Offer "Invisible mode" toggle switch!

assets/l10n/app_en.arb

@@ -773,6 +773,18 @@
   "@yesterday": {
     "description": "Term to use to reference the previous day."
   },
+  "invisibleMode": "Invisible mode",
+  "@invisibleMode": {
+    "description": "Label for the 'Invisible mode' switch on the profile page."
+  },
+  "turnOnInvisibleModeErrorTitle": "Error turning on invisible mode. Please try again.",
+  "@turnOnInvisibleModeErrorTitle": {
+    "description": "Error title when turning on invisible mode failed."
+  },
+  "turnOffInvisibleModeErrorTitle": "Error turning off invisible mode. Please try again.",
+  "@turnOffInvisibleModeErrorTitle": {
+    "description": "Error title when turning off invisible mode failed."
+  },
   "userRoleOwner": "Owner",
   "@userRoleOwner": {
     "description": "Label for UserRole.owner"

lib/api/model/events.dart

@@ -178,6 +178,8 @@ class UserSettingsUpdateEvent extends Event {
         return value as bool;
       case UserSettingName.emojiset:
         return Emojiset.fromRawString(value as String);
+      case UserSettingName.presenceEnabled:
+        return value as bool;
       case null:
         return null;
     }

lib/api/model/initial_snapshot.dart

@@ -68,13 +68,7 @@ class InitialSnapshot {
 
   final List<ZulipStream> streams;
 
-  // Servers pre-5.0 don't have `user_settings`, and instead provide whatever
-  // user settings they support at toplevel in the initial snapshot. Since we're
-  // likely to desupport pre-5.0 servers before wide release, we prefer to
-  // ignore the toplevel fields and use `user_settings` where present instead,
-  // even at the expense of functionality with pre-5.0 servers.
-  // TODO(server-5) remove pre-5.0 comment
-  final UserSettings? userSettings; // TODO(server-5)
+  final UserSettings userSettings;
 
   final List<UserTopicItem>? userTopics; // TODO(server-6)
 
@@ -257,16 +251,19 @@ class UserSettings {
   bool twentyFourHourTime;
   bool? displayEmojiReactionUsers; // TODO(server-6)
   Emojiset emojiset;
+  bool presenceEnabled;
 
   // TODO more, as needed. When adding a setting here, please also:
   // (1) add it to the [UserSettingName] enum
   // (2) then re-run the command to refresh the .g.dart files
   // (3) handle the event that signals an update to the setting
+  // (4) add the setting to the [updateSettings] route binding
 
   UserSettings({
     required this.twentyFourHourTime,
     required this.displayEmojiReactionUsers,
     required this.emojiset,
+    required this.presenceEnabled,
   });
 
   factory UserSettings.fromJson(Map<String, dynamic> json) =>

lib/api/model/model.dart

@@ -167,7 +167,9 @@ class RealmEmojiItem {
 enum UserSettingName {
   twentyFourHourTime,
   displayEmojiReactionUsers,
-  emojiset;
+  emojiset,
+  presenceEnabled,
+  ;
 
   /// Get a [UserSettingName] from a raw, snake-case string we recognize, else null.
   ///
@@ -178,6 +180,8 @@ enum UserSettingName {
   // _$…EnumMap is thanks to `alwaysCreate: true` and `fieldRename: FieldRename.snake`
   static final _byRawString = _$UserSettingNameEnumMap
     .map((key, value) => MapEntry(value, key));
+
+  String toJson() => _$UserSettingNameEnumMap[this]!;
 }
 
 /// As in [UserSettings.emojiset].
@@ -197,6 +201,8 @@ enum Emojiset {
   // _$…EnumMap is thanks to `alwaysCreate: true` and `fieldRename: FieldRename.kebab`
   static final _byRawString = _$EmojisetEnumMap
     .map((key, value) => MapEntry(value, key));
+
+  String toJson() => _$EmojisetEnumMap[this]!;
 }
 
 /// As in [InitialSnapshot.realmUserGroups] or [UserGroupAddEvent].

