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comparison src/specifier.h @ 380:8626e4521993 r21-2-5

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Import from CVS: tag r21-2-5
author cvs
date Mon, 13 Aug 2007 11:07:10 +0200
parents 7df0dd720c89
children 74fd4e045ea6
comparison
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379:76b7d63099ad 380:8626e4521993
32 system provided specifications, reflecting user preferences on the 32 system provided specifications, reflecting user preferences on the
33 window system, such as default fonts, colors, scrollbar thickness 33 window system, such as default fonts, colors, scrollbar thickness
34 etc. 34 etc.
35 35
36 A magic specifier consists of two specifier objects. The first one 36 A magic specifier consists of two specifier objects. The first one
37 behaves like a normal specifier in all sences. The second one, a 37 behaves like a normal specifier in all senses. The second one, a
38 ghost specifier, is a fallback value for the first one, and contains 38 ghost specifier, is a fallback value for the first one, and contains
39 values provided by window system, resources etc. which reflect 39 values provided by window system, resources etc. which reflect
40 default settings for values being specified. 40 default settings for values being specified.
41 41
42 A magic specifier has an "ultimate" fallback value, as any usual 42 A magic specifier has an "ultimate" fallback value, as any usual
59 Vunlock_ghost_specifiers. It is not exposed to lisp, and is set 59 Vunlock_ghost_specifiers. It is not exposed to lisp, and is set
60 during calls to lisp functions which initialize global, device and 60 during calls to lisp functions which initialize global, device and
61 frame defaults, such as 61 frame defaults, such as
62 init-{global,frame,device}-{faces,toolbars,etc}. 62 init-{global,frame,device}-{faces,toolbars,etc}.
63 63
64 Thus, values supplied by resources or other means of a window system 64 Thus, values supplied by resources or other means of a window system
65 stored in externally unmodifiable ghost objects. Regular lisp code 65 stored in externally unmodifiable ghost objects. Regular lisp code
66 may thus freely modify the normal part of a magic specifier, and 66 may thus freely modify the normal part of a magic specifier, and
67 removing a specification for a particular domain causes the 67 removing a specification for a particular domain causes the
68 specification to consider ghost-provided fallback values, or its own 68 specification to consider ghost-provided fallback values, or its own
69 fallback value. 69 fallback value.
70 70
71 Rules of conduct for magic specifiers 71 Rules of conduct for magic specifiers
72 ------------------------------------- 72 -------------------------------------
73 1. recompute_*() functions always operate on the whole specifier 73 1. recompute_*() functions always operate on the whole specifier
74 when passed only a ghost object, by substituting it with their 74 when passed only a ghost object, by substituting it with their
75 parent bodily object. 75 parent bodily object.
76 2. All specifier methods, except for instantiate method, are passed 76 2. All specifier methods, except for instantiate method, are passed
77 the bodily object of the magic specifier. Instantiate method is 77 the bodily object of the magic specifier. Instantiate method is
78 passed the specifier being instantiated. 78 passed the specifier being instantiated.
79 3. Only bodily objects are passed to set_specifier_caching function, 79 3. Only bodily objects are passed to set_specifier_caching function,
80 and only these may be cached. 80 and only these may be cached.
81 4. All specifiers are added to Vall_specifiers list, both bodily and 81 4. All specifiers are added to Vall_specifiers list, both bodily and
82 ghost. The pair of objects is always removed from the list at the 82 ghost. The pair of objects is always removed from the list at the
83 same time. 83 same time.
84 */ 84 */
85 85
86 struct specifier_methods 86 struct specifier_methods
87 { 87 {
96 /* Mark method: Mark any lisp object within specifier data 96 /* Mark method: Mark any lisp object within specifier data
97 structure. Not required if no specifier data are Lisp_Objects. */ 97 structure. Not required if no specifier data are Lisp_Objects. */
98 void (*mark_method) (Lisp_Object specifier, void (*markobj) (Lisp_Object)); 98 void (*mark_method) (Lisp_Object specifier, void (*markobj) (Lisp_Object));
99 99
100 /* Equal method: Compare two specifiers. This is called after 100 /* Equal method: Compare two specifiers. This is called after
101 ensuring that the two specifiers are of the same type, and habe 101 ensuring that the two specifiers are of the same type, and have
102 the same specs. Quit is inhibited during the call so it is safe 102 the same specs. Quit is inhibited during the call so it is safe
103 to call internal_equal(). 103 to call internal_equal().
104 104
105 If this function is not present, specifiers considered equal when 105 If this function is not present, specifiers considered equal when
106 the above conditions are met, i.e. as if the method returned 106 the above conditions are met, i.e. as if the method returned
218 /* This can be either nil, for a plain, non-magic specifier object, 218 /* This can be either nil, for a plain, non-magic specifier object,
219 t for the normal part of the magic specifier, or #<specifier> for 219 t for the normal part of the magic specifier, or #<specifier> for
220 the ghost part of the magic specifier, a pointer to its parent 220 the ghost part of the magic specifier, a pointer to its parent
221 object */ 221 object */
222 Lisp_Object magic_parent; 222 Lisp_Object magic_parent;
223 223
224 /* Fallback value. For magic specifiers, it is a pointer to the ghost. */ 224 /* Fallback value. For magic specifiers, it is a pointer to the ghost. */
225 Lisp_Object fallback; 225 Lisp_Object fallback;
226 226
227 /* type-specific extra data attached to a specifier */ 227 /* type-specific extra data attached to a specifier */
228 char data[1]; 228 char data[1];
242 #define HAS_SPECMETH_P(sp, m) (!!RAW_SPECMETH (sp, m)) 242 #define HAS_SPECMETH_P(sp, m) (!!RAW_SPECMETH (sp, m))
243 #define SPECMETH(sp, m, args) (((sp)->methods->m##_method) args) 243 #define SPECMETH(sp, m, args) (((sp)->methods->m##_method) args)
244 244
245 /* Call a void-returning specifier method, if it exists. */ 245 /* Call a void-returning specifier method, if it exists. */
246 #define MAYBE_SPECMETH(sp, m, args) do { \ 246 #define MAYBE_SPECMETH(sp, m, args) do { \
247 struct Lisp_Specifier *_maybe_specmeth_sp = (sp); \ 247 struct Lisp_Specifier *maybe_specmeth_sp = (sp); \
248 if (HAS_SPECMETH_P (_maybe_specmeth_sp, m)) \ 248 if (HAS_SPECMETH_P (maybe_specmeth_sp, m)) \
249 SPECMETH (_maybe_specmeth_sp, m, args); \ 249 SPECMETH (maybe_specmeth_sp, m, args); \
250 } while (0) 250 } while (0)
251 251
252 /***** Defining new specifier types *****/ 252 /***** Defining new specifier types *****/
253 253
254 #ifdef ERROR_CHECK_TYPECHECK 254 #ifdef ERROR_CHECK_TYPECHECK