PopupMenuButton constructor Null safety

const PopupMenuButton(
  1. {Key? key,
  2. required List<PopupMenuEntry> items,
  3. String? initialValue,
  4. Callback? onOpened,
  5. FormStringField? field,
  6. Callback? onCanceled,
  7. String? tooltip,
  8. double? elevation,
  9. Color? shadowColor,
  10. Color? surfaceTintColor,
  11. EdgeInsets padding,
  12. Widget? child,
  13. double? splashRadius,
  14. Widget? icon,
  15. double? iconSize,
  16. Offset offset,
  17. bool enabled,
  18. ShapeBorder? shape,
  19. Color? color,
  20. bool? enableFeedback,
  21. BoxConstraints? constraints,
  22. PopupMenuPosition? position,
  23. Clip clipBehavior}
)

Implementation

const factory PopupMenuButton(
    {final Key? key,
    required final List<PopupMenuEntry> items,
    final String? initialValue,
    final Callback? onOpened,
    final FormStringField? field,
    final Callback? onCanceled,
    final String? tooltip,
    final double? elevation,
    final Color? shadowColor,
    final Color? surfaceTintColor,
    final EdgeInsets padding,
    final Widget? child,
    final double? splashRadius,
    final Widget? icon,
    final double? iconSize,
    final Offset offset,
    final bool enabled,
    final ShapeBorder? shape,
    final Color? color,
    final bool? enableFeedback,
    final BoxConstraints? constraints,
    final PopupMenuPosition? position,
    final Clip clipBehavior}) = _$PopupMenuButton;