I took some code from stack overflow which open an overlay with transparent background but my issue is when I put a text field in the center so when pressing on it the screen not scroll to top, the text field hide behind the keyboard.

I tried to put SingleChildScrollView in Center widget and doesn't work!

any one help please

import 'package:flutter/material.dart';
import 'package:smooth_star_rating/smooth_star_rating.dart';

class feedback extends ModalRoute<void> {

    TextEditingController _reviewController = TextEditingController();

    @override
    Duration get transitionDuration => Duration(milliseconds: 700);

    @override
    bool get opaque => false;

    @override
    bool get barrierDismissible => false;

    @override
    Color get barrierColor => Colors.black.withOpacity(0.5);

    @override
    String get barrierLabel => null;

    @override
    bool get maintainState => true;

    @override
    Widget buildPage(BuildContext context,
        Animation<double> animation,
        Animation<double> secondaryAnimation,) {
        // This makes sure that text and other content follows the material style
        return Material(
            type: MaterialType.transparency,
            // make sure that the overlay content is not cut off
            child: SafeArea(
                child: _buildOverlayContent(context),
            ),
        );
    }

    Widget _buildOverlayContent(BuildContext context) {
        return  new GestureDetector(
            onTap: () {
                FocusScope.of(context).requestFocus(new FocusNode());
            },
            child: Center( 
              child: Column(
                  mainAxisAlignment: MainAxisAlignment.center,
                  crossAxisAlignment: CrossAxisAlignment.center,
                  children: [
                      Container(
                          decoration: BoxDecoration( 
                              color: Colors.grey[50],
                              boxShadow: [
                                  BoxShadow(
                                      color: Colors.grey[300],
                                      offset: Offset(0.0, 1.0), //(x,y)
                                      blurRadius: 6.0,
                                  ),
                              ],
                              borderRadius: new BorderRadius.all(const Radius.circular(15))
                          ),
                          margin: EdgeInsets.all(10),
                          alignment: Alignment.center,
                          child: Column(
                              mainAxisAlignment: MainAxisAlignment.center,
                              crossAxisAlignment: CrossAxisAlignment.center,
                              mainAxisSize: MainAxisSize.min,
                              children:[
                                  Container(
                                      color: Colors.grey[50],
                                    //  padding: EdgeInsets.only(right: 5, top: 8),
                                      alignment: Alignment.topRight,
                                      child: IconButton(
                                          icon: Icon(Icons.close_rounded, color: Colors.grey),
                                          onPressed: () {

                                          }),
                                  ),
                                  Container(
                                      color: Colors.grey[50],
                                      padding: EdgeInsets.only(top: 20),
                                      alignment: Alignment.center,
                                      child: Text(
                                          "Send us your feedback!",
                                          style: new TextStyle(
                                              fontSize: 25,
                                              color: Colors.blue
                                          ),
                                      )
                                  ),
                                  Container(
                                      color: Colors.grey[50],
                                      padding: EdgeInsets.only(top: 8),
                                      alignment: Alignment.center,
                                      child: Text(
                                          "Rate this service",
                                          style: new TextStyle(
                                              fontSize: 17,
                                              color: Colors.grey[700]
                                          ),
                                      )
                                  ),
                                  Container(
                                      color: Colors.grey[50],
                                      padding: EdgeInsets.only(top: 30),
                                      child: SmoothStarRating(
                                          starCount: 5,
                                          rating: 4,
                                          size: 40.0,
                                          isReadOnly: false,
                                          //    fullRatedIconData: Icons.blur_off,
                                          //  halfRatedIconData: Icons.blur_on,
                                          color: Colors.amber,
                                          borderColor: Colors.amber,
                                          spacing: 0.0
                                      )
                                  ),
                                  Container(
                                      color: Colors.grey[50],
                                      padding: EdgeInsets.only(
                                          top: 40, left: 18, right: 18),
                                      child: TextFormField(
                                        maxLines: 3,
                                          autovalidateMode: AutovalidateMode
                                              .onUserInteraction,
                                          controller: _reviewController,
                                          decoration: InputDecoration(
                                              border: OutlineInputBorder(),
                                              labelText: 'Write a review',
                                              hintText: ''
                                          ),
                                      ),
                                  ),
                                  Container(
                                      color: Colors.grey[50],
                                      padding: EdgeInsets.only(top: 30, bottom: 20),
                                      child: RaisedButton(
                                          color: Colors.blue,
                                          shape: RoundedRectangleBorder(
                                              borderRadius: BorderRadius.circular(50)
                                          ),
                                          child: Text("Send", style: new TextStyle(
                                              fontSize: 20, color: Colors.white)),
                                          onPressed: () {

