xref: /freebsd/contrib/ncurses/ncurses/widechar/lib_add_wch.c (revision 21817992b3314c908ab50f0bb88d2ee750b9c4ac)
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2  * Copyright 2019-2021,2023 Thomas E. Dickey                                *
3  * Copyright 2004-2011,2016 Free Software Foundation, Inc.                  *
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29 
30 /*
31 **	lib_add_wch.c
32 **
33 **	The routine wadd_wch().
34 **
35 */
36 
37 #include <curses.priv.h>
38 
39 #if HAVE_WCTYPE_H
40 #include <wctype.h>
41 #endif
42 
43 MODULE_ID("$Id: lib_add_wch.c,v 1.18 2023/07/15 17:34:12 tom Exp $")
44 
45 /* clone/adapt lib_addch.c */
46 static const cchar_t blankchar = NewChar(BLANK_TEXT);
47 
48 /*
49  * Ugly microtweaking alert.  Everything from here to end of module is
50  * likely to be speed-critical -- profiling data sure says it is!
51  * Most of the important screen-painting functions are shells around
52  * wadd_wch().  So we make every effort to reduce function-call overhead
53  * by inlining stuff, even at the cost of making wrapped copies for
54  * export.  Also we supply some internal versions that don't call the
55  * window sync hook, for use by string-put functions.
56  */
57 
58 /* Return bit mask for clearing color pair number if given ch has color */
59 #define COLOR_MASK(ch) (~(attr_t)(((ch) & A_COLOR) ? A_COLOR : 0))
60 
61 static NCURSES_INLINE cchar_t
render_char(WINDOW * win,cchar_t ch)62 render_char(WINDOW *win, cchar_t ch)
63 /* compute a rendition of the given char correct for the current context */
64 {
65     attr_t a = WINDOW_ATTRS(win);
66     int pair = GetPair(ch);
67 
68     if (ISBLANK(ch)
69 	&& AttrOf(ch) == A_NORMAL
70 	&& pair == 0) {
71 	/* color/pair in attrs has precedence over bkgrnd */
72 	ch = win->_nc_bkgd;
73 	SetAttr(ch, a | AttrOf(win->_nc_bkgd));
74 	if ((pair = GET_WINDOW_PAIR(win)) == 0)
75 	    pair = GetPair(win->_nc_bkgd);
76 	SetPair(ch, pair);
77     } else {
78 	/* color in attrs has precedence over bkgrnd */
79 	a |= AttrOf(win->_nc_bkgd) & COLOR_MASK(a);
80 	/* color in ch has precedence */
81 	if (pair == 0) {
82 	    if ((pair = GET_WINDOW_PAIR(win)) == 0)
83 		pair = GetPair(win->_nc_bkgd);
84 	}
85 	AddAttr(ch, (a & COLOR_MASK(AttrOf(ch))));
86 	SetPair(ch, pair);
87     }
88 
89     TR(TRACE_VIRTPUT,
90        ("render_char bkg %s (%d), attrs %s (%d) -> ch %s (%d)",
91 	_tracech_t2(1, CHREF(win->_nc_bkgd)),
92 	GetPair(win->_nc_bkgd),
93 	_traceattr(WINDOW_ATTRS(win)),
94 	GET_WINDOW_PAIR(win),
95 	_tracech_t2(3, CHREF(ch)),
96 	GetPair(ch)));
97 
98     return (ch);
99 }
100 
101 /* check if position is legal; if not, return error */
102 #ifndef NDEBUG			/* treat this like an assertion */
103 #define CHECK_POSITION(win, x, y) \
104 	if (y > win->_maxy \
105 	 || x > win->_maxx \
106 	 || y < 0 \
107 	 || x < 0) { \
108 		TR(TRACE_VIRTPUT, ("Alert! Win=%p _curx = %d, _cury = %d " \
109 				   "(_maxx = %d, _maxy = %d)", win, x, y, \
110 				   win->_maxx, win->_maxy)); \
111 		return(ERR); \
112 	}
113 #else
114 #define CHECK_POSITION(win, x, y)	/* nothing */
115 #endif
116 
117 static bool
newline_forces_scroll(WINDOW * win,NCURSES_SIZE_T * ypos)118 newline_forces_scroll(WINDOW *win, NCURSES_SIZE_T *ypos)
119 {
120     bool result = FALSE;
121 
122     if (*ypos >= win->_regtop && *ypos == win->_regbottom) {
123 	*ypos = win->_regbottom;
124 	result = TRUE;
125     } else {
126 	*ypos = (NCURSES_SIZE_T) (*ypos + 1);
127     }
128     return result;
129 }
130 
131 /*
132  * The _WRAPPED flag is useful only for telling an application that we've just
133  * wrapped the cursor.  We don't do anything with this flag except set it when
134  * wrapping, and clear it whenever we move the cursor.  If we try to wrap at
135  * the lower-right corner of a window, we cannot move the cursor (since that
136  * wouldn't be legal).  So we return an error (which is what SVr4 does).
