Java Swing Tutorial - Java JComboBox .firePopupMenuWillBecomeVisible ()

Syntax

JComboBox.firePopupMenuWillBecomeVisible() has the following syntax.

public void firePopupMenuWillBecomeVisible()

Example

In the following code shows how to use JComboBox.firePopupMenuWillBecomeVisible() method.

/*from  w w w  .  j a v  a  2 s .c om*/
import java.awt.Color;
import java.awt.Component;
import java.awt.Graphics;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;

import javax.swing.Icon;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class Main extends JPanel implements ItemListener {
  public Main() {
      JComboBox jc = new JComboBox(); 
      jc.addItem("France"); 
      jc.addItem("Germany"); 
      jc.addItem("Italy"); 
      jc.addItem("Japan"); 
      jc.addItemListener(this); 
      add(jc); 
      
      jc.firePopupMenuWillBecomeVisible();
  }

  public void itemStateChanged(ItemEvent ie) {
      String s = (String)ie.getItem(); 
      System.out.println(s); 
  }

  public static void main(String[] args) {
    JFrame frame = new JFrame();
    frame.getContentPane().add(new Main());

    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setSize(200, 200);
    frame.setVisible(true);
  }

}