profile: Display user's local time

assets/l10n/app_ar.arb

@@ -7,5 +7,12 @@
   "wildcardMentionChannelDescription": "إخطار القناة",
   "wildcardMentionStreamDescription": "إخطار الدفق",
   "wildcardMentionAllDmDescription": "إخطار المستلمين",
-  "wildcardMentionTopicDescription": "إخطار الموضوع"
+  "wildcardMentionTopicDescription": "إخطار الموضوع",
+  "userLocalTime": "{userTime} الوقت المحلي",
+  "@userLocalTime": {
+    "description": "Current time in the user's timezone",
+    "placeholders": {
+      "userTime": {"type": "DateTime", "format": "jm"}
+    }
+  }
 }

assets/l10n/app_en.arb

@@ -824,5 +824,12 @@
   "zulipAppTitle": "Zulip",
   "@zulipAppTitle": {
     "description": "The name of Zulip. This should be either 'Zulip' or a transliteration."
+  },
+  "userLocalTime": "{userTime} local time",
+  "@userLocalTime": {
+    "description": "Current time in the user's timezone",
+    "placeholders": {
+      "userTime": {"type": "DateTime", "format": "jm"}
+    }
   }
 }

assets/l10n/app_ja.arb

@@ -16,5 +16,12 @@
   "userRoleGuest": "ゲスト",
   "@userRoleGuest": {},
   "userRoleUnknown": "不明",
-  "@userRoleUnknown": {}
+  "@userRoleUnknown": {},
+  "userLocalTime": "現地時間 {userTime}",
+  "@userLocalTime": {
+    "description": "Current time in the user's timezone",
+    "placeholders": {
+      "userTime": {"type": "DateTime", "format": "jm"}
+    }
+  }
 }

assets/l10n/app_pl.arb

@@ -900,5 +900,12 @@
   "unpinnedSubscriptionsLabel": "Odpięte",
   "@unpinnedSubscriptionsLabel": {
     "description": "Label for the list of unpinned subscribed channels."
+  },
+  "userLocalTime": "{userTime} czas lokalny",
+  "@userLocalTime": {
+    "description": "Current time in the user's timezone",
+    "placeholders": {
+      "userTime": {"type": "DateTime", "format": "jm"}
+    }
   }
 }

assets/l10n/app_ru.arb

@@ -772,5 +772,12 @@
   "errorMessageNotSent": "Сообщение не отправлено",
   "@errorMessageNotSent": {
     "description": "Error message for compose box when a message could not be sent."
+  },
+  "userLocalTime": "{userTime} местное время",
+  "@userLocalTime": {
+    "description": "Current time in the user's timezone",
+    "placeholders": {
+      "userTime": {"type": "DateTime", "format": "jm"}
+    }
   }
 }

lib/generated/l10n/zulip_localizations.dart

@@ -1208,6 +1208,12 @@ abstract class ZulipLocalizations {
   /// In en, this message translates to:
   /// **'Zulip'**
   String get zulipAppTitle;
+
+  /// Current time in the user's timezone
+  ///
+  /// In en, this message translates to:
+  /// **'{userTime} local time'**
+  String userLocalTime(DateTime userTime);
 }
 
 class _ZulipLocalizationsDelegate extends LocalizationsDelegate<ZulipLocalizations> {

lib/generated/l10n/zulip_localizations_ar.dart

@@ -643,4 +643,12 @@ class ZulipLocalizationsAr extends ZulipLocalizations {
 
   @override
   String get zulipAppTitle => 'Zulip';
+
+  @override
+  String userLocalTime(DateTime userTime) {
+    final intl.DateFormat userTimeDateFormat = intl.DateFormat.jm(localeName);
+    final String userTimeString = userTimeDateFormat.format(userTime);
+
+    return '$userTimeString الوقت المحلي';
+  }
 }

