title: Flutter Stack with background image and form
body: <p>I have a screen where the background image is set to fill the whole screen and on top of that, there are input fields. When I click on TextFormField, the keyboard is shown and the background image is pushed to the top, which is the behaviour I do not want to. </p>
  
  <p>Do you know how not top push image up? I think Form (with SingleChildScrollView) widget is rendered on top of the screen (index > that backgroundImage), so I do not understand why the image is deformed. Any ideas?</p>
  
  <p>Code:</p>
  
  <pre><code>   class LoginScreen extends StatelessWidget {
        @override
        Widget build(BuildContext context) {
          return Scaffold(
              body: Stack(
            children: &lt;Widget&gt;[
              Container(
                width: double.infinity,
                child: Image.asset("imageAsset",
                       fit: BoxFit.fitWidth),
              ),
              SingleChildScrollView(
                child: Form(
                  child: Column(
                    mainAxisSize: MainAxisSize.max,
                    mainAxisAlignment: MainAxisAlignment.start,
                    children: &lt;Widget&gt;[
                      FormField(), // Example
                      FormField(), // Example
                      FormField(), // Example
                    ]),
              )
            ],
          )));
        }
      }
  </code></pre>