On 5/3/2018 11:35 AM, Henri Menke wrote:
On 05/03/2018 07:13 PM, Hans Hagen wrote:
On 5/1/2018 11:50 PM, Henri Menke wrote:
On 02/05/18 03:17, Hans Hagen wrote:
On 5/1/2018 12:16 PM, Henri Menke wrote:
Dear list,
It seems as if the pre_output_filter only gives you the nodes in the
body block but without the \headline and \footline. I would have
expected that those are included because \plainoutput performs
\shipout\vbox{\makeheadline\pagebody\makefootline}
and I would have expected to get the vlist defined by the above \vbox
inside the callback. Am I doing it wrong or am I using the wrong
callback?
you can for instance use vpack_filter
But how do I detect whether what is being packed is the main vertical
list? According the manual `groupcode` should be <empty> for the main
vertical list but that just never happens. With the following MWE
\directlua{
callback.register("vpack_filter",
function(head,groupcode)
print('"' .. groupcode .. '"')
return head
end)
}
Hello World!
\bye
build_page_filter
Sorry for being such a pain in the neck :(
How can I access the material to be pushed from within this callback?
Box 255 (the shipout box) is nil. The reason I am asking this is
because I want to implement visual debugging like in ConTeXt. Therefore
I want to walk the main vertical list on shipout and sprinkle it with
whatits to draw rules for boxes, glues, kerns, etc.
\directlua{
callback.register("buildpage_filter",
function() print(tex.box[255]) end)
}
Hello World!
just hook code into the shipout routine at the tex end: take the box,
pass it to soem lua code and walk over its content (there is no shipout
callback - as it's not needed)
Hans
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