1 /****************************************************************************
2  * Copyright (c) 1998-2004,2005 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  ****************************************************************************/
34 
35 /*-----------------------------------------------------------------
36  *
37  *	lib_doupdate.c
38  *
39  * 	The routine doupdate() and its dependents.
40  * 	All physical output is concentrated here (except _nc_outch()
41   *	in lib_tputs.c).
42  *
43  *-----------------------------------------------------------------*/
44 
45 #include <curses.priv.h>
46 
47 #ifdef __BEOS__
48 #undef false
49 #undef true
50 #include <OS.h>
51 #endif
52 
53 #if defined(TRACE) && HAVE_SYS_TIMES_H && HAVE_TIMES
54 #define USE_TRACE_TIMES 1
55 #else
56 #define USE_TRACE_TIMES 0
57 #endif
58 
59 #if HAVE_SYS_TIME_H && HAVE_SYS_TIME_SELECT
60 #include <sys/time.h>
61 #endif
62 
63 #if USE_TRACE_TIMES
64 #include <sys/times.h>
65 #endif
66 
67 #if USE_FUNC_POLL
68 #elif HAVE_SELECT
69 #if HAVE_SYS_SELECT_H
70 #include <sys/select.h>
71 #endif
72 #endif
73 
74 #include <ctype.h>
75 #include <term.h>
76 
77 MODULE_ID("$Id: tty_update.c,v 1.220 2005/08/13 17:12:32 tom Exp $")
78 
79 /*
80  * This define controls the line-breakout optimization.  Every once in a
81  * while during screen refresh, we want to check for input and abort the
82  * update if there's some waiting.  CHECK_INTERVAL controls the number of
83  * changed lines to be emitted between input checks.
84  *
85  * Note: Input-check-and-abort is no longer done if the screen is being
86  * updated from scratch.  This is a feature, not a bug.
87  */
88 #define CHECK_INTERVAL	5
89 
90 #define FILL_BCE() (SP->_coloron && !SP->_default_color && !back_color_erase)
91 
92 static const NCURSES_CH_T normal = NewChar2(BLANK_TEXT, BLANK_ATTR);
93 
94 /*
95  * Enable checking to see if doupdate and friends are tracking the true
96  * cursor position correctly.  NOTE: this is a debugging hack which will
97  * work ONLY on ANSI-compatible terminals!
98  */
99 /* #define POSITION_DEBUG */
100 
101 static inline NCURSES_CH_T ClrBlank(WINDOW *win);
102 static int ClrBottom(int total);
103 static void ClearScreen(NCURSES_CH_T blank);
104 static void ClrUpdate(void);
105 static void DelChar(int count);
106 static void InsStr(NCURSES_CH_T * line, int count);
107 static void TransformLine(int const lineno);
108 
109 #ifdef POSITION_DEBUG
110 /****************************************************************************
111  *
112  * Debugging code.  Only works on ANSI-standard terminals.
113  *
114  ****************************************************************************/
115 
116 static void
position_check(int expected_y,int expected_x,char * legend)117 position_check(int expected_y, int expected_x, char *legend)
118 /* check to see if the real cursor position matches the virtual */
119 {
120     char buf[20];
121     char *s;
122     int y, x;
123 
124     if (!_nc_tracing || (expected_y < 0 && expected_x < 0))
125 	return;
126 
127     _nc_flush();
128     memset(buf, '\0', sizeof(buf));
129     putp("\033[6n");		/* only works on ANSI-compatibles */
130     _nc_flush();
131     *(s = buf) = 0;
132     do {
133 	int ask = sizeof(buf) - 1 - (s - buf);
134 	int got = read(0, s, ask);
135 	if (got == 0)
136 	    break;
137 	s += got;
138     } while (strchr(buf, 'R') == 0);
139     _tracef("probe returned %s", _nc_visbuf(buf));
140 
141     /* try to interpret as a position report */
142     if (sscanf(buf, "\033[%d;%dR", &y, &x) != 2) {
143 	_tracef("position probe failed in %s", legend);
144     } else {
145 	if (expected_x < 0)
146 	    expected_x = x - 1;
147 	if (expected_y < 0)
148 	    expected_y = y - 1;
149 	if (y - 1 != expected_y || x - 1 != expected_x) {
150 	    beep();
151 	    tputs(tparm("\033[%d;%dH", expected_y + 1, expected_x + 1), 1, _nc_outch);
152 	    _tracef("position seen (%d, %d) doesn't match expected one (%d, %d) in %s",
153 		    y - 1, x - 1, expected_y, expected_x, legend);
154 	} else {
155 	    _tracef("position matches OK in %s", legend);
156 	}
157     }
158 }
159 #else
160 #define position_check(expected_y, expected_x, legend)	/* nothing */
161 #endif /* POSITION_DEBUG */
162 
163 /****************************************************************************
164  *
165  * Optimized update code
166  *
167  ****************************************************************************/
168 
169 static inline void
GoTo(int const row,int const col)170 GoTo(int const row, int const col)
171 {
172     TR(TRACE_MOVE, ("GoTo(%d, %d) from (%d, %d)",
173 		    row, col, SP->_cursrow, SP->_curscol));
174 
175     position_check(SP->_cursrow, SP->_curscol, "GoTo");
176 
177     mvcur(SP->_cursrow, SP->_curscol, row, col);
178     position_check(SP->_cursrow, SP->_curscol, "GoTo2");
179 }
180 
181 static inline void
PutAttrChar(CARG_CH_T ch)182 PutAttrChar(CARG_CH_T ch)
183 {
184     int chlen = 1;
185     NCURSES_CH_T my_ch;
186     PUTC_DATA;
187     NCURSES_CH_T tilde;
188     NCURSES_CH_T attr = CHDEREF(ch);
189 
190     TR(TRACE_CHARPUT, ("PutAttrChar(%s) at (%d, %d)",
191 		       _tracech_t(ch),
192 		       SP->_cursrow, SP->_curscol));
193 #if USE_WIDEC_SUPPORT
194     /*
195      * If this is not a valid character, there is nothing more to do.
196      */
197     if (isWidecExt(CHDEREF(ch))) {
198 	TR(TRACE_CHARPUT, ("...skip"));
199 	return;
200     }
201     /*
202      * Determine the number of character cells which the 'ch' value will use
203      * on the screen.  It should be at least one.
204      */
205     if ((chlen = wcwidth(CharOf(CHDEREF(ch)))) <= 0) {
206 	static NCURSES_CH_T blank = NewChar(BLANK_TEXT);
207 
208 	if (is8bits(CharOf(CHDEREF(ch)))
209 	    && (isprint(CharOf(CHDEREF(ch)))
210 		|| (SP->_legacy_coding && CharOf(CHDEREF(ch)) >= 160))) {
211 	    ;
212 	} else {
213 	    ch = CHREF(blank);
214 	    TR(TRACE_CHARPUT, ("forced to blank"));
215 	}
216 	chlen = 1;
217     }
218 #endif
219 
220     if ((AttrOf(attr) & A_ALTCHARSET)
221 	&& SP->_acs_map != 0
222 	&& CharOfD(ch) < ACS_LEN) {
223 	my_ch = CHDEREF(ch);	/* work around const param */
224 #if USE_WIDEC_SUPPORT
225 	/*
226 	 * This is crude & ugly, but works most of the time.  It checks if the
227 	 * acs_chars string specified that we have a mapping for this
228 	 * character, and uses the wide-character mapping when we expect the
229 	 * normal one to be broken (by mis-design ;-).
230 	 */
231 	if (SP->_screen_acs_fix
232 	    && SP->_screen_acs_map[CharOf(my_ch)]) {
233 	    RemAttr(attr, A_ALTCHARSET);
234 	    my_ch = _nc_wacs[CharOf(my_ch)];
235 	}
236 #endif
237 	/*
238 	 * If we (still) have alternate character set, it is the normal 8bit
239 	 * flavor.  The _screen_acs_map[] array tells if the character was
240 	 * really in acs_chars, needed because of the way wide/normal line
241 	 * drawing flavors are integrated.
242 	 */
243 	if (AttrOf(attr) & A_ALTCHARSET) {
244 	    int j = CharOfD(ch);
245 	    chtype temp = UChar(SP->_acs_map[j]);
246 
247 	    if (!(SP->_screen_acs_map[j]))
248 		RemAttr(attr, A_ALTCHARSET);
249 	    if (temp != 0)
250 		SetChar(my_ch, temp, AttrOf(attr));
251 	}
252 	ch = CHREF(my_ch);
253     }
254     if (tilde_glitch && (CharOfD(ch) == L('~'))) {
255 	SetChar(tilde, L('`'), AttrOf(attr));
256 	ch = CHREF(tilde);
257     }
258 
259     UpdateAttrs(attr);
260 #if !USE_WIDEC_SUPPORT
261     /* FIXME - we do this special case for signal handling, should see how to
262      * make it work for wide characters.
