Copy cell value of JTable with right click

Question

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.

Did you get any errors? Or did the value just fail to get copied to the clipboard? — MadProgrammer, Sep 19 '12 at 09:31
Does the `ClipboardOwner.lostOwnership` get fired?? Highly unlikely, but something might have replaced the contents. Also, the `setContents` method throws a `IllegalStateException`. It might be worth trying to catch this and see if this is possibly causing you any problems — MadProgrammer, Sep 19 '12 at 09:35
Even the printed value to console does not give the correct value. If it fails, it's always the last try that was copied correctly. — Stefan, Sep 19 '12 at 09:37
What is wrong with the default copy action of the default transfer handler of the table ? — Robin, Sep 19 '12 at 10:07
What do you mean with default transfer handler? I want the user to appear a menu at right-click on the cell to choose "copy" (and later more) and it should copy the cell value to clipboard. I did not find any default action that does this? — Stefan, Sep 19 '12 at 10:14

score 5 · Accepted Answer · edited Feb 21 '13 at 14:12

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)

please DYM to use `ListSelectionListener` rather that `flying Point` from `mouse_hover_over` or ... — mKorbel, Sep 19 '12 at 11:33
@mKorbel don't understand - which flying point and where does the mouseOver come into play? Anyway, no selectionListener needed, you can statically query for the lead selection (both for column and row) — kleopatra, Sep 19 '12 at 11:42
You should be checking `MouseEvent.isPopupTrigger` as the trigger point is platform dependent. This does mean you need to monitor `mousePressed`, `mouseReleased` and `mouseClicked` though :P — MadProgrammer, Sep 19 '12 at 20:41
@MadProgrammer don't think so: the getPopupLocation is called only if the event _is_ a popupTrigger (at least that's what I expect, didn't check - but could be the implementation - in rootPaneUI or BasicLookAndFeel, forgot - be that bad .. nooo, we have some faith, don't we :-) — kleopatra, Sep 20 '12 at 07:56
@kleopatra Yes, you're right, wasn't paying attention to the use of the method in the `JTable`. Still a good idea if you're just using a mouse listener — MadProgrammer, Sep 20 '12 at 09:11
@MadProgrammer true - but the whole point of using the high-level componentPopup property is to hide away those dirty details of the low-level triggers :-) — kleopatra, Sep 20 '12 at 09:16

Copy cell value of JTable with right click

1 Answers1