draw method
Implementation
@override
void draw(Canvas canvas, Paint paint, Offset offset, Size size) {
paint.reset();
paint.style = fill ? PaintingStyle.fill : PaintingStyle.stroke;
if (!fill) {
paint.strokeWidth = strokeWidth;
}
paint.color = outerColor;
double radius = min(size.width, size.height) * 0.5;
canvas.drawCircle(offset, outerRadius.convert(radius), paint);
double ir = innerRadius.convert(radius);
if (ir > 0) {
paint.color = innerColor;
canvas.drawCircle(offset, ir, paint);
}
}