263      */
264     if (SP->_outch != 0) {
265 	SP->_outch(UChar(ch));
266     } else
267 #endif
268     {
269 	PUTC(CHDEREF(ch), SP->_ofp);	/* macro's fastest... */
270 	TRACE_OUTCHARS(1);
271     }
272     SP->_curscol += chlen;
273     if (char_padding) {
274 	TPUTS_TRACE("char_padding");
275 	putp(char_padding);
276     }
277 }
278 
279 static bool
check_pending(void)280 check_pending(void)
281 /* check for pending input */
282 {
283     bool have_pending = FALSE;
284 
285     /*
286      * Only carry out this check when the flag is zero, otherwise we'll
287      * have the refreshing slow down drastically (or stop) if there's an
288      * unread character available.
289      */
290     if (SP->_fifohold != 0)
291 	return FALSE;
292 
293     if (SP->_checkfd >= 0) {
294 #if USE_FUNC_POLL
295 	struct pollfd fds[1];
296 	fds[0].fd = SP->_checkfd;
297 	fds[0].events = POLLIN;
298 	if (poll(fds, 1, 0) > 0) {
299 	    have_pending = TRUE;
300 	}
301 #elif defined(__BEOS__)
302 	/*
303 	 * BeOS's select() is declared in socket.h, so the configure script does
304 	 * not see it.  That's just as well, since that function works only for
305 	 * sockets.  This (using snooze and ioctl) was distilled from Be's patch
306 	 * for ncurses which uses a separate thread to simulate select().
307 	 *
308 	 * FIXME: the return values from the ioctl aren't very clear if we get
309 	 * interrupted.
310 	 */
311 	int n = 0;
312 	int howmany = ioctl(0, 'ichr', &n);
313 	if (howmany >= 0 && n > 0) {
314 	    have_pending = TRUE;
315 	}
316 #elif HAVE_SELECT
317 	fd_set fdset;
318 	struct timeval ktimeout;
319 
320 	ktimeout.tv_sec =
321 	    ktimeout.tv_usec = 0;
322 
323 	FD_ZERO(&fdset);
324 	FD_SET(SP->_checkfd, &fdset);
325 	if (select(SP->_checkfd + 1, &fdset, NULL, NULL, &ktimeout) != 0) {
326 	    have_pending = TRUE;
327 	}
328 #endif
329     }
330     if (have_pending) {
331 	SP->_fifohold = 5;
332 	_nc_flush();
333     }
334     return FALSE;
335 }
336 
337 /* put char at lower right corner */
338 static void
PutCharLR(const ARG_CH_T ch)339 PutCharLR(const ARG_CH_T ch)
340 {
341     if (!auto_right_margin) {
342 	/* we can put the char directly */
343 	PutAttrChar(ch);
344     } else if (enter_am_mode && exit_am_mode) {
345 	/* we can suppress automargin */
346 	TPUTS_TRACE("exit_am_mode");
347 	putp(exit_am_mode);
348 
349 	PutAttrChar(ch);
350 	SP->_curscol--;
351 	position_check(SP->_cursrow, SP->_curscol, "exit_am_mode");
352 
353 	TPUTS_TRACE("enter_am_mode");
354 	putp(enter_am_mode);
355     } else if ((enter_insert_mode && exit_insert_mode)
356 	       || insert_character || parm_ich) {
357 	GoTo(screen_lines - 1, screen_columns - 2);
358 	PutAttrChar(ch);
359 	GoTo(screen_lines - 1, screen_columns - 2);
360 	InsStr(newscr->_line[screen_lines - 1].text + screen_columns - 2, 1);
361     }
362 }
363 
364 static void
wrap_cursor(void)365 wrap_cursor(void)
366 {
367     if (eat_newline_glitch) {
368 	/*
369 	 * xenl can manifest two different ways.  The vt100
370 	 * way is that, when you'd expect the cursor to wrap,
371 	 * it stays hung at the right margin (on top of the
372 	 * character just emitted) and doesn't wrap until the
373 	 * *next* graphic char is emitted.  The c100 way is
374 	 * to ignore LF received just after an am wrap.
375 	 *
376 	 * An aggressive way to handle this would be to
377 	 * emit CR/LF after the char and then assume the wrap
378 	 * is done, you're on the first position of the next
379 	 * line, and the terminal out of its weird state.
380 	 * Here it's safe to just tell the code that the
381 	 * cursor is in hyperspace and let the next mvcur()
382 	 * call straighten things out.
383 	 */
384 	SP->_curscol = -1;
385 	SP->_cursrow = -1;
386     } else if (auto_right_margin) {
387 	SP->_curscol = 0;
388 	SP->_cursrow++;
389     } else {
390 	SP->_curscol--;
391     }
392     position_check(SP->_cursrow, SP->_curscol, "wrap_cursor");
393 }
394 
395 static inline void
PutChar(const ARG_CH_T ch)396 PutChar(const ARG_CH_T ch)
397 /* insert character, handling automargin stuff */
398 {
399     if (SP->_cursrow == screen_lines - 1 && SP->_curscol == screen_columns - 1)
400 	PutCharLR(ch);
401     else
402 	PutAttrChar(ch);
403 
404     if (SP->_curscol >= screen_columns)
405 	wrap_cursor();
406 
407     position_check(SP->_cursrow, SP->_curscol, "PutChar");
408 }
409 
410 /*
411  * Check whether the given character can be output by clearing commands.  This
412  * includes test for being a space and not including any 'bad' attributes, such
413  * as A_REVERSE.  All attribute flags which don't affect appearance of a space
414  * or can be output by clearing (A_COLOR in case of bce-terminal) are excluded.
415  */
416 static inline bool
can_clear_with(ARG_CH_T ch)417 can_clear_with(ARG_CH_T ch)
418 {
419     if (!back_color_erase && SP->_coloron) {
420 #if NCURSES_EXT_FUNCS
421 	int pair;
422 
423 	if (!SP->_default_color)
424 	    return FALSE;
425 	if (SP->_default_fg != C_MASK || SP->_default_bg != C_MASK)
426 	    return FALSE;
427 	if ((pair = GetPair(CHDEREF(ch))) != 0) {
428 	    short fg, bg;
429 	    pair_content(pair, &fg, &bg);
430 	    if (fg != C_MASK || bg != C_MASK)
431 		return FALSE;
432 	}
433 #else
434 	if (AttrOfD(ch) & A_COLOR)
435 	    return FALSE;
436 #endif
437     }
438     return (ISBLANK(CHDEREF(ch)) &&
439 	    (AttrOfD(ch) & ~(NONBLANK_ATTR | A_COLOR)) == BLANK_ATTR);
440 }
441 
442 /*
443  * Issue a given span of characters from an array.
444  * Must be functionally equivalent to:
445  *	for (i = 0; i < num; i++)
446  *	    PutChar(ntext[i]);
447  * but can leave the cursor positioned at the middle of the interval.
448  *
449  * Returns: 0 - cursor is at the end of interval
450  *	    1 - cursor is somewhere in the middle
451  *
452  * This code is optimized using ech and rep.
453  */
454 static int
EmitRange(const NCURSES_CH_T * ntext,int num)455 EmitRange(const NCURSES_CH_T * ntext, int num)
456 {
457     int i;
458 
459     if (erase_chars || repeat_char) {
460 	while (num > 0) {
461 	    int runcount;
462 	    NCURSES_CH_T ntext0;
463 
464 	    while (num > 1 && !CharEq(ntext[0], ntext[1])) {
465 		PutChar(CHREF(ntext[0]));
466 		ntext++;
467 		num--;
468 	    }
469 	    ntext0 = ntext[0];
470 	    if (num == 1) {
471 		PutChar(CHREF(ntext0));
472 		return 0;
473 	    }
474 	    runcount = 2;
475 
476 	    while (runcount < num && CharEq(ntext[runcount], ntext0))
477 		runcount++;
478 
479 	    /*
480 	     * The cost expression in the middle isn't exactly right.
481 	     * _cup_ch_cost is an upper bound on the cost for moving to the
482 	     * end of the erased area, but not the cost itself (which we
483 	     * can't compute without emitting the move).  This may result
484 	     * in erase_chars not getting used in some situations for
485 	     * which it would be marginally advantageous.
486 	     */
487 	    if (erase_chars
488 		&& runcount > SP->_ech_cost + SP->_cup_ch_cost
489 		&& can_clear_with(CHREF(ntext0))) {
490 		UpdateAttrs(ntext0);
491 		putp(tparm(erase_chars, runcount));
492 
493 		/*
494 		 * If this is the last part of the given interval,
495 		 * don't bother moving cursor, since it can be the
496 		 * last update on the line.
