summaryrefslogtreecommitdiff
path: root/Master/texmf-dist/tex/context/base/mkxl/anch-bck.mklx
diff options
context:
space:
mode:
Diffstat (limited to 'Master/texmf-dist/tex/context/base/mkxl/anch-bck.mklx')
-rw-r--r--Master/texmf-dist/tex/context/base/mkxl/anch-bck.mklx775
1 files changed, 775 insertions, 0 deletions
diff --git a/Master/texmf-dist/tex/context/base/mkxl/anch-bck.mklx b/Master/texmf-dist/tex/context/base/mkxl/anch-bck.mklx
new file mode 100644
index 00000000000..36416c93da3
--- /dev/null
+++ b/Master/texmf-dist/tex/context/base/mkxl/anch-bck.mklx
@@ -0,0 +1,775 @@
+%D \module
+%D [ file=anch-bck, % moved from anch-pgr (1999.08.01)
+%D version=2011.12.19,
+%D title=\CONTEXT\ Anchoring 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.
+
+% when tested for a while: \MPgetmultipars -> getmultipars
+% when tested for a while: \MPvar -> mpvar
+
+\writestatus{loading}{ConTeXt Anchoring Macros / Backgrounds}
+
+%D This module is quite okay but at some point I might add methods that use
+%D attributes although not too much is to be expected, apart from better anchoring.
+%D In fact better anchoring can be done independent of that.
+
+\unprotect
+
+% This might be overloaded later on:
+
+% \defineoverlay[\v!text-2][\positionoverlay{\v!text-2}]
+% \defineoverlay[\v!text-1][\positionoverlay{\v!text-1}]
+% \defineoverlay[\v!text+1][\positionoverlay{\v!text+1}]
+% \defineoverlay[\v!text+2][\positionoverlay{\v!text+2}]
+
+% Paragraph positions:
+
+\newcount\c_anch_backgrounds_text_n
+
+\def\v_anch_backgrounds_text_current {tbg:0}
+\def\v_anch_backgrounds_anchor_current_b{b:\v_anch_backgrounds_text_current}
+\def\v_anch_backgrounds_anchor_current_e{e:\v_anch_backgrounds_text_current}
+
+\def\anch_backgrounds_text_initialize_next
+ {\global\advance\c_anch_backgrounds_text_n\plusone
+ \edef\v_anch_backgrounds_text_current{tbg:\number\c_anch_backgrounds_text_n}}
+
+% The first position can be used in the middle of a paragraph in which case we're
+% too late with initializing par positions. Therefore we check if positions are
+% used at all.
+%
+% tricky: we need to catch newly set! otherwise an old run can have positions
+
+\protected\def\anch_backgrounds_text_initialize
+ {\doifelsepositionsused\enableparpositions\donothing
+ \glet\anch_backgrounds_text_initialize\relax}
+
+\appendtoks
+ \anch_backgrounds_text_initialize
+\to \everystarttext
+
+%D Some MP
+
+\newcount\MPparcounter
+
+\permanent\def\MPself {\MPvar{self}}
+\permanent\def\MPbself {b:\MPvar{self}}
+\permanent\def\MPeself {e:\MPvar{self}}
+\permanent\def\MPparanchor{p:\number\MPparcounter}
+
+% \carryoverpar is needed for left/right floats
+
+% \definetextbackground[more][state=start,backgroundcolor=red] % location=paragraph
+% \definetextbackground[test][state=start,backgroundcolor=green]
+%
+% \page \placefigure[left]{}{}
+%
+% \starttextbackground[test]
+% \readfile{ward}{}{}
+% \starttextbackground[more]
+% \readfile{ward}{}{}
+% \stoptextbackground
+% \readfile{ward}{}{}
+% \stoptextbackground
+%
+% \page \placefigure[right]{}{}
+%
