xref: /freebsd/contrib/dialog/calendar.c (revision f7c32ed617858bcd22f8d1b03199099d50125721)
1 /*
2  * $Id: calendar.c,v 1.106 2020/11/23 09:03:49 tom Exp $
3  *
4  *  calendar.c -- implements the calendar box
5  *
6  *  Copyright 2001-2019,2020	Thomas E. Dickey
7  *
8  *  This program is free software; you can redistribute it and/or modify
9  *  it under the terms of the GNU Lesser General Public License, version 2.1
10  *  as published by the Free Software Foundation.
11  *
12  *  This program is distributed in the hope that it will be useful, but
13  *  WITHOUT ANY WARRANTY; without even the implied warranty of
14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  *  Lesser General Public License for more details.
16  *
17  *  You should have received a copy of the GNU Lesser General Public
18  *  License along with this program; if not, write to
19  *	Free Software Foundation, Inc.
20  *	51 Franklin St., Fifth Floor
21  *	Boston, MA 02110, USA.
22  */
23 
24 #include <dlg_internals.h>
25 #include <dlg_keys.h>
26 
27 #include <time.h>
28 
29 #ifdef HAVE_STDINT_H
30 #include <stdint.h>
31 #else
32 #define intptr_t long
33 #endif
34 
35 #define ONE_DAY  (60 * 60 * 24)
36 
37 #define MON_WIDE 4		/* width of a month-name */
38 #define DAY_HIGH 6		/* maximum lines in day-grid */
39 #define DAY_WIDE (8 * MON_WIDE)	/* width of the day-grid */
40 #define HDR_HIGH 1		/* height of cells with month/year */
41 #define BTN_HIGH 1		/* height of button-row excluding margin */
42 
43 /* two more lines: titles for day-of-week and month/year boxes */
44 #define MIN_HIGH (DAY_HIGH + 2 + HDR_HIGH + BTN_HIGH + (MAX_DAYS * MARGIN))
45 #define MIN_WIDE (DAY_WIDE + (4 * MARGIN))
46 
47 typedef enum {
48     sMONTH = -3
49     ,sYEAR = -2
50     ,sDAY = -1
51 } STATES;
52 
53 struct _box;
54 
55 typedef int (*BOX_DRAW) (struct _box *, struct tm *);
56 
57 typedef struct _box {
58     WINDOW *parent;
59     WINDOW *window;
60     int x;
61     int y;
62     int width;
63     int height;
64     BOX_DRAW box_draw;
65     int week_start;
66 } BOX;
67 
68 #define MAX_DAYS 7
69 #define MAX_MONTHS 12
70 
71 static char *cached_days[MAX_DAYS];
72 static char *cached_months[MAX_MONTHS];
73 
74 static const char *
75 nameOfDayOfWeek(int n)
76 {
77     static bool shown[MAX_DAYS];
78 
79     while (n < 0) {
80 	n += MAX_DAYS;
81     }
82     n %= MAX_DAYS;
83 #ifdef ENABLE_NLS
84     if (cached_days[n] == 0) {
85 	const nl_item items[MAX_DAYS] =
86 	{
87 	    ABDAY_1, ABDAY_2, ABDAY_3, ABDAY_4, ABDAY_5, ABDAY_6, ABDAY_7
88 	};
89 	cached_days[n] = dlg_strclone(nl_langinfo(items[n]));
90 	memset(shown, 0, sizeof(shown));
91     }
92 #endif
93     if (cached_days[n] == 0) {
94 	static const char *posix_days[MAX_DAYS] =
95 	{
96 	    "Sunday",
97 	    "Monday",
98 	    "Tuesday",
99 	    "Wednesday",
100 	    "Thursday",
101 	    "Friday",
102 	    "Saturday"
103 	};
104 	size_t limit = MON_WIDE - 1;
105 	char *value = dlg_strclone(posix_days[n]);
106 
107 	/*
108 	 * POSIX does not actually say what the length of an abbreviated name
109 	 * is.  Typically it is 2, which will fit into our layout.  That also
110 	 * happens to work with CJK entries as seen in glibc, which are a
111 	 * double-width cell.  For now (2016/01/26), handle too-long names only
112 	 * for POSIX values.
