code: protected ModalShownHandler createShownHandler(final DisplayerSettings settings) {
  
          return new ModalShownHandler() {
              @Override
              public void onShown(ModalShownEvent modalShownEvent) {
                  editor.init(settings);
                  setTitle(editor.isBrandNewDisplayer() ? newDisplayerTitle : editDisplayerTitle);
                  removeShownHandler();
              }
          };
      }
docs: <p>The popup must be visible in order that the table can display the different row's values. So after popup is shown, initialize the editor.</p>