summaryrefslogtreecommitdiffstats
path: root/lib/libedit/refresh.c
blob: c85e84513b6e31fce79dbc13288069b6514422e9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
/*	$NetBSD: refresh.c,v 1.37 2011/07/29 23:44:45 christos Exp $	*/

/*-
 * Copyright (c) 1992, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Christos Zoulas of Cornell University.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "config.h"
#if !defined(lint) && !defined(SCCSID)
#if 0
static char sccsid[] = "@(#)refresh.c	8.1 (Berkeley) 6/4/93";
#else
__RCSID("$NetBSD: refresh.c,v 1.37 2011/07/29 23:44:45 christos Exp $");
#endif
#endif /* not lint && not SCCSID */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

/*
 * refresh.c: Lower level screen refreshing functions
 */
#include <stdio.h>
#include <ctype.h>
#include <unistd.h>
#include <string.h>

#include "el.h"

private void	re_nextline(EditLine *);
private void	re_addc(EditLine *, Int);
private void	re_update_line(EditLine *, Char *, Char *, int);
private void	re_insert (EditLine *, Char *, int, int, Char *, int);
private void	re_delete(EditLine *, Char *, int, int, int);
private void	re_fastputc(EditLine *, Int);
private void	re_clear_eol(EditLine *, int, int, int);
private void	re__strncopy(Char *, Char *, size_t);
private void	re__copy_and_pad(Char *, const Char *, size_t);

#ifdef DEBUG_REFRESH
private void	re_printstr(EditLine *, const char *, char *, char *);
#define	__F el->el_errfile
#define	ELRE_ASSERT(a, b, c)	do 				\
				    if (/*CONSTCOND*/ a) {	\
					(void) fprintf b;	\
					c;			\
				    }				\
				while (/*CONSTCOND*/0)
#define	ELRE_DEBUG(a, b)	ELRE_ASSERT(a,b,;)

/* re_printstr():
 *	Print a string on the debugging pty
 */
private void
re_printstr(EditLine *el, const char *str, char *f, char *t)
{

	ELRE_DEBUG(1, (__F, "%s:\"", str));
	while (f < t)
		ELRE_DEBUG(1, (__F, "%c", *f++ & 0177));
	ELRE_DEBUG(1, (__F, "\"\r\n"));
}
#else
#define	ELRE_ASSERT(a, b, c)
#define	ELRE_DEBUG(a, b)
#endif

/* re_nextline():
 *	Move to the next line or scroll
 */
private void
re_nextline(EditLine *el)
{
	el->el_refresh.r_cursor.h = 0;	/* reset it. */

	/*
	 * If we would overflow (input is longer than terminal size),
	 * emulate scroll by dropping first line and shuffling the rest.
	 * We do this via pointer shuffling - it's safe in this case
	 * and we avoid memcpy().
	 */
	if (el->el_refresh.r_cursor.v + 1 >= el->el_terminal.t_size.v) {
		int i, lins = el->el_terminal.t_size.v;
		Char *firstline = el->el_vdisplay[0];

		for(i = 1; i < lins; i++)
			el->el_vdisplay[i - 1] = el->el_vdisplay[i];

		firstline[0] = '\0';		/* empty the string */	
		el->el_vdisplay[i - 1] = firstline;
	} else
		el->el_refresh.r_cursor.v++;

	ELRE_ASSERT(el->el_refresh.r_cursor.v >= el->el_terminal.t_size.v,
	    (__F, "\r\nre_putc: overflow! r_cursor.v == %d > %d\r\n",
	    el->el_refresh.r_cursor.v, el->el_terminal.t_size.v),
	    abort());
}

/* re_addc():
 *	Draw c, expanding tabs, control chars etc.
 */
private void
re_addc(EditLine *el, Int c)
{
	switch (ct_chr_class((Char)c)) {
	case CHTYPE_TAB:        /* expand the tab */
		for (;;) {
			re_putc(el, ' ', 1);
			if ((el->el_refresh.r_cursor.h & 07) == 0)
				break;			/* go until tab stop */
		}
		break;
	case CHTYPE_NL: {
		int oldv = el->el_refresh.r_cursor.v;
		re_putc(el, '\0', 0);			/* assure end of line */
		if (oldv == el->el_refresh.r_cursor.v)	/* XXX */
			re_nextline(el);
		break;
	}
	case CHTYPE_PRINT:
		re_putc(el, c, 1);
		break;
	default: {
		Char visbuf[VISUAL_WIDTH_MAX];
		ssize_t i, n =
		    ct_visual_char(visbuf, VISUAL_WIDTH_MAX, (Char)c);
		for (i = 0; n-- > 0; ++i)
		    re_putc(el, visbuf[i], 1);
		break;
	}
	}
}


