title: how to custom position button in flutter?
body: <p>I'm trying to position a button in custom place in Flutter web app but i cant.
  Here is my code:</p>
  
  <pre><code>class HomeScreen extends StatelessWidget {
    @override
    Widget build(BuildContext context) {
      Size size = MediaQuery.of(context)
          .size; // This method will give us the height and width of our device screen
      return Container(
          height: size.height,
          width: size.width,
          decoration: BoxDecoration(
              image: DecorationImage(
                  image: AssetImage("assets/images/687.jpg"), fit: BoxFit.cover)),
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: &lt;Widget&gt;[
              FlatButton(
                color: Colors.black,
                onPressed: () {},
                child: Text("Login"),
                textColor: Colors.white,
              ),
            ],
          ));
    }
  }
  </code></pre>
  
  <p>Here is picture for demonstration the custom place that i want:
  <a href="https://i.stack.imgur.com/JO0io.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/JO0io.jpg" alt="enter image description here"></a></p>