drawVerticalText method
Implementation
@override
void drawVerticalText(canvas, textStyle, int gridRows) {
TextSpan span = TextSpan(text: "${NumberUtil.format(maxValue)}", style: textStyle);
TextPainter tp = TextPainter(text: span, textDirection: TextDirection.ltr);
tp.layout();
tp.paint(canvas, Offset(chartRect.width - tp.width - style.padding.right, chartRect.top - style.padding.top));
}