/* re_putc():
 *	Draw the character given
 */
protected void
re_putc(EditLine *el, Int c, int shift)
{
	int i, w = Width(c);
	ELRE_DEBUG(1, (__F, "printing %5x '%c'\r\n", c, c));

	while (shift && (el->el_refresh.r_cursor.h + w > el->el_terminal.t_size.h))
	    re_putc(el, ' ', 1);

	el->el_vdisplay[el->el_refresh.r_cursor.v]
	    [el->el_refresh.r_cursor.h] = c;
	/* assumes !shift is only used for single-column chars */
	i = w;
	while (--i > 0)
		el->el_vdisplay[el->el_refresh.r_cursor.v]
		    [el->el_refresh.r_cursor.h + i] = MB_FILL_CHAR;

	if (!shift)
		return;

	el->el_refresh.r_cursor.h += w;	/* advance to next place */
	if (el->el_refresh.r_cursor.h >= el->el_terminal.t_size.h) {
		/* assure end of line */
		el->el_vdisplay[el->el_refresh.r_cursor.v][el->el_terminal.t_size.h]
		    = '\0';
		re_nextline(el);
	}
}


/* re_refresh():
 *	draws the new virtual screen image from the current input
 *  	line, then goes line-by-line changing the real image to the new
 *	virtual image. The routine to re-draw a line can be replaced
 *	easily in hopes of a smarter one being placed there.
 */
protected void
re_refresh(EditLine *el)
{
	int i, rhdiff;
	Char *cp, *st;
	coord_t cur;
#ifdef notyet
	size_t termsz;
#endif

	ELRE_DEBUG(1, (__F, "el->el_line.buffer = :%s:\r\n",
	    el->el_line.buffer));

	/* reset the Drawing cursor */
	el->el_refresh.r_cursor.h = 0;
	el->el_refresh.r_cursor.v = 0;

	/* temporarily draw rprompt to calculate its size */
	prompt_print(el, EL_RPROMPT);

	/* reset the Drawing cursor */
	el->el_refresh.r_cursor.h = 0;
	el->el_refresh.r_cursor.v = 0;

	if (el->el_line.cursor >= el->el_line.lastchar) {
		if (el->el_map.current == el->el_map.alt
		    && el->el_line.lastchar != el->el_line.buffer)
			el->el_line.cursor = el->el_line.lastchar - 1;
		else
			el->el_line.cursor = el->el_line.lastchar;
	}

	cur.h = -1;		/* set flag in case I'm not set */
	cur.v = 0;

	prompt_print(el, EL_PROMPT);

	/* draw the current input buffer */
#if notyet
	termsz = el->el_terminal.t_size.h * el->el_terminal.t_size.v;
	if (el->el_line.lastchar - el->el_line.buffer > termsz) {
		/*
		 * If line is longer than terminal, process only part
		 * of line which would influence display.
		 */
		size_t rem = (el->el_line.lastchar-el->el_line.buffer)%termsz;

		st = el->el_line.lastchar - rem
			- (termsz - (((rem / el->el_terminal.t_size.v) - 1)
					* el->el_terminal.t_size.v));
	} else
#endif
		st = el->el_line.buffer;

	for (cp = st; cp < el->el_line.lastchar; cp++) {
		if (cp == el->el_line.cursor) {
                        int w = Width(*cp);
			/* save for later */
			cur.h = el->el_refresh.r_cursor.h;
			cur.v = el->el_refresh.r_cursor.v;
                        /* handle being at a linebroken doublewidth char */
                        if (w > 1 && el->el_refresh.r_cursor.h + w >
			    el->el_terminal.t_size.h) {
				cur.h = 0;
				cur.v++;
                        }
		}
		re_addc(el, *cp);
	}

	if (cur.h == -1) {	/* if I haven't been set yet, I'm at the end */
		cur.h = el->el_refresh.r_cursor.h;
		cur.v = el->el_refresh.r_cursor.v;
	}
	rhdiff = el->el_terminal.t_size.h - el->el_refresh.r_cursor.h -
	    el->el_rprompt.p_pos.h;
	if (el->el_rprompt.p_pos.h && !el->el_rprompt.p_pos.v &&
	    !el->el_refresh.r_cursor.v && rhdiff > 1) {
		/*
		 * have a right-hand side prompt that will fit
		 * on the end of the first line with at least
		 * one character gap to the input buffer.
		 */
		while (--rhdiff > 0)	/* pad out with spaces */
			re_putc(el, ' ', 1);
		prompt_print(el, EL_RPROMPT);
	} else {
		el->el_rprompt.p_pos.h = 0;	/* flag "not using rprompt" */
		el->el_rprompt.p_pos.v = 0;
	}

	re_putc(el, '\0', 0);	/* make line ended with NUL, no cursor shift */

	el->el_refresh.r_newcv = el->el_refresh.r_cursor.v;

