All choices have a selection. This is a state representing the items currently selected. The selection is represented as a vector of offsets into the list of the choice's items, unless it is a single-selection choice, in which case it is just represented as an offset.
The initial selection is controlled with the initarg
. The accessor
Generally, it is easier to refer to the selection in terms of the items selected, rather than by offsets, so the CAPI provides the notion of a selected item and the selected items . The first of these is the selected item in a single-selection choice. The second is a list of the selected items in any choice.
provide access to these conceptual slots, and you can also supply the values at
time via the initargs
CAPI User Guide (Macintosh version) - 30 Aug 2011