title: Flutter Pin Input Field
body: <p>I am trying to create <a href="https://i.stack.imgur.com/R83KM.png" rel="nofollow noreferrer">this pin input</a> using flutter. I found a few examples like <a href="https://medium.com/developing-custom-flutter-pin-entry-textfield/developing-custom-flutter-pin-entry-textfield-7da8acb0a3fa" rel="nofollow noreferrer">this one</a> online but run into problems when it comes to scaling the input to fill the width of the container or performing validation - the user should only be allowed to enter numbers.</p>
  
  <p>Is there a better way to go about this than the examples provided?</p>