keyboardTest.dart

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

class Keyboard extends StatefulWidget {
  
  @override
  State<StatefulWidget> createState() => KeyboardState();
}

class KeyboardState extends State<Keyboard> {
  final FocusNode _keyboardWithDone = FocusNode();

  KeyboardActionsConfig _buildConfig(BuildContext context) {
    return KeyboardActionsConfig(
      keyboardActionsPlatform: KeyboardActionsPlatform.ALL,
      keyboardBarColor: Colors.grey[200],
      nextFocus: true,
      actions: [
        KeyboardAction(
          focusNode: _keyboardWithDone
        )
      ]
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Column(
        children: <Widget>[
          Text('HEADER'),
          Expanded(
            child:ListView(
              padding: EdgeInsets.only(left: 20, right: 20, top: 10),
              children: <Widget>[     
                Container(
                  height: 500,
                  color: Colors.blue,
                ),
                Container(
                  margin: EdgeInsets.symmetric(vertical: 15),
                  height: 150,
                  child: KeyboardActions(
                    config: _buildConfig(context),
                    child: TextField(
                      focusNode: _keyboardWithDone,
                      maxLines: 5,
                      decoration: InputDecoration(
                        focusedBorder: OutlineInputBorder(
                          borderRadius: BorderRadius.all(Radius.circular(8)),
                          borderSide: BorderSide(color: Colors.blue, width: 5),      
                        ),
                        enabledBorder: OutlineInputBorder(
                          borderRadius: BorderRadius.all(Radius.circular(8)),
                          borderSide: BorderSide(color: Colors.grey, width: 3),      
                        ),
                        hintText: '... Meet me at the corner of 5th ave and ...'
                      ),
                    ),
                  ),  
                )
              ]
            )
          )
        ],
      ),
    );
  }
}