How to wrap a derived RaisedButton object with SizedBox in its own class?

Question

I have a class MyButton derived from RaisedButton as follows.

class MyButton extends RaisedButton {
  final double height;

  MyButton({
    String text,
    VoidCallback onPressed,
    this.height,
  }) : super(child: Text(text), onPressed: onPressed);

  @override
  Widget build(BuildContext context) => SizedBox(
        height: height,
        child: this,
      );
}

I use it in the main method as follows.

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('Hello World'),
        ),
        body: Center(
          child: MyButton(text: 'Press Me', height: 80, onPressed: () {}),
        ),
      ),
    );
  }
}

It produces a blank white page with some errors

The following StackOverflowError was thrown building MyButton:

Question

How to wrap the derived RaisedButton with SizedBox in its own class?

score 1 · Accepted Answer · answered Nov 03 '20 at 11:19

1

Why do you want to extend RaisedButton?

Another way is to simply create a custom widget:

class MyButton {
  final double height;
  final String text;
  final VoidCallback onPressed;
 
  MyButton({
    this.text,
    this.onPressed,
    this.height,
  });

  @override
  Widget build(BuildContext context) => SizedBox(
        height: height,
        child: RaisedButton(child: Text(text), onPressed: onPressed),
      );
}

answered Nov 03 '20 at 11:19

Farhan Syah

753
3
14

I know this approach. I want to learn how to extend `RaisedButton` and do composition. – Second Person Shooter Nov 03 '20 at 11:22
By default, you should not extend any widget, but if you have the need and still want to use that way, try reading this post https://stackoverflow.com/questions/51476234/subclass-a-class-that-extends-statelesswidget-or-statefulwidget-class – Farhan Syah Nov 03 '20 at 11:24
Thank you very much. Let me wait for a couple of hours or days to accept the best answer. – Second Person Shooter Nov 03 '20 at 11:26

How to wrap a derived RaisedButton object with SizedBox in its own class?

Question

1 Answers1