title: Flutter - Continuously call a function as long as a button is pressed
body: <p>I was wondering if it exists a way to continuously call a function on Flutter as long as a button (any kind of button is okay) is pressed.</p>
  <p>For example:</p>
  <pre><code>GestureDetector(
   child: Container(),
   onLongPressStart: () {}, // Start of the function
   onLongPressEnd: () {}, // End of the function
  )
  </code></pre>