lib/generated/l10n/zulip_localizations_en.dart

@@ -643,4 +643,12 @@ class ZulipLocalizationsEn extends ZulipLocalizations {
 
   @override
   String get zulipAppTitle => 'Zulip';
+
+  @override
+  String userLocalTime(DateTime userTime) {
+    final intl.DateFormat userTimeDateFormat = intl.DateFormat.jm(localeName);
+    final String userTimeString = userTimeDateFormat.format(userTime);
+
+    return '$userTimeString local time';
+  }
 }

lib/generated/l10n/zulip_localizations_ja.dart

@@ -643,4 +643,12 @@ class ZulipLocalizationsJa extends ZulipLocalizations {
 
   @override
   String get zulipAppTitle => 'Zulip';
+
+  @override
+  String userLocalTime(DateTime userTime) {
+    final intl.DateFormat userTimeDateFormat = intl.DateFormat.jm(localeName);
+    final String userTimeString = userTimeDateFormat.format(userTime);
+
+    return '現地時間 $userTimeString';
+  }
 }

lib/generated/l10n/zulip_localizations_nb.dart

@@ -643,4 +643,12 @@ class ZulipLocalizationsNb extends ZulipLocalizations {
 
   @override
   String get zulipAppTitle => 'Zulip';
+
+  @override
+  String userLocalTime(DateTime userTime) {
+    final intl.DateFormat userTimeDateFormat = intl.DateFormat.jm(localeName);
+    final String userTimeString = userTimeDateFormat.format(userTime);
+
+    return '$userTimeString local time';
+  }
 }

lib/generated/l10n/zulip_localizations_pl.dart

@@ -643,4 +643,12 @@ class ZulipLocalizationsPl extends ZulipLocalizations {
 
   @override
   String get zulipAppTitle => 'Zulip';
+
+  @override
+  String userLocalTime(DateTime userTime) {
+    final intl.DateFormat userTimeDateFormat = intl.DateFormat.jm(localeName);
+    final String userTimeString = userTimeDateFormat.format(userTime);
+
+    return '$userTimeString czas lokalny';
+  }
 }

lib/generated/l10n/zulip_localizations_ru.dart

@@ -643,4 +643,12 @@ class ZulipLocalizationsRu extends ZulipLocalizations {
 
   @override
   String get zulipAppTitle => 'Zulip';
+
+  @override
+  String userLocalTime(DateTime userTime) {
+    final intl.DateFormat userTimeDateFormat = intl.DateFormat.jm(localeName);
+    final String userTimeString = userTimeDateFormat.format(userTime);
+
+    return '$userTimeString местное время';
+  }
 }

lib/generated/l10n/zulip_localizations_sk.dart

@@ -643,4 +643,12 @@ class ZulipLocalizationsSk extends ZulipLocalizations {
 
   @override
   String get zulipAppTitle => 'Zulip';
+
+  @override
+  String userLocalTime(DateTime userTime) {
+    final intl.DateFormat userTimeDateFormat = intl.DateFormat.jm(localeName);
+    final String userTimeString = userTimeDateFormat.format(userTime);
+
+    return '$userTimeString local time';
+  }
 }

lib/model/binding.dart

@@ -118,6 +118,12 @@ abstract class ZulipBinding {
   /// Outside tests, this just calls the [Stopwatch] constructor.
   Stopwatch stopwatch();
 
+  /// Provides access to current time.
+  ///
+  /// Please refer to this issue:
+  ///   https://github.com/dart-lang/sdk/issues/28985
+  DateTime now();
+
   /// Provides device and operating system information,
   /// via package:device_info_plus.
   ///
@@ -368,6 +374,9 @@ class LiveZulipBinding extends ZulipBinding {
   @override
   Stopwatch stopwatch() => Stopwatch();
 
