Format and improve documentation of internal grob properties.
[lilypond.git] / lily / grob-property.cc
blob55b06d6dfa2f522052b929b881bf2a974d7609c4
1 /*
2 Implement storage and manipulation of grob properties.
3 */
5 #include <cstring>
7 #include "main.hh"
8 #include "input.hh"
9 #include "pointer-group-interface.hh"
10 #include "misc.hh"
11 #include "paper-score.hh"
12 #include "output-def.hh"
13 #include "spanner.hh"
14 #include "international.hh"
15 #include "item.hh"
16 #include "misc.hh"
17 #include "item.hh"
18 #include "program-option.hh"
19 #include "profile.hh"
20 #include "simple-closure.hh"
21 #include "warn.hh"
22 #include "protected-scm.hh"
24 Protected_scm grob_property_callback_stack = SCM_EOL;
26 extern bool debug_property_callbacks;
28 #ifndef NDEBUG
29 static void
30 print_property_callback_stack ()
32 int frame = 0;
33 for (SCM s = grob_property_callback_stack; scm_is_pair (s); s = scm_cdr (s))
34 message (_f ("%d: %s", frame++, ly_scm_write_string (scm_car (s)).c_str ()));
36 #endif
38 static SCM modification_callback = SCM_EOL;
39 static SCM cache_callback = SCM_EOL;
44 FIXME: this should use ly:set-option interface instead.
48 LY_DEFINE (ly_set_grob_modification_callback, "ly:set-grob-modification-callback",
49 1, 0, 0, (SCM cb),
50 "Specify a procedure that will be called every time LilyPond"
51 " modifies a grob property. The callback will receive as"
52 " arguments the grob that is being modified, the name of the"
53 " C++ file in which the modification was requested, the line"
54 " number in the C++ file in which the modification was requested,"
55 " the name of the function in which the modification was"
56 " requested, the property to be changed, and the new value for"
57 " the property.")
59 modification_callback = (ly_is_procedure (cb)) ? cb : SCM_BOOL_F;
60 return SCM_UNSPECIFIED;
63 LY_DEFINE (ly_set_property_cache_callback, "ly:set-property-cache-callback",
64 1, 0, 0, (SCM cb),
65 "Specify a procedure that will be called whenever lilypond"
66 " calculates a callback function and caches the result. The"
67 " callback will receive as arguments the grob whose property it"
68 " is, the name of the property, the name of the callback that"
69 " calculated the property, and the new (cached) value of the"
70 " property.")
72 cache_callback = (ly_is_procedure (cb)) ? cb : SCM_BOOL_F;
73 return SCM_UNSPECIFIED;
77 void
78 Grob::instrumented_set_property (SCM sym, SCM v,
79 char const *file,
80 int line,
81 char const *fun)
83 #ifndef NDEBUG
84 if (ly_is_procedure (modification_callback))
85 scm_apply_0 (modification_callback,
86 scm_list_n (self_scm (),
87 scm_from_locale_string (file),
88 scm_from_int (line),
89 scm_from_locale_string (fun),
90 sym, v, SCM_UNDEFINED));
91 #else
92 (void) file;
93 (void) line;
94 (void) fun;
95 #endif
97 internal_set_property (sym, v);
101 Grob::get_property_alist_chain (SCM def) const
103 return scm_list_n (mutable_property_alist_,
104 immutable_property_alist_,
105 def,
106 SCM_UNDEFINED);
109 extern void check_interfaces_for_property (Grob const *me, SCM sym);
111 void
112 Grob::internal_set_property (SCM sym, SCM v)
114 internal_set_value_on_alist (&mutable_property_alist_,
115 sym, v);
119 void
120 Grob::internal_set_value_on_alist (SCM *alist, SCM sym, SCM v)
122 /* Perhaps we simply do the assq_set, but what the heck. */
123 if (!is_live ())
124 return;
126 if (do_internal_type_checking_global)
128 if (!ly_is_procedure (v)
129 && !is_simple_closure (v)
130 && v != ly_symbol2scm ("calculation-in-progress"))
131 type_check_assignment (sym, v, ly_symbol2scm ("backend-type?"));
133 check_interfaces_for_property (this, sym);
136 *alist = scm_assq_set_x (*alist, sym, v);
140 Grob::internal_get_property_data (SCM sym) const
142 #ifndef NDEBUG
143 if (profile_property_accesses)
144 note_property_access (&grob_property_lookup_table, sym);
