%D \module
%D   [       file=attr-ini,
%D        version=2007.06.06,
%D          title=\CONTEXT\ Attribute Macros,
%D       subtitle=Initialization,
%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 Attribute Macros / Initialization}

\unprotect

\registerctxluafile{attr-ini}{autosuffix}

\installcorenamespace{attributecount}  % the counter representing the attribute (attrdef'd)
\installcorenamespace{attributeid}     % the internal number
\installcorenamespace{attributestack}  % the attribute specific stack
\installcorenamespace{attributepickup}

\permanent\protected\def\pushattribute#1%
  {\global\advanceby\csname\??attributestack\string#1\endcsname\plusone
   \gdefcsname\??attributestack\string#1:\number\csname\??attributestack\string#1\endcsname\endcsname{\number\attribute#1}}

\permanent\protected\def\popattribute#1%
  {\attribute#1\csname\??attributestack\string#1:\number\csname\??attributestack\string#1\endcsname\endcsname\relax
   \global\advanceby\csname\??attributestack\string#1\endcsname\minusone}

\permanent\protected\def\installattributestack#1%
  {\ifcsname\??attributestack\string#1\endcsname \else
     \expandafter\newinteger\csname\??attributestack\string#1\endcsname
   \fi}

\newtoks \t_attr_list_global
\newtoks \t_attr_list_local
\newtoks \t_attr_list_pickup
\newtoks \t_attr_list_nomath

\ifdefined \s!global    \else \immutable\def\s!global   {global}    \fi % for metatex % or hard check later
\ifdefined \s!public    \else \immutable\def\s!public   {public}    \fi % for metatex % or hard check later
\ifdefined \s!private   \else \immutable\def\s!private  {private}   \fi % for metatex % or hard check later
\ifdefined \s!attribute \else \immutable\def\s!attribute{attribute} \fi % for metatex % or hard check later
\ifdefined \s!pickup    \else \immutable\def\s!pickup   {pickup}    \fi % for metatex % or hard check later
\ifdefined \s!forget    \else \immutable\def\s!forget   {forget}    \fi % for metatex % or hard check later

\immutable\def\??attributeprefix{c_attr_}

\permanent\protected\def\defineattribute      {\attr_basics_define_indeed[\s!public ]}
\permanent\protected\def\definesystemattribute{\attr_basics_define_indeed[\s!private]}

\tolerant\def\attr_basics_define_indeed[#1]#*[#2]#*[#3]%
  {\ifcsname\??attributeprefix#2\endcsname\else
     \scratchcounter\clf_defineattribute{#2}{#1}\relax
    %\writestatus\m!system{defining #1 attribute #2 with number \number\scratchcounter}%
     \global\permanent\expandafter\attributedef\csname\??attributeprefix#2\endcsname\scratchcounter %           \foo = 123
     \global\permanent\expandafter\integerdef  \csname\??attributeid    #2\endcsname\scratchcounter % \attribute\foo = 123
     % some attributes are always global
     \doifelseinset\s!global{#3}%
       {\xtoksapp\t_attr_list_global{\csname\??attributeprefix#2\endcsname\attributeunsetvalue}}% \c_attr_foo
       {\xtoksapp\t_attr_list_local {\csname\??attributeprefix#2\endcsname\attributeunsetvalue}}%
     \doifinset\s!nomath{#3}%
       {\xtoksapp\t_attr_list_nomath{\csname\??attributeprefix#2\endcsname\attributeunsetvalue}}%
     \doifinset\s!public{#3}%
       {\aliased\gletcsname#2\s!attribute\expandafter\endcsname\csname\??attributeid#2\endcsname}% \attribute\fooattribute
     % used to sync in the page builder .. used for directions and scripts ... i start forgetting these details .. (seldom used)
     \doifinset\s!pickup{#3}%
       {\global\expandafter\integerdef\csname\??attributepickup#2\endcsname\attributeunsetvalue
        \xtoksapp\t_attr_list_pickup{\csname\??attributeprefix#2\endcsname\csname\??attributepickup#2\endcsname}%
        \ifcsname#2\s!attribute\endcsname
          \permanent\xdefcsname\s!pickup#2\s!attribute\endcsname{\expandafter\integerdef\csname\??attributepickup#2\endcsname\csname\??attributeprefix#2\endcsname}%
          \permanent\xdefcsname\s!forget#2\s!attribute\endcsname{\expandafter\integerdef\csname\??attributepickup#2\endcsname\attributeunsetvalue}%
        \fi}%
   \fi}

\permanent\protected\def\pickupattributes
  {\the\t_attr_list_pickup\relax}

\permanent\protected\def\newattribute#1%
  {\attr_basics_define_indeed[\s!public][\csstring#1][]%
   \expandafter\glet\expandafter#1\csname\??attributeid\csstring#1\endcsname}

% expandable so we can \edef them for speed

\permanent\def\dosetattribute#1#2{\csname\??attributeprefix#1\endcsname#2\relax}
\permanent\def\doresetattribute#1{\csname\??attributeprefix#1\endcsname\attributeunsetvalue}
\permanent\def\dogetattribute  #1{\number\csname\??attributeprefix#1\endcsname}
\permanent\def\dogetattributeid#1{\number\csname\??attributeid    #1\endcsname}

\aliased\let\dompattribute\gobbletwoarguments

\permanent\protected\def\resetglobalattributes{\the\t_attr_list_global\glyphdatafield\zerocount\glyphscriptfield\zerocount}
\permanent\protected\def\resetlocalattributes {\the\t_attr_list_local \glyphdatafield\zerocount\glyphscriptfield\zerocount}

\aliased\let\resetallattributes\resetlocalattributes

%D Rather special.

\permanent\protected\def\savecurrentattributes   #1{\clf_savecurrentattributes   {#1}}
\permanent\protected\def\restorecurrentattributes#1{\clf_restorecurrentattributes{#1}}

%D For the moment we put this here. The order of definition matters a bit because
%D performance is better when we put frequently accessed attributes at the front.
%D So, we might move more here.

%definesystemattribute [state]                                  % nomath
\definesystemattribute [color]               [public]           % global
\definesystemattribute [colormodel]          [public,global]
%definesystemattribute [skip]
%definesystemattribute [penalty]
\definesystemattribute [transparency]        [public]
\definesystemattribute [reference]           [public]
\definesystemattribute [destination]         [public]
\definesystemattribute [case]                [public]
\definesystemattribute [visual]              [public,global]
\definesystemattribute [viewerlayer]         [public]
\definesystemattribute [background]          [public]
\definesystemattribute [alignbackground]     [public]
\definesystemattribute [colorintent]         [public]
\definesystemattribute [negative]            [public]
\definesystemattribute [effect]              [public]
\definesystemattribute [layoutcomponent]     [public]
\definesystemattribute [internal]            [public]
\definesystemattribute [ruled]               [public]
\definesystemattribute [shifted]             [public]
\definesystemattribute [checkedbreak]        [public]
\definesystemattribute [alternate]           [public]
\definesystemattribute [vboxtohboxseparator] [public]

\permanent\protected\let\showattributes\clf_showattributes % maybe at lua end

%D Todo:

% \appendtoks
%     \clf_cleanupattributes
% \to \everyafterpagebreak

\protect \endinput