vs_split.c revision 19305
1/*-
2 * Copyright (c) 1993, 1994
3 *	The Regents of the University of California.  All rights reserved.
4 * Copyright (c) 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#ifndef lint
13static const char sccsid[] = "@(#)vs_split.c	10.31 (Berkeley) 10/13/96";
14#endif /* not lint */
15
16#include <sys/types.h>
17#include <sys/queue.h>
18#include <sys/time.h>
19
20#include <bitstring.h>
21#include <errno.h>
22#include <limits.h>
23#include <stdio.h>
24#include <stdlib.h>
25#include <string.h>
26
27#include "../common/common.h"
28#include "vi.h"
29
30static SCR *vs_getbg __P((SCR *, char *));
31
32/*
33 * vs_split --
34 *	Create a new screen.
35 *
36 * PUBLIC: int vs_split __P((SCR *, SCR *, int));
37 */
38int
39vs_split(sp, new, ccl)
40	SCR *sp, *new;
41	int ccl;		/* Colon-command line split. */
42{
43	GS *gp;
44	SMAP *smp;
45	size_t half;
46	int issmallscreen, splitup;
47
48	gp = sp->gp;
49
50	/* Check to see if it's possible. */
51	/* XXX: The IS_ONELINE fix will change this, too. */
52	if (sp->rows < 4) {
53		msgq(sp, M_ERR,
54		    "222|Screen must be larger than %d lines to split", 4 - 1);
55		return (1);
56	}
57
58	/* Wait for any messages in the screen. */
59	vs_resolve(sp, NULL, 1);
60
61	half = sp->rows / 2;
62	if (ccl && half > 6)
63		half = 6;
64
65	/* Get a new screen map. */
66	CALLOC(sp, _HMAP(new), SMAP *, SIZE_HMAP(sp), sizeof(SMAP));
67	if (_HMAP(new) == NULL)
68		return (1);
69	_HMAP(new)->lno = sp->lno;
70	_HMAP(new)->coff = 0;
71	_HMAP(new)->soff = 1;
72
73	/*
74	 * Small screens: see vs_refresh.c section 6a.  Set a flag so
75	 * we know to fix the screen up later.
76	 */
77	issmallscreen = IS_SMALL(sp);
78
79	/* The columns in the screen don't change. */
80	new->cols = sp->cols;
81
82	/*
83	 * Split the screen, and link the screens together.  If creating a
84	 * screen to edit the colon command line or the cursor is in the top
85	 * half of the current screen, the new screen goes under the current
86	 * screen.  Else, it goes above the current screen.
87	 *
88	 * Recalculate current cursor position based on sp->lno, we're called
89	 * with the cursor on the colon command line.  Then split the screen
90	 * in half and update the shared information.
91	 */
92	splitup =
93	    !ccl && (vs_sm_cursor(sp, &smp) ? 0 : (smp - HMAP) + 1) >= half;
94	if (splitup) {				/* Old is bottom half. */
95		new->rows = sp->rows - half;	/* New. */
96		new->woff = sp->woff;
97		sp->rows = half;		/* Old. */
98		sp->woff += new->rows;
99						/* Link in before old. */
100		CIRCLEQ_INSERT_BEFORE(&gp->dq, sp, new, q);
101
102		/*
103		 * If the parent is the bottom half of the screen, shift
104		 * the map down to match on-screen text.
105		 */
106		memmove(_HMAP(sp), _HMAP(sp) + new->rows,
107		    (sp->t_maxrows - new->rows) * sizeof(SMAP));
108	} else {				/* Old is top half. */
109		new->rows = half;		/* New. */
110		sp->rows -= half;		/* Old. */
111		new->woff = sp->woff + sp->rows;
112						/* Link in after old. */
113		CIRCLEQ_INSERT_AFTER(&gp->dq, sp, new, q);
114	}
115
116	/* Adjust maximum text count. */
117	sp->t_maxrows = IS_ONELINE(sp) ? 1 : sp->rows - 1;
118	new->t_maxrows = IS_ONELINE(new) ? 1 : new->rows - 1;
119
120	/*
121	 * Small screens: see vs_refresh.c, section 6a.
