add typing indicator widget

example/lib/main.dart

@@ -3,13 +3,13 @@ import 'package:stream_chat_flutter/stream_chat_flutter.dart';
 
 void main() async {
   final client = Client(
-    'b67pax5b2wdq',
+    's2dxdhpxd94g',
     logLevel: Level.INFO,
   );
 
   await client.setUser(
-    User(id: 'falling-mountain-7'),
-    'eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJ1c2VyX2lkIjoiZmFsbGluZy1tb3VudGFpbi03In0.AKgRXHMQQMz6vJAKszXdY8zMFfsAgkoUeZHlI-Szz9E',
+    User(id: 'super-band-9'),
+    'eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJ1c2VyX2lkIjoic3VwZXItYmFuZC05In0.0L6lGoeLwkz0aZRUcpZKsvaXtNEDHBcezVTZ0oPq40A',
   );
 
   runApp(MyApp(client));

lib/src/channel_preview.dart

@@ -5,6 +5,7 @@ import 'package:stream_chat/stream_chat.dart';
 
 import '../stream_chat_flutter.dart';
 import 'channel_name.dart';
+import 'typing_indicator.dart';
 
 /// ![screenshot](https://raw.githubusercontent.com/GetStream/stream-chat-flutter/master/screenshots/channel_preview.png)
 /// ![screenshot](https://raw.githubusercontent.com/GetStream/stream-chat-flutter/master/screenshots/channel_preview_paint.png)
@@ -88,7 +89,19 @@ class ChannelPreview extends StatelessWidget {
           final typings = snapshot.data;
           final opacity = channel.state.unreadCount > 0 ? 1.0 : 0.5;
           return typings.isNotEmpty
-              ? _buildTypings(typings, context, opacity)
+              ? TypingIndicator(
+                  typings: typings,
+                  style: StreamChatTheme.of(context)
+                      .channelPreviewTheme
+                      .subtitle
+                      .copyWith(
+                        color: StreamChatTheme.of(context)
+                            .channelPreviewTheme
+                            .subtitle
+                            .color
+                            .withOpacity(opacity),
+                      ),
+                )
               : _buildLastMessage(context, opacity);
         });
   }
@@ -141,18 +154,4 @@ class ChannelPreview extends StatelessWidget {
       },
     );
   }
-
-  Text _buildTypings(List<User> typings, BuildContext context, double opacity) {
-    return Text(
-      '${typings.map((u) => u.extraData.containsKey('name') ? u.extraData['name'] : u.id).join(',')} ${typings.length == 1 ? 'is' : 'are'} typing...',
-      maxLines: 1,
-      style: StreamChatTheme.of(context).channelPreviewTheme.subtitle.copyWith(
-            color: StreamChatTheme.of(context)
-                .channelPreviewTheme
-                .subtitle
-                .color
-                .withOpacity(opacity),
-          ),
-    );
-  }
 }

lib/src/message_widget.dart

@@ -62,7 +62,7 @@ class MessageWidget extends StatefulWidget {
 }
 
 class _MessageWidgetState extends State<MessageWidget>
-    with AutomaticKeepAliveClientMixin {
+    with AutomaticKeepAliveClientMixin, TickerProviderStateMixin {
   final Map<String, ChangeNotifier> _videoControllers = {};
   final Map<String, ChangeNotifier> _chuwieControllers = {};
 
@@ -126,8 +126,7 @@ class _MessageWidgetState extends State<MessageWidget>
       row = row.reversed.toList();
     }
 
-    child = AnimatedContainer(
-      duration: Duration(milliseconds: 300),
+    child = Container(
       padding: const EdgeInsets.symmetric(horizontal: 10.0),
       margin: EdgeInsets.only(
         top: isLastUser ? 5 : 24,
@@ -674,9 +673,7 @@ class _MessageWidgetState extends State<MessageWidget>
         padding: EdgeInsets.symmetric(
           vertical: widget.message.reactionCounts?.isNotEmpty == true ? 4.0 : 0,
         ),
-        child: AnimatedContainer(
-          duration: Duration(milliseconds: 300),
-          curve: Curves.decelerate,
+        child: Container(
           padding: widget.message.reactionCounts?.isNotEmpty == true
               ? const EdgeInsets.all(8)
               : EdgeInsets.zero,
@@ -685,7 +682,12 @@ class _MessageWidgetState extends State<MessageWidget>
               borderRadius: BorderRadius.all(Radius.circular(14))),
           child: (widget.message.reactionCounts != null &&
                   widget.message.reactionCounts.isNotEmpty)
-              ? _buildReactionRow()
+              ? AnimatedSize(
+                  duration: Duration(milliseconds: 300),
+                  vsync: this,
+                  curve: Curves.easeInQuad,
+                  child: _buildReactionRow(),
+                )
               : SizedBox(),
         ),
       ),

lib/src/typing_indicator.dart

@@ -0,0 +1,26 @@
+import 'package:flutter/material.dart';
+import 'package:stream_chat/stream_chat.dart';
+
+/// Widget to show the current list of typing users
+class TypingIndicator extends StatelessWidget {
+  const TypingIndicator({
+    Key key,
+    @required this.typings,
+    this.style,
+  }) : super(key: key);
+
+  /// Style of the text widget
+  final TextStyle style;
+
+  /// List of typing users
+  final List<User> typings;
+
+  @override
+  Widget build(BuildContext context) {
+    return Text(
+      '${typings.map((u) => u.name).join(',')} ${typings.length == 1 ? 'is' : 'are'} typing...',
+      maxLines: 1,
+      style: style,
+    );
+  }
+}

lib/stream_chat_flutter.dart

@@ -13,3 +13,4 @@ export 'src/stream_channel.dart';
 export 'src/stream_chat.dart';
 export 'src/stream_chat_theme.dart';
 export 'src/thread_header.dart';
+export 'src/typing_indicator.dart';