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.

However, this is not perfect. My intention is to have something without the horizontal scroll bar, as follow.

My question is, how can I have a JComboBox drop down list, which is wider than the JComboBox itself? I just want to get rid of the horizontal scroll bar. Yet, able to fit in 3 columns into a single list.

The source code are ResultSetCellRenderer and AjaxAutoCompleteJComboBox

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