+  @override
+  DateTime now() => DateTime.now();
+
   @override
   Future<BaseDeviceInfo?> get deviceInfo => _deviceInfo;
   late Future<BaseDeviceInfo?> _deviceInfo;

lib/model/store.dart

@@ -20,6 +20,7 @@ import '../api/route/realm.dart';
 import '../log.dart';
 import '../notifications/receive.dart';
 import 'autocomplete.dart';
+import 'binding.dart';
 import 'database.dart';
 import 'emoji.dart';
 import 'localizations.dart';
@@ -447,7 +448,7 @@ class PerAccountStore extends ChangeNotifier with EmojiStore, ChannelStore, Mess
   ///
   /// To determine if a user is a full member, callers must also check that the
   /// user's role is at least [UserRole.member].
-  bool hasPassedWaitingPeriod(User user, {required DateTime byDate}) {
+  bool hasPassedWaitingPeriod(User user) {
     // [User.dateJoined] is in UTC. For logged-in users, the format is:
     // YYYY-MM-DDTHH:mm+00:00, which includes the timezone offset for UTC.
     // For logged-out spectators, the format is: YYYY-MM-DD, which doesn't
@@ -459,7 +460,8 @@ class PerAccountStore extends ChangeNotifier with EmojiStore, ChannelStore, Mess
     // See the related discussion:
     //   https://chat.zulip.org/#narrow/channel/412-api-documentation/topic/provide.20an.20explicit.20format.20for.20.60realm_user.2Edate_joined.60/near/1980194
     final dateJoined = DateTime.parse(user.dateJoined);
-    return byDate.difference(dateJoined).inDays >= realmWaitingPeriodThreshold;
+    final now = ZulipBinding.instance.now();
+    return now.difference(dateJoined).inDays >= realmWaitingPeriodThreshold;
   }
 
   ////////////////////////////////
@@ -483,7 +485,6 @@ class PerAccountStore extends ChangeNotifier with EmojiStore, ChannelStore, Mess
   bool hasPostingPermission({
     required ZulipStream inChannel,
     required User user,
-    required DateTime byDate,
   }) {
     final role = user.role;
     // We let the users with [unknown] role to send the message, then the server
@@ -495,7 +496,7 @@ class PerAccountStore extends ChangeNotifier with EmojiStore, ChannelStore, Mess
       case ChannelPostPolicy.fullMembers:     {
         if (!role.isAtLeast(UserRole.member)) return false;
         return role == UserRole.member
-          ? hasPassedWaitingPeriod(user, byDate: byDate)
+          ? hasPassedWaitingPeriod(user)
           : true;
       }
       case ChannelPostPolicy.moderators:      return role.isAtLeast(UserRole.moderator);

lib/widgets/compose_box.dart

@@ -1410,8 +1410,7 @@ class _ComposeBoxState extends State<ComposeBox> with PerAccountStoreAwareStateM
       case ChannelNarrow(:final streamId):
       case TopicNarrow(:final streamId):
         final channel = store.streams[streamId];
-        if (channel == null || !store.hasPostingPermission(inChannel: channel,
-            user: selfUser, byDate: DateTime.now())) {
+        if (channel == null || !store.hasPostingPermission(inChannel: channel, user: selfUser)) {
           return _ErrorBanner(label:
             ZulipLocalizations.of(context).errorBannerCannotPostInChannelLabel);
         }

lib/widgets/message_list.dart

@@ -7,6 +7,7 @@ import 'package:intl/intl.dart' hide TextDirection;
 
 import '../api/model/model.dart';
 import '../generated/l10n/zulip_localizations.dart';
+import '../model/binding.dart';
 import '../model/message_list.dart';
 import '../model/narrow.dart';
 import '../model/store.dart';
@@ -1271,19 +1272,19 @@ class DateText extends StatelessWidget {
       ),
       formatHeaderDate(
         zulipLocalizations,
-        DateTime.fromMillisecondsSinceEpoch(timestamp * 1000),
-        now: DateTime.now()));
+        DateTime.fromMillisecondsSinceEpoch(timestamp * 1000)));
   }
 }
 
