1 /****************************************************************************
2  * Copyright (c) 1998-2009,2010 Free Software Foundation, Inc.              *
3  *                                                                          *
4  * Permission is hereby granted, free of charge, to any person obtaining a  *
5  * copy of this software and associated documentation files (the            *
6  * "Software"), to deal in the Software without restriction, including      *
7  * without limitation the rights to use, copy, modify, merge, publish,      *
8  * distribute, distribute with modifications, sublicense, and/or sell       *
9  * copies of the Software, and to permit persons to whom the Software is    *
10  * furnished to do so, subject to the following conditions:                 *
11  *                                                                          *
12  * The above copyright notice and this permission notice shall be included  *
13  * in all copies or substantial portions of the Software.                   *
14  *                                                                          *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
16  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
18  * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
19  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
20  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
21  * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
22  *                                                                          *
23  * Except as contained in this notice, the name(s) of the above copyright   *
24  * holders shall not be used in advertising or otherwise to promote the     *
25  * sale, use or other dealings in this Software without prior written       *
26  * authorization.                                                           *
27  ****************************************************************************/
28 
29 /****************************************************************************
30  *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
31  *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
32  *     and: Thomas E. Dickey                        1996-on                 *
33  *     and: Juergen Pfeifer                         2009                    *
34  ****************************************************************************/
35 
36 /*-----------------------------------------------------------------
37  *
38  *	lib_doupdate.c
39  *
40  * 	The routine doupdate() and its dependents.
41  * 	All physical output is concentrated here (except _nc_outch()
42  *	in lib_tputs.c).
43  *
44  *-----------------------------------------------------------------*/
45 
46 #include <curses.priv.h>
47 
48 #ifndef CUR
49 #define CUR SP_TERMTYPE
50 #endif
51 
52 #if defined __HAIKU__ && defined __BEOS__
53 #undef __BEOS__
54 #endif
55 
56 #ifdef __BEOS__
57 #undef false
58 #undef true
59 #include <OS.h>
60 #endif
61 
62 #if defined(TRACE) && HAVE_SYS_TIMES_H && HAVE_TIMES
63 #define USE_TRACE_TIMES 1
64 #else
65 #define USE_TRACE_TIMES 0
66 #endif
67 
68 #if HAVE_SYS_TIME_H && HAVE_SYS_TIME_SELECT
69 #include <sys/time.h>
70 #endif
71 
72 #if USE_TRACE_TIMES
73 #include <sys/times.h>
74 #endif
75 
76 #if USE_FUNC_POLL
77 #elif HAVE_SELECT
78 #if HAVE_SYS_SELECT_H
79 #include <sys/select.h>
80 #endif
81 #endif
82 
83 #include <ctype.h>
84 
85 MODULE_ID("$Id: tty_update.c,v 1.264 2010/12/19 01:21:02 tom Exp $")
86 
87 /*
88  * This define controls the line-breakout optimization.  Every once in a
89  * while during screen refresh, we want to check for input and abort the
90  * update if there's some waiting.  CHECK_INTERVAL controls the number of
91  * changed lines to be emitted between input checks.
92  *
93  * Note: Input-check-and-abort is no longer done if the screen is being
94  * updated from scratch.  This is a feature, not a bug.
95  */
96 #define CHECK_INTERVAL	5
97 
98 #define FILL_BCE(sp) (sp->_coloron && !sp->_default_color && !back_color_erase)
99 
100 static const NCURSES_CH_T blankchar = NewChar(BLANK_TEXT);
101 static NCURSES_CH_T normal = NewChar(BLANK_TEXT);
102 
103 /*
104  * Enable checking to see if doupdate and friends are tracking the true
105  * cursor position correctly.  NOTE: this is a debugging hack which will
106  * work ONLY on ANSI-compatible terminals!
107  */
108 /* #define POSITION_DEBUG */
109 
110 static NCURSES_INLINE NCURSES_CH_T ClrBlank(NCURSES_SP_DCLx WINDOW *win);
111 
112 #if NCURSES_SP_FUNCS
113 static int ClrBottom(SCREEN *, int total);
114 static void ClearScreen(SCREEN *, NCURSES_CH_T blank);
115 static void ClrUpdate(SCREEN *);
116 static void DelChar(SCREEN *, int count);
117 static void InsStr(SCREEN *, NCURSES_CH_T * line, int count);
118 static void TransformLine(SCREEN *, int const lineno);
119 #else
120 static int ClrBottom(int total);
121 static void ClearScreen(NCURSES_CH_T blank);
122 static void ClrUpdate(void);
123 static void DelChar(int count);
124 static void InsStr(NCURSES_CH_T * line, int count);
125 static void TransformLine(int const lineno);
126 #endif
127 
128 #ifdef POSITION_DEBUG
129 /****************************************************************************
130  *
131  * Debugging code.  Only works on ANSI-standard terminals.
132  *
133  ****************************************************************************/
134 
135 static void
136 position_check(NCURSES_SP_DCLx int expected_y, int expected_x, char *legend)
137 /* check to see if the real cursor position matches the virtual */
138 {
139     char buf[20];
140     char *s;
141     int y, x;
142 
143     if (!_nc_tracing || (expected_y < 0 && expected_x < 0))
144 	return;
145 
146     NCURSES_SP_NAME(_nc_flush) (NCURSES_SP_ARG);
147     memset(buf, '\0', sizeof(buf));
148     NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx "\033[6n");	/* only works on ANSI-compatibles */
149     NCURSES_SP_NAME(_nc_flush) (NCURSES_SP_ARG);
150     *(s = buf) = 0;
151     do {
152 	int ask = sizeof(buf) - 1 - (s - buf);
153 	int got = read(0, s, ask);
154 	if (got == 0)
155 	    break;
156 	s += got;
157     } while (strchr(buf, 'R') == 0);
158     _tracef("probe returned %s", _nc_visbuf(buf));
159 
160     /* try to interpret as a position report */
161     if (sscanf(buf, "\033[%d;%dR", &y, &x) != 2) {
162 	_tracef("position probe failed in %s", legend);
163     } else {
164 	if (expected_x < 0)
165 	    expected_x = x - 1;
166 	if (expected_y < 0)
167 	    expected_y = y - 1;
168 	if (y - 1 != expected_y || x - 1 != expected_x) {
169 	    NCURSES_SP_NAME(beep) (NCURSES_SP_ARG);
170 	    NCURSES_SP_NAME(tputs) (NCURSES_SP_ARGx
171 				    tparm("\033[%d;%dH",
172 					  expected_y + 1,
173 					  expected_x + 1),
174 				    1, NCURSES_SP_NAME(_nc_outch));
175 	    _tracef("position seen (%d, %d) doesn't match expected one (%d, %d) in %s",
176 		    y - 1, x - 1, expected_y, expected_x, legend);
177 	} else {
178 	    _tracef("position matches OK in %s", legend);
179 	}
180     }
181 }
182 #else
183 #define position_check(sp, expected_y, expected_x, legend)	/* nothing */
184 #endif /* POSITION_DEBUG */
185 
186 /****************************************************************************
187  *
188  * Optimized update code
189  *
190  ****************************************************************************/
191 
192 static NCURSES_INLINE void
193 GoTo(NCURSES_SP_DCLx int const row, int const col)
194 {
195     TR(TRACE_MOVE, ("GoTo(%p, %d, %d) from (%d, %d)",
196 		    (void *) SP_PARM, row, col, SP_PARM->_cursrow, SP_PARM->_curscol));
197 
198     position_check(SP_PARM, SP_PARM->_cursrow, SP_PARM->_curscol, "GoTo");
199 
200     TINFO_MVCUR(NCURSES_SP_ARGx
201 		SP_PARM->_cursrow,
202 		SP_PARM->_curscol,
203 		row, col);
204     position_check(SP_PARM, SP_PARM->_cursrow, SP_PARM->_curscol, "GoTo2");
205 }
206 
207 static NCURSES_INLINE void
208 PutAttrChar(NCURSES_SP_DCLx CARG_CH_T ch)
209 {
210     int chlen = 1;
211     NCURSES_CH_T my_ch;
212     PUTC_DATA;
213     NCURSES_CH_T tilde;
214     NCURSES_CH_T attr = CHDEREF(ch);
215 
216     TR(TRACE_CHARPUT, ("PutAttrChar(%s) at (%d, %d)",
217 		       _tracech_t(ch),
218 		       SP_PARM->_cursrow, SP_PARM->_curscol));
219 #if USE_WIDEC_SUPPORT
220     /*
221      * If this is not a valid character, there is nothing more to do.
222      */
223     if (isWidecExt(CHDEREF(ch))) {
224 	TR(TRACE_CHARPUT, ("...skip"));
225 	return;
226     }
227     /*
228      * Determine the number of character cells which the 'ch' value will use
229      * on the screen.  It should be at least one.
230      */
231     if ((chlen = wcwidth(CharOf(CHDEREF(ch)))) <= 0) {
232 	static const NCURSES_CH_T blank = NewChar(BLANK_TEXT);
233 
234 	/*
235 	 * If the character falls into any of these special cases, do
236 	 * not force the result to a blank:
237 	 *
238 	 * a) it is printable (this works around a bug in wcwidth()).
239 	 * b) use_legacy_coding() has been called to modify the treatment
240 	 *    of codes 128-255.
241 	 * c) the acs_map[] has been initialized to allow codes 0-31
242 	 *    to be rendered.  This supports Linux console's "PC"
243 	 *    characters.  Codes 128-255 are allowed though this is
244 	 *    not checked.
245 	 */
246 	if (is8bits(CharOf(CHDEREF(ch)))
247 	    && (isprint(CharOf(CHDEREF(ch)))
248 		|| (SP_PARM->_legacy_coding > 0 && CharOf(CHDEREF(ch)) >= 160)
249 		|| (SP_PARM->_legacy_coding > 1 && CharOf(CHDEREF(ch)) >= 128)
250 		|| (AttrOf(attr) & A_ALTCHARSET
251 		    && ((CharOfD(ch) < ACS_LEN
252 			 && SP_PARM->_acs_map != 0
253 			 && SP_PARM->_acs_map[CharOfD(ch)] != 0)
254 			|| (CharOfD(ch) >= 128))))) {
255 	    ;
256 	} else {
257 	    ch = CHREF(blank);
258 	    TR(TRACE_CHARPUT, ("forced to blank"));
259 	}
260 	chlen = 1;
261     }
262 #endif
263 
264     if ((AttrOf(attr) & A_ALTCHARSET)
265 	&& SP_PARM->_acs_map != 0
266 	&& CharOfD(ch) < ACS_LEN) {
267 	my_ch = CHDEREF(ch);	/* work around const param */
268 #if USE_WIDEC_SUPPORT
269 	/*
270 	 * This is crude & ugly, but works most of the time.  It checks if the
271 	 * acs_chars string specified that we have a mapping for this
272 	 * character, and uses the wide-character mapping when we expect the
273 	 * normal one to be broken (by mis-design ;-).
274 	 */
275 	if (SP_PARM->_screen_acs_fix
276 	    && SP_PARM->_screen_acs_map[CharOf(my_ch)]) {
277 	    RemAttr(attr, A_ALTCHARSET);
278 	    my_ch = _nc_wacs[CharOf(my_ch)];
279 	}
280 #endif
281 	/*
282 	 * If we (still) have alternate character set, it is the normal 8bit
283 	 * flavor.  The _screen_acs_map[] array tells if the character was
284 	 * really in acs_chars, needed because of the way wide/normal line
285 	 * drawing flavors are integrated.