122	 *
123	 * The child may have different screen options sizes than the parent,
124	 * so use them.  Guarantee that text counts aren't larger than the
125	 * new screen sizes.
126	 */
127	if (issmallscreen) {
128		/* Fix the text line count for the parent. */
129		if (splitup)
130			sp->t_rows -= new->rows;
131
132		/* Fix the parent screen. */
133		if (sp->t_rows > sp->t_maxrows)
134			sp->t_rows = sp->t_maxrows;
135		if (sp->t_minrows > sp->t_maxrows)
136			sp->t_minrows = sp->t_maxrows;
137
138		/* Fix the child screen. */
139		new->t_minrows = new->t_rows = O_VAL(sp, O_WINDOW);
140		if (new->t_rows > new->t_maxrows)
141			new->t_rows = new->t_maxrows;
142		if (new->t_minrows > new->t_maxrows)
143			new->t_minrows = new->t_maxrows;
144	} else {
145		sp->t_minrows = sp->t_rows = IS_ONELINE(sp) ? 1 : sp->rows - 1;
146
147		/*
148		 * The new screen may be a small screen, even if the parent
149		 * was not.  Don't complain if O_WINDOW is too large, we're
150		 * splitting the screen so the screen is much smaller than
151		 * normal.
152		 */
153		new->t_minrows = new->t_rows = O_VAL(sp, O_WINDOW);
154		if (new->t_rows > new->rows - 1)
155			new->t_minrows = new->t_rows =
156			    IS_ONELINE(new) ? 1 : new->rows - 1;
157	}
158
159	/* Adjust the ends of the new and old maps. */
160	_TMAP(sp) = IS_ONELINE(sp) ?
161	    _HMAP(sp) : _HMAP(sp) + (sp->t_rows - 1);
162	_TMAP(new) = IS_ONELINE(new) ?
163	    _HMAP(new) : _HMAP(new) + (new->t_rows - 1);
164
165	/* Reset the length of the default scroll. */
166	if ((sp->defscroll = sp->t_maxrows / 2) == 0)
167		sp->defscroll = 1;
168	if ((new->defscroll = new->t_maxrows / 2) == 0)
169		new->defscroll = 1;
170
171	/*
172	 * Initialize the screen flags:
173	 *
174	 * If we're in vi mode in one screen, we don't have to reinitialize.
175	 * This isn't just a cosmetic fix.  The path goes like this:
176	 *
177	 *	return into vi(), SC_SSWITCH set
178	 *	call vs_refresh() with SC_STATUS set
179	 *	call vs_resolve to display the status message
180	 *	call vs_refresh() because the SC_SCR_VI bit isn't set
181	 *
182	 * Things go downhill at this point.
183	 *
184	 * Draw the new screen from scratch, and add a status line.
185	 */
186	F_SET(new,
187	    SC_SCR_REFORMAT | SC_STATUS |
188	    F_ISSET(sp, SC_EX | SC_VI | SC_SCR_VI | SC_SCR_EX));
189	return (0);
190}
191
192/*
193 * vs_discard --
194 *	Discard the screen, folding the real-estate into a related screen,
195 *	if one exists, and return that screen.
196 *
197 * PUBLIC: int vs_discard __P((SCR *, SCR **));
198 */
199int
200vs_discard(sp, spp)
201	SCR *sp, **spp;
202{
203	SCR *nsp;
204	dir_t dir;
205
206	/*
207	 * Save the old screen's cursor information.
208	 *
209	 * XXX
210	 * If called after file_end(), and the underlying file was a tmp
211	 * file, it may have gone away.
212	 */
213	if (sp->frp != NULL) {
214		sp->frp->lno = sp->lno;
215		sp->frp->cno = sp->cno;
216		F_SET(sp->frp, FR_CURSORSET);
217	}
218
219	/*
220	 * Add into a previous screen and then into a subsequent screen, as
221	 * they're the closest to the current screen.  If that doesn't work,
222	 * there was no screen to join.