+% \starttextbackground[test]
+% \readfile{ward}{}{}
+% \starttextbackground[more]
+% \readfile{ward}{}{}
+% \stoptextbackground
+% \readfile{ward}{}{}
+% \stoptextbackground
+
+\newcount\c_anch_backgrounds_text_level
+
+\installcorenamespace{textbackground}
+\installcorenamespace{textbackgroundlevel}
+
+\installcommandhandler \??textbackground {textbackground} \??textbackground
+
+\appendtoks
+ \frozen\instance\setuevalue{\currenttextbackground}{\groupedcommand{\starttextbackground[\currenttextbackground]}{\stoptextbackground}}%
+ \frozen\instance\setuevalue{\e!start\currenttextbackground}{\starttextbackground[\currenttextbackground]}%
+ \frozen\instance\setuevalue{\e!stop \currenttextbackground}{\stoptextbackground}%
+\to \everydefinetextbackground
+
+\newconstant \c_anch_backgrounds_pos_state
+\newconditional\c_anch_backgrounds_pos_no_shape
+
+\def\anch_backgrounds_bpos
+ {\ifconditional\c_anch_backgrounds_pos_no_shape
+ \bposkind\v_anch_backgrounds_text_current\plusthree
+ \else
+ \bposkind\v_anch_backgrounds_text_current\c_anch_backgrounds_pos_state
+ \fi}
+
+\def\anch_backgrounds_epos
+ {\ifconditional\c_anch_backgrounds_pos_no_shape
+ \eposkind\v_anch_backgrounds_text_current\plusthree
+ \else
+ \eposkind\v_anch_backgrounds_text_current\c_anch_backgrounds_pos_state
+ \fi}
+
+% \permanent\tolerant\protected\def\starttextbackground[#tag]#spacer[#settings]%
+% {\begingroup
+% \advance\c_anch_backgrounds_text_level\plusone
+% \def\currenttextbackground{#tag}%
+% \anch_backgrounds_text_initialize_next
+% \ifparameter#settings\or
+% \setupcurrenttextbackground[#settings]%
+% \fi
+% \doifelse{\textbackgroundparameter\c!state}\v!start
+% \anch_backgrounds_text_preset_yes
+% \anch_backgrounds_text_preset_nop
+% \anch_backgrounds_text_start_indeed}
+
+% ugly hack to register usage
+
+\newcount \c_anch_backgrounds_text_count
+\newcount \c_anch_backgrounds_text_check
+\newconstant\c_anch_backgrounds_text_state
+
+\permanent\tolerant\protected\def\starttextbackground[#tag]#spacer[#settings]%
+ {\begingroup
+ \global\advance\c_anch_backgrounds_text_count\plusone
+ \advance\c_anch_backgrounds_text_level\plusone
+ \def\currenttextbackground{#tag}%
+ \anch_backgrounds_text_initialize_next
+ \ifparameter#settings\or
+ \setupcurrenttextbackground[#settings]%
+ \fi
+ \doifelse{\textbackgroundparameter\c!state}\v!start
+ \anch_backgrounds_text_preset_yes
+ \anch_backgrounds_text_preset_nop
+ \anch_backgrounds_text_start_indeed}
+
+\def\anch_backgrounds_text_level_start
+ {\c_anch_backgrounds_text_check\c_anch_backgrounds_text_count}
+
+\def\anch_backgrounds_text_level_stop
+ {\c_anch_backgrounds_text_state
+ \ifnum\c_anch_backgrounds_text_count>\c_anch_backgrounds_text_check
+ \plusone
+ \else
+ \zerocount
+ \fi}
+
+% todo \backgroundvariable\c!variant
+
+% criterium determines when we fall back on text
+% always is always forcing paragraphs
+
+\let\anch_backgrounds_text_start_indeed\relax
+\let\anch_backgrounds_text_stop_indeed \relax
+
+\setvalue{\??textbackgroundlevel\v!text}%
+ {\let\anch_backgrounds_text_start_indeed\anch_backgrounds_text_start_txt