lib/api/route/settings.dart

@@ -0,0 +1,22 @@
+import '../core.dart';
+import '../model/model.dart';
+
+/// https://zulip.com/api/update-settings
+Future<void> updateSettings(ApiConnection connection, {
+  required Map<UserSettingName, Object?> newSettings,
+}) {
+  final params = <String, Object?>{};
+  for (final entry in newSettings.entries) {
+    final name = entry.key;
+    final valueRaw = entry.value;
+    final value = switch (name) {
+      UserSettingName.twentyFourHourTime => valueRaw as bool,
+      UserSettingName.displayEmojiReactionUsers => valueRaw as bool,
+      UserSettingName.emojiset => RawParameter((valueRaw as Emojiset).toJson()),
+      UserSettingName.presenceEnabled => valueRaw as bool,
+    };
+    params[name.toJson()] = value;
+  }
+
+  return connection.patch('updateSettings', (_) {}, 'settings', params);
+}

lib/basic.dart

@@ -0,0 +1,68 @@
+
+/// Either a value, or the absence of a value.
+///
+/// An `Option<T>` is either an `OptionSome` representing a `T` value,
+/// or an `OptionNone` representing the absence of a value.
+///
+/// When `T` is non-nullable, this is the same information that is
+/// normally represented as a `T?`.
+/// This class is useful when T is nullable (or might be nullable).
+/// In that case `null` is already a T value,
+/// and so can't also be used to represent the absence of a T value,
+/// but `OptionNone()` is a different value from `OptionSome(null)`.
+///
+/// This interface is small because members are added lazily when needed.
+/// If adding another member, consider borrowing the naming from Rust:
+///   https://doc.rust-lang.org/std/option/enum.Option.html
+sealed class Option<T> {
+  const Option();
+
+  /// The value contained in this option, if any; else the given value.
+  T or(T optb);
+
+  /// The value contained in this option, if any;
+  /// else the value returned by [fn].
+  ///
+  /// [fn] is called only if its return value is needed.
+  T orElse(T Function() fn);
+}
+
+class OptionNone<T> extends Option<T> {
+  const OptionNone();
+
+  @override
+  T or(T optb) => optb;
+
+  @override
+  T orElse(T Function() fn) => fn();
+
+  @override
+  bool operator ==(Object other) => other is OptionNone;
+
+  @override
+  int get hashCode => 'OptionNone'.hashCode;
+
+  @override
+  String toString() => 'OptionNone';
+}
+
+class OptionSome<T> extends Option<T> {
+  const OptionSome(this.value);
+
+  final T value;
+
+  @override
+  T or(T optb) => value;
+
+  @override
+  T orElse(T Function() fn) => value;
+
+  @override
+  bool operator ==(Object other) => other is OptionSome && value == other.value;
+
+  @override
+  int get hashCode => Object.hash('OptionSome', value);
+
+  @override
+  String toString() => 'OptionSome($value)';
+}

lib/generated/l10n/zulip_localizations.dart

@@ -1173,6 +1173,24 @@ abstract class ZulipLocalizations {
   /// **'Yesterday'**
   String get yesterday;
 
+  /// Label for the 'Invisible mode' switch on the profile page.
+  ///
+  /// In en, this message translates to:
+  /// **'Invisible mode'**
+  String get invisibleMode;
+
+  /// Error title when turning on invisible mode failed.
+  ///
+  /// In en, this message translates to:
+  /// **'Error turning on invisible mode. Please try again.'**
+  String get turnOnInvisibleModeErrorTitle;
+
+  /// Error title when turning off invisible mode failed.
+  ///
+  /// In en, this message translates to:
+  /// **'Error turning off invisible mode. Please try again.'**
+  String get turnOffInvisibleModeErrorTitle;
+
   /// Label for UserRole.owner
   ///
   /// In en, this message translates to:

lib/generated/l10n/zulip_localizations_ar.dart

@@ -635,6 +635,17 @@ class ZulipLocalizationsAr extends ZulipLocalizations {
   @override
   String get yesterday => 'Yesterday';
 
