added basic replacements for controller

packages/stream_chat_flutter_core/lib/src/message_input_controller.dart

@@ -0,0 +1,170 @@
+import 'dart:async';
+import 'dart:convert';
+
+import 'package:flutter/material.dart';
+import 'package:flutter/widgets.dart';
+import 'package:stream_chat/stream_chat.dart';
+
+class MessageInputController extends ValueNotifier<Message> {
+  /// Creates a controller for an editable text field.
+  ///
+  /// This constructor treats a null [message] argument as if it were the empty
+  /// message.
+  factory MessageInputController({Message? message}) =>
+      MessageInputController._(message ?? Message());
+
+  /// Creates a controller for an editable text field from an initial [text].
+  factory MessageInputController.fromText(String? text) =>
+      MessageInputController._(Message(text: text));
+
+  /// Creates a controller for an editable text field from an initial [attachments].
+  factory MessageInputController.fromAttachments(
+    List<Attachment> attachments,
+  ) =>
+      MessageInputController._(Message(attachments: attachments));
+
+  MessageInputController._(Message message)
+      : _textEditingController = TextEditingController(text: message.text),
+        super(message);
+
+  ///
+  TextEditingController get textEditingController => _textEditingController;
+  final TextEditingController _textEditingController;
+
+  ///
+  String get text => value.text ?? '';
+
+  ///
+  set message(Message message) {
+    value = message;
+  }
+
+  set text(String? newText) {
+    value = value.copyWith(text: newText);
+    _textEditingController.text = newText ?? '';
+  }
+
+  set textEditingValue(TextEditingValue newValue) {
+    _textEditingController.value = newValue;
+    value = value.copyWith(text: _textEditingController.text);
+  }
+
+  ///
+  List<Attachment> get attachments => value.attachments;
+
+  set attachments(List<Attachment> attachments) {
+    value = value.copyWith(attachments: attachments);
+  }
+
+  ///
+  get baseOffset {
+    return textEditingController.selection.baseOffset;
+  }
+
+  ///
+  void addAttachment(Attachment attachment) {
+    attachments = [...attachments, attachment];
+  }
+
+  ///
+  void addAttachmentAt(int index, Attachment attachment) {
+    attachments = [...attachments]..insert(index, attachment);
+  }
+
+  ///
+  void removeAttachment(Attachment attachment) {
+    attachments = [...attachments]..remove(attachment);
+  }
+
+  ///
+  void removeAttachmentById(String attachmentId) {
+    attachments = [...attachments]..removeWhere((it) => it.id == attachmentId);
+  }
+
+  ///
+  void removeAttachmentAt(int index) {
+    attachments = [...attachments]..removeAt(index);
+  }
+
+  ///
+  List<User> get mentionedUsers => value.mentionedUsers;
+
+  set mentionedUsers(List<User> users) {
+    value = value.copyWith(mentionedUsers: users);
+  }
+
+  ///
+  void addMentionedUser(User user) {
+    mentionedUsers = [...mentionedUsers, user];
+  }
+
+  ///
+  void removeMentionedUser(User user) {
+    mentionedUsers = [...mentionedUsers]..remove(user);
+  }
+
+  ///
+  void removeMentionedUserById(String userId) {
+    mentionedUsers = [...mentionedUsers]..removeWhere((it) => it.id == userId);
+  }
+
+  /// Set the [value] to empty.
+  ///
+  /// After calling this function, [text], [attachments] and [mentionedUsers]
+  /// all will be empty.
+  ///
+  /// Calling this will notify all the listeners of this [MessageInputController]
+  /// that they need to update (it calls [notifyListeners]). For this reason,
+  /// this method should only be called between frames, e.g. in response to user
+  /// actions, not during the build, layout, or paint phases.
+  void clear() {
+    value = Message();
+    _textEditingController.clear();
+  }
+
+  @override
+  void dispose() {
+    super.dispose();
+    _textEditingController.dispose();
+  }
+}
+
+/// A [RestorableProperty] that knows how to store and restore a
+/// [MessageInputController].
+///
+/// The [MessageInputController] is accessible via the [value] getter. During
+/// state restoration, the property will restore [MessageInputController.value]
+/// to the value it had when the restoration data it is getting restored from
+/// was collected.
+class RestorableMessageInputController
+    extends RestorableChangeNotifier<MessageInputController> {
+  /// Creates a [RestorableMessageInputController].
+  ///
+  /// This constructor treats a null `text` argument as if it were the empty
+  /// string.
+  RestorableMessageInputController({Message? message})
+      : _initialValue = message ?? Message();
+
+  /// Creates a [RestorableMessageInputController] from an initial
+  /// [TextEditingValue].
+  ///
+  /// This constructor treats a null `value` argument as if it were
+  /// [TextEditingValue.empty].
+  factory RestorableMessageInputController.fromText(String? text) =>
+      RestorableMessageInputController(message: Message(text: text));
+
+  final Message _initialValue;
+
+  @override
+  MessageInputController createDefaultValue() =>
+      MessageInputController(message: _initialValue);
+
+  @override
+  MessageInputController fromPrimitives(Object? data) {
+    final message = Message.fromJson(json.decode(data! as String));
+    return MessageInputController(message: message);
+  }
+
+  @override
+  String toPrimitives() => json.encode(value.value);
+}

packages/stream_chat_flutter_core/lib/stream_chat_flutter_core.dart

@@ -7,6 +7,7 @@ export 'src/better_stream_builder.dart';
 export 'src/channel_list_core.dart' hide ChannelListCoreState;
 export 'src/channels_bloc.dart';
 export 'src/lazy_load_scroll_view.dart';
+export 'src/message_input_controller.dart';
 export 'src/message_list_core.dart' hide MessageListCoreState;
 export 'src/message_search_bloc.dart';
 export 'src/message_search_list_core.dart' hide MessageSearchListCoreState;