Apply dim to Activity

ApplyDimToActivity.java

public static void applyDim(@NonNull Activity activity){
    float dimAmount = 0.5f;
    ViewGroup rootView = (ViewGroup) (activity.getWindow().getDecorView().getRootView());
    Drawable dim = new ColorDrawable(Color.BLACK);
    dim.setBounds(0, 0, rootView.getWidth(), rootView.getHeight());
    dim.setAlpha((int) (255 * dimAmount));

    ViewGroupOverlay overlay = rootView.getOverlay();
    overlay.add(dim);
}

public static void clearDim(@NonNull Activity activity) {
    ViewGroup rootView = (ViewGroup) (activity.getWindow().getDecorView().getRootView());
    ViewGroupOverlay overlay = rootView.getOverlay();
    overlay.clear();
}