gnu/dist/texinfo/info/footnotes.c

   1 /*      $NetBSD$        */
   2
   3 /* footnotes.c -- Some functions for manipulating footnotes.
   4    Id: footnotes.c,v 1.4 2004/04/11 17:56:45 karl Exp
   5
   6    Copyright (C) 1993, 1997, 1998, 1999, 2002, 2004 Free Software
   7    Foundation, Inc.
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 2, or (at your option)
  12    any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program; if not, write to the Free Software
  21    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  22
  23    Originally written by Brian Fox (bfox@ai.mit.edu). */
  24
  25 #include "info.h"
  26
  27 /* Nonzero means attempt to show footnotes when displaying a new window. */
  28 int auto_footnotes_p = 0;
  29
  30 static char *footnote_nodename = "*Footnotes*";
  31
  32 NODE * make_footnotes_node (NODE *node);
  33
  34 #define FOOTNOTE_HEADER_FORMAT \
  35    "*** Footnotes appearing in the node `%s' ***\n"
  36
  37 /* Find the window currently showing footnotes. */
  38 static WINDOW *
  39 find_footnotes_window (void)
  40 {
  41   WINDOW *win;
  42
  43   /* Try to find an existing window first. */
  44   for (win = windows; win; win = win->next)
  45     if (internal_info_node_p (win->node) &&
  46         (strcmp (win->node->nodename, footnote_nodename) == 0))
  47       break;
  48
  49   return (win);
  50 }
  51
  52 /* Manufacture a node containing the footnotes of this node, and
  53    return the manufactured node.  If NODE has no footnotes, return a
  54    NULL pointer. */
  55 NODE *
  56 make_footnotes_node (NODE *node)
  57 {
  58   NODE *fn_node, *result = (NODE *)NULL;
  59   long fn_start;
  60
  61   /* Make the initial assumption that the footnotes appear as simple
  62      text within this windows node. */
  63   fn_node = node;
  64
  65   /* See if this node contains the magic footnote label. */
  66   fn_start =
  67     info_search_in_node (FOOTNOTE_LABEL, node, 0, (WINDOW *)NULL, 1, 0);
  68
  69   /* If it doesn't, check to see if it has an associated footnotes node. */
  70   if (fn_start == -1)
  71     {
  72       REFERENCE **refs;
  73
  74       refs = info_xrefs_of_node (node);
  75
  76       if (refs)
  77         {
  78           register int i;
  79           char *refname;
  80           int reflen = strlen ("-Footnotes") + strlen (node->nodename);
  81
  82           refname = (char *)xmalloc (reflen + 1);
  83
  84           strcpy (refname, node->nodename);
  85           strcat (refname, "-Footnotes");
  86
  87           for (i = 0; refs[i]; i++)
  88             if ((refs[i]->nodename != (char *)NULL) &&
  89                 /* Support both the older "foo-Footnotes" and the new
  90                    style "foo-Footnote-NN" references.  */
  91                 (strcmp (refs[i]->nodename, refname) == 0 ||
  92                  (strncmp (refs[i]->nodename, refname, reflen - 1) == 0 &&
  93                   refs[i]->nodename[reflen - 1] == '-' &&
  94                   isdigit (refs[i]->nodename[reflen]))))
  95               {
  96                 char *filename;
  97
  98                 filename = node->parent;
  99                 if (!filename)
 100                   filename = node->filename;
 101
 102                 fn_node = info_get_node (filename, refname);
 103
 104                 if (fn_node)
 105                   fn_start = 0;
 106
 107                 break;
 108               }
 109
 110           free (refname);
 111           info_free_references (refs);
 112         }
 113     }
 114
 115   /* If we never found the start of a footnotes area, quit now. */
 116   if (fn_start == -1)
 117     return ((NODE *)NULL);
 118
 119   /* Make the new node. */
 120   result = (NODE *)xmalloc (sizeof (NODE));
 121   result->flags = 0;
 122   result->display_pos = 0;
 123
 124   /* Get the size of the footnotes appearing within this node. */
 125   {
 126     char *header;
 127     long text_start = fn_start;
 128
 129     header = (char *)xmalloc
 130       (1 + strlen (node->nodename) + strlen (FOOTNOTE_HEADER_FORMAT));
 131     sprintf (header, FOOTNOTE_HEADER_FORMAT, node->nodename);
 132
 133     /* Move the start of the displayed text to right after the first line.
