1 /****************************************************************************
2  * Copyright 2019-2020,2021 Thomas E. Dickey                                *
3  * Copyright 1998-2016,2017 Free Software Foundation, Inc.                  *
4  *                                                                          *
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29 
30 /*
31 **	lib_addch.c
32 **
33 **	The routine waddch().
34 **
35 */
36 
37 #include <curses.priv.h>
38 #include <ctype.h>
39 
40 MODULE_ID("$Id: lib_addch.c,v 1.137 2021/02/20 22:24:34 tom Exp $")
41 
42 static const NCURSES_CH_T blankchar = NewChar(BLANK_TEXT);
43 
44 /*
45  * Ugly microtweaking alert.  Everything from here to end of module is
46  * likely to be speed-critical -- profiling data sure says it is!
47  * Most of the important screen-painting functions are shells around
48  * waddch().  So we make every effort to reduce function-call overhead
49  * by inlining stuff, even at the cost of making wrapped copies for
50  * export.  Also we supply some internal versions that don't call the
51  * window sync hook, for use by string-put functions.
52  */
53 
54 /* Return bit mask for clearing color pair number if given ch has color */
55 #define COLOR_MASK(ch) (~(attr_t)(((ch) & A_COLOR) ? A_COLOR : 0))
56 
57 static NCURSES_INLINE NCURSES_CH_T
render_char(WINDOW * win,NCURSES_CH_T ch)58 render_char(WINDOW *win, NCURSES_CH_T ch)
59 /* compute a rendition of the given char correct for the current context */
60 {
61     attr_t a = WINDOW_ATTRS(win);
62     int pair = GetPair(ch);
63 
64     if (ISBLANK(ch)
65 	&& AttrOf(ch) == A_NORMAL
66 	&& pair == 0) {
67 	/* color/pair in attrs has precedence over bkgrnd */
68 	ch = win->_nc_bkgd;
69 	SetAttr(ch, a | AttrOf(win->_nc_bkgd));
70 	if ((pair = GET_WINDOW_PAIR(win)) == 0)
71 	    pair = GetPair(win->_nc_bkgd);
72 	SetPair(ch, pair);
73     } else {
74 	/* color in attrs has precedence over bkgrnd */
75 	a |= AttrOf(win->_nc_bkgd) & COLOR_MASK(a);
76 	/* color in ch has precedence */
77 	if (pair == 0) {
78 	    if ((pair = GET_WINDOW_PAIR(win)) == 0)
79 		pair = GetPair(win->_nc_bkgd);
80 	}
81 	AddAttr(ch, (a & COLOR_MASK(AttrOf(ch))));
82 	SetPair(ch, pair);
83     }
84 
85     TR(TRACE_VIRTPUT,
86        ("render_char bkg %s (%d), attrs %s (%d) -> ch %s (%d)",
87 	_tracech_t2(1, CHREF(win->_nc_bkgd)),
88 	GetPair(win->_nc_bkgd),
89 	_traceattr(WINDOW_ATTRS(win)),
90 	GET_WINDOW_PAIR(win),
91 	_tracech_t2(3, CHREF(ch)),
92 	GetPair(ch)));
93 
94     return (ch);
95 }
96 
97 NCURSES_EXPORT(NCURSES_CH_T)
_nc_render(WINDOW * win,NCURSES_CH_T ch)98 _nc_render(WINDOW *win, NCURSES_CH_T ch)
99 /* make render_char() visible while still allowing us to inline it below */
100 {
101     return render_char(win, ch);
102 }
103 
104 /* check if position is legal; if not, return error */
105 #ifndef NDEBUG			/* treat this like an assertion */
106 #define CHECK_POSITION(win, x, y) \
107 	if (y > win->_maxy \
108 	 || x > win->_maxx \
109 	 || y < 0 \
110 	 || x < 0) { \
111 		TR(TRACE_VIRTPUT, ("Alert! Win=%p _curx = %d, _cury = %d " \
112 				   "(_maxx = %d, _maxy = %d)", win, x, y, \
113 				   win->_maxx, win->_maxy)); \
114 		return(ERR); \
115 	}
116 #else
117 #define CHECK_POSITION(win, x, y)	/* nothing */
118 #endif
119 
120 static bool
newline_forces_scroll(WINDOW * win,NCURSES_SIZE_T * ypos)121 newline_forces_scroll(WINDOW *win, NCURSES_SIZE_T *ypos)
122 {
123     bool result = FALSE;
124 
125     if (*ypos >= win->_regtop && *ypos <= win->_regbottom) {
126 	if (*ypos == win->_regbottom) {
127 	    *ypos = win->_regbottom;
128 	    result = TRUE;
129 	} else if (*ypos < win->_maxy) {
130 	    *ypos = (NCURSES_SIZE_T) (*ypos + 1);
131 	}
132     } else if (*ypos < win->_maxy) {
133 	*ypos = (NCURSES_SIZE_T) (*ypos + 1);
134     }
135     return result;
136 }
137 
138 /*
139  * The _WRAPPED flag is useful only for telling an application that we've just
140  * wrapped the cursor.  We don't do anything with this flag except set it when
141  * wrapping, and clear it whenever we move the cursor.  If we try to wrap at
142  * the lower-right corner of a window, we cannot move the cursor (since that
143  * wouldn't be legal).  So we return an error (which is what SVr4 does).
