Indy9000

  @override
  void paint(Canvas canvas, Size size) {
    // compute the drawable chart width and height
    final drawableHeight = size.height - 2.0 * border;
    final drawableWidth = size.width - 2.0 * border;
    final hu = drawableHeight / 5.0; // height unit
    final wu = drawableWidth / _X.length.toDouble(); // width unit

    // compute box dimensions
    final boxH = hu * 3.0;

Indy9000

const WeekDays = ["", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"];

class LineChartPainter extends CustomPainter {
  final List<Score> scores;
  late double _min, _max;
  late List<double> _Y;
  late List<String> _X;
  LineChartPainter(this.scores) {
    var min = double.maxFinite;
    var max = -double.maxFinite;

Indy9000

class LineChartWidget extends StatelessWidget {
  final List<Score> scores;
  const LineChartWidget(this.scores, {Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Container(
        child: CustomPaint(
      child: Container(),
      painter: LineChartPainter(scores),

Indy9000

import 'dart:math';

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

final rng = Random();
const dayCount = 7;

class MyApp extends StatelessWidget {

Indy9000

class Score {
  final double value;
  final DateTime time;
  Score(this.value, this.time);
}

Indy9000

class _DonutChartWidgetState extends State<DonutChartWidget> {

  late Timer timer;
  double fullAngle = 0.0;
  double secondsToComplete = 3.0;

  @override
  void initState() {
    super.initState();
    timer = Timer.periodic(Duration(milliseconds: 1000 ~/ 60), (timer) {

Indy9000

void drawLabels(Canvas canvas, Offset c, double radius, double startAngle,
    double sweepAngle, String label) {
  final r = radius * 0.4;
  final dx = r * cos(startAngle + sweepAngle / 2.0);
  final dy = r * sin(startAngle + sweepAngle / 2.0);
  final position = c + Offset(dx, dy);
  drawTextCentered(canvas, position, label, labelStyle, 100.0, (Size sz) {
    final rect = Rect.fromCenter(
        center: position, width: sz.width + 5, height: sz.height + 5);
    final rrect = RRect.fromRectAndRadius(rect, Radius.circular(5));

Indy9000

  TextPainter measureText(
      String s, TextStyle style, double maxWidth, TextAlign align) {
    final span = TextSpan(text: s, style: style);
    final tp = TextPainter(
        text: span, textAlign: align, textDirection: TextDirection.ltr);
    // ellipsis: "...");
    tp.layout(minWidth: 0, maxWidth: maxWidth);
    return tp;
  }

Indy9000

void drawSector(Canvas canvas, DataItem di, Rect rect, double startAngle,
    double sweepAngle) {
  final paint = Paint()
    ..style = PaintingStyle.fill
    ..color = di.color;
  canvas.drawArc(rect, startAngle, sweepAngle, true, paint);
}

Indy9000

class DonutChartPainter extends CustomPainter {
  final List<DataItem> dataset;
  DonutChartPainter(this.dataset);

  @override
  void paint(Canvas canvas, Size size) {
    final c = Offset(size.width / 2.0, size.height / 2.0);
    final radius = size.width * 0.9;
    final rect = Rect.fromCenter(center: c, width: radius, height: radius);
    final fullAngle = 360.0;