286 	 */
287 	if (AttrOf(attr) & A_ALTCHARSET) {
288 	    int j = CharOfD(ch);
289 	    chtype temp = UChar(SP_PARM->_acs_map[j]);
290 
291 	    if (!(SP_PARM->_screen_acs_map[j])) {
292 		RemAttr(attr, A_ALTCHARSET);
293 		if (temp == 0)
294 		    temp = ' ';
295 	    }
296 	    if (temp != 0)
297 		SetChar(my_ch, temp, AttrOf(attr));
298 	}
299 	ch = CHREF(my_ch);
300     }
301     if (tilde_glitch && (CharOfD(ch) == L('~'))) {
302 	SetChar(tilde, L('`'), AttrOf(attr));
303 	ch = CHREF(tilde);
304     }
305 
306     UpdateAttrs(SP_PARM, attr);
307 #if !USE_WIDEC_SUPPORT
308     /* FIXME - we do this special case for signal handling, should see how to
309      * make it work for wide characters.
310      */
311     if (SP_PARM->_outch != 0) {
312 	SP_PARM->_outch(NCURSES_SP_ARGx UChar(ch));
313     } else
314 #endif
315     {
316 	PUTC(CHDEREF(ch), SP_PARM->_ofp);	/* macro's fastest... */
317 	COUNT_OUTCHARS(1);
318     }
319     SP_PARM->_curscol += chlen;
320     if (char_padding) {
321 	TPUTS_TRACE("char_padding");
322 	NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx char_padding);
323     }
324 }
325 
326 static bool
327 check_pending(NCURSES_SP_DCL0)
328 /* check for pending input */
329 {
330     bool have_pending = FALSE;
331 
332     /*
333      * Only carry out this check when the flag is zero, otherwise we'll
334      * have the refreshing slow down drastically (or stop) if there's an
335      * unread character available.
336      */
337     if (SP_PARM->_fifohold != 0)
338 	return FALSE;
339 
340     if (SP_PARM->_checkfd >= 0) {
341 #if USE_FUNC_POLL
342 	struct pollfd fds[1];
343 	fds[0].fd = SP_PARM->_checkfd;
344 	fds[0].events = POLLIN;
345 	if (poll(fds, 1, 0) > 0) {
346 	    have_pending = TRUE;
347 	}
348 #elif defined(__BEOS__)
349 	/*
350 	 * BeOS's select() is declared in socket.h, so the configure script does
351 	 * not see it.  That's just as well, since that function works only for
352 	 * sockets.  This (using snooze and ioctl) was distilled from Be's patch
353 	 * for ncurses which uses a separate thread to simulate select().
354 	 *
355 	 * FIXME: the return values from the ioctl aren't very clear if we get
356 	 * interrupted.
357 	 */
358 	int n = 0;
359 	int howmany = ioctl(0, 'ichr', &n);
360 	if (howmany >= 0 && n > 0) {
361 	    have_pending = TRUE;
362 	}
363 #elif HAVE_SELECT
364 	fd_set fdset;
365 	struct timeval ktimeout;
366 
367 	ktimeout.tv_sec =
368 	    ktimeout.tv_usec = 0;
369 
370 	FD_ZERO(&fdset);
371 	FD_SET(SP_PARM->_checkfd, &fdset);
372 	if (select(SP_PARM->_checkfd + 1, &fdset, NULL, NULL, &ktimeout) != 0) {
373 	    have_pending = TRUE;
374 	}
375 #endif
376     }
377     if (have_pending) {
378 	SP_PARM->_fifohold = 5;
379 	NCURSES_SP_NAME(_nc_flush) (NCURSES_SP_ARG);
380     }
381     return FALSE;
382 }
383 
384 /* put char at lower right corner */
385 static void
386 PutCharLR(NCURSES_SP_DCLx const ARG_CH_T ch)
387 {
388     if (!auto_right_margin) {
389 	/* we can put the char directly */
390 	PutAttrChar(NCURSES_SP_ARGx ch);
391     } else if (enter_am_mode && exit_am_mode) {
392 	/* we can suppress automargin */
393 	TPUTS_TRACE("exit_am_mode");
394 	NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx exit_am_mode);
395 
396 	PutAttrChar(NCURSES_SP_ARGx ch);
397 	SP_PARM->_curscol--;
398 	position_check(SP_PARM,
399 		       SP_PARM->_cursrow,
400 		       SP_PARM->_curscol,
401 		       "exit_am_mode");
402 
403 	TPUTS_TRACE("enter_am_mode");
404 	NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx enter_am_mode);
405     } else if ((enter_insert_mode && exit_insert_mode)
406 	       || insert_character || parm_ich) {
407 	GoTo(NCURSES_SP_ARGx
408 	     screen_lines(SP_PARM) - 1,
409 	     screen_columns(SP_PARM) - 2);
410 	PutAttrChar(NCURSES_SP_ARGx ch);
411 	GoTo(NCURSES_SP_ARGx
412 	     screen_lines(SP_PARM) - 1,
413 	     screen_columns(SP_PARM) - 2);
414 	InsStr(NCURSES_SP_ARGx
415 	       NewScreen(SP_PARM)->_line[screen_lines(SP_PARM) - 1].text +
416 	       screen_columns(SP_PARM) - 2, 1);
417     }
418 }
419 
420 /*
421  * Wrap the cursor position, i.e., advance to the beginning of the next line.
422  */
423 static void
424 wrap_cursor(NCURSES_SP_DCL0)
425 {
426     if (eat_newline_glitch) {
427 	/*
428 	 * xenl can manifest two different ways.  The vt100 way is that, when
429 	 * you'd expect the cursor to wrap, it stays hung at the right margin
430 	 * (on top of the character just emitted) and doesn't wrap until the
431 	 * *next* graphic char is emitted.  The c100 way is to ignore LF
432 	 * received just after an am wrap.
433 	 *
434 	 * An aggressive way to handle this would be to emit CR/LF after the
435 	 * char and then assume the wrap is done, you're on the first position
436 	 * of the next line, and the terminal out of its weird state.  Here
437 	 * it's safe to just tell the code that the cursor is in hyperspace and
438 	 * let the next mvcur() call straighten things out.
439 	 */
440 	SP_PARM->_curscol = -1;
441 	SP_PARM->_cursrow = -1;
442     } else if (auto_right_margin) {
443 	SP_PARM->_curscol = 0;
444 	SP_PARM->_cursrow++;
445 	/*
446 	 * We've actually moved - but may have to work around problems with
447 	 * video attributes not working.
448 	 */
449 	if (!move_standout_mode && AttrOf(SCREEN_ATTRS(SP_PARM))) {
450 	    TR(TRACE_CHARPUT, ("turning off (%#lx) %s before wrapping",
451 			       (unsigned long) AttrOf(SCREEN_ATTRS(SP_PARM)),
452 			       _traceattr(AttrOf(SCREEN_ATTRS(SP_PARM)))));
453 	    (void) VIDATTR(SP_PARM, A_NORMAL, 0);
454 	}
455     } else {
456 	SP_PARM->_curscol--;
457     }
458     position_check(SP_PARM,
459 		   SP_PARM->_cursrow,
460 		   SP_PARM->_curscol,
461 		   "wrap_cursor");
462 }
463 
464 static NCURSES_INLINE void
465 PutChar(NCURSES_SP_DCLx const ARG_CH_T ch)
466 /* insert character, handling automargin stuff */
467 {
468     if (SP_PARM->_cursrow == screen_lines(SP_PARM) - 1 &&
469 	SP_PARM->_curscol == screen_columns(SP_PARM) - 1) {
470 	PutCharLR(NCURSES_SP_ARGx ch);
471     } else {
472 	PutAttrChar(NCURSES_SP_ARGx ch);
473     }
474 
475     if (SP_PARM->_curscol >= screen_columns(SP_PARM))
476 	wrap_cursor(NCURSES_SP_ARG);
477 
478     position_check(SP_PARM, SP_PARM->_cursrow, SP_PARM->_curscol, "PutChar");
479 }
480 
481 /*
482  * Check whether the given character can be output by clearing commands.  This
483  * includes test for being a space and not including any 'bad' attributes, such
484  * as A_REVERSE.  All attribute flags which don't affect appearance of a space
485  * or can be output by clearing (A_COLOR in case of bce-terminal) are excluded.
486  */
487 static NCURSES_INLINE bool
488 can_clear_with(NCURSES_SP_DCLx ARG_CH_T ch)
489 {
490     if (!back_color_erase && SP_PARM->_coloron) {
491 #if NCURSES_EXT_FUNCS
492 	int pair;
493 
494 	if (!SP_PARM->_default_color)
495 	    return FALSE;
496 	if (SP_PARM->_default_fg != C_MASK || SP_PARM->_default_bg != C_MASK)
497 	    return FALSE;
498 	if ((pair = GetPair(CHDEREF(ch))) != 0) {
499 	    short fg, bg;
500 	    NCURSES_SP_NAME(pair_content) (NCURSES_SP_ARGx
501 					   (short) pair,
502 					   &fg, &bg);
503 	    if (fg != C_MASK || bg != C_MASK)
504 		return FALSE;
505 	}
506 #else
507 	if (AttrOfD(ch) & A_COLOR)
508 	    return FALSE;
509 #endif
510     }
511     return (ISBLANK(CHDEREF(ch)) &&
512 	    (AttrOfD(ch) & ~(NONBLANK_ATTR | A_COLOR)) == BLANK_ATTR);
513 }
514 
515 /*
516  * Issue a given span of characters from an array.
517  * Must be functionally equivalent to:
518  *	for (i = 0; i < num; i++)
519  *	    PutChar(ntext[i]);
520  * but can leave the cursor positioned at the middle of the interval.
521  *
522  * Returns: 0 - cursor is at the end of interval
523  *	    1 - cursor is somewhere in the middle
524  *
525  * This code is optimized using ech and rep.
526  */
527 static int
528 EmitRange(NCURSES_SP_DCLx const NCURSES_CH_T * ntext, int num)
529 {
530     int i;
531 
532     TR(TRACE_CHARPUT, ("EmitRange %d:%s", num, _nc_viscbuf(ntext, num)));
533 
534     if (erase_chars || repeat_char) {
535 	while (num > 0) {
536 	    int runcount;
537 	    NCURSES_CH_T ntext0;
538 
539 	    while (num > 1 && !CharEq(ntext[0], ntext[1])) {
540 		PutChar(NCURSES_SP_ARGx CHREF(ntext[0]));
541 		ntext++;
542 		num--;
543 	    }
544 	    ntext0 = ntext[0];
545 	    if (num == 1) {
546 		PutChar(NCURSES_SP_ARGx CHREF(ntext0));
547 		return 0;
548 	    }
549 	    runcount = 2;
550 
551 	    while (runcount < num && CharEq(ntext[runcount], ntext0))
552 		runcount++;
553 
554 	    /*
555 	     * The cost expression in the middle isn't exactly right.
556 	     * _cup_ch_cost is an upper bound on the cost for moving to the
557 	     * end of the erased area, but not the cost itself (which we
558 	     * can't compute without emitting the move).  This may result
559 	     * in erase_chars not getting used in some situations for
560 	     * which it would be marginally advantageous.
561 	     */
562 	    if (erase_chars
563 		&& runcount > SP_PARM->_ech_cost + SP_PARM->_cup_ch_cost
564 		&& can_clear_with(NCURSES_SP_ARGx CHREF(ntext0))) {
565 		UpdateAttrs(SP_PARM, ntext0);
566 		NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx
567 				       TPARM_1(erase_chars, runcount));
568 
569 		/*
570 		 * If this is the last part of the given interval,
571 		 * don't bother moving cursor, since it can be the
572 		 * last update on the line.
