code: private boolean notDelayedStyle(Chunk c, String gt, Collection<? extends BaseStyler> stylers) {
        if (stylers == null) {
           return true;
        }
        try {
           Collection<Advanced> a = new ArrayList<>(stylers.size());
           for (Advanced adv : StyleHelper.getStylers(stylers, Advanced.class)) {
              Advanced.EVENTMODE mode = adv.getEventmode();
              if (Advanced.EVENTMODE.ALL.equals(mode) || Advanced.EVENTMODE.TEXT.equals(mode)) {
                 // remember data and chunk
                 adv.addDelayedData(gt, c);
                 a.add(adv);
              }
           }
           if (a.size() > 0) {
              styleHelper.delayedStyle(c, gt, a, ph);
              return false;
           }
        } catch (VectorPrintException ex) {
           log.log(Level.SEVERE, null, ex);
        }
        return true;
     }
docs: register advanced stylers together with data(part) with the EventHelper to do the styling later
  
  @param c
  @param data
  @param stylers
  @return
  @see PageHelper#onGenericTag(com.itextpdf.text.pdf.PdfWriter, com.itextpdf.text.Document,
  com.itextpdf.text.Rectangle, java.lang.String)