Background covering RootView #26

public static ExplosionField attach2Window(Activity activity) {
ViewGroup rootView = (ViewGroup) activity.findViewById(Window.ID_ANDROID_CONTENT);
ExplosionField explosionField = new ExplosionField(activity);
rootView.addView(explosionField, new ViewGroup.LayoutParams(
ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT));
return explosionField;
}

public static ExplosionField attach2WindowViewGroup(ViewGroup viewGroup,Context context) {
    ExplosionField explosionField = new ExplosionField(context);
    viewGroup.addView(explosionField, new ViewGroup.LayoutParams(
            ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT));
    return explosionField;
}