Replying to myself, though not sure that the threading will be
preserved (long story short: I use gmail+pop, and as a consequence
don't see my posts to the list, so I am responding to my sent message).
The problem is "explained" by the following code:
tktest <- function(parent) {
fr <- tkframe(parent, borderwidth=2, relief="raised") # Line 1
l1 <- tklabel(parent, text="b") # Line 2
l2 <- tklabel(fr,text="a")
tkgrid(l1,l2, `in`=fr)
fr
}
tt <- tktoplevel()
tf1 <- tktest(tt)
tkgrid(tf1)
The above code, as it stands, produces a nice frame with two letters,
a and b, in it.
Now, if we interchange the lines I called Line 1 and Line 2 above,
then in the resulting frame b doesn't show up any more, though there
is space reserved for it.
In other words, a widget cannot be inserted into a frame that was
created after the widget came to existence (in which case we have to
use the "in" argument). A quick check with code directly in Tcl/Tk
seems to indicate that this is actually a limitation of Tcl/Tk
(sounds to me a bit silly to have such limitation though).
Unfortunately, this makes what I was intending to do a lot more
difficult. I was hoping to create "tkcbind" and "tkrbind" commands to
allow one to build the GUI from the ground up. It sounds like I would
need, at the very least, to specify beforehand the overall frame
structure, and thus move top-to-bottom instead.
Is this problem documented anywhere?
Haris Skiadas
Department of Mathematics and Computer Science
Hanover College
On Dec 21, 2007, at 7:38 PM, Charilaos Skiadas wrote:
> Hello all,
>
> I've been struggling for the best part of the last couple of hours
> with the following simple problem. Consider the following code:
>
> library(tcltk)
> tktest <- function(parent, wdgt) {
> fr <- tkframe(parent, borderwidth=2, relief="raised")
> tkgrid(wdgt, `in`=fr)
> tmp <- tklabel(fr, text="hi")
> tmp2 <- tklabel(parent, text="there")
> tkgrid(tmp)
> tkgrid(tmp2, `in`=fr)
> fr
> }
> tt <- tktoplevel()
> t2 <- tklabel(tt,text="a")
> t3 <- tklabel(tt,text="b")
> sg <- tktest(tt,t2)
> t4 <- tklabel(sg,text="c")
> tkgrid(t3,`in`=sg)
> tkgrid(t4)
> tkgrid(sg)
>
>
>
> Now, the resulting window contains the frame sg, with room in it
> for all 5 strings a, hi, there, b, c, BUT a and b are not showing!
> So, I am wondering what I am doing wrong. The `in` call seem to
> work in one case, and fail in the other two cases, and I can't tell
> what the difference is, especially between the "there" and "b"
> cases. What I find more weird is that the space is allotted, but
> not used.
>
> Any help appreciated, I am starting to lose my mind over here.
>
> Haris Skiadas
> Department of Mathematics and Computer Science
> Hanover College
>
>
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