144  * Unlike SVr4, we can successfully add a character to the lower-right corner
145  * (Solaris 2.6 does this also, however).
146  */
147 static int
wrap_to_next_line(WINDOW * win)148 wrap_to_next_line(WINDOW *win)
149 {
150     win->_flags |= _WRAPPED;
151     if (newline_forces_scroll(win, &(win->_cury))) {
152 	win->_curx = win->_maxx;
153 	if (!win->_scroll)
154 	    return (ERR);
155 	scroll(win);
156     }
157     win->_curx = 0;
158     return (OK);
159 }
160 
161 #if USE_WIDEC_SUPPORT
162 static int waddch_literal(WINDOW *, NCURSES_CH_T);
163 /*
164  * Fill the given number of cells with blanks using the current background
165  * rendition.  This saves/restores the current x-position.
166  */
167 static void
fill_cells(WINDOW * win,int count)168 fill_cells(WINDOW *win, int count)
169 {
170     NCURSES_CH_T blank = blankchar;
171     int save_x = win->_curx;
172     int save_y = win->_cury;
173 
174     while (count-- > 0) {
175 	if (waddch_literal(win, blank) == ERR)
176 	    break;
177     }
178     win->_curx = (NCURSES_SIZE_T) save_x;
179     win->_cury = (NCURSES_SIZE_T) save_y;
180 }
181 #endif
182 
183 /*
184  * Build up the bytes for a multibyte character, returning the length when
185  * complete (a positive number), -1 for error and -2 for incomplete.
186  */
187 #if USE_WIDEC_SUPPORT
188 NCURSES_EXPORT(int)
_nc_build_wch(WINDOW * win,ARG_CH_T ch)189 _nc_build_wch(WINDOW *win, ARG_CH_T ch)
190 {
191     char *buffer = WINDOW_EXT(win, addch_work);
192     int len;
193     int x = win->_curx;
194     int y = win->_cury;
195     mbstate_t state;
196     wchar_t result;
197 
198     if ((WINDOW_EXT(win, addch_used) != 0) &&
199 	(WINDOW_EXT(win, addch_x) != x ||
200 	 WINDOW_EXT(win, addch_y) != y)) {
201 	/* discard the incomplete multibyte character */
202 	WINDOW_EXT(win, addch_used) = 0;
203 	TR(TRACE_VIRTPUT,
204 	   ("Alert discarded multibyte on move (%d,%d) -> (%d,%d)",
205 	    WINDOW_EXT(win, addch_y), WINDOW_EXT(win, addch_x),
206 	    y, x));
207     }
208     WINDOW_EXT(win, addch_x) = x;
209     WINDOW_EXT(win, addch_y) = y;
210 
211     /*
212      * If the background character is a wide-character, that may interfere with
213      * processing multibyte characters in this function.
