drawSegment method

void drawSegment(Canvas canvas, FastChartData datum, double startAngle, double sweepAngle, Paint paint, Rect rect, double radius, double labelRadius,)

Implementation

void drawSegment(
  Canvas canvas,
  FastChartData datum,
  double startAngle,
  double sweepAngle,
  Paint paint,
  Rect rect,
  double radius,
  double labelRadius,
) {
  canvas.drawArc(
    rect,
    degreesToRadian(startAngle),
    degreesToRadian(sweepAngle),
    paint.style == PaintingStyle.fill,
    paint,
  );

  if (showLabel && datum.value >= labelValueThreshold) {
    // Draw the percentage text in the middle of the segment
    final textPainter = TextPainter(
      text: TextSpan(
        text: formatPercentage(
          value: datum.value,
          maximumFractionDigits: 1,
          minimumFractionDigits: 0,
        ),
        style: const TextStyle(
          fontWeight: kFastFontWeightLight,
          fontSize: kFastFontSize10,
          color: Colors.white,
        ),
      ),
      textDirection: TextDirection.ltr,
    )..layout();

    final labelAngle = startAngle + sweepAngle / 2;
    final labelX = radius + labelRadius * cos(degreesToRadian(labelAngle));
    final labelY = radius + labelRadius * sin(degreesToRadian(labelAngle));

    textPainter.paint(
      canvas,
      Offset(labelX - textPainter.width / 2, labelY - textPainter.height / 2),
    );
  }
}