contrib/less/mark.c

   1 /*
   2  * Copyright (C) 1984-2015  Mark Nudelman
   3  *
   4  * You may distribute under the terms of either the GNU General Public
   5  * License or the Less License, as specified in the README file.
   6  *
   7  * For more information, see the README file.
   8  */
   9
  10
  11 #include "less.h"
  12
  13 extern IFILE curr_ifile;
  14 extern int sc_height;
  15 extern int jump_sline;
  16
  17 /*
  18  * The table of marks.
  19  * Each mark is identified by a lowercase or uppercase letter.
  20  * The final one is lmark, for the "last mark"; addressed by the apostrophe.
  21  */
  22 #define NMARKS          ((2*26)+1)      /* a-z, A-Z, lastmark */
  23 #define LASTMARK        (NMARKS-1)
  24 static struct mark marks[NMARKS];
  25
  26 /*
  27  * Initialize the mark table to show no marks are set.
  28  */
  29         public void
  30 init_mark()
  31 {
  32         int i;
  33
  34         for (i = 0;  i < NMARKS;  i++)
  35                 marks[i].m_scrpos.pos = NULL_POSITION;
  36 }
  37
  38 /*
  39  * See if a mark letter is valid (between a and z).
  40  */
  41         static struct mark *
  42 getumark(c)
  43         int c;
  44 {
  45         if (c >= 'a' && c <= 'z')
  46                 return (&marks[c-'a']);
  47
  48         if (c >= 'A' && c <= 'Z')
  49                 return (&marks[c-'A'+26]);
  50
  51         error("Invalid mark letter", NULL_PARG);
  52         return (NULL);
  53 }
  54
  55 /*
  56  * Get the mark structure identified by a character.
  57  * The mark struct may come either from the mark table
  58  * or may be constructed on the fly for certain characters like ^, $.
  59  */
  60         static struct mark *
  61 getmark(c)
  62         int c;
  63 {
  64         register struct mark *m;
  65         static struct mark sm;
  66
  67         switch (c)
  68         {
  69         case '^':
  70                 /*
  71                  * Beginning of the current file.
  72                  */
  73                 m = &sm;
  74                 m->m_scrpos.pos = ch_zero();
  75                 m->m_scrpos.ln = 0;
  76                 m->m_ifile = curr_ifile;
  77                 break;
  78         case '$':
  79                 /*
  80                  * End of the current file.
  81                  */
  82                 if (ch_end_seek())
  83                 {
  84                         error("Cannot seek to end of file", NULL_PARG);
  85                         return (NULL);
  86                 }
  87                 m = &sm;
  88                 m->m_scrpos.pos = ch_tell();
  89                 m->m_scrpos.ln = sc_height-1;
  90                 m->m_ifile = curr_ifile;
  91                 break;
  92         case '.':
  93                 /*
  94                  * Current position in the current file.
  95                  */
  96                 m = &sm;
  97                 get_scrpos(&m->m_scrpos);
  98                 m->m_ifile = curr_ifile;
  99                 break;
 100         case '\'':
 101                 /*
 102                  * The "last mark".
 103                  */
 104                 m = &marks[LASTMARK];
 105                 break;
 106         default:
 107                 /*
 108                  * Must be a user-defined mark.
 109                  */
 110                 m = getumark(c);
 111                 if (m == NULL)
 112                         break;
 113                 if (m->m_scrpos.pos == NULL_POSITION)
 114                 {
 115                         error("Mark not set", NULL_PARG);
 116                         return (NULL);
 117                 }
 118                 break;
 119         }
 120         return (m);
 121 }
 122
 123 /*
 124  * Is a mark letter is invalid?
 125  */
 126         public int
 127 badmark(c)
 128         int c;
 129 {
 130         return (getmark(c) == NULL);
 131 }
 132
 133 /*
 134  * Set a user-defined mark.
 135  */
 136         public void
 137 setmark(c)
 138         int c;
 139 {
 140         register struct mark *m;
 141         struct scrpos scrpos;
 142
 143         m = getumark(c);
 144         if (m == NULL)
 145                 return;
 146         get_scrpos(&scrpos);
 147         m->m_scrpos = scrpos;
 148         m->m_ifile = curr_ifile;
 149 }
 150
 151 /*
 152  * Set lmark (the mark named by the apostrophe).
 153  */
 154         public void
 155 lastmark()
 156 {
 157         struct scrpos scrpos;
 158
 159         if (ch_getflags() & CH_HELPFILE)
 160                 return;
 161         get_scrpos(&scrpos);
 162         if (scrpos.pos == NULL_POSITION)
 163                 return;
 164         marks[LASTMARK].m_scrpos = scrpos;
 165         marks[LASTMARK].m_ifile = curr_ifile;
 166 }
 167
 168 /*
 169  * Go to a mark.
 170  */
 171         public void
 172 gomark(c)
 173         int c;
 174 {
 175         register struct mark *m;
 176         struct scrpos scrpos;
 177
 178         m = getmark(c);
 179         if (m == NULL)
 180                 return;
 181
 182         /*
 183          * If we're trying to go to the lastmark and
 184          * it has not been set to anything yet,
 185          * set it to the beginning of the current file.
 186          */
 187         if (m == &marks[LASTMARK] && m->m_scrpos.pos == NULL_POSITION)
 188         {
 189                 m->m_ifile = curr_ifile;
 190                 m->m_scrpos.pos = ch_zero();
 191                 m->m_scrpos.ln = jump_sline;
 192         }
 193
 194         /*
 195          * If we're using lmark, we must save the screen position now,
 196          * because if we call edit_ifile() below, lmark will change.
 197          * (We save the screen position even if we're not using lmark.)
 198          */
 199         scrpos = m->m_scrpos;
 200         if (m->m_ifile != curr_ifile)
 201         {
 202                 /*
 203                  * Not in the current file; edit the correct file.
 204                  */
 205                 if (edit_ifile(m->m_ifile))
 206                         return;
 207         }
 208
 209         jump_loc(scrpos.pos, scrpos.ln);
 210 }
 211
 212 /*
 213  * Return the position associated with a given mark letter.
 214  *
 215  * We don't return which screen line the position
 216  * is associated with, but this doesn't matter much,
 217  * because it's always the first non-blank line on the screen.
 218  */
 219         public POSITION
 220 markpos(c)
 221         int c;
 222 {
 223         register struct mark *m;
 224
 225         m = getmark(c);
 226         if (m == NULL)
 227                 return (NULL_POSITION);
 228
 229         if (m->m_ifile != curr_ifile)
 230         {
 231                 error("Mark not in current file", NULL_PARG);
 232                 return (NULL_POSITION);
 233         }
 234         return (m->m_scrpos.pos);
 235 }
 236
 237 /*
 238  * Clear the marks associated with a specified ifile.
 239  */
 240         public void
 241 unmark(ifile)
 242         IFILE ifile;
 243 {
 244         int i;
 245
 246         for (i = 0;  i < NMARKS;  i++)
 247                 if (marks[i].m_ifile == ifile)
 248                         marks[i].m_scrpos.pos = NULL_POSITION;
 249 }