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 <errno.h>
18#include <limits.h>
19#include <stdio.h>
20
21#include "../common/common.h"
22#include "vi.h"
23
24static void goto_adjust(VICMD *);
25
26/*
27 * The historic vi had a problem in that all movements were by physical
28 * lines, not by logical, or screen lines.  Arguments can be made that this
29 * is the right thing to do.  For example, single line movements, such as
30 * 'j' or 'k', should probably work on physical lines.  Commands like "dj",
31 * or "j.", where '.' is a change command, make more sense for physical lines
32 * than they do for logical lines.
33 *
34 * These arguments, however, don't apply to scrolling commands like ^D and
35 * ^F -- if the window is fairly small, using physical lines can result in
36 * a half-page scroll repainting the entire screen, which is not what the
37 * user wanted.  Second, if the line is larger than the screen, using physical
38 * lines can make it impossible to display parts of the line -- there aren't
39 * any commands that don't display the beginning of the line in historic vi,
40 * and if both the beginning and end of the line can't be on the screen at
41 * the same time, you lose.  This is even worse in the case of the H, L, and
42 * M commands -- for large lines, they may all refer to the same line and
43 * will result in no movement at all.
44 *
45 * Another issue is that page and half-page scrolling commands historically
46 * moved to the first non-blank character in the new line.  If the line is
47 * approximately the same size as the screen, this loses because the cursor
48 * before and after a ^D, may refer to the same location on the screen.  In
49 * this implementation, scrolling commands set the cursor to the first non-
50 * blank character if the line changes because of the scroll.  Otherwise,
51 * the cursor is left alone.
52 *
53 * This implementation does the scrolling (^B, ^D, ^F, ^U, ^Y, ^E), and the
54 * cursor positioning commands (H, L, M) commands using logical lines, not
55 * physical.
56 */
57
58/*
59 * v_lgoto -- [count]G
60 *	Go to first non-blank character of the line count, the last line
61 *	of the file by default.
62 *
63 * PUBLIC: int v_lgoto(SCR *, VICMD *);
64 */
65int
66v_lgoto(SCR *sp, VICMD *vp)
67{
68	recno_t nlines;
69
70	if (F_ISSET(vp, VC_C1SET)) {
71		if (!db_exist(sp, vp->count)) {
72			/*
73			 * !!!
74			 * Historically, 1G was legal in an empty file.
75			 */
76			if (vp->count == 1) {
77				if (db_last(sp, &nlines))
78					return (1);
79				if (nlines == 0)
80					return (0);
81			}
82			v_eof(sp, &vp->m_start);
83			return (1);
84		}
85		vp->m_stop.lno = vp->count;
86	} else {
87		if (db_last(sp, &nlines))
88			return (1);
89		vp->m_stop.lno = nlines ? nlines : 1;
90	}
91	goto_adjust(vp);
92	return (0);
93}
94
95/*
96 * v_home -- [count]H
97 *	Move to the first non-blank character of the logical line
98 *	count - 1 from the top of the screen, 0 by default.
99 *
100 * PUBLIC: int v_home(SCR *, VICMD *);
101 */
102int
103v_home(SCR *sp, VICMD *vp)
104{
105	if (vs_sm_position(sp, &vp->m_stop,
106	    F_ISSET(vp, VC_C1SET) ? vp->count - 1 : 0, P_TOP))
107		return (1);
108	goto_adjust(vp);
109	return (0);
110}
111
112/*
113 * v_middle -- M
114 *	Move to the first non-blank character of the logical line
115 *	in the middle of the screen.
116 *
117 * PUBLIC: int v_middle(SCR *, VICMD *);
118 */
119int
120v_middle(SCR *sp, VICMD *vp)
121{
122	/*
123	 * Yielding to none in our quest for compatibility with every
124	 * historical blemish of vi, no matter how strange it might be,
125	 * we permit the user to enter a count and then ignore it.
126	 */
127	if (vs_sm_position(sp, &vp->m_stop, 0, P_MIDDLE))
128		return (1);
129	goto_adjust(vp);
130	return (0);
131}
132
133/*
134 * v_bottom -- [count]L
135 *	Move to the first non-blank character of the logical line
136 *	count - 1 from the bottom of the screen, 0 by default.
137 *
138 * PUBLIC: int v_bottom(SCR *, VICMD *);
139 */
140int
141v_bottom(SCR *sp, VICMD *vp)
142{
143	if (vs_sm_position(sp, &vp->m_stop,
144	    F_ISSET(vp, VC_C1SET) ? vp->count - 1 : 0, P_BOTTOM))
145		return (1);
146	goto_adjust(vp);
147	return (0);
148}
149
150static void
151goto_adjust(VICMD *vp)
152{
153	/* Guess that it's the end of the range. */
154	vp->m_final = vp->m_stop;
155
156	/*
157	 * Non-motion commands move the cursor to the end of the range, and
158	 * then to the NEXT nonblank of the line.  Historic vi always moved
159	 * to the first nonblank in the line; since the H, M, and L commands
160	 * are logical motions in this implementation, we do the next nonblank
161	 * so that it looks approximately the same to the user.  To make this
162	 * happen, the VM_RCM_SETNNB flag is set in the vcmd.c command table.
