JavaFX TableColumn调整大小以适合单元格内容

Question

我正在寻找一种在TableView中调整TableColumn大小的方法，以便所有内容在每个单元格中都是可见的(即无截断)。

我注意到双击列分隔符的确使该列自动适合其单元格的内容。有没有办法以编程方式触发此操作？

Answer 1

深入研究javafx源，我发现单击TableView列分隔符时调用的实际方法是

/*
 * FIXME: Naive implementation ahead
 * Attempts to resize column based on the pref width of all items contained
 * in this column. This can be potentially very expensive if the number of
 * rows is large.
 */
@Override protected void resizeColumnToFitContent(TableColumn<T, ?> tc, int maxRows) {
    if (!tc.isResizable()) return;

// final TableColumn<T, ?> col = tc;
    List<?> items = itemsProperty().get();
    if (items == null || items.isEmpty()) return;

    Callback/*<TableColumn<T, ?>, TableCell<T,?>>*/ cellFactory = tc.getCellFactory();
    if (cellFactory == null) return;

    TableCell<T,?> cell = (TableCell<T, ?>) cellFactory.call(tc);
    if (cell == null) return;

    // set this property to tell the TableCell we want to know its actual
    // preferred width, not the width of the associated TableColumnBase
    cell.getProperties().put(TableCellSkin.DEFER_TO_PARENT_PREF_WIDTH, Boolean.TRUE);

    // determine cell padding
    double padding = 10;
    Node n = cell.getSkin() == null ? null : cell.getSkin().getNode();
    if (n instanceof Region) {
        Region r = (Region) n;
        padding = r.snappedLeftInset() + r.snappedRightInset();
    } 

    int rows = maxRows == -1 ? items.size() : Math.min(items.size(), maxRows);
    double maxWidth = 0;
    for (int row = 0; row < rows; row++) {
        cell.updateTableColumn(tc);
        cell.updateTableView(tableView);
        cell.updateIndex(row);

        if ((cell.getText() != null && !cell.getText().isEmpty()) || cell.getGraphic() != null) {
            getChildren().add(cell);
            cell.applyCss();
            maxWidth = Math.max(maxWidth, cell.prefWidth(-1));
            getChildren().remove(cell);
        }
    }

    // dispose of the cell to prevent it retaining listeners (see RT-31015)
    cell.updateIndex(-1);

    // RT-36855 - take into account the column header text / graphic widths.
    // Magic 10 is to allow for sort arrow to appear without text truncation.
    TableColumnHeader header = getTableHeaderRow().getColumnHeaderFor(tc);
    double headerTextWidth = Utils.computeTextWidth(header.label.getFont(), tc.getText(), -1);
    Node graphic = header.label.getGraphic();
    double headerGraphicWidth = graphic == null ? 0 : graphic.prefWidth(-1) + header.label.getGraphicTextGap();
    double headerWidth = headerTextWidth + headerGraphicWidth + 10 + header.snappedLeftInset() + header.snappedRightInset();
    maxWidth = Math.max(maxWidth, headerWidth);

    // RT-23486
    maxWidth += padding;
    if(tableView.getColumnResizePolicy() == TableView.CONSTRAINED_RESIZE_POLICY) {
        maxWidth = Math.max(maxWidth, tc.getWidth());
    }

    tc.impl_setWidth(maxWidth);
}

声明在

com.sun.javafx.scene.control.skin.TableViewSkinBase

方法签名

protected abstract void resizeColumnToFitContent(TC tc, int maxRows)

由于它是 protected ，因此您无法通过例如tableView.getSkin()，但是您始终可以扩展TableViewSkin，使其仅覆盖resizeColumnToFitContent方法并将其公开。