@Route
public class MainView extends VerticalLayout {
    public MainView() {
        final ArrayList<String> searchTerms = new ArrayList<>();
        final AtomicBoolean ignoreValueChangeListener = new AtomicBoolean(false);

        final MultiSelectComboBox<String> searchTermsComboBox = new MultiSelectComboBox<>("Search terms");
        searchTermsComboBox.setSelectedItemsOnTop(true);
        searchTermsComboBox.setAutoExpand(MultiSelectComboBox.AutoExpandMode.BOTH);

        // When entering a new search string, add it to the list of selected search strings
        searchTermsComboBox.addCustomValueSetListener(e -> {
            final String newTerm = e.getDetail();
            if (!searchTerms.contains(newTerm)) {
                ignoreValueChangeListener.set(true); // Temporarily ignore value change listener
                searchTerms.add(newTerm);
                // Update the items in the ComboBox to include the new term
                searchTermsComboBox.setItems(searchTerms);
                searchTermsComboBox.select(searchTerms);
                ignoreValueChangeListener.set(false);
            }
        });
        // Handle deselection of search terms
        searchTermsComboBox.addValueChangeListener(e -> {
            if (ignoreValueChangeListener.get()) {
                return; // Ignore the listener if we are currently updating items
            }

            ignoreValueChangeListener.set(true); // Temporarily ignore value change listener to update items
            final Set<String> selectedTerms = e.getValue();
            searchTerms.removeIf(term -> !selectedTerms.contains(term));
            searchTermsComboBox.setItems(searchTerms);
            searchTermsComboBox.select(searchTerms);

            ignoreValueChangeListener.set(false);
        });
        add(searchTermsComboBox);
    }
}