revision:
The hasPointerCapture() method of the Element interface checks whether the element on which it is invoked has pointer capture for the pointer identified by the given pointer ID.
hasPointerCapture(pointerId)
Parameters:
pointerID : The pointerId of a PointerEvent object.
<html lang="en">
<script>
function downHandler(ev) {
const el = document.getElementById("target");
// Element 'target' will receive/capture further events
el.setPointerCapture(ev.pointerId);
// …
// Check whether element still has pointer capture
let pointerCap = el.hasPointerCapture(ev.pointerId);
if (pointerCap) {
// We've still got pointer capture
} else {
// oops, we've lost pointer capture!
}
}
function init() {
const el = document.getElementById("target");
el.onpointerdown = downHandler;
}
</script>
<body onload="init();">
<div id="target">Touch this element with a pointer.</div>
</body>
</html>