Check out this blog post. It gives a workaround so that document.activeElement works in all browsers.
function _dom_trackActiveElement(evt) {
if (evt && evt.target) {
document.activeElement = evt.target == document ? null : evt.target;
}
}
function _dom_trackActiveElementLost(evt) {
document.activeElement = null;
}
if (!document.activeElement) {
document.addEventListener("focus",_dom_trackActiveElement,true);
document.addEventListener("blur",_dom_trackActiveElementLost,true);
}
Something to note:
This implementation is slightly over-pessimistic; if the browser window loses focus, the activeElement is set to null (as the input control loses focus as well). If your application needs the activeElement value even when the browser window doesn't have the focus, you could remove the blur event listener.
