import 'package:flutter/material.dart'; class SmoothTransition extends PageRouteBuilder { final Widget page; SmoothTransition({required this.page}) : super( pageBuilder: ( BuildContext context, Animation animation, Animation secondaryAnimation, ) => TweenAnimationBuilder( duration: const Duration(seconds: 5), tween: Tween(begin: 200, end: 200), builder: (BuildContext context, dynamic value, Widget? child) { return page; }, ), ); }