Scale Route Transition Sample (encapsulates widget)

scale_route.dart

import 'package:flutter/material.dart';
class ScaleRoute extends PageRouteBuilder {
  final Widget widget;
  ScaleRoute({this.widget})
    : super(
        pageBuilder: (BuildContext context, Animation<double> animation, Animation<double> secondaryAnimation) {
          return widget;
        },
        transitionsBuilder: (BuildContext context, Animation<double> animation, Animation<double> secondaryAnimation, Widget child) {
          return new ScaleTransition(
            scale: new Tween<double>(
              begin: 0.0,
              end: 1.0,
            ).animate(
                CurvedAnimation(
                  parent: animation,
                  curve: Interval(
                    0.00,
                    0.50,
                    curve: Curves.linear,
                  ),
                ),
              ),
            child: ScaleTransition(
                     scale: Tween<double>(
                       begin: 1.5,
                       end: 1.0,
                     ).animate(
                       CurvedAnimation(
                         parent: animation,
                         curve: Interval(
                           0.50,
                           1.00,
                           curve: Curves.linear,
                         ),
                       ),
                     ),
                     child: child,
                   ),
           );
         }
      );
  
  //Later you can use this effect by calling
  import 'package:myapp/scale_route.dart'
  
  Navigator.push(
    context,
    ScaleRoute(widget: DetailScreen()),
  );