action_sheet: Add "Mark topic as read" button

fixes: zulip#1225

Author: lakshya1goel

assets/l10n/app_en.arb

@@ -120,6 +120,10 @@
   "@actionSheetOptionUnstarMessage":  {
     "description": "Label for unstar button on action sheet."
   },
+  "actionSheetOptionMarkTopicAsRead": "Mark topic as read",
+  "@actionSheetOptionMarkTopicAsRead": {
+    "description": "Option to mark a specific topic as read in the action sheet."
+  },
   "errorWebAuthOperationalErrorTitle": "Something went wrong",
   "@errorWebAuthOperationalErrorTitle": {
     "description": "Error title when third-party authentication has an operational error (not necessarily caused by invalid credentials)."

lib/generated/l10n/zulip_localizations.dart

@@ -285,6 +285,12 @@ abstract class ZulipLocalizations {
   /// **'Unstar message'**
   String get actionSheetOptionUnstarMessage;
 
+  /// Option to mark a specific topic as read in the action sheet.
+  ///
+  /// In en, this message translates to:
+  /// **'Mark topic as read'**
+  String get actionSheetOptionMarkTopicAsRead;
+
   /// Error title when third-party authentication has an operational error (not necessarily caused by invalid credentials).
   ///
   /// In en, this message translates to:

lib/generated/l10n/zulip_localizations_ar.dart

@@ -100,6 +100,9 @@ class ZulipLocalizationsAr extends ZulipLocalizations {
   @override
   String get actionSheetOptionUnstarMessage => 'Unstar message';
 
+  @override
+  String get actionSheetOptionMarkTopicAsRead => 'Mark topic as read';
+
   @override
   String get errorWebAuthOperationalErrorTitle => 'Something went wrong';
 

lib/generated/l10n/zulip_localizations_en.dart

@@ -100,6 +100,9 @@ class ZulipLocalizationsEn extends ZulipLocalizations {
   @override
   String get actionSheetOptionUnstarMessage => 'Unstar message';
 
+  @override
+  String get actionSheetOptionMarkTopicAsRead => 'Mark topic as read';
+
   @override
   String get errorWebAuthOperationalErrorTitle => 'Something went wrong';
 

lib/generated/l10n/zulip_localizations_ja.dart

@@ -100,6 +100,9 @@ class ZulipLocalizationsJa extends ZulipLocalizations {
   @override
   String get actionSheetOptionUnstarMessage => 'Unstar message';
 
+  @override
+  String get actionSheetOptionMarkTopicAsRead => 'Mark topic as read';
+
   @override
   String get errorWebAuthOperationalErrorTitle => 'Something went wrong';
 

lib/generated/l10n/zulip_localizations_nb.dart

@@ -100,6 +100,9 @@ class ZulipLocalizationsNb extends ZulipLocalizations {
   @override
   String get actionSheetOptionUnstarMessage => 'Unstar message';
 
+  @override
+  String get actionSheetOptionMarkTopicAsRead => 'Mark topic as read';
+
   @override
   String get errorWebAuthOperationalErrorTitle => 'Something went wrong';
 

lib/generated/l10n/zulip_localizations_pl.dart

@@ -100,6 +100,9 @@ class ZulipLocalizationsPl extends ZulipLocalizations {
   @override
   String get actionSheetOptionUnstarMessage => 'Odbierz gwiazdkę';
 
+  @override
+  String get actionSheetOptionMarkTopicAsRead => 'Mark topic as read';
+
   @override
   String get errorWebAuthOperationalErrorTitle => 'Coś poszło nie tak';
 

lib/generated/l10n/zulip_localizations_ru.dart

@@ -100,6 +100,9 @@ class ZulipLocalizationsRu extends ZulipLocalizations {
   @override
   String get actionSheetOptionUnstarMessage => 'Снять отметку с сообщения';
 