223	 */
224	if ((nsp = sp->q.cqe_prev) != (void *)&sp->gp->dq) {
225		nsp->rows += sp->rows;
226		sp = nsp;
227		dir = FORWARD;
228	} else if ((nsp = sp->q.cqe_next) != (void *)&sp->gp->dq) {
229		nsp->woff = sp->woff;
230		nsp->rows += sp->rows;
231		sp = nsp;
232		dir = BACKWARD;
233	} else
234		sp = NULL;
235
236	if (spp != NULL)
237		*spp = sp;
238	if (sp == NULL)
239		return (0);
240
241	/*
242	 * Make no effort to clean up the discarded screen's information.  If
243	 * it's not exiting, we'll do the work when the user redisplays it.
244	 *
245	 * Small screens: see vs_refresh.c section 6a.  Adjust text line info,
246	 * unless it's a small screen.
247	 *
248	 * Reset the length of the default scroll.
249	 */
250	if (!IS_SMALL(sp))
251		sp->t_rows = sp->t_minrows = sp->rows - 1;
252	sp->t_maxrows = sp->rows - 1;
253	sp->defscroll = sp->t_maxrows / 2;
254	*(HMAP + (sp->t_rows - 1)) = *TMAP;
255	TMAP = HMAP + (sp->t_rows - 1);
256
257	/*
258	 * Draw the new screen from scratch, and add a status line.
259	 *
260	 * XXX
261	 * We could play games with the map, if this were ever to be a
262	 * performance problem, but I wrote the code a few times and it
263	 * was never clean or easy.
264	 */
265	switch (dir) {
266	case FORWARD:
267		vs_sm_fill(sp, OOBLNO, P_TOP);
268		break;
269	case BACKWARD:
270		vs_sm_fill(sp, OOBLNO, P_BOTTOM);
271		break;
272	default:
273		abort();
274	}
275
276	F_SET(sp, SC_STATUS);
277	return (0);
278}
279
280/*
281 * vs_fg --
282 *	Background the current screen, and foreground a new one.
283 *
284 * PUBLIC: int vs_fg __P((SCR *, SCR **, CHAR_T *, int));
285 */
286int
287vs_fg(sp, nspp, name, newscreen)
288	SCR *sp, **nspp;
289	CHAR_T *name;
290	int newscreen;
291{
292	GS *gp;
293	SCR *nsp;
294
295	gp = sp->gp;
296
297	if (newscreen)
298		/* Get the specified background screen. */
299		nsp = vs_getbg(sp, name);
300	else
301		/* Swap screens. */
302		if (vs_swap(sp, &nsp, name))
303			return (1);
304
305	if ((*nspp = nsp) == NULL) {
306		msgq_str(sp, M_ERR, name,
307		    name == NULL ?
308		    "223|There are no background screens" :
309		    "224|There's no background screen editing a file named %s");
310		return (1);
311	}
312
313	if (newscreen) {
314		/* Remove the new screen from the background queue. */
315		CIRCLEQ_REMOVE(&gp->hq, nsp, q);
316
317		/* Split the screen; if we fail, hook the screen back in. */
318		if (vs_split(sp, nsp, 0)) {
319			CIRCLEQ_INSERT_TAIL(&gp->hq, nsp, q);
320			return (1);
321		}
322	} else {
323		/* Move the old screen to the background queue. */
324		CIRCLEQ_REMOVE(&gp->dq, sp, q);
325		CIRCLEQ_INSERT_TAIL(&gp->hq, sp, q);
326	}
327	return (0);
328}
329
330/*
331 * vs_bg --
332 *	Background the screen, and switch to the next one.
333 *
334 * PUBLIC: int vs_bg __P((SCR *));
335 */
336int
337vs_bg(sp)
338	SCR *sp;
339{
340	GS *gp;
341	SCR *nsp;
342
343	gp = sp->gp;
344
345	/* Try and join with another screen. */
346	if (vs_discard(sp, &nsp))
347		return (1);
348	if (nsp == NULL) {
349		msgq(sp, M_ERR,
350		    "225|You may not background your only displayed screen");
351		return (1);
352	}
353
354	/* Move the old screen to the background queue. */
355	CIRCLEQ_REMOVE(&gp->dq, sp, q);
356	CIRCLEQ_INSERT_TAIL(&gp->hq, sp, q);
357
358	/* Toss the screen map. */
359	free(_HMAP(sp));
360	_HMAP(sp) = NULL;
361
362	/* Switch screens. */
363	sp->nextdisp = nsp;
364	F_SET(sp, SC_SSWITCH);
365
366	return (0);
367}
368
369/*
370 * vs_swap --
371 *	Swap the current screen with a backgrounded one.