+ \let\anch_backgrounds_text_stop_indeed \anch_backgrounds_text_stop_txt}
+
+\setvalue{\??textbackgroundlevel\v!paragraph}%
+ {\ifnum\c_anch_backgrounds_text_level>\textbackgroundparameter\c!criterium\relax
+ \let\anch_backgrounds_text_start_indeed\anch_backgrounds_text_start_txt
+ \let\anch_backgrounds_text_stop_indeed \anch_backgrounds_text_stop_txt
+ \else
+ \let\anch_backgrounds_text_start_indeed\anch_backgrounds_text_start_par
+ \let\anch_backgrounds_text_stop_indeed \anch_backgrounds_text_stop_par
+ \fi}
+
+\setvalue{\??textbackgroundlevel\v!always}%
+ {\let\anch_backgrounds_text_start_indeed\anch_backgrounds_text_start_par
+ \let\anch_backgrounds_text_stop_indeed \anch_backgrounds_text_stop_par}
+
+\setvalue{\??textbackgroundlevel\v!none}%
+ {\anch_backgrounds_text_preset_nop}
+
+\def\anch_backgrounds_text_preset_nop
+ {\let\anch_backgrounds_text_start_indeed\relax
+ \let\anch_backgrounds_text_stop_indeed \relax}
+
+\def\anch_backgrounds_text_preset_yes
+ {\anch_backgrounds_text_preset_nop
+ \csname\??textbackgroundlevel\textbackgroundparameter\c!location\endcsname
+ \edef\p_anch_backgrounds_text_frame {\textbackgroundparameter\c!frame}%
+ \edef\p_anch_backgrounds_text_corner {\textbackgroundparameter\c!corner}%
+ \edef\p_anch_backgrounds_text_background{\textbackgroundparameter\c!background}%
+ \ifx\p_anch_backgrounds_text_frame\v!on
+ \ifx\p_anch_backgrounds_text_corner\v!round
+ \let\p_anch_backgrounds_text_frame\!!plustwo
+ \else
+ \let\p_anch_backgrounds_text_frame\!!plusone
+ \fi
+ \else
+ \let\p_anch_backgrounds_text_frame\!!zerocount
+ \fi
+ \ifx\p_anch_backgrounds_text_background\v!color
+ \let\p_anch_backgrounds_text_background\!!plusone
+ \else
+ \let\p_anch_backgrounds_text_background\!!zerocount
+ \fi
+ \startpositionoverlay{\textbackgroundoverlay{\textbackgroundparameter\c!level}}%
+ \anch_backgrounds_text_meta_graphic % gets expanded directly
+ \stoppositionoverlay}
+
+\def\anch_backgrounds_text_meta_graphic
+ {\normalexpanded
+ {\setMPpositiongraphicrange % needs to be optimized
+ {\v_anch_backgrounds_anchor_current_b}%
+ {\v_anch_backgrounds_anchor_current_e}%
+ {\textbackgroundparameter\c!method}%
+ {self=\v_anch_backgrounds_text_current,
+ mp=\textbackgroundparameter\c!mp,
+ gridtype=\textbackgroundparameter\c!alternative,
+ filltype=\p_anch_backgrounds_text_background,
+ linetype=\p_anch_backgrounds_text_frame,
+ dashtype=\textbackgroundparameter\c!dash,
+ gridcolor=\textbackgroundparameter\c!framecolor,
+ linecolor=\textbackgroundparameter\c!framecolor,
+ lineoffset=\textbackgroundparameter\c!frameoffset,
+ fillcolor=\textbackgroundparameter\c!backgroundcolor,
+ filloffset=\textbackgroundparameter\c!backgroundoffset,
+ gridwidth=\textbackgroundparameter\c!rulethickness,
+ gridshift=\textbackgroundparameter\c!voffset,
+ linewidth=\textbackgroundparameter\c!rulethickness,
+ lineradius=\textbackgroundparameter\c!radius}}}
+
+\permanent\protected\def\stoptextbackground
+ {\anch_backgrounds_text_stop_indeed
+ \carryoverpar\endgroup} % why doesn't this work ?
