import 'package:flutter/material.dart';

void main() {
  return runApp(const MaterialApp(home: TextScaleFactorReactor()));
}

class TextScaleFactorReactor extends StatefulWidget {
  const TextScaleFactorReactor({super.key});

  @override
  State<TextScaleFactorReactor> createState() => _TextScaleFactorReactorState();
}

class _TextScaleFactorReactorState extends State<TextScaleFactorReactor>
    with WidgetsBindingObserver {
  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addObserver(this);
  }

  @override
  void dispose() {
    WidgetsBinding.instance.removeObserver(this);
    super.dispose();
  }

  double _lastTextScaleFactor =
      WidgetsBinding.instance.platformDispatcher.textScaleFactor;

  @override
  void didChangeTextScaleFactor() {
    setState(() {
      _lastTextScaleFactor =
          WidgetsBinding.instance.platformDispatcher.textScaleFactor;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Text('Current scale factor: $_lastTextScaleFactor');
  }
}