Round Linear progress indicator

linear_indicator.dart

class RoundLinearProgress extends StatelessWidget {
  const RoundLinearProgress({super.key, double progress = 0})
      : _progress = progress,
        assert(
          progress >= 0 && progress <= 100,
          'indicator progress must be between 0 and 100',
        );

  final double _progress;

  @override
  Widget build(BuildContext context) {
    return TweenAnimationBuilder(
      curve: Curves.easeInOut,
      duration: const Duration(milliseconds: 1300),
      tween: Tween<double>(begin: 0, end: _progress),
      builder: (_, progressValue, __) {
        return CustomPaint(
          painter: ProgressPainter(progressValue),
          size: const Size(double.infinity, 8),
        );
      },
    );
  }
}

class ProgressPainter extends CustomPainter {
  final double progress;

  const ProgressPainter([this.progress = 0]);

  @override
  void paint(Canvas canvas, Size size) {
    final paint = Paint()
      ..strokeCap = StrokeCap.round
      ..strokeWidth = size.height
      ..style = PaintingStyle.stroke
      ..color = Colors.blueAccent.withOpacity(0.3);
    final foregroundPaint = Paint()
      ..strokeCap = StrokeCap.round
      ..strokeWidth = size.height
      ..style = PaintingStyle.stroke
      ..color = Colors.blue;

    final bgPath = Path()
      ..moveTo(0, size.height)
      ..lineTo(size.width, size.height);

    final fgPath = Path()
      ..moveTo(0, size.height)
      ..lineTo((progress / 100) * size.width, size.height);

    canvas.drawPath(bgPath, paint);
    canvas.drawPath(fgPath, foregroundPaint);
  }

  @override
  bool shouldRepaint(CustomPainter oldDelegate) {
    if (oldDelegate is! ProgressPainter) return false;
    if (oldDelegate.progress == progress) return false;

    return true;
  }
}