+
+\permanent\protected\def\starttextbackgroundmanual
+ {\begingroup
+ \c_anch_backgrounds_pos_state\plusone
+ \usetextbackgroundstyleandcolor\c!style\c!color
+ \anch_backgrounds_bpos}
+
+\permanent\protected\def\stoptextbackgroundmanual
+ {\anch_backgrounds_epos
+ \carryoverpar\endgroup}
+
+\def\anch_backgrounds_text_start_txt
+ {\ifvmode \dontleavehmode \fi
+ \begingroup
+ \c_anch_backgrounds_pos_state\plusone
+ \usetextbackgroundstyleandcolor\c!style\c!color
+ \anch_backgrounds_bpos}
+
+\def\anch_backgrounds_text_stop_txt
+ {\anch_backgrounds_epos
+ \carryoverpar\endgroup}
+
+\newskip\textbackgroundskip
+
+% maybe we should have a resetter for such compensation struts
+
+\def\anch_backgrounds_reset_attributes
+ {\scratchcounter\c_attr_snapmethod
+ \resetallattributes % \c_attr_linenumber\attributeunsetvalue
+ \c_attr_snapmethod\scratchcounter}
+
+\def\anch_backgrounds_text_start_par % beware .. background shapes
+ {\endgraf % new
+ \textbackgroundparameter\c!before
+ \begingroup
+ \c_anch_backgrounds_pos_state\plustwo
+ \begingroup
+ \anch_backgrounds_reset_attributes
+ \noindent
+ \ifgridsnapping
+ \spac_helpers_assign_skip\textbackgroundskip{\textbackgroundparameter\c!topoffset}%
+ \ifdim\textbackgroundskip>\zeropoint
+ \struttedbox % not always ok (e.g. setups)
+ {\hpack{\raise\textbackgroundskip\hpack{\anch_backgrounds_bpos}}}%
+ \else
+ \anch_backgrounds_bpos
+ \fi
+ \else
+ \anch_backgrounds_bpos
+ \fi
+ \endgraf % we need a vertical nobreak - 29/06/2004
+ \endgroup
+ \nobreak
+ \vskip-\lineheight
+ \nobreak
+ \ifgridsnapping \else
+ \spac_helpers_assign_skip\textbackgroundskip{\textbackgroundparameter\c!topoffset}%
+ \ifdim\textbackgroundskip>\zeropoint
+ \kern\textbackgroundskip\nobreak
+ \fi
+ \fi
+ \dosetleftskipadaption{\textbackgroundparameter\c!leftoffset}%
+ \advance\leftskip\leftskipadaption
+ \dosetleftskipadaption{\textbackgroundparameter\c!rightoffset}%
+ \advance\rightskip\leftskipadaption
+ % new
+ \dosetraggedcommand{\textbackgroundparameter\c!align}%
+ \raggedcommand
+ %
+ \usetextbackgroundstyleandcolor\c!style\c!color
+ \nowhitespace
+ \seteffectivehsize
+ \doinhibitblank % \blank[\v!disable]% new
+ \par}
+
+\def\anch_backgrounds_text_stop_par
+ {\par
+ \removelastskip % new
+ \spac_helpers_assign_skip\textbackgroundskip{\textbackgroundparameter\c!bottomoffset}%
+ \ifdim\lastskip>\zeropoint
+ \advance\textbackgroundskip-\lastskip
+ \fi
+ \ifgridsnapping
+ \orelse\ifdim\textbackgroundskip>\zeropoint
+ \kern\textbackgroundskip\nobreak
+ \fi
+ \nobreak
+ \vskip-\dimexpr\lineheight+\parskip\relax % problem: we loose the hangindent
+ \nobreak
+ \endgroup
+ \begingroup
+ \forgeteverypar % NOT REALLY NEEDED, SAVES HASH/MEM
+ \anch_backgrounds_reset_attributes
+ \nobreak \noindent \strut \hfill \kern\zeropoint
+ % so far
+ \spac_helpers_assign_skip\textbackgroundskip{\textbackgroundparameter\c!bottomoffset}%
+ \ifgridsnapping % experimental, pascal (todo: topoffset in same way)
