drawMaxAndMin method

@override void drawMaxAndMin(Canvas canvas)

Implementation

@override
void drawMaxAndMin(Canvas canvas) {
  if (isLine == true) return;
  double lineSize = 20;
  double lineToTextOffset = 5;

  Paint linePaint = Paint()
    ..strokeWidth = 1
    ..color = chartColors.minColor;

  //绘制最大值和最小值
  double x = translateXtoX(getX(mMainMinIndex));
  double y = getMainY(mMainLowMinValue);
  if (x < mWidth / 2) {
    //画右边
    TextPainter tp = getTextPainter(
      mMainLowMinValue.toStringAsFixed(fixedLength),
      chartColors.minColor,
    );

    canvas.drawLine(
      Offset(x, y),
      Offset(x + lineSize, y),
      linePaint,
    );

    tp.paint(
      canvas,
      Offset(
        x + lineSize + lineToTextOffset,
        y - tp.height / 2,
      ),
    );
  } else {
    TextPainter tp = getTextPainter(
      mMainLowMinValue.toStringAsFixed(fixedLength),
      chartColors.minColor,
    );

    canvas.drawLine(
      Offset(x, y),
      Offset(x - lineSize, y),
      linePaint,
    );

    tp.paint(
      canvas,
      Offset(
        x - tp.width - lineSize - lineToTextOffset,
        y - tp.height / 2,
      ),
    );
  }
  x = translateXtoX(getX(mMainMaxIndex));
  y = getMainY(mMainHighMaxValue);
  if (x < mWidth / 2) {
    //画右边
    TextPainter tp = getTextPainter(
      mMainHighMaxValue.toStringAsFixed(fixedLength),
      chartColors.maxColor,
    );

    canvas.drawLine(
      Offset(x, y),
      Offset(x + lineSize, y),
      linePaint,
    );

    tp.paint(
      canvas,
      Offset(
        x + lineSize + lineToTextOffset,
        y - tp.height / 2,
      ),
    );
  } else {
    TextPainter tp = getTextPainter(
      mMainHighMaxValue.toStringAsFixed(fixedLength),
      chartColors.maxColor,
    );

    canvas.drawLine(
      Offset(x, y),
      Offset(x - lineSize, y),
      linePaint,
    );

    tp.paint(
      canvas,
      Offset(
        x - tp.width - lineSize - lineToTextOffset,
        y - tp.height / 2,
      ),
    );
  }
}