JavaFX 2.0 Choice Box Issue. How to update a choiceBox, which represents a list of objects, when an object is updated?

Question

I have a choiceBox which represents a list objects. When the name representing one of those objects is changed by another bit of code the name in the drop down list for the

Answer 1

Just for completeness - in fx2 you are probably stuck with the replace approach as outlined in the other answer. Since fx8, there's a mechanism to tell the list to listen to changes of its contained items (precondition being, of course, that your item has properties and notifies listeners on change):

/** changed item to 
 *  - use property and notify on change
 *  - not override toString (for visuals, use converter instead)
 */ 
class Test {
    StringProperty name;

    public Test(String name) {
        setName(name);
    }

    public StringProperty nameProperty() {
         if (name == null) name = new SimpleStringProperty(this, "name");
         return name;
    }
    public void setName(String name) {
        nameProperty().set(name);
    }

    public String getName() {
        return nameProperty().get();
    }

} 

// use in collection with extractor
ObservableList<Test> items = FXCollections.observableList(
    e -> new Observable[] {e.nameProperty()} );
items.addAll(...);
choiceBox = new ChoiceBox<>(items);
// tell the choice how to represent the item
StringConverter<Test> converter = new StringConverter<Test>() {

    @Override
    public String toString(Test album) {
        return album != null ? album.getName() : null;
    }

    @Override
    public Test fromString(String string) {
        return null;
    }

};
choiceBox.setConverter(converter);

Answer 2

I had the same issue in JavaFX 8 (with ComboBox too). I was able to get the same functionality by removing the item then adding a new one at the same location.

Example:

This gets selected item, creates a new item, then calls the replace method:

Channel selected = channelChoiceBox.getSelectionModel().getSelectedItem();
Channel newChan = new Channel("Example", "Channel");
replaceChannel(newChan, selected);

This replaces the selected channel with the new one, effectively editing it:

private void replaceChannel(Channel newChan, Channel oldChan) {
    int i = channelChoiceBox.getItems().indexOf(oldChan);
    channelChoiceBox.getItems().remove(oldChan);
    channelChoiceBox.getItems().add(i, newChan);
    channelChoiceBox.setValue(newChan);
}

It's not ideal, but does the job.

Disclaimer: I'm new to Java and programming in general.

Answer 3

Yes. This seems to be issue with JavaFx. I too had faced that. Use ComboBox instead of ChoiceBox that will work.