add threads example

example/lib/threads.dart

@@ -0,0 +1,91 @@
+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],
+          }
+        },
+        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(
+              threadBuilder: (_, message) {
+                return ThreadPage(
+                  parent: message,
+                );
+              },
+            ),
+          ),
+          MessageInput(),
+        ],
+      ),
+    );
+  }
+}
+
+class ThreadPage extends StatelessWidget {
+  final Message parent;
+
+  ThreadPage({
+    Key key,
+    this.parent,
+  }) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      body: Column(
+        children: <Widget>[
+          Expanded(
+            child: MessageListView(
+              parentMessage: parent,
+            ),
+          ),
+          MessageInput(),
+        ],
+      ),
+    );
+  }
+}

lib/src/channel_list_view.dart

@@ -18,8 +18,7 @@ class ChannelListView extends StatefulWidget {
     this.onChannelTap,
     this.channelWidget,
     this.channelPreviewBuilder,
-  })  : assert(channelWidget != null || onChannelTap != null),
+  }) : super(key: key);
-        super(key: key);
 
   final Map<String, dynamic> filter;
   final Map<String, dynamic> options;

lib/src/message_list_view.dart

@@ -9,7 +9,8 @@ import 'stream_channel.dart';
 
 typedef MessageBuilder = Widget Function(BuildContext, Message, int index);
 typedef ParentMessageBuilder = Widget Function(BuildContext, Message);
-typedef OnThreadSelectCallback = void Function(Message parent);
+typedef ThreadBuilder = Widget Function(BuildContext context, Message parent);
+typedef ThreadTapCallback = void Function(Message, Widget);
 
 class MessageListView extends StatefulWidget {
   MessageListView({
@@ -17,13 +18,15 @@ class MessageListView extends StatefulWidget {
     MessageBuilder messageBuilder,
     this.parentMessageBuilder,
     this.parentMessage,
-    this.onThreadSelect,
+    this.threadBuilder,
+    this.onThreadTap,
   })  : _messageBuilder = messageBuilder,
         super(key: key);
 
   final MessageBuilder _messageBuilder;
   final ParentMessageBuilder parentMessageBuilder;
-  final OnThreadSelectCallback onThreadSelect;
+  final ThreadBuilder threadBuilder;
+  final ThreadTapCallback onThreadTap;
   final Message parentMessage;
 
   @override
@@ -38,6 +41,8 @@ class _MessageListViewState extends State<MessageListView> {
   List<Message> _messages = [];
   List<Message> _newMessageList = [];
 
+  Function _onThreadTap;
+
   @override
   Widget build(BuildContext context) {
     final streamChannel = StreamChannel.of(context);
@@ -74,7 +79,7 @@ class _MessageListViewState extends State<MessageListView> {
                         previousMessage: null,
                         message: widget.parentMessage.copyWith(replyCount: 0),
                         nextMessage: null,
-                        onThreadSelect: widget.onThreadSelect,
+                        onThreadTap: _onThreadTap,
                       ),
                       Padding(
                         padding: const EdgeInsets.symmetric(horizontal: 32),
@@ -131,7 +136,7 @@ class _MessageListViewState extends State<MessageListView> {
               previousMessage: previousMessage,
               message: message,
               nextMessage: nextMessage,
-              onThreadSelect: widget.onThreadSelect,
+              onThreadTap: _onThreadTap,
             );
           },
           childCount: _messages.length + 2,
@@ -185,7 +190,7 @@ class _MessageListViewState extends State<MessageListView> {
         previousMessage: null,
         message: message,
         nextMessage: nextMessage,
-        onThreadSelect: widget.onThreadSelect,
+        onThreadTap: _onThreadTap,
       ),
       onVisibilityChanged: (visibility) {
         final topIsVisible = visibility.visibleBounds != Rect.zero;
@@ -218,7 +223,7 @@ class _MessageListViewState extends State<MessageListView> {
         previousMessage: previousMessage,
         message: message,
         nextMessage: null,
-        onThreadSelect: widget.onThreadSelect,
+        onThreadTap: _onThreadTap,
       ),
     );
   }
@@ -270,6 +275,32 @@ class _MessageListViewState extends State<MessageListView> {
         });
       }
     });
+
+    _getOnThreadTap();
+  }
+
+  void _getOnThreadTap() {
+    if (widget.onThreadTap != null) {
+      _onThreadTap = (message) {
+        widget.onThreadTap(
+            message,
+            widget.threadBuilder != null
+                ? widget.threadBuilder(context, message)
+                : null);
+      };
+    } else {
+      _onThreadTap = (message) {
+        Navigator.push(
+          context,
+          MaterialPageRoute(builder: (_) {
+            return StreamChannel(
+              channelClient: StreamChannel.of(context).channelClient,
+              child: widget.threadBuilder(context, message),
+            );
+          }),
+        );
+      };
+    }
   }
 
   @override

lib/src/message_widget.dart

@@ -9,7 +9,6 @@ import 'package:stream_chat_flutter/src/user_avatar.dart';
 import 'package:url_launcher/url_launcher.dart';
 import 'package:video_player/video_player.dart';
 
-import 'message_list_view.dart';
 import 'stream_chat.dart';
 
 class MessageWidget extends StatefulWidget {
@@ -18,13 +17,13 @@ class MessageWidget extends StatefulWidget {
     @required this.previousMessage,
     @required this.message,
     @required this.nextMessage,
-    this.onThreadSelect,
+    this.onThreadTap,
   }) : super(key: key);
 
   final Message previousMessage;
   final Message message;
   final Message nextMessage;
-  final OnThreadSelectCallback onThreadSelect;
+  final void Function(Message) onThreadTap;
 
   @override
   _MessageWidgetState createState() => _MessageWidgetState();
@@ -59,8 +58,8 @@ class _MessageWidgetState extends State<MessageWidget>
           widget.message.replyCount > 0
               ? GestureDetector(
                   onTap: () {
-                    if (widget.onThreadSelect != null) {
+                    if (widget.onThreadTap != null) {
-                      widget.onThreadSelect(widget.message);
+                      widget.onThreadTap(widget.message);
                     }
                   },
                   child: Padding(