code: public void navigateHandlerView() {
          // if endpoint tab
          if (tabLayoutpanel.getSelectedIndex() == 1) {
              if (endpointHandlerPages.getPage() == 0)
                  endpointHandlerPages.showPage(1);
          // else the client tab
          } else if (tabLayoutpanel.getSelectedIndex() == 2) {
              if (clientHandlerPages.getPage() == 0)
                  clientHandlerPages.showPage(1);
          }
      }
docs: to show a specific panel accordingly to the selected tab