public static void setActivity(Activity act) {
host = act;
ViewTools.setActivity(act);
View rootView = host.getWindow().getDecorView().getRootView();
rootView.setDrawingCacheEnabled(true);
rootView.buildDrawingCache();
// host.getWindow().getDecorView().getViewTreeObserver().addOnGlobalLayoutListener(new
// LayoutObserver());
}
