fake-wake-lock.html

<!DOCTYPE html>
<!--
Copyright and related rights waived via CC0:
https://creativecommons.org/publicdomain/zero/1.0/
-->
<html>
<head>
<meta charset=utf-8>
<script src=fake-wake-lock.js></script>
</head>
<body>
<h1 id=e_status></h1>
<script>
'use strict';

let wake_lock = null;

e_status.textContent = `wake_lock: ${wake_lock}`;

if (true) {
   document.addEventListener('click', async () => {
      if (wake_lock) {
         document.body.style.backgroundColor = 'red';
         {
            await wake_lock.release();
            wake_lock = null;
         }
         document.body.style.backgroundColor = '';
      } else {
         document.body.style.backgroundColor = 'magenta';
         {
            wake_lock = await navigator.wakeLock.request('screen');
         }
         document.body.style.backgroundColor = 'cyan';
      }
      e_status.textContent = `wake_lock: ${wake_lock}`;
   });
}

</script>
</body>
</html>