	ELRE_DEBUG(1, (__F,
		"term.h=%d vcur.h=%d vcur.v=%d vdisplay[0]=\r\n:%80.80s:\r\n",
		el->el_terminal.t_size.h, el->el_refresh.r_cursor.h,
		el->el_refresh.r_cursor.v, ct_encode_string(el->el_vdisplay[0])));

	ELRE_DEBUG(1, (__F, "updating %d lines.\r\n", el->el_refresh.r_newcv));
	for (i = 0; i <= el->el_refresh.r_newcv; i++) {
		/* NOTE THAT re_update_line MAY CHANGE el_display[i] */
		re_update_line(el, el->el_display[i], el->el_vdisplay[i], i);

		/*
		 * Copy the new line to be the current one, and pad out with
		 * spaces to the full width of the terminal so that if we try
		 * moving the cursor by writing the character that is at the
		 * end of the screen line, it won't be a NUL or some old
		 * leftover stuff.
		 */
		re__copy_and_pad(el->el_display[i], el->el_vdisplay[i],
		    (size_t) el->el_terminal.t_size.h);
	}
	ELRE_DEBUG(1, (__F,
	"\r\nel->el_refresh.r_cursor.v=%d,el->el_refresh.r_oldcv=%d i=%d\r\n",
	    el->el_refresh.r_cursor.v, el->el_refresh.r_oldcv, i));

	if (el->el_refresh.r_oldcv > el->el_refresh.r_newcv)
		for (; i <= el->el_refresh.r_oldcv; i++) {
			terminal_move_to_line(el, i);
			terminal_move_to_char(el, 0);
                        /* This Strlen should be safe even with MB_FILL_CHARs */
			terminal_clear_EOL(el, (int) Strlen(el->el_display[i]));
#ifdef DEBUG_REFRESH
			terminal_overwrite(el, "C\b", (size_t)2);
#endif /* DEBUG_REFRESH */
			el->el_display[i][0] = '\0';
		}

	el->el_refresh.r_oldcv = el->el_refresh.r_newcv; /* set for next time */
	ELRE_DEBUG(1, (__F,
	    "\r\ncursor.h = %d, cursor.v = %d, cur.h = %d, cur.v = %d\r\n",
	    el->el_refresh.r_cursor.h, el->el_refresh.r_cursor.v,
	    cur.h, cur.v));
	terminal_move_to_line(el, cur.v);	/* go to where the cursor is */
	terminal_move_to_char(el, cur.h);
}


/* re_goto_bottom():
 *	 used to go to last used screen line
 */
protected void
re_goto_bottom(EditLine *el)
{

	terminal_move_to_line(el, el->el_refresh.r_oldcv);
	terminal__putc(el, '\n');
	re_clear_display(el);
	terminal__flush(el);
}


/* re_insert():
 *	insert num characters of s into d (in front of the character)
 *	at dat, maximum length of d is dlen
 */
private void
/*ARGSUSED*/
re_insert(EditLine *el __attribute__((__unused__)),
    Char *d, int dat, int dlen, Char *s, int num)
{
	Char *a, *b;

	if (num <= 0)
		return;
	if (num > dlen - dat)
		num = dlen - dat;

	ELRE_DEBUG(1,
	    (__F, "re_insert() starting: %d at %d max %d, d == \"%s\"\n",
	    num, dat, dlen, ct_encode_string(d)));
	ELRE_DEBUG(1, (__F, "s == \"%s\"\n", ct_encode_string(s)));

	/* open up the space for num chars */
	if (num > 0) {
		b = d + dlen - 1;
		a = b - num;
		while (a >= &d[dat])
			*b-- = *a--;
		d[dlen] = '\0';	/* just in case */
	}

	ELRE_DEBUG(1, (__F,
		"re_insert() after insert: %d at %d max %d, d == \"%s\"\n",
		num, dat, dlen, ct_encode_string(d)));
	ELRE_DEBUG(1, (__F, "s == \"%s\"\n", ct_encode_string(s)));

	/* copy the characters */
	for (a = d + dat; (a < d + dlen) && (num > 0); num--)
		*a++ = *s++;

#ifdef notyet
        /* ct_encode_string() uses a static buffer, so we can't conveniently
         * encode both d & s here */
	ELRE_DEBUG(1,
	    (__F, "re_insert() after copy: %d at %d max %d, %s == \"%s\"\n",
	    num, dat, dlen, d, s));
	ELRE_DEBUG(1, (__F, "s == \"%s\"\n", s));
#endif
}


/* re_delete():
 *	delete num characters d at dat, maximum length of d is dlen
 */
private void
/*ARGSUSED*/
re_delete(EditLine *el __attribute__((__unused__)),
    Char *d, int dat, int dlen, int num)
{
	Char *a, *b;

	if (num <= 0)
		return;
	if (dat + num >= dlen) {
		d[dat] = '\0';
		return;
	}
	ELRE_DEBUG(1,
	    (__F, "re_delete() starting: %d at %d max %d, d == \"%s\"\n",
	    num, dat, dlen, ct_encode_string(d)));

