%D \module
%D   [       file=pack-mrl, % was pack-rul/core-rul,
%D        version=1998.10.16,
%D          title=\CONTEXT\ Packaging Macros,
%D       subtitle=More Rules,
%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 Packaging Macros / More Rules}

%D This module needs an overhaul.

\unprotect

%D \macros
%D   {setupblackrules,blackrule}
%D
%D The graphic capabilities of \TEX\ do not go beyond simple
%D filled rules, except of course when using specials. Let's
%D start with a warning: using this commands is far more slower
%D than using the \TEX\ primitives \type{\hrule} and
%D \type{\vrule}, but they save us some tokens. The
%D characteristics of these rule drawing command can be set by:
%D
%D \showsetup{setupblackrules}
%D
%D The simple command draws only one rule. Its optional
%D argument can be used to specify the dimensions. By setting
%D the width, height or depth to \type {max}, one gets the
%D natural dimensions.
%D
%D \showsetup{blackrule}

\installcorenamespace{blackrules}

\installsimplecommandhandler \??blackrules {blackrules}

\unexpanded\def\blackrule
  {\hbox\bgroup
   \doifnextoptionalelse\pack_black_rule_pickup\pack_black_rule_indeed}

\def\pack_black_rule_pickup[#1]%
  {\setupcurrentblackrules[#1]%
   \pack_black_rule_indeed}

\def\pack_black_rule_indeed
  {\edef\p_width {\directblackrulesparameter\c!width }%
   \edef\p_height{\directblackrulesparameter\c!height}%
   \edef\p_depth {\directblackrulesparameter\c!depth }%
   \ifx\p_height\v!max
     \setstrut
   \else\ifx\p_depth\v!max
     \setstrut
   \fi\fi
   \useblackrulesstyleandcolor\c!style\c!color
   \vrule
     \!!width \ifx\p_width \v!max\emwidth\else\p_width \fi
     \!!height\ifx\p_height\v!max\strutht\else\p_height\fi
     \!!depth \ifx\p_depth \v!max\strutdp\else\p_depth \fi
   \egroup}

\setupblackrules
  [\c!width=\emwidth,
   \c!height=\exheight,
   \c!depth=\zeropoint,
   \c!color=]

%D \macros
%D   {blackrules}
%D
%D One can call for a sequence of black rules, if needed
%D equally spaced over the given width.
%D
%D \showsetup{blackrules}
%D
%D The two alternative calls are therefore:
%D
%D \startbuffer
%D Tell me, is this according to the \blackrules[n=6]?
%D These \blackrules[alternativevariant=b,n=10,distance=.2em,width=4cm] are quite clear.
%D \stopbuffer
%D
%D \typebuffer
%D
%D or:
%D
%D \startlines
%D \getbuffer
%D \stoplines
%D
%D We could of course have implemented this macro using
%D \type{\leaders}, but this would probably have taken more
%D tokens.

\unexpanded\def\blackrules % probably never used
  {\hbox\bgroup
   \doifnextoptionalelse\pack_black_rules_pickup\pack_black_rules_indeed}

\def\pack_black_rules_pickup[#1]%
  {\setupcurrentblackrules[#1]%
   \pack_black_rules_indeed}

\def\pack_black_rules_indeed % no max handling here
  {\scratchwidth   \directblackrulesparameter\c!width
   \scratchheight  \directblackrulesparameter\c!height
   \scratchdepth   \directblackrulesparameter\c!depth
   \scratchdistance\directblackrulesparameter\c!distance
   \scratchcounter \directblackrulesparameter\c!n
   \edef\p_alternative{\blackrulesparameter\c!alternative}%
   \ifx\p_alternative\c!b
     \ifnum\scratchcounter=\plusone
       \scratchdistance\zeropoint
     \else
       \scratchwidth\dimexpr(\scratchwidth-\scratchcounter\scratchdistance+\scratchdistance)/\scratchcounter\relax
     \fi
   \fi
   \useblackrulesstyleandcolor\c!style\c!color
   \dorecurse\scratchcounter % a typical case of where we can use a simple loop
     {\vrule
        \!!width \scratchwidth
        \!!height\scratchheight
        \!!depth \scratchdepth
      \hskip\scratchdistance}%
   \unskip
   \egroup}

\setupblackrules
  [\c!n=3,
   \c!alternative=\c!a,
   \c!distance=.25\emwidth,
   \c!color=]

%D Marginrules will either become obsolete or be redone.

