%D \module
%D   [       file=typo-drp, % was typo-par
%D        version=2011.10.27,
%D          title=\CONTEXT\ Typesetting Macros,
%D       subtitle=Initials,
%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 / Initials}

%D This will change ... par specific attribute set and such.

\unprotect

\registerctxluafile{typo-drp}{autosuffix}

\definesystemattribute[initial][public]

\appendtoks
    \c_attr_initial\attributeunsetvalue
\to \everyforgetall

%D For the moment here: dropped caps redone. In addition to the parameters shown in
%D the example you can use the \type {style} and more low level \type {font} keys to
%D set up the font where the first one wins. If you don't like the behaviour you can
%D always roll out your own command.
%D
%D \starttyping
%D \placeinitial \input ward \par \input ward \par \placeinitial \input tufte
%D
%D \setupinitial
%D   [location=text,
%D    n=2,
%D    color=darkred,
%D    distance=-1em,
%D    hoffset=1em,
%D    voffset=-3ex,
%D    before=\blank]
%D
%D \placeinitial \input ward \par \input ward \placeinitial \input tufte
%D \stoptyping

% todo: angle (once we can set parshape at the Lua end)

\installcorenamespace{initial}

\installcommandhandler \??initial {initial} \??initial

\definemeasure[initial:n][\lineheight*\initialparameter\c!n - \strutdp]

\setupinitial
  [\c!location=\v!text,
   \c!n=3,
   \c!m=1,
   \c!method=\v!none,
   \c!continue=\v!no, % yes will handle single line cases
 % \c!font=Bold sa 4,
 % \c!font=Bold ht \measure{initial:n},
   \c!font=Bold cp \measure{initial:n},
   \c!distance=.125\emwidth,
   \c!hoffset=\zeropoint,
   \c!voffset=\v!line, % \dimexp\lineheight*\initialparameter\c!n-\lineheight\relax]
   \c!style=,
   \c!color=,
   \c!before=\blank]

\permanent\tolerant\protected\def\placeinitial[#1]% old command
  {\par
   \namedinitialparameter{#1}\c!before
   \enforced\edef\typo_initial_handle{\typo_initial_handle_indeed{#1}{}}}

\permanent\tolerant\protected\def\setinitial[#1]#*[#S#2]%
  {\enforced\edef\typo_initial_handle{\typo_initial_handle_indeed{#1}{#2}}}

%D \starttyping
%D \framed
%D   [width=10cm,align=normal,strut=no,toffset=1ex]
%D   {\placeinitial \flushinitial \samplefile{ward}}
%D \stoptyping

\permanent\tolerant\protected\def\flushinitial % when used inside a mechanism that forgets
  {\typo_initial_handle}

\newconstant   \c_initial_lines
\newconditional\c_initial_synchronize

% First experiment:
%
% \startluacode
%     function nodes.handlers.forgetinitial(mode,indented,context)
%         token.expandmacro("forgetinitial")
%         return indented
%     end
%     utilities.sequencers.prependaction("paragraph","system","nodes.handlers.forgetinitial")
%     utilities.sequencers.enableaction("paragraph","nodes.handlers.forgetinitial")
% \stopluacode
%
% Second experiment:
%
% \appendtoks
%     \forgetinitial
% \to \everybeforepar

\protected\def\typo_initial_handle_indeed#1#2%
  {\dontleavehmode
   \begingroup
   \cdef\currentinitial{#1}%
   \setupcurrentinitial[#2]%
   \resetfontfeature % might be needed in more places
   \ifempty{\initialparameter\c!style}%
     \definedfont[\initialparameter\c!font]%
   \else
     \useinitialstyleparameter\c!style
   \fi
   \useinitialcolorparameter\c!color
   \edef\p_voffset{\initialparameter\c!voffset}%
   \scratchcounter \initialparameter\c!n\relax
   \scratchvoffset\dimexpr\ifx\p_voffset\v!line\scratchcounter\lineheight-\lineheight\else\p_voffset\fi\relax
   \clf_setinitial
        location   {\initialparameter\c!location}%
        enabled    true\space
        n          \scratchcounter
        m          \numexpr\initialparameter\c!m\relax
        method     {\initialparameter\c!method}%
        continue   {\initialparameter\c!continue}%
        distance   \dimexpr\initialparameter\c!distance\relax
        hoffset    \dimexpr\initialparameter\c!hoffset\relax
        voffset    \scratchvoffset
        ma         \c_attr_colormodel
        ca         \c_attr_color
        ta         \c_attr_transparency
        font       \fontid\font
        glyphscale \glyphscale
        dynamic    \font_dynamic_value % it's a bit over the top to support this here
   \relax
   \c_attr_initial\plusone
   \initialparameter\c!text
   \normalexpanded{\endgroup\c_initial_lines\the\scratchcounter}%
   \enforced\glettonothing\typo_initial_handle
   \ifconditional\c_initial_synchronize
     \appendtoks \forgetinitial \to \everybeforepar
   \fi}

\lettonothing\typo_initial_handle % hook into everypar

\permanent\protected\def\forgetinitial
  {\ifcase\c_initial_lines\else
     \begingroup
     \advanceby\c_initial_lines-\prevgraf\relax
     \ifcase\c_initial_lines\else
       \obeydepth
       \forgetall
       \testpage[\the\c_initial_lines]%
       \dorecurse\c_initial_lines{\nointerlineskip\hpack to \hsize{\strut}\par}%
     \fi
     \endgroup
     \c_initial_lines\zerocount
     \ifconditional\c_initial_synchronize
       \removetoks \forgetinitial \from \everybeforepar
     \fi
  \fi}

%D \starttyping
%D \setupinitial[n=2,style=\tfd,location=text]
%D \setuphead[chapter][after=\placeinitial]
%D \enableexperiments[autoforgetinitials]
%D
%D \starttext
%D   \chapter{Test me} Hello world!
%D  %\forgetinitial \input tufte
%D   \input tufte
%D \stoptext
%D \stoptyping

% \enableexperiments[autoforgetinitials]

\installtexexperiment
   {autoforgetinitials}
   {\c_initial_synchronize\conditionaltrue}
   {\c_initial_synchronize\conditionalfalse}

% \setupbodyfont[dejavu,9pt]
%
% \startbuffer
% \setinitial[two]            D. E. Knuth   \ignorespaces\input knuth \par
% \setinitial[two]                  Knuth   \ignorespaces\input knuth \par
% \setinitial[two] \quotation{D. E. Knuth}  \ignorespaces\input knuth \par
% \setinitial[two] \quotation      {Knuth}  \ignorespaces\input knuth \par
% \setinitial[two]      [text={D.E. Knuth}] \ignorespaces\input knuth \par
% \setinitial[two]       [m=4] D. E. Knuth  \ignorespaces\input knuth \par
% \stopbuffer
%
% \type{m=2}                          \start \defineinitial[two][m=2,method=none]              \getbuffer \page \stop
% \type{m=1,method=auto}              \start \defineinitial[two][m=1,method=auto]              \getbuffer \page \stop
% \type{m=1,method={auto,first,last}} \start \defineinitial[two][m=1,method={first,auto,last}] \getbuffer \page \stop

\protect \endinput

