UtilCss utilCss = MainResourceHolder.getUtilCss();
switch (o) {
case PORTRAIT:
Document.get().getBody().addClassName(utilCss.portrait());
Document.get().getBody().removeClassName(utilCss.landscape());
break;
case LANDSCAPE:
Document.get().getBody().addClassName(utilCss.landscape());
Document.get().getBody().removeClassName(utilCss.portrait());
break;