113 	 */
114 	if (strlen(value) > limit)
115 	    value[limit] = '\0';
116 	cached_days[n] = value;
117     }
118     if (!shown[n]) {
119 	DLG_TRACE(("# DAY(%d) = '%s'\n", n, cached_days[n]));
120 	shown[n] = TRUE;
121     }
122     return cached_days[n];
123 }
124 
125 static const char *
126 nameOfMonth(int n)
127 {
128     static bool shown[MAX_MONTHS];
129 
130     while (n < 0) {
131 	n += MAX_MONTHS;
132     }
133     n %= MAX_MONTHS;
134 #ifdef ENABLE_NLS
135     if (cached_months[n] == 0) {
136 	const nl_item items[MAX_MONTHS] =
137 	{
138 	    MON_1, MON_2, MON_3, MON_4, MON_5, MON_6,
139 	    MON_7, MON_8, MON_9, MON_10, MON_11, MON_12
140 	};
141 	cached_months[n] = dlg_strclone(nl_langinfo(items[n]));
142 	memset(shown, 0, sizeof(shown));
143     }
144 #endif
145     if (cached_months[n] == 0) {
146 	static const char *posix_mons[MAX_MONTHS] =
147 	{
148 	    "January",
149 	    "February",
150 	    "March",
151 	    "April",
152 	    "May",
153 	    "June",
154 	    "July",
155 	    "August",
156 	    "September",
157 	    "October",
158 	    "November",
159 	    "December"
160 	};
161 	cached_months[n] = dlg_strclone(posix_mons[n]);
162     }
163     if (!shown[n]) {
164 	DLG_TRACE(("# MON(%d) = '%s'\n", n, cached_months[n]));
165 	shown[n] = TRUE;
166     }
167     return cached_months[n];
168 }
169 
170 /*
171  * Algorithm for Gregorian calendar.
172  */
173 static int
174 isleap(int y)
175 {
176     return ((y % 4 == 0) &&
177 	    ((y % 100 != 0) ||
178 	     (y % 400 == 0))) ? 1 : 0;
179 }
180 
181 static void
182 adjust_year_month(int *year, int *month)
183 {
184     while (*month < 0) {
185 	*month += MAX_MONTHS;
186 	*year -= 1;
187     }
188     while (*month >= MAX_MONTHS) {
189 	*month -= MAX_MONTHS;
190 	*year += 1;
191     }
192 }
193 
194 static int
195 days_per_month(int year, int month)
196 {
197     static const int nominal[] =
198     {
199 	31, 28, 31, 30, 31, 30,
200 	31, 31, 30, 31, 30, 31
201     };
202     int result;
203 
204     adjust_year_month(&year, &month);
205     result = nominal[month];
206     if (month == 1)
207 	result += isleap(year);
208     return result;
209 }
210 
211 static int
212 days_in_month(struct tm *current, int offset /* -1, 0, 1 */ )
213 {
214     int year = current->tm_year + 1900;
215     int month = current->tm_mon + offset;
216 
217     adjust_year_month(&year, &month);
218     return days_per_month(year, month);
219 }
220 
221 static int
222 days_per_year(int year)
223 {
224     return (isleap(year) ? 366 : 365);
225 }
226 
227 static int
228 days_in_year(struct tm *current, int offset /* -1, 0, 1 */ )
229 {
230     return days_per_year(current->tm_year + 1900 + offset);
231 }
232 
233 /*
234  * Adapted from C FAQ
235  * "17.28: How can I find the day of the week given the date?"
236  * implementation by Tomohiko Sakamoto.
237  *
238  * d = day (0 to whatever)
239  * m = month (1 through 12)
240  * y = year (1752 and later, for Gregorian calendar)
241  */
242 static int
243 day_of_week(int y, int m, int d)
244 {
245     static int t[] =
246     {
247 	0, 3, 2, 5, 0, 3, 5, 1, 4, 6, 2, 4
248     };
249     y -= (m < 3);
250     return (6 + (y + (y / 4) - (y / 100) + (y / 400) + t[m - 1] + d)) % MAX_DAYS;
251 }
252 
253 static int
254 day_in_year(int year, int month, int day)
255 {
256     int result = day;
257     while (--month >= 1)
258 	result += days_per_month(year, month);
259     return result;
260 }
261 
262 static int
263 iso_week(int year, int month, int day)
264 {
265     int week = 1;
266     int dow;
267     int new_year_dow;
268     int diy;
269     int new_years_eve_dow;
270     static const int thursday = 3;
271 
272     /* add the number weeks *between* date and newyear */
273     diy = day_in_year(year, month, day);
274     week += (diy - 1) / MAX_DAYS;
275 
276     /* 0 = Monday */
277     dow = day_of_week(year, month, day);
278     new_year_dow = day_of_week(year, 1, 1);
279 
280     /*
281      * If New Year falls on Friday, Saturday or Sunday, then New Years's week
282      * is the last week of the preceding year.  In that case subtract one week.