+ \ifdim\textbackgroundskip>\zeropoint
+ \struttedbox % not always ok (e.g. setups)
+ {\hpack{\lower\textbackgroundskip\hpack{\anch_backgrounds_epos}}}%
+ \else
+ \anch_backgrounds_epos
+ \fi
+ \else
+ \anch_backgrounds_epos
+ \fi
+ \endgraf
+ \carryoverpar\endgroup
+ \endgraf % new
+ \textbackgroundparameter\c!after}
+
+\permanent\protected\def\checkpositionoverlays % overloads \relax in anch-pgr
+ {\ifproductionrun
+ \enabletextarearegistration
+ \enablehiddenbackground
+ \enforced\glet\checkpositionoverlays\relax
+ \fi}
+
+% shape handling
+
+\definesystemattribute[textbackground][public]
+
+% \def\page_prepare_backgrounds#1%
+% {\clf_collectbackgrounds\realpageno#1\relax}
+
+\def\anch_backgrounds_bpos
+ {\ifconditional\c_anch_backgrounds_pos_no_shape
+ \c_attr_textbackground\attributeunsetvalue
+ \bposkind\v_anch_backgrounds_text_current\plusthree
+ \orelse\ifnum\c_anch_backgrounds_pos_state=\plusone
+ \bposkind\v_anch_backgrounds_text_current\c_anch_backgrounds_pos_state
+ \clf_registerbackground{\v_anch_backgrounds_text_current}%
+ \else
+ \bposkind\v_anch_backgrounds_text_current\c_anch_backgrounds_pos_state
+ \c_attr_textbackground\attributeunsetvalue
+ \fi}
+
+% plugs into other code
+
+\def\strc_floats_wrap_free_region
+ {\global\setbox\floatbox\hpack % we always need to wrap
+ {\ifconditional\c_strc_floats_trace_free
+ \strc_floats_show_free_region
+ \fi
+ \box\floatbox}}
+
+\startuseMPgraphic{floatfree}
+ draw_free_region(
+ \the\wd\floatbox,
+ \the\ht\floatbox,
+ \the\dp\floatbox,
+ \the\d_free_offset_left,
+ \the\d_free_offset_right,
+ \the\d_free_offset_top,
+ \the\d_free_offset_bottom
+ ) ;
+\stopuseMPgraphic
+
+\def\strc_floats_show_free_region
+ {\lower\dp\floatbox\hpack to \zeropoint {\useMPgraphic{floatfree}}}
+
+\newconditional\c_strc_floats_mark_as_free
+\newconditional\c_strc_floats_trace_free
+\newconstant \c_free_offset_kind
+\newdimen \d_free_offset_left
+\newdimen \d_free_offset_right
+\newdimen \d_free_offset_top
+\newdimen \d_free_offset_bottom
+
+\installtextracker{floats.freeregion}
+ {\settrue \c_strc_floats_trace_free}
+ {\setfalse\c_strc_floats_trace_free}
+
+\def\strc_floats_mark_as_free#1#2#3#4#5%
+ {\c_free_offset_kind #1%
+ \d_free_offset_left #2%
+ \d_free_offset_right #3%
+ \d_free_offset_top #4%
+ \d_free_offset_bottom#5%
+ \strc_floats_wrap_free_region
+ \anch_mark_tagged_box_free
+ \floatbox
+ \c_free_offset_kind
+ \d_free_offset_left
+ \d_free_offset_right
+ \d_free_offset_top
+ \d_free_offset_bottom}
+
+\ifrelax\strc_floats_mark_pag_as_free \else
+ \writestatus{error}{wrong place for pag_as_free}\wait
+\fi
+
+\ifrelax\strc_floats_mark_par_as_free \else
+ \writestatus{error}{wrong place for par_as_free}\wait
+\fi
+
+\def\strc_floats_mark_pag_as_free
+ {\ifpositioning
+ \ifconditional\c_strc_floats_mark_as_free
+ \strc_floats_mark_as_free
+ \plusone
+ \zeropoint
+ \zeropoint
+ \d_strc_floats_top
