%D \module
%D   [       file=strc-mar,
%D        version=2008.10.20,
%D          title=\CONTEXT\ Structure Macros,
%D       subtitle=Markings,
%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 Structure Macros / Markings}

\registerctxluafile{strc-mar}{1.001}

\unprotect

%D Synchronizing marks is a rather tricky and messy business. When
%D setting a mark, a node is added to the list in order for to \TEX\
%D be able to figure out the 3 current marks when a page is made
%D (last mark on previous page, first on current page, last on
%D current page; in \LUATEX\ we might at one point have the first on
%D the next page as well).
%D
%D Resetting a mark is not easy. An empty one will not erase the last
%D one on the previous page for instance. In \LUATEX\ we can clear a
%D marks state register with \type {\clearmarks} but since this is an
%D immediate operation it might have unwanted side effects when \TEX\
%D has collected several pages of text and finishing off these pages
%D uses marks.
%D
%D In \MKIV\ we provide an alternative model that permits some more
%D control over the way marks are used. It is not entirely compatible
%D with \MKII\ or previous \MKIV\ implementations but in practice this
%D is not a real problem. It's also easier now to extend this mechanism.

% if global has side effects we will need to nil it selectively
% and optionally enable it in for instance postponed content

\definesystemattribute [marks] [global]

\let\currentmarking\empty

\def\markingparameter          #1{\csname\domarkingparameter{\??mk\currentmarking}#1\endcsname}
\def\namedmarkingparameter   #1#2{\csname\domarkingparameter{\??mk#1}#2\endcsname}
\def\domarkingparameter      #1#2{\ifcsname#1#2\endcsname#1#2\else\expandafter\domarkingparentparameter\csname#1\s!parent\endcsname#2\fi}
\def\domarkingparentparameter#1#2{\ifx#1\relax\s!empty\else\domarkingparameter#1#2\fi}

% \def\markingparameterhash          #1{\domarkingparameterhash{\??mk\currentmarking}#1}
% \def\domarkingparameterhash      #1#2{\ifcsname#1#2\endcsname#1\else\expandafter\domarkingparentparameterhash\csname#1\s!parent\endcsname#2\fi}
% \def\domarkingparentparameterhash#1#2{\ifx#1\relax\else\domarkingparameterhash#1#2\fi}
%
% \def\detokenizedmarkingparameter#1{\detokenize\expandafter\expandafter\expandafter{\csname\??mk\currentmarking#1\endcsname}}
%
% \def\dosetmarkingattributes#1#2% style color
%   {\edef\fontattributehash {\markingparameterhash#1}%
%    \edef\colorattributehash{\markingparameterhash#2}%
%    \ifx\fontattributehash \empty\else\dosetfontattribute \fontattributehash #1\fi
%    \ifx\colorattributehash\empty\else\dosetcolorattribute\colorattributehash#2\fi}

\newconditional\inhibitgetmarking
\newconditional\inhibitsetmarking
\newtoks       \everymarking

\unexpanded\def\setupmarking
  {\dodoubleargument\dosetupmarking}

\def\dosetupmarking[#1][#2]%
  {\ifsecondargument
     \def\docommand##1{\getparameters[\??mk##1][#2]}%
     \processcommalist[#1]\docommand
   \else
     \getparameters[\??mk][#1]%
   \fi}

% management

\unexpanded\def\definemarking     {\dodoubleempty   \dodefinemarking}
\unexpanded\def\relatemarking     {\dodoubleempty   \dorelatemarking}
\unexpanded\def\setmarking        {\dosingleargument\dosetmarking   } \let\marking\setmarking
\unexpanded\def\resetmarking      {\dosingleargument\doresetmarking }
\unexpanded\def\synchronizemarking{\dodoubleargument\dosynchronizemarking }

\def\dodefinemarking[#1][#2]% marking parent
  {\doifelsenothing{#2}
     {\ctxcommand{definemarking("#1")}%
      \getparameters[\??mk#1][\s!parent=\??mk]}
     {\ctxcommand{definemarking("#1",{ parent = "#2" })}%
      \getparameters[\??mk#1][\s!parent=\??mk#2]}}