573 		 */
574 		if (runcount < num) {
575 		    GoTo(NCURSES_SP_ARGx
576 			 SP_PARM->_cursrow,
577 			 SP_PARM->_curscol + runcount);
578 		} else {
579 		    return 1;	/* cursor stays in the middle */
580 		}
581 	    } else if (repeat_char && runcount > SP_PARM->_rep_cost) {
582 		bool wrap_possible = (SP_PARM->_curscol + runcount >=
583 				      screen_columns(SP_PARM));
584 		int rep_count = runcount;
585 
586 		if (wrap_possible)
587 		    rep_count--;
588 
589 		UpdateAttrs(SP_PARM, ntext0);
590 		NCURSES_SP_NAME(tputs) (NCURSES_SP_ARGx
591 					TPARM_2(repeat_char,
592 						CharOf(ntext0),
593 						rep_count),
594 					rep_count,
595 					NCURSES_SP_NAME(_nc_outch));
596 		SP_PARM->_curscol += rep_count;
597 
598 		if (wrap_possible)
599 		    PutChar(NCURSES_SP_ARGx CHREF(ntext0));
600 	    } else {
601 		for (i = 0; i < runcount; i++)
602 		    PutChar(NCURSES_SP_ARGx CHREF(ntext[i]));
603 	    }
604 	    ntext += runcount;
605 	    num -= runcount;
606 	}
607 	return 0;
608     }
609 
610     for (i = 0; i < num; i++)
611 	PutChar(NCURSES_SP_ARGx CHREF(ntext[i]));
612     return 0;
613 }
614 
615 /*
616  * Output the line in the given range [first .. last]
617  *
618  * If there's a run of identical characters that's long enough to justify
619  * cursor movement, use that also.
620  *
621  * Returns: same as EmitRange
622  */
623 static int
624 PutRange(NCURSES_SP_DCLx
625 	 const NCURSES_CH_T * otext,
626 	 const NCURSES_CH_T * ntext,
627 	 int row,
628 	 int first, int last)
629 {
630     int i, j, same;
631 
632     TR(TRACE_CHARPUT, ("PutRange(%p, %p, %p, %d, %d, %d)",
633 		       (void *) SP_PARM,
634 		       (const void *) otext,
635 		       (const void *) ntext,
636 		       row, first, last));
637 
638     if (otext != ntext
639 	&& (last - first + 1) > SP_PARM->_inline_cost) {
640 	for (j = first, same = 0; j <= last; j++) {
641 	    if (!same && isWidecExt(otext[j]))
642 		continue;
643 	    if (CharEq(otext[j], ntext[j])) {
644 		same++;
645 	    } else {
646 		if (same > SP_PARM->_inline_cost) {
647 		    EmitRange(NCURSES_SP_ARGx ntext + first, j - same - first);
648 		    GoTo(NCURSES_SP_ARGx row, first = j);
649 		}
650 		same = 0;
651 	    }
652 	}
653 	i = EmitRange(NCURSES_SP_ARGx ntext + first, j - same - first);
654 	/*
655 	 * Always return 1 for the next GoTo() after a PutRange() if we found
656 	 * identical characters at end of interval
657 	 */
658 	return (same == 0 ? i : 1);
659     }
660     return EmitRange(NCURSES_SP_ARGx ntext + first, last - first + 1);
661 }
662 
663 /* leave unbracketed here so 'indent' works */
664 #define MARK_NOCHANGE(win,row) \
665 		win->_line[row].firstchar = _NOCHANGE; \
666 		win->_line[row].lastchar = _NOCHANGE; \
667 		if_USE_SCROLL_HINTS(win->_line[row].oldindex = row)
668 
669 NCURSES_EXPORT(int)
670 TINFO_DOUPDATE(NCURSES_SP_DCL0)
671 {
672     int i;
673     int nonempty;
674 #if USE_TRACE_TIMES
675     struct tms before, after;
676 #endif /* USE_TRACE_TIMES */
677 
678     T((T_CALLED("_nc_tinfo:doupdate(%p)"), (void *) SP_PARM));
679 
680 #if !USE_REENTRANT
681     /*
682      * It is "legal" but unlikely that an application could assign a new
683      * value to one of the standard windows.  Check for that possibility
684      * and try to recover.
685      *
686      * We do not allow applications to assign new values in the reentrant
687      * model.
688      */
689 #define SyncScreens(internal,exported) \
690 	if (internal == 0) internal = exported; \
691 	if (internal != exported) exported = internal
692 
693     SyncScreens(CurScreen(SP_PARM), curscr);
694     SyncScreens(NewScreen(SP_PARM), newscr);
695     SyncScreens(StdScreen(SP_PARM), stdscr);
696 #endif
697 
698     if (CurScreen(SP_PARM) == 0
699 	|| NewScreen(SP_PARM) == 0
700 	|| StdScreen(SP_PARM) == 0)
701 	returnCode(ERR);
702 
703 #ifdef TRACE
704     if (USE_TRACEF(TRACE_UPDATE)) {
705 	if (CurScreen(SP_PARM)->_clear)
706 	    _tracef("curscr is clear");
707 	else
708 	    _tracedump("curscr", CurScreen(SP_PARM));
709 	_tracedump("newscr", NewScreen(SP_PARM));
710 	_nc_unlock_global(tracef);
711     }
712 #endif /* TRACE */
713 
714     _nc_signal_handler(FALSE);
715 
716     if (SP_PARM->_fifohold)
717 	SP_PARM->_fifohold--;
718 
719 #if USE_SIZECHANGE
720     if (SP_PARM->_endwin || _nc_handle_sigwinch(SP_PARM)) {
721 	/*
722 	 * This is a transparent extension:  XSI does not address it,
723 	 * and applications need not know that ncurses can do it.
724 	 *
725 	 * Check if the terminal size has changed while curses was off
726 	 * (this can happen in an xterm, for example), and resize the
727 	 * ncurses data structures accordingly.
728 	 */
729 	_nc_update_screensize(SP_PARM);
730     }
731 #endif
732 
733     if (SP_PARM->_endwin) {
734 
735 	T(("coming back from shell mode"));
736 	NCURSES_SP_NAME(reset_prog_mode) (NCURSES_SP_ARG);
737 
738 	NCURSES_SP_NAME(_nc_mvcur_resume) (NCURSES_SP_ARG);
739 	NCURSES_SP_NAME(_nc_screen_resume) (NCURSES_SP_ARG);
740 	SP_PARM->_mouse_resume(SP_PARM);
741 
742 	SP_PARM->_endwin = FALSE;
743     }
744 #if USE_TRACE_TIMES
745     /* zero the metering machinery */
746     RESET_OUTCHARS();
747     (void) times(&before);
748 #endif /* USE_TRACE_TIMES */
749 
750     /*
751      * This is the support for magic-cookie terminals.  The theory:  we scan
752      * the virtual screen looking for attribute turnons.  Where we find one,
753      * check to make sure it's realizable by seeing if the required number of
754      * un-attributed blanks are present before and after the attributed range;
755      * try to shift the range boundaries over blanks (not changing the screen
756      * display) so this becomes true.  If it is, shift the beginning attribute
757      * change appropriately (the end one, if we've gotten this far, is
758      * guaranteed room for its cookie).  If not, nuke the added attributes out
759      * of the span.
760      */
761 #if USE_XMC_SUPPORT
762     if (magic_cookie_glitch > 0) {
763 	int j, k;
764 	attr_t rattr = A_NORMAL;
765 
766 	for (i = 0; i < screen_lines(SP_PARM); i++) {
767 	    for (j = 0; j < screen_columns(SP_PARM); j++) {
768 		bool failed = FALSE;
769 		NCURSES_CH_T *thisline = NewScreen(SP_PARM)->_line[i].text;
770 		attr_t thisattr = AttrOf(thisline[j]) & SP_PARM->_xmc_triggers;
771 		attr_t turnon = thisattr & ~rattr;
772 
773 		/* is an attribute turned on here? */
774 		if (turnon == 0) {
775 		    rattr = thisattr;
776 		    continue;
777 		}
778 
779 		TR(TRACE_ATTRS, ("At (%d, %d): from %s...", i, j, _traceattr(rattr)));
780 		TR(TRACE_ATTRS, ("...to %s", _traceattr(turnon)));
781 
782 		/*
783 		 * If the attribute change location is a blank with a "safe"
784 		 * attribute, undo the attribute turnon.  This may ensure
785 		 * there's enough room to set the attribute before the first
786 		 * non-blank in the run.
787 		 */
788 #define SAFE(scr,a)	(!((a) & (scr)->_xmc_triggers))
789 		if (ISBLANK(thisline[j]) && SAFE(SP_PARM, turnon)) {
790 		    RemAttr(thisline[j], turnon);
791 		    continue;
792 		}
793 
794 		/* check that there's enough room at start of span */
795 		for (k = 1; k <= magic_cookie_glitch; k++) {
796 		    if (j - k < 0
797 			|| !ISBLANK(thisline[j - k])
798 			|| !SAFE(SP_PARM, AttrOf(thisline[j - k]))) {
799 			failed = TRUE;
800 			TR(TRACE_ATTRS, ("No room at start in %d,%d%s%s",
801 					 i, j - k,
802 					 (ISBLANK(thisline[j - k])
803 					  ? ""
804 					  : ":nonblank"),
805 					 (SAFE(SP_PARM, AttrOf(thisline[j - k]))
806 					  ? ""
807 					  : ":unsafe")));
808 			break;
809 		    }
810 		}
811 		if (!failed) {
812 		    bool end_onscreen = FALSE;
813 		    int m, n = j;
814 
815 		    /* find end of span, if it's onscreen */
816 		    for (m = i; m < screen_lines(SP_PARM); m++) {
817 			for (; n < screen_columns(SP_PARM); n++) {
818 			    attr_t testattr =
819 			    AttrOf(NewScreen(SP_PARM)->_line[m].text[n]);
820 			    if ((testattr & SP_PARM->_xmc_triggers) == rattr) {
821 				end_onscreen = TRUE;
822 				TR(TRACE_ATTRS,
823 				   ("Range attributed with %s ends at (%d, %d)",
824 				    _traceattr(turnon), m, n));
825 				goto foundit;
826 			    }
827 			}
828 			n = 0;
829 		    }
830 		    TR(TRACE_ATTRS,
831 		       ("Range attributed with %s ends offscreen",
832 			_traceattr(turnon)));
833 		  foundit:;
834 
835 		    if (end_onscreen) {
836 			NCURSES_CH_T *lastline =
837 			NewScreen(SP_PARM)->_line[m].text;
838 
839 			/*
840 			 * If there are safely-attributed blanks at the end of
841 			 * the range, shorten the range.  This will help ensure
842 			 * that there is enough room at end of span.
843 			 */
844 			while (n >= 0
845 			       && ISBLANK(lastline[n])
846 			       && SAFE(SP_PARM, AttrOf(lastline[n]))) {
847 			    RemAttr(lastline[n--], turnon);
848 			}
849 
850 			/* check that there's enough room at end of span */
851 			for (k = 1; k <= magic_cookie_glitch; k++) {
852 			    if (n + k >= screen_columns(SP_PARM)
853 				|| !ISBLANK(lastline[n + k])
854 				|| !SAFE(SP_PARM, AttrOf(lastline[n + k]))) {
855 				failed = TRUE;
856 				TR(TRACE_ATTRS,
857 				   ("No room at end in %d,%d%s%s",
858 				    i, j - k,
859 				    (ISBLANK(lastline[n + k])
860 				     ? ""
861 				     : ":nonblank"),
862 				    (SAFE(SP_PARM, AttrOf(lastline[n + k]))
863 				     ? ""
864 				     : ":unsafe")));
865 				break;
866 			    }
867 			}
868 		    }
869 		}
870 
871 		if (failed) {
872 		    int p, q = j;
873 
874 		    TR(TRACE_ATTRS,
875 		       ("Clearing %s beginning at (%d, %d)",
876 			_traceattr(turnon), i, j));
877 
878 		    /* turn off new attributes over span */
879 		    for (p = i; p < screen_lines(SP_PARM); p++) {
880 			for (; q < screen_columns(SP_PARM); q++) {
881 			    attr_t testattr = AttrOf(newscr->_line[p].text[q]);
882 			    if ((testattr & SP_PARM->_xmc_triggers) == rattr)
883 				goto foundend;
884 			    RemAttr(NewScreen(SP_PARM)->_line[p].text[q], turnon);
885 			}
886 			q = 0;
887 		    }
888 		  foundend:;
889 		} else {
890 		    TR(TRACE_ATTRS,
891 		       ("Cookie space for %s found before (%d, %d)",
892 			_traceattr(turnon), i, j));
893 
894 		    /*
895 		     * Back up the start of range so there's room for cookies
896 		     * before the first nonblank character.
