Can tkgrid() and tkpack() be used in the same function or window in R, or is there an alternative to tkframe()?

Question

I'm creating a user interface using tcl/tk in R. I need to include several buttons and other widgets in a single top level window and I need to group some widgets into a container within the top level window. I've been using tkframe() as the container, which as far as I know requires tkpack() for widget placement. But I'm using tkgrid() for placing the frame and other widgets in the top level window. I suspect this is causing the inconsistencies I'm experiencing when I try to run the interface function. Can tkpack() and tkgrid() be used together? If not, is there another type of container that I can use instead of tkframe() that will work better with tkgrid()?

Here is some simplified code as an example that works with only tkpack():

 require(tcltk)   
 tclRequire("BWidget")



interface1 <- function(){

  ww <- tktoplevel()

  buttons.f <- tkframe(ww)

   getdata.b <- tkbutton(buttons.f, text = "Import Data", command = function() {
    filepath <<- file.choose()
    })
   viewdata.b <- tkbutton(buttons.f, text = "Print Data", command = function() {
    print(read.csv(filepath))
    })
   tkpack(getdata.b, fill = "both")
   tkpack(viewdata.b, fill = "both")

  tree.f = tkframe(ww)

   treeWidget = tkwidget(tree.f,"Tree", width = 30, height = 6)

   tkinsert(treeWidget,"end","root","Species1",text="Elk")
   tkinsert(treeWidget,"end","root","Species2",text="Deer")

   tkpack(treeWidget,fill='both',expand=1)

   getvars  <- function() { 
    selection <<- tclvalue(tcl(treeWidget,"selection","get")) 
    print(selection)
    }

  run.b <- tkbutton(ww, text = "Run", command = getvars)

  close.b <- tkbutton(ww, text = "Close", command = function(){
    tkdestroy(ww)
    filepath <<- NULL
    })

  tkpack(buttons.f)
  tkpack(tklabel(ww,text="Select One:"))
  tkpack(tree.f)
  tkpack(run.b, fill = "both")
  tkpack(close.b, fill = "both")
}
interface1()

But with tkgrid() it doesn't always display correctly:

interface2 <- function(){

  ww <- tktoplevel()

  buttons.f <- tkframe(ww)

   getdata.b <- tkbutton(buttons.f, text = "Import Data", command = function() {
    filepath <<- file.choose()
    })
   viewdata.b <- tkbutton(buttons.f, text = "Print Data", command = function() {
    print(read.csv(filepath))
    })
   tkpack(getdata.b, fill = "both")
   tkpack(viewdata.b, fill = "both")

  tree.f = tkframe(ww)

   treeWidget = tkwidget(tree.f,"Tree", width = 30, height = 6)

   tkinsert(treeWidget,"end","root","Species1",text="Elk")
   tkinsert(treeWidget,"end","root","Species2",text="Deer")

   tkpack(treeWidget,fill='both',expand=1)

   getvars  <- function() { 
    selection <<- tclvalue(tcl(treeWidget,"selection","get")) 
    print(selection)
    }

  run.b <- tkbutton(ww, text = "Run", command = getvars)

  close.b <- tkbutton(ww, text = "Close", command = function(){
    tkdestroy(ww)
    filepath <<- NULL
    })

  tkgrid(buttons.f, pady = 10, columnspan = 2)
  tkgrid(tklabel(ww,text="Select One:"), columnspan = 2)
  tkgrid(tree.f, columnspan = 2)
  tkgrid(run.b, close.b, padx = 20, pady = 10)
}
interface2()

Since I would prefer to use tkgrid, can anyone identify whether the combination of tkgrid/tkpack is causing the error or can anyone suggest an alternative to tkframe? Thanks for the help!

(I'm sure there's a great package to run this task, but I'm creating an interface for a project at work and I've been directed not to use any packages that don't come with base R)

Answer 1

Strictly, you can use both the packer and the gridder in the same frame if you turn off geometry propagation for (at least) one of them . If you don't, they fight over what the size of the parent frame should be. But you probably don't want to do that in the first place; it's very unlikely that that's a widget layout that you would need, as the widgets would be stacked on top of each other and not kept from overlapping.

Using the packer in a frame and the gridder in a sub-frame of that, or the other way round, is entirely reasonable. It's almost certainly what you want to do.