Flutter Widget | 96 | 3. Circular Chart [Random Radial Chart] Useful Widget in Flutter

 Here is the video tutorial

Code

main.dart

import 'dart:math'; import 'dart:math' as Math; import 'package:flutter/material.dart';
import 'package:flutter_circular_chart/flutter_circular_chart.dart';
class ColorPalette {
static final ColorPalette _palette = ColorPalette(<Color>[
Color(0xFFC41A3B),
Colors.pinkAccent,
Color(0xFF1B1F32),
Colors.blue,
Colors.green,
Colors.yellow,
Colors.purple,
Colors.orange,
Colors.teal,
]);
ColorPalette(List<Color> _colors) : _color = _colors {
assert(_colors.isNotEmpty);
}
final List<Color> _color;
Color operator [](int index) => _color[index % _length];
int get _length => _color.length;
Color _random(Random _random) => this[_random.nextInt(_length)];
}
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
debugShowCheckedModeBanner: false,
title: 'Flutter Demo',
theme: ThemeData(
primaryColor: Color(0xFFC41A3B),
primaryColorLight: Color(0xFFFBE0E6),
accentColor: Color(0xFF1B1F32),
),
home: MyHomePage(),
);
}
}
class MyHomePage extends StatefulWidget {
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
final GlobalKey<AnimatedCircularChartState> _chartkey = GlobalKey<AnimatedCircularChartState>();
String title = 'Circular Chart (3. Random Radial Chart)';
List<CircularStackEntry> _chartData;
final _size = Size(400.0, 400.0);
final Math.Random _random = Math.Random();
@override
void initState() {
super.initState();
_chartData = _generateRandomData();
}
void _randoms() {
setState(() {
_chartData = _generateRandomData();
_chartkey.currentState.updateData(_chartData);
});
}
List<CircularStackEntry> _generateRandomData() {
int _stackCount = _random.nextInt(16);
List<CircularStackEntry> _chartData = List.generate(_stackCount, (index) {
int _segmentCount = _random.nextInt(16);
List<CircularSegmentEntry> _segment = List.generate(_segmentCount, (j) {
Color _randomColor = ColorPalette._palette._random(_random);
return CircularSegmentEntry(_random.nextDouble(), _randomColor);
});
return CircularStackEntry(_segment);
});
return _chartData;
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(title),
centerTitle: true,
),
body: Center(
child: AnimatedCircularChart(
key: _chartkey,
size: _size,
initialChartData: _chartData,
chartType: CircularChartType.Radial,
),
),
floatingActionButton: FloatingActionButton(
onPressed: _randoms,
backgroundColor: Color(0xFFC41A3B),
child: Icon(Icons.refresh),
),
);
}
}