How to scroll flutter web app using arrow keys - flutter

Question

I just build and deployed a flutter web app. The problem I encountered is that it doesn't scroll when I press arrow keys, also there is no scroll bar. (Only 2 figure gesture scrolling is possible)
I'm using SingleChildScrollView() with the column as its child.
Is there a way to implement them?
Or just one of them?

Answer 1

The code from Karan works, but when the app is in Debug Mode, instead of using the event.logicalKey.debugName == "Arrow Up", we could use event.logicalKey == LogicalKeyboardKey.arrowUp which works in both the debug and release mode.
class _MyKeyboardScrollingPageState extends State<MyKeyboardScrollingPage> {
final ScrollController _controller = ScrollController();
final FocusNode _focusNode = FocusNode();
void _handleKeyEvent(RawKeyEvent event) {
var offset = _controller.offset;
if (event.logicalKey == LogicalKeyboardKey.arrowUp) {
setState(() {
if (kReleaseMode) {
_controller.animateTo(offset - 200, duration: Duration(milliseconds: 30), curve: Curves.ease);
} else {
_controller.animateTo(offset - 200, duration: Duration(milliseconds: 30), curve: Curves.ease);
}
});
}
else if (event.logicalKey == LogicalKeyboardKey.arrowDown) {
setState(() {
if (kReleaseMode) {
_controller.animateTo(offset + 200, duration: Duration(milliseconds: 30), curve: Curves.ease);
} else {
_controller.animateTo(offset + 200, duration: Duration(milliseconds: 30), curve: Curves.ease);
}
});
}
}
#override
void dispose() {
_focusNode.dispose();
super.dispose();
}
#override
Widget build(BuildContext context) {
return Scaffold(
body: RawKeyboardListener(
autoFocus = true,
focusNode = _focusNode,
onKey: _handleKeyEvent,
child: SingleChildScrollView(
controller: _controller,
child: SomeAwesomeWidget(),
),
),
);
}
}

Answer 2

I found one solution ...
Hope this helps someone with the same issue...
Using RawKeyboardListener(), we can listen to any keyboard stroke.
class _MyHomePageState extends State<MyHomePage> {
final ScrollController _controller = ScrollController();
final FocusNode _focusNode = FocusNode()
#override
void dispose() {
_focusNode.dispose();
super.dispose();
}
void _handleKeyEvent(RawKeyEvent event) {
var offset = _controller.offset; //Getting current position
if (event.logicalKey.debugName == "Arrow Down") {
setState(() {
if (kReleaseMode) {
//This block only runs when the application was compiled in release mode.
_controller.animateTo(offset + 50,
duration: Duration(milliseconds: 200), curve: Curves.ease);
} else {
// This will only print useful information in debug mode.
// print(_controller.position); to get information..
_controller.animateTo(offset + 50,
duration: Duration(milliseconds: 200), curve: Curves.ease);
}
});
} else if (event.logicalKey.debugName == "Arrow Up"){
setState(() {
if (kReleaseMode) {
_controller.animateTo(offset - 50,
duration: Duration(milliseconds: 200), curve: Curves.ease);
} else {
_controller.animateTo(offset - 50,
duration: Duration(milliseconds: 200), curve: Curves.ease);
}
});
#override
Widget build(BuildContext context) {
return Scaffold(
body: RawKeyboardListener(
autofocus: true,
focusNode: _focusNode,
onKey: _handleKeyEvent,
child: SingleChildScrollView(
controller: _controller,
child:...
}
}

Answer 3

You can wrap ScrollBar to SingleChildScrollView to show scroll bar, like this:
Scrollbar(
child: SingleChildScrollView(
child: Container(),
));

Answer 4

For the answers that are mentioned above to work, you need the following imports:
import 'package:flutter/services.dart';
import 'package:flutter/foundation.dart';

Answer 5

The Most simplest way to Scroll using mouse or Keyboard Arrow keys on Flutter Web is
ListView(
primary: true,
scrollDirection: Axis.vertical,
children:
No need to pass any ScrollController