import javafx.application.Application;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.scene.Scene;
import javafx.scene.control.ComboBox;
import javafx.scene.control.ToggleButton;
import javafx.scene.layout.HBox;
import javafx.stage.Stage;

public class ComboBoxApp extends Application {
    
    public static void main(String[] args) {
        launch(args);
    }

    @Override
    public void start(Stage stage) throws Exception {
        stage.setTitle("ComboBoxApp " + System.getProperty("javafx.runtime.version") );
        stage.setScene(createScene());

        stage.show();
    }

    private Scene createScene() {
        final ComboBox comboBox = new ComboBox();
        for (int i = 0; i < 5; i ++) comboBox.getItems().add("Item " + i);
        
        HBox root = new HBox();
        root.setSpacing(20);
        root.getChildren().add(comboBox);

        ToggleButton editable = new ToggleButton("Editable");
        editable.selectedProperty().addListener(new ChangeListener<Boolean>() {
            public void changed(ObservableValue<? extends Boolean> ov, Boolean t, Boolean t1) {
                comboBox.setEditable(t1);
            }
        });

        root.getChildren().add(editable);
        return new Scene(root, 400, 300);
    }
}