214      */
215     if (!is8bits(CharOf(CHDEREF(ch)))) {
216 	if (WINDOW_EXT(win, addch_used) != 0) {
217 	    /* discard the incomplete multibyte character */
218 	    WINDOW_EXT(win, addch_used) = 0;
219 	    TR(TRACE_VIRTPUT,
220 	       ("Alert discarded incomplete multibyte"));
221 	}
222 	return 1;
223     }
224 
225     init_mb(state);
226     buffer[WINDOW_EXT(win, addch_used)] = (char) CharOf(CHDEREF(ch));
227     WINDOW_EXT(win, addch_used) += 1;
228     buffer[WINDOW_EXT(win, addch_used)] = '\0';
229     if ((len = (int) mbrtowc(&result,
230 			     buffer,
231 			     (size_t) WINDOW_EXT(win, addch_used),
232 			     &state)) > 0) {
233 	attr_t attrs = AttrOf(CHDEREF(ch));
234 	if_EXT_COLORS(int pair = GetPair(CHDEREF(ch)));
235 	SetChar(CHDEREF(ch), result, attrs);
236 	if_EXT_COLORS(SetPair(CHDEREF(ch), pair));
237 	WINDOW_EXT(win, addch_used) = 0;
238     } else if (len == -1) {
239 	/*
240 	 * An error occurred.  We could either discard everything,
241 	 * or assume that the error was in the previous input.
242 	 * Try the latter.
243 	 */
244 	TR(TRACE_VIRTPUT, ("Alert! mbrtowc returns error"));
245 	/* handle this with unctrl() */
246 	WINDOW_EXT(win, addch_used) = 0;
247     }
248     return len;
249 }
250 #endif /* USE_WIDEC_SUPPORT */
251 
252 static
253 #if !USE_WIDEC_SUPPORT		/* cannot be inline if it is recursive */
254 NCURSES_INLINE
255 #endif
256 int
waddch_literal(WINDOW * win,NCURSES_CH_T ch)257 waddch_literal(WINDOW *win, NCURSES_CH_T ch)
258 {
259     int x;
260     int y;
261     struct ldat *line;
262 
263     x = win->_curx;
264     y = win->_cury;
265 
266     CHECK_POSITION(win, x, y);
267 
268     ch = render_char(win, ch);
269 
270     line = win->_line + y;
271 
272     CHANGED_CELL(line, x);
273 
274     /*
275      * Build up multibyte characters until we have a wide-character.
276      */
277 #if NCURSES_SP_FUNCS
278 #define DeriveSP() SCREEN *sp = _nc_screen_of(win);
279 #else
280 #define DeriveSP()		/*nothing */
281 #endif
282     if_WIDEC({
283 	DeriveSP();
284 	if (WINDOW_EXT(win, addch_used) != 0 || !Charable(ch)) {
285 	    int len = _nc_build_wch(win, CHREF(ch));
286 
287 	    if (len >= -1) {
288 		attr_t attr = AttrOf(ch);
289 
290 		/* handle EILSEQ (i.e., when len >= -1) */
291 		if (len == -1 && is8bits(CharOf(ch))) {
292 		    const char *s = NCURSES_SP_NAME(unctrl)
293 		      (NCURSES_SP_ARGx (chtype) CharOf(ch));
294 
295 		    if (s[1] != '\0') {
296 			int rc = OK;
297 			while (*s != '\0') {
298 			    rc = waddch(win, UChar(*s) | attr);
299 			    if (rc != OK)
300 				break;
301 			    ++s;
302 			}
303 			return rc;
304 		    }
305 		}
306 		if (len == -1)
307 		    return waddch(win, ' ' | attr);
308 	    } else {
309 		return OK;
310 	    }
311 	}
312     });
313 
314     /*
315      * Non-spacing characters are added to the current cell.
316      *
317      * Spacing characters that are wider than one column require some display
318      * adjustments.
319      */
320     if_WIDEC({
321 	int len = _nc_wacs_width(CharOf(ch));
322 	int i;
323 	int j;
324 	wchar_t *chars;
325 
326 	if (len == 0) {		/* non-spacing */
327 	    if ((x > 0 && y >= 0)
328 		|| (win->_maxx >= 0 && win->_cury >= 1)) {
329 		if (x > 0 && y >= 0)
330 		    chars = (win->_line[y].text[x - 1].chars);
331 		else
332 		    chars = (win->_line[y - 1].text[win->_maxx].chars);
333 		for (i = 0; i < CCHARW_MAX; ++i) {
334 		    if (chars[i] == 0) {
335 			TR(TRACE_VIRTPUT,
336 			   ("added non-spacing %d: %x",
337 			    x, (int) CharOf(ch)));
338 			chars[i] = CharOf(ch);
339 			break;
340 		    }
341 		}
342 	    }
343 	    goto testwrapping;
344 	} else if (len > 1) {	/* multi-column characters */
345 	    /*
346 	     * Check if the character will fit on the current line.  If it does
347 	     * not fit, fill in the remainder of the line with blanks.  and
348 	     * move to the next line.
349 	     */
350 	    if (len > win->_maxx + 1) {
351 		TR(TRACE_VIRTPUT, ("character will not fit"));
352 		return ERR;
353 	    } else if (x + len > win->_maxx + 1) {
354 		int count = win->_maxx + 1 - x;
355 		TR(TRACE_VIRTPUT, ("fill %d remaining cells", count));
356 		fill_cells(win, count);
357 		if (wrap_to_next_line(win) == ERR)
358 		    return ERR;
359 		x = win->_curx;
360 		y = win->_cury;
361 		CHECK_POSITION(win, x, y);
362 		line = win->_line + y;
363 	    }
364 	    /*
365 	     * Check for cells which are orphaned by adding this character, set
366 	     * those to blanks.
367 	     *
368 	     * FIXME: this actually could fill j-i cells, more complicated to
369 	     * setup though.
370 	     */
371 	    for (i = 0; i < len; ++i) {
372 		if (isWidecBase(win->_line[y].text[x + i])) {
373 		    break;
374 		} else if (isWidecExt(win->_line[y].text[x + i])) {
375 		    for (j = i; x + j <= win->_maxx; ++j) {
376 			if (!isWidecExt(win->_line[y].text[x + j])) {
377 			    TR(TRACE_VIRTPUT, ("fill %d orphan cells", j));
378 			    fill_cells(win, j);
379 			    break;
380 			}
381 		    }
382 		    break;
383 		}
384 	    }
385 	    /*
386 	     * Finally, add the cells for this character.
387 	     */
388 	    for (i = 0; i < len; ++i) {
389 		NCURSES_CH_T value = ch;
390 		SetWidecExt(value, i);
391 		TR(TRACE_VIRTPUT, ("multicolumn %d:%d (%d,%d)",
392 				   i + 1, len,
393 				   win->_begy + y, win->_begx + x));
394 		line->text[x] = value;
395 		CHANGED_CELL(line, x);
396 		++x;
397 	    }
398 	    goto testwrapping;
399 	}
400     });
401 
402     /*
403      * Single-column characters.
404      */
405     line->text[x++] = ch;
406     /*
407      * This label is used only for wide-characters.
408      */
409     if_WIDEC(
410   testwrapping:
411     );
412 
413     TR(TRACE_VIRTPUT, ("cell (%ld, %ld..%d) = %s",
414 		       (long) win->_cury, (long) win->_curx, x - 1,
415 		       _tracech_t(CHREF(ch))));
416 
417     if (x > win->_maxx) {
418 	return wrap_to_next_line(win);
419     }
420     win->_curx = (NCURSES_SIZE_T) x;
421     return OK;
422 }
423 
424 static NCURSES_INLINE int
waddch_nosync(WINDOW * win,const NCURSES_CH_T ch)425 waddch_nosync(WINDOW *win, const NCURSES_CH_T ch)
426 /* the workhorse function -- add a character to the given window */
427 {
428     NCURSES_SIZE_T x, y;
429     chtype t = (chtype) CharOf(ch);
430 #if USE_WIDEC_SUPPORT || NCURSES_SP_FUNCS || USE_REENTRANT
431     SCREEN *sp = _nc_screen_of(win);
432 #endif
433     const char *s = NCURSES_SP_NAME(unctrl) (NCURSES_SP_ARGx t);
434     int tabsize = 8;
435 
436     /*
437      * If we are using the alternate character set, forget about locale.
438      * Otherwise, if unctrl() returns a single-character or the locale
439      * claims the code is printable (and not also a control character),
440      * treat it that way.
441      */
442     if ((AttrOf(ch) & A_ALTCHARSET)
443 	|| (
444 #if USE_WIDEC_SUPPORT
445 	       (sp != 0 && sp->_legacy_coding) &&
446 #endif
447 	       s[1] == 0
448 	)
449 	|| (
450 	       (isprint((int) t) && !iscntrl((int) t))
451 #if USE_WIDEC_SUPPORT
452 	       || ((sp == 0 || !sp->_legacy_coding) &&
453 		   (WINDOW_EXT(win, addch_used)
454 		    || !_nc_is_charable(CharOf(ch))))
455 #endif
456 	)) {
457 	return waddch_literal(win, ch);
458     }
459 
460     /*
461      * Handle carriage control and other codes that are not printable, or are
462      * known to expand to more than one character according to unctrl().
