1/*	$NetBSD: ex_shift.c,v 1.3 2009/08/07 16:19:54 lukem Exp $ */
2
3/*-
4 * Copyright (c) 1992, 1993, 1994
5 *	The Regents of the University of California.  All rights reserved.
6 * Copyright (c) 1992, 1993, 1994, 1995, 1996
7 *	Keith Bostic.  All rights reserved.
8 *
9 * See the LICENSE file for redistribution information.
10 */
11
12#include "config.h"
13
14#ifndef lint
15static const char sccsid[] = "Id: ex_shift.c,v 10.17 2001/06/25 15:19:20 skimo Exp (Berkeley) Date: 2001/06/25 15:19:20";
16#endif /* not lint */
17
18#include <sys/types.h>
19#include <sys/queue.h>
20
21#include <bitstring.h>
22#include <limits.h>
23#include <stdio.h>
24#include <stdlib.h>
25#include <string.h>
26
27#include "../common/common.h"
28
29enum which {LEFT, RIGHT};
30static int shift __P((SCR *, EXCMD *, enum which));
31
32/*
33 * ex_shiftl -- :<[<...]
34 *
35 *
36 * PUBLIC: int ex_shiftl __P((SCR *, EXCMD *));
37 */
38int
39ex_shiftl(SCR *sp, EXCMD *cmdp)
40{
41	return (shift(sp, cmdp, LEFT));
42}
43
44/*
45 * ex_shiftr -- :>[>...]
46 *
47 * PUBLIC: int ex_shiftr __P((SCR *, EXCMD *));
48 */
49int
50ex_shiftr(SCR *sp, EXCMD *cmdp)
51{
52	return (shift(sp, cmdp, RIGHT));
53}
54
55/*
56 * shift --
57 *	Ex shift support.
58 */
59static int
60shift(SCR *sp, EXCMD *cmdp, enum which rl)
61{
62	db_recno_t from, to;
63	size_t blen, len, newcol, newidx, oldcol, oldidx, sw;
64	int curset;
65	CHAR_T *p;
66	CHAR_T *bp, *tbp;
67
68	NEEDFILE(sp, cmdp);
69
70	if (O_VAL(sp, O_SHIFTWIDTH) == 0) {
71		msgq(sp, M_INFO, "152|shiftwidth option set to 0");
72		return (0);
73	}
74
75	/* Copy the lines being shifted into the unnamed buffer. */
76	if (cut(sp, NULL, &cmdp->addr1, &cmdp->addr2, CUT_LINEMODE))
77		return (1);
78
79	/*
80	 * The historic version of vi permitted the user to string any number
81	 * of '>' or '<' characters together, resulting in an indent of the
82	 * appropriate levels.  There's a special hack in ex_cmd() so that
83	 * cmdp->argv[0] points to the string of '>' or '<' characters.
84	 *
85	 * Q: What's the difference between the people adding features
86	 *    to vi and the Girl Scouts?
87	 * A: The Girl Scouts have mint cookies and adult supervision.
88	 */
89	for (p = cmdp->argv[0]->bp, sw = 0; *p == '>' || *p == '<'; ++p)
90		sw += O_VAL(sp, O_SHIFTWIDTH);
91
92	GET_SPACE_RETW(sp, bp, blen, 256);
93
94	curset = 0;
95	for (from = cmdp->addr1.lno, to = cmdp->addr2.lno; from <= to; ++from) {
96		if (db_get(sp, from, DBG_FATAL, &p, &len))
97			goto err;
98		if (!len) {
99			if (sp->lno == from)
100				curset = 1;
101			continue;
102		}
103
104		/*
105		 * Calculate the old indent amount and the number of
106		 * characters it used.
107		 */
108		for (oldidx = 0, oldcol = 0; oldidx < len; ++oldidx)
109			if (p[oldidx] == ' ')
110				++oldcol;
111			else if (p[oldidx] == '\t')
112				oldcol += O_VAL(sp, O_TABSTOP) -
113				    oldcol % O_VAL(sp, O_TABSTOP);
114			else
115				break;
116
117		/* Calculate the new indent amount. */
118		if (rl == RIGHT)
119			newcol = oldcol + sw;
120		else {
121			newcol = oldcol < sw ? 0 : oldcol - sw;
122			if (newcol == oldcol) {
123				if (sp->lno == from)
124					curset = 1;
125				continue;
126			}
127		}
128
129		/* Get a buffer that will hold the new line. */
130		ADD_SPACE_RETW(sp, bp, blen, newcol + len);
131
132		/*
133		 * Build a new indent string and count the number of
134		 * characters it uses.
135		 */
136		tbp = bp;
137		newidx = 0;
138		if (!O_ISSET(sp, O_EXPANDTAB)) {
139			for (; newcol >= O_VAL(sp, O_TABSTOP); ++newidx) {
140				*tbp++ = '\t';
141				newcol -= O_VAL(sp, O_TABSTOP);
142			}
143		}
144		for (; newcol > 0; --newcol, ++newidx)
145			*tbp++ = ' ';
146
147		/* Add the original line. */
148		MEMCPYW(tbp, p + oldidx, len - oldidx);
149
150		/* Set the replacement line. */
151		if (db_set(sp, from, bp, (tbp + (len - oldidx)) - bp)) {
152err:			FREE_SPACEW(sp, bp, blen);
153			return (1);
154		}
155
156		/*
157		 * !!!
158		 * The shift command in historic vi had the usual bizarre
159		 * collection of cursor semantics.  If called from vi, the
160		 * cursor was repositioned to the first non-blank character
161		 * of the lowest numbered line shifted.  If called from ex,
162		 * the cursor was repositioned to the first non-blank of the
163		 * highest numbered line shifted.  Here, if the cursor isn't
164		 * part of the set of lines that are moved, move it to the
165		 * first non-blank of the last line shifted.  (This makes
166		 * ":3>>" in vi work reasonably.)  If the cursor is part of
167		 * the shifted lines, it doesn't get moved at all.  This
168		 * permits shifting of marked areas, i.e. ">'a." shifts the
169		 * marked area twice, something that couldn't be done with
170		 * historic vi.
171		 */
172		if (sp->lno == from) {
173			curset = 1;
174			if (newidx > oldidx)
175				sp->cno += newidx - oldidx;
176			else if (sp->cno >= oldidx - newidx)
177				sp->cno -= oldidx - newidx;
178		}
179	}
180	if (!curset) {
181		sp->lno = to;
182		sp->cno = 0;
183		(void)nonblank(sp, to, &sp->cno);
184	}
185
186	FREE_SPACEW(sp, bp, blen);
187
188	sp->rptlines[L_SHIFT] += cmdp->addr2.lno - cmdp->addr1.lno + 1;
189	return (0);
190}
191