1/*-
2 * Copyright (c) 1992, 1993, 1994
3 *	The Regents of the University of California.  All rights reserved.
4 * Copyright (c) 1992, 1993, 1994, 1995, 1996
5 *	Keith Bostic.  All rights reserved.
6 *
7 * See the LICENSE file for redistribution information.
8 */
9
10#include "config.h"
11
12#include <sys/types.h>
13#include <sys/queue.h>
14#include <sys/time.h>
15
16#include <bitstring.h>
17#include <limits.h>
18#include <stdio.h>
19#include <stdlib.h>
20#include <string.h>
21
22#include "../common/common.h"
23
24enum which {RETAB, LEFT, RIGHT};
25static int shift(SCR *, EXCMD *, enum which);
26
27/*
28 * ex_shiftl -- :<[<...]
29 *
30 *
31 * PUBLIC: int ex_shiftl(SCR *, EXCMD *);
32 */
33int
34ex_shiftl(SCR *sp, EXCMD *cmdp)
35{
36	return (shift(sp, cmdp, LEFT));
37}
38
39/*
40 * ex_shiftr -- :>[>...]
41 *
42 * PUBLIC: int ex_shiftr(SCR *, EXCMD *);
43 */
44int
45ex_shiftr(SCR *sp, EXCMD *cmdp)
46{
47	return (shift(sp, cmdp, RIGHT));
48}
49
50/*
51 * ex_retab -- Expand tabs (if enabled)
52 *
53 *
54 * PUBLIC: int ex_retab(SCR *, EXCMD *);
55 */
56int
57ex_retab(SCR *sp, EXCMD *cmdp)
58{
59	return (shift(sp, cmdp, RETAB));
60}
61
62/*
63 * shift --
64 *	Ex shift support.
65 */
66static int
67shift(SCR *sp, EXCMD *cmdp, enum which rl)
68{
69	recno_t from, to;
70	size_t blen, len, newcol, newidx, oldcol, oldidx, sw;
71	int curset;
72	CHAR_T *p;
73	CHAR_T *bp, *tbp;
74
75	NEEDFILE(sp, cmdp);
76
77	if (O_VAL(sp, O_SHIFTWIDTH) == 0) {
78		msgq(sp, M_INFO, "152|shiftwidth option set to 0");
79		return (0);
80	}
81
82	/* Copy the lines being shifted into the unnamed buffer. */
83	if (cut(sp, NULL, &cmdp->addr1, &cmdp->addr2, CUT_LINEMODE))
84		return (1);
85
86	/*
87	 * The historic version of vi permitted the user to string any number
88	 * of '>' or '<' characters together, resulting in an indent of the
89	 * appropriate levels.  There's a special hack in ex_cmd() so that
90	 * cmdp->argv[0] points to the string of '>' or '<' characters.
91	 *
92	 * Q: What's the difference between the people adding features
93	 *    to vi and the Girl Scouts?
94	 * A: The Girl Scouts have mint cookies and adult supervision.
95	 */
96	for (p = cmdp->argv[0]->bp, sw = 0; *p == '>' || *p == '<'; ++p)
97		sw += O_VAL(sp, O_SHIFTWIDTH);
98
99	GET_SPACE_RETW(sp, bp, blen, 256);
100
101	curset = 0;
102	for (from = cmdp->addr1.lno, to = cmdp->addr2.lno; from <= to; ++from) {
103		if (db_get(sp, from, DBG_FATAL, &p, &len))
104			goto err;
105		if (!len) {
106			if (sp->lno == from)
107				curset = 1;
108			continue;
109		}
110
111		/*
112		 * Calculate the old indent amount and the number of
113		 * characters it used.
114		 */
115		for (oldidx = 0, oldcol = 0; oldidx < len; ++oldidx)
116			if (p[oldidx] == ' ')
117				++oldcol;
118			else if (p[oldidx] == '\t')
119				oldcol += O_VAL(sp, O_TABSTOP) -
120				    oldcol % O_VAL(sp, O_TABSTOP);
121			else
122				break;
123
124		/* Calculate the new indent amount. */
125		if (rl == RETAB)
126			newcol = oldcol;
127		else if (rl == RIGHT)
128			newcol = oldcol + sw;
129		else {
130			newcol = oldcol < sw ? 0 : oldcol - sw;
131			if (newcol == oldcol) {
132				if (sp->lno == from)
133					curset = 1;
134				continue;
135			}
136		}
137
138		/* Get a buffer that will hold the new line. */
139		ADD_SPACE_RETW(sp, bp, blen, newcol + len);
140
141		/*
142		 * Build a new indent string and count the number of
143		 * characters it uses.
144		 */
145		tbp = bp;
146		newidx = 0;
147		if (!O_ISSET(sp, O_EXPANDTAB)) {
148			for (; newcol >= O_VAL(sp, O_TABSTOP); ++newidx) {
149				*tbp++ = '\t';
150				newcol -= O_VAL(sp, O_TABSTOP);
151			}
152		}
153		for (; newcol > 0; --newcol, ++newidx)
154			*tbp++ = ' ';
155
156		/* Add the original line. */
157		MEMCPY(tbp, p + oldidx, len - oldidx);
158
159		/* Set the replacement line. */
160		if (db_set(sp, from, bp, (tbp + (len - oldidx)) - bp)) {
161err:			FREE_SPACEW(sp, bp, blen);
162			return (1);
163		}
164
165		/*
166		 * !!!
167		 * The shift command in historic vi had the usual bizarre
168		 * collection of cursor semantics.  If called from vi, the
169		 * cursor was repositioned to the first non-blank character
170		 * of the lowest numbered line shifted.  If called from ex,
171		 * the cursor was repositioned to the first non-blank of the
172		 * highest numbered line shifted.  Here, if the cursor isn't
173		 * part of the set of lines that are moved, move it to the
174		 * first non-blank of the last line shifted.  (This makes
175		 * ":3>>" in vi work reasonably.)  If the cursor is part of
176		 * the shifted lines, it doesn't get moved at all.  This
177		 * permits shifting of marked areas, i.e. ">'a." shifts the
178		 * marked area twice, something that couldn't be done with
179		 * historic vi.
180		 */
181		if (sp->lno == from) {
182			curset = 1;
183			if (newidx > oldidx)
184				sp->cno += newidx - oldidx;
185			else if (sp->cno >= oldidx - newidx)
186				sp->cno -= oldidx - newidx;
187		}
188	}
189	if (!curset) {
190		sp->lno = to;
191		sp->cno = 0;
192		(void)nonblank(sp, to, &sp->cno);
193	}
194
195	FREE_SPACEW(sp, bp, blen);
196
197	sp->rptlines[L_SHIFT] += cmdp->addr2.lno - cmdp->addr1.lno + 1;
198	return (0);
199}
200