| Before |
After |
import 'package:flutter/material.dart';
void main() {
runApp(MaterialApp(home: MyScreen()));
}
class AppColors extends InheritedWidget {
const AppColors({
required this.buttonColor,
required super.child,
});
final Color buttonColor;
static AppColors? maybeOf(BuildContext context) {
return context.dependOnInheritedWidgetOfExactType<AppColors>();
}
static AppColors of(BuildContext context) {
final AppColors? model = maybeOf(context);
assert(model != null);
return model!;
}
@override
bool updateShouldNotify(AppColors oldWidget) {
return oldWidget.buttonColor != buttonColor;
}
}
class MyScreen extends StatelessWidget {
@override
Widget build(BuildContext context) {
return AppColors(
buttonColor: Colors.blue,
child: Scaffold(
body: Center(child: MyButton()),
),
);
}
}
class MyButton extends StatelessWidget {
@override
Widget build(BuildContext context) {
return TextButton(
style: TextButton.styleFrom(
foregroundColor: AppColors.of(context).buttonColor,
),
onPressed: () {},
child: const Text('Hello world'),
);
}
} |
import 'package:flutter/material.dart';
void main() {
runApp(MaterialApp(home: MyScreen()));
}
class AppColors({required final Color buttonColor});
class MyScreen extends StatelessWidget {
@override
Widget build(BuildContext context) {
return InheritedValue(
create: () => AppColors(buttonColor: Colors.blue),
child: Scaffold(
body: Center(child: MyButton()),
),
);
}
}
class MyButton extends StatelessWidget {
@override
Widget build(BuildContext context) {
final AppColors colors = InheritedValue<AppColors>.of(context);
return TextButton(
style: TextButton.styleFrom(foregroundColor: colors.buttonColor),
onPressed: () {},
child: const Text('Hello world'),
);
}
} |
| Before |
After |
import 'package:flutter/material.dart';
void main() {
runApp(MaterialApp(home: MyScreen()));
}
class AppColors extends InheritedWidget {
const AppColors({
required this.buttonColor,
required super.child,
});
final Color buttonColor;
static AppColors? maybeOf(BuildContext context) {
return context.dependOnInheritedWidgetOfExactType<AppColors>();
}
static AppColors of(BuildContext context) {
final AppColors? model = maybeOf(context);
assert(model != null);
return model!;
}
@override
bool updateShouldNotify(AppColors oldWidget) {
return oldWidget.buttonColor != buttonColor;
}
}
class MyScreen extends StatelessWidget {
@override
Widget build(BuildContext context) {
return AppColors(
buttonColor: Colors.blue,
child: Scaffold(
body: Center(child: MyButton()),
),
);
}
}
class MyButton extends StatelessWidget {
@override
Widget build(BuildContext context) {
return TextButton(
style: TextButton.styleFrom(
foregroundColor: AppColors.of(context).buttonColor,
),
onPressed: () {},
child: const Text('Hello world'),
);
}
} |
import 'package:flutter/material.dart';
void main() {
runApp(MaterialApp(home: MyScreen()));
}
class AppColors({required final Color buttonColor});
class MyScreen extends StatelessWidget {
@override
Widget build(BuildContext context) {
return InheritedValue.value(
value: AppColors(buttonColor: Colors.blue),
updateShouldNotify: (oldValue, newValue) {
return oldValue.buttonColor != newValue.buttonColor;
},
child: Scaffold(
body: Center(child: MyButton()),
),
);
}
}
class MyButton extends StatelessWidget {
@override
Widget build(BuildContext context) {
final AppColors colors = InheritedValue<AppColors>.of(context);
return TextButton(
style: TextButton.styleFrom(foregroundColor: colors.buttonColor),
onPressed: () {},
child: const Text('Hello world'),
);
}
} |
import 'package:flutter/material.dart';
void main() {
runApp(MaterialApp(home: CounterScreen()));
}
class AppColors({final Color buttonColor});
class CounterModel({final VoidCallback increment});
class CounterScreen extends StatefulWidget {
@override
State<CounterScreen> createState() => _CounterScreenState();
}
class _CounterScreenState extends State<CounterScreen> {
int counter = 0;
@override
Widget build(BuildContext context) {
return InheritedValue.multiple(
create: () => [
AppColors(buttonColor: Colors.blue),
CounterModel(increment: () => setState(() => counter++)),
],
child: Scaffold(
body: Center(child: Text('Count: $counter')),
floatingActionButton: IncrementButton(),
),
);
}
}
class IncrementButton extends StatelessWidget {
@override
Widget build(BuildContext context) {
final colors = InheritedValue<AppColors>.of(context);
final counter = InheritedValue<CounterModel>.of(context);
return FloatingActionButton(
foregroundColor: colors.buttonColor,
onPressed: counter.increment,
child: const Icon(Icons.add),
);
}
}