+ \d_strc_floats_bottom
+ \fi
+ \fi}
+
+\def\strc_floats_mark_par_as_free
+ {\ifpositioning
+ \ifconditional\c_strc_floats_mark_as_free
+ \ifcase\c_page_sides_float_type
+ \or % backspace
+ \strc_floats_mark_as_free
+ \plustwo
+ \zeropoint
+ \d_page_sides_rightoffset
+ \d_page_sides_topskip
+ \d_page_sides_bottomskip
+ \or % leftedge
+ \strc_floats_mark_as_free
+ \plustwo
+ \zeropoint
+ \d_page_sides_rightoffset
+ \d_page_sides_topskip
+ \d_page_sides_bottomskip
+ \or % leftmargin
+ \strc_floats_mark_as_free
+ \plustwo
+ \zeropoint
+ \d_page_sides_rightoffset
+ \d_page_sides_topskip
+ \d_page_sides_bottomskip
+ \or % leftside
+ \strc_floats_mark_as_free
+ \plustwo
+ \d_page_sides_leftskip % maybe too
+ \d_page_sides_margin
+ \d_page_sides_topskip
+ \d_page_sides_bottomskip
+ \or % rightside
+ \strc_floats_mark_as_free
+ \plusthree
+ \d_page_sides_margin
+ \d_page_sides_rightskip % maybe too
+ \d_page_sides_topskip
+ \d_page_sides_bottomskip
+ \or % rightmargin
+ \strc_floats_mark_as_free
+ \plusthree
+ \d_page_sides_leftoffset
+ \zeropoint
+ \d_page_sides_topskip
+ \d_page_sides_bottomskip
+ \or % rightedge
+ \strc_floats_mark_as_free
+ \plusthree
+ \d_page_sides_leftoffset
+ \zeropoint
+ \d_page_sides_topskip
+ \d_page_sides_bottomskip
+ \or % cutspace
+ \strc_floats_mark_as_free
+ \plusthree
+ \d_page_sides_leftoffset
+ \zeropoint
+ \d_page_sides_topskip
+ \d_page_sides_bottomskip
+ \fi
+ \fi
+ \fi}
+
+% so far
+
+\setuptextbackground
+ [\c!mp=mpos:region:draw,
+ \c!method=mpos:region,
+ \c!state=\v!start,
+ \c!location=\v!text,
+ \c!leftoffset=\!!zeropoint, % 1em,
+ \c!rightoffset=\textbackgroundparameter\c!leftoffset,
+ \c!topoffset=\!!zeropoint, % \v!medium,
+ \c!bottomoffset=\textbackgroundparameter\c!topoffset,
+ \c!criterium=\plusone,
+ \c!level=-1,
+ \c!alternative=0,
+ \c!align=,
+ \c!dash=0, % to be internationalized
+ \c!background=\v!color,
+ \c!backgroundcolor=lightgray,
+ \c!backgroundoffset=\!!zeropoint,
+ \c!corner=\v!rectangular,
+ \c!radius=.5\bodyfontsize,
+ \c!voffset=\!!zeropoint,
+ \c!frame=\v!on,
+ \c!framecolor=blue,
+ \c!frameoffset=\!!zeropoint,
+ \c!rulethickness=\linewidth]
+
+%D The \METAPOST\ connection:
+
+% gridtype = 1 => baseline
+% gridtype = 2 => betweenline
+
+\setupMPvariables
+ [mpos:region]
+ [mp=mpos:region:unset,
+ gridtype=0,
+ linetype=1,
+ filltype=1,
+ dashtype=0, % 1 = dashed, 2 = dashed with background
+ gridcolor=red,
+ linecolor=blue,
+ fillcolor=lightgray,
+ filloffset=\!!zeropoint,
+ linewidth=\linewidth,
+ gridwidth=\linewidth,
+ gridshift=\!!zeropoint,
+ lineradius=.5\bodyfontsize,
+ lineoffset=\!!zeropoint,
+ dashtype=1]
+
+\startuseMPgraphic{mpos:region:setup}
+ boxgridtype := \MPvar{gridtype} ;
+ boxlinetype := \MPvar{linetype} ;
+ boxfilltype := \MPvar{filltype} ;
+ boxdashtype := \MPvar{dashtype} ;
+ boxfilloffset := \MPvar{filloffset} ;
+ boxlinewidth := \MPvar{linewidth} ;
+ boxgridwidth := \MPvar{gridwidth} ;
