%D \module
%D   [       file=node-bck,
%D        version=2009.06.08,
%D          title=\CONTEXT\ Node Macros,
%D       subtitle=Backgrounds,
%D         author=Hans Hagen,
%D           date=\currentdate,
%D      copyright=PRAGMA]
%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 Node Support / Backgrounds}

%D This is first attempt to replacing backgrounds in a few
%D tables mechanisms.

\unprotect

\registerctxluafile{node-bck}{1.001}

\def\doinitializeboxbackgrounds
  {\ctxlua{nodes.tasks.enableaction("shipouts","nodes.handlers.backgrounds")}%
   \glet\doinitializeboxbackgrounds\donothing}

%D Box helpers:

% \backgroundvbox[green] {\input tufte } \par
% \backgroundvbox[blue]  {\input ward } \par
% \backgroundvbox[red]   {\input knuth } \par
% \backgroundhbox[yellow]{\rotate[rotation=45]{hello world}} \par

\def\doaddbackgroundtobox#1[#2]%
  {\begingroup\doinitializeboxbackgrounds\faststartcolor[#2]%
   \normalexpanded{\noexpand\faststopcolor\endgroup#1
     attr \backgroundattribute   \plusone
     attr \colormodelattribute   \the\attribute\colormodelattribute
     attr \colorattribute        \the\attribute\colorattribute
     attr \transparencyattribute \the\attribute\transparencyattribute}}

\def\backgroundvbox{\doaddbackgroundtobox\vbox}
\def\backgroundvtop{\doaddbackgroundtobox\vtop}
\def\backgroundhbox{\doaddbackgroundtobox\hbox}

\def\colorattr#1%
  {\ifcsname(cs:\currentpalet#1)\endcsname
     \thecolorattr{\currentpalet#1}%
   \else\ifcsname(cs:#1)\endcsname
     \thecolorattr{#1}%
   \fi\fi}

\def\thecolorattr#1%
  {attr \colormodelattribute   \attribute\colormodelattribute
   attr \colorattribute        \csname(cs:#1)\endcsname
   attr \transparencyattribute \csname(ts:#1)\endcsname}

\def\backgroundcolorattr#1%
  {\ifcsname(cs:\currentpalet#1)\endcsname
     \thebackgroundcolorattr{\currentpalet#1}%
   \else\ifcsname(cs:#1)\endcsname
     \thebackgroundcolorattr{#1}%
   \fi\fi}

\def\thebackgroundcolorattr#1%
  {attr \backgroundattribute   \plusone
   attr \colormodelattribute   \attribute\colormodelattribute
   attr \colorattribute        \csname(cs:#1)\endcsname
   attr \transparencyattribute \csname(ts:#1)\endcsname}

% \def\backgroundvbox[#1]{\vbox \backgroundcolorattr{#1}}
% \def\backgroundvtop[#1]{\vtop \backgroundcolorattr{#1}}
% \def\backgroundhbox[#1]{\hbox \backgroundcolorattr{#1}}

\protect \endinput