bard flutter pie chart https://g.co/bard/share/bb4ed89ed37b

main.dart

// Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

import 'package:flutter/material.dart';
import 'dart:math' as math;

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

class PieChart extends CustomPainter {
  final List<double> data; // percentages for each slice
  final List<Color> colors; // colors for each slice

  PieChart({required this.data, required this.colors});

  @override
  void paint(Canvas canvas, Size size) {
    // calculate center and radius
    final center = Offset(size.width / 2, size.height / 2);
    final radius = math.min(size.width / 2, size.height / 2);

    // draw background circle
    final paint = Paint()
      ..color = Colors.grey.shade300
      ..style = PaintingStyle.fill;
    canvas.drawCircle(center, radius, paint);

    // calculate starting angle for each slice
    double startAngle = 0;

    // draw pie slices
    for (int i = 0; i < data.length; i++) {
      final sweepAngle = 2 * math.pi * data[i] / 100;
      final arcPaint = Paint()
        ..color = colors[i]
        ..style = PaintingStyle.fill;
      canvas.drawArc(
          Rect.fromCircle(center: center, radius: radius), startAngle, sweepAngle, true, arcPaint);
      startAngle += sweepAngle;
    }
  }

  @override
  bool shouldRepaint(PieChart oldDelegate) =>
      data != oldDelegate.data || colors != oldDelegate.colors;
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
        useMaterial3: true,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  final String title;

  const MyHomePage({
    Key? key,
    required this.title,
  }) : super(key: key);

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

List<double> data = [30, 20, 50];
List<Color> colors = [Colors.blue, Colors.green, Colors.orange];


class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            const Text(
              'You have pushed the button this many times:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.headlineMedium,
            ),
            CustomPaint(
              painter:
            PieChart( 
              data: data,
              colors: colors,),
            size: const Size(100,100))
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: const Icon(Icons.add),
      ),
    );
  }
}