import 'package:flutter/material.dart'; class LineChartPainter extends CustomPainter { final List data; LineChartPainter(this.data); @override void paint(Canvas canvas, Size size) { // Calculate the scale factor. final scaleFactor = size.height / 240; // Draw the line chart. for (var i = 0; i < data.length - 1; i++) { final x1 = i * size.width / data.length; final y1 = data[i] * scaleFactor; final x2 = (i + 1) * size.width / data.length; final y2 = data[i + 1] * scaleFactor; canvas.drawLine(Offset(x1, y1), Offset(x2, y2), Paint()); } } @override bool shouldRepaint(LineChartPainter oldDelegate) => false; }