Question

我一直在试图弄清楚如何自动调整TreeView列的大小以适应他们的内容一段时间。之前已经提出这个问题，但反应很小，不可接受。

[javafx column in tableview auto fit size

奇怪的是，我正在寻找的行为正是您在TableView中双击列调整大小行时所发生的情况。但是，在查看JavaFX源代码时，我一直无法弄清楚这是如何发生的。

有没有人知道在JavaFX TableView / TableColumn / TableColumnHeader中处理列调整大小行上的双击行为的方式/位置？

如果可能的话，我只想让列首先自动执行渲染双击调整大小行时会发生什么。这是如何已经不存在的预先创建的列大小约束策略之一。

Answer 1

适用于JavaFX8的解决方案：

将columnResizePolciy设置为CONSTRAINED_RESIZE_POLICY

<TableView fx:id="table" >
    <columnResizePolicy>
        <TableView fx:constant="CONSTRAINED_RESIZE_POLICY" />
    </columnResizePolicy>
</TableView>

Answer 2

这是我为JavaFX 2.2提出的最终解决方案，它现在也考虑了列标题的宽度：

/**
 * Auto-sizes table view columns to fit its contents.
 * 
 * @note This is not a column resize policy and does not prevent manual
 *       resizing after this method has been called.
 * @param tableView
 *            The table view in which to resize all columns.
 */
public static void autoSizeTableViewColumns(final TableView<?> tableView)
{
    autoSizeTableViewColumns(tableView, -1, -1);
}

/**
 * Auto-sizes table view columns to fit its contents.
 * 
 * @note This is not a column resize policy and does not prevent manual
 *       resizing after this method has been called.
 *       
 * @param tableView
 *            The table view in which to resize all columns.
 * @param minWidth
 *            Minimum desired width of text for all columns.
 * @param maxWidth
 *            Maximum desired width of text for all columns.
 */
public static void autoSizeTableViewColumns(final TableView<?> tableView, int minWidth, int maxWidth)
{
    TableViewSkin<?> skin = (TableViewSkin<?>) tableView.getSkin();

    if (skin == null)
    {
        AppLogger.getLogger().warning(tableView + " skin is null.");
        return;
    }

    TableHeaderRow headerRow = skin.getTableHeaderRow();
    NestedTableColumnHeader rootHeader = headerRow.getRootHeader();
    for (Node node : rootHeader.getChildren())
    {
        if (node instanceof TableColumnHeader)
        {
            TableColumnHeader columnHeader = (TableColumnHeader) node;
            try
            {
                autoSizeTableViewColumn(columnHeader, minWidth, maxWidth, -1);
            }
            catch (Throwable e)
            {
                e = e.getCause();
                AppLogger.getLogger().log(Level.WARNING, "Unable to automatically resize tableView column.", e);
            }
        }
    }
}

/**
 * Auto-sizes table view columns to fit its contents.
 * 
 * @note This is not a column resize policy and does not prevent manual
 *       resizing after this method has been called.
 *       
 * @param col
 *            The column to resize.
 * @param minWidth
 *            Minimum desired width of text for this column. Use -1 for no minimum
 *            width.
 * @param maxWidth
 *            Maximum desired width of text for this column. Use -1 for no maximum
 *            width.
 * @param maxRows
 *            Maximum number of rows to examine for auto-resizing. Use -1
 *            for all rows.
 */
public static void autoSizeTableViewColumn(TableColumn<?,?> column, int minWidth, int maxWidth, int maxRows)
{
    TableView<?> tableView = column.getTableView();
    TableViewSkin<?> skin = (TableViewSkin<?>) tableView.getSkin();

    if (skin == null)
    {
        AppLogger.getLogger().warning(tableView + " skin is null.");
        return;
    }

    TableHeaderRow headerRow = skin.getTableHeaderRow();
    NestedTableColumnHeader rootHeader = headerRow.getRootHeader();
    for (Node node : rootHeader.getChildren())
    {
        if (node instanceof TableColumnHeader)
        {
            TableColumnHeader columnHeader = (TableColumnHeader) node;
            if(columnHeader.getTableColumn().equals(column))
            {
                autoSizeTableViewColumn(columnHeader, minWidth, maxWidth, maxRows);
            }
        }
    }
}

/**
 * Auto-sizes a table view column to fit its contents.
 * 
 * @note This is not a column resize policy and does not prevent manual
 *       resizing after this method has been called.
 * 
 * @param col
 *            The column to resize.
 * @param minWidth
 *            Minimum desired width of text for this column. Use -1 for no minimum
 *            width.
 * @param maxWidth
 *            Maximum desired width of text for this column. Use -1 for no maximum
 *            width.
 * @param maxRows
 *            Maximum number of rows to examine for auto-resizing. Use -1
 *            for all rows.
 */
@SuppressWarnings({ "rawtypes", "unchecked" })
public static void autoSizeTableViewColumn(TableColumnHeader header, int minWidth, int maxWidth, int maxRows)
{
    TableColumn<?, ?> col = header.getTableColumn();
    if(col != null)
    {
        List<?> items = col.getTableView().getItems();
        if (items == null || items.isEmpty())
            return;

