1 /* footnotes.c -- Some functions for manipulating footnotes.
2 $Id: footnotes.c,v 1.4 2006/07/17 16:12:36 espie Exp $
3
4 Copyright (C) 1993, 1997, 1998, 1999, 2002, 2004 Free Software
5 Foundation, Inc.
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 2, or (at your option)
10 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, write to the Free Software
19 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
20
21 Originally written by Brian Fox (bfox@ai.mit.edu). */
22
23 #include "info.h"
24
25 /* Nonzero means attempt to show footnotes when displaying a new window. */
26 int auto_footnotes_p = 0;
27
28 static char *footnote_nodename = "*Footnotes*";
29
30 NODE * make_footnotes_node (NODE *node);
31
32 #define FOOTNOTE_HEADER_FORMAT \
33 "*** Footnotes appearing in the node `%s' ***\n"
34
35 /* Find the window currently showing footnotes. */
36 static WINDOW *
find_footnotes_window(void)37 find_footnotes_window (void)
38 {
39 WINDOW *win;
40
41 /* Try to find an existing window first. */
42 for (win = windows; win; win = win->next)
43 if (internal_info_node_p (win->node) &&
44 (strcmp (win->node->nodename, footnote_nodename) == 0))
45 break;
46
47 return (win);
48 }
49
50 /* Manufacture a node containing the footnotes of this node, and
51 return the manufactured node. If NODE has no footnotes, return a
52 NULL pointer. */
53 NODE *
make_footnotes_node(NODE * node)54 make_footnotes_node (NODE *node)
55 {
56 NODE *fn_node, *result = (NODE *)NULL;
57 long fn_start;
58
59 /* Make the initial assumption that the footnotes appear as simple
60 text within this windows node. */
61 fn_node = node;
62
63 /* See if this node contains the magic footnote label. */
64 fn_start =
65 info_search_in_node (FOOTNOTE_LABEL, node, 0, (WINDOW *)NULL, 1, 0);
66
67 /* If it doesn't, check to see if it has an associated footnotes node. */
68 if (fn_start == -1)
69 {
70 REFERENCE **refs;
71
72 refs = info_xrefs_of_node (node);
73
74 if (refs)
75 {
76 register int i;
77 char *refname;
78 int reflen = strlen ("-Footnotes") + strlen (node->nodename);
79
80 refname = (char *)xmalloc (reflen + 1);
81
82 strcpy (refname, node->nodename);
83 strcat (refname, "-Footnotes");
84
85 for (i = 0; refs[i]; i++)
86 if ((refs[i]->nodename != (char *)NULL) &&
87 /* Support both the older "foo-Footnotes" and the new
88 style "foo-Footnote-NN" references. */
89 (strcmp (refs[i]->nodename, refname) == 0 ||
90 (strncmp (refs[i]->nodename, refname, reflen - 1) == 0 &&
91 refs[i]->nodename[reflen - 1] == '-' &&
92 isdigit (refs[i]->nodename[reflen]))))
93 {
94 char *filename;
95
96 filename = node->parent;
97 if (!filename)
98 filename = node->filename;
99
100 fn_node = info_get_node (filename, refname);
101
102 if (fn_node)
103 fn_start = 0;
104
105 break;
106 }
107
108 free (refname);
109 info_free_references (refs);
110 }
111 }
112
113 /* If we never found the start of a footnotes area, quit now. */
114 if (fn_start == -1)
115 return ((NODE *)NULL);
116
117 /* Make the new node. */
118 result = (NODE *)xmalloc (sizeof (NODE));
119 result->flags = 0;
120 result->display_pos = 0;
121
122 /* Get the size of the footnotes appearing within this node. */
123 {
124 char *header;
125 long text_start = fn_start;
126
127 header = (char *)xmalloc
128 (1 + strlen (node->nodename) + strlen (FOOTNOTE_HEADER_FORMAT));
129 sprintf (header, FOOTNOTE_HEADER_FORMAT, node->nodename);
130
131 /* Move the start of the displayed text to right after the first line.