497 		 */
498 		if (runcount < num) {
499 		    GoTo(SP->_cursrow, SP->_curscol + runcount);
500 		} else {
501 		    return 1;	/* cursor stays in the middle */
502 		}
503 	    } else if (repeat_char && runcount > SP->_rep_cost) {
504 		bool wrap_possible = (SP->_curscol + runcount >= screen_columns);
505 		int rep_count = runcount;
506 
507 		if (wrap_possible)
508 		    rep_count--;
509 
510 		UpdateAttrs(ntext0);
511 		tputs(tparm(repeat_char, CharOf(ntext0), rep_count),
512 		      rep_count, _nc_outch);
513 		SP->_curscol += rep_count;
514 
515 		if (wrap_possible)
516 		    PutChar(CHREF(ntext0));
517 	    } else {
518 		for (i = 0; i < runcount; i++)
519 		    PutChar(CHREF(ntext[i]));
520 	    }
521 	    ntext += runcount;
522 	    num -= runcount;
523 	}
524 	return 0;
525     }
526 
527     for (i = 0; i < num; i++)
528 	PutChar(CHREF(ntext[i]));
529     return 0;
530 }
531 
532 /*
533  * Output the line in the given range [first .. last]
534  *
535  * If there's a run of identical characters that's long enough to justify
536  * cursor movement, use that also.
537  *
538  * Returns: same as EmitRange
539  */
540 static int
PutRange(const NCURSES_CH_T * otext,const NCURSES_CH_T * ntext,int row,int first,int last)541 PutRange(const NCURSES_CH_T * otext,
542 	 const NCURSES_CH_T * ntext,
543 	 int row,
544 	 int first, int last)
545 {
546     int i, j, same;
547 
548     TR(TRACE_CHARPUT, ("PutRange(%p, %p, %d, %d, %d)",
549 		       otext, ntext, row, first, last));
550 
551     if (otext != ntext
552 	&& (last - first + 1) > SP->_inline_cost) {
553 	for (j = first, same = 0; j <= last; j++) {
554 	    if (!same && isWidecExt(otext[j]))
555 		continue;
556 	    if (CharEq(otext[j], ntext[j])) {
557 		same++;
558 	    } else {
559 		if (same > SP->_inline_cost) {
560 		    EmitRange(ntext + first, j - same - first);
561 		    GoTo(row, first = j);
562 		}
563 		same = 0;
564 	    }
565 	}
566 	i = EmitRange(ntext + first, j - same - first);
567 	/*
568 	 * Always return 1 for the next GoTo() after a PutRange() if we found
569 	 * identical characters at end of interval
570 	 */
571 	return (same == 0 ? i : 1);
572     }
573     return EmitRange(ntext + first, last - first + 1);
574 }
575 
576 /* leave unbracketed here so 'indent' works */
577 #define MARK_NOCHANGE(win,row) \
578 		win->_line[row].firstchar = _NOCHANGE; \
579 		win->_line[row].lastchar = _NOCHANGE; \
580 		if_USE_SCROLL_HINTS(win->_line[row].oldindex = row)
581 
582 NCURSES_EXPORT(int)
doupdate(void)583 doupdate(void)
584 {
585     int i;
586     int nonempty;
587 #if USE_TRACE_TIMES
588     struct tms before, after;
589 #endif /* USE_TRACE_TIMES */
590 
591     T((T_CALLED("doupdate()")));
592 
593 #ifdef TRACE
594     if (_nc_tracing & TRACE_UPDATE) {
595 	if (curscr->_clear)
596 	    _tracef("curscr is clear");
597 	else
598 	    _tracedump("curscr", curscr);
599 	_tracedump("newscr", newscr);
600     }
601 #endif /* TRACE */
602 
603     _nc_signal_handler(FALSE);
604 
605     if (SP->_fifohold)
606 	SP->_fifohold--;
607 
608 #if USE_SIZECHANGE
609     if (SP->_endwin || SP->_sig_winch) {
610 	/*
611 	 * This is a transparent extension:  XSI does not address it,
612 	 * and applications need not know that ncurses can do it.
613 	 *
614 	 * Check if the terminal size has changed while curses was off
615 	 * (this can happen in an xterm, for example), and resize the
616 	 * ncurses data structures accordingly.
617 	 */
618 	_nc_update_screensize();
619     }
620 #endif
621 
622     if (SP->_endwin) {
623 
624 	T(("coming back from shell mode"));
625 	reset_prog_mode();
626 
627 	_nc_mvcur_resume();
628 	_nc_screen_resume();
629 	SP->_mouse_resume(SP);
630 
631 	SP->_endwin = FALSE;
632     }
633 #if USE_TRACE_TIMES
634     /* zero the metering machinery */
635     _nc_outchars = 0;
636     (void) times(&before);
637 #endif /* USE_TRACE_TIMES */
638 
639     /*
640      * This is the support for magic-cookie terminals.  The
641      * theory: we scan the virtual screen looking for attribute
642      * turnons.  Where we find one, check to make sure it's
643      * realizable by seeing if the required number of
644      * un-attributed blanks are present before and after the
645      * attributed range; try to shift the range boundaries over
646      * blanks (not changing the screen display) so this becomes
647      * true.  If it is, shift the beginning attribute change
648      * appropriately (the end one, if we've gotten this far, is
649      * guaranteed room for its cookie). If not, nuke the added
650      * attributes out of the span.
651      */
652 #if USE_XMC_SUPPORT
653     if (magic_cookie_glitch > 0) {
654 	int j, k;
655 	attr_t rattr = A_NORMAL;
656 
657 	for (i = 0; i < screen_lines; i++) {
658 	    for (j = 0; j < screen_columns; j++) {
659 		bool failed = FALSE;
660 		attr_t turnon = AttrOf(newscr->_line[i].text[j]) & ~rattr;
661 
662 		/* is an attribute turned on here? */
663 		if (turnon == 0) {
664 		    rattr = AttrOf(newscr->_line[i].text[j]);
665 		    continue;
666 		}
667 
668 		TR(TRACE_ATTRS, ("At (%d, %d): from %s...", i, j, _traceattr(rattr)));
669 		TR(TRACE_ATTRS, ("...to %s", _traceattr(turnon)));
670 
671 		/*
672 		 * If the attribute change location is a blank with a
673 		 * "safe" attribute, undo the attribute turnon.  This may
674 		 * ensure there's enough room to set the attribute before
675 		 * the first non-blank in the run.
676 		 */
677 #define SAFE(a)	(!((a) & (attr_t)~NONBLANK_ATTR))
678 		if (ISBLANK(newscr->_line[i].text[j]) && SAFE(turnon)) {
679 		    RemAttr(newscr->_line[i].text[j], turnon);
680 		    continue;
681 		}
682 
683 		/* check that there's enough room at start of span */
684 		for (k = 1; k <= magic_cookie_glitch; k++) {
685 		    if (j - k < 0
686 			|| !ISBLANK(newscr->_line[i].text[j - k])
687 			|| !SAFE(AttrOf(newscr->_line[i].text[j - k])))
688 			failed = TRUE;
689 		}
690 		if (!failed) {
691 		    bool end_onscreen = FALSE;
692 		    int m, n = j;
693 
694 		    /* find end of span, if it's onscreen */
695 		    for (m = i; m < screen_lines; m++) {
696 			for (; n < screen_columns; n++) {
697 			    if (AttrOf(newscr->_line[m].text[n]) == rattr) {
698 				end_onscreen = TRUE;
699 				TR(TRACE_ATTRS,
700 				   ("Range attributed with %s ends at (%d, %d)",
701 				    _traceattr(turnon), m, n));
702 				goto foundit;
703 			    }
704 			}
705 			n = 0;
706 		    }
707 		    TR(TRACE_ATTRS,
708 		       ("Range attributed with %s ends offscreen",
709 			_traceattr(turnon)));
710 		  foundit:;
711 
712 		    if (end_onscreen) {
713 			NCURSES_CH_T *lastline = newscr->_line[m].text;
714 
715 			/*
716 			 * If there are safely-attributed blanks at the
717 			 * end of the range, shorten the range.  This will
718 			 * help ensure that there is enough room at end
719 			 * of span.
720 			 */
721 			while (n >= 0
722 			       && ISBLANK(lastline[n])
723 			       && SAFE(AttrOf(lastline[n])))
724 			    RemAttr(lastline[n--], turnon);
725 
726 			/* check that there's enough room at end of span */
727 			for (k = 1; k <= magic_cookie_glitch; k++)
728 			    if (n + k >= screen_columns
729 				|| !ISBLANK(lastline[n + k])
730 				|| !SAFE(AttrOf(lastline[n + k])))
731 				failed = TRUE;
732 		    }
733 		}
734 
735 		if (failed) {
736 		    int p, q = j;
737 
738 		    TR(TRACE_ATTRS,
739 		       ("Clearing %s beginning at (%d, %d)",
740 			_traceattr(turnon), i, j));
741 
742 		    /* turn off new attributes over span */
743 		    for (p = i; p < screen_lines; p++) {
744 			for (; q < screen_columns; q++) {
745 			    if (AttrOf(newscr->_line[p].text[q]) == rattr)
746 				goto foundend;
747 			    RemAttr(newscr->_line[p].text[q], turnon);
748 			}
749 			q = 0;
750 		    }
751 		  foundend:;
752 		} else {
753 		    TR(TRACE_ATTRS,
754 		       ("Cookie space for %s found before (%d, %d)",
755 			_traceattr(turnon), i, j));
756 
757 		    /*
758 		     * back up the start of range so there's room
759 		     * for cookies before the first nonblank character
760 		     */
761 		    for (k = 1; k <= magic_cookie_glitch; k++)
762 			AddAttr(newscr->_line[i].text[j - k], turnon);
763 		}
764 
765 		rattr = AttrOf(newscr->_line[i].text[j]);
766 	    }
767 	}
768 
769 #ifdef TRACE
770 	/* show altered highlights after magic-cookie check */
771 	if (_nc_tracing & TRACE_UPDATE) {
772 	    _tracef("After magic-cookie check...");
773 	    _tracedump("newscr", newscr);
774 	}
775 #endif /* TRACE */
776     }
777 #endif /* USE_XMC_SUPPORT */
778 
779     nonempty = 0;
780     if (curscr->_clear || newscr->_clear) {	/* force refresh ? */
781 	TR(TRACE_UPDATE, ("clearing and updating from scratch"));
782 	ClrUpdate();
783 	curscr->_clear = FALSE;	/* reset flag */
784 	newscr->_clear = FALSE;	/* reset flag */
785     } else {
786 	int changedlines = CHECK_INTERVAL;
787 
788 	if (check_pending())
789 	    goto cleanup;
790 
791 	nonempty = min(screen_lines, newscr->_maxy + 1);
792 
793 	if (SP->_scrolling) {
794 	    _nc_scroll_optimize();
795 	}
796 
797 	nonempty = ClrBottom(nonempty);
798 
799 	TR(TRACE_UPDATE, ("Transforming lines, nonempty %d", nonempty));
800 	for (i = 0; i < nonempty; i++) {
801 	    /*
802 	     * Here is our line-breakout optimization.