897 		     */
898 		    for (k = 1; k <= magic_cookie_glitch; k++)
899 			AddAttr(thisline[j - k], turnon);
900 		}
901 
902 		rattr = thisattr;
903 	    }
904 	}
905 
906 #ifdef TRACE
907 	/* show altered highlights after magic-cookie check */
908 	if (USE_TRACEF(TRACE_UPDATE)) {
909 	    _tracef("After magic-cookie check...");
910 	    _tracedump("newscr", NewScreen(SP_PARM));
911 	    _nc_unlock_global(tracef);
912 	}
913 #endif /* TRACE */
914     }
915 #endif /* USE_XMC_SUPPORT */
916 
917     nonempty = 0;
918     if (CurScreen(SP_PARM)->_clear || NewScreen(SP_PARM)->_clear) {	/* force refresh ? */
919 	ClrUpdate(NCURSES_SP_ARG);
920 	CurScreen(SP_PARM)->_clear = FALSE;	/* reset flag */
921 	NewScreen(SP_PARM)->_clear = FALSE;	/* reset flag */
922     } else {
923 	int changedlines = CHECK_INTERVAL;
924 
925 	if (check_pending(NCURSES_SP_ARG))
926 	    goto cleanup;
927 
928 	nonempty = min(screen_lines(SP_PARM), NewScreen(SP_PARM)->_maxy + 1);
929 
930 	if (SP_PARM->_scrolling) {
931 	    NCURSES_SP_NAME(_nc_scroll_optimize) (NCURSES_SP_ARG);
932 	}
933 
934 	nonempty = ClrBottom(NCURSES_SP_ARGx nonempty);
935 
936 	TR(TRACE_UPDATE, ("Transforming lines, nonempty %d", nonempty));
937 	for (i = 0; i < nonempty; i++) {
938 	    /*
939 	     * Here is our line-breakout optimization.
940 	     */
941 	    if (changedlines == CHECK_INTERVAL) {
942 		if (check_pending(NCURSES_SP_ARG))
943 		    goto cleanup;
944 		changedlines = 0;
945 	    }
946 
947 	    /*
948 	     * newscr->line[i].firstchar is normally set
949 	     * by wnoutrefresh.  curscr->line[i].firstchar
950 	     * is normally set by _nc_scroll_window in the
951 	     * vertical-movement optimization code,
952 	     */
953 	    if (NewScreen(SP_PARM)->_line[i].firstchar != _NOCHANGE
954 		|| CurScreen(SP_PARM)->_line[i].firstchar != _NOCHANGE) {
955 		TransformLine(NCURSES_SP_ARGx i);
956 		changedlines++;
957 	    }
958 
959 	    /* mark line changed successfully */
960 	    if (i <= NewScreen(SP_PARM)->_maxy) {
961 		MARK_NOCHANGE(NewScreen(SP_PARM), i);
962 	    }
963 	    if (i <= CurScreen(SP_PARM)->_maxy) {
964 		MARK_NOCHANGE(CurScreen(SP_PARM), i);
965 	    }
966 	}
967     }
968 
969     /* put everything back in sync */
970     for (i = nonempty; i <= NewScreen(SP_PARM)->_maxy; i++) {
971 	MARK_NOCHANGE(NewScreen(SP_PARM), i);
972     }
973     for (i = nonempty; i <= CurScreen(SP_PARM)->_maxy; i++) {
974 	MARK_NOCHANGE(CurScreen(SP_PARM), i);
975     }
976 
977     if (!NewScreen(SP_PARM)->_leaveok) {
978 	CurScreen(SP_PARM)->_curx = NewScreen(SP_PARM)->_curx;
979 	CurScreen(SP_PARM)->_cury = NewScreen(SP_PARM)->_cury;
980 
981 	GoTo(NCURSES_SP_ARGx CurScreen(SP_PARM)->_cury, CurScreen(SP_PARM)->_curx);
982     }
983 
984   cleanup:
985     /*
986      * We would like to keep the physical screen in normal mode in case we get
987      * other processes writing to the screen.  This goal cannot be met for
988      * magic cookies since it interferes with attributes that may propagate
989      * past the current position.
990      */
991 #if USE_XMC_SUPPORT
992     if (magic_cookie_glitch != 0)
993 #endif
994 	UpdateAttrs(SP_PARM, normal);
995 
996     NCURSES_SP_NAME(_nc_flush) (NCURSES_SP_ARG);
997     WINDOW_ATTRS(CurScreen(SP_PARM)) = WINDOW_ATTRS(NewScreen(SP_PARM));
998 
999 #if USE_TRACE_TIMES
1000     (void) times(&after);
1001     TR(TRACE_TIMES,
1002        ("Update cost: %ld chars, %ld clocks system time, %ld clocks user time",
1003 	_nc_outchars,
1004 	(long) (after.tms_stime - before.tms_stime),
1005 	(long) (after.tms_utime - before.tms_utime)));
1006 #endif /* USE_TRACE_TIMES */
1007 
1008     _nc_signal_handler(TRUE);
1009 
1010     returnCode(OK);
1011 }
1012 
1013 #if NCURSES_SP_FUNCS && !defined(USE_TERM_DRIVER)
1014 NCURSES_EXPORT(int)
1015 doupdate(void)
1016 {
1017     return TINFO_DOUPDATE(CURRENT_SCREEN);
1018 }
1019 #endif
1020 
1021 /*
1022  *	ClrBlank(win)
1023  *
1024  *	Returns the attributed character that corresponds to the "cleared"
1025  *	screen.  If the terminal has the back-color-erase feature, this will be
1026  *	colored according to the wbkgd() call.
1027  *
1028  *	We treat 'curscr' specially because it isn't supposed to be set directly
1029  *	in the wbkgd() call.  Assume 'stdscr' for this case.
1030  */
1031 #define BCE_ATTRS (A_NORMAL|A_COLOR)
1032 #define BCE_BKGD(sp,win) (((win) == CurScreen(sp) ? StdScreen(sp) : (win))->_nc_bkgd)
1033 
1034 static NCURSES_INLINE NCURSES_CH_T
1035 ClrBlank(NCURSES_SP_DCLx WINDOW *win)
1036 {
1037     NCURSES_CH_T blank = blankchar;
1038     if (back_color_erase)
1039 	AddAttr(blank, (AttrOf(BCE_BKGD(SP_PARM, win)) & BCE_ATTRS));
1040     return blank;
1041 }
1042 
1043 /*
1044 **	ClrUpdate()
1045 **
1046 **	Update by clearing and redrawing the entire screen.
1047 **
1048 */
1049 
1050 static void
1051 ClrUpdate(NCURSES_SP_DCL0)
1052 {
1053     TR(TRACE_UPDATE, (T_CALLED("ClrUpdate")));
1054     if (0 != SP_PARM) {
1055 	int i;
1056 	NCURSES_CH_T blank = ClrBlank(NCURSES_SP_ARGx StdScreen(SP_PARM));
1057 	int nonempty = min(screen_lines(SP_PARM),
1058 			   NewScreen(SP_PARM)->_maxy + 1);
1059 
1060 	ClearScreen(NCURSES_SP_ARGx blank);
1061 
1062 	TR(TRACE_UPDATE, ("updating screen from scratch"));
1063 
1064 	nonempty = ClrBottom(NCURSES_SP_ARGx nonempty);
1065 
1066 	for (i = 0; i < nonempty; i++)
1067 	    TransformLine(NCURSES_SP_ARGx i);
1068     }
1069     TR(TRACE_UPDATE, (T_RETURN("")));
1070 }
1071 
1072 /*
1073 **	ClrToEOL(blank)
1074 **
1075 **	Clear to end of current line, starting at the cursor position
1076 */
1077 
1078 static void
1079 ClrToEOL(NCURSES_SP_DCLx NCURSES_CH_T blank, bool needclear)
1080 {
1081     int j;
1082 
1083     if (SP_PARM != 0) {
1084 	if (CurScreen(SP_PARM) != 0
1085 	    && SP_PARM->_cursrow >= 0) {
1086 	    for (j = SP_PARM->_curscol; j < screen_columns(SP_PARM); j++) {
1087 		if (j >= 0) {
1088 		    NCURSES_CH_T *cp =
1089 		    &(CurScreen(SP_PARM)->_line[SP_PARM->_cursrow].text[j]);
1090 
1091 		    if (!CharEq(*cp, blank)) {
1092 			*cp = blank;
1093 			needclear = TRUE;
1094 		    }
1095 		}
1096 	    }
1097 	}
1098     }
1099 
1100     if (needclear && (SP_PARM != 0)) {
1101 	UpdateAttrs(SP_PARM, blank);
1102 	TPUTS_TRACE("clr_eol");
1103 	if (clr_eol && SP_PARM->_el_cost <= (screen_columns(SP_PARM) - SP_PARM->_curscol)) {
1104 	    NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx clr_eol);
1105 	} else {
1106 	    int count = (screen_columns(SP_PARM) - SP_PARM->_curscol);
1107 	    while (count-- > 0)
1108 		PutChar(NCURSES_SP_ARGx CHREF(blank));
1109 	}
1110     }
1111 }
1112 
1113 /*
1114 **	ClrToEOS(blank)
1115 **
1116 **	Clear to end of screen, starting at the cursor position
1117 */
1118 
1119 static void
1120 ClrToEOS(NCURSES_SP_DCLx NCURSES_CH_T blank)
1121 {
1122     int row, col;
1123 
1124     if (0 == SP_PARM)
1125 	return;
1126 
1127     row = SP_PARM->_cursrow;
1128     col = SP_PARM->_curscol;
1129 
1130     UpdateAttrs(SP_PARM, blank);
1131     TPUTS_TRACE("clr_eos");
1132     NCURSES_SP_NAME(tputs) (NCURSES_SP_ARGx
1133 			    clr_eos,
1134 			    screen_lines(SP_PARM) - row,
1135 			    NCURSES_SP_NAME(_nc_outch));
1136 
1137     while (col < screen_columns(SP_PARM))
1138 	CurScreen(SP_PARM)->_line[row].text[col++] = blank;
1139 
1140     for (row++; row < screen_lines(SP_PARM); row++) {
1141 	for (col = 0; col < screen_columns(SP_PARM); col++)
1142 	    CurScreen(SP_PARM)->_line[row].text[col] = blank;
1143     }
1144 }
1145 
1146 /*
1147  *	ClrBottom(total)
1148  *
1149  *	Test if clearing the end of the screen would satisfy part of the
1150  *	screen-update.  Do this by scanning backwards through the lines in the
1151  *	screen, checking if each is blank, and one or more are changed.
