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28 
29 /*
30 **	lib_addch.c
31 **
32 **	The routine waddch().
33 **
34 */
35 
36 #include <curses.priv.h>
37 #include <ctype.h>
38 
39 MODULE_ID("$Id: lib_addch.c,v 1.113 2008/08/16 19:20:04 tom Exp $")
40 
41 static const NCURSES_CH_T blankchar = NewChar(BLANK_TEXT);
42 
43 /*
44  * Ugly microtweaking alert.  Everything from here to end of module is
45  * likely to be speed-critical -- profiling data sure says it is!
46  * Most of the important screen-painting functions are shells around
47  * waddch().  So we make every effort to reduce function-call overhead
48  * by inlining stuff, even at the cost of making wrapped copies for
49  * export.  Also we supply some internal versions that don't call the
50  * window sync hook, for use by string-put functions.
51  */
52 
53 /* Return bit mask for clearing color pair number if given ch has color */
54 #define COLOR_MASK(ch) (~(attr_t)((ch) & A_COLOR ? A_COLOR : 0))
55 
56 static NCURSES_INLINE NCURSES_CH_T
57 render_char(WINDOW *win, NCURSES_CH_T ch)
58 /* compute a rendition of the given char correct for the current context */
59 {
60     attr_t a = WINDOW_ATTRS(win);
61     int pair = GetPair(ch);
62 
63     if (ISBLANK(ch)
64 	&& AttrOf(ch) == A_NORMAL
65 	&& pair == 0) {
66 	/* color/pair in attrs has precedence over bkgrnd */
67 	ch = win->_nc_bkgd;
68 	SetAttr(ch, a | AttrOf(win->_nc_bkgd));
69 	if ((pair = GET_WINDOW_PAIR(win)) == 0)
70 	    pair = GetPair(win->_nc_bkgd);
71 	SetPair(ch, pair);
72     } else {
73 	/* color in attrs has precedence over bkgrnd */
74 	a |= AttrOf(win->_nc_bkgd) & COLOR_MASK(a);
75 	/* color in ch has precedence */
76 	if (pair == 0) {
77 	    if ((pair = GET_WINDOW_PAIR(win)) == 0)
78 		pair = GetPair(win->_nc_bkgd);
79 	}
80 #if 0
81 	if (pair > 255) {
82 	    NCURSES_CH_T fixme = ch;
83 	    SetPair(fixme, pair);
84 	}
85 #endif
86 	AddAttr(ch, (a & COLOR_MASK(AttrOf(ch))));
87 	SetPair(ch, pair);
88     }
89 
90     TR(TRACE_VIRTPUT,
91        ("render_char bkg %s (%d), attrs %s (%d) -> ch %s (%d)",
92 	_tracech_t2(1, CHREF(win->_nc_bkgd)),
93 	GetPair(win->_nc_bkgd),
94 	_traceattr(WINDOW_ATTRS(win)),
95 	GET_WINDOW_PAIR(win),
96 	_tracech_t2(3, CHREF(ch)),
97 	GetPair(ch)));
98 
99     return (ch);
100 }
101 
102 NCURSES_EXPORT(NCURSES_CH_T)
103 _nc_render(WINDOW *win, NCURSES_CH_T ch)
104 /* make render_char() visible while still allowing us to inline it below */
105 {
106     return render_char(win, ch);
107 }
108 
109 /* check if position is legal; if not, return error */
110 #ifndef NDEBUG			/* treat this like an assertion */
111 #define CHECK_POSITION(win, x, y) \
112 	if (y > win->_maxy \
113 	 || x > win->_maxx \
114 	 || y < 0 \
115 	 || x < 0) { \
116 		TR(TRACE_VIRTPUT, ("Alert! Win=%p _curx = %d, _cury = %d " \
117 				   "(_maxx = %d, _maxy = %d)", win, x, y, \
118 				   win->_maxx, win->_maxy)); \
119 		return(ERR); \
120 	}
121 #else
122 #define CHECK_POSITION(win, x, y)	/* nothing */
123 #endif
124 
125 static bool
126 newline_forces_scroll(WINDOW *win, NCURSES_SIZE_T * ypos)
127 {
128     bool result = FALSE;
129 
130     if (*ypos >= win->_regtop && *ypos == win->_regbottom) {
131 	*ypos = win->_regbottom;
132 	result = TRUE;
133     } else {
134 	*ypos += 1;
135     }
136     return result;
137 }
138 
139 /*
140  * The _WRAPPED flag is useful only for telling an application that we've just
141  * wrapped the cursor.  We don't do anything with this flag except set it when
142  * wrapping, and clear it whenever we move the cursor.  If we try to wrap at
143  * the lower-right corner of a window, we cannot move the cursor (since that
144  * wouldn't be legal).  So we return an error (which is what SVr4 does).