803 	     */
804 	    if (changedlines == CHECK_INTERVAL) {
805 		if (check_pending())
806 		    goto cleanup;
807 		changedlines = 0;
808 	    }
809 
810 	    /*
811 	     * newscr->line[i].firstchar is normally set
812 	     * by wnoutrefresh.  curscr->line[i].firstchar
813 	     * is normally set by _nc_scroll_window in the
814 	     * vertical-movement optimization code,
815 	     */
816 	    if (newscr->_line[i].firstchar != _NOCHANGE
817 		|| curscr->_line[i].firstchar != _NOCHANGE) {
818 		TransformLine(i);
819 		changedlines++;
820 	    }
821 
822 	    /* mark line changed successfully */
823 	    if (i <= newscr->_maxy) {
824 		MARK_NOCHANGE(newscr, i);
825 	    }
826 	    if (i <= curscr->_maxy) {
827 		MARK_NOCHANGE(curscr, i);
828 	    }
829 	}
830     }
831 
832     /* put everything back in sync */
833     for (i = nonempty; i <= newscr->_maxy; i++) {
834 	MARK_NOCHANGE(newscr, i);
835     }
836     for (i = nonempty; i <= curscr->_maxy; i++) {
837 	MARK_NOCHANGE(curscr, i);
838     }
839 
840     if (!newscr->_leaveok) {
841 	curscr->_curx = newscr->_curx;
842 	curscr->_cury = newscr->_cury;
843 
844 	GoTo(curscr->_cury, curscr->_curx);
845     }
846 
847   cleanup:
848     /*
849      * Keep the physical screen in normal mode in case we get other
850      * processes writing to the screen.
851      */
852     UpdateAttrs(normal);
853 
854     _nc_flush();
855     curscr->_attrs = newscr->_attrs;
856 
857 #if USE_TRACE_TIMES
858     (void) times(&after);
859     TR(TRACE_TIMES,
860        ("Update cost: %ld chars, %ld clocks system time, %ld clocks user time",
861 	_nc_outchars,
862 	(long) (after.tms_stime - before.tms_stime),
863 	(long) (after.tms_utime - before.tms_utime)));
864 #endif /* USE_TRACE_TIMES */
865 
866     _nc_signal_handler(TRUE);
867 
868     returnCode(OK);
869 }
870 
871 /*
872  *	ClrBlank(win)
873  *
874  *	Returns the attributed character that corresponds to the "cleared"
875  *	screen.  If the terminal has the back-color-erase feature, this will be
876  *	colored according to the wbkgd() call.
877  *
878  *	We treat 'curscr' specially because it isn't supposed to be set directly
879  *	in the wbkgd() call.  Assume 'stdscr' for this case.
880  */
881 #define BCE_ATTRS (A_NORMAL|A_COLOR)
882 #define BCE_BKGD(win) (((win) == curscr ? stdscr : (win))->_nc_bkgd)
883 
884 static inline NCURSES_CH_T
ClrBlank(WINDOW * win)885 ClrBlank(WINDOW *win)
886 {
887     NCURSES_CH_T blank = NewChar(BLANK_TEXT);
888     if (back_color_erase)
889 	AddAttr(blank, (AttrOf(BCE_BKGD(win)) & BCE_ATTRS));
890     return blank;
891 }
892 
893 /*
894 **	ClrUpdate()
895 **
896 **	Update by clearing and redrawing the entire screen.
897 **
898 */
899 
900 static void
ClrUpdate(void)901 ClrUpdate(void)
902 {
903     int i;
904     NCURSES_CH_T blank = ClrBlank(stdscr);
905     int nonempty = min(screen_lines, newscr->_maxy + 1);
906 
907     TR(TRACE_UPDATE, ("ClrUpdate() called"));
908 
909     ClearScreen(blank);
910 
911     TR(TRACE_UPDATE, ("updating screen from scratch"));
912 
913     nonempty = ClrBottom(nonempty);
914 
915     for (i = 0; i < nonempty; i++)
916 	TransformLine(i);
917 }
918 
919 /*
920 **	ClrToEOL(blank)
921 **
922 **	Clear to end of current line, starting at the cursor position
923 */
924 
925 static void
ClrToEOL(NCURSES_CH_T blank,bool needclear)926 ClrToEOL(NCURSES_CH_T blank, bool needclear)
927 {
928     int j;
929 
930     if (curscr != 0
931 	&& SP->_cursrow >= 0) {
932 	for (j = SP->_curscol; j < screen_columns; j++) {
933 	    if (j >= 0) {
934 		NCURSES_CH_T *cp = &(curscr->_line[SP->_cursrow].text[j]);
935 
936 		if (!CharEq(*cp, blank)) {
937 		    *cp = blank;
938 		    needclear = TRUE;
939 		}
940 	    }
941 	}
942     } else {
943 	needclear = TRUE;
944     }
945 
946     if (needclear) {
947 	UpdateAttrs(blank);
948 	TPUTS_TRACE("clr_eol");
949 	if (clr_eol && SP->_el_cost <= (screen_columns - SP->_curscol)) {
950 	    putp(clr_eol);
951 	} else {
952 	    int count = (screen_columns - SP->_curscol);
953 	    while (count-- > 0)
954 		PutChar(CHREF(blank));
955 	}
956     }
957 }
958 
959 /*
960 **	ClrToEOS(blank)
961 **
962 **	Clear to end of screen, starting at the cursor position
963 */
964 
965 static void
ClrToEOS(NCURSES_CH_T blank)966 ClrToEOS(NCURSES_CH_T blank)
967 {
968     int row, col;
969 
970     row = SP->_cursrow;
971     col = SP->_curscol;
972 
973     UpdateAttrs(blank);
974     TPUTS_TRACE("clr_eos");
975     tputs(clr_eos, screen_lines - row, _nc_outch);
976 
977     while (col < screen_columns)
978 	curscr->_line[row].text[col++] = blank;
979 
980     for (row++; row < screen_lines; row++) {
981 	for (col = 0; col < screen_columns; col++)
982 	    curscr->_line[row].text[col] = blank;
983     }
984 }
985 
986 /*
987  *	ClrBottom(total)
988  *
989  *	Test if clearing the end of the screen would satisfy part of the
990  *	screen-update.  Do this by scanning backwards through the lines in the
991  *	screen, checking if each is blank, and one or more are changed.
992  */
993 static int
ClrBottom(int total)994 ClrBottom(int total)
995 {
996     int row;
997     int col;
998     int top = total;
999     int last = min(screen_columns, newscr->_maxx + 1);
1000     NCURSES_CH_T blank = newscr->_line[total - 1].text[last - 1];
1001     bool ok;
1002 
1003     if (clr_eos && can_clear_with(CHREF(blank))) {
1004 
1005 	for (row = total - 1; row >= 0; row--) {
1006 	    for (col = 0, ok = TRUE; ok && col < last; col++) {
1007 		ok = (CharEq(newscr->_line[row].text[col], blank));
1008 	    }
1009 	    if (!ok)
1010 		break;
1011 
1012 	    for (col = 0; ok && col < last; col++) {
1013 		ok = (CharEq(curscr->_line[row].text[col], blank));
1014 	    }
1015 	    if (!ok)
1016 		top = row;
1017 	}
1018 
1019 	/* don't use clr_eos for just one line if clr_eol available */
1020 	if (top < total) {
1021 	    GoTo(top, 0);
1022 	    ClrToEOS(blank);
1023 	    if (SP->oldhash && SP->newhash) {
1024 		for (row = top; row < screen_lines; row++)
1025 		    SP->oldhash[row] = SP->newhash[row];
1026 	    }
1027 	}
1028     }
1029     return top;
1030 }
1031 
1032 #if USE_XMC_SUPPORT
1033 #if USE_WIDEC_SUPPORT
1034 static inline bool
check_xmc_transition(NCURSES_CH_T * a,NCURSES_CH_T * b)1035 check_xmc_transition(NCURSES_CH_T * a, NCURSES_CH_T * b)
1036 {
1037     if (((a->attr ^ b->attr) & ~(a->attr) & SP->_xmc_triggers) != 0) {
1038 	return TRUE;
1039     }
1040     return FALSE;
1041 }
1042 #define xmc_turn_on(a,b) check_xmc_transition(&(a), &(b))
1043 #else
1044 #define xmc_turn_on(a,b) ((((a)^(b)) & ~(a) & SP->_xmc_triggers) != 0)
1045 #endif
1046 
1047 #define xmc_new(r,c) newscr->_line[r].text[c]
1048 #define xmc_turn_off(a,b) xmc_turn_on(b,a)
1049 #endif /* USE_XMC_SUPPORT */
1050 
1051 /*
1052 **	TransformLine(lineno)
1053 **
1054 **	Transform the given line in curscr to the one in newscr, using
1055 **	Insert/Delete Character if _nc_idcok && has_ic().