	/* open up the space for num chars */
	if (num > 0) {
		b = d + dat;
		a = b + num;
		while (a < &d[dlen])
			*b++ = *a++;
		d[dlen] = '\0';	/* just in case */
	}
	ELRE_DEBUG(1,
	    (__F, "re_delete() after delete: %d at %d max %d, d == \"%s\"\n",
	    num, dat, dlen, ct_encode_string(d)));
}


/* re__strncopy():
 *	Like strncpy without padding.
 */
private void
re__strncopy(Char *a, Char *b, size_t n)
{

	while (n-- && *b)
		*a++ = *b++;
}

/* re_clear_eol():
 *	Find the number of characters we need to clear till the end of line
 *	in order to make sure that we have cleared the previous contents of
 *	the line. fx and sx is the number of characters inserted or deleted
 *	in the first or second diff, diff is the difference between the
 * 	number of characters between the new and old line.
 */
private void
re_clear_eol(EditLine *el, int fx, int sx, int diff)
{

	ELRE_DEBUG(1, (__F, "re_clear_eol sx %d, fx %d, diff %d\n",
	    sx, fx, diff));

	if (fx < 0)
		fx = -fx;
	if (sx < 0)
		sx = -sx;
	if (fx > diff)
		diff = fx;
	if (sx > diff)
		diff = sx;

	ELRE_DEBUG(1, (__F, "re_clear_eol %d\n", diff));
	terminal_clear_EOL(el, diff);
}

/*****************************************************************
    re_update_line() is based on finding the middle difference of each line
    on the screen; vis:

			     /old first difference
	/beginning of line   |              /old last same       /old EOL
	v		     v              v                    v
old:	eddie> Oh, my little gruntle-buggy is to me, as lurgid as
new:	eddie> Oh, my little buggy says to me, as lurgid as
	^		     ^        ^			   ^
	\beginning of line   |        \new last same	   \new end of line
			     \new first difference

    all are character pointers for the sake of speed.  Special cases for
    no differences, as well as for end of line additions must be handled.
**************************************************************** */

/* Minimum at which doing an insert it "worth it".  This should be about
 * half the "cost" of going into insert mode, inserting a character, and
 * going back out.  This should really be calculated from the termcap
 * data...  For the moment, a good number for ANSI terminals.
 */
#define	MIN_END_KEEP	4

private void
re_update_line(EditLine *el, Char *old, Char *new, int i)
{
	Char *o, *n, *p, c;
	Char *ofd, *ols, *oe, *nfd, *nls, *ne;
	Char *osb, *ose, *nsb, *nse;
	int fx, sx;
	size_t len;

	/*
         * find first diff
         */
	for (o = old, n = new; *o && (*o == *n); o++, n++)
		continue;
	ofd = o;
	nfd = n;

	/*
         * Find the end of both old and new
         */
	while (*o)
		o++;
	/*
         * Remove any trailing blanks off of the end, being careful not to
         * back up past the beginning.
         */
	while (ofd < o) {
		if (o[-1] != ' ')
			break;
		o--;
	}
	oe = o;
	*oe = '\0';

	while (*n)
		n++;

	/* remove blanks from end of new */
	while (nfd < n) {
		if (n[-1] != ' ')
			break;
		n--;
	}
	ne = n;
	*ne = '\0';

	/*
         * if no diff, continue to next line of redraw
         */
	if (*ofd == '\0' && *nfd == '\0') {
		ELRE_DEBUG(1, (__F, "no difference.\r\n"));
		return;
	}
	/*
         * find last same pointer
         */
	while ((o > ofd) && (n > nfd) && (*--o == *--n))
		continue;
	ols = ++o;
	nls = ++n;

	/*
         * find same begining and same end
         */
	osb = ols;
	nsb = nls;
	ose = ols;
	nse = nls;

	/*
         * case 1: insert: scan from nfd to nls looking for *ofd
         */
	if (*ofd) {
		for (c = *ofd, n = nfd; n < nls; n++) {
			if (c == *n) {
				for (o = ofd, p = n;
				    p < nls && o < ols && *o == *p;
				    o++, p++)
					continue;
				/*
				 * if the new match is longer and it's worth
				 * keeping, then we take it
				 */
				if (((nse - nsb) < (p - n)) &&
				    (2 * (p - n) > n - nfd)) {
					nsb = n;
					nse = p;
					osb = ofd;
					ose = o;
				}
			}
		}
	}
	/*
         * case 2: delete: scan from ofd to ols looking for *nfd
         */
	if (*nfd) {
		for (c = *nfd, o = ofd; o < ols; o++) {
			if (c == *o) {
				for (n = nfd, p = o;
				    p < ols && n < nls && *p == *n;
				    p++, n++)
					continue;
				/*
				 * if the new match is longer and it's worth
				 * keeping, then we take it
				 */
				if (((ose - osb) < (p - o)) &&
				    (2 * (p - o) > o - ofd)) {
					nsb = nfd;
					nse = n;
					osb = o;
					ose = p;
				}
			}
		}
	}
	/*
         * Pragmatics I: If old trailing whitespace or not enough characters to
         * save to be worth it, then don't save the last same info.
         */
	if ((oe - ols) < MIN_END_KEEP) {
		ols = oe;
		nls = ne;
	}
	/*
         * Pragmatics II: if the terminal isn't smart enough, make the data
         * dumber so the smart update doesn't try anything fancy
         */