283      */
284     if (new_year_dow > thursday)
285 	--week;
286 
287     /* Add one week if there is a Sunday to Monday transition. */
288     if (dow - new_year_dow < 0)
289 	++week;
290 
291     /* Check if we are in the last week of the preceding year. */
292     if (week < 1) {
293 	week = iso_week(--year, 12, 31);
294     }
295 
296     /*
297      * If we are in the same week as New Year's eve, check if New Year's eve is
298      * in the first week of the next year.
299      */
300     new_years_eve_dow = (new_year_dow + 364 + isleap(year)) % MAX_DAYS;
301     if (365 + isleap(year) - diy < MAX_DAYS
302 	&& new_years_eve_dow >= dow
303 	&& new_years_eve_dow < thursday) {
304 	week = 1;
305     }
306     return week;
307 }
308 
309 static int *
310 getisoweeks(int year, int month)
311 {
312     static int result[10];
313     int windx = 0;
314     int day;
315     int dpm = days_per_month(year, month);
316 
317     for (day = 1; day <= dpm; day += MAX_DAYS)
318 	result[windx++] = iso_week(year, month, day);
319     /*
320      * Ensure that there is a week number associated with the last day of the
321      * month, e.g., in case the last day of the month falls before Thursday,
322      * so that we have to show the week-number for the beginning of the
323      * following month.
324      */
325     result[windx] = iso_week(year, month, dpm);
326     return result;
327 }
328 
329 static int
330 day_cell_number(struct tm *current)
331 {
332     int cell;
333     cell = current->tm_mday - ((6 + current->tm_mday - current->tm_wday) % MAX_DAYS);
334     if ((current->tm_mday - 1) % MAX_DAYS != current->tm_wday)
335 	cell += 6;
336     else
337 	cell--;
338     return cell;
339 }
340 
341 static int
342 next_or_previous(int key, int two_d)
343 {
344     int result = 0;
345 
346     switch (key) {
347     case DLGK_GRID_UP:
348 	result = two_d ? -MAX_DAYS : -1;
349 	break;
350     case DLGK_GRID_LEFT:
351 	result = -1;
352 	break;
353     case DLGK_GRID_DOWN:
354 	result = two_d ? MAX_DAYS : 1;
355 	break;
356     case DLGK_GRID_RIGHT:
357 	result = 1;
358 	break;
359     default:
360 	beep();
361 	break;
362     }
363     return result;
364 }
365 
366 /*
367  * Draw the day-of-month selection box
368  */
369 static int
370 draw_day(BOX * data, struct tm *current)
371 {
372     int cell_wide = MON_WIDE;
373     int y, x, this_x;
374     int save_y = 0, save_x = 0;
375     int day = current->tm_mday;
376     int mday;
377     int week = 0;
378     int windx = 0;
379     int *weeks = 0;
380     int last = days_in_month(current, 0);
381     int prev = days_in_month(current, -1);
382 
383     werase(data->window);
384     dlg_draw_box2(data->parent,
385 		  data->y - MARGIN, data->x - MARGIN,
386 		  data->height + (2 * MARGIN), data->width + (2 * MARGIN),
387 		  menubox_attr,
388 		  menubox_border_attr,
389 		  menubox_border2_attr);
390 
391     dlg_attrset(data->window, menubox_attr);	/* daynames headline */
392     for (x = 0; x < MAX_DAYS; x++) {
393 	mvwprintw(data->window,
394 		  0, (x + 1) * cell_wide, "%*.*s ",
395 		  cell_wide - 1,
396 		  cell_wide - 1,
397 		  nameOfDayOfWeek(x + data->week_start));
398     }
399 
400     mday = ((6 + current->tm_mday -
401 	     current->tm_wday +
402 	     data->week_start) % MAX_DAYS) - MAX_DAYS;
403     if (mday <= -MAX_DAYS)
404 	mday += MAX_DAYS;
405 
406     if (dialog_vars.iso_week) {
407 	weeks = getisoweeks(current->tm_year + 1900, current->tm_mon + 1);
408     } else {
409 	/* mday is now in the range -6 to 0. */
410 	week = (current->tm_yday + 6 + mday - current->tm_mday) / MAX_DAYS;
411     }
412 
413     for (y = 1; mday < last; y++) {
414 	dlg_attrset(data->window, menubox_attr);	/* weeknumbers headline */
415 	mvwprintw(data->window,
416 		  y, 0,
417 		  "%*d ",
418 		  cell_wide - 1,
419 		  weeks ? weeks[windx++] : ++week);
420 	for (x = 0; x < MAX_DAYS; x++) {
421 	    this_x = 1 + (x + 1) * cell_wide;
422 	    ++mday;
423 	    if (wmove(data->window, y, this_x) == ERR)
424 		continue;
425 	    dlg_attrset(data->window, item_attr);	/* not selected days */
426 	    if (mday == day) {
427 		dlg_attrset(data->window, item_selected_attr);	/* selected day */
428 		save_y = y;
