%D \module
%D   [       file=attr-eff,
%D        version=2007.06.06,
%D          title=\CONTEXT\ Attribute Macros,
%D       subtitle=Effects,
%D         author=Hans Hagen,
%D           date=\currentdate,
%D      copyright=PRAGMA-ADE]
%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 Attribute Macros / Effects}

\registerctxluafile{attr-eff}{1.001}

% more will move to the lua end (old code, early luatex approach)

\unprotect

\def\registereffect#1#2#3% #2=stretch #3=rulethickness
  {\setxvalue{(es:#1:#2:\number\dimexpr#3\relax)}%
     {\attribute\effectattribute\ctxlua{tex.write(attributes.effects.register('#1',#2,\number\dimexpr#3\relax))}\relax}}

\def\dotriggereffect
  {\ctxlua{attributes.effects.enable()}%
   \gdef\dotriggereffect##1##2##3%
     {\ifcsname(es:##1:##2:\number\dimexpr##3\relax)\endcsname\else\registereffect{##1}{##2}{##3}\fi
      \csname(es:##1:##2:\number\dimexpr##3\relax)\endcsname}%
   \dotriggereffect}

\unexpanded\def\setupeffect
  {\dodoubleargument\dosetupeffect}

\def\dosetupeffect[#1][#2]%
  {\getparameters[\??et#1][#2]}

\unexpanded\def\defineeffect
  {\dodoubleargument\dodefineeffect}

\def\dodefineeffect[#1][#2]%
  {\getparameters[\??et#1][\c!method=\v!none,\c!stretch=0,\c!rulethickness=\zeropoint,\c!alternative=\v!normal,#2]%
   \doif{\getvalue{\??et#1\c!method}}\v!command
     {\setugvalue{\e!start#1}{\starteffect[#1]}%
      \setugvalue{\e!stop #1}{\stopeffect     }}}

% yes or no grouped

\unexpanded\def\starteffect[#1]%
  {\dotriggereffect{\getvalue{\??et#1\c!alternative}}{\getvalue{\??et#1\c!stretch}}{\getvalue{\??et#1\c!rulethickness}}}

\unexpanded\def\stopeffect % can be special
  {\dotriggereffect\v!normal0\zeropoint}

\unexpanded\def\effect[#1]%
  {\groupedcommand{\starteffect[#1]}{\stopeffect}}

\defineeffect [\v!inner]   [\c!alternative=\v!inner,\c!rulethickness=.25pt]
\defineeffect [\v!outer]   [\c!alternative=\v!outer,\c!rulethickness=.25pt]
\defineeffect [\v!both]    [\c!alternative=\v!both, \c!rulethickness=.25pt]
\defineeffect [\v!normal]  [\c!alternative=\v!normal]
\defineeffect [\v!hidden]  [\c!alternative=\v!hidden]
\defineeffect [\v!stretch] [\c!alternative=\v!stretch,\c!stretch=1]

\protect \endinput