Multiplying windows in Java App

Question

another problem. I wanted to make doubleclick on JTable which open new window with form. So finally i made it this way:

    table.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);

    table.getSelectionModel().addListSelectionListener(new ListSelectionListener(){
        public void valueChanged(ListSelectionEvent event){
            int viewRow = table.getSelectedRow();
            if(viewRow < 0)
                System.out.println("LOL");
            else{
                final int modelRow = table.convertRowIndexToModel(viewRow);
                table.addMouseListener(new MouseAdapter(){
                    public void mouseClicked(MouseEvent e){
                        if(e.getClickCount() == 2)
                            try {
                                new BookForm();
                            } catch (IOException e1) {
                                e1.printStackTrace();
                            }

                    }
                });
            }   

        }
    });

It works, but not perfect. First time when i doubleclick on JTable it opens 2 windows (why not one?), next time it opens 4 windows, next another 6 windows, etc. Any ideas? Maybe i should have to use different method? Thanks for help!

Answer 1

Take a second to look over your code...

Each time the selection changes, you add a new MouseListener

table.getSelectionModel().addListSelectionListener(new ListSelectionListener(){
    public void valueChanged(ListSelectionEvent event){
        int viewRow = table.getSelectedRow();
        if(viewRow < 0)
            System.out.println("LOL");
        else{
            // You add a new mouse listener...
            final int modelRow = table.convertRowIndexToModel(viewRow);
            table.addMouseListener(new MouseAdapter(){
                public void mouseClicked(MouseEvent e){
                    if(e.getClickCount() == 2)
                        try {
                            new BookForm();
                        } catch (IOException e1) {
                            e1.printStackTrace();
                        }

                }
            });
        }   

    }
});

So, when you "finally" double click a row, you will have 1-n MouseListeners registered against the table...

You could just get rid of the selection listener and simple add the MouseListener directly to the table...

table.addMouseListener(new MouseAdapter(){
    public void mouseClicked(MouseEvent e){
        if(e.getClickCount() == 2)
            int selectedRow = table.getSelectedRow();
            if (selectedRow > -1) {
                int modelRow = table.convertRowIndexToModel(selectedRow);
                try {
                    new BookForm();
                } catch (IOException e1) {
                    e1.printStackTrace();
                }
            }
    }
});

Also take a look at The Use of Multiple JFrames: Good or Bad Practice? before you bomb bard your user with lots of new windows...