\def\dorelatemarking[#1][#2]%
  {\ctxcommand{relatemarking("#1","#2")}}

\def\dosetmarking[#1]#2%
  {\ifconditional\inhibitsetmarking
     % nothing
   \else
     \doifelse{\namedmarkingparameter{#1}\c!expansion}\v!yes
       {\ctxcommand{setmarking("#1",\!!bs#2\!!es)}}
       {\ctxcommand{setmarking("#1",\!!bs\detokenize{#2}\!!es)}}%
   \fi}

\def\doresetmarking[#1]%
  {\ctxcommand{resetmarking("#1")}}

\def\doifelsemarking#1%
  {\ctxcommand{doifelsemarking("#1")}}

\def\dosynchronizemarking[#1][#2]% class boxnumber (some day also name), maybe second argument table
  {\ifvoid#2\else\ctxcommand{synchronizemarking("#1",\number#2)}\fi}

% \appendtoks
%     \dosynchronizemarking[\v!page][\normalpagebox]%
% \to \everybeforepagebody

% defaults

\setupmarking
  [\c!expansion=\v!no,
   \c!separator=\space\emdash\space,
   \c!filtercommand=\firstofoneargument,
   \c!state=\v!start]

% fetching, regular interface

\unexpanded\def\getmarking
  {\ifconditional\inhibitgetmarking
     \expandafter\dotripleargument\expandafter\nogetmarking
   \else
     \expandafter\dotripleargument\expandafter\dogetmarking
   \fi}

\def\nogetmarking[#1][#2][#3]%
  {}

\def\dogetmarking[#1][#2][#3]%
  {\doif{\namedmarkingparameter{#1}\c!state}\v!start
     {\begingroup
      \setsystemmode\v!marking
      \the\everymarking
      \ifthirdargument
        \ctxcommand{getmarking("#1","#2","#3")}%
      \else
        \ctxcommand{getmarking("#1","\v!page","#2")}%
      \fi
      \endgroup}}

% the fetchers are fully expandable: [name][method]

\def\fetchonemark[#1]#2[#3]{\ifconditional\inhibitgetmarking\else\ctxcommand{fetchonemark ("#1","\v!page","#2")}\fi}
\def\fetchtwomarks     [#1]{\ifconditional\inhibitgetmarking\else\ctxcommand{fetchtwomarks("#1","\v!page")}\fi}
\def\fetchallmarks     [#1]{\ifconditional\inhibitgetmarking\else\ctxcommand{fetchallmarks("#1","\v!page")}\fi}

\let\fetchmark\fetchonemark

% also fully expandable but here we have: [name][range][method]

\def\fetchonemarking[#1]#2[#3]#4[#5]{\ifconditional\inhibitgetmarking\else\ctxcommand{fetchonemark ("#1","#3","#5")}\fi}
\def\fetchtwomarkings     [#1]#2[#3]{\ifconditional\inhibitgetmarking\else\ctxcommand{fetchtwomarks("#1","#3")}\fi}
\def\fetchallmarkings     [#1]#2[#3]{\ifconditional\inhibitgetmarking\else\ctxcommand{fetchallmarks("#1","#3")}\fi}

\let\fetchmarking\fetchonemarking

\def\markingseparator#1{\namedmarkingparameter{#1}\c!separator}
\def\markingcommand  #1{\namedmarkingparameter{#1}\c!filtercommand}

%D Experimental:
%D
%D \starttyping
%D \definemarking[boxmark]
%D
%D \setbox0\ruledvbox{
%D     \marking[boxmark]{tufte} \input tufte \par
%D     \marking[boxmark]{ward}  \input ward  \par
%D }
%D
%D \synchronizemarking[zerobox][0] \box0
%D
%D marks: (\getmarking[boxmark][zerobox][first],\getmarking[boxmark][zerobox][last])
%D \stoptyping

\protect \endinput