%D The next commands can be used to draw margin rules. We
%D support two methods: \marginrule{one for in||line use} and
%D one that acts on a paragraph. Drawing a margin rule is
%D rather straightforward because we can use the commands that
%D put text in the margin.

\def\dodrawmarginrule
  {\setbox\scratchbox\hbox
     {\vrule\!!depth\strutdepth\!!height\strutheight\!!width\@@karulethickness}%
   \smashbox\scratchbox % no \vsmash !!!
   \box\scratchbox}

\def\drawmarginrule
  {\strut\inleft{\dodrawmarginrule}}

%D \macros
%D   {marginrule}
%D
%D The first method gobbles words and simply puts a bar in the
%D margin. This method is not entirely robust.
%D
%D \showsetup{marginrule}

\definecomplexorsimple\marginrule

\def\simplemarginrule
  {\let\processword\drawmarginrule
   \processwords}

\def\complexmarginrule[#1]%
  {\ifnum#1<\@@kalevel\relax \else
     \def\@@kadefaultwidth{#1}%
     \expandafter\simplemarginrule
   \fi}

%D We need an auxiliary variable

\def\@@kadefaultwidth{1}

%D \macros
%D   {setupmarginrules}
%D
%D This macro definitions show us that we can pass an optional
%D level, which is matched against the previous set one. The
%D level can be set up with
%D
%D \showsetup{setupmarginrules}

\unexpanded\def\setupmarginrules
  {\dodoubleargument\getparameters[\??ka]}

%D \macros
%D   {startmarginrule}
%D
%D The second method collects text and reformats it afterwards,
%D using the shapebox macros. We prevent local margin rules.
%D
%D \showsetup{startmarginrule}

\definecomplexorsimple\startmarginrule

\def\simplestartmarginrule
  {\bgroup
   \let\drawmarginrule\relax
   \let\stopmarginrule\dostopmarginrule
   \beginofshapebox}

\def\complexstartmarginrule[#1]%
  {\bgroup
   \let\drawmarginrule\relax
   \ifnum#1<\@@kalevel\relax
     \let\stopmarginrule\egroup
   \else
     \def\@@kadefaultwidth{#1}%
     \let\stopmarginrule\dostopmarginrule
     \expandafter\beginofshapebox
   \fi}

\def\dostopmarginrule
  {\endofshapebox
   \reshapebox
     {\hbox{\inleftmargin{\dodrawmarginrule}\box\shapebox}}%
   \flushshapebox
   \egroup}

%D \startbuffer
%D \setupmarginrules[level=5]
%D
%D \startmarginrule[1]
%D First we set the level at~5. Next we typeset this first
%D paragraph as a level~1 one. As expected no rule show up.
%D \stopmarginrule
%D
%D \startmarginrule[5]
%D The second paragraph is a level~5 one. As we can see here,
%D the marginal rule gets a width according to its level.
%D \stopmarginrule
%D
%D \startmarginrule[8]
%D It will of course be no surprise that this third paragraph
%D has a even thicker margin rule. This behavior can be
%D overruled by specifying the width explictly.
%D \stopmarginrule
%D \stopbuffer
%D
%D In next example we show most features. Watch the rule
%D thickness adapting itself to the level.
%D
%D \startexample
%D \getbuffer
%D \stopexample
%D
%D We just said:
%D
%D \typebuffer

