%D \module
%D   [       file=typo-pin,
%D        version=2026.01.06,
%D          title=\CONTEXT\ Typesetting Macros,
%D       subtitle=Paragraph Inserts,
%D         author=Hans Hagen,
%D           date=\currentdate,
%D      copyright={PRAGMA ADE \& \CONTEXT\ Development Team}]
%C
%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 Typesetting Macros / Paragraph inserts}

%D An experiment turned feature by Mikael Sundqvist and Hans during cold and snowy
%D winter days in the first weekl of 2026. A sort of follow up on our par builder
%D experiments.

%D \starttyping
%D \setupexternalfigures
%D   [location={global,local,default}]
%D
%D \enabletrackers[parinsert]
%D
%D \starttext
%D
%D \samplefile{tufte}%
%D \space\leftparinsert[color=darkred]{An example.}\space
%D \samplefile{ward}%
%D \space\rightparinsert[color=darkgreen]{Another example.}\space
%D \samplefile{tufte}
%D
%D \page
%D
%D \samplefile{tufte}%
%D \space
%D \leftparinsert
%D   [lines=3]
%D   {\externalfigure[cow.pdf][height=3lh,location=top]}%
%D \rightparinsert
%D   [lines=4]
%D   {\mirror{\externalfigure[cow.pdf][height=4lh,location=top]}}%
%D \space
%D \samplefile{ward}%
%D \space
%D \rightparinsert
%D   [distance=2em,lines=2]
%D   {\mirror{\externalfigure[cow.pdf][height=2lh,location=top]}}%
%D \space
%D \samplefile{tufte}
%D \stoptyping

\unprotect

\installcorenamespace{parinsert}

\installcommandhandler \??parinsert {parinsert} \??parinsert

\setupparinsert
  [\c!location=\v!left,
   \c!distance=\emwidth,
   \c!xoffset=\zeropoint,
   \c!yoffset=\zeropoint,
   \c!option=,
   \c!lines=3]

\permanent\tolerant\protected\def\typo_parinsert_handle#1#*[#2]#*#:#3%
  {\begingroup
   \cdef\currentparinsert{#1}%
   \ifparameter#2\or
      \setupcurrentparinsert[#2]%
   \fi
   \setbox\scratchbox\hbox
      \s!xoffset {\parinsertparameter\c!xoffset}%
      \s!yoffset {\parinsertparameter\c!yoffset}%
   \bgroup
      \useparinsertstyleandcolor\c!style\c!color
      #3%
   \egroup
   \scratchdistance{\parinsertparameter\c!distance}%
   \scratchwidth\wd\scratchbox
   \scratchcounter{\parinsertparameter\c!lines}%
   \ifzero\scratchcounter
     \getnoflines{\htdp\scratchbox}%
     \scratchcounter\noflines
   \fi
   \ifcstok{\parinsertparameter\c!location}\v!right
     \atrightmargin{\llap{\box\scratchbox}}%
     \scratchcounter-\scratchcounter
   \else
     \atleftmargin{\rlap{\box\scratchbox}}%
   \fi
   \localhangindent{\scratchwidth+\scratchdistance}%
   \localhangafter \scratchcounter
   \typo_par_insert_trace
   \ifcstok{\parinsertparameter\c!option}\v!depth
     \paroptions\plusone % todo: symbolic
   \fi
   \endgroup}

\def\typo_par_insert_trace_indeed
  {\begingroup
     \darkgray
     \scratchwidth.125\emwidth
     \kern-\scratchwidth
     \vrule \s!width 2\scratchwidth \s!pair \strutht \strutdp
     \kern-\scratchwidth
   \endgroup}

\installtextracker
  {parinsert}
  {\let\typo_par_insert_trace\typo_par_insert_trace_indeed}
  {\lettonothing\typo_par_insert_trace}

\lettonothing\typo_par_insert_trace

\appendtoks
    \protected\instance\edefcsname\currentparinsert\endcsname{\typo_parinsert_handle{\currentparinsert}}
\to \everydefineparinsert

%D In case we ended a paragraph and want to continue:

\permanent\protected\def\pickupparinsert
  {\expanded{%
     \ifcase{\breaklasthangleftslack+\breaklasthangrightslack}\else
       \strut
       \ifcase\breaklasthangleftslack\else
         \localhangindent\the\breaklasthangleftindent
         \localhangafter \the\breaklasthangleftslack
       \fi
       \ifcase\breaklasthangrightslack\else
         \localhangindent  \the\breaklasthangrightindent
         \localhangafter  -\the\breaklasthangrightslack
       \fi
     \fi}}

\permanent\protected\def\wrapupparinsert
  {\ifvmode
     \ifcase{\breaklasthangleftslack+\breaklasthangrightslack}\else
       \vskip
         \ifnum\breaklasthangleftslack>\breaklasthangrightslack
           \breaklasthangleftslack
         \else
           \breaklasthangrightslack
         \fi
         \lineheight
       \relax
     \fi
   \fi}

%D Not yet interfaced:

\defineparinsert[leftparinsert]
\defineparinsert[rightparinsert]

\setupparinsert[leftparinsert] [\c!location=\v!left]
\setupparinsert[rightparinsert][\c!location=\v!right]

\protect \endinput