372 *
373 * PUBLIC: int vs_swap __P((SCR *, SCR **, char *));
374 */
375int
376vs_swap(sp, nspp, name)
377	SCR *sp, **nspp;
378	char *name;
379{
380	GS *gp;
381	SCR *nsp;
382
383	gp = sp->gp;
384
385	/* Get the specified background screen. */
386	if ((*nspp = nsp = vs_getbg(sp, name)) == NULL)
387		return (0);
388
389	/*
390	 * Save the old screen's cursor information.
391	 *
392	 * XXX
393	 * If called after file_end(), and the underlying file was a tmp
394	 * file, it may have gone away.
395	 */
396	if (sp->frp != NULL) {
397		sp->frp->lno = sp->lno;
398		sp->frp->cno = sp->cno;
399		F_SET(sp->frp, FR_CURSORSET);
400	}
401
402	/* Switch screens. */
403	sp->nextdisp = nsp;
404	F_SET(sp, SC_SSWITCH);
405
406	/* Initialize terminal information. */
407	VIP(nsp)->srows = VIP(sp)->srows;
408
409	/* Initialize screen information. */
410	nsp->cols = sp->cols;
411	nsp->rows = sp->rows;	/* XXX: Only place in vi that sets rows. */
412	nsp->woff = sp->woff;
413
414	/*
415	 * Small screens: see vs_refresh.c, section 6a.
416	 *
417	 * The new screens may have different screen options sizes than the
418	 * old one, so use them.  Make sure that text counts aren't larger
419	 * than the new screen sizes.
420	 */
421	if (IS_SMALL(nsp)) {
422		nsp->t_minrows = nsp->t_rows = O_VAL(nsp, O_WINDOW);
423		if (nsp->t_rows > sp->t_maxrows)
424			nsp->t_rows = nsp->t_maxrows;
425		if (nsp->t_minrows > sp->t_maxrows)
426			nsp->t_minrows = nsp->t_maxrows;
427	} else
428		nsp->t_rows = nsp->t_maxrows = nsp->t_minrows = nsp->rows - 1;
429
430	/* Reset the length of the default scroll. */
431	nsp->defscroll = nsp->t_maxrows / 2;
432
433	/* Allocate a new screen map. */
434	CALLOC_RET(nsp, _HMAP(nsp), SMAP *, SIZE_HMAP(nsp), sizeof(SMAP));
435	_TMAP(nsp) = _HMAP(nsp) + (nsp->t_rows - 1);
436
437	/* Fill the map. */
438	if (vs_sm_fill(nsp, nsp->lno, P_FILL))
439		return (1);
440
441	/*
442	 * The new screen replaces the old screen in the parent/child list.
443	 * We insert the new screen after the old one.  If we're exiting,
444	 * the exit will delete the old one, if we're foregrounding, the fg
445	 * code will move the old one to the background queue.
446	 */
447	CIRCLEQ_REMOVE(&gp->hq, nsp, q);
448	CIRCLEQ_INSERT_AFTER(&gp->dq, sp, nsp, q);
449
450	/*
451	 * Don't change the screen's cursor information other than to
452	 * note that the cursor is wrong.
453	 */
454	F_SET(VIP(nsp), VIP_CUR_INVALID);
455
456	/* Draw the new screen from scratch, and add a status line. */
457	F_SET(nsp, SC_SCR_REDRAW | SC_STATUS);
458	return (0);
459}
460
461/*
462 * vs_resize --
463 *	Change the absolute size of the current screen.
464 *
465 * PUBLIC: int vs_resize __P((SCR *, long, adj_t));
466 */
467int
468vs_resize(sp, count, adj)
469	SCR *sp;
470	long count;
471	adj_t adj;
472{
473	GS *gp;
474	SCR *g, *s;
475	size_t g_off, s_off;
476
477	gp = sp->gp;
478
479	/*
480	 * Figure out which screens will grow, which will shrink, and
481	 * make sure it's possible.
