xref: /freebsd/contrib/less/mark.c (revision 40a8ac8f62b535d30349faf28cf47106b7041b83)
1 /*
2  * Copyright (C) 1984-2012  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  * A mark is an ifile (input file) plus a position within the file.
19  */
20 struct mark {
21 	IFILE m_ifile;
22 	struct scrpos m_scrpos;
23 };
24 
25 /*
26  * The table of marks.
27  * Each mark is identified by a lowercase or uppercase letter.
28  * The final one is lmark, for the "last mark"; addressed by the apostrophe.
29  */
30 #define	NMARKS		((2*26)+1)	/* a-z, A-Z, lastmark */
31 #define	LASTMARK	(NMARKS-1)
32 static struct mark marks[NMARKS];
33 
34 /*
35  * Initialize the mark table to show no marks are set.
36  */
37 	public void
38 init_mark()
39 {
40 	int i;
41 
42 	for (i = 0;  i < NMARKS;  i++)
43 		marks[i].m_scrpos.pos = NULL_POSITION;
44 }
45 
46 /*
47  * See if a mark letter is valid (between a and z).
48  */
49 	static struct mark *
50 getumark(c)
51 	int c;
52 {
53 	if (c >= 'a' && c <= 'z')
54 		return (&marks[c-'a']);
55 
56 	if (c >= 'A' && c <= 'Z')
57 		return (&marks[c-'A'+26]);
58 
59 	error("Invalid mark letter", NULL_PARG);
60 	return (NULL);
61 }
62 
63 /*
64  * Get the mark structure identified by a character.
65  * The mark struct may come either from the mark table
66  * or may be constructed on the fly for certain characters like ^, $.
67  */
68 	static struct mark *
69 getmark(c)
70 	int c;
71 {
72 	register struct mark *m;
73 	static struct mark sm;
74 
75 	switch (c)
76 	{
77 	case '^':
78 		/*
79 		 * Beginning of the current file.
80 		 */
81 		m = &sm;
82 		m->m_scrpos.pos = ch_zero();
83 		m->m_scrpos.ln = 0;
84 		m->m_ifile = curr_ifile;
85 		break;
86 	case '$':
87 		/*
88 		 * End of the current file.
89 		 */
90 		if (ch_end_seek())
91 		{
92 			error("Cannot seek to end of file", NULL_PARG);
93 			return (NULL);
94 		}
95 		m = &sm;
96 		m->m_scrpos.pos = ch_tell();
97 		m->m_scrpos.ln = sc_height-1;
98 		m->m_ifile = curr_ifile;
99 		break;
100 	case '.':
101 		/*
102 		 * Current position in the current file.
103 		 */
104 		m = &sm;
105 		get_scrpos(&m->m_scrpos);
106 		m->m_ifile = curr_ifile;
107 		break;
108 	case '\'':
109 		/*
110 		 * The "last mark".
111 		 */
112 		m = &marks[LASTMARK];
113 		break;
114 	default:
115 		/*
116 		 * Must be a user-defined mark.
117 		 */
118 		m = getumark(c);
119 		if (m == NULL)
120 			break;
121 		if (m->m_scrpos.pos == NULL_POSITION)
122 		{
123 			error("Mark not set", NULL_PARG);
124 			return (NULL);
125 		}
126 		break;
127 	}
128 	return (m);
129 }
130 
131 /*
132  * Is a mark letter is invalid?
133  */
134 	public int
135 badmark(c)
136 	int c;
137 {
138 	return (getmark(c) == NULL);
139 }
140 
141 /*
142  * Set a user-defined mark.
143  */
144 	public void
145 setmark(c)
146 	int c;
147 {
148 	register struct mark *m;
149 	struct scrpos scrpos;
150 
151 	m = getumark(c);
152 	if (m == NULL)
153 		return;
154 	get_scrpos(&scrpos);
155 	m->m_scrpos = scrpos;
156 	m->m_ifile = curr_ifile;
157 }
158 
159 /*
160  * Set lmark (the mark named by the apostrophe).
161  */
162 	public void
163 lastmark()
164 {
165 	struct scrpos scrpos;
166 
167 	if (ch_getflags() & CH_HELPFILE)
168 		return;
169 	get_scrpos(&scrpos);
170 	if (scrpos.pos == NULL_POSITION)
171 		return;
172 	marks[LASTMARK].m_scrpos = scrpos;
173 	marks[LASTMARK].m_ifile = curr_ifile;
174 }
175 
176 /*
177  * Go to a mark.
178  */
179 	public void
180 gomark(c)
181 	int c;
182 {
183 	register struct mark *m;
184 	struct scrpos scrpos;
185 
186 	m = getmark(c);
187 	if (m == NULL)
188 		return;
189 
190 	/*
191 	 * If we're trying to go to the lastmark and
192 	 * it has not been set to anything yet,
193 	 * set it to the beginning of the current file.
194 	 */
195 	if (m == &marks[LASTMARK] && m->m_scrpos.pos == NULL_POSITION)
196 	{
197 		m->m_ifile = curr_ifile;
198 		m->m_scrpos.pos = ch_zero();
199 		m->m_scrpos.ln = jump_sline;
200 	}
201 
202 	/*
203 	 * If we're using lmark, we must save the screen position now,
204 	 * because if we call edit_ifile() below, lmark will change.
205 	 * (We save the screen position even if we're not using lmark.)
206 	 */
207 	scrpos = m->m_scrpos;
208 	if (m->m_ifile != curr_ifile)
209 	{
210 		/*
211 		 * Not in the current file; edit the correct file.
212 		 */
213 		if (edit_ifile(m->m_ifile))
214 			return;
215 	}
216 
217 	jump_loc(scrpos.pos, scrpos.ln);
218 }
219 
220 /*
221  * Return the position associated with a given mark letter.
222  *
223  * We don't return which screen line the position
224  * is associated with, but this doesn't matter much,
225  * because it's always the first non-blank line on the screen.
226  */
227 	public POSITION
228 markpos(c)
229 	int c;
230 {
231 	register struct mark *m;
232 
233 	m = getmark(c);
234 	if (m == NULL)
235 		return (NULL_POSITION);
236 
237 	if (m->m_ifile != curr_ifile)
238 	{
239 		error("Mark not in current file", NULL_PARG);
240 		return (NULL_POSITION);
241 	}
242 	return (m->m_scrpos.pos);
243 }
244 
245 /*
246  * Clear the marks associated with a specified ifile.
247  */
248 	public void
249 unmark(ifile)
250 	IFILE ifile;
251 {
252 	int i;
253 
254 	for (i = 0;  i < NMARKS;  i++)
255 		if (marks[i].m_ifile == ifile)
256 			marks[i].m_scrpos.pos = NULL_POSITION;
257 }
258