migrate ui

packages/stream_chat_flutter/lib/src/unread_indicator.dart

@@ -4,23 +4,23 @@ import 'package:stream_chat_flutter/stream_chat_flutter.dart';
 
 class UnreadIndicator extends StatelessWidget {
   const UnreadIndicator({
-    Key key,
+    Key? key,
     this.cid,
   }) : super(key: key);
 
   /// Channel cid used to retrieve unread count
-  final String cid;
+  final String? cid;
 
   @override
   Widget build(BuildContext context) {
     final client = StreamChat.of(context).client;
     return IgnorePointer(
-      child: StreamBuilder<int>(
+      child: StreamBuilder<int?>(
         stream: cid != null
-            ? client.state.channels[cid].state.unreadCountStream
+            ? client.state.channels[cid]?.state?.unreadCountStream
             : client.state.totalUnreadCountStream,
         initialData: cid != null
-            ? client.state.channels[cid].state.unreadCount
+            ? client.state.channels[cid]?.state?.unreadCount
             : client.state.totalUnreadCount,
         builder: (context, snapshot) {
           if (!snapshot.hasData || snapshot.data == 0) {
@@ -40,7 +40,7 @@ class UnreadIndicator extends StatelessWidget {
               ),
               child: Center(
                 child: Text(
-                  '${snapshot.data > 99 ? '99+' : snapshot.data}',
+                  '${snapshot.data! > 99 ? '99+' : snapshot.data}',
                   style: TextStyle(
                     fontSize: 11,
                     color: Colors.white,