JComboBox auto visibility
Within a JFrame I've built a JComboBox with a series of items, i.e. A, B, C, etc.
I would like to achieve the situation that when the frame is displayed the combobox's drop-down list is visible, not as the default behaviour, that is, to be invisible and selected the first element at its text field.
Something knowing how to do it?
Thank you very much in advance.