title: Bucket filling in flutter
body: <p>I am working on drawing app, which needs bucket filling also.
  Any idea on how to perform bucket filling in Flutter?  </p>
  
  <p><a href="https://i.stack.imgur.com/x5PVC.png" rel="noreferrer"><img src="https://i.stack.imgur.com/x5PVC.png" alt="enter image description here"></a></p>