145 #endif
147 SCM handle = scm_sloppy_assq (sym, mutable_property_alist_);
148 if (handle != SCM_BOOL_F)
149 return scm_cdr (handle);
151 handle = scm_sloppy_assq (sym, immutable_property_alist_);
153 if (do_internal_type_checking_global && scm_is_pair (handle))
155 SCM val = scm_cdr (handle);
156 if (!ly_is_procedure (val) && !is_simple_closure (val))
157 type_check_assignment (sym, val, ly_symbol2scm ("backend-type?"));
159 check_interfaces_for_property (this, sym);
162 return (handle == SCM_BOOL_F) ? SCM_EOL : scm_cdr (handle);
166 Grob::internal_get_property (SCM sym) const
168 SCM val = get_property_data (sym);
170 #ifndef NDEBUG
171 if (val == ly_symbol2scm ("calculation-in-progress"))
173 programming_error (_f ("cyclic dependency: calculation-in-progress encountered for #'%s (%s)",
174 ly_symbol2string (sym).c_str (),
175 name ().c_str ()));
176 if (debug_property_callbacks)
178 message ("backtrace: ");
179 print_property_callback_stack ();
182 #endif
184 if (ly_is_procedure (val)
185 || is_simple_closure (val))
187 Grob *me = ((Grob*)this);
188 val = me->try_callback_on_alist (&me->mutable_property_alist_, sym, val);
191 return val;
195 Grob::try_callback_on_alist (SCM *alist, SCM sym, SCM proc)
197 SCM marker = ly_symbol2scm ("calculation-in-progress");
199 need to put a value in SYM to ensure that we don't get a
200 cyclic call chain.
202 *alist = scm_assq_set_x (*alist, sym, marker);
204 #ifndef NDEBUG
205 if (debug_property_callbacks)
206 grob_property_callback_stack = scm_cons (scm_list_3 (self_scm (), sym, proc), grob_property_callback_stack);
207 #endif
209 SCM value = SCM_EOL;
210 if (ly_is_procedure (proc))
211 value = scm_call_1 (proc, self_scm ());
212 else if (is_simple_closure (proc))
214 value = evaluate_with_simple_closure (self_scm (),
215 simple_closure_expression (proc),
216 false, 0, 0);
219 #ifndef NDEBUG
220 if (debug_property_callbacks)
221 grob_property_callback_stack = scm_cdr (grob_property_callback_stack);
222 #endif
225 If the function returns SCM_UNSPECIFIED, we assume the
226 property has been set with an explicit set_property ()
227 call.
229 if (value == SCM_UNSPECIFIED)
231 value = get_property_data (sym);
232 assert (value == SCM_EOL || value == marker);
233 if (value == marker)
234 *alist = scm_assq_remove_x (*alist, marker);
236 else
238 #ifndef NDEBUG
239 if (ly_is_procedure (cache_callback))
240 scm_apply_0 (cache_callback,
241 scm_list_n (self_scm (),
242 sym,
243 proc,
244 value,
245 SCM_UNDEFINED));
246 #endif
247 internal_set_value_on_alist (alist, sym, value);
250 return value;
253 void
254 Grob::internal_set_object (SCM s, SCM v)
256 /* Perhaps we simply do the assq_set, but what the heck. */
257 if (!is_live ())
258 return;
260 object_alist_ = scm_assq_set_x (object_alist_, s, v);
263 void
264 Grob::internal_del_property (SCM sym)
266 mutable_property_alist_ = scm_assq_remove_x (mutable_property_alist_, sym);
270 Grob::internal_get_object (SCM sym) const
272 if (profile_property_accesses)
273 note_property_access (&grob_property_lookup_table, sym);
275 SCM s = scm_sloppy_assq (sym, object_alist_);
277 if (s != SCM_BOOL_F)
279 SCM val = scm_cdr (s);
280 if (ly_is_procedure (val)
281 || is_simple_closure (val))
283 Grob *me = ((Grob*)this);
284 val = me->try_callback_on_alist (&me->object_alist_, sym, val);
287 return val;
290 return SCM_EOL;
293 bool
294 Grob::is_live () const
296 return scm_is_pair (immutable_property_alist_);
299 bool
300 Grob::internal_has_interface (SCM k)
302 return scm_c_memq (k, interfaces_) != SCM_BOOL_F;
306 call_pure_function (SCM unpure, SCM args, int start, int end)
308 SCM scm_call_pure_function = ly_lily_module_constant ("call-pure-function");
310 return scm_apply_0 (scm_call_pure_function,
311 scm_list_4 (unpure, args, scm_from_int (start), scm_from_int (end)));