1 files changed, 110 insertions, 0 deletions
diff --git a/tex/context/base/node-rul.mkiv b/tex/context/base/node-rul.mkiv
index ea9f5364b..40d0014dc 100644
--- a/tex/context/base/node-rul.mkiv
+++ b/tex/context/base/node-rul.mkiv
@@ -56,6 +56,7 @@
 \unprotect
 
 \definesystemattribute[ruled]
+\definesystemattribute[shifted]
 
 \registerctxluafile{node-rul}{1.001}
 
@@ -191,6 +192,115 @@
 \def\setupunderbar[#1]% too incompatible for the moment
   {}
 
+%D This will move: (a bit duplicated)
+
+\newtoks\checkalldefinedshifts
+
+\def\shiftparameter    #1{\csname\doshiftparameter\currentshift#1\endcsname}
+\def\shiftparameterhash#1{\doshiftparameterhash{\??ra\currentshift}#1}
+
+\def\doshiftparameter    #1#2{\ifcsname\??ra#1#2\endcsname\??ra#1#2\else\expandafter\doshiftparentparameter\csname\??ra#1\s!parent\endcsname#2\fi}
+\def\doshiftparameterhash#1#2{\ifcsname#1#2\endcsname#1\else\expandafter\doshiftparentparameterhash\csname#1\s!parent\endcsname#2\fi}
+
+\def\doshiftparentparameter    #1#2{\ifx#1\relax\s!empty\else\doshiftparameter    #1#2\fi}
+\def\doshiftparentparameterhash#1#2{\ifx#1\relax        \else\doshiftparameterhash#1#2\fi}
+
+\def\dosetshiftattributes#1#2% style color
+  {\edef\fontattributehash {\shiftparameterhash#1}%
+   \edef\colorattributehash{\shiftparameterhash#2}%
+   \ifx\fontattributehash \empty\else\dosetfontattribute \fontattributehash #1\fi
+   \ifx\colorattributehash\empty\else\dosetcolorattribute\colorattributehash#2\fi}
+
+\def\defineshift
+  {\dotripleempty\dodefineshift}
+
+\def\dodefineshift[#1][#2][#3]%
+  {\ifthirdargument
+     \getparameters[\??ra#1][\s!parent=#2,#3]%
+   \else
+     \getparameters[\??ra#1][\s!parent=,#2]%
+   \fi
+   %
+   %\setvalue{\??ra:#1}{0}%
+   %
+   \ifcsname\??ra:#1:c\endcsname
+     \csname\??ra:#1:c\endcsname\zerocount
+   \else
+     \expandafter\newcount\csname\??ra:#1:c\endcsname
+   \fi
+   \normalexpanded{\checkalldefinedshifts{\noexpand\doredefineshift{#1}\the\checkalldefinedshifts}}%
+   \dodefineshiftindeed{#1}%
+   \unexpanded\setvalue{#1}{\doshifted{#1}}}
+
+\def\dodefineshiftindeed#1%
+  {\bgroup
+   \def\currentshift{#1}%
+   \normalexpanded
+     {\egroup
+      \scratchcounter\ctxlua{nodes.shifts.define {
+        method   = \shiftparameter\c!method,
+        continue = "\shiftparameter\c!continue",
+        dy       = \shiftparameter\c!dy,
+        unit     = "\shiftparameter\c!unit",
+      }}}%
+   \setevalue{\??ra#1:a}{\the\scratchcounter}}
+
+\let\doredefineshift\dodefineshiftindeed
+
+\def\doshifted#1%
+  {\groupedcommand{\dodoshifted{#1}}\relax}
+
+\def\dodoshifted
+  {\ctxlua{nodes.shifts.enable()}%
+   \glet\dodoshifted\dodoshiftedindeed
+   \dodoshifted}
+
+\def\dodoshiftedindeed#1%
+  {\def\currentshift{#1}%
+   \advance\csname\??ra:#1:c\endcsname\plusone
+   \scratchcounter\csname\??ra:#1:c\endcsname
+   \dosetattribute{shifted}{\numexpr1000*\scratchcounter
+     +\csname\??ra#1\ifcsname\??ra#1:\number\scratchcounter\s!parent\endcsname:\number\scratchcounter\fi:a\endcsname}%
+   \dosetshiftattributes\c!style\c!color}
+
+\unexpanded\def\startshift[#1]%
+  {\begingroup
+   \dodoshifted{#1}}
+
+\unexpanded\def\stopshift
+  {\endgroup}
+
+\def\setupshifts
+  {\dodoubleempty\dosetupshifts}
+
+\def\dosetupshifts[#1][#2]% not that efficient
+  {\ifsecondargument
+     \getparameters[\??ra#1][#2]%
+     \dodefineshiftindeed{#1}%
+   \else
+     \getparameters[\??ra][#1]%
+     \the\checkalldefinedshifts
+   \fi}
+
+\setupshifts
+  [\c!method=0,
+   \c!continue=\v!no,
+   \c!dy=0,
+   \c!unit=ex,
+   \c!style=,
+   \c!color=]
+
+\def\v!shiftup  {shiftup}
+\def\v!shiftdown{shiftdown}
+
+\defineshift [\v!shiftup]   [\c!method=0,\c!dy=-1,\c!unit=ex,\c!continue=\v!yes,\c!style=\txx,\c!color=]
+\defineshift [\v!shiftdown] [\c!method=1,\c!dy=.3,\c!unit=ex,\c!continue=\v!yes,\c!style=\txx,\c!color=]
+
+% we want these always so ...
+
+\expandafter\let\expandafter\shiftup   \csname\v!shiftup   \endcsname
+\expandafter\let\expandafter\shiftdown \csname\v!shiftdown \endcsname
+
 \protect \endinput
 
 % obsolete: