public void showCodePreviewPanel() {
    CaptionPanel showCode = new CaptionPanel(constants.showCodeTitle());
    showCode.setWidth("185px");

    VerticalPanel vp = new VerticalPanel();
    vp.setWidth("100%");
    vp.setHorizontalAlignment(HasHorizontalAlignment.ALIGN_CENTER);

    showCodeButton = new Button(constants.showCode());

    vp.add(showCodeButton);

    showCode.setContentWidget(vp);

    builderContent.add(showCode);
  }