%D \macros
%D   {vl, hl}
%D
%D The command \type{\vl} draws a vertical rule \vl\ with strut
%D dimensions, multiplied with the factor specified in the
%D optional argument. The height and depth are clipped \vl[3]
%D to the baselinedistance. Its horizontal counterpart
%D \type{\hl} draws a horizontal rule \hl\ with a width of 1em,
%D multiplied with the optional factor. The horizontal rule is
%D drawn on top of the baseline.
%D
%D \showsetup{vl}
%D \showsetup{hl}

\unexpanded\def\dovlwdhtdp#1#2#3% used elsewhere
  {\bgroup
   \setbox\scratchbox\hbox
     {\vrule
        \!!width #1\linewidth
        \!!height#2\strutht
        \!!depth #3\strutdp}%
   \dp\scratchbox\strutdp
   \ht\scratchbox\strutht
   \box\scratchbox
   \egroup}

\def\complexvl[#1]%
  {\dovlwdhtdp\plusone{#1}{#1}}

\def\complexhl[#1]%
  {\hbox
     {\vrule
        \!!width #1\emwidth
        \!!height\linewidth
        \!!depth \zeropoint}}

\definecomplexorsimple\vl \def\simplevl{\complexvl[\plusone]}
\definecomplexorsimple\hl \def\simplehl{\complexhl[\plusone]}

%D \macros
%D   {hairline, thinrule, thinrules, setupthinrules}
%D
%D Drawing thin lines can of course easily be accomplished by
%D the \TEX\ primitives \type{\hrule} and \type{\vrule}. The
%D next few macros however free us from some specifications.
%D
%D \startbuffer
%D some text
%D
%D \hairline
%D
%D some more text
%D
%D \thinrule
%D
%D more and more text
%D
%D hi \thinrule\ there
%D
%D and then the final text
%D \stopbuffer
%D
%D \typebuffer
%D
%D becomes
%D
%D \startexample
%D \getbuffer
%D \stopexample
%D
%D So we've got
%D
%D \showsetup{hairline}
%D \showsetup{thinrule}
%D
%D Both can be set up with:
%D
%D \showsetup{setupthinrules}
%D
%D We also have
%D
%D \showsetup{thinrules}
%D
%D which looks like: \thinrules[n=2]

\newconstant\ruletype

\def\thinrule
  {\strut
   \bgroup
   \ruletype\plusone
   \processaction
     [\@@dlalternative]
     [ \v!a=>\ruletype\zerocount,% no line
      %\v!b=>\ruletype\plusone  ,% height/depth
       \v!c=>\ruletype\plustwo  ,% topheight/botdepth
      %  11=>\ruletype\plusone  ,% fallback for  backgrounds
          0=>\ruletype\zerocount,% compatible with backgrounds
      %   1=>\ruletype\plusone  ,% compatible with backgrounds
          2=>\ruletype\plustwo  ]% compatible with backgrounds
   \doifsomething\@@dlrulethickness
     {\linewidth\@@dlrulethickness}%
   \ifdim\linewidth=\zeropoint
     \ruletype\zerocount
   \else
     \doifnot\@@dlframe\v!on{\ruletype\zerocount}%
   \fi
   \ifnum\ruletype=\plusone
     \doif\@@dlheight\v!max{\let\@@dlheight\!!plusone}%
     \doif\@@dldepth \v!max{\let\@@dldepth \!!plusone}%
   \else
     \let\@@dlheight\!!plusone
     \let\@@dldepth\!!plusone
   \fi
   \freezedimensionwithunit\@@dlheight\strutht
   \freezedimensionwithunit\@@dldepth\strutdp
   \divide\linewidth \plustwo
   \doifelse\@@dlbackground\v!color
     {\startcolor[\@@dlbackgroundcolor]%
      \ifnum\ruletype=\plustwo % prevent overshoot due to rounding
        \leaders
          \hrule
            \!!height\dimexpr\@@dlheight-.5\linewidth\relax
            \!!depth \dimexpr\@@dldepth -.5\linewidth\relax
          \hfill
      \else
        \leaders
          \hrule
            \!!height\@@dlheight
            \!!depth \@@dldepth
          \hfill
      \fi
      \stopcolor
      \ifcase\ruletype
        % no rule
      \or
        \startcolor[\@@dlcolor]%
        \hfillneg
        \leaders\hrule\!!height\linewidth\!!depth\linewidth\hfill
        \stopcolor
      \or
        \startcolor[\@@dlcolor]%
        \hfillneg\leaders\hrule\!!height\dimexpr-\@@dldepth+\linewidth\relax\!!depth\@@dldepth\hfill
        \hfillneg\leaders\hrule\!!height\@@dlheight\!!depth\dimexpr-\@@dlheight+\linewidth\relax\hfill
        \stopcolor
      \fi}
     {\ifcase\ruletype \else
        \startcolor[\@@dlcolor]%
        \leaders\hrule\!!height\@@dlheight\!!depth\@@dldepth\hfill
        \stopcolor
      \fi}%
   \strut
   \carryoverpar\egroup}

