Re: No output for layers

[Uwe Koloska <ml@koloro.de>]

Hello,

Am Dienstag, 8. Juli 2008 schrieb Wolfgang Schuster:
> On Tue, Jul 8, 2008 at 2:17 PM, Oliver Buerschaper
> > ---
> > \definelayer
> >        [mylayer]
> >        [x=78mm,
> >         y=3mm,
> >         height=43.5mm,
> >         width=128mm]
> >
> > \starttext
> >
> > \setlayer[mylayer][preset=middle]{Hello world!}
> >
> > \stoptext
> > ---

The layer is now only defined and has some content, but is not related to any 
page element. So you has to define it as the background of some pageelement:

  \setupbackgrounds[page][background=mylayer]

or you have to "flush" it (but I don't know what this is supposed to do, maybe 
it's just another way of calling the OTR -- see below)

  \flushlayer[mylayer]

> You have to invoke the OTR.

OTR = Output Routine

Without invoking the OTR nothing is generated.

(but you can leave out \starttext \stoptext -- why?)

> You could use
>
> \startstandardmakeup
> \stopstandardmakeup
>
> or
>
> \page[empty]

Both of these produce an empty page (without pagenumber) and the layer at the 
intended position.

> or
>
> \dontleavehmode
>
> or
>
> \null
>
> or

These two variants produce pages with the standard layout (in this easy setup 
this consists only of the page number at the top).

The last alternative I know of: instead of defining the layer as background 
for the page, you can just call

  \flushlayer[mylayer]

But this positions the layer relative to the textarea (and not the pagearea) 
and produces a standard layout with pagenumber, too, if you don't use 
standardmakeup.

This has helped, to make some concepts regarding layers clear to me;-)
Regards
Uwe
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