borderRadius property
Computes the visual border radius from the current crop rect.
Lets the radius scale with the rect's dimensions — e.g.,
(r) => BorderRadius.circular(r.shortestSide / 2) for a circular
preview, (r) => BorderRadius.circular(r.shortestSide / 8) for a
soft-rounded square. Null = rectangular preview.
Implementation
final BorderRadius Function(Rect cropRect)? borderRadius;