How to use

isDisabled

method

in

javafx.scene.control.ComboBoxBase

@Override protected void handleControlPropertyChanged(String p) {
  super.handleControlPropertyChanged(p);
  if (p == "DISABLED") {
    if (getSkinnable().isDisabled()) {
      getSkinnable().setEffect(null);
    } else {
      setDropShadow();
    }
  }
}

public AquaComboBoxListViewSkin(ComboBox<T> comboBox) {
  super(comboBox);
  registerChangeListener(comboBox.disabledProperty(), "DISABLED");
  if (getSkinnable().isFocused()) {
    setFocusBorder();
  } else if (!getSkinnable().isFocused() && !getSkinnable().isDisabled()) {
    setDropShadow();
  }
  for (Object child : getChildren()) {
    ((Node) child).focusedProperty().addListener(focusListener);
  }
  if (comboBox.isEditable()) {
    getDisplayNode().focusedProperty().addListener(focusListener);
  }
  getSkinnable().focusedProperty().addListener(focusListener);
}