auto-refresh message-list on FB message receive

flutter/lib/state/scn_data_cache.dart

@@ -0,0 +1,60 @@
+import 'package:hive_flutter/hive_flutter.dart';
+import 'package:simplecloudnotifier/models/channel.dart';
+import 'package:simplecloudnotifier/models/scn_message.dart';
+import 'package:simplecloudnotifier/settings/app_settings.dart';
+
+class SCNDataCache {
+  SCNDataCache._internal();
+  static final SCNDataCache _instance = SCNDataCache._internal();
+  factory SCNDataCache() => _instance;
+
+  Future<void> addToMessageCache(List<SCNMessage> newItems) async {
+    final cfg = AppSettings();
+
+    final cache = Hive.box<SCNMessage>('scn-message-cache');
+
+    for (var msg in newItems) await cache.put(msg.messageID, msg);
+
+    // delete all but the newest 128 messages
+
+    if (cache.length < cfg.messagePageSize) return;
+
+    final allValues = cache.values.toList();
+
+    allValues.sort((a, b) => -1 * a.timestamp.compareTo(b.timestamp));
+
+    for (var val in allValues.sublist(cfg.messagePageSize)) {
+      await cache.delete(val.messageID);
+    }
+  }
+
+  Future<void> setChannelCache(List<ChannelWithSubscription> channels) async {
+    final cache = Hive.box<Channel>('scn-channel-cache');
+
+    if (cache.length != channels.length) await cache.clear();
+
+    for (var chn in channels) await cache.put(chn.channel.channelID, chn.channel);
+  }
+
+  bool hasMessagesAndChannels() {
+    final chnCache = Hive.box<Channel>('scn-channel-cache');
+    final msgCache = Hive.box<SCNMessage>('scn-message-cache');
+
+    return chnCache.isNotEmpty && msgCache.isNotEmpty;
+  }
+
+  Map<String, Channel> getChannelMap() {
+    final chnCache = Hive.box<Channel>('scn-channel-cache');
+
+    return <String, Channel>{for (var v in chnCache.values) v.channelID: v};
+  }
+
+  List<SCNMessage> getMessagesSorted() {
+    final msgCache = Hive.box<SCNMessage>('scn-message-cache');
+
+    final cacheMessages = msgCache.values.toList();
+    cacheMessages.sort((a, b) => -1 * a.timestamp.compareTo(b.timestamp));
+
+    return cacheMessages;
+  }
+}