Change value column header in TableView JavaFX

Question

I am trying to create a TableView in JavaFX where the user can change the value of the column header by double clicking on the table header. A Textbox should appear and after filling in a new value, the value should be assigned to the column header.

Example of output below

Answer 1

A slightly different approach than outlined in James' comment:

• register the mouse handler with the table
• on double-click (which interferes with sorting ... but that's a different problem), find the TableColumnHeader that represents the tableColumn, if any
• create and wire a TextField and set it as the column's graphic (as James suggested)

Note that the TableColumnHeader's package is version-dependent, for fx8 it's considered internal api residing in com.xx.skin, for fx9 it's public in javafx.xx.skin.

The example:

public class TableHeaderWithInput extends Application {
    TableView<Locale> table;

    protected void installHeaderHandler(Observable s) {
        table.addEventFilter(MouseEvent.MOUSE_PRESSED, e -> {
            if (e.isPrimaryButtonDown() &&  e.getClickCount() > 1) {
                EventTarget target = e.getTarget();
                TableColumnBase<?, ?> column = null;
                while (target instanceof Node) {
                    target = ((Node) target).getParent();
                    // beware: package of TableColumnHeader is version specific
                    if (target instanceof TableColumnHeader) {
                        column = ((TableColumnHeader) target).getTableColumn();
                        if (column != null) break;
                    }
                }
                if (column != null) {
                    TableColumnBase<?,?> tableColumn = column;
                    TextField textField = new TextField(column.getText());
                    textField.setMaxWidth(column.getWidth());
                    textField.setOnAction(a -> {
                        tableColumn.setText(textField.getText());
                        tableColumn.setGraphic(null);
                    });
                    textField.focusedProperty().addListener((src, ov, nv) -> {
                        if (!nv) tableColumn.setGraphic(null);
                    });
                    column.setGraphic(textField);
                    textField.requestFocus();
                }
                e.consume();
            }
        });
    }

    private Parent getContent() {
        table = new TableView<>(FXCollections.observableArrayList(
                Locale.getAvailableLocales()));
        table.setTableMenuButtonVisible(true);
        // quick hack: don't let sorting interfere ...
        table.setSortPolicy(e -> {return false;});
        TableColumn<Locale, String> countryCode = new TableColumn<>("CountryCode");
        countryCode.setCellValueFactory(new PropertyValueFactory<>("country"));
        TableColumn<Locale, String> language = new TableColumn<>("Language");
        language.setCellValueFactory(new PropertyValueFactory<>("language"));
        table.getColumns().addAll(countryCode, language);
        table.skinProperty().addListener(this::installHeaderHandler);
        BorderPane pane = new BorderPane(table);
        return pane;
    }

    @Override
    public void start(Stage primaryStage) throws Exception {
        primaryStage.setScene(new Scene(getContent(), 800, 400));
        primaryStage.setTitle(FXUtils.version());
        primaryStage.show();
    }

    public static void main(String[] args) {
        launch(args);
    }

    @SuppressWarnings("unused")
    private static final Logger LOG = Logger
            .getLogger(TableHeaderWithInput.class.getName());
}