Hi,
I have written a program that heavily uses JComboBoxes to have the
user select some stuff. In oder to allow for a quick exchange between
JComboBox and JList, I have coded a class that could serve as Model
for both JComponents.  In my program it is frequently the case that
when the user selects an item from a JComboBox, the selection in other
JComboBoxes needs to be updated and the new selection shown in the
JTextField of the JComboBox. The latter is not working. Only when you
click on the JComboBox is the entry updated, though in the drop down
box, the correct item was already selected. Here is some sample code.
Is there something wrong with my CombinedListModel class?
Many thanks in advance!
Regards, Piet
import javax.swing.*;
import javax.swing.event.*;
import java.awt.event.*;
import java.awt.*;
import java.util.*;

public class ComboProblemDemo extends JFrame implements
ActionListener{
    JComboBox fruit;
    JComboBox basket;
    ArrayList<Fruit> fruitlist = new ArrayList<Fruit>();
    ArrayList<Basket> basketlist = new ArrayList<Basket>();
    CombinedListModel fruitModel;
    CombinedListModel basketModel;
    public static void main(String[] args){
        ComboProblemDemo cpd = new ComboProblemDemo("Combo Problem Demo");
        cpd.pack();
        cpd.setVisible(true);
    }
    public ComboProblemDemo(String title){
        super(title);
        fruitModel = new CombinedListModel();
        basketModel = new CombinedListModel();
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JPanel panel = new JPanel();
        fruit = new JComboBox(fruitModel);
        fruit.addActionListener(this);
        basket = new JComboBox(basketModel);
        for(int b = 0;b<2;b++){
            basketlist.add(new Basket(b));
        }

        for(int f = 0;f<2;f++){
            Fruit fr = new Fruit(f);
            fruitlist.add(fr);
            fr.setBasket(basketlist.get(0));
        }

        for(int f = 3;f<5;f++){
            Fruit fr = new Fruit(f);
            fruitlist.add(fr);
            fr.setBasket(basketlist.get(1));
        }
        fruitModel.setItems(fruitlist);
        basketModel.setItems(basketlist);
        panel.add(fruit);
        panel.add(basket);
        setContentPane(panel);
    }
    public void actionPerformed(ActionEvent ae){
   
basketModel.setSelectedItem(((Fruit)fruit.getSelectedItem()).getBasket());
    }
}
class Fruit{
    private int index;
    private Basket basket;
    public Fruit(int index){
        this.index = index;
    }
    public String toString(){
        return "Fruit "+index;
    }
    public Basket getBasket(){
        return this.basket;
    }
    public void setBasket(Basket basket){
        this.basket = basket;
    }
}
class Basket{
    private int index;
    public Basket(int index){
        this.index = index;
    }
    public String toString(){
        return "Basket "+index;
    }
}
class CombinedListModel extends AbstractListModel implements
ComboBoxModel,ListSelectionListener{
    private java.util.List<? extends Object> items = new
ArrayList<Object>();
    private Object selected = null;
    public CombinedListModel(){
    }
    public void valueChanged(ListSelectionEvent lse){
        System.out.println("value changed, index is "+lse.getFirstIndex()+"
is adjusting:"+lse.getValueIsAdjusting() );
        //if (lse.getValueIsAdjusting()){
            //selected = this.items.get(lse.getLastIndex());
        selected = ((JList)lse.getSource()).getSelectedValue();
        //}
        //setSelectedItem(lse.getSource().);
    }
    public void setItems(java.util.List<? extends Object> items){
        this.items = items;
        if (items.size() > 0) selected = this.items.get(0);
        fireContentsChanged(this,0,getSize());
    }
    public Object getElementAt(int index){
        return items.get(index);
    }
    public int getSize(){
        int size = items == null ? 0 : items.size();
        return size;
    }
    public void setSelectedItem(Object item){
        System.out.println("Selection changed");
        if(items.contains(item)){
            selected =item;
        }
        else{
            System.out.println("Selection not possible");
        }
    }
    public Object getSelectedItem(){
        return selected;
    }
    public void clear(){
        this.items.clear();
        fireContentsChanged(this,0,this.items.size()-1);
    }
}