> > > groups" (OCGs)?
> > >
> > > In Adobe's jargon OCGs are also known as "layers" (not to confuse with
> > > layers in ConTeXt). See Section "4.10.2 Making Graphical Content
> > > Optional" in the PDF Reference 1.7 available at
> > >
http://wwwimages.adobe.com/content/dam/Adobe/en/devnet/pdf/pdfs/pdf_reference_1-7.pdf> > >
> > > I cannot find anything on the Wiki nor in the ntg-context emails and
> > > grepping through the source code for "ocg" does not give reasonable
> > > results.
> >
> > You have to look for \defineviewerlayer and \startviewerlayer.
>
> A quick test if your pdf viewer supports is is:
>
> \showlayoutcomponents
>
> \starttext
> \input tufte
> \stoptext
Many thanks to all of you Hans, Wolfgang, and Pablo!
\definelayer and \startviewerlayer is a nice interface to basic OCGs construction.
Is there any way to construct "Set-OCG-State Actions" with ConTeXt? (See Section 8.5 Actions in the PDF Reference.) I admit that this is an advanced feature of PDF and that most viewers apart from the Adobe Reader are not capable of handling OCGs correctly.
Kind Regards, Christoph