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);
  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 int ren_last(char *s)
  59 {
  60         int n = uc_slen(s);
  61         int *pos = ren_position(s);
  62         int ret = n ? pos[n - 1] : 0;
  63         free(pos);
  64         return ret;
  65 }
  66
  67 /* find the next character after visual position p; if cur start from p itself */
  68 static int pos_next(int *pos, int n, int p, int cur)
  69 {
  70         int i, ret = -1;
  71         for (i = 0; i < n; i++)
  72                 if (pos[i] - !cur >= p && (ret < 0 || pos[i] < pos[ret]))
  73                         ret = i;
  74         return ret >= 0 ? pos[ret] : -1;
  75 }
  76
  77 /* find the previous character after visual position p; if cur start from p itself */
  78 static int pos_prev(int *pos, int n, int p, int cur)
  79 {
  80         int i, ret = -1;
  81         for (i = 0; i < n; i++)
  82                 if (pos[i] + !cur <= p && (ret < 0 || pos[i] > pos[ret]))
  83                         ret = i;
  84         return ret >= 0 ? pos[ret] : -1;
  85 }
  86
  87 /* convert visual position to character offset */
  88 int ren_pos(char *s, int off)
  89 {
  90         int n = uc_slen(s);
  91         int *pos = ren_position(s);
  92         int ret = off < n ? pos[off] : 0;
  93         free(pos);
  94         return ret;
  95 }
  96
  97 /* convert visual position to character offset */
  98 int ren_off(char *s, int p)
  99 {
 100         int off = -1;
 101         int n = uc_slen(s);
 102         int *pos = ren_position(s);
 103         int i;
 104         p = pos_prev(pos, n, p, 1);
 105         for (i = 0; i < n; i++)
 106                 if (pos[i] == p)
 107                         off = i;
 108         free(pos);
 109         return off >= 0 ? off : 0;
 110 }
 111
 112 /* adjust cursor position */
 113 int ren_cursor(char *s, int p)
 114 {
 115         int n, next;
 116         int *pos;
 117         if (!s)
 118                 return 0;
 119         n = uc_slen(s);
 120         pos = ren_position(s);
 121         p = pos_prev(pos, n, p, 1);
 122         next = pos_next(pos, n, p, 0);
 123         p = (next >= 0 ? next : pos[n]) - 1;
 124         free(pos);
 125         return p >= 0 ? p : 0;
 126 }
 127
 128 /* the position of the next character */
 129 int ren_next(char *s, int p, int dir)
 130 {
 131         int n = uc_slen(s);
 132         int *pos = ren_position(s);
 133         p = pos_prev(pos, n, p, 1);
 134         if (dir >= 0)
 135                 p = pos_next(pos, n, p, 0);
 136         else
 137                 p = pos_prev(pos, n, p, 0);
 138         free(pos);
 139         return p;
 140 }
 141
 142 static void swap(int *i1, int *i2)
 143 {
 144         int t = *i1;
 145         *i1 = *i2;
 146         *i2 = t;
 147 }
 148
 149 /* the region specified by two visual positions */
 150 int ren_region(char *s, int c1, int c2, int *l1, int *l2, int closed)
 151 {
 152         int *ord;               /* ord[i]: the order of the i-th char on the screen */
 153         int o1, o2;
 154         int beg, end;
 155         int n = uc_slen(s);
 156         int i;
 157         if (c1 == c2 && !closed) {
 158                 *l1 = ren_off(s, c1);
 159                 *l2 = ren_off(s, c2);
 160                 return 0;
 161         }
 162         ord = malloc(n * sizeof(ord[0]));
 163         for (i = 0; i < n; i++)
 164                 ord[i] = i;
 165         dir_reorder(s, ord);
 166
 167         if (c2 < c1)
 168                 swap(&c1, &c2);
 169         if (!closed)
 170                 c2 = ren_next(s, c2, -1);
 171         beg = ren_off(s, c1);
 172         end = ren_off(s, c2);
 173         if (end < beg)
 174                 swap(&beg, &end);
 175         o1 = ord[beg];
 176         o2 = ord[end];
 177         if (o2 < o1)
 178                 swap(&o1, &o2);
 179         for (i = beg; i <= end; i++)
 180                 if (ord[i] < o1 || ord[i] > o2)
 181                         break;
 182         *l1 = beg;
 183         *l2 = i;
 184         free(ord);
 185         return 0;
 186 }