class ListBarWidgetImpl extends ResizeComposite implements ListBarWidget {

    void resizePanelBody() {
        //When an Item is added to the PanelHeader recalculate the PanelBody size.
        //This cannot be performed in either the @PostConstruct or onAttach() methods as at
        //these times the PanelHeader may not have any content and hence have no size.
        if (currentPart != null && !currentPart.getK1().isSelectable()) {
            content.getElement().getStyle().setProperty("height",
                                                        "100%");
        } else {
            content.getElement().getStyle().setProperty("height",
                                                        "calc(100% - " + header.getOffsetHeight() + "px)");
        }
    }

}