Skip to content

Instantly share code, notes, and snippets.

@c5n8
Created May 14, 2020
Embed
What would you like to do?
Proof of concept: wrapper extension for widget
import 'package:flutter/material.dart';
extension Wrapper on Widget {
Widget wrap(List<Function> wrappers) {
var next = this;
for (var i = wrappers.length - 1; i >= 0; i--) {
next = wrappers[i](next);
}
return next;
}
}
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
visualDensity: VisualDensity.adaptivePlatformDensity,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
double _counter = 0;
void _incrementCounter() {
setState(() {
_counter++;
});
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text(
'You have pushed the button this many times:',
),
Text(
'$_counter',
style: Theme.of(context).textTheme.headline4,
).wrap([
(next) => GestureDetector(
onTap: () {
print('hai');
setState(() {
_counter++;
});
},
child: next,
),
(next) => Container(
padding: EdgeInsets.all(_counter),
decoration: BoxDecoration(
border: Border.all(width: 1, color: Colors.black),
),
child: next,
),
]),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add),
),
);
}
}
@c5n8
Copy link
Author

c5n8 commented May 15, 2020

Another variant with fold

Widget wrap(List<Function> wrappers) {
  return wrappers.reversed.fold(this, (next, wrapper) => wrapper(next));
}

Loading

@c5n8
Copy link
Author

c5n8 commented May 15, 2020

Naming is hard!

extension Modifier on Widget {
  Widget modify(List<Function> modifiers) {
    return modifiers.reversed.fold(this, (next, modifier) => modifier(next));
  }
}

Loading

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment