"Activating" a ComboBox programatically?

How can you make a ComboBox expand and show it’s optons, programatically?

Perhaps you can try something like this:

final ComboBox[] combos = new ComboBox[10]
;
Property.ValueChangeListener listener = new Property.ValueChangeListener() {
    public void valueChange(ValueChangeEvent event) {
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < 10; i++) {
            sb.append(i > 0 ? "-" : "");
            sb.append(combos[i]
.toString());
        }
        mainWindow.showNotification("State = " + sb);
    }
};
for (int i = 0; i < 10; i++) {
    combos[i]
 = new ComboBox("Box " + i);
    combos[i]
.addListener(listener);
    mainWindow.addComponent(combos[i]
);
}