        Callback cellFactory = col.getCellFactory();
        if (cellFactory == null)
            return;

        TableCell cell = (TableCell) cellFactory.call(col);
        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 TableColumn
        cell.getProperties().put("deferToParentPrefWidth", 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.getInsets().getLeft() + r.getInsets().getRight();
        }

        int rows = maxRows == -1 ? items.size() : Math.min(items.size(), maxRows);

        double desiredWidth = 0;

        // Check header
        Label headerLabel = (Label) header.lookup(".label");
        String headerText = headerLabel.getText();
        if (!headerLabel.getContentDisplay().equals(ContentDisplay.GRAPHIC_ONLY) && headerText != null)
        {
            Text text = new Text(headerLabel.getText());
            text.setFont(headerLabel.getFont());
            desiredWidth += text.getLayoutBounds().getWidth() + headerLabel.getLabelPadding().getLeft() + headerLabel.getLabelPadding().getRight();
        }

        Node headerGraphic = headerLabel.getGraphic();
        if((headerLabel.getContentDisplay().equals(ContentDisplay.LEFT) || headerLabel.getContentDisplay().equals(ContentDisplay.RIGHT)) && headerGraphic != null)
        {
            desiredWidth += headerGraphic.getLayoutBounds().getWidth();
        }

        // Handle minimum width calculations
        // Use a "w" because it is typically the widest character
        Text minText = new Text(StringUtils.repeat("W", Math.min(0, minWidth)));
        minText.setFont(headerLabel.getFont());

        // Check rows
        double minPxWidth = 0;
        for (int row = 0; row < rows; row++)
        {
            cell.updateTableColumn(col);
            cell.updateTableView(col.getTableView());
            cell.updateIndex(row);

            // Handle minimum width calculations
            // Just do this once
            if(row == 0)
            {
                String oldText = cell.getText();
                // Use a "w" because it is typically the widest character
                cell.setText(StringUtils.repeat("W", Math.max(0, minWidth)));

                header.getChildren().add(cell);
                cell.impl_processCSS(false);
                minPxWidth = cell.prefWidth(-1);
                header.getChildren().remove(cell);

                cell.setText(oldText);
            }

            if ((cell.getText() != null && !cell.getText().isEmpty()) || cell.getGraphic() != null)
            {
                header.getChildren().add(cell);
                cell.impl_processCSS(false);
                desiredWidth = Math.max(desiredWidth, cell.prefWidth(-1));
                desiredWidth = Math.max(desiredWidth, minPxWidth);
                header.getChildren().remove(cell);
            }
        }

        desiredWidth = desiredWidth + padding;

        if(maxWidth > 0)
        {
            desiredWidth = Math.min(maxWidth, desiredWidth);
        }

        col.impl_setWidth(desiredWidth);
    }
}

请记住，这是＆＃34;黑客攻击＆＃34;受保护的方法，可以随时使用JavaFX更新进行更改并破坏方法。我相信这已经在JavaFX 8中发生了变化。这也可能会因应用程序签署部署的方式而中断。

它不是很漂亮，但是JavaFX隐藏了这个功能，所以除非你想重新实现整个功能，否则这是我发现的最佳方法。

Answer 3

您的代码中有一些缺失的部分，例如obj未声明。我也找不到你在该课程中任何地方使用的方法。我正在使用1.8.0_20-ea-b05，或者反过来告诉我。我在TableViewSkin中找到了类似的方法。

public static void autoSizeTableViewColumns(final TableView<?> tableView) {
    TableViewSkin<?> skin = (TableViewSkin<?>) tableView.getSkin();
    TableHeaderRow headerRow = skin.getTableHeaderRow();
    NestedTableColumnHeader rootHeader = headerRow.getRootHeader();
    for (TableColumnHeader columnHeader : rootHeader.getColumnHeaders()) {
        try {
            TableColumn<?, ?> column = (TableColumn<?, ?>) columnHeader.getTableColumn();
            if (column != null) {
                Method method = skin.getClass().getDeclaredMethod("resizeColumnToFitContent", TableColumn.class, int.class);
                method.setAccessible(true);
                method.invoke(skin,column, 30);
            }
        } catch (Throwable e) {
            e = e.getCause();
            e.printStackTrace(System.err);
        }
    }
}

JavaFX TreeView TreeColumn自动调整大小以适应内容

3 个答案: