flutter_ring_indicator/lib/main.dart

import 'dart:math';

import 'package:flutter/material.dart';
import 'package:flutter_ring_indicator/ring_indicator.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const FittedBox(
        fit: BoxFit.fitWidth,
        child: SizedBox(
          width: 720,
          height: 1080,
          child: MyHomePage(title: 'Flutter Demo Home Page'),
        ),
      ),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  double value = 0;

  void _incrementCounter() {
    setState(() {
      value = Random().nextDouble() * 100;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            SizedBox.square(
              dimension: 100,
              child: RingIndicator(
                ringColor: Colors.deepPurpleAccent,
                startAngel: pi * -0.7,
                endAngel: pi * 0.7,
                maxValue: 100,
                value: value,
                labelBuilder: (value) => Center(
                    child: Text(
                  value.toStringAsFixed(1),
                  style: const TextStyle(color: Colors.teal, fontSize: 24),
                )),
              ),
            ),
            Text(
              '$value',
              style: Theme.of(context).textTheme.headline4,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: const Icon(Icons.add),
      ),
    );
  }
}