[R-gui] pure tcl/tk to R-tcltk / labeled frame and image

[Thomas Unternaehrer]

Dear Peter Dalgaard


Peter Dalgaard wrote:

>Thomas Unternaehrer <uth at zhwin.ch> writes:
>
>  
>
>>Dear List,
>>
>>I try to have a picture in a labeled frame like this example shows it:
>>http://incrtcl.sourceforge.net/iwidgets/iwidgets/labeledframe.html
>>
>>At this point I have the following R-code (An example with the R-Logo
>>based on the example by James Wettenhall):
>>
>>## R =================
>>library(tcltk)
>>tclRequire("Iwidgets")
>>setwd(paste(system.file(), "/../../doc/html",sep=""))
>>.base <- tktoplevel()
>>tkwm.title(.base, "Labeledframe")
>>tkpack(.base.labelframe <- tkwidget(.base, "iwidgets::labeledframe",
>>                                    labelpos = "nw",
>>                                    labeltext = "Labelframe"),
>>       fill = "both", expand = TRUE)
>>
>>.base.labelframe.cs <- .Tk.subwin(.base.labelframe)
>>
>>tclRequire("Img")
>>t.Logo <- tclVar()
>>tkcmd("image", "create", "photo", t.Logo,
>>      file = "logo.jpg")
>>tkpack(tklabel(.base.labelframe.cs, image = t.Logo, bg = "white"),
>>       fill = "both", expand = TRUE, padx = 5, pady = 5)
>> ##===================
>>
>>With the following errormessage:
>>Error in structure(.External("dotTclObjv", objv, PACKAGE = "tcltk"),
>>class = "tclObj") :
>>    [tcl] bad window path name ".10.1.2".
>>
>>As I understand it right the problem has to do with the fact that
>>"...cs" needs to be a child/sub - window.
>>See the following pure tcl-code:
>>
>>## Tcl/Tk===============
>>
>>##	Need to get the childsite so that
>>##	we can properly pack other widgets
>>##	inside
>>
>>set cs [.lf childsite]
>>
>>##====================
>>
>>.Tk.subwin seems not to be the right way. I also tried it with
>>.Tcl("pure Tcl commands") and tkcmd but faild.
>>Has anybody an idea how to solve my problem?
>>    
>>
>
>The problem is a generic one: If a Tcl extension package generates a
>widget with internal subwidgets, these are not readily available to
>the R side of the interface. .Tk.subwin is not going to help because
>that invents a *new* name.
>
>  
>
Ok, this is the same "problem" in all of that Megawidgets, isn't it?

>What I presume is going on in your example is that
>iwidgets::labeledframe creates a widget called ".10.1" and then
>.Tk.subwin() sets up .10.1.2 (Why 2? Did you run it twice?) which
>could be OK as an argument to a further widget creation call, but
>will not help you get at the subwidgets that have already been created
>and named according to the likings of iwidgets::labeledframe. I would
>guess that the name you are looking for is ".10.1.cs" (I don't have
>Iwidgets to hand on this system).
>
>So what to do about it? You might try passing the the raw ID instead
>of the widget, but things like tklabel(".10.1.cs",...) is not going to
>work because something will expect it to be an object of class
>"tkwin". One fairly obvious idea is to modify .Tk.subwin to take a
>name argument, like this:
>
>.Tk.subwin <- 
>function (parent, name=evalq(num.subwin <- num.subwin + 1, parent$env))
>{
>    ID <- paste(parent$ID, name,
>        parent$env), sep = ".")
>    win <- .Tk.newwin(ID)
>    assign(ID, win, envir = parent$env)
>    assign("parent", parent, envir = win$env)
>    win
>}
>
>so that .base.labelname.cs <- .Tk.subwin(.base.labelname, "cs") would
>work. 
>
>
>  
>
If I use your function I get the following error:

....
.Tk.subwin2 <- function (parent, name=evalq(num.subwin <- num.subwin + 1,
                                   parent$env)) {
  ID <- paste(c(parent$ID, name, parent$env), sep = ".")
  win <- .Tk.newwin(ID)
  assign(ID, win, envir = parent$env)
  assign("parent", parent, envir = win$env)
  win
}

.base.labelframe.cs <- .Tk.subwin2(.base.labelframe, "cs")
tclRequire("Img")
t.Logo <- tclVar()
tcl("image", "create", "photo", t.Logo, file = "logo.jpg")
tkpack(tklabel(.base.labelframe.cs, image = t.Logo, bg = "white"),
       fill = "both", expand = TRUE, padx = 5, pady = 5)

Error in structure(.External("dotTclObjv", objv, PACKAGE = "tcltk"), 
class = "tclObj") :
    [tcl] bad window path name ".1.1.1 cs.1 <environment>".


I've seen that you use the same trick in the tabbed notebook example. 
Maybe I have to study that part again.


>  
>
>>Thanks a lot
>>
>>Thomas
>>
>>
>>ps: and sorry for my poor english
>>    
>>
>
>That's not a problem. However, a couple of programming issues caught
>my eye:
>
>(1) There's really no need to use Tcl style names like
>    .base.labelframe in R. In fact the R interface is designed to
>    enable you to avoid that.
>
>  
>
Yes I know, but the name .base.labelframe.image tells me that image (or 
what ever) is on top of base and labelframe.
I find it just usefull.

>(2) tkcmd() has been renamed to tcl() (since it was never specific to
>    Tk) and if people would stop piling new issues on top of me, I
>    might actually get around to deprecating the old name.
> 
>  
>
Ok, last time I used tcl/tk there was just the tkcmd, I think. I have to 
read the CHANGES/NEWS-files next time again before posting.
Thanks for that correction.

Just to understand what happend I've tried these two examples

## 1
.base <- tktoplevel()
tkwm.title(.base, "Labelframe")
tkpack(.base.labelframe <- tkwidget(.base, "iwidgets::labeledframe",
                                    labelpos = "nw",
                                    labeltext = "Labelframe"),
       fill = "both", expand = TRUE)

cs <- tclVar()
tcl("set", cs, paste("[", .Tk.ID(.base.labelframe), "childsite]"))
t.Logo <- tclVar()
tcl("image", "create", "photo", t.Logo, file = "logo.jpg")
.Tcl(paste("label $cs.l -image ", .Tk.ID(t.Logo)))

[tcl] can't read "cs": no such variable.

This is what you said above I think. The variable "cs" can't be passed 
from R to Tcl and back.

 ## 2    
## what I can't understand is that
.Tk.ID(cs) ## is NULL

If I give it an ID by hand it gives me the following:
...
cs$ID <- ".2.1.cs"
.Tcl(paste("label $",.Tk.ID(cs),".l -image ", .Tk.ID(t.Logo), sep = ""))

bad window path name "$.2.1.cs"

That it does not work is not really surprising, but there is maybe more 
than just set the path name correctly, isn't it?


Thanks for your help. I'll try to get it work, but if you have a hint 
again... would be great.
And thanks for writing that great package.

Thomas