code: public void setPreviewVisible(boolean visible) {
  
          m_previewVisible = visible;
          if (m_previewVisible) {
              useMaxDimensions();
              m_previewVisibility.setValue(I_CmsLayoutBundle.INSTANCE.previewDialogCss().previewVisible());
              if (m_galleryHandler instanceof CmsGalleryPopup) {
                  ((CmsGalleryPopup)m_galleryHandler).center();
              }
          } else {
              m_previewVisibility.setValue(I_CmsLayoutBundle.INSTANCE.previewDialogCss().hidePreview());
              updateSizes();
          }
      }
docs: Sets the preview visibility.<p>
  
  @param visible the preview visibility