429 		save_x = this_x;
430 	    }
431 	    if (mday > 0) {
432 		if (mday <= last) {
433 		    wprintw(data->window, "%*d", cell_wide - 2, mday);
434 		} else if (mday == day) {
435 		    wprintw(data->window, "%*d", cell_wide - 2, mday - last);
436 		}
437 	    } else if (mday == day) {
438 		wprintw(data->window, "%*d", cell_wide - 2, mday + prev);
439 	    }
440 	}
441 	wmove(data->window, save_y, save_x);
442     }
443     /* just draw arrows - scrollbar is unsuitable here */
444     dlg_draw_arrows(data->parent, TRUE, TRUE,
445 		    data->x + ARROWS_COL,
446 		    data->y - 1,
447 		    data->y + data->height);
448 
449     return 0;
450 }
451 
452 /*
453  * Draw the month-of-year selection box
454  */
455 static int
456 draw_month(BOX * data, struct tm *current)
457 {
458     int month;
459 
460     month = current->tm_mon + 1;
461 
462     dlg_attrset(data->parent, dialog_attr);	/* Headline "Month" */
463     (void) mvwprintw(data->parent, data->y - 2, data->x - 1, _("Month"));
464     dlg_draw_box2(data->parent,
465 		  data->y - 1, data->x - 1,
466 		  data->height + 2, data->width + 2,
467 		  menubox_attr,
468 		  menubox_border_attr,
469 		  menubox_border2_attr);
470     dlg_attrset(data->window, item_attr);	/* color the month selection */
471     mvwprintw(data->window, 0, 0, "%s", nameOfMonth(month - 1));
472     wmove(data->window, 0, 0);
473     return 0;
474 }
475 
476 /*
477  * Draw the year selection box
478  */
479 static int
480 draw_year(BOX * data, struct tm *current)
481 {
482     int year = current->tm_year + 1900;
483 
484     dlg_attrset(data->parent, dialog_attr);	/* Headline "Year" */
485     (void) mvwprintw(data->parent, data->y - 2, data->x - 1, _("Year"));
486     dlg_draw_box2(data->parent,
487 		  data->y - 1, data->x - 1,
488 		  data->height + 2, data->width + 2,
489 		  menubox_attr,
490 		  menubox_border_attr,
491 		  menubox_border2_attr);
492     dlg_attrset(data->window, item_attr);	/* color the year selection */
493     mvwprintw(data->window, 0, 0, "%4d", year);
494     wmove(data->window, 0, 0);
495     return 0;
496 }
497 
498 static int
499 init_object(BOX * data,
500 	    WINDOW *parent,
501 	    int x, int y,
502 	    int width, int height,
503 	    BOX_DRAW box_draw,
504 	    int key_offset,
505 	    int code)
506 {
507     data->parent = parent;
508     data->x = x;
509     data->y = y;
510     data->width = width;
511     data->height = height;
512     data->box_draw = box_draw;
513     data->week_start = key_offset;
514 
515     data->window = dlg_der_window(data->parent,
516 				  data->height, data->width,
517 				  data->y, data->x);
518     if (data->window == 0)
519 	return -1;
520 
521     dlg_mouse_setbase(getbegx(parent), getbegy(parent));
522     if (code == 'D') {
523 	dlg_mouse_mkbigregion(y + 1, x + MON_WIDE, height - 1, width - MON_WIDE,
524 			      KEY_MAX + key_offset, 1, MON_WIDE, 3);
525     } else {
526 	dlg_mouse_mkregion(y, x, height, width, code);
527     }
528 
529     return 0;
530 }
531 
532 #if defined(ENABLE_NLS) && defined(HAVE_NL_LANGINFO_1STDAY)
533 #elif defined(HAVE_DLG_GAUGE)
534 static int
535 read_locale_setting(const char *name, int which)
536 {
537     FILE *fp;
538     char command[80];
539     int result = -1;
540 
541     sprintf(command, "locale %s", name);
542     if ((fp = dlg_popen(command, "r")) != 0) {
543 	int count = 0;
544 	char buf[80];
545 
546 	while (fgets(buf, (int) sizeof(buf) - 1, fp) != 0) {
547 	    if (++count > which) {
548 		char *next = 0;
549 		long check = strtol(buf, &next, 0);
550 		if (next != 0 &&
551 		    next != buf &&
552 		    *next == '\n') {
553 		    result = (int) check;
554 		}
555 		break;
556 	    }
557 	}
558 	pclose(fp);
559     }
560     return result;
561 }
562 #endif
563 
564 static int
565 WeekStart(void)
566 {
567     int result = 0;
568     char *option = dialog_vars.week_start;
569     if (option != 0) {
570 	if (option[0]) {
571 	    char *next = 0;
572 	    long check = strtol(option, &next, 0);
573 	    if (next == 0 ||
574 		next == option ||
575 		*next != '\0') {
576 		if (!strcmp(option, "locale")) {
577 #if defined(ENABLE_NLS) && defined(HAVE_NL_LANGINFO_1STDAY)
578 		    /*
579 		     * glibc-specific.