\def\hairline
  {\endgraf
   \thinrule
   \endgraf}

\def\dosetupthinrules[#1]%
  {\getparameters[\??dl][#1]}

\unexpanded\def\setupthinrules
  {\dosingleargument\dosetupthinrules}

\def\dothinrules[#1]%
  {\bgroup
   \dosetupthinrules[#1]%
   \@@dlbefore
   \assignvalue\@@dlinterlinespace\@@dlinterlinespace{1.0}{1.5}{2.0}%
   \spacing\@@dlinterlinespace
   \dorecurse\@@dln
     {\ifnum\recurselevel=\@@dln \dothinrulesnobreak \else
      \ifnum\recurselevel=2      \dothinrulesnobreak \fi\fi
                                 \thinrule
      \ifnum\recurselevel<\@@dln\relax
        % test needed, else messed up whitespace
        \ifx\@@dlinbetween\empty
          \softbreak
        \else
          \endgraf
          \nowhitespace
          \@@dlinbetween
        \fi
      \fi}%
   \doifelsenothing\@@dlafter
     {\carryoverpar\egroup}
     {\@@dlafter\egroup}}

\def\thinrules
  {\dosingleempty\dothinrules}

%D A couple of examples are given below.
%D
%D \startbuffer
%D \setupthinrules[n=3,inbetween=,color=gray]
%D
%D test test \thinrules\ test test \par
%D test test \thinrules [color=green] test test \par
%D test test \thinrules [height=max, depth=max] test test \par
%D
%D \setupthinrules[height=.9,depth=.9]
%D
%D test test \thinrules\ test test \par
%D test test \thinrules [alternativevariant=b] test test \par
%D test test \thinrules [alternativevariant=c] test test \par
%D test test \thinrules [alternativevariant=c,inbetween=\vskip2ex] test test \par
%D \stopbuffer
%D
%D \typebuffer {\getbuffer}
%D
%D There are a couple of alternative ways to visualize rules
%D using backgrounds. At first sight these may look strange,
%D but they make sense in educational settings. The
%D alternatives are more or less compatible with the more
%D advanced \METAPOST\ based implementation.
%D
%D \startbuffer[a]
%D \setupthinrules
%D   [n=2,
%D    backgroundcolor=gray  ,
%D    rulethickness=1pt,
%D    colorkleur=donkerblauw,
%D    after=\blank,
%D    before=\blank]
%D \stopbuffer
%D
%D \typebuffer[a]
%D
%D \startbuffer[b]
%D \thinrules[alternativevariant=a]
%D \thinrules[alternativevariant=b]
%D \thinrules[alternativevariant=c]
%D \stopbuffer
%D
%D \typebuffer[b] \getbuffer[a,b]
%D
%D \startbuffer[b]
%D \thinrules[alternativevariant=a,background=color]
%D \thinrules[alternativevariant=b,background=color]
%D \thinrules[alternativevariant=c,background=color]
%D \stopbuffer
%D
%D \typebuffer[b] \getbuffer[a,b]
%D
%D \startbuffer[b]
%D \thinrules[alternativevariant=a,height=.8,depth=.8,background=color]
%D \thinrules[alternativevariant=b,height=.8,depth=.8,background=color]
%D \thinrules[alternativevariant=c,height=.8,depth=.8,background=color]
%D \stopbuffer
%D
%D \typebuffer[b] \getbuffer[a,b]

%D \macros
%D   {optimizethinrules}
%D
%D By saying \type {\thinrulestrue} or \type {-false}, we
%D can influence the way dangling lines are handled.

