scaled_app

Scale the entire UI design proportionally.

Button, image, font, every widget is scaled simultaneously.

Before:

• 250x250 square is the same size across devices

After:

• 250x250 square is two thirds the screen width across devices

• if we resize the screenshots above to be the same width
• then everything appears the same size as below

Sponsor

This package is sponsored by 庞征博引, which breaks complex subjects into 5–10 minute reads you work through, and ask questions about, at your own pace.

Live demo

https://lastmonopoly.github.io/flutter_web_app/scaled_app_demo/

Features

Use this package in your Flutter app when:

• your UI design is fixed-width
• you want to scale the entire UI, not just part of it

Usage

Firstly, replace runApp with runAppScaled

void main() {
  // 1st way to use this package
  runAppScaled(const MyApp(), scaleFactor: (deviceSize) {
    // screen width used in your UI design
    const double widthOfDesign = 375;
    return deviceSize.width / widthOfDesign;
  });
}

Or, replace WidgetsFlutterBinding with ScaledWidgetsFlutterBinding

void main() {
  // 2nd way to use this package
  // Scaling will be applied based on [scaleFactor] callback.
  ScaledWidgetsFlutterBinding.ensureInitialized(
    scaleFactor: (deviceSize) {
      // screen width used in your UI design
      const double widthOfDesign = 375;
      return deviceSize.width / widthOfDesign;
    },
  );
  runApp(const MyApp());
}

Then, use MediaQueryData.scale to scale size, viewInsets, viewPadding, etc.

class PageRoute extends StatelessWidget {
  const PageRoute({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MediaQuery(
      data: MediaQuery.of(context).scale(),
      child: const Scaffold(...),
    );
  }
}

Optionally, update ScaledWidgetsFlutterBinding.instance.scaleFactor to enable / disable scaling on demand.

Reference

https://juejin.cn/post/7078816723666731021