javafx StringConverter Last Object

问题:

i have a little problem for creating an editable ListView.

so i have a City Class with two field : id and name, i have created a ObservableList of cities from a database and assigned it to my ListView, and i have created my cellFactory :

@DatabaseTable(tableName = "city")
public class City {

    @DatabaseField(generatedId = true)
    private int id;

    @DatabaseField
    private String name;

    public City() {}
}

---

citiesList.setCellFactory(new Callback<ListView<City>, ListCell<City>>() {

            @Override
            public ListCell<City> call(ListView<City> param) {

                ListCell<City> cells = new TextFieldListCell<>(new StringConverter<City>() {

                    @Override
                    public String toString(City object) {
                        return object.getName().trim();
                    }

                    @Override
                    public City fromString(String string) {
                        // how to modify the object that was in the cell???
                        return null;
                    }
                });

                return cells;
            }
        });

I want to know if its possible to get a reference of the current value in the cell(City) when fromString is called

i want to do that to allow user to change City name without having to change its Id field.

回答1:

If you create the cell first, then create the converter, you can reference cell.getItem() in the converter. The following seems to work:

citiesList.setCellFactory(lv -> {
    TextFieldListCell<City> cell = new TextFieldListCell<City>();
    StringConverter<City> converter = new StringConverter<City>() {

        @Override
        public String toString(City city) {
            return city.getName();
        }

        @Override
        public City fromString(String string) {
            City city = cell.getItem();
            if (city == null) {
                City newCity = new City();
                newCity.setName(string);
                return newCity;
            } else {
                city.setName(string);
                return city ;
            }
        }

    };

    cell.setConverter(converter);

    return cell ;
});