add customize_channel_preview example

example/android/app/src/main/AndroidManifest.xml

@@ -5,6 +5,7 @@
          In most cases you can leave this as-is, but you if you want to provide
          additional functionality it is fine to subclass or reimplement
          FlutterApplication and put your custom class here. -->
+    <uses-permission android:name="android.permission.INTERNET"/>
     <application
         android:name="io.flutter.app.FlutterApplication"
         android:label="example"

example/lib/customize_channel_preview.dart

@@ -0,0 +1,78 @@
+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',
+  );
+
+  runApp(
+    StreamChat(
+      client: client,
+      child: MaterialApp(
+        home: ChannelListPage(),
+      ),
+    ),
+  );
+}
+
+class ChannelListPage extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      body: ChannelListView(
+        filter: {
+          'members': {
+            '\$in': [StreamChat.of(context).user.id],
+          }
+        },
+        channelPreviewBuilder: (context, channelClient) {
+          final channelState = channelClient.state.channelState;
+          return ListTile(
+            leading: CircleAvatar(
+              backgroundImage:
+                  channelState.channel.extraData.containsKey('image')
+                      ? NetworkImage(channelState.channel.extraData['image'])
+                      : null,
+            ),
+            title: Text(channelState.channel.extraData['name'] ?? ''),
+            trailing: channelClient.state.unreadCount > 0
+                ? CircleAvatar(
+                    radius: 10,
+                    child: Text(channelClient.state.unreadCount.toString()),
+                  )
+                : Container(),
+          );
+        },
+        sort: [SortOption('last_message_at')],
+        pagination: PaginationParams(
+          limit: 20,
+        ),
+        channelWidget: 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(),
+          ),
+          MessageInput(),
+        ],
+      ),
+    );
+  }
+}

example/lib/multiple_conversation.dart

@@ -5,7 +5,7 @@ void main() async {
   final client = Client('qk4nn7rpcn75');
 
   await client.setUser(
-    User(id: "wild-breeze-7"),
+    User(id: 'wild-breeze-7'),
     'eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJ1c2VyX2lkIjoid2lsZC1icmVlemUtNyJ9.VM2EX1EXOfgqa-bTH_3JzeY0T99ngWzWahSauP3dBMo',
   );
 
@@ -29,7 +29,7 @@ class ChannelListPage extends StatelessWidget {
             '\$in': [StreamChat.of(context).user.id],
           }
         },
-        sort: [SortOption("last_message_at")],
+        sort: [SortOption('last_message_at')],
         pagination: PaginationParams(
           limit: 20,
         ),

example/lib/single_conversation.dart

@@ -5,12 +5,13 @@ void main() async {
   final client = Client('qk4nn7rpcn75');
 
   await client.setUser(
-    User(id: "wild-breeze-7"),
+    User(id: 'wild-breeze-7'),
     'eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJ1c2VyX2lkIjoid2lsZC1icmVlemUtNyJ9.VM2EX1EXOfgqa-bTH_3JzeY0T99ngWzWahSauP3dBMo',
   );
 
   final channelClient = client.channel('messaging', id: 'godevs');
 
+  // ignore: unawaited_futures
   channelClient.watch();
 
   runApp(