List Boxes in R TclTk

The following examples illustrate how to use a list box in a Tk window. The first example does not have a scrollbar, so it is simpler.

List Box Without A Scroll Bar

require(tcltk)
tt<-tktoplevel()
tl<-tklistbox(tt,height=4,selectmode="single",background="white")
tkgrid(tklabel(tt,text="What's your favorite fruit?"))
tkgrid(tl)
fruits <- c("Apple","Orange","Banana","Pear")
for (i in (1:4))
{
    tkinsert(tl,"end",fruits[i])
}
tkselection.set(tl,2)  # Default fruit is Banana.  Indexing starts at zero.

OnOK <- function()
{
	fruitChoice <- fruits[as.numeric(tkcurselection(tl))+1]
    tkdestroy(tt)
    msg <- paste("Good choice! ",fruitChoice,"s are delicious!",sep="")
    tkmessageBox(message=msg)

}
OK.but <-tkbutton(tt,text="   OK   ",command=OnOK)
tkgrid(OK.but)
tkfocus(tt)

The code above produces the following window:

The user can then select their favorite fruit with the mouse:

List Box With A Scroll Bar

require(tcltk)
tt<-tktoplevel()
scr <- tkscrollbar(tt, repeatinterval=5,
				   command=function(...)tkyview(tl,...))
tl<-tklistbox(tt,height=4,selectmode="single",yscrollcommand=function(...)tkset(scr,...),background="white")
tkgrid(tklabel(tt,text="What's your favorite fruit?"))
tkgrid(tl,scr)
tkgrid.configure(scr,rowspan=4,sticky="nsw")
fruits <- c("Apple","Orange","Banana","Pear","Cherry","Apricot","Peach")
for (i in (1:7))
{
    tkinsert(tl,"end",fruits[i])
}
tkselection.set(tl,2)  # Default fruit is Banana.  Indexing starts at zero.

OnOK <- function()
{
	fruitChoice <- fruits[as.numeric(tkcurselection(tl))+1]
    tkdestroy(tt)
    msg <- paste("Good choice! ",fruitChoice,"s are delicious!",sep="")
    tkmessageBox(message=msg)

}
OK.but <-tkbutton(tt,text="   OK   ",command=OnOK)
tkgrid(OK.but)
tkfocus(tt)

The code above produces the following window:

The user can then select their favorite fruit by scrolling down or up with the mouse or arrow keys:

Deleting An Item From A List

require(tcltk)
tt<-tktoplevel()
tl<-tklistbox(tt,height=4,selectmode="single",background="white")
tkgrid(tklabel(tt,text="Please delete the fruit(s) which you don't like."))
tkgrid(tl)
fruits <- c("Apple","Orange","Banana","Pear")
for (i in (1:4))
{
    tkinsert(tl,"end",fruits[i])
}
tkselection.set(tl,2)  # Default fruit is Banana.  Indexing starts at zero.

OK.but <-tkbutton(tt,text="   OK   ",command=function() tkdestroy(tt))
DeleteSelection <- function()
{
    fruitIndex <- as.integer(tkcurselection(tl))
    tkdelete(tl,fruitIndex)
}
DeleteSelection.but <- tkbutton(tt,text="Delete",command=DeleteSelection)
tkgrid(DeleteSelection.but)
tkgrid(tklabel(tt,text="    "))
tkgrid(OK.but)
tkfocus(tt)

Running the code above gives the following window:

We will delete "Orange" from the list

The window below shows that "Orange" has now been deleted from the list.