code: protected void openGalleryDialog() {
  
          if (m_popup == null) {
              m_popup = createPopup();
              m_popup.center();
          } else {
              if (CmsStringUtil.isNotEmptyOrWhitespaceOnly(getCurrentElement())) {
                  m_popup.searchElement(getCurrentElement());
              } else {
                  m_popup.center();
              }
          }
      }
docs: Internal method which opens the gallery dialog.<p>