 @visibleForTesting
 String formatHeaderDate(
   ZulipLocalizations zulipLocalizations,
-  DateTime dateTime, {
-  required DateTime now,
-}) {
-  assert(!dateTime.isUtc && !now.isUtc,
-    '`dateTime` and `now` need to be in local time.');
+  DateTime dateTime,
+) {
+  assert(!dateTime.isUtc,
+    '`dateTime` need to be in local time.');
+
+  final now = ZulipBinding.instance.now();
 
   if (dateTime.year == now.year &&
       dateTime.month == now.month &&

lib/widgets/profile.dart

@@ -1,10 +1,14 @@
+import 'dart:async';
 import 'dart:convert';
 
 import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+import 'package:timezone/timezone.dart' as tz;
 
 import '../api/model/initial_snapshot.dart';
 import '../api/model/model.dart';
 import '../generated/l10n/zulip_localizations.dart';
+import '../model/binding.dart';
 import '../model/content.dart';
 import '../model/narrow.dart';
 import '../model/store.dart';
@@ -90,7 +94,11 @@ class ProfilePage extends StatelessWidget {
         style: _TextStyles.primaryFieldText),
       // TODO(#197) render user status
       // TODO(#196) render active status
-      // TODO(#292) render user local time
+      DefaultTextStyle.merge(
+        textAlign: TextAlign.center,
+        style: _TextStyles.primaryFieldText,
+        child: UserLocalTimeText(user: user)
+      ),
 
       _ProfileDataTable(profileData: user.profileData),
       const SizedBox(height: 16),
@@ -307,3 +315,66 @@ class _UserWidget extends StatelessWidget {
         ])));
   }
 }
+
+/// The text of current time in [user]'s timezone.
+class UserLocalTimeText extends StatefulWidget {
+  const UserLocalTimeText({
+    super.key,
+    required this.user,
+  });
+
+  final User user;
+
+  /// Initialize the timezone database used to know time difference from a timezone string.
+  ///
+  /// Usually, database initialization is done using `initializeTimeZones`, but it takes >100ms and not asynchronous.
+  /// So, we initialize database from the assets file copied from timezone library.
+  /// This file is checked up-to-date in `test/widgets/profile_test.dart`.
+  static Future<void> initializeTimezonesUsingAssets() async {
+    final blob = Uint8List.sublistView(await rootBundle.load('assets/timezone/latest_all.tzf'));
+    tz.initializeDatabase(blob);
+  }
+
+  @override
+  State<UserLocalTimeText> createState() => _UserLocalTimeTextState();
+}
+
+class _UserLocalTimeTextState extends State<UserLocalTimeText> {
+  late final Timer _timer;
+  final StreamController<DateTime> _streamController = StreamController();
+  Stream<DateTime> get _stream => _streamController.stream;
+
+  @override
+  void initState() {
+    _streamController.add(ZulipBinding.instance.now());
+    _timer = Timer.periodic(const Duration(seconds: 1), (_) { _streamController.add(ZulipBinding.instance.now()); });
+    super.initState();
+  }
+
+  @override
+  void dispose() {
+    _timer.cancel();
+    super.dispose();
+  }
+
+  Stream<String> _getDisplayLocalTimeFor(User user, ZulipLocalizations zulipLocalizations) async* {
+    if (!tz.timeZoneDatabase.isInitialized) await UserLocalTimeText.initializeTimezonesUsingAssets();
+
+    await for (final DateTime time in _stream) {
+      final location = tz.getLocation(user.timezone);
+      final localTime = tz.TZDateTime.from(time, location);
+      yield zulipLocalizations.userLocalTime(localTime);
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return StreamBuilder(
+      stream: _getDisplayLocalTimeFor(widget.user, ZulipLocalizations.of(context)),
+      builder: (context, snapshot) {
+        if (snapshot.hasError) Error.throwWithStackTrace(snapshot.error!, snapshot.stackTrace!);
+        return Text(snapshot.data ?? '');
+      }
+    );
+  }
+}

pubspec.lock

@@ -1104,6 +1104,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "0.6.8"
+  timezone:
+    dependency: "direct main"
+    description:
+      name: timezone
+      sha256: ffc9d5f4d1193534ef051f9254063fa53d588609418c84299956c3db9383587d
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.10.0"
   timing:
     dependency: transitive
     description: