ren.c

   1 /* rendering strings */
   2 #include <ctype.h>
   3 #include <stdio.h>
   4 #include <stdlib.h>
   5 #include <string.h>
   6 #include "vi.h"
   7
   8 /* specify the screen position of the characters in s */
   9 int *ren_position(char *s)
  10 {
  11         int i, n;
  12         char **chrs = uc_chop(s, &n);
  13         int *off, *pos;
  14         int diff = 0;
  15         pos = malloc((n + 1) * sizeof(pos[0]));
  16         for (i = 0; i < n; i++)
  17                 pos[i] = i;
  18         dir_reorder(s, pos);
  19         off = malloc(n * sizeof(off[0]));
  20         for (i = 0; i < n; i++)
  21                 off[pos[i]] = i;
  22         for (i = 0; i < n; i++) {
  23                 pos[off[i]] += diff;
  24                 if (*chrs[i] == '\t')
  25                         diff += 8 - (pos[off[i]] & 7) - 1;
  26         }
  27         pos[n] = n + diff;
  28         free(chrs);
  29         free(off);
  30         return pos;
  31 }
  32
  33 int ren_wid(char *s)
  34 {
  35         int *pos = ren_position(s);
  36         int n = uc_slen(s);
  37         int ret = pos[n];
  38         free(pos);
  39         return ret;
  40 }
  41
  42 char *ren_translate(char *s)
  43 {
  44         struct sbuf *sb = sbuf_make();
  45         char *r = s;
  46         while (*r) {
  47                 char *c = uc_shape(s, r);
  48                 if (!strcmp(c, "‌"))
  49                         c = "-";
  50                 if (!strcmp(c, "‍"))
  51                         c = "-";
  52                 sbuf_str(sb, c);
  53                 r = uc_next(r);
  54         }
  55         return sbuf_done(sb);
  56 }
  57
  58 /* find the next character after visual position p; if cur start from p itself */
  59 static int pos_next(int *pos, int n, int p, int cur)
  60 {
  61         int i, ret = -1;
  62         for (i = 0; i < n; i++)
  63                 if (pos[i] - !cur >= p && (ret < 0 || pos[i] < pos[ret]))
  64                         ret = i;
  65         return ret >= 0 ? pos[ret] : -1;
  66 }
  67
  68 /* find the previous character after visual position p; if cur start from p itself */
  69 static int pos_prev(int *pos, int n, int p, int cur)
  70 {
  71         int i, ret = -1;
  72         for (i = 0; i < n; i++)
  73                 if (pos[i] + !cur <= p && (ret < 0 || pos[i] > pos[ret]))
  74                         ret = i;
  75         return ret >= 0 ? pos[ret] : -1;
  76 }
  77
  78 /* convert visual position to character offset */
  79 int ren_pos(char *s, int off)
  80 {
  81         int n = uc_slen(s);
  82         int *pos = ren_position(s);
  83         int ret = off < n ? pos[off] : 0;
  84         free(pos);
  85         return ret;
  86 }
  87
  88 /* convert visual position to character offset */
  89 int ren_off(char *s, int p)
  90 {
  91         int off = -1;
  92         int n = uc_slen(s);
  93         int *pos = ren_position(s);
  94         int i;
  95         p = pos_prev(pos, n, p, 1);
  96         for (i = 0; i < n; i++)
  97                 if (pos[i] == p)
  98                         off = i;
  99         free(pos);
 100         return off >= 0 ? off : 0;
 101 }
 102
 103 /* adjust cursor position */
 104 int ren_cursor(char *s, int p)
 105 {
 106         int n, next;
 107         int *pos;
 108         if (!s)
 109                 return 0;
 110         n = uc_slen(s);
 111         pos = ren_position(s);
 112         p = pos_prev(pos, n, p, 1);
 113         next = pos_next(pos, n, p, 0);
 114         p = (next >= 0 ? next : pos[n]) - 1;
 115         free(pos);
 116         return p >= 0 ? p : 0;
 117 }
 118
 119 /* the position of the next character */
 120 int ren_next(char *s, int p, int dir)
 121 {
 122         int n = uc_slen(s);
 123         int *pos = ren_position(s);
 124         p = pos_prev(pos, n, p, 1);
 125         if (dir >= 0)
 126                 p = pos_next(pos, n, p, 0);
 127         else
 128                 p = pos_prev(pos, n, p, 0);
 129         free(pos);
 130         return p;
 131 }
 132
 133 static void swap(int *i1, int *i2)
 134 {
 135         int t = *i1;
 136         *i1 = *i2;
 137         *i2 = t;
 138 }
 139
 140 /* the region specified by two visual positions */
 141 int ren_region(char *s, int c1, int c2, int *l1, int *l2, int closed)
 142 {
 143         int *ord;               /* ord[i]: the order of the i-th char on the screen */
 144         int o1, o2;
 145         int beg, end;
 146         int n = uc_slen(s);
 147         int i;
 148         if (c1 == c2 && !closed) {
 149                 *l1 = ren_off(s, c1);
 150                 *l2 = ren_off(s, c2);
 151                 return 0;
 152         }
 153         ord = malloc(n * sizeof(ord[0]));
 154         for (i = 0; i < n; i++)
 155                 ord[i] = i;
 156         dir_reorder(s, ord);
 157
 158         if (c2 < c1)
 159                 swap(&c1, &c2);
 160         if (!closed)
 161                 c2 = ren_next(s, c2, -1);
 162         beg = ren_off(s, c1);
 163         end = ren_off(s, c2);
 164         if (end < beg)
 165                 swap(&beg, &end);
 166         o1 = ord[beg];
 167         o2 = ord[end];
 168         if (o2 < o1)
 169                 swap(&o1, &o2);
 170         for (i = beg; i <= end; i++)
 171                 if (ord[i] < o1 || ord[i] > o2)
 172                         break;
 173         *l1 = beg;
 174         *l2 = i;
 175         free(ord);
 176         return 0;
 177 }