1056 **
1057 **		firstChar = position of first different character in line
1058 **		oLastChar = position of last different character in old line
1059 **		nLastChar = position of last different character in new line
1060 **
1061 **		move to firstChar
1062 **		overwrite chars up to min(oLastChar, nLastChar)
1063 **		if oLastChar < nLastChar
1064 **			insert newLine[oLastChar+1..nLastChar]
1065 **		else
1066 **			delete oLastChar - nLastChar spaces
1067 */
1068 
1069 static void
TransformLine(int const lineno)1070 TransformLine(int const lineno)
1071 {
1072     int firstChar, oLastChar, nLastChar;
1073     NCURSES_CH_T *newLine = newscr->_line[lineno].text;
1074     NCURSES_CH_T *oldLine = curscr->_line[lineno].text;
1075     int n;
1076     bool attrchanged = FALSE;
1077 
1078     TR(TRACE_UPDATE, (T_CALLED("TransformLine(%d)"), lineno));
1079 
1080     /* copy new hash value to old one */
1081     if (SP->oldhash && SP->newhash)
1082 	SP->oldhash[lineno] = SP->newhash[lineno];
1083 
1084     /*
1085      * If we have colors, there is the possibility of having two color pairs
1086      * that display as the same colors.  For instance, Lynx does this.  Check
1087      * for this case, and update the old line with the new line's colors when
1088      * they are equivalent.
1089      */
1090     if (SP->_coloron) {
1091 	int oldPair;
1092 	int newPair;
1093 
1094 	for (n = 0; n < screen_columns; n++) {
1095 	    if (!CharEq(newLine[n], oldLine[n])) {
1096 		oldPair = GetPair(oldLine[n]);
1097 		newPair = GetPair(newLine[n]);
1098 		if (oldPair != newPair
1099 		    && unColor(oldLine[n]) == unColor(newLine[n])) {
1100 		    if (oldPair < COLOR_PAIRS
1101 			&& newPair < COLOR_PAIRS
1102 			&& SP->_color_pairs[oldPair] == SP->_color_pairs[newPair]) {
1103 			SetPair(oldLine[n], GetPair(newLine[n]));
1104 		    }
1105 		}
1106 	    }
1107 	}
1108     }
1109 
1110     if (ceol_standout_glitch && clr_eol) {
1111 	firstChar = 0;
1112 	while (firstChar < screen_columns) {
1113 	    if (!SameAttrOf(newLine[firstChar], oldLine[firstChar])) {
1114 		attrchanged = TRUE;
1115 		break;
1116 	    }
1117 	    firstChar++;
1118 	}
1119     }
1120 
1121     firstChar = 0;
1122 
1123     if (attrchanged) {		/* we may have to disregard the whole line */
1124 	GoTo(lineno, firstChar);
1125 	ClrToEOL(ClrBlank(curscr), FALSE);
1126 	PutRange(oldLine, newLine, lineno, 0, (screen_columns - 1));
1127 #if USE_XMC_SUPPORT
1128 
1129 	/*
1130 	 * This is a very simple loop to paint characters which may have the
1131 	 * magic cookie glitch embedded.  It doesn't know much about video
1132 	 * attributes which are continued from one line to the next.  It
1133 	 * assumes that we have filtered out requests for attribute changes
1134 	 * that do not get mapped to blank positions.
1135 	 *
1136 	 * FIXME: we are not keeping track of where we put the cookies, so this
1137 	 * will work properly only once, since we may overwrite a cookie in a
1138 	 * following operation.
1139 	 */
1140     } else if (magic_cookie_glitch > 0) {
1141 	GoTo(lineno, firstChar);
1142 	for (n = 0; n < screen_columns; n++) {
1143 	    int m = n + magic_cookie_glitch;
1144 
1145 	    /* check for turn-on:
1146 	     * If we are writing an attributed blank, where the
1147 	     * previous cell is not attributed.
1148 	     */
1149 	    if (ISBLANK(newLine[n])
1150 		&& ((n > 0
1151 		     && xmc_turn_on(newLine[n - 1], newLine[n]))
1152 		    || (n == 0
1153 			&& lineno > 0
1154 			&& xmc_turn_on(xmc_new(lineno - 1, screen_columns - 1),
1155 				       newLine[n])))) {
1156 		n = m;
1157 	    }
1158 
1159 	    PutChar(CHREF(newLine[n]));
1160 
1161 	    /* check for turn-off:
1162 	     * If we are writing an attributed non-blank, where the
1163 	     * next cell is blank, and not attributed.
1164 	     */
1165 	    if (!ISBLANK(newLine[n])
1166 		&& ((n + 1 < screen_columns
1167 		     && xmc_turn_off(newLine[n], newLine[n + 1]))
1168 		    || (n + 1 >= screen_columns
1169 			&& lineno + 1 < screen_lines
1170 			&& xmc_turn_off(newLine[n], xmc_new(lineno + 1, 0))))) {
1171 		n = m;
1172 	    }
1173 
1174 	}
1175 #endif
1176     } else {
1177 	NCURSES_CH_T blank;
1178 
1179 	/* it may be cheap to clear leading whitespace with clr_bol */
1180 	blank = newLine[0];
1181 	if (clr_bol && can_clear_with(CHREF(blank))) {
1182 	    int oFirstChar, nFirstChar;
1183 
1184 	    for (oFirstChar = 0; oFirstChar < screen_columns; oFirstChar++)
1185 		if (!CharEq(oldLine[oFirstChar], blank))
1186 		    break;
1187 	    for (nFirstChar = 0; nFirstChar < screen_columns; nFirstChar++)
1188 		if (!CharEq(newLine[nFirstChar], blank))
1189 		    break;
1190 
1191 	    if (nFirstChar == oFirstChar) {
1192 		firstChar = nFirstChar;
1193 		/* find the first differing character */
1194 		while (firstChar < screen_columns
1195 		       && CharEq(newLine[firstChar], oldLine[firstChar]))
1196 		    firstChar++;
1197 	    } else if (oFirstChar > nFirstChar) {
1198 		firstChar = nFirstChar;
1199 	    } else {		/* oFirstChar < nFirstChar */
1200 		firstChar = oFirstChar;
1201 		if (SP->_el1_cost < nFirstChar - oFirstChar) {
1202 		    if (nFirstChar >= screen_columns
1203 			&& SP->_el_cost <= SP->_el1_cost) {
1204 			GoTo(lineno, 0);
1205 			UpdateAttrs(blank);
1206 			TPUTS_TRACE("clr_eol");
1207 			putp(clr_eol);
1208 		    } else {
1209 			GoTo(lineno, nFirstChar - 1);
1210 			UpdateAttrs(blank);
1211 			TPUTS_TRACE("clr_bol");
1212 			putp(clr_bol);
1213 		    }
1214 
1215 		    while (firstChar < nFirstChar)
1216 			oldLine[firstChar++] = blank;
1217 		}
1218 	    }
1219 	} else {
1220 	    /* find the first differing character */
1221 	    while (firstChar < screen_columns
1222 		   && CharEq(newLine[firstChar], oldLine[firstChar]))
1223 		firstChar++;
1224 	}
1225 	/* if there wasn't one, we're done */
1226 	if (firstChar >= screen_columns) {
1227 	    TR(TRACE_UPDATE, (T_RETURN("")));
1228 	    return;
1229 	}
1230 
1231 	blank = newLine[screen_columns - 1];
1232 
1233 	if (!can_clear_with(CHREF(blank))) {
1234 	    /* find the last differing character */
1235 	    nLastChar = screen_columns - 1;
1236 
1237 	    while (nLastChar > firstChar
1238 		   && CharEq(newLine[nLastChar], oldLine[nLastChar]))
1239 		nLastChar--;
1240 
1241 	    if (nLastChar >= firstChar) {
1242 		GoTo(lineno, firstChar);
1243 		PutRange(oldLine, newLine, lineno, firstChar, nLastChar);
1244 		memcpy(oldLine + firstChar,
1245 		       newLine + firstChar,
1246 		       (nLastChar - firstChar + 1) * sizeof(NCURSES_CH_T));
1247 	    }
1248 	    TR(TRACE_UPDATE, (T_RETURN("")));
1249 	    return;
1250 	}
1251 
1252 	/* find last non-blank character on old line */
1253 	oLastChar = screen_columns - 1;
1254 	while (oLastChar > firstChar && CharEq(oldLine[oLastChar], blank))
1255 	    oLastChar--;
1256 
1257 	/* find last non-blank character on new line */
1258 	nLastChar = screen_columns - 1;
1259 	while (nLastChar > firstChar && CharEq(newLine[nLastChar], blank))
1260 	    nLastChar--;
1261 
1262 	if ((nLastChar == firstChar)
1263 	    && (SP->_el_cost < (oLastChar - nLastChar))) {
1264 	    GoTo(lineno, firstChar);
1265 	    if (!CharEq(newLine[firstChar], blank))
1266 		PutChar(CHREF(newLine[firstChar]));
