updatedCount += result.updatedCount;
 
-    if (result.foundNewest) {
-      if (responseCount > 1) {
-        // We previously showed an in-progress [SnackBar], so say we're done.
-        // There may be a backlog of [SnackBar]s accumulated in the queue
-        // so be sure to clear them out here.
-        scaffoldMessenger
-          ..clearSnackBars()
-          ..showSnackBar(SnackBar(behavior: SnackBarBehavior.floating,
-              content: Text(zulipLocalizations.markAsReadComplete(updatedCount))));
+      if (result.foundNewest) {
+        if (responseCount > 1) {
+          // We previously showed an in-progress [SnackBar], so say we're done.
+          // There may be a backlog of [SnackBar]s accumulated in the queue
+          // so be sure to clear them out here.
+          scaffoldMessenger
+            ..clearSnackBars()
+            ..showSnackBar(SnackBar(behavior: SnackBarBehavior.floating,
+                content: Text(onCompletedMessage(updatedCount))));
+        }
+        return true;
       }
-      return;
-    }
 
-    if (result.lastProcessedId == null) {
-      // No messages were in the range of the request.
-      // This should be impossible given that `foundNewest` was false
-      // (and that our `numAfter` was positive.)
-      await showErrorDialog(context: context,
-        title: zulipLocalizations.errorMarkAsReadFailedTitle,
-        message: zulipLocalizations.errorInvalidResponse);
-      return;
-    }
-    anchor = NumericAnchor(result.lastProcessedId!);
+      if (result.lastProcessedId == null) {
+        final zulipLocalizations = ZulipLocalizations.of(context);
+        // No messages were in the range of the request.
+        // This should be impossible given that `foundNewest` was false
+        // (and that our `numAfter` was positive.)
+        showErrorDialog(context: context,
+          title: onFailedTitle,
+          message: zulipLocalizations.errorInvalidResponse);
+        return false;
+      }
+      anchor = NumericAnchor(result.lastProcessedId!);
+      includeAnchor = false;
 
-    // The task is taking a while, so tell the user we're working on it.
-    // No need to say how many messages, as the [MarkAsUnread] widget
-    // should follow along.
-    // TODO: Ideally we'd have a progress widget here that showed up based
-    //   on actual time elapsed -- so it could appear before the first
-    //   batch returns, if that takes a while -- and that then stuck
-    //   around continuously until the task ends. For now we use a
-    //   series of [SnackBar]s, which may feel a bit janky.
-    //   There is complexity in tracking the status of each [SnackBar],
-    //   due to having no way to determine which is currently active,
-    //   or if there is an active one at all.  Resetting the [SnackBar] here
-    //   results in the same message popping in and out and the user experience
-    //   is better for now if we allow them to run their timer through
-    //   and clear the backlog later.
-    scaffoldMessenger.showSnackBar(SnackBar(behavior: SnackBarBehavior.floating,
-      content: Text(zulipLocalizations.markAsReadInProgress)));
+      // The task is taking a while, so tell the user we're working on it.
+      // TODO: Ideally we'd have a progress widget here that showed up based
+      //   on actual time elapsed -- so it could appear before the first
+      //   batch returns, if that takes a while -- and that then stuck
+      //   around continuously until the task ends. For now we use a
+      //   series of [SnackBar]s, which may feel a bit janky.
+      //   There is complexity in tracking the status of each [SnackBar],
+      //   due to having no way to determine which is currently active,
+      //   or if there is an active one at all.  Resetting the [SnackBar] here
+      //   results in the same message popping in and out and the user experience
+      //   is better for now if we allow them to run their timer through
+      //   and clear the backlog later.
+      scaffoldMessenger.showSnackBar(SnackBar(behavior: SnackBarBehavior.floating,
+        content: Text(progressMessage)));
+    }
+  } catch (e) {
+    if (!context.mounted) return false;
+    showErrorDialog(context: context,
+      title: onFailedTitle,
+      message: e.toString()); // TODO(#741): extract user-facing message better
+    return false;
   }
 }
 

lib/widgets/message_list.dart

@@ -16,7 +16,6 @@ import 'actions.dart';
 import 'app_bar.dart';
 import 'compose_box.dart';
 import 'content.dart';
-import 'dialog.dart';
 import 'emoji_reaction.dart';
 import 'icons.dart';
 import 'page.dart';
@@ -709,28 +708,9 @@ class _MarkAsReadWidgetState extends State<MarkAsReadWidget> {
 
   void _handlePress(BuildContext context) async {
     if (!context.mounted) return;
-
-    final store = PerAccountStoreWidget.of(context);
-    final connection = store.connection;
-    final useLegacy = connection.zulipFeatureLevel! < 155;
     setState(() => _loading = true);
-
-    try {
-      await markNarrowAsRead(context, widget.narrow, useLegacy);
-    } catch (e) {
-      if (!context.mounted) return;
-      final zulipLocalizations = ZulipLocalizations.of(context);
-      showErrorDialog(context: context,
-        title: zulipLocalizations.errorMarkAsReadFailedTitle,
-        message: e.toString()); // TODO(#741): extract user-facing message better
-      return;
-    } finally {
-      setState(() => _loading = false);
-    }
-    if (!context.mounted) return;
-    if (widget.narrow is CombinedFeedNarrow && !useLegacy) {
-      PerAccountStoreWidget.of(context).unreads.handleAllMessagesReadSuccess();
-    }
+    await markNarrowAsRead(context, widget.narrow);
+    setState(() => _loading = false);
   }
 
   @override