Question

I have the following Programm

package utests;

import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.util.ArrayList;

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

class Foo extends JFrame {
    private JComboBox combo;

    public static void main(String... args) {
    Foo f = new Foo();
    f.showUI();
    }

    public void showUI() {
    this.setVisible(true);
    JPanel pane = new JPanel();
    this.setContentPane(pane);
    combo = new JComboBox();
    combo.addItemListener(new ItemListener() {
        @Override
        public void itemStateChanged(ItemEvent arg0) {
        if (arg0.getStateChange() == ItemEvent.SELECTED) {
            System.out.println("You selected " + combo.getSelectedItem());
        }
        }
    });
    refreshBox();

    pane.add(combo);
    this.pack();
    }

    public void refreshBox(){
    combo.removeAllItems();
ArrayList<String> list = new ArrayList<String>();
    list.add("godsf");
    list.add("södlkf");
    list.add("ldsjlkfdsj");

    for (String s : list) {
        combo.addItem(s);
    }
    }
}

The programm will immediatly show you the string

You selected godsf

How can i check if the user checked something and not the program?

edit: i changed the programm a bit: The problem is that i need to refresh the box some times. Every Time i refresh the data in the box, the ItemListener is hit, and i get wrong results.
How can i check that a Action is done by the User and not by the Programm itself? To add some booleans seems to be not very Java-like…

Answer 1

Change the code of method refreshBox to code below:

public void refreshBox()
{
    combo.removeAllItems();
    ArrayList<String> list = new ArrayList<String>();
    list.add("godsf");
    list.add("södlkf");
    list.add("ldsjlkfdsj");

    for (String s : list) 
    {
        combo.insertItemAt(s, 0);
    }
}

does it meet your requirement?
I just change the code:

combo.addItem(s);

to the code:

combo.insertItemAt(s, 0);