maybeWhen<TResult extends Object?> method

  1. @optionalTypeArgs
TResult maybeWhen<TResult extends Object?>(
  1. TResult $default(
    1. double scrollOffsetX,
    2. double scrollOffsetY,
    3. double viewportWidth,
    4. double viewportHeight,
    5. int firstVisibleRow,
    6. int lastVisibleRow,
    7. int firstVisibleColumn,
    8. int lastVisibleColumn,
    )?, {
  2. required TResult orElse(),
})

A variant of when that fallback to an orElse callback.

It is equivalent to doing:

switch (sealedClass) {
  case Subclass(:final field):
    return ...;
  case _:
    return orElse();
}

Implementation

@optionalTypeArgs TResult maybeWhen<TResult extends Object?>(TResult Function( double scrollOffsetX,  double scrollOffsetY,  double viewportWidth,  double viewportHeight,  int firstVisibleRow,  int lastVisibleRow,  int firstVisibleColumn,  int lastVisibleColumn)?  $default,{required TResult orElse(),}) {final _that = this;
switch (_that) {
case _ViewportState() when $default != null:
return $default(_that.scrollOffsetX,_that.scrollOffsetY,_that.viewportWidth,_that.viewportHeight,_that.firstVisibleRow,_that.lastVisibleRow,_that.firstVisibleColumn,_that.lastVisibleColumn);case _:
  return orElse();

}
}