获取JavaFX TableCell以更改其样式

Question

I'm working on real time data stock gathering, everything works smoothly with real time update on change. I'm not an expert in JavaFX I went through documentation but still not very comfortable with it.

Anyway long story short what I'm trying to do is: Change the style of certain Cell ( Intersection of a Row and Column ) depending on a condition (not worth mentioning or code posting).

---

I have:

• class Stock with an attribute variation
• An observable list ObservableList<Stock> myStocksObservableList contains the data I'm willing to display
• TableView myStockTable declared as such TableView<Stock> myStockTable;
• A set of TableColumns with _variation as the column in which I'm interested

---

Code (front end):

Declaration:

@FXML
private TableView<Stock> mystockTable;
@FXML
private TableColumn<Stock, String> _symbol;
@FXML
private TableColumn<Stock, Float> _open;
@FXML
private TableColumn<Stock, Float> _high;
@FXML
private TableColumn<Stock, Float> _low;
@FXML
private TableColumn<Stock, Float> _close;
@FXML
private TableColumn<Stock, Long> _volume;
@FXML
private TableColumn<Stock, Float> _variation;
@FXML
private TableColumn<Stock, String> _comment;
@FXML
private ObservableList<Stock> myStocksObservableList;

Initialize (let's say myStocksObservableList is already filled with a list of Stock 's:

    _symbol.setCellValueFactory(new PropertyValueFactory<>("symbol"));
    _open.setCellValueFactory(new PropertyValueFactory<>("open"));
    _high.setCellValueFactory(new PropertyValueFactory<>("high"));
    _low.setCellValueFactory(new PropertyValueFactory<>("low"));
    _close.setCellValueFactory(new PropertyValueFactory<>("close"));
    _volume.setCellValueFactory(new PropertyValueFactory<>("volume"));
    _variation.setCellValueFactory(new PropertyValueFactory<>("variation"));
    _comment.setCellValueFactory(new PropertyValueFactory<>("comment"));
     mystockTable.setItems(myStocksObservableList);

---

How can I add a listener or any such trick that can check a specific TableCell value that will be the intersection of the column _variation and a row I specify, then changes its style accordingly ?

Any solution would be strongly appreciated, any suggestion as well!

Answer 1

If you can provide a ObservableValue<Stock> that contains the item to style (or any other way of storing the info in a way that allows you to add a listener), you can use custom TableRow s to add a pseudoclass to the row and style the cell using an external stylesheet:

ObservableValue<Stock> markedItem = ...;
PseudoClass marked = PseudoClass.getPseudoClass("marked");
_variation.getStyleClass().add("variation");

mystockTable.setRowFactory(tv -> new TableRow<Stock>() {

    private void updatePseudoclass() {
        pseudoClassStateChanged(marked, !isEmpty() && getItem() == markedItem.getValue());
    }

    {
        markedItem.addListener(o -> updatePseudoclass());
    }

    @Override
    protected void updateItem(Stock item, boolean empty) {
        super.updateItem(item, empty);
        updatePseudoclass();
    }

});

CSS stylesheet

.table-row-cell:marked .table-cell.variation {
    -fx-font-style: italic; /* or some other style */
}

Answer 2

I don't think there is a way to directly get a table cell and modify it.

However, you can try to create a CellFactory that changes the cell's properties (eg style) according to the updates of the cell.

Callback factory = new Callback<TableColumn<String[], String>, TableCell<String[], String>>() {
    @Override
    public TableCell<String[], String> call(TableColumn<String[], String> param)
    {
        return new TableCell<String[], String>() {
            @Override
            protected void updateItem(String item, boolean empty) {
                super.updateItem(item, empty);

                // depending on item's value do something. . .
                // for instance, if item == 'bla' change cell color 
                // this.setStyle(.....)

                // don't forget to set item's text
                setText(item);
            }
        };
    }
};

// your table data in the from of String[][] where the first row holds the column titles
//String[][] data = ...
tableView.getColumns().clear();
tableView.getItems().clear();

// populating the tableView
for (int rowIndex = 0 ; rowIndex < data.length ; rowIndex++)
{
    for (int columnIndex = tableView.getColumns().size(); columnIndex < data[rowIndex].length; columnIndex++)
    {
        TableColumn<String[], String> column = new TableColumn<>();
        final int index = columnIndex;
        column.setCellFactory(factory); // Important line
        column.setCellValueFactory(cellData -> {
            String[] row = cellData.getValue();
            String value = row[index];
            return new SimpleStringProperty(value);
        });
        tableView.getColumns().add(column);
    }
    tableView.getItems().add(data[rowIndex]);
}