How to have JComboBox drop down list which is wider than the JComboBox itself

Question

By referring to the answer at Multi Columns Combo Box for Swing, I manage to implement a 3 multi columns JComboBox as follow.

Answer 1

I got my problem resolved through the following forum Oracle Java Swing Forum

For future reference, I include the complete workable source code, for anyone who are interested.

AjaxAutoCompleteJComboBox.java