private void buildFooterButtons() {

    FooterCell cell = footer.getCell("clientName");

    HorizontalLayout btnLayout = new HorizontalLayout();
    btnLayout.setSpacing(true);

    Button exportBtn = new Button("Export");
    exportBtn.addStyleName(ValoTheme.BUTTON_TINY);
    exportBtn.addStyleName(ValoTheme.BUTTON_FRIENDLY);
    exportBtn.setIcon(FontAwesome.FILE_EXCEL_O);

    Button refreshBtn = new Button("Refresh");
    refreshBtn.addStyleName(ValoTheme.BUTTON_TINY);
    refreshBtn.addStyleName(ValoTheme.BUTTON_FRIENDLY);
    refreshBtn.setIcon(FontAwesome.REFRESH);

    refreshBtn.addClickListener(
        new Button.ClickListener() {

          private static final long serialVersionUID = 1L;

          @Override
          public void buttonClick(ClickEvent event) {

            queryAndRefresh(
                PerisaiUtil.convertDateToString(today, dtFormat),
                PerisaiUtil.convertDateToString(tmrw, dtFormat));
          }
        });

    // btnLayout.addComponent(exportBtn);
    // btnLayout.addComponent(refreshBtn);
    cell.setComponent(btnLayout);
  }