482	 */
483	if (count == 0)
484		return (0);
485	if (adj == A_SET) {
486		if (sp->t_maxrows == count)
487			return (0);
488		if (sp->t_maxrows > count) {
489			adj = A_DECREASE;
490			count = sp->t_maxrows - count;
491		} else {
492			adj = A_INCREASE;
493			count = count - sp->t_maxrows;
494		}
495	}
496
497	g_off = s_off = 0;
498	if (adj == A_DECREASE) {
499		if (count < 0)
500			count = -count;
501		s = sp;
502		if (s->t_maxrows < MINIMUM_SCREEN_ROWS + count)
503			goto toosmall;
504		if ((g = sp->q.cqe_prev) == (void *)&gp->dq) {
505			if ((g = sp->q.cqe_next) == (void *)&gp->dq)
506				goto toobig;
507			g_off = -count;
508		} else
509			s_off = count;
510	} else {
511		g = sp;
512		if ((s = sp->q.cqe_next) != (void *)&gp->dq)
513			if (s->t_maxrows < MINIMUM_SCREEN_ROWS + count)
514				s = NULL;
515			else
516				s_off = count;
517		else
518			s = NULL;
519		if (s == NULL) {
520			if ((s = sp->q.cqe_prev) == (void *)&gp->dq) {
521toobig:				msgq(sp, M_BERR, adj == A_DECREASE ?
522				    "227|The screen cannot shrink" :
523				    "228|The screen cannot grow");
524				return (1);
525			}
526			if (s->t_maxrows < MINIMUM_SCREEN_ROWS + count) {
527toosmall:			msgq(sp, M_BERR,
528				    "226|The screen can only shrink to %d rows",
529				    MINIMUM_SCREEN_ROWS);
530				return (1);
531			}
532			g_off = -count;
533		}
534	}
535
536	/*
537	 * Fix up the screens; we could optimize the reformatting of the
538	 * screen, but this isn't likely to be a common enough operation
539	 * to make it worthwhile.
540	 */
541	s->rows += -count;
542	s->woff += s_off;
543	g->rows += count;
544	g->woff += g_off;
545
546	g->t_rows += count;
547	if (g->t_minrows == g->t_maxrows)
548		g->t_minrows += count;
549	g->t_maxrows += count;
550	_TMAP(g) += count;
551	F_SET(g, SC_SCR_REFORMAT | SC_STATUS);
552
553	s->t_rows -= count;
554	s->t_maxrows -= count;
555	if (s->t_minrows > s->t_maxrows)
556		s->t_minrows = s->t_maxrows;
557	_TMAP(s) -= count;
558	F_SET(s, SC_SCR_REFORMAT | SC_STATUS);
559
560	return (0);
561}
562
563/*
564 * vs_getbg --
565 *	Get the specified background screen, or, if name is NULL, the first
566 *	background screen.
567 */
568static SCR *
569vs_getbg(sp, name)
570	SCR *sp;
571	char *name;
572{
573	GS *gp;
574	SCR *nsp;
575	char *p;
576
577	gp = sp->gp;
578
579	/* If name is NULL, return the first background screen on the list. */
580	if (name == NULL) {
581		nsp = gp->hq.cqh_first;
582		return (nsp == (void *)&gp->hq ? NULL : nsp);
583	}
584
585	/* Search for a full match. */
586	for (nsp = gp->hq.cqh_first;
587	    nsp != (void *)&gp->hq; nsp = nsp->q.cqe_next)
588		if (!strcmp(nsp->frp->name, name))
589			break;
590	if (nsp != (void *)&gp->hq)
591		return (nsp);
592
593	/* Search for a last-component match. */
594	for (nsp = gp->hq.cqh_first;
595	    nsp != (void *)&gp->hq; nsp = nsp->q.cqe_next) {
596		if ((p = strrchr(nsp->frp->name, '/')) == NULL)
597			p = nsp->frp->name;
598		else
599			++p;
600		if (!strcmp(p, name))
601			break;
602	}
603	if (nsp != (void *)&gp->hq)
604		return (nsp);
605
606	return (NULL);
607}
608