xref: /freebsd/contrib/less/mark.c (revision 2be1a816b9ff69588e55be0a84cbe2a31efc0f2f)
1 /*
2  * Copyright (C) 1984-2007  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 about less, or for information on how to
8  * contact the author, see the README file.
9  */
10 
11 
12 #include "less.h"
13 
14 extern IFILE curr_ifile;
15 extern int sc_height;
16 extern int jump_sline;
17 
18 /*
19  * A mark is an ifile (input file) plus a position within the file.
20  */
21 struct mark {
22 	IFILE m_ifile;
23 	struct scrpos m_scrpos;
24 };
25 
26 /*
27  * The table of marks.
28  * Each mark is identified by a lowercase or uppercase letter.
29  * The final one is lmark, for the "last mark"; addressed by the apostrophe.
30  */
31 #define	NMARKS		((2*26)+1)	/* a-z, A-Z, lastmark */
32 #define	LASTMARK	(NMARKS-1)
33 static struct mark marks[NMARKS];
34 
35 /*
36  * Initialize the mark table to show no marks are set.
37  */
38 	public void
39 init_mark()
40 {
41 	int i;
42 
43 	for (i = 0;  i < NMARKS;  i++)
44 		marks[i].m_scrpos.pos = NULL_POSITION;
45 }
46 
47 /*
48  * See if a mark letter is valid (between a and z).
49  */
50 	static struct mark *
51 getumark(c)
52 	int c;
53 {
54 	if (c >= 'a' && c <= 'z')
55 		return (&marks[c-'a']);
56 
57 	if (c >= 'A' && c <= 'Z')
58 		return (&marks[c-'A'+26]);
59 
60 	error("Invalid mark letter", NULL_PARG);
61 	return (NULL);
62 }
63 
64 /*
65  * Get the mark structure identified by a character.
66  * The mark struct may come either from the mark table
67  * or may be constructed on the fly for certain characters like ^, $.
68  */
69 	static struct mark *
70 getmark(c)
71 	int c;
72 {
73 	register struct mark *m;
74 	static struct mark sm;
75 
76 	switch (c)
77 	{
78 	case '^':
79 		/*
80 		 * Beginning of the current file.
81 		 */
82 		m = &sm;
83 		m->m_scrpos.pos = ch_zero();
84 		m->m_scrpos.ln = 0;
85 		m->m_ifile = curr_ifile;
86 		break;
87 	case '$':
88 		/*
89 		 * End of the current file.
90 		 */
91 		if (ch_end_seek())
92 		{
93 			error("Cannot seek to end of file", NULL_PARG);
94 			return (NULL);
95 		}
96 		m = &sm;
97 		m->m_scrpos.pos = ch_tell();
98 		m->m_scrpos.ln = sc_height-1;
99 		m->m_ifile = curr_ifile;
100 		break;
101 	case '.':
102 		/*
103 		 * Current position in the current file.
104 		 */
105 		m = &sm;
106 		get_scrpos(&m->m_scrpos);
107 		m->m_ifile = curr_ifile;
108 		break;
109 	case '\'':
110 		/*
111 		 * The "last mark".
112 		 */
113 		m = &marks[LASTMARK];
114 		break;
115 	default:
116 		/*
117 		 * Must be a user-defined mark.
118 		 */
119 		m = getumark(c);
120 		if (m == NULL)
121 			break;
122 		if (m->m_scrpos.pos == NULL_POSITION)
123 		{
124 			error("Mark not set", NULL_PARG);
125 			return (NULL);
126 		}
127 		break;
128 	}
129 	return (m);
130 }
131 
132 /*
133  * Is a mark letter is invalid?
134  */
135 	public int
136 badmark(c)
137 	int c;
138 {
139 	return (getmark(c) == NULL);
140 }
141 
142 /*
143  * Set a user-defined mark.
144  */
145 	public void
146 setmark(c)
147 	int c;
148 {
149 	register struct mark *m;
150 	struct scrpos scrpos;
151 
152 	m = getumark(c);
153 	if (m == NULL)
154 		return;
155 	get_scrpos(&scrpos);
156 	m->m_scrpos = scrpos;
157 	m->m_ifile = curr_ifile;
158 }
159 
160 /*
161  * Set lmark (the mark named by the apostrophe).
162  */
163 	public void
164 lastmark()
165 {
166 	struct scrpos scrpos;
167 
168 	if (ch_getflags() & CH_HELPFILE)
169 		return;
170 	get_scrpos(&scrpos);
171 	if (scrpos.pos == NULL_POSITION)
172 		return;
173 	marks[LASTMARK].m_scrpos = scrpos;
174 	marks[LASTMARK].m_ifile = curr_ifile;
175 }
176 
177 /*
178  * Go to a mark.
179  */
180 	public void
181 gomark(c)
182 	int c;
183 {
184 	register struct mark *m;
185 	struct scrpos scrpos;
186 
187 	m = getmark(c);
188 	if (m == NULL)
189 		return;
190 
191 	/*
192 	 * If we're trying to go to the lastmark and
193 	 * it has not been set to anything yet,
194 	 * set it to the beginning of the current file.
195 	 */
196 	if (m == &marks[LASTMARK] && m->m_scrpos.pos == NULL_POSITION)
197 	{
198 		m->m_ifile = curr_ifile;
199 		m->m_scrpos.pos = ch_zero();
200 		m->m_scrpos.ln = jump_sline;
201 	}
202 
203 	/*
204 	 * If we're using lmark, we must save the screen position now,
205 	 * because if we call edit_ifile() below, lmark will change.
206 	 * (We save the screen position even if we're not using lmark.)
207 	 */
208 	scrpos = m->m_scrpos;
209 	if (m->m_ifile != curr_ifile)
210 	{
211 		/*
212 		 * Not in the current file; edit the correct file.
213 		 */
214 		if (edit_ifile(m->m_ifile))
215 			return;
216 	}
217 
218 	jump_loc(scrpos.pos, scrpos.ln);
219 }
220 
221 /*
222  * Return the position associated with a given mark letter.
223  *
224  * We don't return which screen line the position
225  * is associated with, but this doesn't matter much,
226  * because it's always the first non-blank line on the screen.
227  */
228 	public POSITION
229 markpos(c)
230 	int c;
231 {
232 	register struct mark *m;
233 
234 	m = getmark(c);
235 	if (m == NULL)
236 		return (NULL_POSITION);
237 
238 	if (m->m_ifile != curr_ifile)
239 	{
240 		error("Mark not in current file", NULL_PARG);
241 		return (NULL_POSITION);
242 	}
243 	return (m->m_scrpos.pos);
244 }
245 
246 /*
247  * Clear the marks associated with a specified ifile.
248  */
249 	public void
250 unmark(ifile)
251 	IFILE ifile;
252 {
253 	int i;
254 
255 	for (i = 0;  i < NMARKS;  i++)
256 		if (marks[i].m_ifile == ifile)
257 			marks[i].m_scrpos.pos = NULL_POSITION;
258 }
259