1152  */
1153 static int
1154 ClrBottom(NCURSES_SP_DCLx int total)
1155 {
1156     int row;
1157     int col;
1158     int top = total;
1159     int last = min(screen_columns(SP_PARM), NewScreen(SP_PARM)->_maxx + 1);
1160     NCURSES_CH_T blank = NewScreen(SP_PARM)->_line[total - 1].text[last - 1];
1161     bool ok;
1162 
1163     if (clr_eos && can_clear_with(NCURSES_SP_ARGx CHREF(blank))) {
1164 
1165 	for (row = total - 1; row >= 0; row--) {
1166 	    for (col = 0, ok = TRUE; ok && col < last; col++) {
1167 		ok = (CharEq(NewScreen(SP_PARM)->_line[row].text[col], blank));
1168 	    }
1169 	    if (!ok)
1170 		break;
1171 
1172 	    for (col = 0; ok && col < last; col++) {
1173 		ok = (CharEq(CurScreen(SP_PARM)->_line[row].text[col], blank));
1174 	    }
1175 	    if (!ok)
1176 		top = row;
1177 	}
1178 
1179 	/* don't use clr_eos for just one line if clr_eol available */
1180 	if (top < total) {
1181 	    GoTo(NCURSES_SP_ARGx top, 0);
1182 	    ClrToEOS(NCURSES_SP_ARGx blank);
1183 	    if (SP_PARM->oldhash && SP_PARM->newhash) {
1184 		for (row = top; row < screen_lines(SP_PARM); row++)
1185 		    SP_PARM->oldhash[row] = SP_PARM->newhash[row];
1186 	    }
1187 	}
1188     }
1189     return top;
1190 }
1191 
1192 #if USE_XMC_SUPPORT
1193 #if USE_WIDEC_SUPPORT
1194 #define check_xmc_transition(sp, a, b)					\
1195     ((((a)->attr ^ (b)->attr) & ~((a)->attr) & (sp)->_xmc_triggers) != 0)
1196 #define xmc_turn_on(sp,a,b) check_xmc_transition(sp,&(a), &(b))
1197 #else
1198 #define xmc_turn_on(sp,a,b) ((((a)^(b)) & ~(a) & (sp)->_xmc_triggers) != 0)
1199 #endif
1200 
1201 #define xmc_new(sp,r,c) NewScreen(sp)->_line[r].text[c]
1202 #define xmc_turn_off(sp,a,b) xmc_turn_on(sp,b,a)
1203 #endif /* USE_XMC_SUPPORT */
1204 
1205 /*
1206 **	TransformLine(lineno)
1207 **
1208 **	Transform the given line in curscr to the one in newscr, using
1209 **	Insert/Delete Character if idcok && has_ic().
1210 **
1211 **		firstChar = position of first different character in line
1212 **		oLastChar = position of last different character in old line
1213 **		nLastChar = position of last different character in new line
1214 **
1215 **		move to firstChar
1216 **		overwrite chars up to min(oLastChar, nLastChar)
1217 **		if oLastChar < nLastChar
1218 **			insert newLine[oLastChar+1..nLastChar]
1219 **		else
1220 **			delete oLastChar - nLastChar spaces
1221 */
1222 
1223 static void
1224 TransformLine(NCURSES_SP_DCLx int const lineno)
1225 {
1226     int firstChar, oLastChar, nLastChar;
1227     NCURSES_CH_T *newLine = NewScreen(SP_PARM)->_line[lineno].text;
1228     NCURSES_CH_T *oldLine = CurScreen(SP_PARM)->_line[lineno].text;
1229     int n;
1230     bool attrchanged = FALSE;
1231 
1232     TR(TRACE_UPDATE, (T_CALLED("TransformLine(%p, %d)"), (void *) SP_PARM, lineno));
1233 
1234     /* copy new hash value to old one */
1235     if (SP_PARM->oldhash && SP_PARM->newhash)
1236 	SP_PARM->oldhash[lineno] = SP_PARM->newhash[lineno];
1237 
1238     /*
1239      * If we have colors, there is the possibility of having two color pairs
1240      * that display as the same colors.  For instance, Lynx does this.  Check
1241      * for this case, and update the old line with the new line's colors when
1242      * they are equivalent.
1243      */
1244     if (SP_PARM->_coloron) {
1245 	int oldPair;
1246 	int newPair;
1247 
1248 	for (n = 0; n < screen_columns(SP_PARM); n++) {
1249 	    if (!CharEq(newLine[n], oldLine[n])) {
1250 		oldPair = GetPair(oldLine[n]);
1251 		newPair = GetPair(newLine[n]);
1252 		if (oldPair != newPair
1253 		    && unColor(oldLine[n]) == unColor(newLine[n])) {
1254 		    if (oldPair < SP_PARM->_pair_limit
1255 			&& newPair < SP_PARM->_pair_limit
1256 			&& (SP_PARM->_color_pairs[oldPair] ==
1257 			    SP_PARM->_color_pairs[newPair])) {
1258 			SetPair(oldLine[n], GetPair(newLine[n]));
1259 		    }
1260 		}
1261 	    }
1262 	}
1263     }
1264 
1265     if (ceol_standout_glitch && clr_eol) {
1266 	firstChar = 0;
1267 	while (firstChar < screen_columns(SP_PARM)) {
1268 	    if (!SameAttrOf(newLine[firstChar], oldLine[firstChar])) {
1269 		attrchanged = TRUE;
1270 		break;
1271 	    }
1272 	    firstChar++;
1273 	}
1274     }
1275 
1276     firstChar = 0;
1277 
1278     if (attrchanged) {		/* we may have to disregard the whole line */
1279 	GoTo(NCURSES_SP_ARGx lineno, firstChar);
1280 	ClrToEOL(NCURSES_SP_ARGx
1281 		 ClrBlank(NCURSES_SP_ARGx
1282 			  CurScreen(SP_PARM)), FALSE);
1283 	PutRange(NCURSES_SP_ARGx
1284 		 oldLine, newLine, lineno, 0,
1285 		 screen_columns(SP_PARM) - 1);
1286 #if USE_XMC_SUPPORT
1287 
1288 	/*
1289 	 * This is a very simple loop to paint characters which may have the
1290 	 * magic cookie glitch embedded.  It doesn't know much about video
1291 	 * attributes which are continued from one line to the next.  It
1292 	 * assumes that we have filtered out requests for attribute changes
1293 	 * that do not get mapped to blank positions.
1294 	 *
1295 	 * FIXME: we are not keeping track of where we put the cookies, so this
1296 	 * will work properly only once, since we may overwrite a cookie in a
1297 	 * following operation.
1298 	 */
1299     } else if (magic_cookie_glitch > 0) {
1300 	GoTo(NCURSES_SP_ARGx lineno, firstChar);
1301 	for (n = 0; n < screen_columns(SP_PARM); n++) {
1302 	    int m = n + magic_cookie_glitch;
1303 
1304 	    /* check for turn-on:
1305 	     * If we are writing an attributed blank, where the
1306 	     * previous cell is not attributed.
1307 	     */
1308 	    if (ISBLANK(newLine[n])
1309 		&& ((n > 0
1310 		     && xmc_turn_on(SP_PARM, newLine[n - 1], newLine[n]))
1311 		    || (n == 0
1312 			&& lineno > 0
1313 			&& xmc_turn_on(SP_PARM,
1314 				       xmc_new(SP_PARM, lineno - 1,
1315 					       screen_columns(SP_PARM) - 1),
1316 				       newLine[n])))) {
1317 		n = m;
1318 	    }
1319 
1320 	    PutChar(NCURSES_SP_ARGx CHREF(newLine[n]));
1321 
1322 	    /* check for turn-off:
1323 	     * If we are writing an attributed non-blank, where the
1324 	     * next cell is blank, and not attributed.
1325 	     */
1326 	    if (!ISBLANK(newLine[n])
1327 		&& ((n + 1 < screen_columns(SP_PARM)
1328 		     && xmc_turn_off(SP_PARM, newLine[n], newLine[n + 1]))
1329 		    || (n + 1 >= screen_columns(SP_PARM)
1330 			&& lineno + 1 < screen_lines(SP_PARM)
1331 			&& xmc_turn_off(SP_PARM,
1332 					newLine[n],
1333 					xmc_new(SP_PARM, lineno + 1, 0))))) {
1334 		n = m;
1335 	    }
1336 
1337 	}
1338 #endif
1339     } else {
1340 	NCURSES_CH_T blank;
1341 
1342 	/* it may be cheap to clear leading whitespace with clr_bol */
1343 	blank = newLine[0];
1344 	if (clr_bol && can_clear_with(NCURSES_SP_ARGx CHREF(blank))) {
1345 	    int oFirstChar, nFirstChar;
1346 
1347 	    for (oFirstChar = 0;
1348 		 oFirstChar < screen_columns(SP_PARM);
1349 		 oFirstChar++)
1350 		if (!CharEq(oldLine[oFirstChar], blank))
1351 		    break;
1352 	    for (nFirstChar = 0;
1353 		 nFirstChar < screen_columns(SP_PARM);
1354 		 nFirstChar++)
1355 		if (!CharEq(newLine[nFirstChar], blank))
1356 		    break;
1357 
1358 	    if (nFirstChar == oFirstChar) {
1359 		firstChar = nFirstChar;
1360 		/* find the first differing character */
1361 		while (firstChar < screen_columns(SP_PARM)
1362 		       && CharEq(newLine[firstChar], oldLine[firstChar]))
1363 		    firstChar++;
1364 	    } else if (oFirstChar > nFirstChar) {
1365 		firstChar = nFirstChar;
1366 	    } else {		/* oFirstChar < nFirstChar */
1367 		firstChar = oFirstChar;
1368 		if (SP_PARM->_el1_cost < nFirstChar - oFirstChar) {
1369 		    if (nFirstChar >= screen_columns(SP_PARM)
1370 			&& SP_PARM->_el_cost <= SP_PARM->_el1_cost) {
1371 			GoTo(NCURSES_SP_ARGx lineno, 0);
1372 			UpdateAttrs(SP_PARM, blank);
1373 			TPUTS_TRACE("clr_eol");
1374 			NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx clr_eol);
1375 		    } else {
1376 			GoTo(NCURSES_SP_ARGx lineno, nFirstChar - 1);
1377 			UpdateAttrs(SP_PARM, blank);
1378 			TPUTS_TRACE("clr_bol");
1379 			NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx clr_bol);
1380 		    }
1381 
1382 		    while (firstChar < nFirstChar)
1383 			oldLine[firstChar++] = blank;
1384 		}
1385 	    }
1386 	} else {
1387 	    /* find the first differing character */
1388 	    while (firstChar < screen_columns(SP_PARM)
1389 		   && CharEq(newLine[firstChar], oldLine[firstChar]))
1390 		firstChar++;
1391 	}
1392 	/* if there wasn't one, we're done */
1393 	if (firstChar >= screen_columns(SP_PARM)) {
1394 	    TR(TRACE_UPDATE, (T_RETURN("")));
1395 	    return;
1396 	}
1397 
1398 	blank = newLine[screen_columns(SP_PARM) - 1];
1399 
1400 	if (!can_clear_with(NCURSES_SP_ARGx CHREF(blank))) {
1401 	    /* find the last differing character */
1402 	    nLastChar = screen_columns(SP_PARM) - 1;
1403 
1404 	    while (nLastChar > firstChar
1405 		   && CharEq(newLine[nLastChar], oldLine[nLastChar]))
1406 		nLastChar--;
1407 
1408 	    if (nLastChar >= firstChar) {
1409 		GoTo(NCURSES_SP_ARGx lineno, firstChar);
1410 		PutRange(NCURSES_SP_ARGx
1411 			 oldLine,
1412 			 newLine,
1413 			 lineno,
1414 			 firstChar,
1415 			 nLastChar);
1416 		memcpy(oldLine + firstChar,
1417 		       newLine + firstChar,
1418 		       (unsigned) (nLastChar - firstChar + 1) * sizeof(NCURSES_CH_T));
1419 	    }
1420 	    TR(TRACE_UPDATE, (T_RETURN("")));
1421 	    return;
1422 	}
1423 
1424 	/* find last non-blank character on old line */
1425 	oLastChar = screen_columns(SP_PARM) - 1;
1426 	while (oLastChar > firstChar && CharEq(oldLine[oLastChar], blank))
