Detect power button long press on fragment on Android

Question

I am working on Kiosk Mode and I looking for a way to close 'Power off, Restart' system dialog while fragment is opened. For now, in my activity I used onWindowFocusChanged.

@Override
public void onWindowFocusChanged(boolean hasFocus) {
    super.onWindowFocusChanged(hasFocus);
    if(!hasFocus) {
        Intent closeDialog = new Intent(Intent.ACTION_CLOSE_SYSTEM_DIALOGS);
        sendBroadcast(closeDialog);
    }
}

But when some fragment is visible and 'Power off' dialog appears onWindowFocusChanged will no be called.