Hi Hans,

I succeed to do what I want thanks to you (once more ;) ) !

I'll put the resulting presentation online at least at the end of the next week (u3d + layer + custom pre-original + animation with JS and fieldstack + program runs including mplayer runs with linux + ... robotics ?)

Renaud

Hans Hagen a écrit :
maybe future version of context will provide more control; for the moment, stick to:  


\definehead [Topic]   [chapter]
\definehead [Subject] [section]

\newcounter\MyTopicCounter

\startsetups MyTopicList
    \blank
    \doglobal\increment\MyTopicCounter
    \doglobal\newcounter\MySubjectCounter
    \placelist[Topic][criterium=text,after=\setups{MySubjectList}]
\stopsetups
\startsetups MySubjectList
    \doglobal\increment\MySubjectCounter
    \doifelse{\MyTopicCounter}{\MySubjectCounter} {
        \placelist[Subject]
    } {
        % whatever
    }
\stopsetups

\starttext

\Topic{first}  \Subject{one}   test \Subject{two}  test \setups[MyTopicList] \page
\Topic{second} \Subject{alpha} test \Subject{beta} test \setups[MyTopicList] \page

\stoptext