Answer a DirectedMessage that is sent when the active item in
the receiver changes, or nil if none has been set up.
callback: aReceiver message: aSymbol
Set up so that aReceiver is sent the aSymbol message (the name of
a selector with at most two arguemtnts) when the active item in
the receiver changegs. If the method accepts two arguments, the
receiver is passed as the first parameter. If the method accepts
one or two arguments, the selected index is passed as the last
parameter.
highlight: index
Highlight the item at the given position in the listbox.
invokeCallback
Generate a synthetic callback.
select: index
Highlight the item at the given position in the listbox,
without unhighlighting other items. This is meant for
multiple- or extended-mode listboxes, but can be used
with other selection mode in particular cases.
show: index
Ensure that the item at the given position in the listbox is
visible.
unhighlight
Unhighlight all the items in the listbox.
unselect: index
Unhighlight the item at the given position in the listbox,
without affecting the state of the other items.