163	 *
164	 * If it's a motion, it's more complicated.  The best possible solution
165	 * is probably to display the first nonblank of the line the cursor
166	 * will eventually rest on.  This is tricky, particularly given that if
167	 * the associated command is a delete, we don't yet know what line that
168	 * will be.  So, we clear the VM_RCM_SETNNB flag, and set the first
169	 * nonblank flag (VM_RCM_SETFNB).  Note, if the lines are sufficiently
170	 * long, this can cause the cursor to warp out of the screen.  It's too
171	 * hard to fix.
172	 *
173	 * XXX
174	 * The G command is always first nonblank, so it's okay to reset it.
175	 */
176	if (ISMOTION(vp)) {
177		F_CLR(vp, VM_RCM_MASK);
178		F_SET(vp, VM_RCM_SETFNB);
179	} else
180		return;
181
182	/*
183	 * If moving backward in the file, delete and yank move to the end
184	 * of the range, unless the line didn't change, in which case yank
185	 * doesn't move.  If moving forward in the file, delete and yank
186	 * stay at the start of the range.  Ignore others.
187	 */
188	if (vp->m_stop.lno < vp->m_start.lno ||
189	    (vp->m_stop.lno == vp->m_start.lno &&
190	    vp->m_stop.cno < vp->m_start.cno)) {
191		if (ISCMD(vp->rkp, 'y') && vp->m_stop.lno == vp->m_start.lno)
192			vp->m_final = vp->m_start;
193	} else
194		vp->m_final = vp->m_start;
195}
196
197/*
198 * v_up -- [count]^P, [count]k, [count]-
199 *	Move up by lines.
200 *
201 * PUBLIC: int v_up(SCR *, VICMD *);
202 */
203int
204v_up(SCR *sp, VICMD *vp)
205{
206	recno_t lno;
207
208	lno = F_ISSET(vp, VC_C1SET) ? vp->count : 1;
209	if (vp->m_start.lno <= lno) {
210		v_sof(sp, &vp->m_start);
211		return (1);
212	}
213	vp->m_stop.lno = vp->m_start.lno - lno;
214	vp->m_final = vp->m_stop;
215	return (0);
216}
217
218/*
219 * v_cr -- [count]^M
220 *	In a script window, send the line to the shell.
221 *	In a regular window, move down by lines.
222 *
223 * PUBLIC: int v_cr(SCR *, VICMD *);
224 */
225int
226v_cr(SCR *sp, VICMD *vp)
227{
228	/* If it's a colon command-line edit window, it's an ex command. */
229	if (F_ISSET(sp, SC_COMEDIT))
230		return (v_ecl_exec(sp));
231
232	/* If it's a script window, exec the line. */
233	if (F_ISSET(sp, SC_SCRIPT))
234		return (sscr_exec(sp, vp->m_start.lno));
235
236	/* Otherwise, it's the same as v_down(). */
237	return (v_down(sp, vp));
238}
239
240/*
241 * v_down -- [count]^J, [count]^N, [count]j, [count]^M, [count]+
242 *	Move down by lines.
243 *
244 * PUBLIC: int v_down(SCR *, VICMD *);
245 */
246int
247v_down(SCR *sp, VICMD *vp)
248{
249	recno_t lno;
250
251	lno = vp->m_start.lno + (F_ISSET(vp, VC_C1SET) ? vp->count : 1);
252	if (!db_exist(sp, lno)) {
253		v_eof(sp, &vp->m_start);
254		return (1);
255	}
256	vp->m_stop.lno = lno;
257	vp->m_final = ISMOTION(vp) ? vp->m_start : vp->m_stop;
258	return (0);
259}
260
261/*
262 * v_hpageup -- [count]^U
263 *	Page up half screens.
264 *
265 * PUBLIC: int v_hpageup(SCR *, VICMD *);
266 */
267int
268v_hpageup(SCR *sp, VICMD *vp)
269{
270	/*
271	 * Half screens always succeed unless already at SOF.
272	 *
273	 * !!!
274	 * Half screens set the scroll value, even if the command
275	 * ultimately failed, in historic vi.  Probably a don't care.
276	 */
277	if (F_ISSET(vp, VC_C1SET))
278		sp->defscroll = vp->count;
279	if (vs_sm_scroll(sp, &vp->m_stop, sp->defscroll, CNTRL_U))
280		return (1);
281	vp->m_final = vp->m_stop;
282	return (0);
283}
284
285/*
286 * v_hpagedown -- [count]^D
287 *	Page down half screens.
288 *
289 * PUBLIC: int v_hpagedown(SCR *, VICMD *);
290 */
291int
292v_hpagedown(SCR *sp, VICMD *vp)
293{
294	/*
295	 * Half screens always succeed unless already at EOF.
296	 *
297	 * !!!
298	 * Half screens set the scroll value, even if the command
299	 * ultimately failed, in historic vi.  Probably a don't care.