145  * Unlike SVr4, we can successfully add a character to the lower-right corner
146  * (Solaris 2.6 does this also, however).
147  */
148 static int
149 wrap_to_next_line(WINDOW *win)
150 {
151     win->_flags |= _WRAPPED;
152     if (newline_forces_scroll(win, &(win->_cury))) {
153 	win->_curx = win->_maxx;
154 	if (!win->_scroll)
155 	    return (ERR);
156 	scroll(win);
157     }
158     win->_curx = 0;
159     return (OK);
160 }
161 
162 #if USE_WIDEC_SUPPORT
163 static int waddch_literal(WINDOW *, NCURSES_CH_T);
164 /*
165  * Fill the given number of cells with blanks using the current background
166  * rendition.  This saves/restores the current x-position.
167  */
168 static void
169 fill_cells(WINDOW *win, int count)
170 {
171     NCURSES_CH_T blank = blankchar;
172     int save_x = win->_curx;
173     int save_y = win->_cury;
174 
175     while (count-- > 0) {
176 	if (waddch_literal(win, blank) == ERR)
177 	    break;
178     }
179     win->_curx = save_x;
180     win->_cury = save_y;
181 }
182 #endif
183 
184 /*
185  * Build up the bytes for a multibyte character, returning the length when
186  * complete (a positive number), -1 for error and -2 for incomplete.
187  */
188 #if USE_WIDEC_SUPPORT
189 NCURSES_EXPORT(int)
190 _nc_build_wch(WINDOW *win, ARG_CH_T ch)
191 {
192     char *buffer = WINDOW_EXT(win, addch_work);
193     int len;
194     int x = win->_curx;
195     int y = win->_cury;
196     mbstate_t state;
197     wchar_t result;
198 
199     if ((WINDOW_EXT(win, addch_used) != 0) &&
200 	(WINDOW_EXT(win, addch_x) != x ||
201 	 WINDOW_EXT(win, addch_y) != y)) {
202 	/* discard the incomplete multibyte character */
203 	WINDOW_EXT(win, addch_used) = 0;
204 	TR(TRACE_VIRTPUT,
205 	   ("Alert discarded multibyte on move (%d,%d) -> (%d,%d)",
206 	    WINDOW_EXT(win, addch_y), WINDOW_EXT(win, addch_x),
207 	    y, x));
208     }
209     WINDOW_EXT(win, addch_x) = x;
210     WINDOW_EXT(win, addch_y) = y;
211 
212     init_mb(state);
213     buffer[WINDOW_EXT(win, addch_used)] = (char) CharOf(CHDEREF(ch));
214     WINDOW_EXT(win, addch_used) += 1;
215     buffer[WINDOW_EXT(win, addch_used)] = '\0';
216     if ((len = mbrtowc(&result,
217 		       buffer,
218 		       WINDOW_EXT(win, addch_used), &state)) > 0) {
219 	attr_t attrs = AttrOf(CHDEREF(ch));
220 	if_EXT_COLORS(int pair = GetPair(CHDEREF(ch)));
221 	SetChar(CHDEREF(ch), result, attrs);
222 	if_EXT_COLORS(SetPair(CHDEREF(ch), pair));
223 	WINDOW_EXT(win, addch_used) = 0;
224     } else if (len == -1) {
225 	/*
226 	 * An error occurred.  We could either discard everything,
227 	 * or assume that the error was in the previous input.
228 	 * Try the latter.
229 	 */
230 	TR(TRACE_VIRTPUT, ("Alert! mbrtowc returns error"));
231 	/* handle this with unctrl() */
232 	WINDOW_EXT(win, addch_used) = 0;
233     }
234     return len;
235 }
236 #endif /* USE_WIDEC_SUPPORT */
237 
238 static
239 #if !USE_WIDEC_SUPPORT		/* cannot be inline if it is recursive */
240 NCURSES_INLINE
241 #endif
242 int
243 waddch_literal(WINDOW *win, NCURSES_CH_T ch)
244 {
245     int x;
246     int y;
247     struct ldat *line;
248 
249     x = win->_curx;
250     y = win->_cury;
251 
252     CHECK_POSITION(win, x, y);
253 
254     ch = render_char(win, ch);
255 
256     line = win->_line + y;
257 
258     CHANGED_CELL(line, x);
259 
260     /*
261      * Build up multibyte characters until we have a wide-character.
