Java Development Tools

I have a javascript

function
enforcePreventUserInput(evt) {
var popup = AdfPage.PAGE.findComponentByAbsoluteId('pt4:Busypopup');
if (popup != null) {
AdfPage.PAGE.addBusyStateListener(popup, handleBusyState);
evt.preventUserInput();
}
}
function handleBusyState(evt) {
var popup = AdfPage.PAGE.findComponentByAbsoluteId('pt4:Busypopup');
if (popup != null) {
if (evt.isBusy()) {
popup.show();
}
else if (popup.isPopupVisible()) {
popup.hide();
AdfPage.PAGE.removeBusyStateListener(popup, handleBusyState);
}
}
}

I'm calling from a button where there is filedownloadListeher configured. but It's not wokrig can anyine tell me

here why popup not coming here.

Studio Edition Version 12.2.1.4.0