Flutter :- Keyboard causes layout to overflow on the bottom when on focus

Question

I have the following code for a layout.

@override
Widget build(BuildContext context) {
return Material(
  child: Scaffold(

//        resizeToAvoidBottomPadding: false,
//        resizeToAvoidBottomInset: false,
    appBar: PreferredSize(
      preferredSize: Size.fromHeight(70),
      child: AppBar(
        centerTitle: true,
        title: AutoSizeText(
          meal['name'],
          minFontSize: 30,
          maxFontSize: 50,
        ),
        backgroundColor: Colors.black,
        elevation: 1,
        actions: <Widget>[
          IconButton(
            icon: Icon(Icons.add),
            onPressed: () => null,
          ),
        ],
      ),
    ),
    body: Builder(
      builder: (context) {
        return Container(
          color: Colors.black,
          alignment: Alignment.center,
          child: FractionallySizedBox(
            widthFactor: 0.85,
            child: Container(
              child: Column(
                children: <Widget>[
                  Spacer(flex: 1,),
                  Container(
                    margin: EdgeInsets.only(bottom: 50),
                    child: Column(
                      children: <Widget>[
                        Container(
                          decoration: BottomWhiteDecoration(6.0),
                          padding: EdgeInsets.only(bottom: 8.0),
                          child: Row(
                            mainAxisAlignment: MainAxisAlignment.spaceBetween,
                            children: <Widget>[
                              Text(
                                'Servings: 1',
                                style: TextStyle(color: Colors.white),
                              ),
                            ],
                          ),
                        ),
                        Container(
                          child: Column(
                            children: <Widget>[
                              RowNutrimentalInfo('Calories', meal['calories'], showGram: false),
                              RowNutrimentalInfo('Protein', meal['macros']['proteins']),
                              RowNutrimentalInfo('Carbs', meal['macros']['carbs']),
                              RowNutrimentalInfo('Fat', meal['macros']['fats']),
                            ],
                          ),
                        )
                      ],
                    ),
                  ),
                Spacer(flex: 2,),
                  Container(
                    child: Column(
                      children: <Widget>[
                        Form(
                          key: this._mealFormKey,
                          child: Row(
                            children: <Widget>[
                              Expanded(
                                flex: 10,
                                child: TextFormField(...),
                              ),
                              Spacer(flex: 1,),
                              Expanded(
                                flex: 10,
                                child: TextFormField(...),
                              ),
                            ],
                          ),
                        ),
                        FractionallySizedBox(
                          widthFactor: .50,
                          child: OutlineButton(
                            borderSide: BorderSide(color: Colors.white),
                            color: Colors.black,
                            onPressed: _eatMeal,
                            child: Padding(
                              padding: EdgeInsets.all(20),
                              child: Text('Ok',
                                  style: TextStyle(color: Colors.white)),
                            ),
                          ),
                        )
                      ],
                    ),
                  ),
                  Spacer(flex: 2,),
                ],
              ),
            ),
          ),
        );
      },
    ),
  ),
);
}

However when I start typing in one of the text fields the keyboard causes the layout to overflow on the bottom as shown in the following image.

The following is the error I'm getting and how it is displayed on the the phone. Any ideas to get around this? I've seen similar questions, solutions like setting resizeToAvoidBottomPadding: false, don't work for me as the keyboard still covers the text input.

The following assertion was thrown during layout:
A RenderFlex overflowed by 45 pixels on the bottom.

The relevant error-causing widget was: 
Column file:///C:/Users/bolon/StudioProjects/macro_counter/lib/Meal.dart:92:26
The overflowing RenderFlex has an orientation of Axis.vertical.
The edge of the RenderFlex that is overflowing has been marked in the rendering with a yellow and 
black striped pattern. This is usually caused by the contents being too big for the RenderFlex.
Consider applying a flex factor (e.g. using an Expanded widget) to force the children of the 
RenderFlex to fit within the available space instead of being sized to their natural size.
This is considered an error condition because it indicates that there is content that cannot be seen. 
If the content is legitimately bigger than the available space, consider clipping it with a ClipRect 
widget before putting it in the flex, or using a scrollable container rather than a Flex, like a 
ListView.

