onPaint method
Implementation
@override
void onPaint(PaintingContext context, Offset offset) {
context.canvas.save();
final Rect clip = clipRect(paintBounds, animationFactor,
isInversed: xAxis!.isInversed, isTransposed: isTransposed);
context.canvas.clipRect(clip);
paintSegments(context, offset);
context.canvas.restore();
paintMarkers(context, offset);
paintDataLabels(context, offset);
paintTrendline(context, offset);
}