CODEWITHSUNDEEP
javauser-interfacejavafxcombobox
Anthony1617
Anthony1617

Reputation: 47

How can I trigger code in JavaFX when the text of a ComboBox changes?

I have a ComboBox in JavaFX. I want to trigger an event whenever the user types or deletes a character in the ComboBox, so that I can call ComboBox.show() and populate the dropdown with custom text, to make a sort of "predictive text" feature.

However, I cannot find any way to trigger an event upon text change. Does any such methodology exist? If not, can you recommend any other way to accomplish what I am trying to do?

Here's my ComboBox:

ObservableList<String> options = 
            FXCollections.observableArrayList(
                "Option 1",
                "Option 2",
                "Option 3"
            );
ComboBox myComboBox = new ComboBox(options);
myComboBox.setEditable(true);

and here's the code that I've tried to use to trigger an event:

myComboBox.setOnAction(new EventHandler<ActionEvent>() {
        @Override
        public void handle(ActionEvent event) {
            System.out.println("Event triggered.");
            myComboBox.show();
        }
    });

The problem with this code, however, is that it only goes off when the user presses "Enter" in the ComboBox, or when they select an item from the dropdown.

Any ideas?

Upvotes: 0

Views: 211

Answers (1)

James_D
James_D

Reputation: 209358

You can retrieve the TextField that is used to edit the content of the combo box with 

myComboBox.getEditor();

Like any text input component, the text in it is represented by an observable StringProperty that you can retrieve with textProperty(). You can add a listener to this property that is notified if the text changes:

myComboBox.getEditor().textProperty().addListener((obs, oldText, newText) -> {
    // do whatever you need with newText (or oldText too if you need)
});

Upvotes: 1

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