public void onDashboardResize(final String widget, final String size) {
        final DashboardWidget dashboard = responsiveModel.getWidget(widget);
        if (dashboard != null) {
            final String newCss = dashboard.getStyleClass().replaceFirst("xl:col-\\d+", size);
            dashboard.setStyleClass(newCss);
        }
    }
Dashboard panel has been resized.

@param widget the DashboardPanel
@param size the new size CSS
primefaces-showcase/src/main/java/org/primefaces/showcase/view/panel/DashboardView.java