[luatex] vpack filter question

[Paul Isambert]

Le 09/12/2010 09:24, Patrick Gundlach a écrit :
> Hi,
>
> (thanks for your answers, Paul and Taco)
>
>>> Anyway it'd be nice indeed to have a switch for node.dimensions which
>>> measure either vertically or horizontally.
>> Vertical lists are usually short and consist of boxes and glues
>> for which all dimensions are already known, so it should be pretty
>> simple to write a lua function for that. The case for horizontal
>> lists is a lot harder to do in lua because of the need to fetch
>> font dimensions.
> So, would it be (in theory) possible to have node.dimensions(...) behave "correct" in both directions (hlist.list, vlist.list)? Does the list itself know whether it is a vertical or a horizontal list? I'd guess the answer is 'no'.
>
> Patrick

It's not possible indeed since, despite some nodes being allowed in 
hlist's only, as Taco said, a list can be made of nodes that can appear 
anywhere (e.g. hboxes), and so its being horizontal or vertical totally 
depends on the container.

Best,
Paul