draw method

@override void draw(Canvas canvas, Size boardSize)

Implementation

@override
void draw(Canvas canvas, Size boardSize) {
  final Paint paint = Paint()
    ..color = color
    ..strokeWidth = size.height
    ..style = style;

  var path = Path();
  // Calculate arrowhead points
  double arrowheadLength = 10.0;
  double arrowheadAngle = pi / 6; // 30 degrees

  double angle =
      atan2(endOffset.dy - startOffset.dy, endOffset.dx - startOffset.dx);

  double arrowX1 =
      endOffset.dx - arrowheadLength * cos(angle - arrowheadAngle);
  double arrowY1 =
      endOffset.dy - arrowheadLength * sin(angle - arrowheadAngle);

  double arrowX2 =
      endOffset.dx - arrowheadLength * cos(angle + arrowheadAngle);
  double arrowY2 =
      endOffset.dy - arrowheadLength * sin(angle + arrowheadAngle);

  // Draw arrowhead
  path.moveTo(endOffset.dx, endOffset.dy);
  path.lineTo(arrowX1, arrowY1);
  path.moveTo(endOffset.dx, endOffset.dy);
  path.lineTo(arrowX2, arrowY2);

  // Draw the line
  canvas.drawPath(path, paint);

  if (isHighlight || isSelected) {
    paint.color = Colors.blue;
    paint.style = PaintingStyle.stroke;
    canvas.drawPath(path, paint);
  }
  super.draw(canvas, boardSize);
}