I've a swing structure : JPopupMenu contains JPanel which contains JCheckBoxMenuItem. The problem is, I cannot use it because JPopupMenu disappears when mouse enters to any MenuItems.
I added JCheckBoxMenuItem to JPanel(because to make it scrollable, as there are large number of menu-items) and then JPanel to JPopupMenu.
I'm using NetBeans IDE.
Here is the code, done so far.