Swing JTable cells will not update as loop executes

stephenlane80

Hello,

I'm haveing a bit of trouble updating a swing jTable with values as i loop through a process and update cells as i go, even though im updating the cells incrementally they don't update until the loop is finished.

I wouldnt be bothered if the loop was fast, but the problem is that each stage in the loop takes about 2 secconds and there are about 20 increments.

As the loop executes i update the cells in the JTabels TableModel using this code:

jTResults.getModel().setValueAt(str[k], j, k)

But the actual table deosnt get updated until the loop finishes, Any idead on how to make it update during the loop ?

Here is all of the code:

PipedOutputStream os = new PipedOutputStream();
            PipedInputStream is = new PipedInputStream();
            os.connect(is);
            new SendAnalysis(os,jTextField1.getText(),"50");
            ReceiveAnalysis ra = new ReceiveAnalysis(is,50);

            String[] str;
            InputStream ins = ra.input;
            ObjectInputStream ois = new ObjectInputStream(ins);
            for (int j = 0; j < 50; j++) {
                str = (String[]) ois.readObject();
                for (int k = 0; k < 4; k++) {
                    
                    System.out.println("  " + str[0] + " " + str[1] + " " + str[2] + " " + str[3]);
                    jTResults.getModel().setValueAt(str[k], j, k);
                }
            }

I've tried overriding the IDE's default DefaultTableModel for the jTable with a new one so i could call fireTableDataChanged or fireTableCellUpdated(j, k) but neither work, jTable.repaint or jTable.validate dont work either.

S

radioactiveman

Did you try:

jTResults.setModel(jTResults.getModel());
?
I'm not sure how often java updates it itself.

stephenlane80

No Doesn't work unfortunately, still waits until the loop in finished, good duggestion thou,

Seems like the TableModel doesnt get updated until the loop finishes, so it has no data for the jTable

patftrears

Not sure how your application works, but

We remove table from the panel
create new table
add it to the panel

or

you could try having the tables cells as jlabels and
get each jlabel in the cell and use .setText(kkjkl);

radioactiveman

a ha!

for (int j = 0; j < 50; j++) {
                str = (String[]) ois.readObject();
                for (int k = 0; k < 4; k++) {
                    
                    System.out.println("  " + str[0] + " " + str[1] + " " + str[2] + " " + str[3]);
                    jTResults.getModel().setValueAt(str[k], j, k);
                    [B]jTResults.getModel().fireTableDataChanged();[/B]
                }

?

stephenlane80

Hi Thanks for suggestions but it still doesn't work i tried fireTableDataChanged before but it was no good,

It can't be called like this: jTResults.getModel().fireTableDataChanged();
because the getModel returns a reference to the TableModel interface which does not implement fireTab....

I overrid the DefaultTableModel for the table then called .fireTableDataChanged() on its overriden DefaultTableModel, and like i say it didnt work,

Maybe swing gives low priority to updating the GUI and theres nothing that can be done ?

radioactiveman

Can you post the class up by any chance?

Did you try:

TableModel myData = jTResults.getModel(); // get a reference to the model
then later:
myData.fireTableDataChanged();

stephenlane80

The TableModel object does not implement fireTableDataChanged, only AbstractTableModel or DefaultTableModel, i tried overrid the TableModel with a DefaultTableModel and called fireTableDataChanged on the new DefaultTableModel but that didn't work, same result, table only got updated after loop had completed. I will try this from patftrears:

We remove table from the panel
create new table
add it to the panel

I cannot post entire class, however it is simple enough,

The class is an ide generated class with one table and only one button,

There is only one method in the calss and it gets called by the button:

public void button_click() {
        try {
            /*
            //make sure table is empty after the last run
            for (int j = 0; j < 50; j++) {
            for (int k = 0; k < 4; k++) {
            
            jTResults.getModel().setValueAt(null, j, k);
            }
            }
             */

            PipedOutputStream os = new PipedOutputStream();
            PipedInputStream is = new PipedInputStream();
            os.connect(is);
            new SendAnalysis(os, jTextField1.getText(), "50");
            ReceiveAnalysis ra = new ReceiveAnalysis(is, 50);

            String[] str;
            InputStream ins = ra.input;
            ObjectInputStream ois = new ObjectInputStream(ins);
            for (int j = 0; j < 50; j++) {
                str = (String[]) ois.readObject();
                for (int k = 0; k < 4; k++) {

                    System.out.println("  " + str[0] + " " + str[1] + " " + str[2] + " " + str[3]);
                    jTResults.getModel().setValueAt(str[k], j, k);
                    jTResults.setModel(jTResults.getModel());

                }
            }
            ins.close();


        } catch (Exception e) {
        }
    }

radioactiveman

I have no idea about this actually.
It could be that the data is not being updated in the event thread, but I did a test to see and doing this (with SwingUtilities.invokeLater()) made no difference.
If anyone can get this I would be very interested in seeing it.

The table will not update without fireTableDataChanged() but getting it to update just after each row is added is a different thing. Maybe this is a limitation in Swing?
I tried repainting the table each time but no go.
I might post this up on JavaRanch to see if they have any idea...

stephenlane80

I have no idea either, seems weird, but i think swing may do things in chunks for performance, i got the invokeLater() suggestion from the sun forums also, but it doesnt make a difference if the update is called there

Blowfish

I've had similar issues previously. Seems repaint() etc. just tell Swing to update when it can, rather than immediately.

This has worked for me as a workaround:

jTResults.paintComponents(jTresults.getGraphics());

stephenlane80

This didn't work for me