Add message limit slider (#45)

lib/core/settings/settings.dart

@@ -26,6 +26,17 @@ class Settings extends StatelessWidget {
                 value: settingsStore.videoEnabled,
                 onChanged: (newValue) => settingsStore.videoEnabled = newValue,
               ),
+              ListTile(
+                title: const Text('Chat Message Limit'),
+                subtitle: Slider(
+                  value: settingsStore.messageLimit,
+                  onChanged: (newValue) => settingsStore.messageLimit = newValue,
+                  min: 0,
+                  max: 1000,
+                  divisions: 10,
+                  label: settingsStore.messageLimit == 1000 ? 'Unlimited' : '${settingsStore.messageLimit}',
+                ),
+              )
             ],
           );
         },

lib/core/settings/settings_store.dart

@@ -7,21 +7,26 @@ part 'settings_store.g.dart';
 class SettingsStore = _SettingsStoreBase with _$SettingsStore;
 
 abstract class _SettingsStoreBase with Store {
+  @observable
+  bool videoEnabled = true;
+
+  @observable
+  double messageLimit = 200;
+
   Future<void> init() async {
     // Retrieve the instance that will allow us to store and persist settings.
     final prefs = await SharedPreferences.getInstance();
 
     // Initialize settings from stored preferences if any.
     videoEnabled = prefs.getBool('video_enabled') ?? videoEnabled;
+    messageLimit = prefs.getDouble('message_limit') ?? messageLimit;
 
     // Set up autorun to store setting anytime they're changed.
     // The ReactionDisposer will not be needed since settings will always exist.
     autorun((_) {
-      debugPrint('video changed');
+      debugPrint('settings changed');
       prefs.setBool('video_enabled', videoEnabled);
+      prefs.setDouble('message_limit', messageLimit);
     });
   }
-
-  @observable
-  bool videoEnabled = true;
 }

lib/core/settings/settings_store.g.dart

@@ -24,10 +24,26 @@ mixin _$SettingsStore on _SettingsStoreBase, Store {
     });
   }
 
+  final _$messageLimitAtom = Atom(name: '_SettingsStoreBase.messageLimit');
+
+  @override
+  double get messageLimit {
+    _$messageLimitAtom.reportRead();
+    return super.messageLimit;
+  }
+
+  @override
+  set messageLimit(double value) {
+    _$messageLimitAtom.reportWrite(value, super.messageLimit, () {
+      super.messageLimit = value;
+    });
+  }
+
   @override
   String toString() {
     return '''
-videoEnabled: ${videoEnabled}
+videoEnabled: ${videoEnabled},
+messageLimit: ${messageLimit}
     ''';
   }
 }

lib/screens/channel/chat/chat_store.dart

@@ -7,6 +7,7 @@ import 'package:frosty/api/irc_api.dart';
 import 'package:frosty/api/seventv_api.dart';
 import 'package:frosty/api/twitch_api.dart';
 import 'package:frosty/core/auth/auth_store.dart';
+import 'package:frosty/core/settings/settings_store.dart';
 import 'package:frosty/models/irc.dart';
 import 'package:mobx/mobx.dart';
 import 'package:web_socket_channel/web_socket_channel.dart';
@@ -38,6 +39,9 @@ abstract class _ChatStoreBase with Store {
   /// The provided auth store to determine login status, get the token, and use the headers for requests.
   final AuthStore auth;
 
+  /// The provided setting store to account for any user-defined behaviors.
+  final SettingsStore settings;
+
   /// The logged-in user's appearance in chat.
   String? _userState;
 
@@ -52,7 +56,11 @@ abstract class _ChatStoreBase with Store {
   @readonly
   var _roomState = const ROOMSTATE();
 
-  _ChatStoreBase({required this.auth, required this.channelName}) {
+  _ChatStoreBase({
+    required this.auth,
+    required this.settings,
+    required this.channelName,
+  }) {
     // Listen for new messages and forward them to the handler.
     _channel.stream.listen(
       (data) => _handleIRCData(data.toString()),
@@ -170,9 +178,9 @@ abstract class _ChatStoreBase with Store {
   @action
   void _deleteAndScrollToEnd() {
     if (_autoScroll) {
-      // If there are over 200 messages, remove at least 20.
-      if (messages.length > 200) {
-        messages.removeRange(0, messages.length - 180);
+      // If there are more messages than the limit, remove around 10% of them from the oldest.
+      if (messages.length > settings.messageLimit && settings.messageLimit != 1000) {
+        messages.removeRange(0, (messages.length - settings.messageLimit * 0.1).ceil());
       }
 
       // After the end of the frame, scroll to the bottom of the chat.

lib/screens/channel/video_chat.dart

@@ -68,6 +68,7 @@ class VideoChat extends StatelessWidget {
                 child: Chat(
                   chatStore: ChatStore(
                     auth: context.read<AuthStore>(),
+                    settings: context.read<SettingsStore>(),
                     channelName: userLogin,
                   ),
                 ),