\newif\ifoptimizethinrules \optimizethinrulestrue

\def\dothinrulesnobreak
  {\ifoptimizethinrules\penalty500\fi}

%D \macros
%D   {textrule, starttextrule, setuptextrules}
%D
%D Putting rules before and after a paragraph is very space
%D sensitive, but the next command handles that quite well. It
%D comes in two disguises:
%D
%D \startbuffer
%D \textrule[top]{fragments}
%D   \input reich
%D \textrule
%D \stopbuffer
%D
%D \start \typebuffer \getbuffer \stop
%D
%D \startbuffer
%D \setuptextrules
%D   [width=90pt,distance=12pt,rulecolor=blue,
%D    bodyfont=small,style=\sc,color=red]
%D
%D \starttextrule{Ship Building Tools}
%D   \nl \setuptolerance[tolerant] \input materie
%D \stoptextrule
%D \stopbuffer
%D
%D \bgroup \typebuffer \getbuffer \egroup
%D
%D \startbuffer
%D \setuptextrules
%D   [location=inmargin,
%D    bodyfont=small,style=slantedbold]
%D
%D \starttextrule{wonderful}
%D   \input tufte
%D \stoptextrule
%D \stopbuffer
%D
%D \bgroup \typebuffer \getbuffer \egroup
%D
%D The formal definition of these commands is:
%D
%D \showsetup{textrule}
%D \showsetup{starttextrule}
%D \showsetup{setuptextrules}
%D
%D The implementation looks a bit complicated due to the
%D optional arguments.

\unexpanded\def\setuptextrules
  {\dodoubleargument\getparameters[\??tl]}

\def\complextextrule[#1]% if needed we can make it installable
  {\let\next\dobottomtextrule
   \processaction
     [#1]
     [    \v!top=>\let\next\dotoptextrule,
       \v!middle=>\let\next\domiddletextrule,
       \v!bottom=>\let\next\dobottomtextrule]%
   \dosinglegroupempty\next}

\definecomplexorsimple\textrule

\def\simpletextrule
  {\dosinglegroupempty\dounknowntextrule}

\def\docomplextextrule#1%
  {\bgroup
   \advance\hsize\dimexpr-\rightskip-\leftskip\relax
   \setbox\scratchbox\hbox to \hsize
     {\dimen4\dimexpr .5ex+.5\linewidth\relax
      \dimen6\dimexpr-.5ex+.5\linewidth\relax
      \doifsomething{#1}
        {\doifelse\@@tllocation\v!inmargin
           {\llap
              {\dousestyleparameter\@@tlstyle
               \dousecolorparameter\@@tlcolor
               #1%
               \hskip\leftmargindistance}}
           {\color[\@@tlrulecolor]
              {\vrule\!!height\dimen4\!!depth\dimen6\!!width\@@tlwidth}%
            \hbox spread 2\dimexpr\@@tldistance\relax
              {\hss
               \dousestyleparameter\@@tlstyle
               \dousecolorparameter\@@tlcolor
               \strut#1%
               \hss}}}%
      \color[\@@tlrulecolor]
        {\leaders\hrule\!!height\dimen4\!!depth\dimen6\hfill}}%
   \ht\scratchbox\strutht
   \dp\scratchbox\strutdp
   \noindent\box\scratchbox
%\nobreak\verticalstrut\kern-\struttotal
% evt \witruimte
   \egroup}

\def\dotoptextrule#1%
  {\page[\v!preference] % interferes
   %\whitespace % no
   \@@tlbefore
   \docomplextextrule{#1}%
% todo, option: \doifnothing{#1}{\ruledvskip-.5ex}
   \nowhitespace
   \@@tlinbetween
   \endgraf}

