This adapter should implement IAccessibleNav and IItemNav. Visible navigation over a closed combobox should just include the currently selected item, not the list items and never the button. Visible navigation over an open combobox should include the visible items in the list popup too, but never the button. When invisible items should also be counted (only_visible=False), the list items should always be traversed, even when hidden. Again, the button should not be reported.

If possible, I'd like to have the list items in a combobox treated as numeric item_offsets in a POR refering to the combobox. That is:

* POR(combobox accessible, None, 0) is the combobox widget with the active selection showing
* POR(combobox accessible, 0, 0) is the first available item in the combobox list
* POR(combobox accessible, 1, 0) is the second available item in the combobox list
etc.

Combobox items can appear at almost any level under a combobox widget.  Current implementation does a depth only search looking for a "list" or "menu" item.  The combobox items, ususally "list item" or "menu item", appear as children of these nodes.  Other nodes may need to be added to the search list if the need arises.   

Created attachment 78650 [details] [review]
patch for combobox navigation improvement

Fixed in the development version. The fix will be available in the next major release. Thank you for your bug report.