1427 	    oLastChar--;
1428 
1429 	/* find last non-blank character on new line */
1430 	nLastChar = screen_columns(SP_PARM) - 1;
1431 	while (nLastChar > firstChar && CharEq(newLine[nLastChar], blank))
1432 	    nLastChar--;
1433 
1434 	if ((nLastChar == firstChar)
1435 	    && (SP_PARM->_el_cost < (oLastChar - nLastChar))) {
1436 	    GoTo(NCURSES_SP_ARGx lineno, firstChar);
1437 	    if (!CharEq(newLine[firstChar], blank))
1438 		PutChar(NCURSES_SP_ARGx CHREF(newLine[firstChar]));
1439 	    ClrToEOL(NCURSES_SP_ARGx blank, FALSE);
1440 	} else if ((nLastChar != oLastChar)
1441 		   && (!CharEq(newLine[nLastChar], oldLine[oLastChar])
1442 		       || !(SP_PARM->_nc_sp_idcok
1443 			    && NCURSES_SP_NAME(has_ic) (NCURSES_SP_ARG)))) {
1444 	    GoTo(NCURSES_SP_ARGx lineno, firstChar);
1445 	    if ((oLastChar - nLastChar) > SP_PARM->_el_cost) {
1446 		if (PutRange(NCURSES_SP_ARGx
1447 			     oldLine,
1448 			     newLine,
1449 			     lineno,
1450 			     firstChar,
1451 			     nLastChar)) {
1452 		    GoTo(NCURSES_SP_ARGx lineno, nLastChar + 1);
1453 		}
1454 		ClrToEOL(NCURSES_SP_ARGx blank, FALSE);
1455 	    } else {
1456 		n = max(nLastChar, oLastChar);
1457 		PutRange(NCURSES_SP_ARGx
1458 			 oldLine,
1459 			 newLine,
1460 			 lineno,
1461 			 firstChar,
1462 			 n);
1463 	    }
1464 	} else {
1465 	    int nLastNonblank = nLastChar;
1466 	    int oLastNonblank = oLastChar;
1467 
1468 	    /* find the last characters that really differ */
1469 	    /* can be -1 if no characters differ */
1470 	    while (CharEq(newLine[nLastChar], oldLine[oLastChar])) {
1471 		/* don't split a wide char */
1472 		if (isWidecExt(newLine[nLastChar]) &&
1473 		    !CharEq(newLine[nLastChar - 1], oldLine[oLastChar - 1]))
1474 		    break;
1475 		nLastChar--;
1476 		oLastChar--;
1477 		if (nLastChar == -1 || oLastChar == -1)
1478 		    break;
1479 	    }
1480 
1481 	    n = min(oLastChar, nLastChar);
1482 	    if (n >= firstChar) {
1483 		GoTo(NCURSES_SP_ARGx lineno, firstChar);
1484 		PutRange(NCURSES_SP_ARGx
1485 			 oldLine,
1486 			 newLine,
1487 			 lineno,
1488 			 firstChar,
1489 			 n);
1490 	    }
1491 
1492 	    if (oLastChar < nLastChar) {
1493 		int m = max(nLastNonblank, oLastNonblank);
1494 #if USE_WIDEC_SUPPORT
1495 		while (isWidecExt(newLine[n + 1]) && n) {
1496 		    --n;
1497 		    --oLastChar;
1498 		}
1499 #endif
1500 		GoTo(NCURSES_SP_ARGx lineno, n + 1);
1501 		if ((nLastChar < nLastNonblank)
1502 		    || InsCharCost(SP_PARM, nLastChar - oLastChar) > (m - n)) {
1503 		    PutRange(NCURSES_SP_ARGx
1504 			     oldLine,
1505 			     newLine,
1506 			     lineno,
1507 			     n + 1,
1508 			     m);
1509 		} else {
1510 		    InsStr(NCURSES_SP_ARGx &newLine[n + 1], nLastChar - oLastChar);
1511 		}
1512 	    } else if (oLastChar > nLastChar) {
1513 		GoTo(NCURSES_SP_ARGx lineno, n + 1);
1514 		if (DelCharCost(SP_PARM, oLastChar - nLastChar)
1515 		    > SP_PARM->_el_cost + nLastNonblank - (n + 1)) {
1516 		    if (PutRange(NCURSES_SP_ARGx oldLine, newLine, lineno,
1517 				 n + 1, nLastNonblank))
1518 			  GoTo(NCURSES_SP_ARGx lineno, nLastNonblank + 1);
1519 		    ClrToEOL(NCURSES_SP_ARGx blank, FALSE);
1520 		} else {
1521 		    /*
1522 		     * The delete-char sequence will
1523 		     * effectively shift in blanks from the
1524 		     * right margin of the screen.  Ensure
1525 		     * that they are the right color by
1526 		     * setting the video attributes from
1527 		     * the last character on the row.
1528 		     */
1529 		    UpdateAttrs(SP_PARM, blank);
1530 		    DelChar(NCURSES_SP_ARGx oLastChar - nLastChar);
1531 		}
1532 	    }
1533 	}
1534     }
1535 
1536     /* update the code's internal representation */
1537     if (screen_columns(SP_PARM) > firstChar)
1538 	memcpy(oldLine + firstChar,
1539 	       newLine + firstChar,
1540 	       (unsigned) (screen_columns(SP_PARM) - firstChar) * sizeof(NCURSES_CH_T));
1541     TR(TRACE_UPDATE, (T_RETURN("")));
1542     return;
1543 }
1544 
1545 /*
1546 **	ClearScreen(blank)
1547 **
1548 **	Clear the physical screen and put cursor at home
1549 **
1550 */
1551 
1552 static void
1553 ClearScreen(NCURSES_SP_DCLx NCURSES_CH_T blank)
1554 {
1555     int i, j;
1556     bool fast_clear = (clear_screen || clr_eos || clr_eol);
1557 
1558     TR(TRACE_UPDATE, ("ClearScreen() called"));
1559 
1560 #if NCURSES_EXT_FUNCS
1561     if (SP_PARM->_coloron
1562 	&& !SP_PARM->_default_color) {
1563 	NCURSES_SP_NAME(_nc_do_color) (NCURSES_SP_ARGx
1564 				       (short) GET_SCREEN_PAIR(SP_PARM),
1565 				       0,
1566 				       FALSE,
1567 				       NCURSES_SP_NAME(_nc_outch));
1568 	if (!back_color_erase) {
1569 	    fast_clear = FALSE;
1570 	}
1571     }
1572 #endif
1573 
1574     if (fast_clear) {
1575 	if (clear_screen) {
1576 	    UpdateAttrs(SP_PARM, blank);
1577 	    TPUTS_TRACE("clear_screen");
1578 	    NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx clear_screen);
1579 	    SP_PARM->_cursrow = SP_PARM->_curscol = 0;
1580 	    position_check(SP_PARM,
1581 			   SP_PARM->_cursrow,
1582 			   SP_PARM->_curscol,
1583 			   "ClearScreen");
1584 	} else if (clr_eos) {
1585 	    SP_PARM->_cursrow = SP_PARM->_curscol = -1;
1586 	    GoTo(NCURSES_SP_ARGx 0, 0);
1587 	    UpdateAttrs(SP_PARM, blank);
1588 	    TPUTS_TRACE("clr_eos");
1589 	    NCURSES_SP_NAME(tputs) (NCURSES_SP_ARGx
1590 				    clr_eos,
1591 				    screen_lines(SP_PARM),
1592 				    NCURSES_SP_NAME(_nc_outch));
1593 	} else if (clr_eol) {
1594 	    SP_PARM->_cursrow = SP_PARM->_curscol = -1;
1595 	    UpdateAttrs(SP_PARM, blank);
1596 	    for (i = 0; i < screen_lines(SP_PARM); i++) {
1597 		GoTo(NCURSES_SP_ARGx i, 0);
1598 		TPUTS_TRACE("clr_eol");
1599 		NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx clr_eol);
1600 	    }
1601 	    GoTo(NCURSES_SP_ARGx 0, 0);
1602 	}
1603     } else {
1604 	UpdateAttrs(SP_PARM, blank);
1605 	for (i = 0; i < screen_lines(SP_PARM); i++) {
1606 	    GoTo(NCURSES_SP_ARGx i, 0);
1607 	    for (j = 0; j < screen_columns(SP_PARM); j++)
1608 		PutChar(NCURSES_SP_ARGx CHREF(blank));
1609 	}
1610 	GoTo(NCURSES_SP_ARGx 0, 0);
1611     }
1612 
1613     for (i = 0; i < screen_lines(SP_PARM); i++) {
1614 	for (j = 0; j < screen_columns(SP_PARM); j++)
1615 	    CurScreen(SP_PARM)->_line[i].text[j] = blank;
1616     }
1617 
1618     TR(TRACE_UPDATE, ("screen cleared"));
1619 }
1620 
1621 /*
1622 **	InsStr(line, count)
1623 **
1624 **	Insert the count characters pointed to by line.
1625 **
1626 */
1627 
1628 static void
1629 InsStr(NCURSES_SP_DCLx NCURSES_CH_T * line, int count)
1630 {
1631     TR(TRACE_UPDATE, ("InsStr(%p, %p,%d) called",
1632 		      (void *) SP_PARM,
1633 		      (void *) line, count));
1634 
1635     /* Prefer parm_ich as it has the smallest cost - no need to shift
1636      * the whole line on each character. */
1637     /* The order must match that of InsCharCost. */
1638     if (parm_ich) {
1639 	TPUTS_TRACE("parm_ich");
1640 	NCURSES_SP_NAME(tputs) (NCURSES_SP_ARGx
1641 				TPARM_1(parm_ich, count),
1642 				count,
1643 				NCURSES_SP_NAME(_nc_outch));
1644 	while (count) {
1645 	    PutAttrChar(NCURSES_SP_ARGx CHREF(*line));
1646 	    line++;
1647 	    count--;
1648 	}
1649     } else if (enter_insert_mode && exit_insert_mode) {
1650 	TPUTS_TRACE("enter_insert_mode");
1651 	NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx enter_insert_mode);
1652 	while (count) {
1653 	    PutAttrChar(NCURSES_SP_ARGx CHREF(*line));
1654 	    if (insert_padding) {
1655 		TPUTS_TRACE("insert_padding");
1656 		NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx insert_padding);
1657 	    }
1658 	    line++;
1659 	    count--;
1660 	}
1661 	TPUTS_TRACE("exit_insert_mode");
1662 	NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx exit_insert_mode);
1663     } else {
1664 	while (count) {
1665 	    TPUTS_TRACE("insert_character");
1666 	    NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx insert_character);
1667 	    PutAttrChar(NCURSES_SP_ARGx CHREF(*line));
1668 	    if (insert_padding) {
1669 		TPUTS_TRACE("insert_padding");
1670 		NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx insert_padding);
1671 	    }
1672 	    line++;
1673 	    count--;
1674 	}
1675     }
1676     position_check(SP_PARM, SP_PARM->_cursrow, SP_PARM->_curscol, "InsStr");
1677 }
1678 
1679 /*
1680 **	DelChar(count)
1681 **
1682 **	Delete count characters at current position
1683 **
1684 */
1685 
1686 static void
1687 DelChar(NCURSES_SP_DCLx int count)
1688 {
1689     int n;
1690 
1691     TR(TRACE_UPDATE, ("DelChar(%p, %d) called, position = (%ld,%ld)",
1692 		      (void *) SP_PARM, count,
1693 		      (long) NewScreen(SP_PARM)->_cury,
1694 		      (long) NewScreen(SP_PARM)->_curx));
1695 
1696     if (parm_dch) {
1697 	TPUTS_TRACE("parm_dch");
1698 	NCURSES_SP_NAME(tputs) (NCURSES_SP_ARGx
1699 				TPARM_1(parm_dch, count),
1700 				count,
1701 				NCURSES_SP_NAME(_nc_outch));
1702     } else {
1703 	for (n = 0; n < count; n++) {
1704 	    TPUTS_TRACE("delete_character");
1705 	    NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx delete_character);
1706 	}
1707     }
1708 }
1709 
1710 /*
1711  * Physical-scrolling support
1712  *
1713  * This code was adapted from Keith Bostic's hardware scrolling
1714  * support for 4.4BSD curses.  I (esr) translated it to use terminfo
1715  * capabilities, narrowed the call interface slightly, and cleaned
1716  * up some convoluted tests.  I also added support for the memory_above
1717  * memory_below, and non_dest_scroll_region capabilities.
