protected int execute(ActionData actionData) {
   TGMeasure measure = getEditor().getTablature().getCaret().getMeasure();
   if (measure != null) {
     MidiPlayerMode pm = TuxGuitar.instance().getPlayer().getMode();
     if (pm.isLoop()) {
       pm.setLoopEHeader(pm.getLoopEHeader() != measure.getNumber() ? measure.getNumber() : -1);
     }
   }
   return 0;
 }
 public void update() {
   TGMeasure measure =
       TuxGuitar.instance().getTablatureEditor().getTablature().getCaret().getMeasure();
   MidiPlayerMode pm = TuxGuitar.instance().getPlayer().getMode();
   this.metronome.setSelection(TuxGuitar.instance().getPlayer().isMetronomeEnabled());
   this.loopSHeader.setEnabled(pm.isLoop());
   this.loopSHeader.setSelection(measure != null && measure.getNumber() == pm.getLoopSHeader());
   this.loopEHeader.setEnabled(pm.isLoop());
   this.loopEHeader.setSelection(measure != null && measure.getNumber() == pm.getLoopEHeader());
   this.loadIcons(false);
 }