1267 	    ClrToEOL(blank, FALSE);
1268 	} else if ((nLastChar != oLastChar)
1269 		   && (!CharEq(newLine[nLastChar], oldLine[oLastChar])
1270 		       || !(_nc_idcok && has_ic()))) {
1271 	    GoTo(lineno, firstChar);
1272 	    if ((oLastChar - nLastChar) > SP->_el_cost) {
1273 		if (PutRange(oldLine, newLine, lineno, firstChar, nLastChar))
1274 		    GoTo(lineno, nLastChar + 1);
1275 		ClrToEOL(blank, FALSE);
1276 	    } else {
1277 		n = max(nLastChar, oLastChar);
1278 		PutRange(oldLine, newLine, lineno, firstChar, n);
1279 	    }
1280 	} else {
1281 	    int nLastNonblank = nLastChar;
1282 	    int oLastNonblank = oLastChar;
1283 
1284 	    /* find the last characters that really differ */
1285 	    /* can be -1 if no characters differ */
1286 	    while (CharEq(newLine[nLastChar], oldLine[oLastChar])) {
1287 		/* don't split a wide char */
1288 		if (isWidecExt(newLine[nLastChar]) &&
1289 		    !CharEq(newLine[nLastChar - 1], oldLine[oLastChar - 1]))
1290 		    break;
1291 		nLastChar--;
1292 		oLastChar--;
1293 		if (nLastChar == -1 || oLastChar == -1)
1294 		    break;
1295 	    }
1296 
1297 	    n = min(oLastChar, nLastChar);
1298 	    if (n >= firstChar) {
1299 		GoTo(lineno, firstChar);
1300 		PutRange(oldLine, newLine, lineno, firstChar, n);
1301 	    }
1302 
1303 	    if (oLastChar < nLastChar) {
1304 		int m = max(nLastNonblank, oLastNonblank);
1305 #if USE_WIDEC_SUPPORT
1306 		while (isWidecExt(newLine[n + 1]) && n) {
1307 		    --n;
1308 		    --oLastChar;
1309 		}
1310 #endif
1311 		GoTo(lineno, n + 1);
1312 		if ((nLastChar < nLastNonblank)
1313 		    || InsCharCost(nLastChar - oLastChar) > (m - n)) {
1314 		    PutRange(oldLine, newLine, lineno, n + 1, m);
1315 		} else {
1316 		    InsStr(&newLine[n + 1], nLastChar - oLastChar);
1317 		}
1318 	    } else if (oLastChar > nLastChar) {
1319 		GoTo(lineno, n + 1);
1320 		if (DelCharCost(oLastChar - nLastChar)
1321 		    > SP->_el_cost + nLastNonblank - (n + 1)) {
1322 		    if (PutRange(oldLine, newLine, lineno,
1323 				 n + 1, nLastNonblank))
1324 			GoTo(lineno, nLastNonblank + 1);
1325 		    ClrToEOL(blank, FALSE);
1326 		} else {
1327 		    /*
1328 		     * The delete-char sequence will
1329 		     * effectively shift in blanks from the
1330 		     * right margin of the screen.  Ensure
1331 		     * that they are the right color by
1332 		     * setting the video attributes from
1333 		     * the last character on the row.
1334 		     */
1335 		    UpdateAttrs(blank);
1336 		    DelChar(oLastChar - nLastChar);
1337 		}
1338 	    }
1339 	}
1340     }
1341 
1342     /* update the code's internal representation */
1343     if (screen_columns > firstChar)
1344 	memcpy(oldLine + firstChar,
1345 	       newLine + firstChar,
1346 	       (screen_columns - firstChar) * sizeof(NCURSES_CH_T));
1347     TR(TRACE_UPDATE, (T_RETURN("")));
1348     return;
1349 }
1350 
1351 /*
1352 **	ClearScreen(blank)
1353 **
1354 **	Clear the physical screen and put cursor at home
1355 **
1356 */
1357 
1358 static void
ClearScreen(NCURSES_CH_T blank)1359 ClearScreen(NCURSES_CH_T blank)
1360 {
1361     int i, j;
1362     bool fast_clear = (clear_screen || clr_eos || clr_eol);
1363 
1364     TR(TRACE_UPDATE, ("ClearScreen() called"));
1365 
1366 #if NCURSES_EXT_FUNCS
1367     if (SP->_coloron
1368 	&& !SP->_default_color) {
1369 	_nc_do_color(GET_SCREEN_PAIR(SP), 0, FALSE, _nc_outch);
1370 	if (!back_color_erase) {
1371 	    fast_clear = FALSE;
1372 	}
1373     }
1374 #endif
1375 
1376     if (fast_clear) {
1377 	if (clear_screen) {
1378 	    UpdateAttrs(blank);
1379 	    TPUTS_TRACE("clear_screen");
1380 	    putp(clear_screen);
1381 	    SP->_cursrow = SP->_curscol = 0;
1382 	    position_check(SP->_cursrow, SP->_curscol, "ClearScreen");
1383 	} else if (clr_eos) {
1384 	    SP->_cursrow = SP->_curscol = -1;
1385 	    GoTo(0, 0);
1386 
1387 	    UpdateAttrs(blank);
1388 	    TPUTS_TRACE("clr_eos");
1389 	    tputs(clr_eos, screen_lines, _nc_outch);
1390 	} else if (clr_eol) {
1391 	    SP->_cursrow = SP->_curscol = -1;
1392 
1393 	    UpdateAttrs(blank);
1394 	    for (i = 0; i < screen_lines; i++) {
1395 		GoTo(i, 0);
1396 		TPUTS_TRACE("clr_eol");
1397 		putp(clr_eol);
1398 	    }
1399 	    GoTo(0, 0);
1400 	}
1401     } else {
1402 	UpdateAttrs(blank);
1403 	for (i = 0; i < screen_lines; i++) {
1404 	    GoTo(i, 0);
1405 	    for (j = 0; j < screen_columns; j++)
1406 		PutChar(CHREF(blank));
1407 	}
1408 	GoTo(0, 0);
1409     }
1410 
1411     for (i = 0; i < screen_lines; i++) {
1412 	for (j = 0; j < screen_columns; j++)
1413 	    curscr->_line[i].text[j] = blank;
1414     }
1415 
1416     TR(TRACE_UPDATE, ("screen cleared"));
1417 }
1418 
1419 /*
1420 **	InsStr(line, count)
1421 **
1422 **	Insert the count characters pointed to by line.
1423 **
1424 */
1425 
1426 static void
InsStr(NCURSES_CH_T * line,int count)1427 InsStr(NCURSES_CH_T * line, int count)
1428 {
1429     TR(TRACE_UPDATE, ("InsStr(%p,%d) called", line, count));
1430 
1431     /* Prefer parm_ich as it has the smallest cost - no need to shift
1432      * the whole line on each character. */
1433     /* The order must match that of InsCharCost. */
1434     if (parm_ich) {
1435 	TPUTS_TRACE("parm_ich");
1436 	tputs(tparm(parm_ich, count), count, _nc_outch);
1437 	while (count) {
1438 	    PutAttrChar(CHREF(*line));
1439 	    line++;
1440 	    count--;
1441 	}
1442     } else if (enter_insert_mode && exit_insert_mode) {
1443 	TPUTS_TRACE("enter_insert_mode");
1444 	putp(enter_insert_mode);
1445 	while (count) {
1446 	    PutAttrChar(CHREF(*line));
1447 	    if (insert_padding) {
1448 		TPUTS_TRACE("insert_padding");
1449 		putp(insert_padding);
1450 	    }
1451 	    line++;
1452 	    count--;
1453 	}
1454 	TPUTS_TRACE("exit_insert_mode");
1455 	putp(exit_insert_mode);
1456     } else {
1457 	while (count) {
1458 	    TPUTS_TRACE("insert_character");
1459 	    putp(insert_character);
1460 	    PutAttrChar(CHREF(*line));
1461 	    if (insert_padding) {
1462 		TPUTS_TRACE("insert_padding");
1463 		putp(insert_padding);
1464 	    }
1465 	    line++;
1466 	    count--;
1467 	}
1468     }
1469     position_check(SP->_cursrow, SP->_curscol, "InsStr");
1470 }
1471 
1472 /*
1473 **	DelChar(count)
1474 **
1475 **	Delete count characters at current position
1476 **
1477 */
1478 
1479 static void
DelChar(int count)1480 DelChar(int count)
1481 {
1482     int n;
1483 
1484     TR(TRACE_UPDATE, ("DelChar(%d) called, position = (%d,%d)", count,
1485 		      newscr->_cury, newscr->_curx));
1486 
1487     if (parm_dch) {
1488 	TPUTS_TRACE("parm_dch");
1489 	tputs(tparm(parm_dch, count), count, _nc_outch);
1490     } else {
1491 	for (n = 0; n < count; n++) {
1492 	    TPUTS_TRACE("delete_character");
1493 	    putp(delete_character);
1494 	}
1495     }
1496 }
1497 
1498 /*
1499  * Physical-scrolling support
1500  *
1501  * This code was adapted from Keith Bostic's hardware scrolling
1502  * support for 4.4BSD curses.  I (esr) translated it to use terminfo
1503  * capabilities, narrowed the call interface slightly, and cleaned
1504  * up some convoluted tests.  I also added support for the memory_above
1505  * memory_below, and non_dest_scroll_region capabilities.
