Image dans ComboBox

Bonjour,
J'aimerais mettre une image + texte dans une ComboBox (Une seule image à coté du premier texte (indice 0)).
J'ai utilisé le code repris ici et ça fonctionne chez moi.
Mais dès que je souhaite implémenter ce code pour ma ComboBox, je rencontre plusieurs problèmes. Le plus récurrent est : 'Exception in thread "main" java.lang.NullPointerException
at renderer.ComboBoxRenderer.getListCellRendererComponent' qui concerne la ligne 'int selectedIndex = ((Integer)value).intValue();' pour la méthode 'getListCellRendererComponent()'.
Est-ce que quelqu'un peut m'aider ?
Merci d'avance.
Marc

Donne ton code simplifié au maximum et compilable reproduisant le problème.

Voici le code de la méthode de la class GUI:

Code:

1
2
3
4
5
6
7
8
9
10
11
private JComboBox getJComboBoxClientsList() {
		if (jComboBoxClientsList == null) {
			CustomComboBox newContentPane = new CustomComboBox();
			ComboBoxRenderer renderer = new ComboBoxRenderer(newContentPane.getImages(), newContentPane.getPetStrings());
			jComboBoxClientsList = new JComboBox(newContentPane.getIntArray());
			jComboBoxClientsList.setRenderer(renderer);
			jComboBoxClientsList.setMaximumSize(jComboBoxClientsList.getPreferredSize());
			jComboBoxClientsList.addActionListener(ccb);
		}
		return jComboBoxClientsList;
	}

Ensuite, la classe que j'ai nommée 'ComboBoxRenderer':

Code:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
public class ComboBoxRenderer extends JLabel implements ListCellRenderer {
	ImageIcon[] images;
    String[] petStrings = {"Bird", "Cat", "Dog", "Rabbit", "Pig"};
    private Font uhOhFont;
 
	public ComboBoxRenderer(ImageIcon[] images,  String[] petStrings) {
		setOpaque(true);
		setHorizontalAlignment(CENTER);
		setVerticalAlignment(CENTER);
		this.images = images;
		this.petStrings = petStrings;
	}
 
	/*
	* This method finds the image and text corresponding
	* to the selected value and returns the label, set up
	* to display the text and image.
	*/
	public Component getListCellRendererComponent(
	                JList list,
	                Object value,
	                int index,
	                boolean isSelected,
	                boolean cellHasFocus) {
	//Get the selected index. (The index param isn't
	//always valid, so just use the value.)
	int selectedIndex = ((Integer)value).intValue();
 
	if (isSelected) {
	setBackground(list.getSelectionBackground());
	setForeground(list.getSelectionForeground());
	} else {
	setBackground(list.getBackground());
	setForeground(list.getForeground());
	}
 
	//Set the icon and text.  If icon was null, say so.
	ImageIcon icon = images[selectedIndex];
	String pet = petStrings[selectedIndex];
	setIcon(icon);
	if (icon != null) {
	setText(pet);
	setFont(list.getFont());
	} else {
	setUhOhText(pet + " (no image available)",
	 list.getFont());
	}
 
	return this;
	}
 
	//Set the font and text when no image was found.
	protected void setUhOhText(String uhOhText, Font normalFont) {
	if (uhOhFont == null) { //lazily create this font
	uhOhFont = normalFont.deriveFont(Font.ITALIC);
	}
	setFont(uhOhFont);
	setText(uhOhText);
	}
}

Et pour finir, la class que j'ai nommée 'CustomComboBox':

Code:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
public class CustomComboBox extends JPanel {
    ImageIcon[] images;
    String[] petStrings = {"Bird", "Cat", "Dog", "Rabbit", "Pig"};
    Integer[] intArray = new Integer[petStrings.length];
 
    /*
     * Despite its use of EmptyBorder, this panel makes a fine content
     * pane because the empty border just increases the panel's size
     * and is "painted" on top of the panel's normal background.  In
     * other words, the JPanel fills its entire background if it's
     * opaque (which it is by default); adding a border doesn't change
     * that.
     */
    public CustomComboBox() {
        super(new BorderLayout());
 
        //Load the pet images and create an array of indexes.
        images = new ImageIcon[petStrings.length];
        Integer[] intArray = new Integer[petStrings.length];
        for (int i = 0; i < petStrings.length; i++) {
            intArray[i] = new Integer(i);
            images[0] = new ImageIcon(ClassLoader.getSystemResource("images/48x48/dualScreen.png"));
            if (images[i] != null) {
                images[i].setDescription(petStrings[i]);
            }
        }
    }
 
    // GETTES-----------------------
 
	public ImageIcon[] getImages() {
		return images;
	}
 
	public String[] getPetStrings() {
		return petStrings;
	}
 
	public Integer[] getIntArray() {
		return intArray;
	}
 
    /**
     * Create the GUI and show it.  For thread safety,
     * this method should be invoked from the
     * event-dispatching thread.
     */
 
}