 134        This effectively skips either "---- footno...", or "File: foo...". */
 135     while (text_start < fn_node->nodelen)
 136       if (fn_node->contents[text_start++] == '\n')
 137         break;
 138
 139     result->nodelen = strlen (header) + fn_node->nodelen - text_start;
 140
 141     /* Set the contents of this node. */
 142     result->contents = (char *)xmalloc (1 + result->nodelen);
 143     sprintf (result->contents, "%s", header);
 144     memcpy (result->contents + strlen (header),
 145             fn_node->contents + text_start, fn_node->nodelen - text_start);
 146
 147     name_internal_node (result, footnote_nodename);
 148     free (header);
 149   }
 150
 151 #if defined (NOTDEF)
 152   /* If the footnotes were gleaned from the node that we were called with,
 153      shorten the calling node's display length. */
 154   if (fn_node == node)
 155     narrow_node (node, 0, fn_start);
 156 #endif /* NOTDEF */
 157
 158   return (result);
 159 }
 160
 161 /* Create or delete the footnotes window depending on whether footnotes
 162    exist in WINDOW's node or not.  Returns FN_FOUND if footnotes were found
 163    and displayed.  Returns FN_UNFOUND if there were no footnotes found
 164    in WINDOW's node.  Returns FN_UNABLE if there were footnotes, but the
 165    window to show them couldn't be made. */
 166 int
 167 info_get_or_remove_footnotes (WINDOW *window)
 168 {
 169   WINDOW *fn_win;
 170   NODE *new_footnotes;
 171
 172   fn_win = find_footnotes_window ();
 173
 174   /* If we are in the footnotes window, change nothing. */
 175   if (fn_win == window)
 176     return (FN_FOUND);
 177
 178   /* Try to find footnotes for this window's node. */
 179   new_footnotes = make_footnotes_node (window->node);
 180
 181   /* If there was a window showing footnotes, and there are no footnotes
 182      for the current window, delete the old footnote window. */
 183   if (fn_win && !new_footnotes)
 184     {
 185       if (windows->next)
 186         info_delete_window_internal (fn_win);
 187     }
 188
 189   /* If there are footnotes for this window's node, but no window around
 190      showing footnotes, try to make a new window. */
 191   if (new_footnotes && !fn_win)
 192     {
 193       WINDOW *old_active;
 194       WINDOW *last, *win;
 195
 196       /* Always make this window be the last one appearing in the list.  Find
 197          the last window in the chain. */
 198       for (win = windows, last = windows; win; last = win, win = win->next);
 199
 200       /* Try to split this window, and make the split window the one to
 201          contain the footnotes. */
 202       old_active = active_window;
 203       active_window = last;
 204       fn_win = window_make_window (new_footnotes);
 205       active_window = old_active;
 206
 207       if (!fn_win)
 208         {
 209           free (new_footnotes->contents);
 210           free (new_footnotes);
 211
 212           /* If we are hacking automatic footnotes, and there are footnotes
 213              but we couldn't display them, print a message to that effect. */
 214           if (auto_footnotes_p)
 215             inform_in_echo_area ((char *) _("Footnotes could not be displayed"));
 216           return (FN_UNABLE);
 217         }
 218     }
 219
 220   /* If there are footnotes, and there is a window to display them,
 221      make that window be the number of lines appearing in the footnotes. */
 222   if (new_footnotes && fn_win)
 223     {
 224       window_set_node_of_window (fn_win, new_footnotes);
 225
 226       window_change_window_height
 227         (fn_win, fn_win->line_count - fn_win->height);
 228
 229       remember_window_and_node (fn_win, new_footnotes);
 230       add_gcable_pointer (new_footnotes->contents);
 231     }
 232
 233   if (!new_footnotes)
 234     return (FN_UNFOUND);
 235   else
 236     return (FN_FOUND);
 237 }
 238
 239 /* Show the footnotes associated with this node in another window. */
 240 DECLARE_INFO_COMMAND (info_show_footnotes,
 241    _("Show the footnotes associated with this node in another window"))
 242 {
 243   /* A negative argument means just make the window go away. */
 244   if (count < 0)
 245     {
 246       WINDOW *fn_win = find_footnotes_window ();
 247
 248       /* If there is an old footnotes window, and it isn't the only window
 249          on the screen, delete it. */
 250       if (fn_win && windows->next)
 251         info_delete_window_internal (fn_win);
 252     }
 253   else
 254     {
 255       int result;
 256
 257       result = info_get_or_remove_footnotes (window);
 258
 259       switch (result)
 260         {
 261         case FN_UNFOUND:
 262           info_error ((char *) msg_no_foot_node, NULL, NULL);
 263           break;
 264
 265         case FN_UNABLE:
 266           info_error ((char *) msg_win_too_small, NULL, NULL);
 267           break;
 268         }
 269     }
 270 }