src/glyphs.c

   1 /* Graphical symbols.
   2
   3    Copyright (C) 2020-2021 Free Software Foundation, Inc.
   4
   5    This file is part of Bison, the GNU Compiler Compiler.
   6
   7    This program is free software: you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation, either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  19
  20 #include <config.h>
  21
  22 #include "glyphs.h"
  23
  24 #include <assert.h>
  25 #include <attribute.h>
  26 #include <stdbool.h>
  27 #include <string.h>
  28 #include <mbswidth.h>
  29 #include <unicodeio.h>
  30
  31
  32 glyph_buffer_t arrow;
  33 int arrow_width;
  34
  35 glyph_buffer_t down_arrow;
  36 int down_arrow_width;
  37
  38 glyph_buffer_t dot;
  39 int dot_width;
  40
  41 glyph_buffer_t empty;
  42 int empty_width;
  43
  44 const char *derivation_separator = " ";
  45 int derivation_separator_width = 1;
  46
  47 typedef struct
  48 {
  49   glyph_buffer_t *pbuf;
  50   const char *fallback;
  51 } callback_arg_t;
  52
  53
  54 static long
  55 on_success (const char *buf, size_t buflen, void *callback_arg)
  56 {
  57   callback_arg_t *arg = (callback_arg_t *) callback_arg;
  58   assert (buflen + 1 < sizeof *arg->pbuf);
  59   *stpncpy (*arg->pbuf, buf, buflen) = '\0';
  60   return 1;
  61 }
  62
  63 static long
  64 on_failure (unsigned code MAYBE_UNUSED, const char *msg MAYBE_UNUSED,
  65             void *callback_arg)
  66 {
  67   callback_arg_t *arg = (callback_arg_t *) callback_arg;
  68   assert (strlen (arg->fallback) + 1 < sizeof *arg->pbuf);
  69   strcpy (*arg->pbuf, arg->fallback);
  70   return 0;
  71 }
  72
  73 static bool
  74 glyph_set (glyph_buffer_t *glyph, int *width,
  75            unsigned code, const char *fallback)
  76 {
  77   callback_arg_t arg = { glyph, fallback };
  78   int res = unicode_to_mb (code, on_success, on_failure, &arg);
  79   *width = mbswidth (*glyph, 0);
  80   return res;
  81 }
  82
  83 void
  84 glyphs_init (void)
  85 {
  86   glyph_set (&arrow,      &arrow_width,      0x2192, "->");
  87   glyph_set (&dot,        &dot_width,        0x2022, ".");
  88   glyph_set (&down_arrow, &down_arrow_width, 0x21b3, "`->");
  89   glyph_set (&empty,      &empty_width,      0x03b5, "%empty");
  90
  91   strncat (down_arrow, " ", sizeof down_arrow - strlen (down_arrow) - 1);
  92   down_arrow_width += 1;
  93 }