262      */
263     if_WIDEC({
264 	if (WINDOW_EXT(win, addch_used) != 0 || !Charable(ch)) {
265 	    int len = _nc_build_wch(win, CHREF(ch));
266 
267 	    if (len >= -1) {
268 		/* handle EILSEQ */
269 		if (is8bits(CharOf(ch))) {
270 		    const char *s = unctrl((chtype) CharOf(ch));
271 		    if (s[1] != 0) {
272 			return waddstr(win, s);
273 		    }
274 		}
275 		if (len == -1)
276 		    return waddch(win, ' ');
277 	    } else {
278 		return OK;
279 	    }
280 	}
281     });
282 
283     /*
284      * Non-spacing characters are added to the current cell.
285      *
286      * Spacing characters that are wider than one column require some display
287      * adjustments.
288      */
289     if_WIDEC({
290 	int len = wcwidth(CharOf(ch));
291 	int i;
292 	int j;
293 	wchar_t *chars;
294 
295 	if (len == 0) {		/* non-spacing */
296 	    if ((x > 0 && y >= 0)
297 		|| (win->_maxx >= 0 && win->_cury >= 1)) {
298 		if (x > 0 && y >= 0)
299 		    chars = (win->_line[y].text[x - 1].chars);
300 		else
301 		    chars = (win->_line[y - 1].text[win->_maxx].chars);
302 		for (i = 0; i < CCHARW_MAX; ++i) {
303 		    if (chars[i] == 0) {
304 			TR(TRACE_VIRTPUT,
305 			   ("added non-spacing %d: %x",
306 			    x, (int) CharOf(ch)));
307 			chars[i] = CharOf(ch);
308 			break;
309 		    }
310 		}
311 	    }
312 	    goto testwrapping;
313 	} else if (len > 1) {	/* multi-column characters */
314 	    /*
315 	     * Check if the character will fit on the current line.  If it does
316 	     * not fit, fill in the remainder of the line with blanks.  and
317 	     * move to the next line.
318 	     */
319 	    if (len > win->_maxx + 1) {
320 		TR(TRACE_VIRTPUT, ("character will not fit"));
321 		return ERR;
322 	    } else if (x + len > win->_maxx + 1) {
323 		int count = win->_maxx + 1 - x;
324 		TR(TRACE_VIRTPUT, ("fill %d remaining cells", count));
325 		fill_cells(win, count);
326 		if (wrap_to_next_line(win) == ERR)
327 		    return ERR;
328 		x = win->_curx;
329 		y = win->_cury;
330 	    }
331 	    /*
332 	     * Check for cells which are orphaned by adding this character, set
333 	     * those to blanks.
334 	     *
335 	     * FIXME: this actually could fill j-i cells, more complicated to
336 	     * setup though.
337 	     */
338 	    for (i = 0; i < len; ++i) {
339 		if (isWidecBase(win->_line[y].text[x + i])) {
340 		    break;
341 		} else if (isWidecExt(win->_line[y].text[x + i])) {
342 		    for (j = i; x + j <= win->_maxx; ++j) {
343 			if (!isWidecExt(win->_line[y].text[x + j])) {
344 			    TR(TRACE_VIRTPUT, ("fill %d orphan cells", j));
345 			    fill_cells(win, j);
346 			    break;
347 			}
348 		    }
349 		    break;
350 		}
351 	    }
352 	    /*
353 	     * Finally, add the cells for this character.
354 	     */
355 	    for (i = 0; i < len; ++i) {
356 		NCURSES_CH_T value = ch;
357 		SetWidecExt(value, i);
358 		TR(TRACE_VIRTPUT, ("multicolumn %d:%d (%d,%d)",
359 				   i + 1, len,
360 				   win->_begy + y, win->_begx + x));
361 		line->text[x] = value;
362 		CHANGED_CELL(line, x);
363 		++x;
364 	    }
365 	    goto testwrapping;
366 	}
367     });
368 
369     /*
370      * Single-column characters.
371      */
372     line->text[x++] = ch;
373     /*
374      * This label is used only for wide-characters.
375      */
376     if_WIDEC(
377   testwrapping:
378     );
379 
380     TR(TRACE_VIRTPUT, ("cell (%ld, %ld..%d) = %s",
381 		       (long) win->_cury, (long) win->_curx, x - 1,
382 		       _tracech_t(CHREF(ch))));
383 
384     if (x > win->_maxx) {
385 	return wrap_to_next_line(win);
386     }
387     win->_curx = x;
388     return OK;
389 }
390 
391 static NCURSES_INLINE int
392 waddch_nosync(WINDOW *win, const NCURSES_CH_T ch)
393 /* the workhorse function -- add a character to the given window */
394 {
395     NCURSES_SIZE_T x, y;
396     chtype t = CharOf(ch);
397     const char *s = unctrl(t);
398 
399     /*
400      * If we are using the alternate character set, forget about locale.
401      * Otherwise, if unctrl() returns a single-character or the locale
402      * claims the code is printable, treat it that way.