+  @override
+  String get invisibleMode => 'Invisible mode';
+
+  @override
+  String get turnOnInvisibleModeErrorTitle =>
+      'Error turning on invisible mode. Please try again.';
+
+  @override
+  String get turnOffInvisibleModeErrorTitle =>
+      'Error turning off invisible mode. Please try again.';
+
   @override
   String get userRoleOwner => 'Owner';
 

lib/generated/l10n/zulip_localizations_de.dart

@@ -656,6 +656,17 @@ class ZulipLocalizationsDe extends ZulipLocalizations {
   @override
   String get yesterday => 'Gestern';
 
+  @override
+  String get invisibleMode => 'Invisible mode';
+
+  @override
+  String get turnOnInvisibleModeErrorTitle =>
+      'Error turning on invisible mode. Please try again.';
+
+  @override
+  String get turnOffInvisibleModeErrorTitle =>
+      'Error turning off invisible mode. Please try again.';
+
   @override
   String get userRoleOwner => 'Besitzer';
 

lib/generated/l10n/zulip_localizations_en.dart

@@ -635,6 +635,17 @@ class ZulipLocalizationsEn extends ZulipLocalizations {
   @override
   String get yesterday => 'Yesterday';
 
+  @override
+  String get invisibleMode => 'Invisible mode';
+
+  @override
+  String get turnOnInvisibleModeErrorTitle =>
+      'Error turning on invisible mode. Please try again.';
+
+  @override
+  String get turnOffInvisibleModeErrorTitle =>
+      'Error turning off invisible mode. Please try again.';
+
   @override
   String get userRoleOwner => 'Owner';
 

lib/generated/l10n/zulip_localizations_it.dart

@@ -650,6 +650,17 @@ class ZulipLocalizationsIt extends ZulipLocalizations {
   @override
   String get yesterday => 'Ieri';
 
+  @override
+  String get invisibleMode => 'Invisible mode';
+
+  @override
+  String get turnOnInvisibleModeErrorTitle =>
+      'Error turning on invisible mode. Please try again.';
+
+  @override
+  String get turnOffInvisibleModeErrorTitle =>
+      'Error turning off invisible mode. Please try again.';
+
   @override
   String get userRoleOwner => 'Proprietario';
 

lib/generated/l10n/zulip_localizations_ja.dart

@@ -635,6 +635,17 @@ class ZulipLocalizationsJa extends ZulipLocalizations {
   @override
   String get yesterday => 'Yesterday';
 
+  @override
+  String get invisibleMode => 'Invisible mode';
+
+  @override
+  String get turnOnInvisibleModeErrorTitle =>
+      'Error turning on invisible mode. Please try again.';
+
+  @override
+  String get turnOffInvisibleModeErrorTitle =>
+      'Error turning off invisible mode. Please try again.';
+
   @override
   String get userRoleOwner => 'オーナー';
 

lib/generated/l10n/zulip_localizations_nb.dart

@@ -635,6 +635,17 @@ class ZulipLocalizationsNb extends ZulipLocalizations {
   @override
   String get yesterday => 'Yesterday';
 
+  @override
+  String get invisibleMode => 'Invisible mode';
+
+  @override
+  String get turnOnInvisibleModeErrorTitle =>
+      'Error turning on invisible mode. Please try again.';
+
+  @override
+  String get turnOffInvisibleModeErrorTitle =>
+      'Error turning off invisible mode. Please try again.';
+
   @override
   String get userRoleOwner => 'Owner';
 

lib/generated/l10n/zulip_localizations_pl.dart

@@ -646,6 +646,17 @@ class ZulipLocalizationsPl extends ZulipLocalizations {
   @override
   String get yesterday => 'Wczoraj';
 
+  @override
+  String get invisibleMode => 'Invisible mode';
+
+  @override
+  String get turnOnInvisibleModeErrorTitle =>
+      'Error turning on invisible mode. Please try again.';
+
+  @override
+  String get turnOffInvisibleModeErrorTitle =>
+      'Error turning off invisible mode. Please try again.';
+
   @override
   String get userRoleOwner => 'Właściciel';