                                          },
                                      )
                                  )
                              ]
                          )
                      )
                    ]
            )
          )
      );
    }

    @override
    Widget buildTransitions(BuildContext context, Animation<double> animation,
        Animation<double> secondaryAnimation, Widget child) {
        return FadeTransition(
            opacity: animation,
            child: ScaleTransition(
                scale: animation,
                child: child,
            ),
        );
    }
}


Solution 1: HeIsDying

May try the code below, should work fine,

class DebugErrorClass2 extends StatefulWidget {
  DebugErrorClass2({
    Key? key,
  }) : super(key: key);

  @override
  _DebugErrorClass2State createState() => _DebugErrorClass2State();
}

class _DebugErrorClass2State extends State<DebugErrorClass2> {

  @override
  void initState() {
    super.initState();
  }

  @override
  void dispose() {
    super.dispose();
  }

  Widget _buildOverlayContent() {
    return new GestureDetector(
        onTap: () {
          FocusScope.of(context).requestFocus(new FocusNode());
        },
        child: Center(
            child: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                crossAxisAlignment: CrossAxisAlignment.center,
                children: [
                  Container(
                      decoration: BoxDecoration(
                          color: Colors.grey[50],
                          boxShadow: [
                            BoxShadow(
                              color: Colors.red,
                              offset: Offset(0.0, 1.0), //(x,y)
                              blurRadius: 6.0,
                            ),
                          ],
                          borderRadius: new BorderRadius.all(
                              const Radius.circular(15))
                      ),
                      margin: EdgeInsets.all(10),
                      alignment: Alignment.center,
                      child: Column(
                          mainAxisAlignment: MainAxisAlignment.center,
                          crossAxisAlignment: CrossAxisAlignment.center,
                          mainAxisSize: MainAxisSize.min,
                          children: [
                            Container(
                              color: Colors.grey[50],
                              //  padding: EdgeInsets.only(right: 5, top: 8),
                              alignment: Alignment.topRight,
                              child: IconButton(
                                  icon: Icon(
                                      Icons.close_rounded, color: Colors.grey),
                                  onPressed: () {

                                  }),
                            ),
                            Container(
                                color: Colors.grey[50],
                                padding: EdgeInsets.only(top: 20),
                                alignment: Alignment.center,
                                child: Text(
                                  "Send us your feedback!",
                                  style: new TextStyle(
                                      fontSize: 25,
                                      color: Colors.blue
                                  ),
                                )
                            ),
                            Container(
                                color: Colors.grey[50],
                                padding: EdgeInsets.only(top: 8),
                                alignment: Alignment.center,
                                child: Text(
                                  "Rate this service",
                                  style: new TextStyle(
                                      fontSize: 17,
                                      color: Colors.grey[700]
                                  ),
                                )
                            ),
                            Container(
                                color: Colors.grey[50],
                                padding: EdgeInsets.only(top: 30),
                                child: SmoothStarRating(
                                    starCount: 5,
                                    rating: 4,
                                    size: 40.0,
                                    isReadOnly: false,
                                    //    fullRatedIconData: Icons.blur_off,
                                    //  halfRatedIconData: Icons.blur_on,
                                    color: Colors.amber,
                                    borderColor: Colors.amber,
                                    spacing: 0.0
                                )
                            ),
                            Container(
                              color: Colors.grey[50],
                              padding: EdgeInsets.only(
                                  top: 40, left: 18, right: 18),
                              child: TextFormField(
                                maxLines: 3,
                                autovalidateMode: AutovalidateMode
                                    .onUserInteraction,
//                                controller: _reviewController,
                                decoration: InputDecoration(
                                    border: OutlineInputBorder(),
                                    labelText: 'Write a review',
                                    hintText: ''
                                ),
                              ),
                            ),
                            Container(
                                color: Colors.grey[50],
                                padding: EdgeInsets.only(top: 30, bottom: 20),
                                child: RaisedButton(
                                  color: Colors.blue,
                                  shape: RoundedRectangleBorder(
                                      borderRadius: BorderRadius.circular(50)
                                  ),
                                  child: Text("Send", style: new TextStyle(
                                      fontSize: 20, color: Colors.white)),
                                  onPressed: () {

                                  },
                                )
                            )
                          ]
                      )
                  )
                ]
            )
        )
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: SafeArea(
        child: Container(
          alignment: Alignment.center,
          width: double.infinity,
          height: double.infinity,
          child: SingleChildScrollView(
            child: Column(
              mainAxisAlignment: MainAxisAlignment.center,
              crossAxisAlignment: CrossAxisAlignment.center,
              children: [
                _buildOverlayContent(),

              ],
            ),
          ),
        ),
      ),
    );
  }
}