137  * Unlike SVr4, we can successfully add a character to the lower-right corner
138  * (Solaris 2.6 does this also, however).
139  */
140 static int
wrap_to_next_line(WINDOW * win)141 wrap_to_next_line(WINDOW *win)
142 {
143     win->_flags |= _WRAPPED;
144     if (newline_forces_scroll(win, &(win->_cury))) {
145 	win->_curx = win->_maxx;
146 	if (!win->_scroll)
147 	    return (ERR);
148 	scroll(win);
149     }
150     win->_curx = 0;
151     return (OK);
152 }
153 
154 static int wadd_wch_literal(WINDOW *, cchar_t);
155 /*
156  * Fill the given number of cells with blanks using the current background
157  * rendition.  This saves/restores the current x-position.
158  */
159 static void
fill_cells(WINDOW * win,int count)160 fill_cells(WINDOW *win, int count)
161 {
162     cchar_t blank = blankchar;
163     int save_x = win->_curx;
164     int save_y = win->_cury;
165 
166     while (count-- > 0) {
167 	if (wadd_wch_literal(win, blank) == ERR)
168 	    break;
169     }
170     win->_curx = (NCURSES_SIZE_T) save_x;
171     win->_cury = (NCURSES_SIZE_T) save_y;
172 }
173 
174 static int
wadd_wch_literal(WINDOW * win,cchar_t ch)175 wadd_wch_literal(WINDOW *win, cchar_t ch)
176 {
177     int x;
178     int y;
179     struct ldat *line;
180 
181     x = win->_curx;
182     y = win->_cury;
183 
184     CHECK_POSITION(win, x, y);
185 
186     ch = render_char(win, ch);
187 
188     line = win->_line + y;
189 
190     CHANGED_CELL(line, x);
191 
192     /*
193      * Non-spacing characters are added to the current cell.
194      *
195      * Spacing characters that are wider than one column require some display
196      * adjustments.
197      */
198     {
199 	int len = _nc_wacs_width(CharOf(ch));
200 	int i;
201 	int j;
202 	wchar_t *chars;
203 
204 	if (len == 0) {		/* non-spacing */
205 	    if ((x > 0 && y >= 0)
206 		|| (win->_maxx >= 0 && win->_cury >= 1)) {
207 		if (x > 0 && y >= 0) {
208 		    for (j = x - 1; j > 0; --j) {
209 			if (!isWidecExt(win->_line[y].text[j])) {
210 			    break;
211 			}
212 		    }
213 		    chars = (win->_line[y].text[j].chars);
214 		} else {
215 		    chars = (win->_line[y - 1].text[win->_maxx].chars);
216 		}
217 		for (i = 0; i < CCHARW_MAX; ++i) {
218 		    if (chars[i] == 0) {
219 			TR(TRACE_VIRTPUT,
220 			   ("added non-spacing %d: %x",
221 			    x, (int) CharOf(ch)));
222 			chars[i] = CharOf(ch);
223 			break;
224 		    }
225 		}
226 	    }
227 	    goto testwrapping;
228 	} else if (len > 1) {	/* multi-column characters */
229 	    /*
230 	     * Check if the character will fit on the current line.  If it does
231 	     * not fit, fill in the remainder of the line with blanks.  and
232 	     * move to the next line.
