single<T> static method

Widget? single<T>({ required BuildContext context, required T valueBuilder(BuildContext context), required Map<T, Widget? Function(BuildContext context)> caseBuilders, required Widget? fallbackBuilder(BuildContext context), })

A function which returns a single Widget

• valueBuilder is a function which returns a value.
• caseBuilders is a Map of value to Widget builders, when one of the keys matches the value returns by valueBuilder, the corresponding Widget builder will be used.
• fallbackBuilder is a function which returns a Widget, it is used when none of the keys in caseBuildersmatches the value returns by valueBuilder.

Implementation

static Widget? single<T>({
  required BuildContext context,
  required T Function(BuildContext context) valueBuilder,
  required Map<T, Widget? Function(BuildContext context)> caseBuilders,
  required Widget? Function(BuildContext context) fallbackBuilder,
}) {
  final T value = valueBuilder(context);
  if (caseBuilders[value] != null) {
    return caseBuilders[value]!(context);
  } else {
    return fallbackBuilder(context);
  }
}