There are many copies of checkbox tree views in the source base. The code for single clicking and focus handling and
having it really work correctly with the keyboard is hard to get right. Platform users also often need this (c.f.
We should take the most generic implementation already in the codebase, adapt it to be truly generic and add it to
(Please refile under openide subcomponent explorer. For some reason "openide" is completely gone from the subcomponent
list in IZ today :-/)
Fixed by Martin Entlicher's CheckableNode, imho: