Add submenuIcon property to override the default SubmenuButton arrow icon (#160086)
Fixes
[https://github.com/flutter/flutter/issues/132898](https://github.com/flutter/flutter/issues/132898)
### Code sample
<details>
<summary>expand to view the code sample</summary>
```dart
import 'package:flutter/material.dart';
void main() => runApp(const MyApp());
class MyApp extends StatelessWidget {
const MyApp({super.key});
@override
Widget build(BuildContext context) {
return MaterialApp(
debugShowCheckedModeBanner: false,
home: Scaffold(
body: SafeArea(
child: Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
children: [
MenuBar(
children: [
SubmenuButton(
menuChildren: <Widget>[
SubmenuButton(
menuChildren: <Widget>[
MenuItemButton(
onPressed: () {},
child: const Text('Menu '),
),
],
child:
const Text('SubmenuButton with default arrow icon'),
),
SubmenuButton(
submenuIcon: const WidgetStateProperty<Widget?>.fromMap(
<WidgetStatesConstraint, Widget?>{
WidgetState.disabled: Icon(Icons.close),
WidgetState.hovered: Icon(Icons.favorite),
WidgetState.focused: Icon(Icons.add),
WidgetState.any: Icon(Icons.arrow_forward_ios),
},
),
menuChildren: <Widget>[
MenuItemButton(
onPressed: () {},
child: const Text('Menu '),
),
],
child:
const Text('SubmenuButton with custom Icon widget'),
),
SubmenuButton(
submenuIcon: WidgetStatePropertyAll(Image.network(
'https://i.imgur.com/SF3mSOY.png',
width: 28,
height: 28)),
menuChildren: <Widget>[
MenuItemButton(
onPressed: () {},
child: const Text('Menu '),
),
],
child:
const Text('SubmenuButton with network image icon'),
),
],
child: const Text('Menu'),
),
],
)
],
),
),
),
);
}
}
```
</details>
### Preview
<img width="803" alt="Screenshot 2024-12-11 at 14 04 57"
src="https://github.com/user-attachments/assets/4b330020-28c6-4af9-967b-630c0d43b01a">
## Pre-launch Checklist
- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [ ] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.
If you need help, consider asking for advice on the #hackers-new channel
on [Discord].
<!-- Links -->
[Contributor Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview
[Tree Hygiene]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md
[test-exempt]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests
[Flutter Style Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md
[Features we expect every widget to implement]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement
[CLA]: https://cla.developers.google.com/
[flutter/tests]: https://github.com/flutter/tests
[breaking change policy]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes
[Discord]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md
[Data Driven Fixes]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md
---------
Co-authored-by: Greg Spencer <gspencergoog@users.noreply.github.com>
275153c234