233 	     */
234 	    if (len > win->_maxx + 1) {
235 		TR(TRACE_VIRTPUT, ("character will not fit"));
236 		return ERR;
237 	    } else if (x + len > win->_maxx + 1) {
238 		int count = win->_maxx + 1 - x;
239 		TR(TRACE_VIRTPUT, ("fill %d remaining cells", count));
240 		fill_cells(win, count);
241 		if (wrap_to_next_line(win) == ERR)
242 		    return ERR;
243 		x = win->_curx;
244 		y = win->_cury;
245 		line = win->_line + y;
246 	    }
247 	    /*
248 	     * Check for cells which are orphaned by adding this character, set
249 	     * those to blanks.
250 	     *
251 	     * FIXME: this actually could fill j-i cells, more complicated to
252 	     * setup though.
253 	     */
254 	    for (i = 0; i < len; ++i) {
255 		if (isWidecBase(win->_line[y].text[x + i])) {
256 		    break;
257 		} else if (isWidecExt(win->_line[y].text[x + i])) {
258 		    for (j = i; x + j <= win->_maxx; ++j) {
259 			if (!isWidecExt(win->_line[y].text[x + j])) {
260 			    TR(TRACE_VIRTPUT, ("fill %d orphan cells", j));
261 			    fill_cells(win, j);
262 			    break;
263 			}
264 		    }
265 		    break;
266 		}
267 	    }
268 	    /*
269 	     * Finally, add the cells for this character.
270 	     */
271 	    for (i = 0; i < len; ++i) {
272 		cchar_t value = ch;
273 		SetWidecExt(value, i);
274 		TR(TRACE_VIRTPUT, ("multicolumn %d:%d (%d,%d)",
275 				   i + 1, len,
276 				   win->_begy + y, win->_begx + x));
277 		line->text[x] = value;
278 		CHANGED_CELL(line, x);
279 		++x;
280 	    }
281 	    goto testwrapping;
282 	}
283     }
284 
285     /*
286      * Single-column characters.
287      */
288     line->text[x++] = ch;
289     /*
290      * This label is used only for wide-characters.
291      */
292   testwrapping:
293 
294     TR(TRACE_VIRTPUT, ("cell (%ld, %ld..%d) = %s",
295 		       (long) win->_cury, (long) win->_curx, x - 1,
296 		       _tracech_t(CHREF(ch))));
297 
298     if (x > win->_maxx) {
299 	return wrap_to_next_line(win);
300     }
301     win->_curx = (NCURSES_SIZE_T) x;
302     return OK;
303 }
304 
305 static NCURSES_INLINE int
wadd_wch_nosync(WINDOW * win,cchar_t ch)306 wadd_wch_nosync(WINDOW *win, cchar_t ch)
307 /* the workhorse function -- add a character to the given window */
308 {
309     NCURSES_SIZE_T x, y;
310     wchar_t *s;
311     int tabsize = 8;
312 #if USE_REENTRANT
313     SCREEN *sp = _nc_screen_of(win);
314 #endif
315 
316     /*
317      * If we are using the alternate character set, forget about locale.
318      * Otherwise, if the locale claims the code is printable, treat it that
319      * way.
320      */
321     if ((AttrOf(ch) & A_ALTCHARSET)
322 	|| iswprint((wint_t) CharOf(ch)))
323 	return wadd_wch_literal(win, ch);
324 
325     /*
326      * Handle carriage control and other codes that are not printable, or are
327      * known to expand to more than one character according to unctrl().
