pack-obj.mkxl /size: 7011 b    last modification: 2023-12-21 09:44
1%D \module
2%D   [       file=pack-obj,
3%D        version=1998.01.15,
4%D          title=\CONTEXT\ Packaging Macros,
5%D       subtitle=Objects,
6%D         author=Hans Hagen,
7%D           date=\currentdate,
8%D      copyright={PRAGMA ADE \& \CONTEXT\ Development Team}]
9%C
10%C This module is part of the \CONTEXT\ macro||package and is
11%C therefore copyrighted by \PRAGMA. See mreadme.pdf for
12%C details.
13
14\writestatus{loading}{ConTeXt Packaging Macros / Objects}
15
16\unprotect
17
18\registerctxluafile{pack-obj}{autosuffix}
19
20%D \macros
21%D   {setobject,getobject,ifinobject}
22%D
23%D Boxes can be considered reuable objects. Traditionally once passed to the \DVI\
24%D file, such objects cannot be reused. In \PDF\ however, reusing is possible and
25%D sometimes even a necessity. Therefore, \CONTEXT\ supports reusable objects and
26%D \LUATEX\ has native support for so called box resources.
27%D
28%D The first application of objects in \CONTEXT\ concerned \METAPOST\ graphics and
29%D fill||in form fields. Reusing resources can save lots of bytes and sometimes also
30%D runtime.
31%D
32%D \starttyping
33%D \setobject{class}{name}\somebox{}
34%D \getobject{class}{name}
35%D \stoptyping
36%D
37%D Here \type {\somebox} can be whatever box specification suits \TEX. Although the
38%D implementation in \MKIV\ is somewhat different the principles have not changed.
39
40\installcorenamespace {objects}
41
42\mutable\def\objectoffset{1cm} % Still public but use with care!
43
44\newif       \ifinobject
45\newbox      \b_pack_objects
46\newdimension\d_pack_objects_offset \permanent\def\objectmargin{\the\d_pack_objects_offset}
47\newdimension\d_pack_objects_width  \permanent\def\objectwidth {\the\d_pack_objects_width}
48\newdimension\d_pack_objects_height \permanent\def\objectheight{\the\d_pack_objects_height}
49\newdimension\d_pack_objects_depth  \permanent\def\objectdepth {\the\d_pack_objects_depth}
50
51%D If I have time I will use the unreferenced variant for e.g. mp reuse. This can be
52%D rewritten in \LUA\ anyway.
53
54\permanent\protected\def\setreferencedobject       #1#2{\begingroup\synctexpause\d_pack_objects_offset\objectoffset\inobjecttrue\dowithnextbox{\pack_objects_set_yes{#1}{#2}}}
55\permanent\protected\def\settightreferencedobject  #1#2{\begingroup\synctexpause\d_pack_objects_offset\zeropoint   \inobjecttrue\dowithnextbox{\pack_objects_set_yes{#1}{#2}}}
56\permanent\protected\def\setunreferencedobject     #1#2{\begingroup\synctexpause\d_pack_objects_offset\objectoffset\inobjecttrue\dowithnextbox{\pack_objects_set_nop{#1}{#2}}}
57\permanent\protected\def\settightunreferencedobject#1#2{\begingroup\synctexpause\d_pack_objects_offset\zeropoint   \inobjecttrue\dowithnextbox{\pack_objects_set_nop{#1}{#2}}}
58
59\aliased\let\setobject     \setreferencedobject
60\aliased\let\settightobject\settightreferencedobject
61
62%D We can get subtle differences in boundingboxes but both methods work ok.
63
64% How useful is this ... delayed but refered objects .. messy concept.
