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Diffstat (limited to 'Master/texmf-dist/tex/context/base/mkii/pack-obj.mkii')
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1 files changed, 371 insertions, 0 deletions
diff --git a/Master/texmf-dist/tex/context/base/mkii/pack-obj.mkii b/Master/texmf-dist/tex/context/base/mkii/pack-obj.mkii new file mode 100644 index 00000000000..81523d52564 --- /dev/null +++ b/Master/texmf-dist/tex/context/base/mkii/pack-obj.mkii @@ -0,0 +1,371 @@ +%D \module +%D [ file=pack-obj, +%D version=1998.01.15, +%D title=\CONTEXT\ Packaging Macros, +%D subtitle=Objects, +%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. + +% todo, move more to mkiv, get rid of blabelgroup + +\writestatus{loading}{ConTeXt Packaging Macros / Objects} + +\unprotect + +%D \macros +%D {setobject,getobject,ifinobject} +%D +%D Boxes can be considered reuable objects. Unfortunaltely once +%D passed to the \DVI\ file, such objects cannot be reused. In +%D \PDF\ however, reusing is possible and sometimes even a +%D necessity. Therefore, \CONTEXT\ supports reusable objects. +%D +%D During the \TEX\ processing run, boxes can serve the purpose +%D of objects, and the \DVI\ driver module implements objects +%D using packed boxes. +%D +%D The \PDF\ and \PDFTEX\ driver modules implement objects +%D using \PDF\ forms. There is no (real) restriction on the +%D number of objects there. +%D +%D The first application of objects in \CONTEXT\ concerned +%D \METAPOST\ graphics and fill||in form fields. The first +%D application can save lots of bytes, while the latter use is +%D more a necessity than byte saving. +%D +%D \starttyping +%D \setobject{class}{name}\somebox{} +%D \getobject{class}{name} +%D \stoptyping +%D +%D Here \type{\somebox} can be whatever box specification suits +%D \TEX. We save the dimensions of an object, although some +%D drivers will do so themselves. This means that when for +%D instance using \PDFTEX\ we could save a hash entry plus some +%D 20+ memory locations per object by delegating this +%D housekeeping to the driver. The current approach permits +%D us to keep the box characteristic too. + +\newif\ifinobject + +\def\checkobjectreferences + {\startnointerference + \protectlabels + \ifx\usedoutputdriver\currentoutput + \doutilities{objectreferences}\jobname\empty\relax\relax + \else + % different format (will fails on \purenumber) + \fi + \global\let\checkobjectreferences\relax + \stopnointerference} + +\def\objectplaceholder{NOT YET FLUSHED}% + +\def\presetobject#1#2% \global added + {\blabelgroup + \ifcsname\r!object#1::#2\endcsname\else + \global\@EA\let\csname\r!object#1::#2\endcsname\objectplaceholder + \fi + \elabelgroup} + +\def\dosetobject#1#2#3% \initializepaper this will move to \everyshipout + {\initializepaper + \blabelgroup + \ifcsname\r!object#2::#3\endcsname + \elabelgroup \expandafter\gobblefivearguments + \else % tzt, overload internal referenced objects to save entries + \elabelgroup \expandafter\dodosetobject + \fi + {#1}{#2}{#3}} + +\def\resetobject#1#2% + {\checkobjectreferences + \letbeundefined{\r!object#1::#2}} + +%D \macros +%D {finalizeobjectbox} +%D +%D This one provides a hook for last minute object box processing +%D we need this in \MKIV. + +\ifx\finalizeobjectbox\undefined + \let\finalizeobjectbox\gobbleoneargument +\fi + +%D Somehow there is a rounding error problem in either \PDFTEX\ +%D or in viewers, or maybe it is conforming the specs. The next +%D variable compensate for it by removing the rather tight +%D clip. + +\def\objectoffset{1cm} + +% \def\dodosetobject#1#2#3% +% {\bgroup +% \inobjecttrue +% \dowithnextbox{\dododosetobject{#1}{#2}{#3}\egroup}} + +\def\dodosetobject#1#2#3% + {\bgroup + \globalpushmacro\crossreferenceobject \objectreferenced + \inobjecttrue + \dowithnextbox + {\globalpopmacro\crossreferenceobject + \dododosetobject{#1}{#2}{#3}\egroup}} + +\def\dododosetobject#1#2#3% + {\blabelgroup + \dontshowcomposition % rather fuzzy in \setxvalue ... \hbox + \scratchdimen\objectoffset + \@EA\xdef\csname\r!object#2::#3\endcsname + {\noexpand\dohandleobject{#2}{#3}% + {\ifhbox\nextbox\hbox\else\vbox\fi}% + %{\the\nextboxwd}{\the\nextboxht}{\the\nextboxdp}}% + {\number\nextboxwd}{\number\nextboxht}{\number\nextboxdp}% + {\number\scratchdimen}}% + \expanded % freeze the dimensions since \dostartobject may use \nextbox + {\dostartobject + {#2}{#3}{\the\nextboxwd}{\the\nextboxht}{\the\nextboxdp}}% + \ifcase#1\relax\else \ifdim\objectoffset>\zeropoint + \setbox\nextbox\vbox spread 2\scratchdimen + {\forgetall \offinterlineskip + \vss\hbox spread 2\scratchdimen{\hss\flushnextbox\hss}\vss}% + \fi \fi + \flushnextbox + \dostopobject + \elabelgroup} + +\def\getobject#1#2% + {\blabelgroup + \let\dohandleobject\dogetobject + \csname\r!object#1::#2\endcsname} + +% \def\dogetobject#1#2#3#4#5#6% +% {\initializepaper +% \forgetall +% \dontshowcomposition +% \setbox\scratchbox\vbox +% {\doinsertobject{#1}{#2}}% +% \setbox\scratchbox#3% +% {\vbox to #5\scaledpoint +% {\ifdim\ht\scratchbox>#5\scaledpoint +% % or \ifdim\wd\scratchbox>#4\scaledpoint +% \vss\hbox to #4\scaledpoint{\hss\box\scratchbox\hss}\vss +% \else +% \vss\box\scratchbox +% \fi}}% +% \wd\scratchbox#4\scaledpoint +% \ht\scratchbox#5\scaledpoint +% \dp\scratchbox#6\scaledpoint +% \box\scratchbox +% \elabelgroup} + +% \def\dogetobject#1#2#3#4#5#6#7% +% {\initializepaper +% \forgetall +% \dontshowcomposition +% \setbox\scratchbox\vbox +% {\doinsertobject{#1}{#2}}% +% \setbox\scratchbox#3% +% {\vbox to #5\scaledpoint +% {\ifdim\ht\scratchbox>#5\scaledpoint +% % or \ifdim\wd\scratchbox>#4\scaledpoint +% \vss\hbox to #4\scaledpoint{\hss\box\scratchbox\hss}\vss +% \else +% \vss\box\scratchbox +% \fi}}% +% \scratchdimen#7\scaledpoint +% \setbox\nextbox\hbox +% {\hskip-\scratchdimen\lower\scratchdimen\flushnextbox}% +% \wd\scratchbox#4\scaledpoint +% \ht\scratchbox#5\scaledpoint +% \dp\scratchbox#6\scaledpoint +% \box\scratchbox +% \elabelgroup} + +\def\dogetobject#1#2#3#4#5#6#7% don't change this, should work for dvi & pdf + {\initializepaper + \forgetall + \dontshowcomposition + \setbox\scratchbox\vbox + {\doinsertobject{#1}{#2}}% + \setbox\scratchbox#3% + {\vbox to #5\scaledpoint + {\ifdim\ht\scratchbox>#5\scaledpoint + \vss\hbox to #4\scaledpoint{\hss\box\scratchbox\hss}\vss + \else\ifdim\wd\scratchbox>#4\scaledpoint + \vss\hbox to #4\scaledpoint{\hss\box\scratchbox\hss}\vss + \else + %\vss\box\scratchbox + \vss\hbox to #4\scaledpoint{\box\scratchbox\hss}% fix Chof + \fi\fi}}% + \box\scratchbox + \elabelgroup} + +%D If needed one can ask for the dimensions of an object with: +%D +%D \starttyping +%D \getobjectdimensions{class}{name} +%D \stoptyping +%D +%D The results are reported in \type {\objectwidth}, \type +%D {\objectheight} and \type {\objectdepth}. + +% \def\dogetobjectdimensions#1#2#3#4#5#6% +% {\def\objectwidth {#4\s!sp}% +% \def\objectheight{#5\s!sp}% +% \def\objectdepth {#6\s!sp}} + +\def\dogetobjectdimensions#1#2#3#4#5#6#7% + {\def\objectwidth {#4\s!sp}% + \def\objectheight{#5\s!sp}% + \def\objectdepth {#6\s!sp}% + \def\objectmargin{#7\s!sp}} + +\def\getobjectdimensions#1#2% + {\let\dohandleobject\dogetobjectdimensions + \let\objectwidth \!!zeropoint + \let\objectheight\!!zeropoint + \let\objectdepth \!!zeropoint + \labelcsname\r!object#1::#2\endcsname} + +%D Apart from this kind of objects, that have typeset content, +%D we can have low level driver specific objects. Both types +%D can have references to internal representations, hidden for +%D the user. We keep track of such references by means of a +%D dedicated cross reference mechanism. Normally, objects are +%D defined before they