问如何检测何时打开通知/系统栏

EN

private static boolean wasOnStopCalledAfterOnWindowFocusChanged;

@Override
protected void onStop() {
    wasOnStopCalledAfterOnWindowFocusChanged = true;
    super.onStop();
}

@Override
public void onWindowFocusChanged(boolean hasFocus) {
    if (!hasFocus) {
        new Handler(Looper.getMainLooper()).postDelayed(new Runnable() {
            @Override
            public void run() {
                if (!wasOnStopCalledAfterOnWindowFocusChanged) {

                    // NOTIFICATION BAR IS DOWN...DO STUFF

                }
                wasOnStopCalledAfterOnWindowFocusChanged = false;
            }
        }, 1000);
    }
}