Source Browser ?

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}{}
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\newif   \ifinobject
43\newbox  \objectbox
44
45\def\objectoffset{1cm}
46
47\newdimen\objectoff  \def\objectmargin{\the\objectoff}
48\newdimen\objectwd   \def\objectwidth {\the\objectwd}
49\newdimen\objectht   \def\objectheight{\the\objectht}
50\newdimen\objectdp   \def\objectdepth {\the\objectdp}
51
52%D If I have time I will use the unreferenced variant for e.g. mp reuse. This can be
53%D rewritten in \LUA\ anyway.
54
55\unexpanded\def\setreferencedobject       #1#2{\begingroup\synctexpause\objectoff\objectoffset\inobjecttrue\dowithnextbox{\pack_objects_set_yes{#1}{#2}}}
56\unexpanded\def\settightreferencedobject  #1#2{\begingroup\synctexpause\objectoff\zeropoint   \inobjecttrue\dowithnextbox{\pack_objects_set_yes{#1}{#2}}}
57\unexpanded\def\setunreferencedobject     #1#2{\begingroup\synctexpause\objectoff\objectoffset\inobjecttrue\dowithnextbox{\pack_objects_set_nop{#1}{#2}}}
58\unexpanded\def\settightunreferencedobject#1#2{\begingroup\synctexpause\objectoff\zeropoint   \inobjecttrue\dowithnextbox{\pack_objects_set_nop{#1}{#2}}}
59
60\let\setobject     \setreferencedobject
61\let\settightobject\settightreferencedobject
62
63%D We can get subtle differences in boundingboxes but both methods work ok.
64
65\newconstant\c_pack_objects_offset_mode % 0=tex 1=box
66
67\unexpanded\def\pack_objects_set_yes#1#2%
68  {\ifcase\c_pack_objects_offset_mode
69     \ifzeropt\objectoff
70       \pack_objects_package_nop\nextbox
71     \else
72       \pack_objects_package_yes\nextbox
73     \fi
74   \else
75     \pack_objects_package_nop\nextbox
76   \fi
77   \clf_registerreferencedobject{#1}{#2}\objectbox\objectoff\c_pack_objects_offset_mode
78   \synctexresume
79   \endgroup}
80
81\unexpanded\def\pack_objects_set_nop#1#2%
82  {\ifcase\c_pack_objects_offset_mode
83     \ifzeropt\objectoff
84       \pack_objects_package_nop\nextbox
85     \else
86       \pack_objects_package_yes\nextbox
87     \fi
88   \else
89     \pack_objects_package_nop\nextbox
90   \fi
91   \clf_registerobject{#1}{#2}\objectbox\objectoff\c_pack_objects_offset_mode
92   \synctexresume
93   \endgroup}
94
95\def\pack_objects_package_nop#1% we pack because otherwise \ruledhbox is still tight
96  {\setbox\objectbox\hpack{\box#1}}
97
98\def\pack_objects_package_yes#1%
99  {\objectwd\dimexpr\wd#1+2\objectoff\relax
100   \objectht\dimexpr\ht#1+ \objectoff\relax
101   \objectdp\dimexpr\dp#1+ \objectoff\relax
102   \setbox\objectbox\hpack
103     {\hskip\objectoff
104      \box#1}%
105   \wd\objectbox\objectwd
106   \ht\objectbox\objectht
107   \dp\objectbox\objectdp}
108
109\unexpanded\def\getobject#1#2%
110  {\begingroup
111   \synctexpause
112   \clf_restoreobject{#1}{#2}%
113   \ifzeropt\objectoff\else
114     \objectoff-\objectoff
115     \pack_objects_package_yes\objectbox
116   \fi
117   \box\objectbox
118   \synctexresume
119   \endgroup}
120
121%D If needed one can ask for the dimensions of an object with:
122%D
123%D \starttyping
124%D \getobjectdimensions{class}{name}
125%D \stoptyping
126%D
127%D The results are reported in \type {\objectwidth}, \type {\objectheight} and \type
128%D {\objectdepth} as well as \type {\objectoffset}.
129
130\unexpanded\def\getobjectdimensions#1#2%
131  {\clf_getobjectdimensions{#1}{#2}}
132
133%D \macros
134%D   {doifobjectfoundelse,doifobjectreferencefoundelse}
135%D
136%D To prevent redundant definition of objects, one can use the next tests:
137%D
138%D \starttyping
139%D \doifobjectfoundelse{class}{object}{do then}{do else}
140%D \doifobjectreferencefoundelse{class}{object}{do then}{do else}
141%D \stoptyping
142
143\def\defaultobjectreference{0}
144\def\defaultobjectpage     {\realfolio}
145
146\unexpanded\def\dogetobjectreference        {\clf_getobjectreference}
147\unexpanded\def\dogetobjectreferencepage    {\clf_getobjectreferencepage}
148
149\unexpanded\def\doifelseobjectfound         {\clf_doifelseobject}
150\unexpanded\def\doifelseobjectreferencefound{\clf_doifelseobjectreference}
151
152\let\doifobjectfoundelse         \doifelseobjectfound
153\let\doifobjectreferencefoundelse\doifelseobjectreferencefound
154
155%D For the moment here:
156
157\let\lastpredefinedsymbol\empty % some day we can do more at the lua end
158
159\unexpanded\def\predefinesymbol[#1]%
160  {\begingroup
161   \xdef\lastpredefinedsymbol{#1}%
162   \settightobject{SYM}{#1}\hbox{\symbol[#1]}% to be checked ... maybe only fitting
163   \dogetobjectreference{SYM}{#1}\m_back_object_reference
164   \clf_registerbackendsymbol{#1}\m_back_object_reference\relax
165   \endgroup}
166
167\protect \endinput
168