page-str.mkiv / last modification: 2020-01-30 14:16
%D \module
%D   [       file=page-str,
%D        version=2010.03.13, % 2006.03.21,
%D          title=\CONTEXT\ Page Macros,
%D       subtitle=Page Streams,
%D         author=Hans Hagen,
%D           date=\currentdate,
%D      copyright={PRAGMA ADE \& \CONTEXT\ Development Team}]
%C This module is part of the \CONTEXT\ macro||package and is
%C therefore copyrighted by \PRAGMA. See mreadme.pdf for
%C details.

\writestatus{loading}{ConTeXt Page Macros / Page Streams}

%D The first version of this component of \CONTEXT\ was written
%D for Thomas Schmitz who asked for parallel page streams. While
%D playing with the code, I decided to make it into a component
%D that can be used to construct all kind of stream related
%D mechanisms. Because I could apply this feature in a project,
%D there is some additional code here (related to graphics).
%D These macros were written while listening to and watching the DVD
%D \quotation {Rush In Rio}.
%D The reimplementation (or rather experimenting with the complete
%D rewrite) was done while looping over \quotation {Wende Snijders
%D No.9}.
%D Remark: marknotes are gone, at least for a while.



\let     \currentoutputstream     \empty
\newif   \ifinoutputstream        % will become a conditional or mode
\newtoks \everyenableoutputstream

\to \everyenableoutputstream


\unexpanded\def\enableoutputstream[#1]% could be \startoutputsubstream
   \prevdepth\zeropoint % maybe more is needed i.e. we need to get rid of leading glue




\unexpanded\def\startoutputsubstream[#1]% just push/pop instead


\def\flushoutputstream  [#1]{\clf_flushstream{#1}}
\def\outputstreambox    [#1]{\vbox{\clf_flushstream{#1}}}
\def\outputstreamcopy   [#1]{\vbox{\clf_flushstreamcopy{#1}}}
\def\outputstreamunvbox [#1]{\clf_flushstream{#1}}
\def\synchronizestreams [#1]{\clf_synchronizestream{#1}}
\def\dopushoutputstream [#1]{\clf_pushstream{#1}}


% \unexpanded\def\defineoutputstream[#1]%
%   {\doifundefined{otrs:#1}{\expandafter\newbox\csname otrs:#1\endcsname}}
% \def\useoutputstream[#1]%
%   {\writestatus{otr}{using output stream #1}%
%    \xdef\currentoutputstream{#1}}
% \directsetup{stream:\firstoutputstream:set}
% \directsetup{stream:\firstoutputstream:top}
% \directsetup{stream:\firstoutputstream:bottom}
% \directsetup{stream:\firstoutputstream:reset}

% Obsolete in \MKIV:
% \unexpanded\def\definemarknote
%   {\dodoubleempty\dodefinemarknote}
% \def\dodefinemarknote[#1][#2]{}
% \def\setmarknote         [#1]{\gobbleoneargument}
% \def\flushmarknotes      [#1]{}
% \def\erasemarknotes      [#1]{}

\protect \endinput

% \enabletrackers[streams.flushing]
% \setuplayout[grid=yes] \showgrid
% \starttext
% \input tufte
% \startoutputstream[nl]
% Wat doen we hier?
% \enableoutputstream[en]
% Are you sleeping, brother John?\footnote{xxx}
% \dorecurse{4}{x \footnote{note \recurselevel}\input tufte \par \pushoutputstream}
% \enableoutputstream[de]
% Bruder Jakob, schläfst du noch?\footnote{yyy}
% \dorecurse{4}{x \footnote{note \recurselevel}\input ward \par \pushoutputstream}
% \disableoutputstream
% \stopoutputstream
% Vader Jacob, slaap je nog?\footnote{zzz}
% \input tufte
% \synchronizestreams[en,de,nl]
% \page \flushoutputstream[en] \input knuth
% \page \flushoutputstream[de] \input knuth
% \page \flushoutputstream[nl] \input knuth
% \stoptext