Java SE7 getpercentinstance

Question

I have a program that uses an actionPerformed listener on a JFormattedTextField that is formatted using the NumberFormat.getPercentInstance. It is set up as follows:

    percentFormat = NumberFormat.getPercentInstance();
    txtRPI = new JFormattedTextField(percentFormat);
    percentFormat.setMinimumFractionDigits(1);
    percentFormat.setMaximumIntegerDigits(2);
    GridBagConstraints gbc_txtRPI = new GridBagConstraints();
    gbc_txtRPI.insets = new Insets(0, 0, 5, 5);
    gbc_txtRPI.gridx = 3;
    gbc_txtRPI.gridy = 2;
    gbc_txtRPI.anchor = GridBagConstraints.FIRST_LINE_START;
    txtRPI.setValue(objParams.getRPI());
    panTop.add(txtRPI, gbc_txtRPI);
    txtRPI.setColumns(10);
    txtRPI.addActionListener(new ActionListener () {
        public void actionPerformed(ActionEvent e) {
            objParams.setRPI((double)txtRPI.getValue());
        }
    });

This worked fine until I added the following code on a different JPanel with a table:

public class MyPercentRender extends DefaultTableCellRenderer {

/**
 * 
 */
private static final long serialVersionUID = 1L;
private static NumberFormat formatter = NumberFormat.getPercentInstance();

public Component getTableCellRendererComponent(
    JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {
    // First format the cell value as required
    formatter.setMinimumFractionDigits(1);
    formatter.setMaximumFractionDigits(2);
    formatter.setMaximumIntegerDigits(2);
    value = formatter.format((Number)value);

    // And pass it on to parent class

    return super.getTableCellRendererComponent(
    table, value, isSelected, hasFocus, row, column );
    }

}

Once this had been added the first field's actionListener stopped being fired and thus I could not save the value.

Has anyone seen this behaviour before and knows what is going on?

Thanks for the reply. I have taken static out. As far as being part of the event dispatch thread, it is.

I have tried a few more things and it seems that the percentinstance is a red herring. Even if I take this out the actionlistener is not being fired. I have checked the object after creation to and the listener is registered along with one other of Class<T> .

I have used this code

    txtRPI = new JFormattedTextField();
    GridBagConstraints gbc_txtRPI = new GridBagConstraints();
    gbc_txtRPI.insets = new Insets(0, 0, 5, 5);
    gbc_txtRPI.gridx = 3;
    gbc_txtRPI.gridy = 2;
    gbc_txtRPI.anchor = GridBagConstraints.FIRST_LINE_START;
    txtRPI.setValue(objParams.getRPI());
    txtRPI.setColumns(10);
    txtRPI.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            objParams.setRPI((double)txtRPI.getValue());
        }
    });
    panTop.add(txtRPI, gbc_txtRPI);
    this.add(panTop, BorderLayout.PAGE_START);

But still the same result. All my other actionListeners (on buttons and ComboBox) work. Is there something about Formatted Text?

I did some experimentation. I changed getPercentInstance to getNumberInstance on the first line and it works but has no percent sign. — , Sep 11 '14 at 13:45

score 1 · Accepted Answer · edited May 23 '17 at 10:26

1

Two related problems arise in looking at your fragment:

A static instance of NumberFormat will be shared by all instances of your TableCellRenderer.
Swing is not thread safe nor are the formatters, NumberFormat and DateFormat, for example. Verify that Swing GUI objects are constructed and manipulated only on the event dispatch thread.

edited May 23 '17 at 10:26

Community

1
1

answered Sep 11 '14 at 19:27

trashgod

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score 1 · Answer 2 · answered Sep 13 '14 at 12:45

The issue was the formatting enforced by the percentInstance. If you just enter a numeric value without the % it fails the validating and thus does a REVERT and does not fire the actionevent. If you put the % sign in it fires the event.

Java SE7 getpercentinstance

2 Answers2