are used, but forward referencing +%D sometimes occurs. +%D +%D \starttyping +%D \dosetobjectreference {class} {identifier} {reference value} {page} +%D \dogetobjectreference {class} {identifier} \csname +%D \stoptyping +%D +%D These commands are to be called by the \type{\startobject}, +%D \type{\stopobject} and \type{\insertobject} specials. + +\def\objectreferenced{\global\chardef\crossreferenceobject\plusone} +\def\driverreferenced{\global\chardef\crossreferenceobject\zerocount} + +\objectreferenced + +% no undefined test ! ! ! ! (pdftex fails on undefined objects) + +\def\setobjectreferences + {\def\objectreference##1##2##3##4% + {\ifundefined{\r!driver##1::##2}% + \setxvalue{\r!driver##1::##2}{{##3}{##4}}% + \else + \showmessage\m!references{31}{[##1 ##2=>##3/##4]}% + \fi}} + +\def\resetobjectreferences + {\let\objectreference\gobblefourarguments} + +\resetobjectreferences + +\def\doregisterobjectreference#1#2#3% + {\checkobjectreferences + \blabelgroup + \expanded{\writeutilitycommand{\noexpand\objectreference{#1}{#2}{#3}{\noexpand\realfolio}}}% + \setxvalue{\r!driver#1::#2}{{#3}{\noexpand\realfolio}}% + \elabelgroup} + +\def\dooverloadobjectreference#1#2#3% + {\checkobjectreferences + \blabelgroup + \setxvalue{\r!driver#1::#2}{{#3}{\noexpand\realfolio}}% + \elabelgroup} + +\def\dosetobjectreference + {\ifcase\crossreferenceobject + \objectreferenced + \expandafter\dooverloadobjectreference + \else + \expandafter\doregisterobjectreference + \fi} + +\def\dosetdriverreference + {\driverreferenced\dosetobjectreference} + +\def\defaultobjectreference#1#2{0} % driver dependent +\def\defaultobjectpage #1#2{\realfolio} + +\def\dogetobjectreference {\dodogetobjectreference\firstoftwoarguments\defaultobjectreference} +\def\dogetobjectreferencepage{\dodogetobjectreference\secondoftwoarguments\defaultobjectpage} + +\def\dodogetobjectreference#1#2#3#4#5% + {\checkobjectreferences + \blabelgroup + \ifundefined{\r!driver#3::#4}% + \showmessage\m!references{30}{[#3 #4=>#3/#4]}% + \xdef#5{#2{#3}{#4}}% + \else + \xdef#5{\@EAEAEA#1\csname\r!driver#3::#4\endcsname}% + \fi + \elabelgroup} + +\def\setobject {\driverreferenced\dosetobject1} +\def\settightobject{\driverreferenced\dosetobject0} + +%D \macros +%D {doifobjectfoundelse,doifobjectreferencefoundelse} +%D +%D To prevent redundant definition of objects, one can use +%D the next tests: +%D +%D \starttyping +%D \doifobjectfoundelse{class}{object}{do then}{do else} +%D \doifobjectreferencefoundelse{class}{object}{do then}{do else} +%D \stoptyping + +\def\doifobjectfoundelse#1#2% + {\blabelgroup \ifcsname\r!object#1::#2\endcsname + \elabelgroup \expandafter\firstoftwoarguments + \else + \elabelgroup \expandafter\secondoftwoarguments + \fi} + +\def\doifobjectreferencefoundelse#1#2% + {\checkobjectreferences + \blabelgroup \ifcsname\r!driver#1::#2\endcsname + \elabelgroup \expandafter\firstoftwoarguments + \else + \elabelgroup \expandafter\secondoftwoarguments + \fi} + +%D \macros +%D {doifobjectssupportedelse} +%D +%D Starting with reuse of graphics, we will implement object +%D reuse when possible. To enable mechanisms to determine +%D what method to use, we provide: +%D +%D \starttyping +%D \doifobjectssupportedelse{true action}{false action} +%D \stoptyping +%D +%D As we can see, currently objects depend on the special +%D driver. + +\newif\ifobjectssupported \objectssupportedtrue + +\def\doifobjectssupportedelse + {\ifobjectssupported + \@EA\doifspecialavailableelse\@EA\doinsertobject + \else + \@EA\secondoftwoarguments + \fi} + +%D There is a conceptual problem here. Objects are not possible +%D in \DVI, unless faked like in \type {spec-dvi}. This means +%D that we must be careful in loading special drivers that do +%D support objects while we still want to be able to use the +%D \DVI\ output. + +\protect \endinput |