1718  *
1719  * For this code to work, we must have either
1720  * change_scroll_region and scroll forward/reverse commands, or
1721  * insert and delete line capabilities.
1722  * When the scrolling region has been set, the cursor has to
1723  * be at the last line of the region to make the scroll up
1724  * happen, or on the first line of region to scroll down.
1725  *
1726  * This code makes one aesthetic decision in the opposite way from
1727  * BSD curses.  BSD curses preferred pairs of il/dl operations
1728  * over scrolls, allegedly because il/dl looked faster.  We, on
1729  * the other hand, prefer scrolls because (a) they're just as fast
1730  * on many terminals and (b) using them avoids bouncing an
1731  * unchanged bottom section of the screen up and down, which is
1732  * visually nasty.
1733  *
1734  * (lav): added more cases, used dl/il when bot==maxy and in csr case.
1735  *
1736  * I used assumption that capabilities il/il1/dl/dl1 work inside
1737  * changed scroll region not shifting screen contents outside of it.
1738  * If there are any terminals behaving different way, it would be
1739  * necessary to add some conditions to scroll_csr_forward/backward.
1740  */
1741 
1742 /* Try to scroll up assuming given csr (miny, maxy). Returns ERR on failure */
1743 static int
1744 scroll_csr_forward(NCURSES_SP_DCLx
1745 		   int n,
1746 		   int top,
1747 		   int bot,
1748 		   int miny,
1749 		   int maxy,
1750 		   NCURSES_CH_T blank)
1751 {
1752     int i;
1753 
1754     if (n == 1 && scroll_forward && top == miny && bot == maxy) {
1755 	GoTo(NCURSES_SP_ARGx bot, 0);
1756 	UpdateAttrs(SP_PARM, blank);
1757 	TPUTS_TRACE("scroll_forward");
1758 	NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx scroll_forward);
1759     } else if (n == 1 && delete_line && bot == maxy) {
1760 	GoTo(NCURSES_SP_ARGx top, 0);
1761 	UpdateAttrs(SP_PARM, blank);
1762 	TPUTS_TRACE("delete_line");
1763 	NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx delete_line);
1764     } else if (parm_index && top == miny && bot == maxy) {
1765 	GoTo(NCURSES_SP_ARGx bot, 0);
1766 	UpdateAttrs(SP_PARM, blank);
1767 	TPUTS_TRACE("parm_index");
1768 	NCURSES_SP_NAME(tputs) (NCURSES_SP_ARGx
1769 				TPARM_2(parm_index, n, 0),
1770 				n,
1771 				NCURSES_SP_NAME(_nc_outch));
1772     } else if (parm_delete_line && bot == maxy) {
1773 	GoTo(NCURSES_SP_ARGx top, 0);
1774 	UpdateAttrs(SP_PARM, blank);
1775 	TPUTS_TRACE("parm_delete_line");
1776 	NCURSES_SP_NAME(tputs) (NCURSES_SP_ARGx
1777 				TPARM_2(parm_delete_line, n, 0),
1778 				n,
1779 				NCURSES_SP_NAME(_nc_outch));
1780     } else if (scroll_forward && top == miny && bot == maxy) {
1781 	GoTo(NCURSES_SP_ARGx bot, 0);
1782 	UpdateAttrs(SP_PARM, blank);
1783 	for (i = 0; i < n; i++) {
1784 	    TPUTS_TRACE("scroll_forward");
1785 	    NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx scroll_forward);
1786 	}
1787     } else if (delete_line && bot == maxy) {
1788 	GoTo(NCURSES_SP_ARGx top, 0);
1789 	UpdateAttrs(SP_PARM, blank);
1790 	for (i = 0; i < n; i++) {
1791 	    TPUTS_TRACE("delete_line");
1792 	    NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx delete_line);
1793 	}
1794     } else
1795 	return ERR;
1796 
1797 #if NCURSES_EXT_FUNCS
1798     if (FILL_BCE(SP_PARM)) {
1799 	int j;
1800 	for (i = 0; i < n; i++) {
1801 	    GoTo(NCURSES_SP_ARGx bot - i, 0);
1802 	    for (j = 0; j < screen_columns(SP_PARM); j++)
1803 		PutChar(NCURSES_SP_ARGx CHREF(blank));
1804 	}
1805     }
1806 #endif
1807     return OK;
1808 }
1809 
1810 /* Try to scroll down assuming given csr (miny, maxy). Returns ERR on failure */
1811 /* n > 0 */
1812 static int
1813 scroll_csr_backward(NCURSES_SP_DCLx
1814 		    int n,
1815 		    int top,
1816 		    int bot,
1817 		    int miny,
1818 		    int maxy,
1819 		    NCURSES_CH_T blank)
1820 {
1821     int i;
1822 
1823     if (n == 1 && scroll_reverse && top == miny && bot == maxy) {
1824 	GoTo(NCURSES_SP_ARGx top, 0);
1825 	UpdateAttrs(SP_PARM, blank);
1826 	TPUTS_TRACE("scroll_reverse");
1827 	NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx scroll_reverse);
1828     } else if (n == 1 && insert_line && bot == maxy) {
1829 	GoTo(NCURSES_SP_ARGx top, 0);
1830 	UpdateAttrs(SP_PARM, blank);
1831 	TPUTS_TRACE("insert_line");
1832 	NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx insert_line);
1833     } else if (parm_rindex && top == miny && bot == maxy) {
1834 	GoTo(NCURSES_SP_ARGx top, 0);
1835 	UpdateAttrs(SP_PARM, blank);
1836 	TPUTS_TRACE("parm_rindex");
1837 	NCURSES_SP_NAME(tputs) (NCURSES_SP_ARGx
1838 				TPARM_2(parm_rindex, n, 0),
1839 				n,
1840 				NCURSES_SP_NAME(_nc_outch));
1841     } else if (parm_insert_line && bot == maxy) {
1842 	GoTo(NCURSES_SP_ARGx top, 0);
1843 	UpdateAttrs(SP_PARM, blank);
1844 	TPUTS_TRACE("parm_insert_line");
1845 	NCURSES_SP_NAME(tputs) (NCURSES_SP_ARGx
1846 				TPARM_2(parm_insert_line, n, 0),
1847 				n,
1848 				NCURSES_SP_NAME(_nc_outch));
1849     } else if (scroll_reverse && top == miny && bot == maxy) {
1850 	GoTo(NCURSES_SP_ARGx top, 0);
1851 	UpdateAttrs(SP_PARM, blank);
1852 	for (i = 0; i < n; i++) {
1853 	    TPUTS_TRACE("scroll_reverse");
1854 	    NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx scroll_reverse);
1855 	}
1856     } else if (insert_line && bot == maxy) {
1857 	GoTo(NCURSES_SP_ARGx top, 0);
1858 	UpdateAttrs(SP_PARM, blank);
1859 	for (i = 0; i < n; i++) {
1860 	    TPUTS_TRACE("insert_line");
1861 	    NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx insert_line);
1862 	}
1863     } else
1864 	return ERR;
1865 
1866 #if NCURSES_EXT_FUNCS
1867     if (FILL_BCE(SP_PARM)) {
1868 	int j;
1869 	for (i = 0; i < n; i++) {
1870 	    GoTo(NCURSES_SP_ARGx top + i, 0);
1871 	    for (j = 0; j < screen_columns(SP_PARM); j++)
1872 		PutChar(NCURSES_SP_ARGx CHREF(blank));
1873 	}
1874     }
1875 #endif
1876     return OK;
1877 }
1878 
1879 /* scroll by using delete_line at del and insert_line at ins */
1880 /* n > 0 */
1881 static int
1882 scroll_idl(NCURSES_SP_DCLx int n, int del, int ins, NCURSES_CH_T blank)
1883 {
1884     int i;
1885 
1886     if (!((parm_delete_line || delete_line) && (parm_insert_line || insert_line)))
1887 	return ERR;
1888 
1889     GoTo(NCURSES_SP_ARGx del, 0);
1890     UpdateAttrs(SP_PARM, blank);
1891     if (n == 1 && delete_line) {
1892 	TPUTS_TRACE("delete_line");
1893 	NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx delete_line);
1894     } else if (parm_delete_line) {
1895 	TPUTS_TRACE("parm_delete_line");
1896 	NCURSES_SP_NAME(tputs) (NCURSES_SP_ARGx
1897 				TPARM_2(parm_delete_line, n, 0),
1898 				n,
1899 				NCURSES_SP_NAME(_nc_outch));
1900     } else {			/* if (delete_line) */
1901 	for (i = 0; i < n; i++) {
1902 	    TPUTS_TRACE("delete_line");
1903 	    NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx delete_line);
1904 	}
1905     }
1906 
1907     GoTo(NCURSES_SP_ARGx ins, 0);
1908     UpdateAttrs(SP_PARM, blank);
1909     if (n == 1 && insert_line) {
1910 	TPUTS_TRACE("insert_line");
1911 	NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx insert_line);
1912     } else if (parm_insert_line) {
1913 	TPUTS_TRACE("parm_insert_line");
1914 	NCURSES_SP_NAME(tputs) (NCURSES_SP_ARGx
1915 				TPARM_2(parm_insert_line, n, 0),
1916 				n,
1917 				NCURSES_SP_NAME(_nc_outch));
1918     } else {			/* if (insert_line) */
1919 	for (i = 0; i < n; i++) {
1920 	    TPUTS_TRACE("insert_line");
1921 	    NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx insert_line);
1922 	}
1923     }
1924 
1925     return OK;
1926 }
1927 
1928 /*
1929  * Note:  some terminals require the cursor to be within the scrolling margins
1930  * before setting them.  Generally, the cursor must be at the appropriate end
1931  * of the scrolling margins when issuing an indexing operation (it is not
1932  * apparent whether it must also be at the left margin; we do this just to be
1933  * safe).  To make the related cursor movement a little faster, we use the
1934  * save/restore cursor capabilities if the terminal has them.
1935  */
1936 NCURSES_EXPORT(int)
1937 NCURSES_SP_NAME(_nc_scrolln) (NCURSES_SP_DCLx
1938 			      int n,
1939 			      int top,
1940 			      int bot,
1941 			      int maxy)
1942 /* scroll region from top to bot by n lines */
1943 {
1944     NCURSES_CH_T blank;
1945     int i;
1946     bool cursor_saved = FALSE;
1947     int res;
1948 
1949     TR(TRACE_MOVE, ("_nc_scrolln(%p, %d, %d, %d, %d)",
1950 		    (void *) SP_PARM, n, top, bot, maxy));
1951 
1952     if (!IsValidScreen(SP_PARM))
1953 	return (ERR);
1954 
1955     blank = ClrBlank(NCURSES_SP_ARGx StdScreen(SP_PARM));
1956 
1957 #if USE_XMC_SUPPORT
1958     /*
1959      * If we scroll, we might remove a cookie.
