Why don't you just use it ttkcombobox?
require(tcltk)
tt <- tktoplevel()
tkwm.title(tt, "Fruits!")
tkwm.geometry(tt, "200x150+300+300")
onOK <- function()
{
fav <- tclvalue(favFruit)
worst <- tclvalue(worstFruit)
if (fav != "Choose one")
tkmessageBox(title="Favorite fruit", message = paste("Your favorite fruit is", fav))
if (worst != "Choose one")
tkmessageBox(title="Worst fruit", message = paste("The fruit you like the least is", worst))
if (fav == "Choose one" & worst == "Choose one")
tkmessageBox(title="Well...", message = "Select a fruit!")
}
label1 <- tklabel(tt, text="What your favorite fruit?")
label2 <- tklabel(tt, text="What fruit you like the least?")
fruits <- c("Choose one", "Apple", "Orange", "Banana", "Pear")
favFruit <- tclVar("Choose one")
worstFruit <- tclVar("Choose one")
combo.1 <- ttkcombobox(tt, values=fruits, textvariable=favFruit, state="readonly")
combo.2 <- ttkcombobox(tt, values=fruits, textvariable=worstFruit, state="readonly")
OK.but <- tkbutton(tt,text=" OK ", command = onOK)
tkpack(label1, combo.1)
tkpack(label2, combo.2)
tkpack(OK.but)
tkfocus(tt)
PS: tcltk RGtk2, , , Glade Interface Designer