tableview - 获取 TableCell 的图形

Question

我已经实现了一个自定义 TableCell 和 TableColumn 以在单元格未编辑时显示超链接。我想为超链接添加 setOnAction 事件。由于我想重用 TableCell，我无法在 TableCell updateItem 方法中添加代码。有什么方法可以实现吗？

public class TableColumnHyperlink<S> extends TableColumn<S, String> {

    public TableColumnHyperlink (String header) {
        super(header);
        Callback<TableColumn<S, String>, TableCell<S, String>> hypCellFactory =
            (TableColumn<S, String> p) -> new TableCellHyperlink();

        setCellFactory(hypCellFactory);
    }
}

TableCell 实现是

public class TableCellHyperlink<S> extends TableCell<S, String> {

    private final TextField textField;
    private final Hyperlink hyperlink;

    public TableCellHyperlink() {

        textField = new TextField();
        hyperlink = new Hyperlink();
        setAlignment(Pos.CENTER_LEFT);
    }

    @Override
    public void startEdit() {
        super.startEdit();
        createTextField();
        setText(null);
        setGraphic(textField);
        textField.requestFocus();
    }

    @Override
    public void cancelEdit() {
        super.cancelEdit();
        setText(getItem());
        setGraphic(null);
    }

    @Override
    public void updateItem(String item, boolean empty) {
        super.updateItem(item, empty && (getTableRow() == null ? true : getTableRow().isEmpty()));
        if (empty) {
            setText(null);
            setGraphic(null);
        } else {
            if(isEditing()) {
                setText(getString());
                setGraphic(textField);
            } else {
                setText(null);
                hyperlink.setText(getString());
                setGraphic(hyperlink);
            }
        }
    }


    private void createTextField() {
        textField.setText(getString());
        textField.setMinWidth(this.getWidth() - this.getGraphicTextGap() * 2);

        textField.addEventFilter(KeyEvent.KEY_PRESSED, (KeyEvent t) -> {
            if (t.getCode() == KeyCode.ENTER) {
                commitEdit(textField.getText());
            } else if (t.getCode() == KeyCode.ESCAPE) {
                cancelEdit();
            }
        });
    }

    private String getString() {
        return (getItem() != null)?getItem():"";
    }
}

Answer 1

如果事件处理程序实现因实例而异，则需要将事件处理程序（或函数）传递给构造函数。由于您可能需要访问该单元格，因此您将执行类似的操作

public class TableCellHyperlink<S> extends TableCell<S, String> {

    private final TextField textField;
    private final Hyperlink hyperlink;


    public TableCellHyperlink(Consumer<TableCellHyperlink<S> handlerFunction) {

        textField = new TextField();
        hyperlink = new Hyperlink();
        hyperlink.setOnAction(event -> handlerFunction.accept(this));
        setAlignment(Pos.CENTER_LEFT);
    }

    // ...
}

现在你可以做类似的事情

TableCellHyperlink<MyType> hyperlinkCell = new TableCellHyperlink<>(cell -> {
    MyType rowValue = (MyType) cell.getTableRow().getValue(); // getTableRow() returns TableRow, not TableRow<MyType>
    String cellValue = cell.getItem();
    // implement action
});

显然，如果您愿意，您可以将参数向上移动并将其传递给自定义 TableColumn 构造函数。