132 This effectively skips either "---- footno...", or "File: foo...". */
133 while (text_start < fn_node->nodelen)
134 if (fn_node->contents[text_start++] == '\n')
135 break;
136
137 result->nodelen = strlen (header) + fn_node->nodelen - text_start;
138
139 /* Set the contents of this node. */
140 result->contents = (char *)xmalloc (1 + result->nodelen);
141 sprintf (result->contents, "%s", header);
142 memcpy (result->contents + strlen (header),
143 fn_node->contents + text_start, fn_node->nodelen - text_start);
144
145 name_internal_node (result, footnote_nodename);
146 free (header);
147 }
148
149 #if defined (NOTDEF)
150 /* If the footnotes were gleaned from the node that we were called with,
151 shorten the calling node's display length. */
152 if (fn_node == node)
153 narrow_node (node, 0, fn_start);
154 #endif /* NOTDEF */
155
156 return (result);
157 }
158
159 /* Create or delete the footnotes window depending on whether footnotes
160 exist in WINDOW's node or not. Returns FN_FOUND if footnotes were found
161 and displayed. Returns FN_UNFOUND if there were no footnotes found
162 in WINDOW's node. Returns FN_UNABLE if there were footnotes, but the
163 window to show them couldn't be made. */
164 int
info_get_or_remove_footnotes(WINDOW * window)165 info_get_or_remove_footnotes (WINDOW *window)
166 {
167 WINDOW *fn_win;
168 NODE *new_footnotes;
169
170 fn_win = find_footnotes_window ();
171
172 /* If we are in the footnotes window, change nothing. */
173 if (fn_win == window)
174 return (FN_FOUND);
175
176 /* Try to find footnotes for this window's node. */
177 new_footnotes = make_footnotes_node (window->node);
178
179 /* If there was a window showing footnotes, and there are no footnotes
180 for the current window, delete the old footnote window. */
181 if (fn_win && !new_footnotes)
182 {
183 if (windows->next)
184 info_delete_window_internal (fn_win);
185 }
186
187 /* If there are footnotes for this window's node, but no window around
188 showing footnotes, try to make a new window. */
189 if (new_footnotes && !fn_win)
190 {
191 WINDOW *old_active;
192 WINDOW *last, *win;
193
194 /* Always make this window be the last one appearing in the list. Find
195 the last window in the chain. */
196 for (win = windows, last = windows; win; last = win, win = win->next);
197
198 /* Try to split this window, and make the split window the one to
199 contain the footnotes. */
200 old_active = active_window;
201 active_window = last;
202 fn_win = window_make_window (new_footnotes);
203 active_window = old_active;
204
205 if (!fn_win)
206 {
207 free (new_footnotes->contents);
208 free (new_footnotes);
209
210 /* If we are hacking automatic footnotes, and there are footnotes
211 but we couldn't display them, print a message to that effect. */
212 if (auto_footnotes_p)
213 inform_in_echo_area ((char *) _("Footnotes could not be displayed"));
214 return (FN_UNABLE);
215 }
216 }
217
218 /* If there are footnotes, and there is a window to display them,
219 make that window be the number of lines appearing in the footnotes. */
220 if (new_footnotes && fn_win)
221 {
222 window_set_node_of_window (fn_win, new_footnotes);
223
224 window_change_window_height
225 (fn_win, fn_win->line_count - fn_win->height);
226
227 remember_window_and_node (fn_win, new_footnotes);
228 add_gcable_pointer (new_footnotes->contents);
229 }
230
231 if (!new_footnotes)
232 return (FN_UNFOUND);
233 else
234 return (FN_FOUND);
235 }
236
237 /* Show the footnotes associated with this node in another window. */
238 DECLARE_INFO_COMMAND (info_show_footnotes,
239 _("Show the footnotes associated with this node in another window"))
240 {
241 /* A negative argument means just make the window go away. */
242 if (count < 0)
243 {
244 WINDOW *fn_win = find_footnotes_window ();
245
246 /* If there is an old footnotes window, and it isn't the only window
247 on the screen, delete it. */
248 if (fn_win && windows->next)
249 info_delete_window_internal (fn_win);
250 }
251 else
252 {
253 int result;
254
255 result = info_get_or_remove_footnotes (window);
256
257 switch (result)
258 {
259 case FN_UNFOUND:
260 info_error ((char *) msg_no_foot_node, NULL, NULL);
261 break;
262
263 case FN_UNABLE:
264 info_error ((char *) msg_win_too_small, NULL, NULL);
265 break;
266 }
267 }
268 }
269