580 		     */
581 		    int first_day = nl_langinfo(_NL_TIME_FIRST_WEEKDAY)[0];
582 		    char *basis_ptr = nl_langinfo(_NL_TIME_WEEK_1STDAY);
583 		    int basis_day = (int) (intptr_t) basis_ptr;
584 #elif defined(HAVE_DLG_GAUGE)
585 		    /*
586 		     * probably Linux-specific, but harmless otherwise.  When
587 		     * available, the locale program will return a single
588 		     * integer on one line.
589 		     */
590 		    int first_day = read_locale_setting("first_weekday", 0);
591 		    int basis_day = read_locale_setting("week-1stday", 0);
592 #endif
593 #if (defined(ENABLE_NLS) && defined(HAVE_NL_LANGINFO_1STDAY)) || defined(HAVE_DLG_GAUGE)
594 		    int week_1stday = -1;
595 		    if (basis_day == 19971130)
596 			week_1stday = 0;	/* Sun */
597 		    else if (basis_day == 19971201)
598 			week_1stday = 1;	/* Mon */
599 		    if (week_1stday >= 0) {
600 			result = first_day - week_1stday - 1;
601 		    }
602 #else
603 		    result = 0;	/* Sun */
604 #endif
605 		} else {
606 		    int day;
607 		    size_t eql = strlen(option);
608 		    for (day = 0; day < MAX_DAYS; ++day) {
609 			if (!strncmp(nameOfDayOfWeek(day), option, eql)) {
610 			    result = day;
611 			    break;
612 			}
613 		    }
614 		}
615 	    } else if (check < 0) {
616 		result = -1;
617 	    } else {
618 		result = (int) (check % MAX_DAYS);
619 	    }
620 	}
621     }
622     return result;
623 }
624 
625 static int
626 CleanupResult(int code, WINDOW *dialog, char *prompt, DIALOG_VARS * save_vars)
627 {
628     int n;
629 
630     if (dialog != 0)
631 	dlg_del_window(dialog);
632     dlg_mouse_free_regions();
633     if (prompt != 0)
634 	free(prompt);
635     dlg_restore_vars(save_vars);
636 
637     for (n = 0; n < MAX_DAYS; ++n) {
638 	free(cached_days[n]);
639 	cached_days[n] = 0;
640     }
641     for (n = 0; n < MAX_MONTHS; ++n) {
642 	free(cached_months[n]);
643 	cached_months[n] = 0;
644     }
645 
646     return code;
647 }
648 
649 static void
650 trace_date(struct tm *current, struct tm *old)
651 {
652     bool changed = (old == 0 ||
653 		    current->tm_mday != old->tm_mday ||
654 		    current->tm_mon != old->tm_mon ||
655 		    current->tm_year != old->tm_year);
656     if (changed) {
657 	DLG_TRACE(("# current %04d/%02d/%02d\n",
658 		   current->tm_year + 1900,
659 		   current->tm_mon + 1,
660 		   current->tm_mday));
661     } else {
662 	DLG_TRACE(("# current (unchanged)\n"));
663     }
664 }
665 
666 #define DrawObject(data) (data)->box_draw(data, &current)
667 
668 /*
669  * Display a dialog box for entering a date
670  */
671 int
672 dialog_calendar(const char *title,
673 		const char *subtitle,
674 		int height,
675 		int width,
676 		int day,
677 		int month,
678 		int year)
679 {
680     /* *INDENT-OFF* */
681     static DLG_KEYS_BINDING binding[] = {
682 	HELPKEY_BINDINGS,
683 	ENTERKEY_BINDINGS,
684 	TOGGLEKEY_BINDINGS,
685 	DLG_KEYS_DATA( DLGK_FIELD_NEXT, TAB ),
686 	DLG_KEYS_DATA( DLGK_FIELD_PREV, KEY_BTAB ),
687 	DLG_KEYS_DATA( DLGK_GRID_DOWN,	'j' ),
688 	DLG_KEYS_DATA( DLGK_GRID_DOWN,	DLGK_MOUSE(KEY_NPAGE) ),
689 	DLG_KEYS_DATA( DLGK_GRID_DOWN,	KEY_DOWN ),
690 	DLG_KEYS_DATA( DLGK_GRID_DOWN,	KEY_NPAGE ),
691 	DLG_KEYS_DATA( DLGK_GRID_LEFT,	'-' ),
692 	DLG_KEYS_DATA( DLGK_GRID_LEFT,  'h' ),
693 	DLG_KEYS_DATA( DLGK_GRID_LEFT,  CHR_BACKSPACE ),
