I'm creating a GUI in R using gWidgets (more specifically gWidgetstcltk). I'd like to know how to update the contents of selection-type widgets, such as gdroplist and gtable. I currently have a rather hackish method of deleting the widget and re-creating it. I'm sure there's a better way.

This simple example displays all the variables in the global environment.

library(gWidgets)
library(gWidgetstcltk)

create.widgets <- function()
{
  grp <- ggroup(container = win)
  ddl <- gdroplist(ls(envir = globalenv()), 
    container = grp)
  refresh <- gimage("refresh", 
    dirname   = "stock",
    container = grp,
    handler   = function(h, ...)
    {
      if(exists("grp") && !is.null(grp)) 
      {
        delete(win, grp)
        rm(grp)
      }
      grp <- create.widgets()   
    }
  )
}

win <- gwindow()
grp <- create.widgets()