gtk:cell-area-context-preferred-width (context)

context -- a gtk:cell-area-context object

minimum-width -- an integer with the minimum width, or nil
natural-width -- an integer with the natural width, or nil

Gets the accumulative preferred width for all rows which have been requested with this context. After the gtk:cell-area-context-reset function is called and/or before ever requesting the size of a gtk:cell-area object, the returned values are 0.