add custom message example

example/lib/custom_message.dart

@@ -0,0 +1,65 @@
+import 'package:flutter/material.dart';
+import 'package:stream_chat_flutter/stream_chat_flutter.dart';
+
+void main() async {
+  final client = Client('qk4nn7rpcn75');
+
+  await client.setUser(
+    User(id: 'wild-breeze-7'),
+    'eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJ1c2VyX2lkIjoid2lsZC1icmVlemUtNyJ9.VM2EX1EXOfgqa-bTH_3JzeY0T99ngWzWahSauP3dBMo',
+  );
+
+  final channelClient = client.channel('messaging', id: 'godevs');
+
+  // ignore: unawaited_futures
+  channelClient.watch();
+
+  runApp(
+    StreamChat(
+      client: client,
+      child: MaterialApp(
+        home: StreamChannel(
+          channelClient: channelClient,
+          child: ChannelPage(),
+        ),
+      ),
+    ),
+  );
+}
+
+class ChannelPage extends StatelessWidget {
+  const ChannelPage({
+    Key key,
+  }) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      body: Column(
+        children: <Widget>[
+          Expanded(
+            child: MessageListView(
+              messageBuilder: (context, message, _) {
+                final isCurrentUser =
+                    StreamChat.of(context).user.id == message.user.id;
+                final textAlign =
+                    isCurrentUser ? TextAlign.right : TextAlign.left;
+                return ListTile(
+                  title: Text(
+                    message.text,
+                    textAlign: textAlign,
+                  ),
+                  subtitle: Text(
+                    message.user.extraData['name'],
+                    textAlign: textAlign,
+                  ),
+                );
+              },
+            ),
+          ),
+          MessageInput(),
+        ],
+      ),
+    );
+  }
+}

lib/src/message_list_view.dart

@@ -15,15 +15,14 @@ typedef ThreadTapCallback = void Function(Message, Widget);
 class MessageListView extends StatefulWidget {
   MessageListView({
     Key key,
-    MessageBuilder messageBuilder,
+    this.messageBuilder,
     this.parentMessageBuilder,
     this.parentMessage,
     this.threadBuilder,
     this.onThreadTap,
-  })  : _messageBuilder = messageBuilder,
+  }) : super(key: key);
-        super(key: key);
 
-  final MessageBuilder _messageBuilder;
+  final MessageBuilder messageBuilder;
   final ParentMessageBuilder parentMessageBuilder;
   final ThreadBuilder threadBuilder;
   final ThreadTapCallback onThreadTap;
@@ -105,8 +104,8 @@ class _MessageListViewState extends State<MessageListView> {
             }
             final message = _messages[i];
 
-            if (widget._messageBuilder != null) {
+            if (widget.messageBuilder != null) {
-              return widget._messageBuilder(context, message, i);
+              return widget.messageBuilder(context, message, i);
             }
 
             final previousMessage =

lib/src/stream_channel.dart

@@ -109,7 +109,7 @@ class StreamChannelState extends State<StreamChannel> {
       future: widget.channelClient.initialized,
       initialData: widget.channelClient.state != null,
       builder: (context, snapshot) {
-        if (!snapshot.hasData) {
+        if (!snapshot.hasData || !snapshot.data) {
           return Scaffold(
             body: Center(
               child: CircularProgressIndicator(),