\def\dodobottomtextrule#1#2%
  {\ifhmode
     \endgraf
   \fi
   \dimen0\strutdp
   \ifdim\prevdepth>\strutdp\else % was <\strutdp
     \ifdim\prevdepth>\zeropoint
       \advance\dimen0 -\prevdepth
     \fi
   \fi
   \advance\dimen0 .5ex
   \vskip\dimen0
% ==
%    \vskip\dimexpr \strutdp + .5ex
%       \ifdim\prevdepth>\strutdp\else\ifdim\prevdepth>\zeropoint-\prevdepth\fi\fi\relax
%
   \@@tlinbetween
   \doifelsenothing{#2}
     {\bgroup
      \advance\hsize\dimexpr-\rightskip-\leftskip\relax
      \nointerlineskip
      \moveleft-\leftskip\vbox
        {\color[\@@tlrulecolor]
           {\hrule\!!depth\linewidth\!!height\zeropoint\!!width\hsize}}%
      \egroup}
     {\docomplextextrule{#2}}%
   \ifvmode\prevdepth\zeropoint\fi
   #1%
   \page[\v!preference]}

\def\dobottomtextrule
  {\dodobottomtextrule\@@tlafter}

\def\domiddletextrule
  {\dodobottomtextrule\@@tlinbetween}

\def\dounknowntextrule
  {\iffirstargument
     \@EA\dotoptextrule
   \else
     \@EA\dobottomtextrule\@EA\empty
   \fi}

%D The grouped commands also supports bodyfont switching:

\unexpanded\def\starttextrule#1%
  {\bgroup
   \def\dounknowntextrule{\domiddletextrule}
   \dotoptextrule{#1}
   \bgroup
   \doifsomething\@@tlbodyfont{\switchtobodyfont[\@@tlbodyfont]}}

\unexpanded\def\stoptextrule
  {\par
   \egroup
   \dobottomtextrule\empty
   \egroup}

%D \macros
%D   {fillinrules, setupfillinrules}
%D
%D The next few commands do not really deserve a place in a
%D core module, because they deal with specific typography.
%D Nevertheless I decided to make them part of the core,
%D because they permit us to make questionaires. Let's start
%D with some examples.
%D
%D \fillinrules[n=2,width=fit]{first}
%D \fillinrules[n=2,width=broad]{first}
%D \fillinrules[n=2,width=3cm]{first}
%D \fillinrules[n=2,width=3cm,distance=.5em,separator=:]{first}
%D \fillinrules[n=2]{first}{last}
%D \fillintext{first}{last} \input reich \par
%D
%D The main command is \type{\fillinrules}. This command takes
%D one and an optional second argument and sets a paragraph with
%D empty visualized lines.
%D
%D \showsetup{fillinrules}
%D \showsetup{setupfillinrules}

\unexpanded\def\setupfillinrules
  {\dodoubleargument\getparameters[\??il]}

\definecomplexorsimpleempty\fillinrules

\def\complexfillinrules[#1]%
  {\def\docomplexfillinrules##1##2%
     {\dodocomplexfillinrules[#1]{##1}{##2}{\thinrules
        [\c!n=\@@iln,\c!interlinespace=\@@ilinterlinespace,\c!before=,\c!after=]}}%
   \dodoublegroupempty\docomplexfillinrules}

\def\dodocomplexfillinrules[#1]#2#3#4%
  {\endgraf
   \@@ilbefore
   \begingroup
   \setupfillinrules[#1]%
   \noindent
   \doifsomething{#2}
     {\doifelse\@@ilwidth\v!fit
        {\let\@@ildistance\!!zeropoint
         \hbox}
        {\doifelse\@@ilwidth\v!broad
           {\hbox}
           {\hbox to \@@ilwidth}}%
        \bgroup
          \dousestyleparameter\@@ilstyle
          \dousecolorparameter\@@ilcolor
          \strut#2\hfill\@@ilseparator\hskip\@@ildistance
        \egroup}%
  %\hangindent=\wd0\relax % tzt hang=yes,n
  %\parindent=\hangindent
  %\box0\relax
   \setupwhitespace[\v!big]%
   \ignorespaces
   #4%
   \doifsomething{#3}
     {\kern\@@ildistance
      \dousestyleparameter\@@ilstyle
      \dousecolorparameter\@@ilcolor
      #3\strut}%
   \endgroup
   \endgraf
   \@@ilafter}

