How to make container fix positioned even after keyboard is displayed

Question

I've been playing with this for some time and can not get this working. Basically I've got bottom navigation bar and I want at the top of the bottom navigation bar fixed positioned container which stay there even if the keyboard is displayed. So far no matter what I tried the container ends up at the top of the keyboard when the keyboard is called. Here is my code where I ended up so far. Basically my last hope was to wrap it in Stack widget but that didn't work.

class HomeScreen extends StatefulWidget {   static const String id = '/app';   final FirebaseUser user;   HomeScreen({this.user});

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

class _HomeScreenState extends State<HomeScreen> {   int _currentIndex
= 0;   final List<Widget> _children = [Screen1(), Screen2()];

  void bottomTabHandler(int index) {
    setState(() {
      _currentIndex = index;
    });   }

  @override   Widget build(BuildContext context) {
    return Scaffold(
      bottomNavigationBar: BottomNavigationBar(
        type: BottomNavigationBarType.fixed,
        currentIndex: _currentIndex,
        onTap: bottomTabHandler,
        items: [
          BottomNavigationBarItem(
            icon: Icon(Icons.receipt),
            title: Text('Option1'),
          ),
          BottomNavigationBarItem(
            icon: Icon(Icons.receipt),
            title: Text('Option2'),
          ),
          BottomNavigationBarItem(
              icon: Icon(Icons.add), title: Text('Option3')),
        ],
      ),
      appBar: AppBar(
        centerTitle: true,
        title: Text('XXX'),
        automaticallyImplyLeading: false,
      ),
      endDrawer: AppbarDrawer(),
      body: Stack(
        children: <Widget>[
          _children[_currentIndex],
          Positioned(
            bottom: 0,
            child: Container(
              width: 250,
              height: 100,
              color: Colors.blue,
            ),
          ),
        ],
      ),
     );
    }    
}

I've got simple TextField at screen1 and this is what I get

Answer 1

If you want to make sure the Widgets don't get adjusted when the keyboard appears, you can use the resizeToAvoidBottomInset property of the Scaffold:

return Scaffold(
  resizeToAvoidBottomInset: false,
  body: Stack(
  ...