403      */
404     if ((AttrOf(ch) & A_ALTCHARSET)
405 	|| (
406 #if USE_WIDEC_SUPPORT
407 	       (SP != 0 && SP->_legacy_coding) &&
408 #endif
409 	       s[1] == 0
410 	)
411 	|| (
412 	       isprint(t)
413 #if USE_WIDEC_SUPPORT
414 	       || ((SP == 0 || !SP->_legacy_coding) &&
415 		   (WINDOW_EXT(win, addch_used)
416 		    || !_nc_is_charable(CharOf(ch))))
417 #endif
418 	))
419 	return waddch_literal(win, ch);
420 
421     /*
422      * Handle carriage control and other codes that are not printable, or are
423      * known to expand to more than one character according to unctrl().
424      */
425     x = win->_curx;
426     y = win->_cury;
427 
428     switch (t) {
429     case '\t':
430 	x += (TABSIZE - (x % TABSIZE));
431 
432 	/*
433 	 * Space-fill the tab on the bottom line so that we'll get the
434 	 * "correct" cursor position.
435 	 */
436 	if ((!win->_scroll && (y == win->_regbottom))
437 	    || (x <= win->_maxx)) {
438 	    NCURSES_CH_T blank = blankchar;
439 	    AddAttr(blank, AttrOf(ch));
440 	    while (win->_curx < x) {
441 		if (waddch_literal(win, blank) == ERR)
442 		    return (ERR);
443 	    }
444 	    break;
445 	} else {
446 	    wclrtoeol(win);
447 	    win->_flags |= _WRAPPED;
448 	    if (newline_forces_scroll(win, &y)) {
449 		x = win->_maxx;
450 		if (win->_scroll) {
451 		    scroll(win);
452 		    x = 0;
453 		}
454 	    } else {
455 		x = 0;
456 	    }
457 	}
458 	break;
459     case '\n':
460 	wclrtoeol(win);
461 	if (newline_forces_scroll(win, &y)) {
462 	    if (win->_scroll)
463 		scroll(win);
464 	    else
465 		return (ERR);
466 	}
467 	/* FALLTHRU */
468     case '\r':
469 	x = 0;
470 	win->_flags &= ~_WRAPPED;
471 	break;
472     case '\b':
473 	if (x == 0)
474 	    return (OK);
475 	x--;
476 	win->_flags &= ~_WRAPPED;
477 	break;
478     default:
479 	while (*s) {
480 	    NCURSES_CH_T sch;
481 	    SetChar(sch, *s++, AttrOf(ch));
482 	    if_EXT_COLORS(SetPair(sch, GetPair(ch)));
483 	    if (waddch_literal(win, sch) == ERR)
484 		return ERR;
485 	}
486 	return (OK);
487     }
488 
489     win->_curx = x;
490     win->_cury = y;
491 
492     return (OK);
493 }
494 
495 NCURSES_EXPORT(int)
496 _nc_waddch_nosync(WINDOW *win, const NCURSES_CH_T c)
497 /* export copy of waddch_nosync() so the string-put functions can use it */
498 {
499     return (waddch_nosync(win, c));
500 }
501 
502 /*
503  * The versions below call _nc_synchook().  We wanted to avoid this in the
504  * version exported for string puts; they'll call _nc_synchook once at end
505  * of run.
506  */
507 
508 /* These are actual entry points */
509 
510 NCURSES_EXPORT(int)
511 waddch(WINDOW *win, const chtype ch)
512 {
513     int code = ERR;
514     NCURSES_CH_T wch;
515     SetChar2(wch, ch);
516 
517     TR(TRACE_VIRTPUT | TRACE_CCALLS, (T_CALLED("waddch(%p, %s)"), win,
518 				      _tracechtype(ch)));
519 
520     if (win && (waddch_nosync(win, wch) != ERR)) {
521 	_nc_synchook(win);
522 	code = OK;
523     }
524 
525     TR(TRACE_VIRTPUT | TRACE_CCALLS, (T_RETURN("%d"), code));
526     return (code);
527 }
528 
529 NCURSES_EXPORT(int)
530 wechochar(WINDOW *win, const chtype ch)
531 {
532     int code = ERR;
533     NCURSES_CH_T wch;
534     SetChar2(wch, ch);
535 
536     TR(TRACE_VIRTPUT | TRACE_CCALLS, (T_CALLED("wechochar(%p, %s)"), win,
537 				      _tracechtype(ch)));
538 
539     if (win && (waddch_nosync(win, wch) != ERR)) {
540 	bool save_immed = win->_immed;
541 	win->_immed = TRUE;
542 	_nc_synchook(win);
543 	win->_immed = save_immed;
544 	code = OK;
545     }
546     TR(TRACE_VIRTPUT | TRACE_CCALLS, (T_RETURN("%d"), code));
547     return (code);
548 }
549