drawText method
Implementation
void drawText(Canvas canvas, Size size, String text, Offset offset) {
textPainter.text = TextSpan(style: textStyle, text: text);
textPainter.layout();
textPainter.paint(canvas, Offset((offset.dx - (textPainter.width * 0.5)), offset.dy - (textPainter.height) * 0.5));
}