	/*
         * fx is the number of characters we need to insert/delete: in the
         * beginning to bring the two same begins together
         */
	fx = (int)((nsb - nfd) - (osb - ofd));
	/*
         * sx is the number of characters we need to insert/delete: in the
         * end to bring the two same last parts together
         */
	sx = (int)((nls - nse) - (ols - ose));

	if (!EL_CAN_INSERT) {
		if (fx > 0) {
			osb = ols;
			ose = ols;
			nsb = nls;
			nse = nls;
		}
		if (sx > 0) {
			ols = oe;
			nls = ne;
		}
		if ((ols - ofd) < (nls - nfd)) {
			ols = oe;
			nls = ne;
		}
	}
	if (!EL_CAN_DELETE) {
		if (fx < 0) {
			osb = ols;
			ose = ols;
			nsb = nls;
			nse = nls;
		}
		if (sx < 0) {
			ols = oe;
			nls = ne;
		}
		if ((ols - ofd) > (nls - nfd)) {
			ols = oe;
			nls = ne;
		}
	}
	/*
         * Pragmatics III: make sure the middle shifted pointers are correct if
         * they don't point to anything (we may have moved ols or nls).
         */
	/* if the change isn't worth it, don't bother */
	/* was: if (osb == ose) */
	if ((ose - osb) < MIN_END_KEEP) {
		osb = ols;
		ose = ols;
		nsb = nls;
		nse = nls;
	}
	/*
         * Now that we are done with pragmatics we recompute fx, sx
         */
	fx = (int)((nsb - nfd) - (osb - ofd));
	sx = (int)((nls - nse) - (ols - ose));

	ELRE_DEBUG(1, (__F, "fx %d, sx %d\n", fx, sx));
	ELRE_DEBUG(1, (__F, "ofd %d, osb %d, ose %d, ols %d, oe %d\n",
		ofd - old, osb - old, ose - old, ols - old, oe - old));
	ELRE_DEBUG(1, (__F, "nfd %d, nsb %d, nse %d, nls %d, ne %d\n",
		nfd - new, nsb - new, nse - new, nls - new, ne - new));
	ELRE_DEBUG(1, (__F,
		"xxx-xxx:\"00000000001111111111222222222233333333334\"\r\n"));
	ELRE_DEBUG(1, (__F,
		"xxx-xxx:\"01234567890123456789012345678901234567890\"\r\n"));
#ifdef DEBUG_REFRESH
	re_printstr(el, "old- oe", old, oe);
	re_printstr(el, "new- ne", new, ne);
	re_printstr(el, "old-ofd", old, ofd);
	re_printstr(el, "new-nfd", new, nfd);
	re_printstr(el, "ofd-osb", ofd, osb);
	re_printstr(el, "nfd-nsb", nfd, nsb);
	re_printstr(el, "osb-ose", osb, ose);
	re_printstr(el, "nsb-nse", nsb, nse);
	re_printstr(el, "ose-ols", ose, ols);
	re_printstr(el, "nse-nls", nse, nls);
	re_printstr(el, "ols- oe", ols, oe);
	re_printstr(el, "nls- ne", nls, ne);
#endif /* DEBUG_REFRESH */

	/*
         * el_cursor.v to this line i MUST be in this routine so that if we
         * don't have to change the line, we don't move to it. el_cursor.h to
         * first diff char
         */
	terminal_move_to_line(el, i);

	/*
         * at this point we have something like this:
         *
         * /old                  /ofd    /osb               /ose    /ols     /oe
         * v.....................v       v..................v       v........v
         * eddie> Oh, my fredded gruntle-buggy is to me, as foo var lurgid as
         * eddie> Oh, my fredded quiux buggy is to me, as gruntle-lurgid as
         * ^.....................^     ^..................^       ^........^
         * \new                  \nfd  \nsb               \nse     \nls    \ne
         *
         * fx is the difference in length between the chars between nfd and
         * nsb, and the chars between ofd and osb, and is thus the number of
         * characters to delete if < 0 (new is shorter than old, as above),
         * or insert (new is longer than short).
         *
         * sx is the same for the second differences.
         */

