didChangeNext method Null safety
- Route? nextRoute
override
This route's next route has changed to the given new route.
This is called on a route whenever the next route changes for any reason, so long as it is in the history, including when a route is first added to a Navigator (e.g. by Navigator.push), except for cases when didPopNext would be called.
The nextRoute argument will be null if there's no new next route (i.e.
if isCurrent is true).
Implementation
@override
void didChangeNext(Route<dynamic>? nextRoute) {
assert(_controller != null, '$runtimeType.didChangeNext called before calling install() or after calling dispose().');
assert(!_transitionCompleter.isCompleted, 'Cannot reuse a $runtimeType after disposing it.');
_updateSecondaryAnimation(nextRoute);
super.didChangeNext(nextRoute);
}