[R] tcltk: click and return table cell index

[Dalthorp, Daniel]

Thanks, John.

The trouble with that solution is that it gives the index for where the
cursor was before clicking rather than the cell that was clicked. The
solution is that the <Button-1> binding gives the x, y pixel coordinates of
the click to the callback, and the pixel coordinates can be translated to
cell index via:

tkindex(table1, as.tclObj(paste0("@",x, ",", y)))

Or, showing the whole example:

# create table
tt<-tktoplevel()
table1<-tkwidget(tt,"table", rows=3,cols=3)
tkgrid(table1)

# bind the mouse click to printing out cell index:
tkbind(table1, "<Button-1>", function(x, y) print(tcl(table1, "index",
as.tclObj(paste0("@",x, ",", y)))))

Thanks again!

-Dan

On Sat, Apr 30, 2016 at 6:43 AM, Fox, John <jfox at mcmaster.ca> wrote:

> Dear Daniel,
>
> Try
>
> tkbind(table1, "<Button-1>", function(){
>      res <- try(tclvalue(tkindex(table1, "active")), silent=TRUE)
>    if (inherits(res, "try-error")) print (NULL)
>    else print(res)
> })
>
> I put in the calls to print() so that you could see how it works.
>
> I hope this helps,
>  John
>
> -----------------------------
> John Fox, Professor
> McMaster University
> Hamilton, Ontario
> Canada L8S 4M4
> Web: socserv.mcmaster.ca/jfox
>
>
> > -----Original Message-----
> > From: R-help [mailto:r-help-bounces at r-project.org] On Behalf Of
> Dalthorp,
> > Daniel
> > Sent: April 29, 2016 1:42 PM
> > To: r-help at R-project.org (r-help at r-project.org) <r-help at r-project.org>
> > Subject: [R] tcltk: click and return table cell index
> >
> > I'm struggling mightily with what should be a simple task...when a user
> clicks
> > on a cell in a tcltk table widget, I need to know which cell was clicked.
> >
> > One idea that gives a cryptic error:
> > tkbind(table1, "<Button-1>", function(x, y){
> >   tcl(table1, "index", x, y)
> > }
> >
> > # x, y give pixel coordinates; "index" should give cell coordinates, but
> format
> > must be correct
> >
> > I get an error message:
> >
> > wrong # args: should be ".25.1 index <index> ?row|col?".
> >
> > To which I respond, "Yes, I know I have the format wrong, but how can I
> make
> > sense of THAT?"
> >
> > Does anyone know a simple fix?
> >
> > Much appreciated!
> >
> > -Dan
> >
> > --
> > Dan Dalthorp, PhD
> > USGS Forest and Rangeland Ecosystem Science Center Forest Sciences Lab,
> Rm
> > 189
> > 3200 SW Jefferson Way
> > Corvallis, OR 97331
> > ph: 541-750-0953
> > ddalthorp at usgs.gov
> >
> >       [[alternative HTML version deleted]]
> >
> > ______________________________________________
> > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> > https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guide http://www.R-project.org/posting-
> > guide.html
> > and provide commented, minimal, self-contained, reproducible code.
>



-- 
Dan Dalthorp, PhD
USGS Forest and Rangeland Ecosystem Science Center
Forest Sciences Lab, Rm 189
3200 SW Jefferson Way
Corvallis, OR 97331
ph: 541-750-0953
ddalthorp at usgs.gov

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