694 	DLG_KEYS_DATA( DLGK_GRID_LEFT,  CHR_PREVIOUS ),
695 	DLG_KEYS_DATA( DLGK_GRID_LEFT,  KEY_LEFT ),
696 	DLG_KEYS_DATA( DLGK_GRID_RIGHT,	'+' ),
697 	DLG_KEYS_DATA( DLGK_GRID_RIGHT, 'l' ),
698 	DLG_KEYS_DATA( DLGK_GRID_RIGHT, CHR_NEXT ),
699 	DLG_KEYS_DATA( DLGK_GRID_RIGHT, KEY_NEXT ),
700 	DLG_KEYS_DATA( DLGK_GRID_RIGHT, KEY_RIGHT ),
701 	DLG_KEYS_DATA( DLGK_GRID_UP,	'k' ),
702 	DLG_KEYS_DATA( DLGK_GRID_UP,	KEY_PPAGE ),
703 	DLG_KEYS_DATA( DLGK_GRID_UP,	KEY_PREVIOUS ),
704 	DLG_KEYS_DATA( DLGK_GRID_UP,	KEY_UP ),
705 	DLG_KEYS_DATA( DLGK_GRID_UP,  	DLGK_MOUSE(KEY_PPAGE) ),
706 	END_KEYS_BINDING
707     };
708     /* *INDENT-ON* */
709 
710 #ifdef KEY_RESIZE
711     int old_height = height;
712     int old_width = width;
713 #endif
714     BOX dy_box, mn_box, yr_box;
715     int fkey;
716     int key;
717     int step;
718     int button;
719     int result = DLG_EXIT_UNKNOWN;
720     int week_start;
721     WINDOW *dialog;
722     time_t now_time;
723     struct tm current;
724     int state = dlg_default_button();
725     const char **buttons = dlg_ok_labels();
726     char *prompt;
727     int mincols = MIN_WIDE;
728     char buffer[MAX_LEN];
729     DIALOG_VARS save_vars;
730 
731     DLG_TRACE(("# calendar args:\n"));
732     DLG_TRACE2S("title", title);
733     DLG_TRACE2S("message", subtitle);
734     DLG_TRACE2N("height", height);
735     DLG_TRACE2N("width", width);
736     DLG_TRACE2N("day", day);
737     DLG_TRACE2N("month", month);
738     DLG_TRACE2N("year", year);
739 
740     dlg_save_vars(&save_vars);
741     dialog_vars.separate_output = TRUE;
742 
743     dlg_does_output();
744 
745     /*
746      * Unless overridden, the current time/date is our starting point.
747      */
748     now_time = time((time_t *) 0);
749     current = *localtime(&now_time);
750 
751 #if HAVE_MKTIME
752     current.tm_isdst = -1;
753     if (year >= 1900) {
754 	current.tm_year = year - 1900;
755     }
756     if (month >= 1) {
757 	current.tm_mon = month - 1;
758     }
759     if (day > 0 && day <= days_per_month(current.tm_year + 1900,
760 					 current.tm_mon + 1)) {
761 	current.tm_mday = day;
762     }
763     now_time = mktime(&current);
764 #else
765     if (day < 0)
766 	day = current.tm_mday;
767     if (month < 0)
768 	month = current.tm_mon + 1;
769     if (year < 0)
770 	year = current.tm_year + 1900;
771 
772     /* compute a struct tm that matches the day/month/year parameters */
773     if (((year -= 1900) > 0) && (year < 200)) {
774 	/* ugly, but I'd like to run this on older machines w/o mktime -TD */
775 	for (;;) {
776 	    if (year > current.tm_year) {
777 		now_time += ONE_DAY * days_in_year(&current, 0);
778 	    } else if (year < current.tm_year) {
779 		now_time -= ONE_DAY * days_in_year(&current, -1);
780 	    } else if (month > current.tm_mon + 1) {
781 		now_time += ONE_DAY * days_in_month(&current, 0);
782 	    } else if (month < current.tm_mon + 1) {
783 		now_time -= ONE_DAY * days_in_month(&current, -1);
784 	    } else if (day > current.tm_mday) {
785 		now_time += ONE_DAY;
786 	    } else if (day < current.tm_mday) {
787 		now_time -= ONE_DAY;
788 	    } else {
789 		break;
790 	    }
791 	    current = *localtime(&now_time);
792 	}
793     }
794 #endif
795 
796     dlg_button_layout(buttons, &mincols);
797 
798 #ifdef KEY_RESIZE
