NullPointerException

[wzj1]

private void updateConfig() {
if (glass == null) {
rebuild();
return;
}

   //This will cause a null object referencel
    glass.post(() -> glass.updateParameters());

}

//When invisible
protected void onDetachedFromWindow() {
removeGlass();
super.onDetachedFromWindow();
}

//glass will be set to null
private void removeGlass() {
if (glass != null) {
removeView(glass);
glass = null;
}
}