300	 */
301	if (F_ISSET(vp, VC_C1SET))
302		sp->defscroll = vp->count;
303	if (vs_sm_scroll(sp, &vp->m_stop, sp->defscroll, CNTRL_D))
304		return (1);
305	vp->m_final = vp->m_stop;
306	return (0);
307}
308
309/*
310 * v_pagedown -- [count]^F
311 *	Page down full screens.
312 * !!!
313 * Historic vi did not move to the EOF if the screen couldn't move, i.e.
314 * if EOF was already displayed on the screen.  This implementation does
315 * move to EOF in that case, making ^F more like the historic ^D.
316 *
317 * PUBLIC: int v_pagedown(SCR *, VICMD *);
318 */
319int
320v_pagedown(SCR *sp, VICMD *vp)
321{
322	recno_t offset;
323
324	/*
325	 * !!!
326	 * The calculation in IEEE Std 1003.2-1992 (POSIX) is:
327	 *
328	 *	top_line = top_line + count * (window - 2);
329	 *
330	 * which was historically wrong.  The correct one is:
331	 *
332	 *	top_line = top_line + count * window - 2;
333	 *
334	 * i.e. the two line "overlap" was only subtracted once.  Which
335	 * makes no sense, but then again, an overlap makes no sense for
336	 * any screen but the "next" one anyway.  We do it the historical
337	 * way as there's no good reason to change it.
338	 *
339	 * If the screen has been split horizontally, use the smaller of
340	 * the current window size and the window option value.
341	 *
342	 * It possible for this calculation to be less than 1; move at
343	 * least one line.
344	 */
345	offset = (F_ISSET(vp, VC_C1SET) ? vp->count : 1) * (IS_SPLIT(sp) ?
346	    MIN(sp->t_maxrows, O_VAL(sp, O_WINDOW)) : O_VAL(sp, O_WINDOW));
347	offset = offset <= 2 ? 1 : offset - 2;
348	if (vs_sm_scroll(sp, &vp->m_stop, offset, CNTRL_F))
349		return (1);
350	vp->m_final = vp->m_stop;
351	return (0);
352}
353
354/*
355 * v_pageup -- [count]^B
356 *	Page up full screens.
357 *
358 * !!!
359 * Historic vi did not move to the SOF if the screen couldn't move, i.e.
360 * if SOF was already displayed on the screen.  This implementation does
361 * move to SOF in that case, making ^B more like the historic ^U.
362 *
363 * PUBLIC: int v_pageup(SCR *, VICMD *);
364 */
365int
366v_pageup(SCR *sp, VICMD *vp)
367{
368	recno_t offset;
369
370	/*
371	 * !!!
372	 * The calculation in IEEE Std 1003.2-1992 (POSIX) is:
373	 *
374	 *	top_line = top_line - count * (window - 2);
375	 *
376	 * which was historically wrong.  The correct one is:
377	 *
378	 *	top_line = (top_line - count * window) + 2;
379	 *
380	 * A simpler expression is that, as with ^F, we scroll exactly:
381	 *
382	 *	count * window - 2
383	 *
384	 * lines.
385	 *
386	 * Bizarre.  As with ^F, an overlap makes no sense for anything
387	 * but the first screen.  We do it the historical way as there's
388	 * no good reason to change it.
389	 *
390	 * If the screen has been split horizontally, use the smaller of
391	 * the current window size and the window option value.
392	 *
393	 * It possible for this calculation to be less than 1; move at
394	 * least one line.
395	 */
396	offset = (F_ISSET(vp, VC_C1SET) ? vp->count : 1) * (IS_SPLIT(sp) ?
397	    MIN(sp->t_maxrows, O_VAL(sp, O_WINDOW)) : O_VAL(sp, O_WINDOW));
398	offset = offset <= 2 ? 1 : offset - 2;
399	if (vs_sm_scroll(sp, &vp->m_stop, offset, CNTRL_B))
400		return (1);
401	vp->m_final = vp->m_stop;
402	return (0);
403}
404
405/*
406 * v_lineup -- [count]^Y
407 *	Page up by lines.
408 *
409 * PUBLIC: int v_lineup(SCR *, VICMD *);
410 */
411int
412v_lineup(SCR *sp, VICMD *vp)
413{
414	/*
415	 * The cursor moves down, staying with its original line, unless it
416	 * reaches the bottom of the screen.
417	 */
418	if (vs_sm_scroll(sp,
419	    &vp->m_stop, F_ISSET(vp, VC_C1SET) ? vp->count : 1, CNTRL_Y))
420		return (1);
421	vp->m_final = vp->m_stop;
422	return (0);
423}
424
425/*
426 * v_linedown -- [count]^E
427 *	Page down by lines.
428 *
429 * PUBLIC: int v_linedown(SCR *, VICMD *);
430 */
431int
432v_linedown(SCR *sp, VICMD *vp)
433{
434	/*
435	 * The cursor moves up, staying with its original line, unless it
436	 * reaches the top of the screen.
437	 */
438	if (vs_sm_scroll(sp,
439	    &vp->m_stop, F_ISSET(vp, VC_C1SET) ? vp->count : 1, CNTRL_E))
440		return (1);
441	vp->m_final = vp->m_stop;
442	return (0);
443}
444