createBoxPainter method Null safety

  1. @override
BoxPainter createBoxPainter(
  1. [VoidCallback? onChanged]
)
override

Returns a BoxPainter that will paint this decoration.

The onChanged argument configures BoxPainter.onChanged. It can be omitted if there is no chance that the painter will change (for example, if it is a BoxDecoration with definitely no DecorationImage).

Implementation

@override
BoxPainter createBoxPainter([ VoidCallback? onChanged ]) {
  assert(onChanged != null || image == null);
  return _ShapeDecorationPainter(this, onChanged!);
}