	/*
         * if we have a net insert on the first difference, AND inserting the
         * net amount ((nsb-nfd) - (osb-ofd)) won't push the last useful
         * character (which is ne if nls != ne, otherwise is nse) off the edge
	 * of the screen (el->el_terminal.t_size.h) else we do the deletes first
	 * so that we keep everything we need to.
         */

	/*
         * if the last same is the same like the end, there is no last same
         * part, otherwise we want to keep the last same part set p to the
         * last useful old character
         */
	p = (ols != oe) ? oe : ose;

	/*
         * if (There is a diffence in the beginning) && (we need to insert
         *   characters) && (the number of characters to insert is less than
         *   the term width)
	 *	We need to do an insert!
	 * else if (we need to delete characters)
	 *	We need to delete characters!
	 * else
	 *	No insert or delete
         */
	if ((nsb != nfd) && fx > 0 &&
	    ((p - old) + fx <= el->el_terminal.t_size.h)) {
		ELRE_DEBUG(1,
		    (__F, "first diff insert at %d...\r\n", nfd - new));
		/*
		 * Move to the first char to insert, where the first diff is.
		 */
		terminal_move_to_char(el, (int)(nfd - new));
		/*
		 * Check if we have stuff to keep at end
		 */
		if (nsb != ne) {
			ELRE_DEBUG(1, (__F, "with stuff to keep at end\r\n"));
			/*
		         * insert fx chars of new starting at nfd
		         */
			if (fx > 0) {
				ELRE_DEBUG(!EL_CAN_INSERT, (__F,
				"ERROR: cannot insert in early first diff\n"));
				terminal_insertwrite(el, nfd, fx);
				re_insert(el, old, (int)(ofd - old),
				    el->el_terminal.t_size.h, nfd, fx);
			}
			/*
		         * write (nsb-nfd) - fx chars of new starting at
		         * (nfd + fx)
			 */
			len = (size_t) ((nsb - nfd) - fx);
			terminal_overwrite(el, (nfd + fx), len);
			re__strncopy(ofd + fx, nfd + fx, len);
		} else {
			ELRE_DEBUG(1, (__F, "without anything to save\r\n"));
			len = (size_t)(nsb - nfd);
			terminal_overwrite(el, nfd, len);
			re__strncopy(ofd, nfd, len);
			/*
		         * Done
		         */
			return;
		}
	} else if (fx < 0) {
		ELRE_DEBUG(1,
		    (__F, "first diff delete at %d...\r\n", ofd - old));
		/*
		 * move to the first char to delete where the first diff is
		 */
		terminal_move_to_char(el, (int)(ofd - old));
		/*
		 * Check if we have stuff to save
		 */
		if (osb != oe) {
			ELRE_DEBUG(1, (__F, "with stuff to save at end\r\n"));
			/*
		         * fx is less than zero *always* here but we check
		         * for code symmetry
		         */
			if (fx < 0) {
				ELRE_DEBUG(!EL_CAN_DELETE, (__F,
				    "ERROR: cannot delete in first diff\n"));
				terminal_deletechars(el, -fx);
				re_delete(el, old, (int)(ofd - old),
				    el->el_terminal.t_size.h, -fx);
			}
			/*
		         * write (nsb-nfd) chars of new starting at nfd
		         */
			len = (size_t) (nsb - nfd);
			terminal_overwrite(el, nfd, len);
			re__strncopy(ofd, nfd, len);

		} else {
			ELRE_DEBUG(1, (__F,
			    "but with nothing left to save\r\n"));
			/*
		         * write (nsb-nfd) chars of new starting at nfd
		         */
			terminal_overwrite(el, nfd, (size_t)(nsb - nfd));
			re_clear_eol(el, fx, sx,
			    (int)((oe - old) - (ne - new)));
			/*
		         * Done
		         */
			return;
		}
	} else
		fx = 0;

	if (sx < 0 && (ose - old) + fx < el->el_terminal.t_size.h) {
		ELRE_DEBUG(1, (__F,
		    "second diff delete at %d...\r\n", (ose - old) + fx));
		/*
		 * Check if we have stuff to delete
		 */
		/*
		 * fx is the number of characters inserted (+) or deleted (-)
		 */

		terminal_move_to_char(el, (int)((ose - old) + fx));
		/*
		 * Check if we have stuff to save
		 */
		if (ols != oe) {
			ELRE_DEBUG(1, (__F, "with stuff to save at end\r\n"));
			/*
		         * Again a duplicate test.
		         */
			if (sx < 0) {
				ELRE_DEBUG(!EL_CAN_DELETE, (__F,
				    "ERROR: cannot delete in second diff\n"));
				terminal_deletechars(el, -sx);
			}
			/*
		         * write (nls-nse) chars of new starting at nse
		         */
			terminal_overwrite(el, nse, (size_t)(nls - nse));
		} else {
			ELRE_DEBUG(1, (__F,
			    "but with nothing left to save\r\n"));
			terminal_overwrite(el, nse, (size_t)(nls - nse));
			re_clear_eol(el, fx, sx,
			    (int)((oe - old) - (ne - new)));
		}
	}
	/*
         * if we have a first insert AND WE HAVEN'T ALREADY DONE IT...
         */
	if ((nsb != nfd) && (osb - ofd) <= (nsb - nfd) && (fx == 0)) {
		ELRE_DEBUG(1, (__F, "late first diff insert at %d...\r\n",
		    nfd - new));

