JavaFX TableView Click on Header

Question

Is there a way to get an mouse-click on an Header of a Table?

Why i need this?

I have a Table with many Columns. But only a specific witdth for the whole Table. To avoid scrolling, i want to give each Column an specific width (50 or so), and just if you click on an header, this column will expand so you can read the content. If you click on another header, the previous one collapse.

Hopefully someone can help me:)

Adam · Accepted Answer · 2017-02-24T11:22:19.467

Unfortunately there isn't a nice way to do this. The only public API option is to replace the "graphic" of the column with your own label, and then add a mouse listener to that. For this to work you also need to clear any existing column text.

Note that columns by default have click listeners to implement sorting, it seems you don't want this behaviour, so you'll also need to call column.setSortable(false)

@Override
public void start(Stage primaryStage) throws Exception {
    TableView<String> tableView = new TableView<>();
    TableColumn<String, Object> x = new TableColumn<>("x");
    tableView.getColumns().add(x);
    TableColumn<String, Object> y = new TableColumn<>("");
    tableView.getColumns().add(y);

    x.setSortable(false);
    y.setSortable(false);

    makeHeader(x, "X", 0);
    makeHeader(y, "Y", 1);

    EventHandler<? super MouseEvent> handler = event -> {
        System.out.println("Column clicked " + ((Node)event.getTarget()).getProperties().get("index"));
    };
    x.getGraphic().addEventFilter(MouseEvent.MOUSE_CLICKED, handler);
    y.getGraphic().addEventFilter(MouseEvent.MOUSE_CLICKED, handler);
    primaryStage.setScene(new Scene(tableView));
    primaryStage.show();
}

private void makeHeader(TableColumn<?, ?> target, String name, int index) {
    VBox vBox = new VBox(new Label(name));
    vBox.setAlignment(Pos.CENTER);
    vBox.getProperties().put("index", index);
    target.setGraphic(vBox);
    target.setText("");
}

Isnt nice, but would work. The only problem now is that i dont want to make an event for every column. Is it possible to get the column-index inside the event? Instead of "X clicked" i need something.getIndex() + " clicked". — Hesk, Feb 24 '17 at 11:16
@Hesk See updated answer. I've stored an index in the custom properties map that every node has and then retrieved in a shared event handler... — Adam, Feb 24 '17 at 11:22
I designed my table in another way. Using this now: http://stackoverflow.com/questions/27739833/adapt-tableview-menu-button (Post vom Balage1551) — Hesk, Feb 24 '17 at 20:42

RestInPeace · Answer 2 · 2018-07-12T03:17:01.837

// Step 0: call setOnShown(...).
stage.setOnShown(event -> {
  setHeaderClickListeners(); // Call this method  when the stage is shown.
});

And then you create a method setHeaderClickListeners(), as follows:

private void setHeaderClickListeners() {
  // Step 1: Get the table header row.
  TableHeaderRow headerRow = null;
  for (Node n : ((TableViewSkin<?>) tableView.getSkin()).getChildren()) {
    if (n instanceof TableHeaderRow) {
      headerRow = (TableHeaderRow) n;
    }
  }
  if (headerRow == null) {
    return;
  }

  // Step 2: Get the list of the header columns.
  NestedTableColumnHeader ntch = (NestedTableColumnHeader) headerRow.getChildren().get(1);
  ObservableList<TableColumnHeader> headers = ntch.getColumnHeaders();

  // Step 3: Add click listener to the header columns.
  for (int i = 0; i < headers.size(); i++) {
    TableColumnHeader header = headers.get(i);
    final int index = i;
    header.setOnMouseClicked(mouseEvent -> {

      // Optional:
      // Get the TableColumnBase (which is the object responsible
      // for displaying the content of the column.)
      TableColumnBase column = header.getTableColumn();

      // Step 4: Handle double mouse click event.
      if (mouseEvent.getButton() == MouseButton.PRIMARY && mouseEvent.getClickCount() == 2) {
        P.x("Header cell " + index + " clicked! " + column.getText());
      }
    });
  }
}

JavaFX TableView Click on Header

2 Answers2