drawGaugePointer method
Draws the main scale of the Gauge
Implementation
void drawGaugePointer(Canvas canvas, Size size) {
final halfMajorStrokeWidth = majorTickStrokeWidth / 2;
final Offset upperLimitDisplay = Offset(
size.width / 2, getActualValuePosition(size) - halfMajorStrokeWidth);
final Offset lowerLimitDisplay =
Offset(size.width / 2, getScaleLowerLimit(size) + halfMajorStrokeWidth);
final gaugeScalePainter = Paint()
..color = pointerColor
..strokeWidth = rangeStrokeWidth;
canvas.drawLine(lowerLimitDisplay, upperLimitDisplay, gaugeScalePainter);
}