%D \module
%D   [       file=strc-bkm,
%D        version=2009.04.01,
%D          title=\CONTEXT\ Structure Macros,
%D       subtitle=Bookmarks,
%D         author=Wolfgang Schuster,
%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 Structure Macros / Userdata}

\registerctxluafile{strc-usr}{}

%D It's a bit like blocks that also use buffers but more lightweight and with
%D inplace settings.
%D
%D \starttyping
%D \defineuserdata [test] [style=italic]
%D
%D \samplefile{klein}
%D
%D \startuserdata [before=\blank,after=\blank,color=red]
%D     \samplefile{greenfield}
%D \stopuserdata
%D
%D \samplefile{sapolsky}
%D
%D \startuserdata [test]
%D     \samplefile{bryson}
%D \stopuserdata
%D
%D \samplefile{jojomayer}
%D
%D \startuserdata [test] [before=\blank,after=\blank,color=red]
%D     \samplefile{linden}
%D \stopuserdata
%D
%D \samplefile{montgomery}
%D \stoptyping
%D
%D Or from \LUA:
%D
%D \starttyping
%D \startluacode
%D     context.startuserdata({color="blue"})
%D         context.samplefile("klein")
%D     context.stopuserdata()
%D \stopluacode
%D \stoptyping
%D
%D An example of an alternative:
%D
%D \starttyping
%D \defineuserdataalternative [epigraph] [renderingsetup=userdata:epigraph]
%D
%D \startsetups [userdata:epigraph]
%D     \startframedtext [location=right,frame=off,align={flushleft,broad},style=\tfx,offset=.25ex,width=.5\textwidth]
%D         \begstrut\inlinebuffer[userdata]\endstrut
%D         \hairline
%D         \wordright{\userdataparameter{author}}
%D     \stopframedtext
%D \stopsetups
%D
%D \defineuserdata
%D   [epigraph]
%D   [alternative=epigraph]
%D
%D \startuserdata [epigraph] [author={Sean B. Carrol}]
%D     The fraction of fossil olfactory receptor genes is significantly higher in
%D     all species with full color vision. This suggests that the evolution of
%D     trichromatic vision --- which allows these primates to detect food, mates,
%D     and danger with visual cues --- has reduced their reliance on the sense of
%D     smell.
%D \stopuserdata
%D
%D \startuserdata [epigraph] [author={Sean B. Carrol}]
%D     \samplefile{carrol}
%D \stopuserdata
%D \stoptyping

\unprotect

\installnamespace {userdata}
\installnamespace {userdataalternative}
\installnamespace {userdatarenderings}

\installcommandhandler \????userdata            {userdata}            \????userdata
\installcommandhandler \????userdataalternative {userdataalternative} \????userdataalternative

\appendtoks
    \protected\frozen\instance\edefcsname\e!start\currentuserdata\endcsname{\userdata_start_instance{\currentuserdata}}%
    \protected\frozen\instance\letcsname \e!stop \currentuserdata\endcsname\userdata_stop_instance
\to \everydefineuserdata

\permanent\protected\def\startuserdata
  {\begingroup
   \lettonothing\currentuserdata
   \doifelsenextoptionalcs\userdata_start_delayed\userdata_start_indeed}

\def\userdata_start_delayed[#S#1]%
  {\doifelseassignmentcs{#1}%
     \userdata_start_delayed_parameters
     \userdata_start_delayed_name
   [#1]}

\def\userdata_start_delayed_parameters[#S#1]%
  {\setupcurrentuserdata[#1]%
   \userdata_start_indeed}

\def\userdata_start_delayed_name[#1]%
  {\cdef\currentuserdata{#1}%
   \checkuserdataparent
   \doifelsenextoptionalcs\userdata_start_delayed_parameters\userdata_start_indeed}

\protected\tolerant\def\userdata_start_instance#1#*[#S#2]%
  {\begingroup
   \cdef\currentuserdata{#1}%
   \setupcurrentuserdata[#2]%
   \grabbufferdatadirect
   % {\s!userdata:\currentuserdata}%
     {\s!userdata}% unnested, as before
     {\e!start\currentuserdata}%
     {\e!stop \currentuserdata}}

\def\userdata_start_indeed
  {\grabbufferdatadirect
   % {\s!userdata:\currentuserdata}%
     {\s!userdata}% unnested, as before
     {\csstring\startuserdata}%
     {\csstring\stopuserdata}}

\permanent\protected\def\stopuserdata
  {\userdataparameter\c!before
   \dostarttagged\t!userdata\currentuserdata
   \begingroup
   \useuserdatastyleandcolor\c!style\c!color
   \usealignparameter\userdataparameter
   \edef\currentuserdataalternative{\userdataparameter\c!alternative}%
   \ifcsname\currentuserdataalternativehash\s!parent\endcsname \else
     \let\currentuserdataalternative\s!default
   \fi
   \usesetupsparameter\userdataparameter
   \edef\p_renderingsetup{\userdataalternativeparameter\c!renderingsetup}%
   \directsetup\p_renderingsetup
   \endgroup
   \dostoptagged
   \userdataparameter\c!after
   \endgroup}

\aliased\let\userdata_stop_instance\stopuserdata

% kind of nested, when we need it:
%
% \permanent\tolerant\protected\def\getuserdata      [#1]{\expanded{\getbufferdata[\s!userdata:\ifparameter#1\or#1\else\currentuserdata\fi]}}
% \permanent\tolerant\protected\def\getinlineuserdata[#1]{\expanded{\inlinebuffer [\s!userdata:\ifparameter#1\or#1\else\currentuserdata\fi]}}

% unnested, as before:

\permanent\tolerant\protected\def\getuserdata      [#1]{\getbufferdata[\s!userdata]}
\permanent\tolerant\protected\def\getinlineuserdata[#1]{\inlinebuffer [\s!userdata]}

\defineuserdataalternative
  [\s!default]
  [\c!renderingsetup=\????userdatarenderings:\s!default]

% \startsetups[\????userdatarenderings:\s!default]
%     \userdataparameter\c!before
%     \usesetupsparameter\userdataparameter
%     \getbufferdata[\s!userdata]
%     \userdataparameter\c!after
% \stopsetups

\startsetups[\????userdatarenderings:\s!default]
    \getuserdata
\stopsetups

\setupuserdata
  [\c!alternative=\s!default]

\protect