+  @override
+  String get actionSheetOptionMarkTopicAsRead => 'Mark topic as read';
+
   @override
   String get errorWebAuthOperationalErrorTitle => 'Что-то пошло не так';
 

lib/generated/l10n/zulip_localizations_sk.dart

@@ -100,6 +100,9 @@ class ZulipLocalizationsSk extends ZulipLocalizations {
   @override
   String get actionSheetOptionUnstarMessage => 'Odhviezdičkovať správu';
 
+  @override
+  String get actionSheetOptionMarkTopicAsRead => 'Mark topic as read';
+
   @override
   String get errorWebAuthOperationalErrorTitle => 'Niečo sa pokazilo';
 

lib/widgets/action_sheet.dart

@@ -240,6 +240,14 @@ void showTopicActionSheet(BuildContext context, {
       pageContext: context);
   }));
 
+  final unreadCount = store.unreads.countInTopicNarrow(channelId, topic);
+  if (unreadCount > 0) {
+    optionButtons.add(MarkTopicAsReadButton(
+      channelId: channelId,
+      topic: topic,
+      pageContext: context));
+  }
+
   if (optionButtons.isEmpty) {
     // TODO(a11y): This case makes a no-op gesture handler; as a consequence,
     //   we're presenting some UI (to people who use screen-reader software) as
@@ -372,6 +380,30 @@ class UserTopicUpdateButton extends ActionSheetMenuItemButton {
   }
 }
 
+class MarkTopicAsReadButton extends ActionSheetMenuItemButton {
+  const MarkTopicAsReadButton({
+    super.key,
+    required this.channelId,
+    required this.topic,
+    required super.pageContext,
+  });
+
+  final int channelId;
+  final TopicName topic;
+
+  @override IconData get icon => ZulipIcons.message_checked;
+
+  @override
+  String label(ZulipLocalizations zulipLocalizations) {
+    return zulipLocalizations.actionSheetOptionMarkTopicAsRead;
+  }
+
+  @override void onPressed() async {
+    if (!pageContext.mounted) return;
+    await markNarrowAsRead(pageContext, TopicNarrow(channelId, topic));
+  }
+}
+
 /// Show a sheet of actions you can take on a message in the message list.
 ///
 /// Must have a [MessageListPage] ancestor.

test/widgets/action_sheet_test.dart

@@ -450,6 +450,44 @@ void main() {
         }
       });
     });
+
+    group('MarkTopicAsReadButton', () {
+      testWidgets('visible if topic has unread messages', (tester) async {
+        await prepare();
+        final message = eg.streamMessage(stream: someChannel, topic: someTopic);
+        await store.handleEvent(MessageEvent(id: 0, message: message));
+        await showFromAppBar(tester, messages: [message]);
+        check(find.text('Mark topic as read')).findsOne();
+      });
+
+      testWidgets('not visible if topic has no unread messages', (tester) async {
+        await prepare();
+        final message = eg.streamMessage(stream: someChannel, topic: someTopic);
+        await showFromAppBar(tester, messages: [message]);
+        check(find.text('Mark topic as read')).findsNothing();
+      });
+
+      testWidgets('marks topic as read when pressed', (tester) async {
+        await prepare();
+        final message = eg.streamMessage(stream: someChannel, topic: someTopic);
+        await store.handleEvent(MessageEvent(id: 0, message: message));
+        await showFromAppBar(tester, messages: [message]);
+
+        connection.prepare(json: UpdateMessageFlagsForNarrowResult(
+          processedCount: 1, updatedCount: 1,
+          firstProcessedId: message.id, lastProcessedId: message.id,
+          foundOldest: true, foundNewest: true).toJson());
+        await tester.tap(find.text('Mark topic as read'));
+        await tester.pumpAndSettle();
+
+        check(connection.lastRequest).isA<http.Request>()
+          ..url.path.equals('/api/v1/messages/flags/narrow')
+          ..bodyFields['narrow'].equals(jsonEncode([
+            ...TopicNarrow(someChannel.streamId, TopicName(someTopic)).apiEncode(),
+            {'operator': 'is', 'operand': 'unread'}
+          ]));
+      });
+    });
   });
 
   group('message action sheet', () {