如何更改 jcombobox 中 jpopupmenu 的高度？

Question

I am working on an application in which I am handling key release event over a editable 'JComboBox', where on every key release a 'JPopupMenu' of the 'JComboBox' appears. I want to increase the height so that user will be able to see more items at a glance without scrolling. Can anyone please demonstrate how to set the height of 'JPopupMenu' deliberately so that it will show considerable amount of items? So far i have tried this, but it doesn not work.

combo.getComponentPopupMenu().setSize(10, 10);

Answer 1

Try following:

ComboPopup popup = (ComboPopup) combo.getUI().getAccessibleChild(combo, 0);
((JComponent) popup).setPreferredSize(size);
((JComponent) popup).setLayout(new GridLayout(1, 1));

It wold be nice to see your SSCCE , so I can test whether my proposal works.

Answer 2

A much cleaner approach with using only public API (and without hacks) is to:

• set the width of the JComboBox with its layout (method setLayout on it's parent) - this will also set the width of the JPopupMenu
• set the height of the JPopupMenu with JComboBox.setMaximumRowCount