title: Event on holding button
body: <p>Is it possible to fire an event when the user is holding the back button for example ?</p>
  
  <p>I'm able to do it for a touch hold on an element on the screen with touchstart/touchend events but for the back button, I have only this kind of event :</p>
  
  <pre><code>window.addEventListener('tizenhwkey', function(ev) {
      if (ev.keyName === 'back') {
          // hold logic here ?
      }
  });
  </code></pre>
  
  <p>I know it's possible using the native API so can I do it with the web API ?</p>
  
  <p>Regards</p>