%D \module
%D   [       file=page-par, % copied from page-lin
%D        version=1997.03.31,
%D          title=\CONTEXT\ Page Macros,
%D       subtitle=Line Numbering,
%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 Page Macros / Paragraph Numbering}

\unprotect

\installcorenamespace {paragraphnumbering}
\installcorenamespace {paragraphnumberingvariants}

\installsimplecommandhandler \??paragraphnumbering {paragraphnumbering} \??paragraphnumbering

\definecounter[\v!paragraph]

\permanent\lettonothing\showparagraphnumber

\appendtoks
    \page_par_check_state
\to \everysetupparagraphnumbering

\protected\def\page_par_check_state
  {\rawprocesscommacommand[\paragraphnumberingparameter\c!state]\page_par_check_state_step}

\def\page_par_check_state_step#1%
  {\ifcsname\??paragraphnumberingvariants#1\endcsname
     \lastnamedcs
   \fi}

\defcsname\??paragraphnumberingvariants\v!start\endcsname
  {\enforced\let\showparagraphnumber\page_par_show_number_normal}

\defcsname\??paragraphnumberingvariants\v!stop\endcsname
  {\enforced\lettonothing\showparagraphnumber}

\defcsname\??paragraphnumberingvariants\v!line\endcsname
  {\enforced\let\showparagraphnumber\page_par_show_number_lines}

\defcsname\??paragraphnumberingvariants\v!reset\endcsname
  {\strc_counters_reset\v!paragraph
   \enforced\let\showparagraphnumber\page_par_show_number_normal}

\permanent\protected\def\page_par_show_number_normal
  {\strc_counters_increment\v!paragraph
   \inleftmargin % todo: \c!location, only a few make sense
     {\hfill % no complaints
      \tf % \tf normalizes em
      \useparagraphnumberingstyleandcolor\c!style\c!color
      \convertedcounter[\v!paragraph]%
      \kern{\paragraphnumberingparameter\c!distance}}}

\permanent\protected\def\page_par_show_number_lines
  {\ifnumberinglines
     \page_par_show_number_normal
   \fi}

\setupparagraphnumbering
  [\c!state=\v!stop,
  %\c!location,
  %\c!style=,
  %\c!color=,
   \c!distance=\ifcase\c_page_lines_location2\emwidth\else\zeropoint\fi] % will change

\protect \endinput