when<TResult extends Object?> method

  1. @optionalTypeArgs
TResult when<TResult extends Object?>(
  1. TResult $default(
    1. double? height,
    2. ExpressCheckoutButtonTheme? buttonTheme,
    3. ExpressCheckoutButtonType? buttonType,
    4. ExpressCheckoutLayout? layout,
    5. ExpressCheckoutPaymentMethods? paymentMethods,
    )
)

A switch-like method, using callbacks.

As opposed to map, this offers destructuring. It is equivalent to doing:

switch (sealedClass) {
  case Subclass(:final field):
    return ...;
  case Subclass2(:final field2):
    return ...;
}

Implementation

@optionalTypeArgs TResult when<TResult extends Object?>(TResult Function( double? height,  ExpressCheckoutButtonTheme? buttonTheme,  ExpressCheckoutButtonType? buttonType,  ExpressCheckoutLayout? layout,  ExpressCheckoutPaymentMethods? paymentMethods)  $default,) {final _that = this;
switch (_that) {
case _ExpressCheckoutOptions():
return $default(_that.height,_that.buttonTheme,_that.buttonType,_that.layout,_that.paymentMethods);case _:
  throw StateError('Unexpected subclass');

}
}