title: Flutter: responsive Positioned in Stack
body: <p>I want to place icon out of parent bounds and make it responsive (relative to parent's height).</p>
  <p><a href="https://i.stack.imgur.com/JFAOml.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/JFAOml.png" alt="enter image description here" /></a></p>
  <p>There is no problem to place an icon outside from parent bounds with <code>Stack</code> and <code>Positioned</code> widgets.</p>
  <p>But there is a problem to make it responsive.</p>
  <p>So, if container height decreases, then the icon size should also decrease.</p>
  <pre><code>Container(
    decoration: BoxDecoration(
      border: Border.all(
        color: Color(0xff2577ff),
        width: 5.0,
      ),
      borderRadius: BorderRadius.all(
        Radius.circular(15.0),
      ),
    ),
    width: 200.0,
    height: 80.0,
    child: Stack(
      clipBehavior: Clip.none,
      children: [
        Center(
          child: Text('Text'),
        ),
        Positioned( // &lt;-- doesn't work
          top: -20.0, // &lt;-- how to make it also relative to parent's height parameter?
          right: -20.0, // &lt;-- how to make it also relative to parent's height parameter?
          child: FractionallySizedBox( // &lt;-- doesn't work
            heightFactor: 0.5,
            child: Image.network('https://i.stack.imgur.com/dOkkG.png'),
          )
        )
      ],
    ),
  )
  </code></pre>
  <p>I've tried to make some sample but with no success. I really don't know how to implement such logic with Flutter and I can't find any reliable example.</p>