799   retry:
800 #endif
801 
802     prompt = dlg_strclone(subtitle);
803     dlg_auto_size(title, prompt, &height, &width, 0, mincols);
804 
805     height += MIN_HIGH - 1;
806     dlg_print_size(height, width);
807     dlg_ctl_size(height, width);
808 
809     dialog = dlg_new_window(height, width,
810 			    dlg_box_y_ordinate(height),
811 			    dlg_box_x_ordinate(width));
812     dlg_register_window(dialog, "calendar", binding);
813     dlg_register_buttons(dialog, "calendar", buttons);
814 
815     /* mainbox */
816     dlg_draw_box2(dialog, 0, 0, height, width, dialog_attr, border_attr, border2_attr);
817     dlg_draw_bottom_box2(dialog, border_attr, border2_attr, dialog_attr);
818     dlg_draw_title(dialog, title);
819 
820     dlg_attrset(dialog, dialog_attr);	/* text mainbox */
821     dlg_print_autowrap(dialog, prompt, height, width);
822 
823     /* compute positions of day, month and year boxes */
824     memset(&dy_box, 0, sizeof(dy_box));
825     memset(&mn_box, 0, sizeof(mn_box));
826     memset(&yr_box, 0, sizeof(yr_box));
827 
828     if ((week_start = WeekStart()) < 0 ||
829 	init_object(&dy_box,
830 		    dialog,
831 		    (width - DAY_WIDE) / 2,
832 		    1 + (height - (DAY_HIGH + BTN_HIGH + (5 * MARGIN))),
833 		    DAY_WIDE,
834 		    DAY_HIGH + 1,
835 		    draw_day,
836 		    week_start,
837 		    'D') < 0 ||
838 	((dy_box.week_start = WeekStart()) < 0) ||
839 	DrawObject(&dy_box) < 0) {
840 	return CleanupResult(DLG_EXIT_ERROR, dialog, prompt, &save_vars);
841     }
842 
843     if (init_object(&mn_box,
844 		    dialog,
845 		    dy_box.x,
846 		    dy_box.y - (HDR_HIGH + 2 * MARGIN),
847 		    (DAY_WIDE / 2) - MARGIN,
848 		    HDR_HIGH,
849 		    draw_month,
850 		    0,
851 		    'M') < 0
852 	|| DrawObject(&mn_box) < 0) {
853 	return CleanupResult(DLG_EXIT_ERROR, dialog, prompt, &save_vars);
854     }
855 
856     if (init_object(&yr_box,
857 		    dialog,
858 		    dy_box.x + mn_box.width + 2,
859 		    mn_box.y,
860 		    mn_box.width,
861 		    mn_box.height,
862 		    draw_year,
863 		    0,
864 		    'Y') < 0
865 	|| DrawObject(&yr_box) < 0) {
866 	return CleanupResult(DLG_EXIT_ERROR, dialog, prompt, &save_vars);
867     }
868 
869     dlg_trace_win(dialog);
870     while (result == DLG_EXIT_UNKNOWN) {
871 	int key2;
872 	BOX *obj = (state == sDAY ? &dy_box
873 		    : (state == sMONTH ? &mn_box :
874 		       (state == sYEAR ? &yr_box : 0)));
875 
876 	button = (state < 0) ? 0 : state;
877 	dlg_draw_buttons(dialog, height - 2, 0, buttons, button, FALSE, width);
878 	if (obj != 0)
879 	    dlg_set_focus(dialog, obj->window);
880 
881 	key = dlg_mouse_wgetch(dialog, &fkey);
882 	if (dlg_result_key(key, fkey, &result)) {
883 	    if (!dlg_button_key(result, &button, &key, &fkey))
884 		break;
885 	}
886 #define Mouse2Key(key) (key - M_EVENT)
887 	if (fkey && (key >= DLGK_MOUSE(KEY_MIN) && key <= DLGK_MOUSE(KEY_MAX))) {
888 	    key = dlg_lookup_key(dialog, Mouse2Key(key), &fkey);
889 	}
890 
891 	if ((key2 = dlg_char_to_button(key, buttons)) >= 0) {
892 	    result = key2;
893 	} else if (fkey) {
894 	    /* handle function-keys */
895 	    switch (key) {
896 	    case DLGK_MOUSE('D'):
897 		state = sDAY;
898 		break;
899 	    case DLGK_MOUSE('M'):
900 		state = sMONTH;
901 		break;
902 	    case DLGK_MOUSE('Y'):
