code: @Override protected void handleEvents(final String EVENT_TYPE) {
          super.handleEvents(EVENT_TYPE);
          if ("VISIBILITY".equals(EVENT_TYPE)) {
              Helper.enableNode(titleText, !gauge.getTitle().isEmpty());
              Helper.enableNode(subTitleText, !gauge.getSubTitle().isEmpty());
              Helper.enableNode(unitText, !gauge.getUnit().isEmpty());
              Helper.enableNode(valueText, gauge.isValueVisible());
              sectionsVisible = gauge.getSectionsVisible();
              redraw();
          } else if ("RECALC".equals(EVENT_TYPE)) {
              angleStep = ANGLE_RANGE / gauge.getRange();
              redraw();
              rotateNeedle(gauge.getCurrentValue());
          } else if ("INTERACTIVITY".equals(EVENT_TYPE)) {
              if (gauge.isInteractive()) {
                  centerKnob.setOnMousePressed(mouseHandler);
                  centerKnob.setOnMouseReleased(mouseHandler);
                  buttonTooltip.setText(gauge.getButtonTooltipText());
                  Tooltip.install(centerKnob, buttonTooltip);
              } else {
                  centerKnob.removeEventHandler(MouseEvent.MOUSE_PRESSED, mouseHandler);
                  centerKnob.removeEventHandler(MouseEvent.MOUSE_RELEASED, mouseHandler);
                  Tooltip.uninstall(centerKnob, buttonTooltip);
              }
          } else if ("SECTIONS".equals(EVENT_TYPE)) {
              sectionsVisible = gauge.getSectionsVisible();
              sections        = gauge.getSections();
          }
      }
docs: ******************** Methods *******************************************