Answer 1

The problem is you're using Expanded widgets, you see expanded widgets are flexible in nature they will consume and shrink according to the available space. If you don't want that you need to specify a height.

So i have used the MediaQueryfor it to set the widget according the device resolutions, please check the below solution for it, I have created the demo of your code.

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
import 'package:flutterlearningapp/colors.dart';

class HomeScreen extends StatefulWidget {
  @override
  State<StatefulWidget> createState() {
    // TODO: implement createState
    return _HomeScreen();
  }
}

class _HomeScreen extends State<HomeScreen> {
  @override
  void initState() {
    super.initState();
  }
  @override
  Widget build(BuildContext context) {
    return Material(
        child: Scaffold(
      appBar: AppBar(
        title: Text("Demo Scroll"),
      ),
      body: Container(
        height: double.infinity,
        width: double.infinity,
        color: Colors.black,
        child: SingleChildScrollView(

            child: Column(

              children: <Widget>[
                Container(
                  height: MediaQuery.of(context).size.height*0.6,
                  child: Column(
                    children: <Widget>[
                      CommonWidget("Calories", "150"),
                      CommonWidget("Protein", "9g"),
                      CommonWidget("Carbs", "15g"),
                      CommonWidget("Fat", "25g"),
                    ],
                  ),
                ),
                Container(
                  height: MediaQuery.of(context).size.height * 0.4,
                  child: Align(
                    alignment: Alignment.topCenter,
                    child: Column(
                      children: <Widget>[
                        Row(
                          children: <Widget>[
                            Expanded(
                              child: TextField(
                                style: new TextStyle(color: Colors.white),
                                decoration: InputDecoration(
                                    enabledBorder: OutlineInputBorder(
                                      borderSide: BorderSide(color: Colors.white),
                                    ),
                                    focusedBorder: OutlineInputBorder(
                                      borderSide: BorderSide(color: Colors.white),
                                    ),
                                    labelText: "Serving"),
                              ),
                            ),
                            SizedBox(
                              width: 10.0,
                            ),
                            Expanded(
                              child: TextField(
                                style: new TextStyle(color: Colors.white),
                                decoration: InputDecoration(
                                    enabledBorder: OutlineInputBorder(
                                      borderSide: BorderSide(color: Colors.white),
                                    ),
                                    focusedBorder: OutlineInputBorder(
                                      borderSide: BorderSide(color: Colors.white),
                                    ),
                                    labelText: "Germs"),
                              ),
                            ),
                          ],
                        ),
                        SizedBox(
                          height: 10.0,
                        ),
                        OutlineButton(
                          borderSide: BorderSide(color: Colors.white),
                          color: Colors.black,
                          onPressed: () {},
                          child: Padding(
                            padding: EdgeInsets.all(20),
                            child: Text('   Ok  ',
                                style: TextStyle(color: Colors.white)),
                          ),
                        )
                      ],
                    ),
                  ),
                )




              ],
            ),
          ),
        ),

    ));
  }

  Widget CommonWidget(var name, var value) {
    return Padding(
      padding: EdgeInsets.all(15.0),
      child: Column(
        children: <Widget>[
          Row(
            children: <Widget>[
              Expanded(
                child: Text(
                  name,
                  style: TextStyle(fontSize: 16.0, color: Colors.white),
                ),
              ),
              Expanded(
                child: Align(
                  alignment: Alignment.centerRight,
                  child: Text(value,
                      style: TextStyle(fontSize: 16.0, color: Colors.white)),
                ),
              )
            ],
          ),
          Divider(
            color: Colors.white,
            height: 20.0,
          )
        ],
      ),
    );
  }
}

And output will be following on the example