LayoutBuilder constructor Null safety

const LayoutBuilder(
  1. {Key? key,
  2. required LayoutWidgetBuilder builder}
)

Creates a widget that defers its building until layout.

The builder argument must not be null.

Implementation

const LayoutBuilder({
  Key? key,
  required LayoutWidgetBuilder builder,
}) : assert(builder != null),
     super(key: key, builder: builder);