1506  *
1507  * For this code to work, we must have either
1508  * change_scroll_region and scroll forward/reverse commands, or
1509  * insert and delete line capabilities.
1510  * When the scrolling region has been set, the cursor has to
1511  * be at the last line of the region to make the scroll up
1512  * happen, or on the first line of region to scroll down.
1513  *
1514  * This code makes one aesthetic decision in the opposite way from
1515  * BSD curses.  BSD curses preferred pairs of il/dl operations
1516  * over scrolls, allegedly because il/dl looked faster.  We, on
1517  * the other hand, prefer scrolls because (a) they're just as fast
1518  * on many terminals and (b) using them avoids bouncing an
1519  * unchanged bottom section of the screen up and down, which is
1520  * visually nasty.
1521  *
1522  * (lav): added more cases, used dl/il when bot==maxy and in csr case.
1523  *
1524  * I used assumption that capabilities il/il1/dl/dl1 work inside
1525  * changed scroll region not shifting screen contents outside of it.
1526  * If there are any terminals behaving different way, it would be
1527  * necessary to add some conditions to scroll_csr_forward/backward.
1528  */
1529 
1530 /* Try to scroll up assuming given csr (miny, maxy). Returns ERR on failure */
1531 static int
scroll_csr_forward(int n,int top,int bot,int miny,int maxy,NCURSES_CH_T blank)1532 scroll_csr_forward(int n, int top, int bot, int miny, int maxy, NCURSES_CH_T blank)
1533 {
1534     int i;
1535 
1536     if (n == 1 && scroll_forward && top == miny && bot == maxy) {
1537 	GoTo(bot, 0);
1538 	UpdateAttrs(blank);
1539 	TPUTS_TRACE("scroll_forward");
1540 	putp(scroll_forward);
1541     } else if (n == 1 && delete_line && bot == maxy) {
1542 	GoTo(top, 0);
1543 	UpdateAttrs(blank);
1544 	TPUTS_TRACE("delete_line");
1545 	putp(delete_line);
1546     } else if (parm_index && top == miny && bot == maxy) {
1547 	GoTo(bot, 0);
1548 	UpdateAttrs(blank);
1549 	TPUTS_TRACE("parm_index");
1550 	tputs(tparm(parm_index, n, 0), n, _nc_outch);
1551     } else if (parm_delete_line && bot == maxy) {
1552 	GoTo(top, 0);
1553 	UpdateAttrs(blank);
1554 	TPUTS_TRACE("parm_delete_line");
1555 	tputs(tparm(parm_delete_line, n, 0), n, _nc_outch);
1556     } else if (scroll_forward && top == miny && bot == maxy) {
1557 	GoTo(bot, 0);
1558 	UpdateAttrs(blank);
1559 	for (i = 0; i < n; i++) {
1560 	    TPUTS_TRACE("scroll_forward");
1561 	    putp(scroll_forward);
1562 	}
1563     } else if (delete_line && bot == maxy) {
1564 	GoTo(top, 0);
1565 	UpdateAttrs(blank);
1566 	for (i = 0; i < n; i++) {
1567 	    TPUTS_TRACE("delete_line");
1568 	    putp(delete_line);
1569 	}
1570     } else
1571 	return ERR;
1572 
1573 #if NCURSES_EXT_FUNCS
1574     if (FILL_BCE()) {
1575 	int j;
1576 	for (i = 0; i < n; i++) {
1577 	    GoTo(bot - i, 0);
1578 	    for (j = 0; j < screen_columns; j++)
1579 		PutChar(CHREF(blank));
1580 	}
1581     }
1582 #endif
1583     return OK;
1584 }
1585 
1586 /* Try to scroll down assuming given csr (miny, maxy). Returns ERR on failure */
1587 /* n > 0 */
1588 static int
scroll_csr_backward(int n,int top,int bot,int miny,int maxy,NCURSES_CH_T blank)1589 scroll_csr_backward(int n, int top, int bot, int miny, int maxy,
1590 		    NCURSES_CH_T blank)
1591 {
1592     int i;
1593 
1594     if (n == 1 && scroll_reverse && top == miny && bot == maxy) {
1595 	GoTo(top, 0);
1596 	UpdateAttrs(blank);
1597 	TPUTS_TRACE("scroll_reverse");
1598 	putp(scroll_reverse);
1599     } else if (n == 1 && insert_line && bot == maxy) {
1600 	GoTo(top, 0);
1601 	UpdateAttrs(blank);
1602 	TPUTS_TRACE("insert_line");
1603 	putp(insert_line);
1604     } else if (parm_rindex && top == miny && bot == maxy) {
1605 	GoTo(top, 0);
1606 	UpdateAttrs(blank);
1607 	TPUTS_TRACE("parm_rindex");
1608 	tputs(tparm(parm_rindex, n, 0), n, _nc_outch);
1609     } else if (parm_insert_line && bot == maxy) {
1610 	GoTo(top, 0);
1611 	UpdateAttrs(blank);
1612 	TPUTS_TRACE("parm_insert_line");
1613 	tputs(tparm(parm_insert_line, n, 0), n, _nc_outch);
1614     } else if (scroll_reverse && top == miny && bot == maxy) {
1615 	GoTo(top, 0);
1616 	UpdateAttrs(blank);
1617 	for (i = 0; i < n; i++) {
1618 	    TPUTS_TRACE("scroll_reverse");
1619 	    putp(scroll_reverse);
1620 	}
1621     } else if (insert_line && bot == maxy) {
1622 	GoTo(top, 0);
1623 	UpdateAttrs(blank);
1624 	for (i = 0; i < n; i++) {
1625 	    TPUTS_TRACE("insert_line");
1626 	    putp(insert_line);
1627 	}
1628     } else
1629 	return ERR;
1630 
1631 #if NCURSES_EXT_FUNCS
1632     if (FILL_BCE()) {
1633 	int j;
1634 	for (i = 0; i < n; i++) {
1635 	    GoTo(top + i, 0);
1636 	    for (j = 0; j < screen_columns; j++)
1637 		PutChar(CHREF(blank));
1638 	}
1639     }
1640 #endif
1641     return OK;
1642 }
1643 
1644 /* scroll by using delete_line at del and insert_line at ins */
1645 /* n > 0 */
1646 static int
scroll_idl(int n,int del,int ins,NCURSES_CH_T blank)1647 scroll_idl(int n, int del, int ins, NCURSES_CH_T blank)
1648 {
1649     int i;
1650 
1651     if (!((parm_delete_line || delete_line) && (parm_insert_line || insert_line)))
1652 	return ERR;
1653 
1654     GoTo(del, 0);
1655     UpdateAttrs(blank);
1656     if (n == 1 && delete_line) {
1657 	TPUTS_TRACE("delete_line");
1658 	putp(delete_line);
1659     } else if (parm_delete_line) {
1660 	TPUTS_TRACE("parm_delete_line");
1661 	tputs(tparm(parm_delete_line, n, 0), n, _nc_outch);
1662     } else {			/* if (delete_line) */
1663 	for (i = 0; i < n; i++) {
1664 	    TPUTS_TRACE("delete_line");
1665 	    putp(delete_line);
1666 	}
1667     }
1668 
1669     GoTo(ins, 0);
1670     UpdateAttrs(blank);
1671     if (n == 1 && insert_line) {
1672 	TPUTS_TRACE("insert_line");
1673 	putp(insert_line);
1674     } else if (parm_insert_line) {
1675 	TPUTS_TRACE("parm_insert_line");
1676 	tputs(tparm(parm_insert_line, n, 0), n, _nc_outch);
1677     } else {			/* if (insert_line) */
1678 	for (i = 0; i < n; i++) {
1679 	    TPUTS_TRACE("insert_line");
1680 	    putp(insert_line);
1681 	}
1682     }
1683 
1684     return OK;
1685 }
1686 
1687 /*
1688  * Note:  some terminals require the cursor to be within the scrolling margins
1689  * before setting them.  Generally, the cursor must be at the appropriate end
1690  * of the scrolling margins when issuing an indexing operation (it is not
1691  * apparent whether it must also be at the left margin; we do this just to be
1692  * safe).  To make the related cursor movement a little faster, we use the
1693  * save/restore cursor capabilities if the terminal has them.
