diff options
Diffstat (limited to 'tex/context/base/core-obj.mkiv')
| -rw-r--r-- | tex/context/base/core-obj.mkiv | 220 |
1 files changed, 214 insertions, 6 deletions
diff --git a/tex/context/base/core-obj.mkiv b/tex/context/base/core-obj.mkiv index 3a54e6507..560a7012d 100644 --- a/tex/context/base/core-obj.mkiv +++ b/tex/context/base/core-obj.mkiv @@ -1,6 +1,6 @@ %D \module %D [ file=core-obj, -%D version=2006.10.16, +%D version=1998.01.15, %D title=\CONTEXT\ Core Macros, %D subtitle=Object Handling, %D author=Hans Hagen, @@ -11,16 +11,224 @@ %C therefore copyrighted by \PRAGMA. See mreadme.pdf for %C details. +\writestatus{loading}{ConTeXt Core Macros / Object Handling} + \unprotect \let\objectreference\gobblefourarguments % catch mkii tuo stuff \registerctxluafile{core-obj}{1.001} -\def\mkregisterobjectreference #1#2#3{\expanded{\ctxlatelua{jobobjects.save("#1::#2",#3,\noexpand\the\realpageno)}}} -\def\mkoverloadobjectreference #1#2#3{\ctxlua{jobobjects.set("#1::#2",#3,\the\realpageno)}} -\def\mkgetobjectreference #1#2#3{\xdef#3{\ctxlua{jobobjects.number("#1::#2","\defaultobjectreference{#1}{#2}")}}} -\def\mkgetobjectreferencepage #1#2#3{\xdef#3{\ctxlua{jobobjects.page("#1::#2","\defaultobjectpage{#1}{#2}")}}} -\def\mkdoifobjectreferencefoundelse#1#2{\ctxlua{jobobjects.doifelse("#1::#2")}} +%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\objectplaceholder{NOT YET FLUSHED}% + +\def\presetobject#1#2% \global added + {\ifcsname\r!object#1::#2\endcsname\else + \global\@EA\let\csname\r!object#1::#2\endcsname\objectplaceholder + \fi} + +\def\dosetobject#1#2#3% \initializepaper this will move to \everyshipout + {\initializepaper + \ifcsname\r!object#2::#3\endcsname + \expandafter\gobblefivearguments + \else % tzt, overload internal referenced objects to save entries + \expandafter\dodosetobject + \fi + {#1}{#2}{#3}} + +\def\resetobject#1#2% + {\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 + \globalpushmacro\crossreferenceobject \objectreferenced + \inobjecttrue + \dowithnextbox + {\globalpopmacro\crossreferenceobject + \dododosetobject{#1}{#2}{#3}\egroup}} + +\def\dododosetobject#1#2#3% + {\begingroup + \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}% + {\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 + \endgroup} + +\def\getobject#1#2% + {\begingroup + \let\dohandleobject\dogetobject + \csname\r!object#1::#2\endcsname} + +\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 + \endgroup} + +%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#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\doregisterobjectreference#1#2#3{\normalexpanded{\noexpand\ctxlatelua{jobobjects.save("#1::#2",#3,\noexpand\the\realpageno)}}} +\def\dooverloadobjectreference#1#2#3{\ctxlua{jobobjects.set("#1::#2",#3,\the\realpageno)}} + +\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 #1#2#3{\xdef#3{\ctxlua{jobobjects.number("#1::#2","\defaultobjectreference{#1}{#2}")}}} +\def\dogetobjectreferencepage#1#2#3{\xdef#3{\ctxlua{jobobjects.page("#1::#2","\defaultobjectpage{#1}{#2}")}}} + +\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% + {\ifcsname\r!object#1::#2\endcsname + \expandafter\firstoftwoarguments + \else + \expandafter\secondoftwoarguments + \fi} + +\def\doifobjectreferencefoundelse#1#2{\ctxlua{jobobjects.doifelse("#1::#2")}} \protect \endinput |