+ boxgridshift := \MPvar{gridshift} ;
+ boxlineradius := \MPvar{lineradius} ;
+ boxlineoffset := \MPvar{lineoffset} ;
+ %
+ def boxgridcolor = \MPvar{gridcolor} enddef ;
+ def boxlinecolor = \MPvar{linecolor} enddef ;
+ def boxfillcolor = \MPvar{fillcolor} enddef ;
+ %
+ def boxgridoptions = withcolor boxgridcolor enddef ;
+ def boxlineoptions = withcolor boxlinecolor enddef ;
+ def boxfilloptions = withcolor boxfillcolor enddef ;
+\stopuseMPgraphic
+
+\startuseMPgraphic{mpos:region:extra}
+ % user stuff
+\stopuseMPgraphic
+
+\startuseMPgraphic{mpos:region:anchor}
+ setbounds currentpicture to multibox ;
+\stopuseMPgraphic
+
+\startMPpositiongraphic{mpos:region}{fillcolor,filloffset,linecolor,gridcolor,linewidth,gridwidth,gridshift,lineradius,lineoffset}
+ \includeMPgraphic{mpos:region:setup} ;
+ \includeMPgraphic{mpos:region:extra} ;
+ % \getmultipars("self","anchor") ;
+ \MPgetmultipars{\MPvar{self}}{\MPanchorid} ;
+ \includeMPgraphic{\MPvar{mp}} ;
+ \includeMPgraphic{mpos:region:anchor} ;
+\stopMPpositiongraphic
+
+%D For old times sake:
+
+\startMPpositiongraphic{mpos:box}{fillcolor,linecolor,linewidth}
+ string tag; tag := "\MPvar{self}" ;
+ path box ; box := positionbox(tag) ;
+
+ box := box enlarged \MPvar{filloffset} ;
+ fill box withcolor \MPvar{fillcolor} ;
+ draw box withcolor \MPvar{linecolor} withpen pencircle scaled \MPvar{linewidth} ;
+
+ positioninregion;
+\stopMPpositiongraphic
+
+\startMPpositionmethod{mpos:region}
+ \MPpositiongraphic{mpos:region}{}%
+\stopMPpositionmethod
+
+\startuseMPgraphic{mpos:region:draw}
+ draw_multi_pars
+\stopuseMPgraphic
+
+\startuseMPgraphic{mpos:region:show}
+ show_multi_pars
+\stopuseMPgraphic
+
+\startuseMPgraphic{mpos:region:kind}
+ show_multi_kind
+\stopuseMPgraphic
+
+\startuseMPgraphic{mpos:region:sideline}
+ draw_multi_side
+\stopuseMPgraphic
+
+\startuseMPgraphic{mpos:region:sideline:dashed}
+ draw_multi_side_path dashed evenly ;
+\stopuseMPgraphic
+
+%D As an example we define a grid background:
+
+\pushoverloadmode
+
+\definetextbackground
+ [\v!grid]
+ [\c!state=\v!stop,
+ \c!location=\v!paragraph,
+ \c!frame=\v!off,
+ \c!framecolor=red,
+ \c!background=,
+ \c!alternative=1]
+
+\ifdefined\basegrid
+ \aliased\letcsname\v!grid\endcsname\basegrid
+\fi
+
+\popoverloadmode
+
+%D Some examples (that might become modules anch-imp-whatever):
+
+\setupMPvariables
+ [mpos:encircle]
+ [fillcolor=lightgray,
+ filloffset=\!!zeropoint,
+ linecolor=blue,
+ lineoffset=5pt,
+ linewidth=1pt]
+
+% \startMPpositiongraphic{mpos:encircle}{linecolor,fillcolor,linewidth,lineoffset}
+% getposboxes("self","anchor") ;
+% if nofposboxes = 1 :
+% posboxes[1] := posboxes[1] enlarged \MPvar{lineoffset} cornered \MPvar{lineoffset} ;
+% fill posboxes[1] withcolor \MPvar{fillcolor} ;
+% draw posboxes[1] withpen pencircle scaled \MPvar{linewidth} withcolor \MPvar{linecolor} ;
+% fi ;
+% \stopMPpositiongraphic
+
