Flutter for Beginners

Defining CustomPainter

The RadialChartPainter class, like the RadialChart widget, differs in very specific parts from PieChartPainter, which was defined before. At first glance, its paint() method is almost the same as in the from pie chart:

// part of radial_chart.dart RadialChartPainter class  @override  void paint(Canvas canvas, Size size) {    var center = Offset(size.width / 2, size.height / 2);    var radius = size.width * 0.75 / 2;    Rect chartRect = Rect.fromCircle(      center: center,      radius: radius,    );    int total = values.reduce((a, b) => a + b);    _paintTotal(canvas, total, chartRect);    _paintCircle(canvas, total, chartRect);  } 

As you can see, the only difference is the additional call to _paintTotal(canvas, total, chartRect);.

Before we check ...