1 /*
2 This file is part of LilyPond, the GNU music typesetter.
3
4 Copyright (C) 1996--2020 Han-Wen Nienhuys <hanwen@xs4all.nl>
5
6 LilyPond is free software: you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation, either version 3 of the License, or
9 (at your option) any later version.
10
11 LilyPond is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with LilyPond. If not, see <http://www.gnu.org/licenses/>.
18 */
19
20 #ifndef ENGRAVER_HH
21 #define ENGRAVER_HH
22
23 #include "callback.hh"
24 #include "grob.hh"
25 #include "grob-info.hh"
26 #include "translator.hh"
27
28 /**
29 a struct which processes events, and creates the #Grob#s.
30 It may use derived classes.
31 */
32 class Engraver : public Translator
33 {
34 Grob *internal_make_grob (SCM sym, SCM cause,
35 char const *f, int l, char const *fun);
36 friend SCM ly_engraver_make_grob (SCM, SCM, SCM);
37 friend class Engraver_group;
38 protected:
39 /*
40 take note of item/spanner
41 put item in spanner. Adjust local key; etc.
42
43 Default: ignore the info
44 */
acknowledge_grob(Grob_info)45 virtual void acknowledge_grob (Grob_info) {}
46 virtual void announce_grob (Grob_info, Context *reroute_context = 0);
47 virtual void announce_end_grob (Grob_info, Context *reroute_context = 0);
48 Engraver_group *get_group () const;
49
50 public:
51 /**
52 Announce element. Default: pass on to daddy. Utility
53 */
54 void announce_grob (Grob *, SCM cause);
55 void announce_end_grob (Grob *, SCM cause);
56
57 Grob_info make_grob_info (Grob *, SCM cause);
58
59 Item *internal_make_item (SCM sym, SCM cause,
60 char const *f, int l, char const *fun);
61 Spanner *internal_make_spanner (SCM sym, SCM cause,
62 char const *f, int l, char const *fun);
63 Paper_column *internal_make_column (SCM sym,
64 char const *f, int l, char const *fun);
65
66 /**
67 override other ctor
68 */
69 OVERRIDE_CLASS_NAME (Engraver);
70 Engraver (Context *);
71 };
72
73 #define make_item(x, cause) internal_make_item (ly_symbol2scm (x), cause, __FILE__, __LINE__, __FUNCTION__)
74 #define make_spanner(x, cause) internal_make_spanner (ly_symbol2scm (x), cause, __FILE__, __LINE__, __FUNCTION__)
75 #define make_paper_column(x) internal_make_column (ly_symbol2scm (x), __FILE__, __LINE__, __FUNCTION__)
76
77 bool ly_is_grob_cause (SCM obj);
78
79 // Acknowledger trampolines
80 template <class T, void (T::*callback) (Grob_info)>
trampoline(SCM target,SCM grob,SCM source_engraver)81 SCM Callbacks::trampoline (SCM target, SCM grob, SCM source_engraver)
82 {
83 T *t = LY_ASSERT_SMOB (T, target, 1);
84 Grob *g = LY_ASSERT_SMOB (Grob, grob, 2);
85 Engraver *e = LY_ASSERT_SMOB (Engraver, source_engraver, 3);
86
87 (t->*callback) (Grob_info (e, g));
88 return SCM_UNSPECIFIED;
89 }
90
91 #endif // ENGRAVER_HH
92