+\startMPpositiongraphic{mpos:encircle}{linecolor,fillcolor,linewidth,lineoffset}
+ getposboxes("self","anchor") ;
+ if nofposboxes = 1 :
+ posboxes[1] := (posboxes[1] enlarged mpvar "lineoffset") cornered mpvar "lineoffset" ;
+ fill posboxes[1] withcolor mpvar "fillcolor" ;
+ draw posboxes[1] withpen pencircle scaled mpvar "linewidth" withcolor mpvar "linecolor" ;
+ fi ;
+\stopMPpositiongraphic
+
+\setupMPvariables
+ [mpos:connect]
+ [linecolor=red,
+ lineoffset=.25ex,
+ linewidth=1pt]
+
+% \startMPpositiongraphic{mpos:connect}{linecolor,lineoffset,linewidth}
+% boxlinewidth := \MPvar{linewidth} ;
+% boxlineoffset := \MPvar{lineoffset} ;
+% def boxlineoptions = withcolor \MPvar{linecolor} enddef ;
+% getposboxes("from,to","anchor") ;
+% connect_positions ;
+% \stopMPpositiongraphic
+
+\startMPpositiongraphic{mpos:connect}{linecolor,lineoffset,linewidth}
+ boxlinewidth := mpvar "linewidth" ;
+ boxlineoffset := mpvar "lineoffset" ;
+ def boxlineoptions = withcolor mpvar "linecolor" enddef ;
+ getposboxes("from,to","anchor") ;
+ connect_positions ;
+\stopMPpositiongraphic
+
+\protect \endinput
+
+\definetextbackground[underline] [location=text,alternative=1,background=,frame=off]
+\definetextbackground[overstrike] [location=text,alternative=2,background=,frame=off]
+\definetextbackground[exlines] [location=text,alternative=3,background=,frame=off]
+\definetextbackground[strikethrough][location=text,alternative=4,background=,frame=off]
+
+\definestartstop [underline]
+ [before={\starttextbackground[underline]},
+ after=\stoptextbackground]
+
+\definestartstop
+ [overstrike]
+ [before={\starttextbackground[overstrike]},
+ after=\stoptextbackground]
+
+\definestartstop
+ [exlines]
+ [before={\starttextbackground[exlines]},
+ after=\stoptextbackground]
+
+\definestartstop
+ [strikethrough]
+ [before={\starttextbackground[strikethrough]},
+ after=\stoptextbackground]
+
+\definetextbackground
+ [sideline]
+ [mp=mpos:region:sideline,
+ location=paragraph,
+ framecolor=red,
+ frameoffset=5mm]
+
+\definestartstop [sideline]
+ [before={\starttextbackground[sideline]},
+ after=\stoptextbackground]
+
+\starttext
+
+ \startunderline \input tufte \stopunderline \blank
+ \startoverstrike \input tufte \stopoverstrike \blank
+ \startexlines \input tufte \stopexlines \blank
+ \startstrikethrough \input tufte \stopstrikethrough \blank
+ \startsideline \input tufte \stopsideline \blank
+
+ \page
+
+ \startpositionoverlay{text-1}
+ \setMPpositiongraphic{connect-1-b}{mpos:connect}{from=connect-1-b,to=connect-1-e}
+ \setMPpositiongraphic{connect-1-e}{mpos:connect}{from=connect-1-b,to=connect-1-e}
+ \stoppositionoverlay
+
+ \startpositionoverlay{text-1}
+ \setMPpositiongraphic{encircle-1}{mpos:encircle}{self=encircle-1}
+ \stoppositionoverlay
+
+ test \hpos{connect-1-b}{START}
+ \dorecurse{10}{\input ward}
+ \hpos{encircle-1}{\strut HERE}
+ \dorecurse{10}{\input ward}
+ \hpos{connect-1-e}{STOP} test
+
+\stoptext