How can I change a JTextField into a JComboBox

Question

I have a desktop GUI application that has a field on a panel, which is usually a JTextField. However, under certain circumstances, this field needs to be restricted to certain known values - and a ComboBox would be great.
Under these circumstances, I would like the Textfield to disapear and the combobox to appear in exactly the same place, but I cannot figure out how to achieve this effect within the GUI.
I am hand crafting this GUI using GroupLayout Layout manager
I am also using Netbeans, so I thought I would try and achieve this effect using its GUI designer, but that wouldn't let me place one field on top of another.
Could anyone help me?
Much thanks in advance.

Answer 1

This should give you the necessary example
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class SwitchExample
    public static final void main(String[] args)
        final JTextField field = new JTextField(20);
        final JComboBox combo = new JComboBox();
            combo.addItem("Item 1");
            combo.addItem("Item 2");
        final JPanel panel = new JPanel();
            panel.add( field );
        JButton button = new JButton("Switch");
            button.addActionListener( new ActionListener() {
                public void actionPerformed(ActionEvent e) {
                    if(field.isShowing()) {
                        panel.remove( field ); // remove old component
                        panel.add(combo, 0); // add new component 
                    } else{
                        panel.remove( combo );
                        panel.add( field, 0 );
                    panel.validate(); // recalculate the layout
                    panel.repaint();  // redraw components on screen
        panel.add( button );
        JFrame fp1 = new JFrame("Switch Example");
        fp1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        fp1.setContentPane(panel);
        fp1.pack();
        fp1.setLocationRelativeTo(null);
        fp1.setVisible(true);
}ICE