setEditable() - Use Combo Box as Text Field

Java Swing Tutorials - Herong's Tutorial Examples

∟setEditable() - Use Combo Box as Text Field

This section provides a tutorial example on how to call the setEditable(true) method to use a combo box as a dropdown list and text field at the same time.

If you want to use a combo box as both a dropdown list and a text text field, you can call the getEditable(true) method on the combo box. Here is a sample program:

/* JComboBoxAsEditable.java
 * Copyright (c) 1997-2018 HerongYang.com. All Rights Reserved.
 */
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class JComboBoxAsEditable implements ActionListener {
   JComboBox<String> combo;
   JLabel myLabel = null;
   public static void main(String[] a) {
      JComboBoxAsEditable myTest = new JComboBoxAsEditable();
      myTest.createFrame();
   }
   public void createFrame() {
    JFrame f = new JFrame("My Combo Box");
      f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      Container c = f.getContentPane();
      c.setLayout(new BoxLayout(c,BoxLayout.Y_AXIS));
    
      JLabel color = new JLabel("Colors:");
      c.add(color);

      String[] options = {"Red", "Green", "Blue"};
      combo = new JComboBox<String>(options);
    combo.setEditable(true);
    combo.setSelectedIndex(-1);
      c.add(combo);
    
      JButton b = new JButton("Done");
      b.addActionListener(this);
      c.add(b);
    
      myLabel = new JLabel("Please end/select");
      c.add(myLabel);
      f.pack();
      f.setVisible(true);
   }
   public void actionPerformed(ActionEvent e) {
    String t = (String) combo.getSelectedItem();
    if (t == null) t = "Nothing entered/selected";
      myLabel.setText(t);
   }
}

If you run this program, you will see none of the options is selected initially and nothing is entered in the text field. If you click "Done", you will get the "Nothing entered/selected" message. If you select an option then click "Done", you will get the selected color. If you enter your own color, and click "Done", you will get the color you entered: