"Odd" JTable 单元格上双值编辑器的行为

Question

我有一个 DoubleEditor 是我从网上提取的 Integer Editor 修改而来的。我正在使用它来验证在 JXTable 单元格中输入的双精度值，该单元格旨在获取从 0.00 到 100.00 的值。但是，我有一个奇怪的问题：如果我在单元格中输入 1.999，我按回车键没有任何反应。 (I expected it to convert this to 2.00)。如果我单击以编辑值为 1.999 的单元格，它会执行转换。如果我输入 1.9999 它会立即执行转换！

我只需要这个编辑器：1) 将我的值表示为 10.00 和 2) 它必须四舍五入到 2d.p 任何输入的值

代码如下：

public class DoubleEditor extends DefaultCellEditor {

JFormattedTextField ftf;
DecimalFormat doubleFormat;
private Double minimum, maximum;
private boolean DEBUG = false;

public DoubleEditor(double min, double max) {
    super(new JFormattedTextField());
    ftf = (JFormattedTextField) getComponent();
    minimum = new Double(min);
    maximum = new Double(max);

    //Set up the editor for the integer cells.
    doubleFormat = new DecimalFormat("###.##");//Setting out the formatter here
    doubleFormat.setMaximumFractionDigits(2);//2dp
    NumberFormatter doubleFormatter = new NumberFormatter(doubleFormat);
    doubleFormatter.setFormat(doubleFormat);
    doubleFormatter.setMinimum(minimum);
    doubleFormatter.setMaximum(maximum);

    ftf.setFormatterFactory(
            new DefaultFormatterFactory(doubleFormatter));
    ftf.setValue(minimum);
    ftf.setHorizontalAlignment(JTextField.CENTER);
    ftf.setFocusLostBehavior(JFormattedTextField.PERSIST);

    //React when the user presses Enter while the editor is
    //active.  (Tab is handled as specified by
    //JFormattedTextField's focusLostBehavior property.)
    ftf.getInputMap().put(KeyStroke.getKeyStroke(
            KeyEvent.VK_ENTER, 0),
            "check");
    ftf.getActionMap().put("check", new AbstractAction() {
        @Override
        public void actionPerformed(ActionEvent e) {
            if (!ftf.isEditValid()) { //The text is invalid.
                if (userSaysRevert()) { //reverted
                    ftf.postActionEvent(); //inform the editor
                }
            } else {
                try {              //The text is valid,
                    ftf.commitEdit();     //so use it.
                    ftf.postActionEvent(); //stop editing
                } catch (java.text.ParseException exc) {
                }
            }
        }
    });
}

//Override to invoke setValue on the formatted text field.
@Override
public Component getTableCellEditorComponent(JTable table,
        Object value, boolean isSelected,
        int row, int column) {
    JFormattedTextField ftf
            = (JFormattedTextField) super.getTableCellEditorComponent(
                    table, value, isSelected, row, column);
    ftf.setValue(value);
    return ftf;
}

//Override to ensure that the value remains an Double.
@Override
public Object getCellEditorValue() {
    JFormattedTextField ftf = (JFormattedTextField) getComponent();
    Object o = ftf.getValue();
    if (o instanceof Double) {//Watch out !!!
        return o;
    } else if (o instanceof Number) {

        return new Double(((Number) o).doubleValue());
    } else {
        if (DEBUG) {
            System.out.println("getCellEditorValue: o isn't a Number");
        }
        try {
            return doubleFormat.parseObject(o.toString());
        } catch (ParseException exc) {
            System.err.println("getCellEditorValue: can't parse o: " + o);
            return null;
        }
    }
}

//Override to check whether the edit is valid,
//setting the value if it is and complaining if
//it isn't.  If it's OK for the editor to go
//away, we need to invoke the superclass's version 
//of this method so that everything gets cleaned up.
@Override
public boolean stopCellEditing() {
    JFormattedTextField ftf = (JFormattedTextField) getComponent();
    if (ftf.isEditValid()) {
        try {
            ftf.commitEdit();
        } catch (java.text.ParseException exc) {
        }

    } else { //text is invalid
        if (!userSaysRevert()) { //user wants to edit
            return false; //don't let the editor go away
        }
    }
    return super.stopCellEditing();
}

/**
 * Lets the user know that the text they entered is bad. Returns true if the
 * user elects to revert to the last good value. Otherwise, returns false,
 * indicating that the user wants to continue editing.
 */
protected boolean userSaysRevert() {
    Toolkit.getDefaultToolkit().beep();
    ftf.selectAll();
    Object[] options = {"Edit",
        "Revert"};
    int answer = JOptionPane.showOptionDialog(
            SwingUtilities.getWindowAncestor(ftf),
            "The value must be an integer between "
            + minimum + " and "
            + maximum + ".\n"
            + "You can either continue editing "
            + "or revert to the last valid value.",
            "Invalid Text Entered",
            JOptionPane.YES_NO_OPTION,
            JOptionPane.ERROR_MESSAGE,
            null,
            options,
            options[1]);

    if (answer == 1) { //Revert!
        ftf.setValue(ftf.getValue());
        return true;
    }
    return false;
}
}

这段代码有什么问题？

Answer 1

根据@trashgod 的评论，我得出了一个答案。我现在没有错过 Table Cell Renderer，而是专注于 Editor。我了解到这两件事的工作方式不同，适用于不同的事物。答案基于 Advice welcomed on creating my own Swing component.

我的自定义呈现器，用于采用双精度值的列。

public class DoubleRenderer extends DefaultTableCellRenderer {

DecimalFormat df;

public DoubleRenderer(DecimalFormat df) {
    this.df = df;
    this.setHorizontalAlignment(JLabel.CENTER);
    this.setBackground(Color.lightGray);
    this.df.setParseBigDecimal(true);
}

@Override
protected void setValue(Object value) {
    setText((value == null) ? "" : df.format(value));
}
 }

"Odd" JTable 单元格上双值编辑器的行为

"Odd" behavior on Double Value editor on JTable cell

java

swing

number-formatting