Above the keyboard widget

main.dart

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

void main() {
  runApp(
    GetMaterialApp(
      initialRoute: '/',
      initialBinding: BindingsBuilder.put(() => HomeController()),
      getPages: [
        GetPage(
          name: '/',
          page: () => Home(),
        )
      ],
    ),
  );
}

class Home extends GetView<HomeController> {
  const Home({Key key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('keyboard'),
      ),
      resizeToAvoidBottomInset: false,
      body: Obx(
        () => Stack(
          children: [
            Container(
              child: Center(
                child: TextFormField(
                    decoration: InputDecoration(
                  border: OutlineInputBorder(
                    borderRadius: BorderRadius.circular(4.0),
                    borderSide: BorderSide(
                      color: Colors.grey,
                    ),
                  ),
                  contentPadding: const EdgeInsets.all(18.0),
                  hintText: 'text form',
                  hintStyle: const TextStyle(color: Colors.grey),
                )),
              ),
            ),
            Visibility(
              visible: controller.isKeyboardOpen,
              child: Positioned(
                bottom: MediaQuery.of(context).viewInsets.bottom,
                left: 0,
                right: 0,
                child: Container(
                  height: 50,
                  child: Center(
                      child: Text(
                    'above keyboard',
                    style: TextStyle(color: Colors.white),
                  )),
                  decoration: BoxDecoration(color: Colors.black),
                ),
              ),
            )
          ],
        ),
      ),
    );
  }
}

class HomeController extends GetxController with WidgetsBindingObserver {
  final _isKeyboardOpen = true.obs;

  @override
  void onInit() {
    super.onInit();
    WidgetsBinding.instance.addObserver(this);
  }

  bool get isKeyboardOpen => _isKeyboardOpen.value;
  @override
  void onClose() {
    WidgetsBinding.instance.removeObserver(this);
    super.onClose();
  }

  @override
  void didChangeMetrics() {
    super.didChangeMetrics();
    _isKeyboardOpen.value =
        WidgetsBinding.instance.window.viewInsets.bottom > 0.0;
    print(isKeyboardOpen);
  }
}