Copy cell value of JTable with right click

I am showing some results in a JTable that consists of 2 columns.

File - Result

I implemented a JPopupMenu which displays a copy entry, and I try to copy the value of the cell, where I right-clicked.

filelistTable.addMouseListener(new MouseAdapter() {
    @Override
    public void mouseClicked(MouseEvent e) {
         if(SwingUtilities.isRightMouseButton(e))
         {
             TablePopupMenu popup = new TablePopupMenu(filelistTable, e.getPoint());
             filelistTable.setComponentPopupMenu(popup);
         }
    }
});

    public TablePopupMenu(JTable table, Point p) {

        this.table = table;
        this.p = p;

        JMenuItem mntmKopieren = new JMenuItem("Kopieren");
        mntmKopieren.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                copyCellToClipboard();
            }
        });
        add(mntmKopieren);
    }

    public void copyCellToClipboard()
    {
        int r = table.rowAtPoint(p);
        int c = table.columnAtPoint(p);
        System.out.println(table.getValueAt(table.convertRowIndexToView(r), 
                table.convertRowIndexToView(c)));
        StringSelection entry = new StringSelection(table.getValueAt(table.convertRowIndexToView(r), 
                table.convertRowIndexToView(c)).toString());
        Clipboard clipboard = Toolkit.getDefaultToolkit().getSystemClipboard();
        clipboard.setContents( entry, this );

    }

Anyhow, this only works for a small number of tests. Did I do something wrong or something missing? It looks to me, as if the cell will not even get choosen correctly.

Solution

Two thingies are slightly off:

setting the componentPopup in the clicked is too late in the sequence of mouseEvents (popups are typically triggered on pressed or released which happen before the click)
the value is taken from the incorrect cell: all coordinates in a JTable are in view coordinate system, converting them to view coordinates will be completely off

That said: getting cell-coordinate related context is poorly supported. Often, the best bet is to (code snippet below)

override getPopupLocation(MouseEvent) and store the location somewhere
implement a popup/action to access the location

Fails if (as should be done in a well-behaved application), the popup could be triggered by keyboard: if that's the case, you'll need to provide some other marker (f.i. the focused cell) to act on.

final String popupLocation = "table.popupLocation";
final JTable table = new JXTable(new AncientSwingTeam()) {

    @Override
    public Point getPopupLocation(MouseEvent event) {
        // event may be null if triggered by keyboard, f.i.
        // thanks to @Mad for the heads up!
        ((JComponent) event.getComponent()).putClientProperty(
                popupLocation, event != null ? event.getPoint() : null);
        return super.getPopupLocation(event);
    }

};
JPopupMenu popup = new JPopupMenu();
Action printLocation = new AbstractAction("print cell") {

    @Override
    public void actionPerformed(ActionEvent e) {
       Point p = (Point) table.getClientProperty(popupLocation);
       if (p != null) { // popup triggered by mouse
           int row = table.rowAtPoint(p);
           int column = table.columnAtPoint(p);
           LOG.info("" + table.getValueAt(row, column)); 
       } else { // popup triggered otherwise
           // could choose f.i. by leadRow/ColumnSelection
           ...
       }
    }

};
popup.add(printLocation);
table.setComponentPopupMenu(popup);

Edit (triggered by Mad's comment):

You should be checking MouseEvent.isPopupTrigger as the trigger point is platform dependent. This does mean you need to monitor mousePressed, mouseReleased and mouseClicked

No, that's not needed (just checked :-): the mechanism that shows the componentPopup in response to a mouseEvent - happens in BasicLookAndFeel.AWTEventHelper - only does so if it is a popupTrigger.

By reading the api doc (should have done yesterday ;-) again, it turns out that the method is called always before showing the componentPopup, that is also if triggered by other means, f.i. keyboard. In that case the event param is null - and the original code would blow. On the bright side, with that guarantee, all the logic of finding the target cell/s could be moved into that method. Didn't try though, so it might not be feasable (f.i. if then the location should be based on the leadRow/ColumnSelection that might not yet be fully handled at that time)