On Thu, 16 Mar 2023 18:27:53 +0100
Wolfgang Schuster via ntg-context <ntg-context@ntg.nl> wrote:

> Keith McKay via ntg-context schrieb am 16.03.2023 um 17:59:
> >
> > Hi,
> >
> > I would like to position a combination of images where the centre
> > of the combination coincides with the centre of the text area of a
> > page. In the example below I have made the combination into a layer
> > thinking that this would be the easiest way to position it where I
> > wanted. However to position in the centre of the page I would need
> > to know the size of the combination and use this to calculate the x
> > and y values for positioning of the layer. I have looked at the
> > Wiki page on image size of combinations but still cant figure out
> > how to do it. Any suggestions on how to go about this or is their a
> > better way?
> >
> > Wiki Page reference:
> > https://wiki.contextgarden.net/Combinations#Image_Width
> >
> > Thanks
> >
> > Keith McKay
> >
> > %%% example %%%
> >
> > \setuppapersize[A4,portrait]%[A4,portrait]
> >
> > \setuplayout
> >
> > [backspace=2.5cm,
> >
> > topspace=1cm,
> >
> > height=28cm,
> >
> > width=17cm,
> >
> > header=0cm,
> >
> > footer=0.75cm,
> >
> > ]
> >
> > \useMPlibrary [dum]
> >
> > \starttext
> >
> > \definelayer[test3]
> >
> > \setlayer[test3][x=2cm,y=15cm]
> >
> > {\startcombination[nx=3,ny=1,distance=15mm,after=,location=middle]
> >
> > {\externalfigure[dummy]}{}
> >
> > \rotate[rotation=90]{\externalfigure[dummy]}{}
> >
> > {\externalfigure[dummy][]}{}
> >
> > \stopcombination}
> >
> > \flushlayer[test3]
> >
> > \stoptext
> > 
>
> \useMPlibrary [dum]
>
> \showframe [text] [text]
>
> \setuplayout [tight]
>
> \starttext
>
> \centerbox
>     {\bTABLE[frame=off,offset=7.5mm,align={middle,lohi}]
>          \bTR
>              \bTD
>                  \externalfigure[dummy]
>              \eTD
>              \bTD
>                  \rotate[rotation=90]{\externalfigure[dummy]}
>              \eTD
>              \bTD
>                  \externalfigure[dummy]
>              \eTD
>          \eTR
>      \eTABLE}
>
> \stoptext
>
> Wolfgang

Or you could put the combination in a frame:

\startparagraph [align=middle]
  \startframed [frame=off,offset=\zeropoint]
    \startcombination [nx=3,ny=1]
      {first} {}
      {second}{}
      {third} {}
    \stopcombination
  \stopframed
\stopparagraph

Alan