463      */
464     x = win->_curx;
465     y = win->_cury;
466     CHECK_POSITION(win, x, y);
467 
468     switch (t) {
469     case '\t':
470 #if USE_REENTRANT
471 	tabsize = *ptrTabsize(sp);
472 #else
473 	tabsize = TABSIZE;
474 #endif
475 	x = (NCURSES_SIZE_T) (x + (tabsize - (x % tabsize)));
476 	/*
477 	 * Space-fill the tab on the bottom line so that we'll get the
478 	 * "correct" cursor position.
479 	 */
480 	if ((!win->_scroll && (y == win->_regbottom))
481 	    || (x <= win->_maxx)) {
482 	    NCURSES_CH_T blank = blankchar;
483 	    AddAttr(blank, AttrOf(ch));
484 	    while (win->_curx < x) {
485 		if (waddch_literal(win, blank) == ERR)
486 		    return (ERR);
487 	    }
488 	    break;
489 	} else {
490 	    wclrtoeol(win);
491 	    win->_flags |= _WRAPPED;
492 	    if (newline_forces_scroll(win, &y)) {
493 		x = win->_maxx;
494 		if (win->_scroll) {
495 		    scroll(win);
496 		    x = 0;
497 		}
498 	    } else {
499 		x = 0;
500 	    }
501 	}
502 	break;
503     case '\n':
504 	wclrtoeol(win);
505 	if (newline_forces_scroll(win, &y)) {
506 	    if (win->_scroll)
507 		scroll(win);
508 	    else
509 		return (ERR);
510 	}
511 	/* FALLTHRU */
512     case '\r':
513 	x = 0;
514 	win->_flags &= ~_WRAPPED;
515 	break;
516     case '\b':
517 	if (x == 0)
518 	    return (OK);
519 	x--;
520 	win->_flags &= ~_WRAPPED;
521 	break;
522     default:
523 	while (*s) {
524 	    NCURSES_CH_T sch;
525 	    SetChar(sch, UChar(*s++), AttrOf(ch));
526 	    if_EXT_COLORS(SetPair(sch, GetPair(ch)));
527 	    if (waddch_literal(win, sch) == ERR)
528 		return ERR;
529 	}
530 	return (OK);
531     }
532 
533     win->_curx = x;
534     win->_cury = y;
535 
536     return (OK);
537 }
538 
539 NCURSES_EXPORT(int)
_nc_waddch_nosync(WINDOW * win,const NCURSES_CH_T c)540 _nc_waddch_nosync(WINDOW *win, const NCURSES_CH_T c)
541 /* export copy of waddch_nosync() so the string-put functions can use it */
542 {
543     return (waddch_nosync(win, c));
544 }
545 
546 /*
547  * The versions below call _nc_synchook().  We wanted to avoid this in the
548  * version exported for string puts; they'll call _nc_synchook once at end
549  * of run.
550  */
551 
552 /* These are actual entry points */
553 
554 NCURSES_EXPORT(int)
waddch(WINDOW * win,const chtype ch)555 waddch(WINDOW *win, const chtype ch)
556 {
557     int code = ERR;
558     NCURSES_CH_T wch;
559     SetChar2(wch, ch);
560 
561     TR(TRACE_VIRTPUT | TRACE_CCALLS, (T_CALLED("waddch(%p, %s)"), (void *) win,
562 				      _tracechtype(ch)));
563 
564     if (win && (waddch_nosync(win, wch) != ERR)) {
565 	_nc_synchook(win);
566 	code = OK;
567     }
568 
569     TR(TRACE_VIRTPUT | TRACE_CCALLS, (T_RETURN("%d"), code));
570     return (code);
571 }
572 
573 NCURSES_EXPORT(int)
wechochar(WINDOW * win,const chtype ch)574 wechochar(WINDOW *win, const chtype ch)
575 {
576     int code = ERR;
577     NCURSES_CH_T wch;
578     SetChar2(wch, ch);
579 
580     TR(TRACE_VIRTPUT | TRACE_CCALLS, (T_CALLED("wechochar(%p, %s)"),
581 				      (void *) win,
582 				      _tracechtype(ch)));
583 
584     if (win && (waddch_nosync(win, wch) != ERR)) {
585 	bool save_immed = win->_immed;
586 	win->_immed = TRUE;
587 	_nc_synchook(win);
588 	win->_immed = save_immed;
589 	code = OK;
590     }
591     TR(TRACE_VIRTPUT | TRACE_CCALLS, (T_RETURN("%d"), code));
592     return (code);
593 }
594