JPopupMenu on JTable -> Get the cell the menu was created on

问题

I have a situation where I have a popup menu created when a JTable is right clicked on. Standard way of creating the popup menu:

aJTable.setComponentPopupMenu(rightClickMenu);

Now afterwards in the action that gets registered, I am unable to find out which cell was right clicked on to get that popup menu to appear.

rightClickMenuItem.addActionListener(new AbstractAction() {
    @Override
    public void actionPerformed(ActionEvent e) {
        // Work out what cell was right clicked to generate the menu
    }

});

Any ideas on how you do this?

回答1:

Astonishing fact: with a componentPopupMenu installed, a mouseListener never sees the mouseEvent that is the popupTrigger (reason is that showing the componentPopup is handled globally by a AWTEventListener installed by BasicLookAndFeel, and that listener consumes the event).

The only place which sees the mousePosition of that trigger is the getPopupLocation(MouseEvent), so the only reliable way to get hold of it (for doing location dependent config/actions) is @Mad's suggestion to override that method and store the value somewhere for later use.

The snippet below uses a clientProperty as storage location:

final JTable table = new JTable(new AncientSwingTeam()) {

    @Override
    public Point getPopupLocation(MouseEvent event) {
        setPopupTriggerLocation(event);
        return super.getPopupLocation(event);
    }

    protected void setPopupTriggerLocation(MouseEvent event) {
        putClientProperty("popupTriggerLocation", 
                event != null ? event.getPoint() : null);
    }
};
JPopupMenu popup = new JPopupMenu();
Action action = new AbstractAction("show trigger location") {

    @Override
    public void actionPerformed(ActionEvent e) {
        JPopupMenu parent = (JPopupMenu) SwingUtilities.getAncestorOfClass(
                JPopupMenu.class, (Component) e.getSource());
        JTable invoker = (JTable) parent.getInvoker();
        Point p = (Point) invoker.getClientProperty("popupTriggerLocation");
        String output = p != null ? "row/col: " 
             + invoker.rowAtPoint(p) + "/" + invoker.columnAtPoint(p) : null; 
        System.out.println(output);
    }
};
popup.add(action);
popup.add("dummy2");
table.setComponentPopupMenu(popup);

回答2:

@MadProgrammer's suggestion of getPopupLocation looked promising, but I couldn't work out how to get the information across between the table and the actionEvent...

I got around this by making sure that the row was selected when you rightclicked on it -> since the popup menu prevents the selection of the row, you can add in a mouse listener that makes sure the row gets selected no matter what click (left or right) is pressed.

aTable.addMouseListener(new MouseAdapter() {
    @Override
    public void mousePressed(MouseEvent e) {
        int r = aTable.rowAtPoint(e.getPoint());
        if (r >= 0 && r < clt.getRowCount()) {
            aTable.setRowSelectionInterval(r, r);
        } else {
            aTable.clearSelection();
        }
    }
});

This means that in the rightClickMenuItem's action listener, you can grab the table's selected cell / row

rightClickMenuItem.addActionListener(new AbstractAction() {
    @Override
    public void actionPerformed(ActionEvent e) {
        aTable.get details about the selected one....
    }
});

Too easy! Thanks everyone for the help.

回答3:

JTable has methods

int row = rowAtPoint(p);
int col = columnAtPoint(p);

So pass the MouseEvent's point and use the values

Add a MouseListener and store the last right click point somewhere.

来源：https://stackoverflow.com/questions/13814861/jpopupmenu-on-jtable-get-the-cell-the-menu-was-created-on

标签

java

swing

jtable

jpopupmenu