328      */
329     x = win->_curx;
330     y = win->_cury;
331 
332     switch (CharOf(ch)) {
333     case '\t':
334 #if USE_REENTRANT
335 	tabsize = *ptrTabsize(sp);
336 #else
337 	tabsize = TABSIZE;
338 #endif
339 	x = (NCURSES_SIZE_T) (x + (tabsize - (x % tabsize)));
340 	/*
341 	 * Space-fill the tab on the bottom line so that we'll get the
342 	 * "correct" cursor position.
343 	 */
344 	if ((!win->_scroll && (y == win->_regbottom))
345 	    || (x <= win->_maxx)) {
346 	    cchar_t blank = blankchar;
347 	    AddAttr(blank, AttrOf(ch));
348 	    while (win->_curx < x) {
349 		if (wadd_wch_literal(win, blank) == ERR)
350 		    return (ERR);
351 	    }
352 	    break;
353 	} else {
354 	    wclrtoeol(win);
355 	    win->_flags |= _WRAPPED;
356 	    if (newline_forces_scroll(win, &y)) {
357 		x = win->_maxx;
358 		if (win->_scroll) {
359 		    scroll(win);
360 		    x = 0;
361 		}
362 	    } else {
363 		x = 0;
364 	    }
365 	}
366 	break;
367     case '\n':
368 	wclrtoeol(win);
369 	if (newline_forces_scroll(win, &y)) {
370 	    if (win->_scroll)
371 		scroll(win);
372 	    else
373 		return (ERR);
374 	}
375 	/* FALLTHRU */
376     case '\r':
377 	x = 0;
378 	win->_flags &= ~_WRAPPED;
379 	break;
380     case '\b':
381 	if (x == 0)
382 	    return (OK);
383 	x--;
384 	win->_flags &= ~_WRAPPED;
385 	break;
386     default:
387 	if ((s = wunctrl(&ch)) != 0) {
388 	    while (*s) {
389 		cchar_t sch;
390 		SetChar(sch, *s++, AttrOf(ch));
391 		if_EXT_COLORS(SetPair(sch, GetPair(ch)));
392 		if (wadd_wch_literal(win, sch) == ERR)
393 		    return ERR;
394 	    }
395 	    return OK;
396 	}
397 	return ERR;
398     }
399 
400     win->_curx = x;
401     win->_cury = y;
402 
403     return OK;
404 }
405 
406 /*
407  * The versions below call _nc_synchook().  We wanted to avoid this in the
408  * version exported for string puts; they'll call _nc_synchook once at end
409  * of run.
410  */
411 
412 /* These are actual entry points */
413 
414 NCURSES_EXPORT(int)
wadd_wch(WINDOW * win,const cchar_t * wch)415 wadd_wch(WINDOW *win, const cchar_t *wch)
416 {
417     int code = ERR;
418 
419     TR(TRACE_VIRTPUT | TRACE_CCALLS, (T_CALLED("wadd_wch(%p, %s)"),
420 				      (void *) win,
421 				      _tracecchar_t(wch)));
422 
423     if (win && (wadd_wch_nosync(win, *wch) != ERR)) {
424 	_nc_synchook(win);
425 	code = OK;
426     }
427 
428     TR(TRACE_VIRTPUT | TRACE_CCALLS, (T_RETURN("%d"), code));
429     return (code);
430 }
431 
432 NCURSES_EXPORT(int)
wecho_wchar(WINDOW * win,const cchar_t * wch)433 wecho_wchar(WINDOW *win, const cchar_t *wch)
434 {
435     int code = ERR;
436 
437     TR(TRACE_VIRTPUT | TRACE_CCALLS, (T_CALLED("wechochar(%p, %s)"),
438 				      (void *) win,
439 				      _tracecchar_t(wch)));
440 
441     if (win && (wadd_wch_nosync(win, *wch) != ERR)) {
442 	bool save_immed = win->_immed;
443 	win->_immed = TRUE;
444 	_nc_synchook(win);
445 	win->_immed = save_immed;
446 	code = OK;
447     }
448     TR(TRACE_VIRTPUT | TRACE_CCALLS, (T_RETURN("%d"), code));
449     return (code);
450 }
451