		terminal_move_to_char(el, (int)(nfd - new));
		/*
		 * Check if we have stuff to keep at the end
		 */
		if (nsb != ne) {
			ELRE_DEBUG(1, (__F, "with stuff to keep at end\r\n"));
			/*
		         * We have to recalculate fx here because we set it
		         * to zero above as a flag saying that we hadn't done
		         * an early first insert.
		         */
			fx = (int)((nsb - nfd) - (osb - ofd));
			if (fx > 0) {
				/*
				 * insert fx chars of new starting at nfd
				 */
				ELRE_DEBUG(!EL_CAN_INSERT, (__F,
				 "ERROR: cannot insert in late first diff\n"));
				terminal_insertwrite(el, nfd, fx);
				re_insert(el, old, (int)(ofd - old),
				    el->el_terminal.t_size.h, nfd, fx);
			}
			/*
		         * write (nsb-nfd) - fx chars of new starting at
		         * (nfd + fx)
			 */
			len = (size_t) ((nsb - nfd) - fx);
			terminal_overwrite(el, (nfd + fx), len);
			re__strncopy(ofd + fx, nfd + fx, len);
		} else {
			ELRE_DEBUG(1, (__F, "without anything to save\r\n"));
			len = (size_t) (nsb - nfd);
			terminal_overwrite(el, nfd, len);
			re__strncopy(ofd, nfd, len);
		}
	}
	/*
         * line is now NEW up to nse
         */
	if (sx >= 0) {
		ELRE_DEBUG(1, (__F,
		    "second diff insert at %d...\r\n", (int)(nse - new)));
		terminal_move_to_char(el, (int)(nse - new));
		if (ols != oe) {
			ELRE_DEBUG(1, (__F, "with stuff to keep at end\r\n"));
			if (sx > 0) {
				/* insert sx chars of new starting at nse */
				ELRE_DEBUG(!EL_CAN_INSERT, (__F,
				    "ERROR: cannot insert in second diff\n"));
				terminal_insertwrite(el, nse, sx);
			}
			/*
		         * write (nls-nse) - sx chars of new starting at
			 * (nse + sx)
		         */
			terminal_overwrite(el, (nse + sx),
			    (size_t)((nls - nse) - sx));
		} else {
			ELRE_DEBUG(1, (__F, "without anything to save\r\n"));
			terminal_overwrite(el, nse, (size_t)(nls - nse));

			/*
	                 * No need to do a clear-to-end here because we were
	                 * doing a second insert, so we will have over
	                 * written all of the old string.
		         */
		}
	}
	ELRE_DEBUG(1, (__F, "done.\r\n"));
}


/* re__copy_and_pad():
 *	Copy string and pad with spaces
 */
private void
re__copy_and_pad(Char *dst, const Char *src, size_t width)
{
	size_t i;

	for (i = 0; i < width; i++) {
		if (*src == '\0')
			break;
		*dst++ = *src++;
	}

	for (; i < width; i++)
		*dst++ = ' ';

	*dst = '\0';
}


/* re_refresh_cursor():
 *	Move to the new cursor position
 */
protected void
re_refresh_cursor(EditLine *el)
{
	Char *cp;
	int h, v, th, w;

	if (el->el_line.cursor >= el->el_line.lastchar) {
		if (el->el_map.current == el->el_map.alt
		    && el->el_line.lastchar != el->el_line.buffer)
			el->el_line.cursor = el->el_line.lastchar - 1;
		else
			el->el_line.cursor = el->el_line.lastchar;
	}

	/* first we must find where the cursor is... */
	h = el->el_prompt.p_pos.h;
	v = el->el_prompt.p_pos.v;
	th = el->el_terminal.t_size.h;	/* optimize for speed */

	/* do input buffer to el->el_line.cursor */
	for (cp = el->el_line.buffer; cp < el->el_line.cursor; cp++) {
                switch (ct_chr_class(*cp)) {
		case CHTYPE_NL:  /* handle newline in data part too */
			h = 0;
			v++;
			break;
		case CHTYPE_TAB: /* if a tab, to next tab stop */
			while (++h & 07)
				continue;
			break;
		default:
			w = Width(*cp);
			if (w > 1 && h + w > th) { /* won't fit on line */
				h = 0;
				v++;
			}
			h += ct_visual_width(*cp);
			break;
                }

		if (h >= th) {	/* check, extra long tabs picked up here also */
			h -= th;
			v++;
		}
	}
        /* if we have a next character, and it's a doublewidth one, we need to
         * check whether we need to linebreak for it to fit */
        if (cp < el->el_line.lastchar && (w = Width(*cp)) > 1)
                if (h + w > th) {
                    h = 0;
                    v++;
                }