%D \macros
%D   {fillintext}
%D
%D To provide compatible layouts when texts and lines are
%D mixed, one can typeset a paragraph by using the command
%D \type{\fillintext}.
%D
%D \showsetup{fillintext}

\definecomplexorsimpleempty\fillintext

\def\complexfillintext[#1]% rather rough, using an \unhbox is suboptimal
  {\def\docomplexfillintext##1##2%
     {\dowithnextbox
        {\dodocomplexfillinrules[#1]{##1}{\hfill##2}{\unhbox\nextbox\unskip}}%
      \hbox\bgroup\let\par\egroup\ignorespaces}%
   \dodoublegroupempty\docomplexfillintext}

%D \macros
%D   {fillinline, setupfillinlines}
%D
%D Another member of the family takes care of putting a (often
%D small) rule after a piece of text, like
%D
%D \startbuffer
%D \fillinline \input reich \par
%D \fillinline[margin=0cm] \input reich \par
%D \stopbuffer
%D
%D \startexample
%D \getbuffer
%D \stopexample
%D
%D which was typeset by saying:
%D
%D \typebuffer
%D
%D The two commands that take care of this are:
%D
%D \showsetup{fillinline}
%D \showsetup{setupfillinlines}

\unexpanded\def\setupfillinlines
  {\dodoubleargument\getparameters[\??iv]}

\definecomplexorsimpleempty\fillinline

\def\complexfillinline[#1]%
  {%\endgraf % interferes with \definedescription cum suis
   \@@ivbefore
   \begingroup
   \setupfillinlines[#1]%
   \advance\rightskip \@@ivmargin
   \parfillskip\zeropoint
   \def\par % very dangerous
     {\let\par\endgraf % -)
      \ifhmode\unskip\hfill\fi
      \scratchdimen\dimexpr\@@ivwidth-\@@ivdistance\relax
      \ifdim\scratchdimen>\@@ivmargin\else\expandafter\rlap\fi
        {\kern\@@ivdistance
         \vrule
           \!!width   \scratchdimen
           \!!height.5\linewidth
           \!!depth .5\linewidth}%
      \endgraf % !
      \endgroup
      \endgraf % !
      \@@ilafter}}

%D Will move up:

\setupmarginrules
  [\c!level=0,
   \c!rulethickness=\@@kadefaultwidth\linewidth]

\setupthinrules
  [\c!interlinespace=\v!small,
   \c!n=3,
   \c!before=,
   \c!inbetween={\blank[\v!white]},
   \c!after=,
   \c!color=,
   \c!height=.5\linewidth,
   \c!depth=.5\linewidth,
   \c!frame=\v!on, % compatible with textbackgrounds
   \c!alternative=\v!b,
   \c!backgroundcolor=,
   \c!background=,
   \c!rulethickness=]

\setuptextrules
  [\c!location=\v!left,
   \c!before=\blank,
   \c!after=\blank,
   \c!inbetween=,
   \c!width=2em,
   \c!style=\v!bold,
   \c!color=,
   \c!rulecolor=,
   \c!bodyfont=,
   \c!distance=.5em]

\setupfillinrules
  [\c!width=\v!broad,
   \c!distance=1em,
   \c!before=\blank,
   \c!after=\blank,
   \c!n=1,
   \c!interlinespace=\v!small,
   \c!separator=,
   \c!style=\v!normal,
   \c!color=]

\setupfillinlines
  [\c!width=3cm,
   \c!margin=\@@ivwidth,
   \c!distance=1em,
   \c!before=\blank,
   \c!after=\blank]

\protect \endinput