%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 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 Node Support / Backgrounds}

%D This is first attempt to replacing backgrounds in a few tables
%D mechanisms. When used more frequently, we can store the color
%D spec in the attribute.

\unprotect

\registerctxluafile{node-bck}{optimize}

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

\def\colorattr#1%
  {\ifcsname\??colorattribute\currentcolorprefix#1\endcsname
     \node_backgrounds_thecolorattr{\currentcolorprefix#1}%
   \else\ifcsname\??colorattribute#1\endcsname
     \node_backgrounds_thecolorattr{#1}%
   \fi\fi}

\def\node_backgrounds_thecolorattr#1%
  {attr \colormodelattribute   \attribute\colormodelattribute
   attr \colorattribute        \lastnamedcs
   attr \transparencyattribute \thetransparencyattribute{#1} } % can be optimized

\def\thecolorattr#1%
  {attr \colormodelattribute   \attribute\colormodelattribute
   attr \colorattribute        \csname\??colorattribute#1\endcsname
   attr \transparencyattribute \thetransparencyattribute{#1} } % can be optimized

\def\backgroundcolorattr#1%
  {\ifcsname\??colorattribute\currentcolorprefix#1\endcsname
     \node_backgrounds_thebackgroundcolorattr{\currentcolorprefix#1}%
   \else\ifcsname\??colorattribute#1\endcsname
     \node_backgrounds_thebackgroundcolorattr{#1}%
   \fi\fi}

\def\thebackgroundcolorattr#1%
  {attr \backgroundattribute      \plusone
   attr \colormodelattribute      \attribute\colormodelattribute
   attr \colorattribute           \csname\??colorattribute#1\endcsname
   attr \transparencyattribute    \thetransparencyattribute{#1} } % can be optimized

\def\node_backgrounds_thebackgroundcolorattr#1%
  {attr \backgroundattribute      \plusone
   attr \colormodelattribute      \attribute\colormodelattribute
   attr \colorattribute           \lastnamedcs
   attr \transparencyattribute    \thetransparencyattribute{#1} } % can be optimized

\def\thealignbackgroundcolorattr#1%
  {attr \alignbackgroundattribute \plusone
   attr \colormodelattribute      \attribute\colormodelattribute
   attr \colorattribute           \csname\??colorattribute#1\endcsname
   attr \transparencyattribute    \thetransparencyattribute{#1} } % can be optimized

\unexpanded\def\backgroundhbox{\node_backgrounds_boxes_add\hbox}
\unexpanded\def\backgroundvbox{\node_backgrounds_boxes_add\vbox}
\unexpanded\def\backgroundvtop{\node_backgrounds_boxes_add\vtop}

\unexpanded\def\backgroundline{\dontleavehmode
                               \node_backgrounds_boxes_add\hbox}

% \def\node_backgrounds_boxes_add#1[#2]%
%   {\begingroup
%    \clf_enablebackgroundboxes
%    \dousecolorparameter{#2}%
%    \normalexpanded{\endgroup#1
%      attr \backgroundattribute   \plusone
%      attr \colormodelattribute   \the\attribute\colormodelattribute
%      attr \colorattribute        \the\attribute\colorattribute
%      attr \transparencyattribute \the\attribute\transparencyattribute}}
%
% more efficient:

\def\node_backgrounds_boxes_add#1[#2]%
  {\clf_enablebackgroundboxes
   #1\backgroundcolorattr{#2}}

\protect \endinput