1694  */
1695 NCURSES_EXPORT(int)
_nc_scrolln(int n,int top,int bot,int maxy)1696 _nc_scrolln(int n, int top, int bot, int maxy)
1697 /* scroll region from top to bot by n lines */
1698 {
1699     NCURSES_CH_T blank = ClrBlank(stdscr);
1700     int i;
1701     bool cursor_saved = FALSE;
1702     int res;
1703 
1704     TR(TRACE_MOVE, ("mvcur_scrolln(%d, %d, %d, %d)", n, top, bot, maxy));
1705 
1706 #if USE_XMC_SUPPORT
1707     /*
1708      * If we scroll, we might remove a cookie.
1709      */
1710     if (magic_cookie_glitch > 0) {
1711 	return (ERR);
1712     }
1713 #endif
1714 
1715     if (n > 0) {		/* scroll up (forward) */
1716 	/*
1717 	 * Explicitly clear if stuff pushed off top of region might
1718 	 * be saved by the terminal.
1719 	 */
1720 	res = scroll_csr_forward(n, top, bot, 0, maxy, blank);
1721 
1722 	if (res == ERR && change_scroll_region) {
1723 	    if ((((n == 1 && scroll_forward) || parm_index)
1724 		 && (SP->_cursrow == bot || SP->_cursrow == bot - 1))
1725 		&& save_cursor && restore_cursor) {
1726 		cursor_saved = TRUE;
1727 		TPUTS_TRACE("save_cursor");
1728 		putp(save_cursor);
1729 	    }
1730 	    TPUTS_TRACE("change_scroll_region");
1731 	    putp(tparm(change_scroll_region, top, bot));
1732 	    if (cursor_saved) {
1733 		TPUTS_TRACE("restore_cursor");
1734 		putp(restore_cursor);
1735 	    } else {
1736 		SP->_cursrow = SP->_curscol = -1;
1737 	    }
1738 
1739 	    res = scroll_csr_forward(n, top, bot, top, bot, blank);
1740 
1741 	    TPUTS_TRACE("change_scroll_region");
1742 	    putp(tparm(change_scroll_region, 0, maxy));
1743 	    SP->_cursrow = SP->_curscol = -1;
1744 	}
1745 
1746 	if (res == ERR && _nc_idlok)
1747 	    res = scroll_idl(n, top, bot - n + 1, blank);
1748 
1749 	/*
1750 	 * Clear the newly shifted-in text.
1751 	 */
1752 	if (res != ERR
1753 	    && (non_dest_scroll_region || (memory_below && bot == maxy))) {
1754 	    NCURSES_CH_T blank2 = NewChar(BLANK_TEXT);
1755 	    if (bot == maxy && clr_eos) {
1756 		GoTo(bot - n + 1, 0);
1757 		ClrToEOS(blank2);
1758 	    } else {
1759 		for (i = 0; i < n; i++) {
1760 		    GoTo(bot - i, 0);
1761 		    ClrToEOL(blank2, FALSE);
1762 		}
1763 	    }
1764 	}
1765 
1766     } else {			/* (n < 0) - scroll down (backward) */
1767 	res = scroll_csr_backward(-n, top, bot, 0, maxy, blank);
1768 
1769 	if (res == ERR && change_scroll_region) {
1770 	    if (top != 0 && (SP->_cursrow == top || SP->_cursrow == top - 1)
1771 		&& save_cursor && restore_cursor) {
1772 		cursor_saved = TRUE;
1773 		TPUTS_TRACE("save_cursor");
1774 		putp(save_cursor);
1775 	    }
1776 	    TPUTS_TRACE("change_scroll_region");
1777 	    putp(tparm(change_scroll_region, top, bot));
1778 	    if (cursor_saved) {
1779 		TPUTS_TRACE("restore_cursor");
1780 		putp(restore_cursor);
1781 	    } else {
1782 		SP->_cursrow = SP->_curscol = -1;
1783 	    }
1784 
1785 	    res = scroll_csr_backward(-n, top, bot, top, bot, blank);
1786 
1787 	    TPUTS_TRACE("change_scroll_region");
1788 	    putp(tparm(change_scroll_region, 0, maxy));
1789 	    SP->_cursrow = SP->_curscol = -1;
1790 	}
1791 
1792 	if (res == ERR && _nc_idlok)
1793 	    res = scroll_idl(-n, bot + n + 1, top, blank);
1794 
1795 	/*
1796 	 * Clear the newly shifted-in text.
1797 	 */
1798 	if (res != ERR
1799 	    && (non_dest_scroll_region || (memory_above && top == 0))) {
1800 	    NCURSES_CH_T blank2 = NewChar(BLANK_TEXT);
1801 	    for (i = 0; i < -n; i++) {
1802 		GoTo(i + top, 0);
1803 		ClrToEOL(blank2, FALSE);
1804 	    }
1805 	}
1806     }
1807 
1808     if (res == ERR)
1809 	return (ERR);
1810 
1811     _nc_scroll_window(curscr, n, top, bot, blank);
1812 
1813     /* shift hash values too - they can be reused */
1814     _nc_scroll_oldhash(n, top, bot);
1815 
1816     return (OK);
1817 }
1818 
1819 NCURSES_EXPORT(void)
_nc_screen_resume(void)1820 _nc_screen_resume(void)
1821 {
1822     /* make sure terminal is in a sane known state */
1823     SetAttr(SCREEN_ATTRS(SP), A_NORMAL);
1824     newscr->_clear = TRUE;
1825 
1826     /* reset color pairs and definitions */
1827     if (SP->_coloron || SP->_color_defs)
1828 	_nc_reset_colors();
1829 
1830     /* restore user-defined colors, if any */
1831     if (SP->_color_defs < 0) {
1832 	int n;
1833 	SP->_color_defs = -(SP->_color_defs);
1834 	for (n = 0; n < SP->_color_defs; ++n) {
1835 	    if (SP->_color_table[n].init) {
1836 		init_color(n,
1837 			   SP->_color_table[n].r,
1838 			   SP->_color_table[n].g,
1839 			   SP->_color_table[n].b);
1840 	    }
1841 	}
1842     }
1843 
1844     if (exit_attribute_mode)
1845 	putp(exit_attribute_mode);
1846     else {
1847 	/* turn off attributes */
1848 	if (exit_alt_charset_mode)
1849 	    putp(exit_alt_charset_mode);
1850 	if (exit_standout_mode)
1851 	    putp(exit_standout_mode);
1852 	if (exit_underline_mode)
1853 	    putp(exit_underline_mode);
1854     }
1855     if (exit_insert_mode)
1856 	putp(exit_insert_mode);
1857     if (enter_am_mode && exit_am_mode)
1858 	putp(auto_right_margin ? enter_am_mode : exit_am_mode);
1859 }
1860 
1861 NCURSES_EXPORT(void)
_nc_screen_init(void)1862 _nc_screen_init(void)
1863 {
1864     _nc_screen_resume();
1865 }
1866 
1867 /* wrap up screen handling */
1868 NCURSES_EXPORT(void)
_nc_screen_wrap(void)1869 _nc_screen_wrap(void)
1870 {
1871     UpdateAttrs(normal);
1872 #if NCURSES_EXT_FUNCS
1873     if (SP->_coloron
1874 	&& !SP->_default_color) {
1875 	NCURSES_CH_T blank = NewChar(BLANK_TEXT);
1876 	SP->_default_color = TRUE;
1877 	_nc_do_color(-1, 0, FALSE, _nc_outch);
1878 	SP->_default_color = FALSE;
1879 
1880 	mvcur(SP->_cursrow, SP->_curscol, screen_lines - 1, 0);
1881 
1882 	ClrToEOL(blank, TRUE);
1883     }
1884 #endif
1885     if (SP->_color_defs) {
1886 	_nc_reset_colors();
1887     }
1888 }
1889 
1890 #if USE_XMC_SUPPORT
1891 NCURSES_EXPORT(void)
_nc_do_xmc_glitch(attr_t previous)1892 _nc_do_xmc_glitch(attr_t previous)
1893 {
1894     attr_t chg = XMC_CHANGES(previous ^ AttrOf(SCREEN_ATTRS(SP)));
1895 
1896     while (chg != 0) {
1897 	if (chg & 1) {
1898 	    SP->_curscol += magic_cookie_glitch;
1899 	    if (SP->_curscol >= SP->_columns)
1900 		wrap_cursor();
1901 	    TR(TRACE_UPDATE, ("bumped to %d,%d after cookie", SP->_cursrow, SP->_curscol));
1902 	}
1903 	chg >>= 1;
1904     }
1905 }
1906 #endif /* USE_XMC_SUPPORT */
1907