AnimatedSwitcherLayoutBuilder typedef
Signature for builders used to generate custom layouts for AnimatedSwitcher.
The builder should return a widget which contains the given children, laid
out as desired. It must not return null. The builder should be able to
handle an empty list of previousChildren, or a null currentChild.
The previousChildren list is an unmodifiable list, sorted with the oldest
at the beginning and the newest at the end. It does not include the
currentChild.
Implementation
typedef AnimatedSwitcherLayoutBuilder = Widget Function(Widget currentChild, List<Widget> previousChildren);