65%
66% \def\InitIt{%
67%     \c_pack_objects_delay\plusone
68%     \setobject{test}{1}\hbox{test me 1}
69%     \c_pack_objects_delay\zerocount
70% }
71%
72% \def\GetIt{%
73%     \c_pack_objects_delay\plusone
74%     \getobject{test}{1}
75%     \c_pack_objects_delay\zerocount
76% }
77%
78% \def\SetIt{%
79%     \c_pack_objects_delay\plustwo
80%     \setobject{test}{1}\hbox{\bf HERE}% we cannot have interactivity in xforms
81%     \c_pack_objects_delay\zerocount
82% }
83
84\newconstant\c_pack_objects_offset_mode % 0=tex 1=box
85\newconstant\c_pack_objects_delay       % 0=immediate 1=delay
86
87\protected\def\pack_objects_set_yes#1#2%
88  {\ifcase\c_pack_objects_offset_mode
89     \ifzeropt\d_pack_objects_offset
90       \pack_objects_package_nop\nextbox
91     \else
92       \pack_objects_package_yes\nextbox
93     \fi
94   \else
95     \pack_objects_package_nop\nextbox
96   \fi
97   \clf_registerreferencedobject
98     {#1}{#2}%
99     \b_pack_objects
100     \d_pack_objects_offset
101     \c_pack_objects_offset_mode
102     \c_pack_objects_delay
103   \synctexresume
104   \endgroup}
105
106\protected\def\pack_objects_set_nop#1#2%
107  {\ifcase\c_pack_objects_offset_mode
108     \ifzeropt\d_pack_objects_offset
109       \pack_objects_package_nop\nextbox
110     \else
111       \pack_objects_package_yes\nextbox
112     \fi
113   \else
114     \pack_objects_package_nop\nextbox
115   \fi
116   \clf_registerobject
117     {#1}{#2}%
118     \b_pack_objects
119     \d_pack_objects_offset
120     \c_pack_objects_offset_mode
121     \c_pack_objects_delay
122   \synctexresume
123   \endgroup}
124
125\def\pack_objects_package_nop#1% we pack because otherwise \ruledhbox is still tight
126  {\setbox\b_pack_objects\hpack{\box#1}}
127
128\def\pack_objects_package_yes#1%
129  {\d_pack_objects_width \dimexpr\wd#1+2\d_pack_objects_offset\relax
130   \d_pack_objects_height\dimexpr\ht#1+ \d_pack_objects_offset\relax
131   \d_pack_objects_depth \dimexpr\dp#1+ \d_pack_objects_offset\relax
132   \setbox\b_pack_objects\hpack{\hskip\d_pack_objects_offset\box#1}%
133   \wd\b_pack_objects\d_pack_objects_width
134   \ht\b_pack_objects\d_pack_objects_height
135   \dp\b_pack_objects\d_pack_objects_depth}
136
137\permanent\protected\def\getobject#1#2%
138  {\begingroup
139   \synctexpause
140   \clf_restoreobject{#1}{#2}%
141   \ifzeropt\d_pack_objects_offset\else
142     \d_pack_objects_offset-\d_pack_objects_offset
143     \pack_objects_package_yes\b_pack_objects
144   \fi
145   \box\b_pack_objects
146   \synctexresume
147   \endgroup}
148
149%D If needed one can ask for the dimensions of an object with:
150%D
151%D \starttyping
152%D \getobjectdimensions{class}{name}
153%D \stoptyping
154%D
155%D The results are reported in \type {\objectwidth}, \type {\objectheight} and \type
156%D {\objectdepth} as well as \type {\objectoffset}.
157
158% \getobjectdimensions #1#2 % defined at the lua end
159
160%D \macros
161%D   {doifobjectfoundelse,doifobjectreferencefoundelse}
162%D
163%D To prevent redundant definition of objects, one can use the next tests:
164%D
165%D \starttyping
166%D \doifobjectfoundelse{class}{object}{do then}{do else}
167%D \doifobjectreferencefoundelse{class}{object}{do then}{do else}
168%D \stoptyping
169
170\immutable\def\defaultobjectreference{0}
171\immutable\def\defaultobjectpage     {\realfolio}
172
173% \getobjectreference           {#1}{#2\csname % define at the lua end
174% \getobjectreferencepage       {#1}{#2\csname % define at the lua end
175% \doifelseobjectfound          {#1}{#2}       % defined atthe lua end
176% \doifelseobjectreferencefound {#1}{#2}       % defined atthe lua end
177
178\aliased\let\dogetobjectreference    \getobjectreference     % for now, will go away
179\aliased\let\dogetobjectreferencepage\getobjectreferencepage % for now, will go away
180
181\aliased\let\doifobjectfoundelse         \doifelseobjectfound
182\aliased\let\doifobjectreferencefoundelse\doifelseobjectreferencefound
183
184%D For the moment here:
185
186\mutable\lettonothing\lastpredefinedsymbol % some day we can do more at the lua end
187
188\permanent\protected\def\predefinesymbol[#1]%
189  {\begingroup
190   \xdef\lastpredefinedsymbol{#1}%
191   \settightobject{SYM}{#1}\hbox{\symbol[#1]}% to be checked ... maybe only fitting
192   \getobjectreference{SYM}{#1}\m_back_object_reference
193   \clf_registerbackendsymbol{#1}\m_back_object_reference\relax
194   \endgroup}
195
196\protect \endinput
197