Problem with JScrollPane

[Nijin puthiya purayil]

Hai,

In my application i'm using a JTextField associated with a JList and a JScrollPane is given to the JList...when i type a name in the JTextField the matched names are displayed in the JList within the JScrollPane...Actually in my application i made the list and pane to be invisible when the window is activted by using a formWindowActivated listener..it will become visible only when i type a name in the JTextField...but whenever i type the name the JScrollPane and the JList are still invisible...but if i click somewhere in the GUI window after entering the first letter of the name the list is becoming visible what can be the problem? Is there any other method to make it visible? is the JList visible already and i can't see it?? There is no MouseListener in my application..... I'm pasting the code below what i used...

 private void tfKeyReleased(java.awt.event.KeyEvent evt) {  
//here tf is the JTextField, list is the JLis and sp is the JScrollPane ...
            String userName1 = "username";
            String password1 = "password";
            String url1 = "jdbc:mysql://localhost:3306/mydbname";
            Class.forName("com.mysql.jdbc.Driver");
            java.sql.Connection con = DriverManager.getConnection(url1, userName1, password1);
            java.sql.Statement stmt = con.createStatement();
            ResultSet rs = stmt.executeQuery("select name from table where name like '" + tf.getText() + "%'");
            ArrayList<String> names = new ArrayList<String>();
            while (rs.next()) {
                String st = rs.getString("name");
                names.add(st);
            }
            rs.close();
            DefaultListModel dlm = new DefaultListModel();
            for (int i = 0, n = names.size(); i < n; i++) {
                Object ob = names.get(i);
                dlm.addElement(ob);
            }
            list.setModel(dlm);
                list.setVisible(true);
                sp.setVisible(true);
            con.close();
            rs.close();
}
            

and the ActionListener for JList is...

private void listValueChanged(javax.swing.event.ListSelectionEvent evt) {                                  
        Object obj = list.getSelectedValue();
        String st = tf.getText();
        if (obj != null) {
            InputMap im = list.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW);
            im.put(KeyStroke.getKeyStroke(KeyEvent.VK_DOWN, 0), "selectNextRow");
            im.put(KeyStroke.getKeyStroke(KeyEvent.VK_UP, 0), "selectPreviousRow");
            list.setInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW, im);
            tf.setText(obj.toString());
        }

any help will be appreciated..thanks in advance...

[Darryl Burke]

... using a formWindowActivated listener.

Since there's no such class in core Java, any questions regarding it should either be accompanied by the code or asked wherever you got the class.

Other comments:

To listen to changes in the content of any text component, you should use a DocumentListener added to the component's Document. Not a KeyListener.

Database queries should normally not be performed on the EDT

To get better help sooner, post a SSCCE (Short, Self Contained, Compilable and Executable) example that demonstrates the problem. And remember that the first 'S' stands for Short.

[Nijin puthiya purayil]

Darryl Burke wrote:

... using a formWindowActivated listener.

Since there's no such class in core Java, any questions regarding it should either be accompanied by the code or asked wherever you got the class.

I'm sorry if i confused you... actually i meant to say WindowListener and the windowActivated(WindowEvent) event in my code...here the form was my JFrame form...
here in this case i just want to display the JList...i'm not bothered about the contents...even if i'm not storing any database values in the JList and i try to make it visible by
typing some values in the JTextField the same problem arises...

[Darryl Burke]

i just want to display the JList...i'm not bothered about the contents...even if i'm not storing any database values in the JList and i try to make it visible by
typing some values in the JTextField the same problem arises...

So where's that SSCCE?

[Nijin puthiya purayil]

Here is the code i used...
When window is activated

///form is my JFrame form...
private void formWindowActivated(WindowEvent evt) {  
           sp.setVisible(false);
           list.setVisible(false);
}

In the KeyReleased event

private void tfKeyReleased(KeyEvent evt) {
           sp.setVisible(true);
           list.setVisible(true);
          // other codes to do stuff..
}

[Rob Spoor]

That's still not an SSCCE.

[Darryl Burke]

Nijin puthiya purayil wrote: In the KeyReleased event

Is my first response not visible?