code: private void drawCenterCircle(Canvas canvas) {
          final PieChartData data = dataProvider.getPieChartData();
          final float circleRadius = originCircleOval.width() / 2f;
          final float centerRadius = circleRadius * data.getCenterCircleScale();
          final float centerX = originCircleOval.centerX();
          final float centerY = originCircleOval.centerY();
  
          canvas.drawCircle(centerX, centerY, centerRadius, centerCirclePaint);
  
          // Draw center text1 and text2 if not empty.
          if (!TextUtils.isEmpty(data.getCenterText1())) {
  
              final int text1Height = Math.abs(centerCircleText1FontMetrics.ascent);
  
              if (!TextUtils.isEmpty(data.getCenterText2())) {
                  // Draw text 2 only if text 1 is not empty.
                  final int text2Height = Math.abs(centerCircleText2FontMetrics.ascent);
                  canvas.drawText(data.getCenterText1(), centerX, centerY - text1Height * 0.2f, centerCircleText1Paint);
                  canvas.drawText(data.getCenterText2(), centerX, centerY + text2Height, centerCircleText2Paint);
              } else {
                  canvas.drawText(data.getCenterText1(), centerX, centerY + text1Height / 4, centerCircleText1Paint);
              }
          }
      }
docs: Draw center circle with text if {@link PieChartData#hasCenterCircle()} is set true.