	/* now go there */
	terminal_move_to_line(el, v);
	terminal_move_to_char(el, h);
	terminal__flush(el);
}


/* re_fastputc():
 *	Add a character fast.
 */
private void
re_fastputc(EditLine *el, Int c)
{
	int w = Width((Char)c);
	while (w > 1 && el->el_cursor.h + w > el->el_terminal.t_size.h)
	    re_fastputc(el, ' ');

	terminal__putc(el, c);
	el->el_display[el->el_cursor.v][el->el_cursor.h++] = c;
	while (--w > 0)
		el->el_display[el->el_cursor.v][el->el_cursor.h++]
			= MB_FILL_CHAR;

	if (el->el_cursor.h >= el->el_terminal.t_size.h) {
		/* if we must overflow */
		el->el_cursor.h = 0;

		/*
		 * If we would overflow (input is longer than terminal size),
		 * emulate scroll by dropping first line and shuffling the rest.
		 * We do this via pointer shuffling - it's safe in this case
		 * and we avoid memcpy().
		 */
		if (el->el_cursor.v + 1 >= el->el_terminal.t_size.v) {
			int i, lins = el->el_terminal.t_size.v;
			Char *firstline = el->el_display[0];
	
			for(i = 1; i < lins; i++)
				el->el_display[i - 1] = el->el_display[i];

			re__copy_and_pad(firstline, STR(""), (size_t)0);
			el->el_display[i - 1] = firstline;
		} else {
			el->el_cursor.v++;
			el->el_refresh.r_oldcv++;
		}
		if (EL_HAS_AUTO_MARGINS) {
			if (EL_HAS_MAGIC_MARGINS) {
				terminal__putc(el, ' ');
				terminal__putc(el, '\b');
			}
		} else {
			terminal__putc(el, '\r');
			terminal__putc(el, '\n');
		}
	}
}


/* re_fastaddc():
 *	we added just one char, handle it fast.
 *	Assumes that screen cursor == real cursor
 */
protected void
re_fastaddc(EditLine *el)
{
	Char c;
	int rhdiff;

	c = el->el_line.cursor[-1];

	if (c == '\t' || el->el_line.cursor != el->el_line.lastchar) {
		re_refresh(el);	/* too hard to handle */
		return;
	}
	rhdiff = el->el_terminal.t_size.h - el->el_cursor.h -
	    el->el_rprompt.p_pos.h;
	if (el->el_rprompt.p_pos.h && rhdiff < 3) {
		re_refresh(el);	/* clear out rprompt if less than 1 char gap */
		return;
	}			/* else (only do at end of line, no TAB) */
	switch (ct_chr_class(c)) {
	case CHTYPE_TAB: /* already handled, should never happen here */
		break;
	case CHTYPE_NL:
	case CHTYPE_PRINT:
		re_fastputc(el, c);
		break;
	case CHTYPE_ASCIICTL:
	case CHTYPE_NONPRINT: {
		Char visbuf[VISUAL_WIDTH_MAX];
		ssize_t i, n =
		    ct_visual_char(visbuf, VISUAL_WIDTH_MAX, (Char)c);
		for (i = 0; n-- > 0; ++i)
			re_fastputc(el, visbuf[i]);
		break;
	}
	}
	terminal__flush(el);
}


/* re_clear_display():
 *	clear the screen buffers so that new new prompt starts fresh.
 */
protected void
re_clear_display(EditLine *el)
{
	int i;

	el->el_cursor.v = 0;
	el->el_cursor.h = 0;
	for (i = 0; i < el->el_terminal.t_size.v; i++)
		el->el_display[i][0] = '\0';
	el->el_refresh.r_oldcv = 0;
}


/* re_clear_lines():
 *	Make sure all lines are *really* blank
 */
protected void
re_clear_lines(EditLine *el)
{

	if (EL_CAN_CEOL) {
		int i;
		for (i = el->el_refresh.r_oldcv; i >= 0; i--) {
			/* for each line on the screen */
			terminal_move_to_line(el, i);
			terminal_move_to_char(el, 0);
			terminal_clear_EOL(el, el->el_terminal.t_size.h);
		}
	} else {
		terminal_move_to_line(el, el->el_refresh.r_oldcv);
					/* go to last line */
		terminal__putc(el, '\r');	/* go to BOL */
		terminal__putc(el, '\n');	/* go to new line */
	}
}
OpenPOWER on IntegriCloud