new chat button on app bar

lib/core/widgets/main_app_bar.dart

@@ -1,20 +1,36 @@
+import 'package:boilerplate/di/service_locator.dart';
+import 'package:boilerplate/presentation/chat_screen/store/chat_store.dart';
 import 'package:flutter/material.dart';
+import 'package:flutter_mobx/flutter_mobx.dart';
 import 'package:font_awesome_flutter/font_awesome_flutter.dart';
 
-class MainAppBar extends StatelessWidget {
+class MainAppBar extends StatefulWidget {
  const MainAppBar({super.key});
 
+ @override
+ State<MainAppBar> createState() => _MainAppBarState();
+}
+
+class _MainAppBarState extends State<MainAppBar> {
+ ChatStore _chatStore = getIt<ChatStore>();
  @override
  Widget build(BuildContext context) {
  return AppBar(
  title: Text('ChatGPT'),
  actions: [
- IconButton(
- icon: FaIcon(FontAwesomeIcons.penToSquare),
- splashRadius: 20,
- iconSize: 20,
- onPressed: () {},
- ),
+ Observer(builder: (context) {
+ return IconButton(
+ icon: FaIcon(FontAwesomeIcons.penToSquare),
+ splashRadius: 20,
+ iconSize: 20,
+ disabledColor: Colors.grey,
+ onPressed: _chatStore.id > 0
+ ? () {
+ _chatStore.setChatThreadId(-1);
+ }
+ : null,
+ );
+ }),
  IconButton(
  icon: FaIcon(FontAwesomeIcons.ellipsisVertical),
  splashRadius: 20,