title: How to show custom toast dialog in flutter?
body: <p>I want to show a custom <code>toast</code> (my own widget layout). I know how to show a custom <code>alert dialogue</code>, but that's not what I want. </p>
  
  <p><strong>Because, <code>Alert dialogue</code>:</strong></p>
  
  <ol>
  <li>Has a black background </li>
  <li>Prevents touches when it's shown</li>
  <li>Has to dismiss manually</li>
  </ol>
  
  <p>I don't want to use <code>flutter</code> toast library because I can't make a custom layout with that. </p>
  
  <p>I want to show my own layout on top of all other widgets and make it disappear after some time. Also, it should not prevent any input when it's shown.</p>