Bind enum values to Combox in FXML

Question

I have a JavaFX application, and I'm trying to map all the values of an enum to a Combobox from FXML.

Something like the below works just fine, however, I'm looking for a more generic solution, where I don't need to list all possible values of the enum manually.

<ComboBox>
     <items>
         <FXCollections fx:factory="observableArrayList">
              <MyEnum fx:constant="VALUE1"/>
              <MyEnum fx:constant="VALUE2"/>
          </FXCollections>
     </items>
</ComboBox>

Answer 1

This is not possible without some additional code, since there's no way of adding multiple objects to a list at once and initializing the list isn't possible either.

You could create a helper class providing static getter/setter methods though. This method could use reflection to add the enum constants:

public class EnumUtil {
    /* getter needed for FXMLLoader */
    public static Class<?> getEnumClass(ObservableList list) {
        return list.isEmpty() ? null : list.get(0).getClass();
    }

    public static <T extends Enum<T>> void setEnumClass(ObservableList<? super T> list, Class<T> enumClass) {
        if (!enumClass.isEnum()) {
            throw new IllegalArgumentException(enumClass.getName() + " is not a enum type");
        }
        list.addAll(enumClass.getEnumConstants());
    }
}

fxml

<ComboBox>
     <items>
         <!-- fill combobox with constants from KeyCode -->
         <FXCollections fx:factory="observableArrayList" EnumUtil.enumClass="javafx.scene.input.KeyCode"/>
     </items>
</ComboBox>