/**
* Sets the icon for an item.
*
* @param itemId the id of the item to be assigned an icon.
* @param icon the icon to use or null.
* @param altText the alternative text for the icon
*/
public void setItemIcon(Object itemId, Resource icon, String altText) {
if (itemId != null) {
super.setItemIcon(itemId, icon);
if (icon == null) {
itemIconAlts.remove(itemId);
} else if (altText == null) {
throw new IllegalArgumentException(NULL_ALT_EXCEPTION_MESSAGE);
} else {
itemIconAlts.put(itemId, altText);
}
markAsDirty();
}
}
