code: public void setTab(DialogTab dialogTab) {
  
          m_dialogTab = dialogTab;
          switch (dialogTab) {
              case checkIn:
                  enableCheckboxesForNotInstalledModules(false);
                  m_okButton.setCaption(CmsVaadinUtils.getMessageText(Messages.GUI_GIT_BUTTON_CHECK_IN_0));
                  break;
              case checkOut:
                  m_fakeEmailField.setValue(m_emailField.getValue());
                  m_fakeUserField.setValue(m_userField.getValue());
                  m_okButton.setCaption(CmsVaadinUtils.getMessageText(Messages.GUI_GIT_BUTTON_IMPORT_0));
                  enableCheckboxesForNotInstalledModules(true);
                  break;
              default:
                  break;
          }
      }
docs: Called when the active tab is switched.<p>
  
  @param dialogTab the dialog tab to which the user has switched