903 		state = sYEAR;
904 		break;
905 	    case DLGK_TOGGLE:
906 	    case DLGK_ENTER:
907 		result = dlg_enter_buttoncode(button);
908 		break;
909 	    case DLGK_LEAVE:
910 		result = dlg_ok_buttoncode(button);
911 		break;
912 	    case DLGK_FIELD_PREV:
913 		state = dlg_prev_ok_buttonindex(state, sMONTH);
914 		break;
915 	    case DLGK_FIELD_NEXT:
916 		state = dlg_next_ok_buttonindex(state, sMONTH);
917 		break;
918 #ifdef KEY_RESIZE
919 	    case KEY_RESIZE:
920 		dlg_will_resize(dialog);
921 		/* reset data */
922 		height = old_height;
923 		width = old_width;
924 		free(prompt);
925 		_dlg_resize_cleanup(dialog);
926 		/* repaint */
927 		goto retry;
928 #endif
929 	    default:
930 		step = 0;
931 		key2 = -1;
932 		if (is_DLGK_MOUSE(key)) {
933 		    if ((key2 = dlg_ok_buttoncode(Mouse2Key(key))) >= 0) {
934 			result = key2;
935 			break;
936 		    } else if (key >= DLGK_MOUSE(KEY_MAX)) {
937 			state = sDAY;
938 			obj = &dy_box;
939 			key2 = 1;
940 			step = (key
941 				- DLGK_MOUSE(KEY_MAX)
942 				- day_cell_number(&current));
943 			DLG_TRACE(("# mouseclick decoded %d\n", step));
944 		    }
945 		}
946 		if (obj != 0) {
947 		    if (key2 < 0) {
948 			step = next_or_previous(key, (obj == &dy_box));
949 		    }
950 		    if (step != 0) {
951 			struct tm old = current;
952 
953 			/* see comment regarding mktime -TD */
954 			if (obj == &dy_box) {
955 			    now_time += ONE_DAY * step;
956 			} else if (obj == &mn_box) {
957 			    if (step > 0)
958 				now_time += ONE_DAY *
959 				    days_in_month(&current, 0);
960 			    else
961 				now_time -= ONE_DAY *
962 				    days_in_month(&current, -1);
963 			} else if (obj == &yr_box) {
964 			    if (step > 0)
965 				now_time += (ONE_DAY
966 					     * days_in_year(&current, 0));
967 			    else
968 				now_time -= (ONE_DAY
969 					     * days_in_year(&current, -1));
970 			}
971 
972 			current = *localtime(&now_time);
973 
974 			trace_date(&current, &old);
975 			if (obj != &dy_box
976 			    && (current.tm_mday != old.tm_mday
977 				|| current.tm_mon != old.tm_mon
978 				|| current.tm_year != old.tm_year))
979 			    DrawObject(&dy_box);
980 			if (obj != &mn_box && current.tm_mon != old.tm_mon)
981 			    DrawObject(&mn_box);
982 			if (obj != &yr_box && current.tm_year != old.tm_year)
983 			    DrawObject(&yr_box);
984 			(void) DrawObject(obj);
985 		    }
986 		} else if (state >= 0) {
987 		    if (next_or_previous(key, FALSE) < 0)
988 			state = dlg_prev_ok_buttonindex(state, sMONTH);
989 		    else if (next_or_previous(key, FALSE) > 0)
990 			state = dlg_next_ok_buttonindex(state, sMONTH);
991 		}
992 		break;
993 	    }
994 	}
995     }
996 
997 #define DefaultFormat(dst, src) \
998 	sprintf(dst, "%02d/%02d/%0d", \
999 		src.tm_mday, src.tm_mon + 1, src.tm_year + 1900)
1000 #ifdef HAVE_STRFTIME
1001     if (dialog_vars.date_format != 0) {
1002 	size_t used = strftime(buffer,
1003 			       sizeof(buffer) - 1,
1004 			       dialog_vars.date_format,
1005 			       &current);
1006 	if (used == 0 || *buffer == '\0')
1007 	    DefaultFormat(buffer, current);
1008     } else
1009 #endif
1010 	DefaultFormat(buffer, current);
1011 
1012     dlg_add_result(buffer);
1013     AddLastKey();
1014 
1015     return CleanupResult(result, dialog, prompt, &save_vars);
1016 }
1017