code: private void setButtonBarVisible(boolean visible) {
  
          if (m_hasButtonBar != visible) {
              m_hasButtonBar = visible;
              if (m_hasButtonBar) {
  
                  m_buttonBar.getStyle().clearDisplay();
                  int width = CmsClientStringUtil.parseInt(m_borderTopStyle.getWidth()) + BUTTON_BAR_WIDTH;
                  m_borderTopStyle.setWidth(width, Unit.PX);
                  m_borderBottomStyle.setWidth(width, Unit.PX);
                  m_borderRightStyle.setLeft(
                      CmsClientStringUtil.parseInt(m_borderRightStyle.getLeft()) + BUTTON_BAR_WIDTH,
                      Unit.PX);
              } else {
                  m_buttonBar.getStyle().setDisplay(Display.NONE);
                  int width = CmsClientStringUtil.parseInt(m_borderTopStyle.getWidth()) - BUTTON_BAR_WIDTH;
                  m_borderTopStyle.setWidth(width, Unit.PX);
                  m_borderBottomStyle.setWidth(width, Unit.PX);
                  m_borderRightStyle.setLeft(
                      CmsClientStringUtil.parseInt(m_borderRightStyle.getLeft()) - BUTTON_BAR_WIDTH,
                      Unit.PX);
              }
          }
      }
docs: Sets button bar visibility.<p>
  
  @param visible <code>true</code> to set the button bar visible