1960      */
1961     if (magic_cookie_glitch > 0) {
1962 	return (ERR);
1963     }
1964 #endif
1965 
1966     if (n > 0) {		/* scroll up (forward) */
1967 	/*
1968 	 * Explicitly clear if stuff pushed off top of region might
1969 	 * be saved by the terminal.
1970 	 */
1971 	res = scroll_csr_forward(NCURSES_SP_ARGx n, top, bot, 0, maxy, blank);
1972 
1973 	if (res == ERR && change_scroll_region) {
1974 	    if ((((n == 1 && scroll_forward) || parm_index)
1975 		 && (SP_PARM->_cursrow == bot || SP_PARM->_cursrow == bot - 1))
1976 		&& save_cursor && restore_cursor) {
1977 		cursor_saved = TRUE;
1978 		TPUTS_TRACE("save_cursor");
1979 		NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx save_cursor);
1980 	    }
1981 	    TPUTS_TRACE("change_scroll_region");
1982 	    NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx
1983 				   TPARM_2(change_scroll_region, top, bot));
1984 	    if (cursor_saved) {
1985 		TPUTS_TRACE("restore_cursor");
1986 		NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx restore_cursor);
1987 	    } else {
1988 		SP_PARM->_cursrow = SP_PARM->_curscol = -1;
1989 	    }
1990 
1991 	    res = scroll_csr_forward(NCURSES_SP_ARGx n, top, bot, top, bot, blank);
1992 
1993 	    TPUTS_TRACE("change_scroll_region");
1994 	    NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx
1995 				   TPARM_2(change_scroll_region, 0, maxy));
1996 	    SP_PARM->_cursrow = SP_PARM->_curscol = -1;
1997 	}
1998 
1999 	if (res == ERR && SP_PARM->_nc_sp_idlok)
2000 	    res = scroll_idl(NCURSES_SP_ARGx n, top, bot - n + 1, blank);
2001 
2002 	/*
2003 	 * Clear the newly shifted-in text.
2004 	 */
2005 	if (res != ERR
2006 	    && (non_dest_scroll_region || (memory_below && bot == maxy))) {
2007 	    static const NCURSES_CH_T blank2 = NewChar(BLANK_TEXT);
2008 	    if (bot == maxy && clr_eos) {
2009 		GoTo(NCURSES_SP_ARGx bot - n + 1, 0);
2010 		ClrToEOS(NCURSES_SP_ARGx blank2);
2011 	    } else {
2012 		for (i = 0; i < n; i++) {
2013 		    GoTo(NCURSES_SP_ARGx bot - i, 0);
2014 		    ClrToEOL(NCURSES_SP_ARGx blank2, FALSE);
2015 		}
2016 	    }
2017 	}
2018 
2019     } else {			/* (n < 0) - scroll down (backward) */
2020 	res = scroll_csr_backward(NCURSES_SP_ARGx -n, top, bot, 0, maxy, blank);
2021 
2022 	if (res == ERR && change_scroll_region) {
2023 	    if (top != 0
2024 		&& (SP_PARM->_cursrow == top ||
2025 		    SP_PARM->_cursrow == top - 1)
2026 		&& save_cursor && restore_cursor) {
2027 		cursor_saved = TRUE;
2028 		TPUTS_TRACE("save_cursor");
2029 		NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx save_cursor);
2030 	    }
2031 	    TPUTS_TRACE("change_scroll_region");
2032 	    NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx
2033 				   TPARM_2(change_scroll_region, top, bot));
2034 	    if (cursor_saved) {
2035 		TPUTS_TRACE("restore_cursor");
2036 		NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx restore_cursor);
2037 	    } else {
2038 		SP_PARM->_cursrow = SP_PARM->_curscol = -1;
2039 	    }
2040 
2041 	    res = scroll_csr_backward(NCURSES_SP_ARGx
2042 				      -n, top, bot, top, bot, blank);
2043 
2044 	    TPUTS_TRACE("change_scroll_region");
2045 	    NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx
2046 				   TPARM_2(change_scroll_region, 0, maxy));
2047 	    SP_PARM->_cursrow = SP_PARM->_curscol = -1;
2048 	}
2049 
2050 	if (res == ERR && SP_PARM->_nc_sp_idlok)
2051 	    res = scroll_idl(NCURSES_SP_ARGx -n, bot + n + 1, top, blank);
2052 
2053 	/*
2054 	 * Clear the newly shifted-in text.
2055 	 */
2056 	if (res != ERR
2057 	    && (non_dest_scroll_region || (memory_above && top == 0))) {
2058 	    static const NCURSES_CH_T blank2 = NewChar(BLANK_TEXT);
2059 	    for (i = 0; i < -n; i++) {
2060 		GoTo(NCURSES_SP_ARGx i + top, 0);
2061 		ClrToEOL(NCURSES_SP_ARGx blank2, FALSE);
2062 	    }
2063 	}
2064     }
2065 
2066     if (res == ERR)
2067 	return (ERR);
2068 
2069     _nc_scroll_window(CurScreen(SP_PARM), n,
2070 		      (NCURSES_SIZE_T) top,
2071 		      (NCURSES_SIZE_T) bot,
2072 		      blank);
2073 
2074     /* shift hash values too - they can be reused */
2075     NCURSES_SP_NAME(_nc_scroll_oldhash) (NCURSES_SP_ARGx n, top, bot);
2076 
2077     return (OK);
2078 }
2079 
2080 #if NCURSES_SP_FUNCS
2081 NCURSES_EXPORT(int)
2082 _nc_scrolln(int n, int top, int bot, int maxy)
2083 {
2084     return NCURSES_SP_NAME(_nc_scrolln) (CURRENT_SCREEN, n, top, bot, maxy);
2085 }
2086 #endif
2087 
2088 NCURSES_EXPORT(void)
2089 NCURSES_SP_NAME(_nc_screen_resume) (NCURSES_SP_DCL0)
2090 {
2091     assert(SP_PARM);
2092 
2093     /* make sure terminal is in a sane known state */
2094     SetAttr(SCREEN_ATTRS(SP_PARM), A_NORMAL);
2095     NewScreen(SP_PARM)->_clear = TRUE;
2096 
2097     /* reset color pairs and definitions */
2098     if (SP_PARM->_coloron || SP_PARM->_color_defs)
2099 	NCURSES_SP_NAME(_nc_reset_colors) (NCURSES_SP_ARG);
2100 
2101     /* restore user-defined colors, if any */
2102     if (SP_PARM->_color_defs < 0) {
2103 	int n;
2104 	SP_PARM->_color_defs = -(SP_PARM->_color_defs);
2105 	for (n = 0; n < SP_PARM->_color_defs; ++n) {
2106 	    if (SP_PARM->_color_table[n].init) {
2107 		NCURSES_SP_NAME(init_color) (NCURSES_SP_ARGx
2108 					     (short) n,
2109 					     SP_PARM->_color_table[n].r,
2110 					     SP_PARM->_color_table[n].g,
2111 					     SP_PARM->_color_table[n].b);
2112 	    }
2113 	}
2114     }
2115 
2116     if (exit_attribute_mode)
2117 	NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx exit_attribute_mode);
2118     else {
2119 	/* turn off attributes */
2120 	if (exit_alt_charset_mode)
2121 	    NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx exit_alt_charset_mode);
2122 	if (exit_standout_mode)
2123 	    NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx exit_standout_mode);
2124 	if (exit_underline_mode)
2125 	    NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx exit_underline_mode);
2126     }
2127     if (exit_insert_mode)
2128 	NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx exit_insert_mode);
2129     if (enter_am_mode && exit_am_mode)
2130 	NCURSES_SP_NAME(putp) (NCURSES_SP_ARGx
2131 			       (auto_right_margin
2132 				? enter_am_mode
2133 				: exit_am_mode));
2134 }
2135 
2136 #if NCURSES_SP_FUNCS
2137 NCURSES_EXPORT(void)
2138 _nc_screen_resume(void)
2139 {
2140     NCURSES_SP_NAME(_nc_screen_resume) (CURRENT_SCREEN);
2141 }
2142 #endif
2143 
2144 NCURSES_EXPORT(void)
2145 NCURSES_SP_NAME(_nc_screen_init) (NCURSES_SP_DCL0)
2146 {
2147     NCURSES_SP_NAME(_nc_screen_resume) (NCURSES_SP_ARG);
2148 }
2149 
2150 #if NCURSES_SP_FUNCS
2151 NCURSES_EXPORT(void)
2152 _nc_screen_init(void)
2153 {
2154     NCURSES_SP_NAME(_nc_screen_init) (CURRENT_SCREEN);
2155 }
2156 #endif
2157 
2158 /* wrap up screen handling */
2159 NCURSES_EXPORT(void)
2160 NCURSES_SP_NAME(_nc_screen_wrap) (NCURSES_SP_DCL0)
2161 {
2162     if (SP_PARM == 0)
2163 	return;
2164 
2165     UpdateAttrs(SP_PARM, normal);
2166 #if NCURSES_EXT_FUNCS
2167     if (SP_PARM->_coloron
2168 	&& !SP_PARM->_default_color) {
2169 	static const NCURSES_CH_T blank = NewChar(BLANK_TEXT);
2170 	SP_PARM->_default_color = TRUE;
2171 	NCURSES_SP_NAME(_nc_do_color) (NCURSES_SP_ARGx
2172 				       -1,
2173 				       0,
2174 				       FALSE,
2175 				       NCURSES_SP_NAME(_nc_outch));
2176 	SP_PARM->_default_color = FALSE;
2177 
2178 	TINFO_MVCUR(NCURSES_SP_ARGx
2179 		    SP_PARM->_cursrow,
2180 		    SP_PARM->_curscol,
2181 		    screen_lines(SP_PARM) - 1,
2182 		    0);
2183 
2184 	ClrToEOL(NCURSES_SP_ARGx blank, TRUE);
2185     }
2186 #endif
2187     if (SP_PARM->_color_defs) {
2188 	NCURSES_SP_NAME(_nc_reset_colors) (NCURSES_SP_ARG);
2189     }
2190 }
2191 
2192 #if NCURSES_SP_FUNCS
2193 NCURSES_EXPORT(void)
2194 _nc_screen_wrap(void)
2195 {
2196     NCURSES_SP_NAME(_nc_screen_wrap) (CURRENT_SCREEN);
2197 }
2198 #endif
2199 
2200 #if USE_XMC_SUPPORT
2201 NCURSES_EXPORT(void)
2202 NCURSES_SP_NAME(_nc_do_xmc_glitch) (NCURSES_SP_DCLx attr_t previous)
2203 {
2204     if (SP_PARM != 0) {
2205 	attr_t chg = XMC_CHANGES(previous ^ AttrOf(SCREEN_ATTRS(SP_PARM)));
2206 
2207 	while (chg != 0) {
2208 	    if (chg & 1) {
2209 		SP_PARM->_curscol += magic_cookie_glitch;
2210 		if (SP_PARM->_curscol >= SP_PARM->_columns)
2211 		    wrap_cursor(NCURSES_SP_ARG);
2212 		TR(TRACE_UPDATE, ("bumped to %d,%d after cookie",
2213 				  SP_PARM->_cursrow, SP_PARM->_curscol));
2214 	    }
2215 	    chg >>= 1;
2216 	}
2217     }
2218 }
2219 
2220 #if NCURSES_SP_FUNCS
2221 NCURSES_EXPORT(void)
2222 _nc_do_xmc_glitch(attr_t previous)
2223 {
2224     NCURSES_SP_NAME(_nc_do_xmc_glitch) (CURRENT_SCREEN, previous);
2225 }
2226 #endif
2227 
2228 #endif /* USE_XMC_SUPPORT */
2229